user/sven/linux.git/fs/notify/fsnotify.c, branch v5.7

fanotify: send FAN_DIR_MODIFY event flavor with dir inode and name

2020-03-25T09:27:16Z

Dirent events are going to be supported in two flavors: 1. Directory fid info + mask that includes the specific event types (e.g. FAN_CREATE) and an optional FAN_ONDIR flag. 2. Directory fid info + name + mask that includes only FAN_DIR_MODIFY. To request the second event flavor, user needs to set the event type FAN_DIR_MODIFY in the mark mask. The first flavor is supported since kernel v5.1 for groups initialized with flag FAN_REPORT_FID. It is intended to be used for watching directories in "batch mode" - the watcher is notified when directory is changed and re-scans the directory content in response. This event flavor is stored more compactly in the event queue, so it is optimal for workloads with frequent directory changes. The second event flavor is intended to be used for watching large directories, where the cost of re-scan of the directory on every change is considered too high. The watcher getting the event with the directory fid and entry name is expected to call fstatat(2) to query the content of the entry after the change. Legacy inotify events are reported with name and event mask (e.g. "foo", FAN_CREATE | FAN_ONDIR). That can lead users to the conclusion that there is *currently* an entry "foo" that is a sub-directory, when in fact "foo" may be negative or non-dir by the time user gets the event. To make it clear that the current state of the named entry is unknown, when reporting an event with name info, fanotify obfuscates the specific event types (e.g. create,delete,rename) and uses a common event type - FAN_DIR_MODIFY to describe the change. This should make it harder for users to make wrong assumptions and write buggy filesystem monitors. At this point, name info reporting is not yet implemented, so trying to set FAN_DIR_MODIFY in mark mask will return -EINVAL. Link: https://lore.kernel.org/r/20200319151022.31456-12-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fsnotify: simplify arguments passing to fsnotify_parent()

2020-03-23T17:22:48Z

Instead of passing both dentry and path and having to figure out which one to use, pass data/data_type to simplify the code. Link: https://lore.kernel.org/r/20200319151022.31456-6-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fsnotify: use helpers to access data by data_type

2020-03-23T17:19:06Z

Create helpers to access path and inode from different data types. Link: https://lore.kernel.org/r/20200319151022.31456-5-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fs: call fsnotify_sb_delete after evict_inodes

2019-12-18T05:03:01Z

When a filesystem is unmounted, we currently call fsnotify_sb_delete() before evict_inodes(), which means that fsnotify_unmount_inodes() must iterate over all inodes on the superblock looking for any inodes with watches. This is inefficient and can lead to livelocks as it iterates over many unwatched inodes. At this point, SB_ACTIVE is gone and dropping refcount to zero kicks the inode out out immediately, so anything processed by fsnotify_sb_delete / fsnotify_unmount_inodes gets evicted in that loop. After that, the call to evict_inodes will evict everything else with a zero refcount. This should speed things up overall, and avoid livelocks in fsnotify_unmount_inodes(). Signed-off-by: Eric Sandeen Reviewed-by: Jan Kara Signed-off-by: Al Viro

fs: avoid softlockups in s_inodes iterators

2019-12-18T05:03:01Z

Anything that walks all inodes on sb->s_inodes list without rescheduling risks softlockups. Previous efforts were made in 2 functions, see: c27d82f fs/drop_caches.c: avoid softlockups in drop_pagecache_sb() ac05fbb inode: don't softlockup when evicting inodes but there hasn't been an audit of all walkers, so do that now. This also consistently moves the cond_resched() calls to the bottom of each loop in cases where it already exists. One loop remains: remove_dquot_ref(), because I'm not quite sure how to deal with that one w/o taking the i_lock. Signed-off-by: Eric Sandeen Reviewed-by: Jan Kara Signed-off-by: Al Viro

fsnotify: move declaration of fsnotify_mark_connector_cachep to fsnotify.h

2019-10-17T08:31:12Z

Move fsnotify_mark_connector_cachep to fsnotify.h to properly share it with the user in mark.c and avoid the following warning from sparse: fs/notify/mark.c:82:19: warning: symbol 'fsnotify_mark_connector_cachep' was not declared. Should it be static? Link: https://lore.kernel.org/r/20191015132518.21819-1-ben.dooks@codethink.co.uk Signed-off-by: Ben Dooks Signed-off-by: Jan Kara

fsnotify: get rid of fsnotify_nameremove()

2019-06-20T12:47:54Z

For all callers of fsnotify_{unlink,rmdir}(), we made sure that d_parent and d_name are stable. Therefore, fsnotify_{unlink,rmdir}() do not need the safety measures in fsnotify_nameremove() to stabilize parent and name. We can now simplify those hooks and get rid of fsnotify_nameremove(). Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 18

2019-05-21T09:28:46Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program see the file copying if not write to the free software foundation 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 52 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Jilayne Lovejoy Reviewed-by: Steve Winslow Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190519154042.342335923@linutronix.de Signed-off-by: Greg Kroah-Hartman

Merge tag 'fsnotify_for_v5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

2019-05-13T22:08:16Z

Pull fsnotify fixes from Jan Kara: "Two fsnotify fixes" * tag 'fsnotify_for_v5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fsnotify: fix unlink performance regression fsnotify: Clarify connector assignment in fsnotify_add_mark_list()

fsnotify: fix unlink performance regression

2019-05-09T10:44:00Z

__fsnotify_parent() has an optimization in place to avoid unneeded take_dentry_name_snapshot(). When fsnotify_nameremove() was changed not to call __fsnotify_parent(), we left out the optimization. Kernel test robot reported a 5% performance regression in concurrent unlink() workload. Reported-by: kernel test robot Link: https://lore.kernel.org/lkml/20190505062153.GG29809@shao2-debian/ Link: https://lore.kernel.org/linux-fsdevel/20190104090357.GD22409@quack2.suse.cz/ Fixes: 5f02a8776384 ("fsnotify: annotate directory entry modification events") CC: stable@vger.kernel.org Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara