The fsnotify main loop has 2 bools which indicated if we processed the
inode or vfsmount mark in that particular pass through the loop. These
bool can we replaced with the inode_group and vfsmount_group variables
and actually make the code a little easier to understand.
Signed-off-by: Eric Paris <eparis@redhat.com>
Marks were stored on the inode and vfsmonut mark list in order from
highest memory address to lowest memory address. The code to walk those
lists thought they were in order from lowest to highest with
unpredictable results when trying to match up marks from each. It was
possible that extra events would be sent to userspace when inode
marks ignoring events wouldn't get matched with the vfsmount marks.
This problem only affected fanotify when using both vfsmount and inode
marks simultaneously.
Signed-off-by: Eric Paris <eparis@redhat.com>
The appropriate error code when privileged operations are denied is
EPERM, not EACCES.
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Eric Paris <paris@paris.rdu.redhat.com>
This reminded me... you have two pr_debugs in fanotify_should_send_event
which output redundant information. Maybe you intended it like that so
it is selectable how much log spam you want, or if not you may want to
apply this patch.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@sophos.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
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 <agruen@suse.de>
Cc: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
The interesting 2 list lockstep walking didn't quite work out if the inode
marks only had ignores and the vfsmount list requested events. The code to
shortcut list traversal would not run the inode list since it didn't have real
event requests. This code forces inode list traversal when a vfsmount mark
matches the event type. Maybe we could add an i_fsnotify_ignored_mask field
to struct inode to get the shortcut back, but it doesn't seem worth it to grow
struct inode again.
I bet with the recent changes to lock the way we do now it would actually not
be a major perf hit to just drop i_fsnotify_mark_mask altogether. But that is
for another day.
Signed-off-by: Eric Paris <eparis@redhat.com>
The fsnotify main loop has 2 booleans which tell if a particular mark was
sent to the listeners or if it should be processed in the next pass. The
problem is that the booleans were not reset on each traversal of the loop.
So marks could get skipped even when they were not sent to the notifiers.
Reported-by: Tvrtko Ursulin <tvrtko.ursulin@sophos.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
The fanotify code is supposed to get the group from the mark. It accidentally
only used the inode_mark. If the vfsmount_mark was set but not the inode_mark
it would deref the NULL inode_mark. Get the group from the correct place.
Reported-by: Tvrtko Ursulin <tvrtko.ursulin@sophos.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
This reverts commit 3bcf3860a4 (and the
accompanying commit c1e5c95402 "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 <torvalds@linux-foundation.org>
* 'for-linus' of git://git.infradead.org/users/eparis/notify: (132 commits)
fanotify: use both marks when possible
fsnotify: pass both the vfsmount mark and inode mark
fsnotify: walk the inode and vfsmount lists simultaneously
fsnotify: rework ignored mark flushing
fsnotify: remove global fsnotify groups lists
fsnotify: remove group->mask
fsnotify: remove the global masks
fsnotify: cleanup should_send_event
fanotify: use the mark in handler functions
audit: use the mark in handler functions
dnotify: use the mark in handler functions
inotify: use the mark in handler functions
fsnotify: send fsnotify_mark to groups in event handling functions
fsnotify: Exchange list heads instead of moving elements
fsnotify: srcu to protect read side of inode and vfsmount locks
fsnotify: use an explicit flag to indicate fsnotify_destroy_mark has been called
fsnotify: use _rcu functions for mark list traversal
fsnotify: place marks on object in order of group memory address
vfs/fsnotify: fsnotify_close can delay the final work in fput
fsnotify: store struct file not struct path
...
Fix up trivial delete/modify conflict in fs/notify/inotify/inotify.c.
add I_CLEAR instead of replacing I_FREEING with it. I_CLEAR is
equivalent to I_FREEING for almost all code looking at either;
it's there to keep track of having called clear_inode() exactly
once per inode lifetime, at some point after having set I_FREEING.
I_CLEAR and I_FREEING never get set at the same time with the
current code, so we can switch to setting i_flags to I_FREEING | I_CLEAR
instead of I_CLEAR without loss of information. As the result of
such change, checks become simpler and the amount of code that needs
to know about I_CLEAR shrinks a lot.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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 <eparis@redhat.com>
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 <eparis@redhat.com>
We currently walk the list of marks on an inode followed by the list of
marks on the vfsmount. These are in order (by the memory address of the
group) so lets walk them both together. Eventually we can pass both the
inode mark and the vfsmount mark to helpers simultaneously.
Signed-off-by: Eric Paris <eparis@redhat.com>
currently ignored_mark clearing is done in a seperate list traversal
before the actual list traversal to send events. There is no need for
this. Do them at the same time.
Signed-off-by: Eric Paris <eparis@redhat.com>
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 <eparis@redhat.com>
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 <eparis@redhat.com>
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 <eparis@redhat.com>
The change to use srcu and walk the object list rather than the global
fsnotify_group list means that should_send_event is no longer needed for a
number of groups and can be simplified for others. Do that.
Signed-off-by: Eric Paris <eparis@redhat.com>
fanotify now gets a mark in the should_send_event and handle_event
functions. Rather than look up the mark themselves fanotify should just use
the mark it was handed.
Signed-off-by: Eric Paris <eparis@redhat.com>
dnotify now gets a mark in the should_send_event and handle_event
functions. Rather than look up the mark themselves dnotify should just use
the mark it was handed.
Signed-off-by: Eric Paris <eparis@redhat.com>
inotify now gets a mark in the should_send_event and handle_event
functions. Rather than look up the mark themselves inotify should just use
the mark it was handed.
Signed-off-by: Eric Paris <eparis@redhat.com>
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 <eparis@redhat.com>
Instead of moving list elements from destroy_list to &private_destroy_list,
exchange the list heads.
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
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 <eparis@redhat.com>
