linux-toradex.git/fs, branch v3.2.26

Btrfs: call the ordered free operation without any locks held

2012-08-02T13:38:02+00:00

commit e9fbcb42201c862fd6ab45c48ead4f47bb2dea9d upstream.

Each ordered operation has a free callback, and this was called with the
worker spinlock held.  Josef made the free callback also call iput,
which we can't do with the spinlock.

This drops the spinlock for the free operation and grabs it again before
moving through the rest of the list.  We'll circle back around to this
and find a cleaner way that doesn't bounce the lock around so much.

Signed-off-by: Chris Mason 
Signed-off-by: Ben Hutchings

locks: fix checking of fcntl_setlease argument

2012-08-02T13:37:59+00:00

commit 0ec4f431eb56d633da3a55da67d5c4b88886ccc7 upstream.

The only checks of the long argument passed to fcntl(fd,F_SETLEASE,.)
are done after converting the long to an int.  Thus some illegal values
may be let through and cause problems in later code.

[ They actually *don't* cause problems in mainline, as of Dave Jones's
  commit 8d657eb3b438 "Remove easily user-triggerable BUG from
  generic_setlease", but we should fix this anyway.  And this patch will
  be necessary to fix real bugs on earlier kernels. ]

Signed-off-by: J. Bruce Fields 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

ext4: undo ext4_calc_metadata_amount if we fail to claim space

2012-08-02T13:37:58+00:00

commit 03179fe92318e7934c180d96f12eff2cb36ef7b6 upstream.

The function ext4_calc_metadata_amount() has side effects, although
it's not obvious from its function name.  So if we fail to claim
space, regardless of whether we retry to claim the space again, or
return an error, we need to undo these side effects.

Otherwise we can end up incorrectly calculating the number of metadata
blocks needed for the operation, which was responsible for an xfstests
failure for test #271 when using an ext2 file system with delalloc
enabled.

Reported-by: Brian Foster 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Ben Hutchings

ext4: don't let i_reserved_meta_blocks go negative

2012-08-02T13:37:58+00:00

commit 97795d2a5b8d3c8dc4365d4bd3404191840453ba upstream.

If we hit a condition where we have allocated metadata blocks that
were not appropriately reserved, we risk underflow of
ei->i_reserved_meta_blocks.  In turn, this can throw
sbi->s_dirtyclusters_counter significantly out of whack and undermine
the nondelalloc fallback logic in ext4_nonda_switch().  Warn if this
occurs and set i_allocated_meta_blocks to avoid this problem.

This condition is reproduced by xfstests 270 against ext2 with
delalloc enabled:

Mar 28 08:58:02 localhost kernel: [  171.526344] EXT4-fs (loop1): delayed block allocation failed for inode 14 at logical offset 64486 with max blocks 64 with error -28
Mar 28 08:58:02 localhost kernel: [  171.526346] EXT4-fs (loop1): This should not happen!! Data will be lost

270 ultimately fails with an inconsistent filesystem and requires an
fsck to repair.  The cause of the error is an underflow in
ext4_da_update_reserve_space() due to an unreserved meta block
allocation.

Signed-off-by: Brian Foster 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Ben Hutchings

udf: Improve table length check to avoid possible overflow

2012-08-02T13:37:46+00:00

commit 57b9655d01ef057a523e810d29c37ac09b80eead upstream.

When a partition table length is corrupted to be close to 1 << 32, the
check for its length may overflow on 32-bit systems and we will think
the length is valid. Later on the kernel can crash trying to read beyond
end of buffer. Fix the check to avoid possible overflow.

Reported-by: Ben Hutchings 
Signed-off-by: Jan Kara 
Signed-off-by: Ben Hutchings

ext4: fix overhead calculation used by ext4_statfs()

2012-08-02T13:37:45+00:00

commit 952fc18ef9ec707ebdc16c0786ec360295e5ff15 upstream.

Commit f975d6bcc7a introduced bug which caused ext4_statfs() to
miscalculate the number of file system overhead blocks.  This causes
the f_blocks field in the statfs structure to be larger than it should
be.  This would in turn cause the "df" output to show the number of
data blocks in the file system and the number of data blocks used to
be larger than they should be.

Signed-off-by: "Theodore Ts'o" 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

ext4: pass a char * to ext4_count_free() instead of a buffer_head ptr

2012-08-02T13:37:43+00:00

commit f6fb99cadcd44660c68e13f6eab28333653621e6 upstream.

Make it possible for ext4_count_free to operate on buffers and not
just data in buffer_heads.

Signed-off-by: "Theodore Ts'o" 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

cifs: when CONFIG_HIGHMEM is set, serialize the read/write kmaps

2012-08-02T13:37:41+00:00

commit 3cf003c08be785af4bee9ac05891a15bcbff856a upstream.

