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commit fcc99734d1d4ced30167eb02e17f656735cb9928 upstream.
[BUG]
One run of btrfs/063 triggered the following lockdep warning:
============================================
WARNING: possible recursive locking detected
5.6.0-rc7-custom+ #48 Not tainted
--------------------------------------------
kworker/u24:0/7 is trying to acquire lock:
ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
but task is already holding lock:
ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(sb_internal#2);
lock(sb_internal#2);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by kworker/u24:0/7:
#0: ffff88817b495948 ((wq_completion)btrfs-endio-write){+.+.}, at: process_one_work+0x557/0xb80
#1: ffff888189ea7db8 ((work_completion)(&work->normal_work)){+.+.}, at: process_one_work+0x557/0xb80
#2: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
#3: ffff888174ca4da8 (&fs_info->reloc_mutex){+.+.}, at: btrfs_record_root_in_trans+0x83/0xd0 [btrfs]
stack backtrace:
CPU: 0 PID: 7 Comm: kworker/u24:0 Not tainted 5.6.0-rc7-custom+ #48
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
Call Trace:
dump_stack+0xc2/0x11a
__lock_acquire.cold+0xce/0x214
lock_acquire+0xe6/0x210
__sb_start_write+0x14e/0x290
start_transaction+0x66c/0x890 [btrfs]
btrfs_join_transaction+0x1d/0x20 [btrfs]
find_free_extent+0x1504/0x1a50 [btrfs]
btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
btrfs_alloc_tree_block+0x1ac/0x570 [btrfs]
btrfs_copy_root+0x213/0x580 [btrfs]
create_reloc_root+0x3bd/0x470 [btrfs]
btrfs_init_reloc_root+0x2d2/0x310 [btrfs]
record_root_in_trans+0x191/0x1d0 [btrfs]
btrfs_record_root_in_trans+0x90/0xd0 [btrfs]
start_transaction+0x16e/0x890 [btrfs]
btrfs_join_transaction+0x1d/0x20 [btrfs]
btrfs_finish_ordered_io+0x55d/0xcd0 [btrfs]
finish_ordered_fn+0x15/0x20 [btrfs]
btrfs_work_helper+0x116/0x9a0 [btrfs]
process_one_work+0x632/0xb80
worker_thread+0x80/0x690
kthread+0x1a3/0x1f0
ret_from_fork+0x27/0x50
It's pretty hard to reproduce, only one hit so far.
[CAUSE]
This is because we're calling btrfs_join_transaction() without re-using
the current running one:
btrfs_finish_ordered_io()
|- btrfs_join_transaction() <<< Call #1
|- btrfs_record_root_in_trans()
|- btrfs_reserve_extent()
|- btrfs_join_transaction() <<< Call #2
Normally such btrfs_join_transaction() call should re-use the existing
one, without trying to re-start a transaction.
But the problem is, in btrfs_join_transaction() call #1, we call
btrfs_record_root_in_trans() before initializing current::journal_info.
And in btrfs_join_transaction() call #2, we're relying on
current::journal_info to avoid such deadlock.
[FIX]
Call btrfs_record_root_in_trans() after we have initialized
current::journal_info.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f135cea30de5f74d5bfb5116682073841fb4af8f upstream.
When we have an inode with a prealloc extent that starts at an offset
lower than the i_size and there is another prealloc extent that starts at
an offset beyond i_size, we can end up losing part of the first prealloc
extent (the part that starts at i_size) and have an implicit hole if we
fsync the file and then have a power failure.
Consider the following example with comments explaining how and why it
happens.
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
# Create our test file with 2 consecutive prealloc extents, each with a
# size of 128Kb, and covering the range from 0 to 256Kb, with a file
# size of 0.
$ xfs_io -f -c "falloc -k 0 128K" /mnt/foo
$ xfs_io -c "falloc -k 128K 128K" /mnt/foo
# Fsync the file to record both extents in the log tree.
$ xfs_io -c "fsync" /mnt/foo
# Now do a redudant extent allocation for the range from 0 to 64Kb.
# This will merely increase the file size from 0 to 64Kb. Instead we
# could also do a truncate to set the file size to 64Kb.
$ xfs_io -c "falloc 0 64K" /mnt/foo
# Fsync the file, so we update the inode item in the log tree with the
# new file size (64Kb). This also ends up setting the number of bytes
# for the first prealloc extent to 64Kb. This is done by the truncation
# at btrfs_log_prealloc_extents().
# This means that if a power failure happens after this, a write into
# the file range 64Kb to 128Kb will not use the prealloc extent and
# will result in allocation of a new extent.
$ xfs_io -c "fsync" /mnt/foo
# Now set the file size to 256K with a truncate and then fsync the file.
# Since no changes happened to the extents, the fsync only updates the
# i_size in the inode item at the log tree. This results in an implicit
# hole for the file range from 64Kb to 128Kb, something which fsck will
# complain when not using the NO_HOLES feature if we replay the log
# after a power failure.
$ xfs_io -c "truncate 256K" -c "fsync" /mnt/foo
So instead of always truncating the log to the inode's current i_size at
btrfs_log_prealloc_extents(), check first if there's a prealloc extent
that starts at an offset lower than the i_size and with a length that
crosses the i_size - if there is one, just make sure we truncate to a
size that corresponds to the end offset of that prealloc extent, so
that we don't lose the part of that extent that starts at i_size if a
power failure happens.
A test case for fstests follows soon.
Fixes: 31d11b83b96f ("Btrfs: fix duplicate extents after fsync of file with prealloc extents")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f6033c5e333238f299c3ae03fac8cc1365b23b77 upstream.
btrfs_remove_block_group() invokes btrfs_lookup_block_group(), which
returns a local reference of the block group that contains the given
bytenr to "block_group" with increased refcount.
When btrfs_remove_block_group() returns, "block_group" becomes invalid,
so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in several exception handling paths
of btrfs_remove_block_group(). When those error scenarios occur such as
btrfs_alloc_path() returns NULL, the function forgets to decrease its
refcnt increased by btrfs_lookup_block_group() and will cause a refcnt
leak.
Fix this issue by jumping to "out_put_group" label and calling
btrfs_put_block_group() when those error scenarios occur.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1402d17dfd9657be0da8458b2079d03c2d61c86a upstream.
btrfs_recover_relocation() invokes btrfs_join_transaction(), which joins
a btrfs_trans_handle object into transactions and returns a reference of
it with increased refcount to "trans".
When btrfs_recover_relocation() returns, "trans" becomes invalid, so the
refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
btrfs_recover_relocation(). When read_fs_root() failed, the refcnt
increased by btrfs_join_transaction() is not decreased, causing a refcnt
leak.
Fix this issue by calling btrfs_end_transaction() on this error path
when read_fs_root() failed.
Fixes: 79787eaab461 ("btrfs: replace many BUG_ONs with proper error handling")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 29566c9c773456467933ee22bbca1c2b72a3506c ]
The space_info list is normally RCU protected and should be traversed
with rcu_read_lock held. There's a warning
[29.104756] WARNING: suspicious RCU usage
[29.105046] 5.6.0-rc4-next-20200305 #1 Not tainted
[29.105231] -----------------------------
[29.105401] fs/btrfs/block-group.c:2011 RCU-list traversed in non-reader section!!
pointing out that the locking is missing in btrfs_read_block_groups.
However this is not necessary as the list traversal happens at mount
time when there's no other thread potentially accessing the list.
To fix the warning and for consistency let's add the RCU lock/unlock,
the code won't be affected much as it's doing some lightweight
operations.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4d4225fc228e46948486d8b8207955f0c031b92e upstream.
Previously we would set the reloc root's last snapshot to transid - 1.
However there was a problem with doing this, and we changed it to
setting the last snapshot to the generation of the commit node of the fs
root.
This however broke should_ignore_root(). The assumption is that if we
are in a generation newer than when the reloc root was created, then we
would find the reloc root through normal backref lookups, and thus can
ignore any fs roots we find with an old enough reloc root.
Now that the last snapshot could be considerably further in the past
than before, we'd end up incorrectly ignoring an fs root. Thus we'd
find no nodes for the bytenr we were searching for, and we'd fail to
relocate anything. We'd loop through the relocate code again and see
that there were still used space in that block group, attempt to
relocate those bytenr's again, fail in the same way, and just loop like
this forever. This is tricky in that we have to not modify the fs root
at all during this time, so we need to have a block group that has data
in this fs root that is not shared by any other root, which is why this
has been difficult to reproduce.
Fixes: 054570a1dc94 ("Btrfs: fix relocation incorrectly dropping data references")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6ff06729c22ec0b7498d900d79cc88cfb8aceaeb upstream.
Ordered ops are started twice in sync file, once outside of inode mutex
and once inside, taking the dio semaphore. There was one error path
missing the semaphore unlock.
Fixes: aab15e8ec2576 ("Btrfs: fix rare chances for data loss when doing a fast fsync")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[ add changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fb2d83eefef4e1c717205bac71cb1941edf8ae11 upstream.
If we fail to load an fs root, or fail to start a transaction we can
bail without unsetting the reloc control, which leads to problems later
when we free the reloc control but still have it attached to the file
system.
In the normal path we'll end up calling unset_reloc_control() twice, but
all it does is set fs_info->reloc_control = NULL, and we can only have
one balance at a time so it's not racey.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 95418ed1d10774cd9a49af6f39e216c1256f1eeb upstream.
When doing a fast fsync for a range that starts at an offset greater than
zero, we can end up with a log that when replayed causes the respective
inode miss a file extent item representing a hole if we are not using the
NO_HOLES feature. This is because for fast fsyncs we don't log any extents
that cover a range different from the one requested in the fsync.
