If the current path's leaf slot is 0, we do search for the previous
leaf (via btrfs_prev_leaf) and set the new path's leaf slot to a
value corresponding to the number of items - 1 of the former leaf.
Fix this by using the slot set by btrfs_prev_leaf, decrementing it
by 1 if it's equal to the leaf's number of items.
Use of btrfs_search_slot_for_read() for backward iteration is used in
particular by the send feature, which could miss items when the input
leaf has less items than its previous leaf.
This could be reproduced by running btrfs/007 from xfstests in a loop.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
There are not any users that use ulist except Btrfs,don't
export them.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
We are really suffering from now ulist's implementation, some developers
gave their try, and i just gave some of my ideas for things:
1. use list+rb_tree instead of arrary+rb_tree
2. add cur_list to iterator rather than ulist structure.
3. add seqnum into every node when they are added, this is
used to do selfcheck when iterating node.
I noticed Zach Brown's comments before, long term is to kick off
ulist implementation, however, for now, we need at least avoid
arrary from ulist.
Cc: Liu Bo <bo.li.liu@oracle.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Zach Brown <zab@redhat.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
When walking backrefs, we may iterate every inode's extent
and add/merge them into ulist, and the caller will free memory
from ulist.
However, if we fail to allocate inode's extents element
memory or ulist_add() fail to allocate memory, we won't
add allocated memory into ulist, and the caller won't
free some allocated memory thus memory leaks happen.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
There was a case where file hole detection was incorrect and it would
cause an incremental send to override a section of a file with zeroes.
This happened in the case where between the last leaf we processed which
contained a file extent item for our current inode and the leaf we're
currently are at (and has a file extent item for our current inode) there
are only leafs containing exclusively file extent items for our current
inode, and none of them was updated since the previous send operation.
The file hole detection code would incorrectly consider the file range
covered by these leafs as a hole.
A test case for xfstests follows soon.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Instead of looking for a file extent item, process it, release the path
and do a btree search for the next file extent item, just process all
file extent items in a leaf without intermediate btree searches. This way
we save cpu and we're not blocking other tasks or affecting concurrency on
the btree, because send's paths use the commit root and skip btree node/leaf
locking.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
We can only tolerate ENOENT here, for other errors, we should
return directly.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
There is a race condition between resolving indirect ref and root deletion,
and we should gurantee that root can not be destroyed to avoid accessing
broken tree here.
Here we fix it by holding @subvol_srcu, and we will release it as soon
as we have held root node lock.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
When we have two adjacent extents in relink_extent_backref,
we try to merge them. When we use btrfs_search_slot to locate the
slot for the current extent, we shouldn't set "ins_len = 1",
because we will merge it into the previous extent rather than
insert a new item. Otherwise, we may happen to create a new leaf
in btrfs_search_slot and path->slot[0] will be 0. Then we try to
fetch the previous item using "path->slots[0]--", and it will cause
a warning as follows:
[ 145.713385] WARNING: CPU: 3 PID: 1796 at fs/btrfs/extent_io.c:5043 map_private_extent_buffer+0xd4/0xe0
[ 145.713387] btrfs bad mapping eb start 5337088 len 4096, wanted 167772306 8
...
[ 145.713462] [<ffffffffa034b1f4>] map_private_extent_buffer+0xd4/0xe0
[ 145.713476] [<ffffffffa030097a>] ? btrfs_free_path+0x2a/0x40
[ 145.713485] [<ffffffffa0340864>] btrfs_get_token_64+0x64/0xf0
[ 145.713498] [<ffffffffa033472c>] relink_extent_backref+0x41c/0x820
[ 145.713508] [<ffffffffa0334d69>] btrfs_finish_ordered_io+0x239/0xa80
I encounter this warning when running defrag having mkfs.btrfs
with option -M. At the same time there are read/writes & snapshots
running at background.
Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
The send operation processes inodes by their ascending number, and assumes
that any rename/move operation can be successfully performed (sent to the
caller) once all previous inodes (those with a smaller inode number than the
one we're currently processing) were processed.
