From patchwork Fri Nov 15 15:30:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 13876451 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02EDFD68BC6 for ; Fri, 15 Nov 2024 15:32:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CB87E6B00A2; Fri, 15 Nov 2024 10:31:52 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C670F6B00A3; Fri, 15 Nov 2024 10:31:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B09DB6B00A4; Fri, 15 Nov 2024 10:31:52 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 901B76B00A2 for ; Fri, 15 Nov 2024 10:31:52 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 4641216193A for ; Fri, 15 Nov 2024 15:31:52 +0000 (UTC) X-FDA: 82788719160.02.50DC622 Received: from mail-ot1-f54.google.com (mail-ot1-f54.google.com [209.85.210.54]) by imf18.hostedemail.com (Postfix) with ESMTP id 118AC1C002A for ; Fri, 15 Nov 2024 15:31:29 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=toxicpanda-com.20230601.gappssmtp.com header.s=20230601 header.b=bgToyVgF; spf=none (imf18.hostedemail.com: domain of josef@toxicpanda.com has no SPF policy when checking 209.85.210.54) smtp.mailfrom=josef@toxicpanda.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1731684472; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Ma7Y5+BFpcWgfxwOepr2mPEvJR7BrAPr6ViHq4rzmZc=; b=I+c3lpJoz4nuIfdMti76wTrJqq2FNh86xIkv1mlocoEc+pX+5Kkvvd4hWWHQ4oox8WcL7G tLxE7FsWwMh/ikm49mrsP513ZvgjbxDaxDAnn19zHoB4Lk+cgn9ViEIECkawuFDTpcviD5 kIAkCuwMDkV5i+YW5wrlMk7rffCG8Jg= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=toxicpanda-com.20230601.gappssmtp.com header.s=20230601 header.b=bgToyVgF; spf=none (imf18.hostedemail.com: domain of josef@toxicpanda.com has no SPF policy when checking 209.85.210.54) smtp.mailfrom=josef@toxicpanda.com; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1731684472; a=rsa-sha256; cv=none; b=Tqk5xjnRysGJWlOZPSUE4t4V0CS94PmVTucghNvCdRu200SEcs7GnfjtQy4LgIhhkszGPp /eUVdQlXlvvDKB+1ZuQpVpxJE3KMgTg5MqzqZpcT6MsfkQ0/M7/cNAXsZ9obkSTEDNogux 0wBjo8Qa2J8RkQp5jhzG5UqTB5zwL4o= Received: by mail-ot1-f54.google.com with SMTP id 46e09a7af769-7180dc76075so917621a34.3 for ; Fri, 15 Nov 2024 07:31:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20230601.gappssmtp.com; s=20230601; t=1731684709; x=1732289509; darn=kvack.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:from:to:cc:subject:date:message-id :reply-to; bh=Ma7Y5+BFpcWgfxwOepr2mPEvJR7BrAPr6ViHq4rzmZc=; b=bgToyVgFOT2AdDc5OrCTnKLtrc2zAOTkJaSpT2hdDn8Gtljzsl2/1FTvEjQqB7uGnp n7eOSTkZYG/W3+xCFuEnqDURBdeERwUGV4TcXvmzOviDjWsFmD745Ueuc6vOtbginPlE gG3ITpt3XNADkSfFNBxnLE45lbRtZ3q7Gr3XVz6MFc+gaXbgs7Ko+Lb4O44RIDC5RV9X 8DZGEdwA6NUli1ON3TsiCCusjtXNrUMcAXfkbjfEVLcbd6FVbtXNN1/0Oa0Z2Xykeo0T RucrHkX7o5A6JpHuZ+eaugereNjn9AUDoP0iTY49n8Ccxph9FsDbSzgzNwM56y9p0IQ6 QG0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1731684709; x=1732289509; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Ma7Y5+BFpcWgfxwOepr2mPEvJR7BrAPr6ViHq4rzmZc=; b=gvO53A34LZBvpxGeJ+hW6e4/37gYwujOYBSdP03FQ/dmRBZVaVJTFVP252ADYLgWQf LRDJ/53x36i7UQpjMfGXPr5lUPvznNtLgRm84lr9F28qachvxQOhqWMWbAS053G07Y62 ewIzusvyk4BXtqRGS8bZY7gI0QfnBnFL2fmUPKoRjwgBNsdQgriMPhVAn1cg912zDInP A2PvL3NonWX+Yfz/WII5t87YtzYTZq47NmFB22pDtzl58H70xm4P4DJ8ueMJIkv7VOE7 JkkHkdqXikb/PgHsYHxmnqddKfWxuVh9fjISP0Z+k/tF9hWj00SGRJYRfM630t2nSer0 xvag== X-Forwarded-Encrypted: i=1; AJvYcCUivXEIkMM25fvkDnq2D7ZNxQNr0KxFb12F78SoWTT22A+ynsQAk4JQ5qmA2fo+gDB829/ABbucjQ==@kvack.org X-Gm-Message-State: AOJu0YwP1pQukYYTAtd9AslEgQlZChbOAik14mbZj3Q9E4Uzt4MIMk4g 25RuL8g0G4uUKRH4pB46corM1OJzHWZedXzfzUJdcei7nUUYPbtkulp9YWu3A1S6rPGp+BsqwJ1 O X-Google-Smtp-Source: AGHT+IH4KF4O/0TeALgb4lQDmEiPTFLtEsIEnnQGgceAZNppg9oa7TyTq0ub2EblRWNTki1B2uNPXQ== X-Received: by 2002:a05:6902:18ce:b0:e30:e1f3:2a9c with SMTP id 3f1490d57ef6-e3825bdd1fbmr2969338276.0.1731684697839; Fri, 15 Nov 2024 07:31:37 -0800 (PST) Received: from localhost (syn-076-182-020-124.res.spectrum.com. [76.182.20.124]) by smtp.gmail.com with ESMTPSA id 3f1490d57ef6-e38152ab555sm1006714276.12.2024.11.15.07.31.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 Nov 2024 07:31:37 -0800 (PST) From: Josef Bacik To: kernel-team@fb.com, linux-fsdevel@vger.kernel.org, jack@suse.cz, amir73il@gmail.com, brauner@kernel.org, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, linux-xfs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-mm@kvack.org, linux-ext4@vger.kernel.org Subject: [PATCH v8 10/19] fanotify: introduce FAN_PRE_ACCESS permission event Date: Fri, 15 Nov 2024 10:30:23 -0500 Message-ID: X-Mailer: git-send-email 2.43.0 In-Reply-To: References: MIME-Version: 1.0 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 118AC1C002A X-Stat-Signature: 5r75htu7qariw443suixh4c55ipunke5 X-Rspam-User: X-HE-Tag: 1731684689-88850 X-HE-Meta: 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 YDb2FwLl 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000011, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Amir Goldstein Similar to FAN_ACCESS_PERM permission event, but it is only allowed with class FAN_CLASS_PRE_CONTENT and only allowed on regular files and dirs. Unlike FAN_ACCESS_PERM, it is safe to write to the file being accessed in the context of the event handler. This pre-content event is meant to be used by hierarchical storage managers that want to fill the content of files on first read access. Signed-off-by: Amir Goldstein --- fs/notify/fanotify/fanotify.c | 3 ++- fs/notify/fanotify/fanotify_user.c | 22 +++++++++++++++++++--- include/linux/fanotify.h | 14 ++++++++++---- include/uapi/linux/fanotify.h | 2 ++ 4 files changed, 33 insertions(+), 8 deletions(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 2e6ba94ec405..da6c3c1c7edf 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -916,8 +916,9 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask, BUILD_BUG_ON(FAN_OPEN_EXEC_PERM != FS_OPEN_EXEC_PERM); BUILD_BUG_ON(FAN_FS_ERROR != FS_ERROR); BUILD_BUG_ON(FAN_RENAME != FS_RENAME); + BUILD_BUG_ON(FAN_PRE_ACCESS != FS_PRE_ACCESS); - BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 21); + BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 22); mask = fanotify_group_event_mask(group, iter_info, &match_mask, mask, data, data_type, dir); diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 456cc3e92c88..5ea447e9e5a8 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -1640,11 +1640,23 @@ static int fanotify_events_supported(struct fsnotify_group *group, unsigned int flags) { unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS; + bool is_dir = d_is_dir(path->dentry); /* Strict validation of events in non-dir inode mask with v5.17+ APIs */ bool strict_dir_events = FAN_GROUP_FLAG(group, FAN_REPORT_TARGET_FID) || (mask & FAN_RENAME) || (flags & FAN_MARK_IGNORE); + /* + * Filesystems need to opt-into pre-content evnets (a.k.a HSM) + * and they are only supported on regular files and directories. + */ + if (mask & FANOTIFY_PRE_CONTENT_EVENTS) { + if (!(path->mnt->mnt_sb->s_iflags & SB_I_ALLOW_HSM)) + return -EINVAL; + if (!is_dir && !d_is_reg(path->dentry)) + return -EINVAL; + } + /* * Some filesystems such as 'proc' acquire unusual locks when opening * files. For them fanotify permission events have high chances of @@ -1677,7 +1689,7 @@ static int fanotify_events_supported(struct fsnotify_group *group, * but because we always allowed it, error only when using new APIs. */ if (strict_dir_events && mark_type == FAN_MARK_INODE && - !d_is_dir(path->dentry) && (mask & FANOTIFY_DIRONLY_EVENT_BITS)) + !is_dir && (mask & FANOTIFY_DIRONLY_EVENT_BITS)) return -ENOTDIR; return 0; @@ -1778,10 +1790,14 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, return -EPERM; /* - * Permission events require minimum priority FAN_CLASS_CONTENT. + * Permission events are not allowed for FAN_CLASS_NOTIF. + * Pre-content permission events are not allowed for FAN_CLASS_CONTENT. */ if (mask & FANOTIFY_PERM_EVENTS && - group->priority < FSNOTIFY_PRIO_CONTENT) + group->priority == FSNOTIFY_PRIO_NORMAL) + return -EINVAL; + else if (mask & FANOTIFY_PRE_CONTENT_EVENTS && + group->priority == FSNOTIFY_PRIO_CONTENT) return -EINVAL; if (mask & FAN_FS_ERROR && diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h index 89ff45bd6f01..c747af064d2c 100644 --- a/include/linux/fanotify.h +++ b/include/linux/fanotify.h @@ -89,6 +89,16 @@ #define FANOTIFY_DIRENT_EVENTS (FAN_MOVE | FAN_CREATE | FAN_DELETE | \ FAN_RENAME) +/* Content events can be used to inspect file content */ +#define FANOTIFY_CONTENT_PERM_EVENTS (FAN_OPEN_PERM | FAN_OPEN_EXEC_PERM | \ + FAN_ACCESS_PERM) +/* Pre-content events can be used to fill file content */ +#define FANOTIFY_PRE_CONTENT_EVENTS (FAN_PRE_ACCESS) + +/* Events that require a permission response from user */ +#define FANOTIFY_PERM_EVENTS (FANOTIFY_CONTENT_PERM_EVENTS | \ + FANOTIFY_PRE_CONTENT_EVENTS) + /* Events that can be reported with event->fd */ #define FANOTIFY_FD_EVENTS (FANOTIFY_PATH_EVENTS | FANOTIFY_PERM_EVENTS) @@ -104,10 +114,6 @@ FANOTIFY_INODE_EVENTS | \ FANOTIFY_ERROR_EVENTS) -/* Events that require a permission response from user */ -#define FANOTIFY_PERM_EVENTS (FAN_OPEN_PERM | FAN_ACCESS_PERM | \ - FAN_OPEN_EXEC_PERM) - /* Extra flags that may be reported with event or control handling of events */ #define FANOTIFY_EVENT_FLAGS (FAN_EVENT_ON_CHILD | FAN_ONDIR) diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h index 79072b6894f2..7596168c80eb 100644 --- a/include/uapi/linux/fanotify.h +++ b/include/uapi/linux/fanotify.h @@ -27,6 +27,8 @@ #define FAN_OPEN_EXEC_PERM 0x00040000 /* File open/exec in perm check */ /* #define FAN_DIR_MODIFY 0x00080000 */ /* Deprecated (reserved) */ +#define FAN_PRE_ACCESS 0x00100000 /* Pre-content access hook */ + #define FAN_EVENT_ON_CHILD 0x08000000 /* Interested in child events */ #define FAN_RENAME 0x10000000 /* File was renamed */