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If when reading a page we find a hole and our caller had already locked
the range (bio flags has the bit EXTENT_BIO_PARENT_LOCKED set), we end
up unlocking the hole's range and then later our caller unlocks it
again, which might have already been locked by some other task once
the first unlock happened.
Currently this can only happen during a call to the extent_same ioctl,
as it's the only caller of __do_readpage() that sets the bit
EXTENT_BIO_PARENT_LOCKED for bio flags.
Fix this by leaving the unlock exclusively to the caller.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
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Currently the clone ioctl allows to clone an inline extent from one file
to another that already has other (non-inlined) extents. This is a problem
because btrfs is not designed to deal with files having inline and regular
extents, if a file has an inline extent then it must be the only extent
in the file and must start at file offset 0. Having a file with an inline
extent followed by regular extents results in EIO errors when doing reads
or writes against the first 4K of the file.
Also, the clone ioctl allows one to lose data if the source file consists
of a single inline extent, with a size of N bytes, and the destination
file consists of a single inline extent with a size of M bytes, where we
have M > N. In this case the clone operation removes the inline extent
from the destination file and then copies the inline extent from the
source file into the destination file - we lose the M - N bytes from the
destination file, a read operation will get the value 0x00 for any bytes
in the the range [N, M] (the destination inode's i_size remained as M,
that's why we can read past N bytes).
So fix this by not allowing such destructive operations to happen and
return errno EOPNOTSUPP to user space.
Currently the fstest btrfs/035 tests the data loss case but it totally
ignores this - i.e. expects the operation to succeed and does not check
the we got data loss.
The following test case for fstests exercises all these cases that result
in file corruption and data loss:
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
# real QA test starts here
_need_to_be_root
_supported_fs btrfs
_supported_os Linux
_require_scratch
_require_cloner
_require_btrfs_fs_feature "no_holes"
_require_btrfs_mkfs_feature "no-holes"
rm -f $seqres.full
test_cloning_inline_extents()
{
local mkfs_opts=$1
local mount_opts=$2
_scratch_mkfs $mkfs_opts >>$seqres.full 2>&1
_scratch_mount $mount_opts
# File bar, the source for all the following clone operations, consists
# of a single inline extent (50 bytes).
$XFS_IO_PROG -f -c "pwrite -S 0xbb 0 50" $SCRATCH_MNT/bar \
| _filter_xfs_io
# Test cloning into a file with an extent (non-inlined) where the
# destination offset overlaps that extent. It should not be possible to
# clone the inline extent from file bar into this file.
$XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 16K" $SCRATCH_MNT/foo \
| _filter_xfs_io
$CLONER_PROG -s 0 -d 0 -l 0 $SCRATCH_MNT/bar $SCRATCH_MNT/foo
# Doing IO against any range in the first 4K of the file should work.
# Due to a past clone ioctl bug which allowed cloning the inline extent,
# these operations resulted in EIO errors.
echo "File foo data after clone operation:"
# All bytes should have the value 0xaa (clone operation failed and did
# not modify our file).
od -t x1 $SCRATCH_MNT/foo
$XFS_IO_PROG -c "pwrite -S 0xcc 0 100" $SCRATCH_MNT/foo | _filter_xfs_io
# Test cloning the inline extent against a file which has a hole in its
# first 4K followed by a non-inlined extent. It should not be possible
# as well to clone the inline extent from file bar into this file.
$XFS_IO_PROG -f -c "pwrite -S 0xdd 4K 12K" $SCRATCH_MNT/foo2 \
| _filter_xfs_io
$CLONER_PROG -s 0 -d 0 -l 0 $SCRATCH_MNT/bar $SCRATCH_MNT/foo2
# Doing IO against any range in the first 4K of the file should work.
# Due to a past clone ioctl bug which allowed cloning the inline extent,
# these operations resulted in EIO errors.
echo "File foo2 data after clone operation:"
# All bytes should have the value 0x00 (clone operation failed and did
# not modify our file).
od -t x1 $SCRATCH_MNT/foo2
$XFS_IO_PROG -c "pwrite -S 0xee 0 90" $SCRATCH_MNT/foo2 | _filter_xfs_io
# Test cloning the inline extent against a file which has a size of zero
# but has a prealloc extent. It should not be possible as well to clone
# the inline extent from file bar into this file.
$XFS_IO_PROG -f -c "falloc -k 0 1M" $SCRATCH_MNT/foo3 | _filter_xfs_io
$CLONER_PROG -s 0 -d 0 -l 0 $SCRATCH_MNT/bar $SCRATCH_MNT/foo3
# Doing IO against any range in the first 4K of the file should work.
# Due to a past clone ioctl bug which allowed cloning the inline extent,
# these operations resulted in EIO errors.
echo "First 50 bytes of foo3 after clone operation:"
# Should not be able to read any bytes, file has 0 bytes i_size (the
# clone operation failed and did not modify our file).
od -t x1 $SCRATCH_MNT/foo3
$XFS_IO_PROG -c "pwrite -S 0xff 0 90" $SCRATCH_MNT/foo3 | _filter_xfs_io
# Test cloning the inline extent against a file which consists of a
# single inline extent that has a size not greater than the size of
# bar's inline extent (40 < 50).
# It should be possible to do the extent cloning from bar to this file.
$XFS_IO_PROG -f -c "pwrite -S 0x01 0 40" $SCRATCH_MNT/foo4 \
| _filter_xfs_io
$CLONER_PROG -s 0 -d 0 -l 0 $SCRATCH_MNT/bar $SCRATCH_MNT/foo4
# Doing IO against any range in the first 4K of the file should work.
echo "File foo4 data after clone operation:"
# Must match file bar's content.
od -t x1 $SCRATCH_MNT/foo4
$XFS_IO_PROG -c "pwrite -S 0x02 0 90" $SCRATCH_MNT/foo4 | _filter_xfs_io
# Test cloning the inline extent against a file which consists of a
# single inline extent that has a size greater than the size of bar's
# inline extent (60 > 50).
# It should not be possible to clone the inline extent from file bar
# into this file.
$XFS_IO_PROG -f -c "pwrite -S 0x03 0 60" $SCRATCH_MNT/foo5 \
| _filter_xfs_io
$CLONER_PROG -s 0 -d 0 -l 0 $SCRATCH_MNT/bar $SCRATCH_MNT/foo5
# Reading the file should not fail.
echo "File foo5 data after clone operation:"
# Must have a size of 60 bytes, with all bytes having a value of 0x03
# (the clone operation failed and did not modify our file).
od -t x1 $SCRATCH_MNT/foo5
# Test cloning the inline extent against a file which has no extents but
# has a size greater than bar's inline extent (16K > 50).
# It should not be possible to clone the inline extent from file bar
# into this file.
$XFS_IO_PROG -f -c "truncate 16K" $SCRATCH_MNT/foo6 | _filter_xfs_io
$CLONER_PROG -s 0 -d 0 -l 0 $SCRATCH_MNT/bar $SCRATCH_MNT/foo6
# Reading the file should not fail.
echo "File foo6 data after clone operation:"
# Must have a size of 16K, with all bytes having a value of 0x00 (the
# clone operation failed and did not modify our file).
od -t x1 $SCRATCH_MNT/foo6
# Test cloning the inline extent against a file which has no extents but
# has a size not greater than bar's inline extent (30 < 50).
# It should be possible to clone the inline extent from file bar into
# this file.
$XFS_IO_PROG -f -c "truncate 30" $SCRATCH_MNT/foo7 | _filter_xfs_io
$CLONER_PROG -s 0 -d 0 -l 0 $SCRATCH_MNT/bar $SCRATCH_MNT/foo7
# Reading the file should not fail.
echo "File foo7 data after clone operation:"
# Must have a size of 50 bytes, with all bytes having a value of 0xbb.
od -t x1 $SCRATCH_MNT/foo7
# Test cloning the inline extent against a file which has a size not
# greater than the size of bar's inline extent (20 < 50) but has
# a prealloc extent that goes beyond the file's size. It should not be
# possible to clone the inline extent from bar into this file.
$XFS_IO_PROG -f -c "falloc -k 0 1M" \
-c "pwrite -S 0x88 0 20" \
$SCRATCH_MNT/foo8 | _filter_xfs_io
$CLONER_PROG -s 0 -d 0 -l 0 $SCRATCH_MNT/bar $SCRATCH_MNT/foo8
echo "File foo8 data after clone operation:"
# Must have a size of 20 bytes, with all bytes having a value of 0x88
# (the clone operation did not modify our file).
od -t x1 $SCRATCH_MNT/foo8
_scratch_unmount
}
echo -e "\nTesting without compression and without the no-holes feature...\n"
test_cloning_inline_extents
echo -e "\nTesting with compression and without the no-holes feature...\n"
test_cloning_inline_extents "" "-o compress"
echo -e "\nTesting without compression and with the no-holes feature...\n"
test_cloning_inline_extents "-O no-holes" ""
echo -e "\nTesting with compression and with the no-holes feature...\n"
test_cloning_inline_extents "-O no-holes" "-o compress"
status=0
exit
Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
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The code for btrfs inode-resolve has never worked properly for
files with enough hard links to trigger extrefs. It was trying to
get the leaf out of a path after freeing the path:
btrfs_release_path(path);
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, slot);
The fix here is to use the extent buffer we cloned just a little higher
up to avoid deadlocks caused by using the leaf in the path.
Signed-off-by: Chris Mason <clm@fb.com>
cc: stable@vger.kernel.org # v3.7+
cc: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
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We don't verify that all the balance filter arguments supplemented by
the flags are actually known to the kernel. Thus we let it silently pass
and do nothing.
At the moment this means only the 'limit' filter, but we're going to add
a few more soon so it's better to have that fixed. Also in older stable
kernels so that it works with newer userspace tools.
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
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This fixes a regression introduced by 37b8d27d between v4.1 and v4.2.
When a snapshot is received, its received_uuid is set to the original
uuid of the subvolume. When that snapshot is then resent to a third
filesystem, it's received_uuid is set to the second uuid
instead of the original one. The same was true for the parent_uuid.
This behaviour was partially changed in 37b8d27d, but in that patch
only the parent_uuid was taken from the real original,
not the uuid itself, causing the search for the parent to fail in
the case below.
This happens for example when trying to send a series of linked
snapshots (e.g. created by snapper) from the backup file system back
to the original one.
The following commands reproduce the issue in v4.2.1
(no error in 4.1.6)
# setup three test file systems
for i in 1 2 3; do
truncate -s 50M fs$i
mkfs.btrfs fs$i
mkdir $i
mount fs$i $i
done
echo "content" > 1/testfile
btrfs su snapshot -r 1/ 1/snap1
echo "changed content" > 1/testfile
btrfs su snapshot -r 1/ 1/snap2
# works fine:
btrfs send 1/snap1 | btrfs receive 2/
btrfs send -p 1/snap1 1/snap2 | btrfs receive 2/
# ERROR: could not find parent subvolume
btrfs send 2/snap1 | btrfs receive 3/
btrfs send -p 2/snap1 2/snap2 | btrfs receive 3/
Signed-off-by: Robin Ruede <rruede+git@gmail.com>
Fixes: 37b8d27de5d0 ("Btrfs: use received_uuid of parent during send")
Cc: stable@vger.kernel.org # v4.2+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Tested-by: Ed Tomlinson <edt@aei.ca>
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If we have a file that shares an extent with other files, when processing
the extent item relative to a shared extent, we blindly issue a clone
operation that will target a length matching the length in the extent item
and uses as a source some other file the receiver already has and points
to the same extent. However that range in the other file might not
exclusively point only to the shared extent, and so using that length
will result in the receiver getting a file with different data from the
one in the send snapshot. This issue happened both for incremental and
full send operations.
So fix this by issuing clone operations with lengths that don't cover
regions of the source file that point to different extents (or have holes).
The following test case for fstests reproduces the problem.
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
rm -fr $send_files_dir
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
# real QA test starts here
_supported_fs btrfs
_supported_os Linux
_require_scratch
_need_to_be_root
_require_cp_reflink
_require_xfs_io_command "fpunch"
send_files_dir=$TEST_DIR/btrfs-test-$seq
rm -f $seqres.full
rm -fr $send_files_dir
mkdir $send_files_dir
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount
# Create our test file with a single 100K extent.
$XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 100K" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Clone our file into a new file named bar.
cp --reflink=always $SCRATCH_MNT/foo $SCRATCH_MNT/bar
# Now overwrite parts of our foo file.
$XFS_IO_PROG -c "pwrite -S 0xbb 50K 10K" \
-c "pwrite -S 0xcc 90K 10K" \
-c "fpunch 70K 10k" \
$SCRATCH_MNT/foo | _filter_xfs_io
_run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT \
$SCRATCH_MNT/snap
echo "File digests in the original filesystem:"
md5sum $SCRATCH_MNT/snap/foo | _filter_scratch
md5sum $SCRATCH_MNT/snap/bar | _filter_scratch
_run_btrfs_util_prog send $SCRATCH_MNT/snap -f $send_files_dir/1.snap
# Now recreate the filesystem by receiving the send stream and verify
# we get the same file contents that the original filesystem had.
_scratch_unmount
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount
_run_btrfs_util_prog receive $SCRATCH_MNT -f $send_files_dir/1.snap
# We expect the destination filesystem to have exactly the same file
# data as the original filesystem.
# The btrfs send implementation had a bug where it sent a clone
# operation from file foo into file bar covering the whole [0, 100K[
# range after creating and writing the file foo. This was incorrect
# because the file bar now included the updates done to file foo after
# we cloned foo to bar, breaking the COW nature of reflink copies
# (cloned extents).
echo "File digests in the new filesystem:"
md5sum $SCRATCH_MNT/snap/foo | _filter_scratch
md5sum $SCRATCH_MNT/snap/bar | _filter_scratch
status=0
exit
Another test case that reproduces the problem when we have compressed
extents:
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
rm -fr $send_files_dir
rm -f $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
_require_cp_reflink
send_files_dir=$TEST_DIR/btrfs-test-$seq
rm -f $seqres.full
rm -fr $send_files_dir
mkdir $send_files_dir
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount "-o compress"
# Create our file with an extent of 100K starting at file offset 0K.
$XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 100K" \
-c "fsync" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Rewrite part of the previous extent (its first 40K) and write a new
# 100K extent starting at file offset 100K.
$XFS_IO_PROG -c "pwrite -S 0xbb 0K 40K" \
-c "pwrite -S 0xcc 100K 100K" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Our file foo now has 3 file extent items in its metadata:
#
# 1) One covering the file range 0 to 40K;
# 2) One covering the file range 40K to 100K, which points to the first
# extent we wrote to the file and has a data offset field with value
# 40K (our file no longer uses the first 40K of data from that
# extent);
# 3) One covering the file range 100K to 200K.
# Now clone our file foo into file bar.
cp --reflink=always $SCRATCH_MNT/foo $SCRATCH_MNT/bar
# Create our snapshot for the send operation.
_run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT \
$SCRATCH_MNT/snap
echo "File digests in the original filesystem:"
md5sum $SCRATCH_MNT/snap/foo | _filter_scratch
md5sum $SCRATCH_MNT/snap/bar | _filter_scratch
_run_btrfs_util_prog send $SCRATCH_MNT/snap -f $send_files_dir/1.snap
# Now recreate the filesystem by receiving the send stream and verify we
# get the same file contents that the original filesystem had.
# Btrfs send used to issue a clone operation from foo's range
# [80K, 140K[ to bar's range [40K, 100K[ when cloning the extent pointed
# to by foo's second file extent item, this was incorrect because of bad
# accounting of the file extent item's data offset field. The correct
# range to clone from should have been [40K, 100K[.
_scratch_unmount
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount "-o compress"
_run_btrfs_util_prog receive $SCRATCH_MNT -f $send_files_dir/1.snap
echo "File digests in the new filesystem:"
# Must match the digests we got in the original filesystem.
md5sum $SCRATCH_MNT/snap/foo | _filter_scratch
md5sum $SCRATCH_MNT/snap/bar | _filter_scratch
status=0
exit
Signed-off-by: Filipe Manana <fdmanana@suse.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.4
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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.4
Signed-off-by: Chris Mason <clm@fb.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.4
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There are atomic operations that imply the barrier for waitqueue_active
mixed in an if-condition.
Signed-off-by: David Sterba <dsterba@suse.com>
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Removing barriers is scary, but a call to atomic_dec_and_test implies
a barrier, so we don't need to issue another one.
Signed-off-by: David Sterba <dsterba@suse.com>
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Reduce number of undocumented barriers out there.
Signed-off-by: David Sterba <dsterba@suse.com>
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Suggested-by: Chris Mason <clm@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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waitqueue_active should be preceded by a barrier, in this function we
don't need to call it all the time.
Signed-off-by: David Sterba <dsterba@suse.com>
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Normally the waitqueue_active would need a barrier, but this is not
necessary here because it's not a performance sensitive context and we
can call wake_up directly.
Suggested-by: Chris Mason <clm@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"These are small and assorted. Neil's is the oldest, I dropped the
ball thinking he was going to send it in"
* 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: support NFSv2 export
Btrfs: open_ctree: Fix possible memory leak
Btrfs: fix deadlock when finalizing block group creation
Btrfs: update fix for read corruption of compressed and shared extents
Btrfs: send, fix corner case for reference overwrite detection
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Convert the simple cases, not all functions provide a way to reach the
fs_info. Also skipped debugging messages (print-tree, integrity
checker and pr_debug) and messages that are printed from possibly
unfinished mount.
Signed-off-by: David Sterba <dsterba@suse.com>
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Signed-off-by: David Sterba <dsterba@suse.com>
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Signed-off-by: David Sterba <dsterba@suse.com>
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Signed-off-by: David Sterba <dsterba@suse.com>
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Signed-off-by: David Sterba <dsterba@suse.com>
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Signed-off-by: David Sterba <dsterba@suse.com>
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Due to the missing variants there are messages that lack the information
printed by btrfs_info etc helpers.
Signed-off-by: David Sterba <dsterba@suse.com>
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The "fh_len" passed to ->fh_to_* is not guaranteed to be that same as
that returned by encode_fh - it may be larger.
With NFSv2, the filehandle is fixed length, so it may appear longer
than expected and be zero-padded.
So we must test that fh_len is at least some value, not exactly equal
to it.
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: David Sterba <dsterba@suse.cz>
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After reading one of chunk or tree root tree's root node from disk, if the
root node does not have EXTENT_BUFFER_UPTODATE flag set, we fail to release
the memory used by the root node. Fix this.
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
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Josef ran into a deadlock while a transaction handle was finalizing the
creation of its block groups, which produced the following trace:
[260445.593112] fio D ffff88022a9df468 0 8924 4518 0x00000084
[260445.593119] ffff88022a9df468 ffffffff81c134c0 ffff880429693c00 ffff88022a9df488
[260445.593126] ffff88022a9e0000 ffff8803490d7b00 ffff8803490d7b18 ffff88022a9df4b0
[260445.593132] ffff8803490d7af8 ffff88022a9df488 ffffffff8175a437 ffff8803490d7b00
[260445.593137] Call Trace:
[260445.593145] [<ffffffff8175a437>] schedule+0x37/0x80
[260445.593189] [<ffffffffa0850f37>] btrfs_tree_lock+0xa7/0x1f0 [btrfs]
[260445.593197] [<ffffffff810db7c0>] ? prepare_to_wait_event+0xf0/0xf0
[260445.593225] [<ffffffffa07eac44>] btrfs_lock_root_node+0x34/0x50 [btrfs]
[260445.593253] [<ffffffffa07eff6b>] btrfs_search_slot+0x88b/0xa00 [btrfs]
[260445.593295] [<ffffffffa08389df>] ? free_extent_buffer+0x4f/0x90 [btrfs]
[260445.593324] [<ffffffffa07f1a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs]
[260445.593351] [<ffffffffa07ea94a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs]
[260445.593394] [<ffffffffa08403b9>] btrfs_finish_chunk_alloc+0x1c9/0x570 [btrfs]
[260445.593427] [<ffffffffa08002ab>] btrfs_create_pending_block_groups+0x11b/0x200 [btrfs]
[260445.593459] [<ffffffffa0800964>] do_chunk_alloc+0x2a4/0x2e0 [btrfs]
[260445.593491] [<ffffffffa0803815>] find_free_extent+0xa55/0xd90 [btrfs]
[260445.593524] [<ffffffffa0803c22>] btrfs_reserve_extent+0xd2/0x220 [btrfs]
[260445.593532] [<ffffffff8119fe5d>] ? account_page_dirtied+0xdd/0x170
[260445.593564] [<ffffffffa0803e78>] btrfs_alloc_tree_block+0x108/0x4a0 [btrfs]
[260445.593597] [<ffffffffa080c9de>] ? btree_set_page_dirty+0xe/0x10 [btrfs]
[260445.593626] [<ffffffffa07eb5cd>] __btrfs_cow_block+0x12d/0x5b0 [btrfs]
[260445.593654] [<ffffffffa07ebbff>] btrfs_cow_block+0x11f/0x1c0 [btrfs]
[260445.593682] [<ffffffffa07ef8c7>] btrfs_search_slot+0x1e7/0xa00 [btrfs]
[260445.593724] [<ffffffffa08389df>] ? free_extent_buffer+0x4f/0x90 [btrfs]
[260445.593752] [<ffffffffa07f1a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs]
[260445.593830] [<ffffffffa07ea94a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs]
[260445.593905] [<ffffffffa08403b9>] btrfs_finish_chunk_alloc+0x1c9/0x570 [btrfs]
[260445.593946] [<ffffffffa08002ab>] btrfs_create_pending_block_groups+0x11b/0x200 [btrfs]
[260445.593990] [<ffffffffa0815798>] btrfs_commit_transaction+0xa8/0xb40 [btrfs]
[260445.594042] [<ffffffffa085abcd>] ? btrfs_log_dentry_safe+0x6d/0x80 [btrfs]
[260445.594089] [<ffffffffa082bc84>] btrfs_sync_file+0x294/0x350 [btrfs]
[260445.594115] [<ffffffff8123e29b>] vfs_fsync_range+0x3b/0xa0
[260445.594133] [<ffffffff81023891>] ? syscall_trace_enter_phase1+0x131/0x180
[260445.594149] [<ffffffff8123e35d>] do_fsync+0x3d/0x70
[260445.594169] [<ffffffff81023bb8>] ? syscall_trace_leave+0xb8/0x110
[260445.594187] [<ffffffff8123e600>] SyS_fsync+0x10/0x20
[260445.594204] [<ffffffff8175de6e>] entry_SYSCALL_64_fastpath+0x12/0x71
This happened because the same transaction handle created a large number
of block groups and while finalizing their creation (inserting new items
and updating existing items in the chunk and device trees) a new metadata
extent had to be allocated and no free space was found in the current
metadata block groups, which made find_free_extent() attempt to allocate
a new block group via do_chunk_alloc(). However at do_chunk_alloc() we
ended up allocating a new system chunk too and exceeded the threshold
of 2Mb of reserved chunk bytes, which makes do_chunk_alloc() enter the
final part of block group creation again (at
btrfs_create_pending_block_groups()) and attempt to lock again the root
of the chunk tree when it's already write locked by the same task.
Similarly we can deadlock on extent tree nodes/leafs if while we are
running delayed references we end up creating a new metadata block group
in order to allocate a new node/leaf for the extent tree (as part of
a CoW operation or growing the tree), as btrfs_create_pending_block_groups
inserts items into the extent tree as well. In this case we get the
following trace:
[14242.773581] fio D ffff880428ca3418 0 3615 3100 0x00000084
[14242.773588] ffff880428ca3418 ffff88042d66b000 ffff88042a03c800 ffff880428ca3438
[14242.773594] ffff880428ca4000 ffff8803e4b20190 ffff8803e4b201a8 ffff880428ca3460
[14242.773600] ffff8803e4b20188 ffff880428ca3438 ffffffff8175a437 ffff8803e4b20190
[14242.773606] Call Trace:
[14242.773613] [<ffffffff8175a437>] schedule+0x37/0x80
[14242.773656] [<ffffffffa057ff07>] btrfs_tree_lock+0xa7/0x1f0 [btrfs]
[14242.773664] [<ffffffff810db7c0>] ? prepare_to_wait_event+0xf0/0xf0
[14242.773692] [<ffffffffa0519c44>] btrfs_lock_root_node+0x34/0x50 [btrfs]
[14242.773720] [<ffffffffa051ef6b>] btrfs_search_slot+0x88b/0xa00 [btrfs]
[14242.773750] [<ffffffffa0520a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs]
[14242.773758] [<ffffffff811ef4a2>] ? kmem_cache_alloc+0x1d2/0x200
[14242.773786] [<ffffffffa0520ad1>] btrfs_insert_item+0x71/0xf0 [btrfs]
[14242.773818] [<ffffffffa052f292>] btrfs_create_pending_block_groups+0x102/0x200 [btrfs]
[14242.773850] [<ffffffffa052f96e>] do_chunk_alloc+0x2ae/0x2f0 [btrfs]
[14242.773934] [<ffffffffa0532825>] find_free_extent+0xa55/0xd90 [btrfs]
[14242.773998] [<ffffffffa0532c22>] btrfs_reserve_extent+0xc2/0x1d0 [btrfs]
[14242.774041] [<ffffffffa0532e38>] btrfs_alloc_tree_block+0x108/0x4a0 [btrfs]
[14242.774078] [<ffffffffa051a5cd>] __btrfs_cow_block+0x12d/0x5b0 [btrfs]
[14242.774118] [<ffffffffa051abff>] btrfs_cow_block+0x11f/0x1c0 [btrfs]
[14242.774155] [<ffffffffa051e8c7>] btrfs_search_slot+0x1e7/0xa00 [btrfs]
[14242.774194] [<ffffffffa0528021>] ? __btrfs_free_extent.isra.70+0x2e1/0xcb0 [btrfs]
[14242.774235] [<ffffffffa0520a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs]
[14242.774274] [<ffffffffa051994a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs]
[14242.774318] [<ffffffffa052c433>] __btrfs_run_delayed_refs+0xbb3/0x1020 [btrfs]
[14242.774358] [<ffffffffa052f404>] btrfs_run_delayed_refs.part.78+0x74/0x280 [btrfs]
[14242.774391] [<ffffffffa052f627>] btrfs_run_delayed_refs+0x17/0x20 [btrfs]
[14242.774432] [<ffffffffa05be236>] commit_cowonly_roots+0x8d/0x2bd [btrfs]
[14242.774474] [<ffffffffa059d07f>] ? __btrfs_run_delayed_items+0x1cf/0x210 [btrfs]
[14242.774516] [<ffffffffa05adac3>] ? btrfs_qgroup_account_extents+0x83/0x130 [btrfs]
[14242.774558] [<ffffffffa0544c40>] btrfs_commit_transaction+0x590/0xb40 [btrfs]
[14242.774599] [<ffffffffa0589b9d>] ? btrfs_log_dentry_safe+0x6d/0x80 [btrfs]
[14242.774642] [<ffffffffa055ac54>] btrfs_sync_file+0x294/0x350 [btrfs]
[14242.774650] [<ffffffff8123e29b>] vfs_fsync_range+0x3b/0xa0
[14242.774657] [<ffffffff81023891>] ? syscall_trace_enter_phase1+0x131/0x180
[14242.774663] [<ffffffff8123e35d>] do_fsync+0x3d/0x70
[14242.774669] [<ffffffff81023bb8>] ? syscall_trace_leave+0xb8/0x110
[14242.774675] [<ffffffff8123e600>] SyS_fsync+0x10/0x20
[14242.774681] [<ffffffff8175de6e>] entry_SYSCALL_64_fastpath+0x12/0x71
Fix this by never recursing into the finalization phase of block group
creation and making sure we never trigger the finalization of block group
creation while running delayed references.
Reported-by: Josef Bacik <jbacik@fb.com>
Fixes: 00d80e342c0f ("Btrfs: fix quick exhaustion of the system array in the superblock")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
|
|
My previous fix in commit 005efedf2c7d ("Btrfs: fix read corruption of
compressed and shared extents") was effective only if the compressed
extents cover a file range with a length that is not a multiple of 16
pages. That's because the detection of when we reached a different range
of the file that shares the same compressed extent as the previously
processed range was done at extent_io.c:__do_contiguous_readpages(),
which covers subranges with a length up to 16 pages, because
extent_readpages() groups the pages in clusters no larger than 16 pages.
So fix this by tracking the start of the previously processed file
range's extent map at extent_readpages().
The following test case for fstests reproduces the issue:
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
# real QA test starts here
_need_to_be_root
_supported_fs btrfs
_supported_os Linux
_require_scratch
_require_cloner
rm -f $seqres.full
test_clone_and_read_compressed_extent()
{
local mount_opts=$1
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount $mount_opts
# Create our test file with a single extent of 64Kb that is going to
# be compressed no matter which compression algo is used (zlib/lzo).
$XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 64K" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Now clone the compressed extent into an adjacent file offset.
$CLONER_PROG -s 0 -d $((64 * 1024)) -l $((64 * 1024)) \
$SCRATCH_MNT/foo $SCRATCH_MNT/foo
echo "File digest before unmount:"
md5sum $SCRATCH_MNT/foo | _filter_scratch
# Remount the fs or clear the page cache to trigger the bug in
# btrfs. Because the extent has an uncompressed length that is a
# multiple of 16 pages, all the pages belonging to the second range
# of the file (64K to 128K), which points to the same extent as the
# first range (0K to 64K), had their contents full of zeroes instead
# of the byte 0xaa. This was a bug exclusively in the read path of
# compressed extents, the correct data was stored on disk, btrfs
# just failed to fill in the pages correctly.
_scratch_remount
echo "File digest after remount:"
# Must match the digest we got before.
md5sum $SCRATCH_MNT/foo | _filter_scratch
}
echo -e "\nTesting with zlib compression..."
test_clone_and_read_compressed_extent "-o compress=zlib"
_scratch_unmount
echo -e "\nTesting with lzo compression..."
test_clone_and_read_compressed_extent "-o compress=lzo"
status=0
exit
Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Tested-by: Timofey Titovets <nefelim4ag@gmail.com>
|
|
When the inode given to did_overwrite_ref() matches the current progress
and has a reference that collides with the reference of other inode that
has the same number as the current progress, we were always telling our
caller that the inode's reference was overwritten, which is incorrect
because the other inode might be a new inode (different generation number)
in which case we must return false from did_overwrite_ref() so that its
callers don't use an orphanized path for the inode (as it will never be
orphanized, instead it will be unlinked and the new inode created later).
The following test case for fstests reproduces the issue:
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
rm -fr $send_files_dir
rm -f $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
send_files_dir=$TEST_DIR/btrfs-test-$seq
rm -f $seqres.full
rm -fr $send_files_dir
mkdir $send_files_dir
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount
# Create our test file with a single extent of 64K.
mkdir -p $SCRATCH_MNT/foo
$XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" $SCRATCH_MNT/foo/bar \
| _filter_xfs_io
_run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT \
$SCRATCH_MNT/mysnap1
_run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT \
$SCRATCH_MNT/mysnap2
echo "File digest before being replaced:"
md5sum $SCRATCH_MNT/mysnap1/foo/bar | _filter_scratch
# Remove the file and then create a new one in the same location with
# the same name but with different content. This new file ends up
# getting the same inode number as the previous one, because that inode
# number was the highest inode number used by the snapshot's root and
# therefore when attempting to find the a new inode number for the new
# file, we end up reusing the same inode number. This happens because
# currently btrfs uses the highest inode number summed by 1 for the
# first inode created once a snapshot's root is loaded (done at
# fs/btrfs/inode-map.c:btrfs_find_free_objectid in the linux kernel
# tree).
# Having these two different files in the snapshots with the same inode
# number (but different generation numbers) caused the btrfs send code
# to emit an incorrect path for the file when issuing an unlink
# operation because it failed to realize they were different files.
rm -f $SCRATCH_MNT/mysnap2/foo/bar
$XFS_IO_PROG -f -c "pwrite -S 0xbb 0 96K" \
$SCRATCH_MNT/mysnap2/foo/bar | _filter_xfs_io
_run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT/mysnap2 \
$SCRATCH_MNT/mysnap2_ro
_run_btrfs_util_prog send $SCRATCH_MNT/mysnap1 -f $send_files_dir/1.snap
_run_btrfs_util_prog send -p $SCRATCH_MNT/mysnap1 \
$SCRATCH_MNT/mysnap2_ro -f $send_files_dir/2.snap
echo "File digest in the original filesystem after being replaced:"
md5sum $SCRATCH_MNT/mysnap2_ro/foo/bar | _filter_scratch
# Now recreate the filesystem by receiving both send streams and verify
# we get the same file contents that the original filesystem had.
_scratch_unmount
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount
_run_btrfs_util_prog receive -vv $SCRATCH_MNT -f $send_files_dir/1.snap
_run_btrfs_util_prog receive -vv $SCRATCH_MNT -f $send_files_dir/2.snap
echo "File digest in the new filesystem:"
# Must match the digest from the new file.
md5sum $SCRATCH_MNT/mysnap2_ro/foo/bar | _filter_scratch
status=0
exit
Reported-by: Martin Raiber <martin@urbackup.org>
Fixes: 8b191a684968 ("Btrfs: incremental send, check if orphanized dir inode needs delayed rename")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
|
|
To avoid deadlock described in commit 084b6e7c7607 ("btrfs: Fix a
lockdep warning when running xfstest."), we should move kobj stuff out
of dev_replace lock range.
"It is because the btrfs_kobj_{add/rm}_device() will call memory
allocation with GFP_KERNEL,
which may flush fs page cache to free space, waiting for it self to do
the commit, causing the deadlock.
To solve the problem, move btrfs_kobj_{add/rm}_device() out of the
dev_replace lock range, also involing split the
btrfs_rm_dev_replace_srcdev() function into remove and free parts.
Now only btrfs_rm_dev_replace_remove_srcdev() is called in dev_replace
lock range, and kobj_{add/rm} and btrfs_rm_dev_replace_free_srcdev() are
called out of the lock range."
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
[added lockup description]
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Anand Jain <anand.jain@oracle.com>
[reworded subject and changelog]
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Originally the message was not in a helper but ended up there. We should
print error messages from callers instead.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
[reworded subject and changelog]
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
By general rule of thumb there shouldn't be any way that user land
could trigger a kernel operation just by sending wrong arguments.
Here do commit cleanups after user input has been verified.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
This patch updates and renames btrfs_scratch_superblocks, (which is used
by the replace device thread), with those fixes from the scratch
superblock code section of btrfs_rm_device(). The fixes are:
Scratch all copies of superblock
Notify kobject that superblock has been changed
Update time on the device
So that btrfs_rm_device() can use the function
btrfs_scratch_superblocks() instead of its own scratch code. And further
replace deivce code which similarly releases device back to the system,
will have the fixes from the btrfs device delete.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
[renamed to btrfs_scratch_superblock]
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
This uses a chunk of code from btrfs_read_dev_super() and creates
a function called btrfs_read_dev_one_super() so that next patch
can use it for scratch superblock.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
[renamed bufhead to bh]
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Use btrfs specific error code BTRFS_ERROR_DEV_MISSING_NOT_FOUND instead
of -ENOENT. Next this removes the logging when user specifies "missing"
and we don't find it in the kernel device list. Logging are for system
events not for user input errors.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
btrfs_error() and btrfs_std_error() does the same thing
and calls _btrfs_std_error(), so consolidate them together.
And the main motivation is that btrfs_error() is closely
named with btrfs_err(), one handles error action the other
is to log the error, so don't closely name them.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Suggested-by: David Sterba <dsterba@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
defined
error handling logic behaves differently with or without
CONFIG_PRINTK defined, since there are two copies of the same
function which a bit of different logic
One, when CONFIG_PRINTK is defined, code is
__btrfs_std_error(..)
{
::
save_error_info(fs_info);
if (sb->s_flags & MS_BORN)
btrfs_handle_error(fs_info);
}
and two when CONFIG_PRINTK is not defined, the code is
__btrfs_std_error(..)
{
::
if (sb->s_flags & MS_BORN) {
save_error_info(fs_info);
btrfs_handle_error(fs_info);
}
}
I doubt if this was intentional ? and appear to have caused since
we maintain two copies of the same function and they got diverged
with commits.
Now to decide which logic is correct reviewed changes as below,
533574c6bc30cf526cc1c41bde050c854a945efb
Commit added two copies of this function
cf79ffb5b79e8a2b587fbf218809e691bb396c98
Commit made change to only one copy of the function and to the
copy when CONFIG_PRINTK is defined.
To fix this, instead of maintaining two copies of same function
approach, maintain single function, and just put the extra
portion of the code under CONFIG_PRINTK define.
This patch just does that. And keeps code of with CONFIG_PRINTK
defined.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
This will return EIO when __bread() fails to read SB,
instead of EINVAL.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"This is an assorted set I've been queuing up:
Jeff Mahoney tracked down a tricky one where we ended up starting IO
on the wrong mapping for special files in btrfs_evict_inode. A few
people reported this one on the list.
Filipe found (and provided a test for) a difficult bug in reading
compressed extents, and Josef fixed up some quota record keeping with
snapshot deletion. Chandan killed off an accounting bug during DIO
that lead to WARN_ONs as we freed inodes"
* 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: keep dropped roots in cache until transaction commit
Btrfs: Direct I/O: Fix space accounting
btrfs: skip waiting on ordered range for special files
Btrfs: fix read corruption of compressed and shared extents
Btrfs: remove unnecessary locking of cleaner_mutex to avoid deadlock
Btrfs: don't initialize a space info as full to prevent ENOSPC
|
|
When dropping a snapshot we need to account for the qgroup changes. If we drop
the snapshot in all one go then the backref code will fail to find blocks from
the snapshot we dropped since it won't be able to find the root in the fs root
cache. This can lead to us failing to find refs from other roots that pointed
at blocks in the now deleted root. To handle this we need to not remove the fs
roots from the cache until after we process the qgroup operations. Do this by
adding dropped roots to a list on the transaction, and letting the transaction
remove the roots at the same time it drops the commit roots. This will keep all
of the backref searching code in sync properly, and fixes a problem Mark was
seeing with snapshot delete and qgroups. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Tested-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
The following call trace is seen when generic/095 test is executed,
WARNING: CPU: 3 PID: 2769 at /home/chandan/code/repos/linux/fs/btrfs/inode.c:8967 btrfs_destroy_inode+0x284/0x2a0()
Modules linked in:
CPU: 3 PID: 2769 Comm: umount Not tainted 4.2.0-rc5+ #31
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20150306_163512-brownie 04/01/2014
ffffffff81c08150 ffff8802ec9cbce8 ffffffff81984058 ffff8802ffd8feb0
0000000000000000 ffff8802ec9cbd28 ffffffff81050385 ffff8802ec9cbd38
ffff8802d12f8588 ffff8802d12f8588 ffff8802f15ab000 ffff8800bb96c0b0
Call Trace:
[<ffffffff81984058>] dump_stack+0x45/0x57
[<ffffffff81050385>] warn_slowpath_common+0x85/0xc0
[<ffffffff81050465>] warn_slowpath_null+0x15/0x20
[<ffffffff81340294>] btrfs_destroy_inode+0x284/0x2a0
[<ffffffff8117ce07>] destroy_inode+0x37/0x60
[<ffffffff8117cf39>] evict+0x109/0x170
[<ffffffff8117cfd5>] dispose_list+0x35/0x50
[<ffffffff8117dd3a>] evict_inodes+0xaa/0x100
[<ffffffff81165667>] generic_shutdown_super+0x47/0xf0
[<ffffffff81165951>] kill_anon_super+0x11/0x20
[<ffffffff81302093>] btrfs_kill_super+0x13/0x110
[<ffffffff81165c99>] deactivate_locked_super+0x39/0x70
[<ffffffff811660cf>] deactivate_super+0x5f/0x70
[<ffffffff81180e1e>] cleanup_mnt+0x3e/0x90
[<ffffffff81180ebd>] __cleanup_mnt+0xd/0x10
[<ffffffff81069c06>] task_work_run+0x96/0xb0
[<ffffffff81003a3d>] do_notify_resume+0x3d/0x50
[<ffffffff8198cbc2>] int_signal+0x12/0x17
This means that the inode had non-zero "outstanding extents" during
eviction. This occurs because, during direct I/O a task which successfully
used up its reserved data space would set BTRFS_INODE_DIO_READY bit and does
not clear the bit after finishing the DIO write. A future DIO write could
actually fail and the unused reserve space won't be freed because of the
previously set BTRFS_INODE_DIO_READY bit.
Clearing the BTRFS_INODE_DIO_READY bit in btrfs_direct_IO() caused the
following issue,
|-----------------------------------+-------------------------------------|
| Task A | Task B |
|-----------------------------------+-------------------------------------|
| Start direct i/o write on inode X.| |
| reserve space | |
| Allocate ordered extent | |
| release reserved space | |
| Set BTRFS_INODE_DIO_READY bit. | |
| | splice() |
| | Transfer data from pipe buffer to |
| | destination file. |
| | - kmap(pipe buffer page) |
| | - Start direct i/o write on |
| | inode X. |
| | - reserve space |
| | - dio_refill_pages() |
| | - sdio->blocks_available == 0 |
| | - Since a kernel address is |
| | being passed instead of a |
| | user space address, |
| | iov_iter_get_pages() returns |
| | -EFAULT. |
| | - Since BTRFS_INODE_DIO_READY is |
| | set, we don't release reserved |
| | space. |
| | - Clear BTRFS_INODE_DIO_READY bit.|
| -EIOCBQUEUED is returned. | |
|-----------------------------------+-------------------------------------|
Hence this commit introduces "struct btrfs_dio_data" to track the usage of
reserved data space. The remaining unused "reserve space" can now be freed
reliably.
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
In btrfs_evict_inode, we properly truncate the page cache for evicted
inodes but then we call btrfs_wait_ordered_range for every inode as well.
It's the right thing to do for regular files but results in incorrect
behavior for device inodes for block devices.
filemap_fdatawrite_range gets called with inode->i_mapping which gets
resolved to the block device inode before getting passed to
wbc_attach_fdatawrite_inode and ultimately to inode_to_bdi. What happens
next depends on whether there's an open file handle associated with the
inode. If there is, we write to the block device, which is unexpected
behavior. If there isn't, we through normally and inode->i_data is used.
We can also end up racing against open/close which can result in crashes
when i_mapping points to a block device inode that has been closed.
Since there can't be any page cache associated with special file inodes,
it's safe to skip the btrfs_wait_ordered_range call entirely and avoid
the problem.
Cc: <stable@vger.kernel.org>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=100911
Tested-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
|
|
If a file has a range pointing to a compressed extent, followed by
another range that points to the same compressed extent and a read
operation attempts to read both ranges (either completely or part of
them), the pages that correspond to the second range are incorrectly
filled with zeroes.
Consider the following example:
File layout
[0 - 8K] [8K - 24K]
| |
| |
points to extent X, points to extent X,
offset 4K, length of 8K offset 0, length 16K
[extent X, compressed length = 4K uncompressed length = 16K]
If a readpages() call spans the 2 ranges, a single bio to read the extent
is submitted - extent_io.c:submit_extent_page() would only create a new
bio to cover the second range pointing to the extent if the extent it
points to had a different logical address than the extent associated with
the first range. This has a consequence of the compressed read end io
handler (compression.c:end_compressed_bio_read()) finish once the extent
is decompressed into the pages covering the first range, leaving the
remaining pages (belonging to the second range) filled with zeroes (done
by compression.c:btrfs_clear_biovec_end()).
So fix this by submitting the current bio whenever we find a range
pointing to a compressed extent that was preceded by a range with a
different extent map. This is the simplest solution for this corner
case. Making the end io callback populate both ranges (or more, if we
have multiple pointing to the same extent) is a much more complex
solution since each bio is tightly coupled with a single extent map and
the extent maps associated to the ranges pointing to the shared extent
can have different offsets and lengths.
The following test case for fstests triggers the issue:
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
# real QA test starts here
_need_to_be_root
_supported_fs btrfs
_supported_os Linux
_require_scratch
_require_cloner
rm -f $seqres.full
test_clone_and_read_compressed_extent()
{
local mount_opts=$1
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount $mount_opts
# Create a test file with a single extent that is compressed (the
# data we write into it is highly compressible no matter which
# compression algorithm is used, zlib or lzo).
$XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 4K" \
-c "pwrite -S 0xbb 4K 8K" \
-c "pwrite -S 0xcc 12K 4K" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Now clone our extent into an adjacent offset.
$CLONER_PROG -s $((4 * 1024)) -d $((16 * 1024)) -l $((8 * 1024)) \
$SCRATCH_MNT/foo $SCRATCH_MNT/foo
# Same as before but for this file we clone the extent into a lower
# file offset.
$XFS_IO_PROG -f -c "pwrite -S 0xaa 8K 4K" \
-c "pwrite -S 0xbb 12K 8K" \
-c "pwrite -S 0xcc 20K 4K" \
$SCRATCH_MNT/bar | _filter_xfs_io
$CLONER_PROG -s $((12 * 1024)) -d 0 -l $((8 * 1024)) \
$SCRATCH_MNT/bar $SCRATCH_MNT/bar
echo "File digests before unmounting filesystem:"
md5sum $SCRATCH_MNT/foo | _filter_scratch
md5sum $SCRATCH_MNT/bar | _filter_scratch
# Evicting the inode or clearing the page cache before reading
# again the file would also trigger the bug - reads were returning
# all bytes in the range corresponding to the second reference to
# the extent with a value of 0, but the correct data was persisted
# (it was a bug exclusively in the read path). The issue happened
# only if the same readpages() call targeted pages belonging to the
# first and second ranges that point to the same compressed extent.
_scratch_remount
echo "File digests after mounting filesystem again:"
# Must match the same digests we got before.
md5sum $SCRATCH_MNT/foo | _filter_scratch
md5sum $SCRATCH_MNT/bar | _filter_scratch
}
echo -e "\nTesting with zlib compression..."
test_clone_and_read_compressed_extent "-o compress=zlib"
_scratch_unmount
echo -e "\nTesting with lzo compression..."
test_clone_and_read_compressed_extent "-o compress=lzo"
status=0
exit
Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo<quwenruo@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs cleanups and fixes from Chris Mason:
"These are small cleanups, and also some fixes for our async worker
thread initialization.
I was having some trouble testing these, but it ended up being a
combination of changing around my test servers and a shiny new
schedule while atomic from the new start/finish_plug in
writeback_sb_inodes().
That one only hits on btrfs raid5/6 or MD raid10, and if I wasn't
changing a bunch of things in my test setup at once it would have been
really clear. Fix for writeback_sb_inodes() on the way as well"
* 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: cleanup: remove unnecessary check before btrfs_free_path is called
btrfs: async_thread: Fix workqueue 'max_active' value when initializing
btrfs: Add raid56 support for updating num_tolerated_disk_barrier_failures in btrfs_balance
btrfs: Cleanup for btrfs_calc_num_tolerated_disk_barrier_failures
btrfs: Remove noused chunk_tree and chunk_objectid from scrub_enumerate_chunks and scrub_chunk
btrfs: Update out-of-date "skip parity stripe" comment
|
|
After commmit e44163e17796 ("btrfs: explictly delete unused block groups
in close_ctree and ro-remount"), added in the 4.3 merge window, we have
calls to btrfs_delete_unused_bgs() while holding the cleaner_mutex.
This can cause a deadlock with a concurrent block group relocation (when
a filesystem balance or shrink operation is in progress for example)
because btrfs_delete_unused_bgs() locks delete_unused_bgs_mutex and the
relocation path locks first delete_unused_bgs_mutex and then it locks
cleaner_mutex, resulting in a classic ABBA deadlock:
CPU 0 CPU 1
lock fs_info->cleaner_mutex
__btrfs_balance() || btrfs_shrink_device()
lock fs_info->delete_unused_bgs_mutex
btrfs_relocate_chunk()
btrfs_relocate_block_group()
lock fs_info->cleaner_mutex
btrfs_delete_unused_bgs()
lock fs_info->delete_unused_bgs_mutex
Fix this by not taking the cleaner_mutex before calling
btrfs_delete_unused_bgs() because it's no longer needed after
commit 67c5e7d464bc ("Btrfs: fix race between balance and unused block
group deletion"). The mutex fs_info->delete_unused_bgs_mutex, the
spinlock fs_info->unused_bgs_lock and a block group's spinlock are
enough to get correct serialization between tasks running relocation
and unused block group deletion (as well as between multiple tasks
concurrently calling btrfs_delete_unused_bgs()).
This issue was discussed (in the mailing list) during the review of
the patch titled "btrfs: explictly delete unused block groups in
close_ctree and ro-remount" and it was agreed that acquiring the
cleaner mutex had to be dropped after the patch titled
"Btrfs: fix race between balance and unused block group deletion"
got merged (both patches were submitted at about the same time, but
one landed in kernel 4.2 and the other in the 4.3 merge window).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
|