This is not true when an incremental send had to process an hierarchical change
between 2 snapshots where the parent-children relationship between directory
inodes was reversed - that is, parents became children and children became
parents. This situation made the path building code go into an infinite loop,
which kept allocating more and more memory that eventually lead to a krealloc
warning being displayed in dmesg:
WARNING: CPU: 1 PID: 5705 at mm/page_alloc.c:2477 __alloc_pages_nodemask+0x365/0xad0()
Modules linked in: btrfs raid6_pq xor pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) snd_hda_codec_hdmi snd_hda_codec_realtek joydev radeon snd_hda_intel snd_hda_codec snd_hwdep snd_seq_midi snd_pcm psmouse i915 snd_rawmidi serio_raw snd_seq_midi_event lpc_ich snd_seq snd_timer ttm snd_seq_device rfcomm drm_kms_helper parport_pc bnep bluetooth drm ppdev snd soundcore i2c_algo_bit snd_page_alloc binfmt_misc video lp parport r8169 mii hid_generic usbhid hid
CPU: 1 PID: 5705 Comm: btrfs Tainted: G O 3.13.0-rc7-fdm-btrfs-next-18+ #3
Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./Z77 Pro4, BIOS P1.50 09/04/2012
[ 5381.660441] 00000000000009ad ffff8806f6f2f4e8 ffffffff81777434 0000000000000007
[ 5381.660447] 0000000000000000 ffff8806f6f2f528 ffffffff8104a9ec ffff8807038f36f0
[ 5381.660452] 0000000000000000 0000000000000206 ffff8807038f2490 ffff8807038f36f0
[ 5381.660457] Call Trace:
[ 5381.660464] [<ffffffff81777434>] dump_stack+0x4e/0x68
[ 5381.660471] [<ffffffff8104a9ec>] warn_slowpath_common+0x8c/0xc0
[ 5381.660476] [<ffffffff8104aa3a>] warn_slowpath_null+0x1a/0x20
[ 5381.660480] [<ffffffff81144995>] __alloc_pages_nodemask+0x365/0xad0
[ 5381.660487] [<ffffffff8108313f>] ? local_clock+0x4f/0x60
[ 5381.660491] [<ffffffff811430e8>] ? free_one_page+0x98/0x440
[ 5381.660495] [<ffffffff8108313f>] ? local_clock+0x4f/0x60
[ 5381.660502] [<ffffffff8113fae4>] ? __get_free_pages+0x14/0x50
[ 5381.660508] [<ffffffff81095fb8>] ? trace_hardirqs_off_caller+0x28/0xd0
[ 5381.660515] [<ffffffff81183caf>] alloc_pages_current+0x10f/0x1f0
[ 5381.660520] [<ffffffff8113fae4>] ? __get_free_pages+0x14/0x50
[ 5381.660524] [<ffffffff8113fae4>] __get_free_pages+0x14/0x50
[ 5381.660530] [<ffffffff8115dace>] kmalloc_order_trace+0x3e/0x100
[ 5381.660536] [<ffffffff81191ea0>] __kmalloc_track_caller+0x220/0x230
[ 5381.660560] [<ffffffffa0729fdb>] ? fs_path_ensure_buf.part.12+0x6b/0x200 [btrfs]
[ 5381.660564] [<ffffffff8178085c>] ? retint_restore_args+0xe/0xe
[ 5381.660569] [<ffffffff811580ef>] krealloc+0x6f/0xb0
[ 5381.660586] [<ffffffffa0729fdb>] fs_path_ensure_buf.part.12+0x6b/0x200 [btrfs]
[ 5381.660601] [<ffffffffa072a208>] fs_path_prepare_for_add+0x98/0xb0 [btrfs]
[ 5381.660615] [<ffffffffa072a2bc>] fs_path_add_path+0x2c/0x60 [btrfs]
[ 5381.660628] [<ffffffffa072c55c>] get_cur_path+0x7c/0x1c0 [btrfs]
Even without this loop, the incremental send couldn't succeed, because it would attempt
to send a rename/move operation for the lower inode before the highest inode number was
renamed/move. This issue is easy to trigger with the following steps:
$ mkfs.btrfs -f /dev/sdb3
$ mount /dev/sdb3 /mnt/btrfs
$ mkdir -p /mnt/btrfs/a/b/c/d
$ mkdir /mnt/btrfs/a/b/c2
$ btrfs subvol snapshot -r /mnt/btrfs /mnt/btrfs/snap1
$ mv /mnt/btrfs/a/b/c/d /mnt/btrfs/a/b/c2/d2
$ mv /mnt/btrfs/a/b/c /mnt/btrfs/a/b/c2/d2/cc
$ btrfs subvol snapshot -r /mnt/btrfs /mnt/btrfs/snap2
$ btrfs send -p /mnt/btrfs/snap1 /mnt/btrfs/snap2 > /tmp/incremental.send
The structure of the filesystem when the first snapshot is taken is:
. (ino 256)
|-- a (ino 257)
|-- b (ino 258)
|-- c (ino 259)
| |-- d (ino 260)
|
|-- c2 (ino 261)
And its structure when the second snapshot is taken is:
. (ino 256)
|-- a (ino 257)
|-- b (ino 258)
|-- c2 (ino 261)
|-- d2 (ino 260)
|-- cc (ino 259)
Before the move/rename operation is performed for the inode 259, the
move/rename for inode 260 must be performed, since 259 is now a child
of 260.
