From patchwork Fri Feb 21 18:01:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397063 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6F1EA92A for ; Fri, 21 Feb 2020 18:02:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 44BEB222C4 for ; Fri, 21 Feb 2020 18:02:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="L6nXZpxD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728441AbgBUSCC (ORCPT ); Fri, 21 Feb 2020 13:02:02 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:35014 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728289AbgBUSCB (ORCPT ); Fri, 21 Feb 2020 13:02:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582308120; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yfA5n8Z+aIk+kyYGrURBEqzc1iGCmKy1Em7iNUliKXo=; b=L6nXZpxDp0g3GuafXb+c5sv7QNsR6vQ43doo/8VDCo/ztDHxvCMxVTcpEvy1HcfKMJaNl3 lZU1v+yvVOgTBE3OFH9x5n9WRNqNyudDPFhgGsy3OF+menH4PglCE9Igji6NQYYTXuS9ng O9vw7H0GWK0VxAhEH62u2x0M1aC4364= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-438-3hKREr8hND6fajc3kShSUw-1; Fri, 21 Feb 2020 13:01:58 -0500 X-MC-Unique: 3hKREr8hND6fajc3kShSUw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5E7A08017CC; Fri, 21 Feb 2020 18:01:57 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-122-163.rdu2.redhat.com [10.10.122.163]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7A432790CF; Fri, 21 Feb 2020 18:01:55 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 01/17] watch_queue: Add security hooks to rule on setting mount and sb watches [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:01:54 +0000 Message-ID: <158230811476.2185128.197216885757764208.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add security hooks that will allow an LSM to rule on whether or not a watch may be set on a mount or on a superblock. More than one hook is required as the watches watch different types of object. Signed-off-by: David Howells cc: Casey Schaufler cc: Stephen Smalley cc: linux-security-module@vger.kernel.org --- include/linux/lsm_hooks.h | 24 ++++++++++++++++++++++++ include/linux/security.h | 16 ++++++++++++++++ security/security.c | 14 ++++++++++++++ 3 files changed, 54 insertions(+) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 16530255dc11..c4451ac197ae 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1427,6 +1427,18 @@ * Check to see if a process is allowed to watch for event notifications * from devices (as a global set). * + * @watch_mount: + * Check to see if a process is allowed to watch for mount topology change + * notifications on a mount subtree. + * @watch: The watch object + * @path: The root of the subtree to watch. + * + * @watch_sb: + * Check to see if a process is allowed to watch for event notifications + * from a superblock. + * @watch: The watch object + * @sb: The superblock to watch. + * * @post_notification: * Check to see if a watch notification can be posted to a particular * queue. @@ -1722,6 +1734,12 @@ union security_list_options { #ifdef CONFIG_DEVICE_NOTIFICATIONS int (*watch_devices)(void); #endif +#ifdef CONFIG_MOUNT_NOTIFICATIONS + int (*watch_mount)(struct watch *watch, struct path *path); +#endif +#ifdef CONFIG_SB_NOTIFICATIONS + int (*watch_sb)(struct watch *watch, struct super_block *sb); +#endif #ifdef CONFIG_WATCH_QUEUE int (*post_notification)(const struct cred *w_cred, const struct cred *cred, @@ -2020,6 +2038,12 @@ struct security_hook_heads { #ifdef CONFIG_DEVICE_NOTIFICATIONS struct hlist_head watch_devices; #endif +#ifdef CONFIG_MOUNT_NOTIFICATIONS + struct hlist_head watch_mount; +#endif +#ifdef CONFIG_SB_NOTIFICATIONS + struct hlist_head watch_sb; +#endif #ifdef CONFIG_WATCH_QUEUE struct hlist_head post_notification; #endif /* CONFIG_WATCH_QUEUE */ diff --git a/include/linux/security.h b/include/linux/security.h index 910a1efa9a79..2ca2569bc12c 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1306,6 +1306,22 @@ static inline int security_post_notification(const struct cred *w_cred, return 0; } #endif +#if defined(CONFIG_SECURITY) && defined(CONFIG_MOUNT_NOTIFICATIONS) +int security_watch_mount(struct watch *watch, struct path *path); +#else +static inline int security_watch_mount(struct watch *watch, struct path *path) +{ + return 0; +} +#endif +#if defined(CONFIG_SECURITY) && defined(CONFIG_SB_NOTIFICATIONS) +int security_watch_sb(struct watch *watch, struct super_block *sb); +#else +static inline int security_watch_sb(struct watch *watch, struct super_block *sb) +{ + return 0; +} +#endif #ifdef CONFIG_SECURITY_NETWORK diff --git a/security/security.c b/security/security.c index db7b574c9c70..5c0463444a90 100644 --- a/security/security.c +++ b/security/security.c @@ -2004,6 +2004,20 @@ int security_watch_key(struct key *key) } #endif +#ifdef CONFIG_MOUNT_NOTIFICATIONS +int security_watch_mount(struct watch *watch, struct path *path) +{ + return call_int_hook(watch_mount, 0, watch, path); +} +#endif + +#ifdef CONFIG_SB_NOTIFICATIONS +int security_watch_sb(struct watch *watch, struct super_block *sb) +{ + return call_int_hook(watch_sb, 0, watch, sb); +} +#endif + #ifdef CONFIG_DEVICE_NOTIFICATIONS int security_watch_devices(void) { From patchwork Fri Feb 21 18:02:02 2020 Content-Type: text/plain; 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 02/17] watch_queue: Implement mount topology and attribute change notifications [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:02:02 +0000 Message-ID: <158230812258.2185128.14372614867325950789.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add a mount notification facility whereby notifications about changes in mount topology and configuration can be received. Note that this only covers vfsmount topology changes and not superblock events. A separate facility will be added for that. Every mount is given a change counter than counts the number of topological rearrangements in which it is involved and the number of attribute changes it undergoes. This allows notification loss to be dealt with. Later patches will provide a way to quickly retrieve this value, along with information about topology and parameters for the superblock. Firstly, an event queue needs to be created: fd = open("/dev/event_queue", O_RDWR); ioctl(fd, IOC_WATCH_QUEUE_SET_SIZE, page_size << n); then a notification can be set up to report notifications via that queue: struct watch_notification_filter filter = { .nr_filters = 1, .filters = { [0] = { .type = WATCH_TYPE_MOUNT_NOTIFY, .subtype_filter[0] = UINT_MAX, }, }, }; ioctl(fd, IOC_WATCH_QUEUE_SET_FILTER, &filter); watch_mount(AT_FDCWD, "/", 0, fd, 0x02); In this case, it would let me monitor the mount topology subtree rooted at "/" for events. Mount notifications propagate up the tree towards the root, so a watch will catch all of the events happening in the subtree rooted at the watch. After setting the watch, records will be placed into the queue when, for example, as superblock switches between read-write and read-only. Records are of the following format: struct mount_notification { struct watch_notification watch; __u32 triggered_on; __u32 changed_mount; } *n; Where: n->watch.type will be WATCH_TYPE_MOUNT_NOTIFY. n->watch.subtype will indicate the type of event, such as NOTIFY_MOUNT_NEW_MOUNT. n->watch.info & WATCH_INFO_LENGTH will indicate the length of the record. n->watch.info & WATCH_INFO_ID will be the fifth argument to watch_mount(), shifted. n->watch.info & NOTIFY_MOUNT_IN_SUBTREE if true indicates that the notifcation was generated in the mount subtree rooted at the watch, and not actually in the watch itself. n->watch.info & NOTIFY_MOUNT_IS_RECURSIVE if true indicates that the notifcation was generated by an event (eg. SETATTR) that was applied recursively. The notification is only generated for the object that initially triggered it. n->watch.info & NOTIFY_MOUNT_IS_NOW_RO will be used for NOTIFY_MOUNT_READONLY, being set if the superblock becomes R/O, and being cleared otherwise, and for NOTIFY_MOUNT_NEW_MOUNT, being set if the new mount is a submount (e.g. an automount). n->watch.info & NOTIFY_MOUNT_IS_SUBMOUNT if true indicates that the NOTIFY_MOUNT_NEW_MOUNT notification is in response to a mount performed by the kernel (e.g. an automount). n->triggered_on indicates the ID of the mount on which the watch was installed. n->changed_mount indicates the ID of the mount that was affected. Note that it is permissible for event records to be of variable length - or, at least, the length may be dependent on the subtype. Note also that the queue can be shared between multiple notifications of various types. Signed-off-by: David Howells --- arch/alpha/kernel/syscalls/syscall.tbl | 1 arch/arm/tools/syscall.tbl | 1 arch/arm64/include/asm/unistd.h | 2 arch/ia64/kernel/syscalls/syscall.tbl | 1 arch/m68k/kernel/syscalls/syscall.tbl | 1 arch/microblaze/kernel/syscalls/syscall.tbl | 1 arch/mips/kernel/syscalls/syscall_n32.tbl | 1 arch/mips/kernel/syscalls/syscall_n64.tbl | 1 arch/mips/kernel/syscalls/syscall_o32.tbl | 1 arch/parisc/kernel/syscalls/syscall.tbl | 1 arch/powerpc/kernel/syscalls/syscall.tbl | 1 arch/s390/kernel/syscalls/syscall.tbl | 1 arch/sh/kernel/syscalls/syscall.tbl | 1 arch/sparc/kernel/syscalls/syscall.tbl | 1 arch/x86/entry/syscalls/syscall_32.tbl | 1 arch/x86/entry/syscalls/syscall_64.tbl | 1 arch/xtensa/kernel/syscalls/syscall.tbl | 1 fs/Kconfig | 9 + fs/Makefile | 1 fs/mount.h | 30 ++++ fs/mount_notify.c | 185 +++++++++++++++++++++++++++ fs/namespace.c | 22 +++ include/linux/dcache.h | 1 include/linux/syscalls.h | 2 include/uapi/asm-generic/unistd.h | 4 - include/uapi/linux/watch_queue.h | 32 +++++ kernel/sys_ni.c | 3 27 files changed, 304 insertions(+), 3 deletions(-) create mode 100644 fs/mount_notify.c diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl index 36d42da7466a..b869428033ef 100644 --- a/arch/alpha/kernel/syscalls/syscall.tbl +++ b/arch/alpha/kernel/syscalls/syscall.tbl @@ -477,3 +477,4 @@ # 545 reserved for clone3 547 common openat2 sys_openat2 548 common pidfd_getfd sys_pidfd_getfd +549 common watch_mount sys_watch_mount diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index 4d1cf74a2caa..9c389da9efcc 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -451,3 +451,4 @@ 435 common clone3 sys_clone3 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd +439 common watch_mount sys_watch_mount diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index 1dd22da1c3a9..75f04a1023be 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -38,7 +38,7 @@ #define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE + 5) #define __ARM_NR_COMPAT_END (__ARM_NR_COMPAT_BASE + 0x800) -#define __NR_compat_syscalls 439 +#define __NR_compat_syscalls 440 #endif #define __ARCH_WANT_SYS_CLONE diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl index 042911e670b8..6817f865cc71 100644 --- a/arch/ia64/kernel/syscalls/syscall.tbl +++ b/arch/ia64/kernel/syscalls/syscall.tbl @@ -358,3 +358,4 @@ # 435 reserved for clone3 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd +439 common watch_mount sys_watch_mount diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index f4f49fcb76d0..fbf85da75ecb 100644 --- a/arch/m68k/kernel/syscalls/syscall.tbl +++ b/arch/m68k/kernel/syscalls/syscall.tbl @@ -437,3 +437,4 @@ 435 common clone3 __sys_clone3 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd +439 common watch_mount sys_watch_mount diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl index 4c67b11f9c9e..b05b192da1e2 100644 --- a/arch/microblaze/kernel/syscalls/syscall.tbl +++ b/arch/microblaze/kernel/syscalls/syscall.tbl @@ -443,3 +443,4 @@ 435 common clone3 sys_clone3 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd +439 common watch_mount sys_watch_mount diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl index 1f9e8ad636cc..0f85d2a033f9 100644 --- a/arch/mips/kernel/syscalls/syscall_n32.tbl +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl @@ -376,3 +376,4 @@ 435 n32 clone3 __sys_clone3 437 n32 openat2 sys_openat2 438 n32 pidfd_getfd sys_pidfd_getfd +439 n32 watch_mount sys_watch_mount diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl index c0b9d802dbf6..905cf9ac0792 100644 --- a/arch/mips/kernel/syscalls/syscall_n64.tbl +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl @@ -352,3 +352,4 @@ 435 n64 clone3 __sys_clone3 437 n64 openat2 sys_openat2 438 n64 pidfd_getfd sys_pidfd_getfd +439 n64 watch_mount sys_watch_mount diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl index ac586774c980..834b26b08d74 100644 --- a/arch/mips/kernel/syscalls/syscall_o32.tbl +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl @@ -425,3 +425,4 @@ 435 o32 clone3 __sys_clone3 437 o32 openat2 sys_openat2 438 o32 pidfd_getfd sys_pidfd_getfd +439 o32 watch_mount sys_watch_mount diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index 52a15f5cd130..badd3449db43 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -435,3 +435,4 @@ 435 common clone3 sys_clone3_wrapper 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd +439 common watch_mount sys_watch_mount diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index 35b61bfc1b1a..b404361bc929 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -519,3 +519,4 @@ 435 nospu clone3 ppc_clone3 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd +439 common watch_mount sys_watch_mount diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index bd7bd3581a0f..33071de24511 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -440,3 +440,4 @@ 435 common clone3 sys_clone3 sys_clone3 437 common openat2 sys_openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd sys_pidfd_getfd +439 common watch_mount sys_watch_mount sys_watch_mount diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl index c7a30fcd135f..682c125122f4 100644 --- a/arch/sh/kernel/syscalls/syscall.tbl +++ b/arch/sh/kernel/syscalls/syscall.tbl @@ -440,3 +440,4 @@ # 435 reserved for clone3 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd +439 common watch_mount sys_watch_mount diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index f13615ecdecc..febf3cd675e3 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -483,3 +483,4 @@ # 435 reserved for clone3 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd +439 common watch_mount sys_watch_mount diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index c17cb77eb150..085bcc5afdf1 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -442,3 +442,4 @@ 435 i386 clone3 sys_clone3 __ia32_sys_clone3 437 i386 openat2 sys_openat2 __ia32_sys_openat2 438 i386 pidfd_getfd sys_pidfd_getfd __ia32_sys_pidfd_getfd +439 i386 watch_mount sys_watch_mount __ia32_sys_watch_mount diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 44d510bc9b78..9cfb6b2eb319 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -359,6 +359,7 @@ 435 common clone3 __x64_sys_clone3/ptregs 437 common openat2 __x64_sys_openat2 438 common pidfd_getfd __x64_sys_pidfd_getfd +439 common watch_mount __x64_sys_watch_mount # # x32-specific system call numbers start at 512 to avoid cache impact diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl index 85a9ab1bc04d..1a066a43a58b 100644 --- a/arch/xtensa/kernel/syscalls/syscall.tbl +++ b/arch/xtensa/kernel/syscalls/syscall.tbl @@ -408,3 +408,4 @@ 435 common clone3 sys_clone3 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd +439 common watch_mount sys_watch_mount diff --git a/fs/Kconfig b/fs/Kconfig index 708ba336e689..d7039137d538 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -117,6 +117,15 @@ source "fs/verity/Kconfig" source "fs/notify/Kconfig" +config MOUNT_NOTIFICATIONS + bool "Mount topology change notifications" + select WATCH_QUEUE + help + This option provides support for getting change notifications on the + mount tree topology. This makes use of the /dev/watch_queue misc + device to handle the notification buffer and provides the + mount_notify() system call to enable/disable watchpoints. + source "fs/quota/Kconfig" source "fs/autofs/Kconfig" diff --git a/fs/Makefile b/fs/Makefile index 505e51166973..4477757780d0 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -22,6 +22,7 @@ obj-y += no-block.o endif obj-$(CONFIG_PROC_FS) += proc_namespace.o +obj-$(CONFIG_MOUNT_NOTIFICATIONS) += mount_notify.o obj-y += notify/ obj-$(CONFIG_EPOLL) += eventpoll.o diff --git a/fs/mount.h b/fs/mount.h index 711a4093e475..3abc5fb49e3c 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -4,6 +4,7 @@ #include #include #include +#include struct mnt_namespace { atomic_t count; @@ -72,6 +73,10 @@ struct mount { int mnt_expiry_mark; /* true if marked for expiry */ struct hlist_head mnt_pins; struct hlist_head mnt_stuck_children; + atomic_t mnt_change_counter; /* Number of changed applied */ +#ifdef CONFIG_MOUNT_NOTIFICATIONS + struct watch_list *mnt_watchers; /* Watches on dentries within this mount */ +#endif } __randomize_layout; #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */ @@ -153,3 +158,28 @@ static inline bool is_anon_ns(struct mnt_namespace *ns) { return ns->seq == 0; } + +extern void post_mount_notification(struct mount *changed, + struct mount_notification *notify); + +static inline void notify_mount(struct mount *changed, + struct mount *aux, + enum mount_notification_subtype subtype, + u32 info_flags) +{ + atomic_inc(&changed->mnt_change_counter); + +#ifdef CONFIG_MOUNT_NOTIFICATIONS + { + struct mount_notification n = { + .watch.type = WATCH_TYPE_MOUNT_NOTIFY, + .watch.subtype = subtype, + .watch.info = info_flags | watch_sizeof(n), + .triggered_on = changed->mnt_id, + .changed_mount = aux ? aux->mnt_id : 0, + }; + + post_mount_notification(changed, &n); + } +#endif +} diff --git a/fs/mount_notify.c b/fs/mount_notify.c new file mode 100644 index 000000000000..2e8ca75d3389 --- /dev/null +++ b/fs/mount_notify.c @@ -0,0 +1,185 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Provide mount topology/attribute change notifications. + * + * Copyright (C) 2019 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include +#include +#include +#include "mount.h" + +/* + * Post mount notifications to all watches going rootwards along the tree. + * + * Must be called with the mount_lock held. + */ +void post_mount_notification(struct mount *changed, + struct mount_notification *notify) +{ + const struct cred *cred = current_cred(); + struct path cursor; + struct mount *mnt; + unsigned seq; + + seq = 0; + rcu_read_lock(); +restart: + cursor.mnt = &changed->mnt; + cursor.dentry = changed->mnt.mnt_root; + mnt = real_mount(cursor.mnt); + notify->watch.info &= ~NOTIFY_MOUNT_IN_SUBTREE; + + read_seqbegin_or_lock(&rename_lock, &seq); + for (;;) { + if (mnt->mnt_watchers && + !hlist_empty(&mnt->mnt_watchers->watchers)) { + if (cursor.dentry->d_flags & DCACHE_MOUNT_WATCH) + post_watch_notification(mnt->mnt_watchers, + ¬ify->watch, cred, + (unsigned long)cursor.dentry); + } else { + cursor.dentry = mnt->mnt.mnt_root; + } + notify->watch.info |= NOTIFY_MOUNT_IN_SUBTREE; + + if (cursor.dentry == cursor.mnt->mnt_root || + IS_ROOT(cursor.dentry)) { + struct mount *parent = READ_ONCE(mnt->mnt_parent); + + /* Escaped? */ + if (cursor.dentry != cursor.mnt->mnt_root) + break; + + /* Global root? */ + if (mnt == parent) + break; + + cursor.dentry = READ_ONCE(mnt->mnt_mountpoint); + mnt = parent; + cursor.mnt = &mnt->mnt; + } else { + cursor.dentry = cursor.dentry->d_parent; + } + } + + if (need_seqretry(&rename_lock, seq)) { + seq = 1; + goto restart; + } + + done_seqretry(&rename_lock, seq); + rcu_read_unlock(); +} + +static void release_mount_watch(struct watch *watch) +{ + struct dentry *dentry = (struct dentry *)(unsigned long)watch->id; + + dput(dentry); +} + +/** + * sys_watch_mount - Watch for mount topology/attribute changes + * @dfd: Base directory to pathwalk from or fd referring to mount. + * @filename: Path to mount to place the watch upon + * @at_flags: Pathwalk control flags + * @watch_fd: The watch queue to send notifications to. + * @watch_id: The watch ID to be placed in the notification (-1 to remove watch) + */ +SYSCALL_DEFINE5(watch_mount, + int, dfd, + const char __user *, filename, + unsigned int, at_flags, + int, watch_fd, + int, watch_id) +{ + struct watch_queue *wqueue; + struct watch_list *wlist = NULL; + struct watch *watch = NULL; + struct mount *m; + struct path path; + unsigned int lookup_flags = + LOOKUP_DIRECTORY | LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT; + int ret; + + if (watch_id < -1 || watch_id > 0xff) + return -EINVAL; + if ((at_flags & ~(AT_NO_AUTOMOUNT | AT_EMPTY_PATH)) != 0) + return -EINVAL; + if (at_flags & AT_NO_AUTOMOUNT) + lookup_flags &= ~LOOKUP_AUTOMOUNT; + if (at_flags & AT_EMPTY_PATH) + lookup_flags |= LOOKUP_EMPTY; + + ret = user_path_at(dfd, filename, lookup_flags, &path); + if (ret) + return ret; + + ret = inode_permission(path.dentry->d_inode, MAY_EXEC); + if (ret) + goto err_path; + + wqueue = get_watch_queue(watch_fd); + if (IS_ERR(wqueue)) + goto err_path; + + m = real_mount(path.mnt); + + if (watch_id >= 0) { + ret = -ENOMEM; + if (!READ_ONCE(m->mnt_watchers)) { + wlist = kzalloc(sizeof(*wlist), GFP_KERNEL); + if (!wlist) + goto err_wqueue; + init_watch_list(wlist, release_mount_watch); + } + + watch = kzalloc(sizeof(*watch), GFP_KERNEL); + if (!watch) + goto err_wlist; + + init_watch(watch, wqueue); + watch->id = (unsigned long)path.dentry; + watch->info_id = (u32)watch_id << 24; + + ret = security_watch_mount(watch, &path); + if (ret < 0) + goto err_watch; + + down_write(&m->mnt.mnt_sb->s_umount); + if (!m->mnt_watchers) { + m->mnt_watchers = wlist; + wlist = NULL; + } + + ret = add_watch_to_object(watch, m->mnt_watchers); + if (ret == 0) { + spin_lock(&path.dentry->d_lock); + path.dentry->d_flags |= DCACHE_MOUNT_WATCH; + spin_unlock(&path.dentry->d_lock); + dget(path.dentry); + watch = NULL; + } + up_write(&m->mnt.mnt_sb->s_umount); + } else { + down_write(&m->mnt.mnt_sb->s_umount); + ret = remove_watch_from_object(m->mnt_watchers, wqueue, + (unsigned long)path.dentry, + false); + up_write(&m->mnt.mnt_sb->s_umount); + } + +err_watch: + kfree(watch); +err_wlist: + kfree(wlist); +err_wqueue: + put_watch_queue(wqueue); +err_path: + path_put(&path); + return ret; +} diff --git a/fs/namespace.c b/fs/namespace.c index 85b5f7bea82e..668f797ae3bd 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -498,6 +498,9 @@ static int mnt_make_readonly(struct mount *mnt) smp_wmb(); mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD; unlock_mount_hash(); + if (ret == 0) + notify_mount(mnt, NULL, NOTIFY_MOUNT_READONLY, + NOTIFY_MOUNT_IS_NOW_RO); return ret; } @@ -506,6 +509,7 @@ static int __mnt_unmake_readonly(struct mount *mnt) lock_mount_hash(); mnt->mnt.mnt_flags &= ~MNT_READONLY; unlock_mount_hash(); + notify_mount(mnt, NULL, NOTIFY_MOUNT_READONLY, 0); return 0; } @@ -819,6 +823,7 @@ static struct mountpoint *unhash_mnt(struct mount *mnt) */ static void umount_mnt(struct mount *mnt) { + notify_mount(mnt->mnt_parent, mnt, NOTIFY_MOUNT_UNMOUNT, 0); put_mountpoint(unhash_mnt(mnt)); } @@ -1159,6 +1164,11 @@ static void mntput_no_expire(struct mount *mnt) mnt->mnt.mnt_flags |= MNT_DOOMED; rcu_read_unlock(); +#ifdef CONFIG_MOUNT_NOTIFICATIONS + if (mnt->mnt_watchers) + remove_watch_list(mnt->mnt_watchers, mnt->mnt_id); +#endif + list_del(&mnt->mnt_instance); if (unlikely(!list_empty(&mnt->mnt_mounts))) { @@ -1453,6 +1463,7 @@ static void umount_tree(struct mount *mnt, enum umount_tree_flags how) p = list_first_entry(&tmp_list, struct mount, mnt_list); list_del_init(&p->mnt_expire); list_del_init(&p->mnt_list); + ns = p->mnt_ns; if (ns) { ns->mounts--; @@ -2078,7 +2089,10 @@ static int attach_recursive_mnt(struct mount *source_mnt, lock_mount_hash(); } if (moving) { + notify_mount(source_mnt->mnt_parent, source_mnt, + NOTIFY_MOUNT_MOVE_FROM, 0); unhash_mnt(source_mnt); + notify_mount(dest_mnt, source_mnt, NOTIFY_MOUNT_MOVE_TO, 0); attach_mnt(source_mnt, dest_mnt, dest_mp); touch_mnt_namespace(source_mnt->mnt_ns); } else { @@ -2087,6 +2101,11 @@ static int attach_recursive_mnt(struct mount *source_mnt, list_del_init(&source_mnt->mnt_ns->list); } mnt_set_mountpoint(dest_mnt, dest_mp, source_mnt); + notify_mount(dest_mnt, source_mnt, NOTIFY_MOUNT_NEW_MOUNT, + (source_mnt->mnt.mnt_sb->s_flags & SB_RDONLY ? + NOTIFY_MOUNT_IS_NOW_RO : 0) | + (source_mnt->mnt.mnt_sb->s_flags & SB_SUBMOUNT ? + NOTIFY_MOUNT_IS_SUBMOUNT : 0)); commit_tree(source_mnt); } @@ -2464,6 +2483,8 @@ static void set_mount_attributes(struct mount *mnt, unsigned int mnt_flags) mnt->mnt.mnt_flags = mnt_flags; touch_mnt_namespace(mnt->mnt_ns); unlock_mount_hash(); + notify_mount(mnt, NULL, NOTIFY_MOUNT_SETATTR, + (mnt_flags & SB_RDONLY ? NOTIFY_MOUNT_IS_NOW_RO : 0)); } static void mnt_warn_timestamp_expiry(struct path *mountpoint, struct vfsmount *mnt) @@ -2898,6 +2919,7 @@ void mark_mounts_for_expiry(struct list_head *mounts) if (!xchg(&mnt->mnt_expiry_mark, 1) || propagate_mount_busy(mnt, 1)) continue; + notify_mount(mnt, NULL, NOTIFY_MOUNT_EXPIRY, 0); list_move(&mnt->mnt_expire, &graveyard); } while (!list_empty(&graveyard)) { diff --git a/include/linux/dcache.h b/include/linux/dcache.h index c1488cc84fd9..7b194d778155 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -217,6 +217,7 @@ struct dentry_operations { #define DCACHE_PAR_LOOKUP 0x10000000 /* being looked up (with parent locked shared) */ #define DCACHE_DENTRY_CURSOR 0x20000000 #define DCACHE_NORCU 0x40000000 /* No RCU delay for freeing */ +#define DCACHE_MOUNT_WATCH 0x80000000 /* There's a mount watch here */ extern seqlock_t rename_lock; diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 1815065d52f3..1fd43af3b22d 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1003,6 +1003,8 @@ asmlinkage long sys_pidfd_send_signal(int pidfd, int sig, siginfo_t __user *info, unsigned int flags); asmlinkage long sys_pidfd_getfd(int pidfd, int fd, unsigned int flags); +asmlinkage long sys_watch_mount(int dfd, const char __user *path, + unsigned int at_flags, int watch_fd, int watch_id); /* * Architecture-specific system calls diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 3a3201e4618e..6b5748287883 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -855,9 +855,11 @@ __SYSCALL(__NR_clone3, sys_clone3) __SYSCALL(__NR_openat2, sys_openat2) #define __NR_pidfd_getfd 438 __SYSCALL(__NR_pidfd_getfd, sys_pidfd_getfd) +#define __NR_watch_mount 439 +__SYSCALL(__NR_watch_mount, sys_watch_mount) #undef __NR_syscalls -#define __NR_syscalls 439 +#define __NR_syscalls 440 /* * 32 bit systems traditionally used different diff --git a/include/uapi/linux/watch_queue.h b/include/uapi/linux/watch_queue.h index c3d8320b5d3a..b0f35cf51394 100644 --- a/include/uapi/linux/watch_queue.h +++ b/include/uapi/linux/watch_queue.h @@ -14,7 +14,8 @@ enum watch_notification_type { WATCH_TYPE_META = 0, /* Special record */ WATCH_TYPE_KEY_NOTIFY = 1, /* Key change event notification */ - WATCH_TYPE__NR = 2 + WATCH_TYPE_MOUNT_NOTIFY = 2, /* Mount topology change notification */ + WATCH_TYPE___NR = 3 }; enum watch_meta_notification_subtype { @@ -101,4 +102,33 @@ struct key_notification { __u32 aux; /* Per-type auxiliary data */ }; +/* + * Type of mount topology change notification. + */ +enum mount_notification_subtype { + NOTIFY_MOUNT_NEW_MOUNT = 0, /* New mount added */ + NOTIFY_MOUNT_UNMOUNT = 1, /* Mount removed manually */ + NOTIFY_MOUNT_EXPIRY = 2, /* Automount expired */ + NOTIFY_MOUNT_READONLY = 3, /* Mount R/O state changed */ + NOTIFY_MOUNT_SETATTR = 4, /* Mount attributes changed */ + NOTIFY_MOUNT_MOVE_FROM = 5, /* Mount moved from here */ + NOTIFY_MOUNT_MOVE_TO = 6, /* Mount moved to here (compare op_id) */ +}; + +#define NOTIFY_MOUNT_IN_SUBTREE WATCH_INFO_FLAG_0 /* Event not actually at watched dentry */ +#define NOTIFY_MOUNT_IS_RECURSIVE WATCH_INFO_FLAG_1 /* Change applied recursively */ +#define NOTIFY_MOUNT_IS_NOW_RO WATCH_INFO_FLAG_2 /* Mount changed to R/O */ +#define NOTIFY_MOUNT_IS_SUBMOUNT WATCH_INFO_FLAG_3 /* New mount is submount */ + +/* + * Mount topology/configuration change notification record. + * - watch.type = WATCH_TYPE_MOUNT_NOTIFY + * - watch.subtype = enum mount_notification_subtype + */ +struct mount_notification { + struct watch_notification watch; /* WATCH_TYPE_MOUNT_NOTIFY */ + __u32 triggered_on; /* The mount that the notify was on */ + __u32 changed_mount; /* The mount that got changed */ +}; + #endif /* _UAPI_LINUX_WATCH_QUEUE_H */ diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 3b69a560a7ac..3e1c5c9d2efe 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -85,6 +85,9 @@ COND_SYSCALL(ioprio_get); /* fs/locks.c */ COND_SYSCALL(flock); +/* fs/mount_notify.c */ +COND_SYSCALL(watch_mount); + /* fs/namei.c */ /* fs/namespace.c */ From patchwork Fri Feb 21 18:02:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397067 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 80FD41395 for ; Fri, 21 Feb 2020 18:02:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6094D24653 for ; 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 03/17] watch_queue: sample: Display mount tree change notifications [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:02:10 +0000 Message-ID: <158230813054.2185128.14599796644062916018.