user/sven/linux.git/include/linux/fsnotify_backend.h, branch v3.18.33

fanotify: fix double free of pending permission events

2014-08-07T01:01:12Z

Commit 85816794240b ("fanotify: Fix use after free for permission events") introduced a double free issue for permission events which are pending in group's notification queue while group is being destroyed. These events are freed from fanotify_handle_event() but they are not removed from groups notification queue and thus they get freed again from fsnotify_flush_notify(). Fix the problem by removing permission events from notification queue before freeing them if we skip processing access response. Also expand comments in fanotify_release() to explain group shutdown in detail. Fixes: 85816794240b9659e66e4d9b0df7c6e814e5f603 Signed-off-by: Jan Kara Reported-by: Douglas Leeder Tested-by: Douglas Leeder Reported-by: Heinrich Schuchard Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fsnotify: rename event handling functions

2014-08-07T01:01:12Z

Rename fsnotify_add_notify_event() to fsnotify_add_event() since the "notify" part is duplicit. Rename fsnotify_remove_notify_event() and fsnotify_peek_notify_event() to fsnotify_remove_first_event() and fsnotify_peek_first_event() respectively since "notify" part is duplicit and they really look at the first event in the queue. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jan Kara Cc: Eric Paris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fanotify: convert access_mutex to spinlock

2014-04-03T23:20:51Z

access_mutex is used only to guard operations on access_list. There's no need for sleeping within this lock so just make a spinlock out of it. Signed-off-by: Jan Kara Cc: Eric Paris Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fsnotify: Allocate overflow events with proper type

2014-02-25T10:18:06Z

Commit 7053aee26a35 "fsnotify: do not share events between notification groups" used overflow event statically allocated in a group with the size of the generic notification event. This causes problems because some code looks at type specific parts of event structure and gets confused by a random data it sees there and causes crashes. Fix the problem by allocating overflow event with type corresponding to the group type so code cannot get confused. Signed-off-by: Jan Kara

inotify: Fix reporting of cookies for inotify events

2014-02-18T10:17:17Z

My rework of handling of notification events (namely commit 7053aee26a35 "fsnotify: do not share events between notification groups") broke sending of cookies with inotify events. We didn't propagate the value passed to fsnotify() properly and passed 4 uninitialized bytes to userspace instead (so it is also an information leak). Sadly I didn't notice this during my testing because inotify cookies aren't used very much and LTP inotify tests ignore them. Fix the problem by passing the cookie value properly. Fixes: 7053aee26a3548ebaba046ae2e52396ccf56ac6c Reported-by: Vegard Nossum Signed-off-by: Jan Kara

fsnotify: Do not return merged event from fsnotify_add_notify_event()

2014-01-29T12:57:10Z

The event returned from fsnotify_add_notify_event() cannot ever be used safely as the event may be freed by the time the function returns (after dropping notification_mutex). So change the prototype to just return whether the event was added or merged into some existing event. Reported-and-tested-by: Jiri Kosina Reported-and-tested-by: Dave Jones Signed-off-by: Jan Kara

fsnotify: remove .should_send_event callback

2014-01-22T00:19:41Z

After removing event structure creation from the generic layer there is no reason for separate .should_send_event and .handle_event callbacks. So just remove the first one. Signed-off-by: Jan Kara Reviewed-by: Christoph Hellwig Cc: Eric Paris Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fsnotify: do not share events between notification groups

2014-01-22T00:19:41Z

Currently fsnotify framework creates one event structure for each notification event and links this event into all interested notification groups. This is done so that we save memory when several notification groups are interested in the event. However the need for event structure shared between inotify & fanotify bloats the event structure so the result is often higher memory consumption. Another problem is that fsnotify framework keeps path references with outstanding events so that fanotify can return open file descriptors with its events. This has the undesirable effect that filesystem cannot be unmounted while there are outstanding events - a regression for inotify compared to a situation before it was converted to fsnotify framework. For fanotify this problem is hard to avoid and users of fanotify should kind of expect this behavior when they ask for file descriptors from notified files. This patch changes fsnotify and its users to create separate event structure for each group. This allows for much simpler code (~400 lines removed by this patch) and also smaller event structures. For example on 64-bit system original struct fsnotify_event consumes 120 bytes, plus additional space for file name, additional 24 bytes for second and each subsequent group linking the event, and additional 32 bytes for each inotify group for private data. After the conversion inotify event consumes 48 bytes plus space for file name which is considerably less memory unless file names are long and there are several groups interested in the events (both of which are uncommon). Fanotify event fits in 56 bytes after the conversion (fanotify doesn't care about file names so its events don't have to have it allocated). A win unless there are four or more fanotify groups interested in the event. The conversion also solves the problem with unmount when only inotify is used as we don't have to grab path references for inotify events. [hughd@google.com: fanotify: fix corruption preventing startup] Signed-off-by: Jan Kara Reviewed-by: Christoph Hellwig Cc: Eric Paris Cc: Al Viro Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

inotify: convert inotify_add_to_idr() to use idr_alloc_cyclic()

2013-04-30T01:28:41Z

Signed-off-by: Jeff Layton Cc: John McCutchan Cc: Robert Love Cc: Eric Paris Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fsnotify: make fasync generic for both inotify and fanotify

2012-12-11T18:44:36Z

inotify is supposed to support async signal notification when information is available on the inotify fd. This patch moves that support to generic fsnotify functions so it can be used by all notification mechanisms. Signed-off-by: Eric Paris