A test case for xfstests, with a more complex scenario, will follow soon.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
The buffer size argument passed to snprintf must account for the
trailing null byte added by snprintf, and it returns a value >= then
sizeof(buffer) when the string can't fit in the buffer.
Since our buffer has a size of 64 characters, and the maximum orphan
name we can generate is 63 characters wide, we must pass 64 as the
buffer size to snprintf, and not 63.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
When defragging a very large file, the cluster variable can wrap its 32-bit
signed int type and become negative, which eventually gets passed to
btrfs_force_ra() as a very large unsigned long value. On 32-bit platforms,
this eventually results in an Oops from the SLAB allocator.
Change the cluster and max_cluster signed int variables to unsigned long to
match the readahead functions. This also allows the min() comparison in
btrfs_defrag_file() to work as intended.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
The COMPRESS_LZOv2 incompat featue is currently not implemented, the bit
is only reserved, no point to list it in sysfs.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
The owner and capability checks in IOC_SUBVOL_SETFLAGS and
SET_RECEIVED_SUBVOL should be called before any other checks are done.
Also unify the error code to EPERM.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Currently, any user can snapshot any subvolume if the path is accessible and
thus indirectly create and keep files he does not own under his direcotries.
This is not possible with traditional directories.
In security context, a user can snapshot root filesystem and pin any
potentially buggy binaries, even if the updates are applied.
All the snapshots are visible to the administrator, so it's possible to
verify if there are suspicious snapshots.
Another more practical problem is that any user can pin the space used
by eg. root and cause ENOSPC.
Original report:
https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/484786
CC: stable@vger.kernel.org
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
We allocate the free space from the former block group, not the current
one, so should use the former one to output the trace information.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
used_block_group is just used for the space cluster which doesn't
belong to the current block group, the other place needn't use it.
Or the logic of code seems unclear.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
It is better that the position of the lock is close to the data which is
protected by it, because they may be in the same cache line, we will load
less cache lines when we access them. So we rearrange the members' position
of btrfs_space_info structure to make the lock be closer to the its data.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
To search tree root without transaction protection, we should neither search commit
root nor skip locking here, fix it.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
The performance of fsync dropped down suddenly sometimes, the main reason
of this problem was that we might only flush part dirty pages in a ordered
extent, then got that ordered extent, wait for the csum calcucation. But if
no task flushed the left part, we would wait until the flusher flushed them,
sometimes we need wait for several seconds, it made the performance drop
down suddenly. (On my box, it drop down from 56MB/s to 4-10MB/s)
This patch improves the above problem by flushing left dirty pages aggressively.
Test Environment:
CPU: 2CPU * 2Cores
Memory: 4GB
Partition: 20GB(HDD)
Test Command:
# sysbench --num-threads=8 --test=fileio --file-num=1 \
> --file-total-size=8G --file-block-size=32768 \
> --file-io-mode=sync --file-fsync-freq=100 \
> --file-fsync-end=no --max-requests=10000 \
> --file-test-mode=rndwr run
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Steps to reproduce:
# mkfs.btrfs -f /dev/sda8
# mount /dev/sda8 /mnt -o flushoncommit
# dd if=/dev/zero of=/mnt/data bs=4k count=102400 &
# mount /dev/sda8 /mnt -o remount, ro
When remounting RW to RO, the logic is to firstly set flag
to RO and then commit transaction, however with option
flushoncommit enabled,we will do RO check within committing
transaction, so we get a transaction abortion here.
Actually,here check is wrong, we should check if FS_STATE_ERROR
is set, fix it.
Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Suggested-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
When we are looking for file extent items that intersect the cloning
range, for each one that falls completely outside the range, don't
release the path and do another full tree search - just move on
to the next slot and copy the file extent item into our buffer only
if the item intersects the cloning range.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
When transaction is aborted, we fail to commit transaction, instead we do
cleanup work. After that when we umount btrfs, we get to free fs roots' log
trees respectively, but that happens after we unpin extents, so those extents
pinned by freeing log trees will remain in memory and lead to the leak.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Since remount will pending the new mount options to the original mount
options, which will make btrfs_parse_options check the old options then
new options, causing some stupid output like "enabling XXX" following by
"disable XXX".
This patch will add extra check before every btrfs_info to skip the
output from old options checking.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Add noinode_cache mount option for btrfs.
Since inode map cache involves all the btrfs_find_free_ino/return_ino
things and if just trigger the mount_opt,
an inode number get from inode map cache will not returned to inode map
cache.
To keep the find and return inode both in the same behavior,
a new bit in mount_opt, CHANGE_INODE_CACHE, is introduced for this idea.
CHANGE_INODE_CACHE is set/cleared in remounting, and the original
INODE_MAP_CACHE is set/cleared according to CHANGE_INODE_CACHE after a
success transaction.
Since find/return inode is all done between btrfs_start_transaction and
btrfs_commit_transaction, this will keep consistent behavior.
Also noinode_cache mount option will not stop the caching_kthread.
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
There is a bug that using btrfs_previous_item() to search metadata extent item.
This is because in btrfs_previous_item(), we need type match, however, since
skinny metada was introduced by josef, we may mix this two types. So just
use btrfs_previous_item() is not working right.
To keep btrfs_previous_item() like normal tree search, i introduce another
function btrfs_previous_extent_item().
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Check if we support skinny metadata firstly and fix to use
right type to search.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
It is possible for the send feature to send clone operations that
request a cloning range (offset + length) that is not aligned with
the block size. This makes the btrfs receive command send issue a
clone ioctl call that will fail, as the ioctl will return an -EINVAL
error because of the unaligned range.
Fix this by not sending clone operations for non block aligned ranges,
and instead send regular write operation for these (less common) cases.
The following xfstest reproduces this issue, which fails on the second
btrfs receive command without this change:
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=`mktemp -d`
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
rm -fr $tmp
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
# real QA test starts here
_supported_fs btrfs
_supported_os Linux
_require_scratch
_need_to_be_root
rm -f $seqres.full
_scratch_mkfs >/dev/null 2>&1
_scratch_mount
$XFS_IO_PROG -f -c "truncate 819200" $SCRATCH_MNT/foo | _filter_xfs_io
$BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT | _filter_scratch
$XFS_IO_PROG -c "falloc -k 819200 667648" $SCRATCH_MNT/foo | _filter_xfs_io
$BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT | _filter_scratch
$XFS_IO_PROG -f -c "pwrite 1482752 2978" $SCRATCH_MNT/foo | _filter_xfs_io
$BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT | _filter_scratch
$BTRFS_UTIL_PROG subvol snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap1 | \
_filter_scratch
$XFS_IO_PROG -f -c "truncate 883305" $SCRATCH_MNT/foo | _filter_xfs_io
$BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT | _filter_scratch
$BTRFS_UTIL_PROG subvol snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap2 | \
