Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
1 年多 前同步成功

通知 160
Star 36
Fork 7
cloud-kernel
cloud-kernel
切换分支/标签
  1. 08 10月, 2016 4 次提交
  3. 20 9月, 2016 2 次提交
  5. 07 8月, 2014 2 次提交
  7. 25 2月, 2014 3 次提交
    • J
      fsnotify: Allocate overflow events with proper type · ff57cd58
      由 Jan Kara 提交于 
      Commit 7053aee2 "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: NJan Kara <jack@suse.cz>
      ff57cd58
    • J
      fanotify: Handle overflow in case of permission events · 482ef06c
      由 Jan Kara 提交于 
      If the event queue overflows when we are handling permission event, we
will never get response from userspace. So we must avoid waiting for it.
Change fsnotify_add_notify_event() to return whether overflow has
happened so that we can detect it in fanotify_handle_event() and act
accordingly.
Signed-off-by: NJan Kara <jack@suse.cz>
      482ef06c
    • J
      fsnotify: Fix detection whether overflow event is queued · 2513190a
      由 Jan Kara 提交于 
      Currently we didn't initialize event's list head when we removed it from
the event list. Thus a detection whether overflow event is already
queued wasn't working. Fix it by always initializing the list head when
deleting event from a list.
Signed-off-by: NJan Kara <jack@suse.cz>
      2513190a
  9. 29 1月, 2014 1 次提交
  11. 22 1月, 2014 1 次提交
    • J
      fsnotify: do not share events between notification groups · 7053aee2
      由 Jan Kara 提交于 
      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: NJan Kara <jack@suse.cz>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7053aee2
  13. 12 12月, 2012 1 次提交
  15. 19 11月, 2012 1 次提交
  17. 24 3月, 2012 1 次提交
  19. 27 7月, 2011 1 次提交
  21. 13 8月, 2010 1 次提交
  23. 28 7月, 2010 14 次提交
    • E
      vfs/fsnotify: fsnotify_close can delay the final work in fput · c1e5c954
      由 Eric Paris 提交于 
      fanotify almost works like so:

user context calls fsnotify_* function with a struct file.
   fsnotify takes a reference on the struct path
user context goes about it's buissiness

at some later point in time the fsnotify listener gets the struct path
   fanotify listener calls dentry_open() to create a file which userspace can deal with
      listener drops the reference on the struct path
at some later point the listener calls close() on it's new file

With the switch from struct path to struct file this presents a problem for
fput() and fsnotify_close().  fsnotify_close() is called when the filp has
already reached 0 and __fput() wants to do it's cleanup.

