linux-stable.git/fs/btrfs, branch v3.2.52

Btrfs: re-add root to dead root list if we stop dropping it

2013-08-02T20:15:00+00:00

commit d29a9f629e009c9b90e5859bce581070fd6247fc upstream.

If we stop dropping a root for whatever reason we need to add it back to the
dead root list so that we will re-start the dropping next transaction commit.
The other case this happens is if we recover a drop because we will add a root
without adding it to the fs radix tree, so we can leak it's root and commit root
extent buffer, adding this to the dead root list makes this cleanup happen.
Thanks,

Reported-by: Alex Lyakas 
Signed-off-by: Josef Bacik 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

Btrfs: fix lock leak when resuming snapshot deletion

2013-08-02T20:15:00+00:00

commit fec386ac1428f9c0e672df952cbca5cebd4e4e2f upstream.

We aren't setting path->locks[level] when we resume a snapshot deletion which
means we won't unlock the buffer when we free the path.  This causes deadlocks
if we happen to re-allocate the block before we've evicted the extent buffer
from cache.  Thanks,

Reported-by: Alex Lyakas 
Signed-off-by: Josef Bacik 
Signed-off-by: Ben Hutchings

btrfs: don't stop searching after encountering the wrong item

2013-05-30T13:35:03+00:00

commit 03b71c6ca6286625d8f1ed44aabab9b5bf5dac10 upstream.

The search ioctl skips items that are too large for a result buffer, but
inline items of a certain size occuring before any search result is
found would trigger an overflow and stop the search entirely.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=57641

Signed-off-by: Gabriel de Perthuis 
Signed-off-by: Josef Bacik 
Signed-off-by: Ben Hutchings

Btrfs: fix race between mmap writes and compression

2013-04-25T19:25:44+00:00

commit 4adaa611020fa6ac65b0ac8db78276af4ec04e63 upstream.

Btrfs uses page_mkwrite to ensure stable pages during
crc calculations and mmap workloads.  We call clear_page_dirty_for_io
before we do any crcs, and this forces any application with the file
mapped to wait for the crc to finish before it is allowed to change
the file.

With compression on, the clear_page_dirty_for_io step is happening after
we've compressed the pages.  This means the applications might be
changing the pages while we are compressing them, and some of those
modifications might not hit the disk.

This commit adds the clear_page_dirty_for_io before compression starts
and makes sure to redirty the page if we have to fallback to
uncompressed IO as well.

Signed-off-by: Chris Mason 
Reported-by: Alexandre Oliva 
Signed-off-by: Ben Hutchings

Btrfs: make sure nbytes are right after log replay

2013-04-25T19:25:38+00:00

commit 4bc4bee4595662d8bff92180d5c32e3313a704b0 upstream.

While trying to track down a tree log replay bug I noticed that fsck was always
complaining about nbytes not being right for our fsynced file.  That is because
the new fsync stuff doesn't wait for ordered extents to complete, so the inodes
nbytes are not necessarily updated properly when we log it.  So to fix this we
need to set nbytes to whatever it is on the inode that is on disk, so when we
replay the extents we can just add the bytes that are being added as we replay
the extent.  This makes it work for the case that we have the wrong nbytes or
the case that we logged everything and nbytes is actually correct.  With this
I'm no longer getting nbytes errors out of btrfsck.

Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

Btrfs: limit the global reserve to 512mb

2013-04-10T02:20:05+00:00

commit fdf30d1c1b386e1b73116cc7e0fb14e962b763b0 upstream.

A user reported a problem where he was getting early ENOSPC with hundreds of
gigs of free data space and 6 gigs of free metadata space.  This is because the
global block reserve was taking up the entire free metadata space.  This is
ridiculous, we have infrastructure in place to throttle if we start using too
much of the global reserve, so instead of letting it get this huge just limit it
to 512mb so that users can still get work done.  This allowed the user to
complete his rsync without issues.  Thanks

Reported-and-tested-by: Stefan Priebe 
Signed-off-by: Josef Bacik 
Signed-off-by: Ben Hutchings

btrfs: use rcu_barrier() to wait for bdev puts at unmount

2013-03-20T15:03:41+00:00

commit bc178622d40d87e75abc131007342429c9b03351 upstream.

Doing this would reliably fail with -EBUSY for me:

# mount /dev/sdb2 /mnt/scratch; umount /mnt/scratch; mkfs.btrfs -f /dev/sdb2
...
unable to open /dev/sdb2: Device or resource busy

because mkfs.btrfs tries to open the device O_EXCL, and somebody still has it.

Using systemtap to track bdev gets & puts shows a kworker thread doing a
blkdev put after mkfs attempts a get; this is left over from the unmount
path:

btrfs_close_devices
	__btrfs_close_devices
		call_rcu(&device->rcu, free_device);
			free_device
				INIT_WORK(&device->rcu_work, __free_device);
				schedule_work(&device->rcu_work);

so unmount might complete before __free_device fires & does its blkdev_put.

Adding an rcu_barrier() to btrfs_close_devices() causes unmount to wait
until all blkdev_put()s are done, and the device is truly free once
unmount completes.

Signed-off-by: Eric Sandeen 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason 
Signed-off-by: Ben Hutchings

btrfs: Init io_lock after cloning btrfs device struct

2013-03-20T15:03:15+00:00

commit 1cba0cdf5e4dbcd9e5fa5b54d7a028e55e2ca057 upstream.

__btrfs_close_devices() clones btrfs device structs with
memcpy(). Some of the fields in the clone are reinitialized, but it's
missing to init io_lock. In mainline this goes unnoticed, but on RT it
leaves the plist pointing to the original about to be freed lock
struct.

Initialize io_lock after cloning, so no references to the original
struct are left.

Reported-and-tested-by: Mike Galbraith 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Chris Mason 
Signed-off-by: Ben Hutchings

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

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