_filter_scratch
$BTRFS_UTIL_PROG send $SCRATCH_MNT/mysnap1 -f $tmp/1.snap 2>&1 | _filter_scratch
$BTRFS_UTIL_PROG send -p $SCRATCH_MNT/mysnap1 $SCRATCH_MNT/mysnap2 \
-f $tmp/2.snap 2>&1 | _filter_scratch
md5sum $SCRATCH_MNT/foo | _filter_scratch
md5sum $SCRATCH_MNT/mysnap1/foo | _filter_scratch
md5sum $SCRATCH_MNT/mysnap2/foo | _filter_scratch
_scratch_unmount
_check_btrfs_filesystem $SCRATCH_DEV
_scratch_mkfs >/dev/null 2>&1
_scratch_mount
$BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/1.snap
md5sum $SCRATCH_MNT/mysnap1/foo | _filter_scratch
$BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/2.snap
md5sum $SCRATCH_MNT/mysnap2/foo | _filter_scratch
_scratch_unmount
_check_btrfs_filesystem $SCRATCH_DEV
status=0
exit
The tests expected output is:
QA output created by 025
FSSync 'SCRATCH_MNT'
FSSync 'SCRATCH_MNT'
wrote 2978/2978 bytes at offset 1482752
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
FSSync 'SCRATCH_MNT'
Create a readonly snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/mysnap1'
FSSync 'SCRATCH_MNT'
Create a readonly snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/mysnap2'
At subvol SCRATCH_MNT/mysnap1
At subvol SCRATCH_MNT/mysnap2
129b8eaee8d3c2bcad49bec596591cb3 SCRATCH_MNT/foo
42b6369eae2a8725c1aacc0440e597aa SCRATCH_MNT/mysnap1/foo
129b8eaee8d3c2bcad49bec596591cb3 SCRATCH_MNT/mysnap2/foo
At subvol mysnap1
42b6369eae2a8725c1aacc0440e597aa SCRATCH_MNT/mysnap1/foo
At snapshot mysnap2
129b8eaee8d3c2bcad49bec596591cb3 SCRATCH_MNT/mysnap2/foo
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
After the change titled "Btrfs: add support for inode properties", if
btrfs was built-in the kernel (i.e. not as a module), it would cause a
kernel panic, as reported recently by Fengguang:
[ 2.024722] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 2.027814] IP: [<ffffffff81501594>] crc32c+0xc/0x6b
[ 2.028684] PGD 0
[ 2.028684] Oops: 0000 [#1] SMP
[ 2.028684] Modules linked in:
[ 2.028684] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.13.0-rc7-04795-ga7b57c2 #1
[ 2.028684] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 2.028684] task: ffff88000edba100 ti: ffff88000edd6000 task.ti: ffff88000edd6000
[ 2.028684] RIP: 0010:[<ffffffff81501594>] [<ffffffff81501594>] crc32c+0xc/0x6b
[ 2.028684] RSP: 0000:ffff88000edd7e58 EFLAGS: 00010246
[ 2.028684] RAX: 0000000000000000 RBX: ffffffff82295550 RCX: 0000000000000000
[ 2.028684] RDX: 0000000000000011 RSI: ffffffff81efe393 RDI: 00000000fffffffe
[ 2.028684] RBP: ffff88000edd7e60 R08: 0000000000000003 R09: 0000000000015d20
[ 2.028684] R10: ffffffff81ef225e R11: ffffffff811b0222 R12: ffffffffffffffff
[ 2.028684] R13: 0000000000000239 R14: 0000000000000000 R15: 0000000000000000
[ 2.028684] FS: 0000000000000000(0000) GS:ffff88000fa00000(0000) knlGS:0000000000000000
[ 2.028684] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 2.028684] CR2: 0000000000000000 CR3: 000000000220c000 CR4: 00000000000006f0
[ 2.028684] Stack:
[ 2.028684] ffffffff82295550 ffff88000edd7e80 ffffffff8238af62 ffffffff8238ac05
[ 2.028684] 0000000000000000 ffff88000edd7e98 ffffffff8238ac0f ffffffff8238ac05
[ 2.028684] ffff88000edd7f08 ffffffff810002ba ffff88000edd7f00 ffffffff810e2404
[ 2.028684] Call Trace:
[ 2.028684] [<ffffffff8238af62>] btrfs_props_init+0x4f/0x96
[ 2.028684] [<ffffffff8238ac05>] ? ftrace_define_fields_btrfs_space_reservation+0x145/0x145
[ 2.028684] [<ffffffff8238ac0f>] init_btrfs_fs+0xa/0xf0
[ 2.028684] [<ffffffff8238ac05>] ? ftrace_define_fields_btrfs_space_reservation+0x145/0x145
[ 2.028684] [<ffffffff810002ba>] do_one_initcall+0xa4/0x13a
[ 2.028684] [<ffffffff810e2404>] ? parse_args+0x25f/0x33d
[ 2.028684] [<ffffffff8234cf75>] kernel_init_freeable+0x1aa/0x230
[ 2.028684] [<ffffffff8234c785>] ? do_early_param+0x88/0x88
[ 2.028684] [<ffffffff819f61b5>] ? rest_init+0x89/0x89
[ 2.028684] [<ffffffff819f61c3>] kernel_init+0xe/0x109
The issue here is that the initialization function of btrfs (super.c:init_btrfs_fs)
started using crc32c (from lib/libcrc32c.c). But when it needs to call crc32c (as
part of the properties initialization routine), the libcrc32c is not yet initialized,
so crc32c derreferenced a NULL pointer (lib/libcrc32c.c:tfm), causing the kernel
panic on boot.
The approach to fix this is to use crypto component directly to use its crc32c (which
is basically what lib/libcrc32c.c is, a wrapper around crypto). This is what ext4 is
doing as well, it uses crypto directly to get crc32c functionality.
Verified this works both when btrfs is built-in and when it's loadable kernel module.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
In the clone ioctl, when the source and target inodes are different,
we can acquire their mutexes in 2 possible different orders. After
we're done cloning, we were releasing the mutexes always in the same
order - the most correct way of doing it is to release them by the
reverse order they were acquired.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Here we are not going to free memory, no need to remove every node
one by one, just init root node here is ok.
Cc: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
We don't have to keep subvolume's block_rsv during transaction commit,
and within transaction commit, we may also need the free space reclaimed
from this block_rsv to process delayed refs.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
When we ran the 274th case of xfstests with nodatacow mount option,
We met the following warning message:
WARNING: CPU: 1 PID: 14185 at fs/btrfs/extent-tree.c:3734 btrfs_free_reserved_data_space+0xa6/0xd0
It is caused by the race between the write back and nocow buffered
write:
Task1 Task2
__btrfs_buffered_write()
skip data reservation
reserve the metadata space
copy the data
dirty the pages
unlock the pages
write back the pages
release the data space
becasue there is no
noreserve flag
set the noreserve flag
This patch fixes this problem by unlocking the pages after
the noreserve flag is set.
Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
The backref walking code will search down to the key it is looking for and then
proceed to walk _all_ of the extents on the file until it hits the end. This is
suboptimal with large files, we only need to look for as many extents as we have
references for that inode. I have a testcase that creates a randomly written 4
gig file and before this patch it took 6min 30sec to do the initial send, with
this patch it takes 2min 30sec to do the intial send. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Could have sworn I fixed this before but apparently not. This makes us pass
btrfs/022 with skinny metadata enabled. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
I don't think this is an issue and I've not seen it in practice but
extent_from_logical will fail to find a skinny extent because it uses
btrfs_previous_item and gives it the normal extent item type. This is just not
a place to use btrfs_previous_item since we care about either normal extents or
skinny extents, so open code btrfs_previous_item to properly check. This would
only affect metadata and the only place this is used for metadata is scrub and
I'm pretty sure it's just for printing stuff out, not actually doing any work so
hopefully it was never a problem other than a cosmetic one. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
On one of our gluster clusters we noticed some pretty big lag spikes. This
turned out to be because our transaction commit was taking like 3 minutes to
complete. This is because we have like 30 gigs of metadata, so our global
reserve would end up being the max which is like 512 mb. So our throttling code
would allow a ridiculous amount of delayed refs to build up and then they'd all
get run at transaction commit time, and for a cold mounted file system that
could take up to 3 minutes to run. So fix the throttling to be based on both
the size of the global reserve and how long it takes us to run delayed refs.
This patch tracks the time it takes to run delayed refs and then only allows 1
seconds worth of outstanding delayed refs at a time. This way it will auto-tune
itself from cold cache up to when everything is in memory and it no longer has
to go to disk. This makes our transaction commits take much less time to run.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Currently we have two rb-trees, one for delayed ref heads and one for all of the
delayed refs, including the delayed ref heads. When we process the delayed refs
we have to hold onto the delayed ref lock for all of the selecting and merging
and such, which results in quite a bit of lock contention. This was solved by
having a waitqueue and only one flusher at a time, however this hurts if we get
a lot of delayed refs queued up.
So instead just have an rb tree for the delayed ref heads, and then attach the
delayed ref updates to an rb tree that is per delayed ref head. Then we only
need to take the delayed ref lock when adding new delayed refs and when
selecting a delayed ref head to process, all the rest of the time we deal with a
per delayed ref head lock which will be much less contentious.
The locking rules for this get a little more complicated since we have to lock
up to 3 things to properly process delayed refs, but I will address that problem
later. For now this passes all of xfstests and my overnight stress tests.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Looking into some performance related issues with large amounts of metadata
revealed that we can have some pretty huge swings in fsync() performance. If we
have a lot of delayed refs backed up (as you will tend to do with lots of
metadata) fsync() will wander off and try to run some of those delayed refs
which can result in reading from disk and such. Since the actual act of fsync()
doesn't create any delayed refs there is no need to make it throttle on delayed
ref stuff, that will be handled by other people. With this patch we get much
smoother fsync performance with large amounts of metadata. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
This change adds infrastructure to allow for generic properties for
inodes. Properties are name/value pairs that can be associated with
inodes for different purposes. They are stored as xattrs with the
prefix "btrfs."
Properties can be inherited - this means when a directory inode has
inheritable properties set, these are added to new inodes created
under that directory. Further, subvolumes can also have properties
associated with them, and they can be inherited from their parent
subvolume. Naturally, directory properties have priority over subvolume
properties (in practice a subvolume property is just a regular
property associated with the root inode, objectid 256, of the
subvolume's fs tree).
This change also adds one specific property implementation, named
"compression", whose values can be "lzo" or "zlib" and it's an
inheritable property.
The corresponding changes to btrfs-progs were also implemented.
A patch with xfstests for this feature will follow once there's
agreement on this change/feature.
Further, the script at the bottom of this commit message was used to
do some benchmarks to measure any performance penalties of this feature.
Basically the tests correspond to:
Test 1 - create a filesystem and mount it with compress-force=lzo,
then sequentially create N files of 64Kb each, measure how long it took
to create the files, unmount the filesystem, mount the filesystem and
perform an 'ls -lha' against the test directory holding the N files, and
report the time the command took.
Test 2 - create a filesystem and don't use any compression option when
mounting it - instead set the compression property of the subvolume's
root to 'lzo'. Then create N files of 64Kb, and report the time it took.
The unmount the filesystem, mount it again and perform an 'ls -lha' like
in the former test. This means every single file ends up with a property
(xattr) associated to it.
Test 3 - same as test 2, but uses 4 properties - 3 are duplicates of the
compression property, have no real effect other than adding more work
when inheriting properties and taking more btree leaf space.
Test 4 - same as test 3 but with 10 properties per file.
Results (in seconds, and averages of 5 runs each), for different N
numbers of files follow.
* Without properties (test 1)
file creation time ls -lha time
10 000 files 3.49 0.76
100 000 files 47.19 8.37
1 000 000 files 518.51 107.06
* With 1 property (compression property set to lzo - test 2)
file creation time ls -lha time
10 000 files 3.63 0.93
100 000 files 48.56 9.74
1 000 000 files 537.72 125.11
* With 4 properties (test 3)
file creation time ls -lha time
10 000 files 3.94 1.20
100 000 files 52.14 11.48
1 000 000 files 572.70 142.13
* With 10 properties (test 4)
file creation time ls -lha time
10 000 files 4.61 1.35
100 000 files 58.86 13.83
1 000 000 files 656.01 177.61
The increased latencies with properties are essencialy because of:
*) When creating an inode, we now synchronously write 1 more item
(an xattr item) for each property inherited from the parent dir
(or subvolume). This could be done in an asynchronous way such
as we do for dir intex items (delayed-inode.c), which could help
reduce the file creation latency;
*) With properties, we now have larger fs trees. For this particular
test each xattr item uses 75 bytes of leaf space in the fs tree.
This could be less by using a new item for xattr items, instead of
the current btrfs_dir_item, since we could cut the 'location' and
'type' fields (saving 18 bytes) and maybe 'transid' too (saving a
total of 26 bytes per xattr item) from the btrfs_dir_item type.
Also tried batching the xattr insertions (ignoring proper hash
collision handling, since it didn't exist) when creating files that
inherit properties from their parent inode/subvolume, but the end
results were (surprisingly) essentially the same.