Example scenario to trigger it:
$ mkfs.btrfs -O ^no-holes -f /dev/sdd
$ mount /dev/sdd /mnt
# Create a file with a single 256K and fsync it to clear to full sync
# bit in the inode - we want the msync below to trigger a fast fsync.
$ xfs_io -f -c "pwrite -S 0xab 0 256K" -c "fsync" /mnt/foo
# Force a transaction commit and wipe out the log tree.
$ sync
# Dirty 768K of data, increasing the file size to 1Mb, and flush only
# the range from 256K to 512K without updating the log tree
# (sync_file_range() does not trigger fsync, it only starts writeback
# and waits for it to finish).
$ xfs_io -c "pwrite -S 0xcd 256K 768K" /mnt/foo
$ xfs_io -c "sync_range -abw 256K 256K" /mnt/foo
# Now dirty the range from 768K to 1M again and sync that range.
$ xfs_io -c "mmap -w 768K 256K" \
-c "mwrite -S 0xef 768K 256K" \
-c "msync -s 768K 256K" \
-c "munmap" \
/mnt/foo
<power fail>
# Mount to replay the log.
$ mount /dev/sdd /mnt
$ umount /mnt
$ btrfs check /dev/sdd
Opening filesystem to check...
Checking filesystem on /dev/sdd
UUID: 482fb574-b288-478e-a190-a9c44a78fca6
[1/7] checking root items
[2/7] checking extents
[3/7] checking free space cache
[4/7] checking fs roots
root 5 inode 257 errors 100, file extent discount
Found file extent holes:
start: 262144, len: 524288
ERROR: errors found in fs roots
found 720896 bytes used, error(s) found
total csum bytes: 512
total tree bytes: 131072
total fs tree bytes: 32768
total extent tree bytes: 16384
btree space waste bytes: 123514
file data blocks allocated: 589824
referenced 589824
Fix this issue by setting the range to full (0 to LLONG_MAX) when the
NO_HOLES feature is not enabled. This results in extra work being done
but it gives the guarantee we don't end up with missing holes after
replaying the log.
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8e19c9732ad1d127b5575a10f4fbcacf740500ff upstream.
If we have an error while building the backref tree in relocation we'll
process all the pending edges and then free the node. However if we
integrated some edges into the cache we'll lose our link to those edges
by simply freeing this node, which means we'll leak memory and
references to any roots that we've found.
Instead we need to use remove_backref_node(), which walks through all of
the edges that are still linked to this node and free's them up and
drops any root references we may be holding.
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 75ec1db8717a8f0a9d9c8d033e542fdaa7b73898 upstream.
In my EIO stress testing I noticed I was getting forced to rescan the
uuid tree pretty often, which was weird. This is because my error
injection stuff would sometimes inject an error after log replay but
before we loaded the UUID tree. If log replay committed the transaction
it wouldn't have updated the uuid tree generation, but the tree was
valid and didn't change, so there's no reason to not update the
generation here.
Fix this by setting the BTRFS_FS_UPDATE_UUID_TREE_GEN bit immediately
after reading all the fs roots if the uuid tree generation matches the
fs generation. Then any transaction commits that happen during mount
won't screw up our uuid tree state, forcing us to do needless uuid
rescans.
Fixes: 70f801754728 ("Btrfs: check UUID tree during mount if required")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6217b0fadd4473a16fabc6aecd7527a9f71af534 upstream.
If we do merge_reloc_roots() we could insert a few roots onto the dirty
subvol roots list, where we hold a ref on them. If we fail to start the
transaction we need to run clean_dirty_subvols() in order to cleanup the
refs.
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f0cc2cd70164efe8f75c5d99560f0f69969c72e4 upstream.
During unmount we can have a job from the delayed inode items work queue
still running, that can lead to at least two bad things:
1) A crash, because the worker can try to create a transaction just
after the fs roots were freed;
2) A transaction leak, because the worker can create a transaction
before the fs roots are freed and just after we committed the last
transaction and after we stopped the transaction kthread.
A stack trace example of the crash:
[79011.691214] kernel BUG at lib/radix-tree.c:982!
[79011.692056] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
[79011.693180] CPU: 3 PID: 1394 Comm: kworker/u8:2 Tainted: G W 5.6.0-rc2-btrfs-next-54 #2
(...)
[79011.696789] Workqueue: btrfs-delayed-meta btrfs_work_helper [btrfs]
[79011.697904] RIP: 0010:radix_tree_tag_set+0xe7/0x170
(...)
[79011.702014] RSP: 0018:ffffb3c84a317ca0 EFLAGS: 00010293
[79011.702949] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[79011.704202] RDX: ffffb3c84a317cb0 RSI: ffffb3c84a317ca8 RDI: ffff8db3931340a0
[79011.705463] RBP: 0000000000000005 R08: 0000000000000005 R09: ffffffff974629d0
[79011.706756] R10: ffffb3c84a317bc0 R11: 0000000000000001 R12: ffff8db393134000
[79011.708010] R13: ffff8db3931340a0 R14: ffff8db393134068 R15: 0000000000000001
[79011.709270] FS: 0000000000000000(0000) GS:ffff8db3b6a00000(0000) knlGS:0000000000000000
[79011.710699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[79011.711710] CR2: 00007f22c2a0a000 CR3: 0000000232ad4005 CR4: 00000000003606e0
[79011.712958] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[79011.714205] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[79011.715448] Call Trace:
[79011.715925] record_root_in_trans+0x72/0xf0 [btrfs]
[79011.716819] btrfs_record_root_in_trans+0x4b/0x70 [btrfs]
[79011.717925] start_transaction+0xdd/0x5c0 [btrfs]
[79011.718829] btrfs_async_run_delayed_root+0x17e/0x2b0 [btrfs]
[79011.719915] btrfs_work_helper+0xaa/0x720 [btrfs]
[79011.720773] process_one_work+0x26d/0x6a0
[79011.721497] worker_thread+0x4f/0x3e0
[79011.722153] ? process_one_work+0x6a0/0x6a0
[79011.722901] kthread+0x103/0x140
[79011.723481] ? kthread_create_worker_on_cpu+0x70/0x70
[79011.724379] ret_from_fork+0x3a/0x50
(...)
The following diagram shows a sequence of steps that lead to the crash
during ummount of the filesystem:
CPU 1 CPU 2 CPU 3
btrfs_punch_hole()
btrfs_btree_balance_dirty()
btrfs_balance_delayed_items()
--> sees
fs_info->delayed_root->items
with value 200, which is greater
than
BTRFS_DELAYED_BACKGROUND (128)
and smaller than
BTRFS_DELAYED_WRITEBACK (512)
btrfs_wq_run_delayed_node()
--> queues a job for
fs_info->delayed_workers to run
btrfs_async_run_delayed_root()
btrfs_async_run_delayed_root()
--> job queued by CPU 1
--> starts picking and running
delayed nodes from the
prepare_list list
close_ctree()
btrfs_delete_unused_bgs()
btrfs_commit_super()
btrfs_join_transaction()
--> gets transaction N
btrfs_commit_transaction(N)
--> set transaction state
to TRANTS_STATE_COMMIT_START
btrfs_first_prepared_delayed_node()
--> picks delayed node X through
the prepared_list list
btrfs_run_delayed_items()
btrfs_first_delayed_node()
--> also picks delayed node X
but through the node_list
list
__btrfs_commit_inode_delayed_items()
--> runs all delayed items from
this node and drops the
node's item count to 0
through call to
btrfs_release_delayed_inode()
--> finishes running any remaining
delayed nodes
--> finishes transaction commit
--> stops cleaner and transaction threads
btrfs_free_fs_roots()
--> frees all roots and removes them
from the radix tree
fs_info->fs_roots_radix
btrfs_join_transaction()
start_transaction()
btrfs_record_root_in_trans()
record_root_in_trans()
radix_tree_tag_set()
--> crashes because
the root is not in
the radix tree
anymore
If the worker is able to call btrfs_join_transaction() before the unmount
task frees the fs roots, we end up leaking a transaction and all its
resources, since after the call to btrfs_commit_super() and stopping the
transaction kthread, we don't expect to have any transaction open anymore.
When this situation happens the worker has a delayed node that has no
more items to run, since the task calling btrfs_run_delayed_items(),
which is doing a transaction commit, picks the same node and runs all
its items first.
We can not wait for the worker to complete when running delayed items
through btrfs_run_delayed_items(), because we call that function in
several phases of a transaction commit, and that could cause a deadlock
because the worker calls btrfs_join_transaction() and the task doing the
transaction commit may have already set the transaction state to
TRANS_STATE_COMMIT_DOING.
Also it's not possible to get into a situation where only some of the
items of a delayed node are added to the fs/subvolume tree in the current
transaction and the remaining ones in the next transaction, because when
running the items of a delayed inode we lock its mutex, effectively
waiting for the worker if the worker is running the items of the delayed
node already.
Since this can only cause issues when unmounting a filesystem, fix it in
a simple way by waiting for any jobs on the delayed workers queue before
calling btrfs_commit_supper() at close_ctree(). This works because at this
point no one can call btrfs_btree_balance_dirty() or
btrfs_balance_delayed_items(), and if we end up waiting for any worker to
complete, btrfs_commit_super() will commit the transaction created by the
worker.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b3ff8f1d380e65dddd772542aa9bff6c86bf715a upstream.
[BUG]
There is a fuzzed image which could cause KASAN report at unmount time.
BUG: KASAN: use-after-free in btrfs_queue_work+0x2c1/0x390
Read of size 8 at addr ffff888067cf6848 by task umount/1922
CPU: 0 PID: 1922 Comm: umount Tainted: G W 5.0.21 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
dump_stack+0x5b/0x8b
print_address_description+0x70/0x280
kasan_report+0x13a/0x19b
btrfs_queue_work+0x2c1/0x390
btrfs_wq_submit_bio+0x1cd/0x240
btree_submit_bio_hook+0x18c/0x2a0
submit_one_bio+0x1be/0x320
flush_write_bio.isra.41+0x2c/0x70
btree_write_cache_pages+0x3bb/0x7f0
do_writepages+0x5c/0x130
__writeback_single_inode+0xa3/0x9a0
writeback_single_inode+0x23d/0x390
write_inode_now+0x1b5/0x280
iput+0x2ef/0x600
close_ctree+0x341/0x750
generic_shutdown_super+0x126/0x370
kill_anon_super+0x31/0x50
btrfs_kill_super+0x36/0x2b0
deactivate_locked_super+0x80/0xc0
deactivate_super+0x13c/0x150
cleanup_mnt+0x9a/0x130
task_work_run+0x11a/0x1b0
exit_to_usermode_loop+0x107/0x130
do_syscall_64+0x1e5/0x280
entry_SYSCALL_64_after_hwframe+0x44/0xa9
[CAUSE]
The fuzzed image has a completely screwd up extent tree:
leaf 29421568 gen 8 total ptrs 6 free space 3587 owner EXTENT_TREE
refs 2 lock (w:0 r:0 bw:0 br:0 sw:0 sr:0) lock_owner 0 current 5938
item 0 key (12587008 168 4096) itemoff 3942 itemsize 53
extent refs 1 gen 9 flags 1
ref#0: extent data backref root 5 objectid 259 offset 0 count 1
item 1 key (12591104 168 8192) itemoff 3889 itemsize 53
extent refs 1 gen 9 flags 1
ref#0: extent data backref root 5 objectid 271 offset 0 count 1
item 2 key (12599296 168 4096) itemoff 3836 itemsize 53
extent refs 1 gen 9 flags 1
ref#0: extent data backref root 5 objectid 259 offset 4096 count 1
item 3 key (29360128 169 0) itemoff 3803 itemsize 33
extent refs 1 gen 9 flags 2
ref#0: tree block backref root 5
item 4 key (29368320 169 1) itemoff 3770 itemsize 33
extent refs 1 gen 9 flags 2
ref#0: tree block backref root 5
item 5 key (29372416 169 0) itemoff 3737 itemsize 33
extent refs 1 gen 9 flags 2
ref#0: tree block backref root 5
Note that leaf 29421568 doesn't have its backref in the extent tree.
Thus extent allocator can re-allocate leaf 29421568 for other trees.
In short, the bug is caused by:
- Existing tree block gets allocated to log tree
This got its generation bumped.
- Log tree balance cleaned dirty bit of offending tree block
It will not be written back to disk, thus no WRITTEN flag.
- Original owner of the tree block gets COWed
Since the tree block has higher transid, no WRITTEN flag, it's reused,
and not traced by transaction::dirty_pages.
- Transaction aborted
Tree blocks get cleaned according to transaction::dirty_pages. But the
offending tree block is not recorded at all.
- Filesystem unmount
All pages are assumed to be are clean, destroying all workqueue, then
call iput(btree_inode).
But offending tree block is still dirty, which triggers writeback, and
causes use-after-free bug.
The detailed sequence looks like this:
- Initial status
eb: 29421568, header=WRITTEN bflags_dirty=0, page_dirty=0, gen=8,
not traced by any dirty extent_iot_tree.
- New tree block is allocated
Since there is no backref for 29421568, it's re-allocated as new tree
block.
Keep in mind that tree block 29421568 is still referred by extent
tree.
- Tree block 29421568 is filled for log tree
eb: 29421568, header=0 bflags_dirty=1, page_dirty=1, gen=9 << (gen bumped)
traced by btrfs_root::dirty_log_pages
- Some log tree operations
Since the fs is using node size 4096, the log tree can easily go a
level higher.
- Log tree needs balance
Tree block 29421568 gets all its content pushed to right, thus now
it is empty, and we don't need it.
btrfs_clean_tree_block() from __push_leaf_right() get called.
eb: 29421568, header=0 bflags_dirty=0, page_dirty=0, gen=9
traced by btrfs_root::dirty_log_pages
- Log tree write back
btree_write_cache_pages() goes through dirty pages ranges, but since
page of tree block 29421568 gets cleaned already, it's not written
back to disk. Thus it doesn't have WRITTEN bit set.
But ranges in dirty_log_pages are cleared.
eb: 29421568, header=0 bflags_dirty=0, page_dirty=0, gen=9
not traced by any dirty extent_iot_tree.
- Extent tree update when committing transaction
Since tree block 29421568 has transid equal to running trans, and has
no WRITTEN bit, should_cow_block() will use it directly without adding
it to btrfs_transaction::dirty_pages.
eb: 29421568, header=0 bflags_dirty=1, page_dirty=1, gen=9
not traced by any dirty extent_iot_tree.
At this stage, we're doomed. We have a dirty eb not tracked by any
extent io tree.
- Transaction gets aborted due to corrupted extent tree
Btrfs cleans up dirty pages according to transaction::dirty_pages and
btrfs_root::dirty_log_pages.
But since tree block 29421568 is not tracked by neither of them, it's
still dirty.
eb: 29421568, header=0 bflags_dirty=1, page_dirty=1, gen=9
not traced by any dirty extent_iot_tree.
- Filesystem unmount
Since all cleanup is assumed to be done, all workqueus are destroyed.
Then iput(btree_inode) is called, expecting no dirty pages.
But tree 29421568 is still dirty, thus triggering writeback.
Since all workqueues are already freed, we cause use-after-free.
This shows us that, log tree blocks + bad extent tree can cause wild
dirty pages.
[FIX]
To fix the problem, don't submit any btree write bio if the filesytem
has any error. This is the last safe net, just in case other cleanup
haven't caught catch it.
Link: https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19377
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ea287ab157c2816bf12aad4cece41372f9d146b4 ]
We always search the commit root of the extent tree for looking up back
references, however we track the reloc roots based on their current
bytenr.
This is wrong, if we commit the transaction between relocating tree
blocks we could end up in this code in build_backref_tree
if (key.objectid == key.offset) {
/*
* Only root blocks of reloc trees use backref
* pointing to itself.
*/
root = find_reloc_root(rc, cur->bytenr);
ASSERT(root);
cur->root = root;
break;
}
find_reloc_root() is looking based on the bytenr we had in the commit
root, but if we've COWed this reloc root we will not find that bytenr,
and we will trip over the ASSERT(root).
Fix this by using the commit_root->start bytenr for indexing the commit
root. Then we change the __update_reloc_root() caller to be used when
we switch the commit root for the reloc root during commit.
This fixes the panic I was seeing when we started throttling relocation
for delayed refs.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 50dbbb71c79df89532ec41d118d59386e5a877e3 ]
There are two bugs here, but fixing them independently would just result
in pain if you happened to bisect between the two patches.
First is how we handle the -EAGAIN from relocate_tree_block(). We don't
set error, unless we happen to be the first node, which makes no sense,
I have no idea what the code was trying to accomplish here.
We in fact _do_ want err set here so that we know we need to restart in
relocate_block_group(). Also we need finish_pending_nodes() to not
actually call link_to_upper(), because we didn't actually relocate the
block.
And then if we do get -EAGAIN we do not want to set our backref cache
last_trans to the one before ours. This would force us to update our
backref cache if we didn't cross transaction ids, which would mean we'd
have some nodes updated to their new_bytenr, but still able to find
their old bytenr because we're searching the same commit root as the
last time we went through relocate_tree_blocks.
Fixing these two things keeps us from panicing when we start breaking
out of relocate_tree_blocks() either for delayed ref flushing or enospc.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7b7b74315b24dc064bc1c683659061c3d48f8668 ]
This was pretty subtle, we default to reloc roots having 0 root refs, so
if we crash in the middle of the relocation they can just be deleted.
If we successfully complete the relocation operations we'll set our root
refs to 1 in prepare_to_merge() and then go on to merge_reloc_roots().
At prepare_to_merge() time if any of the reloc roots have a 0 reference
still, we will remove that reloc root from our reloc root rb tree, and
then clean it up later.
However this only happens if we successfully start a transaction. If
we've aborted previously we will skip this step completely, and only
have reloc roots with a reference count of 0, but were never properly
removed from the reloc control's rb tree.
This isn't a problem per-se, our references are held by the list the
reloc roots are on, and by the original root the reloc root belongs to.
If we end up in this situation all the reloc roots will be added to the
dirty_reloc_list, and then properly dropped at that point. The reloc
control will be free'd and the rb tree is no longer used.
There were two options when fixing this, one was to remove the BUG_ON(),
the other was to make prepare_to_merge() handle the case where we
couldn't start a trans handle.
IMO this is the cleaner solution. I started with handling the error in
prepare_to_merge(), but it turned out super ugly. And in the end this
BUG_ON() simply doesn't matter, the cleanup was happening properly, we
were just panicing because this BUG_ON() only matters in the success
case. So I've opted to just remove it and add a comment where it was.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d61acbbf54c612ea9bf67eed609494cda0857b3a ]
[BUG]
There are some reports about btrfs wait forever to unmount itself, with
the following call trace:
INFO: task umount:4631 blocked for more than 491 seconds.
Tainted: G X 5.3.8-2-default #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
umount D 0 4631 3337 0x00000000
Call Trace:
([<00000000174adf7a>] __schedule+0x342/0x748)
[<00000000174ae3ca>] schedule+0x4a/0xd8
[<00000000174b1f08>] schedule_timeout+0x218/0x420
[<00000000174af10c>] wait_for_common+0x104/0x1d8
[<000003ff804d6994>] btrfs_qgroup_wait_for_completion+0x84/0xb0 [btrfs]
[<000003ff8044a616>] close_ctree+0x4e/0x380 [btrfs]
[<0000000016fa3136>] generic_shutdown_super+0x8e/0x158
[<0000000016fa34d6>] kill_anon_super+0x26/0x40
[<000003ff8041ba88>] btrfs_kill_super+0x28/0xc8 [btrfs]
[<0000000016fa39f8>] deactivate_locked_super+0x68/0x98
[<0000000016fcb198>] cleanup_mnt+0xc0/0x140
[<0000000016d6a846>] task_work_run+0xc6/0x110
[<0000000016d04f76>] do_notify_resume+0xae/0xb8
[<00000000174b30ae>] system_call+0xe2/0x2c8
[CAUSE]
The problem happens when we have called qgroup_rescan_init(), but
not queued the worker. It can be caused mostly by error handling.
Qgroup ioctl thread | Unmount thread
----------------------------------------+-----------------------------------
|
btrfs_qgroup_rescan() |
|- qgroup_rescan_init() |
| |- qgroup_rescan_running = true; |
| |
|- trans = btrfs_join_transaction() |
| Some error happened |
| |
|- btrfs_qgroup_rescan() returns error |
But qgroup_rescan_running == true; |
| close_ctree()
| |- btrfs_qgroup_wait_for_completion()
| |- running == true;
| |- wait_for_completion();
btrfs_qgroup_rescan_worker is never queued, thus no one is going to wake
up close_ctree() and we get a deadlock.
All involved qgroup_rescan_init() callers are:
- btrfs_qgroup_rescan()
The example above. It's possible to trigger the deadlock when error
happened.
- btrfs_quota_enable()
Not possible. Just after qgroup_rescan_init() we queue the work.
- btrfs_read_qgroup_config()
It's possible to trigger the deadlock. It only init the work, the
work queueing happens in btrfs_qgroup_rescan_resume().
Thus if error happened in between, deadlock is possible.
We shouldn't set fs_info->qgroup_rescan_running just in
qgroup_rescan_init(), as at that stage we haven't yet queued qgroup
rescan worker to run.
[FIX]
Set qgroup_rescan_running before queueing the work, so that we ensure
the rescan work is queued when we wait for it.
Fixes: 8d9eddad1946 ("Btrfs: fix qgroup rescan worker initialization")
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
[ Change subject and cause analyse, use a smaller fix ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 236ebc20d9afc5e9ff52f3cf3f365a91583aac10 upstream.
During a rename whiteout, if btrfs_whiteout_for_rename() returns an error
we can end up returning from btrfs_rename() with the log context object
still in the root's log context list - this happens if 'sync_log' was
set to true before we called btrfs_whiteout_for_rename() and it is
dangerous because we end up with a corrupt linked list (root->log_ctxs)
as the log context object was allocated on the stack.
After btrfs_rename() returns, any task that is running btrfs_sync_log()
concurrently can end up crashing because that linked list is traversed by
btrfs_sync_log() (through btrfs_remove_all_log_ctxs()). That results in
the same issue that commit e6c617102c7e4 ("Btrfs: fix log context list
corruption after rename exchange operation") fixed.
Fixes: d4682ba03ef618 ("Btrfs: sync log after logging new name")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e7a04894c766daa4248cb736efee93550f2d5872 upstream.
btrfs_lookup_and_bind_dio_csum() does pointer arithmetic which assumes
32-bit checksums. If using a larger checksum, this leads to spurious
failures when a direct I/O read crosses a stripe. This is easy
to reproduce:
# mkfs.btrfs -f --checksum blake2 -d raid0 /dev/vdc /dev/vdd
...
# mount /dev/vdc /mnt
# cd /mnt
# dd if=/dev/urandom of=foo bs=1M count=1 status=none
# dd if=foo of=/dev/null bs=1M iflag=direct status=none
dd: error reading 'foo': Input/output error
# dmesg | tail -1
[ 135.821568] BTRFS warning (device vdc): csum failed root 5 ino 257 off 421888 ...
Fix it by using the actual checksum size.
Fixes: 1e25a2e3ca0d ("btrfs: don't assume ordered sums to be 4 bytes")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a5ae50dea9111db63d30d700766dd5509602f7ad upstream.
While logging the prealloc extents of an inode during a fast fsync we call
btrfs_truncate_inode_items(), through btrfs_log_prealloc_extents(), while
holding a read lock on a leaf of the inode's root (not the log root, the
fs/subvol root), and then that function locks the file range in the inode's
iotree. This can lead to a deadlock when:
* the fsync is ranged
* the file has prealloc extents beyond eof
* writeback for a range different from the fsync range starts
during the fsync
* the size of the file is not sector size aligned
Because when finishing an ordered extent we lock first a file range and
then try to COW the fs/subvol tree to insert an extent item.
The following diagram shows how the deadlock can happen.
CPU 1 CPU 2
btrfs_sync_file()
--> for range [0, 1MiB)
--> inode has a size of
1MiB and has 1 prealloc
extent beyond the
i_size, starting at offset
4MiB
flushes all delalloc for the
range [0MiB, 1MiB) and waits
for the respective ordered
extents to complete
--> before task at CPU 1 locks the
inode, a write into file range
[1MiB, 2MiB + 1KiB) is made
--> i_size is updated to 2MiB + 1KiB
--> writeback is started for that
range, [1MiB, 2MiB + 4KiB)
--> end offset rounded up to
be sector size aligned
btrfs_log_dentry_safe()
btrfs_log_inode_parent()
btrfs_log_inode()
btrfs_log_changed_extents()
btrfs_log_prealloc_extents()
--> does a search on the
inode's root
--> holds a read lock on
leaf X
btrfs_finish_ordered_io()
--> locks range [1MiB, 2MiB + 4KiB)
--> end offset rounded up
to be sector size aligned
--> tries to cow leaf X, through
insert_reserved_file_extent()
--> already locked by the
task at CPU 1
btrfs_truncate_inode_items()
--> gets an i_size of
2MiB + 1KiB, which is
not sector size
aligned
--> tries to lock file
range [2MiB, (u64)-1)
--> the start range
is rounded down
from 2MiB + 1K
to 2MiB to be sector
size aligned
--> but the subrange
[2MiB, 2MiB + 4KiB) is
already locked by
task at CPU 2 which
is waiting to get a
write lock on leaf X
for which we are
holding a read lock
*** deadlock ***
This results in a stack trace like the following, triggered by test case
generic/561 from fstests:
[ 2779.973608] INFO: task kworker/u8:6:247 blocked for more than 120 seconds.
[ 2779.979536] Not tainted 5.6.0-rc2-btrfs-next-53 #1
[ 2779.984503] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 2779.990136] kworker/u8:6 D 0 247 2 0x80004000
[ 2779.990457] Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
[ 2779.990466] Call Trace:
[ 2779.990491] ? __schedule+0x384/0xa30
[ 2779.990521] schedule+0x33/0xe0
[ 2779.990616] btrfs_tree_read_lock+0x19e/0x2e0 [btrfs]
[ 2779.990632] ? remove_wait_queue+0x60/0x60
[ 2779.990730] btrfs_read_lock_root_node+0x2f/0x40 [btrfs]
[ 2779.990782] btrfs_search_slot+0x510/0x1000 [btrfs]
[ 2779.990869] btrfs_lookup_file_extent+0x4a/0x70 [btrfs]
[ 2779.990944] __btrfs_drop_extents+0x161/0x1060 [btrfs]
[ 2779.990987] ? mark_held_locks+0x6d/0xc0
[ 2779.990994] ? __slab_alloc.isra.49+0x99/0x100
[ 2779.991060] ? insert_reserved_file_extent.constprop.19+0x64/0x300 [btrfs]
[ 2779.991145] insert_reserved_file_extent.constprop.19+0x97/0x300 [btrfs]
[ 2779.991222] ? start_transaction+0xdd/0x5c0 [btrfs]
[ 2779.991291] btrfs_finish_ordered_io+0x4f4/0x840 [btrfs]
[ 2779.991405] btrfs_work_helper+0xaa/0x720 [btrfs]
[ 2779.991432] process_one_work+0x26d/0x6a0
[ 2779.991460] worker_thread+0x4f/0x3e0
[ 2779.991481] ? process_one_work+0x6a0/0x6a0
[ 2779.991489] kthread+0x103/0x140
[ 2779.991499] ? kthread_create_worker_on_cpu+0x70/0x70
[ 2779.991515] ret_from_fork+0x3a/0x50
(...)
[ 2780.026211] INFO: task fsstress:17375 blocked for more than 120 seconds.
[ 2780.027480] Not tainted 5.6.0-rc2-btrfs-next-53 #1
[ 2780.028482] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 2780.030035] fsstress D 0 17375 17373 0x00004000
[ 2780.030038] Call Trace:
[ 2780.030044] ? __schedule+0x384/0xa30
[ 2780.030052] schedule+0x33/0xe0
[ 2780.030075] lock_extent_bits+0x20c/0x320 [btrfs]
[ 2780.030094] ? btrfs_truncate_inode_items+0xf4/0x1150 [btrfs]
[ 2780.030098] ? rcu_read_lock_sched_held+0x59/0xa0
[ 2780.030102] ? remove_wait_queue+0x60/0x60
[ 2780.030122] btrfs_truncate_inode_items+0x133/0x1150 [btrfs]
[ 2780.030151] ? btrfs_set_path_blocking+0xb2/0x160 [btrfs]
[ 2780.030165] ? btrfs_search_slot+0x379/0x1000 [btrfs]
[ 2780.030195] btrfs_log_changed_extents.isra.8+0x841/0x93e [btrfs]
[ 2780.030202] ? do_raw_spin_unlock+0x49/0xc0
[ 2780.030215] ? btrfs_get_num_csums+0x10/0x10 [btrfs]
[ 2780.030239] btrfs_log_inode+0xf83/0x1124 [btrfs]
[ 2780.030251] ? __mutex_unlock_slowpath+0x45/0x2a0
[ 2780.030275] btrfs_log_inode_parent+0x2a0/0xe40 [btrfs]
[ 2780.030282] ? dget_parent+0xa1/0x370
[ 2780.030309] btrfs_log_dentry_safe+0x4a/0x70 [btrfs]
[ 2780.030329] btrfs_sync_file+0x3f3/0x490 [btrfs]
[ 2780.030339] do_fsync+0x38/0x60
[ 2780.030343] __x64_sys_fdatasync+0x13/0x20
[ 2780.030345] do_syscall_64+0x5c/0x280
[ 2780.030348] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 2780.030356] RIP: 0033:0x7f2d80f6d5f0
[ 2780.030361] Code: Bad RIP value.
[ 2780.030362] RSP: 002b:00007ffdba3c8548 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
[ 2780.030364] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f2d80f6d5f0
[ 2780.030365] RDX: 00007ffdba3c84b0 RSI: 00007ffdba3c84b0 RDI: 0000000000000003
[ 2780.030367] RBP: 000000000000004a R08: 0000000000000001 R09: 00007ffdba3c855c
[ 2780.030368] R10: 0000000000000078 R11: 0000000000000246 R12: 00000000000001f4
[ 2780.030369] R13: 0000000051eb851f R14: 00007ffdba3c85f0 R15: 0000557a49220d90
So fix this by making btrfs_truncate_inode_items() not lock the range in
the inode's iotree when the target root is a log root, since it's not
needed to lock the range for log roots as the protection from the inode's
lock and log_mutex are all that's needed.
