Граф коммитов

37 Коммитов

Автор SHA1 Сообщение Дата
Ralf Baechle 12b1b32168 Inotify: Fix build failure in inotify user support
CONFIG_INOTIFY_USER defined but CONFIG_ANON_INODES undefined will result
in the following build failure:

    LD      vmlinux
  fs/built-in.o: In function 'sys_inotify_init1':
  (.text.sys_inotify_init1+0x22c): undefined reference to 'anon_inode_getfd'
  fs/built-in.o: In function `sys_inotify_init1':
  (.text.sys_inotify_init1+0x22c): relocation truncated to fit: R_MIPS_26 against 'anon_inode_getfd'
  make[2]: *** [vmlinux] Error 1
  make[1]: *** [sub-make] Error 2
  make: *** [all] Error 2

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-30 10:14:56 -07:00
Al Viro c44dcc56d2 switch inotify_user to anon_inode
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-02-19 03:35:12 -05:00
Eric Paris 976ae32be4 inotify: only warn once for inotify problems
inotify will WARN() if it finds that the idr and the fsnotify internals
somehow got out of sync.  It was only supposed to do this once but due
to this stupid bug it would warn every single time a problem was
detected.

Signed-off-by: Eric Paris <eparis@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-15 14:49:23 -08:00
Eric Paris 9e572cc987 inotify: do not reuse watch descriptors
Since commit 7e790dd5fc ("inotify: fix
error paths in inotify_update_watch") inotify changed the manor in which
it gave watch descriptors back to userspace.  Previous to this commit
inotify acted like the following:

  inotify_add_watch(X, Y, Z) = 1
  inotify_rm_watch(X, 1);
  inotify_add_watch(X, Y, Z) = 2

but after this patch inotify would return watch descriptors like so:

  inotify_add_watch(X, Y, Z) = 1
  inotify_rm_watch(X, 1);
  inotify_add_watch(X, Y, Z) = 1

which I saw as equivalent to opening an fd where

  open(file) = 1;
  close(1);
  open(file) = 1;

seemed perfectly reasonable.  The issue is that quite a bit of userspace
apparently relies on the behavior in which watch descriptors will not be
quickly reused.  KDE relies on it, I know some selinux packages rely on
it, and I have heard complaints from other random sources such as debian
bug 558981.

Although the man page implies what we do is ok, we broke userspace so
this patch almost reverts us to the old behavior.  It is still slightly
racey and I have patches that would fix that, but they are rather large
and this will fix it for all real world cases.  The race is as follows:

 - task1 creates a watch and blocks in idr_new_watch() before it updates
   the hint.
 - task2 creates a watch and updates the hint.
 - task1 updates the hint with it's older wd
 - task removes the watch created by task2
 - task adds a new watch and will reuse the wd originally given to task2

it requires moving some locking around the hint (last_wd) but this should
solve it for the real world and be -stable safe.

As a side effect this patch papers over a bug in the lib/idr code which
is causing a large number WARN's to pop on people's system and many
reports in kerneloops.org.  I'm working on the root cause of that idr
bug seperately but this should make inotify immune to that issue.

Signed-off-by: Eric Paris <eparis@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-15 14:49:23 -08:00
Al Viro 2c48b9c455 switch alloc_file() to passing struct path
... and have the caller grab both mnt and dentry; kill
leak in infiniband, while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16 12:16:42 -05:00
Al Viro 825f9692fb switched inotify_init1() to alloc_file()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16 12:16:40 -05:00
Linus Torvalds 4ef58d4e2a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits)
  tree-wide: fix misspelling of "definition" in comments
  reiserfs: fix misspelling of "journaled"
  doc: Fix a typo in slub.txt.
  inotify: remove superfluous return code check
  hdlc: spelling fix in find_pvc() comment
  doc: fix regulator docs cut-and-pasteism
  mtd: Fix comment in Kconfig
  doc: Fix IRQ chip docs
  tree-wide: fix assorted typos all over the place
  drivers/ata/libata-sff.c: comment spelling fixes
  fix typos/grammos in Documentation/edac.txt
  sysctl: add missing comments
  fs/debugfs/inode.c: fix comment typos
  sgivwfb: Make use of ARRAY_SIZE.
  sky2: fix sky2_link_down copy/paste comment error
  tree-wide: fix typos "couter" -> "counter"
  tree-wide: fix typos "offest" -> "offset"
  fix kerneldoc for set_irq_msi()
  spidev: fix double "of of" in comment
  comment typo fix: sybsystem -> subsystem
  ...
2009-12-09 19:43:33 -08:00
Giuseppe Scrivano 336e8683b9 inotify: remove superfluous return code check
Signed-off-by: Giuseppe Scrivano <gscrivano@gnu.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-04 15:39:58 +01:00
Eric W. Biederman 6d4561110a sysctl: Drop & in front of every proc_handler.
For consistency drop & in front of every proc_handler.  Explicity
taking the address is unnecessary and it prevents optimizations
like stubbing the proc_handlers to NULL.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-18 08:37:40 -08:00
Eric W. Biederman ab09203e30 sysctl fs: Remove dead binary sysctl support
Now that sys_sysctl is a generic wrapper around /proc/sys  .ctl_name
and .strategy members of sysctl tables are dead code.  Remove them.

Cc: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-12 02:04:55 -08:00
Eric Paris 750a8870fe inotify: update the group mask on mark addition
Seperating the addition and update of marks in inotify resulted in a
regression in that inotify never gets events.  The inotify group mask is
always 0.  This mask should be updated any time a new mark is added.

Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-28 12:51:14 -04:00
Eric Paris 83cb10f0ef inotify: fix length reporting and size checking
0db501bd06 introduced a regresion in that it now sends a nul
terminator but the length accounting when checking for space or
reporting to userspace did not take this into account.  This corrects
all of the rounding logic.

Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-28 11:57:55 -04:00
Brian Rogers b962e7312a inotify: do not send a block of zeros when no pathname is available
When an event has no pathname, there's no need to pad it with a null byte and
therefore generate an inotify_event sized block of zeros. This fixes a
regression introduced by commit 0db501bd06 where
my system wouldn't finish booting because some process was being confused by
this.

Signed-off-by: Brian Rogers <brian@xyzw.org>
Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-28 10:03:06 -04:00
Eric W. Biederman 0db501bd06 inotify: Ensure we alwasy write the terminating NULL.
Before the rewrite copy_event_to_user always wrote a terqminating '\0'
byte to user space after the filename.  Since the rewrite that
terminating byte was skipped if your filename is exactly a multiple of
event_size.  Ouch!

So add one byte to name_size before we round up and use clear_user to
set userspace to zero like /dev/zero does instead of copying the
strange nul_inotify_event.  I can't quite convince myself len_to_zero
will never exceed 16 and even if it doesn't clear_user should be more
efficient and a more accurate reflection of what the code is trying to
do.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-27 08:02:10 -04:00
Eric Paris dead537dd8 inotify: fix locking around inotify watching in the idr
The are races around the idr storage of inotify watches.  It's possible
that a watch could be found from sys_inotify_rm_watch() in the idr, but it
could be removed from the idr before that code does it's removal.  Move the
locking and the refcnt'ing so that these have to happen atomically.

Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-27 08:02:04 -04:00
Eric Paris cf4374267f inotify: do not BUG on idr entries at inotify destruction
If an inotify watch is left in the idr when an fsnotify group is destroyed
this will lead to a BUG.  This is not a dangerous situation and really
indicates a programming bug and leak of memory.  This patch changes it to
use a WARN and a printk rather than killing people's boxes.

Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-27 08:02:04 -04:00
Eric Paris 52cef7555a inotify: seperate new watch creation updating existing watches
There is nothing known wrong with the inotify watch addition/modification
but this patch seperates the two code paths to make them each easy to
verify as correct.

Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-27 08:02:04 -04:00
Eric Paris 08e53fcb0d inotify: start watch descriptor count at 1
The inotify_add_watch man page specifies that inotify_add_watch() will
return a non-negative integer.  However, historically the inotify
watches started at 1, not at 0.

Turns out that the inotifywait program provided by the inotify-tools
package doesn't properly handle a 0 watch descriptor.  In 7e790dd5 we
changed from starting at 1 to starting at 0.  This patch starts at 1,
just like in previous kernels, but also just like in previous kernels
it's possible for it to wrap back to 0.  This preserves the kernel
functionality exactly like it was before the patch (neither method broke
the spec)

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-17 13:37:37 -07:00
Eric Paris eef3a116be notify: unused event private race
inotify decides if private data it passed to get added to an event was
used by checking list_empty().  But it's possible that the event may
have been dequeued and the private event removed so it would look empty.

The fix is to use the return code from fsnotify_add_notify_event rather
than looking at the list.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-17 13:37:37 -07:00
Eric Paris f44aebcc56 inotify: use GFP_NOFS under potential memory pressure
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: Eric Paris <eparis@redhat.com>
2009-07-21 15:26:27 -04:00
Eric Paris 520dc2a526 fsnotify: use def_bool in kconfig instead of letting the user choose
fsnotify doens't give the user anything.  If someone chooses inotify or
dnotify it should build fsnotify, if they don't select one it shouldn't be
built.  This patch changes fsnotify to be a def_bool=n and makes everything
else select it.  Also fixes the issue people complained about on lwn where
gdm hung because they didn't have inotify and they didn't get the inotify
build option.....

Signed-off-by: Eric Paris <eparis@redhat.com>
2009-07-21 15:26:26 -04:00
Eric Paris 7e790dd5fc inotify: fix error paths in inotify_update_watch
inotify_update_watch could leave things in a horrid state on a number of
error paths.  We could try to remove idr entries that didn't exist, we
could send an IN_IGNORED to userspace for watches that don't exist, and a
bit of other stupidity.  Clean these up by doing the idr addition before we
put the mark on the inode since we can clean that up on error and getting
off the inode's mark list is hard.

Signed-off-by: Eric Paris <eparis@redhat.com>
2009-07-21 15:26:26 -04:00
Eric Paris 75fe2b2639 inotify: do not leak inode marks in inotify_add_watch
inotify_add_watch had a couple of problems.  The biggest being that if
inotify_add_watch was called on the same inode twice (to update or change the
event mask) a refence was taken on the original inode mark by
fsnotify_find_mark_entry but was not being dropped at the end of the
inotify_add_watch call.  Thus if inotify_rm_watch was called although the mark
was removed from the inode, the refcnt wouldn't hit zero and we would leak
memory.

Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2009-07-21 15:26:26 -04:00
Eric Paris 5549f7cdf8 inotify: drop user watch count when a watch is removed
The inotify rewrite forgot to drop the inotify watch use cound when a watch
was removed.  This means that a single inotify fd can only ever register a
maximum of /proc/sys/fs/max_user_watches even if some of those had been
freed.

Signed-off-by: Eric Paris <eparis@redhat.com>
2009-07-21 15:26:26 -04:00
Keith Packard bdae997f44 fs/notify/inotify: decrement user inotify count on close
The per-user inotify_devs value is incremented each time a new file is
allocated, but never decremented. This led to inotify_init failing after a
limited number of calls.

Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2009-07-02 08:23:00 -04:00
Eric Paris 528da3e9e2 inotify: inotify_destroy_mark_entry could get called twice
inotify_destroy_mark_entry could get called twice for the same mark since it
is called directly in inotify_rm_watch and when the mark is being destroyed for
another reason.  As an example assume that the file being watched was just
deleted so inotify_destroy_mark_entry would get called from the path
fsnotify_inoderemove() -> fsnotify_destroy_marks_by_inode() ->
fsnotify_destroy_mark_entry() -> inotify_destroy_mark_entry().  If this
happened at the same time as userspace tried to remove a watch via
inotify_rm_watch we could attempt to remove the mark from the idr twice and
could thus double dec the ref cnt and potentially could be in a use after
free/double free situation.  The fix is to have inotify_rm_watch use the
generic recursive safe fsnotify_destroy_mark_by_entry() so we are sure the
inotify_destroy_mark_entry() function can only be called one.

