linux-toradex.git/fs/ext3, branch v2.6.31-rc5

ext3: Get rid of extenddisksize parameter of ext3_get_blocks_handle()

2009-07-15T19:30:46+00:00

Get rid of extenddisksize parameter of ext3_get_blocks_handle(). This seems to
be a relict from some old days and setting disksize in this function does not
make much sence. Currently it was set only by ext3_getblk().  Since the
parameter has some effect only if create == 1, it is easy to check that the
three callers which end up calling ext3_getblk() with create == 1 (ext3_append,
ext3_quota_write, ext3_mkdir) do the right thing and set disksize themselves.

Signed-off-by: Jan Kara

ext3: Fix truncation of symlinks after failed write

2009-07-15T19:28:07+00:00

Contents of long symlinks is written via standard write methods. So when the
write fails, we add inode to orphan list. But symlinks don't have .truncate
method defined so nobody properly removes them from the orphan list (both on
disk and in memory).

Fix this by calling ext3_truncate() directly instead of calling vmtruncate()
(which is saner anyway since we don't need anything vmtruncate() does except
from calling .truncate in these paths).  We also add inode to orphan list only
if ext3_can_truncate() is true (currently, it can be false for symlinks when
there are no blocks allocated) - otherwise orphan list processing will complain
and ext3_truncate() will not remove inode from on-disk orphan list.

Signed-off-by: Jan Kara

helpers for acl caching + switch to those

2009-06-24T12:17:07+00:00

helpers: get_cached_acl(inode, type), set_cached_acl(inode, type, acl),
forget_cached_acl(inode, type).

ubifs/xattr.c needed includes reordered, the rest is a plain switchover.

Signed-off-by: Al Viro

switch ext3 to inode->i_acl

2009-06-24T12:17:04+00:00

Signed-off-by: Al Viro

Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

2009-06-20T00:43:04+00:00

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  Fix kernel-doc parameter name typo in blk-settings.c:
  block: rename CONFIG_LBD to CONFIG_LBDAF
  block: Fix bounce_pfn setting
  hd: stop defining MAJOR_NR

block: rename CONFIG_LBD to CONFIG_LBDAF

2009-06-19T06:08:50+00:00

Follow-up to "block: enable by default support for large devices
and files on 32-bit archs".

Rename CONFIG_LBD to CONFIG_LBDAF to:
- allow update of existing [def]configs for "default y" change
- reflect that it is used also for large files support nowadays

Signed-off-by: Bartlomiej Zolnierkiewicz 
Signed-off-by: Jens Axboe

ext3: make sure inode is deleted from orphan list after truncate

2009-06-18T20:03:45+00:00

As Ted pointed out, it can happen that ext3_truncate() returns without
removing inode from orphan list.  This way we could in some rare cases
(like when we get ENOMEM from an allocation in ext3_truncate called
because of failed ext3_write_begin) leave the inode on orphan list and
that triggers assertion failure on umount.

So make ext3_truncate() always remove inode from in-memory orphan list.

Cc: Theodore Ts'o 
Signed-off-by: Jan Kara 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ext3: fix chain verification in ext3_get_blocks()

2009-06-18T20:03:45+00:00

Chain verification in ext3_get_blocks() has been hosed since it called
verify_chain(chain, NULL) which always returns success.  As a result
readers could in theory race with truncate.  On the other hand the race
probably cannot happen with the current locking scheme, since by the
time ext3_truncate() is called all the pages are already removed and
hence get_block() shouldn't be called on such pages...

Signed-off-by: Jan Kara 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ext3: avoid unnecessary spinlock in critical POSIX ACL path

2009-06-17T04:36:35+00:00

If a filesystem supports POSIX ACL's, the VFS layer expects the filesystem
to do POSIX ACL checks on any files not owned by the caller, and it does
this for every single pathname component that it looks up.

That obviously can be pretty expensive if the filesystem isn't careful
about it, especially with locking. That's doubly sad, since the common
case tends to be that there are no ACL's associated with the files in
question.

ext3 already caches the ACL data so that it doesn't have to look it up
over and over again, but it does so by taking the inode->i_lock spinlock
on every lookup. Which is a noticeable overhead even if it's a private
lock, especially on CPU's where the serialization is expensive (eg Intel
Netburst aka 'P4').

For the special case of not actually having any ACL's, all that locking is
unnecessary. Even if somebody else were to be changing the ACL's on
another CPU, we simply don't care - if we've seen a NULL ACL, we might as
well use it.

So just load the ACL speculatively without any locking, and if it was
NULL, just use it. If it's non-NULL (either because we had a cached
entry, or because the cache hasn't been filled in at all), it means that
we'll need to get the lock and re-load it properly.

This is noticeable even on Nehalem, which does locking quite well (much
better than P4). From lmbench:

	Processor, Processes - times in microseconds - smaller is better
	--------------------------------------------------------------------
	Host                 OS  Mhz null null      open slct fork exec sh
	                             call  I/O stat clos TCP  proc proc proc
	--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ----
 - before:
	nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.95 1.45 2.18 69.1 273. 1141
	nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.95 1.48 2.28 69.9 253. 1140
	nehalem.l Linux 2.6.30- 3193 0.04 0.10 0.95 1.42 2.19 68.6 284. 1141
 - after:
	nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.44 2.12 68.3 282. 1094
	nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.39 2.20 67.0 308. 1123
	nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.39 2.36 67.4 293. 1148

where you can see what appears to be a roughly 3% improvement in stat
and open/close latencies from just the removal of the locking overhead.

Of course, this only matters for files you don't own (the owner never
needs to do the ACL checks), but that's the common case for libraries,
header files, and executables. As well as for the base components of any
absolute pathname, even if you are the owner of the final file.

[ At some point we probably want to move this ACL caching logic entirely
  into the VFS layer (and only call down to the filesystem when
  uncached), but in the meantime this improves ext3 a bit.

  A similar fix to btrfs makes a much bigger difference (15x improvement
  in lmbench) due to broken caching. ]

Signed-off-by: Linus Torvalds 
Signed-off-by: "Theodore Ts'o" 
Acked-by: Jan Kara 
Cc: Al Viro 
Signed-off-by: Al Viro

Push BKL down into ->remount_fs()

2009-06-12T01:36:11+00:00

[xfs, btrfs, capifs, shmem don't need BKL, exempt]

Signed-off-by: Alessio Igor Bogani 
Signed-off-by: Al Viro