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This is run like: ./watch_test and watches "/" for changes to the mount topology and the attributes of individual mount objects. # mount -t tmpfs none /mnt # mount -o remount,ro /mnt # mount -o remount,rw /mnt producing: # ./watch_test read() = 16 NOTIFY[000]: ty=000002 sy=00 i=02000010 MOUNT 00000060 change=0[new_mount] aux=416 read() = 16 NOTIFY[000]: ty=000002 sy=04 i=02010010 MOUNT 000001a0 change=4[setattr] aux=0 read() = 16 NOTIFY[000]: ty=000002 sy=04 i=02010010 MOUNT 000001a0 change=4[setattr] aux=0 Signed-off-by: David Howells --- samples/watch_queue/watch_test.c | 39 +++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) diff --git a/samples/watch_queue/watch_test.c b/samples/watch_queue/watch_test.c index 0eaff5dc04c3..49d185150506 100644 --- a/samples/watch_queue/watch_test.c +++ b/samples/watch_queue/watch_test.c @@ -26,6 +26,9 @@ #ifndef __NR_watch_devices #define __NR_watch_devices -1 #endif +#ifndef __NR_watch_mount +#define __NR_watch_mount -1 +#endif #define BUF_SIZE 256 @@ -58,6 +61,27 @@ static void saw_key_change(struct watch_notification *n, size_t len) k->key_id, n->subtype, key_subtypes[n->subtype], k->aux); } +static const char *mount_subtypes[256] = { + [NOTIFY_MOUNT_NEW_MOUNT] = "new_mount", + [NOTIFY_MOUNT_UNMOUNT] = "unmount", + [NOTIFY_MOUNT_EXPIRY] = "expiry", + [NOTIFY_MOUNT_READONLY] = "readonly", + [NOTIFY_MOUNT_SETATTR] = "setattr", + [NOTIFY_MOUNT_MOVE_FROM] = "move_from", + [NOTIFY_MOUNT_MOVE_TO] = "move_to", +}; + +static void saw_mount_change(struct watch_notification *n, size_t len) +{ + struct mount_notification *m = (struct mount_notification *)n; + + if (len != sizeof(struct mount_notification)) + return; + + printf("MOUNT %08x change=%u[%s] aux=%u\n", + m->triggered_on, n->subtype, mount_subtypes[n->subtype], m->changed_mount); +} + /* * Consume and display events. */ @@ -134,6 +158,9 @@ static void consumer(int fd) default: printf("other type\n"); break; + case WATCH_TYPE_MOUNT_NOTIFY: + saw_mount_change(&n.n, len); + break; } p += len; @@ -142,12 +169,17 @@ static void consumer(int fd) } static struct watch_notification_filter filter = { - .nr_filters = 1, + .nr_filters = 2, .filters = { [0] = { .type = WATCH_TYPE_KEY_NOTIFY, .subtype_filter[0] = UINT_MAX, }, + [1] = { + .type = WATCH_TYPE_MOUNT_NOTIFY, + // Reject move-from notifications + .subtype_filter[0] = UINT_MAX & ~(1 << NOTIFY_MOUNT_MOVE_FROM), + }, }, }; @@ -181,6 +213,11 @@ int main(int argc, char **argv) exit(1); } + if (syscall(__NR_watch_mount, AT_FDCWD, "/", 0, fd, 0x02) == -1) { + perror("watch_mount"); + exit(1); + } + consumer(fd); exit(0); } From patchwork Fri Feb 21 18:02:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397069 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DB6E01395 for ; Fri, 21 Feb 2020 18:02:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA9DB2467B for ; Fri, 21 Feb 2020 18:02:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XWTC97dh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729451AbgBUSC3 (ORCPT ); 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 04/17] watch_queue: Introduce a non-repeating system-unique superblock ID [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:02:18 +0000 Message-ID: <158230813823.2185128.2640121651515347574.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Introduce an (effectively) non-repeating system-unique superblock ID that can be used to determine that two object are in the same superblock without risking reuse of the ID in the meantime (as is possible with device IDs). The ID is time-based to make it harder to use it as a covert communications channel. In future patches, this ID will be used to tag superblock notification messages. It will also be made queryable. Signed-off-by: David Howells --- fs/super.c | 24 ++++++++++++++++++++++++ include/linux/fs.h | 3 +++ 2 files changed, 27 insertions(+) diff --git a/fs/super.c b/fs/super.c index cd352530eca9..a63073e6127e 100644 --- a/fs/super.c +++ b/fs/super.c @@ -44,6 +44,8 @@ static int thaw_super_locked(struct super_block *sb); static LIST_HEAD(super_blocks); static DEFINE_SPINLOCK(sb_lock); +static u64 sb_last_identifier; +static u64 sb_identifier_offset; static char *sb_writers_name[SB_FREEZE_LEVELS] = { "sb_writers", @@ -188,6 +190,27 @@ static void destroy_unused_super(struct super_block *s) destroy_super_work(&s->destroy_work); } +/* + * Generate a unique identifier for a superblock. + */ +static void generate_super_id(struct super_block *s) +{ + u64 id = ktime_to_ns(ktime_get()); + + spin_lock(&sb_lock); + + id += sb_identifier_offset; + if (id <= sb_last_identifier) { + id = sb_last_identifier + 1; + sb_identifier_offset = sb_last_identifier - id; + } + + sb_last_identifier = id; + spin_unlock(&sb_lock); + + s->s_unique_id = id; +} + /** * alloc_super - create new superblock * @type: filesystem type superblock should belong to @@ -273,6 +296,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags, goto fail; if (list_lru_init_memcg(&s->s_inode_lru, &s->s_shrink)) goto fail; + generate_super_id(s); return s; fail: diff --git a/include/linux/fs.h b/include/linux/fs.h index 3cd4fe6b845e..9de6bfe41016 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1548,6 +1548,9 @@ struct super_block { spinlock_t s_inode_wblist_lock; struct list_head s_inodes_wb; /* writeback inodes */ + + /* Superblock event notifications */ + u64 s_unique_id; } __randomize_layout; /* Helper functions so that in most cases filesystems will From patchwork Fri Feb 21 18:02:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397071 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AE45A92A for ; Fri, 21 Feb 2020 18:02:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72A2124656 for ; Fri, 21 Feb 2020 18:02:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="c4sb7YxP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729528AbgBUSCj (ORCPT ); Fri, 21 Feb 2020 13:02:39 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:20960 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729495AbgBUSCj (ORCPT ); Fri, 21 Feb 2020 13:02:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582308157; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=33Iq1B7dM8sRZxtDtAg0gj6PbaIpfk1u5tU64k5Edss=; b=c4sb7YxPtq57XllIbv+jiayE4XJrx6YZqtYCrN+HnREKHWSalzj/awgsbfzM0MXOCverif JZPCC0OUjO9Ev3IlwasfPJHa5YFzAsZdv8kCY+/DvCv10f400OfDVpcqqeT0nlrc6wk33v QPfsiDYQ4t64qtliwZW4GFLJp4Oun8Q= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-205-id5hTd-lP5-U572RBQI8VQ-1; Fri, 21 Feb 2020 13:02:32 -0500 X-MC-Unique: id5hTd-lP5-U572RBQI8VQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 20E90805722; Fri, 21 Feb 2020 18:02:31 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-122-163.rdu2.redhat.com [10.10.122.163]) by smtp.corp.redhat.com (Postfix) with ESMTP id 93CE09077C; Fri, 21 Feb 2020 18:02:26 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 05/17] watch_queue: Add superblock notifications [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:02:25 +0000 Message-ID: <158230814575.2185128.14652288302879169043.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add a superblock event notification facility whereby notifications about superblock events, such as I/O errors (EIO), quota limits being hit (EDQUOT) and running out of space (ENOSPC) can be reported to a monitoring process asynchronously. Note that this does not cover vfsmount topology changes. watch_mount() is used for that. Firstly, an event queue needs to be created: fd = open("/dev/event_queue", O_RDWR); ioctl(fd, IOC_WATCH_QUEUE_SET_SIZE, page_size << n); then a notification can be set up to report notifications via that queue: struct watch_notification_filter filter = { .nr_filters = 1, .filters = { [0] = { .type = WATCH_TYPE_SB_NOTIFY, .subtype_filter[0] = UINT_MAX, }, }, }; ioctl(fd, IOC_WATCH_QUEUE_SET_FILTER, &filter); watch_sb(AT_FDCWD, "/home/dhowells", 0, fd, 0x03); In this case, it would let me monitor my own homedir for events. After setting the watch, records will be placed into the queue when, for example, as superblock switches between read-write and read-only. Records are of the following format: struct superblock_notification { struct watch_notification watch; __u64 sb_id; } *n; Where: n->watch.type will be WATCH_TYPE_SB_NOTIFY. n->watch.subtype will indicate the type of event, such as NOTIFY_SUPERBLOCK_READONLY. n->watch.info & WATCH_INFO_LENGTH will indicate the length of the record. n->watch.info & WATCH_INFO_ID will be the fifth argument to watch_sb(), shifted. n->watch.info & NOTIFY_SUPERBLOCK_IS_NOW_RO will be used for NOTIFY_SUPERBLOCK_READONLY, being set if the superblock becomes R/O, and being cleared otherwise. n->sb_id will be the ID of the superblock, as can be retrieved with the fsinfo() syscall, as part of the fsinfo_sb_notifications attribute in the the watch_id field. Note that it is permissible for event records to be of variable length - or, at least, the length may be dependent on the subtype. Note also that the queue can be shared between multiple notifications of various types. Signed-off-by: David Howells --- arch/alpha/kernel/syscalls/syscall.tbl | 1 arch/arm/tools/syscall.tbl | 1 arch/arm64/include/asm/unistd.h | 2 arch/ia64/kernel/syscalls/syscall.tbl | 1 arch/m68k/kernel/syscalls/syscall.tbl | 1 arch/microblaze/kernel/syscalls/syscall.tbl | 1 arch/mips/kernel/syscalls/syscall_n32.tbl | 1 arch/mips/kernel/syscalls/syscall_n64.tbl | 1 arch/mips/kernel/syscalls/syscall_o32.tbl | 1 arch/parisc/kernel/syscalls/syscall.tbl | 1 arch/powerpc/kernel/syscalls/syscall.tbl | 1 arch/s390/kernel/syscalls/syscall.tbl | 1 arch/sh/kernel/syscalls/syscall.tbl | 1 arch/sparc/kernel/syscalls/syscall.tbl | 1 arch/x86/entry/syscalls/syscall_32.tbl | 1 arch/x86/entry/syscalls/syscall_64.tbl | 1 arch/xtensa/kernel/syscalls/syscall.tbl | 1 fs/Kconfig | 12 ++ fs/super.c | 132 +++++++++++++++++++++++++++ include/linux/fs.h | 80 ++++++++++++++++ include/linux/syscalls.h | 2 include/uapi/asm-generic/unistd.h | 4 + include/uapi/linux/watch_queue.h | 31 ++++++ kernel/sys_ni.c | 3 + 24 files changed, 279 insertions(+), 3 deletions(-) diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl index b869428033ef..7c0115af9010 100644 --- a/arch/alpha/kernel/syscalls/syscall.tbl +++ b/arch/alpha/kernel/syscalls/syscall.tbl @@ -478,3 +478,4 @@ 547 common openat2 sys_openat2 548 common pidfd_getfd sys_pidfd_getfd 549 common watch_mount sys_watch_mount +550 common watch_sb sys_watch_sb diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index 9c389da9efcc..f256f009a89f 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -452,3 +452,4 @@ 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount +440 common watch_sb sys_watch_sb diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index 75f04a1023be..bc0f923e0e04 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -38,7 +38,7 @@ #define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE + 5) #define __ARM_NR_COMPAT_END (__ARM_NR_COMPAT_BASE + 0x800) -#define __NR_compat_syscalls 440 +#define __NR_compat_syscalls 441 #endif #define __ARCH_WANT_SYS_CLONE diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl index 6817f865cc71..a4dafc659647 100644 --- a/arch/ia64/kernel/syscalls/syscall.tbl +++ b/arch/ia64/kernel/syscalls/syscall.tbl @@ -359,3 +359,4 @@ 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount +440 common watch_sb sys_watch_sb diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index fbf85da75ecb..893fb4151547 100644 --- a/arch/m68k/kernel/syscalls/syscall.tbl +++ b/arch/m68k/kernel/syscalls/syscall.tbl @@ -438,3 +438,4 @@ 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount +440 common watch_sb sys_watch_sb diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl index b05b192da1e2..54aaf0d40c64 100644 --- a/arch/microblaze/kernel/syscalls/syscall.tbl +++ b/arch/microblaze/kernel/syscalls/syscall.tbl @@ -444,3 +444,4 @@ 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount +440 common watch_sb sys_watch_sb diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl index 0f85d2a033f9..fd34dd0efed0 100644 --- a/arch/mips/kernel/syscalls/syscall_n32.tbl +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl @@ -377,3 +377,4 @@ 437 n32 openat2 sys_openat2 438 n32 pidfd_getfd sys_pidfd_getfd 439 n32 watch_mount sys_watch_mount +440 n32 watch_sb sys_watch_sb diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl index 905cf9ac0792..db0f4c0a0a0b 100644 --- a/arch/mips/kernel/syscalls/syscall_n64.tbl +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl @@ -353,3 +353,4 @@ 437 n64 openat2 sys_openat2 438 n64 pidfd_getfd sys_pidfd_getfd 439 n64 watch_mount sys_watch_mount +440 n64 watch_sb sys_watch_sb diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl index 834b26b08d74..ce2e1326de8f 100644 --- a/arch/mips/kernel/syscalls/syscall_o32.tbl +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl @@ -426,3 +426,4 @@ 437 o32 openat2 sys_openat2 438 o32 pidfd_getfd sys_pidfd_getfd 439 o32 watch_mount sys_watch_mount +440 o32 watch_sb sys_watch_sb diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index badd3449db43..6e4a7c08b64b 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -436,3 +436,4 @@ 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount +440 common watch_sb sys_watch_sb diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index b404361bc929..08943f3b8206 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -520,3 +520,4 @@ 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount +440 common watch_sb sys_watch_sb diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index 33071de24511..b3b8529d2b74 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -441,3 +441,4 @@ 437 common openat2 sys_openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount sys_watch_mount +440 common watch_sb sys_watch_sb sys_watch_sb diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl index 682c125122f4..89307a20657c 100644 --- a/arch/sh/kernel/syscalls/syscall.tbl +++ b/arch/sh/kernel/syscalls/syscall.tbl @@ -441,3 +441,4 @@ 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount +440 common watch_sb sys_watch_sb diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index febf3cd675e3..4ff841a00450 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -484,3 +484,4 @@ 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount +440 common watch_sb sys_watch_sb diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 085bcc5afdf1..e2731d295f88 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -443,3 +443,4 @@ 437 i386 openat2 sys_openat2 __ia32_sys_openat2 438 i386 pidfd_getfd sys_pidfd_getfd __ia32_sys_pidfd_getfd 439 i386 watch_mount sys_watch_mount __ia32_sys_watch_mount +440 i386 watch_sb sys_watch_sb __ia32_sys_watch_sb diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 9cfb6b2eb319..f4391176102c 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -360,6 +360,7 @@ 437 common openat2 __x64_sys_openat2 438 common pidfd_getfd __x64_sys_pidfd_getfd 439 common watch_mount __x64_sys_watch_mount +440 common watch_sb __x64_sys_watch_sb # # x32-specific system call numbers start at 512 to avoid cache impact diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl index 1a066a43a58b..8e7d731ed6cf 100644 --- a/arch/xtensa/kernel/syscalls/syscall.tbl +++ b/arch/xtensa/kernel/syscalls/syscall.tbl @@ -409,3 +409,4 @@ 437 common openat2 sys_openat2 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount +440 common watch_sb sys_watch_sb diff --git a/fs/Kconfig b/fs/Kconfig index d7039137d538..fef1365c23a5 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -126,6 +126,18 @@ config MOUNT_NOTIFICATIONS device to handle the notification buffer and provides the mount_notify() system call to enable/disable watchpoints. +config SB_NOTIFICATIONS + bool "Superblock event notifications" + select WATCH_QUEUE + help + This option provides support for receiving superblock event + notifications. This makes use of the /dev/watch_queue misc device to + handle the notification buffer and provides the sb_notify() system + call to enable/disable watches. + + Events can include things like changing between R/W and R/O, EIO + generation, ENOSPC generation and EDQUOT generation. + source "fs/quota/Kconfig" source "fs/autofs/Kconfig" diff --git a/fs/super.c b/fs/super.c index a63073e6127e..0d84cbbf3662 100644 --- a/fs/super.c +++ b/fs/super.c @@ -37,6 +37,8 @@ #include #include #include +#include +#include #include #include "internal.h" @@ -354,6 +356,10 @@ void deactivate_locked_super(struct super_block *s) { struct file_system_type *fs = s->s_type; if (atomic_dec_and_test(&s->s_active)) { +#ifdef CONFIG_SB_NOTIFICATIONS + if (s->s_watchers) + remove_watch_list(s->s_watchers, s->s_unique_id); +#endif cleancache_invalidate_fs(s); unregister_shrinker(&s->s_shrink); fs->kill_sb(s); @@ -993,6 +999,8 @@ int reconfigure_super(struct fs_context *fc) /* Needs to be ordered wrt mnt_is_readonly() */ smp_wmb(); sb->s_readonly_remount = 0; + notify_sb(sb, NOTIFY_SUPERBLOCK_READONLY, + remount_ro ? NOTIFY_SUPERBLOCK_IS_NOW_RO : 0); /* * Some filesystems modify their metadata via some other path than the @@ -1891,3 +1899,127 @@ int thaw_super(struct super_block *sb) return thaw_super_locked(sb); } EXPORT_SYMBOL(thaw_super); + +#ifdef CONFIG_SB_NOTIFICATIONS +/* + * Post superblock notifications. + */ +void post_sb_notification(struct super_block *s, struct superblock_notification *n) +{ + post_watch_notification(s->s_watchers, &n->watch, current_cred(), + s->s_unique_id); +} + +static void sb_release_watch(struct watch *watch) +{ + put_super(watch->private); +} + +/** + * sys_watch_sb - Watch for superblock events. + * @dfd: Base directory to pathwalk from or fd referring to superblock. + * @filename: Path to superblock to place the watch upon + * @at_flags: Pathwalk control flags + * @watch_fd: The watch queue to send notifications to. + * @watch_id: The watch ID to be placed in the notification (-1 to remove watch) + */ +SYSCALL_DEFINE5(watch_sb, + int, dfd, + const char __user *, filename, + unsigned int, at_flags, + int, watch_fd, + int, watch_id) +{ + struct watch_queue *wqueue; + struct super_block *s; + struct watch_list *wlist = NULL; + struct watch *watch = NULL; + struct path path; + unsigned int lookup_flags = + LOOKUP_DIRECTORY | LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT; + bool drop_s_count = false; + int ret; + + if (watch_id < -1 || watch_id > 0xff) + return -EINVAL; + if ((at_flags & ~(AT_NO_AUTOMOUNT | AT_EMPTY_PATH)) != 0) + return -EINVAL; + if (at_flags & AT_NO_AUTOMOUNT) + lookup_flags &= ~LOOKUP_AUTOMOUNT; + if (at_flags & AT_EMPTY_PATH) + lookup_flags |= LOOKUP_EMPTY; + + ret = user_path_at(dfd, filename, at_flags, &path); + if (ret) + return ret; + + ret = inode_permission(path.dentry->d_inode, MAY_EXEC); + if (ret) + goto err_path; + + wqueue = get_watch_queue(watch_fd); + if (IS_ERR(wqueue)) + goto err_path; + + s = path.dentry->d_sb; + if (watch_id >= 0) { + ret = -ENOMEM; + if (!READ_ONCE(s->s_watchers)) { + wlist = kzalloc(sizeof(*wlist), GFP_KERNEL); + if (!wlist) + goto err_wqueue; + init_watch_list(wlist, sb_release_watch); + } + + watch = kzalloc(sizeof(*watch), GFP_KERNEL); + if (!watch) + goto err_wlist; + + init_watch(watch, wqueue); + watch->id = s->s_unique_id; + watch->private = s; + watch->info_id = (u32)watch_id << 24; + + ret = security_watch_sb(watch, s); + if (ret < 0) + goto err_watch; + + down_write(&s->s_umount); + ret = -EIO; + if (atomic_read(&s->s_active)) { + if (!s->s_watchers) { + s->s_watchers = wlist; + wlist = NULL; + } + + spin_lock(&sb_lock); + s->s_count++; + spin_unlock(&sb_lock); + ret = add_watch_to_object(watch, s->s_watchers); + if (ret == 0) + watch = NULL; /* It worked */ + else + drop_s_count = true; + } + up_write(&s->s_umount); + if (drop_s_count) + put_super(s); + } else { + ret = -EBADSLT; + down_write(&s->s_umount); + ret = remove_watch_from_object(s->s_watchers, wqueue, + s->s_unique_id, false); + up_write(&s->s_umount); + } + +err_watch: + kfree(watch); +err_wlist: + kfree(wlist); +err_wqueue: + put_watch_queue(wqueue); +err_path: + path_put(&path); + return ret; +} +#endif diff --git a/include/linux/fs.h b/include/linux/fs.h index 9de6bfe41016..d5128d112384 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -40,6 +40,7 @@ #include #include #include +#include #include #include @@ -1551,6 +1552,11 @@ struct super_block { /* Superblock event notifications */ u64 s_unique_id; + +#ifdef CONFIG_SB_NOTIFICATIONS + struct watch_list *s_watchers; +#endif + atomic_t s_notify_counter; } __randomize_layout; /* Helper functions so that in most cases filesystems will @@ -3654,4 +3660,78 @@ static inline int inode_drain_writes(struct inode *inode) return filemap_write_and_wait(inode->i_mapping); } +extern void post_sb_notification(struct super_block *, struct superblock_notification *); + +/** + * notify_sb: Post simple superblock notification. + * @s: The superblock the notification is about. + * @subtype: The type of notification. + * @info: WATCH_INFO_FLAG_* flags to be set in the record. + */ +static inline void notify_sb(struct super_block *s, + enum superblock_notification_type subtype, + u32 info) +{ +#ifdef CONFIG_SB_NOTIFICATIONS + atomic_inc(&s->s_notify_counter); + if (unlikely(READ_ONCE(s->s_watchers))) { + struct superblock_notification n = { + .watch.type = WATCH_TYPE_SB_NOTIFY, + .watch.subtype = subtype, + .watch.info = watch_sizeof(n) | info, + .sb_id = s->s_unique_id, + }; + + post_sb_notification(s, &n); + } +#endif +} + +/** + * notify_sb_error: Post superblock error notification. + * @s: The superblock the notification is about. + * @error: The error number to be recorded. + */ +static inline int notify_sb_error(struct super_block *s, int error) +{ +#ifdef CONFIG_SB_NOTIFICATIONS + atomic_inc(&s->s_notify_counter); + if (unlikely(READ_ONCE(s->s_watchers))) { + struct superblock_error_notification n = { + .s.watch.type = WATCH_TYPE_SB_NOTIFY, + .s.watch.subtype = NOTIFY_SUPERBLOCK_ERROR, + .s.watch.info = watch_sizeof(n), + .s.sb_id = s->s_unique_id, + .error_number = error, + .error_cookie = 0, + }; + + post_sb_notification(s, &n.s); + } +#endif + return error; +} + +/** + * notify_sb_EDQUOT: Post superblock quota overrun notification. + * @s: The superblock the notification is about. + */ +static inline int notify_sb_EQDUOT(struct super_block *s) +{ +#ifdef CONFIG_SB_NOTIFICATIONS + atomic_inc(&s->s_notify_counter); + if (unlikely(READ_ONCE(s->s_watchers))) { + struct superblock_notification n = { + .watch.type = WATCH_TYPE_SB_NOTIFY, + .watch.subtype = NOTIFY_SUPERBLOCK_EDQUOT, + .watch.info = watch_sizeof(n), + .sb_id = s->s_unique_id, + }; + + post_sb_notification(s, &n); + } +#endif + return -EDQUOT; +} + #endif /* _LINUX_FS_H */ diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 1fd43af3b22d..c84440d57f52 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1005,6 +1005,8 @@ asmlinkage long sys_pidfd_send_signal(int pidfd, int sig, asmlinkage long sys_pidfd_getfd(int pidfd, int fd, unsigned int flags); asmlinkage long sys_watch_mount(int dfd, const char __user *path, unsigned int at_flags, int watch_fd, int watch_id); +asmlinkage long sys_watch_sb(int dfd, const char __user *path, + unsigned int at_flags, int watch_fd, int watch_id); /* * Architecture-specific system calls diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 6b5748287883..5bff318b7ffa 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -857,9 +857,11 @@ __SYSCALL(__NR_openat2, sys_openat2) __SYSCALL(__NR_pidfd_getfd, sys_pidfd_getfd) #define __NR_watch_mount 439 __SYSCALL(__NR_watch_mount, sys_watch_mount) +#define __NR_watch_sb 440 +__SYSCALL(__NR_watch_sb, sys_watch_sb) #undef __NR_syscalls -#define __NR_syscalls 440 +#define __NR_syscalls 441 /* * 32 bit systems traditionally used different diff --git a/include/uapi/linux/watch_queue.h b/include/uapi/linux/watch_queue.h index b0f35cf51394..e9c37b1ae68d 100644 --- a/include/uapi/linux/watch_queue.h +++ b/include/uapi/linux/watch_queue.h @@ -15,7 +15,8 @@ enum watch_notification_type { WATCH_TYPE_META = 0, /* Special record */ WATCH_TYPE_KEY_NOTIFY = 1, /* Key change event notification */ WATCH_TYPE_MOUNT_NOTIFY = 2, /* Mount topology change notification */ - WATCH_TYPE___NR = 3 + WATCH_TYPE_SB_NOTIFY = 3, /* Superblock event notification */ + WATCH_TYPE___NR = 4 }; enum watch_meta_notification_subtype { @@ -131,4 +132,32 @@ struct mount_notification { __u32 changed_mount; /* The mount that got changed */ }; +/* + * Type of superblock notification. + */ +enum superblock_notification_type { + NOTIFY_SUPERBLOCK_READONLY = 0, /* Filesystem toggled between R/O and R/W */ + NOTIFY_SUPERBLOCK_ERROR = 1, /* Error in filesystem or blockdev */ + NOTIFY_SUPERBLOCK_EDQUOT = 2, /* EDQUOT notification */ + NOTIFY_SUPERBLOCK_NETWORK = 3, /* Network status change */ +}; + +#define NOTIFY_SUPERBLOCK_IS_NOW_RO WATCH_INFO_FLAG_0 /* Superblock changed to R/O */ + +/* + * Superblock notification record. + * - watch.type = WATCH_TYPE_MOUNT_NOTIFY + * - watch.subtype = enum superblock_notification_subtype + */ +struct superblock_notification { + struct watch_notification watch; /* WATCH_TYPE_SB_NOTIFY */ + __u64 sb_id; /* 64-bit superblock ID */ +}; + +struct superblock_error_notification { + struct superblock_notification s; /* subtype = notify_superblock_error */ + __u32 error_number; + __u32 error_cookie; +}; + #endif /* _UAPI_LINUX_WATCH_QUEUE_H */ diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 3e1c5c9d2efe..0ce01f86e5db 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -119,6 +119,9 @@ COND_SYSCALL_COMPAT(signalfd4); /* fs/sync.c */ +/* fs/super.c */ +COND_SYSCALL(watch_sb); + /* fs/timerfd.c */ COND_SYSCALL(timerfd_create); COND_SYSCALL(timerfd_settime); From patchwork Fri Feb 21 18:02:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397073 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DB96C92A for ; Fri, 21 Feb 2020 18:02:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB35024656 for ; Fri, 21 Feb 2020 18:02:46 +0000 (UTC) Authentication-Results: mail.kernel.org; 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 06/17] watch_queue: sample: Display superblock notifications [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:02:36 +0000 Message-ID: <158230815634.2185128.9507318728078606539.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The notification is run as: ./watch_test and it then watches "/mnt" for superblock notifications: # mount -t tmpfs none /mnt # ./watch_test & # mount -o remount,ro /mnt # mount -o remount,rw /mnt producing: # ./watch_test NOTIFY[000]: ty=000003 sy=00 i=03010010 SUPER 157eb57ca7 change=0[readonly] read() = 16 NOTIFY[000]: ty=000002 sy=04 i=02010010 MOUNT 000001a0 change=4[setattr] aux=0 read() = 16 NOTIFY[000]: ty=000002 sy=04 i=02010010 MOUNT 000001a0 change=4[setattr] aux=0 Signed-off-by: David Howells --- samples/watch_queue/watch_test.c | 39 +++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) diff --git a/samples/watch_queue/watch_test.c b/samples/watch_queue/watch_test.c index 49d185150506..eea3bd8c6569 100644 --- a/samples/watch_queue/watch_test.c +++ b/samples/watch_queue/watch_test.c @@ -29,6 +29,9 @@ #ifndef __NR_watch_mount #define __NR_watch_mount -1 #endif +#ifndef __NR_watch_sb +#define __NR_watch_sb -1 +#endif #define BUF_SIZE 256 @@ -82,6 +85,24 @@ static void saw_mount_change(struct watch_notification *n, size_t len) m->triggered_on, n->subtype, mount_subtypes[n->subtype], m->changed_mount); } +static const char *super_subtypes[256] = { + [NOTIFY_SUPERBLOCK_READONLY] = "readonly", + [NOTIFY_SUPERBLOCK_ERROR] = "error", + [NOTIFY_SUPERBLOCK_EDQUOT] = "edquot", + [NOTIFY_SUPERBLOCK_NETWORK] = "network", +}; + +static void saw_super_change(struct watch_notification *n, size_t len) +{ + struct superblock_notification *s = (struct superblock_notification *)n; + + if (len < sizeof(struct superblock_notification)) + return; + + printf("SUPER %08llx change=%u[%s]\n", + s->sb_id, n->subtype, super_subtypes[n->subtype]); +} + /* * Consume and display events. */ @@ -161,6 +182,9 @@ static void consumer(int fd) case WATCH_TYPE_MOUNT_NOTIFY: saw_mount_change(&n.n, len); break; + case WATCH_TYPE_SB_NOTIFY: + saw_super_change(&n.n, len); + break; } p += len; @@ -169,7 +193,7 @@ static void consumer(int fd) } static struct watch_notification_filter filter = { - .nr_filters = 2, + .nr_filters = 3, .filters = { [0] = { .type = WATCH_TYPE_KEY_NOTIFY, @@ -180,6 +204,14 @@ static struct watch_notification_filter filter = { // Reject move-from notifications .subtype_filter[0] = UINT_MAX & ~(1 << NOTIFY_MOUNT_MOVE_FROM), }, + [2] = { + .type = WATCH_TYPE_SB_NOTIFY, + // Only accept notification of changes to R/O state + .subtype_filter[0] = (1 << NOTIFY_SUPERBLOCK_READONLY), + // Only accept notifications of change-to-R/O + .info_mask = WATCH_INFO_FLAG_0, + .info_filter = WATCH_INFO_FLAG_0, + }, }, }; @@ -218,6 +250,11 @@ int main(int argc, char **argv) exit(1); } + if (syscall(__NR_watch_sb, AT_FDCWD, "/mnt", 0, fd, 0x03) == -1) { + perror("watch_sb"); + exit(1); + } + consumer(fd); exit(0); } From patchwork Fri Feb 21 18:02:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397075 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C3E641395 for ; Fri, 21 Feb 2020 18:02:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7488324653 for ; Fri, 21 Feb 2020 18:02:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="f5t+iGbl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729573AbgBUSCy (ORCPT ); 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 07/17] fsinfo: Add fsinfo() syscall to query filesystem information [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:02:44 +0000 Message-ID: <158230816405.2185128.14624101691579582829.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add a system call to allow filesystem information to be queried. A request value can be given to indicate the desired attribute. Support is provided for enumerating multi-value attributes. =============== NEW SYSTEM CALL =============== The new system call looks like: int ret = fsinfo(int dfd, const char *filename, const struct fsinfo_params *params, void *buffer, size_t buf_size); The params parameter optionally points to a block of parameters: struct fsinfo_params { __u32 at_flags; __u32 flags; __u32 request; __u32 Nth; __u32 Mth; __u64 __reserved[3]; }; If params is NULL, it is assumed params->request should be FSINFO_ATTR_STATFS, params->Nth should be 0, params->Mth should be 0, params->at_flags should be 0 and params->flags should be 0. If params is given, all of params->__reserved[] must be 0. dfd, filename and params->at_flags indicate the file to query. There is no equivalent of lstat() as that can be emulated with fsinfo() by setting AT_SYMLINK_NOFOLLOW in params->at_flags. There is also no equivalent of fstat() as that can be emulated by passing a NULL filename to fsinfo() with the fd of interest in dfd. AT_NO_AUTOMOUNT can also be used to an allow automount point to be queried without triggering it. params->request indicates the attribute/attributes to be queried. This can be one of: FSINFO_ATTR_STATFS - statfs-style info FSINFO_ATTR_IDS - Filesystem IDs FSINFO_ATTR_LIMITS - Filesystem limits FSINFO_ATTR_SUPPORTS - What's supported in statx(), IOC flags FSINFO_ATTR_TIMESTAMP_INFO - Inode timestamp info FSINFO_ATTR_VOLUME_ID - Volume ID (string) FSINFO_ATTR_VOLUME_UUID - Volume UUID FSINFO_ATTR_VOLUME_NAME - Volume name (string) FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO - Information about attr Nth FSINFO_ATTR_FSINFO_ATTRIBUTES - List of supported attrs Some attributes (such as the servers backing a network filesystem) can have multiple values. These can be enumerated by setting params->Nth and params->Mth to 0, 1, ... until ENODATA is returned. buffer and buf_size point to the reply buffer. The buffer is filled up to the specified size, even if this means truncating the reply. The full size of the reply is returned. In future versions, this will allow extra fields to be tacked on to the end of the reply, but anyone not expecting them will only get the subset they're expecting. If either buffer of buf_size are 0, no copy will take place and the data size will be returned. At the moment, this will only work on x86_64 and i386 as it requires the system call to be wired up. Signed-off-by: David Howells cc: linux-api@vger.kernel.org --- arch/alpha/kernel/syscalls/syscall.tbl | 1 arch/arm/tools/syscall.tbl | 1 arch/arm64/include/asm/unistd.h | 2 arch/ia64/kernel/syscalls/syscall.tbl | 1 arch/m68k/kernel/syscalls/syscall.tbl | 1 arch/microblaze/kernel/syscalls/syscall.tbl | 1 arch/mips/kernel/syscalls/syscall_n32.tbl | 1 arch/mips/kernel/syscalls/syscall_n64.tbl | 1 arch/mips/kernel/syscalls/syscall_o32.tbl | 1 arch/parisc/kernel/syscalls/syscall.tbl | 1 arch/powerpc/kernel/syscalls/syscall.tbl | 1 arch/s390/kernel/syscalls/syscall.tbl | 1 arch/sh/kernel/syscalls/syscall.tbl | 1 arch/sparc/kernel/syscalls/syscall.tbl | 1 arch/x86/entry/syscalls/syscall_32.tbl | 1 arch/x86/entry/syscalls/syscall_64.tbl | 1 arch/xtensa/kernel/syscalls/syscall.tbl | 1 fs/Kconfig | 7 fs/Makefile | 1 fs/fsinfo.c | 566 +++++++++++++++++++++++++ include/linux/fs.h | 4 include/linux/fsinfo.h | 72 +++ include/linux/syscalls.h | 4 include/uapi/asm-generic/unistd.h | 4 include/uapi/linux/fsinfo.h | 187 ++++++++ kernel/sys_ni.c | 1 samples/vfs/Makefile | 5 samples/vfs/test-fsinfo.c | 607 +++++++++++++++++++++++++++ 28 files changed, 1474 insertions(+), 2 deletions(-) create mode 100644 fs/fsinfo.c create mode 100644 include/linux/fsinfo.h create mode 100644 include/uapi/linux/fsinfo.h create mode 100644 samples/vfs/test-fsinfo.c diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl index 7c0115af9010..4d0b07dde12d 100644 --- a/arch/alpha/kernel/syscalls/syscall.tbl +++ b/arch/alpha/kernel/syscalls/syscall.tbl @@ -479,3 +479,4 @@ 548 common pidfd_getfd sys_pidfd_getfd 549 common watch_mount sys_watch_mount 550 common watch_sb sys_watch_sb +551 common fsinfo sys_fsinfo diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index f256f009a89f..fdda8382b420 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -453,3 +453,4 @@ 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount 440 common watch_sb sys_watch_sb +441 common fsinfo sys_fsinfo diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index bc0f923e0e04..388eeb71cff0 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -38,7 +38,7 @@ #define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE + 5) #define __ARM_NR_COMPAT_END (__ARM_NR_COMPAT_BASE + 0x800) -#define __NR_compat_syscalls 441 +#define __NR_compat_syscalls 442 #endif #define __ARCH_WANT_SYS_CLONE diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl index a4dafc659647..2316e60e031a 100644 --- a/arch/ia64/kernel/syscalls/syscall.tbl +++ b/arch/ia64/kernel/syscalls/syscall.tbl @@ -360,3 +360,4 @@ 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount 440 common watch_sb sys_watch_sb +441 common fsinfo sys_fsinfo diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index 893fb4151547..efc2723ca91f 100644 --- a/arch/m68k/kernel/syscalls/syscall.tbl +++ b/arch/m68k/kernel/syscalls/syscall.tbl @@ -439,3 +439,4 @@ 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount 440 common watch_sb sys_watch_sb +441 common fsinfo sys_fsinfo diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl index 54aaf0d40c64..745c0f462fce 100644 --- a/arch/microblaze/kernel/syscalls/syscall.tbl +++ b/arch/microblaze/kernel/syscalls/syscall.tbl @@ -445,3 +445,4 @@ 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount 440 common watch_sb sys_watch_sb +441 common fsinfo sys_fsinfo diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl index fd34dd0efed0..499f83562a8c 100644 --- a/arch/mips/kernel/syscalls/syscall_n32.tbl +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl @@ -378,3 +378,4 @@ 438 n32 pidfd_getfd sys_pidfd_getfd 439 n32 watch_mount sys_watch_mount 440 n32 watch_sb sys_watch_sb +441 n32 fsinfo sys_fsinfo diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl index db0f4c0a0a0b..b3188bc3ab3c 100644 --- a/arch/mips/kernel/syscalls/syscall_n64.tbl +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl @@ -354,3 +354,4 @@ 438 n64 pidfd_getfd sys_pidfd_getfd 439 n64 watch_mount sys_watch_mount 440 n64 watch_sb sys_watch_sb +441 n64 fsinfo sys_fsinfo diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl index ce2e1326de8f..1a3e8ed5e538 100644 --- a/arch/mips/kernel/syscalls/syscall_o32.tbl +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl @@ -427,3 +427,4 @@ 438 o32 pidfd_getfd sys_pidfd_getfd 439 o32 watch_mount sys_watch_mount 440 o32 watch_sb sys_watch_sb +441 o32 fsinfo sys_fsinfo diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index 6e4a7c08b64b..2572c215d861 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -437,3 +437,4 @@ 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount 440 common watch_sb sys_watch_sb +441 common fsinfo sys_fsinfo diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index 08943f3b8206..39d7ac7e918c 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -521,3 +521,4 @@ 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount 440 common watch_sb sys_watch_sb +441 common fsinfo sys_fsinfo diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index b3b8529d2b74..ae4cefd3dd1b 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -442,3 +442,4 @@ 438 common pidfd_getfd sys_pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount sys_watch_mount 440 common watch_sb sys_watch_sb sys_watch_sb +441 common fsinfo sys_fsinfo sys_fsinfo diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl index 89307a20657c..05945b9aee4b 100644 --- a/arch/sh/kernel/syscalls/syscall.tbl +++ b/arch/sh/kernel/syscalls/syscall.tbl @@ -442,3 +442,4 @@ 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount 440 common watch_sb sys_watch_sb +441 common fsinfo sys_fsinfo diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index 4ff841a00450..b71b34d4b45c 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -485,3 +485,4 @@ 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount 440 common watch_sb sys_watch_sb +441 common fsinfo sys_fsinfo diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index e2731d295f88..e118ba9aca4c 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -444,3 +444,4 @@ 438 i386 pidfd_getfd sys_pidfd_getfd __ia32_sys_pidfd_getfd 439 i386 watch_mount sys_watch_mount __ia32_sys_watch_mount 440 i386 watch_sb sys_watch_sb __ia32_sys_watch_sb +441 i386 fsinfo sys_fsinfo __ia32_sys_fsinfo diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index f4391176102c..067f247471d0 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -361,6 +361,7 @@ 438 common pidfd_getfd __x64_sys_pidfd_getfd 439 common watch_mount __x64_sys_watch_mount 440 common watch_sb __x64_sys_watch_sb +441 common fsinfo __x64_sys_fsinfo # # x32-specific system call numbers start at 512 to avoid cache impact diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl index 8e7d731ed6cf..e1ec25099d10 100644 --- a/arch/xtensa/kernel/syscalls/syscall.tbl +++ b/arch/xtensa/kernel/syscalls/syscall.tbl @@ -410,3 +410,4 @@ 438 common pidfd_getfd sys_pidfd_getfd 439 common watch_mount sys_watch_mount 440 common watch_sb sys_watch_sb +441 common fsinfo sys_fsinfo diff --git a/fs/Kconfig b/fs/Kconfig index fef1365c23a5..01d0d436b3cd 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -15,6 +15,13 @@ config VALIDATE_FS_PARSER Enable this to perform validation of the parameter description for a filesystem when it is registered. +config FSINFO + bool "Enable the fsinfo() system call" + help + Enable the file system information querying system call to allow + comprehensive information to be retrieved about a filesystem, + superblock or mount object. + if BLOCK config FS_IOMAP diff --git a/fs/Makefile b/fs/Makefile index 4477757780d0..b6bf2424c7f7 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -55,6 +55,7 @@ obj-$(CONFIG_COREDUMP) += coredump.o obj-$(CONFIG_SYSCTL) += drop_caches.o obj-$(CONFIG_FHANDLE) += fhandle.o +obj-$(CONFIG_FSINFO) += fsinfo.o obj-y += iomap/ obj-y += quota/ diff --git a/fs/fsinfo.c b/fs/fsinfo.c new file mode 100644 index 000000000000..5d3ba3c3a7ad --- /dev/null +++ b/fs/fsinfo.c @@ -0,0 +1,566 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Filesystem information query. + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "internal.h" + +/** + * fsinfo_string - Store a NUL-terminated string as an fsinfo attribute value. + * @s: The string to store (may be NULL) + * @ctx: The parameter context + */ +int fsinfo_string(const char *s, struct fsinfo_context *ctx) +{ + unsigned int len; + char *p = ctx->buffer; + int ret = 0; + + if (s) { + len = min_t(size_t, strlen(s), ctx->buf_size - 1); + if (!ctx->want_size_only) { + memcpy(p, s, len); + p[len] = 0; + } + ret = len; + } + + return ret; +} +EXPORT_SYMBOL(fsinfo_string); + +/* + * Get basic filesystem stats from statfs. + */ +static int fsinfo_generic_statfs(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_statfs *p = ctx->buffer; + struct kstatfs buf; + int ret; + + ret = vfs_statfs(path, &buf); + if (ret < 0) + return ret; + + p->f_blocks.lo = buf.f_blocks; + p->f_bfree.lo = buf.f_bfree; + p->f_bavail.lo = buf.f_bavail; + p->f_files.lo = buf.f_files; + p->f_ffree.lo = buf.f_ffree; + p->f_favail.lo = buf.f_ffree; + p->f_bsize = buf.f_bsize; + p->f_frsize = buf.f_frsize; + return sizeof(*p); +} + +static int fsinfo_generic_ids(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_ids *p = ctx->buffer; + struct super_block *sb; + struct kstatfs buf; + int ret; + + ret = vfs_statfs(path, &buf); + if (ret < 0 && ret != -ENOSYS) + return ret; + if (ret == 0) + memcpy(&p->f_fsid, &buf.f_fsid, sizeof(p->f_fsid)); + + sb = path->dentry->d_sb; + p->f_fstype = sb->s_magic; + p->f_dev_major = MAJOR(sb->s_dev); + p->f_dev_minor = MINOR(sb->s_dev); + p->f_sb_id = sb->s_unique_id; + strlcpy(p->f_fs_name, sb->s_type->name, sizeof(p->f_fs_name)); + return sizeof(*p); +} + +int fsinfo_generic_limits(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_limits *p = ctx->buffer; + struct super_block *sb = path->dentry->d_sb; + + p->max_file_size.hi = 0; + p->max_file_size.lo = sb->s_maxbytes; + p->max_ino.hi = 0; + p->max_ino.lo = UINT_MAX; + p->max_hard_links = sb->s_max_links; + p->max_uid = UINT_MAX; + p->max_gid = UINT_MAX; + p->max_projid = UINT_MAX; + p->max_filename_len = NAME_MAX; + p->max_symlink_len = PATH_MAX; + p->max_xattr_name_len = XATTR_NAME_MAX; + p->max_xattr_body_len = XATTR_SIZE_MAX; + p->max_dev_major = 0xffffff; + p->max_dev_minor = 0xff; + return sizeof(*p); +} +EXPORT_SYMBOL(fsinfo_generic_limits); + +int fsinfo_generic_supports(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_supports *p = ctx->buffer; + struct super_block *sb = path->dentry->d_sb; + + p->stx_mask = STATX_BASIC_STATS; + if (sb->s_d_op && sb->s_d_op->d_automount) + p->stx_attributes |= STATX_ATTR_AUTOMOUNT; + return sizeof(*p); +} +EXPORT_SYMBOL(fsinfo_generic_supports); + +static const struct fsinfo_timestamp_info fsinfo_default_timestamp_info = { + .atime = { + .minimum = S64_MIN, + .maximum = S64_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, + .mtime = { + .minimum = S64_MIN, + .maximum = S64_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, + .ctime = { + .minimum = S64_MIN, + .maximum = S64_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, + .btime = { + .minimum = S64_MIN, + .maximum = S64_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, +}; + +int fsinfo_generic_timestamp_info(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_timestamp_info *p = ctx->buffer; + struct super_block *sb = path->dentry->d_sb; + s8 exponent; + + *p = fsinfo_default_timestamp_info; + + if (sb->s_time_gran < 1000000000) { + if (sb->s_time_gran < 1000) + exponent = -9; + else if (sb->s_time_gran < 1000000) + exponent = -6; + else + exponent = -3; + + p->atime.gran_exponent = exponent; + p->mtime.gran_exponent = exponent; + p->ctime.gran_exponent = exponent; + p->btime.gran_exponent = exponent; + } + + return sizeof(*p); +} +EXPORT_SYMBOL(fsinfo_generic_timestamp_info); + +static int fsinfo_generic_volume_uuid(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_volume_uuid *p = ctx->buffer; + struct super_block *sb = path->dentry->d_sb; + + memcpy(p, &sb->s_uuid, sizeof(*p)); + return sizeof(*p); +} + +static int fsinfo_generic_volume_id(struct path *path, struct fsinfo_context *ctx) +{ + return fsinfo_string(path->dentry->d_sb->s_id, ctx); +} + +static const struct fsinfo_attribute fsinfo_common_attributes[] = { + FSINFO_VSTRUCT (FSINFO_ATTR_STATFS, fsinfo_generic_statfs), + FSINFO_VSTRUCT (FSINFO_ATTR_IDS, fsinfo_generic_ids), + FSINFO_VSTRUCT (FSINFO_ATTR_LIMITS, fsinfo_generic_limits), + FSINFO_VSTRUCT (FSINFO_ATTR_SUPPORTS, fsinfo_generic_supports), + FSINFO_VSTRUCT (FSINFO_ATTR_TIMESTAMP_INFO, fsinfo_generic_timestamp_info), + FSINFO_STRING (FSINFO_ATTR_VOLUME_ID, fsinfo_generic_volume_id), + FSINFO_VSTRUCT (FSINFO_ATTR_VOLUME_UUID, fsinfo_generic_volume_uuid), + + FSINFO_LIST (FSINFO_ATTR_FSINFO_ATTRIBUTES, (void *)123UL), + FSINFO_VSTRUCT_N(FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO, (void *)123UL), + {} +}; + +/* + * Determine an attribute's minimum buffer size and, if the buffer is large + * enough, get the attribute value. + */ +static int fsinfo_get_this_attribute(struct path *path, + struct fsinfo_context *ctx, + const struct fsinfo_attribute *attr) +{ + int buf_size; + + if (ctx->Nth != 0 && !(attr->flags & (FSINFO_FLAGS_N | FSINFO_FLAGS_NM))) + return -ENODATA; + if (ctx->Mth != 0 && !(attr->flags & FSINFO_FLAGS_NM)) + return -ENODATA; + + switch (attr->type) { + case FSINFO_TYPE_VSTRUCT: + ctx->clear_tail = true; + buf_size = attr->size; + break; + case FSINFO_TYPE_STRING: + case FSINFO_TYPE_OPAQUE: + case FSINFO_TYPE_LIST: + buf_size = 4096; + break; + default: + return -ENOPKG; + } + + if (ctx->buf_size < buf_size) + return buf_size; + + return attr->get(path, ctx); +} + +static void fsinfo_attributes_insert(struct fsinfo_context *ctx, + const struct fsinfo_attribute *attr) +{ + __u32 *p = ctx->buffer; + unsigned int i; + + if (ctx->usage >= ctx->buf_size || + ctx->buf_size - ctx->usage < sizeof(__u32)) { + ctx->usage += sizeof(__u32); + return; + } + + for (i = 0; i < ctx->usage / sizeof(__u32); i++) + if (p[i] == attr->attr_id) + return; + + p[i] = attr->attr_id; + ctx->usage += sizeof(__u32); +} + +static int fsinfo_list_attributes(struct path *path, + struct fsinfo_context *ctx, + const struct fsinfo_attribute *attributes) +{ + const struct fsinfo_attribute *a; + + for (a = attributes; a->get; a++) + fsinfo_attributes_insert(ctx, a); + return -EOPNOTSUPP; /* We want to go through all the lists */ +} + +static int fsinfo_get_attribute_info(struct path *path, + struct fsinfo_context *ctx, + const struct fsinfo_attribute *attributes) +{ + const struct fsinfo_attribute *a; + struct fsinfo_attribute_info *p = ctx->buffer; + + if (!ctx->buf_size) + return sizeof(*p); + + for (a = attributes; a->get; a++) { + if (a->attr_id == ctx->Nth) { + p->attr_id = a->attr_id; + p->type = a->type; + p->flags = a->flags; + p->size = a->size; + p->size = a->size; + return sizeof(*p); + } + } + return -EOPNOTSUPP; /* We want to go through all the lists */ +} + +/** + * fsinfo_get_attribute - Look up and handle an attribute + * @path: The object to query + * @params: Parameters to define a request and place to store result + * @attributes: List of attributes to search. + * + * Look through a list of attributes for one that matches the requested + * attribute then call the handler for it. + */ +int fsinfo_get_attribute(struct path *path, struct fsinfo_context *ctx, + const struct fsinfo_attribute *attributes) +{ + const struct fsinfo_attribute *a; + + switch (ctx->requested_attr) { + case FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO: + return fsinfo_get_attribute_info(path, ctx, attributes); + case FSINFO_ATTR_FSINFO_ATTRIBUTES: + return fsinfo_list_attributes(path, ctx, attributes); + default: + for (a = attributes; a->get; a++) + if (a->attr_id == ctx->requested_attr) + return fsinfo_get_this_attribute(path, ctx, a); + return -EOPNOTSUPP; + } +} +EXPORT_SYMBOL(fsinfo_get_attribute); + +/** + * generic_fsinfo - Handle an fsinfo attribute generically + * @path: The object to query + * @params: Parameters to define a request and place to store result + */ +static int fsinfo_call(struct path *path, struct fsinfo_context *ctx) +{ + int ret; + + if (path->dentry->d_sb->s_op->fsinfo) { + ret = path->dentry->d_sb->s_op->fsinfo(path, ctx); + if (ret != -EOPNOTSUPP) + return ret; + } + ret = fsinfo_get_attribute(path, ctx, fsinfo_common_attributes); + if (ret != -EOPNOTSUPP) + return ret; + + switch (ctx->requested_attr) { + case FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO: + return -ENODATA; + case FSINFO_ATTR_FSINFO_ATTRIBUTES: + return ctx->usage; + default: + return -EOPNOTSUPP; + } +} + +/** + * vfs_fsinfo - Retrieve filesystem information + * @path: The object to query + * @params: Parameters to define a request and place to store result + * + * Get an attribute on a filesystem or an object within a filesystem. The + * filesystem attribute to be queried is indicated by @ctx->requested_attr, and + * if it's a multi-valued attribute, the particular value is selected by + * @ctx->Nth and then @ctx->Mth. + * + * For common attributes, a value may be fabricated if it is not supported by + * the filesystem. + * + * On success, the size of the attribute's value is returned (0 is a valid + * size). A buffer will have been allocated and will be pointed to by + * @ctx->buffer. The caller must free this with kvfree(). + * + * Errors can also be returned: -ENOMEM if a buffer cannot be allocated, -EPERM + * or -EACCES if permission is denied by the LSM, -EOPNOTSUPP if an attribute + * doesn't exist for the specified object or -ENODATA if the attribute exists, + * but the Nth,Mth value does not exist. -EMSGSIZE indicates that the value is + * unmanageable internally and -ENOPKG indicates other internal failure. + * + * Errors such as -EIO may also come from attempts to access media or servers + * to obtain the requested information if it's not immediately to hand. + * + * [*] Note that the caller may set @ctx->want_size_only if it only wants the + * size of the value and not the data. If this is set, a buffer may not be + * allocated under some circumstances. This is intended for size query by + * userspace. + * + * [*] Note that @ctx->clear_tail will be returned set if the data should be + * padded out with zeros when writing it to userspace. + */ +static int vfs_fsinfo(struct path *path, struct fsinfo_context *ctx) +{ + struct dentry *dentry = path->dentry; + int ret; + + ret = security_sb_statfs(dentry); + if (ret) + return ret; + + /* Call the handler to find out the buffer size required. */ + ctx->buf_size = 0; + ret = fsinfo_call(path, ctx); + if (ret < 0 || ctx->want_size_only) + return ret; + ctx->buf_size = ret; + + do { + /* Allocate a buffer of the requested size. */ + if (ctx->buf_size > INT_MAX) + return -EMSGSIZE; + ctx->buffer = kvzalloc(ctx->buf_size, GFP_KERNEL); + if (!ctx->buffer) + return -ENOMEM; + + ctx->usage = 0; + ret = fsinfo_call(path, ctx); + if (IS_ERR_VALUE((long)ret)) + return ret; + if ((unsigned int)ret <= ctx->buf_size) + return ret; /* It fitted */ + + /* We need to resize the buffer */ + ctx->buf_size = roundup(ret, PAGE_SIZE); + kvfree(ctx->buffer); + ctx->buffer = NULL; + } while (!signal_pending(current)); + + return -ERESTARTSYS; +} + +static int vfs_fsinfo_path(int dfd, const char __user *pathname, + unsigned int at_flags, struct fsinfo_context *ctx) +{ + struct path path; + unsigned lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT; + int ret = -EINVAL; + + if ((at_flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | + AT_EMPTY_PATH)) != 0) + return -EINVAL; + + if (at_flags & AT_SYMLINK_NOFOLLOW) + lookup_flags &= ~LOOKUP_FOLLOW; + if (at_flags & AT_NO_AUTOMOUNT) + lookup_flags &= ~LOOKUP_AUTOMOUNT; + if (at_flags & AT_EMPTY_PATH) + lookup_flags |= LOOKUP_EMPTY; + +retry: + ret = user_path_at(dfd, pathname, lookup_flags, &path); + if (ret) + goto out; + + ret = vfs_fsinfo(&path, ctx); + path_put(&path); + if (retry_estale(ret, lookup_flags)) { + lookup_flags |= LOOKUP_REVAL; + goto retry; + } +out: + return ret; +} + +static int vfs_fsinfo_fd(unsigned int fd, struct fsinfo_context *ctx) +{ + struct fd f = fdget_raw(fd); + int ret = -EBADF; + + if (f.file) { + ret = vfs_fsinfo(&f.file->f_path, ctx); + fdput(f); + } + return ret; +} + +/** + * sys_fsinfo - System call to get filesystem information + * @dfd: Base directory to pathwalk from or fd referring to filesystem. + * @pathname: Filesystem to query or NULL. + * @_params: Parameters to define request (or NULL for enhanced statfs). + * @user_buffer: Result buffer. + * @user_buf_size: Size of result buffer. + * + * Get information on a filesystem. The filesystem attribute to be queried is + * indicated by @_params->request, and some of the attributes can have multiple + * values, indexed by @_params->Nth and @_params->Mth. If @_params is NULL, + * then the 0th fsinfo_attr_statfs attribute is queried. If an attribute does + * not exist, EOPNOTSUPP is returned; if the Nth,Mth value does not exist, + * ENODATA is returned. + * + * On success, the size of the attribute's value is returned. If + * @user_buf_size is 0 or @user_buffer is NULL, only the size is returned. If + * the size of the value is larger than @user_buf_size, it will be truncated by + * the copy. If the size of the value is smaller than @user_buf_size then the + * excess buffer space will be cleared. The full size of the value will be + * returned, irrespective of how much data is actually placed in the buffer. + */ +SYSCALL_DEFINE5(fsinfo, + int, dfd, const char __user *, pathname, + struct fsinfo_params __user *, params, + void __user *, user_buffer, size_t, user_buf_size) +{ + struct fsinfo_context ctx; + struct fsinfo_params user_params; + unsigned int at_flags = 0, result_size; + int ret; + + if (!user_buffer && user_buf_size) + return -EINVAL; + if (user_buffer && !user_buf_size) + return -EINVAL; + if (user_buf_size > UINT_MAX) + return -EOVERFLOW; + + memset(&ctx, 0, sizeof(ctx)); + ctx.requested_attr = FSINFO_ATTR_STATFS; + if (user_buf_size == 0) + ctx.want_size_only = true; + + if (params) { + if (copy_from_user(&user_params, params, sizeof(user_params))) + return -EFAULT; + if (user_params.__reserved32[0] || + user_params.__reserved[0] || + user_params.__reserved[1] || + user_params.__reserved[2] || + user_params.flags & ~FSINFO_FLAGS_QUERY_MASK) + return -EINVAL; + at_flags = user_params.at_flags; + ctx.flags = user_params.flags; + ctx.requested_attr = user_params.request; + ctx.Nth = user_params.Nth; + ctx.Mth = user_params.Mth; + } + + switch (ctx.flags & FSINFO_FLAGS_QUERY_MASK) { + case FSINFO_FLAGS_QUERY_PATH: + ret = vfs_fsinfo_path(dfd, pathname, at_flags, &ctx); + break; + case FSINFO_FLAGS_QUERY_FD: + if (pathname) + return -EINVAL; + ret = vfs_fsinfo_fd(dfd, &ctx); + break; + default: + return -EINVAL; + } + + if (ret < 0) + goto error; + + result_size = min_t(size_t, ret, user_buf_size); + if (result_size > 0 && + copy_to_user(user_buffer, ctx.buffer, result_size) != 0) { + ret = -EFAULT; + goto error; + } + + /* Clear any part of the buffer that we won't fill if we're putting a + * struct in there. Strings, opaque objects and arrays are expected to + * be variable length. + */ + if (ctx.clear_tail && + user_buf_size > result_size && + clear_user(user_buffer + result_size, user_buf_size - result_size) != 0) { + ret = -EFAULT; + goto error; + } + +error: + kvfree(ctx.buffer); + return ret; +} diff --git a/include/linux/fs.h b/include/linux/fs.h index d5128d112384..d2476c0fc978 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -69,6 +69,7 @@ struct fsverity_info; struct fsverity_operations; struct fs_context; struct fs_parameter_spec; +struct fsinfo_context; extern void __init inode_init(void); extern void __init inode_init_early(void); @@ -1963,6 +1964,9 @@ struct super_operations { int (*thaw_super) (struct super_block *); int (*unfreeze_fs) (struct super_block *); int (*statfs) (struct dentry *, struct kstatfs *); +#ifdef CONFIG_FSINFO + int (*fsinfo)(struct path *, struct fsinfo_context *); +#endif int (*remount_fs) (struct super_block *, int *, char *); void (*umount_begin) (struct super_block *); diff --git a/include/linux/fsinfo.h b/include/linux/fsinfo.h new file mode 100644 index 000000000000..943fbd6640f9 --- /dev/null +++ b/include/linux/fsinfo.h @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Filesystem information query + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#ifndef _LINUX_FSINFO_H +#define _LINUX_FSINFO_H + +#ifdef CONFIG_FSINFO + +#include + +struct path; + +#define FSINFO_NORMAL_ATTR_MAX_SIZE 4096 + +struct fsinfo_context { + __u32 flags; /* [in] FSINFO_FLAGS_* */ + __u32 requested_attr; /* [in] What is being asking for */ + __u32 Nth; /* [in] Instance of it (some may have multiple) */ + __u32 Mth; /* [in] Subinstance */ + bool want_size_only; /* [in] Just want to know the size, not the data */ + bool clear_tail; /* [out] T if tail of buffer should be cleared */ + unsigned int usage; /* [tmp] Amount of buffer used (if large) */ + unsigned int buf_size; /* [tmp] Size of ->buffer[] */ + void *buffer; /* [out] The reply buffer */ +}; + +/* + * A filesystem information attribute definition. + */ +struct fsinfo_attribute { + unsigned int attr_id; /* The ID of the attribute */ + enum fsinfo_value_type type:8; /* The type of the attribute's value(s) */ + unsigned int flags:8; + unsigned int size:16; /* - Value size (FSINFO_STRUCT/LIST) */ + int (*get)(struct path *path, struct fsinfo_context *params); +}; + +#define __FSINFO(A, T, S, G, F) \ + { .attr_id = A, .type = T, .flags = F, .size = S, .get = G } + +#define _FSINFO(A, T, S, G) __FSINFO(A, T, S, G, 0) +#define _FSINFO_N(A, T, S, G) __FSINFO(A, T, S, G, FSINFO_FLAGS_N) +#define _FSINFO_NM(A, T, S, G) __FSINFO(A, T, S, G, FSINFO_FLAGS_NM) + +#define _FSINFO_VSTRUCT(A,S,G) _FSINFO (A, FSINFO_TYPE_VSTRUCT, sizeof(S), G) +#define _FSINFO_VSTRUCT_N(A,S,G) _FSINFO_N (A, FSINFO_TYPE_VSTRUCT, sizeof(S), G) +#define _FSINFO_VSTRUCT_NM(A,S,G) _FSINFO_NM(A, FSINFO_TYPE_VSTRUCT, sizeof(S), G) + +#define FSINFO_VSTRUCT(A,G) _FSINFO_VSTRUCT (A, A##__STRUCT, G) +#define FSINFO_VSTRUCT_N(A,G) _FSINFO_VSTRUCT_N (A, A##__STRUCT, G) +#define FSINFO_VSTRUCT_NM(A,G) _FSINFO_VSTRUCT_NM(A, A##__STRUCT, G) +#define FSINFO_STRING(A,G) _FSINFO (A, FSINFO_TYPE_STRING, 0, G) +#define FSINFO_STRING_N(A,G) _FSINFO_N (A, FSINFO_TYPE_STRING, 0, G) +#define FSINFO_STRING_NM(A,G) _FSINFO_NM(A, FSINFO_TYPE_STRING, 0, G) +#define FSINFO_OPAQUE(A,G) _FSINFO (A, FSINFO_TYPE_OPAQUE, 0, G) +#define FSINFO_LIST(A,G) _FSINFO (A, FSINFO_TYPE_LIST, sizeof(A##__STRUCT), G) +#define FSINFO_LIST_N(A,G) _FSINFO_N (A, FSINFO_TYPE_LIST, sizeof(A##__STRUCT), G) + +extern int fsinfo_string(const char *, struct fsinfo_context *); +extern int fsinfo_generic_timestamp_info(struct path *, struct fsinfo_context *); +extern int fsinfo_generic_supports(struct path *, struct fsinfo_context *); +extern int fsinfo_generic_limits(struct path *, struct fsinfo_context *); +extern int fsinfo_get_attribute(struct path *, struct fsinfo_context *, + const struct fsinfo_attribute *); + +#endif /* CONFIG_FSINFO */ + +#endif /* _LINUX_FSINFO_H */ diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index c84440d57f52..936e2eb76c8f 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -47,6 +47,7 @@ struct stat64; struct statfs; struct statfs64; struct statx; +struct fsinfo_params; struct __sysctl_args; struct sysinfo; struct timespec; @@ -1007,6 +1008,9 @@ asmlinkage long sys_watch_mount(int dfd, const char __user *path, unsigned int at_flags, int watch_fd, int watch_id); asmlinkage long sys_watch_sb(int dfd, const char __user *path, unsigned int at_flags, int watch_fd, int watch_id); +asmlinkage long sys_fsinfo(int dfd, const char __user *pathname, + struct fsinfo_params __user *params, + void __user *buffer, size_t buf_size); /* * Architecture-specific system calls diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 5bff318b7ffa..7d764f86d3f5 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -859,9 +859,11 @@ __SYSCALL(__NR_pidfd_getfd, sys_pidfd_getfd) __SYSCALL(__NR_watch_mount, sys_watch_mount) #define __NR_watch_sb 440 __SYSCALL(__NR_watch_sb, sys_watch_sb) +#define __NR_fsinfo 441 +__SYSCALL(__NR_fsinfo, sys_fsinfo) #undef __NR_syscalls -#define __NR_syscalls 441 +#define __NR_syscalls 442 /* * 32 bit systems traditionally used different diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h new file mode 100644 index 000000000000..6eb02de8a631 --- /dev/null +++ b/include/uapi/linux/fsinfo.h @@ -0,0 +1,187 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* fsinfo() definitions. + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ +#ifndef _UAPI_LINUX_FSINFO_H +#define _UAPI_LINUX_FSINFO_H + +#include +#include + +/* + * The filesystem attributes that can be requested. Note that some attributes + * may have multiple instances which can be switched in the parameter block. + */ +#define FSINFO_ATTR_STATFS 0x00 /* statfs()-style state */ +#define FSINFO_ATTR_IDS 0x01 /* Filesystem IDs */ +#define FSINFO_ATTR_LIMITS 0x02 /* Filesystem limits */ +#define FSINFO_ATTR_SUPPORTS 0x03 /* What's supported in statx, iocflags, ... */ +#define FSINFO_ATTR_TIMESTAMP_INFO 0x04 /* Inode timestamp info */ +#define FSINFO_ATTR_VOLUME_ID 0x05 /* Volume ID (string) */ +#define FSINFO_ATTR_VOLUME_UUID 0x06 /* Volume UUID (LE uuid) */ +#define FSINFO_ATTR_VOLUME_NAME 0x07 /* Volume name (string) */ + +#define FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO 0x100 /* Information about attr N (for path) */ +#define FSINFO_ATTR_FSINFO_ATTRIBUTES 0x101 /* List of supported attrs (for path) */ + +/* + * Optional fsinfo() parameter structure. + * + * If this is not given, it is assumed that fsinfo_attr_statfs instance 0,0 is + * desired. + */ +struct fsinfo_params { + __u32 at_flags; /* AT_SYMLINK_NOFOLLOW and similar flags */ + __u32 flags; /* Flags controlling fsinfo() specifically */ +#define FSINFO_FLAGS_QUERY_MASK 0x0007 /* What object should fsinfo() query? */ +#define FSINFO_FLAGS_QUERY_PATH 0x0000 /* - path, specified by dirfd,pathname,AT_EMPTY_PATH */ +#define FSINFO_FLAGS_QUERY_FD 0x0001 /* - fd specified by dirfd */ + __u32 request; /* ID of requested attribute */ + __u32 Nth; /* Instance of it (some may have multiple) */ + __u32 Mth; /* Subinstance of Nth instance */ + __u32 __reserved32[1]; /* Reserved params; all must be 0 */ + __u64 __reserved[3]; +}; + +enum fsinfo_value_type { + FSINFO_TYPE_VSTRUCT = 0, /* Version-lengthed struct (up to 4096 bytes) */ + FSINFO_TYPE_STRING = 1, /* NUL-term var-length string (up to 4095 chars) */ + FSINFO_TYPE_OPAQUE = 2, /* Opaque blob (unlimited size) */ + FSINFO_TYPE_LIST = 3, /* List of ints/structs (unlimited size) */ +}; + +/* + * Information struct for fsinfo(FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO). + * + * This gives information about the attributes supported by fsinfo for the + * given path. + */ +struct fsinfo_attribute_info { + unsigned int attr_id; /* The ID of the attribute */ + enum fsinfo_value_type type; /* The type of the attribute's value(s) */ + unsigned int flags; +#define FSINFO_FLAGS_N 0x01 /* - Attr has a set of values */ +#define FSINFO_FLAGS_NM 0x02 /* - Attr has a set of sets of values */ + unsigned int size; /* - Value size (FSINFO_STRUCT/FSINFO_LIST) */ +}; + +#define FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO__STRUCT struct fsinfo_attribute_info +#define FSINFO_ATTR_FSINFO_ATTRIBUTES__STRUCT __u32 + +struct fsinfo_u128 { +#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN) + __u64 hi; + __u64 lo; +#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN) + __u64 lo; + __u64 hi; +#endif +}; + +/* + * Information struct for fsinfo(FSINFO_ATTR_STATFS). + * - This gives extended filesystem information. + */ +struct fsinfo_statfs { + struct fsinfo_u128 f_blocks; /* Total number of blocks in fs */ + struct fsinfo_u128 f_bfree; /* Total number of free blocks */ + struct fsinfo_u128 f_bavail; /* Number of free blocks available to ordinary user */ + struct fsinfo_u128 f_files; /* Total number of file nodes in fs */ + struct fsinfo_u128 f_ffree; /* Number of free file nodes */ + struct fsinfo_u128 f_favail; /* Number of file nodes available to ordinary user */ + __u64 f_bsize; /* Optimal block size */ + __u64 f_frsize; /* Fragment size */ +}; + +#define FSINFO_ATTR_STATFS__STRUCT struct fsinfo_statfs + +/* + * Information struct for fsinfo(FSINFO_ATTR_IDS). + * + * List of basic identifiers as is normally found in statfs(). + */ +struct fsinfo_ids { + char f_fs_name[15 + 1]; /* Filesystem name */ + __u64 f_fsid; /* Short 64-bit Filesystem ID (as statfs) */ + __u64 f_sb_id; /* Internal superblock ID for sbnotify()/mntnotify() */ + __u32 f_fstype; /* Filesystem type from linux/magic.h [uncond] */ + __u32 f_dev_major; /* As st_dev_* from struct statx [uncond] */ + __u32 f_dev_minor; + __u32 __padding[1]; +}; + +#define FSINFO_ATTR_IDS__STRUCT struct fsinfo_ids + +/* + * Information struct for fsinfo(FSINFO_ATTR_LIMITS). + * + * List of supported filesystem limits. + */ +struct fsinfo_limits { + struct fsinfo_u128 max_file_size; /* Maximum file size */ + struct fsinfo_u128 max_ino; /* Maximum inode number */ + __u64 max_uid; /* Maximum UID supported */ + __u64 max_gid; /* Maximum GID supported */ + __u64 max_projid; /* Maximum project ID supported */ + __u64 max_hard_links; /* Maximum number of hard links on a file */ + __u64 max_xattr_body_len; /* Maximum xattr content length */ + __u32 max_xattr_name_len; /* Maximum xattr name length */ + __u32 max_filename_len; /* Maximum filename length */ + __u32 max_symlink_len; /* Maximum symlink content length */ + __u32 max_dev_major; /* Maximum device major representable */ + __u32 max_dev_minor; /* Maximum device minor representable */ + __u32 __padding[1]; +}; + +#define FSINFO_ATTR_LIMITS__STRUCT struct fsinfo_limits + +/* + * Information struct for fsinfo(FSINFO_ATTR_SUPPORTS). + * + * What's supported in various masks, such as statx() attribute and mask bits + * and IOC flags. + */ +struct fsinfo_supports { + __u64 stx_attributes; /* What statx::stx_attributes are supported */ + __u32 stx_mask; /* What statx::stx_mask bits are supported */ + __u32 fs_ioc_getflags; /* What FS_IOC_GETFLAGS may return */ + __u32 fs_ioc_setflags_set; /* What FS_IOC_SETFLAGS may set */ + __u32 fs_ioc_setflags_clear; /* What FS_IOC_SETFLAGS may clear */ + __u32 win_file_attrs; /* What DOS/Windows FILE_* attributes are supported */ + __u32 __padding[1]; +}; + +#define FSINFO_ATTR_SUPPORTS__STRUCT struct fsinfo_supports + +struct fsinfo_timestamp_one { + __s64 minimum; /* Minimum timestamp value in seconds */ + __s64 maximum; /* Maximum timestamp value in seconds */ + __u16 gran_mantissa; /* Granularity(secs) = mant * 10^exp */ + __s8 gran_exponent; + __u8 __padding[5]; +}; + +/* + * Information struct for fsinfo(FSINFO_ATTR_TIMESTAMP_INFO). + */ +struct fsinfo_timestamp_info { + struct fsinfo_timestamp_one atime; /* Access time */ + struct fsinfo_timestamp_one mtime; /* Modification time */ + struct fsinfo_timestamp_one ctime; /* Change time */ + struct fsinfo_timestamp_one btime; /* Birth/creation time */ +}; + +#define FSINFO_ATTR_TIMESTAMP_INFO__STRUCT struct fsinfo_timestamp_info + +/* + * Information struct for fsinfo(FSINFO_ATTR_VOLUME_UUID). + */ +struct fsinfo_volume_uuid { + __u8 uuid[16]; +}; + +#define FSINFO_ATTR_VOLUME_UUID__STRUCT struct fsinfo_volume_uuid + +#endif /* _UAPI_LINUX_FSINFO_H */ diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 0ce01f86e5db..519317f3904c 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -51,6 +51,7 @@ COND_SYSCALL_COMPAT(io_pgetevents); COND_SYSCALL(io_uring_setup); COND_SYSCALL(io_uring_enter); COND_SYSCALL(io_uring_register); +COND_SYSCALL(fsinfo); /* fs/xattr.c */ diff --git a/samples/vfs/Makefile b/samples/vfs/Makefile index 65acdde5c117..9159ad1d7fc5 100644 --- a/samples/vfs/Makefile +++ b/samples/vfs/Makefile @@ -1,10 +1,15 @@ # SPDX-License-Identifier: GPL-2.0-only # List of programs to build + hostprogs := \ + test-fsinfo \ test-fsmount \ test-statx always-y := $(hostprogs) +HOSTCFLAGS_test-fsinfo.o += -I$(objtree)/usr/include +HOSTLDLIBS_test-fsinfo += -static -lm + HOSTCFLAGS_test-fsmount.o += -I$(objtree)/usr/include HOSTCFLAGS_test-statx.o += -I$(objtree)/usr/include diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c new file mode 100644 index 000000000000..22fe3c47ff42 --- /dev/null +++ b/samples/vfs/test-fsinfo.c @@ -0,0 +1,607 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Test the fsinfo() system call + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define _GNU_SOURCE +#define _ATFILE_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifndef __NR_fsinfo +#define __NR_fsinfo -1 +#endif + +static bool debug = 0; + +static __attribute__((unused)) +ssize_t fsinfo(int dfd, const char *filename, struct fsinfo_params *params, + void *buffer, size_t buf_size) +{ + return syscall(__NR_fsinfo, dfd, filename, params, buffer, buf_size); +} + +struct fsinfo_attribute { + unsigned int attr_id; + enum fsinfo_value_type type; + unsigned int size; + const char *name; + void (*dump)(void *reply, unsigned int size); +}; + +static const struct fsinfo_attribute fsinfo_attributes[]; + +static void dump_hex(unsigned int *data, int from, int to) +{ + unsigned offset, print_offset = 1, col = 0; + + from /= 4; + to = (to + 3) / 4; + + for (offset = from; offset < to; offset++) { + if (print_offset) { + printf("%04x: ", offset * 8); + print_offset = 0; + } + printf("%08x", data[offset]); + col++; + if ((col & 3) == 0) { + printf("\n"); + print_offset = 1; + } else { + printf(" "); + } + } + + if (!print_offset) + printf("\n"); +} + +static void dump_attribute_info(void *reply, unsigned int size) +{ + struct fsinfo_attribute_info *attr_info = reply; + const struct fsinfo_attribute *attr; + char type[32], val_size[32]; + + switch (attr_info->type) { + case FSINFO_TYPE_VSTRUCT: strcpy(type, "V-STRUCT"); break; + case FSINFO_TYPE_STRING: strcpy(type, "STRING"); break; + case FSINFO_TYPE_OPAQUE: strcpy(type, "OPAQUE"); break; + case FSINFO_TYPE_LIST: strcpy(type, "LIST"); break; + default: + sprintf(type, "type-%x", attr_info->type); + break; + } + + if (attr_info->flags & FSINFO_FLAGS_N) + strcat(type, " x N"); + else if (attr_info->flags & FSINFO_FLAGS_NM) + strcat(type, " x NM"); + + for (attr = fsinfo_attributes; attr->name; attr++) + if (attr->attr_id == attr_info->attr_id) + break; + + if (attr_info->size) + sprintf(val_size, "%u", attr_info->size); + else + strcpy(val_size, "-"); + + printf("%8x %-12s %08x %5s %s\n", + attr_info->attr_id, + type, + attr_info->flags, + val_size, + attr->name ? attr->name : ""); +} + +static void dump_fsinfo_generic_statfs(void *reply, unsigned int size) +{ + struct fsinfo_statfs *f = reply; + + printf("\n"); + printf("\tblocks : n=%llu fr=%llu av=%llu\n", + (unsigned long long)f->f_blocks.lo, + (unsigned long long)f->f_bfree.lo, + (unsigned long long)f->f_bavail.lo); + + printf("\tfiles : n=%llu fr=%llu av=%llu\n", + (unsigned long long)f->f_files.lo, + (unsigned long long)f->f_ffree.lo, + (unsigned long long)f->f_favail.lo); + printf("\tbsize : %llu\n", f->f_bsize); + printf("\tfrsize : %llu\n", f->f_frsize); +} + +static void dump_fsinfo_generic_ids(void *reply, unsigned int size) +{ + struct fsinfo_ids *f = reply; + + printf("\n"); + printf("\tdev : %02x:%02x\n", f->f_dev_major, f->f_dev_minor); + printf("\tfs : type=%x name=%s\n", f->f_fstype, f->f_fs_name); + printf("\tfsid : %llx\n", (unsigned long long)f->f_fsid); + printf("\tsbid : %llx\n", (unsigned long long)f->f_sb_id); +} + +static void dump_fsinfo_generic_limits(void *reply, unsigned int size) +{ + struct fsinfo_limits *f = reply; + + printf("\n"); + printf("\tmax file size: %llx%016llx\n", + (unsigned long long)f->max_file_size.hi, + (unsigned long long)f->max_file_size.lo); + printf("\tmax ino : %llx%016llx\n", + (unsigned long long)f->max_ino.hi, + (unsigned long long)f->max_ino.lo); + printf("\tmax ids : u=%llx g=%llx p=%llx\n", + (unsigned long long)f->max_uid, + (unsigned long long)f->max_gid, + (unsigned long long)f->max_projid); + printf("\tmax dev : maj=%x min=%x\n", + f->max_dev_major, f->max_dev_minor); + printf("\tmax links : %llx\n", + (unsigned long long)f->max_hard_links); + printf("\tmax xattr : n=%x b=%llx\n", + f->max_xattr_name_len, + (unsigned long long)f->max_xattr_body_len); + printf("\tmax len : file=%x sym=%x\n", + f->max_filename_len, f->max_symlink_len); +} + +static void dump_fsinfo_generic_supports(void *reply, unsigned int size) +{ + struct fsinfo_supports *f = reply; + + printf("\n"); + printf("\tstx_attr : %llx\n", (unsigned long long)f->stx_attributes); + printf("\tstx_mask : %x\n", f->stx_mask); + printf("\tfs_ioc_*flags: get=%x set=%x clr=%x\n", + f->fs_ioc_getflags, f->fs_ioc_setflags_set, f->fs_ioc_setflags_clear); + printf("\twin_fattrs : %x\n", f->win_file_attrs); +} + +static void print_time(struct fsinfo_timestamp_one *t, char stamp) +{ + printf("\t%ctime : gran=%gs range=%llx-%llx\n", + stamp, + t->gran_mantissa * pow(10., t->gran_exponent), + (long long)t->minimum, + (long long)t->maximum); +} + +static void dump_fsinfo_generic_timestamp_info(void *reply, unsigned int size) +{ + struct fsinfo_timestamp_info *f = reply; + + printf("\n"); + print_time(&f->atime, 'a'); + print_time(&f->mtime, 'm'); + print_time(&f->ctime, 'c'); + print_time(&f->btime, 'b'); +} + +static void dump_fsinfo_generic_volume_uuid(void *reply, unsigned int size) +{ + struct fsinfo_volume_uuid *f = reply; + + printf("%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x" + "-%02x%02x%02x%02x%02x%02x\n", + f->uuid[ 0], f->uuid[ 1], + f->uuid[ 2], f->uuid[ 3], + f->uuid[ 4], f->uuid[ 5], + f->uuid[ 6], f->uuid[ 7], + f->uuid[ 8], f->uuid[ 9], + f->uuid[10], f->uuid[11], + f->uuid[12], f->uuid[13], + f->uuid[14], f->uuid[15]); +} + +static void dump_string(void *reply, unsigned int size) +{ + char *s = reply, *p; + + p = s; + if (size >= 4096) { + size = 4096; + p[4092] = '.'; + p[4093] = '.'; + p[4094] = '.'; + p[4095] = 0; + } else { + p[size] = 0; + } + + for (p = s; *p; p++) { + if (!isprint(*p)) { + printf("\n"); + continue; + } + } + + printf("%s\n", s); +} + +#define dump_fsinfo_generic_volume_id dump_string +#define dump_fsinfo_generic_volume_name dump_string + +/* + * + */ +#define __FSINFO(A, T, S, U, G, F) \ + { .attr_id = A, .type = T, .size = S, .name = #G, .dump = dump_##G } + +#define _FSINFO(A, T, S, U, G) __FSINFO(A, T, S, U, G, 0) +#define _FSINFO_N(A, T, S, U, G) __FSINFO(A, T, S, U, G, FSINFO_FLAGS_N) +#define _FSINFO_NM(A, T, S, U, G) __FSINFO(A, T, S, U, G, FSINFO_FLAGS_NM) + +#define _FSINFO_VSTRUCT(A,S,G) _FSINFO (A, FSINFO_TYPE_VSTRUCT, sizeof(S), 0, G) +#define _FSINFO_VSTRUCT_N(A,S,G) _FSINFO_N (A, FSINFO_TYPE_VSTRUCT, sizeof(S), 0, G) +#define _FSINFO_VSTRUCT_NM(A,S,G) _FSINFO_NM(A, FSINFO_TYPE_VSTRUCT, sizeof(S), 0, G) + +#define FSINFO_VSTRUCT(A,G) _FSINFO_VSTRUCT (A, A##__STRUCT, G) +#define FSINFO_VSTRUCT_N(A,G) _FSINFO_VSTRUCT_N (A, A##__STRUCT, G) +#define FSINFO_VSTRUCT_NM(A,G) _FSINFO_VSTRUCT_NM(A, A##__STRUCT, G) +#define FSINFO_STRING(A,G) _FSINFO (A, FSINFO_TYPE_STRING, 0, 0, G) +#define FSINFO_STRING_N(A,G) _FSINFO_N (A, FSINFO_TYPE_STRING, 0, 0, G) +#define FSINFO_STRING_NM(A,G) _FSINFO_NM(A, FSINFO_TYPE_STRING, 0, 0, G) +#define FSINFO_OPAQUE(A,G) _FSINFO (A, FSINFO_TYPE_OPAQUE, 0, 0, G) +#define FSINFO_LIST(A,G) _FSINFO (A, FSINFO_TYPE_LIST, 0, sizeof(A##__STRUCT), G) +#define FSINFO_LIST_N(A,G) _FSINFO_N (A, FSINFO_TYPE_LIST, 0, sizeof(A##__STRUCT), G) + +static const struct fsinfo_attribute fsinfo_attributes[] = { + FSINFO_VSTRUCT (FSINFO_ATTR_STATFS, fsinfo_generic_statfs), + FSINFO_VSTRUCT (FSINFO_ATTR_IDS, fsinfo_generic_ids), + FSINFO_VSTRUCT (FSINFO_ATTR_LIMITS, fsinfo_generic_limits), + FSINFO_VSTRUCT (FSINFO_ATTR_SUPPORTS, fsinfo_generic_supports), + FSINFO_VSTRUCT (FSINFO_ATTR_TIMESTAMP_INFO, fsinfo_generic_timestamp_info), + FSINFO_STRING (FSINFO_ATTR_VOLUME_ID, fsinfo_generic_volume_id), + FSINFO_VSTRUCT (FSINFO_ATTR_VOLUME_UUID, fsinfo_generic_volume_uuid), + FSINFO_STRING (FSINFO_ATTR_VOLUME_NAME, fsinfo_generic_volume_name), + {} +}; + +static void dump_value(unsigned int attr_id, + const struct fsinfo_attribute *attr, + const struct fsinfo_attribute_info *attr_info, + void *reply, unsigned int size) +{ + if (!attr || !attr->dump) { + printf("\n"); + return; + } + + if (attr->type == FSINFO_TYPE_VSTRUCT && size < attr->size) { + printf("\n", size, attr->size); + return; + } + + attr->dump(reply, size); +} + +static void dump_list(unsigned int attr_id, + const struct fsinfo_attribute *attr, + const struct fsinfo_attribute_info *attr_info, + void *reply, unsigned int size) +{ + size_t elem_size = attr_info->size; + unsigned int ix = 0; + + printf("\n"); + if (!attr || !attr->dump) { + printf("\n"); + return; + } + + if (attr->type == FSINFO_TYPE_VSTRUCT && size < attr->size) { + printf("\n", size, attr->size); + return; + } + + while (size >= elem_size) { + printf("\t[%02x] ", ix); + attr->dump(reply, size); + reply += elem_size; + size -= elem_size; + ix++; + } +} + +/* + * Call fsinfo, expanding the buffer as necessary. + */ +static ssize_t get_fsinfo(const char *file, const char *name, + struct fsinfo_params *params, void **_r) +{ + ssize_t ret; + size_t buf_size = 4096; + void *r; + + for (;;) { + r = malloc(buf_size); + if (!r) { + perror("malloc"); + exit(1); + } + memset(r, 0xbd, buf_size); + + errno = 0; + ret = fsinfo(AT_FDCWD, file, params, r, buf_size); + if (ret == -1) { + free(r); + *_r = NULL; + return ret; + } + + if (ret <= buf_size) + break; + buf_size = (ret + 4096 - 1) & ~(4096 - 1); + } + + if (debug) { + if (ret == -1) + printf("fsinfo(%s,%s,%u,%u) = %m\n", + file, name, params->Nth, params->Mth); + else + printf("fsinfo(%s,%s,%u,%u) = %zd\n", + file, name, params->Nth, params->Mth, ret); + } + + *_r = r; + return ret; +} + +/* + * Try one subinstance of an attribute. + */ +static int try_one(const char *file, struct fsinfo_params *params, + const struct fsinfo_attribute_info *attr_info, bool raw) +{ + const struct fsinfo_attribute *attr; + const char *name; + size_t size = 4096; + char namebuf[32]; + void *r; + + for (attr = fsinfo_attributes; attr->name; attr++) { + if (attr->attr_id == params->request) { + name = attr->name; + if (strncmp(name, "fsinfo_generic_", 15) == 0) + name += 15; + goto found; + } + } + + sprintf(namebuf, "", params->request); + name = namebuf; + attr = NULL; + +found: + size = get_fsinfo(file, name, params, &r); + + if (size == -1) { + if (errno == ENODATA) { + if (!(attr_info->flags & (FSINFO_FLAGS_N | FSINFO_FLAGS_NM)) && + params->Nth == 0 && params->Mth == 0) { + fprintf(stderr, + "Unexpected ENODATA (0x%x{%u}{%u})\n", + params->request, params->Nth, params->Mth); + exit(1); + } + free(r); + return (params->Mth == 0) ? 2 : 1; + } + if (errno == EOPNOTSUPP) { + if (params->Nth > 0 || params->Mth > 0) { + fprintf(stderr, + "Should return -ENODATA (0x%x{%u}{%u})\n", + params->request, params->Nth, params->Mth); + exit(1); + } + //printf("\e[33m%s\e[m: \n", + // fsinfo_attr_names[attr]); + free(r); + return 2; + } + perror(file); + exit(1); + } + + if (raw) { + if (size > 4096) + size = 4096; + dump_hex(r, 0, size); + free(r); + return 0; + } + + switch (attr_info->flags & (FSINFO_FLAGS_N | FSINFO_FLAGS_NM)) { + case 0: + printf("\e[33m%s\e[m: ", name); + break; + case FSINFO_FLAGS_N: + printf("\e[33m%s{%u}\e[m: ", name, params->Nth); + break; + case FSINFO_FLAGS_NM: + printf("\e[33m%s{%u,%u}\e[m: ", name, params->Nth, params->Mth); + break; + } + + switch (attr_info->type) { + case FSINFO_TYPE_VSTRUCT: + case FSINFO_TYPE_STRING: + dump_value(params->request, attr, attr_info, r, size); + free(r); + return 0; + + case FSINFO_TYPE_LIST: + dump_list(params->request, attr, attr_info, r, size); + free(r); + return 0; + + case FSINFO_TYPE_OPAQUE: + free(r); + return 0; + + default: + fprintf(stderr, "Fishy about %u 0x%x,%x,%x\n", + params->request, attr_info->type, attr_info->flags, attr_info->size); + exit(1); + } +} + +static int cmp_u32(const void *a, const void *b) +{ + return *(const int *)a - *(const int *)b; +} + +/* + * + */ +int main(int argc, char **argv) +{ + struct fsinfo_attribute_info attr_info; + struct fsinfo_params params = { + .at_flags = AT_SYMLINK_NOFOLLOW, + .flags = FSINFO_FLAGS_QUERY_PATH, + }; + unsigned int *attrs, ret, nr, i; + bool meta = false; + int raw = 0, opt, Nth, Mth; + + while ((opt = getopt(argc, argv, "adlmr"))) { + switch (opt) { + case 'a': + params.at_flags |= AT_NO_AUTOMOUNT; + continue; + case 'd': + debug = true; + continue; + case 'l': + params.at_flags &= ~AT_SYMLINK_NOFOLLOW; + continue; + case 'm': + meta = true; + continue; + case 'r': + raw = 1; + continue; + } + break; + } + + argc -= optind; + argv += optind; + + if (argc != 1) { + printf("Format: test-fsinfo [-alr] \n"); + exit(2); + } + + /* Retrieve a list of supported attribute IDs */ + params.request = FSINFO_ATTR_FSINFO_ATTRIBUTES; + params.Nth = 0; + params.Mth = 0; + ret = get_fsinfo(argv[0], "attributes", ¶ms, (void **)&attrs); + if (ret == -1) { + fprintf(stderr, "Unable to get attribute list: %m\n"); + exit(1); + } + + if (ret % sizeof(attrs[0])) { + fprintf(stderr, "Bad length of attribute list (0x%x)\n", ret); + exit(2); + } + + nr = ret / sizeof(attrs[0]); + qsort(attrs, nr, sizeof(attrs[0]), cmp_u32); + + if (meta) { + printf("ATTR ID TYPE FLAGS SIZE NAME\n"); + printf("======== ============ ======== ===== =========\n"); + for (i = 0; i < nr; i++) { + params.request = FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO; + params.Nth = attrs[i]; + params.Mth = 0; + ret = fsinfo(AT_FDCWD, argv[0], ¶ms, &attr_info, sizeof(attr_info)); + if (ret == -1) { + fprintf(stderr, "Can't get info for attribute %x: %m\n", attrs[i]); + exit(1); + } + + dump_attribute_info(&attr_info, ret); + } + exit(0); + } + + for (i = 0; i < nr; i++) { + params.request = FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO; + params.Nth = attrs[i]; + params.Mth = 0; + ret = fsinfo(AT_FDCWD, argv[0], ¶ms, &attr_info, sizeof(attr_info)); + if (ret == -1) { + fprintf(stderr, "Can't get info for attribute %x: %m\n", attrs[i]); + exit(1); + } + + if (attrs[i] == FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO || + attrs[i] == FSINFO_ATTR_FSINFO_ATTRIBUTES) + continue; + + if (attrs[i] != attr_info.attr_id) { + fprintf(stderr, "ID for %03x returned %03x\n", + attrs[i], attr_info.attr_id); + break; + } + Nth = 0; + do { + Mth = 0; + do { + params.request = attrs[i]; + params.Nth = Nth; + params.Mth = Mth; + + switch (try_one(argv[0], ¶ms, &attr_info, raw)) { + case 0: + continue; + case 1: + goto done_M; + case 2: + goto done_N; + } + } while (++Mth < 100); + + done_M: + if (Mth >= 100) { + fprintf(stderr, "Fishy: Mth %x[%u][%u]\n", attrs[i], Nth, Mth); + break; + } + + } while (++Nth < 100); + + done_N: + if (Nth >= 100) { + fprintf(stderr, "Fishy: Nth %x[%u]\n", attrs[i], Nth); + break; + } + } + + return 0; +} From patchwork Fri Feb 21 18:02:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397077 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6A8D01395 for ; Fri, 21 Feb 2020 18:03:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 37B7B24656 for ; 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 08/17] fsinfo: Provide a bitmap of supported features [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:02:52 +0000 Message-ID: <158230817278.2185128.5829650395549432816.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Provide a bitmap of features that a filesystem may provide for the path being queried. Features include such things as: (1) The general class of filesystem, such as kernel-interface, block-based, flash-based, network-based. (2) Supported inode features, such as which timestamps are supported, whether simple numeric user, group or project IDs are supported and whether user identification is actually more complex behind the scenes. (3) Supported volume features, such as it having a UUID, a name or a filesystem ID. (4) Supported filesystem features, such as what types of file are supported, whether sparse files, extended attributes and quotas are supported. (5) Supported interface features, such as whether locking and leases are supported, what open flags are honoured and how i_version is managed. For some filesystems, this may be an immutable set and can just be memcpy'd into the reply buffer. Signed-off-by: David Howells --- fs/fsinfo.c | 30 +++++++++++++++++++ include/linux/fsinfo.h | 38 ++++++++++++++++++++++++ include/uapi/linux/fsinfo.h | 67 ++++++++++++++++++++++++++++++++++++++++++ samples/vfs/test-fsinfo.c | 69 +++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 204 insertions(+) diff --git a/fs/fsinfo.c b/fs/fsinfo.c index 5d3ba3c3a7ad..f423a4c5afd9 100644 --- a/fs/fsinfo.c +++ b/fs/fsinfo.c @@ -121,6 +121,35 @@ int fsinfo_generic_supports(struct path *path, struct fsinfo_context *ctx) } EXPORT_SYMBOL(fsinfo_generic_supports); +int fsinfo_generic_features(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_features *p = ctx->buffer; + struct super_block *sb = path->dentry->d_sb; + + fsinfo_init_features(p); + if (sb->s_mtd) + fsinfo_set_feature(p, FSINFO_FEAT_IS_FLASH_FS); + else if (sb->s_bdev) + fsinfo_set_feature(p, FSINFO_FEAT_IS_BLOCK_FS); + + if (sb->s_quota_types & QTYPE_MASK_USR) + fsinfo_set_feature(p, FSINFO_FEAT_USER_QUOTAS); + if (sb->s_quota_types & QTYPE_MASK_GRP) + fsinfo_set_feature(p, FSINFO_FEAT_GROUP_QUOTAS); + if (sb->s_quota_types & QTYPE_MASK_PRJ) + fsinfo_set_feature(p, FSINFO_FEAT_PROJECT_QUOTAS); + if (sb->s_d_op && sb->s_d_op->d_automount) + fsinfo_set_feature(p, FSINFO_FEAT_AUTOMOUNTS); + if (sb->s_id[0]) + fsinfo_set_feature(p, FSINFO_FEAT_VOLUME_ID); + + fsinfo_set_feature(p, FSINFO_FEAT_HAS_ATIME); + fsinfo_set_feature(p, FSINFO_FEAT_HAS_CTIME); + fsinfo_set_feature(p, FSINFO_FEAT_HAS_MTIME); + return sizeof(*p); +} +EXPORT_SYMBOL(fsinfo_generic_features); + static const struct fsinfo_timestamp_info fsinfo_default_timestamp_info = { .atime = { .minimum = S64_MIN, @@ -196,6 +225,7 @@ static const struct fsinfo_attribute fsinfo_common_attributes[] = { FSINFO_VSTRUCT (FSINFO_ATTR_TIMESTAMP_INFO, fsinfo_generic_timestamp_info), FSINFO_STRING (FSINFO_ATTR_VOLUME_ID, fsinfo_generic_volume_id), FSINFO_VSTRUCT (FSINFO_ATTR_VOLUME_UUID, fsinfo_generic_volume_uuid), + FSINFO_VSTRUCT (FSINFO_ATTR_FEATURES, fsinfo_generic_features), FSINFO_LIST (FSINFO_ATTR_FSINFO_ATTRIBUTES, (void *)123UL), FSINFO_VSTRUCT_N(FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO, (void *)123UL), diff --git a/include/linux/fsinfo.h b/include/linux/fsinfo.h index 943fbd6640f9..1b141e8e88e0 100644 --- a/include/linux/fsinfo.h +++ b/include/linux/fsinfo.h @@ -66,6 +66,44 @@ extern int fsinfo_generic_supports(struct path *, struct fsinfo_context *); extern int fsinfo_generic_limits(struct path *, struct fsinfo_context *); extern int fsinfo_get_attribute(struct path *, struct fsinfo_context *, const struct fsinfo_attribute *); +extern int fsinfo_generic_features(struct path *, struct fsinfo_context *); + +static inline void fsinfo_init_features(struct fsinfo_features *p) +{ + p->nr_features = FSINFO_FEAT__NR; +} + +static inline void fsinfo_set_feature(struct fsinfo_features *p, + enum fsinfo_feature feature) +{ + p->features[feature / 8] |= 1 << (feature % 8); +} + +static inline void fsinfo_clear_feature(struct fsinfo_features *p, + enum fsinfo_feature feature) +{ + p->features[feature / 8] &= ~(1 << (feature % 8)); +} + +/** + * fsinfo_set_unix_features - Set standard UNIX features. + * @f: The features mask to alter + */ +static inline void fsinfo_set_unix_features(struct fsinfo_features *p) +{ + fsinfo_set_feature(p, FSINFO_FEAT_UIDS); + fsinfo_set_feature(p, FSINFO_FEAT_GIDS); + fsinfo_set_feature(p, FSINFO_FEAT_DIRECTORIES); + fsinfo_set_feature(p, FSINFO_FEAT_SYMLINKS); + fsinfo_set_feature(p, FSINFO_FEAT_HARD_LINKS); + fsinfo_set_feature(p, FSINFO_FEAT_DEVICE_FILES); + fsinfo_set_feature(p, FSINFO_FEAT_UNIX_SPECIALS); + fsinfo_set_feature(p, FSINFO_FEAT_SPARSE); + fsinfo_set_feature(p, FSINFO_FEAT_HAS_ATIME); + fsinfo_set_feature(p, FSINFO_FEAT_HAS_CTIME); + fsinfo_set_feature(p, FSINFO_FEAT_HAS_MTIME); + fsinfo_set_feature(p, FSINFO_FEAT_HAS_INODE_NUMBERS); +} #endif /* CONFIG_FSINFO */ diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h index 6eb02de8a631..d7f24da36f0e 100644 --- a/include/uapi/linux/fsinfo.h +++ b/include/uapi/linux/fsinfo.h @@ -22,6 +22,7 @@ #define FSINFO_ATTR_VOLUME_ID 0x05 /* Volume ID (string) */ #define FSINFO_ATTR_VOLUME_UUID 0x06 /* Volume UUID (LE uuid) */ #define FSINFO_ATTR_VOLUME_NAME 0x07 /* Volume name (string) */ +#define FSINFO_ATTR_FEATURES 0x08 /* Filesystem features (bits) */ #define FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO 0x100 /* Information about attr N (for path) */ #define FSINFO_ATTR_FSINFO_ATTRIBUTES 0x101 /* List of supported attrs (for path) */ @@ -155,6 +156,72 @@ struct fsinfo_supports { #define FSINFO_ATTR_SUPPORTS__STRUCT struct fsinfo_supports +/* + * Information struct for fsinfo(FSINFO_ATTR_FEATURES). + * + * Bitmask indicating filesystem features where renderable as single bits. + */ +enum fsinfo_feature { + FSINFO_FEAT_IS_KERNEL_FS = 0, /* fs is kernel-special filesystem */ + FSINFO_FEAT_IS_BLOCK_FS = 1, /* fs is block-based filesystem */ + FSINFO_FEAT_IS_FLASH_FS = 2, /* fs is flash filesystem */ + FSINFO_FEAT_IS_NETWORK_FS = 3, /* fs is network filesystem */ + FSINFO_FEAT_IS_AUTOMOUNTER_FS = 4, /* fs is automounter special filesystem */ + FSINFO_FEAT_IS_MEMORY_FS = 5, /* fs is memory-based filesystem */ + FSINFO_FEAT_AUTOMOUNTS = 6, /* fs supports automounts */ + FSINFO_FEAT_ADV_LOCKS = 7, /* fs supports advisory file locking */ + FSINFO_FEAT_MAND_LOCKS = 8, /* fs supports mandatory file locking */ + FSINFO_FEAT_LEASES = 9, /* fs supports file leases */ + FSINFO_FEAT_UIDS = 10, /* fs supports numeric uids */ + FSINFO_FEAT_GIDS = 11, /* fs supports numeric gids */ + FSINFO_FEAT_PROJIDS = 12, /* fs supports numeric project ids */ + FSINFO_FEAT_STRING_USER_IDS = 13, /* fs supports string user identifiers */ + FSINFO_FEAT_GUID_USER_IDS = 14, /* fs supports GUID user identifiers */ + FSINFO_FEAT_WINDOWS_ATTRS = 15, /* fs has windows attributes */ + FSINFO_FEAT_USER_QUOTAS = 16, /* fs has per-user quotas */ + FSINFO_FEAT_GROUP_QUOTAS = 17, /* fs has per-group quotas */ + FSINFO_FEAT_PROJECT_QUOTAS = 18, /* fs has per-project quotas */ + FSINFO_FEAT_XATTRS = 19, /* fs has xattrs */ + FSINFO_FEAT_JOURNAL = 20, /* fs has a journal */ + FSINFO_FEAT_DATA_IS_JOURNALLED = 21, /* fs is using data journalling */ + FSINFO_FEAT_O_SYNC = 22, /* fs supports O_SYNC */ + FSINFO_FEAT_O_DIRECT = 23, /* fs supports O_DIRECT */ + FSINFO_FEAT_VOLUME_ID = 24, /* fs has a volume ID */ + FSINFO_FEAT_VOLUME_UUID = 25, /* fs has a volume UUID */ + FSINFO_FEAT_VOLUME_NAME = 26, /* fs has a volume name */ + FSINFO_FEAT_VOLUME_FSID = 27, /* fs has a volume FSID */ + FSINFO_FEAT_IVER_ALL_CHANGE = 28, /* i_version represents data + meta changes */ + FSINFO_FEAT_IVER_DATA_CHANGE = 29, /* i_version represents data changes only */ + FSINFO_FEAT_IVER_MONO_INCR = 30, /* i_version incremented monotonically */ + FSINFO_FEAT_DIRECTORIES = 31, /* fs supports (sub)directories */ + FSINFO_FEAT_SYMLINKS = 32, /* fs supports symlinks */ + FSINFO_FEAT_HARD_LINKS = 33, /* fs supports hard links */ + FSINFO_FEAT_HARD_LINKS_1DIR = 34, /* fs supports hard links in same dir only */ + FSINFO_FEAT_DEVICE_FILES = 35, /* fs supports bdev, cdev */ + FSINFO_FEAT_UNIX_SPECIALS = 36, /* fs supports pipe, fifo, socket */ + FSINFO_FEAT_RESOURCE_FORKS = 37, /* fs supports resource forks/streams */ + FSINFO_FEAT_NAME_CASE_INDEP = 38, /* Filename case independence is mandatory */ + FSINFO_FEAT_NAME_NON_UTF8 = 39, /* fs has non-utf8 names */ + FSINFO_FEAT_NAME_HAS_CODEPAGE = 40, /* fs has a filename codepage */ + FSINFO_FEAT_SPARSE = 41, /* fs supports sparse files */ + FSINFO_FEAT_NOT_PERSISTENT = 42, /* fs is not persistent */ + FSINFO_FEAT_NO_UNIX_MODE = 43, /* fs does not support unix mode bits */ + FSINFO_FEAT_HAS_ATIME = 44, /* fs supports access time */ + FSINFO_FEAT_HAS_BTIME = 45, /* fs supports birth/creation time */ + FSINFO_FEAT_HAS_CTIME = 46, /* fs supports change time */ + FSINFO_FEAT_HAS_MTIME = 47, /* fs supports modification time */ + FSINFO_FEAT_HAS_ACL = 48, /* fs supports ACLs of some sort */ + FSINFO_FEAT_HAS_INODE_NUMBERS = 49, /* fs has inode numbers */ + FSINFO_FEAT__NR +}; + +struct fsinfo_features { + __u32 nr_features; /* Number of supported features (FSINFO_FEAT__NR) */ + __u8 features[(FSINFO_FEAT__NR + 7) / 8]; +}; + +#define FSINFO_ATTR_FEATURES__STRUCT struct fsinfo_features + struct fsinfo_timestamp_one { __s64 minimum; /* Minimum timestamp value in seconds */ __s64 maximum; /* Maximum timestamp value in seconds */ diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c index 22fe3c47ff42..7f49c2125ed3 100644 --- a/samples/vfs/test-fsinfo.c +++ b/samples/vfs/test-fsinfo.c @@ -178,6 +178,74 @@ static void dump_fsinfo_generic_supports(void *reply, unsigned int size) printf("\twin_fattrs : %x\n", f->win_file_attrs); } +#define FSINFO_FEATURE_NAME(C) [FSINFO_FEAT_##C] = #C +static const char *fsinfo_feature_names[FSINFO_FEAT__NR] = { + FSINFO_FEATURE_NAME(IS_KERNEL_FS), + FSINFO_FEATURE_NAME(IS_BLOCK_FS), + FSINFO_FEATURE_NAME(IS_FLASH_FS), + FSINFO_FEATURE_NAME(IS_NETWORK_FS), + FSINFO_FEATURE_NAME(IS_AUTOMOUNTER_FS), + FSINFO_FEATURE_NAME(IS_MEMORY_FS), + FSINFO_FEATURE_NAME(AUTOMOUNTS), + FSINFO_FEATURE_NAME(ADV_LOCKS), + FSINFO_FEATURE_NAME(MAND_LOCKS), + FSINFO_FEATURE_NAME(LEASES), + FSINFO_FEATURE_NAME(UIDS), + FSINFO_FEATURE_NAME(GIDS), + FSINFO_FEATURE_NAME(PROJIDS), + FSINFO_FEATURE_NAME(STRING_USER_IDS), + FSINFO_FEATURE_NAME(GUID_USER_IDS), + FSINFO_FEATURE_NAME(WINDOWS_ATTRS), + FSINFO_FEATURE_NAME(USER_QUOTAS), + FSINFO_FEATURE_NAME(GROUP_QUOTAS), + FSINFO_FEATURE_NAME(PROJECT_QUOTAS), + FSINFO_FEATURE_NAME(XATTRS), + FSINFO_FEATURE_NAME(JOURNAL), + FSINFO_FEATURE_NAME(DATA_IS_JOURNALLED), + FSINFO_FEATURE_NAME(O_SYNC), + FSINFO_FEATURE_NAME(O_DIRECT), + FSINFO_FEATURE_NAME(VOLUME_ID), + FSINFO_FEATURE_NAME(VOLUME_UUID), + FSINFO_FEATURE_NAME(VOLUME_NAME), + FSINFO_FEATURE_NAME(VOLUME_FSID), + FSINFO_FEATURE_NAME(IVER_ALL_CHANGE), + FSINFO_FEATURE_NAME(IVER_DATA_CHANGE), + FSINFO_FEATURE_NAME(IVER_MONO_INCR), + FSINFO_FEATURE_NAME(DIRECTORIES), + FSINFO_FEATURE_NAME(SYMLINKS), + FSINFO_FEATURE_NAME(HARD_LINKS), + FSINFO_FEATURE_NAME(HARD_LINKS_1DIR), + FSINFO_FEATURE_NAME(DEVICE_FILES), + FSINFO_FEATURE_NAME(UNIX_SPECIALS), + FSINFO_FEATURE_NAME(RESOURCE_FORKS), + FSINFO_FEATURE_NAME(NAME_CASE_INDEP), + FSINFO_FEATURE_NAME(NAME_NON_UTF8), + FSINFO_FEATURE_NAME(NAME_HAS_CODEPAGE), + FSINFO_FEATURE_NAME(SPARSE), + FSINFO_FEATURE_NAME(NOT_PERSISTENT), + FSINFO_FEATURE_NAME(NO_UNIX_MODE), + FSINFO_FEATURE_NAME(HAS_ATIME), + FSINFO_FEATURE_NAME(HAS_BTIME), + FSINFO_FEATURE_NAME(HAS_CTIME), + FSINFO_FEATURE_NAME(HAS_MTIME), + FSINFO_FEATURE_NAME(HAS_ACL), + FSINFO_FEATURE_NAME(HAS_INODE_NUMBERS), +}; + +static void dump_fsinfo_generic_features(void *reply, unsigned int size) +{ + struct fsinfo_features *f = reply; + int i; + + printf("\n\t"); + for (i = 0; i < sizeof(f->features); i++) + printf("%02x", f->features[i]); + printf(" (nr=%u)\n", f->nr_features); + for (i = 0; i < FSINFO_FEAT__NR; i++) + if (f->features[i / 8] & (1 << (i % 8))) + printf("\t- %s\n", fsinfo_feature_names[i]); +} + static void print_time(struct fsinfo_timestamp_one *t, char stamp) { printf("\t%ctime : gran=%gs range=%llx-%llx\n", @@ -271,6 +339,7 @@ static const struct fsinfo_attribute fsinfo_attributes[] = { FSINFO_VSTRUCT (FSINFO_ATTR_IDS, fsinfo_generic_ids), FSINFO_VSTRUCT (FSINFO_ATTR_LIMITS, fsinfo_generic_limits), FSINFO_VSTRUCT (FSINFO_ATTR_SUPPORTS, fsinfo_generic_supports), + FSINFO_VSTRUCT (FSINFO_ATTR_FEATURES, fsinfo_generic_features), FSINFO_VSTRUCT (FSINFO_ATTR_TIMESTAMP_INFO, fsinfo_generic_timestamp_info), FSINFO_STRING (FSINFO_ATTR_VOLUME_ID, fsinfo_generic_volume_id), FSINFO_VSTRUCT (FSINFO_ATTR_VOLUME_UUID, fsinfo_generic_volume_uuid), From patchwork Fri Feb 21 18:03:00 2020 Content-Type: text/plain; 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Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 09/17] fsinfo: Allow fsinfo() to look up a mount object by ID [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:03:00 +0000 Message-ID: <158230818093.2185128.14307281032993574387.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Allow the fsinfo() syscall to look up a mount object by ID rather than by pathname. This is necessary as there can be multiple mounts stacked up at the same pathname and there's no way to look through them otherwise. This is done by passing FSINFO_FLAGS_QUERY_MOUNT to fsinfo() in the parameters and then passing the mount ID as a string to fsinfo() in place of the filename: struct fsinfo_params params = { .flags = FSINFO_FLAGS_QUERY_MOUNT, .request = FSINFO_ATTR_IDS, }; ret = fsinfo(AT_FDCWD, "21", ¶ms, buffer, sizeof(buffer)); The caller is only permitted to query a mount object if the root directory of that mount connects directly to the current chroot if dfd == AT_FDCWD[*] or the directory specified by dfd otherwise. Note that this is not available to the pathwalk of any other syscall. [*] This needs to be something other than AT_FDCWD, perhaps AT_FDROOT. [!] This probably needs an LSM hook. [!] This might want to check the permissions on all the intervening dirs - but it would have to do that under RCU conditions. [!] This might want to check a CAP_* flag. Signed-off-by: David Howells --- fs/fsinfo.c | 53 +++++++++++++++++++ fs/internal.h | 2 + fs/namespace.c | 117 ++++++++++++++++++++++++++++++++++++++++++- include/uapi/linux/fsinfo.h | 1 samples/vfs/test-fsinfo.c | 11 +++- 5 files changed, 179 insertions(+), 5 deletions(-) diff --git a/fs/fsinfo.c b/fs/fsinfo.c index f423a4c5afd9..9712d340dd7d 100644 --- a/fs/fsinfo.c +++ b/fs/fsinfo.c @@ -496,6 +496,56 @@ static int vfs_fsinfo_fd(unsigned int fd, struct fsinfo_context *ctx) return ret; } +/* + * Look up the root of a mount object. This allows access to mount objects + * (and their attached superblocks) that can't be retrieved by path because + * they're entirely covered. + * + * We only permit access to a mount that has a direct path between either the + * dentry pointed to by dfd or to our chroot (if dfd is AT_FDCWD). + */ +static int vfs_fsinfo_mount(int dfd, const char __user *filename, + struct fsinfo_context *ctx) +{ + struct path path; + struct fd f = {}; + char *name; + long mnt_id; + int ret; + + if (!filename) + return -EINVAL; + + name = strndup_user(filename, 32); + if (IS_ERR(name)) + return PTR_ERR(name); + ret = kstrtoul(name, 0, &mnt_id); + if (ret < 0) + goto out_name; + if (mnt_id > INT_MAX) + goto out_name; + + if (dfd != AT_FDCWD) { + ret = -EBADF; + f = fdget_raw(dfd); + if (!f.file) + goto out_name; + } + + ret = lookup_mount_object(f.file ? &f.file->f_path : NULL, + mnt_id, &path); + if (ret < 0) + goto out_fd; + + ret = vfs_fsinfo(&path, ctx); + path_put(&path); +out_fd: + fdput(f); +out_name: + kfree(name); + return ret; +} + /** * sys_fsinfo - System call to get filesystem information * @dfd: Base directory to pathwalk from or fd referring to filesystem. @@ -565,6 +615,9 @@ SYSCALL_DEFINE5(fsinfo, return -EINVAL; ret = vfs_fsinfo_fd(dfd, &ctx); break; + case FSINFO_FLAGS_QUERY_MOUNT: + ret = vfs_fsinfo_mount(dfd, pathname, &ctx); + break; default: return -EINVAL; } diff --git a/fs/internal.h b/fs/internal.h index f3f280b952a3..2ccd2b2eae88 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -91,6 +91,8 @@ extern int __mnt_want_write_file(struct file *); extern void __mnt_drop_write_file(struct file *); extern void dissolve_on_fput(struct vfsmount *); +extern int lookup_mount_object(struct path *, int, struct path *); + /* * fs_struct.c */ diff --git a/fs/namespace.c b/fs/namespace.c index 668f797ae3bd..696fcc5010ca 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -63,7 +63,7 @@ static int __init set_mphash_entries(char *str) __setup("mphash_entries=", set_mphash_entries); static u64 event; -static DEFINE_IDA(mnt_id_ida); +static DEFINE_IDR(mnt_id_ida); static DEFINE_IDA(mnt_group_ida); static struct hlist_head *mount_hashtable __read_mostly; @@ -104,17 +104,27 @@ static inline struct hlist_head *mp_hash(struct dentry *dentry) static int mnt_alloc_id(struct mount *mnt) { - int res = ida_alloc(&mnt_id_ida, GFP_KERNEL); + int res; + /* Allocate an ID, but don't set the pointer back to the mount until + * later, as once we do that, we have to follow RCU protocols to get + * rid of the mount struct. + */ + res = idr_alloc(&mnt_id_ida, NULL, 0, INT_MAX, GFP_KERNEL); if (res < 0) return res; mnt->mnt_id = res; return 0; } +static void mnt_publish_id(struct mount *mnt) +{ + idr_replace(&mnt_id_ida, mnt, mnt->mnt_id); +} + static void mnt_free_id(struct mount *mnt) { - ida_free(&mnt_id_ida, mnt->mnt_id); + idr_remove(&mnt_id_ida, mnt->mnt_id); } /* @@ -958,6 +968,7 @@ struct vfsmount *vfs_create_mount(struct fs_context *fc) lock_mount_hash(); list_add_tail(&mnt->mnt_instance, &mnt->mnt.mnt_sb->s_mounts); unlock_mount_hash(); + mnt_publish_id(mnt); return &mnt->mnt; } EXPORT_SYMBOL(vfs_create_mount); @@ -1051,6 +1062,7 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root, lock_mount_hash(); list_add_tail(&mnt->mnt_instance, &sb->s_mounts); unlock_mount_hash(); + mnt_publish_id(mnt); if ((flag & CL_SLAVE) || ((flag & CL_SHARED_TO_SLAVE) && IS_MNT_SHARED(old))) { @@ -3997,3 +4009,102 @@ const struct proc_ns_operations mntns_operations = { .install = mntns_install, .owner = mntns_owner, }; + +/* + * See if one path point connects directly to another by ancestral relationship + * across mountpoints. Must call with the RCU read lock held. + */ +static bool are_paths_connected(struct path *ancestor, struct path *to_check) +{ + struct mount *mnt, *parent; + struct path cursor; + unsigned seq; + bool connected; + + seq = 0; +restart: + cursor = *to_check; + + read_seqbegin_or_lock(&rename_lock, &seq); + while (cursor.mnt != ancestor->mnt) { + mnt = real_mount(cursor.mnt); + parent = READ_ONCE(mnt->mnt_parent); + if (mnt == parent) + goto failed; + cursor.dentry = READ_ONCE(mnt->mnt_mountpoint); + cursor.mnt = &parent->mnt; + } + + while (cursor.dentry != ancestor->dentry) { + if (cursor.dentry == cursor.mnt->mnt_root || + IS_ROOT(cursor.dentry)) + goto failed; + cursor.dentry = READ_ONCE(cursor.dentry->d_parent); + } + + connected = true; +out: + done_seqretry(&rename_lock, seq); + return connected; + +failed: + if (need_seqretry(&rename_lock, seq)) { + seq = 1; + goto restart; + } + connected = false; + goto out; +} + +/** + * lookup_mount_object - Look up a vfsmount object by ID + * @root: The mount root must connect backwards to this point (or chroot if NULL). + * @id: The ID of the mountpoint. + * @_mntpt: Where to return the resulting mountpoint path. + * + * Look up the root of the mount with the corresponding ID. This is only + * permitted if that mount connects directly to the specified root/chroot. + */ +int lookup_mount_object(struct path *root, int mnt_id, struct path *_mntpt) +{ + struct mount *mnt; + struct path stop, mntpt = {}; + int ret = -EPERM; + + if (!root) + get_fs_root(current->fs, &stop); + else + stop = *root; + + rcu_read_lock(); + lock_mount_hash(); + mnt = idr_find(&mnt_id_ida, mnt_id); + if (!mnt) + goto out_unlock_mh; + if (mnt->mnt.mnt_flags & (MNT_SYNC_UMOUNT | MNT_UMOUNT | MNT_DOOMED)) + goto out_unlock_mh; + if (mnt_get_count(mnt) == 0) + goto out_unlock_mh; + mnt_add_count(mnt, 1); + mntpt.mnt = &mnt->mnt; + mntpt.dentry = dget(mnt->mnt.mnt_root); + unlock_mount_hash(); + + if (are_paths_connected(&stop, &mntpt)) { + *_mntpt = mntpt; + mntpt.mnt = NULL; + mntpt.dentry = NULL; + ret = 0; + } + +out_unlock: + rcu_read_unlock(); + if (!root) + path_put(&stop); + path_put(&mntpt); + return ret; + +out_unlock_mh: + unlock_mount_hash(); + goto out_unlock; +} diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h index d7f24da36f0e..3ce7810d96b4 100644 --- a/include/uapi/linux/fsinfo.h +++ b/include/uapi/linux/fsinfo.h @@ -39,6 +39,7 @@ struct fsinfo_params { #define FSINFO_FLAGS_QUERY_MASK 0x0007 /* What object should fsinfo() query? */ #define FSINFO_FLAGS_QUERY_PATH 0x0000 /* - path, specified by dirfd,pathname,AT_EMPTY_PATH */ #define FSINFO_FLAGS_QUERY_FD 0x0001 /* - fd specified by dirfd */ +#define FSINFO_FLAGS_QUERY_MOUNT 0x0002 /* - mount object (path=>mount_id, dirfd=>subtree) */ __u32 request; /* ID of requested attribute */ __u32 Nth; /* Instance of it (some may have multiple) */ __u32 Mth; /* Subinstance of Nth instance */ diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c index 7f49c2125ed3..546bf4f530d0 100644 --- a/samples/vfs/test-fsinfo.c +++ b/samples/vfs/test-fsinfo.c @@ -555,16 +555,22 @@ int main(int argc, char **argv) bool meta = false; int raw = 0, opt, Nth, Mth; - while ((opt = getopt(argc, argv, "adlmr"))) { + while ((opt = getopt(argc, argv, "Madlmr"))) { switch (opt) { + case 'M': + params.at_flags = 0; + params.flags = FSINFO_FLAGS_QUERY_MOUNT; + continue; case 'a': params.at_flags |= AT_NO_AUTOMOUNT; + params.flags |= FSINFO_FLAGS_QUERY_PATH; continue; case 'd': debug = true; continue; case 'l': params.at_flags &= ~AT_SYMLINK_NOFOLLOW; + params.flags |= FSINFO_FLAGS_QUERY_PATH; continue; case 'm': meta = true; @@ -580,7 +586,8 @@ int main(int argc, char **argv) argv += optind; if (argc != 1) { - printf("Format: test-fsinfo [-alr] \n"); + printf("Format: test-fsinfo [-adlr] \n"); + printf("Format: test-fsinfo [-dr] -M \n"); exit(2); } From patchwork Fri Feb 21 18:03:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397081 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 01C391395 for ; Fri, 21 Feb 2020 18:03:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C27F724650 for ; Fri, 21 Feb 2020 18:03:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="STRzwvZ2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729626AbgBUSDR (ORCPT ); Fri, 21 Feb 2020 13:03:17 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:45239 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726946AbgBUSDQ (ORCPT ); Fri, 21 Feb 2020 13:03:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582308195; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+8bdzcPvK7VukzYPxxOK7S4lzkR998bwGqjZTrZWM+E=; b=STRzwvZ2bWEJNQuhHvfgj40WEafJrbfWY/nW7MreFb3V5IwJuIIGCJtnnilQWz5/ZUgNaF JWhwi0BW4IIw0roF2O5gwMhsvDlqezXsDKdXKqyQlYABIACt2p8j/gXBdEnL5se4K13GrO vc0CbpkLZIULrsSd9EQ4QesuEDaJMKg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-267-uaPpYhJ6O2-U6R0YBBl1lA-1; Fri, 21 Feb 2020 13:03:13 -0500 X-MC-Unique: uaPpYhJ6O2-U6R0YBBl1lA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 690CF1034B49; Fri, 21 Feb 2020 18:03:11 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-122-163.rdu2.redhat.com [10.10.122.163]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5B3355DA76; Fri, 21 Feb 2020 18:03:09 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 10/17] fsinfo: Allow mount information to be queried [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:03:08 +0000 Message-ID: <158230818859.2185128.8921928947340497977.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Allow mount information, including information about the topology tree to be queried with the fsinfo() system call. Setting AT_FSINFO_QUERY_MOUNT allows overlapping mounts to be queried by indicating that the syscall should interpet the pathname as a number indicating the mount ID. To this end, four fsinfo() attributes are provided: (1) FSINFO_ATTR_MOUNT_INFO. This is a structure providing information about a mount, including: - Mounted superblock ID. - Mount ID (can be used with AT_FSINFO_QUERY_MOUNT). - Parent mount ID. - Mount attributes (eg. R/O, NOEXEC). - A change counter. Note that the parent mount ID is overridden to the ID of the queried mount if the parent lies outside of the chroot or dfd tree. (2) FSINFO_ATTR_MOUNT_DEVNAME. This a string providing the device name associated with the mount. Note that the device name may be a path that lies outside of the root. (3) FSINFO_ATTR_MOUNT_POINT. This is a string indicating the name of the mountpoint within the parent mount, limited to the parent's mounted root and the chroot. (4) FSINFO_ATTR_MOUNT_CHILDREN. This produces an array of structures, one for each child and capped with one for the argument mount (checked after listing all the children). Each element contains the mount ID and the change counter of the respective mount object. Signed-off-by: David Howells --- fs/d_path.c | 2 fs/fsinfo.c | 5 + fs/internal.h | 10 ++ fs/namespace.c | 179 +++++++++++++++++++++++++++++++++++++++++++ include/uapi/linux/fsinfo.h | 34 ++++++++ samples/vfs/test-fsinfo.c | 27 ++++++ 6 files changed, 256 insertions(+), 1 deletion(-) diff --git a/fs/d_path.c b/fs/d_path.c index 0f1fc1743302..4c203f64e45e 100644 --- a/fs/d_path.c +++ b/fs/d_path.c @@ -229,7 +229,7 @@ static int prepend_unreachable(char **buffer, int *buflen) return prepend(buffer, buflen, "(unreachable)", 13); } -static void get_fs_root_rcu(struct fs_struct *fs, struct path *root) +void get_fs_root_rcu(struct fs_struct *fs, struct path *root) { unsigned seq; diff --git a/fs/fsinfo.c b/fs/fsinfo.c index 9712d340dd7d..e3377842a2c1 100644 --- a/fs/fsinfo.c +++ b/fs/fsinfo.c @@ -229,6 +229,11 @@ static const struct fsinfo_attribute fsinfo_common_attributes[] = { FSINFO_LIST (FSINFO_ATTR_FSINFO_ATTRIBUTES, (void *)123UL), FSINFO_VSTRUCT_N(FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO, (void *)123UL), + + FSINFO_VSTRUCT (FSINFO_ATTR_MOUNT_INFO, fsinfo_generic_mount_info), + FSINFO_STRING (FSINFO_ATTR_MOUNT_DEVNAME, fsinfo_generic_mount_devname), + FSINFO_STRING (FSINFO_ATTR_MOUNT_POINT, fsinfo_generic_mount_point), + FSINFO_LIST (FSINFO_ATTR_MOUNT_CHILDREN, fsinfo_generic_mount_children), {} }; diff --git a/fs/internal.h b/fs/internal.h index 2ccd2b2eae88..6804cf54846d 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -15,6 +15,7 @@ struct mount; struct shrink_control; struct fs_context; struct user_namespace; +struct fsinfo_context; /* * block_dev.c @@ -47,6 +48,11 @@ extern int __block_write_begin_int(struct page *page, loff_t pos, unsigned len, */ extern void __init chrdev_init(void); +/* + * d_path.c + */ +extern void get_fs_root_rcu(struct fs_struct *fs, struct path *root); + /* * fs_context.c */ @@ -92,6 +98,10 @@ extern void __mnt_drop_write_file(struct file *); extern void dissolve_on_fput(struct vfsmount *); extern int lookup_mount_object(struct path *, int, struct path *); +extern int fsinfo_generic_mount_info(struct path *, struct fsinfo_context *); +extern int fsinfo_generic_mount_devname(struct path *, struct fsinfo_context *); +extern int fsinfo_generic_mount_point(struct path *, struct fsinfo_context *); +extern int fsinfo_generic_mount_children(struct path *, struct fsinfo_context *); /* * fs_struct.c diff --git a/fs/namespace.c b/fs/namespace.c index 696fcc5010ca..fc22aea18e2d 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -30,6 +30,7 @@ #include #include #include +#include #include "pnode.h" #include "internal.h" @@ -4108,3 +4109,181 @@ int lookup_mount_object(struct path *root, int mnt_id, struct path *_mntpt) unlock_mount_hash(); goto out_unlock; } + +#ifdef CONFIG_FSINFO +/* + * Retrieve information about the nominated mount. + */ +int fsinfo_generic_mount_info(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_mount_info *p = ctx->buffer; + struct super_block *sb; + struct mount *m; + struct path root; + unsigned int flags; + + if (!path->mnt) + return -ENODATA; + + m = real_mount(path->mnt); + sb = m->mnt.mnt_sb; + + p->f_sb_id = sb->s_unique_id; + p->mnt_id = m->mnt_id; + p->parent_id = m->mnt_parent->mnt_id; + p->change_counter = atomic_read(&m->mnt_change_counter); + + get_fs_root(current->fs, &root); + if (path->mnt == root.mnt) { + p->parent_id = p->mnt_id; + } else { + rcu_read_lock(); + if (!are_paths_connected(&root, path)) + p->parent_id = p->mnt_id; + rcu_read_unlock(); + } + if (IS_MNT_SHARED(m)) + p->group_id = m->mnt_group_id; + if (IS_MNT_SLAVE(m)) { + int master = m->mnt_master->mnt_group_id; + int dom = get_dominating_id(m, &root); + p->master_id = master; + if (dom && dom != master) + p->from_id = dom; + } + path_put(&root); + + flags = READ_ONCE(m->mnt.mnt_flags); + if (flags & MNT_READONLY) + p->attr |= MOUNT_ATTR_RDONLY; + if (flags & MNT_NOSUID) + p->attr |= MOUNT_ATTR_NOSUID; + if (flags & MNT_NODEV) + p->attr |= MOUNT_ATTR_NODEV; + if (flags & MNT_NOEXEC) + p->attr |= MOUNT_ATTR_NOEXEC; + if (flags & MNT_NODIRATIME) + p->attr |= MOUNT_ATTR_NODIRATIME; + + if (flags & MNT_NOATIME) + p->attr |= MOUNT_ATTR_NOATIME; + else if (flags & MNT_RELATIME) + p->attr |= MOUNT_ATTR_RELATIME; + else + p->attr |= MOUNT_ATTR_STRICTATIME; + return sizeof(*p); +} + +int fsinfo_generic_mount_devname(struct path *path, struct fsinfo_context *ctx) +{ + if (!path->mnt) + return -ENODATA; + + return fsinfo_string(real_mount(path->mnt)->mnt_devname, ctx); +} + +/* + * Return the path of this mount relative to its parent and clipped to + * the current chroot. + */ +int fsinfo_generic_mount_point(struct path *path, struct fsinfo_context *ctx) +{ + struct mountpoint *mp; + struct mount *m, *parent; + struct path mountpoint, root; + size_t len; + void *p; + + if (!path->mnt) + return -ENODATA; + + rcu_read_lock(); + + m = real_mount(path->mnt); + parent = m->mnt_parent; + if (parent == m) + goto skip; + mp = READ_ONCE(m->mnt_mp); + if (mp) + goto found; +skip: + rcu_read_unlock(); + return -ENODATA; + +found: + mountpoint.mnt = &parent->mnt; + mountpoint.dentry = READ_ONCE(mp->m_dentry); + + get_fs_root_rcu(current->fs, &root); + if (path->mnt == root.mnt) { + rcu_read_unlock(); + len = snprintf(ctx->buffer, ctx->buf_size, "/"); + } else { + if (root.mnt != &parent->mnt) { + root.mnt = &parent->mnt; + root.dentry = parent->mnt.mnt_root; + } + + p = __d_path(&mountpoint, &root, ctx->buffer, ctx->buf_size); + rcu_read_unlock(); + + if (IS_ERR(p)) + return PTR_ERR(p); + if (!p) + return -EPERM; + + len = (ctx->buffer + ctx->buf_size) - p; + memmove(ctx->buffer, p, len); + } + return len; +} + +/* + * Store a mount record into the fsinfo buffer. + */ +static void store_mount_fsinfo(struct fsinfo_context *ctx, + struct fsinfo_mount_child *child) +{ + unsigned int usage = ctx->usage; + unsigned int total = sizeof(*child); + + if (ctx->usage >= INT_MAX) + return; + ctx->usage = usage + total; + if (ctx->buffer && ctx->usage <= ctx->buf_size) + memcpy(ctx->buffer + usage, child, total); +} + +/* + * Return information about the submounts relative to path. + */ +int fsinfo_generic_mount_children(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_mount_child record; + struct mount *m, *child; + + if (!path->mnt) + return -ENODATA; + + m = real_mount(path->mnt); + + rcu_read_lock(); + list_for_each_entry_rcu(child, &m->mnt_mounts, mnt_child) { + if (child->mnt_parent != m) + continue; + record.mnt_id = child->mnt_id; + record.change_counter = atomic_read(&child->mnt_change_counter); + store_mount_fsinfo(ctx, &record); + } + rcu_read_unlock(); + + /* End the list with a copy of the parameter mount's details so that + * userspace can quickly check for changes. + */ + record.mnt_id = m->mnt_id; + record.change_counter = atomic_read(&m->mnt_change_counter); + store_mount_fsinfo(ctx, &record); + return ctx->usage; +} + +#endif /* CONFIG_FSINFO */ diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h index 3ce7810d96b4..29940d110ce3 100644 --- a/include/uapi/linux/fsinfo.h +++ b/include/uapi/linux/fsinfo.h @@ -27,6 +27,11 @@ #define FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO 0x100 /* Information about attr N (for path) */ #define FSINFO_ATTR_FSINFO_ATTRIBUTES 0x101 /* List of supported attrs (for path) */ +#define FSINFO_ATTR_MOUNT_INFO 0x200 /* Mount object information */ +#define FSINFO_ATTR_MOUNT_DEVNAME 0x201 /* Mount object device name (string) */ +#define FSINFO_ATTR_MOUNT_POINT 0x202 /* Relative path of mount in parent (string) */ +#define FSINFO_ATTR_MOUNT_CHILDREN 0x203 /* Children of this mount (list) */ + /* * Optional fsinfo() parameter structure. * @@ -69,6 +74,7 @@ struct fsinfo_attribute_info { unsigned int size; /* - Value size (FSINFO_STRUCT/FSINFO_LIST) */ }; +#define FSINFO_ATTR_FSINFO_ATTRIBUTES__STRUCT __u32 #define FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO__STRUCT struct fsinfo_attribute_info #define FSINFO_ATTR_FSINFO_ATTRIBUTES__STRUCT __u32 @@ -82,6 +88,34 @@ struct fsinfo_u128 { #endif }; +/* + * Information struct for fsinfo(FSINFO_ATTR_MOUNT_INFO). + */ +struct fsinfo_mount_info { + __u64 f_sb_id; /* Superblock ID */ + __u32 mnt_id; /* Mount identifier (use with AT_FSINFO_MOUNTID_PATH) */ + __u32 parent_id; /* Parent mount identifier */ + __u32 group_id; /* Mount group ID */ + __u32 master_id; /* Slave master group ID */ + __u32 from_id; /* Slave propagated from ID */ + __u32 attr; /* MOUNT_ATTR_* flags */ + __u32 change_counter; /* Number of changes applied. */ + __u32 __reserved[1]; +}; + +#define FSINFO_ATTR_MOUNT_INFO__STRUCT struct fsinfo_mount_info + +/* + * Information struct element for fsinfo(FSINFO_ATTR_MOUNT_CHILDREN). + * - An extra element is placed on the end representing the parent mount. + */ +struct fsinfo_mount_child { + __u32 mnt_id; /* Mount identifier (use with AT_FSINFO_MOUNTID_PATH) */ + __u32 change_counter; /* Number of changes applied to mount. */ +}; + +#define FSINFO_ATTR_MOUNT_CHILDREN__STRUCT struct fsinfo_mount_child + /* * Information struct for fsinfo(FSINFO_ATTR_STATFS). * - This gives extended filesystem information. diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c index 546bf4f530d0..f761ded6a52c 100644 --- a/samples/vfs/test-fsinfo.c +++ b/samples/vfs/test-fsinfo.c @@ -282,6 +282,26 @@ static void dump_fsinfo_generic_volume_uuid(void *reply, unsigned int size) f->uuid[14], f->uuid[15]); } +static void dump_fsinfo_generic_mount_info(void *reply, unsigned int size) +{ + struct fsinfo_mount_info *f = reply; + + printf("\n"); + printf("\tsb_id : %llx\n", (unsigned long long)f->f_sb_id); + printf("\tmnt_id : %x\n", f->mnt_id); + printf("\tparent : %x\n", f->parent_id); + printf("\tgroup : %x\n", f->group_id); + printf("\tattr : %x\n", f->attr); + printf("\tchanges : %x\n", f->change_counter); +} + +static void dump_fsinfo_generic_mount_child(void *reply, unsigned int size) +{ + struct fsinfo_mount_child *f = reply; + + printf("%8x %8x\n", f->mnt_id, f->change_counter); +} + static void dump_string(void *reply, unsigned int size) { char *s = reply, *p; @@ -309,6 +329,8 @@ static void dump_string(void *reply, unsigned int size) #define dump_fsinfo_generic_volume_id dump_string #define dump_fsinfo_generic_volume_name dump_string +#define dump_fsinfo_generic_mount_devname dump_string +#define dump_fsinfo_generic_mount_point dump_string /* * @@ -344,6 +366,11 @@ static const struct fsinfo_attribute fsinfo_attributes[] = { FSINFO_STRING (FSINFO_ATTR_VOLUME_ID, fsinfo_generic_volume_id), FSINFO_VSTRUCT (FSINFO_ATTR_VOLUME_UUID, fsinfo_generic_volume_uuid), FSINFO_STRING (FSINFO_ATTR_VOLUME_NAME, fsinfo_generic_volume_name), + + FSINFO_VSTRUCT (FSINFO_ATTR_MOUNT_INFO, fsinfo_generic_mount_info), + FSINFO_STRING (FSINFO_ATTR_MOUNT_DEVNAME, fsinfo_generic_mount_devname), + FSINFO_LIST (FSINFO_ATTR_MOUNT_CHILDREN, fsinfo_generic_mount_child), + FSINFO_STRING_N (FSINFO_ATTR_MOUNT_POINT, fsinfo_generic_mount_point), {} }; From patchwork Fri Feb 21 18:03:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397083 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D03D992A for ; Fri, 21 Feb 2020 18:03:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C5DB222C4 for ; Fri, 21 Feb 2020 18:03:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="PZjS5jtZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729633AbgBUSDZ (ORCPT ); Fri, 21 Feb 2020 13:03:25 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:36512 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726066AbgBUSDZ (ORCPT ); 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 11/17] fsinfo: sample: Mount listing program [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:03:16 +0000 Message-ID: <158230819662.2185128.7616577805802640363.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Implement a program to demonstrate mount listing using the new fsinfo() syscall, for example: # ./test-mntinfo -M 21 MOUNT MOUNT ID CHANGE# TYPE & DEVICE ------------------------------------- ---------- ---------- --------------- 21 21 8 sysfs 0:15 \_ kernel/security 24 0 securityfs 0:8 \_ fs/cgroup 28 16 tmpfs 0:19 | \_ unified 29 0 cgroup2 0:1a | \_ systemd 30 0 cgroup 0:1b | \_ freezer 34 0 cgroup 0:1f | \_ cpu,cpuacct 35 0 cgroup 0:20 | \_ devices 36 0 cgroup 0:21 | \_ memory 37 0 cgroup 0:22 | \_ cpuset 38 0 cgroup 0:23 | \_ net_cls,net_prio 39 0 cgroup 0:24 | \_ hugetlb 40 0 cgroup 0:25 | \_ rdma 41 0 cgroup 0:26 | \_ blkio 42 0 cgroup 0:27 | \_ perf_event 43 0 cgroup 0:28 \_ fs/pstore 31 0 pstore 0:1c \_ firmware/efi/efivars 32 0 efivarfs 0:1d \_ fs/bpf 33 0 bpf 0:1e \_ kernel/config 92 0 configfs 0:10 \_ fs/selinux 44 0 selinuxfs 0:12 \_ kernel/debug 48 0 debugfs 0:7 Signed-off-by: David Howells --- samples/vfs/Makefile | 2 samples/vfs/test-mntinfo.c | 243 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 245 insertions(+) create mode 100644 samples/vfs/test-mntinfo.c diff --git a/samples/vfs/Makefile b/samples/vfs/Makefile index 9159ad1d7fc5..19be60ab950e 100644 --- a/samples/vfs/Makefile +++ b/samples/vfs/Makefile @@ -4,12 +4,14 @@ hostprogs := \ test-fsinfo \ test-fsmount \ + test-mntinfo \ test-statx always-y := $(hostprogs) HOSTCFLAGS_test-fsinfo.o += -I$(objtree)/usr/include HOSTLDLIBS_test-fsinfo += -static -lm +HOSTCFLAGS_test-mntinfo.o += -I$(objtree)/usr/include HOSTCFLAGS_test-fsmount.o += -I$(objtree)/usr/include HOSTCFLAGS_test-statx.o += -I$(objtree)/usr/include diff --git a/samples/vfs/test-mntinfo.c b/samples/vfs/test-mntinfo.c new file mode 100644 index 000000000000..f4d90d0671c5 --- /dev/null +++ b/samples/vfs/test-mntinfo.c @@ -0,0 +1,243 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Test the fsinfo() system call + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define _GNU_SOURCE +#define _ATFILE_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifndef __NR_fsinfo +#define __NR_fsinfo -1 +#endif + +static __attribute__((unused)) +ssize_t fsinfo(int dfd, const char *filename, struct fsinfo_params *params, + void *buffer, size_t buf_size) +{ + return syscall(__NR_fsinfo, dfd, filename, params, buffer, buf_size); +} + +static char tree_buf[4096]; +static char bar_buf[4096]; + +/* + * Get an fsinfo attribute in a statically allocated buffer. + */ +static void get_attr(unsigned int mnt_id, unsigned int attr, + void *buf, size_t buf_size) +{ + struct fsinfo_params params = { + .flags = FSINFO_FLAGS_QUERY_MOUNT, + .request = attr, + }; + char file[32]; + long ret; + + sprintf(file, "%u", mnt_id); + + memset(buf, 0xbd, buf_size); + + ret = fsinfo(AT_FDCWD, file, ¶ms, buf, buf_size); + if (ret == -1) { + fprintf(stderr, "mount-%s: %m\n", file); + exit(1); + } +} + +/* + * Get an fsinfo attribute in a dynamically allocated buffer. + */ +static void *get_attr_alloc(unsigned int mnt_id, unsigned int attr, + unsigned int Nth, size_t *_size) +{ + struct fsinfo_params params = { + .flags = FSINFO_FLAGS_QUERY_MOUNT, + .request = attr, + .Nth = Nth, + }; + size_t buf_size = 4096; + char file[32]; + void *r; + long ret; + + sprintf(file, "%u", mnt_id); + + for (;;) { + r = malloc(buf_size); + if (!r) { + perror("malloc"); + exit(1); + } + memset(r, 0xbd, buf_size); + + ret = fsinfo(AT_FDCWD, file, ¶ms, r, buf_size); + if (ret == -1) { + fprintf(stderr, "mount-%s: %x,%x,%x %m\n", + file, params.request, params.Nth, params.Mth); + exit(1); + } + + if (ret <= buf_size) { + *_size = ret; + break; + } + buf_size = (ret + 4096 - 1) & ~(4096 - 1); + } + + return r; +} + +/* + * Display a mount and then recurse through its children. + */ +static void display_mount(unsigned int mnt_id, unsigned int depth, char *path) +{ + struct fsinfo_mount_child *children; + struct fsinfo_mount_info info; + struct fsinfo_ids ids; + unsigned int d; + size_t ch_size, p_size; + char dev[64]; + int i, n, s; + + get_attr(mnt_id, FSINFO_ATTR_MOUNT_INFO, &info, sizeof(info)); + get_attr(mnt_id, FSINFO_ATTR_IDS, &ids, sizeof(ids)); + if (depth > 0) + printf("%s", tree_buf); + + s = strlen(path); + printf("%s", !s ? "\"\"" : path); + if (!s) + s += 2; + s += depth; + if (s < 38) + s = 38 - s; + else + s = 1; + printf("%*.*s", s, s, ""); + + sprintf(dev, "%x:%x", ids.f_dev_major, ids.f_dev_minor); + printf("%10u %8x %2x %5s %s", + info.mnt_id, info.change_counter, + info.attr, + dev, ids.f_fs_name); + putchar('\n'); + + children = get_attr_alloc(mnt_id, FSINFO_ATTR_MOUNT_CHILDREN, 0, &ch_size); + n = ch_size / sizeof(children[0]) - 1; + + bar_buf[depth + 1] = '|'; + if (depth > 0) { + tree_buf[depth - 4 + 1] = bar_buf[depth - 4 + 1]; + tree_buf[depth - 4 + 2] = ' '; + } + + tree_buf[depth + 0] = ' '; + tree_buf[depth + 1] = '\\'; + tree_buf[depth + 2] = '_'; + tree_buf[depth + 3] = ' '; + tree_buf[depth + 4] = 0; + d = depth + 4; + + for (i = 0; i < n; i++) { + if (i == n - 1) + bar_buf[depth + 1] = ' '; + path = get_attr_alloc(children[i].mnt_id, FSINFO_ATTR_MOUNT_POINT, + 0, &p_size); + display_mount(children[i].mnt_id, d, path + 1); + free(path); + } + + free(children); + if (depth > 0) { + tree_buf[depth - 4 + 1] = '\\'; + tree_buf[depth - 4 + 2] = '_'; + } + tree_buf[depth] = 0; +} + +/* + * Find the ID of whatever is at the nominated path. + */ +static unsigned int lookup_mnt_by_path(const char *path) +{ + struct fsinfo_mount_info mnt; + struct fsinfo_params params = { + .flags = FSINFO_FLAGS_QUERY_PATH, + .request = FSINFO_ATTR_MOUNT_INFO, + }; + + if (fsinfo(AT_FDCWD, path, ¶ms, &mnt, sizeof(mnt)) == -1) { + perror(path); + exit(1); + } + + return mnt.mnt_id; +} + +/* + * + */ +int main(int argc, char **argv) +{ + unsigned int mnt_id; + char *path; + bool use_mnt_id = false; + int opt; + + while ((opt = getopt(argc, argv, "M"))) { + switch (opt) { + case 'M': + use_mnt_id = true; + continue; + } + break; + } + + argc -= optind; + argv += optind; + + switch (argc) { + case 0: + mnt_id = lookup_mnt_by_path("/"); + path = "ROOT"; + break; + case 1: + path = argv[0]; + if (use_mnt_id) { + mnt_id = strtoul(argv[0], NULL, 0); + break; + } + + mnt_id = lookup_mnt_by_path(argv[0]); + break; + default: + printf("Format: test-mntinfo\n"); + printf("Format: test-mntinfo \n"); + printf("Format: test-mntinfo -M \n"); + exit(2); + } + + printf("MOUNT MOUNT ID CHANGE# AT DEV TYPE\n"); + printf("------------------------------------- ---------- -------- -- ----- --------\n"); + display_mount(mnt_id, 0, path); + return 0; +} From patchwork Fri Feb 21 18:03:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397085 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 51D261395 for ; Fri, 21 Feb 2020 18:03:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 286AD24656 for ; Fri, 21 Feb 2020 18:03:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="RgE+HdRJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729646AbgBUSDd (ORCPT ); Fri, 21 Feb 2020 13:03:33 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:51876 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728907AbgBUSDd (ORCPT ); Fri, 21 Feb 2020 13:03:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582308212; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R5J393Ux38mLI90fhyfC4Zp3RLoNyH3WwtQ6YbFOpwQ=; b=RgE+HdRJq//LkSUf7i9qwnZYMDXJtfCydnKRA9Gb9qutYr3bXwJ8vZO5Gy0VdrzNL6bR+e 73ff+f2aVgWvv6xfzFw+hrt2YhimgNdQXpMTr18f5obpVAvFKPHsMfRhLY+ABXq9XPwadw NhiOHhtj42x46zEobpGze0u+frM09ls= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-60-JUnbB8tnOwyNZE6-RH-u4g-1; Fri, 21 Feb 2020 13:03:28 -0500 X-MC-Unique: JUnbB8tnOwyNZE6-RH-u4g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 154BF108839B; Fri, 21 Feb 2020 18:03:27 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-122-163.rdu2.redhat.com [10.10.122.163]) by smtp.corp.redhat.com (Postfix) with ESMTP id 310FA909E2; Fri, 21 Feb 2020 18:03:25 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 12/17] fsinfo: Allow the mount topology propogation flags to be retrieved [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:03:24 +0000 Message-ID: <158230820446.2185128.17437159809665554655.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Allow the mount topology propogation flags to be retrieved as part of the FSINFO_ATTR_MOUNT_INFO attributes. Signed-off-by: David Howells --- fs/namespace.c | 7 ++++++- include/uapi/linux/fsinfo.h | 2 +- include/uapi/linux/mount.h | 10 +++++++++- samples/vfs/test-fsinfo.c | 1 + samples/vfs/test-mntinfo.c | 8 ++++---- 5 files changed, 21 insertions(+), 7 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index fc22aea18e2d..bbfd6cd5c501 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -4142,15 +4142,20 @@ int fsinfo_generic_mount_info(struct path *path, struct fsinfo_context *ctx) p->parent_id = p->mnt_id; rcu_read_unlock(); } - if (IS_MNT_SHARED(m)) + if (IS_MNT_SHARED(m)) { p->group_id = m->mnt_group_id; + p->propagation |= MOUNT_PROPAGATION_SHARED; + } if (IS_MNT_SLAVE(m)) { int master = m->mnt_master->mnt_group_id; int dom = get_dominating_id(m, &root); p->master_id = master; if (dom && dom != master) p->from_id = dom; + p->propagation |= MOUNT_PROPAGATION_SLAVE; } + if (IS_MNT_UNBINDABLE(m)) + p->propagation |= MOUNT_PROPAGATION_UNBINDABLE; path_put(&root); flags = READ_ONCE(m->mnt.mnt_flags); diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h index 29940d110ce3..119c371697be 100644 --- a/include/uapi/linux/fsinfo.h +++ b/include/uapi/linux/fsinfo.h @@ -100,7 +100,7 @@ struct fsinfo_mount_info { __u32 from_id; /* Slave propagated from ID */ __u32 attr; /* MOUNT_ATTR_* flags */ __u32 change_counter; /* Number of changes applied. */ - __u32 __reserved[1]; + __u32 propagation; /* MOUNT_PROPAGATION_* flags */ }; #define FSINFO_ATTR_MOUNT_INFO__STRUCT struct fsinfo_mount_info diff --git a/include/uapi/linux/mount.h b/include/uapi/linux/mount.h index 96a0240f23fe..39e50fe9d8d9 100644 --- a/include/uapi/linux/mount.h +++ b/include/uapi/linux/mount.h @@ -105,7 +105,7 @@ enum fsconfig_command { #define FSMOUNT_CLOEXEC 0x00000001 /* - * Mount attributes. + * Mount object attributes (these are separate to filesystem attributes). */ #define MOUNT_ATTR_RDONLY 0x00000001 /* Mount read-only */ #define MOUNT_ATTR_NOSUID 0x00000002 /* Ignore suid and sgid bits */ @@ -117,4 +117,12 @@ enum fsconfig_command { #define MOUNT_ATTR_STRICTATIME 0x00000020 /* - Always perform atime updates */ #define MOUNT_ATTR_NODIRATIME 0x00000080 /* Do not update directory access times */ +/* + * Mount object propogation attributes. + */ +#define MOUNT_PROPAGATION_UNBINDABLE 0x00000001 /* Mount is unbindable */ +#define MOUNT_PROPAGATION_SLAVE 0x00000002 /* Mount is slave */ +#define MOUNT_PROPAGATION_PRIVATE 0x00000000 /* Mount is private (ie. not shared) */ +#define MOUNT_PROPAGATION_SHARED 0x00000004 /* Mount is shared */ + #endif /* _UAPI_LINUX_MOUNT_H */ diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c index f761ded6a52c..6a61f3426982 100644 --- a/samples/vfs/test-fsinfo.c +++ b/samples/vfs/test-fsinfo.c @@ -291,6 +291,7 @@ static void dump_fsinfo_generic_mount_info(void *reply, unsigned int size) printf("\tmnt_id : %x\n", f->mnt_id); printf("\tparent : %x\n", f->parent_id); printf("\tgroup : %x\n", f->group_id); + printf("\tpropag : %x\n", f->propagation); printf("\tattr : %x\n", f->attr); printf("\tchanges : %x\n", f->change_counter); } diff --git a/samples/vfs/test-mntinfo.c b/samples/vfs/test-mntinfo.c index f4d90d0671c5..5a3d6b917447 100644 --- a/samples/vfs/test-mntinfo.c +++ b/samples/vfs/test-mntinfo.c @@ -135,9 +135,9 @@ static void display_mount(unsigned int mnt_id, unsigned int depth, char *path) printf("%*.*s", s, s, ""); sprintf(dev, "%x:%x", ids.f_dev_major, ids.f_dev_minor); - printf("%10u %8x %2x %5s %s", + printf("%10u %8x %2x %x %5s %s", info.mnt_id, info.change_counter, - info.attr, + info.attr, info.propagation, dev, ids.f_fs_name); putchar('\n'); @@ -236,8 +236,8 @@ int main(int argc, char **argv) exit(2); } - printf("MOUNT MOUNT ID CHANGE# AT DEV TYPE\n"); - printf("------------------------------------- ---------- -------- -- ----- --------\n"); + printf("MOUNT MOUNT ID CHANGE# AT P DEV TYPE\n"); + printf("------------------------------------- ---------- -------- -- - ----- --------\n"); display_mount(mnt_id, 0, path); return 0; } From patchwork Fri Feb 21 18:03:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397087 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1A49B1395 for ; Fri, 21 Feb 2020 18:03:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E2F0320722 for ; Fri, 21 Feb 2020 18:03:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AMUzRDWA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729573AbgBUSDk (ORCPT ); Fri, 21 Feb 2020 13:03:40 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:21083 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726423AbgBUSDk (ORCPT ); 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 13/17] fsinfo: Query superblock unique ID and notification counter [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:03:32 +0000 Message-ID: <158230821229.2185128.1448235461648568556.