Commit Graph

4462 Commits

Author SHA1 Message Date
Filipe Manana 2000552396 Btrfs: improve free space cache management and space allocation
While under random IO, a block group's free space cache eventually reaches
a state where it has a mix of extent entries and bitmap entries representing
free space regions.

As later free space regions are returned to the cache, some of them are merged
with existing extent entries if they are contiguous with them. But others are
not merged, because despite the existence of adjacent free space regions in
the cache, the merging doesn't happen because the existing free space regions
are represented in bitmap extents. Even when new free space regions are merged
with existing extent entries (enlarging the free space range they represent),
we create chances of having after an enlarged region that is contiguous with
some other region represented in a bitmap entry.

Both clustered and non-clustered space allocation work by iterating over our
extent and bitmap entries and skipping any that represents a region smaller
then the allocation request (and giving preference to extent entries before
bitmap entries). By having a contiguous free space region that is represented
by 2 (or more) entries (mix of extent and bitmap entries), we end up not
satisfying an allocation request with a size larger than the size of any of
the entries but no larger than the sum of their sizes. Making the caller assume
we're under a ENOSPC condition or force it to allocate multiple smaller space
regions (as we do for file data writes), which adds extra overhead and more
chances of causing fragmentation due to the smaller regions being all spread
apart from each other (more likely when under concurrency).

For example, if we have the following in the cache:

* extent entry representing free space range: [128Mb - 256Kb, 128Mb[

* bitmap entry covering the range [128Mb, 256Mb[, but only with the bits
  representing the range [128Mb, 128Mb + 768Kb[ set - that is, only that
  space in this 128Mb area is marked as free

An allocation request for 1Mb, starting at offset not greater than 128Mb - 256Kb,
would fail before, despite the existence of such contiguous free space area in the
cache. The caller could only allocate up to 768Kb of space at once and later another
256Kb (or vice-versa). In between each smaller allocation request, another task
working on a different file/inode might come in and take that space, preventing the
former task of getting a contiguous 1Mb region of free space.

Therefore this change implements the ability to move free space from bitmap
entries into existing and new free space regions represented with extent
entries. This is done when a space region is added to the cache.

A test was added to the sanity tests that explains in detail the issue too.

Some performance test results with compilebench on a 4 cores machine, with
32Gb of ram and using an HDD follow.

Test: compilebench -D /mnt -i 30 -r 1000 --makej

Before this change:

   intial create total runs 30 avg 69.02 MB/s (user 0.28s sys 0.57s)
   compile total runs 30 avg 314.96 MB/s (user 0.12s sys 0.25s)
   read compiled tree total runs 3 avg 27.14 MB/s (user 1.52s sys 0.90s)
   delete compiled tree total runs 30 avg 3.14 seconds (user 0.15s sys 0.66s)

After this change:

   intial create total runs 30 avg 68.37 MB/s (user 0.29s sys 0.55s)
   compile total runs 30 avg 382.83 MB/s (user 0.12s sys 0.24s)
   read compiled tree total runs 3 avg 27.82 MB/s (user 1.45s sys 0.97s)
   delete compiled tree total runs 30 avg 3.18 seconds (user 0.17s sys 0.65s)

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:13 -07:00
Anand Jain 3c1dbdf54a btrfs: rename total_bytes to avoid confusion
we are assigning number_devices to the total_bytes,
that's very confusing for a moment

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:12 -07:00
Anand Jain de4c296f63 btrfs: fix typo in the log message
there is no matching open parenthesis for the closing parenthesis

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:11 -07:00
Anand Jain b2efedca68 btrfs: rw_devices shouldn't be incremented for seed fs in btrfs_rm_dev_replace_srcdev()
seed fs devices don't participate as rw_device, so don't increment
rw_devices when the device being handled belongs to a seed fs.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:10 -07:00
Anand Jain 8bef8401a0 btrfs: fix memory leak when there is no more seed device
When we replace all the seed device in the system there is
no point in just keeping the btrfs_fs_devices with out
any device

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:09 -07:00
Anand Jain 94d5f0c2ae btrfs: update sprout seed pointer when seed fs is relinquished
We are not updating sprout fs seed pointer when all seed device
is replaced. This patch will check if all seed device has been
replaced and then update the sprout pointer accordingly.

Same reproducer as in the previous patch would apply here.
And notice that btrfs_close_device will check if seed fs is
present and spits out the error with out this patch.

int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
{
::
                seed_devices = fs_devices->seed;
::
        while (seed_devices) {
                fs_devices = seed_devices;
                seed_devices = fs_devices->seed;
                __btrfs_close_devices(fs_devices);
                free_fs_devices(fs_devices);
        }

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:08 -07:00
Anand Jain 63dd86fa79 btrfs: fix rw_devices miss match after seed replace
reproducer:
    reproducer:
    mount /dev/sdb /btrfs
    btrfs dev add /dev/sdc /btrfs
    btrfs rep start -B /dev/sdb /dev/sdd /btrfs
    umount /btrfs

WARNING: CPU: 0 PID: 3882 at fs/btrfs/volumes.c:892 __btrfs_close_devices+0x1c8/0x200 [btrfs]()

which is

        WARN_ON(fs_devices->rw_devices);

   The problem here is that we did not add one to the rw_devices when
   we replace the seed device with a writable device.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:06 -07:00
Anand Jain 25e8e9113d btrfs: replace seed device followed by unmount causes kernel WARNING
reproducer:
mount /dev/sdb /btrfs
btrfs dev add /dev/sdc /btrfs
btrfs rep start -B /dev/sdb /dev/sdd /btrfs
umount /btrfs

WARNING: CPU: 0 PID: 12661 at fs/btrfs/volumes.c:891 __btrfs_close_devices+0x1b0/0x200 [btrfs]()
::

__btrfs_close_devices()
::
        WARN_ON(fs_devices->open_devices);

After the seed device has been replaced the new target device
is no more a seed device. So we need to update the device
numbers in the fs_devices as pointed by the fs_info.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:05 -07:00
Anand Jain d51908ce4e btrfs: preparatory to make btrfs_rm_dev_replace_srcdev() seed aware
There is no logical change in this patch, just a preparatory patch,
so that changes can be easily reasoned.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:04 -07:00
Andrey Utkin 56094eecd3 btrfs: Drop stray check of fixup_workers creation
The issue was introduced in a79b7d4b3e,
adding allocation of extent_workers, so this stray check is surely not
meant to be a check of something else.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=82021
Reported-by: Maks Naumov <maksqwe1@ukr.net>
Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:03 -07:00
Filipe Manana f98de9b9c0 Btrfs: make btrfs_search_forward return with nodes unlocked
None of the uses of btrfs_search_forward() need to have the path
nodes (level >= 1) read locked, only the leaf needs to be locked
while the caller processes it. Therefore make it return a path
with all nodes unlocked, except for the leaf.

This change is motivated by the observation that during a file
fsync we repeatdly call btrfs_search_forward() and process the
returned leaf while upper nodes of the returned path (level >= 1)
are read locked, which unnecessarily blocks other tasks that want
to write to the same fs/subvol btree.
Therefore instead of modifying the fsync code to unlock all nodes
with level >= 1 immediately after calling btrfs_search_forward(),
change btrfs_search_forward() to do it, so that it benefits all
callers.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:02 -07:00
Anand Jain 79aec2b80d btrfs: sysfs label interface should check for read only FS
Not sure how this escaped many eyes so far

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:38:01 -07:00
Anand Jain 20ee0825ec btrfs: code optimize: BTRFS_ATTR_RW could set the mode
BTRFS_ATTR_RW could set the mode and be inline with BTRFS_ATTR

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:59 -07:00
Anand Jain 98b3d389eb btrfs: code optimize: BTRFS_ATTR could handle the mode
All that uses BTRFS_ATTR want mode to be set at 0444 so just do
it at the define.  And few spacing alignments.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:58 -07:00
Anand Jain 3f4b57e09d btrfs: use BTRFS_ATTR instead of btrfs_no_store()
we have BTRFS_ATTR define to create sysfs RO file, use that.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:57 -07:00
Filipe Manana 160f4089c8 Btrfs: avoid unnecessary switch of path locks to blocking mode
If we need to cow a node, increase the write lock level and retry the
tree search, there's no point of changing the node locks in our path
to blocking mode, as we only waste time and unnecessarily wake up other
tasks waiting on the spinning locks (just to block them again shortly
after) because we release our path before repeating the tree search.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:56 -07:00
Filipe Manana 24cdc847d9 Btrfs: unlock nodes earlier when inserting items in a btree
In ctree.c:setup_items_for_insert(), we can unlock all nodes in our
path before we process the leaf (shift items and data, adjust data
offsets, etc). This allows for better btree concurrency, as we're
often holding a write lock on at least the node at level 1.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:55 -07:00
Satoru Takeuchi d1b00a4711 btrfs: use IS_ALIGNED() for assertion in btrfs_lookup_csums_range() for simplicity
btrfs_lookup_csums_range() uses ALIGN() to check if "start"
and "end + 1" are aligned to "root->sectorsize". It's better to
replace these with IS_ALIGNED() for simplicity.

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:54 -07:00
Mark Fasheh d3982100ba btrfs: add trace for qgroup accounting
We want this to debug qgroup changes on live systems.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:50 -07:00
Miao Xie 443f24fee7 Btrfs: cleanup unused latest_devid and latest_trans in fs_devices
The member variants - latest_devid and latest_trans - of fs_devices structure
are set, but no one use them to do anything. so remove them.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:49 -07:00
Miao Xie 6ba40b615f Btrfs: update the comment of total_bytes and disk_total_bytes of btrfs_devie
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:48 -07:00
Miao Xie addc3fa74e Btrfs: Fix the problem that the dirty flag of dev stats is cleared
The io error might happen during writing out the device stats, and the
device stats information and dirty flag would be update at that time,
but the current code didn't consider this case, just clear the dirty
flag, it would cause that we forgot to write out the new device stats
information. Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:46 -07:00
Miao Xie d5ee37bcb1 Btrfs: make the device lock and its protected data in the same cacheline
The lock in btrfs_device structure was far away from its protected data, it would
make CPU load the cache line twice when we accessed them, move them together.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:45 -07:00
Miao Xie 5f546063ce Btrfs: fix wrong generation check of super block on a seed device
The super block generation of the seed devices is not the same as the
filesystem which sprouted from them because we don't update the super
block on the seed devices when we change that new filesystem. So we
should not use the generation of that new filesystem to check the super
block generation on the seed devices, Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:44 -07:00
Miao Xie 17a9be2f28 Btrfs: fix wrong fsid check of scrub
All the metadata in the seed devices has the same fsid as the fsid
of the seed filesystem which is on the seed device, so we should check
them by the current filesystem. Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:43 -07:00
David Sterba 2fad4e83e1 btrfs: wake up transaction thread from SYNC_FS ioctl
The transaction thread may want to do more work, namely it pokes the
cleaner ktread that will start processing uncleaned subvols.

This can be triggered by user via the 'btrfs fi sync' command, otherwise
there was a delay up to 30 seconds before the cleaner started to clean
old snapshots.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:42 -07:00
Wang Shilong c01a5c074c Btrfs: fix wrong max inline data size limit
inline data is stored from offset of @disk_bytenr in
struct btrfs_file_extent_item. So substracting total
size of struct btrfs_file_extent_item is wrong, fix it.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:40 -07:00
Wang Shilong 354877befa Btrfs: fix off-by-one in cow_file_range_inline()
Btrfs could still inline file data if its size is same as
page size, so don't skip max value here.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:39 -07:00
Wang Shilong 7816030eb4 Btrfs: fall into nocompression codes quickly if possible
If flag NOCOMPRESS is set which means bad compression ratio,
we could avoid call cow_file_range_async() for this case earlier.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:38 -07:00
Wang Shilong f79707b092 Btrfs: fix wrong skipping compression for an inode
If a file's compression ratios is bad, we will set NOCOMPRESS
flag for it, and it will skip compression for that inode next time.

However, if we remount fs to COMPRESS_FORCE, it still should try
if we could compress pages for that inode, this patch fix wrong
check for this problem.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:36 -07:00
Fabian Frederick d447d0da44 Btrfs: fix sparse warning
Fix the following sparse warning:
fs/btrfs/send.c:518:51: warning: incorrect type in argument 2 (different address spaces)
fs/btrfs/send.c:518:51:    expected char const [noderef] <asn:1>*<noident>
fs/btrfs/send.c:518:51:    got char *

We can safely use (const char __user *) with set_fs(KERNEL_DS)

__force added to avoid sparse-all warning:
fs/btrfs/send.c:518:40: warning: cast adds address space to expression (<asn:1>)

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Reviewed-by: Zach Brown <zab@zabbo.net>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:35 -07:00
HIMANGI SARAOGI 14586651ed Btrfs: use BUG_ON
Use BUG_ON(x) rather than if(x) BUG();

The semantic patch that fixes this problem is as follows:

// <smpl>
@@ identifier x; @@
-if (x) BUG();
+BUG_ON(x);
// </smpl>

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:34 -07:00
Sergey Senozhatsky 7880991344 btrfs compression: merge inflate and deflate z_streams
`struct workspace' used for zlib compression contains two zlib
z_stream-s: `def_strm' used in zlib_compress_pages(), and `inf_strm'
used in zlib_decompress/zlib_decompress_biovec(). None of these
functions use `inf_strm' and `def_strm' simultaniously, meaning that
for every compress/decompress operation we need only one z_stream
(out of two available).

`inf_strm' and `def_strm' are different in size of ->workspace. For
inflate stream we vmalloc() zlib_inflate_workspacesize() bytes, for
deflate stream - zlib_deflate_workspacesize() bytes. On my system zlib
returns the following workspace sizes, correspondingly: 42312 and 268104
(+ guard pages).

Keep only one `z_stream' in `struct workspace' and use it for both
compression and decompression. Hence, instead of vmalloc() of two
z_stream->worskpace-s, allocate only one of size:
	max(zlib_deflate_workspacesize(), zlib_inflate_workspacesize())

Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:33 -07:00
Filipe Manana 555e128640 Btrfs: set error return value in btrfs_get_blocks_direct
We were returning with 0 (success) because we weren't extracting the
error code from em (PTR_ERR(em)). Fix it.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:32 -07:00
Filipe Manana 27a3507de9 Btrfs: reduce size of struct extent_state
The tree field of struct extent_state was only used to figure out if
an extent state was connected to an inode's io tree or not. For this
we can just use the rb_node field itself.

On a x86_64 system with this change the sizeof(struct extent_state) is
reduced from 96 bytes down to 88 bytes, meaning that with a page size
of 4096 bytes we can now store 46 extent states per page instead of 42.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:30 -07:00
Fabian Frederick 6f84e23646 btrfs: use PTR_ERR_OR_ZERO
replace IS_ERR/PTR_ERR

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:29 -07:00
Wang Shilong 29549aec76 Btrfs: print btrfs specific info for some fatal error cases
Marc argued that if there are several btrfs filesystems mounted,
while users even don't know which filesystem hit the corrupted
errors something like generation verification failure.

Since @extent_buffer structure has a member @fs_info, let's output
btrfs device info.

Reported-by: Marc MERLIN <marc@merlins.org>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:28 -07:00
Miao Xie d20983b40e Btrfs: fix writing data into the seed filesystem
If we mounted a seed filesystem with degraded option, and then added a new
device into the seed filesystem, then we found adding device failed because
of the IO failure.

Steps to reproduce:
 # mkfs.btrfs -d raid1 -m raid1 <dev0> <dev1>
 # btrfstune -S 1 <dev0>
 # mount <dev0> -o degraded <mnt>
 # btrfs device add -f <dev2> <mnt>

It is because the original didn't set the chunk on the seed device to be
read-only if the degraded flag was set. It was introduced by patch f48b90756,
which fixed the problem the raid1 filesystem became read-only after one device
of it was missing. But this fix method was not right, we should set the read-only
flag according to the number of the missing devices, not the degraded mount
option, if the number of the missing devices is less than the max error number
that the profile of the chunk tolerates, we don't set it to be read-only.

Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:27 -07:00
Wang Shilong 47059d930f Btrfs: make defragment work with nodatacow option
Btrfs defragment will utilize COW feature, which means this
did not work for nodatacow option, this problem was detected
by xfstests generic/018 with nodatacow mount option.

Fix this problem by forcing cow for a extent with state
@EXTETN_DEFRAG setting.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:26 -07:00
Satoru Takeuchi 48fcc3ff7d btrfs: label should not contain return char
Rediffed remaining parts of original patch from Anand Jain.  This makes
sure to avoid trailing newlines in the btrfs label output

reproducer.sh:

===============================================================================

TEST_DEV=/dev/vdb
TEST_DIR=/home/sat/mnt

umount /home/sat/mnt

mkfs.btrfs -f $TEST_DEV
UUID=$(btrfs fi show $TEST_DEV | head -1 | sed -e 's/.*uuid: \([-0-9a-z]*\)$/\1/')
mount $TEST_DEV $TEST_DIR
LABELFILE=/sys/fs/btrfs/$UUID/label

echo "Test for empty label..." >&2
LINES="$(cat $LABELFILE | wc -l | awk '{print $1}')"
RET=0

if [ $LINES -eq 0 ] ; then
    echo '[PASS] Trailing \n is removed correctly.' >&2
else
    echo '[FAIL] Trailing \n still exists.' >&2
    RET=1
fi

echo "Test for non-empty label..." >&2

echo testlabel >$LABELFILE
LINES="$(cat $LABELFILE | wc -l | awk '{print $1}')"

if [ $LINES -eq 1 ] ; then
    echo '[PASS] Trailing \n is removed correctly.' >&2
else
    echo '[FAIL] Trailing \n still exists.' >&2
    RET=1
fi

exit $RET
===============================================================================

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:25 -07:00
Anand Jain ec95d4917b btrfs: device delete must be sysloged
as in the disk add patch, disk detached from the volume must be
recorded in the syslog as well for the same reason.

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:23 -07:00
Anand Jain 43d2076168 btrfs: device add must be sysloged
when we add a new disk to the mounted btrfs we don't record it
as of now, disk add is a critical change of btrfs configuration,
it must be recorded in the syslog to help offline investigations
of customer problems when reported.

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:20 -07:00
Wang Shilong 4027e0f4c4 Btrfs: clear compress-force when remounting with compress option
Steps to reproduce:
 # mkfs.btrfs -f /dev/sdb
 # mount /dev/sdb /mnt -o compress-force=lzo
 # mount /dev/sdb /mnt -o remount,compress=zlib
 # cat /proc/mounts

Remounting from compress-force to compress could not clear compress-force
option. The problem is there is no way for users to clear compress-force
option separately.

Fix this problem by clearing @FORCE_COMPRESS flag when remounting to
compress=xxx.

Suggested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Tested-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:19 -07:00
David Sterba ed6078f703 btrfs: use DIV_ROUND_UP instead of open-coded variants
The form

  (value + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT

is equivalent to

  (value + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE

The rest is a simple subsitution, no difference in the generated
assembly code.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:17 -07:00
David Sterba 4e54b17ad6 btrfs: clean away stripe_align helper
Only wraps the ALIGN macro.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:16 -07:00
David Sterba 707e8a0715 btrfs: use nodesize everywhere, kill leafsize
The nodesize and leafsize were never of different values. Unify the
usage and make nodesize the one. Cleanup the redundant checks and
helpers.

Shaves a few bytes from .text:

  text    data     bss     dec     hex filename
852418   24560   23112  900090   dbbfa btrfs.ko.before
851074   24584   23112  898770   db6d2 btrfs.ko.after

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:14 -07:00
David Sterba 962a298f35 btrfs: kill the key type accessor helpers
btrfs_set_key_type and btrfs_key_type are used inconsistently along with
open coded variants. Other members of btrfs_key are accessed directly
without any helpers anyway.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:12 -07:00
David Sterba 3abdbd780e btrfs: make close_ctree return void
There's no user of the return value and we can get rid of the comment in
put_super.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:11 -07:00
David Sterba 57cdc8db21 btrfs: cleanup ino cache members of btrfs_root
The naming is confusing, generic yet used for a specific cache. Add a
prefix 'ino_' or rename appropriately.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:09 -07:00
David Sterba c6f83c74fd btrfs: clenaup: don't call btrfs_release_path before free_path
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:08 -07:00
David Sterba 32471dc2ba btrfs: remove obsolete comment in btrfs_clean_one_deleted_snapshot
The comment applied when there was a BUG_ON.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17 13:37:07 -07:00
Filipe Manana 125c4cf9f3 Btrfs: set inode's logged_trans/last_log_commit after ranged fsync
When a ranged fsync finishes if there are still extent maps in the modified
list, still set the inode's logged_trans and last_log_commit. This is important
in case an inode is fsync'ed and unlinked in the same transaction, to ensure its
inode ref gets deleted from the log and the respective dentries in its parent
are deleted too from the log (if the parent directory was fsync'ed in the same
transaction).

Instead make btrfs_inode_in_log() return false if the list of modified extent
maps isn't empty.

This is an incremental on top of the v4 version of the patch:

    "Btrfs: fix fsync data loss after a ranged fsync"

which was added to its v5, but didn't make it on time.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-16 16:12:19 -07:00
Linus Torvalds 7ed641be75 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "Filipe is doing a careful pass through fsync problems, and these are
  the fixes so far.  I'll have one more for rc6 that we're still
  testing.

  My big commit is fixing up some inode hash races that Al Viro found
  (thanks Al)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: use insert_inode_locked4 for inode creation
  Btrfs: fix fsync data loss after a ranged fsync
  Btrfs: kfree()ing ERR_PTRs
  Btrfs: fix crash while doing a ranged fsync
  Btrfs: fix corruption after write/fsync failure + fsync + log recovery
  Btrfs: fix autodefrag with compression
2014-09-12 11:53:30 -07:00
Jens Axboe b207892b06 Merge branch 'for-linus' into for-3.18/core
A bit of churn on the for-linus side that would be nice to have
in the core bits for 3.18, so pull it in to catch us up and make
forward progress easier.

Signed-off-by: Jens Axboe <axboe@fb.com>

Conflicts:
	block/scsi_ioctl.c
2014-09-11 09:31:18 -06:00
Chris Mason b0d5d10f41 Btrfs: use insert_inode_locked4 for inode creation
Btrfs was inserting inodes into the hash table before we had fully
set the inode up on disk.  This leaves us open to rare races that allow
two different inodes in memory for the same [root, inode] pair.

This patch fixes things by using insert_inode_locked4 to insert an I_NEW
inode and unlock_new_inode when we're ready for the rest of the kernel
to use the inode.

It also makes sure to init the operations pointers on the inode before
going into the error handling paths.

Signed-off-by: Chris Mason <clm@fb.com>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
2014-09-08 13:56:45 -07:00
Filipe Manana 49dae1bc1c Btrfs: fix fsync data loss after a ranged fsync
While we're doing a full fsync (when the inode has the flag
BTRFS_INODE_NEEDS_FULL_SYNC set) that is ranged too (covers only a
portion of the file), we might have ordered operations that are started
before or while we're logging the inode and that fall outside the fsync
range.

Therefore when a full ranged fsync finishes don't remove every extent
map from the list of modified extent maps - as for some of them, that
fall outside our fsync range, their respective ordered operation hasn't
finished yet, meaning the corresponding file extent item wasn't inserted
into the fs/subvol tree yet and therefore we didn't log it, and we must
let the next fast fsync (one that checks only the modified list) see this
extent map and log a matching file extent item to the log btree and wait
for its ordered operation to finish (if it's still ongoing).

A test case for xfstests follows.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-08 13:56:43 -07:00
Dan Carpenter c47ca32d3a Btrfs: kfree()ing ERR_PTRs
The "inherit" in btrfs_ioctl_snap_create_v2() and "vol_args" in
btrfs_ioctl_rm_dev() are ERR_PTRs so we can't call kfree() on them.

These kind of bugs are "One Err Bugs" where there is just one error
label that does everything.  I could set the "inherit = NULL" and keep
the single out label but it ends up being more complicated that way.  It
makes the code simpler to re-order the unwind so it's in the mirror
order of the allocation and introduce some new error labels.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-08 13:56:42 -07:00
Tejun Heo ff9ea32381 block, bdi: an active gendisk always has a request_queue associated with it
bdev_get_queue() returns the request_queue associated with the
specified block_device.  blk_get_backing_dev_info() makes use of
bdev_get_queue() to determine the associated bdi given a block_device.

All the callers of bdev_get_queue() including
blk_get_backing_dev_info() assume that bdev_get_queue() may return
NULL and implement NULL handling; however, bdev_get_queue() requires
the passed in block_device is opened and attached to its gendisk.
Because an active gendisk always has a valid request_queue associated
with it, bdev_get_queue() can never return NULL and neither can
blk_get_backing_dev_info().

Make it clear that neither of the two functions can return NULL and
remove NULL handling from all the callers.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chris Mason <clm@fb.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-08 10:00:35 -06:00
Tejun Heo 908c7f1949 percpu_counter: add @gfp to percpu_counter_init()
Percpu allocator now supports allocation mask.  Add @gfp to
percpu_counter_init() so that !GFP_KERNEL allocation masks can be used
with percpu_counters too.

We could have left percpu_counter_init() alone and added
percpu_counter_init_gfp(); however, the number of users isn't that
high and introducing _gfp variants to all percpu data structures would
be quite ugly, so let's just do the conversion.  This is the one with
the most users.  Other percpu data structures are a lot easier to
convert.

This patch doesn't make any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: x86@kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
2014-09-08 09:51:29 +09:00
Filipe Manana dac5705cad Btrfs: fix crash while doing a ranged fsync
While doing a ranged fsync, that is, one whose range doesn't cover the
whole possible file range (0 to LLONG_MAX), we can crash under certain
circumstances with a trace like the following:

[41074.641913] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
(...)
[41074.642692] CPU: 0 PID: 24580 Comm: fsx Not tainted 3.16.0-fdm-btrfs-next-45+ #1
(...)
[41074.643886] RIP: 0010:[<ffffffffa01ecc99>]  [<ffffffffa01ecc99>] btrfs_ordered_update_i_size+0x279/0x2b0 [btrfs]
(...)
[41074.644919] Stack:
(...)
[41074.644919] Call Trace:
[41074.644919]  [<ffffffffa01db531>] btrfs_truncate_inode_items+0x3f1/0xa10 [btrfs]
[41074.644919]  [<ffffffffa01eb54f>] ? btrfs_get_logged_extents+0x4f/0x80 [btrfs]
[41074.644919]  [<ffffffffa02137a9>] btrfs_log_inode+0x2f9/0x970 [btrfs]
[41074.644919]  [<ffffffff81090875>] ? sched_clock_local+0x25/0xa0
[41074.644919]  [<ffffffff8164a55e>] ? mutex_unlock+0xe/0x10
[41074.644919]  [<ffffffff810af51d>] ? trace_hardirqs_on+0xd/0x10
[41074.644919]  [<ffffffffa0214b4f>] btrfs_log_inode_parent+0x1ef/0x560 [btrfs]
[41074.644919]  [<ffffffff811d0c55>] ? dget_parent+0x5/0x180
[41074.644919]  [<ffffffffa0215d11>] btrfs_log_dentry_safe+0x51/0x80 [btrfs]
[41074.644919]  [<ffffffffa01e2d1a>] btrfs_sync_file+0x1ba/0x3e0 [btrfs]
[41074.644919]  [<ffffffff811eda6b>] vfs_fsync_range+0x1b/0x30
(...)

The necessary conditions that lead to such crash are:

* an incremental fsync (when the inode doesn't have the
  BTRFS_INODE_NEEDS_FULL_SYNC flag set) happened for our file and it logged
  a file extent item ending at offset X;

* the file got the flag BTRFS_INODE_NEEDS_FULL_SYNC set in its inode, due
  to a file truncate operation that reduces the file to a size smaller
  than X;

* a ranged fsync call happens (via an msync for example), with a range that
  doesn't cover the whole file and the end of this range, lets call it Y, is
  smaller than X;

* btrfs_log_inode, sees the flag BTRFS_INODE_NEEDS_FULL_SYNC set and
  calls btrfs_truncate_inode_items() to remove all items from the log
  tree that are associated with our file;

* btrfs_truncate_inode_items() removes all of the inode's items, and the lowest
  file extent item it removed is the one ending at offset X, where X > 0 and
  X > Y - before returning, it calls btrfs_ordered_update_i_size() with an offset
  parameter set to X;

* btrfs_ordered_update_i_size() sees that X is greater then the current ordered
  size (btrfs_inode's disk_i_size) and then it assumes there can't be any ongoing
  ordered operation with a range covering the offset X, calling a BUG_ON() if
  such ordered operation exists. This assumption is made because the disk_i_size
  is only increased after the corresponding file extent item is added to the
  btree (btrfs_finish_ordered_io);

* But because our fsync covers only a limited range, such an ordered extent might
  exist, and our fsync callback (btrfs_sync_file) doesn't wait for such ordered
  extent to finish when calling btrfs_wait_ordered_range();

And then by the time btrfs_ordered_update_i_size() is called, via:

   btrfs_sync_file() ->
       btrfs_log_dentry_safe() ->
           btrfs_log_inode_parent() ->
               btrfs_log_inode() ->
                   btrfs_truncate_inode_items() ->
                       btrfs_ordered_update_i_size()

We hit the BUG_ON(), which could never happen if the fsync range covered the whole
possible file range (0 to LLONG_MAX), as we would wait for all ordered extents to
finish before calling btrfs_truncate_inode_items().

So just don't call btrfs_ordered_update_i_size() if we're removing the inode's items
from a log tree, which isn't supposed to change the in memory inode's disk_i_size.

Issue found while running xfstests/generic/127 (happens very rarely for me), more
specifically via the fsx calls that use memory mapped IO (and issue msync calls).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-02 16:46:05 -07:00
Filipe Manana d9f85963e3 Btrfs: fix corruption after write/fsync failure + fsync + log recovery
While writing to a file, in inode.c:cow_file_range() (and same applies to
submit_compressed_extents()), after reserving an extent for the file data,
we create a new extent map for the written range and insert it into the
extent map cache. After that, we create an ordered operation, but if it
fails (due to a transient/temporary-ENOMEM), we return without dropping
that extent map, which points to a reserved extent that is freed when we
return. A subsequent incremental fsync (when the btrfs inode doesn't have
the flag BTRFS_INODE_NEEDS_FULL_SYNC) considers this extent map valid and
logs a file extent item based on that extent map, which points to a disk
extent that doesn't contain valid data - it was freed by us earlier, at this
point it might contain any random/garbage data.

Therefore, if we reach an error condition when cowing a file range after
we added the new extent map to the cache, drop it from the cache before
returning.

Some sequence of steps that lead to this:

    $ mkfs.btrfs -f /dev/sdd
    $ mount -o commit=9999 /dev/sdd /mnt
    $ cd /mnt

    $ xfs_io -f -c "pwrite -S 0x01 -b 4096 0 4096" -c "fsync" foo
    $ xfs_io -c "pwrite -S 0x02 -b 4096 4096 4096"
    $ sync

    $ od -t x1 foo
    0000000 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01
    *
    0010000 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02
    *
    0020000

    $ xfs_io -c "pwrite -S 0xa1 -b 4096 0 4096" foo

    # Now this write + fsync fail with -ENOMEM, which was returned by
    # btrfs_add_ordered_extent() in inode.c:cow_file_range().
    $ xfs_io -c "pwrite -S 0xff -b 4096 4096 4096" foo
    $ xfs_io -c "fsync" foo
    fsync: Cannot allocate memory

    # Now do a new write + fsync, which will succeed. Our previous
    # -ENOMEM was a transient/temporary error.
    $ xfs_io -c "pwrite -S 0xee -b 4096 16384 4096" foo
    $ xfs_io -c "fsync" foo

    # Our file content (in page cache) is now:
    $ od -t x1 foo
    0000000 a1 a1 a1 a1 a1 a1 a1 a1 a1 a1 a1 a1 a1 a1 a1 a1
    *
    0010000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
    *
    0020000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    *
    0040000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee
    *
    0050000

    # Now reboot the machine, and mount the fs, so that fsync log replay
    # takes place.

    # The file content is now weird, in particular the first 8Kb, which
    # do not match our data before nor after the sync command above.
    $ od -t x1 foo
    0000000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee
    *
    0010000 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01
    *
    0020000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    *
    0040000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee
    *
    0050000

    # In fact these first 4Kb are a duplicate of the last 4kb block.
    # The last write got an extent map/file extent item that points to
    # the same disk extent that we got in the write+fsync that failed
    # with the -ENOMEM error. btrfs-debug-tree and btrfsck allow us to
    # verify that:

    $ btrfs-debug-tree /dev/sdd
    (...)
	item 6 key (257 EXTENT_DATA 0) itemoff 15819 itemsize 53
		extent data disk byte 12582912 nr 8192
		extent data offset 0 nr 8192 ram 8192
	item 7 key (257 EXTENT_DATA 8192) itemoff 15766 itemsize 53
		extent data disk byte 0 nr 0
		extent data offset 0 nr 8192 ram 8192
	item 8 key (257 EXTENT_DATA 16384) itemoff 15713 itemsize 53
		extent data disk byte 12582912 nr 4096
		extent data offset 0 nr 4096 ram 4096

    $ umount /dev/sdd
    $ btrfsck /dev/sdd
    Checking filesystem on /dev/sdd
    UUID: db5e60e1-050d-41e6-8c7f-3d742dea5d8f
    checking extents
    extent item 12582912 has multiple extent items
    ref mismatch on [12582912 4096] extent item 1, found 2
    Backref bytes do not match extent backref, bytenr=12582912, ref bytes=4096, backref bytes=8192
    backpointer mismatch on [12582912 4096]
    Errors found in extent allocation tree or chunk allocation
    checking free space cache
    checking fs roots
    root 5 inode 257 errors 1000, some csum missing
    found 131074 bytes used err is 1
    total csum bytes: 4
    total tree bytes: 131072
    total fs tree bytes: 32768
    total extent tree bytes: 16384
    btree space waste bytes: 123404
    file data blocks allocated: 274432
     referenced 274432
    Btrfs v3.14.1-96-gcc7fd5a-dirty

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-09-02 16:46:05 -07:00
Linus Torvalds 1fb00cbca0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "The biggest of these comes from Liu Bo, who tracked down a hang we've
  been hitting since moving to kernel workqueues (it's a btrfs bug, not
  in the generic code).  His patch needs backporting to 3.16 and 3.15
  stable, which I'll send once this is in.

  Otherwise these are assorted fixes.  Most were integrated last week
  during KS, but I wanted to give everyone the chance to test the
  result, so I waited for rc2 to come out before sending"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (24 commits)
  Btrfs: fix task hang under heavy compressed write
  Btrfs: fix filemap_flush call in btrfs_file_release
  Btrfs: fix crash on endio of reading corrupted block
  btrfs: fix leak in qgroup_subtree_accounting() error path
  btrfs: Use right extent length when inserting overlap extent map.
  Btrfs: clone, don't create invalid hole extent map
  Btrfs: don't monopolize a core when evicting inode
  Btrfs: fix hole detection during file fsync
  Btrfs: ensure tmpfile inode is always persisted with link count of 0
  Btrfs: race free update of commit root for ro snapshots
  Btrfs: fix regression of btrfs device replace
  Btrfs: don't consider the missing device when allocating new chunks
  Btrfs: Fix wrong device size when we are resizing the device
  Btrfs: don't write any data into a readonly device when scrub
  Btrfs: Fix the problem that the replace destroys the seed filesystem
  btrfs: Return right extent when fiemap gives unaligned offset and len.
  Btrfs: fix wrong extent mapping for DirectIO
  Btrfs: fix wrong write range for filemap_fdatawrite_range()
  Btrfs: fix wrong missing device counter decrease
  Btrfs: fix unzeroed members in fs_devices when creating a fs from seed fs
  ...
2014-08-27 09:14:17 -07:00
Chris Mason e9512d72e8 Btrfs: fix autodefrag with compression
The autodefrag code skips defrag when two extents are adjacent.  But one
big advantage for autodefrag is cutting down on the number of small
extents, even when they are adjacent.  This commit changes it to defrag
all small extents.

Signed-off-by: Chris Mason <clm@fb.com>
2014-08-27 08:45:37 -07:00
Rasmus Villemoes a71db86e86 fs/btrfs/tree-log.c: Fix closing brace followed by if
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-26 09:35:51 +02:00
Liu Bo 9e0af23764 Btrfs: fix task hang under heavy compressed write
This has been reported and discussed for a long time, and this hang occurs in
both 3.15 and 3.16.

Btrfs now migrates to use kernel workqueue, but it introduces this hang problem.

Btrfs has a kind of work queued as an ordered way, which means that its
ordered_func() must be processed in the way of FIFO, so it usually looks like --

normal_work_helper(arg)
    work = container_of(arg, struct btrfs_work, normal_work);

    work->func() <---- (we name it work X)
    for ordered_work in wq->ordered_list
            ordered_work->ordered_func()
            ordered_work->ordered_free()

The hang is a rare case, first when we find free space, we get an uncached block
group, then we go to read its free space cache inode for free space information,
so it will

file a readahead request
    btrfs_readpages()
         for page that is not in page cache
                __do_readpage()
                     submit_extent_page()
                           btrfs_submit_bio_hook()
                                 btrfs_bio_wq_end_io()
                                 submit_bio()
                                 end_workqueue_bio() <--(ret by the 1st endio)
                                      queue a work(named work Y) for the 2nd
                                      also the real endio()

So the hang occurs when work Y's work_struct and work X's work_struct happens
to share the same address.

A bit more explanation,

A,B,C -- struct btrfs_work
arg   -- struct work_struct

kthread:
worker_thread()
    pick up a work_struct from @worklist
    process_one_work(arg)
	worker->current_work = arg;  <-- arg is A->normal_work
	worker->current_func(arg)
		normal_work_helper(arg)
		     A = container_of(arg, struct btrfs_work, normal_work);

		     A->func()
		     A->ordered_func()
		     A->ordered_free()  <-- A gets freed

		     B->ordered_func()
			  submit_compressed_extents()
			      find_free_extent()
				  load_free_space_inode()
				      ...   <-- (the above readhead stack)
				      end_workqueue_bio()
					   btrfs_queue_work(work C)
		     B->ordered_free()

As if work A has a high priority in wq->ordered_list and there are more ordered
works queued after it, such as B->ordered_func(), its memory could have been
freed before normal_work_helper() returns, which means that kernel workqueue
code worker_thread() still has worker->current_work pointer to be work
A->normal_work's, ie. arg's address.

Meanwhile, work C is allocated after work A is freed, work C->normal_work
and work A->normal_work are likely to share the same address(I confirmed this
with ftrace output, so I'm not just guessing, it's rare though).

When another kthread picks up work C->normal_work to process, and finds our
kthread is processing it(see find_worker_executing_work()), it'll think
work C as a collision and skip then, which ends up nobody processing work C.

So the situation is that our kthread is waiting forever on work C.

Besides, there're other cases that can lead to deadlock, but the real problem
is that all btrfs workqueue shares one work->func, -- normal_work_helper,
so this makes each workqueue to have its own helper function, but only a
wraper pf normal_work_helper.

With this patch, I no long hit the above hang.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-24 07:17:02 -07:00
Chris Mason f6dc45c7a9 Btrfs: fix filemap_flush call in btrfs_file_release
We should only be flushing on close if the file was flagged as needing
it during truncate.  I broke this with my ordered data vs transaction
commit deadlock fix.

Thanks to Miao Xie for catching this.

Signed-off-by: Chris Mason <clm@fb.com>
Reported-by: Miao Xie <miaox@cn.fujitsu.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
2014-08-21 07:55:31 -07:00
Liu Bo 38c1c2e44b Btrfs: fix crash on endio of reading corrupted block
The crash is

------------[ cut here ]------------
kernel BUG at fs/btrfs/extent_io.c:2124!
[...]
Workqueue: btrfs-endio normal_work_helper [btrfs]
RIP: 0010:[<ffffffffa02d6055>]  [<ffffffffa02d6055>] end_bio_extent_readpage+0xb45/0xcd0 [btrfs]

This is in fact a regression.

It is because we forgot to increase @offset properly in reading corrupted block,
so that the @offset remains, and this leads to checksum errors while reading
left blocks queued up in the same bio, and then ends up with hiting the above
BUG_ON.

Reported-by: Chris Murphy <lists@colorremedies.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-21 07:55:30 -07:00
Eric Sandeen a3c108950d btrfs: fix leak in qgroup_subtree_accounting() error path
Coverity pointed this out; in the newly added
qgroup_subtree_accounting(), if btrfs_find_all_roots()
returns an error, we leak at least the parents pointer,
and possibly the roots pointer, depending on what failure
occurs.

If btrfs_find_all_roots() returns an error, we need to
free up all allocations before we return.  "roots" is
initialized to NULL, so it should be safe to free
it unconditionally (ulist_free() handles that case).

Cc: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-21 07:55:29 -07:00
Qu Wenruo 51f395ad40 btrfs: Use right extent length when inserting overlap extent map.
When current btrfs finds that a new extent map is going to be insereted
but failed with -EEXIST, it will try again to insert the extent map
but with the length of sectorsize.
This is OK if we don't enable 'no-holes' feature since all extent space
is continuous, we will not go into the not found->insert routine.

But if we enable 'no-holes' feature, it will make things out of control.
e.g. in 4K sectorsize, we pass the following args to btrfs_get_extent():
btrfs_get_extent() args: start:  27874 len 4100
28672		  27874		28672	27874+4100	32768
                    |-----------------------|
|---------hole--------------------|---------data----------|

1) not found and insert
Since no extent map containing the range, btrfs_get_extent() will go
into the not_found and insert routine, which will try to insert the
extent map (27874, 27847 + 4100).

2) first overlap
But it overlaps with (28672, 32768) extent, so -EEXIST will be returned
by add_extent_mapping().

3) retry but still overlap
After catching the -EEXIST, then btrfs_get_extent() will try insert it
again but with 4K length, which still overlaps, so -EEXIST will be
returned.

This makes the following patch fail to punch hole.
d77815461f btrfs: Avoid trucating page or punching hole in a already existed hole.

This patch will use the right length, which is the (exsisting->start -
em->start) to insert, making the above patch works in 'no-holes' mode.
Also, some small code style problems in above patch is fixed too.

Reported-by: Filipe David Manana <fdmanana@gmail.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Filipe David Manana <fdmanana@suse.com>
Tested-by: Filipe David Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-21 07:55:27 -07:00
Filipe Manana 62e2390e1a Btrfs: clone, don't create invalid hole extent map
When cloning a file that consists of an inline extent, we were creating
an extent map that represents a non-existing trailing hole starting at a
file offset that isn't a multiple of the sector size. This happened because
when processing an inline extent we weren't aligning the extent's length to
the sector size, and therefore incorrectly treating the range
[inline_extent_length; sector_size[ as a hole.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-21 07:55:26 -07:00
Filipe Manana 7064dd5c36 Btrfs: don't monopolize a core when evicting inode
If an inode has a very large number of extent maps, we can spend
a lot of time freeing them, which triggers a soft lockup warning.
Therefore reschedule if we need to when freeing the extent maps
while evicting the inode.

I could trigger this all the time by running xfstests/generic/299 on
a file system with the no-holes feature enabled. That test creates
an inode with 11386677 extent maps.

    $ mkfs.btrfs -f -O no-holes $TEST_DEV
    $ MKFS_OPTIONS="-O no-holes" ./check generic/299
    generic/299 382s ...
    Message from syslogd@debian-vm3 at Aug  7 10:44:29 ...
     kernel:[85304.208017] BUG: soft lockup - CPU#0 stuck for 22s! [umount:25330]
     384s
    Ran: generic/299
    Passed all 1 tests

    $ dmesg
    (...)
    [86304.300017] BUG: soft lockup - CPU#0 stuck for 23s! [umount:25330]
    (...)
    [86304.300036] Call Trace:
    [86304.300036]  [<ffffffff81698ba9>] __slab_free+0x54/0x295
    [86304.300036]  [<ffffffffa02ee9cc>] ? free_extent_map+0x5c/0xb0 [btrfs]
    [86304.300036]  [<ffffffff811a6cd2>] kmem_cache_free+0x282/0x2a0
    [86304.300036]  [<ffffffffa02ee9cc>] free_extent_map+0x5c/0xb0 [btrfs]
    [86304.300036]  [<ffffffffa02e3775>] btrfs_evict_inode+0xd5/0x660 [btrfs]
    [86304.300036]  [<ffffffff811e7c8d>] ? __inode_wait_for_writeback+0x6d/0xc0
    [86304.300036]  [<ffffffff816a389b>] ? _raw_spin_unlock+0x2b/0x40
    [86304.300036]  [<ffffffff811d8cbb>] evict+0xab/0x180
    [86304.300036]  [<ffffffff811d8dce>] dispose_list+0x3e/0x60
    [86304.300036]  [<ffffffff811d9b04>] evict_inodes+0xf4/0x110
    [86304.300036]  [<ffffffff811bd953>] generic_shutdown_super+0x53/0x110
    [86304.300036]  [<ffffffff811bdaa6>] kill_anon_super+0x16/0x30
    [86304.300036]  [<ffffffffa02a78ba>] btrfs_kill_super+0x1a/0xa0 [btrfs]
    [86304.300036]  [<ffffffff811bd3a9>] deactivate_locked_super+0x59/0x80
    [86304.300036]  [<ffffffff811be44e>] deactivate_super+0x4e/0x70
    [86304.300036]  [<ffffffff811dec14>] mntput_no_expire+0x174/0x1f0
    [86304.300036]  [<ffffffff811deab7>] ? mntput_no_expire+0x17/0x1f0
    [86304.300036]  [<ffffffff811e0517>] SyS_umount+0x97/0x100
    (...)

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Tested-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-21 07:55:25 -07:00
Filipe Manana 74121f7cbb Btrfs: fix hole detection during file fsync
The file hole detection logic during a file fsync wasn't correct,
because it didn't look back (in a previous leaf) for the last file
extent item that can be in a leaf to the left of our leaf and that
has a generation lower than the current transaction id. This made it
assume that a hole exists when it really doesn't exist in the file.

Such false positive hole detection happens in the following scenario:

* We have a file that has many file extent items, covering 3 or more
  btree leafs (the first leaf must contain non file extent items too).

* Two ranges of the file are modified, with their extent items being
  located at 2 different leafs and those leafs aren't consecutive.

* When processing the second modified leaf, we weren't checking if
  some file extent item exists that is located in some leaf that is
  between our 2 modified leafs, and therefore assumed the range defined
  between the last file extent item in the first leaf and the first file
  extent item in the second leaf matched a hole.

Fortunately this didn't result in overriding the log with wrong data,
instead it made the last loop in copy_items() attempt to insert a
duplicated key (for a hole file extent item), which makes the file
fsync code return with -EEXIST to file.c:btrfs_sync_file() which in
turn ends up doing a full transaction commit, which is much more
expensive then writing only to the log tree and wait for it to be
durably persisted (as well as the file's modified extents/pages).
Therefore fix the hole detection logic, so that we don't pay the
cost of doing full transaction commits.

I could trigger this issue with the following test for xfstests (which
never fails, either without or with this patch). The last fsync call
results in a full transaction commit, due to the -EEXIST error mentioned
above. I could also observe this behaviour happening frequently when
running xfstests/generic/075 in a loop.

