kernel.git/fs/notify/fsnotify.h, branch linux-4.7.y

fsnotify: avoid spurious EMFILE errors from inotify_init()

2016-05-20T02:12:14Z

Inotify instance is destroyed when all references to it are dropped. That not only means that the corresponding file descriptor needs to be closed but also that all corresponding instance marks are freed (as each mark holds a reference to the inotify instance). However marks are freed only after SRCU period ends which can take some time and thus if user rapidly creates and frees inotify instances, number of existing inotify instances can exceed max_user_instances limit although from user point of view there is always at most one existing instance. Thus inotify_init() returns EMFILE error which is hard to justify from user point of view. This problem is exposed by LTP inotify06 testcase on some machines. We fix the problem by making sure all group marks are properly freed while destroying inotify instance. We wait for SRCU period to end in that path anyway since we have to make sure there is no event being added to the instance while we are tearing down the instance. So it takes only some plumbing to allow for marks to be destroyed in that path as well and not from a dedicated work item. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jan Kara Reported-by: Xiaoguang Wang Tested-by: Xiaoguang Wang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fsnotify: remove mark->free_list

2015-09-04T23:54:41Z

Free list is used when all marks on given inode / mount should be destroyed when inode / mount is going away. However we can free all of the marks without using a special list with some care. Signed-off-by: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fsnotify: unify inode and mount marks handling

2014-12-13T20:42:53Z

There's a lot of common code in inode and mount marks handling. Factor it out to a common helper function. Signed-off-by: Jan Kara Cc: Eric Paris Cc: Heinrich Schuchardt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fanotify: fix notification of groups with inode & mount marks

2014-11-14T00:17:06Z

fsnotify() needs to merge inode and mount marks lists when notifying groups about events so that ignore masks from inode marks are reflected in mount mark notifications and groups are notified in proper order (according to priorities). Currently the sorting of the lists done by fsnotify_add_inode_mark() / fsnotify_add_vfsmount_mark() and fsnotify() differed which resulted ignore masks not being used in some cases. Fix the problem by always using the same comparison function when sorting / merging the mark lists. Thanks to Heinrich Schuchardt for improvements of my patch. Link: https://bugzilla.kernel.org/show_bug.cgi?id=87721 Signed-off-by: Jan Kara Reported-by: Heinrich Schuchardt Tested-by: Heinrich Schuchardt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs/notify/group.c: make fsnotify_final_destroy_group() static

2014-10-10T02:25:45Z

No callers outside this file. Cc: Sasha Levin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fsnotify: remove global fsnotify groups lists

2010-07-28T14:18:54Z

The global fsnotify groups lists were invented as a way to increase the performance of fsnotify by shortcutting events which were not interesting. With the changes to walk the object lists rather than global groups lists these shortcuts are not useful. Signed-off-by: Eric Paris

fsnotify: remove the global masks

2010-07-28T14:18:54Z

Because we walk the object->fsnotify_marks list instead of the global fsnotify groups list we don't need the fsnotify_inode_mask and fsnotify_vfsmount_mask as these were simply shortcuts in fsnotify() for performance. They are now extra checks, rip them out. Signed-off-by: Eric Paris

fsnotify: srcu to protect read side of inode and vfsmount locks

2010-07-28T14:18:52Z

Currently reading the inode->i_fsnotify_marks or vfsmount->mnt_fsnotify_marks lists are protected by a spinlock on both the read and the write side. This patch protects the read side of those lists with a new single srcu. Signed-off-by: Eric Paris

fsnotify: allow marks to not pin inodes in core

2010-07-28T13:58:59Z

inotify marks must pin inodes in core. dnotify doesn't technically need to since they are closed when the directory is closed. fanotify also need to pin inodes in core as it works today. But the next step is to introduce the concept of 'ignored masks' which is actually a mask of events for an inode of no interest. I claim that these should be liberally sent to the kernel and should not pin the inode in core. If the inode is brought back in the listener will get an event it may have thought excluded, but this is not a serious situation and one any listener should deal with. This patch lays the ground work for non-pinning inode marks by using lazy inode pinning. We do not pin a mark until it has a non-zero mask entry. If a listener new sets a mask we never pin the inode. Signed-off-by: Eric Paris

fsnotify: Infrastructure for per-mount watches

2010-07-28T13:58:57Z

Per-mount watches allow groups to listen to fsnotify events on an entire mount. This patch simply adds and initializes the fields needed in the vfsmount struct to make this happen. Signed-off-by: Andreas Gruenbacher Signed-off-by: Eric Paris