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Provide an fsinfo attribute to query the superblock unique ID and notification counter. The unique ID is placed in notification events and the counted it provided so that the changed superblock can be determined in the event of a notification buffer overrun. This is accessed with: struct fsinfo_params params = { .request = FSINFO_ATTR_SB_NOTIFICATIONS, }; and returns a structure that looks like: struct fsinfo_sb_notifications { __u64 watch_id; __u32 notify_counter; __u32 __reserved[1]; }; Where watch_id is a number uniquely identifying the superblock in notification records and notify_counter is incremented for each superblock notification posted. Signed-off-by: David Howells --- fs/fsinfo.c | 11 +++++++++++ include/uapi/linux/fsinfo.h | 12 ++++++++++++ include/uapi/linux/watch_queue.h | 2 +- samples/vfs/test-fsinfo.c | 10 ++++++++++ 4 files changed, 34 insertions(+), 1 deletion(-) diff --git a/fs/fsinfo.c b/fs/fsinfo.c index e3377842a2c1..4334249339f9 100644 --- a/fs/fsinfo.c +++ b/fs/fsinfo.c @@ -217,6 +217,16 @@ static int fsinfo_generic_volume_id(struct path *path, struct fsinfo_context *ct return fsinfo_string(path->dentry->d_sb->s_id, ctx); } +static int fsinfo_generic_sb_notifications(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_sb_notifications *p = ctx->buffer; + struct super_block *sb = path->dentry->d_sb; + + p->watch_id = sb->s_unique_id; + p->notify_counter = atomic_read(&sb->s_notify_counter); + return sizeof(*p); +} + static const struct fsinfo_attribute fsinfo_common_attributes[] = { FSINFO_VSTRUCT (FSINFO_ATTR_STATFS, fsinfo_generic_statfs), FSINFO_VSTRUCT (FSINFO_ATTR_IDS, fsinfo_generic_ids), @@ -226,6 +236,7 @@ static const struct fsinfo_attribute fsinfo_common_attributes[] = { FSINFO_STRING (FSINFO_ATTR_VOLUME_ID, fsinfo_generic_volume_id), FSINFO_VSTRUCT (FSINFO_ATTR_VOLUME_UUID, fsinfo_generic_volume_uuid), FSINFO_VSTRUCT (FSINFO_ATTR_FEATURES, fsinfo_generic_features), + FSINFO_VSTRUCT (FSINFO_ATTR_SB_NOTIFICATIONS, fsinfo_generic_sb_notifications), FSINFO_LIST (FSINFO_ATTR_FSINFO_ATTRIBUTES, (void *)123UL), FSINFO_VSTRUCT_N(FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO, (void *)123UL), diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h index 119c371697be..2f9280d16293 100644 --- a/include/uapi/linux/fsinfo.h +++ b/include/uapi/linux/fsinfo.h @@ -23,6 +23,7 @@ #define FSINFO_ATTR_VOLUME_UUID 0x06 /* Volume UUID (LE uuid) */ #define FSINFO_ATTR_VOLUME_NAME 0x07 /* Volume name (string) */ #define FSINFO_ATTR_FEATURES 0x08 /* Filesystem features (bits) */ +#define FSINFO_ATTR_SB_NOTIFICATIONS 0x09 /* sb_notify() information */ #define FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO 0x100 /* Information about attr N (for path) */ #define FSINFO_ATTR_FSINFO_ATTRIBUTES 0x101 /* List of supported attrs (for path) */ @@ -286,4 +287,15 @@ struct fsinfo_volume_uuid { #define FSINFO_ATTR_VOLUME_UUID__STRUCT struct fsinfo_volume_uuid +/* + * Information struct for fsinfo(FSINFO_ATTR_SB_NOTIFICATIONS). + */ +struct fsinfo_sb_notifications { + __u64 watch_id; /* Watch ID for superblock. */ + __u32 notify_counter; /* Number of notifications. */ + __u32 __reserved[1]; +}; + +#define FSINFO_ATTR_SB_NOTIFICATIONS__STRUCT struct fsinfo_sb_notifications + #endif /* _UAPI_LINUX_FSINFO_H */ diff --git a/include/uapi/linux/watch_queue.h b/include/uapi/linux/watch_queue.h index e9c37b1ae68d..9ac2ea6f4a75 100644 --- a/include/uapi/linux/watch_queue.h +++ b/include/uapi/linux/watch_queue.h @@ -151,7 +151,7 @@ enum superblock_notification_type { */ struct superblock_notification { struct watch_notification watch; /* WATCH_TYPE_SB_NOTIFY */ - __u64 sb_id; /* 64-bit superblock ID */ + __u64 sb_id; /* 64-bit superblock ID [FSINFO_ATTR_SB_NOTIFICATIONS] */ }; struct superblock_error_notification { diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c index 6a61f3426982..247fae5bbb74 100644 --- a/samples/vfs/test-fsinfo.c +++ b/samples/vfs/test-fsinfo.c @@ -303,6 +303,15 @@ static void dump_fsinfo_generic_mount_child(void *reply, unsigned int size) printf("%8x %8x\n", f->mnt_id, f->change_counter); } +static void dump_fsinfo_generic_sb_notifications(void *reply, unsigned int size) +{ + struct fsinfo_sb_notifications *f = reply; + + printf("\n"); + printf("\twatch_id: %llx\n", (unsigned long long)f->watch_id); + printf("\tnotifs : %llx\n", (unsigned long long)f->notify_counter); +} + static void dump_string(void *reply, unsigned int size) { char *s = reply, *p; @@ -367,6 +376,7 @@ static const struct fsinfo_attribute fsinfo_attributes[] = { FSINFO_STRING (FSINFO_ATTR_VOLUME_ID, fsinfo_generic_volume_id), FSINFO_VSTRUCT (FSINFO_ATTR_VOLUME_UUID, fsinfo_generic_volume_uuid), FSINFO_STRING (FSINFO_ATTR_VOLUME_NAME, fsinfo_generic_volume_name), + FSINFO_VSTRUCT (FSINFO_ATTR_SB_NOTIFICATIONS, fsinfo_generic_sb_notifications), FSINFO_VSTRUCT (FSINFO_ATTR_MOUNT_INFO, fsinfo_generic_mount_info), FSINFO_STRING (FSINFO_ATTR_MOUNT_DEVNAME, fsinfo_generic_mount_devname), From patchwork Fri Feb 21 18:03:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397089 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4F6C792A for ; 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 14/17] fsinfo: Add API documentation [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:03:40 +0000 Message-ID: <158230822028.2185128.5408262159157374165.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add API documentation for fsinfo. Signed-off-by: David Howells --- Documentation/filesystems/fsinfo.rst | 491 ++++++++++++++++++++++++++++++++++ 1 file changed, 491 insertions(+) create mode 100644 Documentation/filesystems/fsinfo.rst diff --git a/Documentation/filesystems/fsinfo.rst b/Documentation/filesystems/fsinfo.rst new file mode 100644 index 000000000000..6283293d3bce --- /dev/null +++ b/Documentation/filesystems/fsinfo.rst @@ -0,0 +1,491 @@ +============================ +Filesystem Information Query +============================ + +The fsinfo() system call allows the querying of filesystem and filesystem +security information beyond what stat(), statx() and statfs() can obtain. It +does not require a file to be opened as does ioctl(). + +fsinfo() may be called with a path, with open file descriptor or a with a mount +object identifier. + +The fsinfo() system call needs to be configured on by enabling: + + "File systems"/"Enable the fsinfo() system call" (CONFIG_FSINFO) + +This document has the following sections: + +.. contents:: :local: + + +Overview +======== + +The fsinfo() system call retrieves one of a number of attributes, the IDs of +which can be found in include/uapi/linux/fsinfo.h:: + + FSINFO_ATTR_STATFS - statfs()-style state + FSINFO_ATTR_IDS - Filesystem IDs + FSINFO_ATTR_LIMITS - Filesystem limits + ... + FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO - Information about an attribute + FSINFO_ATTR_FSINFO_ATTRIBUTES - List of available attributes + ... + FSINFO_ATTR_MOUNT_INFO - Information about the mount topology + ... + +Each attribute can have zero or more values, which can be of one of the +following types: + + * ``VStruct``. This is a structure with a version-dependent length. New + versions of the kernel may append more fields, though they are not + permitted to remove or replace old ones. + + Older applications, expecting an older version of the field, can ask for a + shorter struct and will only get the fields they requested; newer + applications running on an older kernel will get the extra fields they + requested filled with zeros. Either way, the system call returns the size + of the internal struct, regardless of how much data it returned. + + This allows for struct-type fields to be extended in future. + + * ``String``. This is a variable-length string of up to 4096 characters (no + NUL character is included). The returned string will be truncated if the + output buffer is too small. The total size of the string is returned, + regardless of any truncation. + + * ``Opaque``. This is a variable-length blob of indeterminate structure. It + may be up to INT_MAX bytes in size. + + * ``List``. This is a variable-length list of fixed-size structures. The + element size may not vary over time, so the element format must be designed + with care. The maximum length is INT_MAX bytes, though this depends on the + kernel being able to allocate an internal buffer large enough. + +Value type is an inherent propery of an attribute and all the values of an +attribute must be of that type. Each attribute can have a single value, a +sequence of values or a sequence-of-sequences of values. + + +Filesystem API +============== + +If the filesystem wishes to provide a list of queryable attributes, it should +set the table pointer in the superblock:: + + const struct fsinfo_attribute *fsinfo_attributes; + +terminating it with a blank entry. Each entry is a ``struct fsinfo_attribute`` +and these can be created with a set of helper macros:: + + FSINFO_VSTRUCT(A,G) + FSINFO_VSTRUCT_N(A,G) + FSINFO_VSTRUCT_NM(A,G) + FSINFO_STRING(A,G) + FSINFO_STRING_N(A,G) + FSINFO_STRING_NM(A,G) + FSINFO_OPAQUE(A,G) + FSINFO_LIST(A,G) + FSINFO_LIST_N(A,G) + +The names of the macro are a combination of type (vstruct, string, opaque and +list) and an optional qualifier, if the attribute has N values or N lots of M +values. ``A`` is the name of the attribute and ``G`` is a function to get a +value for that attribute. + +For vstruct- and list-type attributes, it is expected that there is a macro +defined with the name ``A##__STRUCT`` that indicates the structure or element +type. + +The get function needs to match the following type:: + + int (*get)(struct path *path, struct fsinfo_context *ctx); + +where "path" indicates the object to be queried and ctx is a context describing +the parameters and the output buffer. The function should return the total +size of the data it would like to produce or an error. + +The parameter struct looks like:: + + struct fsinfo_context { + __u32 requested_attr; + __u32 Nth; + __u32 Mth; + bool want_size_only; + unsigned int buf_size; + unsigned int usage; + void *buffer; + ... + }; + +The fields relevant to the filesystem are as follows: + + * ``requested_attr`` + + Which attribute is being requested. EOPNOTSUPP should be returned if the + attribute is not supported by the filesystem or the LSM. + + * ``Nth`` and ``Mth`` + + Which value of an attribute is being requested. + + For a single-value attribute Nth and Mth will both be 0. + + For a "1D" attribute, Nth will indicate which value and Mth will always + be 0. Take, for example, FSINFO_ATTR_SERVER_NAME - for a network + filesystem, the superblock will be backed by a number of servers. This will + return the name of the Nth server. ENODATA will be returned if Nth goes + beyond the end of the array. + + For a "2D" attribute, Mth will indicate the index in the Nth set of values. + Take, for example, an attribute for a network filesystems that returns + server addresses - each server may have one or more addresses. This could + return the Mth address of the Nth server. ENODATA should be returned if the + Nth set doesn't exist or the Mth element of the Nth set doesn't exist. + + * ``want_size_only`` + + Is set to true if the caller only wants the size of the value so that the + get function doesn't have to make expensive calculations or calls to + retrieve the value. + + * ``buf_size`` + + This indicates the current size of the buffer. For the list type and the + opaque type this will be increased if the current buffer won't hold the + value and the filesystem will be called again. + + * ``usage`` + + This indicates how much of the buffer has been used so far for an list or + opaque type attribute. This is updated by the fsinfo_note_param*() + functions. + + * ``buffer`` + + This points to the output buffer. For struct- and string-type attributes it + will always be big enough; for list- and opaque-type, it will be buf_size in + size and will be resized if the returned size is larger than this. + +To simplify filesystem code, there will always be at least a minimal buffer +available if the ->fsinfo() method gets called - and the filesystem should +always write what it can into the buffer. It's possible that the fsinfo() +system call will then throw the contents away and just return the length. + + +Helper Functions +================ + +The API includes a number of helper functions: + + * ``void fsinfo_set_feature(struct fsinfo_features *ft, + enum fsinfo_feature feature);`` + + This function sets a feature flag. + + * ``void fsinfo_clear_feature(struct fsinfo_features *ft, + enum fsinfo_feature feature);`` + + This function clears a feature flag. + + * ``void fsinfo_set_unix_features(struct fsinfo_features *ft);`` + + Set feature flags appropriate to the features of a standard UNIX filesystem, + such as having numeric UIDS and GIDS; allowing the creation of directories, + symbolic links, hard links, device files, FIFO and socket files; permitting + sparse files; and having access, change and modification times. + + +Attribute Summary +================= + +To summarise the attributes that are defined:: + + Symbolic name Type + ===================================== =============== + FSINFO_ATTR_STATFS vstruct + FSINFO_ATTR_IDS vstruct + FSINFO_ATTR_LIMITS vstruct + FSINFO_ATTR_SUPPORTS vstruct + FSINFO_ATTR_FEATURES vstruct + FSINFO_ATTR_TIMESTAMP_INFO vstruct + FSINFO_ATTR_VOLUME_ID string + FSINFO_ATTR_VOLUME_UUID vstruct + FSINFO_ATTR_VOLUME_NAME string + FSINFO_ATTR_NAME_ENCODING string + FSINFO_ATTR_NAME_CODEPAGE string + FSINFO_ATTR_FSINFO vstruct + FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO vstruct + FSINFO_ATTR_FSINFO_ATTRIBUTES list + FSINFO_ATTR_MOUNT_INFO vstruct + FSINFO_ATTR_MOUNT_DEVNAME string + FSINFO_ATTR_MOUNT_POINT string + FSINFO_ATTR_MOUNT_CHILDREN list + FSINFO_ATTR_AFS_CELL_NAME string + FSINFO_ATTR_AFS_SERVER_NAME N × string + FSINFO_ATTR_AFS_SERVER_ADDRESS N × struct + + +Attribute Catalogue +=================== + +A number of the attributes convey information about a filesystem superblock: + + * ``FSINFO_ATTR_STATFS`` + + This struct-type attribute gives most of the equivalent data to statfs(), + but with all the fields as unconditional 64-bit or 128-bit integers. Note + that static data like IDs that don't change are retrieved with + FSINFO_ATTR_IDS instead. + + Further, superblock flags (such as MS_RDONLY) are not exposed by this + attribute; rather the parameters must be listed and the attributes picked + out from that. + + * ``FSINFO_ATTR_IDS`` + + This struct-type attribute conveys various identifiers used by the target + filesystem. This includes the filesystem name, the NFS filesystem ID, the + superblock ID used in notifications, the filesystem magic type number and + the primary device ID. + + * ``FSINFO_ATTR_LIMITS`` + + This struct-type attribute conveys the limits on various aspects of a + filesystem, such as maximum file, symlink and xattr sizes, maxiumm filename + and xattr name length, maximum number of symlinks, maximum device major and + minor numbers and maximum UID, GID and project ID numbers. + + * ``FSINFO_ATTR_SUPPORTS`` + + This struct-type attribute conveys information about the support the + filesystem has for various UAPI features of a filesystem. This includes + information about which bits are supported in various masks employed by the + statx system call, what FS_IOC_* flags are supported by ioctls and what + DOS/Windows file attribute flags are supported. + + * ``FSINFO_ATTR_TIMESTAMP_INFO`` + + This struct-type attribute conveys information about the resolution and + range of the timestamps available in a filesystem. The resolutions are + given as a mantissa and exponent (resolution = mantissa * 10^exponent + seconds), where the exponent can be negative to indicate a sub-second + resolution (-9 being nanoseconds, for example). + + * ``FSINFO_ATTR_VOLUME_ID`` + + This is a string-type attribute that conveys the superblock identifier for + the volume. By default it will be filled in from the contents of s_id from + the superblock. For a block-based filesystem, for example, this might be + the name of the primary block device. + + * ``FSINFO_ATTR_VOLUME_UUID`` + + This is a struct-type attribute that conveys the UUID identifier for the + volume. By default it will be filled in from the contents of s_uuid from + the superblock. If this doesn't exist, it will be an entirely zeros. + + * ``FSINFO_ATTR_VOLUME_NAME`` + + This is a string-type attribute that conveys the name of the volume. By + default it will return EOPNOTSUPP. For a disk-based filesystem, it might + convey the partition label; for a network-based filesystem, it might convey + the name of the remote volume. + + * ``FSINFO_ATTR_FEATURES`` + + This is a special attribute, being a set of single-bit feature flags, + formatted as struct-type attribute. The meanings of the feature bits are + listed below - see the "Feature Bit Catalogue" section. The feature bits + are grouped numerically into bytes, such that features 0-7 are in byte 0, + 8-15 are in byte 1, 16-23 in byte 2 and so on. + + Any feature bit that's not supported by the kernel will be set to false if + asked for. The highest supported feature can be obtained from attribute + "FSINFO_ATTR_FSINFO". + + +Some attributes give information about fsinfo itself: + + * ``FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO`` + + This struct-type attribute gives metadata about the attribute with the ID + specified by the Nth parameter, including its type, default size and + element size. + + * ``FSINFO_ATTR_FSINFO_ATTRIBUTES`` + + This list-type attribute gives a list of the attribute IDs available at the + point of reference. FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO can then be used to + query each attribute. + + * ``FSINFO_ATTR_FSINFO`` + + This struct-type attribute gives information about the fsinfo() system call + itself, including the maximum number of feature bits supported. + + +Then there are filesystem-specific attributes, e.g.: + + * ``FSINFO_ATTR_AFS_CELL_NAME`` + + This is a string-type attribute that retrieves the AFS cell name of the + target object. + + * ``FSINFO_ATTR_AFS_SERVER_NAME`` + + This is a string-type attribute that conveys the name of the Nth server + backing a network-filesystem superblock. + + * ``FSINFO_ATTR_AFS_SERVER_ADDRESSES`` + + This is a list-type attribute that conveys the Mth address of the Nth + server, as returned by FSINFO_ATTR_SERVER_NAME. + + +Feature Bit Catalogue +===================== + +The feature bits convey single true/false assertions about a specific instance +of a filesystem (ie. a specific superblock). They are accessed using the +"FSINFO_ATTR_FEATURE" attribute: + + * ``FSINFO_FEAT_IS_KERNEL_FS`` + * ``FSINFO_FEAT_IS_BLOCK_FS`` + * ``FSINFO_FEAT_IS_FLASH_FS`` + * ``FSINFO_FEAT_IS_NETWORK_FS`` + * ``FSINFO_FEAT_IS_AUTOMOUNTER_FS`` + * ``FSINFO_FEAT_IS_MEMORY_FS`` + + These indicate what kind of filesystem the target is: kernel API (proc), + block-based (ext4), flash/nvm-based (jffs2), remote over the network (NFS), + local quasi-filesystem that acts as a tray of mountpoints (autofs), plain + in-memory filesystem (shmem). + + * ``FSINFO_FEAT_AUTOMOUNTS`` + + This indicate if a filesystem may have objects that are automount points. + + * ``FSINFO_FEAT_ADV_LOCKS`` + * ``FSINFO_FEAT_MAND_LOCKS`` + * ``FSINFO_FEAT_LEASES`` + + These indicate if a filesystem supports advisory locks, mandatory locks or + leases. + + * ``FSINFO_FEAT_UIDS`` + * ``FSINFO_FEAT_GIDS`` + * ``FSINFO_FEAT_PROJIDS`` + + These indicate if a filesystem supports/stores/transports numeric user IDs, + group IDs or project IDs. The "FSINFO_ATTR_LIMITS" attribute can be used + to find out the upper limits on the IDs values. + + * ``FSINFO_FEAT_STRING_USER_IDS`` + + This indicates if a filesystem supports/stores/transports string user + identifiers. + + * ``FSINFO_FEAT_GUID_USER_IDS`` + + This indicates if a filesystem supports/stores/transports Windows GUIDs as + user identifiers (eg. ntfs). + + * ``FSINFO_FEAT_WINDOWS_ATTRS`` + + This indicates if a filesystem supports Windows FILE_* attribute bits + (eg. cifs, jfs). The "FSINFO_ATTR_SUPPORTS" attribute can be used to find + out which windows file attributes are supported by the filesystem. + + * ``FSINFO_FEAT_USER_QUOTAS`` + * ``FSINFO_FEAT_GROUP_QUOTAS`` + * ``FSINFO_FEAT_PROJECT_QUOTAS`` + + These indicate if a filesystem supports quotas for users, groups or + projects. + + * ``FSINFO_FEAT_XATTRS`` + + These indicate if a filesystem supports extended attributes. The + "FSINFO_ATTR_LIMITS" attribute can be used to find out the upper limits on + the supported name and body lengths. + + * ``FSINFO_FEAT_JOURNAL`` + * ``FSINFO_FEAT_DATA_IS_JOURNALLED`` + + These indicate whether the filesystem has a journal and whether data + changes are logged to it. + + * ``FSINFO_FEAT_O_SYNC`` + * ``FSINFO_FEAT_O_DIRECT`` + + These indicate whether the filesystem supports the O_SYNC and O_DIRECT + flags. + + * ``FSINFO_FEAT_VOLUME_ID`` + * ``FSINFO_FEAT_VOLUME_UUID`` + * ``FSINFO_FEAT_VOLUME_NAME`` + * ``FSINFO_FEAT_VOLUME_FSID`` + + These indicate whether ID, UUID, name and FSID identifiers actually exist + in the filesystem and thus might be considered persistent. + + * ``FSINFO_FEAT_IVER_ALL_CHANGE`` + * ``FSINFO_FEAT_IVER_DATA_CHANGE`` + * ``FSINFO_FEAT_IVER_MONO_INCR`` + + These indicate whether i_version in the inode is supported and, if so, what + mode it operates in. The first two indicate if it's changed for any data + or metadata change, or whether it's only changed for any data changes; the + last indicates whether or not it's monotonically increasing for each such + change. + + * ``FSINFO_FEAT_HARD_LINKS`` + * ``FSINFO_FEAT_HARD_LINKS_1DIR`` + + These indicate whether the filesystem can have hard links made in it, and + whether they can be made between directory or only within the same + directory. + + * ``FSINFO_FEAT_DIRECTORIES`` + * ``FSINFO_FEAT_SYMLINKS`` + * ``FSINFO_FEAT_DEVICE_FILES`` + * ``FSINFO_FEAT_UNIX_SPECIALS`` + + These indicate whether directories; symbolic links; device files; or pipes + and sockets can be made within the filesystem. + + * ``FSINFO_FEAT_RESOURCE_FORKS`` + + This indicates if the filesystem supports resource forks. + + * ``FSINFO_FEAT_NAME_CASE_INDEP`` + * ``FSINFO_FEAT_NAME_NON_UTF8`` + * ``FSINFO_FEAT_NAME_HAS_CODEPAGE`` + + These indicate if the filesystem supports case-independent file names, + whether the filenames are non-utf8 (see the "FSINFO_ATTR_NAME_ENCODING" + attribute) and whether a codepage is in use to transliterate them (see + the "FSINFO_ATTR_NAME_CODEPAGE" attribute). + + * ``FSINFO_FEAT_SPARSE`` + + This indicates if a filesystem supports sparse files. + + * ``FSINFO_FEAT_NOT_PERSISTENT`` + + This indicates if a filesystem is not persistent. + + * ``FSINFO_FEAT_NO_UNIX_MODE`` + + This indicates if a filesystem doesn't support UNIX mode bits (though they + may be manufactured from other bits, such as Windows file attribute flags). + + * ``FSINFO_FEAT_HAS_ATIME`` + * ``FSINFO_FEAT_HAS_BTIME`` + * ``FSINFO_FEAT_HAS_CTIME`` + * ``FSINFO_FEAT_HAS_MTIME`` + + These indicate which timestamps a filesystem supports (access, birth, + change, modify). The range and resolutions can be queried with the + "FSINFO_ATTR_TIMESTAMPS" attribute). 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 15/17] fsinfo: Add support for AFS [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:03:48 +0000 Message-ID: <158230822826.2185128.4823789618200195685.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add fsinfo support to the AFS filesystem. Signed-off-by: David Howells --- fs/afs/internal.h | 1 fs/afs/super.c | 218 +++++++++++++++++++++++++++++++++++++++++++ include/uapi/linux/fsinfo.h | 15 +++ samples/vfs/test-fsinfo.c | 51 ++++++++++ 4 files changed, 283 insertions(+), 2 deletions(-) diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 1d81fc4c3058..b4b2a8a18e9f 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -248,6 +248,7 @@ struct afs_super_info { struct afs_volume *volume; /* volume record */ enum afs_flock_mode flock_mode:8; /* File locking emulation mode */ bool dyn_root; /* True if dynamic root */ + bool autocell; /* True if autocell */ }; static inline struct afs_super_info *AFS_FS_S(struct super_block *sb) diff --git a/fs/afs/super.c b/fs/afs/super.c index dda7a9a66848..969248a192a2 100644 --- a/fs/afs/super.c +++ b/fs/afs/super.c @@ -26,9 +26,13 @@ #include #include #include +#include #include #include "internal.h" +#ifdef CONFIG_FSINFO +static int afs_fsinfo(struct path *path, struct fsinfo_context *ctx); +#endif static void afs_i_init_once(void *foo); static void afs_kill_super(struct super_block *sb); static struct inode *afs_alloc_inode(struct super_block *sb); @@ -54,6 +58,9 @@ int afs_net_id; static const struct super_operations afs_super_ops = { .statfs = afs_statfs, +#ifdef CONFIG_FSINFO + .fsinfo = afs_fsinfo, +#endif .alloc_inode = afs_alloc_inode, .drop_inode = afs_drop_inode, .destroy_inode = afs_destroy_inode, @@ -193,7 +200,7 @@ static int afs_show_options(struct seq_file *m, struct dentry *root) if (as->dyn_root) seq_puts(m, ",dyn"); - if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags)) + if (as->autocell) seq_puts(m, ",autocell"); switch (as->flock_mode) { case afs_flock_mode_unset: break; @@ -458,7 +465,7 @@ static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx) if (IS_ERR(inode)) return PTR_ERR(inode); - if (ctx->autocell || as->dyn_root) + if (as->autocell || as->dyn_root) set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags); ret = -ENOMEM; @@ -498,6 +505,8 @@ static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc) as->cell = afs_get_cell(ctx->cell); as->volume = __afs_get_volume(ctx->volume); } + if (ctx->autocell) + as->autocell = true; } return as; } @@ -760,3 +769,208 @@ static int afs_statfs(struct dentry *dentry, struct kstatfs *buf) return ret; } + +#ifdef CONFIG_FSINFO +static const struct fsinfo_timestamp_info afs_timestamp_info = { + .atime = { + .minimum = 0, + .maximum = UINT_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, + .mtime = { + .minimum = 0, + .maximum = UINT_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, + .ctime = { + .minimum = 0, + .maximum = UINT_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, + .btime = { + .minimum = 0, + .maximum = UINT_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, +}; + +static int afs_fsinfo_get_timestamp(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_timestamp_info *tsinfo = ctx->buffer; + *tsinfo = afs_timestamp_info; + return sizeof(*tsinfo); +} + +static int afs_fsinfo_get_limits(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_limits *lim = ctx->buffer; + + lim->max_file_size.hi = 0; + lim->max_file_size.lo = MAX_LFS_FILESIZE; + /* Inode numbers can be 96-bit on YFS, but that's hard to determine. */ + lim->max_ino.hi = 0; + lim->max_ino.lo = UINT_MAX; + lim->max_hard_links = UINT_MAX; + lim->max_uid = UINT_MAX; + lim->max_gid = UINT_MAX; + lim->max_filename_len = AFSNAMEMAX - 1; + lim->max_symlink_len = AFSPATHMAX - 1; + return sizeof(*lim); +} + +static int afs_fsinfo_get_supports(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_supports *p = ctx->buffer; + + p->stx_mask = (STATX_TYPE | STATX_MODE | + STATX_NLINK | + STATX_UID | STATX_GID | + STATX_MTIME | STATX_INO | + STATX_SIZE); + p->stx_attributes = STATX_ATTR_AUTOMOUNT; + return sizeof(*p); +} + +static int afs_fsinfo_get_features(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_features *p = ctx->buffer; + + fsinfo_set_feature(p, FSINFO_FEAT_IS_NETWORK_FS); + fsinfo_set_feature(p, FSINFO_FEAT_AUTOMOUNTS); + fsinfo_set_feature(p, FSINFO_FEAT_ADV_LOCKS); + fsinfo_set_feature(p, FSINFO_FEAT_UIDS); + fsinfo_set_feature(p, FSINFO_FEAT_GIDS); + fsinfo_set_feature(p, FSINFO_FEAT_VOLUME_ID); + fsinfo_set_feature(p, FSINFO_FEAT_VOLUME_NAME); + fsinfo_set_feature(p, FSINFO_FEAT_IVER_MONO_INCR); + fsinfo_set_feature(p, FSINFO_FEAT_SYMLINKS); + fsinfo_set_feature(p, FSINFO_FEAT_HARD_LINKS_1DIR); + fsinfo_set_feature(p, FSINFO_FEAT_HAS_MTIME); + fsinfo_set_feature(p, FSINFO_FEAT_HAS_INODE_NUMBERS); + return sizeof(*p); +} + +static int afs_dyn_fsinfo_get_features(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_features *p = ctx->buffer; + + fsinfo_set_feature(p, FSINFO_FEAT_IS_AUTOMOUNTER_FS); + fsinfo_set_feature(p, FSINFO_FEAT_AUTOMOUNTS); + return sizeof(*p); +} + +static int afs_fsinfo_get_volume_name(struct path *path, struct fsinfo_context *ctx) +{ + struct afs_super_info *as = AFS_FS_S(path->dentry->d_sb); + struct afs_volume *volume = as->volume; + + memcpy(ctx->buffer, volume->name, volume->name_len); + return volume->name_len; +} + +static int afs_fsinfo_get_cell_name(struct path *path, struct fsinfo_context *ctx) +{ + struct afs_super_info *as = AFS_FS_S(path->dentry->d_sb); + struct afs_cell *cell = as->cell; + + memcpy(ctx->buffer, cell->name, cell->name_len); + return cell->name_len; +} + +static int afs_fsinfo_get_server_name(struct path *path, struct fsinfo_context *ctx) +{ + struct afs_server_list *slist; + struct afs_super_info *as = AFS_FS_S(path->dentry->d_sb); + struct afs_volume *volume = as->volume; + struct afs_server *server; + int ret = -ENODATA; + + read_lock(&volume->servers_lock); + slist = volume->servers; + if (slist) { + if (ctx->Nth < slist->nr_servers) { + server = slist->servers[ctx->Nth].server; + ret = sprintf(ctx->buffer, "%pU", &server->uuid); + } + } + + read_unlock(&volume->servers_lock); + return ret; +} + +static int afs_fsinfo_get_server_address(struct path *path, struct fsinfo_context *ctx) +{ + struct fsinfo_afs_server_address *p = ctx->buffer; + struct afs_server_list *slist; + struct afs_super_info *as = AFS_FS_S(path->dentry->d_sb); + struct afs_addr_list *alist; + struct afs_volume *volume = as->volume; + struct afs_server *server; + struct afs_net *net = afs_d2net(path->dentry); + unsigned int i; + int ret = -ENODATA; + + read_lock(&volume->servers_lock); + slist = afs_get_serverlist(volume->servers); + read_unlock(&volume->servers_lock); + + if (ctx->Nth >= slist->nr_servers) + goto put_slist; + server = slist->servers[ctx->Nth].server; + + read_lock(&server->fs_lock); + alist = afs_get_addrlist(rcu_dereference_protected( + server->addresses, + lockdep_is_held(&server->fs_lock))); + read_unlock(&server->fs_lock); + if (!alist) + goto put_slist; + + ret = alist->nr_addrs * sizeof(*p); + if (ret <= ctx->buf_size) { + for (i = 0; i < alist->nr_addrs; i++) + memcpy(&p[i].address, &alist->addrs[i], + sizeof(struct sockaddr_rxrpc)); + } + + afs_put_addrlist(alist); +put_slist: + afs_put_serverlist(net, slist); + return ret; +} + +static const struct fsinfo_attribute afs_fsinfo_attributes[] = { + FSINFO_VSTRUCT (FSINFO_ATTR_TIMESTAMP_INFO, afs_fsinfo_get_timestamp), + FSINFO_VSTRUCT (FSINFO_ATTR_LIMITS, afs_fsinfo_get_limits), + FSINFO_VSTRUCT (FSINFO_ATTR_SUPPORTS, afs_fsinfo_get_supports), + FSINFO_VSTRUCT (FSINFO_ATTR_FEATURES, afs_fsinfo_get_features), + FSINFO_STRING (FSINFO_ATTR_VOLUME_NAME, afs_fsinfo_get_volume_name), + FSINFO_STRING (FSINFO_ATTR_AFS_CELL_NAME, afs_fsinfo_get_cell_name), + FSINFO_STRING_N (FSINFO_ATTR_AFS_SERVER_NAME, afs_fsinfo_get_server_name), + FSINFO_LIST_N (FSINFO_ATTR_AFS_SERVER_ADDRESSES, afs_fsinfo_get_server_address), + {} +}; + +static const struct fsinfo_attribute afs_dyn_fsinfo_attributes[] = { + FSINFO_VSTRUCT(FSINFO_ATTR_TIMESTAMP_INFO, afs_fsinfo_get_timestamp), + FSINFO_VSTRUCT(FSINFO_ATTR_FEATURES, afs_dyn_fsinfo_get_features), + {} +}; + +static int afs_fsinfo(struct path *path, struct fsinfo_context *ctx) +{ + struct afs_super_info *as = AFS_FS_S(path->dentry->d_sb); + int ret; + + if (as->dyn_root) + ret = fsinfo_get_attribute(path, ctx, afs_dyn_fsinfo_attributes); + else + ret = fsinfo_get_attribute(path, ctx, afs_fsinfo_attributes); + return ret; +} + +#endif /* CONFIG_FSINFO */ diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h index 2f9280d16293..a587b6f9847c 100644 --- a/include/uapi/linux/fsinfo.h +++ b/include/uapi/linux/fsinfo.h @@ -33,6 +33,10 @@ #define FSINFO_ATTR_MOUNT_POINT 0x202 /* Relative path of mount in parent (string) */ #define FSINFO_ATTR_MOUNT_CHILDREN 0x203 /* Children of this mount (list) */ +#define FSINFO_ATTR_AFS_CELL_NAME 0x300 /* AFS cell name (string) */ +#define FSINFO_ATTR_AFS_SERVER_NAME 0x301 /* Name of the Nth server (string) */ +#define FSINFO_ATTR_AFS_SERVER_ADDRESSES 0x302 /* List of addresses of the Nth server */ + /* * Optional fsinfo() parameter structure. * @@ -298,4 +302,15 @@ struct fsinfo_sb_notifications { #define FSINFO_ATTR_SB_NOTIFICATIONS__STRUCT struct fsinfo_sb_notifications +/* + * Information struct for fsinfo(FSINFO_ATTR_AFS_SERVER_ADDRESSES). + * + * Get the addresses of the Nth server for a network filesystem. + */ +struct fsinfo_afs_server_address { + struct __kernel_sockaddr_storage address; +}; + +#define FSINFO_ATTR_AFS_SERVER_ADDRESSES__STRUCT struct fsinfo_afs_server_address + #endif /* _UAPI_LINUX_FSINFO_H */ diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c index 247fae5bbb74..f0dc90fdd49d 100644 --- a/samples/vfs/test-fsinfo.c +++ b/samples/vfs/test-fsinfo.c @@ -23,6 +23,7 @@ #include #include #include +#include #ifndef __NR_fsinfo #define __NR_fsinfo -1 @@ -312,6 +313,50 @@ static void dump_fsinfo_generic_sb_notifications(void *reply, unsigned int size) printf("\tnotifs : %llx\n", (unsigned long long)f->notify_counter); } +static void dump_afs_fsinfo_server_address(void *reply, unsigned int size) +{ + struct fsinfo_afs_server_address *f = reply; + struct sockaddr_storage *ss = (struct sockaddr_storage *)&f->address; + struct sockaddr_rxrpc *srx; + struct sockaddr_in6 *sin6; + struct sockaddr_in *sin; + char proto[32], buf[1024]; + + if (ss->ss_family == AF_RXRPC) { + srx = (struct sockaddr_rxrpc *)ss; + printf("%5u ", srx->srx_service); + switch (srx->transport_type) { + case SOCK_DGRAM: + sprintf(proto, "udp"); + break; + case SOCK_STREAM: + sprintf(proto, "tcp"); + break; + default: + sprintf(proto, "%3u", srx->transport_type); + break; + } + ss = (struct sockaddr_storage *)&srx->transport; + } + + switch (ss->ss_family) { + case AF_INET: + sin = (struct sockaddr_in *)ss; + if (!inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf))) + break; + printf("%5u/%s %s\n", ntohs(sin->sin_port), proto, buf); + return; + case AF_INET6: + sin6 = (struct sockaddr_in6 *)ss; + if (!inet_ntop(AF_INET6, &sin6->sin6_addr, buf, sizeof(buf))) + break; + printf("%5u/%s %s\n", ntohs(sin6->sin6_port), proto, buf); + return; + } + + printf("family=%u\n", ss->ss_family); +} + static void dump_string(void *reply, unsigned int size) { char *s = reply, *p; @@ -341,6 +386,8 @@ static void dump_string(void *reply, unsigned int size) #define dump_fsinfo_generic_volume_name dump_string #define dump_fsinfo_generic_mount_devname dump_string #define dump_fsinfo_generic_mount_point dump_string +#define dump_afs_cell_name dump_string +#define dump_afs_server_name dump_string /* * @@ -382,6 +429,10 @@ static const struct fsinfo_attribute fsinfo_attributes[] = { FSINFO_STRING (FSINFO_ATTR_MOUNT_DEVNAME, fsinfo_generic_mount_devname), FSINFO_LIST (FSINFO_ATTR_MOUNT_CHILDREN, fsinfo_generic_mount_child), FSINFO_STRING_N (FSINFO_ATTR_MOUNT_POINT, fsinfo_generic_mount_point), + + FSINFO_STRING (FSINFO_ATTR_AFS_CELL_NAME, afs_cell_name), + FSINFO_STRING (FSINFO_ATTR_AFS_SERVER_NAME, afs_server_name), + FSINFO_LIST_N (FSINFO_ATTR_AFS_SERVER_ADDRESSES, afs_fsinfo_server_address), {} }; 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 16/17] fsinfo: Add example support for Ext4 [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:03:56 +0000 Message-ID: <158230823604.2185128.8555422827729144419.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add the ability to list some Ext4 volume timestamps as an example. Signed-off-by: David Howells cc: linux-ext4@vger.kernel.org --- fs/ext4/Makefile | 1 + fs/ext4/ext4.h | 6 ++++++ fs/ext4/fsinfo.c | 45 +++++++++++++++++++++++++++++++++++++++++++ fs/ext4/super.c | 3 +++ include/uapi/linux/fsinfo.h | 16 +++++++++++++++ samples/vfs/test-fsinfo.c | 35 +++++++++++++++++++++++++++++++++ 6 files changed, 106 insertions(+) create mode 100644 fs/ext4/fsinfo.c diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile index 4ccb3c9189d8..71d5b460c7c7 100644 --- a/fs/ext4/Makefile +++ b/fs/ext4/Makefile @@ -16,3 +16,4 @@ ext4-$(CONFIG_EXT4_FS_SECURITY) += xattr_security.o ext4-inode-test-objs += inode-test.o obj-$(CONFIG_EXT4_KUNIT_TESTS) += ext4-inode-test.o ext4-$(CONFIG_FS_VERITY) += verity.o +ext4-$(CONFIG_FSINFO) += fsinfo.o diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 9a2ee2428ecc..461968a87cd6 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -42,6 +42,7 @@ #include #include +#include #include @@ -3166,6 +3167,11 @@ extern const struct inode_operations ext4_file_inode_operations; extern const struct file_operations ext4_file_operations; extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin); +/* fsinfo.c */ +#ifdef CONFIG_FSINFO +extern int ext4_fsinfo(struct path *path, struct fsinfo_context *ctx); +#endif + /* inline.c */ extern int ext4_get_max_inline_size(struct inode *inode); extern int ext4_find_inline_data_nolock(struct inode *inode); diff --git a/fs/ext4/fsinfo.c b/fs/ext4/fsinfo.c new file mode 100644 index 000000000000..785f82a74dc9 --- /dev/null +++ b/fs/ext4/fsinfo.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Filesystem information for ext4 + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include "ext4.h" + +static int ext4_fsinfo_get_volume_name(struct path *path, struct fsinfo_context *ctx) +{ + const struct ext4_sb_info *sbi = EXT4_SB(path->mnt->mnt_sb); + const struct ext4_super_block *es = sbi->s_es; + + memcpy(ctx->buffer, es->s_volume_name, sizeof(es->s_volume_name)); + return strlen(ctx->buffer); +} + +static int ext4_fsinfo_get_timestamps(struct path *path, struct fsinfo_context *ctx) +{ + const struct ext4_sb_info *sbi = EXT4_SB(path->mnt->mnt_sb); + const struct ext4_super_block *es = sbi->s_es; + struct fsinfo_ext4_timestamps *ts = ctx->buffer; + +#define Z(R,S) R = S | (((u64)S##_hi) << 32) + Z(ts->mkfs_time, es->s_mkfs_time); + Z(ts->mount_time, es->s_mtime); + Z(ts->write_time, es->s_wtime); + Z(ts->last_check_time, es->s_lastcheck); + Z(ts->first_error_time, es->s_first_error_time); + Z(ts->last_error_time, es->s_last_error_time); + return sizeof(*ts); +} + +static const struct fsinfo_attribute ext4_fsinfo_attributes[] = { + FSINFO_STRING (FSINFO_ATTR_VOLUME_NAME, ext4_fsinfo_get_volume_name), + FSINFO_VSTRUCT (FSINFO_ATTR_EXT4_TIMESTAMPS, ext4_fsinfo_get_timestamps), + {} +}; + +int ext4_fsinfo(struct path *path, struct fsinfo_context *ctx) +{ + return fsinfo_get_attribute(path, ctx, ext4_fsinfo_attributes); +} diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 8434217549b3..02b4df073c4b 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1477,6 +1477,9 @@ static const struct super_operations ext4_sops = { .freeze_fs = ext4_freeze, .unfreeze_fs = ext4_unfreeze, .statfs = ext4_statfs, +#ifdef CONFIG_FSINFO + .fsinfo = ext4_fsinfo, +#endif .remount_fs = ext4_remount, .show_options = ext4_show_options, #ifdef CONFIG_QUOTA diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h index a587b6f9847c..6a8a7a8e4910 100644 --- a/include/uapi/linux/fsinfo.h +++ b/include/uapi/linux/fsinfo.h @@ -37,6 +37,8 @@ #define FSINFO_ATTR_AFS_SERVER_NAME 0x301 /* Name of the Nth server (string) */ #define FSINFO_ATTR_AFS_SERVER_ADDRESSES 0x302 /* List of addresses of the Nth server */ +#define FSINFO_ATTR_EXT4_TIMESTAMPS 0x400 /* Ext4 superblock timestamps */ + /* * Optional fsinfo() parameter structure. * @@ -313,4 +315,18 @@ struct fsinfo_afs_server_address { #define FSINFO_ATTR_AFS_SERVER_ADDRESSES__STRUCT struct fsinfo_afs_server_address +/* + * Information struct for fsinfo(FSINFO_ATTR_EXT4_TIMESTAMPS). + */ +struct fsinfo_ext4_timestamps { + __u64 mkfs_time; + __u64 mount_time; + __u64 write_time; + __u64 last_check_time; + __u64 first_error_time; + __u64 last_error_time; +}; + +#define FSINFO_ATTR_EXT4_TIMESTAMPS__STRUCT struct fsinfo_ext4_timestamps + #endif /* _UAPI_LINUX_FSINFO_H */ diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c index f0dc90fdd49d..df8d2449fc22 100644 --- a/samples/vfs/test-fsinfo.c +++ b/samples/vfs/test-fsinfo.c @@ -357,6 +357,40 @@ static void dump_afs_fsinfo_server_address(void *reply, unsigned int size) printf("family=%u\n", ss->ss_family); } +static char *dump_ext4_time(char *buffer, time_t tim) +{ + struct tm tm; + int len; + + if (tim == 0) + return "-"; + + if (!localtime_r(&tim, &tm)) { + perror("localtime_r"); + exit(1); + } + len = strftime(buffer, 100, "%F %T", &tm); + if (len == 0) { + perror("strftime"); + exit(1); + } + return buffer; +} + +static void dump_ext4_fsinfo_timestamps(void *reply, unsigned int size) +{ + struct fsinfo_ext4_timestamps *r = reply; + char buffer[100]; + + printf("\n"); + printf("\tmkfs : %s\n", dump_ext4_time(buffer, r->mkfs_time)); + printf("\tmount : %s\n", dump_ext4_time(buffer, r->mount_time)); + printf("\twrite : %s\n", dump_ext4_time(buffer, r->write_time)); + printf("\tfsck : %s\n", dump_ext4_time(buffer, r->last_check_time)); + printf("\t1st-err : %s\n", dump_ext4_time(buffer, r->first_error_time)); + printf("\tlast-err: %s\n", dump_ext4_time(buffer, r->last_error_time)); +} + static void dump_string(void *reply, unsigned int size) { char *s = reply, *p; @@ -433,6 +467,7 @@ static const struct fsinfo_attribute fsinfo_attributes[] = { FSINFO_STRING (FSINFO_ATTR_AFS_CELL_NAME, afs_cell_name), FSINFO_STRING (FSINFO_ATTR_AFS_SERVER_NAME, afs_server_name), FSINFO_LIST_N (FSINFO_ATTR_AFS_SERVER_ADDRESSES, afs_fsinfo_server_address), + FSINFO_VSTRUCT (FSINFO_ATTR_EXT4_TIMESTAMPS, ext4_fsinfo_timestamps), {} }; From patchwork Fri Feb 21 18:04:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11397095 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EE5AF92A for ; 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 17/17] fsinfo: Add example support for NFS [ver #17] From: David Howells To: viro@zeniv.linux.org.uk Cc: dhowells@redhat.com, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, jannh@google.com, darrick.wong@oracle.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 21 Feb 2020 18:04:03 +0000 Message-ID: <158230824387.2185128.15121791656930144608.stgit@warthog.procyon.org.uk> In-Reply-To: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> References: <158230810644.2185128.16726948836367716086.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.21 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add the ability to list NFS server addresses and hostname, timestamp information and capabilities as an example. Signed-off-by: David Howells cc: linux-nfs@vger.kernel.org --- fs/nfs/Makefile | 1 fs/nfs/fsinfo.c | 230 ++++++++++++++++++++++++++++++++++++++++++ fs/nfs/internal.h | 6 + fs/nfs/nfs4super.c | 3 + fs/nfs/super.c | 3 + include/uapi/linux/fsinfo.h | 29 +++++ include/uapi/linux/windows.h | 35 ++++++ samples/vfs/test-fsinfo.c | 40 +++++++ 8 files changed, 347 insertions(+) create mode 100644 fs/nfs/fsinfo.c create mode 100644 include/uapi/linux/windows.h diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile index 2433c3e03cfa..20fbc9596833 100644 --- a/fs/nfs/Makefile +++ b/fs/nfs/Makefile @@ -13,6 +13,7 @@ nfs-y := client.o dir.o file.o getroot.o inode.o super.o \ nfs-$(CONFIG_ROOT_NFS) += nfsroot.o nfs-$(CONFIG_SYSCTL) += sysctl.o nfs-$(CONFIG_NFS_FSCACHE) += fscache.o fscache-index.o +nfs-$(CONFIG_FSINFO) += fsinfo.o obj-$(CONFIG_NFS_V2) += nfsv2.o nfsv2-y := nfs2super.o proc.o nfs2xdr.o diff --git a/fs/nfs/fsinfo.c b/fs/nfs/fsinfo.c new file mode 100644 index 000000000000..a0299ec27efd --- /dev/null +++ b/fs/nfs/fsinfo.c @@ -0,0 +1,230 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Filesystem information for NFS + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include "internal.h" + +static const struct fsinfo_timestamp_info nfs_timestamp_info = { + .atime = { + .minimum = 0, + .maximum = UINT_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, + .mtime = { + .minimum = 0, + .maximum = UINT_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, + .ctime = { + .minimum = 0, + .maximum = UINT_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, + .btime = { + .minimum = 0, + .maximum = UINT_MAX, + .gran_mantissa = 1, + .gran_exponent = 0, + }, +}; + +static int nfs_fsinfo_get_timestamp_info(struct path *path, struct fsinfo_context *ctx) +{ + const struct nfs_server *server = NFS_SB(path->dentry->d_sb); + struct fsinfo_timestamp_info *r = ctx->buffer; + unsigned long long nsec; + unsigned int rem, mant; + int exp = -9; + + *r = nfs_timestamp_info; + + nsec = server->time_delta.tv_nsec; + nsec += server->time_delta.tv_sec * 1000000000ULL; + if (nsec == 0) + goto out; + + do { + mant = nsec; + rem = do_div(nsec, 10); + if (rem) + break; + exp++; + } while (nsec); + + r->atime.gran_mantissa = mant; + r->atime.gran_exponent = exp; + r->btime.gran_mantissa = mant; + r->btime.gran_exponent = exp; + r->ctime.gran_mantissa = mant; + r->ctime.gran_exponent = exp; + r->mtime.gran_mantissa = mant; + r->mtime.gran_exponent = exp; + +out: + return sizeof(*r); +} + +static int nfs_fsinfo_get_info(struct path *path, struct fsinfo_context *ctx) +{ + const struct nfs_server *server = NFS_SB(path->dentry->d_sb); + const struct nfs_client *clp = server->nfs_client; + struct fsinfo_nfs_info *r = ctx->buffer; + + r->version = clp->rpc_ops->version; + r->minor_version = clp->cl_minorversion; + r->transport_proto = clp->cl_proto; + return sizeof(*r); +} + +static int nfs_fsinfo_get_server_name(struct path *path, struct fsinfo_context *ctx) +{ + const struct nfs_server *server = NFS_SB(path->dentry->d_sb); + const struct nfs_client *clp = server->nfs_client; + + return fsinfo_string(clp->cl_hostname, ctx); +} + +static int nfs_fsinfo_get_server_addresses(struct path *path, struct fsinfo_context *ctx) +{ + const struct nfs_server *server = NFS_SB(path->dentry->d_sb); + const struct nfs_client *clp = server->nfs_client; + struct fsinfo_nfs_server_address *addr = ctx->buffer; + int ret; + + ret = 1 * sizeof(*addr); + if (ret <= ctx->buf_size) + memcpy(&addr[0].address, &clp->cl_addr, clp->cl_addrlen); + return ret; + +} + +static int nfs_fsinfo_get_gssapi_name(struct path *path, struct fsinfo_context *ctx) +{ + const struct nfs_server *server = NFS_SB(path->dentry->d_sb); + const struct nfs_client *clp = server->nfs_client; + + return fsinfo_string(clp->cl_acceptor, ctx); +} + +static int nfs_fsinfo_get_limits(struct path *path, struct fsinfo_context *ctx) +{ + const struct nfs_server *server = NFS_SB(path->dentry->d_sb); + struct fsinfo_limits *lim = ctx->buffer; + + lim->max_file_size.hi = 0; + lim->max_file_size.lo = server->maxfilesize; + lim->max_ino.hi = 0; + lim->max_ino.lo = U64_MAX; + lim->max_hard_links = UINT_MAX; + lim->max_uid = UINT_MAX; + lim->max_gid = UINT_MAX; + lim->max_filename_len = NAME_MAX - 1; + lim->max_symlink_len = PATH_MAX - 1; + return sizeof(*lim); +} + +static int nfs_fsinfo_get_supports(struct path *path, struct fsinfo_context *ctx) +{ + const struct nfs_server *server = NFS_SB(path->dentry->d_sb); + struct fsinfo_supports *sup = ctx->buffer; + + /* Don't set STATX_INO as i_ino is fabricated and may not be unique. */ + + if (!(server->caps & NFS_CAP_MODE)) + sup->stx_mask |= STATX_TYPE | STATX_MODE; + if (server->caps & NFS_CAP_OWNER) + sup->stx_mask |= STATX_UID; + if (server->caps & NFS_CAP_OWNER_GROUP) + sup->stx_mask |= STATX_GID; + if (server->caps & NFS_CAP_ATIME) + sup->stx_mask |= STATX_ATIME; + if (server->caps & NFS_CAP_CTIME) + sup->stx_mask |= STATX_CTIME; + if (server->caps & NFS_CAP_MTIME) + sup->stx_mask |= STATX_MTIME; + if (server->attr_bitmask[0] & FATTR4_WORD0_SIZE) + sup->stx_mask |= STATX_SIZE; + if (server->attr_bitmask[1] & FATTR4_WORD1_NUMLINKS) + sup->stx_mask |= STATX_NLINK; + + if (server->attr_bitmask[0] & FATTR4_WORD0_ARCHIVE) + sup->win_file_attrs |= ATTR_ARCHIVE; + if (server->attr_bitmask[0] & FATTR4_WORD0_HIDDEN) + sup->win_file_attrs |= ATTR_HIDDEN; + if (server->attr_bitmask[1] & FATTR4_WORD1_SYSTEM) + sup->win_file_attrs |= ATTR_SYSTEM; + + sup->stx_attributes = STATX_ATTR_AUTOMOUNT; + return sizeof(*sup); +} + +static int nfs_fsinfo_get_features(struct path *path, struct fsinfo_context *ctx) +{ + const struct nfs_server *server = NFS_SB(path->dentry->d_sb); + struct fsinfo_features *ft = ctx->buffer; + + fsinfo_set_feature(ft, FSINFO_FEAT_IS_NETWORK_FS); + fsinfo_set_feature(ft, FSINFO_FEAT_AUTOMOUNTS); + fsinfo_set_feature(ft, FSINFO_FEAT_O_SYNC); + fsinfo_set_feature(ft, FSINFO_FEAT_O_DIRECT); + fsinfo_set_feature(ft, FSINFO_FEAT_ADV_LOCKS); + fsinfo_set_feature(ft, FSINFO_FEAT_DEVICE_FILES); + fsinfo_set_feature(ft, FSINFO_FEAT_UNIX_SPECIALS); + if (server->nfs_client->rpc_ops->version == 4) { + fsinfo_set_feature(ft, FSINFO_FEAT_LEASES); + fsinfo_set_feature(ft, FSINFO_FEAT_IVER_ALL_CHANGE); + } + + if (server->caps & NFS_CAP_OWNER) + fsinfo_set_feature(ft, FSINFO_FEAT_UIDS); + if (server->caps & NFS_CAP_OWNER_GROUP) + fsinfo_set_feature(ft, FSINFO_FEAT_GIDS); + if (!(server->caps & NFS_CAP_MODE)) + fsinfo_set_feature(ft, FSINFO_FEAT_NO_UNIX_MODE); + if (server->caps & NFS_CAP_ACLS) + fsinfo_set_feature(ft, FSINFO_FEAT_HAS_ACL); + if (server->caps & NFS_CAP_SYMLINKS) + fsinfo_set_feature(ft, FSINFO_FEAT_SYMLINKS); + if (server->caps & NFS_CAP_HARDLINKS) + fsinfo_set_feature(ft, FSINFO_FEAT_HARD_LINKS); + if (server->caps & NFS_CAP_ATIME) + fsinfo_set_feature(ft, FSINFO_FEAT_HAS_ATIME); + if (server->caps & NFS_CAP_CTIME) + fsinfo_set_feature(ft, FSINFO_FEAT_HAS_CTIME); + if (server->caps & NFS_CAP_MTIME) + fsinfo_set_feature(ft, FSINFO_FEAT_HAS_MTIME); + + if (server->attr_bitmask[0] & FATTR4_WORD0_CASE_INSENSITIVE) + fsinfo_set_feature(ft, FSINFO_FEAT_NAME_CASE_INDEP); + if ((server->attr_bitmask[0] & FATTR4_WORD0_ARCHIVE) || + (server->attr_bitmask[0] & FATTR4_WORD0_HIDDEN) || + (server->attr_bitmask[1] & FATTR4_WORD1_SYSTEM)) + fsinfo_set_feature(ft, FSINFO_FEAT_WINDOWS_ATTRS); + + return sizeof(*ft); +} + +static const struct fsinfo_attribute nfs_fsinfo_attributes[] = { + FSINFO_VSTRUCT (FSINFO_ATTR_TIMESTAMP_INFO, nfs_fsinfo_get_timestamp_info), + FSINFO_VSTRUCT (FSINFO_ATTR_LIMITS, nfs_fsinfo_get_limits), + FSINFO_VSTRUCT (FSINFO_ATTR_SUPPORTS, nfs_fsinfo_get_supports), + FSINFO_VSTRUCT (FSINFO_ATTR_FEATURES, nfs_fsinfo_get_features), + FSINFO_VSTRUCT (FSINFO_ATTR_NFS_INFO, nfs_fsinfo_get_info), + FSINFO_STRING (FSINFO_ATTR_NFS_SERVER_NAME, nfs_fsinfo_get_server_name), + FSINFO_LIST (FSINFO_ATTR_NFS_SERVER_ADDRESSES, nfs_fsinfo_get_server_addresses), + FSINFO_STRING (FSINFO_ATTR_NFS_GSSAPI_NAME, nfs_fsinfo_get_gssapi_name), + {} +}; + +int nfs_fsinfo(struct path *path, struct fsinfo_context *ctx) +{ + return fsinfo_get_attribute(path, ctx, nfs_fsinfo_attributes); +} diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index f80c47d5ff27..59e407066b45 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -10,6 +10,7 @@ #include #include #include +#include #define NFS_SB_MASK (SB_RDONLY|SB_NOSUID|SB_NODEV|SB_NOEXEC|SB_SYNCHRONOUS) @@ -247,6 +248,11 @@ extern const struct svc_version nfs4_callback_version4; /* fs_context.c */ extern struct file_system_type nfs_fs_type; +/* fsinfo.c */ +#ifdef CONFIG_FSINFO +extern int nfs_fsinfo(struct path *path, struct fsinfo_context *ctx); +#endif + /* pagelist.c */ extern int __init nfs_init_nfspagecache(void); extern void nfs_destroy_nfspagecache(void); diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c index 1475f932d7da..cd38da87cbd3 100644 --- a/fs/nfs/nfs4super.c +++ b/fs/nfs/nfs4super.c @@ -26,6 +26,9 @@ static const struct super_operations nfs4_sops = { .write_inode = nfs4_write_inode, .drop_inode = nfs_drop_inode, .statfs = nfs_statfs, +#ifdef CONFIG_FSINFO + .fsinfo = nfs_fsinfo, +#endif .evict_inode = nfs4_evict_inode, .umount_begin = nfs_umount_begin, .show_options = nfs_show_options, diff --git a/fs/nfs/super.c b/fs/nfs/super.c index dada09b391c6..27ac751d3789 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -76,6 +76,9 @@ const struct super_operations nfs_sops = { .write_inode = nfs_write_inode, .drop_inode = nfs_drop_inode, .statfs = nfs_statfs, +#ifdef CONFIG_FSINFO + .fsinfo = nfs_fsinfo, +#endif .evict_inode = nfs_evict_inode, .umount_begin = nfs_umount_begin, .show_options = nfs_show_options, diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h index 6a8a7a8e4910..d5c4fe681333 100644 --- a/include/uapi/linux/fsinfo.h +++ b/include/uapi/linux/fsinfo.h @@ -39,6 +39,11 @@ #define FSINFO_ATTR_EXT4_TIMESTAMPS 0x400 /* Ext4 superblock timestamps */ +#define FSINFO_ATTR_NFS_INFO 0x500 /* Information about an NFS mount */ +#define FSINFO_ATTR_NFS_SERVER_NAME 0x501 /* Name of the server (string) */ +#define FSINFO_ATTR_NFS_SERVER_ADDRESSES 0x502 /* List of addresses of the server */ +#define FSINFO_ATTR_NFS_GSSAPI_NAME 0x503 /* GSSAPI acceptor name */ + /* * Optional fsinfo() parameter structure. * @@ -329,4 +334,28 @@ struct fsinfo_ext4_timestamps { #define FSINFO_ATTR_EXT4_TIMESTAMPS__STRUCT struct fsinfo_ext4_timestamps +/* + * Information struct for fsinfo(FSINFO_ATTR_NFS_INFO). + * + * Get information about an NFS mount. + */ +struct fsinfo_nfs_info { + __u32 version; + __u32 minor_version; + __u32 transport_proto; +}; + +#define FSINFO_ATTR_NFS_INFO__STRUCT struct fsinfo_nfs_info + +/* + * Information struct for fsinfo(FSINFO_ATTR_NFS_SERVER_ADDRESSES). + * + * Get the addresses of the server for an NFS mount. + */ +struct fsinfo_nfs_server_address { + struct __kernel_sockaddr_storage address; +}; + +#define FSINFO_ATTR_NFS_SERVER_ADDRESSES__STRUCT struct fsinfo_nfs_server_address + #endif /* _UAPI_LINUX_FSINFO_H */ diff --git a/include/uapi/linux/windows.h b/include/uapi/linux/windows.h new file mode 100644 index 000000000000..17efb9a40529 --- /dev/null +++ b/include/uapi/linux/windows.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * Common windows attributes + */ +#ifndef _UAPI_LINUX_WINDOWS_H +#define _UAPI_LINUX_WINDOWS_H + +/* + * File Attribute flags + */ +#define ATTR_READONLY 0x0001 +#define ATTR_HIDDEN 0x0002 +#define ATTR_SYSTEM 0x0004 +#define ATTR_VOLUME 0x0008 +#define ATTR_DIRECTORY 0x0010 +#define ATTR_ARCHIVE 0x0020 +#define ATTR_DEVICE 0x0040 +#define ATTR_NORMAL 0x0080 +#define ATTR_TEMPORARY 0x0100 +#define ATTR_SPARSE 0x0200 +#define ATTR_REPARSE 0x0400 +#define ATTR_COMPRESSED 0x0800 +#define ATTR_OFFLINE 0x1000 /* ie file not immediately available - + on offline storage */ +#define ATTR_NOT_CONTENT_INDEXED 0x2000 +#define ATTR_ENCRYPTED 0x4000 +#define ATTR_POSIX_SEMANTICS 0x01000000 +#define ATTR_BACKUP_SEMANTICS 0x02000000 +#define ATTR_DELETE_ON_CLOSE 0x04000000 +#define ATTR_SEQUENTIAL_SCAN 0x08000000 +#define ATTR_RANDOM_ACCESS 0x10000000 +#define ATTR_NO_BUFFERING 0x20000000 +#define ATTR_WRITE_THROUGH 0x80000000 + +#endif /* _UAPI_LINUX_WINDOWS_H */ diff --git a/samples/vfs/test-fsinfo.c b/samples/vfs/test-fsinfo.c index df8d2449fc22..87239f0b6a50 100644 --- a/samples/vfs/test-fsinfo.c +++ b/samples/vfs/test-fsinfo.c @@ -391,6 +391,40 @@ static void dump_ext4_fsinfo_timestamps(void *reply, unsigned int size) printf("\tlast-err: %s\n", dump_ext4_time(buffer, r->last_error_time)); } +static void dump_nfs_fsinfo_info(void *reply, unsigned int size) +{ + struct fsinfo_nfs_info *r = reply; + + printf("ver=%u.%u proto=%u\n", r->version, r->minor_version, r->transport_proto); +} + +static void dump_nfs_fsinfo_server_addresses(void *reply, unsigned int size) +{ + struct fsinfo_nfs_server_address *r = reply; + struct sockaddr_storage *ss = (struct sockaddr_storage *)&r->address; + struct sockaddr_in6 *sin6; + struct sockaddr_in *sin; + char buf[1024]; + + switch (ss->ss_family) { + case AF_INET: + sin = (struct sockaddr_in *)ss; + if (!inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf))) + break; + printf("%5u %s\n", ntohs(sin->sin_port), buf); + return; + case AF_INET6: + sin6 = (struct sockaddr_in6 *)ss; + if (!inet_ntop(AF_INET6, &sin6->sin6_addr, buf, sizeof(buf))) + break; + printf("%5u %s\n", ntohs(sin6->sin6_port), buf); + return; + default: + printf("family=%u\n", ss->ss_family); + return; + } +} + static void dump_string(void *reply, unsigned int size) { char *s = reply, *p; @@ -422,6 +456,8 @@ static void dump_string(void *reply, unsigned int size) #define dump_fsinfo_generic_mount_point dump_string #define dump_afs_cell_name dump_string #define dump_afs_server_name dump_string +#define dump_nfs_fsinfo_server_name dump_string +#define dump_nfs_fsinfo_gssapi_name dump_string /* * @@ -468,6 +504,10 @@ static const struct fsinfo_attribute fsinfo_attributes[] = { FSINFO_STRING (FSINFO_ATTR_AFS_SERVER_NAME, afs_server_name), FSINFO_LIST_N (FSINFO_ATTR_AFS_SERVER_ADDRESSES, afs_fsinfo_server_address), FSINFO_VSTRUCT (FSINFO_ATTR_EXT4_TIMESTAMPS, ext4_fsinfo_timestamps), + FSINFO_VSTRUCT (FSINFO_ATTR_NFS_INFO, nfs_fsinfo_info), + FSINFO_STRING (FSINFO_ATTR_NFS_SERVER_NAME, nfs_fsinfo_server_name), + FSINFO_LIST (FSINFO_ATTR_NFS_SERVER_ADDRESSES, nfs_fsinfo_server_addresses), + FSINFO_STRING (FSINFO_ATTR_NFS_GSSAPI_NAME, nfs_fsinfo_gssapi_name), {} };