Test script:
$ cat test.pl
#!/usr/bin/perl -w
use strict;
use Time::HiRes qw(time);
use constant NUM_FILES => 10_000;
use constant FILE_SIZES => (64 * 1024);
use constant DEV => '/dev/sdb4';
use constant MNT_POINT => '/home/fdmanana/btrfs-tests/dev';
use constant TEST_DIR => (MNT_POINT . '/testdir');
system("mkfs.btrfs", "-l", "16384", "-f", DEV) == 0 or die "mkfs.btrfs failed!";
# following line for testing without properties
#system("mount", "-o", "compress-force=lzo", DEV, MNT_POINT) == 0 or die "mount failed!";
# following 2 lines for testing with properties
system("mount", DEV, MNT_POINT) == 0 or die "mount failed!";
system("btrfs", "prop", "set", MNT_POINT, "compression", "lzo") == 0 or die "set prop failed!";
system("mkdir", TEST_DIR) == 0 or die "mkdir failed!";
my ($t1, $t2);
$t1 = time();
for (my $i = 1; $i <= NUM_FILES; $i++) {
my $p = TEST_DIR . '/file_' . $i;
open(my $f, '>', $p) or die "Error opening file!";
$f->autoflush(1);
for (my $j = 0; $j < FILE_SIZES; $j += 4096) {
print $f ('A' x 4096) or die "Error writing to file!";
}
close($f);
}
$t2 = time();
print "Time to create " . NUM_FILES . ": " . ($t2 - $t1) . " seconds.\n";
system("umount", DEV) == 0 or die "umount failed!";
system("mount", DEV, MNT_POINT) == 0 or die "mount failed!";
$t1 = time();
system("bash -c 'ls -lha " . TEST_DIR . " > /dev/null'") == 0 or die "ls failed!";
$t2 = time();
print "Time to ls -lha all files: " . ($t2 - $t1) . " seconds.\n";
system("umount", DEV) == 0 or die "umount failed!";
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
When writing to a file we drop existing file extent items that cover the
write range and then add a new file extent item that represents that write
range.
Before this change we were doing a tree lookup to remove the file extent
items, and then after we did another tree lookup to insert the new file
extent item.
Most of the time all the file extent items we need to drop are located
within a single leaf - this is the leaf where our new file extent item ends
up at. Therefore, in this common case just combine these 2 operations into
a single one.
By avoiding the second btree navigation for insertion of the new file extent
item, we reduce btree node/leaf lock acquisitions/releases, btree block/leaf
COW operations, CPU time on btree node/leaf key binary searches, etc.
Besides for file writes, this is an operation that happens for file fsync's
as well. However log btrees are much less likely to big as big as regular
fs btrees, therefore the impact of this change is smaller.
The following benchmark was performed against an SSD drive and a
HDD drive, both for random and sequential writes:
sysbench --test=fileio --file-num=4096 --file-total-size=8G \
--file-test-mode=[rndwr|seqwr] --num-threads=512 \
--file-block-size=8192 \ --max-requests=1000000 \
--file-fsync-freq=0 --file-io-mode=sync [prepare|run]
All results below are averages of 10 runs of the respective test.
** SSD sequential writes
Before this change: 225.88 Mb/sec
After this change: 277.26 Mb/sec
** SSD random writes
Before this change: 49.91 Mb/sec
After this change: 56.39 Mb/sec
** HDD sequential writes
Before this change: 68.53 Mb/sec
After this change: 69.87 Mb/sec
** HDD random writes
Before this change: 13.04 Mb/sec
After this change: 14.39 Mb/sec
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
We may return early in btrfs_drop_snapshot(), we shouldn't
call btrfs_std_err() for this case, fix it.
Cc: stable@vger.kernel.org
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
We will finish orphan cleanups during snapshot, so we don't
have to commit transaction here.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
We should gurantee that parent and clone roots can not be destroyed
during send, for this we have two ideas.
1.by holding @subvol_sem, this might be a nightmare, because it will
block all subvolumes deletion for a long time.
2.Miao pointed out we can reuse @send_in_progress, that mean we will
skip snapshot deletion if root sending is in progress.
Here we adopt the second approach since it won't block other subvolumes
deletion for a long time.
Besides in btrfs_clean_one_deleted_snapshot(), we only check first root
, if this root is involved in send, we return directly rather than
continue to check.There are several reasons about it:
1.this case happen seldomly.
2.after sending,cleaner thread can continue to drop that root.
3.make code simple
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Steps to reproduce:
# mkfs.btrfs -f /dev/sda8
# mount /dev/sda8 /mnt
# btrfs sub snapshot -r /mnt /mnt/snap1
# btrfs sub snapshot -r /mnt /mnt/snap2
# btrfs send /mnt/snap1 -p /mnt/snap2 -f /mnt/1
# dmesg
The problem is that we will sort clone roots(include @send_root), it
might push @send_root before thus @send_root's @send_in_progress will
be decreased twice.
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Add treelog mount option to enable tree log with
remount option.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
