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  1. Aug 28, 2006
    • Peter Zijlstra's avatar
      [PATCH] lockdep: fix blkdev_open() warning · 6946bd63
      Peter Zijlstra authored 
      

On Wed, 2006-08-09 at 07:57 +0200, Rolf Eike Beer wrote:
> =============================================
> [ INFO: possible recursive locking detected ]
> ---------------------------------------------
> parted/7929 is trying to acquire lock:
>  (&bdev->bd_mutex){--..}, at: [<c105eb8d>] __blkdev_put+0x1e/0x13c
>
> but task is already holding lock:
>  (&bdev->bd_mutex){--..}, at: [<c105eec6>] do_open+0x72/0x3a8
>
> other info that might help us debug this:
> 1 lock held by parted/7929:
>  #0:  (&bdev->bd_mutex){--..}, at: [<c105eec6>] do_open+0x72/0x3a8
> stack backtrace:
>  [<c1003aad>] show_trace_log_lvl+0x58/0x15b
>  [<c100495f>] show_trace+0xd/0x10
>  [<c1004979>] dump_stack+0x17/0x1a
>  [<c102dee5>] __lock_acquire+0x753/0x99c
>  [<c102e3b0>] lock_acquire+0x4a/0x6a
>  [<c1204501>] mutex_lock_nested+0xc8/0x20c
>  [<c105eb8d>] __blkdev_put+0x1e/0x13c
>  [<c105ecc4>] blkdev_put+0xa/0xc
>  [<c105f18a>] do_open+0x336/0x3a8
>  [<c105f21b>] blkdev_open+0x1f/0x4c
>  [<c1057b40>] __dentry_open+0xc7/0x1aa
>  [<c1057c91>] nameidata_to_filp+0x1c/0x2e
>  [<c1057cd1>] do_filp_open+0x2e/0x35
>  [<c1057dd7>] do_sys_open+0x38/0x68
>  [<c1057e33>] sys_open+0x16/0x18
>  [<c1002845>] sysenter_past_esp+0x56/0x8d

OK, I'm having a look here; its all new to me so bear with me.

blkdev_open() calls
  do_open(bdev, ...,BD_MUTEX_NORMAL) and takes
    mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_NORMAL)

then something fails, and we're thrown to:

out_first: where
    if (bdev != bdev->bd_contains)
      blkdev_put(bdev->bd_contains) which is
        __blkdev_put(bdev->bd_contains, BD_MUTEX_NORMAL) which does
          mutex_lock_nested(&bdev->bd_contains->bd_mutex, BD_MUTEX_NORMAL) <--- lockdep trigger

When going to out_first, dbev->bd_contains is either bdev or whole, and
since we take the branch it must be whole. So it seems to me the
following patch would be the right one:

[akpm@osdl.org: compile fix]
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: default avatarNeilBrown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      6946bd63
    • Danny Tholen's avatar
      [PATCH] 1394: fix for recently added firewire patch that breaks things on ppc · 7334bb4a
      Danny Tholen authored 
      

Recently a patch was added for preliminary suspend/resume handling on
!PPC_PMAC.  However, this broke both suspend and firewire on powerpc
because it saves the pci state after the device has already been disabled.

This moves the save state to before the pmac specific code.

Signed-off-by: default avatarDanny Tholen <obiwan@mailmij.org>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ben Collins <bcollins@ubuntu.com>
Cc: Jody McIntyre <scjody@modernduck.com>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      7334bb4a
    • Alexey Dobriyan's avatar
      [PATCH] Fix docs for fs.suid_dumpable · a2e0b563
      Alexey Dobriyan authored 
      

Sergey Vlasov noticed that there is not kernel.suid_dumpable, but
fs.suid_dumpable.

How KERN_SETUID_DUMPABLE ended up in fs_table[]? Hell knows...

Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      a2e0b563
    • Rolf Eike Beer's avatar
      [PATCH] tty: remove bogus call to cdev_del() · cc36e7f1
      Rolf Eike Beer authored 
      

When cdev_add() failed there is no reason to call cdev_del().

Signed-off-by: default avatarRolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      cc36e7f1
    • Ben Dooks's avatar
      [PATCH] rtc-s3c.c: fix time setting checks · 641741e0
      Ben Dooks authored 
      

Fix the year check on setting the time with the S3C24XX RTC driver.  Also
move the debug to before the set to see what is going on if it does fail.

Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      641741e0
    • Rafael J. Wysocki's avatar
      [PATCH] swsusp: Fix swap_type_of · b6b5bce3
      Rafael J. Wysocki authored 
      

There is a bug in mm/swapfile.c#swap_type_of() that makes swsusp only be
able to use the first active swap partition as the resume device.  Fix it.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Cc: Hugh Dickins <hugh@veritas.com>
Acked-by: default avatarPavel Machek <pavel@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      b6b5bce3
    • Daniel Kobras's avatar
      [PATCH] dm: Fix deadlock under high i/o load in raid1 setup. · c06aad85
      Daniel Kobras authored 
      On an nForce4-equipped machine with two SATA disk in raid1 setup using dmraid,
we experienced frequent deadlock of the system under high i/o load.  'cat
/dev/zero > ~/zero' was the most reliable way to reproduce them: Randomly
after a few GB, 'cp' would be left in 'D' state along with kjournald and
kmirrord.  The functions cp and kjournald were blocked in did vary, but
kmirrord's wchan always pointed to 'mempool_alloc()'.  We've seen this pattern
on 2.6.15 and 2.6.17 kernels.  http://lkml.org/lkml/2005/4/20/142

 indicates
that this problem has been around even before.

So much for the facts, here's my interpretation: mempool_alloc() first tries
to atomically allocate the requested memory, or falls back to hand out
preallocated chunks from the mempool.  If both fail, it puts the calling
process (kmirrord in this case) on a private waitqueue until somebody refills
the pool.  Where the only 'somebody' is kmirrord itself, so we have a
deadlock.

I worked around this problem by falling back to a (blocking) kmalloc when
before kmirrord would have ended up on the waitqueue.  This defeats part of
the benefits of using the mempool, but at least keeps the system running.  And
it could be done with a two-line change.  Note that mempool_alloc() clears the
GFP_NOIO flag internally, and only uses it to decide whether to wait or return
an error if immediate allocation fails, so the attached patch doesn't change
behaviour in the non-deadlocking case.  Path is against current git
(2.6.18-rc4), but should apply to earlier versions as well.  I've tested on
2.6.15, where this patch makes the difference between random lockup and a
stable system.

Signed-off-by: default avatarDaniel Kobras <kobras@linux.de>
Acked-by: default avatarAlasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      c06aad85
    • Ben Dooks's avatar
      [PATCH] drivers/rtc: fix rtc-s3c.c · 9a654518
      Ben Dooks authored 
      

In the cleanups of drivers/rtc/s3c-rtc.c, the base address for the
registers got broken.  This patch fixes that by ensuring the readb/writeb
are all prefixed with the base returned from ioremap()ing the registers.

Also fix check for valid year range, which was the wrong way around.

Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      9a654518
  3. Aug 27, 2006
  5. Aug 26, 2006
  7. Aug 25, 2006