Fixes: 28553fa992cb28 ("Btrfs: fix race between shrinking truncate and fiemap")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 52e29e331070cd7d52a64cbf1b0958212a340e28 upstream.
The only time we actually leave the path spinning is if we're truncating
a small amount and don't actually free an extent, which is not a common
occurrence. We have to set the path blocking in order to add the
delayed ref anyway, so the first extent we find we set the path to
blocking and stay blocking for the duration of the operation. With the
upcoming file extent map stuff there will be another case that we have
to have the path blocking, so just swap to blocking always.
Note: this patch also fixes a warning after 28553fa992cb ("Btrfs: fix
race between shrinking truncate and fiemap") got merged that inserts
extent locks around truncation so the path must not leave spinning locks
after btrfs_search_slot.
[70.794783] BUG: sleeping function called from invalid context at mm/slab.h:565
[70.794834] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1141, name: rsync
[70.794863] 5 locks held by rsync/1141:
[70.794876] #0: ffff888417b9c408 (sb_writers#17){.+.+}, at: mnt_want_write+0x20/0x50
[70.795030] #1: ffff888428de28e8 (&type->i_mutex_dir_key#13/1){+.+.}, at: lock_rename+0xf1/0x100
[70.795051] #2: ffff888417b9c608 (sb_internal#2){.+.+}, at: start_transaction+0x394/0x560
[70.795124] #3: ffff888403081768 (btrfs-fs-01){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160
[70.795203] #4: ffff888403086568 (btrfs-fs-00){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160
[70.795222] CPU: 5 PID: 1141 Comm: rsync Not tainted 5.6.0-rc2-backup+ #2
[70.795362] Call Trace:
[70.795374] dump_stack+0x71/0xa0
[70.795445] ___might_sleep.part.96.cold.106+0xa6/0xb6
[70.795459] kmem_cache_alloc+0x1d3/0x290
[70.795471] alloc_extent_state+0x22/0x1c0
[70.795544] __clear_extent_bit+0x3ba/0x580
[70.795557] ? _raw_spin_unlock_irq+0x24/0x30
[70.795569] btrfs_truncate_inode_items+0x339/0xe50
[70.795647] btrfs_evict_inode+0x269/0x540
[70.795659] ? dput.part.38+0x29/0x460
[70.795671] evict+0xcd/0x190
[70.795682] __dentry_kill+0xd6/0x180
[70.795754] dput.part.38+0x2ad/0x460
[70.795765] do_renameat2+0x3cb/0x540
[70.795777] __x64_sys_rename+0x1c/0x20
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 28553fa992cb ("Btrfs: fix race between shrinking truncate and fiemap")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 28553fa992cb28be6a65566681aac6cafabb4f2d upstream.
When there is a fiemap executing in parallel with a shrinking truncate
we can end up in a situation where we have extent maps for which we no
longer have corresponding file extent items. This is generally harmless
and at the moment the only consequences are missing file extent items
representing holes after we expand the file size again after the
truncate operation removed the prealloc extent items, and stale
information for future fiemap calls (reporting extents that no longer
exist or may have been reallocated to other files for example).
Consider the following example:
1) Our inode has a size of 128KiB, one 128KiB extent at file offset 0
and a 1MiB prealloc extent at file offset 128KiB;
2) Task A starts doing a shrinking truncate of our inode to reduce it to
a size of 64KiB. Before it searches the subvolume tree for file
extent items to delete, it drops all the extent maps in the range
from 64KiB to (u64)-1 by calling btrfs_drop_extent_cache();
3) Task B starts doing a fiemap against our inode. When looking up for
the inode's extent maps in the range from 128KiB to (u64)-1, it
doesn't find any in the inode's extent map tree, since they were
removed by task A. Because it didn't find any in the extent map
tree, it scans the inode's subvolume tree for file extent items, and
it finds the 1MiB prealloc extent at file offset 128KiB, then it
creates an extent map based on that file extent item and adds it to
inode's extent map tree (this ends up being done by
btrfs_get_extent() <- btrfs_get_extent_fiemap() <-
get_extent_skip_holes());
4) Task A then drops the prealloc extent at file offset 128KiB and
shrinks the 128KiB extent file offset 0 to a length of 64KiB. The
truncation operation finishes and we end up with an extent map
representing a 1MiB prealloc extent at file offset 128KiB, despite we
don't have any more that extent;
After this the two types of problems we have are:
1) Future calls to fiemap always report that a 1MiB prealloc extent
exists at file offset 128KiB. This is stale information, no longer
correct;
2) If the size of the file is increased, by a truncate operation that
increases the file size or by a write into a file offset > 64KiB for
example, we end up not inserting file extent items to represent holes
for any range between 128KiB and 128KiB + 1MiB, since the hole
expansion function, btrfs_cont_expand() will skip hole insertion for
any range for which an extent map exists that represents a prealloc
extent. This causes fsck to complain about missing file extent items
when not using the NO_HOLES feature.
The second issue could be often triggered by test case generic/561 from
fstests, which runs fsstress and duperemove in parallel, and duperemove
does frequent fiemap calls.
Essentially the problems happens because fiemap does not acquire the
inode's lock while truncate does, and fiemap locks the file range in the
inode's iotree while truncate does not. So fix the issue by making
btrfs_truncate_inode_items() lock the file range from the new file size
to (u64)-1, so that it serializes with fiemap.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e75fd33b3f744f644061a4f9662bd63f5434f806 upstream.
In btrfs_wait_ordered_range() once we find an ordered extent that has
finished with an error we exit the loop and don't wait for any other
ordered extents that might be still in progress.
All the users of btrfs_wait_ordered_range() expect that there are no more
ordered extents in progress after that function returns. So past fixes
such like the ones from the two following commits:
ff612ba7849964 ("btrfs: fix panic during relocation after ENOSPC before
writeback happens")
28aeeac1dd3080 ("Btrfs: fix panic when starting bg cache writeout after
IO error")
don't work when there are multiple ordered extents in the range.
Fix that by making btrfs_wait_ordered_range() wait for all ordered extents
even after it finds one that had an error.
Link: https://github.com/kdave/btrfs-progs/issues/228#issuecomment-569777554
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1e90315149f3fe148e114a5de86f0196d1c21fa5 upstream.
btrfs_assert_delayed_root_empty() will check if the delayed root is
completely empty, but this is a filesystem-wide check. On cleanup we
may have allowed other transactions to begin, for whatever reason, and
thus the delayed root is not empty.
So remove this check from cleanup_one_transation(). This however can
stay in btrfs_cleanup_transaction(), because it checks only after all of
the transactions have been properly cleaned up, and thus is valid.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 315bf8ef914f31d51d084af950703aa1e09a728c upstream.
While running my error injection script I hit a panic when we tried to
clean up the fs_root when freeing the fs_root. This is because
fs_info->fs_root == PTR_ERR(-EIO), which isn't great. Fix this by
setting fs_info->fs_root = NULL; if we fail to read the root.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b778cf962d71a0e737923d55d0432f3bd287258e upstream.
I hit the following warning while running my error injection stress
testing:
WARNING: CPU: 3 PID: 1453 at fs/btrfs/space-info.h:108 btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs]
RIP: 0010:btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs]
Call Trace:
btrfs_free_reserved_data_space+0x4f/0x70 [btrfs]
__btrfs_prealloc_file_range+0x378/0x470 [btrfs]
elfcorehdr_read+0x40/0x40
? elfcorehdr_read+0x40/0x40
? btrfs_commit_transaction+0xca/0xa50 [btrfs]
? dput+0xb4/0x2a0
? btrfs_log_dentry_safe+0x55/0x70 [btrfs]
? btrfs_sync_file+0x30e/0x420 [btrfs]
? do_fsync+0x38/0x70
? __x64_sys_fdatasync+0x13/0x20
? do_syscall_64+0x5b/0x1b0
? entry_SYSCALL_64_after_hwframe+0x44/0xa9
This happens if we fail to insert our reserved file extent. At this
point we've already converted our reservation from ->bytes_may_use to
->bytes_reserved. However once we break we will attempt to free
everything from [cur_offset, end] from ->bytes_may_use, but our extent
reservation will overlap part of this.
Fix this problem by adding ins.offset (our extent allocation size) to
cur_offset so we remove the actual remaining part from ->bytes_may_use.
I validated this fix using my inject-error.py script
python inject-error.py -o should_fail_bio -t cache_save_setup -t \
__btrfs_prealloc_file_range \
-t insert_reserved_file_extent.constprop.0 \
-r "-5" ./run-fsstress.sh
where run-fsstress.sh simply mounts and runs fsstress on a disk.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 81f7eb00ff5bb8326e82503a32809421d14abb8a upstream.
We clean up the delayed references when we abort a transaction but we
leave the pending qgroup extent records behind, leaking memory.
This patch destroys the extent records when we destroy the delayed refs
and makes sure ensure they're gone before releasing the transaction.
Fixes: 3368d001ba5d ("btrfs: qgroup: Record possible quota-related extent for qgroup.")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
[ Rebased to latest upstream, remove to_qgroup() helper, use
rbtree_postorder_for_each_entry_safe() wrapper ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bd727173e4432fe6cb70ba108dc1f3602c5409d7 upstream.
