Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 23 7月, 2012 2 次提交
  3. 11 5月, 2012 1 次提交
    • L
      vfs: make it possible to access the dentry hash/len as one 64-bit entry · 26fe5750
      由 Linus Torvalds 提交于 
      This allows comparing hash and len in one operation on 64-bit
architectures.  Right now only __d_lookup_rcu() takes advantage of this,
since that is the case we care most about.

The use of anonymous struct/unions hides the alternate 64-bit approach
from most users, the exception being a few cases where we initialize a
'struct qstr' with a static initializer.  This makes the problematic
cases use a new QSTR_INIT() helper function for that (but initializing
just the name pointer with a "{ .name = xyzzy }" initializer remains
valid, as does just copying another qstr structure).
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      26fe5750
  5. 29 3月, 2012 1 次提交
  7. 21 3月, 2012 2 次提交
  9. 07 1月, 2012 1 次提交
  11. 04 1月, 2012 1 次提交
    • A
      vfs: fix the stupidity with i_dentry in inode destructors · 6b520e05
      由 Al Viro 提交于 
      Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else.  Not to mention the removal of
boilerplate code from ->destroy_inode() instances...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      6b520e05
  13. 31 3月, 2011 1 次提交
  15. 03 3月, 2011 1 次提交
    • A
      ufs: remove the BKL · 788257d6
      由 Arnd Bergmann 提交于 
      This introduces a new per-superblock mutex in UFS to replace
the big kernel lock. I have been careful to avoid nested
calls to lock_ufs and to get the lock order right with
respect to other mutexes, in particular lock_super.

I did not make any attempt to prove that the big kernel
lock is not needed in a particular place in the code,
which is very possible.

The mutex has a significant performance impact, so it is only
used on SMP or PREEMPT configurations.

As Nick Piggin noticed, any allocation inside of the lock
may end up deadlocking when we get to ufs_getfrag_block
in the reclaim task, so we now use GFP_NOFS.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Tested-by: NNick Bowler <nbowler@elliptictech.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Nick Piggin <npiggin@gmail.com>
      788257d6
  17. 07 1月, 2011 1 次提交
    • N
      fs: icache RCU free inodes · fa0d7e3d
      由 Nick Piggin 提交于 
      RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>
      fa0d7e3d
  19. 29 10月, 2010 1 次提交
  21. 05 10月, 2010 1 次提交
    • J
      BKL: Explicitly add BKL around get_sb/fill_super · db719222
      由 Jan Blunck 提交于 
      This patch is a preparation necessary to remove the BKL from do_new_mount().
It explicitly adds calls to lock_kernel()/unlock_kernel() around
get_sb/fill_super operations for filesystems that still uses the BKL.

I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.

do_kern_mount() is already called without the BKL when mounting the rootfs
and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
afs_mntpt_follow_link(). Both later functions are actually the filesystems
follow_link inode operation. vfs_kern_mount() is calling the specified
get_sb function and lets the filesystem do its job by calling the given
fill_super function.

Therefore I think it is safe to push down the BKL from the VFS to the
low-level filesystems get_sb/fill_super operation.

[arnd: do not add the BKL to those file systems that already
       don't use it elsewhere]
Signed-off-by: NJan Blunck <jblunck@infradead.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Christoph Hellwig <hch@infradead.org>
      db719222
  23. 10 8月, 2010 1 次提交
  25. 28 5月, 2010 1 次提交
    • T
      ufs: permit mounting of BorderWare filesystems · d27d7a9a
      由 Thomas Stewart 提交于 
      I recently had to recover some files from an old broken machine that was
running BorderWare Document Gateway.  It's basically a drop in web server
for sharing files.  From the look of the init process and using strings on
of a few files it seems to be based on FreeBSD 3.3.

The process turned out to be more difficult than I imagined, but to cut a
long story short BorderWare in their wisdom use a nonstandard magic number
in their UFS (ufstype=44bsd) file systems.  Thus Linux refuses to mount
the file systems in order to recover the data.  After a bit of hunting I
was able to make a quick fix to fs/ufs/super.c in order to detect the new
magic number.

I assume that this number is the same for all installations.  It's quite
easy to find out from ufs_fs.h.  The superblock sits 8k into the block
device and the magic number its 1372 bytes into the superblock struct.

