linux.git/fs/sysfs, branch v2.6.31

sysfs: fix hardlink count on device_move

2009-07-28T20:45:21+00:00

Update directory hardlink count when moving kobjects to a new parent.
Fixes the following problem which occurs when several devices are
moved to the same parent and then unregistered:

> ls -laF /sys/devices/css0/defunct/
> total 0
> drwxr-xr-x 4294967295 root root    0 2009-07-14 17:02 ./
> drwxr-xr-x        114 root root    0 2009-07-14 17:02 ../
> drwxr-xr-x          2 root root    0 2009-07-14 17:01 power/
> -rw-r--r--          1 root root 4096 2009-07-14 17:01 uevent

Signed-off-by: Peter Oberparleiter 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

Free the memory allocated by memdup_user() in fs/sysfs/bin.c

2009-07-08T16:34:07+00:00

Commit 1c8542c7bb replaced kmalloc() with memdup_user() in the write()
function but also dropped the kfree(temp). The memdup_user() function
allocates memory which is never freed.

Signed-off-by: Catalin Marinas 
Cc: Parag Warudkar 
Signed-off-by: Linus Torvalds

Sysfs: fix possible memleak in sysfs_follow_link

2009-06-16T04:30:23+00:00

There is the possiblity of a memory leak if a page is allocated and if
sysfs_getlink() fails in the sysfs_follow_link.

Signed-off-by: Armin Kuster 
Signed-off-by: Greg Kroah-Hartman

sysfs: file.c: use create_singlethread_workqueue()

2009-05-28T21:24:07+00:00

We don't need a kernel thread per CPU for this application.

Acked-by: Alex Chiang 
Cc: Lai Jiangshan 
Cc: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

sysfs: use memdup_user()

2009-04-21T03:02:50+00:00

Remove open-coded memdup_user().

Signed-off-by: Li Zefan 
Signed-off-by: Al Viro

sysfs: sysfs poll keep the poll rule of regular file.

2009-04-16T23:17:09+00:00

Currently, following test programs don't finished.

% ruby -e '
Thread.new { sleep }
File.read("/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies")
'

strace expose the reason.

...
open("/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies", O_RDONLY|O_LARGEFILE) = 3
ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbf9fa6b8) = -1 ENOTTY (Inappropriate ioctl for device)
fstat64(3, {st_mode=S_IFREG|0444, st_size=4096, ...}) = 0
_llseek(3, 0, [0], SEEK_CUR)            = 0
select(4, [3], NULL, NULL, NULL)        = 1 (in [3])
read(3, "1400000 1300000 1200000 1100000 1"..., 4096) = 62
select(4, [3], NULL, NULL, NULL


Because Ruby (the scripting language) VM assume select system-call
against regular file don't block.  it because SUSv3 says "Regular files
shall always poll TRUE for reading and writing".  see
http://www.opengroup.org/onlinepubs/009695399/functions/poll.html it
seems valid assumption.

But sysfs_poll() don't keep this rule although sysfs file can read and
write always.

This patch restore proper poll behavior to sysfs.
/sys/block/md*/md/sync_action polling application and another sysfs
updating sensitive application still can use POLLERR and POLLPRI.

Cc: Neil Brown 
Signed-off-by: KOSAKI Motohiro 
Signed-off-by: Greg Kroah-Hartman

sysfs: don't use global workqueue in sysfs_schedule_callback()

2009-04-16T23:17:08+00:00

A sysfs attribute using sysfs_schedule_callback() to commit suicide
may end up calling device_unregister(), which will eventually call
a driver's ->remove function.

Drivers may call flush_scheduled_work() in their shutdown routines,
in which case lockdep will complain with something like the following:

  =============================================
  [ INFO: possible recursive locking detected ]
  2.6.29-rc8-kk #1
  ---------------------------------------------
  events/4/56 is trying to acquire lock:
  (events){--..}, at: [] flush_workqueue+0x0/0xa0

  but task is already holding lock:
  (events){--..}, at: [] run_workqueue+0x108/0x230

  other info that might help us debug this:
  3 locks held by events/4/56:
  #0:  (events){--..}, at: [] run_workqueue+0x108/0x230
  #1:  (&ss->work){--..}, at: [] run_workqueue+0x108/0x230
  #2:  (pci_remove_rescan_mutex){--..}, at: [] remove_callback+0x21/0x40

  stack backtrace:
  Pid: 56, comm: events/4 Not tainted 2.6.29-rc8-kk #1
  Call Trace:
  [] validate_chain+0xb7d/0x1260
  [] __lock_acquire+0x42e/0xa40
  [] lock_acquire+0x58/0x80
  [] ? flush_workqueue+0x0/0xa0
  [] flush_workqueue+0x4d/0xa0
  [] ? flush_workqueue+0x0/0xa0
  [] flush_scheduled_work+0x10/0x20
  [] e1000_remove+0x55/0xfe [e1000e]
  [] ? sysfs_schedule_callback_work+0x0/0x50
  [] pci_device_remove+0x32/0x70
  [] __device_release_driver+0x59/0x90
  [] device_release_driver+0x2b/0x40
  [] bus_remove_device+0xa6/0x120
  [] device_del+0x12b/0x190
  [] device_unregister+0x26/0x70
  [] pci_stop_dev+0x49/0x60
  [] pci_remove_bus_device+0x40/0xc0
  [] remove_callback+0x29/0x40
  [] sysfs_schedule_callback_work+0x1f/0x50
  [] run_workqueue+0x15a/0x230
  [] ? run_workqueue+0x108/0x230
  [] worker_thread+0x9f/0x100
  [] ? autoremove_wake_function+0x0/0x40
  [] ? worker_thread+0x0/0x100
  [] kthread+0x4d/0x80
  [] child_rip+0xa/0x20
  [] ? restore_args+0x0/0x30
  [] ? kthread+0x0/0x80
  [] ? child_rip+0x0/0x20

Although we know that the device_unregister path will never acquire
a lock that a driver might try to acquire in its ->remove, in general
we should never attempt to flush a workqueue from within the same
workqueue, and lockdep rightly complains.

So as long as sysfs attributes cannot commit suicide directly and we
are stuck with this callback mechanism, put the sysfs callbacks on
their own workqueue instead of the global one.

This has the side benefit that if a suicidal sysfs attribute kicks
off a long chain of ->remove callbacks, we no longer induce a long
delay on the global queue.

This also fixes a missing module_put in the error path introduced
by sysfs-only-allow-one-scheduled-removal-callback-per-kobj.patch.

We never destroy the workqueue, but I'm not sure that's a
problem.

Reported-by: Kenji Kaneshige 
Tested-by: Kenji Kaneshige 
Signed-off-by: Alex Chiang 
Signed-off-by: Greg Kroah-Hartman

mm: page_mkwrite change prototype to match fault: fix sysfs

2009-04-01T15:59:14+00:00

Fix warnings and return values in sysfs bin_page_mkwrite(), fixing
fs/sysfs/bin.c: In function `bin_page_mkwrite':
fs/sysfs/bin.c:250: warning: passing argument 2 of `bb->vm_ops->page_mkwrite' from incompatible pointer type
fs/sysfs/bin.c: At top level:
fs/sysfs/bin.c:280: warning: initialization from incompatible pointer type

Expects to have my [PATCH next] sysfs: fix some bin_vm_ops errors

Signed-off-by: Hugh Dickins 
Cc: Nick Piggin 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

2009-03-27T23:23:12+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (37 commits)
  fs: avoid I_NEW inodes
  Merge code for single and multiple-instance mounts
  Remove get_init_pts_sb()
  Move common mknod_ptmx() calls into caller
  Parse mount options just once and copy them to super block
  Unroll essentials of do_remount_sb() into devpts
  vfs: simple_set_mnt() should return void
  fs: move bdev code out of buffer.c
  constify dentry_operations: rest
  constify dentry_operations: configfs
  constify dentry_operations: sysfs
  constify dentry_operations: JFS
  constify dentry_operations: OCFS2
  constify dentry_operations: GFS2
  constify dentry_operations: FAT
  constify dentry_operations: FUSE
  constify dentry_operations: procfs
  constify dentry_operations: ecryptfs
  constify dentry_operations: CIFS
  constify dentry_operations: AFS
  ...

constify dentry_operations: sysfs

2009-03-27T18:44:02+00:00

Signed-off-by: Al Viro