If we're allocating a logged extent we attempt to insert an extent
record for the file extent directly. We increase
space_info->bytes_reserved, because the extent entry addition will call
btrfs_update_block_group(), which will convert the ->bytes_reserved to
->bytes_used. However if we fail at any point while inserting the
extent entry we will bail and leave space on ->bytes_reserved, which
will trigger a WARN_ON() on umount. Fix this by pinning the space if we
fail to insert, which is what happens in every other failure case that
involves adding the extent entry.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f4b1363cae43fef7c86c993b7ca7fe7d546b3c68 ]
We ran into a deadlock in production with the fixup worker. The stack
traces were as follows:
Thread responsible for the writeout, waiting on the page lock
[<0>] io_schedule+0x12/0x40
[<0>] __lock_page+0x109/0x1e0
[<0>] extent_write_cache_pages+0x206/0x360
[<0>] extent_writepages+0x40/0x60
[<0>] do_writepages+0x31/0xb0
[<0>] __writeback_single_inode+0x3d/0x350
[<0>] writeback_sb_inodes+0x19d/0x3c0
[<0>] __writeback_inodes_wb+0x5d/0xb0
[<0>] wb_writeback+0x231/0x2c0
[<0>] wb_workfn+0x308/0x3c0
[<0>] process_one_work+0x1e0/0x390
[<0>] worker_thread+0x2b/0x3c0
[<0>] kthread+0x113/0x130
[<0>] ret_from_fork+0x35/0x40
[<0>] 0xffffffffffffffff
Thread of the fixup worker who is holding the page lock
[<0>] start_delalloc_inodes+0x241/0x2d0
[<0>] btrfs_start_delalloc_roots+0x179/0x230
[<0>] btrfs_alloc_data_chunk_ondemand+0x11b/0x2e0
[<0>] btrfs_check_data_free_space+0x53/0xa0
[<0>] btrfs_delalloc_reserve_space+0x20/0x70
[<0>] btrfs_writepage_fixup_worker+0x1fc/0x2a0
[<0>] normal_work_helper+0x11c/0x360
[<0>] process_one_work+0x1e0/0x390
[<0>] worker_thread+0x2b/0x3c0
[<0>] kthread+0x113/0x130
[<0>] ret_from_fork+0x35/0x40
[<0>] 0xffffffffffffffff
Thankfully the stars have to align just right to hit this. First you
have to end up in the fixup worker, which is tricky by itself (my
reproducer does DIO reads into a MMAP'ed region, so not a common
operation). Then you have to have less than a page size of free data
space and 0 unallocated space so you go down the "commit the transaction
to free up pinned space" path. This was accomplished by a random
balance that was running on the host. Then you get this deadlock.
I'm still in the process of trying to force the deadlock to happen on
demand, but I've hit other issues. I can still trigger the fixup worker
path itself so this patch has been tested in that regard, so the normal
case is fine.
Fixes: 87826df0ec36 ("btrfs: delalloc for page dirtied out-of-band in fixup worker")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1362089d2ad7e20d16371b39d3c11990d4ec23e4 ]
Current code doesn't correctly handle the situation which arises when
a file system that has METADATA_UUID_INCOMPAT flag set and has its FSID
changed to the one in metadata uuid. This causes the incompat flag to
disappear.
In case of a power failure we could end up in a situation where part of
the disks in a multi-disk filesystem are correctly reverted to
METADATA_UUID_INCOMPAT flag unset state, while others have
METADATA_UUID_INCOMPAT set and CHANGING_FSID_V2_IN_PROGRESS.
This patch corrects the behavior required to handle the case where a
disk of the second type is scanned first, creating the necessary
btrfs_fs_devices. Subsequently, when a disk which has already completed
the transition is scanned it should overwrite the data in
btrfs_fs_devices.
Reported-by: Su Yue <Damenly_Su@gmx.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 68c467cbb2f389b6c933e235bce0d1756fc8cc34 ]
There's a report where objtool detects unreachable instructions, eg.:
fs/btrfs/ctree.o: warning: objtool: btrfs_search_slot()+0x2d4: unreachable instruction
This seems to be a false positive due to compiler version. The cause is
in the ASSERT macro implementation that does the conditional check as
IS_DEFINED(CONFIG_BTRFS_ASSERT) and not an #ifdef.
To avoid that, use the ifdefs directly.
There are still 2 reports that aren't fixed:
fs/btrfs/extent_io.o: warning: objtool: __set_extent_bit()+0x71f: unreachable instruction
fs/btrfs/relocation.o: warning: objtool: find_data_references()+0x4e0: unreachable instruction
Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a69976bc69308aa475d0ba3b8b3efd1d013c0460 ]
We had a report indicating that some read errors aren't reported by the
device stats in the userland. It is important to have the errors
reported in the device stat as user land scripts might depend on it to
take the reasonable corrective actions. But to debug these issue we need
to be really sure that request to reset the device stat did not come
from the userland itself. So log an info message when device error reset
happens.
For example:
BTRFS info (device sdc): device stats zeroed by btrfs(9223)
Reported-by: philip@philip-seeger.de
Link: https://www.spinics.net/lists/linux-btrfs/msg96528.html
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4babad10198fa73fe73239d02c2e99e3333f5f5c ]
Dan's smatch tool reports
fs/btrfs/file-item.c:295 btrfs_lookup_bio_sums()
warn: should this be 'count == -1'
which points to the while (count--) loop. With count == 0 the check
itself could decrement it to -1. There's a WARN_ON a few lines below
that has never been seen in practice though.
It turns out that the value of page_bytes_left matches the count (by
sectorsize multiples). The loop never reaches the state where count
would go to -1, because page_bytes_left == 0 is found first and this
breaks out.
For clarity, use only plain check on count (and only for positive
value), decrement safely inside the loop. Any other discrepancy after
the whole bio list processing should be reported by the exising
WARN_ON_ONCE as well.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3dbd351df42109902fbcebf27104149226a4fcd9 ]
A user reports a possible NULL-pointer dereference in
btrfsic_process_superblock(). We are assigning state->fs_info to a local
fs_info variable and afterwards checking for the presence of state.
While we would BUG_ON() a NULL state anyways, we can also just remove
the local fs_info copy, as fs_info is only used once as the first
argument for btrfs_num_copies(). There we can just pass in
state->fs_info as well.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205003
Signed-off-by: Johannes Thumshirn <jth@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 25f3c5021985e885292980d04a1423fd83c967bb ]
For COW, btrfs expects pages dirty pages to have been through a few setup
steps. This includes reserving space for the new block allocations and marking
the range in the state tree for delayed allocation.
A few places outside btrfs will dirty pages directly, especially when unmapping
mmap'd pages. In order for these to properly go through COW, we run them
through a fixup worker to wait for stable pages, and do the delalloc prep.
87826df0ec36 added a window where the dirty pages were cleaned, but pending
more action from the fixup worker. We clear_page_dirty_for_io() before
we call into writepage, so the page is no longer dirty. The commit
changed it so now we leave the page clean between unlocking it here and
the fixup worker starting at some point in the future.
During this window, page migration can jump in and relocate the page. Once our
fixup work actually starts, it finds page->mapping is NULL and we end up
freeing the page without ever writing it.
This leads to crc errors and other exciting problems, since it screws up the
whole statemachine for waiting for ordered extents. The fix here is to keep
the page dirty while we're waiting for the fixup worker to get to work.
This is accomplished by returning -EAGAIN from btrfs_writepage_cow_fixup
if we queued the page up for fixup, which will cause the writepage
function to redirty the page.
Because we now expect the page to be dirty once it gets to the fixup
worker we must adjust the error cases to call clear_page_dirty_for_io()
on the page. That is the bulk of the patch, but it is not the fix, the
fix is the -EAGAIN from btrfs_writepage_cow_fixup. We cannot separate
these two changes out because the error conditions change with the new
expectations.
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 10a3a3edc5b89a8cd095bc63495fb1e0f42047d9 upstream.
A remount to a read-write filesystem is not safe when there's tree-log
to be replayed. Files that could be opened until now might be affected
by the changes in the tree-log.
A regular mount is needed to replay the log so the filesystem presents
the consistent view with the pending changes included.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e8294f2f6aa6208ed0923aa6d70cea3be178309a upstream.
There's no logged information about tree-log replay although this is
something that points to previous unclean unmount. Other filesystems
report that as well.
Suggested-by: Chris Murphy <lists@colorremedies.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f311ade3a7adf31658ed882aaab9f9879fdccef7 upstream.
In btrfs_ref_tree_mod(), 'ref' and 'ra' are allocated through kzalloc() and
kmalloc(), respectively. In the following code, if an error occurs, the
execution will be redirected to 'out' or 'out_unlock' and the function will
be exited. However, on some of the paths, 'ref' and 'ra' are not
deallocated, leading to memory leaks. For example, if 'action' is
BTRFS_ADD_DELAYED_EXTENT, add_block_entry() will be invoked. If the return
value indicates an error, the execution will be redirected to 'out'. But,
'ref' is not deallocated on this path, causing a memory leak.
To fix the above issues, deallocate both 'ref' and 'ra' before exiting from
the function when an error is encountered.
CC: stable@vger.kernel.org # 4.15+
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ac05ca913e9f3871126d61da275bfe8516ff01ca upstream.
We have a few cases where we allow an extent map that is in an extent map
tree to be merged with other extents in the tree. Such cases include the
unpinning of an extent after the respective ordered extent completed or
after logging an extent during a fast fsync. This can lead to subtle and
dangerous problems because when doing the merge some other task might be
using the same extent map and as consequence see an inconsistent state of
the extent map - for example sees the new length but has seen the old start
offset.
With luck this triggers a BUG_ON(), and not some silent bug, such as the
following one in __do_readpage():
$ cat -n fs/btrfs/extent_io.c
3061 static int __do_readpage(struct extent_io_tree *tree,
3062 struct page *page,
(...)
3127 em = __get_extent_map(inode, page, pg_offset, cur,
3128 end - cur + 1, get_extent, em_cached);
3129 if (IS_ERR_OR_NULL(em)) {
3130 SetPageError(page);
3131 unlock_extent(tree, cur, end);
3132 break;
3133 }
3134 extent_offset = cur - em->start;
3135 BUG_ON(extent_map_end(em) <= cur);
(...)
Consider the following example scenario, where we end up hitting the
BUG_ON() in __do_readpage().
We have an inode with a size of 8KiB and 2 extent maps:
extent A: file offset 0, length 4KiB, disk_bytenr = X, persisted on disk by
a previous transaction
extent B: file offset 4KiB, length 4KiB, disk_bytenr = X + 4KiB, not yet
persisted but writeback started for it already. The extent map
is pinned since there's writeback and an ordered extent in
progress, so it can not be merged with extent map A yet
The following sequence of steps leads to the BUG_ON():
1) The ordered extent for extent B completes, the respective page gets its
writeback bit cleared and the extent map is unpinned, at that point it
is not yet merged with extent map A because it's in the list of modified
extents;
2) Due to memory pressure, or some other reason, the MM subsystem releases
the page corresponding to extent B - btrfs_releasepage() is called and
returns 1, meaning the page can be released as it's not dirty, not under
writeback anymore and the extent range is not locked in the inode's
iotree. However the extent map is not released, either because we are
not in a context that allows memory allocations to block or because the
inode's size is smaller than 16MiB - in this case our inode has a size
of 8KiB;
3) Task B needs to read extent B and ends up __do_readpage() through the
btrfs_readpage() callback. At __do_readpage() it gets a reference to
extent map B;
4) Task A, doing a fast fsync, calls clear_em_loggin() against extent map B
while holding the write lock on the inode's extent map tree - this
results in try_merge_map() being called and since it's possible to merge
extent map B with extent map A now (the extent map B was removed from
the list of modified extents), the merging begins - it sets extent map
B's start offset to 0 (was 4KiB), but before it increments the map's
length to 8KiB (4kb + 4KiB), task A is at:
BUG_ON(extent_map_end(em) <= cur);
The call to extent_map_end() sees the extent map has a start of 0
and a length still at 4KiB, so it returns 4KiB and 'cur' is 4KiB, so
the BUG_ON() is triggered.
So it's dangerous to modify an extent map that is in the tree, because some
other task might have got a reference to it before and still using it, and
needs to see a consistent map while using it. Generally this is very rare
since most paths that lookup and use extent maps also have the file range
locked in the inode's iotree. The fsync path is pretty much the only
exception where we don't do it to avoid serialization with concurrent
reads.
Fix this by not allowing an extent map do be merged if if it's being used
by tasks other then the one attempting to merge the extent map (when the
reference count of the extent map is greater than 2).
Reported-by: ryusuke1925 <st13s20@gm.ibaraki-ct.ac.jp>
Reported-by: Koki Mitani <koki.mitani.xg@hco.ntt.co.jp>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=206211
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4e19443da1941050b346f8fc4c368aa68413bc88 ]
Sometimes when running generic/475 we would trip the
WARN_ON(cache->reserved) check when free'ing the block groups on umount.
This is because sometimes we don't commit the transaction because of IO
errors and thus do not cleanup the tree logs until at umount time.
These blocks are still reserved until they are cleaned up, but they
aren't cleaned up until _after_ we do the free block groups work. Fix
this by moving the free after free'ing the fs roots, that way all of the
tree logs are cleaned up and we have a properly cleaned fs. A bunch of
loops of generic/475 confirmed this fixes the problem.
CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4273eaff9b8d5e141113a5bdf9628c02acf3afe5 ]
We don't need int argument bool shall do in free_root_pointers(). And
rename the argument as it confused two people.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5750c37523a2c8cbb450b9ef31e21c2ba876b05e upstream.
Raviu reported that running his regular fs_trim segfaulted with the
following backtrace:
[ 237.525947] assertion failed: prev, in ../fs/btrfs/extent_io.c:1595
[ 237.525984] ------------[ cut here ]------------
[ 237.525985] kernel BUG at ../fs/btrfs/ctree.h:3117!
[ 237.525992] invalid opcode: 0000 [#1] SMP PTI
[ 237.525998] CPU: 4 PID: 4423 Comm: fstrim Tainted: G U OE 5.4.14-8-vanilla #1
[ 237.526001] Hardware name: ASUSTeK COMPUTER INC.
[ 237.526044] RIP: 0010:assfail.constprop.58+0x18/0x1a [btrfs]
[ 237.526079] Call Trace:
[ 237.526120] find_first_clear_extent_bit+0x13d/0x150 [btrfs]
[ 237.526148] btrfs_trim_fs+0x211/0x3f0 [btrfs]
[ 237.526184] btrfs_ioctl_fitrim+0x103/0x170 [btrfs]
[ 237.526219] btrfs_ioctl+0x129a/0x2ed0 [btrfs]
[ 237.526227] ? filemap_map_pages+0x190/0x3d0
[ 237.526232] ? do_filp_open+0xaf/0x110
[ 237.526238] ? _copy_to_user+0x22/0x30
[ 237.526242] ? cp_new_stat+0x150/0x180
[ 237.526247] ? do_vfs_ioctl+0xa4/0x640
[ 237.526278] ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
[ 237.526283] do_vfs_ioctl+0xa4/0x640
[ 237.526288] ? __do_sys_newfstat+0x3c/0x60
[ 237.526292] ksys_ioctl+0x70/0x80
[ 237.526297] __x64_sys_ioctl+0x16/0x20
[ 237.526303] do_syscall_64+0x5a/0x1c0
[ 237.526310] entry_SYSCALL_64_after_hwframe+0x49/0xbe
That was due to btrfs_fs_device::aloc_tree being empty. Initially I
thought this wasn't possible and as a percaution have put the assert in
find_first_clear_extent_bit. Turns out this is indeed possible and could
happen when a file system with SINGLE data/metadata profile has a 2nd
device added. Until balance is run or a new chunk is allocated on this
device it will be completely empty.
In this case find_first_clear_extent_bit should return the full range
[0, -1ULL] and let the caller handle this i.e for trim the end will be
capped at the size of actual device.
Link: https://lore.kernel.org/linux-btrfs/izW2WNyvy1dEDweBICizKnd2KDwDiDyY2EYQr4YCwk7pkuIpthx-JRn65MPBde00ND6V0_Lh8mW0kZwzDiLDv25pUYWxkskWNJnVP0kgdMA=@protonmail.com/
Fixes: 45bfcfc168f8 ("btrfs: Implement find_first_clear_extent_bit")
CC: stable@vger.kernel.org # 5.2+
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 42ffb0bf584ae5b6b38f72259af1e0ee417ac77f upstream.
There exists a deadlock with range_cyclic that has existed forever. If
we loop around with a bio already built we could deadlock with a writer
who has the page locked that we're attempting to write but is waiting on
a page in our bio to be written out. The task traces are as follows
PID: 1329874 TASK: ffff889ebcdf3800 CPU: 33 COMMAND: "kworker/u113:5"
#0 [ffffc900297bb658] __schedule at ffffffff81a4c33f
#1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3
#2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42
#3 [ffffc900297bb708] __lock_page at ffffffff811f145b
#4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502
#5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684
#6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff
#7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0
#8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2
#9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd
PID: 2167901 TASK: ffff889dc6a59c00 CPU: 14 COMMAND:
"aio-dio-invalid"
#0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f
#1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3
#2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42
#3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6
#4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7
#5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359
#6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933
#7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8
#8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d
#9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032
I used drgn to find the respective pages we were stuck on
page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901
page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874
As you can see the kworker is waiting for bit 0 (PG_locked) on index
7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index
8148. aio-dio-invalid has 7680, and the kworker epd looks like the
following
crash> struct extent_page_data ffffc900297bbbb0
struct extent_page_data {
bio = 0xffff889f747ed830,
tree = 0xffff889eed6ba448,
extent_locked = 0,
sync_io = 0
}
Probably worth mentioning as well that it waits for writeback of the
page to complete while holding a lock on it (at prepare_pages()).
Using drgn I walked the bio pages looking for page
0xffffea00fbfc7500 which is the one we're waiting for writeback on
bio = Object(prog, 'struct bio', address=0xffff889f747ed830)
for i in range(0, bio.bi_vcnt.value_()):
bv = bio.bi_io_vec[i]
if bv.bv_page.value_() == 0xffffea00fbfc7500:
print("FOUND IT")
which validated what I suspected.
The fix for this is simple, flush the epd before we loop back around to
the beginning of the file during writeout.
Fixes: b293f02e1423 ("Btrfs: Add writepages support")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7227ff4de55d931bbdc156c8ef0ce4f100c78a5b upstream.
There is a race between adding and removing elements to the tree mod log
list and rbtree that can lead to use-after-free problems.
Consider the following example that explains how/why the problems happens:
1) Task A has mod log element with sequence number 200. It currently is
the only element in the mod log list;
2) Task A calls btrfs_put_tree_mod_seq() because it no longer needs to
access the tree mod log. When it enters the function, it initializes
'min_seq' to (u64)-1. Then it acquires the lock 'tree_mod_seq_lock'
before checking if there are other elements in the mod seq list.
Since the list it empty, 'min_seq' remains set to (u64)-1. Then it
unlocks the lock 'tree_mod_seq_lock';
3) Before task A acquires the lock 'tree_mod_log_lock', task B adds
itself to the mod seq list through btrfs_get_tree_mod_seq() and gets a
sequence number of 201;
4) Some other task, name it task C, modifies a btree and because there
elements in the mod seq list, it adds a tree mod elem to the tree
mod log rbtree. That node added to the mod log rbtree is assigned
a sequence number of 202;
5) Task B, which is doing fiemap and resolving indirect back references,
calls btrfs get_old_root(), with 'time_seq' == 201, which in turn
calls tree_mod_log_search() - the search returns the mod log node
from the rbtree with sequence number 202, created by task C;
6) Task A now acquires the lock 'tree_mod_log_lock', starts iterating
the mod log rbtree and finds the node with sequence number 202. Since
202 is less than the previously computed 'min_seq', (u64)-1, it
removes the node and frees it;
7) Task B still has a pointer to the node with sequence number 202, and
it dereferences the pointer itself and through the call to
__tree_mod_log_rewind(), resulting in a use-after-free problem.
This issue can be triggered sporadically with the test case generic/561
from fstests, and it happens more frequently with a higher number of
duperemove processes. When it happens to me, it either freezes the VM or
it produces a trace like the following before crashing:
[ 1245.321140] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
[ 1245.321200] CPU: 1 PID: 26997 Comm: pool Not tainted 5.5.0-rc6-btrfs-next-52 #1
[ 1245.321235] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
[ 1245.321287] RIP: 0010:rb_next+0x16/0x50
[ 1245.321307] Code: ....
[ 1245.321372] RSP: 0018:ffffa151c4d039b0 EFLAGS: 00010202
[ 1245.321388] RAX: 6b6b6b6b6b6b6b6b RBX: ffff8ae221363c80 RCX: 6b6b6b6b6b6b6b6b
[ 1245.321409] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff8ae221363c80
[ 1245.321439] RBP: ffff8ae20fcc4688 R08: 0000000000000002 R09: 0000000000000000
[ 1245.321475] R10: ffff8ae20b120910 R11: 00000000243f8bb1 R12: 0000000000000038
[ 1245.321506] R13: ffff8ae221363c80 R14: 000000000000075f R15: ffff8ae223f762b8
[ 1245.321539] FS: 00007fdee1ec7700(0000) GS:ffff8ae236c80000(0000) knlGS:0000000000000000
[ 1245.321591] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1245.321614] CR2: 00007fded4030c48 CR3: 000000021da16003 CR4: 00000000003606e0
[ 1245.321642] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1245.321668] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1245.321706] Call Trace:
[ 1245.321798] __tree_mod_log_rewind+0xbf/0x280 [btrfs]
[ 1245.321841] btrfs_search_old_slot+0x105/0xd00 [btrfs]
[ 1245.321877] resolve_indirect_refs+0x1eb/0xc60 [btrfs]
[ 1245.321912] find_parent_nodes+0x3dc/0x11b0 [btrfs]
[ 1245.321947] btrfs_check_shared+0x115/0x1c0 [btrfs]
[ 1245.321980] ? extent_fiemap+0x59d/0x6d0 [btrfs]
[ 1245.322029] extent_fiemap+0x59d/0x6d0 [btrfs]
[ 1245.322066] do_vfs_ioctl+0x45a/0x750
[ 1245.322081] ksys_ioctl+0x70/0x80
[ 1245.322092] ? trace_hardirqs_off_thunk+0x1a/0x1c
[ 1245.322113] __x64_sys_ioctl+0x16/0x20
[ 1245.322126] do_syscall_64+0x5c/0x280
[ 1245.322139] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 1245.322155] RIP: 0033:0x7fdee3942dd7
[ 1245.322177] Code: ....
[ 1245.322258] RSP: 002b:00007fdee1ec6c88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 1245.322294] RAX: ffffffffffffffda RBX: 00007fded40210d8 RCX: 00007fdee3942dd7
[ 1245.322314] RDX: 00007fded40210d8 RSI: 00000000c020660b RDI: 0000000000000004
[ 1245.322337] RBP: 0000562aa89e7510 R08: 0000000000000000 R09: 00007fdee1ec6d44
[ 1245.322369] R10: 0000000000000073 R11: 0000000000000246 R12: 00007fdee1ec6d48
[ 1245.322390] R13: 00007fdee1ec6d40 R14: 00007fded40210d0 R15: 00007fdee1ec6d50
[ 1245.322423] Modules linked in: ....
[ 1245.323443] ---[ end trace 01de1e9ec5dff3cd ]---
Fix this by ensuring that btrfs_put_tree_mod_seq() computes the minimum
sequence number and iterates the rbtree while holding the lock
'tree_mod_log_lock' in write mode. Also get rid of the 'tree_mod_seq_lock'
lock, since it is now redundant.
Fixes: bd989ba359f2ac ("Btrfs: add tree modification log functions")
Fixes: 097b8a7c9e48e2 ("Btrfs: join tree mod log code with the code holding back delayed refs")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 889bfa39086e86b52fcfaa04d72c95eaeb12f9a5 upstream.
If we fsync on a subvolume and create a log root for that volume, and
then later delete that subvolume we'll never clean up its log root. Fix
this by making switch_commit_roots free the log for any dropped roots we
encounter. The extra churn is because we need a btrfs_trans_handle, not
the btrfs_transaction.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d62b23c94952e78211a383b7d90ef0afbd9a3717 upstream.
If we abort a transaction we have the following sequence
if (!trans->dirty && list_empty(&trans->new_bgs))
return;
WRITE_ONCE(trans->transaction->aborted, err);
The idea being if we didn't modify anything with our trans handle then
we don't really need to abort the whole transaction, maybe the other
trans handles are fine and we can carry on.
However in the case of create_snapshot we add a pending_snapshot object
to our transaction and then commit the transaction. We don't actually
modify anything. sync() behaves the same way, attach to an existing
transaction and commit it. This means that if we have an IO error in
the right places we could abort the committing transaction with our
trans->dirty being not set and thus not set transaction->aborted.
This is a problem because in the create_snapshot() case we depend on
pending->error being set to something, or btrfs_commit_transaction
returning an error.
If we are not the trans handle that gets to commit the transaction, and
we're waiting on the commit to happen we get our return value from
cur_trans->aborted. If this was not set to anything because sync() hit
an error in the transaction commit before it could modify anything then
cur_trans->aborted would be 0. Thus we'd return 0 from
btrfs_commit_transaction() in create_snapshot.
This is a problem because we then try to do things with
pending_snapshot->snap, which will be NULL because we didn't create the
snapshot, and then we'll get a NULL pointer dereference like the
following
"BUG: kernel NULL pointer dereference, address: 00000000000001f0"
RIP: 0010:btrfs_orphan_cleanup+0x2d/0x330
Call Trace:
? btrfs_mksubvol.isra.31+0x3f2/0x510
btrfs_mksubvol.isra.31+0x4bc/0x510
? __sb_start_write+0xfa/0x200
? mnt_want_write_file+0x24/0x50
btrfs_ioctl_snap_create_transid+0x16c/0x1a0
btrfs_ioctl_snap_create_v2+0x11e/0x1a0
btrfs_ioctl+0x1534/0x2c10
? free_debug_processing+0x262/0x2a3
do_vfs_ioctl+0xa6/0x6b0
? do_sys_open+0x188/0x220
? syscall_trace_enter+0x1f8/0x330
ksys_ioctl+0x60/0x90
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x4a/0x1b0
In order to fix this we need to make sure anybody who calls
commit_transaction has trans->dirty set so that they properly set the
trans->transaction->aborted value properly so any waiters know bad
things happened.
This was found while I was running generic/475 with my modified
fsstress, it reproduced within a few runs. I ran with this patch all
night and didn't see the problem again.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b5e4ff9d465da1233a2d9a47ebce487c70d8f4ab upstream.
Recently fsstress (from fstests) sporadically started to trigger an
infinite loop during fsync operations. This turned out to be because
support for the rename exchange and whiteout operations was added to
fsstress in fstests. These operations, unlike any others in fsstress,
cause file names to be reused, whence triggering this issue. However
it's not necessary to use rename exchange and rename whiteout operations
trigger this issue, simple rename operations and file creations are
enough to trigger the issue.
The issue boils down to when we are logging inodes that conflict (that
had the name of any inode we need to log during the fsync operation), we
keep logging them even if they were already logged before, and after
that we check if there's any other inode that conflicts with them and
then add it again to the list of inodes to log. Skipping already logged
inodes fixes the issue.
Consider the following example:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir /mnt/testdir # inode 257
$ touch /mnt/testdir/zz # inode 258
$ ln /mnt/testdir/zz /mnt/testdir/zz_link
$ touch /mnt/testdir/a # inode 259
$ sync
# The following 3 renames achieve the same result as a rename exchange
# operation (<rename_exchange> /mnt/testdir/zz_link to /mnt/testdir/a).
$ mv /mnt/testdir/a /mnt/testdir/a/tmp
$ mv /mnt/testdir/zz_link /mnt/testdir/a
$ mv /mnt/testdir/a/tmp /mnt/testdir/zz_link
# The following rename and file creation give the same result as a
# rename whiteout operation (<rename_whiteout> zz to a2).
$ mv /mnt/testdir/zz /mnt/testdir/a2
$ touch /mnt/testdir/zz # inode 260
$ xfs_io -c fsync /mnt/testdir/zz
--> results in the infinite loop
The following steps happen:
1) When logging inode 260, we find that its reference named "zz" was
used by inode 258 in the previous transaction (through the commit
root), so inode 258 is added to the list of conflicting indoes that
need to be logged;
2) After logging inode 258, we find that its reference named "a" was
used by inode 259 in the previous transaction, and therefore we add
inode 259 to the list of conflicting inodes to be logged;
3) After logging inode 259, we find that its reference named "zz_link"
was used by inode 258 in the previous transaction - we add inode 258
to the list of conflicting inodes to log, again - we had already
logged it before at step 3. After logging it again, we find again
that inode 259 conflicts with him, and we add again 259 to the list,
etc - we end up repeating all the previous steps.
So fix this by skipping logging of conflicting inodes that were already
logged.
Fixes: 6b5fc433a7ad67 ("Btrfs: fix fsync after succession of renames of different files")
CC: stable@vger.kernel.org # 5.1+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 831d2fa25ab8e27592b1b0268dae6f2dfaf7cc43 upstream.
Since btrfs was migrated to use the generic VFS helpers for clone and
deduplication, it stopped allowing for the last block of a file to be
deduplicated when the source file size is not sector size aligned (when
eof is somewhere in the middle of the last block). There are two reasons
for that:
1) The generic code always rounds down, to a multiple of the block size,
the range's length for deduplications. This means we end up never
deduplicating the last block when the eof is not block size aligned,
even for the safe case where the destination range's end offset matches
the destination file's size. That rounding down operation is done at
generic_remap_check_len();
2) Because of that, the btrfs specific code does not expect anymore any
non-aligned range length's for deduplication and therefore does not
work if such nona-aligned length is given.
This patch addresses that second part, and it depends on a patch that
fixes generic_remap_check_len(), in the VFS, which was submitted ealier
and has the following subject:
"fs: allow deduplication of eof block into the end of the destination file"
These two patches address reports from users that started seeing lower
deduplication rates due to the last block never being deduplicated when
the file size is not aligned to the filesystem's block size.
Link: https://lore.kernel.org/linux-btrfs/2019-1576167349.500456@svIo.N5dq.dFFD/
CC: stable@vger.kernel.org # 5.1+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Qu Wenruo
Filipe Manana
Xiyu Yang
Madhuparna Bhowmik
Josef Bacik
Robbie Ko
Omar Sandoval
Jeff Mahoney
Nikolay Borisov
David Sterba
Anand Jain
Johannes Thumshirn
Chris Mason
Wenwen Wang