Test:

    _cleanup()
    {
        _cleanup_flakey
        rm -fr $tmp
    }

    # get standard environment, filters and checks
    . ./common/rc
    . ./common/filter
    . ./common/dmflakey

    # real QA test starts here
    _supported_fs btrfs
    _supported_os Linux
    _require_scratch
    _require_dm_flakey
    _need_to_be_root

    rm -f $seqres.full

    # Create a file with many file extent items, each representing a 4Kb extent.
    # These items span 3 btree leaves, of 16Kb each (default mkfs.btrfs leaf size
    # as of btrfs-progs 3.12).
    _scratch_mkfs -l 16384 >/dev/null 2>&1
    _init_flakey
    SAVE_MOUNT_OPTIONS="$MOUNT_OPTIONS"
    MOUNT_OPTIONS="$MOUNT_OPTIONS -o commit=999"
    _mount_flakey

    # First fsync, inode has BTRFS_INODE_NEEDS_FULL_SYNC flag set.
    $XFS_IO_PROG -f -c "pwrite -S 0x01 -b 4096 0 4096" -c "fsync" \
            $SCRATCH_MNT/foo | _filter_xfs_io

    # For any of the following fsync calls, inode doesn't have the flag
    # BTRFS_INODE_NEEDS_FULL_SYNC set.
    for ((i = 1; i <= 500; i++)); do
        OFFSET=$((4096 * i))
        LEN=4096
        $XFS_IO_PROG -c "pwrite -S 0x01 $OFFSET $LEN" -c "fsync" \
                $SCRATCH_MNT/foo | _filter_xfs_io
    done

    # Commit transaction and bump next transaction's id (to 7).
    sync

    # Truncate will set the BTRFS_INODE_NEEDS_FULL_SYNC flag in the btrfs's
    # inode runtime flags.
    $XFS_IO_PROG -c "truncate 2048000" $SCRATCH_MNT/foo

    # Commit transaction and bump next transaction's id (to 8).
    sync

    # Touch 1 extent item from the first leaf and 1 from the last leaf. The leaf
    # in the middle, containing only file extent items, isn't touched. So the
    # next fsync, when calling btrfs_search_forward(), won't visit that middle
    # leaf. First and 3rd leaf have now a generation with value 8, while the
    # middle leaf remains with a generation with value 6.
    $XFS_IO_PROG \
        -c "pwrite -S 0xee -b 4096 0 4096" \
        -c "pwrite -S 0xff -b 4096 2043904 4096" \
        -c "fsync" \
        $SCRATCH_MNT/foo | _filter_xfs_io

    _load_flakey_table $FLAKEY_DROP_WRITES
    md5sum $SCRATCH_MNT/foo | _filter_scratch
    _unmount_flakey

    _load_flakey_table $FLAKEY_ALLOW_WRITES
    # During mount, we'll replay the log created by the fsync above, and the file's
    # md5 digest should be the same we got before the unmount.
    _mount_flakey
    md5sum $SCRATCH_MNT/foo | _filter_scratch
    _unmount_flakey
    MOUNT_OPTIONS="$SAVE_MOUNT_OPTIONS"

    status=0
    exit

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-21 07:55:24 -07:00
Filipe Manana 5762b5c958 Btrfs: ensure tmpfile inode is always persisted with link count of 0
If we open a file with O_TMPFILE, don't do any further operation on
it (so that the inode item isn't updated) and then force a transaction
commit, we get a persisted inode item with a link count of 1, and not 0
as it should be.

Steps to reproduce it (requires a modern xfs_io with -T support):

    $ mkfs.btrfs -f /dev/sdd
    $ mount -o /dev/sdd /mnt
    $ xfs_io -T /mnt &
    $ sync

Then btrfs-debug-tree shows the inode item with a link count of 1:

    $ btrfs-debug-tree /dev/sdd
    (...)
    fs tree key (FS_TREE ROOT_ITEM 0)
    leaf 29556736 items 4 free space 15851 generation 6 owner 5
    fs uuid f164d01b-1b92-481d-a4e4-435fb0f843d0
    chunk uuid 0e3d0e56-bcca-4a1c-aa5f-cec2c6f4f7a6
    	item 0 key (256 INODE_ITEM 0) itemoff 16123 itemsize 160
		inode generation 3 transid 6 size 0 block group 0 mode 40755 links 1
    	item 1 key (256 INODE_REF 256) itemoff 16111 itemsize 12
    		inode ref index 0 namelen 2 name: ..
    	item 2 key (257 INODE_ITEM 0) itemoff 15951 itemsize 160
    		inode generation 6 transid 6 size 0 block group 0 mode 100600 links 1
    	item 3 key (ORPHAN ORPHAN_ITEM 257) itemoff 15951 itemsize 0
		orphan item
    checksum tree key (CSUM_TREE ROOT_ITEM 0)
    (...)

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-21 07:55:23 -07:00
Filipe Manana 9c3b306e1c Btrfs: race free update of commit root for ro snapshots
This is a better solution for the problem addressed in the following
commit:

    Btrfs: update commit root on snapshot creation after orphan cleanup
    (3821f34888)

The previous solution wasn't the best because of 2 reasons:

    1) It added another full transaction commit, which is more expensive
       than just swapping the commit root with the root;

    2) If a reboot happened after the first transaction commit (the one
       that creates the snapshot) and before the second transaction commit,
       then we would end up with the same problem if a send using that
       snapshot was requested before the first transaction commit after
       the reboot.

This change addresses those 2 issues. The second issue is addressed by
switching the commit root in the dentry lookup VFS callback, which is
also called by the snapshot/subvol creation ioctl and performs orphan
cleanup if needed. Like the vfs, the ioctl locks the parent inode too,
preventing race issues between a dentry lookup and snapshot creation.

Cc: Alex Lyakas <alex.btrfs@zadarastorage.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-21 07:55:21 -07:00
Liu Bo 87fa3bb078 Btrfs: fix regression of btrfs device replace
Commit 49c6f736f34f901117c20960ebd7d5e60f12fcac(
btrfs: dev replace should replace the sysfs entry) added the missing sysfs entry
in the process of device replace, but didn't take missing devices into account,
so now we have

BUG: unable to handle kernel NULL pointer dereference at 0000000000000088
IP: [<ffffffffa0268551>] btrfs_kobj_rm_device+0x21/0x40 [btrfs]
...

To reproduce it,
1. mkfs.btrfs -f disk1 disk2
2. mkfs.ext4 disk1
3. mount disk2 /mnt -odegraded
4. btrfs replace start -B 1 disk3 /mnt
--------------------------

This fixes the problem.

Reported-by: Chris Murphy <lists@colorremedies.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Tested-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-21 07:55:20 -07:00
Miao Xie 95669976bd Btrfs: don't consider the missing device when allocating new chunks
The original code allocated new chunks by the number of the writable devices
and missing devices to make sure that any RAID levels on a degraded FS continue
to be honored, but it introduced a problem that it stopped us to allocating
new chunks, the steps to reproduce is following:

 # mkfs.btrfs -m raid1 -d raid1 -f <dev0> <dev1>
 # mkfs.btrfs -f <dev1>			//Removing <dev1> from the original fs
 # mount -o degraded <dev0> <mnt>
 # dd if=/dev/null of=<mnt>/tmpfile bs=1M

It is because we allocate new chunks only on the writable devices, if we take
the number of missing devices into account, and want to allocate new chunks
with higher RAID level, we will fail becaue we don't have enough writable
device. Fix it by ignoring the number of missing devices when allocating
new chunks.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:52:19 -07:00
Miao Xie 7df69d3e94 Btrfs: Fix wrong device size when we are resizing the device
total_bytes of device is just a in-memory variant which is used to record
the size of the device, and it might be changed before we resize a device,
if the resize operation fails, it will be fallbacked. But some code used it
to update on-disk metadata of the device, it would cause the problem that
on-disk metadata of the devices was not consistent. We should use the other
variant named disk_total_bytes to update the on-disk metadata of device,
because that variant is updated only when the resize operation is successful.
Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:52:18 -07:00
Miao Xie 5d68da3b8e Btrfs: don't write any data into a readonly device when scrub
We should not write data into a readonly device especially seed device when
doing scrub, skip those devices.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:52:17 -07:00
Miao Xie ff61d17c63 Btrfs: Fix the problem that the replace destroys the seed filesystem
The seed filesystem was destroyed by the device replace, the reproduce
method is:
 # mkfs.btrfs -f <dev0>
 # btrfstune -S 1 <dev0>
 # mount <dev0> <mnt>
 # btrfs device add <dev1> <mnt>
 # umount <mnt>
 # mount <dev1> <mnt>
 # btrfs replace start -f <dev0> <dev2> <mnt>
 # umount <mnt>
 # mount <dev0> <mnt>

It is because we erase the super block on the seed device. It is wrong,
we should not change anything on the seed device.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:52:16 -07:00
Qu Wenruo 2c91943b50 btrfs: Return right extent when fiemap gives unaligned offset and len.
When page aligned start and len passed to extent_fiemap(), the result is
good, but when start and len is not aligned, e.g. start = 1 and len =
4095 is passed to extent_fiemap(), it returns no extent.

The problem is that start and len is all rounded down which causes the
problem. This patch will round down start and round up (start + len) to
return right extent.

Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:52:14 -07:00
Wang Shilong e2eca69dc6 Btrfs: fix wrong extent mapping for DirectIO
btrfs_next_leaf() will use current leaf's last key to search
and then return a bigger one. So it may still return a file extent
item that is smaller than expected value and we will
get an overflow here for @em->len.

This is easy to reproduce for Btrfs Direct writting, it did not
cause any problem, because writting will re-insert right mapping later.

However, by hacking code to make DIO support compression, wrong extent
mapping is kept and it encounter merging failure(EEXIST) quickly.

Fix this problem by looping to find next file extent item that is bigger
than @start or we could not find anything more.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:52:13 -07:00
Wang Shilong 9a025a0860 Btrfs: fix wrong write range for filemap_fdatawrite_range()
filemap_fdatawrite_range() expect the third arg to be @end
not @len, fix it.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:52:12 -07:00
Miao Xie 3a7d55c84c Btrfs: fix wrong missing device counter decrease
The missing devices are accounted by its own fs device, for example
the missing devices in seed filesystem will be accounted by the fs device
of the seed filesystem, not by the new filesystem which is based on
the seed filesystem, so when we remove the missing device in the
seed filesystem, we should decrease the counter of its own fs device.
Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:52:10 -07:00
Miao Xie 69611ac810 Btrfs: fix unzeroed members in fs_devices when creating a fs from seed fs
We forgot to zero some members in fs_devices when we create new fs_devices
from the one of the seed fs. It would cause the problem that we got wrong
chunk profile when allocating chunks. Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:36:32 -07:00
Anand Jain 77bdae4d13 btrfs: check generation as replace duplicates devid+uuid
When FS in unmounted we need to check generation number as well
since devid+uuid combination could match with the missing replaced
disk when it reappears, and without this patch it might pair with
the replaced disk again.

 device_list_add() function is called in the following threads,
	mount device option
	mount argument
	ioctl BTRFS_IOC_SCAN_DEV (btrfs dev scan)
	ioctl BTRFS_IOC_DEVICES_READY (btrfs dev ready <dev>)
 they have been unit tested to work fine with this patch.

 If the user knows what he is doing and really want to pair with
 replaced disk (which is not a standard operation), then he should
 first clear the kernel btrfs device list in the memory by doing
 the module unload/load and followed with the mount -o device option.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:36:30 -07:00
Anand Jain b96de000bc Btrfs: device_list_add() should not update list when mounted
device_list_add() is called when user runs btrfs dev scan, which would add
any btrfs device into the btrfs_fs_devices list.

Now think of a mounted btrfs. And a new device which contains the a SB
from the mounted btrfs devices.

In this situation when user runs btrfs dev scan, the current code would
just replace existing device with the new device.

Which is to note that old device is neither closed nor gracefully
removed from the btrfs.

The FS is still operational with the old bdev however the device name
is the btrfs_device is new which is provided by the btrfs dev scan.

reproducer:

devmgt[1] detach /dev/sdc

replace the missing disk /dev/sdc

btrfs rep start -f 1 /dev/sde /btrfs
Label: none  uuid: 5dc0aaf4-4683-4050-b2d6-5ebe5f5cd120
        Total devices 2 FS bytes used 32.00KiB
        devid    1 size 958.94MiB used 115.88MiB path /dev/sde
        devid    2 size 958.94MiB used 103.88MiB path /dev/sdd

make /dev/sdc to reappear

devmgt attach host2

btrfs dev scan

btrfs fi show -m
Label: none  uuid: 5dc0aaf4-4683-4050-b2d6-5ebe5f5cd120^M
        Total devices 2 FS bytes used 32.00KiB^M
        devid    1 size 958.94MiB used 115.88MiB path /dev/sdc <- Wrong.
        devid    2 size 958.94MiB used 103.88MiB path /dev/sdd

since /dev/sdc has been replaced with /dev/sde, the /dev/sdc shouldn't be
part of the btrfs-fsid when it reappears. If user want it to be part of it
then sys admin should be using btrfs device add instead.

[1] github.com/anajain/devmgt.git

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:36:28 -07:00
chandan 1707e26d6a Btrfs: fill_holes: Fix slot number passed to hole_mergeable() call.
For a non-existent key, btrfs_search_slot() sets path->slots[0] to the slot
where the key could have been present, which in this case would be the slot
containing the extent item which would be the next neighbor of the file range
being punched. The current code passes an incremented path->slots[0] and we
skip to the wrong file extent item. This would mean that we would fail to
merge the "yet to be created" hole with the next neighboring hole (if one
exists). Fix this.

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:36:26 -07:00
Miao Xie 7a5c3c9be1 Btrfs: fix put dio bio twice when we submit dio bio fail
The caller of btrfs_submit_direct_hook() will put the original dio bio
when btrfs_submit_direct_hook() return a error number, so we needn't
put the original bio in btrfs_submit_direct_hook().

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19 08:36:24 -07:00
Linus Torvalds e64df3ebe8 Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "These are all fixes I'd like to get out to a broader audience.

  The biggest of the bunch is Mark's quota fix, which is also in the
  SUSE kernel, and makes our subvolume quotas dramatically more
  accurate.

  I've been running xfstests with these against your current git
  overnight, but I'm queueing up longer tests as well"

* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: disable strict file flushes for renames and truncates
  Btrfs: fix csum tree corruption, duplicate and outdated checksums
  Btrfs: Fix memory corruption by ulist_add_merge() on 32bit arch
  Btrfs: fix compressed write corruption on enospc
  btrfs: correctly handle return from ulist_add
  btrfs: qgroup: account shared subtrees during snapshot delete
  Btrfs: read lock extent buffer while walking backrefs
  Btrfs: __btrfs_mod_ref should always use no_quota
  btrfs: adjust statfs calculations according to raid profiles
2014-08-16 09:06:55 -06:00
Chris Mason 8d875f95da btrfs: disable strict file flushes for renames and truncates
Truncates and renames are often used to replace old versions of a file
with new versions.  Applications often expect this to be an atomic
replacement, even if they haven't done anything to make sure the new
version is fully on disk.

Btrfs has strict flushing in place to make sure that renaming over an
old file with a new file will fully flush out the new file before
allowing the transaction commit with the rename to complete.

This ordering means the commit code needs to be able to lock file pages,
and there are a few paths in the filesystem where we will try to end a
transaction with the page lock held.  It's rare, but these things can
deadlock.

This patch removes the ordered flushes and switches to a best effort
filemap_flush like ext4 uses. It's not perfect, but it should fix the
deadlocks.

Signed-off-by: Chris Mason <clm@fb.com>
2014-08-15 07:43:42 -07:00
Filipe Manana 27b9a8122f Btrfs: fix csum tree corruption, duplicate and outdated checksums
Under rare circumstances we can end up leaving 2 versions of a checksum
for the same file extent range.

The reason for this is that after calling btrfs_next_leaf we process
slot 0 of the leaf it returns, instead of processing the slot set in
path->slots[0]. Most of the time (by far) path->slots[0] is 0, but after
btrfs_next_leaf() releases the path and before it searches for the next
leaf, another task might cause a split of the next leaf, which migrates
some of its keys to the leaf we were processing before calling
btrfs_next_leaf(). In this case btrfs_next_leaf() returns again the
same leaf but with path->slots[0] having a slot number corresponding
to the first new key it got, that is, a slot number that didn't exist
before calling btrfs_next_leaf(), as the leaf now has more keys than
it had before. So we must really process the returned leaf starting at
path->slots[0] always, as it isn't always 0, and the key at slot 0 can
have an offset much lower than our search offset/bytenr.

For example, consider the following scenario, where we have:

sums->bytenr: 40157184, sums->len: 16384, sums end: 40173568
four 4kb file data blocks with offsets 40157184, 40161280, 40165376, 40169472

  Leaf N:

    slot = 0                           slot = btrfs_header_nritems() - 1
  |-------------------------------------------------------------------|
  | [(CSUM CSUM 39239680), size 8] ... [(CSUM CSUM 40116224), size 4] |
  |-------------------------------------------------------------------|

  Leaf N + 1:

      slot = 0                          slot = btrfs_header_nritems() - 1
  |--------------------------------------------------------------------|
  | [(CSUM CSUM 40161280), size 32] ... [((CSUM CSUM 40615936), size 8 |
  |--------------------------------------------------------------------|

Because we are at the last slot of leaf N, we call btrfs_next_leaf() to
find the next highest key, which releases the current path and then searches
for that next key. However after releasing the path and before finding that
next key, the item at slot 0 of leaf N + 1 gets moved to leaf N, due to a call
to ctree.c:push_leaf_left() (via ctree.c:split_leaf()), and therefore
btrfs_next_leaf() will returns us a path again with leaf N but with the slot
pointing to its new last key (CSUM CSUM 40161280). This new version of leaf N
is then:

    slot = 0                        slot = btrfs_header_nritems() - 2  slot = btrfs_header_nritems() - 1
  |----------------------------------------------------------------------------------------------------|
  | [(CSUM CSUM 39239680), size 8] ... [(CSUM CSUM 40116224), size 4]  [(CSUM CSUM 40161280), size 32] |
  |----------------------------------------------------------------------------------------------------|

And incorrecly using slot 0, makes us set next_offset to 39239680 and we jump
into the "insert:" label, which will set tmp to:

    tmp = min((sums->len - total_bytes) >> blocksize_bits,
        (next_offset - file_key.offset) >> blocksize_bits) =
    min((16384 - 0) >> 12, (39239680 - 40157184) >> 12) =
    min(4, (u64)-917504 = 18446744073708634112 >> 12) = 4

and

   ins_size = csum_size * tmp = 4 * 4 = 16 bytes.

In other words, we insert a new csum item in the tree with key
(CSUM_OBJECTID CSUM_KEY 40157184 = sums->bytenr) that contains the checksums
for all the data (4 blocks of 4096 bytes each = sums->len). Which is wrong,
because the item with key (CSUM CSUM 40161280) (the one that was moved from
leaf N + 1 to the end of leaf N) contains the old checksums of the last 12288
bytes of our data and won't get those old checksums removed.

So this leaves us 2 different checksums for 3 4kb blocks of data in the tree,
and breaks the logical rule:

   Key_N+1.offset >= Key_N.offset + length_of_data_its_checksums_cover

An obvious bad effect of this is that a subsequent csum tree lookup to get
the checksum of any of the blocks with logical offset of 40161280, 40165376
or 40169472 (the last 3 4kb blocks of file data), will get the old checksums.

Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-15 07:43:40 -07:00
Takashi Iwai 4eb1f66dce Btrfs: Fix memory corruption by ulist_add_merge() on 32bit arch
We've got bug reports that btrfs crashes when quota is enabled on
32bit kernel, typically with the Oops like below:
 BUG: unable to handle kernel NULL pointer dereference at 00000004
 IP: [<f9234590>] find_parent_nodes+0x360/0x1380 [btrfs]
 *pde = 00000000
 Oops: 0000 [#1] SMP
 CPU: 0 PID: 151 Comm: kworker/u8:2 Tainted: G S      W 3.15.2-1.gd43d97e-default #1
 Workqueue: btrfs-qgroup-rescan normal_work_helper [btrfs]
 task: f1478130 ti: f147c000 task.ti: f147c000
 EIP: 0060:[<f9234590>] EFLAGS: 00010213 CPU: 0
 EIP is at find_parent_nodes+0x360/0x1380 [btrfs]
 EAX: f147dda8 EBX: f147ddb0 ECX: 00000011 EDX: 00000000
 ESI: 00000000 EDI: f147dda4 EBP: f147ddf8 ESP: f147dd38
  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
 CR0: 8005003b CR2: 00000004 CR3: 00bf3000 CR4: 00000690
 Stack:
  00000000 00000000 f147dda4 00000050 00000001 00000000 00000001 00000050
  00000001 00000000 d3059000 00000001 00000022 000000a8 00000000 00000000
  00000000 000000a1 00000000 00000000 00000001 00000000 00000000 11800000
 Call Trace:
  [<f923564d>] __btrfs_find_all_roots+0x9d/0xf0 [btrfs]
  [<f9237bb1>] btrfs_qgroup_rescan_worker+0x401/0x760 [btrfs]
  [<f9206148>] normal_work_helper+0xc8/0x270 [btrfs]
  [<c025e38b>] process_one_work+0x11b/0x390
  [<c025eea1>] worker_thread+0x101/0x340
  [<c026432b>] kthread+0x9b/0xb0
  [<c0712a71>] ret_from_kernel_thread+0x21/0x30
  [<c0264290>] kthread_create_on_node+0x110/0x110

This indicates a NULL corruption in prefs_delayed list.  The further
investigation and bisection pointed that the call of ulist_add_merge()
results in the corruption.

ulist_add_merge() takes u64 as aux and writes a 64bit value into
old_aux.  The callers of this function in backref.c, however, pass a
pointer of a pointer to old_aux.  That is, the function overwrites
64bit value on 32bit pointer.  This caused a NULL in the adjacent
variable, in this case, prefs_delayed.

Here is a quick attempt to band-aid over this: a new function,
ulist_add_merge_ptr() is introduced to pass/store properly a pointer
value instead of u64.  There are still ugly void ** cast remaining
in the callers because void ** cannot be taken implicitly.  But, it's
safer than explicit cast to u64, anyway.

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=887046
Cc: <stable@vger.kernel.org> [v3.11+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-15 07:43:19 -07:00
Liu Bo ce62003f69 Btrfs: fix compressed write corruption on enospc
When failing to allocate space for the whole compressed extent, we'll
fallback to uncompressed IO, but we've forgotten to redirty the pages
which belong to this compressed extent, and these 'clean' pages will
simply skip 'submit' part and go to endio directly, at last we got data
corruption as we write nothing.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Tested-By: Martin Steigerwald <martin@lichtvoll.de>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-15 07:43:18 -07:00
Mark Fasheh f90e579c2b btrfs: correctly handle return from ulist_add
ulist_add() can return '1' on sucess, which qgroup_subtree_accounting()
doesn't take into account. As a result, that value can be bubbled up to
callers, causing an error to be printed. Fix this by only returning the
value of ulist_add() when it indicates an error.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-15 07:43:16 -07:00
Mark Fasheh 1152651a08 btrfs: qgroup: account shared subtrees during snapshot delete
During its tree walk, btrfs_drop_snapshot() will skip any shared
subtrees it encounters. This is incorrect when we have qgroups
turned on as those subtrees need to have their contents
accounted. In particular, the case we're concerned with is when
removing our snapshot root leaves the subtree with only one root
reference.

In those cases we need to find the last remaining root and add
each extent in the subtree to the corresponding qgroup exclusive
counts.

This patch implements the shared subtree walk and a new qgroup
operation, BTRFS_QGROUP_OPER_SUB_SUBTREE. When an operation of
this type is encountered during qgroup accounting, we search for
any root references to that extent and in the case that we find
only one reference left, we go ahead and do the math on it's
exclusive counts.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-15 07:43:14 -07:00
Filipe Manana 6f7ff6d783 Btrfs: read lock extent buffer while walking backrefs
Before processing the extent buffer, acquire a read lock on it, so
that we're safe against concurrent updates on the extent buffer.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-15 07:43:13 -07:00
Josef Bacik e339a6b097 Btrfs: __btrfs_mod_ref should always use no_quota
Before I extended the no_quota arg to btrfs_dec/inc_ref because I didn't
understand how snapshot delete was using it and assumed that we needed the
quota operations there.  With Mark's work this has turned out to be not the
case, we _always_ need to use no_quota for btrfs_dec/inc_ref, so just drop the
argument and make __btrfs_mod_ref call it's process function with no_quota set
always.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-15 07:43:11 -07:00
David Sterba ba7b6e62f4 btrfs: adjust statfs calculations according to raid profiles
This has been discussed in thread:
http://thread.gmane.org/gmane.comp.file-systems.btrfs/32528

and this patch implements this proposal:
http://thread.gmane.org/gmane.comp.file-systems.btrfs/32536

Works fine for "clean" raid profiles where the raid factor correction
does the right job. Otherwise it's pessimistic and may show low space
although there's still some left.

The df nubmers are lightly wrong in case of mixed block groups, but this
is not a major usecase and can be addressed later.

The RAID56 numbers are wrong almost the same way as before and will be
addressed separately.

