From patchwork Sat Apr 22 08:40:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dominique Martinet X-Patchwork-Id: 13220924 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C08D1C6FD18 for ; Sat, 22 Apr 2023 08:40:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229683AbjDVIky (ORCPT ); Sat, 22 Apr 2023 04:40:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229556AbjDVIkx (ORCPT ); Sat, 22 Apr 2023 04:40:53 -0400 Received: from nautica.notk.org (ipv6.notk.org [IPv6:2001:41d0:1:7a93::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9934419A8; Sat, 22 Apr 2023 01:40:49 -0700 (PDT) Received: by nautica.notk.org (Postfix, from userid 108) id CB667C01A; Sat, 22 Apr 2023 10:40:47 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codewreck.org; s=2; t=1682152847; bh=RA6UWL31G5rZTzHkX1AYBBgu9w7TFJ4fnvpZQaj5+Mg=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=JmbiAsZSL/seMxU/J7XKeeofqV9+ITvc76e6ns1Zep0ZpfmPlEUbq456d+FRRK9ma yZ1w0QeMcGCpTM3z5yK+x/3vJ8V9zU6j3vOBaFae/NNsk7ZtfZcspWLBbTI+Cm2+v8 jVFWL45gQhnDBB9aK0fOI0iJD5ZYXf6iDJiTFdeo+ViNTz3K13JgkeaZ96x1otjKyH YK+jL2yvRDP/wMhcVfwHi/I48nXg1zCmMUa1WG4SK357UaxyOcEPuzbwG35i5OZwh6 JFRBbmlVKZPZg0xNqMArYFOH6B4LHoaYovl5zwpXpcN9i1ApRzaC6v7rN5qm2yaz+P QquFIFMEyS/8g== Received: from odin.codewreck.org (localhost [127.0.0.1]) by nautica.notk.org (Postfix) with ESMTPS id CEDF1C009; Sat, 22 Apr 2023 10:40:42 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codewreck.org; s=2; t=1682152847; bh=RA6UWL31G5rZTzHkX1AYBBgu9w7TFJ4fnvpZQaj5+Mg=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=JmbiAsZSL/seMxU/J7XKeeofqV9+ITvc76e6ns1Zep0ZpfmPlEUbq456d+FRRK9ma yZ1w0QeMcGCpTM3z5yK+x/3vJ8V9zU6j3vOBaFae/NNsk7ZtfZcspWLBbTI+Cm2+v8 jVFWL45gQhnDBB9aK0fOI0iJD5ZYXf6iDJiTFdeo+ViNTz3K13JgkeaZ96x1otjKyH YK+jL2yvRDP/wMhcVfwHi/I48nXg1zCmMUa1WG4SK357UaxyOcEPuzbwG35i5OZwh6 JFRBbmlVKZPZg0xNqMArYFOH6B4LHoaYovl5zwpXpcN9i1ApRzaC6v7rN5qm2yaz+P QquFIFMEyS/8g== Received: from [127.0.0.2] (localhost [::1]) by odin.codewreck.org (OpenSMTPD) with ESMTP id e1be628b; Sat, 22 Apr 2023 08:40:36 +0000 (UTC) From: Dominique Martinet Date: Sat, 22 Apr 2023 17:40:18 +0900 Subject: [PATCH RFC 1/2] fs: split off vfs_getdents function of getdents64 syscall MIME-Version: 1.0 Message-Id: <20230422-uring-getdents-v1-1-14c1db36e98c@codewreck.org> References: <20230422-uring-getdents-v1-0-14c1db36e98c@codewreck.org> In-Reply-To: <20230422-uring-getdents-v1-0-14c1db36e98c@codewreck.org> To: Alexander Viro , Christian Brauner , Jens Axboe , Pavel Begunkov , Stefan Roesch Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, Dominique Martinet X-Mailer: b4 0.13-dev-f371f X-Developer-Signature: v=1; a=openpgp-sha256; l=2445; i=asmadeus@codewreck.org; h=from:subject:message-id; bh=Gh7fdCatlZczIf9VabQSU+kiFAoMRFxRCv7HGXEYR3E=; b=owEBbQKS/ZANAwAIAatOm+xqmOZwAcsmYgBkQ52ENkniSXAAbmVN2Twl1R208JYpAVJA4z6+I RdAmroz4/OJAjMEAAEIAB0WIQT8g9txgG5a3TOhiE6rTpvsapjmcAUCZEOdhAAKCRCrTpvsapjm cLzeD/9lgmYuQM4qeN4s0UrUXOrMe7OnPWZtJN6Af/HJ+FnYYVKvV0rEWeMo8VUQi2cm44U4x4z WqduiImPchIbbQ1FjGl5Yaxhbltxs8dmCs1AyOr4VHOOL/g7x1YzlSQthMMZLyZSeRQ8dr4WwSf ww84tmrn81jkvYlo18GUznvmuwBqjLjnY+Gu5P0c9lUyNe5/6kHnG0lr3CPuACHxfkFvNxR69qK zFjM4F+SBkgfKrEPjkca9JsCIYCQB2DxXnrmtKwZScLa8H4eRWia29CbxZrg1DmOJV/dq+bU/R3 0ykcgIwLn8E7+inTSwibLCig6Qwx8N2MuufEewPsmorEV/31+3xY/9VyYSmDEpmzt2XcoOktfCD JI4910CsUD5A3/lLIDOO7LhOoVbsls1kG6OZbUNs4hKanaizpt+nvnwFu61b6hRCP5PcIG9Gwxz xNsKKFMLN2L33NSk007QOm/vIXU/Wa7OH9AoQyu2sM+q3E+Yj1XDA3kggQxkvnqGbYNZK+u/UGy XNQbYm1lNAUpMH0V51BwNWAFoBSAVBKjHGV1sNdWArcABECR1sVZFE4TLHvssJB51TX7hTuUAkE e0OoRkM08czBtve0WlFjoK1R7gr5CrFHVkGJHN9OQzmMYJd7UYIIBm5+S7931algbAQRGQgWG33 OCyjKCPoRvNX0xA== X-Developer-Key: i=asmadeus@codewreck.org; a=openpgp; fpr=B894379F662089525B3FB1B9333F1F391BBBB00A Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org This splits off the vfs_getdents function from the getdents64 system call. This will allow io_uring to call the vfs_getdents function. Co-authored-by: Stefan Roesch Signed-off-by: Dominique Martinet --- fs/internal.h | 8 ++++++++ fs/readdir.c | 33 +++++++++++++++++++++++++-------- 2 files changed, 33 insertions(+), 8 deletions(-) diff --git a/fs/internal.h b/fs/internal.h index dc4eb91a577a..92eeaf3837d1 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -264,3 +264,11 @@ int setattr_should_drop_sgid(struct mnt_idmap *idmap, struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns); struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap); void mnt_idmap_put(struct mnt_idmap *idmap); + +/* + * fs/readdir.c + */ +struct linux_dirent64; + +int vfs_getdents(struct file *file, struct linux_dirent64 __user *dirent, + unsigned int count); diff --git a/fs/readdir.c b/fs/readdir.c index 9c53edb60c03..1d541a6f2d55 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -351,10 +351,16 @@ static bool filldir64(struct dir_context *ctx, const char *name, int namlen, return false; } -SYSCALL_DEFINE3(getdents64, unsigned int, fd, - struct linux_dirent64 __user *, dirent, unsigned int, count) + +/** + * vfs_getdents - getdents without fdget + * @file : pointer to file struct of directory + * @dirent : pointer to user directory structure + * @count : size of buffer + */ +int vfs_getdents(struct file *file, struct linux_dirent64 __user *dirent, + unsigned int count) { - struct fd f; struct getdents_callback64 buf = { .ctx.actor = filldir64, .count = count, @@ -362,11 +368,7 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd, }; int error; - f = fdget_pos(fd); - if (!f.file) - return -EBADF; - - error = iterate_dir(f.file, &buf.ctx); + error = iterate_dir(file, &buf.ctx); if (error >= 0) error = buf.error; if (buf.prev_reclen) { @@ -379,6 +381,21 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd, else error = count - buf.count; } + return error; +} + +SYSCALL_DEFINE3(getdents64, unsigned int, fd, + struct linux_dirent64 __user *, dirent, unsigned int, count) +{ + struct fd f; + int error; + + f = fdget_pos(fd); + if (!f.file) + return -EBADF; + + error = vfs_getdents(f.file, dirent, count); + fdput_pos(f); return error; } From patchwork Sat Apr 22 08:40:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dominique Martinet X-Patchwork-Id: 13220926 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07DE4C6FD18 for ; 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Sat, 22 Apr 2023 10:40:45 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codewreck.org; s=2; t=1682152850; bh=fmiVfF7XjOAyzByT51CixzO2cWUnuN4nSoCZntxTvEk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=QOZoELBEiPEWSRqYNF9xE3Ml2EFrvW6//F3yKRElRhvFYyZLBFROvkkESYxmvfV2S m6VMEOSlGjMy6ViVN3BtUKxvFzcNMQQ3fWkNP58oTeuFMLmzt4CzUhePtdueYpdLHS t3L5anqSH0ur+jKlfFh6JDCu0qfqElqm7XfG9SKHrGUw6A/4W5xzHehoryKAgABE+T cE9rwNOO7u14eol9mvEyBEX9e7sk4W3RcTDWCkpo8gOVdBlkMhztkrbf/EaAPPb0v1 ya9cxkdHtwiPWVTau2o4rlJ+MKVjNnKCQmBaLJ35Vhp6DO7cmI2X9QrE5q5TC7kLAE GxNVrTZFBv8Ew== Received: from [127.0.0.2] (localhost [::1]) by odin.codewreck.org (OpenSMTPD) with ESMTP id 2a928d4e; Sat, 22 Apr 2023 08:40:36 +0000 (UTC) From: Dominique Martinet Date: Sat, 22 Apr 2023 17:40:19 +0900 Subject: [PATCH RFC 2/2] io_uring: add support for getdents MIME-Version: 1.0 Message-Id: <20230422-uring-getdents-v1-2-14c1db36e98c@codewreck.org> References: <20230422-uring-getdents-v1-0-14c1db36e98c@codewreck.org> In-Reply-To: <20230422-uring-getdents-v1-0-14c1db36e98c@codewreck.org> To: Alexander Viro , Christian Brauner , Jens Axboe , Pavel Begunkov , Stefan Roesch Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, Dominique Martinet X-Mailer: b4 0.13-dev-f371f X-Developer-Signature: v=1; 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a=openpgp; fpr=B894379F662089525B3FB1B9333F1F391BBBB00A Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org This add support for getdents64 to io_uring, acting exactly like the syscall: the directory is iterated from it's current's position as stored in the file struct, and the file's position is updated exactly as if getdents64 had been called. Additionally, since io_uring has no way of issuing a seek, a flag IORING_GETDENTS_REWIND has been added that will seek to the start of the directory like rewinddir(3) for users that might require such a thing. This will act exactly as if seek then getdents64 have been called sequentially with no atomicity guarantee: if this wasn't clear it is the responsibility of the caller to not use getdents multiple time on a single file in parallel if they want useful results, as is currently the case when using the syscall from multiple threads. Signed-off-by: Dominique Martinet --- include/uapi/linux/io_uring.h | 7 ++++++ io_uring/fs.c | 51 +++++++++++++++++++++++++++++++++++++++++++ io_uring/fs.h | 3 +++ io_uring/opdef.c | 8 +++++++ 4 files changed, 69 insertions(+) diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 709de6d4feb2..44c87fad2714 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -65,6 +65,7 @@ struct io_uring_sqe { __u32 xattr_flags; __u32 msg_ring_flags; __u32 uring_cmd_flags; + __u32 getdents_flags; }; __u64 user_data; /* data to be passed back at completion time */ /* pack this