# dd if=/dev/sda5 skip=$(( 8192 + 1372 )) bs=1 count=4 2> /dev/null | hd
00000000  97 26 24 0f                                       |.&$.|
#
Signed-off-by: NThomas Stewart <thomas@stewarts.org.uk>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d27d7a9a
  27. 24 5月, 2010 6 次提交
  29. 13 3月, 2010 1 次提交
  31. 05 3月, 2010 2 次提交
  33. 16 12月, 2009 1 次提交
  35. 12 6月, 2009 6 次提交
    • C
      ufs: add ->sync_fs · 8c800656
      由 Christoph Hellwig 提交于 
      Add a ->sync_fs method for data integrity syncs, and reimplement
->write_super ontop of it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      8c800656
    • A
      Push BKL down into ->remount_fs() · 337eb00a
      由 Alessio Igor Bogani 提交于 
      [xfs, btrfs, capifs, shmem don't need BKL, exempt]
Signed-off-by: NAlessio Igor Bogani <abogani@texware.it>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      337eb00a
    • C
      ->write_super lock_super pushdown · ebc1ac16
      由 Christoph Hellwig 提交于 
      Push down lock_super into ->write_super instances and remove it from the
caller.

Following filesystem don't need ->s_lock in ->write_super and are skipped:

 * bfs, nilfs2 - no other uses of s_lock and have internal locks in
	->write_super
 * ext2 - uses BKL in ext2_write_super and has internal calls without s_lock
 * reiserfs - no other uses of s_lock as has reiserfs_write_lock (BKL) in
 	->write_super
 * xfs - no other uses of s_lock and uses internal lock (buffer lock on
	superblock buffer) to serialize ->write_super.  Also xfs_fs_write_super
	is superflous and will go away in the next merge window
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      ebc1ac16
    • A
      Push lock_super() into the ->remount_fs() of filesystems that care about it · bbd6851a
      由 Al Viro 提交于 
      Note that since we can't run into contention between remount_fs and write_super
(due to exclusion on s_umount), we have to care only about filesystems that
touch lock_super() on their own.  Out of those ext3, ext4, hpfs, sysv and ufs
do need it; fat doesn't since its ->remount_fs() only accesses assign-once
data (basically, it's "we have no atime on directories and only have atime on
files for vfat; force nodiratime and possibly noatime into *flags").

[folded a build fix from hch]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      bbd6851a
    • C
      push BKL down into ->put_super · 6cfd0148
      由 Christoph Hellwig 提交于 
      Move BKL into ->put_super from the only caller.  A couple of
filesystems had trivial enough ->put_super (only kfree and NULLing of
s_fs_info + stuff in there) to not get any locking: coda, cramfs, efs,
hugetlbfs, omfs, qnx4, shmem, all others got the full treatment.  Most
of them probably don't need it, but I'd rather sort that out individually.
Preferably after all the other BKL pushdowns in that area.

[AV: original used to move lock_super() down as well; these changes are
removed since we don't do lock_super() at all in generic_shutdown_super()
now]
[AV: fuse, btrfs and xfs are known to need no damn BKL, exempt]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      6cfd0148
    • C
      remove ->write_super call in generic_shutdown_super · 8c85e125
      由 Christoph Hellwig 提交于 
      We just did a full fs writeout using sync_filesystem before, and if
that's not enough for the filesystem it can perform it's own writeout
in ->put_super, which many filesystems already do.

Move a call to foofs_write_super into every foofs_put_super for now to
guarantee identical behaviour until it's cleaned up by the individual
filesystem maintainers.

Exceptions:

 - affs already has identical copy & pasted code at the beginning of
   affs_put_super so no need to do it twice.
 - xfs does the right thing without it and I have changes pending for
   the xfs tree touching this are so I don't really need conflicts
   here..
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      8c85e125
  37. 03 4月, 2009 1 次提交
  39. 28 3月, 2009 1 次提交
  41. 23 3月, 2009 1 次提交
  43. 14 10月, 2008 1 次提交
  45. 05 8月, 2008 1 次提交
  47. 27 7月, 2008 1 次提交
  49. 26 7月, 2008 1 次提交
  51. 25 7月, 2008 1 次提交
  53. 09 2月, 2008 1 次提交