From: NeilBrown <neilb@suse.de> mainline inclusion from mainline-v6.10-rc7 commit 7d1cf5e624ef5d81b933e8b7f4927531166c0f7a category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IBCU3L Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ---------------------------------------------------------------------- When a file is opened and created with open(..., O_CREAT) we get both the CREATE and OPEN fsnotify events and would expect them in that order. For most filesystems we get them in that order because open_last_lookups() calls fsnofify_create() and then do_open() (from path_openat()) calls vfs_open()->do_dentry_open() which calls fsnotify_open(). However when ->atomic_open is used, the do_dentry_open() -> fsnotify_open() call happens from finish_open() which is called from the ->atomic_open handler in lookup_open() which is called *before* open_last_lookups() calls fsnotify_create. So we get the "open" notification before "create" - which is backwards. ltp testcase inotify02 tests this and reports the inconsistency. This patch lifts the fsnotify_open() call out of do_dentry_open() and places it higher up the call stack. There are three callers of do_dentry_open(). For vfs_open() and kernel_file_open() the fsnotify_open() is placed directly in that caller so there should be no behavioural change. For finish_open() there are two cases: - finish_open is used in ->atomic_open handlers. For these we add a call to fsnotify_open() at open_last_lookups() if FMODE_OPENED is set - which means do_dentry_open() has been called. - finish_open is used in ->tmpfile() handlers. For these a similar call to fsnotify_open() is added to vfs_tmpfile() With this patch NFSv3 is restored to its previous behaviour (before ->atomic_open support was added) of generating CREATE notifications before OPEN, and NFSv4 now has that same correct ordering that is has not had before. I haven't tested other filesystems. Fixes: 7c6c5249f061 ("NFS: add atomic_open for NFSv3 to handle O_TRUNC correctly.") Reported-by: James Clark <james.clark@arm.com> Closes: https://lore.kernel.org/all/01c3bf2e-eb1f-4b7f-a54f-d2a05dd3d8c8@arm.com Signed-off-by: NeilBrown <neilb@suse.de> Link: https://lore.kernel.org/r/171817619547.14261.975798725161704336@noble.neil.b... Fixes: 7b8c9d7bb457 ("fsnotify: move fsnotify_open() hook into do_dentry_open()") Tested-by: James Clark <james.clark@arm.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20240617162303.1596-2-jack@suse.cz Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org> Conflicts: fs/open.c [Commit 0f4a2cebe256 ("do_dentry_open(): kill inode argument") remove inode from the parameter list.] Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> --- fs/namei.c | 10 ++++++++-- fs/open.c | 22 +++++++++++++++------- 2 files changed, 23 insertions(+), 9 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 13d1ca4f6842..19199d81bf17 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3589,8 +3589,12 @@ static const char *open_last_lookups(struct nameidata *nd, else inode_lock_shared(dir->d_inode); dentry = lookup_open(nd, file, op, got_write); - if (!IS_ERR(dentry) && (file->f_mode & FMODE_CREATED)) - fsnotify_create(dir->d_inode, dentry); + if (!IS_ERR(dentry)) { + if (file->f_mode & FMODE_CREATED) + fsnotify_create(dir->d_inode, dentry); + if (file->f_mode & FMODE_OPENED) + fsnotify_open(file); + } if (open_flag & O_CREAT) inode_unlock(dir->d_inode); else @@ -3717,6 +3721,8 @@ static int vfs_tmpfile(struct mnt_idmap *idmap, mode = vfs_prepare_mode(idmap, dir, mode, mode, mode); error = dir->i_op->tmpfile(idmap, dir, file, mode); dput(child); + if (file->f_mode & FMODE_OPENED) + fsnotify_open(file); if (error) return error; /* Don't check for other permissions, the inode was just created */ diff --git a/fs/open.c b/fs/open.c index 4679db501d43..ae3d152a770f 100644 --- a/fs/open.c +++ b/fs/open.c @@ -997,11 +997,6 @@ static int do_dentry_open(struct file *f, } } - /* - * Once we return a file with FMODE_OPENED, __fput() will call - * fsnotify_close(), so we need fsnotify_open() here for symmetry. - */ - fsnotify_open(f); return 0; cleanup_all: @@ -1078,8 +1073,19 @@ EXPORT_SYMBOL(file_path); */ int vfs_open(const struct path *path, struct file *file) { + int ret; + file->f_path = *path; - return do_dentry_open(file, d_backing_inode(path->dentry), NULL); + ret = do_dentry_open(file, d_backing_inode(path->dentry), NULL); + if (!ret) { + /* + * Once we return a file with FMODE_OPENED, __fput() will call + * fsnotify_close(), so we need fsnotify_open() here for + * symmetry. + */ + fsnotify_open(file); + } + return ret; } struct file *dentry_open(const struct path *path, int flags, @@ -1171,8 +1177,10 @@ struct file *kernel_file_open(const struct path *path, int flags, error = do_dentry_open(f, inode, NULL); if (error) { fput(f); - f = ERR_PTR(error); + return ERR_PTR(error); } + + fsnotify_open(f); return f; } EXPORT_SYMBOL_GPL(kernel_file_open); -- 2.31.1