CC: Hugo Mills <hugo@carfax.org.uk>
CC: cwillu <cwillu@cwillu.com>
CC: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-08-15 07:43:10 -07:00
Linus Torvalds f6f993328b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "Stuff in here:

   - acct.c fixes and general rework of mnt_pin mechanism.  That allows
     to go for delayed-mntput stuff, which will permit mntput() on deep
     stack without worrying about stack overflows - fs shutdown will
     happen on shallow stack.  IOW, we can do Eric's umount-on-rmdir
     series without introducing tons of stack overflows on new mntput()
     call chains it introduces.
   - Bruce's d_splice_alias() patches
   - more Miklos' rename() stuff.
   - a couple of regression fixes (stable fodder, in the end of branch)
     and a fix for API idiocy in iov_iter.c.

  There definitely will be another pile, maybe even two.  I'd like to
  get Eric's series in this time, but even if we miss it, it'll go right
  in the beginning of for-next in the next cycle - the tricky part of
  prereqs is in this pile"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
  fix copy_tree() regression
  __generic_file_write_iter(): fix handling of sync error after DIO
  switch iov_iter_get_pages() to passing maximal number of pages
  fs: mark __d_obtain_alias static
  dcache: d_splice_alias should detect loops
  exportfs: update Exporting documentation
  dcache: d_find_alias needn't recheck IS_ROOT && DCACHE_DISCONNECTED
  dcache: remove unused d_find_alias parameter
  dcache: d_obtain_alias callers don't all want DISCONNECTED
  dcache: d_splice_alias should ignore DCACHE_DISCONNECTED
  dcache: d_splice_alias mustn't create directory aliases
  dcache: close d_move race in d_splice_alias
  dcache: move d_splice_alias
  namei: trivial fix to vfs_rename_dir comment
  VFS: allow ->d_manage() to declare -EISDIR in rcu_walk mode.
  cifs: support RENAME_NOREPLACE
  hostfs: support rename flags
  shmem: support RENAME_EXCHANGE
  shmem: support RENAME_NOREPLACE
  btrfs: add RENAME_NOREPLACE
  ...
2014-08-11 11:44:11 -07:00
J. Bruce Fields 1a0a397e41 dcache: d_obtain_alias callers don't all want DISCONNECTED
There are a few d_obtain_alias callers that are using it to get the
root of a filesystem which may already have an alias somewhere else.

This is not the same as the filehandle-lookup case, and none of them
actually need DCACHE_DISCONNECTED set.

It isn't really a serious problem, but it would really be clearer if we
reserved DCACHE_DISCONNECTED for those cases where it's actually needed.

In the btrfs case this was causing a spurious printk from
nfsd/nfsfh.c:fh_verify when it found an unexpected DCACHE_DISCONNECTED
dentry.  Josef worked around this by unsetting DCACHE_DISCONNECTED
manually in 3a0dfa6a12 "Btrfs: unset DCACHE_DISCONNECTED when mounting
default subvol", and this replaces that workaround.

Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:10 -04:00
Miklos Szeredi 80ace85c91 btrfs: add RENAME_NOREPLACE
RENAME_NOREPLACE is trivial to implement for most filesystems: switch over
to ->rename2() and check for the supported flags.  The rest is done by the
VFS.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Chris Mason <clm@fb.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:09 -04:00
Ingo Molnar ca5bc6cd5d Merge branch 'sched/urgent' into sched/core, to merge fixes before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-28 10:03:00 +02:00
Linus Torvalds da83fc6e0f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "We have two more fixes in my for-linus branch.

  I was hoping to also include a fix for a btrfs deadlock with
  compression enabled, but we're still nailing that one down"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: test for valid bdev before kobj removal in btrfs_rm_device
  Btrfs: fix abnormal long waiting in fsync
2014-07-20 20:21:05 -07:00
Eric Sandeen 0bfaa9c5cb btrfs: test for valid bdev before kobj removal in btrfs_rm_device
commit 99994cd btrfs: dev delete should remove sysfs entry
added a btrfs_kobj_rm_device, which dereferences device->bdev...
right after we check whether device->bdev might be NULL.

I don't honestly know if it's possible to have a NULL device->bdev
here, but assuming that it is (given the test), we need to move
the kobject removal to be under that test.

(Coverity spotted this)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-19 11:49:44 -07:00
Liu Bo 98ce2deda2 Btrfs: fix abnormal long waiting in fsync
xfstests generic/127 detected this problem.

With commit 7fc34a62ca, now fsync will only flush
data within the passed range.  This is the cause of the above problem,
-- btrfs's fsync has a stage called 'sync log' which will wait for all the
ordered extents it've recorded to finish.

In xfstests/generic/127, with mixed operations such as truncate, fallocate,
punch hole, and mapwrite, we get some pre-allocated extents, and mapwrite will
mmap, and then msync.  And I find that msync will wait for quite a long time
(about 20s in my case), thanks to ftrace, it turns out that the previous
fallocate calls 'btrfs_wait_ordered_range()' to flush dirty pages, but as the
range of dirty pages may be larger than 'btrfs_wait_ordered_range()' wants,
there can be some ordered extents created but not getting corresponding pages
flushed, then they're left in memory until we fsync which runs into the
stage 'sync log', and fsync will just wait for the system writeback thread
to flush those pages and get ordered extents finished, so the latency is
inevitable.

This adds a flush similar to btrfs_start_ordered_extent() in
btrfs_wait_logged_extents() to fix that.

Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-19 11:49:44 -07:00
NeilBrown 743162013d sched: Remove proliferation of wait_on_bit() action functions
The current "wait_on_bit" interface requires an 'action'
function to be provided which does the actual waiting.
There are over 20 such functions, many of them identical.
Most cases can be satisfied by one of just two functions, one
which uses io_schedule() and one which just uses schedule().

So:
 Rename wait_on_bit and        wait_on_bit_lock to
        wait_on_bit_action and wait_on_bit_lock_action
 to make it explicit that they need an action function.

 Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io
 which are *not* given an action function but implicitly use
 a standard one.
 The decision to error-out if a signal is pending is now made
 based on the 'mode' argument rather than being encoded in the action
 function.

 All instances of the old wait_on_bit and wait_on_bit_lock which
 can use the new version have been changed accordingly and their
 action functions have been discarded.
 wait_on_bit{_lock} does not return any specific error code in the
 event of a signal so the caller must check for non-zero and
 interpolate their own error code as appropriate.

The wait_on_bit() call in __fscache_wait_on_invalidate() was
ambiguous as it specified TASK_UNINTERRUPTIBLE but used
fscache_wait_bit_interruptible as an action function.
David Howells confirms this should be uniformly
"uninterruptible"

The main remaining user of wait_on_bit{,_lock}_action is NFS
which needs to use a freezer-aware schedule() call.

A comment in fs/gfs2/glock.c notes that having multiple 'action'
functions is useful as they display differently in the 'wchan'
field of 'ps'. (and /proc/$PID/wchan).
As the new bit_wait{,_io} functions are tagged "__sched", they
will not show up at all, but something higher in the stack.  So
the distinction will still be visible, only with different
function names (gds2_glock_wait versus gfs2_glock_dq_wait in the
gfs2/glock.c case).

Since first version of this patch (against 3.15) two new action
functions appeared, on in NFS and one in CIFS.  CIFS also now
uses an action function that makes the same freezer aware
schedule call as NFS.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: David Howells <dhowells@redhat.com> (fscache, keys)
Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2)
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16 15:10:39 +02:00
Linus Torvalds b82207b8e8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "We've queued up a few fixes in my for-linus branch"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix crash when starting transaction
  Btrfs: fix btrfs_print_leaf for skinny metadata
  Btrfs: fix race of using total_bytes_pinned
  btrfs: use E2BIG instead of EIO if compression does not help
  btrfs: remove stale comment from btrfs_flush_all_pending_stuffs
  Btrfs: fix use-after-free when cloning a trailing file hole
  btrfs: fix null pointer dereference in btrfs_show_devname when name is null
  btrfs: fix null pointer dereference in clone_fs_devices when name is null
  btrfs: fix nossd and ssd_spread mount option regression
  Btrfs: fix race between balance recovery and root deletion
  Btrfs: atomically set inode->i_flags in btrfs_update_iflags
  btrfs: only unlock block in verify_parent_transid if we locked it
  Btrfs: assert send doesn't attempt to start transactions
  btrfs compression: reuse recently used workspace
  Btrfs: fix crash when mounting raid5 btrfs with missing disks
  btrfs: create sprout should rename fsid on the sysfs as well
  btrfs: dev replace should replace the sysfs entry
  btrfs: dev add should add its sysfs entry
  btrfs: dev delete should remove sysfs entry
  btrfs: rename add_device_membership to btrfs_kobj_add_device
2014-07-04 08:53:53 -07:00
Filipe Manana abdd2e80a5 Btrfs: fix crash when starting transaction
Often when starting a transaction we commit the currently running transaction,
which can end up writing block group caches when the current process has its
journal_info set to NULL (and not to a transaction). This makes our assertion
at btrfs_check_data_free_space() (current_journal != NULL) fail, resulting
in a crash/hang. Therefore fix it by setting journal_info.

Two different traces of this issue follow below.

1)

    [51502.241936] BTRFS: assertion failed: current->journal_info, file: fs/btrfs/extent-tree.c, line: 3670
    [51502.242213] ------------[ cut here ]------------
    [51502.242493] kernel BUG at fs/btrfs/ctree.h:3964!
    [51502.242669] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
    (...)
    [51502.244010] Call Trace:
    [51502.244010]  [<ffffffffa02bc025>] btrfs_check_data_free_space+0x395/0x3a0 [btrfs]
    [51502.244010]  [<ffffffffa02c3bdc>] btrfs_write_dirty_block_groups+0x4ac/0x640 [btrfs]
    [51502.244010]  [<ffffffffa0357a6a>] commit_cowonly_roots+0x164/0x226 [btrfs]
    [51502.244010]  [<ffffffffa02d53cd>] btrfs_commit_transaction+0x4ed/0xab0 [btrfs]
    [51502.244010]  [<ffffffff8168ec7b>] ? _raw_spin_unlock+0x2b/0x40
    [51502.244010]  [<ffffffffa02d6259>] start_transaction+0x459/0x620 [btrfs]
    [51502.244010]  [<ffffffffa02d67ab>] btrfs_start_transaction+0x1b/0x20 [btrfs]
    [51502.244010]  [<ffffffffa02d73e1>] __unlink_start_trans+0x31/0xe0 [btrfs]
    [51502.244010]  [<ffffffffa02dea67>] btrfs_unlink+0x37/0xc0 [btrfs]
    [51502.244010]  [<ffffffff811bb054>] ? do_unlinkat+0x114/0x2a0
    [51502.244010]  [<ffffffff811baebc>] vfs_unlink+0xcc/0x150
    [51502.244010]  [<ffffffff811bb1a0>] do_unlinkat+0x260/0x2a0
    [51502.244010]  [<ffffffff811a9ef4>] ? filp_close+0x64/0x90
    [51502.244010]  [<ffffffff810aaea6>] ? trace_hardirqs_on_caller+0x16/0x1e0
    [51502.244010]  [<ffffffff81349cab>] ? trace_hardirqs_on_thunk+0x3a/0x3f
    [51502.244010]  [<ffffffff811be9eb>] SyS_unlinkat+0x1b/0x40
    [51502.244010]  [<ffffffff81698452>] system_call_fastpath+0x16/0x1b
    [51502.244010] Code: 0b 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 55 89 f1 48 c7 c2 71 13 36 a0 48 89 fe 31 c0 48 c7 c7 b8 43 36 a0 48 89 e5 e8 5d b0 32 e1 <0f> 0b 0f 1f 44 00 00 55 b9 11 00 00 00 48 89 e5 41 55 49 89 f5
    [51502.244010] RIP  [<ffffffffa03575da>] assfail.constprop.88+0x1e/0x20 [btrfs]

2)

    [25405.097230] BTRFS: assertion failed: current->journal_info, file: fs/btrfs/extent-tree.c, line: 3670
    [25405.097488] ------------[ cut here ]------------
    [25405.097767] kernel BUG at fs/btrfs/ctree.h:3964!
    [25405.097940] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
    (...)
    [25405.100008] Call Trace:
    [25405.100008]  [<ffffffffa02bc025>] btrfs_check_data_free_space+0x395/0x3a0 [btrfs]
    [25405.100008]  [<ffffffffa02c3bdc>] btrfs_write_dirty_block_groups+0x4ac/0x640 [btrfs]
    [25405.100008]  [<ffffffffa035755a>] commit_cowonly_roots+0x164/0x226 [btrfs]
    [25405.100008]  [<ffffffffa02d53cd>] btrfs_commit_transaction+0x4ed/0xab0 [btrfs]
    [25405.100008]  [<ffffffff8109c170>] ? bit_waitqueue+0xc0/0xc0
    [25405.100008]  [<ffffffffa02d6259>] start_transaction+0x459/0x620 [btrfs]
    [25405.100008]  [<ffffffffa02d67ab>] btrfs_start_transaction+0x1b/0x20 [btrfs]
    [25405.100008]  [<ffffffffa02e3407>] btrfs_create+0x47/0x210 [btrfs]
    [25405.100008]  [<ffffffffa02d74cc>] ? btrfs_permission+0x3c/0x80 [btrfs]
    [25405.100008]  [<ffffffff811bc63b>] vfs_create+0x9b/0x130
    [25405.100008]  [<ffffffff811bcf19>] do_last+0x849/0xe20
    [25405.100008]  [<ffffffff811b9409>] ? link_path_walk+0x79/0x820
    [25405.100008]  [<ffffffff811bd5b5>] path_openat+0xc5/0x690
    [25405.100008]  [<ffffffff810ab07d>] ? trace_hardirqs_on+0xd/0x10
    [25405.100008]  [<ffffffff811cdcd2>] ? __alloc_fd+0x32/0x1d0
    [25405.100008]  [<ffffffff811be2a3>] do_filp_open+0x43/0xa0
    [25405.100008]  [<ffffffff811cddf1>] ? __alloc_fd+0x151/0x1d0
    [25405.100008]  [<ffffffff811abcfc>] do_sys_open+0x13c/0x230
    [25405.100008]  [<ffffffff810aaea6>] ? trace_hardirqs_on_caller+0x16/0x1e0
    [25405.100008]  [<ffffffff811abe12>] SyS_open+0x22/0x30
    [25405.100008]  [<ffffffff81698452>] system_call_fastpath+0x16/0x1b
    [25405.100008] Code: 0b 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 55 89 f1 48 c7 c2 51 13 36 a0 48 89 fe 31 c0 48 c7 c7 d0 43 36 a0 48 89 e5 e8 6d b5 32 e1 <0f> 0b 0f 1f 44 00 00 55 b9 11 00 00 00 48 89 e5 41 55 49 89 f5
    [25405.100008] RIP  [<ffffffffa03570ca>] assfail.constprop.88+0x1e/0x20 [btrfs]

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:18 -07:00
Josef Bacik be2c765dff Btrfs: fix btrfs_print_leaf for skinny metadata
We wouldn't actuall print the extent information if we had a skinny metadata
item, this fixes that.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:16 -07:00
Liu Bo d288db5dc0 Btrfs: fix race of using total_bytes_pinned
This percpu counter @total_bytes_pinned is introduced to skip unnecessary
operations of 'commit transaction', it accounts for those space we may free
but are stuck in delayed refs.

And we zero out @space_info->total_bytes_pinned every transaction period so
we have a better idea of how much space we'll actually free up by committing
this transaction.  However, we do the 'zero out' part a little earlier, before
we actually unpin space, so we end up returning ENOSPC when we actually have
free space that's just unpinned from committing transaction.

xfstests/generic/074 complained then.

This fixes it by actually accounting the percpu pinned number when 'unpin',
and since it's protected by space_info->lock, the race is gone now.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:15 -07:00
David Sterba 130d5b415a btrfs: use E2BIG instead of EIO if compression does not help
Return codes got updated in 60e1975acb
(btrfs: return errno instead of -1 from compression)
lzo wrapper returns E2BIG in this case, do the same for zlib.

Signed-off-by: David Sterba <dsterba@suse.cz>
2014-07-03 07:04:13 -07:00
David Sterba 0a4eaea892 btrfs: remove stale comment from btrfs_flush_all_pending_stuffs
Commit fcebe4562d (Btrfs: rework qgroup
accounting) removed the qgroup accounting after delayed refs.

Signed-off-by: David Sterba <dsterba@suse.cz>
2014-07-03 07:04:12 -07:00
Filipe Manana 14f5979633 Btrfs: fix use-after-free when cloning a trailing file hole
The transaction handle was being used after being freed.

Cc: Chris Mason <clm@fb.com>
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:10 -07:00
Anand Jain 0aeb8a6e67 btrfs: fix null pointer dereference in btrfs_show_devname when name is null
dev->name is null but missing flag is not set.
Strictly speaking the missing flag should have been set, but there
are more places where code just checks if name is null. For now this
patch does the same.

stack:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000064
IP: [<ffffffffa0228908>] btrfs_show_devname+0x58/0xf0 [btrfs]

[<ffffffff81198879>] show_vfsmnt+0x39/0x130
[<ffffffff81178056>] m_show+0x16/0x20
[<ffffffff8117d706>] seq_read+0x296/0x390
[<ffffffff8115aa7d>] vfs_read+0x9d/0x160
[<ffffffff8115b549>] SyS_read+0x49/0x90
[<ffffffff817abe52>] system_call_fastpath+0x16/0x1b

reproducer:
mkfs.btrfs -draid1 -mraid1 /dev/sdg1 /dev/sdg2
btrfstune -S 1 /dev/sdg1
modprobe -r btrfs && modprobe btrfs
mount -o degraded /dev/sdg1 /btrfs
btrfs dev add /dev/sdg3 /btrfs

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:09 -07:00
Anand Jain e755f78086 btrfs: fix null pointer dereference in clone_fs_devices when name is null
when one of the device path is missing btrfs_device name is null. So this
patch will check for that.

stack:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: [<ffffffff812e18c0>] strlen+0x0/0x30
[<ffffffffa01cd92a>] ? clone_fs_devices+0xaa/0x160 [btrfs]
[<ffffffffa01cdcf7>] btrfs_init_new_device+0x317/0xca0 [btrfs]
[<ffffffff81155bca>] ? __kmalloc_track_caller+0x15a/0x1a0
[<ffffffffa01d6473>] btrfs_ioctl+0xaa3/0x2860 [btrfs]
[<ffffffff81132a6c>] ? handle_mm_fault+0x48c/0x9c0
[<ffffffff81192a61>] ? __blkdev_put+0x171/0x180
[<ffffffff817a784c>] ? __do_page_fault+0x4ac/0x590
[<ffffffff81193426>] ? blkdev_put+0x106/0x110
[<ffffffff81179175>] ? mntput+0x35/0x40
[<ffffffff8116d4b0>] do_vfs_ioctl+0x460/0x4a0
[<ffffffff8115c72e>] ? ____fput+0xe/0x10
[<ffffffff81068033>] ? task_work_run+0xb3/0xd0
[<ffffffff8116d547>] SyS_ioctl+0x57/0x90
[<ffffffff817a793e>] ? do_page_fault+0xe/0x10
[<ffffffff817abe52>] system_call_fastpath+0x16/0x1b

reproducer:
mkfs.btrfs -draid1 -mraid1 /dev/sdg1 /dev/sdg2
btrfstune -S 1 /dev/sdg1
modprobe -r btrfs && modprobe btrfs
mount -o degraded /dev/sdg1 /btrfs
btrfs dev add /dev/sdg3 /btrfs

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:07 -07:00
Eric Sandeen 2aa06a35d0 btrfs: fix nossd and ssd_spread mount option regression
The commit

0780253 btrfs: Cleanup the btrfs_parse_options for remount.

broke ssd options quite badly; it stopped making ssd_spread
imply ssd, and it made "nossd" unsettable.

Put things back at least as well as they were before
(though ssd mount option handling is still pretty odd:
# mount -o "nossd,ssd_spread" works?)

Reported-by: Roman Mamedov <rm@romanrm.net>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:06 -07:00
Wang Shilong 5f3164813b Btrfs: fix race between balance recovery and root deletion
Balance recovery is called when RW mounting or remounting from
RO to RW, it is called to finish roots merging.

When doing balance recovery, relocation root's corresponding
fs root(whose root refs is 0) might be destroyed by cleaner
thread, this will make btrfs fail to mount.

Fix this problem by holding @cleaner_mutex when doing balance
recovery.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:04:04 -07:00
Filipe Manana 3cc7939255 Btrfs: atomically set inode->i_flags in btrfs_update_iflags
This change is based on the corresponding recent change for ext4:

  ext4: atomically set inode->i_flags in ext4_set_inode_flags()

That has the following commit message that applies to btrfs as well:

  "Use cmpxchg() to atomically set i_flags instead of clearing out the
   S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
   EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race
   where an immutable file has the immutable flag cleared for a brief
   window of time."

Replacing EXT4_IMMUTABLE_FL and EXT4_APPEND_FL with BTRFS_INODE_IMMUTABLE
and BTRFS_INODE_APPEND, respectively.

Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-07-03 07:03:23 -07:00
Josef Bacik 472b909ff6 btrfs: only unlock block in verify_parent_transid if we locked it
This is a regression from my patch a26e8c9f75, we
need to only unlock the block if we were the one who locked it.  Otherwise this
will trip BUG_ON()'s in locking.c  Thanks,

cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:47 -07:00
Filipe Manana 46c4e71e9b Btrfs: assert send doesn't attempt to start transactions
When starting a transaction just assert that current->journal_info
doesn't contain a send transaction stub, since send isn't supposed
to start transactions and when it finishes (either successfully or
not) it's supposed to set current->journal_info to NULL.

This is motivated by the change titled:

    Btrfs: fix crash when starting transaction

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:46 -07:00
Sergey Senozhatsky c39aa7056f btrfs compression: reuse recently used workspace
Add compression `workspace' in free_workspace() to
`idle_workspace' list head, instead of tail. So we have
better chances to reuse most recently used `workspace'.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:46 -07:00
Liu Bo 5588383ece Btrfs: fix crash when mounting raid5 btrfs with missing disks
The reproducer is

$ mkfs.btrfs D1 D2 D3 -mraid5
$ mkfs.ext4 D2 && mkfs.ext4 D3
$ mount D1 /btrfs -odegraded

-------------------

[   87.672992] ------------[ cut here ]------------
[   87.673845] kernel BUG at fs/btrfs/raid56.c:1828!
...
[   87.673845] RIP: 0010:[<ffffffff813efc7e>]  [<ffffffff813efc7e>] __raid_recover_end_io+0x4ae/0x4d0
...
[   87.673845] Call Trace:
[   87.673845]  [<ffffffff8116bbc6>] ? mempool_free+0x36/0xa0
[   87.673845]  [<ffffffff813f0255>] raid_recover_end_io+0x75/0xa0
[   87.673845]  [<ffffffff81447c5b>] bio_endio+0x5b/0xa0
[   87.673845]  [<ffffffff81447cb2>] bio_endio_nodec+0x12/0x20
[   87.673845]  [<ffffffff81374621>] end_workqueue_fn+0x41/0x50
[   87.673845]  [<ffffffff813ad2aa>] normal_work_helper+0xca/0x2c0
[   87.673845]  [<ffffffff8108ba2b>] process_one_work+0x1eb/0x530
[   87.673845]  [<ffffffff8108b9c9>] ? process_one_work+0x189/0x530
[   87.673845]  [<ffffffff8108c15b>] worker_thread+0x11b/0x4f0
[   87.673845]  [<ffffffff8108c040>] ? rescuer_thread+0x290/0x290
[   87.673845]  [<ffffffff810939c4>] kthread+0xe4/0x100
[   87.673845]  [<ffffffff810938e0>] ? kthread_create_on_node+0x220/0x220
[   87.673845]  [<ffffffff817e7c7c>] ret_from_fork+0x7c/0xb0
[   87.673845]  [<ffffffff810938e0>] ? kthread_create_on_node+0x220/0x220

-------------------

It's because that we miscalculate @rbio->bbio->error so that it doesn't
reach maximum of tolerable errors while it should have.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Tested-by: Satoru Takeuchi<takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:45 -07:00
Anand Jain b2373f255c btrfs: create sprout should rename fsid on the sysfs as well
Creating sprout will change the fsid of the mounted root.
do the same on the sysfs as well.

reproducer:
 mount /dev/sdb /btrfs (seed disk)
 btrfs dev add /dev/sdc /btrfs
 mount -o rw,remount /btrfs
 btrfs dev del /dev/sdb /btrfs
 mount /dev/sdb /btrfs

Error:
kobject_add_internal failed for fe350492-dc28-4051-a601-e017b17e6145 with -EEXIST, don't try to register things with the same name in the same directory.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:44 -07:00
Anand Jain 49c6f736f3 btrfs: dev replace should replace the sysfs entry
when we replace the device its corresponding sysfs
entry has to be replaced as well

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:44 -07:00
Anand Jain 0d39376aa2 btrfs: dev add should add its sysfs entry
we would need the device links to be created,
when device is added.