to avoid bogus arm OABI complaints */ @@ -223,6 +224,7 @@ enum io_uring_op { IORING_OP_URING_CMD, IORING_OP_SEND_ZC, IORING_OP_SENDMSG_ZC, + IORING_OP_GETDENTS, /* this goes last, obviously */ IORING_OP_LAST, @@ -258,6 +260,11 @@ enum io_uring_op { */ #define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */ +/* + * sqe->getdents_flags + */ +#define IORING_GETDENTS_REWIND (1U << 0) + /* * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the * command flags for POLL_ADD are stored in sqe->len. diff --git a/io_uring/fs.c b/io_uring/fs.c index f6a69a549fd4..cb555bc738bd 100644 --- a/io_uring/fs.c +++ b/io_uring/fs.c @@ -47,6 +47,13 @@ struct io_link { int flags; }; +struct io_getdents { + struct file *file; + struct linux_dirent64 __user *dirent; + unsigned int count; + int flags; +}; + int io_renameat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_rename *ren = io_kiocb_to_cmd(req, struct io_rename); @@ -291,3 +298,47 @@ void io_link_cleanup(struct io_kiocb *req) putname(sl->oldpath); putname(sl->newpath); } + +int io_getdents_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_getdents *gd = io_kiocb_to_cmd(req, struct io_getdents); + + if (READ_ONCE(sqe->off) != 0) + return -EINVAL; + + gd->dirent = u64_to_user_ptr(READ_ONCE(sqe->addr)); + gd->count = READ_ONCE(sqe->len); + gd->flags = READ_ONCE(sqe->getdents_flags); + if (gd->flags & ~IORING_GETDENTS_REWIND) + return -EINVAL; + + return 0; +} + +int io_getdents(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_getdents *gd = io_kiocb_to_cmd(req, struct io_getdents); + int ret; + + if (issue_flags & IO_URING_F_NONBLOCK) + return -EAGAIN; + + if ((gd->flags & IORING_GETDENTS_REWIND)) { + ret = vfs_llseek(req->file, 0, SEEK_SET); + if (ret < 0) + goto out; + } + + ret = vfs_getdents(req->file, gd->dirent, gd->count); +out: + if (ret < 0) { + if (ret == -ERESTARTSYS) + ret = -EINTR; + + req_set_fail(req); + } + + io_req_set_res(req, ret, 0); + return 0; +} + diff --git a/io_uring/fs.h b/io_uring/fs.h index 0bb5efe3d6bb..f83a6f3a678d 100644 --- a/io_uring/fs.h +++ b/io_uring/fs.h @@ -18,3 +18,6 @@ int io_symlinkat(struct io_kiocb *req, unsigned int issue_flags); int io_linkat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); int io_linkat(struct io_kiocb *req, unsigned int issue_flags); void io_link_cleanup(struct io_kiocb *req); + +int io_getdents_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); +int io_getdents(struct io_kiocb *req, unsigned int issue_flags); diff --git a/io_uring/opdef.c b/io_uring/opdef.c index cca7c5b55208..8f770c582ab3 100644 --- a/io_uring/opdef.c +++ b/io_uring/opdef.c @@ -428,6 +428,11 @@ const struct io_issue_def io_issue_defs[] = { .prep = io_eopnotsupp_prep, #endif }, + [IORING_OP_GETDENTS] = { + .needs_file = 1, + .prep = io_getdents_prep, + .issue = io_getdents, + }, }; @@ -648,6 +653,9 @@ const struct io_cold_def io_cold_defs[] = { .fail = io_sendrecv_fail, #endif }, + [IORING_OP_GETDENTS] = { + .name = "GETDENTS", + }, }; const char *io_uring_get_opcode(u8 opcode)