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  1. 20 8月, 2008 1 次提交
    • L
      vfat: fix 'sync' mount deadlock due to BKL->lock_super conversion · 5f22ca9b
      由 Linus Torvalds 提交于 
      There was another FAT BKL conversion deadlock reported by Bart
Trojanowski due to the BKL being used as a recursive lock by FAT, which
was missed because it only triggers with 'sync' (or 'dirsync') mounts.

The recursion worked for the BKL, but after the conversion to lock_super
(which uses a mutex), it just deadlocks.

Thanks to Bart for debugging this and testing the fix.  The lock
debugging information from the original report:

  =============================================
  [ INFO: possible recursive locking detected ]
  2.6.27-rc3-bisect-00448-ga7f5aaf3 #16
  ---------------------------------------------
  mv/4020 is trying to acquire lock:
   (&type->s_lock_key#9){--..}, at: [<c01a90fe>] lock_super+0x1e/0x20

  but task is already holding lock:
   (&type->s_lock_key#9){--..}, at: [<c01a90fe>] lock_super+0x1e/0x20

  other info that might help us debug this:
  3 locks held by mv/4020:
   #0:  (&sb->s_type->i_mutex_key#9/1){--..}, at: [<c01b2336>] do_unlinkat+0x66/0x140
   #1:  (&sb->s_type->i_mutex_key#9){--..}, at: [<c01b0954>] vfs_unlink+0x84/0x110
   #2:  (&type->s_lock_key#9){--..}, at: [<c01a90fe>] lock_super+0x1e/0x20

  stack backtrace:
  Pid: 4020, comm: mv Not tainted 2.6.27-rc3-bisect-00448-ga7f5aaf3 #16
   [<c014e694>] validate_chain+0x984/0xea0
   [<c0108d70>] ? native_sched_clock+0x0/0xf0
   [<c014ee9c>] __lock_acquire+0x2ec/0x9b0
   [<c014f5cf>] lock_acquire+0x6f/0x90
   [<c01a90fe>] ? lock_super+0x1e/0x20
   [<c044e5fd>] mutex_lock_nested+0xad/0x300
   [<c01a90fe>] ? lock_super+0x1e/0x20
   [<c01a90fe>] ? lock_super+0x1e/0x20
   [<c01a90fe>] lock_super+0x1e/0x20
   [<f8b3a700>] fat_write_inode+0x60/0x2b0 [fat]
   [<c0450878>] ? _spin_unlock_irqrestore+0x48/0x80
   [<f8b3a953>] ? fat_sync_inode+0x3/0x20 [fat]
   [<f8b3a962>] fat_sync_inode+0x12/0x20 [fat]
   [<f8b37c7e>] fat_remove_entries+0xbe/0x120 [fat]
   [<f8b422ef>] vfat_unlink+0x5f/0x90 [vfat]
   [<f8b42290>] ? vfat_unlink+0x0/0x90 [vfat]
   [<c01b0968>] vfs_unlink+0x98/0x110
   [<c01b2400>] do_unlinkat+0x130/0x140
   [<c016a8f5>] ? audit_syscall_entry+0x105/0x150
   [<c01b253b>] sys_unlinkat+0x3b/0x40
   [<c01040d3>] sysenter_do_call+0x12/0x3f
   =======================

where the deadlock is due to the nesting of lock_super from vfat_unlink
to fat_write_inode:

 - do_unlinkat
   - vfs_unlink
     - vfat_unlink
       * lock_super
       - fat_remove_entries
         - fat_sync_inode
           - fat_write_inode
             * lock_super

and the fix is to simply remove the use of lock_super() in fat_write_inode.

The lock_super() there had been just an automatic conversion of the
kernel lock to the superblock lock, but no locking was actually needed
there, since the code in fat_write_inode already protected all relevant
accesses with a spinlock (sbi->inode_hash_lock to be exact).  The only
code inside the BKL (and thus the superblock lock) was accesses tp local
variables or calls to functions that have long been SMP-safe (i.e.
sb_bread, mark_buffe_dirty and brlese).

Bart reports:
 "Looks good.  I ran 10 parallel processes creating 1M files truncating
  them, writing to them again and then deleting them.  This patch fixes
  the issue I ran into.

  Signed-off-by: Bart Trojanowski <bart@jukie.net>"
Reported-and-tested-by: NBart Trojanowski <bart@jukie.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5f22ca9b
  3. 27 7月, 2008 1 次提交
  5. 26 7月, 2008 2 次提交
    • J
      fatfs: add UTC timestamp option · b271e067
      由 Joe Peterson 提交于 
      Provide a new mount option ("tz=UTC") for DOS (vfat/msdos) filesystems,
allowing timestamps to be in coordinated universal time (UTC) rather than
local time in applications where doing this is advantageous.

In particular, portable devices that use fat/vfat (such as digital
cameras) can benefit from using UTC in their internal clocks, thus
avoiding daylight saving time errors and general time ambiguity issues.
The user of the device does not have to worry about changing the time when
moving from place or when daylight saving changes.

The new mount option, when set, disables the counter-adjustment that Linux
currently makes to FAT timestamp info in anticipation of the normal
userspace time zone correction.  When used in this new mode, all daylight
saving time and time zone handling is done in userspace as is normal for
many other filesystems (like ext3).  The default mode, which remains
unchanged, is still appropriate when mounting volumes written in Windows
(because of its use of local time).

I originally based this patch on one submitted last year by Paul Collins,
but I updated it to work with current source and changed variable/option
naming.  Ogawa Hirofumi (who maintains these filesystems) and I discussed
this patch at length on lkml, and he suggested using the option name in
the attached version of the patch.  Barry Bouwsma pointed out a good
addition to the patch as well.
Signed-off-by: NJoe Peterson <joe@skyrush.com>
Signed-off-by: NPaul Collins <paul@ondioline.org>
Acked-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Barry Bouwsma <free_beer_for_all@yahoo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b271e067
    • O
      fat: fix parse_options() · 8d44d974
      由 OGAWA Hirofumi 提交于 
      Current parse_options() exits too early.  We need to run the code of
bottom in this function even if users doesn't specify options.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8d44d974
  7. 21 6月, 2008 1 次提交
    • L
      Replace BKL with superblock lock in fat/msdos/vfat · 8f593427
      由 Linus Torvalds 提交于 
      This replaces the use of the BKL in the FAT family of filesystems with the
existing superblock lock instead.

The code already appears to do mostly proper locking with its own private
spinlocks (and mutexes), but while the BKL could possibly have been
dropped entirely, converting it to use the superblock lock (which is just
a regular mutex) is the conservative thing to do.

As a per-filesystem mutex, it not only won't have any of the possible
latency issues related to the BKL, but the lock is obviously private to
the particular filesystem instance and will thus not cause problems for
entirely unrelated users like the BKL can.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>
      8f593427
  9. 29 4月, 2008 1 次提交
  11. 28 4月, 2008 5 次提交
  13. 09 2月, 2008 1 次提交
  15. 08 2月, 2008 2 次提交
  17. 07 2月, 2008 1 次提交
  19. 22 10月, 2007 2 次提交
  21. 17 10月, 2007 2 次提交
  23. 20 7月, 2007 1 次提交
    • P
      mm: Remove slab destructors from kmem_cache_create(). · 20c2df83
      由 Paul Mundt 提交于 
      Slab destructors were no longer supported after Christoph's
c59def9f change. They've been
BUGs for both slab and slub, and slob never supported them
either.

This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      20c2df83
  25. 18 7月, 2007 1 次提交
  27. 17 7月, 2007 1 次提交
  29. 17 5月, 2007 1 次提交
    • C
      Remove SLAB_CTOR_CONSTRUCTOR · a35afb83
      由 Christoph Lameter 提交于 
      SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@ucw.cz>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a35afb83
  31. 09 5月, 2007 2 次提交
  33. 08 5月, 2007 1 次提交
    • C
      slab allocators: Remove SLAB_DEBUG_INITIAL flag · 50953fe9
      由 Christoph Lameter 提交于 
      I have never seen a use of SLAB_DEBUG_INITIAL.  It is only supported by
SLAB.

I think its purpose was to have a callback after an object has been freed
to verify that the state is the constructor state again?  The callback is
performed before each freeing of an object.

I would think that it is much easier to check the object state manually
before the free.  That also places the check near the code object
manipulation of the object.

Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was
compiled with SLAB debugging on.  If there would be code in a constructor
handling SLAB_DEBUG_INITIAL then it would have to be conditional on
SLAB_DEBUG otherwise it would just be dead code.  But there is no such code
in the kernel.  I think SLUB_DEBUG_INITIAL is too problematic to make real
use of, difficult to understand and there are easier ways to accomplish the
same effect (i.e.  add debug code before kfree).

There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be
clear in fs inode caches.  Remove the pointless checks (they would even be
pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors.

This is the last slab flag that SLUB did not support.  Remove the check for
unimplemented flags from SLUB.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      50953fe9
  35. 21 2月, 2007 1 次提交
  37. 13 2月, 2007 2 次提交
  39. 08 12月, 2006 2 次提交
  41. 12 10月, 2006 1 次提交
  43. 11 10月, 2006 1 次提交
  45. 30 9月, 2006 1 次提交
  47. 27 9月, 2006 4 次提交
  49. 29 6月, 2006 1 次提交
  51. 23 6月, 2006 1 次提交