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:43 -07:00
Anand Jain 99994cde9c btrfs: dev delete should remove sysfs entry
when we delete the device from the mounted btrfs,
we would need its corresponding sysfs enty to
be removed as well.

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:42 -07:00
Anand Jain 9b4eaf43f4 btrfs: rename add_device_membership to btrfs_kobj_add_device
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-28 13:48:41 -07:00
Linus Torvalds e13d100beb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "This fixes some lockups in btrfs reported with rc1.  It probably has
  some performance impact because it is backing off our spinning locks
  more often and switching to a blocking lock.  I'll be able to nail
  that down next week, but for now I want to get the lockups taken care
  of.

  Otherwise some more stack reduction and assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix wrong error handle when the device is missing or is not writeable
  Btrfs: fix deadlock when mounting a degraded fs
  Btrfs: use bio_endio_nodec instead of open code
  Btrfs: fix NULL pointer crash when running balance and scrub concurrently
  btrfs: Skip scrubbing removed chunks to avoid -ENOENT.
  Btrfs: fix broken free space cache after the system crashed
  Btrfs: make free space cache write out functions more readable
  Btrfs: remove unused wait queue in struct extent_buffer
  Btrfs: fix deadlocks with trylock on tree nodes
2014-06-21 14:21:43 -10:00
Miao Xie 8408c716d7 Btrfs: fix wrong error handle when the device is missing or is not writeable
The original bio might be submitted, so we shoud increase bi_remaining to
account for it when we deal with the error that the device is missing or
is not writeable, or we would skip the endio handle.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:56 -07:00
Miao Xie c55f139640 Btrfs: fix deadlock when mounting a degraded fs
The deadlock happened when we mount degraded filesystem, the reproduced
steps are following:
 # mkfs.btrfs -f -m raid1 -d raid1 <dev0> <dev1>
 # echo 1 > /sys/block/`basename <dev0>`/device/delete
 # mount -o degraded <dev1> <mnt>

The reason was that the counter -- bi_remaining was wrong. If the missing
or unwriteable device was the last device in the mapping array, we would
not submit the original bio, so we shouldn't increase bi_remaining of it
in btrfs_end_bio(), or we would skip the final endio handle.

Fix this problem by adding a flag into btrfs bio structure. If we submit
the original bio, we will set the flag, and we increase bi_remaining counter,
or we don't.

Though there is another way to fix it -- decrease bi_remaining counter of the
original bio when we make sure the original bio is not submitted, this method
need add more check and is easy to make mistake.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:56 -07:00
Miao Xie e990f16763 Btrfs: use bio_endio_nodec instead of open code
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:55 -07:00
Wang Shilong 298a8f9cf1 Btrfs: fix NULL pointer crash when running balance and scrub concurrently
While running balance, scrub, fsstress concurrently we hit the
following kernel crash:

[56561.448845] BTRFS info (device sde): relocating block group 11005853696 flags 132
[56561.524077] BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
[56561.524237] IP: [<ffffffffa038956d>] scrub_chunk.isra.12+0xdd/0x130 [btrfs]
[56561.524297] PGD 9be28067 PUD 7f3dd067 PMD 0
[56561.524325] Oops: 0000 [#1] SMP
[....]
[56561.527237] Call Trace:
[56561.527309]  [<ffffffffa038980e>] scrub_enumerate_chunks+0x24e/0x490 [btrfs]
[56561.527392]  [<ffffffff810abe00>] ? abort_exclusive_wait+0x50/0xb0
[56561.527476]  [<ffffffffa038add4>] btrfs_scrub_dev+0x1a4/0x530 [btrfs]
[56561.527561]  [<ffffffffa0368107>] btrfs_ioctl+0x13f7/0x2a90 [btrfs]
[56561.527639]  [<ffffffff811c82f0>] do_vfs_ioctl+0x2e0/0x4c0
[56561.527712]  [<ffffffff8109c384>] ? vtime_account_user+0x54/0x60
[56561.527788]  [<ffffffff810f768c>] ? __audit_syscall_entry+0x9c/0xf0
[56561.527870]  [<ffffffff811c8551>] SyS_ioctl+0x81/0xa0
[56561.527941]  [<ffffffff815707f7>] tracesys+0xdd/0xe2
[...]
[56561.528304] RIP  [<ffffffffa038956d>] scrub_chunk.isra.12+0xdd/0x130 [btrfs]
[56561.528395]  RSP <ffff88004c0f5be8>
[56561.528454] CR2: 0000000000000078

This is because in btrfs_relocate_chunk(), we will free @bdev directly while
scrub may still hold extent mapping, and may access freed memory.

Fix this problem by wrapping freeing @bdev work into free_extent_map() which
is based on reference count.

Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:55 -07:00
Qu Wenruo ced96edc48 btrfs: Skip scrubbing removed chunks to avoid -ENOENT.
When run scrub with balance, sometimes -ENOENT will be returned, since
in scrub_enumerate_chunks() will search dev_extent in *COMMIT_ROOT*, but
btrfs_lookup_block_group() will search block group in *MEMORY*, so if a
chunk is removed but not committed, -ENOENT will be returned.

However, there is no need to stop scrubbing since other chunks may be
scrubbed without problem.

So this patch changes the behavior to skip removed chunks and continue
to scrub the rest.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:54 -07:00
Miao Xie e570fd27f2 Btrfs: fix broken free space cache after the system crashed
When we mounted the filesystem after the crash, we got the following
message:
  BTRFS error (device xxx): block group xxxx has wrong amount of free space
  BTRFS error (device xxx): failed to load free space cache for block group xxx

It is because we didn't update the metadata of the allocated space (in extent
tree) until the file data was written into the disk. During this time, there was
no information about the allocated spaces in either the extent tree nor the
free space cache. when we wrote out the free space cache at this time (commit
transaction), those spaces were lost. In fact, only the free space that is
used to store the file data had this problem, the others didn't because
the metadata of them is updated in the same transaction context.

There are many methods which can fix the above problem
- track the allocated space, and write it out when we write out the free
  space cache
- account the size of the allocated space that is used to store the file
  data, if the size is not zero, don't write out the free space cache.

The first one is complex and may make the performance drop down.
This patch chose the second method, we use a per-block-group variant to
account the size of that allocated space. Besides that, we also introduce
a per-block-group read-write semaphore to avoid the race between
the allocation and the free space cache write out.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:54 -07:00
Miao Xie 5349d6c3ff Btrfs: make free space cache write out functions more readable
This patch makes the free space cache write out functions more readable,
and beisdes that, it also reduces the stack space that the function --
__btrfs_write_out_cache uses from 194bytes to 144bytes.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:54 -07:00
Filipe Manana 46fefe41b5 Btrfs: remove unused wait queue in struct extent_buffer
The lock_wq wait queue is not used anywhere, therefore just remove it.
On a x86_64 system, this reduced sizeof(struct extent_buffer) from 320
bytes down to 296 bytes, which means a 4Kb page can now be used for
13 extent buffers instead of 12.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:28 -07:00
Chris Mason ea4ebde02e Btrfs: fix deadlocks with trylock on tree nodes
The Btrfs tree trylock function is poorly named.  It always takes
the spinlock and backs off if the blocking lock is held.  This
can lead to surprising lockups because people expect it to really be a
trylock.

This commit makes it a pure trylock, both for the spinlock and the
blocking lock.  It also reworks the nested lock handling slightly to
avoid taking the read lock while a spinning write lock might be held.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:19:55 -07:00
Linus Torvalds 16d52ef7c0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull more btrfs updates from Chris Mason:
 "This has a few fixes since our last pull and a new ioctl for doing
  btree searches from userland.  It's very similar to the existing
  ioctl, but lets us return larger items back down to the app"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: fix error handling in create_pending_snapshot
  btrfs: fix use of uninit "ret" in end_extent_writepage()
  btrfs: free ulist in qgroup_shared_accounting() error path
  Btrfs: fix qgroups sanity test crash or hang
  btrfs: prevent RCU warning when dereferencing radix tree slot
  Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting
  btrfs: new ioctl TREE_SEARCH_V2
  btrfs: tree_search, search_ioctl: direct copy to userspace
  btrfs: new function read_extent_buffer_to_user
  btrfs: tree_search, copy_to_sk: return needed size on EOVERFLOW
  btrfs: tree_search, copy_to_sk: return EOVERFLOW for too small buffer
  btrfs: tree_search, search_ioctl: accept varying buffer
  btrfs: tree_search: eliminate redundant nr_items check
2014-06-14 19:48:43 -05:00
Eric Sandeen 47a306a748 btrfs: fix error handling in create_pending_snapshot
fcebe456 cut and pasted some code to a later point
in create_pending_snapshot(), but didn't switch
to the appropriate error handling for this stage
of the function.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:30 -07:00
Eric Sandeen 3e2426bd0e btrfs: fix use of uninit "ret" in end_extent_writepage()
If this condition in end_extent_writepage() is false:

	if (tree->ops && tree->ops->writepage_end_io_hook)

we will then test an uninitialized "ret" at:

	ret = ret < 0 ? ret : -EIO;

The test for ret is for the case where ->writepage_end_io_hook
failed, and we'd choose that ret as the error; but if
there is no ->writepage_end_io_hook, nothing sets ret.

Initializing ret to 0 should be sufficient; if
writepage_end_io_hook wasn't set, (!uptodate) means
non-zero err was passed in, so we choose -EIO in that case.

Signed-of-by: Eric Sandeen <sandeen@redhat.com>

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:28 -07:00
Eric Sandeen d737278091 btrfs: free ulist in qgroup_shared_accounting() error path
If tmp = ulist_alloc(GFP_NOFS) fails, we return without
freeing the previously allocated qgroups = ulist_alloc(GFP_NOFS)
and cause a memory leak.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:26 -07:00
Filipe Manana b050f9f6dd Btrfs: fix qgroups sanity test crash or hang
Often when running the qgroups sanity test, a crash or a hang happened.
This is because the extent buffer the test uses for the root node doesn't
have an header level explicitly set, making it have a random level value.
This is a problem when it's not zero for the btrfs_search_slot() calls
the test ends up doing, resulting in crashes or hangs such as the following:

[ 6454.127192] Btrfs loaded, debug=on, assert=on, integrity-checker=on
(...)
[ 6454.127760] BTRFS: selftest: Running qgroup tests
[ 6454.127964] BTRFS: selftest: Running test_test_no_shared_qgroup
[ 6454.127966] BTRFS: selftest: Qgroup basic add
[ 6480.152005] BUG: soft lockup - CPU#0 stuck for 23s! [modprobe:5383]
[ 6480.152005] Modules linked in: btrfs(+) xor raid6_pq binfmt_misc nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc i2c_piix4 i2c_core pcspkr evbug psmouse serio_raw e1000 [last unloaded: btrfs]
[ 6480.152005] irq event stamp: 188448
[ 6480.152005] hardirqs last  enabled at (188447): [<ffffffff8168ef5c>] restore_args+0x0/0x30
[ 6480.152005] hardirqs last disabled at (188448): [<ffffffff81698e6a>] apic_timer_interrupt+0x6a/0x80
[ 6480.152005] softirqs last  enabled at (188446): [<ffffffff810516cf>] __do_softirq+0x1cf/0x450
[ 6480.152005] softirqs last disabled at (188441): [<ffffffff81051c25>] irq_exit+0xb5/0xc0
[ 6480.152005] CPU: 0 PID: 5383 Comm: modprobe Not tainted 3.15.0-rc8-fdm-btrfs-next-33+ #4
[ 6480.152005] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 6480.152005] task: ffff8802146125a0 ti: ffff8800d0d00000 task.ti: ffff8800d0d00000
[ 6480.152005] RIP: 0010:[<ffffffff81349a63>]  [<ffffffff81349a63>] __write_lock_failed+0x13/0x20
[ 6480.152005] RSP: 0018:ffff8800d0d038e8  EFLAGS: 00000287
[ 6480.152005] RAX: 0000000000000000 RBX: ffffffff8168ef5c RCX: 000005deb8525852
[ 6480.152005] RDX: 0000000000000000 RSI: 0000000000001d45 RDI: ffff8802105000b8
[ 6480.152005] RBP: ffff8800d0d038e8 R08: fffffe12710f63db R09: ffffffffa03196fb
[ 6480.152005] R10: ffff8802146125a0 R11: ffff880214612e28 R12: ffff8800d0d03858
[ 6480.152005] R13: 0000000000000000 R14: ffff8800d0d00000 R15: ffff8802146125a0
[ 6480.152005] FS:  00007f14ff804700(0000) GS:ffff880215e00000(0000) knlGS:0000000000000000
[ 6480.152005] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 6480.152005] CR2: 00007fff4df0dac8 CR3: 00000000d1796000 CR4: 00000000000006f0
[ 6480.152005] Stack:
[ 6480.152005]  ffff8800d0d03908 ffffffff810ae967 0000000000000001 ffff8802105000b8
[ 6480.152005]  ffff8800d0d03938 ffffffff8168e57e ffffffffa0319c16 0000000000000007
[ 6480.152005]  ffff880210500000 ffff880210500100 ffff8800d0d039b8 ffffffffa0319c16
[ 6480.152005] Call Trace:
[ 6480.152005]  [<ffffffff810ae967>] do_raw_write_lock+0x47/0xa0
[ 6480.152005]  [<ffffffff8168e57e>] _raw_write_lock+0x5e/0x80
[ 6480.152005]  [<ffffffffa0319c16>] ? btrfs_tree_lock+0x116/0x270 [btrfs]
[ 6480.152005]  [<ffffffffa0319c16>] btrfs_tree_lock+0x116/0x270 [btrfs]
[ 6480.152005]  [<ffffffffa02b2acb>] btrfs_lock_root_node+0x3b/0x50 [btrfs]
[ 6480.152005]  [<ffffffffa02b81a6>] btrfs_search_slot+0x916/0xa20 [btrfs]
[ 6480.152005]  [<ffffffff811a727f>] ? create_object+0x23f/0x300
[ 6480.152005]  [<ffffffffa02b9958>] btrfs_insert_empty_items+0x78/0xd0 [btrfs]
[ 6480.152005]  [<ffffffffa036041a>] insert_normal_tree_ref.constprop.4+0xa2/0x19a [btrfs]
[ 6480.152005]  [<ffffffffa03605c3>] test_no_shared_qgroup+0xb1/0x1ca [btrfs]
[ 6480.152005]  [<ffffffff8108cad6>] ? local_clock+0x16/0x30
[ 6480.152005]  [<ffffffffa035ef8e>] btrfs_test_qgroups+0x1ae/0x1d7 [btrfs]
[ 6480.152005]  [<ffffffffa03a69d2>] ? ftrace_define_fields_btrfs_space_reservation+0xfd/0xfd [btrfs]
[ 6480.152005]  [<ffffffffa03a6a86>] init_btrfs_fs+0xb4/0x153 [btrfs]
[ 6480.152005]  [<ffffffff81000352>] do_one_initcall+0x102/0x150
[ 6480.152005]  [<ffffffff8103d223>] ? set_memory_nx+0x43/0x50
[ 6480.152005]  [<ffffffff81682668>] ? set_section_ro_nx+0x6d/0x74
[ 6480.152005]  [<ffffffff810d91cc>] load_module+0x1cdc/0x2630
(...)

Therefore initialize the extent buffer as an empty leaf (level 0).

Issue easy to reproduce when btrfs is built as a module via:

    $ for ((i = 1; i <= 1000000; i++)); do rmmod btrfs; modprobe btrfs; done

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:24 -07:00
Sasha Levin f1e3c28949 btrfs: prevent RCU warning when dereferencing radix tree slot
Mark the dereference as protected by lock. Not doing so triggers
an RCU warning since the radix tree assumed that RCU is in use.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:22 -07:00
Wang Shilong 5fbc7c59fd Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting
Steps to reproduce:

 # mkfs.btrfs -f /dev/sd[b-f] -m raid5 -d raid5
 # mkfs.ext4 /dev/sdc --->corrupt one of btrfs device
 # mount /dev/sdb /mnt -o degraded
 # btrfs scrub start -BRd /mnt

This is because readahead would skip missing device, this is not true
for RAID5/6, because REQ_GET_READ_MIRRORS return 1 for RAID5/6 block
mapping. If expected data locates in missing device, readahead thread
would not call __readahead_hook() which makes event @rc->elems=0
wait forever.

Fix this problem by checking return value of btrfs_map_block(),we
can only skip missing device safely if there are several mirrors.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13 09:52:21 -07:00
Gerhard Heift cc68a8a5a4 btrfs: new ioctl TREE_SEARCH_V2
This new ioctl call allows the user to supply a buffer of varying size in which
a tree search can store its results. This is much more flexible if you want to
receive items which are larger than the current fixed buffer of 3992 bytes or
if you want to fetch more items at once. Items larger than this buffer are for
example some of the type EXTENT_CSUM.

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-13 09:52:19 -07:00
Gerhard Heift ba346b357d btrfs: tree_search, search_ioctl: direct copy to userspace
By copying each found item seperatly to userspace, we do not need extra
buffer in the kernel.

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:22:05 -07:00
Gerhard Heift 550ac1d85e btrfs: new function read_extent_buffer_to_user
This new function reads the content of an extent directly to user memory.

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:21:56 -07:00
Gerhard Heift 9b6e817d02 btrfs: tree_search, copy_to_sk: return needed size on EOVERFLOW
If an item in tree_search is too large to be stored in the given buffer, return
the needed size (including the header).

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:21:47 -07:00
Gerhard Heift 8f5f6178f3 btrfs: tree_search, copy_to_sk: return EOVERFLOW for too small buffer
In copy_to_sk, if an item is too large for the given buffer, it now returns
-EOVERFLOW instead of copying a search_header with len = 0. For backward
compatibility for the first item it still copies such a header to the buffer,
but not any other following items, which could have fitted.

tree_search changes -EOVERFLOW back to 0 to behave similiar to the way it
behaved before this patch.

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:21:39 -07:00
Gerhard Heift 1254444288 btrfs: tree_search, search_ioctl: accept varying buffer
rewrite search_ioctl to accept a buffer with varying size

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:21:26 -07:00
Gerhard Heift 25c9bc2e2b btrfs: tree_search: eliminate redundant nr_items check
If the amount of items reached the given limit of nr_items, we can leave
copy_to_sk without updating the key. Also by returning 1 we leave the loop in
search_ioctl without rechecking if we reached the given limit.

Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
2014-06-12 18:20:39 -07:00
Linus Torvalds 16b9057804 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "This the bunch that sat in -next + lock_parent() fix.  This is the
  minimal set; there's more pending stuff.

  In particular, I really hope to get acct.c fixes merged this cycle -
  we need that to deal sanely with delayed-mntput stuff.  In the next
  pile, hopefully - that series is fairly short and localized
  (kernel/acct.c, fs/super.c and fs/namespace.c).  In this pile: more
  iov_iter work.  Most of prereqs for ->splice_write with sane locking
  order are there and Kent's dio rewrite would also fit nicely on top of
  this pile"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (70 commits)
  lock_parent: don't step on stale ->d_parent of all-but-freed one
  kill generic_file_splice_write()
  ceph: switch to iter_file_splice_write()
  shmem: switch to iter_file_splice_write()
  nfs: switch to iter_splice_write_file()
  fs/splice.c: remove unneeded exports
  ocfs2: switch to iter_file_splice_write()
  ->splice_write() via ->write_iter()
  bio_vec-backed iov_iter
  optimize copy_page_{to,from}_iter()
  bury generic_file_aio_{read,write}
  lustre: get rid of messing with iovecs
  ceph: switch to ->write_iter()
  ceph_sync_direct_write: stop poking into iov_iter guts
  ceph_sync_read: stop poking into iov_iter guts
  new helper: copy_page_from_iter()
  fuse: switch to ->write_iter()
  btrfs: switch to ->write_iter()
  ocfs2: switch to ->write_iter()
  xfs: switch to ->write_iter()
  ...
2014-06-12 10:30:18 -07:00
Al Viro 9c1d5284c7 Merge commit '9f12600fe425bc28f0ccba034a77783c09c15af4' into for-linus
Backmerge of dcache.c changes from mainline.  It's that, or complete
rebase...

Conflicts:
	fs/splice.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-06-12 00:28:09 -04:00
Linus Torvalds 859862ddd2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "The biggest change here is Josef's rework of the btrfs quota
  accounting, which improves the in-memory tracking of delayed extent
  operations.

  I had been working on Btrfs stack usage for a while, mostly because it
  had become impossible to do long stress runs with slab, lockdep and
  pagealloc debugging turned on without blowing the stack.  Even though
  you upgraded us to a nice king sized stack, I kept most of the
  patches.

  We also have some very hard to find corruption fixes, an awesome sysfs
  use after free, and the usual assortment of optimizations, cleanups
  and other fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (80 commits)
  Btrfs: convert smp_mb__{before,after}_clear_bit
  Btrfs: fix scrub_print_warning to handle skinny metadata extents
  Btrfs: make fsync work after cloning into a file
  Btrfs: use right type to get real comparison
  Btrfs: don't check nodes for extent items
  Btrfs: don't release invalid page in btrfs_page_exists_in_range()
  Btrfs: make sure we retry if page is a retriable exception
  Btrfs: make sure we retry if we couldn't get the page
  btrfs: replace EINVAL with EOPNOTSUPP for dev_replace raid56
  trivial: fs/btrfs/ioctl.c: fix typo s/substract/subtract/
  Btrfs: fix leaf corruption after __btrfs_drop_extents
  Btrfs: ensure btrfs_prev_leaf doesn't miss 1 item
  Btrfs: fix clone to deal with holes when NO_HOLES feature is enabled
  btrfs: free delayed node outside of root->inode_lock
  btrfs: replace EINVAL with ERANGE for resize when ULLONG_MAX
  Btrfs: fix transaction leak during fsync call
  btrfs: Avoid trucating page or punching hole in a already existed hole.
  Btrfs: update commit root on snapshot creation after orphan cleanup
  Btrfs: ioctl, don't re-lock extent range when not necessary
  Btrfs: avoid visiting all extent items when cloning a range
  ...
2014-06-11 09:22:21 -07:00
Chris Mason c7548af69d Btrfs: convert smp_mb__{before,after}_clear_bit
The new call is smp_mb__{before,after}_atomic.  The __ gives us extra
protection from the atomic rays.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-10 13:10:47 -07:00
Liu Bo 6eda71d0c0 Btrfs: fix scrub_print_warning to handle skinny metadata extents
The skinny extents are intepreted incorrectly in scrub_print_warning(),
and end up hitting the BUG() in btrfs_extent_inline_ref_size.

Reported-by: Konstantinos Skarlatos <k.skarlatos@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:17 -07:00
Filipe Manana 7ffbb598a0 Btrfs: make fsync work after cloning into a file
When cloning into a file, we were correctly replacing the extent
items in the target range and removing the extent maps. However
we weren't replacing the extent maps with new ones that point to
the new extents - as a consequence, an incremental fsync (when the
inode doesn't have the full sync flag) was a NOOP, since it relies
on the existence of extent maps in the modified list of the inode's
extent map tree, which was empty. Therefore add new extent maps to
reflect the target clone range.

A test case for xfstests follows.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:16 -07:00
Liu Bo cd857dd6bc Btrfs: use right type to get real comparison
We want to make sure the point is still within the extent item, not to verify
the memory it's pointing to.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:15 -07:00
Josef Bacik 8a56457f5f Btrfs: don't check nodes for extent items
The backref code was looking at nodes as well as leaves when we tried to
populate extent item entries.  This is not good, and although we go away with it
for the most part because we'd skip where disk_bytenr != random_memory,
sometimes random_memory would match and suddenly boom.  This fixes that problem.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:14 -07:00
Filipe Manana 6fdef6d43c Btrfs: don't release invalid page in btrfs_page_exists_in_range()
In inode.c:btrfs_page_exists_in_range(), if the page we got from
the radix tree is an exception entry, which can't be retried, we
exit the loop with a non-NULL page and then call page_cache_release
against it, which is not ok since it's not a valid page. This could
also make us return true when we shouldn't.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:14 -07:00
Filipe Manana 809f901625 Btrfs: make sure we retry if page is a retriable exception
In inode.c:btrfs_page_exists_in_range(), if the page we get from the
radix tree is an exception which should make us retry, set page to
NULL in order to really retry, because otherwise we don't get another
loop iteration executed (page != NULL makes the while loop exit).
This also was making us call page_cache_release after exiting the loop,
which isn't correct because page doesn't point to a valid page, and
possibly return true from the function when we shouldn't.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:13 -07:00
Filipe Manana 91405151eb Btrfs: make sure we retry if we couldn't get the page
In inode.c:btrfs_page_exists_in_range(), if we can't get the page
we need to retry. However we weren't retrying because we weren't
setting page to NULL, which makes the while loop exit immediately
and will make us call page_cache_release after exiting the loop
which is incorrect because our page get didn't succeed. This could
also make us return true when we shouldn't.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:12 -07:00
Gui Hecheng c81d57679e btrfs: replace EINVAL with EOPNOTSUPP for dev_replace raid56
To return EOPNOTSUPP is more user friendly than to return EINVAL,
and then user-space tool will show that the dev_replace operation
for raid56 is not currently supported rather than showing that
there is an invalid argument.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:12 -07:00
Antonio Ospite 9391558411 trivial: fs/btrfs/ioctl.c: fix typo s/substract/subtract/
Signed-off-by: Antonio Ospite <ao2@ao2.it>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:11 -07:00
Liu Bo 0b43e04f70 Btrfs: fix leaf corruption after __btrfs_drop_extents
Several reports about leaf corruption has been floating on the list, one of them
points to __btrfs_drop_extents(), and we find that the leaf becomes corrupted
after __btrfs_drop_extents(), it's really a rare case but it does exist.

The problem turns out to be btrfs_next_leaf() called in __btrfs_drop_extents().

So in btrfs_next_leaf(), we release the current path to re-search the last key of
the leaf for locating next leaf, and we've taken it into account that there might
be balance operations between leafs during this 'unlock and re-lock' dance, so
we check the path again and advance it if there are now more items available.
But things are a bit different if that last key happens to be removed and balance
gets a bigger key as the last one, and btrfs_search_slot will return it with
ret > 0, IOW, nothing change in this leaf except the new last key, then we think
we're okay because there is no more item balanced in, fine, we thinks we can
go to the next leaf.

However, we should return that bigger key, otherwise we deserve leaf corruption,
for example, in endio, skipping that key means that __btrfs_drop_extents() thinks
it has dropped all extent matched the required range and finish_ordered_io can
safely insert a new extent, but it actually doesn't and ends up a leaf
corruption.

One may be asking that why our locking on extent io tree doesn't work as
expected, ie. it should avoid this kind of race situation.  But in
__btrfs_drop_extents(), we don't always find extents which are included within
our locking range, IOW, extents can start before our searching start, in this
case locking on extent io tree doesn't protect us from the race.

This takes the special case into account.

Reviewed-by: Filipe Manana <fdmanana@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:10 -07:00
Filipe Manana 337c6f6830 Btrfs: ensure btrfs_prev_leaf doesn't miss 1 item
We might have had an item with the previous key in the tree right
before we released our path. And after we released our path, that
item might have been pushed to the first slot (0) of the leaf we
were holding due to a tree balance. Alternatively, an item with the
previous key can exist as the only element of a leaf (big fat item).
Therefore account for these 2 cases, so that our callers (like
btrfs_previous_item) don't miss an existing item with a key matching
the previous key we computed above.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:09 -07:00
Filipe Manana f82a9901b0 Btrfs: fix clone to deal with holes when NO_HOLES feature is enabled
If the NO_HOLES feature is enabled holes don't have file extent items in
the btree that represent them anymore. This made the clone operation
ignore the gaps that exist between consecutive file extent items and
therefore not create the holes at the destination. When not using the
NO_HOLES feature, the holes were created at the destination.

A test case for xfstests follows.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:09 -07:00
Jeff Mahoney 964930312a btrfs: free delayed node outside of root->inode_lock
On heavy workloads, we're seeing soft lockup warnings on
root->inode_lock in __btrfs_release_delayed_node. The low hanging fruit
is to reduce the size of the critical section.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:08 -07:00
Gui Hecheng 902c68a4da btrfs: replace EINVAL with ERANGE for resize when ULLONG_MAX
To be accurate about the error case,
if the new size is beyond ULLONG_MAX, return ERANGE instead of EINVAL.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:07 -07:00
Filipe Manana b05fd8742f Btrfs: fix transaction leak during fsync call
If btrfs_log_dentry_safe() returns an error, we set ret to 1 and
fall through with the goal of committing the transaction. However,
in the case where the inode doesn't need a full sync, we would call
btrfs_wait_ordered_range() against the target range for our inode,
and if it returned an error, we would return without commiting or
ending the transaction.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:06 -07:00
Qu Wenruo d77815461f btrfs: Avoid trucating page or punching hole in a already existed hole.
btrfs_punch_hole() will truncate unaligned pages or punch hole on a
already existed hole.
This will cause unneeded zero page or holes splitting the original huge
hole.

This patch will skip already existed holes before any page truncating or
hole punching.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:06 -07:00
Filipe Manana 3821f34888 Btrfs: update commit root on snapshot creation after orphan cleanup
On snapshot creation (either writable or read-only), we do orphan cleanup
against the root of the snapshot. If the cleanup did remove any orphans,
then the current root node will be different from the commit root node
until the next transaction commit happens.

A send operation always uses the commit root of a snapshot - this means
it will see the orphans if it starts computing the send stream before the
next transaction commit happens (triggered by a timer or sync() for .e.g),
which is when the commit root gets assigned a reference to current root,
where the orphans are not visible anymore. The consequence of send seeing
the orphans is explained below.

For example:

    mkfs.btrfs -f /dev/sdd
    mount -o commit=999 /dev/sdd /mnt

    # open a file with O_TMPFILE and leave it open
    # write some data to the file
    btrfs subvolume snapshot -r /mnt /mnt/snap1

    btrfs send /mnt/snap1 -f /tmp/send.data

The send operation will fail with the following error:

    ERROR: send ioctl failed with -116: Stale file handle

What happens here is that our snapshot has an orphan inode still visible
through the commit root, that corresponds to the tmpfile. However send
will attempt to call inode.c:btrfs_iget(), with the goal of reading the
file's data, which will return -ESTALE because it will use the current
root (and not the commit root) of the snapshot.

Of course, there are other cases where we can get orphans, but this
example using a tmpfile makes it much easier to reproduce the issue.

Therefore on snapshot creation, after calling btrfs_orphan_cleanup, if
the commit root is different from the current root, just commit the
transaction associated with the snapshot's root (if it exists), so that
a send will not see any orphans that don't exist anymore. This also
guarantees a send will always see the same content regardless of whether
a transaction commit happened already before the send was requested and
after the orphan cleanup (meaning the commit root and current roots are
the same) or it hasn't happened yet (commit and current roots are
different).

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:05 -07:00
Filipe Manana ff5df9b884 Btrfs: ioctl, don't re-lock extent range when not necessary
In ioctl.c:lock_extent_range(), after locking our target range, the
ordered extent that btrfs_lookup_first_ordered_extent() returns us
may not overlap our target range at all. In this case we would just
unlock our target range, wait for any new ordered extents that overlap
the range to complete, lock again the range and repeat all these steps
until we don't get any ordered extent and the delalloc flag isn't set
in the io tree for our target range.

Therefore just stop if we get an ordered extent that doesn't overlap
our target range and the dealalloc flag isn't set for the range in
the inode's io tree.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:04 -07:00
Filipe Manana 2c463823cb Btrfs: avoid visiting all extent items when cloning a range
When cloning a range of a file, we were visiting all the extent items in
the btree that belong to our source inode. We don't need to visit those
extent items that don't overlap the range we are cloning, as doing so only
makes us waste time and do unnecessary btree navigations (btrfs_next_leaf)
for inodes that have a large number of file extent items in the btree.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:04 -07:00
Filipe Manana c55bfa67e9 Btrfs: set dead flag on the right root when destroying snapshot
We were setting the BTRFS_ROOT_SUBVOL_DEAD flag on the root of the
parent of our target snapshot, instead of setting it in the target
snapshot's root.

This is easy to observe by running the following scenario:

    mkfs.btrfs -f /dev/sdd
    mount /dev/sdd /mnt

    btrfs subvolume create /mnt/first_subvol
    btrfs subvolume snapshot -r /mnt /mnt/mysnap1

    btrfs subvolume delete /mnt/first_subvol
    btrfs subvolume snapshot -r /mnt /mnt/mysnap2

    btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/send.data

The send command failed because the send ioctl returned -EPERM.
A test case for xfstests follows.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:03 -07:00
Filipe Manana c125b8bff1 Btrfs: ensure readers see new data after a clone operation
We were cleaning the clone target file range from the page cache before
we did replace the file extent items in the fs tree. This was racy,
as right after cleaning the relevant range from the page cache and before
replacing the file extent items, a read against that range could be
performed by another task and populate again the page cache with stale
data (stale after the cloning finishes). This would result in reads after
the clone operation successfully finishes to get old data (and potentially
for a very long time). Therefore evict the pages after replacing the file
extent items, so that subsequent reads will always get the new data.

Similarly, we were prone to races while cloning the file extent items
because we weren't locking the target range and wait for any existing
ordered extents against that range to complete. It was possible that
after cloning the extent items, a write operation that was performed
before the clone operation and overlaps the same range, would end up
undoing all or part of the work the clone operation did (a worker task
running inode.c:btrfs_finish_ordered_io). Therefore lock the target
range in the io tree, wait for all pending ordered extents against that
range to finish and then safely perform the cloning.

The issue of reading stale data after the clone operation is easy to
reproduce by running the following C program in a loop until it exits
with return value 1.

 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
 #include <pthread.h>
 #include <fcntl.h>
 #include <assert.h>
 #include <asm/types.h>
 #include <linux/ioctl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/ioctl.h>

 #define SRC_FILE "/mnt/sdd/foo"
 #define DST_FILE "/mnt/sdd/bar"
 #define FILE_SIZE (16 * 1024)
 #define PATTERN_SRC 'X'
 #define PATTERN_DST 'Y'

struct btrfs_ioctl_clone_range_args {
	__s64 src_fd;
	__u64 src_offset, src_length;
	__u64 dest_offset;
};

 #define BTRFS_IOCTL_MAGIC 0x94
 #define BTRFS_IOC_CLONE_RANGE _IOW(BTRFS_IOCTL_MAGIC, 13, \
				   struct btrfs_ioctl_clone_range_args)

static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
static int clone_done = 0;
static int reader_ready = 0;
static int stale_data = 0;

static void *reader_loop(void *arg)
{
	char buf[4096], want_buf[4096];

	memset(want_buf, PATTERN_SRC, 4096);
	pthread_mutex_lock(&mutex);
	reader_ready = 1;
	pthread_mutex_unlock(&mutex);

	while (1) {
		int done, fd, ret;

		fd = open(DST_FILE, O_RDONLY);
		assert(fd != -1);

		pthread_mutex_lock(&mutex);
		done = clone_done;
		pthread_mutex_unlock(&mutex);

		ret = read(fd, buf, 4096);
		assert(ret == 4096);
		close(fd);

		if (done) {
			ret = memcmp(buf, want_buf, 4096);
			if (ret == 0) {
				printf("Found new content\n");
			} else {
				printf("Found old content\n");
				pthread_mutex_lock(&mutex);
				stale_data = 1;
				pthread_mutex_unlock(&mutex);
			}
			break;
		}
	}
	return NULL;
}

int main(int argc, char *argv[])
{
	pthread_t reader;
	int ret, i, fd;
	struct btrfs_ioctl_clone_range_args clone_args;
	int fd1, fd2;

	ret = remove(SRC_FILE);
	if (ret == -1 && errno != ENOENT) {
		fprintf(stderr, "Error deleting src file: %s\n", strerror(errno));
		return 1;
	}
	ret = remove(DST_FILE);
	if (ret == -1 && errno != ENOENT) {
		fprintf(stderr, "Error deleting dst file: %s\n", strerror(errno));
		return 1;
	}

	fd = open(SRC_FILE, O_CREAT | O_WRONLY | O_TRUNC, S_IRWXU);
	assert(fd != -1);
	for (i = 0; i < FILE_SIZE; i++) {
		char c = PATTERN_SRC;
		ret = write(fd, &c, 1);
		assert(ret == 1);
	}
	close(fd);
	fd = open(DST_FILE, O_CREAT | O_WRONLY | O_TRUNC, S_IRWXU);
	assert(fd != -1);
	for (i = 0; i < FILE_SIZE; i++) {
		char c = PATTERN_DST;
		ret = write(fd, &c, 1);
		assert(ret == 1);
	}
	close(fd);
        sync();

	ret = pthread_create(&reader, NULL, reader_loop, NULL);
	assert(ret == 0);
	while (1) {
		int r;
		pthread_mutex_lock(&mutex);
		r = reader_ready;
		pthread_mutex_unlock(&mutex);
		if (r) break;
	}

	fd1 = open(SRC_FILE, O_RDONLY);
	if (fd1 < 0) {
		fprintf(stderr, "Error open src file: %s\n", strerror(errno));
		return 1;
	}
	fd2 = open(DST_FILE, O_RDWR);
	if (fd2 < 0) {
		fprintf(stderr, "Error open dst file: %s\n", strerror(errno));
		return 1;
	}
	clone_args.src_fd = fd1;
	clone_args.src_offset = 0;
	clone_args.src_length = 4096;
	clone_args.dest_offset = 0;
	ret = ioctl(fd2, BTRFS_IOC_CLONE_RANGE, &clone_args);
	assert(ret == 0);
	close(fd1);
	close(fd2);

	pthread_mutex_lock(&mutex);
	clone_done = 1;
	pthread_mutex_unlock(&mutex);
	ret = pthread_join(reader, NULL);
	assert(ret == 0);

	pthread_mutex_lock(&mutex);
	ret = stale_data ? 1 : 0;
	pthread_mutex_unlock(&mutex);
	return ret;
}

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:02 -07:00
Rickard Strandqvist 8321cf2596 fs: btrfs: volumes.c: Fix for possible null pointer dereference
There is otherwise a risk of a possible null pointer dereference.

Was largely found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:01 -07:00
Jeff Mahoney c1895442be btrfs: allocate raid type kobjects dynamically
We are currently allocating space_info objects in an array when we
allocate space_info. When a user does something like:

# btrfs balance start -mconvert=raid1 -dconvert=raid1 /mnt
# btrfs balance start -mconvert=single -dconvert=single /mnt -f
# btrfs balance start -mconvert=raid1 -dconvert=raid1 /

We can end up with memory corruption since the kobject hasn't
been reinitialized properly and the name pointer was left set.

The rationale behind allocating them statically was to avoid
creating a separate kobject container that just contained the
raid type. It used the index in the array to determine the index.

Ultimately, though, this wastes more memory than it saves in all
but the most complex scenarios and introduces kobject lifetime
questions.

This patch allocates the kobjects dynamically instead. Note that
we also remove the kobject_get/put of the parent kobject since
kobject_add and kobject_del do that internally.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:01 -07:00
Filipe Manana 7e3ae33efa Btrfs: send, use the right limits for xattr names and values
We were limiting the sum of the xattr name and value lengths to PATH_MAX,
which is not correct, specially on filesystems created with btrfs-progs
v3.12 or higher, where the default leaf size is max(16384, PAGE_SIZE), or
systems with page sizes larger than 4096 bytes.

Xattrs have their own specific maximum name and value lengths, which depend
on the leaf size, therefore use these limits to be able to send xattrs with
sizes larger than PATH_MAX.

A test case for xfstests follows.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:21:00 -07:00
Filipe Manana 1af56070e3 Btrfs: send, don't error in the presence of subvols/snapshots
If we are doing an incremental send and the base snapshot has a
directory with name X that doesn't exist anymore in the second
snapshot and a new subvolume/snapshot exists in the second snapshot
that has the same name as the directory (name X), the incremental
send would fail with -ENOENT error. This is because it attempts
to lookup for an inode with a number matching the objectid of a
root, which doesn't exist.

Steps to reproduce:

    mkfs.btrfs -f /dev/sdd
    mount /dev/sdd /mnt

    mkdir /mnt/testdir
    btrfs subvolume snapshot -r /mnt /mnt/mysnap1

    rmdir /mnt/testdir
    btrfs subvolume create /mnt/testdir
    btrfs subvolume snapshot -r /mnt /mnt/mysnap2

    btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/send.data

A test case for xfstests follows.

Reported-by: Robert White <rwhite@pobox.com>
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:59 -07:00
Chris Mason a79b7d4b3e Btrfs: async delayed refs
Delayed extent operations are triggered during transaction commits.
The goal is to queue up a healthly batch of changes to the extent
allocation tree and run through them in bulk.

This farms them off to async helper threads.  The goal is to have the
bulk of the delayed operations being done in the background, but this is
also important to limit our stack footprint.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:58 -07:00
Chris Mason 40f765805f Btrfs: split up __extent_writepage to lower stack usage
__extent_writepage has two unrelated parts.  First it does the delayed
allocation dance and second it does the mapping and IO for the page
we're actually writing.

This splits it up into those two parts so the stack from one doesn't
impact the stack from the other.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:58 -07:00
Alex Gartrell fc4adbff82 btrfs: Drop EXTENT_UPTODATE check in hole punching and direct locking
In these instances, we are trying to determine if a page has been accessed
since we began the operation for the sake of retry.  This is easily
accomplished by doing a gang lookup in the page mapping radix tree, and it
saves us the dependency on the flag (so that we might eventually delete
it).

btrfs_page_exists_in_range borrows heavily from find_get_page, replacing
the radix tree look up with a gang lookup of 1, so that we can find the
next highest page >= index and see if it falls into our lock range.

Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Alex Gartrell <agartrell@fb.com>
2014-06-09 17:20:57 -07:00
Chris Mason 0e378df15c Btrfs: cut down stack usage in btree_write_cache_pages
This adds noinline_for_stack to two helpers used by
btree_write_cache_pages.  It shaves us down from 424 bytes on the
stack to 280.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:56 -07:00
Chris Mason d4452bc526 Btrfs: break up __btrfs_write_out_cache to cut down stack usage
__btrfs_write_out_cache was one of our stack pigs.  This breaks it
up into helper functions and slims it down to 194 bytes.

Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:55 -07:00
Josef Bacik 2a10840945 Btrfs: free tmp ulist for qgroup rescan
Memory leaks are bad mmkay?

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:55 -07:00
Anand Jain 402a0f4759 btrfs: usage error should not be logged into system log
I have an opinion that system logs /var/log/messages are
valuable info to investigate the real system issues at
the data center. People handling data center issues
do spend a lot time and efforts analyzing messages
files. Having usage error logged into /var/log/messages
is something we should avoid.

Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:54 -07:00
David Sterba 67a77eb147 btrfs: remove newline from inode cache kthread name
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:53 -07:00
David Sterba 351fd35321 btrfs: remove stale newlines from log messages
I've noticed an extra line after "use no compression", but search
revealed much more in messages of more critical levels and rare errors.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:53 -07:00
Chris Mason 7d78874273 Btrfs: fix double free in find_lock_delalloc_range
We need to NULL the cached_state after freeing it, otherwise
we might free it again if find_delalloc_range doesn't find anything.

Signed-off-by: Chris Mason <clm@fb.com>
cc: stable@vger.kernel.org
2014-06-09 17:20:52 -07:00
ZhangZhen 58dfae6365 btrfs: replace simple_strtoull() with kstrtoull()
use the newer and more pleasant kstrtoull() to replace simple_strtoull(),
because simple_strtoull() is marked for obsoletion.

Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:51 -07:00
Wang Shilong 298658414a Btrfs: set right total device count for seeding support
Seeding device support allows us to create a new filesystem
based on existed filesystem.

However newly created filesystem's @total_devices should include seed
devices. This patch fix the following problem:

 # mkfs.btrfs -f /dev/sdb
 # btrfstune -S 1 /dev/sdb
 # mount /dev/sdb /mnt
 # btrfs device add -f /dev/sdc /mnt --->fs_devices->total_devices = 1
 # umount /mnt
 # mount /dev/sdc /mnt               --->fs_devices->total_devices = 2

This is because we record right @total_devices in superblock, but
@fs_devices->total_devices is reset to be 0 in btrfs_prepare_sprout().

Fix this problem by not resetting @fs_devices->total_devices.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:50 -07:00
Guangliang Zhao 45ff35d6b9 Btrfs: remove OPT_acl parse when acl disabled
Even CONFIG_BTRFS_FS_POSIX_ACL is not defined, the acl still could
been enabled using a mount option, and now fs/btrfs/acl.o is not
built, so the mount options will appear to be supported but will
be silently ignored.

Signed-off-by: Guangliang Zhao <lucienchao@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:50 -07:00
Josef Bacik faa2dbf004 Btrfs: add sanity tests for new qgroup accounting code
This exercises the various parts of the new qgroup accounting code.  We do some
basic stuff and do some things with the shared refs to make sure all that code
works.  I had to add a bunch of infrastructure because I needed to be able to
insert items into a fake tree without having to do all the hard work myself,
hopefully this will be usefull in the future.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:49 -07:00
Josef Bacik fcebe4562d Btrfs: rework qgroup accounting
Currently qgroups account for space by intercepting delayed ref updates to fs
trees.  It does this by adding sequence numbers to delayed ref updates so that
it can figure out how the tree looked before the update so we can adjust the
counters properly.  The problem with this is that it does not allow delayed refs
to be merged, so if you say are defragging an extent with 5k snapshots pointing
to it we will thrash the delayed ref lock because we need to go back and
manually merge these things together.  Instead we want to process quota changes
when we know they are going to happen, like when we first allocate an extent, we
free a reference for an extent, we add new references etc.  This patch
accomplishes this by only adding qgroup operations for real ref changes.  We
only modify the sequence number when we need to lookup roots for bytenrs, this
reduces the amount of churn on the sequence number and allows us to merge
delayed refs as we add them most of the time.  This patch encompasses a bunch of
architectural changes

1) qgroup ref operations: instead of tracking qgroup operations through the
delayed refs we simply add new ref operations whenever we notice that we need to
when we've modified the refs themselves.

2) tree mod seq:  we no longer have this separation of major/minor counters.
this makes the sequence number stuff much more sane and we can remove some
locking that was needed to protect the counter.

3) delayed ref seq: we now read the tree mod seq number and use that as our
sequence.  This means each new delayed ref doesn't have it's own unique sequence
number, rather whenever we go to lookup backrefs we inc the sequence number so
we can make sure to keep any new operations from screwing up our world view at
that given point.  This allows us to merge delayed refs during runtime.

With all of these changes the delayed ref stuff is a little saner and the qgroup
accounting stuff no longer goes negative in some cases like it was before.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:48 -07:00
Liu Bo 5dca6eea91 Btrfs: mark mapping with error flag to report errors to userspace
According to commit 865ffef379
(fs: fix fsync() error reporting),
it's not stable to just check error pages because pages can be
truncated or invalidated, we should also mark mapping with error
flag so that a later fsync can catch the error.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:47 -07:00
Liu Bo 29cc83f69c Btrfs: fix NULL pointer crash of deleting a seed device
Same as normal devices, seed devices should be initialized with
fs_info->dev_root as well, otherwise we'll get a NULL pointer crash.

