lwn.git/fs/notify/inotify/inotify_user.c, branch v3.14.53

fsnotify: Allocate overflow events with proper type

2014-02-25T10:18:06+00:00

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

2014-02-18T10:17:17+00:00

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 share events between notification groups

2014-01-22T00:19:41+00:00

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: provide function for name length rounding

2014-01-22T00:19:41+00:00

Rounding of name length when passing it to userspace was done in several places. Provide a function to do it and use it in all places. 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

inotify: fix race when adding a new watch

2013-07-09T17:33:20+00:00

In inotify_new_watch() the number of watches for a group is compared against the max number of allowed watches and increased afterwards. The check and incrementation is not done atomically, so it is possible for multiple concurrent threads to pass the check and increment the number of marks above the allowed max. This patch uses an inotify groups mark_lock to ensure that both check and incrementation are done atomic. Furthermore we dont have to worry about the race that allows a concurrent thread to add a watch just after inotify_update_existing_watch() returned with -ENOENT anymore, since this is also synchronized by the groups mark mutex now. Signed-off-by: Lino Sanfilippo Cc: Eric Paris Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2013-05-02T00:51:54+00:00

Pull VFS updates from Al Viro, Misc cleanups all over the place, mainly wrt /proc interfaces (switch create_proc_entry to proc_create(), get rid of the deprecated create_proc_read_entry() in favor of using proc_create_data() and seq_file etc). 7kloc removed. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits) don't bother with deferred freeing of fdtables proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h proc: Make the PROC_I() and PDE() macros internal to procfs proc: Supply a function to remove a proc entry by PDE take cgroup_open() and cpuset_open() to fs/proc/base.c ppc: Clean up scanlog ppc: Clean up rtas_flash driver somewhat hostap: proc: Use remove_proc_subtree() drm: proc: Use remove_proc_subtree() drm: proc: Use minor->index to label things, not PDE->name drm: Constify drm_proc_list[] zoran: Don't print proc_dir_entry data in debug reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show() proc: Supply an accessor for getting the data from a PDE's parent airo: Use remove_proc_subtree() rtl8192u: Don't need to save device proc dir PDE rtl8187se: Use a dir under /proc/net/r8180/ proc: Add proc_mkdir_data() proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h} proc: Move PDE_NET() to fs/proc/proc_net.c ...

inotify: invalid mask should return a error number but not set it

2013-05-01T00:04:00+00:00

When we run the crackerjack testsuite, the inotify_add_watch test is stalled. This is caused by the invalid mask 0 - the task is waiting for the event but it never comes. inotify_add_watch() should return -EINVAL as it did before commit 676a0675cf92 ("inotify: remove broken mask checks causing unmount to be EINVAL"). That commit removes the invalid mask check, but that check is needed. Check the mask's ALL_INOTIFY_BITS before the inotify_arg_to_mask() call. If none are set, just return -EINVAL. Because IN_UNMOUNT is in ALL_INOTIFY_BITS, this change will not trigger the problem that above commit fixed. [akpm@linux-foundation.org: fix build] Signed-off-by: Zhao Hongjiang Acked-by: Jim Somerville Cc: Paul Gortmaker Cc: Jerome Marchand Cc: Eric Paris Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

inotify: convert inotify_add_to_idr() to use idr_alloc_cyclic()

2013-04-30T01:28:41+00:00

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

fanotify: don't wank with FASYNC on ->release()

2013-04-29T19:41:43+00:00

... it's done already by __fput() Signed-off-by: Al Viro

inotify: convert to idr_alloc()

2013-02-28T03:10:19+00:00

Convert to the much saner new idr interface. Note that the adhoc cyclic id allocation is buggy. If wraparound happens, the previous code with idr_get_new_above() may segfault and the converted code will trigger WARN and return -EINVAL. Even if it's fixed to wrap to zero, the code will be prone to unnecessary -ENOSPC failures after the first wraparound. We probably need to implement proper cyclic support in idr. Signed-off-by: Tejun Heo Cc: John McCutchan Cc: Robert Love Cc: Eric Paris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds