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btrfs: Update out-of-date "skip parity stripe" comment
Pull vfs updates from Al Viro:
"In this one:
- d_move fixes (Eric Biederman)
- UFS fixes (me; locking is mostly sane now, a bunch of bugs in error
handling ought to be fixed)
- switch of sb_writers to percpu rwsem (Oleg Nesterov)
- superblock scalability (Josef Bacik and Dave Chinner)
- swapon(2) race fix (Hugh Dickins)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (65 commits)
vfs: Test for and handle paths that are unreachable from their mnt_root
dcache: Reduce the scope of i_lock in d_splice_alias
dcache: Handle escaped paths in prepend_path
mm: fix potential data race in SyS_swapon
inode: don't softlockup when evicting inodes
inode: rename i_wb_list to i_io_list
sync: serialise per-superblock sync operations
inode: convert inode_sb_list_lock to per-sb
inode: add hlist_fake to avoid the inode hash lock in evict
writeback: plug writeback at a high level
change sb_writers to use percpu_rw_semaphore
shift percpu_counter_destroy() into destroy_super_work()
percpu-rwsem: kill CONFIG_PERCPU_RWSEM
percpu-rwsem: introduce percpu_rwsem_release() and percpu_rwsem_acquire()
percpu-rwsem: introduce percpu_down_read_trylock()
document rwsem_release() in sb_wait_write()
fix the broken lockdep logic in __sb_start_write()
introduce __sb_writers_{acquired,release}() helpers
ufs_inode_get{frag,block}(): get rid of 'phys' argument
ufs_getfrag_block(): tidy up a bit
...
Pull btrfs updates from Chris Mason:
"This has Jeff Mahoney's long standing trim patch that fixes corners
where trims were missing. Omar has some raid5/6 fixes, especially for
using scrub and device replace when devices are missing.
Zhao Lie continues cleaning and fixing things, this series fixes some
really hard to hit corners in xfstests. I had to pull it last merge
window due to some deadlocks, but those are now resolved.
I added support for Tejun's new blkio controllers. It seems to work
well for single devices, we'll expand to multi-device as well"
* 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (47 commits)
btrfs: fix compile when block cgroups are not enabled
Btrfs: fix file read corruption after extent cloning and fsync
Btrfs: check if previous transaction aborted to avoid fs corruption
btrfs: use __GFP_NOFAIL in alloc_btrfs_bio
btrfs: Prevent from early transaction abort
btrfs: Remove unused arguments in tree-log.c
btrfs: Remove useless condition in start_log_trans()
Btrfs: add support for blkio controllers
Btrfs: remove unused mutex from struct 'btrfs_fs_info'
Btrfs: fix parity scrub of RAID 5/6 with missing device
Btrfs: fix device replace of a missing RAID 5/6 device
Btrfs: add RAID 5/6 BTRFS_RBIO_REBUILD_MISSING operation
Btrfs: count devices correctly in readahead during RAID 5/6 replace
Btrfs: remove misleading handling of missing device scrub
btrfs: fix clone / extent-same deadlocks
Btrfs: fix defrag to merge tail file extent
Btrfs: fix warning in backref walking
btrfs: Add WARN_ON() for double lock in btrfs_tree_lock()
btrfs: Remove root argument in extent_data_ref_count()
btrfs: Fix wrong comment of btrfs_alloc_tree_block()
...
Pull core block updates from Jens Axboe:
"This first core part of the block IO changes contains:
- Cleanup of the bio IO error signaling from Christoph. We used to
rely on the uptodate bit and passing around of an error, now we
store the error in the bio itself.
- Improvement of the above from myself, by shrinking the bio size
down again to fit in two cachelines on x86-64.
- Revert of the max_hw_sectors cap removal from a revision again,
from Jeff Moyer. This caused performance regressions in various
tests. Reinstate the limit, bump it to a more reasonable size
instead.
- Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me.
Most devices have huge trim limits, which can cause nasty latencies
when deleting files. Enable the admin to configure the size down.
We will look into having a more sane default instead of UINT_MAX
sectors.
- Improvement of the SGP gaps logic from Keith Busch.
- Enable the block core to handle arbitrarily sized bios, which
enables a nice simplification of bio_add_page() (which is an IO hot
path). From Kent.
- Improvements to the partition io stats accounting, making it
faster. From Ming Lei.
- Also from Ming Lei, a basic fixup for overflow of the sysfs pending
file in blk-mq, as well as a fix for a blk-mq timeout race
condition.
- Ming Lin has been carrying Kents above mentioned patches forward
for a while, and testing them. Ming also did a few fixes around
that.
- Sasha Levin found and fixed a use-after-free problem introduced by
the bio->bi_error changes from Christoph.
- Small blk cgroup cleanup from Viresh Kumar"
* 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits)
blk: Fix bio_io_vec index when checking bvec gaps
block: Replace SG_GAPS with new queue limits mask
block: bump BLK_DEF_MAX_SECTORS to 2560
Revert "block: remove artifical max_hw_sectors cap"
blk-mq: fix race between timeout and freeing request
blk-mq: fix buffer overflow when reading sysfs file of 'pending'
Documentation: update notes in biovecs about arbitrarily sized bios
block: remove bio_get_nr_vecs()
fs: use helper bio_add_page() instead of open coding on bi_io_vec
block: kill merge_bvec_fn() completely
md/raid5: get rid of bio_fits_rdev()
md/raid5: split bio for chunk_aligned_read
block: remove split code in blkdev_issue_{discard,write_same}
btrfs: remove bio splitting and merge_bvec_fn() calls
bcache: remove driver private bio splitting code
block: simplify bio_add_page()
block: make generic_make_request handle arbitrarily sized bios
blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL)
block: don't access bio->bi_error after bio_put()
block: shrink struct bio down to 2 cache lines again
...
We need not check path before btrfs_free_path() is called because
path is checked in btrfs_free_path().
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
At initializing time, for threshold-able workqueue, it's max_active
of kernel workqueue should be 1 and grow if it hits threshold.
But due to the bad naming, there is both 'max_active' for kernel
workqueue and btrfs workqueue.
So wrong value is given at workqueue initialization.
This patch fixes it, and to avoid further misunderstanding, change the
member name of btrfs_workqueue to 'current_active' and 'limit_active'.
Also corresponding comment is added for readability.
Reported-by: Alex Lyakas <alex.btrfs@zadarastorage.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
num_tolerated_disk_barrier_failures in btrfs_balance
Code for updating fs_info->num_tolerated_disk_barrier_failures in
btrfs_balance() lacks raid56 support.
Reason:
Above code was wroten in 2012-08-01, together with
btrfs_calc_num_tolerated_disk_barrier_failures()'s first version.
Then, btrfs_calc_num_tolerated_disk_barrier_failures() got updated
later to support raid56, but code in btrfs_balance() was not
updated together.
Fix:
Merge above similar code to a common function:
btrfs_get_num_tolerated_disk_barrier_failures()
and make it support both case.
It can fix this bug with a bonus of cleanup, and make these code
never in above no-sync state from now on.
Suggested-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
1: Use ARRAY_SIZE(types) to replace a static-value variant:
int num_types = 4;
2: Use 'continue' on condition to reduce one level tab
if (!XXX) {
code;
...
}
->
if (XXX)
continue;
code;
...
3: Put setting 'num_tolerated_disk_barrier_failures = 2' to
(num_tolerated_disk_barrier_failures > 2) condition to make
make logic neat.
if (num_tolerated_disk_barrier_failures > 0 && XXX)
num_tolerated_disk_barrier_failures = 0;
else if (num_tolerated_disk_barrier_failures > 1) {
if (XXX)
num_tolerated_disk_barrier_failures = 1;
else if (XXX)
num_tolerated_disk_barrier_failures = 2;
->
if (num_tolerated_disk_barrier_failures > 0 && XXX)
num_tolerated_disk_barrier_failures = 0;
if (num_tolerated_disk_barrier_failures > 1 && XXX)
num_tolerated_disk_barrier_failures = ;
if (num_tolerated_disk_barrier_failures > 2 && XXX)
num_tolerated_disk_barrier_failures = 2;
4: Remove comment of:
num_mirrors - 1: if RAID1 or RAID10 is configured and more
than 2 mirrors are used.
which is not fit with code.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
These variables are not used from introduced version, remove them.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
bio->bi_css and bio->bi_ioc don't exist when block cgroups are not on.
This adds an ifdef around them. It's not perfect, but our
use of bi_ioc is being removed in the 4.3 merge window.
The bi_css usage really should go into bio_clone, but I want to make
sure that doesn't introduce problems for other bio_clone use cases.
Signed-off-by: Chris Mason <clm@fb.com>
If we partially clone one extent of a file into a lower offset of the
file, fsync the file, power fail and then mount the fs to trigger log
replay, we can get multiple checksum items in the csum tree that overlap
each other and result in checksum lookup failures later. Those failures
can make file data read requests assume a checksum value of 0, but they
will not return an error (-EIO for example) to userspace exactly because
the expected checksum value 0 is a special value that makes the read bio
endio callback return success and set all the bytes of the corresponding
page with the value 0x01 (at fs/btrfs/inode.c:__readpage_endio_check()).
From a userspace perspective this is equivalent to file corruption
because we are not returning what was written to the file.
Details about how this can happen, and why, are included inline in the
following reproducer test case for fstests and the comment added to
tree-log.c.
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()
{
_cleanup_flakey
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
. ./common/dmflakey
# real QA test starts here
_need_to_be_root
_supported_fs btrfs
_supported_os Linux
_require_scratch
_require_dm_flakey
_require_cloner
_require_metadata_journaling $SCRATCH_DEV
rm -f $seqres.full
_scratch_mkfs >>$seqres.full 2>&1
_init_flakey
_mount_flakey
# Create our test file with a single 100K extent starting at file
# offset 800K. We fsync the file here to make the fsync log tree gets
# a single csum item that covers the whole 100K extent, which causes
# the second fsync, done after the cloning operation below, to not
# leave in the log tree two csum items covering two sub-ranges
# ([0, 20K[ and [20K, 100K[)) of our extent.
$XFS_IO_PROG -f -c "pwrite -S 0xaa 800K 100K" \
-c "fsync" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Now clone part of our extent into file offset 400K. This adds a file
# extent item to our inode's metadata that points to the 100K extent
# we created before, using a data offset of 20K and a data length of
# 20K, so that it refers to the sub-range [20K, 40K[ of our original
# extent.
$CLONER_PROG -s $((800 * 1024 + 20 * 1024)) -d $((400 * 1024)) \
-l $((20 * 1024)) $SCRATCH_MNT/foo $SCRATCH_MNT/foo
# Now fsync our file to make sure the extent cloning is durably
# persisted. This fsync will not add a second csum item to the log
# tree containing the checksums for the blocks in the sub-range
# [20K, 40K[ of our extent, because there was already a csum item in
# the log tree covering the whole extent, added by the first fsync
# we did before.
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo
echo "File digest before power failure:"
md5sum $SCRATCH_MNT/foo | _filter_scratch
# Silently drop all writes and ummount to simulate a crash/power
# failure.
_load_flakey_table $FLAKEY_DROP_WRITES
_unmount_flakey
# Allow writes again, mount to trigger log replay and validate file
# contents.
# The fsync log replay first processes the file extent item
# corresponding to the file offset 400K (the one which refers to the
# [20K, 40K[ sub-range of our 100K extent) and then processes the file
# extent item for file offset 800K. It used to happen that when
# processing the later, it erroneously left in the csum tree 2 csum
# items that overlapped each other, 1 for the sub-range [20K, 40K[ and
# 1 for the whole range of our extent. This introduced a problem where
# subsequent lookups for the checksums of blocks within the range
# [40K, 100K[ of our extent would not find anything because lookups in
# the csum tree ended up looking only at the smaller csum item, the
# one covering the subrange [20K, 40K[. This made read requests assume
# an expected checksum with a value of 0 for those blocks, which caused
# checksum verification failure when the read operations finished.
# However those checksum failure did not result in read requests
# returning an error to user space (like -EIO for e.g.) because the
# expected checksum value had the special value 0, and in that case
# btrfs set all bytes of the corresponding pages with the value 0x01
# and produce the following warning in dmesg/syslog:
#
# "BTRFS warning (device dm-0): csum failed ino 257 off 917504 csum\
# 1322675045 expected csum 0"
#
_load_flakey_table $FLAKEY_ALLOW_WRITES
_mount_flakey
echo "File digest after log replay:"
# Must match the same digest he had after cloning the extent and
# before the power failure happened.
md5sum $SCRATCH_MNT/foo | _filter_scratch
_unmount_flakey
status=0
exit
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
While we are committing a transaction, it's possible the previous one is
still finishing its commit and therefore we wait for it to finish first.
However we were not checking if that previous transaction ended up getting
aborted after we waited for it to commit, so we ended up committing the
current transaction which can lead to fs corruption because the new
superblock can point to trees that have had one or more nodes/leafs that
were never durably persisted.
The following sequence diagram exemplifies how this is possible:
CPU 0 CPU 1
transaction N starts
(...)
btrfs_commit_transaction(N)
cur_trans->state = TRANS_STATE_COMMIT_START;
(...)
cur_trans->state = TRANS_STATE_COMMIT_DOING;
(...)
cur_trans->state = TRANS_STATE_UNBLOCKED;
root->fs_info->running_transaction = NULL;
btrfs_start_transaction()
--> starts transaction N + 1
btrfs_write_and_wait_transaction(trans, root);
--> starts writing all new or COWed ebs created
at transaction N
creates some new ebs, COWs some
existing ebs but doesn't COW or
deletes eb X
btrfs_commit_transaction(N + 1)
(...)
cur_trans->state = TRANS_STATE_COMMIT_START;
(...)
wait_for_commit(root, prev_trans);
--> prev_trans == transaction N
btrfs_write_and_wait_transaction() continues
writing ebs
--> fails writing eb X, we abort transaction N
and set bit BTRFS_FS_STATE_ERROR on
fs_info->fs_state, so no new transactions
can start after setting that bit
cleanup_transaction()
btrfs_cleanup_one_transaction()
wakes up task at CPU 1
continues, doesn't abort because
cur_trans->aborted (transaction N + 1)
is zero, and no checks for bit
BTRFS_FS_STATE_ERROR in fs_info->fs_state
are made
btrfs_write_and_wait_transaction(trans, root);
--> succeeds, no errors during writeback
write_ctree_super(trans, root, 0);
--> succeeds
--> we have now a superblock that points us
to some root that uses eb X, which was
never written to disk
In this scenario future attempts to read eb X from disk results in an
error message like "parent transid verify failed on X wanted Y found Z".
So fix this by aborting the current transaction if after waiting for the
previous transaction we verify that it was aborted.
Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
alloc_btrfs_bio relies on GFP_NOFS allocation when committing the
transaction but this allocation context is rather weak wrt. reclaim
capabilities. The page allocator currently tries hard to not fail these
allocations if they are small (<=PAGE_ALLOC_COSTLY_ORDER) but it can
still fail if the _current_ process is the OOM killer victim. Moreover
there is an attempt to move away from the default no-fail behavior and
allow these allocation to fail more eagerly. This would lead to:
[ 37.928625] kernel BUG at fs/btrfs/extent_io.c:4045
which is clearly undesirable and the nofail behavior should be explicit
if the allocation failure cannot be tolerated.
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Following arguments are not used in tree-log.c:
insert_one_name(): path, type
wait_log_commit(): trans
wait_for_writer(): trans
This patch remove them.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Dan Carpenter <dan.carpenter@oracle.com> reported a smatch warning
for start_log_trans():
fs/btrfs/tree-log.c:178 start_log_trans()
warn: we tested 'root->log_root' before and it was 'false'
fs/btrfs/tree-log.c
147 if (root->log_root) {
We test "root->log_root" here.
...
Reason:
Condition of:
fs/btrfs/tree-log.c:178: if (!root->log_root) {
is not necessary after commit: 7237f1833
It caused a smatch warning, and no functionally error.
Fix:
Deleting above condition will make smatch shut up,
but a better way is to do cleanup for start_log_trans()
to remove duplicated code and make code more readable.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Preparation to hide the sb->s_writers internals from xfs and btrfs.
Add 2 trivial define's they can use rather than play with ->s_writers
directly. No changes in btrfs/transaction.o and xfs/xfs_aops.o.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jan Kara <jack@suse.com>
We can always fill up the bio now, no need to estimate the possible
size based on queue parameters.
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[hch: rebased and wrote a changelog]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Btrfs has been doing bio splitting from btrfs_map_bio(), by checking
device limits as well as calling ->merge_bvec_fn() etc. That is not
necessary any more, because generic_make_request() is now able to
handle arbitrarily sized bios. So clean up unnecessary code paths.
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
[dpark: add more description in commit message]
Signed-off-by: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This attaches accounting information to bios as we submit them so the
new blkio controllers can throttle on btrfs filesystems.
Not much is required, we're just associating bios with blkcgs during clone,
calling wbc_init_bio()/wbc_account_io() during writepages submission,
and attaching the bios to the current context during direct IO.
Finally if we are splitting bios during btrfs_map_bio, this attaches
accounting information to the split.
The end result is able to throttle nicely on single disk filesystems. A
little more work is required for multi-device filesystems.
Signed-off-by: Chris Mason <clm@fb.com>
The code using 'ordered_extent_flush_mutex' mutex has removed by below
commit.
- 8d875f95da
btrfs: disable strict file flushes for renames and truncates
But the mutex still lives in struct 'btrfs_fs_info'.
So, this patch removes the mutex from struct 'btrfs_fs_info' and its
initialization code.
Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
When testing the previous patch, Zhao Lei reported a similar bug when
attempting to scrub a degraded RAID 5/6 filesystem with a missing
device, leading to NULL pointer dereferences from the RAID 5/6 parity
scrubbing code.
The first cause was the same as in the previous patch: attempting to
call bio_add_page() on a missing block device. To fix this,
scrub_extent_for_parity() can just mark the sectors on the missing
device as errors instead of attempting to read from it.
Additionally, the code uses scrub_remap_extent() to map the extent of
the corresponding data stripe, but the extent wasn't already mapped. If
scrub_remap_extent() finds a missing block device, it doesn't initialize
extent_dev, so we're left with a NULL struct btrfs_device. The solution
is to use btrfs_map_block() directly.
Reported-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
The original implementation of device replace on RAID 5/6 seems to have
missed support for replacing a missing device. When this is attempted,
we end up calling bio_add_page() on a bio with a NULL ->bi_bdev, which
crashes when we try to dereference it. This happens because
btrfs_map_block() has no choice but to return us the missing device
because RAID 5/6 don't have any alternate mirrors to read from, and a
missing device has a NULL bdev.
The idea implemented here is to handle the missing device case
separately, which better only happen when we're replacing a missing RAID
5/6 device. We use the new BTRFS_RBIO_REBUILD_MISSING operation to
reconstruct the data from parity, check it with
scrub_recheck_block_checksum(), and write it out with
scrub_write_block_to_dev_replace().
Reported-by: Philip <bugzilla@philip-seeger.de>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96141
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
The current RAID 5/6 recovery code isn't quite prepared to handle
missing devices. In particular, it expects a bio that we previously
attempted to use in the read path, meaning that it has valid pages
allocated. However, missing devices have a NULL blkdev, and we can't
call bio_add_page() on a bio with a NULL blkdev. We could do manual
manipulation of bio->bi_io_vec, but that's pretty gross. So instead, add
a separate path that allows us to manually add pages to the rbio.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Commit 5fbc7c59fd ("Btrfs: fix unfinished readahead thread for raid5/6
degraded mounting") fixed a problem where we would skip a missing device
when we shouldn't have because there are no other mirrors to read from
in RAID 5/6. After commit 2c8cdd6ee4 ("Btrfs, replace: write dirty
pages into the replace target device"), the fix doesn't work when we're
doing a missing device replace on RAID 5/6 because the replace device is
counted as a mirror so we're tricked into thinking we can safely skip
the missing device. The fix is to count only the real stripes and decide
based on that.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
scrub_submit() claims that it can handle a bio with a NULL block device,
but this is misleading, as calling bio_add_page() on a bio with a NULL
->bi_bdev would've already crashed. Delete this, as we're about to
properly handle a missing block device.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Clone and extent same lock their source and target inodes in opposite order.
In addition to this, the range locking in clone doesn't take ordering into
account. Fix this by having clone use the same locking helpers as
btrfs-extent-same.
In addition, I do a small cleanup of the locking helpers, removing a case
(both inodes being the same) which was poorly accounted for and never
actually used by the callers.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
The file layout is
[extent 1]...[extent n][4k extent][HOLE][extent x]
extent 1~n and 4k extent can be merged during defrag, and the whole
defrag bytes is larger than our defrag thresh(256k), 4k extent as a
tail is left unmerged since we check if its next extent can be merged
(the next one is a hole, so the check will fail), the layout thus can
be
[new extent][4k extent][HOLE][extent x]
(1~n)
To fix it, beside looking at the next one, this also looks at the
previous one by checking @defrag_end, which is set to 0 when we
decide to stop merging contiguous extents, otherwise, we can merge
the previous one with our extent.
Also, this makes btrfs behave consistent with how xfs and ext4 do.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
When we do backref walking, we search firstly in queued delayed refs
and then the on-disk backrefs, but we parse differently for shared
references, for delayed refs we also add 'ref->root' while for on-disk
backrefs we don't, this can prevent us from merging refs indexed
by the same bytenr and cause find_parent_nodes() to throw a warning at
'WARN_ON(ref->count < 0)', for example, when we have a shared data extent
with 'ref_cnt=1' and a delayed shared data with a BTRFS_DROP_DELAYED_REF,
that happens.
For shared references, no matter if it's delayed or on-disk, ref->root is
not at all used, instead it's ref->parent that really matters, so this has
delayed refs handled as the same way as on-disk refs.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
When a task trying to double lock a extent buffer, there are no
lockdep warning about it because this lock may be in "blocking_lock"
state, and make us hard to debug.
This patch add a WARN_ON() for above condition, it can not report
all deadlock cases(as lock between tasks), but at least helps us
some.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
These wrong comment was copyed from another function(expired) from
init, this patch fixed them.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
When btrfs_reloc_cow_block() failed in __btrfs_cow_block(), current
code just return a err-value to caller, but leave new_created extent
buffer exist and locked.
Then subsequent code (in relocate) try to lock above eb again,
and caused deadlock without any dmesg.
(eb lock use wait_event(), so no lockdep message)
It is hard to do recover work in __btrfs_cow_block() at this error
point, but we can abort transaction to avoid deadlock and operate on
unstable state.a
It also helps developer to find wrong place quickly.
(better than a frozen fs without any dmesg before patch)
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
These arguments are not used in functions, remove them for cleanup
and make kernel stack happy.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Remove chunk_objectid argument from btrfs_relocate_chunk() because
it is not necessary, it can also cleanup some code in caller for
prepare its value.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
objectid's init-value is not used in any case, remove it.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
We need error checking code for get_ref_objectid_v0() in
relocate_block_group(), to avoid unpredictable result, especially
for accessing uninitialized value(when function failed) after
this line.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
xfstests btrfs/070 sometimes failed.
In my test machine, its fail rate is about 30%.
In another vm(vmware), its fail rate is about 50%.
Reason:
btrfs/070 do replace and defrag with fsstress simultaneously,
after above operation, checksum error is found by scrub.
Actually, it have no relationship with defrag operation, only
replace with fsstress can trigger this bug.
New data writen to target device have possibility rewrited by
old data from source device by replace code in debug, to avoid
above problem, we can set target block group to readonly in
replace period, so new data requested by other operation will
not write to same place with replace code.
Before patch(4.1-rc3):
30% failed in 100 xfstests.
After patch:
0% failed in 300 xfstests.
It also happened in btrfs/071 as it's another scrub with IO load tests.
Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Use new intruduced scrub_pause_on/off() can make this code block
clean and more readable.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
It can reduce current duplicated code which is similar to
scrub_blocked_if_needed() but can not call it because little
different.
It also used by my next patch which is in same case.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
More than one code call set_block_group_ro() and restore rw in fail.
Old code use bool bit to save blockgroup's ro state, it can not
support parallel case(it is confirmd exist in my debug log).
This patch use ref count to store ro state, and rename
set_block_group_ro/set_block_group_rw
to
inc_block_group_ro/dec_block_group_ro.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
When we access extent_root in scrub_stripe() and
scrub_raid56_parity(), we need bypass unrelated tree item firstly
before using its contents to do other condition.
It is not a bug fix, only making code sequence in logic.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
We need not load csum of whole strip in scrub because strip is trimed
before use, it is to say, what we really need to calculate csum is
data between [extent_logical, extent_len).
This patch changed to use above segment for btrfs_lookup_csums_range()
in scrub_stripe()
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
For example, in scrub_raid56_parity(), following lines are used
to judge is all data processed:
place1: if (key.objectid > logic_end) ...
place2: if (logic_start >= logic_end) ...
...
(place2 is typo, is should be ">", it is copied from other
place, where logic_end's meaning is different, long story...)
We can fix above typo directly, but the root reason is ambiguous
meaning of logic_end in scrub raid56 parity.
In other place, XXX_end is pointed to data which is not included,
and we need to process segment of [XXX_start, XXX_end).
But for scrub raid56 parity, logic_end is pointed to lattest data
need to process, and introduced many "+ 1" and "- 1" in code as
below:
length = sparity->logic_end - sparity->logic_start + 1
logic_end - logic_start + 1
stripe_logical + increment - 1
This patch changed logic_end's meaning to make it in normal understanding
in raid56 parity functions and data struct alone with above bugfix.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
When scrub_extent() failed, we need to free previois created
checksum list.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Old code checking cancel and pause request inside scrub stripe
operation, like:
loop() {
if (parity) {
scrub_parity_stripe();
continue;
}
check_cancel_and_pause()
scrub_normal_stripe();
}
Reason is when introduce raid56 stripe scrub, new code is inserted
simplely to front of loop.
Better to:
loop() {
check_cancel_and_pause()
if (parity)
scrub_parity_stripe();
else
scrub_normal_stripe();
}
This patch adjusted code place to realize above sequence.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Linus Torvalds
Tsutomu Itoh
Qu Wenruo
Zhao Lei
Chris Mason
Filipe Manana
Michal Hocko
Oleg Nesterov
Kent Overstreet
Greg Kroah-Hartman
Byongho Lee
Omar Sandoval
Mark Fasheh
Liu Bo