linux-toradex.git/include/linux/fsnotify_backend.h, branch v2.6.36-rc5

fanotify: flush outstanding perm requests on group destroy

2010-08-23T00:28:16+00:00

When an fanotify listener is closing it may cause a deadlock between the
listener and the original task doing an fs operation.  If the original task
is waiting for a permissions response it will be holding the srcu lock.  The
listener cannot clean up and exit until after that srcu lock is syncronized.
Thus deadlock.  The fix introduced here is to stop accepting new permissions
events when a listener is shutting down and to grant permission for all
outstanding events.  Thus the original task will eventually release the srcu
lock and the listener can complete shutdown.

Reported-by: Andreas Gruenbacher 
Cc: Andreas Gruenbacher 
Signed-off-by: Eric Paris

Revert "fsnotify: store struct file not struct path"

2010-08-12T21:23:04+00:00

This reverts commit 3bcf3860a4ff9bbc522820b4b765e65e4deceb3e (and the
accompanying commit c1e5c954020e "vfs/fsnotify: fsnotify_close can delay
the final work in fput" that was a horribly ugly hack to make it work at
all).

The 'struct file' approach not only causes that disgusting hack, it
somehow breaks pulseaudio, probably due to some other subtlety with
f_count handling.

Fix up various conflicts due to later fsnotify work.

Signed-off-by: Linus Torvalds

fanotify: use both marks when possible

2010-07-28T14:18:55+00:00

fanotify currently, when given a vfsmount_mark will look up (if it exists)
the corresponding inode mark.  This patch drops that lookup and uses the
mark provided.

Signed-off-by: Eric Paris

fsnotify: pass both the vfsmount mark and inode mark

2010-07-28T14:18:54+00:00

should_send_event() and handle_event() will both need to look up the inode
event if they get a vfsmount event.  Lets just pass both at the same time
since we have them both after walking the lists in lockstep.

Signed-off-by: Eric Paris

fsnotify: remove global fsnotify groups lists

2010-07-28T14:18:54+00:00

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 group->mask

2010-07-28T14:18:54+00:00

group->mask is now useless.  It was originally a shortcut for fsnotify to
save on performance.  These checks are now redundant, so we remove them.

Signed-off-by: Eric Paris

fsnotify: remove the global masks

2010-07-28T14:18:54+00:00

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: send fsnotify_mark to groups in event handling functions

2010-07-28T14:18:52+00:00

With the change of fsnotify to use srcu walking the marks list instead of
walking the global groups list we now know the mark in question.  The code can
send the mark to the group's handling functions and the groups won't have to
find those marks themselves.

Signed-off-by: Eric Paris

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

2010-07-28T14:18:52+00:00

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: use an explicit flag to indicate fsnotify_destroy_mark has been called

2010-07-28T14:18:52+00:00

Currently fsnotify check is mark->group is NULL to decide if
fsnotify_destroy_mark() has already been called or not.  With the upcoming
rcu work it is a heck of a lot easier to use an explicit flag than worry
about group being set to NULL.

Signed-off-by: Eric Paris