The solution presented here is a bit odd.  If an event is created from a
struct file we take a reference on the file.  We check however if the f_count
was already 0 and if so we take an EXTRA reference EVEN THOUGH IT WAS ZERO.
In __fput() (where we know the f_count hit 0 once) we check if the f_count is
non-zero and if so we drop that 'extra' ref and return without destroying the
file.
Signed-off-by: NEric Paris <eparis@redhat.com>
      c1e5c954
    • E
      fsnotify: store struct file not struct path · 3bcf3860
      由 Eric Paris 提交于 
      Al explains that calling dentry_open() with a mnt/dentry pair is only
garunteed to be safe if they are already used in an open struct file.  To
make sure this is the case don't store and use a struct path in fsnotify,
always use a struct file.
Signed-off-by: NEric Paris <eparis@redhat.com>
      3bcf3860
    • E
      fsnotify: fsnotify_add_notify_event should return an event · f70ab54c
      由 Eric Paris 提交于 
      Rather than the horrific void ** argument and such just to pass the
fanotify_merge event back to the caller of fsnotify_add_notify_event() have
those things return an event if it was different than the event suggusted to
be added.
Signed-off-by: NEric Paris <eparis@redhat.com>
      f70ab54c
    • E
      fsnotify: add pr_debug throughout · 5ba08e2e
      由 Eric Paris 提交于 
      It can be hard to debug fsnotify since there are so few printks.  Use
pr_debug to allow for dynamic debugging.
Signed-off-by: NEric Paris <eparis@redhat.com>
      5ba08e2e
    • E
      fsnotify: use unsigned char * for dentry->d_name.name · 59b0df21
      由 Eric Paris 提交于 
      fsnotify was using char * when it passed around the d_name.name string
internally but it is actually an unsigned char *.  This patch switches
fsnotify to use unsigned and should silence some pointer signess warnings
which have popped out of xfs.  I do not add -Wpointer-sign to the fsnotify
code as there are still issues with kstrdup and strlen which would pop
out needless warnings.
Signed-off-by: NEric Paris <eparis@redhat.com>
      59b0df21
    • E
      fsnotify: intoduce a notification merge argument · 6e5f77b3
      由 Eric Paris 提交于 
      Each group can define their own notification (and secondary_q) merge
function.  Inotify does tail drop, fanotify does matching and drop which
can actually allocate a completely new event.  But for fanotify to properly
deal with permissions events it needs to know the new event which was
ultimately added to the notification queue.  This patch just implements a
void ** argument which is passed to the merge function.  fanotify can use
this field to pass the new event back to higher layers.
Signed-off-by: NEric Paris <eparis@redhat.com>
for fanotify to properly deal with permissions events
      6e5f77b3
    • A
      fanotify: Add pids to events · 32c32632
      由 Andreas Gruenbacher 提交于 
      Pass the process identifiers of the triggering processes to fanotify
listeners: this information is useful for event filtering and logging.
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Signed-off-by: NEric Paris <eparis@redhat.com>
      32c32632
    • A
      fsnotify: kill FSNOTIFY_EVENT_FILE · 72acc854
      由 Andreas Gruenbacher 提交于 
      Some fsnotify operations send a struct file.  This is more information than
we technically need.  We instead send a struct path in all cases instead of
sometimes a path and sometimes a file.
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Signed-off-by: NEric Paris <eparis@redhat.com>
      72acc854
    • E
      fsnotify: lock annotation for event replacement · cac69dad
      由 Eric Paris 提交于 
      fsnotify_replace_event need to lock both the old and the new event.  This
causes lockdep to get all pissed off since it dosn't know this is safe.
It's safe in this case since the new event is impossible to be reached from
other places in the kernel.
Signed-off-by: NEric Paris <eparis@redhat.com>
      cac69dad
    • E
      fsnotify: replace an event on a list · 1201a536
      由 Eric Paris 提交于 
      fanotify would like to clone events already on its notification list, make
changes to the new event, and then replace the old event on the list with
the new event.  This patch implements the replace functionality of that
process.
Signed-off-by: NEric Paris <eparis@redhat.com>
      1201a536
    • E
      fsnotify: clone existing events · b4e4e140
      由 Eric Paris 提交于 
      fsnotify_clone_event will take an event, clone it, and return the cloned
event to the caller.  Since events may be in use by multiple fsnotify
groups simultaneously certain event entries (such as the mask) cannot be
changed after the event was created.  Since fanotify would like to merge
events happening on the same file it needs a new clean event to work with
so it can change any fields it wishes.
Signed-off-by: NEric Paris <eparis@redhat.com>
      b4e4e140
    • E
      fsnotify: per group notification queue merge types · 74766bbf
      由 Eric Paris 提交于 
      inotify only wishes to merge a new event with the last event on the
notification fifo.  fanotify is willing to merge any events including by
means of bitwise OR masks of multiple events together.  This patch moves
the inotify event merging logic out of the generic fsnotify notification.c
and into the inotify code.  This allows each use of fsnotify to provide
their own merge functionality.
Signed-off-by: NEric Paris <eparis@redhat.com>
      74766bbf
    • E
      fsnotify: use kmem_cache_zalloc to simplify event initialization · 6f3a539e
      由 Eric Paris 提交于 
      fsnotify event initialization is done entry by entry with almost everything
set to either 0 or NULL.  Use kmem_cache_zalloc and only initialize things
that need non-zero initialization.  Also means we don't have to change
initialization entries based on the config options.
Signed-off-by: NEric Paris <eparis@redhat.com>
      6f3a539e
    • E
      fsnotify: use fsnotify_create_event to allocate the q_overflow event · b4277d3d
      由 Eric Paris 提交于 
      Currently fsnotify defines a static fsnotify event which is sent when a
group overflows its allotted queue length.  This patch just allocates that
event from the event cache rather than defining it statically.  There is no
known reason that the current implementation is wrong, but this makes sure the
event is initialized and created like any other.
Signed-off-by: NEric Paris <eparis@redhat.com>
      b4277d3d
  25. 19 10月, 2009 1 次提交
  27. 18 8月, 2009 2 次提交
  29. 22 7月, 2009 3 次提交
    • E
      inotify: use GFP_NOFS under potential memory pressure · f44aebcc
      由 Eric Paris 提交于 
      inotify can have a watchs removed under filesystem reclaim.