Cc: Chris Murphy <lists@colorremedies.com>
Reported-by: Chris Murphy <lists@colorremedies.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:47 -07:00
Wang Shilong f017f15f7c Btrfs: fix joining same transaction handle more than twice
We hit something like the following function call flows:

|->run_delalloc_range()
 |->btrfs_join_transaction()
   |->cow_file_range()
     |->btrfs_join_transaction()
       |->find_free_extent()
         |->btrfs_join_transaction()

Trace infomation can be seen as:

[ 7411.127040] ------------[ cut here ]------------
[ 7411.127060] WARNING: CPU: 0 PID: 11557 at fs/btrfs/transaction.c:383 start_transaction+0x561/0x580 [btrfs]()
[ 7411.127079] CPU: 0 PID: 11557 Comm: kworker/u8:9 Tainted: G           O 3.13.0+ #4
[ 7411.127080] Hardware name: LENOVO QiTianM4350/ , BIOS F1KT52AUS 05/24/2013
[ 7411.127085] Workqueue: writeback bdi_writeback_workfn (flush-btrfs-5)
[ 7411.127092] Call Trace:
[ 7411.127097]  [<ffffffff815b87b0>] dump_stack+0x45/0x56
[ 7411.127101]  [<ffffffff81051ffd>] warn_slowpath_common+0x7d/0xa0
[ 7411.127102]  [<ffffffff810520da>] warn_slowpath_null+0x1a/0x20
[ 7411.127109]  [<ffffffffa0444fb1>] start_transaction+0x561/0x580 [btrfs]
[ 7411.127115]  [<ffffffffa0445027>] btrfs_join_transaction+0x17/0x20 [btrfs]
[ 7411.127120]  [<ffffffffa0431c91>] find_free_extent+0xa21/0xb50 [btrfs]
[ 7411.127126]  [<ffffffffa0431f68>] btrfs_reserve_extent+0xa8/0x1a0 [btrfs]
[ 7411.127131]  [<ffffffffa04322ce>] btrfs_alloc_free_block+0xee/0x440 [btrfs]
[ 7411.127137]  [<ffffffffa043bd6e>] ? btree_set_page_dirty+0xe/0x10 [btrfs]
[ 7411.127142]  [<ffffffffa041da51>] __btrfs_cow_block+0x121/0x530 [btrfs]
[ 7411.127146]  [<ffffffffa041dfff>] btrfs_cow_block+0x11f/0x1c0 [btrfs]
[ 7411.127151]  [<ffffffffa0421b74>] btrfs_search_slot+0x1d4/0x9c0 [btrfs]
[ 7411.127157]  [<ffffffffa0438567>] btrfs_lookup_file_extent+0x37/0x40 [btrfs]
[ 7411.127163]  [<ffffffffa0456bfc>] __btrfs_drop_extents+0x16c/0xd90 [btrfs]
[ 7411.127169]  [<ffffffffa0444ae3>] ? start_transaction+0x93/0x580 [btrfs]
[ 7411.127171]  [<ffffffff811663e2>] ? kmem_cache_alloc+0x132/0x140
[ 7411.127176]  [<ffffffffa041cd9a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs]
[ 7411.127182]  [<ffffffffa044aa61>] cow_file_range_inline+0x181/0x2e0 [btrfs]
[ 7411.127187]  [<ffffffffa044aead>] cow_file_range+0x2ed/0x440 [btrfs]
[ 7411.127194]  [<ffffffffa0464d7f>] ? free_extent_buffer+0x4f/0xb0 [btrfs]
[ 7411.127200]  [<ffffffffa044b38f>] run_delalloc_nocow+0x38f/0xa60 [btrfs]
[ 7411.127207]  [<ffffffffa0461600>] ? test_range_bit+0x30/0x180 [btrfs]
[ 7411.127212]  [<ffffffffa044bd48>] run_delalloc_range+0x2e8/0x350 [btrfs]
[ 7411.127219]  [<ffffffffa04618f9>] ? find_lock_delalloc_range+0x1a9/0x1e0 [btrfs]
[ 7411.127222]  [<ffffffff812a1e71>] ? blk_queue_bio+0x2c1/0x330
[ 7411.127228]  [<ffffffffa0462ad4>] __extent_writepage+0x2f4/0x760 [btrfs]

Here we fix it by avoiding joining transaction again if we have held
a transaction handle when allocating chunk in find_free_extent().

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:46 -07:00
Miao Xie 995946dd29 Btrfs: use helpers for last_trans_log_full_commit instead of opencode
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:45 -07:00
Filipe Manana 1f21ef0a34 Btrfs: check if items are ordered when a leaf is marked dirty
To ease finding bugs during development related to modifying btree leaves
in such a way that it makes its items not sorted by key anymore. Since this
is an expensive check, it's only enabled if CONFIG_BTRFS_FS_CHECK_INTEGRITY
is set, which isn't meant to be enabled for regular users.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:45 -07:00
Filipe Manana 35045bf2fd Btrfs: don't access non-existent key when csum tree is empty
When the csum tree is empty, our leaf (path->nodes[0]) has a number
of items equal to 0 and since btrfs_header_nritems() returns an
unsigned integer (and so is our local nritems variable) the following
comparison always evaluates to false:

     if (path->slots[0] >= nritems - 1) {

As the casting rules lead to:

     if ((u32)0 >= (u32)4294967295) {

This makes us access key at slot paths->slots[0] + 1 (1) of the empty leaf
some lines below:

    btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
    if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
        found_key.type != BTRFS_EXTENT_CSUM_KEY) {
		found_next = 1;
		goto insert;
    }

So just don't access such non-existent slot and don't set found_next to 1
when the tree is empty. It's very unlikely we'll get a random key with the
objectid and type values above, which is where we could go into trouble.

If nritems is 0, just set found_next to 1 anyway as it will make us insert
a csum item covering our whole extent (or the whole leaf) when the tree is
empty.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:44 -07:00
Wang Shilong de348ee022 Btrfs: make sure there are not any read requests before stopping workers
In close_ctree(), after we have stopped all workers,there maybe still
some read requests(for example readahead) to submit and this *maybe* trigger
an oops that user reported before:

kernel BUG at fs/btrfs/async-thread.c:619!

By hacking codes, i can reproduce this problem with one cpu available.
We fix this potential problem by invalidating all btree inode pages before
stopping all workers.

Thanks to Miao for pointing out this problem.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:43 -07:00
Tsutomu Itoh 59885b3930 Btrfs: fix possible memory leak in btrfs_create_tree()
In btrfs_create_tree(), if btrfs_insert_root() fails, we should
free root->commit_root.

Reported-by: Alex Lyakas <alex@zadarastorage.com>
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:42 -07:00
ZhangZhen 776e4aae55 btrfs: remove useless ACL check
posix_acl_xattr_set() already does the check, and it's the only
way to feed in an ACL from userspace.
So the check here is useless, remove it.

Signed-off-by: zhang zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:42 -07:00
Anand Jain 4d90d28b1c btrfs: btrfs_rm_device() should zero mirror SB as well
This fix will ensure all SB copies on the disk is zeroed
when the disk is intentionally removed. This helps to
better manage disks in the user land.

This version of patch also merges the Zach patch as below.

 btrfs: don't double brelse on device rm

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:41 -07:00
Miao Xie 27cdeb7096 Btrfs: use bitfield instead of integer data type for the some variants in btrfs_root
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:40 -07:00
Filipe Manana f959492fc1 Btrfs: send, fix more issues related to directory renames
This is a continuation of the previous changes titled:

   Btrfs: fix incremental send's decision to delay a dir move/rename
   Btrfs: part 2, fix incremental send's decision to delay a dir move/rename

There's a few more cases where a directory rename/move must be delayed which was
previously overlooked. If our immediate ancestor has a lower inode number than
ours and it doesn't have a delayed rename/move operation associated to it, it
doesn't mean there isn't any non-direct ancestor of our current inode that needs
to be renamed/moved before our current inode (i.e. with a higher inode number
than ours).

So we can't stop the search if our immediate ancestor has a lower inode number than
ours, we need to navigate the directory hierarchy upwards until we hit the root or:

1) find an ancestor with an higher inode number that was renamed/moved in the send
   root too (or already has a pending rename/move registered);
2) find an ancestor that is a new directory (higher inode number than ours and
   exists only in the send root).

Reproducer for case 1)

    $ mkfs.btrfs -f /dev/sdd
    $ mount /dev/sdd /mnt

    $ mkdir -p /mnt/a/b
    $ mkdir -p /mnt/a/c/d
    $ mkdir /mnt/a/b/e
    $ mkdir /mnt/a/c/d/f
    $ mv /mnt/a/b /mnt/a/c/d/2b
    $ mkdir /mnt/a/x
    $ mkdir /mnt/a/y

    $ btrfs subvolume snapshot -r /mnt /mnt/snap1
    $ btrfs send /mnt/snap1 -f /tmp/base.send

    $ mv /mnt/a/x /mnt/a/y
    $ mv /mnt/a/c/d/2b/e /mnt/a/c/d/2b/2e
    $ mv /mnt/a/c/d /mnt/a/h/2d
    $ mv /mnt/a/c /mnt/a/h/2d/2b/2c

    $ btrfs subvolume snapshot -r /mnt /mnt/snap2
    $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send

Simple reproducer for case 2)

    $ mkfs.btrfs -f /dev/sdd
    $ mount /dev/sdd /mnt

    $ mkdir -p /mnt/a/b
    $ mkdir /mnt/a/c
    $ mv /mnt/a/b /mnt/a/c/b2
    $ mkdir /mnt/a/e

    $ btrfs subvolume snapshot -r /mnt /mnt/snap1
    $ btrfs send /mnt/snap1 -f /tmp/base.send

    $ mv /mnt/a/c/b2 /mnt/a/e/b3
    $ mkdir /mnt/a/e/b3/f
    $ mkdir /mnt/a/h
    $ mv /mnt/a/c /mnt/a/e/b3/f/c2
    $ mv /mnt/a/e /mnt/a/h/e2

    $ btrfs subvolume snapshot -r /mnt /mnt/snap2
    $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send

Another simple reproducer for case 2)

    $ mkfs.btrfs -f /dev/sdd
    $ mount /dev/sdd /mnt

    $ mkdir -p /mnt/a/b
    $ mkdir /mnt/a/c
    $ mkdir /mnt/a/b/d
    $ mkdir /mnt/a/c/e

    $ btrfs subvolume snapshot -r /mnt /mnt/snap1
    $ btrfs send /mnt/snap1 -f /tmp/base.send

    $ mkdir /mnt/a/b/d/f
    $ mkdir /mnt/a/b/g
    $ mv /mnt/a/c/e /mnt/a/b/g/e2
    $ mv /mnt/a/c /mnt/a/b/d/f/c2
    $ mv /mnt/a/b/d/f /mnt/a/b/g/e2/f2

    $ btrfs subvolume snapshot -r /mnt /mnt/snap2
    $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send

More complex reproducer for case 2)

    $ mkfs.btrfs -f /dev/sdd
    $ mount /dev/sdd /mnt

    $ mkdir -p /mnt/a/b
    $ mkdir -p /mnt/a/c/d
    $ mkdir /mnt/a/b/e
    $ mkdir /mnt/a/c/d/f
    $ mv /mnt/a/b /mnt/a/c/d/2b
    $ mkdir /mnt/a/x
    $ mkdir /mnt/a/y

    $ btrfs subvolume snapshot -r /mnt /mnt/snap1
    $ btrfs send /mnt/snap1 -f /tmp/base.send

    $ mv /mnt/a/x /mnt/a/y
    $ mv /mnt/a/c/d/2b/e /mnt/a/c/d/2b/2e
    $ mv /mnt/a/c/d /mnt/a/h/2d
    $ mv /mnt/a/c /mnt/a/h/2d/2b/2c

    $ btrfs subvolume snapshot -r /mnt /mnt/snap2
    $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send

For both cases the incremental send would enter an infinite loop when building
path strings.

While solving these cases, this change also re-implements the code to detect
when directory moves/renames should be delayed. Instead of dealing with several
specific cases separately, it's now more generic handling all cases with a simple
detection algorithm and if when applying a delayed move/rename there's a path loop
detected, it further delays the move/rename registering a new ancestor inode as
the dependency inode (so our rename happens after that ancestor is renamed).

Tests for these cases is being added to xfstests too.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:40 -07:00
Filipe Manana a10c40766c Btrfs: send, remove dead code from __get_cur_name_and_parent
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:39 -07:00
Filipe Manana c992ec94f2 Btrfs: send, account for orphan directories when building path strings
If we have directories with a pending move/rename operation, we must take into
account any orphan directories that got created before executing the pending
move/rename. Those orphan directories are directories with an inode number higher
then the current send progress and that don't exist in the parent snapshot, they
are created before current progress reaches their inode number, with a generated
name of the form oN-M-I and at the root of the filesystem tree, and later when
progress matches their inode number, moved/renamed to their final location.

Reproducer:

          $ mkfs.btrfs -f /dev/sdd
          $ mount /dev/sdd /mnt

          $ mkdir -p /mnt/a/b/c/d
          $ mkdir /mnt/a/b/e
          $ mv /mnt/a/b/c /mnt/a/b/e/CC
          $ mkdir /mnt/a/b/e/CC/d/f
	  $ mkdir /mnt/a/g

          $ btrfs subvolume snapshot -r /mnt /mnt/snap1
          $ btrfs send /mnt/snap1 -f /tmp/base.send

          $ mkdir /mnt/a/g/h
	  $ mv /mnt/a/b/e /mnt/a/g/h/EE
          $ mv /mnt/a/g/h/EE/CC/d /mnt/a/g/h/EE/DD

          $ btrfs subvolume snapshot -r /mnt /mnt/snap2
          $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send

The second receive command failed with the following error:

    ERROR: rename a/b/e/CC/d -> o264-7-0/EE/DD failed. No such file or directory

A test case for xfstests follows soon.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:38 -07:00
Filipe Manana b46ab97bcd Btrfs: send, avoid unnecessary inode item lookup in the btree
Regardless of whether the caller is interested or not in knowing the inode's
generation (dir_gen != NULL), get_first_ref always does a btree lookup to get
the inode item. Avoid this useless lookup if dir_gen parameter is NULL (which
is in some cases).

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:37 -07:00
Gui Hecheng 23f8f9b7ca btrfs: add dev maxs limit for __btrfs_alloc_chunk in kernel space
For RAID0,5,6,10,
For system chunk, there shouldn't be too many stripes to
make a btrfs_chunk that exceeds BTRFS_SYSTEM_CHUNK_ARRAY_SIZE
For data/meta chunk, there shouldn't be too many stripes to
make a btrfs_chunk that exceeds a leaf.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:36 -07:00
Gui Hecheng 5f43f86e3f btrfs: fix wrong max system array size check in kernel space
For system chunk array,
We copy a "disk_key" and an chunk item each time,
so there should be enough space to hold both of them,
not only the chunk item.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:36 -07:00
Qu Wenruo 65d33fd7a6 btrfs: Add check to avoid cleanup roots already in fs_info->dead_roots.
Current btrfs_orphan_cleanup will also cleanup roots which is already in
fs_info->dead_roots without protection.
This will have conditional race with fs_info->cleaner_kthread.

This patch will use refs in root->root_item to detect roots in
dead_roots and avoid conflicts.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:35 -07:00
Miao Xie 21c7e75654 Btrfs: reclaim the reserved metadata space at background
Before applying this patch, the task had to reclaim the metadata space
by itself if the metadata space was not enough. And When the task started
the space reclamation, all the other tasks which wanted to reserve the
metadata space were blocked. At some cases, they would be blocked for
a long time, it made the performance fluctuate wildly.

So we introduce the background metadata space reclamation, when the space
is about to be exhausted, we insert a reclaim work into the workqueue, the
worker of the workqueue helps us to reclaim the reserved space at the
background. By this way, the tasks needn't reclaim the space by themselves at
most cases, and even if the tasks have to reclaim the space or are blocked
for the space reclamation, they will get enough space more quickly.

Here is my test result(Tested by compilebench):
 Memory:	2GB
 CPU:		2Cores * 1CPU
 Partition:	40GB(SSD)

Test command:
 # compilebench -D <mnt> -m

Without this patch:
 intial create total runs 30 avg 54.36 MB/s (user 0.52s sys 2.44s)
 compile total runs 30 avg 123.72 MB/s (user 0.13s sys 1.17s)
 read compiled tree total runs 3 avg 81.15 MB/s (user 0.74s sys 4.89s)
 delete compiled tree total runs 30 avg 5.32 seconds (user 0.35s sys 4.37s)

With this patch:
 intial create total runs 30 avg 59.80 MB/s (user 0.52s sys 2.53s)
 compile total runs 30 avg 151.44 MB/s (user 0.13s sys 1.11s)
 read compiled tree total runs 3 avg 83.25 MB/s (user 0.76s sys 4.91s)
 delete compiled tree total runs 30 avg 5.29 seconds (user 0.34s sys 4.34s)

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:34 -07:00
Miao Xie 32d6b47fe6 Btrfs: output warning instead of error when loading free space cache failed
If we fail to load a free space cache, we can rebuild it from the extent tree,
so it is not a serious error, we should not output a error message that
would make the users uncomfortable. This patch uses warning message instead
of it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:33 -07:00
Qu Wenruo 5a1972bd9f btrfs: Add ctime/mtime update for btrfs device add/remove.
Btrfs will send uevent to udev inform the device change,
but ctime/mtime for the block device inode is not udpated, which cause
libblkid used by btrfs-progs unable to detect device change and use old
cache, causing 'btrfs dev scan; btrfs dev rmove; btrfs dev scan' give an
error message.

Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Cc: Karel Zak <kzak@redhat.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:33 -07:00
David Sterba 61155aa04e btrfs: assert that send is not in progres before root deletion
CC: Miao Xie <miaox@cn.fujitsu.com>
CC: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:32 -07:00
David Sterba 521e0546c9 btrfs: protect snapshots from deleting during send
The patch "Btrfs: fix protection between send and root deletion"
(18f687d538) does not actually prevent to delete the snapshot
and just takes care during background cleaning, but this seems rather
user unfriendly, this patch implements the idea presented in

http://www.spinics.net/lists/linux-btrfs/msg30813.html

- add an internal root_item flag to denote a dead root
- check if the send_in_progress is set and refuse to delete, otherwise
  set the flag and proceed
- check the flag in send similar to the btrfs_root_readonly checks, for
  all involved roots

The root lookup in send via btrfs_read_fs_root_no_name will check if the
root is really dead or not. If it is, ENOENT, aborted send. If it's
alive, it's protected by send_in_progress, send can continue.

CC: Miao Xie <miaox@cn.fujitsu.com>
CC: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:31 -07:00
Daeseok Youn 944a4515b2 btrfs: remove redundant null check in btrfs_dentry_release()
It doesn't need to check NULL for kfree()

Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:31 -07:00
Filipe Manana ef3b9af50b Btrfs: implement inode_operations callback tmpfile
This implements the tmpfile callback of struct inode_operations, introduced
in the linux kernel 3.11, and implemented already by some filesystems. This
callback is invoked by the VFS when the flag O_TMPFILE is passed to the open
system call.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
2014-06-09 17:20:30 -07:00
David Sterba e4ef90ff61 btrfs: make FS_INFO ioctl available to anyone
This ioctl provides basic info about the filesystem that can be obtained
in other ways (eg. sysfs), there's no reason to restrict it to
CAP_SYSADMIN.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:29 -07:00
David Sterba 7d6213c5a7 btrfs: make DEV_INFO ioctl available to anyone
This ioctl provides basic info about the devices that can be obtained in
other ways (eg. sysfs), there's no reason to restrict it to
CAP_SYSADMIN.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:28 -07:00
David Sterba df93589a17 btrfs: export more from FS_INFO to sysfs
Similar to the FS_INFO updates, export the basic filesystem info through
sysfs: node size, sector size and clone alignment.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:28 -07:00
David Sterba 80a773fbfc btrfs: retrieve more info from FS_INFO ioctl
Provide the basic information about filesystem through the ioctl:
* b-tree node size (same as leaf size)
* sector size
* expected alignment of CLONE_RANGE and EXTENT_SAME ioctl arguments

Backward compatibility: if the values are 0, kernel does not provide
this information, the applications should ignore them.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:27 -07:00
David Sterba 7d824b6f9c btrfs: balance filter: add limit of processed chunks
This started as debugging helper, to watch the effects of converting
between raid levels on multiple devices, but could be useful standalone.

In my case the usage filter was not finegrained enough and led to
converting too many chunks at once. Another example use is in connection
with drange+devid or vrange filters that allow to work with a specific
chunk or even with a chunk on a given device.

The limit filter applies last, the value of 0 means no limiting.

CC: Ilya Dryomov <idryomov@gmail.com>
CC: Hugo Mills <hugo@carfax.org.uk>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:26 -07:00
Filipe Manana fc19c5e736 Btrfs: fix leaf corruption caused by ENOSPC while hole punching
While running a stress test with multiple threads writing to the same btrfs
file system, I ended up with a situation where a leaf was corrupted in that
it had 2 file extent item keys that had the same exact key. I was able to
detect this quickly thanks to the following patch which triggers an assertion
as soon as a leaf is marked dirty if there are duplicated keys or out of order
keys:

    Btrfs: check if items are ordered when a leaf is marked dirty
    (https://patchwork.kernel.org/patch/3955431/)

Basically while running the test, I got the following in dmesg:

    [28877.415877] WARNING: CPU: 2 PID: 10706 at fs/btrfs/file.c:553 btrfs_drop_extent_cache+0x435/0x440 [btrfs]()
    (...)
    [28877.415917] Call Trace:
    [28877.415922]  [<ffffffff816f1189>] dump_stack+0x4e/0x68
    [28877.415926]  [<ffffffff8104a32c>] warn_slowpath_common+0x8c/0xc0
    [28877.415929]  [<ffffffff8104a37a>] warn_slowpath_null+0x1a/0x20
    [28877.415944]  [<ffffffffa03775a5>] btrfs_drop_extent_cache+0x435/0x440 [btrfs]
    [28877.415949]  [<ffffffff8118e7be>] ? kmem_cache_alloc+0xfe/0x1c0
    [28877.415962]  [<ffffffffa03777d9>] fill_holes+0x229/0x3e0 [btrfs]
    [28877.415972]  [<ffffffffa0345865>] ? block_rsv_add_bytes+0x55/0x80 [btrfs]
    [28877.415984]  [<ffffffffa03792cb>] btrfs_fallocate+0xb6b/0xc20 [btrfs]
    (...)
    [29854.132560] BTRFS critical (device sdc): corrupt leaf, bad key order: block=955232256,root=1, slot=24
    [29854.132565] BTRFS info (device sdc): leaf 955232256 total ptrs 40 free space 778
    (...)
    [29854.132637] 	item 23 key (3486 108 667648) itemoff 2694 itemsize 53
    [29854.132638] 		extent data disk bytenr 14574411776 nr 286720
    [29854.132639] 		extent data offset 0 nr 286720 ram 286720
    [29854.132640] 	item 24 key (3486 108 954368) itemoff 2641 itemsize 53
    [29854.132641] 		extent data disk bytenr 0 nr 0
    [29854.132643] 		extent data offset 0 nr 0 ram 0
    [29854.132644] 	item 25 key (3486 108 954368) itemoff 2588 itemsize 53
    [29854.132645] 		extent data disk bytenr 8699670528 nr 77824
    [29854.132646] 		extent data offset 0 nr 77824 ram 77824
    [29854.132647] 	item 26 key (3486 108 1146880) itemoff 2535 itemsize 53
    [29854.132648] 		extent data disk bytenr 8699670528 nr 77824
    [29854.132649] 		extent data offset 0 nr 77824 ram 77824
    (...)
    [29854.132707] kernel BUG at fs/btrfs/ctree.h:3901!
    (...)
    [29854.132771] Call Trace:
    [29854.132779]  [<ffffffffa0342b5c>] setup_items_for_insert+0x2dc/0x400 [btrfs]
    [29854.132791]  [<ffffffffa0378537>] __btrfs_drop_extents+0xba7/0xdd0 [btrfs]
    [29854.132794]  [<ffffffff8109c0d6>] ? trace_hardirqs_on_caller+0x16/0x1d0
    [29854.132797]  [<ffffffff8109c29d>] ? trace_hardirqs_on+0xd/0x10
    [29854.132800]  [<ffffffff8118e7be>] ? kmem_cache_alloc+0xfe/0x1c0
    [29854.132810]  [<ffffffffa036783b>] insert_reserved_file_extent.constprop.66+0xab/0x310 [btrfs]
    [29854.132820]  [<ffffffffa036a6c6>] __btrfs_prealloc_file_range+0x116/0x340 [btrfs]
    [29854.132830]  [<ffffffffa0374d53>] btrfs_prealloc_file_range+0x23/0x30 [btrfs]
    (...)

