litmus-rt.git/fs/notify, branch linux-tip

make fanotify_read() restartable across signals

2010-10-30T18:07:35+00:00

    In fanotify_read() return -ERESTARTSYS instead of -EINTR to
    make read() restartable across signals (BSD semantic).

Signed-off-by: Eric Paris

fs/notify/fanotify/fanotify_user.c: fix warnings

2010-10-28T21:22:16+00:00

fs/notify/fanotify/fanotify_user.c: In function 'fanotify_release':
fs/notify/fanotify/fanotify_user.c:375: warning: unused variable 'lre'
fs/notify/fanotify/fanotify_user.c:375: warning: unused variable 're'

this is really ugly.

Cc: Eric Paris 
Signed-off-by: Andrew Morton 
Signed-off-by: Eric Paris

fanotify: do not recalculate the mask if the ignored mask changed

2010-10-28T21:22:16+00:00

If fanotify sets a new bit in the ignored mask it will cause the generic
fsnotify layer to recalculate the real mask.  This is stupid since we
didn't change that part.

Signed-off-by: Eric Paris

fanotify: ignore events on directories unless specifically requested

2010-10-28T21:22:16+00:00

fanotify has a very limited number of events it sends on directories.  The
usefulness of these events is yet to be seen and still we send them.  This
is particularly painful for mount marks where one might receive many of
these useless events.  As such this patch will drop events on IS_DIR()
inodes unless they were explictly requested with FAN_ON_DIR.

This means that a mark on a directory without FAN_EVENT_ON_CHILD or
FAN_ON_DIR is meaningless and will result in no events ever (although it
will still be allowed since detecting it is hard)

Signed-off-by: Eric Paris

fsnotify: rename FS_IN_ISDIR to FS_ISDIR

2010-10-28T21:22:15+00:00

The _IN_ in the naming is reserved for flags only used by inotify.  Since I
am about to use this flag for fanotify rename it to be generic like the
rest.

Signed-off-by: Eric Paris

fanotify: do not send events for irregular files

2010-10-28T21:22:15+00:00

fanotify_should_send_event has a test to see if an object is a file or
directory and does not send an event otherwise.  The problem is that the
test is actually checking if the object with a mark is a file or directory,
not if the object the event happened on is a file or directory.  We should
check the latter.

Signed-off-by: Eric Paris

fanotify: limit number of listeners per user

2010-10-28T21:22:15+00:00

fanotify currently has no limit on the number of listeners a given user can
have open.  This patch limits the total number of listeners per user to
128.  This is the same as the inotify default limit.

Signed-off-by: Eric Paris

fanotify: allow userspace to override max marks

2010-10-28T21:22:15+00:00

Some fanotify groups, especially those like AV scanners, will need to place
lots of marks, particularly ignore marks.  Since ignore marks do not pin
inodes in cache and are cleared if the inode is removed from core (usually
under memory pressure) we expose an interface for listeners, with
CAP_SYS_ADMIN, to override the maximum number of marks and be allowed to
set and 'unlimited' number of marks.  Programs which make use of this
feature will be able to OOM a machine.

Signed-off-by: Eric Paris

fanotify: limit the number of marks in a single fanotify group

2010-10-28T21:22:14+00:00

There is currently no limit on the number of marks a given fanotify group
can have.  Since fanotify is gated on CAP_SYS_ADMIN this was not seen as
a serious DoS threat.  This patch implements a default of 8192, the same as
inotify to work towards removing the CAP_SYS_ADMIN gating and eliminating
the default DoS'able status.

Signed-off-by: Eric Paris

fanotify: allow userspace to override max queue depth

2010-10-28T21:22:14+00:00

fanotify has a defualt max queue depth.  This patch allows processes which
explicitly request it to have an 'unlimited' queue depth.  These processes
need to be very careful to make sure they cannot fall far enough behind
that they OOM the box.  Thus this flag is gated on CAP_SYS_ADMIN.

Signed-off-by: Eric Paris