=================================
[ INFO: inconsistent lock state ]
2.6.31-rc2 #16
---------------------------------
inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
khubd/217 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (iprune_mutex){+.+.?.}, at: [<c10ba899>] invalidate_inodes+0x20/0xe3
{IN-RECLAIM_FS-W} state was registered at:
  [<c10536ab>] __lock_acquire+0x2c9/0xac4
  [<c1053f45>] lock_acquire+0x9f/0xc2
  [<c1308872>] __mutex_lock_common+0x2d/0x323
  [<c1308c00>] mutex_lock_nested+0x2e/0x36
  [<c10ba6ff>] shrink_icache_memory+0x38/0x1b2
  [<c108bfb6>] shrink_slab+0xe2/0x13c
  [<c108c3e1>] kswapd+0x3d1/0x55d
  [<c10449b5>] kthread+0x66/0x6b
  [<c1003fdf>] kernel_thread_helper+0x7/0x10
  [<ffffffff>] 0xffffffff

Two things are needed to fix this.  First we need a method to tell
fsnotify_create_event() to use GFP_NOFS and second we need to stop using
one global IN_IGNORED event and allocate them one at a time.  This solves
current issues with multiple IN_IGNORED on a queue having tail drop
problems and simplifies the allocations since we don't have to worry about
two tasks opperating on the IGNORED event concurrently.
Signed-off-by: NEric Paris <eparis@redhat.com>
      f44aebcc
    • E
      fsnotify: fix inotify tail drop check with path entries · c05594b6
      由 Eric Paris 提交于 
      fsnotify drops new events when they are the same as the tail event on the
queue to be sent to userspace.  The problem is that if the event comes with
a path we forget to break out of the switch statement and fall into the
code path which matches on events that do not have any type of file backed
information (things like IN_UNMOUNT and IN_Q_OVERFLOW).  The problem is
that this code thinks all such events should be dropped.  Fix is to add a
break.
Signed-off-by: NEric Paris <eparis@redhat.com>
      c05594b6
    • E
      inotify: check filename before dropping repeat events · 4a148ba9
      由 Eric Paris 提交于 
      inotify drops events if the last event on the queue is the same as the
current event.  But it does 2 things wrong.  First it is comparing old->inode
with new->inode.  But after an event if put on the queue the ->inode is no
longer allowed to be used.  It's possible between the last event and this new
event the inode could be reused and we would falsely match the inode's memory
address between two differing events.

The second problem is that when a file is removed fsnotify is passed the
negative dentry for the removed object rather than the postive dentry from
immediately before the removal.  This mean the (broken) inotify tail drop code
was matching the NULL ->inode of differing events.

The fix is to check the file name which is stored with events when doing the
tail drop instead of wrongly checking the address of the stored ->inode.
Reported-by: NScott James Remnant <scott@ubuntu.com>
Signed-off-by: NEric Paris <eparis@redhat.com>
      4a148ba9
  31. 12 6月, 2009 2 次提交