So this is caused by getting an -ENOSPC error while punching a file hole, more
specifically, we get -ENOSPC error from __btrfs_drop_extents in the while loop
of file.c:btrfs_punch_hole() when it's unable to modify the btree to delete one
or more file extent items due to lack of enough free space. When this happens,
in btrfs_punch_hole(), we attempt to reclaim free space by switching our transaction
block reservation object to root->fs_info->trans_block_rsv, end our transaction and
start a new transaction basically - and, we keep increasing our current offset
(cur_offset) as long as it's smaller than the end of the target range (lockend) -
this makes use leave the loop with cur_offset == drop_end which in turn makes us
call fill_holes() for inserting a file extent item that represents a 0 bytes range
hole (and this insertion succeeds, as in the meanwhile more space became available).

This 0 bytes file hole extent item is a problem because any subsequent caller of
__btrfs_drop_extents (regular file writes, or fallocate calls for e.g.), with a
start file offset that is equal to the offset of the hole, will not remove this
extent item due to the following conditional in the while loop of
__btrfs_drop_extents:

    if (extent_end <= search_start) {
            path->slots[0]++;
            goto next_slot;
    }

This later makes the call to setup_items_for_insert() (at the very end of
__btrfs_drop_extents), insert a new file extent item with the same offset as
the 0 bytes file hole extent item that follows it. Needless is to say that this
causes chaos, either when reading the leaf from disk (btree_readpage_end_io_hook),
where we perform leaf sanity checks or in subsequent operations that manipulate
file extent items, as in the fallocate call as shown by the dmesg trace above.

Without my other patch to perform the leaf sanity checks once a leaf is marked
as dirty (if the integrity checker is enabled), it would have been much harder
to debug this issue.

This change might fix a few similar issues reported by users in the mailing
list regarding assertion failures in btrfs_set_item_key_safe calls performed
by __btrfs_drop_extents, such as the following report:

    http://comments.gmane.org/gmane.comp.file-systems.btrfs/32938

Asking fill_holes() to create a 0 bytes wide file hole item also produced the
first warning in the trace above, as we passed a range to btrfs_drop_extent_cache
that has an end smaller (by -1) than its start.

On 3.14 kernels this issue manifests itself through leaf corruption, as we get
duplicated file extent item keys in a leaf when calling setup_items_for_insert(),
but on older kernels, setup_items_for_insert() isn't called by __btrfs_drop_extents(),
instead we have callers of __btrfs_drop_extents(), namely the functions
inode.c:insert_inline_extent() and inode.c:insert_reserved_file_extent(), calling
btrfs_insert_empty_item() to insert the new file extent item, which would fail with
error -EEXIST, instead of inserting a duplicated key - which is still a serious
issue as it would make all similar file extent item replace operations keep
failing if they target the same file range.

Cc: stable@vger.kernel.org
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:26 -07:00
Liu Bo d2cbf2a260 Btrfs: do not increment on bio_index one by one
'bio_index' is just a index, it's really not necessary to do increment
one by one.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:25 -07:00
Filipe Manana a1a50f60a6 Btrfs: read inode size after acquiring the mutex when punching a hole
In a previous change, commit 12870f1c9b,
I accidentally moved the roundup of inode->i_size to outside of the
critical section delimited by the inode mutex, which is not atomic and
not correct since the size can be changed by other task before we acquire
the mutex. Therefore fix it.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:24 -07:00
Tobias Klauser 7fb18a0664 btrfs: Remove unnecessary check for NULL
iput() already checks for the inode being NULL, thus it's unnecessary to
check before calling.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:23 -07:00
Zach Brown 166ae5a418 btrfs: fix inline compressed read err corruption
uncompress_inline() is dropping the error from btrfs_decompress() after
testing it and zeroing the page that was supposed to hold decompressed
data.  This can silently turn compressed inline data in to zeros if
decompression fails due to corrupt compressed data or memory allocation
failure.

I verified this by manually forcing the error from btrfs_decompress()
for a silly named copy of od:

	if (!strcmp(current->comm, "failod"))
		ret = -ENOMEM;

  # od -x /mnt/btrfs/dir/80 | head -1
  0000000 3031 3038 310a 2d30 6f70 6e69 0a74 3031
  # echo 3 > /proc/sys/vm/drop_caches
  # cp $(which od) /tmp/failod
  # /tmp/failod -x /mnt/btrfs/dir/80 | head -1
  0000000 0000 0000 0000 0000 0000 0000 0000 0000

The fix is to pass the error to its caller.  Which still has a BUG_ON().
So we fix that too.

There seems to be no reason for the zeroing of the page on the error
from btrfs_decompress() but not from the allocation error a few lines
above.  So the page zeroing is removed.

Signed-off-by: Zach Brown <zab@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:23 -07:00
Zach Brown 774bcb35f0 btrfs: return ptr error from compression workspace
The btrfs compression wrappers translated errors from workspace
allocation to either -ENOMEM or -1.  The compression type workspace
allocators are already returning a ERR_PTR(-ENOMEM).  Just return that
and get rid of the magical -1.

This helps a future patch return errors from the compression wrappers.

Signed-off-by: Zach Brown <zab@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:22 -07:00
Zach Brown 60e1975acb btrfs: return errno instead of -1 from compression
The compression layer seems to have been built to return -1 and have
callers make up errors that make sense.  This isn't great because there
are different errors that originate down in the compression layer.

Let's return real negative errnos from the compression layer so that
callers can pass on the error without having to guess what happened.
ENOMEM for allocation failure, E2BIG when compression exceeds the
uncompressed input, and EIO for everything else.

This helps a future path return errors from btrfs_decompress().

Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:21 -07:00
Stefan Behrens 98806b446d btrfs: check_int: propagate out-of-memory error upwards
This issue was not causing any harm but IMO (and in the opinion of the
static code checker) it is better to propagate this error status upwards.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:21 -07:00
Filipe Manana 61391d5622 Btrfs: fix hang on error (such as ENOSPC) when writing extent pages
When running low on available disk space and having several processes
doing buffered file IO, I got the following trace in dmesg:

[ 4202.720152] INFO: task kworker/u8:1:5450 blocked for more than 120 seconds.
[ 4202.720401]       Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[ 4202.720596] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4202.720874] kworker/u8:1    D 0000000000000001     0  5450      2 0x00000000
[ 4202.720904] Workqueue: btrfs-flush_delalloc normal_work_helper [btrfs]
[ 4202.720908]  ffff8801f62ddc38 0000000000000082 ffff880203ac2490 00000000001d3f40
[ 4202.720913]  ffff8801f62ddfd8 00000000001d3f40 ffff8800c4f0c920 ffff880203ac2490
[ 4202.720918]  00000000001d4a40 ffff88020fe85a40 ffff88020fe85ab8 0000000000000001
[ 4202.720922] Call Trace:
[ 4202.720931]  [<ffffffff816a3cb9>] schedule+0x29/0x70
[ 4202.720950]  [<ffffffffa01ec48d>] btrfs_start_ordered_extent+0x6d/0x110 [btrfs]
[ 4202.720956]  [<ffffffff8108e620>] ? bit_waitqueue+0xc0/0xc0
[ 4202.720972]  [<ffffffffa01ec559>] btrfs_run_ordered_extent_work+0x29/0x40 [btrfs]
[ 4202.720988]  [<ffffffffa0201987>] normal_work_helper+0x137/0x2c0 [btrfs]
[ 4202.720994]  [<ffffffff810680e5>] process_one_work+0x1f5/0x530
(...)
[ 4202.721027] 2 locks held by kworker/u8:1/5450:
[ 4202.721028]  #0:  (%s-%s){++++..}, at: [<ffffffff81068083>] process_one_work+0x193/0x530
[ 4202.721037]  #1:  ((&work->normal_work)){+.+...}, at: [<ffffffff81068083>] process_one_work+0x193/0x530
[ 4202.721054] INFO: task btrfs:7891 blocked for more than 120 seconds.
[ 4202.721258]       Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[ 4202.721444] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4202.721699] btrfs           D 0000000000000001     0  7891   7890 0x00000001
[ 4202.721704]  ffff88018c2119e8 0000000000000086 ffff8800a33d2490 00000000001d3f40
[ 4202.721710]  ffff88018c211fd8 00000000001d3f40 ffff8802144b0000 ffff8800a33d2490
[ 4202.721714]  ffff8800d8576640 ffff88020fe85bc0 ffff88020fe85bc8 7fffffffffffffff
[ 4202.721718] Call Trace:
[ 4202.721723]  [<ffffffff816a3cb9>] schedule+0x29/0x70
[ 4202.721727]  [<ffffffff816a2ebc>] schedule_timeout+0x1dc/0x270
[ 4202.721732]  [<ffffffff8109bd79>] ? mark_held_locks+0xb9/0x140
[ 4202.721736]  [<ffffffff816a90c0>] ? _raw_spin_unlock_irq+0x30/0x40
[ 4202.721740]  [<ffffffff8109bf0d>] ? trace_hardirqs_on_caller+0x10d/0x1d0
[ 4202.721744]  [<ffffffff816a488f>] wait_for_completion+0xdf/0x120
[ 4202.721749]  [<ffffffff8107fa90>] ? try_to_wake_up+0x310/0x310
[ 4202.721765]  [<ffffffffa01ebee4>] btrfs_wait_ordered_extents+0x1f4/0x280 [btrfs]
[ 4202.721781]  [<ffffffffa020526e>] btrfs_mksubvol.isra.62+0x30e/0x5a0 [btrfs]
[ 4202.721786]  [<ffffffff8108e620>] ? bit_waitqueue+0xc0/0xc0
[ 4202.721799]  [<ffffffffa02056a9>] btrfs_ioctl_snap_create_transid+0x1a9/0x1b0 [btrfs]
[ 4202.721813]  [<ffffffffa020583a>] btrfs_ioctl_snap_create_v2+0x10a/0x170 [btrfs]
(...)

It turns out that extent_io.c:__extent_writepage(), which ends up being called
through filemap_fdatawrite_range() in btrfs_start_ordered_extent(), was getting
-ENOSPC when calling the fill_delalloc callback. In this situation, it returned
without the writepage_end_io_hook callback (inode.c:btrfs_writepage_end_io_hook)
ever being called for the respective page, which prevents the ordered extent's
bytes_left count from ever reaching 0, and therefore a finish_ordered_fn work
is never queued into the endio_write_workers queue. This makes the task that
called btrfs_start_ordered_extent() hang forever on the wait queue of the ordered
extent.

This is fairly easy to reproduce using a small filesystem and fsstress on
a quad core vm:

    mkfs.btrfs -f -b `expr 2100 \* 1024 \* 1024` /dev/sdd
    mount /dev/sdd /mnt

    fsstress -p 6 -d /mnt -n 100000 -x \
        "btrfs subvolume snapshot -r /mnt /mnt/mysnap" \
	    -f allocsp=0 \
	    -f bulkstat=0 \
	    -f bulkstat1=0 \
	    -f chown=0 \
	    -f creat=1 \
	    -f dread=0 \
	    -f dwrite=0 \
	    -f fallocate=1 \
	    -f fdatasync=0 \
	    -f fiemap=0 \
	    -f freesp=0 \
	    -f fsync=0 \
	    -f getattr=0 \
	    -f getdents=0 \
	    -f link=0 \
	    -f mkdir=0 \
	    -f mknod=0 \
	    -f punch=1 \
	    -f read=0 \
	    -f readlink=0 \
	    -f rename=0 \
	    -f resvsp=0 \
	    -f rmdir=0 \
	    -f setxattr=0 \
	    -f stat=0 \
	    -f symlink=0 \
	    -f sync=0 \
	    -f truncate=1 \
	    -f unlink=0 \
	    -f unresvsp=0 \
	    -f write=4

So just ensure that if an error happens while writing the extent page
we call the writepage_end_io_hook callback. Also make it return the
error code and ensure the caller (extent_write_cache_pages) processes
all pages in the page vector even if an error happens only for some
of them, so that ordered extents end up released.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09 17:20:20 -07:00
Linus Torvalds 3f17ea6dea Merge branch 'next' (accumulated 3.16 merge window patches) into master
Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...
2014-06-08 11:31:16 -07:00
Filipe Manana 01a9a8a9e2 Btrfs: send, fix corrupted path strings for long paths
If a path has more than 230 characters, we allocate a new buffer to
use for the path, but we were forgotting to copy the contents of the
previous buffer into the new one, which has random content from the
kmalloc call.

Test:

    mkfs.btrfs -f /dev/sdd
    mount /dev/sdd /mnt

    TEST_PATH="/mnt/fdmanana/.config/google-chrome-mysetup/Default/Pepper_Data/Shockwave_Flash/WritableRoot/#SharedObjects/JSHJ4ZKN/s.wsj.net/[[IMPORT]]/players.edgesuite.net/flash/plugins/osmf/advanced-streaming-plugin/v2.7/osmf1.6/Ak#"
    mkdir -p $TEST_PATH
    echo "hello world" > $TEST_PATH/amaiAdvancedStreamingPlugin.txt

    btrfs subvolume snapshot -r /mnt /mnt/mysnap1
    btrfs send /mnt/mysnap1 -f /tmp/1.snap

A test for xfstests follows.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Cc: Marc Merlin <marc@merlins.org>
Tested-by: Marc MERLIN <marc@merlins.org>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-06 12:00:46 -07:00
Mel Gorman 2457aec637 mm: non-atomically mark page accessed during page cache allocation where possible
aops->write_begin may allocate a new page and make it visible only to have
mark_page_accessed called almost immediately after.  Once the page is
visible the atomic operations are necessary which is noticable overhead
when writing to an in-memory filesystem like tmpfs but should also be
noticable with fast storage.  The objective of the patch is to initialse
the accessed information with non-atomic operations before the page is
visible.

The bulk of filesystems directly or indirectly use
grab_cache_page_write_begin or find_or_create_page for the initial
allocation of a page cache page.  This patch adds an init_page_accessed()
helper which behaves like the first call to mark_page_accessed() but may
called before the page is visible and can be done non-atomically.

The primary APIs of concern in this care are the following and are used
by most filesystems.

	find_get_page
	find_lock_page
	find_or_create_page
	grab_cache_page_nowait
	grab_cache_page_write_begin

All of them are very similar in detail to the patch creates a core helper
pagecache_get_page() which takes a flags parameter that affects its
behavior such as whether the page should be marked accessed or not.  Then
old API is preserved but is basically a thin wrapper around this core
function.

Each of the filesystems are then updated to avoid calling
mark_page_accessed when it is known that the VM interfaces have already
done the job.  There is a slight snag in that the timing of the
mark_page_accessed() has now changed so in rare cases it's possible a page
gets to the end of the LRU as PageReferenced where as previously it might
have been repromoted.  This is expected to be rare but it's worth the
filesystem people thinking about it in case they see a problem with the
timing change.  It is also the case that some filesystems may be marking
pages accessed that previously did not but it makes sense that filesystems
have consistent behaviour in this regard.

The test case used to evaulate this is a simple dd of a large file done
multiple times with the file deleted on each iterations.  The size of the
file is 1/10th physical memory to avoid dirty page balancing.  In the
async case it will be possible that the workload completes without even
hitting the disk and will have variable results but highlight the impact
of mark_page_accessed for async IO.  The sync results are expected to be
more stable.  The exception is tmpfs where the normal case is for the "IO"
to not hit the disk.

The test machine was single socket and UMA to avoid any scheduling or NUMA
artifacts.  Throughput and wall times are presented for sync IO, only wall
times are shown for async as the granularity reported by dd and the
variability is unsuitable for comparison.  As async results were variable
do to writback timings, I'm only reporting the maximum figures.  The sync
results were stable enough to make the mean and stddev uninteresting.

The performance results are reported based on a run with no profiling.
Profile data is based on a separate run with oprofile running.

async dd
                                    3.15.0-rc3            3.15.0-rc3
                                       vanilla           accessed-v2
ext3    Max      elapsed     13.9900 (  0.00%)     11.5900 ( 17.16%)
tmpfs	Max      elapsed      0.5100 (  0.00%)      0.4900 (  3.92%)
btrfs   Max      elapsed     12.8100 (  0.00%)     12.7800 (  0.23%)
ext4	Max      elapsed     18.6000 (  0.00%)     13.3400 ( 28.28%)
xfs	Max      elapsed     12.5600 (  0.00%)      2.0900 ( 83.36%)

The XFS figure is a bit strange as it managed to avoid a worst case by
sheer luck but the average figures looked reasonable.

        samples percentage
ext3       86107    0.9783  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
ext3       23833    0.2710  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext3        5036    0.0573  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
ext4       64566    0.8961  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
ext4        5322    0.0713  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext4        2869    0.0384  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs        62126    1.7675  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
xfs         1904    0.0554  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs          103    0.0030  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
btrfs      10655    0.1338  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
btrfs       2020    0.0273  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
btrfs        587    0.0079  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
tmpfs      59562    3.2628  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
tmpfs       1210    0.0696  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
tmpfs         94    0.0054  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed

[akpm@linux-foundation.org: don't run init_page_accessed() against an uninitialised pointer]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Tested-by: Prabhakar Lad <prabhakar.csengg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:10 -07:00
Linus Torvalds 776edb5931 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull core locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - reduced/streamlined smp_mb__*() interface that allows more usecases
     and makes the existing ones less buggy, especially in rarer
     architectures

   - add rwsem implementation comments

   - bump up lockdep limits"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  rwsem: Add comments to explain the meaning of the rwsem's count field
  lockdep: Increase static allocations
  arch: Mass conversion of smp_mb__*()
  arch,doc: Convert smp_mb__*()
  arch,xtensa: Convert smp_mb__*()
  arch,x86: Convert smp_mb__*()
  arch,tile: Convert smp_mb__*()
  arch,sparc: Convert smp_mb__*()
  arch,sh: Convert smp_mb__*()
  arch,score: Convert smp_mb__*()
  arch,s390: Convert smp_mb__*()
  arch,powerpc: Convert smp_mb__*()
  arch,parisc: Convert smp_mb__*()
  arch,openrisc: Convert smp_mb__*()
  arch,mn10300: Convert smp_mb__*()
  arch,mips: Convert smp_mb__*()
  arch,metag: Convert smp_mb__*()
  arch,m68k: Convert smp_mb__*()
  arch,m32r: Convert smp_mb__*()
  arch,ia64: Convert smp_mb__*()
  ...
2014-06-03 12:57:53 -07:00
Linus Torvalds 11da37b263 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull two btrfs fixes from Chris Mason:
 "This has two fixes that we've been testing for 3.16, but since both
  are safe and fix real bugs, it makes sense to send for 3.15 instead"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: send, fix incorrect ref access when using extrefs
  Btrfs: fix EIO on reading file after ioctl clone works on it
2014-05-22 05:40:13 +09:00
Filipe Manana 51a60253a5 Btrfs: send, fix incorrect ref access when using extrefs
When running send, if an inode only has extended reference items
associated to it and no regular references, send.c:get_first_ref()
was incorrectly assuming the reference it found was of type
BTRFS_INODE_REF_KEY due to use of the wrong key variable.
This caused weird behaviour when using the found item has a regular
reference, such as weird path string, and occasionally (when lucky)
a crash:

[  190.600652] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
[  190.600994] Modules linked in: btrfs xor raid6_pq binfmt_misc nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc psmouse serio_raw evbug pcspkr i2c_piix4 e1000 floppy
[  190.602565] CPU: 2 PID: 14520 Comm: btrfs Not tainted 3.13.0-fdm-btrfs-next-26+ #1
[  190.602728] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  190.602868] task: ffff8800d447c920 ti: ffff8801fa79e000 task.ti: ffff8801fa79e000
[  190.603030] RIP: 0010:[<ffffffff813266b4>]  [<ffffffff813266b4>] memcpy+0x54/0x110
[  190.603262] RSP: 0018:ffff8801fa79f880  EFLAGS: 00010202
[  190.603395] RAX: ffff8800d4326e3f RBX: 000000000000036a RCX: ffff880000000000
[  190.603553] RDX: 000000000000032a RSI: ffe708844042936a RDI: ffff8800d43271a9
[  190.603710] RBP: ffff8801fa79f8c8 R08: 00000000003a4ef0 R09: 0000000000000000
[  190.603867] R10: 793a4ef09f000000 R11: 9f0000000053726f R12: ffff8800d43271a9
[  190.604020] R13: 0000160000000000 R14: ffff8802110134f0 R15: 000000000000036a
[  190.604020] FS:  00007fb423d09b80(0000) GS:ffff880216200000(0000) knlGS:0000000000000000
[  190.604020] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  190.604020] CR2: 00007fb4229d4b78 CR3: 00000001f5d76000 CR4: 00000000000006e0
[  190.604020] Stack:
[  190.604020]  ffffffffa01f4d49 ffff8801fa79f8f0 00000000000009f9 ffff8801fa79f8c8
[  190.604020]  00000000000009f9 ffff880211013260 000000000000f971 ffff88021147dba8
[  190.604020]  00000000000009f9 ffff8801fa79f918 ffffffffa02367f5 ffff8801fa79f928
[  190.604020] Call Trace:
[  190.604020]  [<ffffffffa01f4d49>] ? read_extent_buffer+0xb9/0x120 [btrfs]
[  190.604020]  [<ffffffffa02367f5>] fs_path_add_from_extent_buffer+0x45/0x60 [btrfs]
[  190.604020]  [<ffffffffa0238806>] get_first_ref+0x1f6/0x210 [btrfs]
[  190.604020]  [<ffffffffa0238994>] __get_cur_name_and_parent+0x174/0x3a0 [btrfs]
[  190.604020]  [<ffffffff8118df3d>] ? kmem_cache_alloc_trace+0x11d/0x1e0
[  190.604020]  [<ffffffffa0236674>] ? fs_path_alloc+0x24/0x60 [btrfs]
[  190.604020]  [<ffffffffa0238c91>] get_cur_path+0xd1/0x240 [btrfs]
(...)

Steps to reproduce (either crash or some weirdness like an odd path string):

    mkfs.btrfs -f -O extref /dev/sdd
    mount /dev/sdd /mnt

    mkdir /mnt/testdir
    touch /mnt/testdir/foobar

    for i in `seq 1 2550`; do
        ln /mnt/testdir/foobar /mnt/testdir/foobar_link_`printf "%04d" $i`
    done

    ln /mnt/testdir/foobar /mnt/testdir/final_foobar_name

    rm -f /mnt/testdir/foobar
    for i in `seq 1 2550`; do
        rm -f /mnt/testdir/foobar_link_`printf "%04d" $i`
    done

    btrfs subvolume snapshot -r /mnt /mnt/mysnap
    btrfs send /mnt/mysnap -f /tmp/mysnap.send

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
2014-05-20 10:18:26 -07:00
Liu Bo d3ecfcdf91 Btrfs: fix EIO on reading file after ioctl clone works on it
For inline data extent, we need to make its length aligned, otherwise,
we can get a phantom extent map which confuses readpages() to return -EIO.

This can be detected by xfstests/btrfs/035.

Reported-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-05-20 10:17:48 -07:00
Al Viro b30ac0fc41 btrfs: switch to ->write_iter()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:39:41 -04:00
Al Viro aad4f8bb42 switch simple generic_file_aio_read() users to ->read_iter()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:37:55 -04:00
Al Viro 0c949334a9 iov_iter_truncate()
Now It Can Be Done(tm) - we don't need to do iov_shorten() in
generic_file_direct_write() anymore, now that all ->direct_IO()
instances are converted to proper iov_iter methods and honour
iter->count and iter->iov_offset properly.

Get rid of count/ocount arguments of generic_file_direct_write(),
while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:54 -04:00
Al Viro 28060d5d9b btrfs: switch check_direct_IO() to iov_iter
... and don't open-code iov_iter_alignment() there

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:53 -04:00
Al Viro 71d8e532b1 start adding the tag to iov_iter
For now, just use the same thing we pass to ->direct_IO() - it's all
iovec-based at the moment.  Pass it explicitly to iov_iter_init() and
account for kvec vs. iovec in there, by the same kludge NFS ->direct_IO()
uses.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:49 -04:00
Al Viro 31b140398c switch {__,}blockdev_direct_IO() to iov_iter
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:46 -04:00
Al Viro a6cbcd4a4a get rid of pointless iov_length() in ->direct_IO()
all callers have iov_length(iter->iov, iter->nr_segs) == iov_iter_count(iter)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:45 -04:00
Al Viro d8d3d94b80 pass iov_iter to ->direct_IO()
unmodified, for now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:44 -04:00
Al Viro cb66a7a1f1 kill generic_segment_checks()
all callers of ->aio_read() and ->aio_write() have iov/nr_segs already
checked - generic_segment_checks() done after that is just an odd way
to spell iov_length().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:43 -04:00