This patch also renames the function to inotify_ingored_remove_idr() so it is
clear what is actually going on in the function.

Hopefully this fixes:
[   20.342058] idr_remove called for id=20 which is not allocated.
[   20.348000] Pid: 1860, comm: udevd Not tainted 2.6.30-tip #1077
[   20.353933] Call Trace:
[   20.356410]  [<ffffffff811a82b7>] idr_remove+0x115/0x18f
[   20.361737]  [<ffffffff8134259d>] ? _spin_lock+0x6d/0x75
[   20.367061]  [<ffffffff8111640a>] ? inotify_destroy_mark_entry+0xa3/0xcf
[   20.373771]  [<ffffffff8111641e>] inotify_destroy_mark_entry+0xb7/0xcf
[   20.380306]  [<ffffffff81115913>] inotify_freeing_mark+0xe/0x10
[   20.386238]  [<ffffffff8111410d>] fsnotify_destroy_mark_by_entry+0x143/0x170
[   20.393293]  [<ffffffff811163a3>] inotify_destroy_mark_entry+0x3c/0xcf
[   20.399829]  [<ffffffff811164d1>] sys_inotify_rm_watch+0x9b/0xc6
[   20.405850]  [<ffffffff8100bcdb>] system_call_fastpath+0x16/0x1b

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Eric Paris <eparis@redhat.com>
Tested-by: Peter Ziljlstra <peterz@infradead.org>
2009-06-19 12:42:48 -04:00
Eric Paris e42e27736d inotify/dnotify: should_send_event shouldn't match on FS_EVENT_ON_CHILD
inotify and dnotify will both indicate that they want any event which came
from a child inode.  The fix is to mask off FS_EVENT_ON_CHILD when deciding
if inotify or dnotify is interested in a given event.

Signed-off-by: Eric Paris <eparis@redhat.com>
2009-06-11 14:57:54 -04:00
Eric Paris 63c882a054 inotify: reimplement inotify using fsnotify
Reimplement inotify_user using fsnotify.  This should be feature for feature
exactly the same as the original inotify_user.  This does not make any changes
to the in kernel inotify feature used by audit.  Those patches (and the eventual
removal of in kernel inotify) will come after the new inotify_user proves to be
working correctly.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
2009-06-11 14:57:54 -04:00
Eric Paris 90586523eb fsnotify: unified filesystem notification backend
fsnotify is a backend for filesystem notification.  fsnotify does
not provide any userspace interface but does provide the basis
needed for other notification schemes such as dnotify.  fsnotify
can be extended to be the backend for inotify or the upcoming
fanotify.  fsnotify provides a mechanism for "groups" to register for
some set of filesystem events and to then deliver those events to
those groups for processing.

fsnotify has a number of benefits, the first being actually shrinking the size
of an inode.  Before fsnotify to support both dnotify and inotify an inode had

        unsigned long           i_dnotify_mask; /* Directory notify events */
        struct dnotify_struct   *i_dnotify; /* for directory notifications */
        struct list_head        inotify_watches; /* watches on this inode */
        struct mutex            inotify_mutex;  /* protects the watches list

But with fsnotify this same functionallity (and more) is done with just

        __u32                   i_fsnotify_mask; /* all events for this inode */
        struct hlist_head       i_fsnotify_mark_entries; /* marks on this inode */

That's right, inotify, dnotify, and fanotify all in 64 bits.  We used that
much space just in inotify_watches alone, before this patch set.

fsnotify object lifetime and locking is MUCH better than what we have today.
inotify locking is incredibly complex.  See 8f7b0ba1c8 as an example of
what's been busted since inception.  inotify needs to know internal semantics
of superblock destruction and unmounting to function.  The inode pinning and
vfs contortions are horrible.

no fsnotify implementers do allocation under locks.  This means things like
f04b30de3 which (due to an overabundance of caution) changes GFP_KERNEL to
GFP_NOFS can be reverted.  There are no longer any allocation rules when using
or implementing your own fsnotify listener.

fsnotify paves the way for fanotify.  In brief fanotify is a notification
mechanism that delivers the lisener both an 'event' and an open file descriptor
to the object in question.  This means that fanotify is pathname agnostic.
Some on lkml may not care for the original companies or users that pushed for
TALPA, but fanotify was designed with flexibility and input for other users in
mind.  The readahead group expressed interest in fanotify as it could be used
to profile disk access on boot without breaking the audit system.  The desktop
search groups have also expressed interest in fanotify as it solves a number
of the race conditions and problems present with managing inotify when more
than a limited number of specific files are of interest.  fanotify can provide
for a userspace access control system which makes it a clean interface for AV
vendors to hook without trying to do binary patching on the syscall table,
LSM, and everywhere else they do their things today.  With this patch series
fanotify can be implemented in less than 1200 lines of easy to review code.
Almost all of which is the socket based user interface.

This patch series builds fsnotify to the point that it can implement
dnotify and inotify_user.  Patches exist and will be sent soon after
acceptance to finish the in kernel inotify conversion (audit) and implement
fanotify.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
2009-06-11 14:57:52 -04:00
Wu Fengguang 381a80e6df inotify: use GFP_NOFS in kernel_event() to work around a lockdep false-positive
There is what we believe to be a false positive reported by lockdep.

inotify_inode_queue_event() => take inotify_mutex => kernel_event() =>
kmalloc() => SLOB => alloc_pages_node() => page reclaim => slab reclaim =>
dcache reclaim => inotify_inode_is_dead => take inotify_mutex => deadlock

The plan is to fix this via lockdep annotation, but that is proving to be
quite involved.

The patch flips the allocation over to GFP_NFS to shut the warning up, for
the 2.6.30 release.

Hopefully we will fix this for real in 2.6.31.  I'll queue a patch in -mm
to switch it back to GFP_KERNEL so we don't forget.

  =================================
  [ INFO: inconsistent lock state ]
  2.6.30-rc2-next-20090417 #203
  ---------------------------------
  inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
  kswapd0/380 [HC0[0]:SC0[0]:HE1:SE1] takes:
   (&inode->inotify_mutex){+.+.?.}, at: [<ffffffff8112f1b5>] inotify_inode_is_dead+0x35/0xb0
  {RECLAIM_FS-ON-W} state was registered at:
    [<ffffffff81079188>] mark_held_locks+0x68/0x90
    [<ffffffff810792a5>] lockdep_trace_alloc+0xf5/0x100
    [<ffffffff810f5261>] __kmalloc_node+0x31/0x1e0
    [<ffffffff81130652>] kernel_event+0xe2/0x190
    [<ffffffff81130826>] inotify_dev_queue_event+0x126/0x230
    [<ffffffff8112f096>] inotify_inode_queue_event+0xc6/0x110
    [<ffffffff8110444d>] vfs_create+0xcd/0x140
    [<ffffffff8110825d>] do_filp_open+0x88d/0xa20
    [<ffffffff810f6b68>] do_sys_open+0x98/0x140
    [<ffffffff810f6c50>] sys_open+0x20/0x30
    [<ffffffff8100c272>] system_call_fastpath+0x16/0x1b
    [<ffffffffffffffff>] 0xffffffffffffffff
  irq event stamp: 690455
  hardirqs last  enabled at (690455): [<ffffffff81564fe4>] _spin_unlock_irqrestore+0x44/0x80
  hardirqs last disabled at (690454): [<ffffffff81565372>] _spin_lock_irqsave+0x32/0xa0
  softirqs last  enabled at (690178): [<ffffffff81052282>] __do_softirq+0x202/0x220
  softirqs last disabled at (690157): [<ffffffff8100d50c>] call_softirq+0x1c/0x50

  other info that might help us debug this:
  2 locks held by kswapd0/380:
   #0:  (shrinker_rwsem){++++..}, at: [<ffffffff810d0bd7>] shrink_slab+0x37/0x180
   #1:  (&type->s_umount_key#17){++++..}, at: [<ffffffff8110cfbf>] shrink_dcache_memory+0x11f/0x1e0

  stack backtrace:
  Pid: 380, comm: kswapd0 Not tainted 2.6.30-rc2-next-20090417 #203
  Call Trace:
   [<ffffffff810789ef>] print_usage_bug+0x19f/0x200
   [<ffffffff81018bff>] ? save_stack_trace+0x2f/0x50
   [<ffffffff81078f0b>] mark_lock+0x4bb/0x6d0
   [<ffffffff810799e0>] ? check_usage_forwards+0x0/0xc0
   [<ffffffff8107b142>] __lock_acquire+0xc62/0x1ae0
   [<ffffffff810f478c>] ? slob_free+0x10c/0x370
   [<ffffffff8107c0a1>] lock_acquire+0xe1/0x120
   [<ffffffff8112f1b5>] ? inotify_inode_is_dead+0x35/0xb0
   [<ffffffff81562d43>] mutex_lock_nested+0x63/0x420
   [<ffffffff8112f1b5>] ? inotify_inode_is_dead+0x35/0xb0
   [<ffffffff8112f1b5>] ? inotify_inode_is_dead+0x35/0xb0
   [<ffffffff81012fe9>] ? sched_clock+0x9/0x10
   [<ffffffff81077165>] ? lock_release_holdtime+0x35/0x1c0
   [<ffffffff8112f1b5>] inotify_inode_is_dead+0x35/0xb0
   [<ffffffff8110c9dc>] dentry_iput+0xbc/0xe0
   [<ffffffff8110cb23>] d_kill+0x33/0x60
   [<ffffffff8110ce23>] __shrink_dcache_sb+0x2d3/0x350
   [<ffffffff8110cffa>] shrink_dcache_memory+0x15a/0x1e0
   [<ffffffff810d0cc5>] shrink_slab+0x125/0x180
   [<ffffffff810d1540>] kswapd+0x560/0x7a0
   [<ffffffff810ce160>] ? isolate_pages_global+0x0/0x2c0
   [<ffffffff81065a30>] ? autoremove_wake_function+0x0/0x40
   [<ffffffff8107953d>] ? trace_hardirqs_on+0xd/0x10
   [<ffffffff810d0fe0>] ? kswapd+0x0/0x7a0
   [<ffffffff8106555b>] kthread+0x5b/0xa0
   [<ffffffff8100d40a>] child_rip+0xa/0x20
   [<ffffffff8100cdd0>] ? restore_args+0x0/0x30
   [<ffffffff81065500>] ? kthread+0x0/0xa0
   [<ffffffff8100d400>] ? child_rip+0x0/0x20

[eparis@redhat.com: fix audit too]
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-06 16:36:09 -07:00
Nick Piggin aabb8fdb41 fs: avoid I_NEW inodes
To be on the safe side, it should be less fragile to exclude I_NEW inodes
from inode list scans by default (unless there is an important reason to
have them).

Normally they will get excluded (eg.  by zero refcount or writecount etc),
however it is a bit fragile for list walkers to know exactly what parts of
the inode state is set up and valid to test when in I_NEW.  So along these
lines, move I_NEW checks upward as well (sometimes taking I_FREEING etc
checks with them too -- this shouldn't be a problem should it?)

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:44:05 -04:00
Ingo Molnar f04b30de3c inotify: fix GFP_KERNEL related deadlock
Enhanced lockdep coverage of __GFP_NOFS turned up this new lockdep
assert:

[ 1093.677775]
[ 1093.677781] =================================
[ 1093.680031] [ INFO: inconsistent lock state ]
[ 1093.680031] 2.6.29-rc5-tip-01504-gb49eca1-dirty #1
[ 1093.680031] ---------------------------------
[ 1093.680031] inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
[ 1093.680031] kswapd0/308 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 1093.680031]  (&inode->inotify_mutex){+.+.?.}, at: [<c0205942>] inotify_inode_is_dead+0x20/0x80
[ 1093.680031] {RECLAIM_FS-ON-W} state was registered at:
[ 1093.680031]   [<c01696b9>] mark_held_locks+0x43/0x5b
[ 1093.680031]   [<c016baa4>] lockdep_trace_alloc+0x6c/0x6e
[ 1093.680031]   [<c01cf8b0>] kmem_cache_alloc+0x20/0x150
[ 1093.680031]   [<c040d0ec>] idr_pre_get+0x27/0x6c
[ 1093.680031]   [<c02056e3>] inotify_handle_get_wd+0x25/0xad
[ 1093.680031]   [<c0205f43>] inotify_add_watch+0x7a/0x129
[ 1093.680031]   [<c020679e>] sys_inotify_add_watch+0x20f/0x250
[ 1093.680031]   [<c010389e>] sysenter_do_call+0x12/0x35
[ 1093.680031]   [<ffffffff>] 0xffffffff
[ 1093.680031] irq event stamp: 60417
[ 1093.680031] hardirqs last  enabled at (60417): [<c018d5f5>] call_rcu+0x53/0x59
[ 1093.680031] hardirqs last disabled at (60416): [<c018d5b9>] call_rcu+0x17/0x59
[ 1093.680031] softirqs last  enabled at (59656): [<c0146229>] __do_softirq+0x157/0x16b
[ 1093.680031] softirqs last disabled at (59651): [<c0106293>] do_softirq+0x74/0x15d
[ 1093.680031]
[ 1093.680031] other info that might help us debug this:
[ 1093.680031] 2 locks held by kswapd0/308:
[ 1093.680031]  #0:  (shrinker_rwsem){++++..}, at: [<c01b0502>] shrink_slab+0x36/0x189
[ 1093.680031]  #1:  (&type->s_umount_key#4){+++++.}, at: [<c01e6d77>] shrink_dcache_memory+0x110/0x1fb
[ 1093.680031]
[ 1093.680031] stack backtrace:
[ 1093.680031] Pid: 308, comm: kswapd0 Not tainted 2.6.29-rc5-tip-01504-gb49eca1-dirty #1
[ 1093.680031] Call Trace:
[ 1093.680031]  [<c016947a>] valid_state+0x12a/0x13d
[ 1093.680031]  [<c016954e>] mark_lock+0xc1/0x1e9
[ 1093.680031]  [<c016a5b4>] ? check_usage_forwards+0x0/0x3f
[ 1093.680031]  [<c016ab74>] __lock_acquire+0x2c6/0xac8
[ 1093.680031]  [<c01688d9>] ? register_lock_class+0x17/0x228
[ 1093.680031]  [<c016b3d3>] lock_acquire+0x5d/0x7a
[ 1093.680031]  [<c0205942>] ? inotify_inode_is_dead+0x20/0x80
[ 1093.680031]  [<c08824c4>] __mutex_lock_common+0x3a/0x4cb
[ 1093.680031]  [<c0205942>] ? inotify_inode_is_dead+0x20/0x80
[ 1093.680031]  [<c08829ed>] mutex_lock_nested+0x2e/0x36
[ 1093.680031]  [<c0205942>] ? inotify_inode_is_dead+0x20/0x80
[ 1093.680031]  [<c0205942>] inotify_inode_is_dead+0x20/0x80
[ 1093.680031]  [<c01e6672>] dentry_iput+0x90/0xc2
[ 1093.680031]  [<c01e67a3>] d_kill+0x21/0x45
[ 1093.680031]  [<c01e6a46>] __shrink_dcache_sb+0x27f/0x355
[ 1093.680031]  [<c01e6dc5>] shrink_dcache_memory+0x15e/0x1fb
[ 1093.680031]  [<c01b05ed>] shrink_slab+0x121/0x189
[ 1093.680031]  [<c01b0d12>] kswapd+0x39f/0x561
[ 1093.680031]  [<c01ae499>] ? isolate_pages_global+0x0/0x233
[ 1093.680031]  [<c0157eae>] ? autoremove_wake_function+0x0/0x43
[ 1093.680031]  [<c01b0973>] ? kswapd+0x0/0x561
[ 1093.680031]  [<c0157daf>] kthread+0x41/0x82
[ 1093.680031]  [<c0157d6e>] ? kthread+0x0/0x82
[ 1093.680031]  [<c01043ab>] kernel_thread_helper+0x7/0x10

inotify_handle_get_wd() does idr_pre_get() which does a
kmem_cache_alloc() without __GFP_FS - and is hence deadlockable under
extreme MM pressure.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: MinChan Kim <minchan.kim@gmail.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18 15:37:56 -08:00
Vegard Nossum 3632dee2f8 inotify: clean up inotify_read and fix locking problems
If userspace supplies an invalid pointer to a read() of an inotify
instance, the inotify device's event list mutex is unlocked twice.
This causes an unbalance which effectively leaves the data structure
unprotected, and we can trigger oopses by accessing the inotify
instance from different tasks concurrently.

The best fix (contributed largely by Linus) is a total rewrite
of the function in question:

On Thu, Jan 22, 2009 at 7:05 AM, Linus Torvalds wrote:
> The thing to notice is that:
>
>  - locking is done in just one place, and there is no question about it
>   not having an unlock.
>
>  - that whole double-while(1)-loop thing is gone.
>
>  - use multiple functions to make nesting and error handling sane
>
>  - do error testing after doing the things you always need to do, ie do
>   this:
>
>        mutex_lock(..)
>        ret = function_call();
>        mutex_unlock(..)
>
>        .. test ret here ..
>
>   instead of doing conditional exits with unlocking or freeing.
>
> So if the code is written in this way, it may still be buggy, but at least
> it's not buggy because of subtle "forgot to unlock" or "forgot to free"
> issues.
>
> This _always_ unlocks if it locked, and it always frees if it got a
> non-error kevent.

Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Robert Love <rlove@google.com>
Cc: <stable@kernel.org>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-26 10:08:05 -08:00
Heiko Carstens 2e4d0924eb [CVE-2009-0029] System call wrappers part 29
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:30 +01:00
Heiko Carstens 938bb9f5e8 [CVE-2009-0029] System call wrappers part 28
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:30 +01:00
Michael Kerrisk 4ae8978cf9 inotify: fix type errors in interfaces
The problems lie in the types used for some inotify interfaces, both at the kernel level and at the glibc level. This mail addresses the kernel problem. I will follow up with some suggestions for glibc changes.

For the sys_inotify_rm_watch() interface, the type of the 'wd' argument is
currently 'u32', it should be '__s32' .  That is Robert's suggestion, and
is consistent with the other declarations of watch descriptors in the
kernel source, in particular, the inotify_event structure in
include/linux/inotify.h:

struct inotify_event {
        __s32           wd;             /* watch descriptor */
        __u32           mask;           /* watch mask */
        __u32           cookie;         /* cookie to synchronize two events */
        __u32           len;            /* length (including nulls) of name */
        char            name[0];        /* stub for possible name */
};

The patch makes the changes needed for inotify_rm_watch().

Signed-off-by: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Robert Love <rlove@google.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05 11:54:29 -05:00
Eric Paris 272eb01485 filesystem notification: create fs/notify to contain all fs notification
Creating a generic filesystem notification interface, fsnotify, which will be
used by inotify, dnotify, and eventually fanotify is really starting to
clutter the fs directory.  This patch simply moves inotify and dnotify into
fs/notify/inotify and fs/notify/dnotify respectively to make both current fs/
and future notification tidier.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:43 -05:00