Jian found that when he ran fsx on a 32 bit arch with a large wsize the
process and one of the bdi writeback kthreads would sometimes deadlock
with a stack trace like this:

crash> bt
PID: 2789   TASK: f02edaa0  CPU: 3   COMMAND: "fsx"
 #0 [eed63cbc] schedule at c083c5b3
 #1 [eed63d80] kmap_high at c0500ec8
 #2 [eed63db0] cifs_async_writev at f7fabcd7 [cifs]
 #3 [eed63df0] cifs_writepages at f7fb7f5c [cifs]
 #4 [eed63e50] do_writepages at c04f3e32
 #5 [eed63e54] __filemap_fdatawrite_range at c04e152a
 #6 [eed63ea4] filemap_fdatawrite at c04e1b3e
 #7 [eed63eb4] cifs_file_aio_write at f7fa111a [cifs]
 #8 [eed63ecc] do_sync_write at c052d202
 #9 [eed63f74] vfs_write at c052d4ee
#10 [eed63f94] sys_write at c052df4c
#11 [eed63fb0] ia32_sysenter_target at c0409a98
    EAX: 00000004  EBX: 00000003  ECX: abd73b73  EDX: 012a65c6
    DS:  007b      ESI: 012a65c6  ES:  007b      EDI: 00000000
    SS:  007b      ESP: bf8db178  EBP: bf8db1f8  GS:  0033
    CS:  0073      EIP: 40000424  ERR: 00000004  EFLAGS: 00000246

Each task would kmap part of its address array before getting stuck, but
not enough to actually issue the write.

This patch fixes this by serializing the marshal_iov operations for
async reads and writes. The idea here is to ensure that cifs
aggressively tries to populate a request before attempting to fulfill
another one. As soon as all of the pages are kmapped for a request, then
we can unlock and allow another one to proceed.

There's no need to do this serialization on non-CONFIG_HIGHMEM arches
however, so optimize all of this out when CONFIG_HIGHMEM isn't set.

Reported-by: Jian Li 
Signed-off-by: Jeff Layton 
Signed-off-by: Steve French 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

mm: compaction: introduce sync-light migration for use by compaction

2012-08-02T13:37:32+00:00

commit a6bc32b899223a877f595ef9ddc1e89ead5072b8 upstream.

Stable note: Not tracked in Buzilla. This was part of a series that
	reduced interactivity stalls experienced when THP was enabled.
	These stalls were particularly noticable when copying data
	to a USB stick but the experiences for users varied a lot.

This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT
mode that avoids writing back pages to backing storage.  Async compaction
maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT.
For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is
used.

This avoids sync compaction stalling for an excessive length of time,
particularly when copying files to a USB stick where there might be a
large number of dirty pages backed by a filesystem that does not support
->writepages.

[aarcange@redhat.com: This patch is heavily based on Andrea's work]
[akpm@linux-foundation.org: fix fs/nfs/write.c build]
[akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build]
Signed-off-by: Mel Gorman 
Reviewed-by: Rik van Riel 
Cc: Andrea Arcangeli 
Cc: Minchan Kim 
Cc: Dave Jones 
Cc: Jan Kara 
Cc: Andy Isaacson 
Cc: Nai Xia 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

mm: compaction: determine if dirty pages can be migrated without blocking within ->migratepage

2012-08-02T13:37:30+00:00

commit b969c4ab9f182a6e1b2a0848be349f99714947b0 upstream.

Stable note: Not tracked in Bugzilla. A fix aimed at preserving page
	aging information by reducing LRU list churning had the side-effect
	of reducing THP allocation success rates. This was part of a series
	to restore the success rates while preserving the reclaim fix.

Asynchronous compaction is used when allocating transparent hugepages to
avoid blocking for long periods of time.  Due to reports of stalling,
there was a debate on disabling synchronous compaction but this severely
impacted allocation success rates.  Part of the reason was that many dirty
pages are skipped in asynchronous compaction by the following check;

	if (PageDirty(page) && !sync &&
		mapping->a_ops->migratepage != migrate_page)
			rc = -EBUSY;

This skips over all mapping aops using buffer_migrate_page() even though
it is possible to migrate some of these pages without blocking.  This
patch updates the ->migratepage callback with a "sync" parameter.  It is
the responsibility of the callback to fail gracefully if migration would
block.

Signed-off-by: Mel Gorman 
Reviewed-by: Rik van Riel 
Cc: Andrea Arcangeli 
Cc: Minchan Kim 
Cc: Dave Jones 
Cc: Jan Kara 
Cc: Andy Isaacson 
Cc: Nai Xia 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings