While doing a reflink operation, if an ordered extent for a file range
that does not overlap with the source and destination ranges of the
reflink operation happens, we can end up having a failure in the reflink
operation and return -EINVAL to user space.
The following sequence of steps explains how this can happen:
1) We have the page at file offset 315392 dirty (under delalloc);
2) A reflink operation for this file starts, using the same file as both
source and destination, the source range is [372736, 409600) (length of
36864 bytes) and the destination range is [208896, 245760);
3) At btrfs_remap_file_range_prep(), we flush all delalloc in the source
and destination ranges, and wait for any ordered extents in those range
to complete;
4) Still at btrfs_remap_file_range_prep(), we then flush all delalloc in
the inode, but we neither wait for it to complete nor any ordered
extents to complete. This results in starting delalloc for the page at
file offset 315392 and creating an ordered extent for that single page
range;
5) We then move to btrfs_clone() and enter the loop to find file extent
items to copy from the source range to destination range;
6) In the first iteration we end up at last file extent item stored in
leaf A:
(...)
item 131 key (143616 108 315392) itemoff 5101 itemsize 53
extent data disk bytenr 1903988736 nr 73728
extent data offset 12288 nr 61440 ram 73728
This represents the file range [315392, 376832), which overlaps with
the source range to clone.
@datal is set to 61440, key.offset is 315392 and @next_key_min_offset
is therefore set to 376832 (315392 + 61440).
@off (372736) is > key.offset (315392), so @new_key.offset is set to
the value of @destoff (208896).
@new_key.offset == @last_dest_end (208896) so @drop_start is set to
208896 (@new_key.offset).
@datal is adjusted to 4096, as @off is > @key.offset.
So in this iteration we call btrfs_replace_file_extents() for the range
[208896, 212991] (a single page, which is
[@drop_start, @new_key.offset + @datal - 1]).
@last_dest_end is set to 212992 (@new_key.offset + @datal =
208896 + 4096 = 212992).
Before the next iteration of the loop, @key.offset is set to the value
376832, which is @next_key_min_offset;
7) On the second iteration btrfs_search_slot() leaves us again at leaf A,
but this time pointing beyond the last slot of leaf A, as that's where
a key with offset 376832 should be at if it existed. So end up calling
btrfs_next_leaf();
8) btrfs_next_leaf() releases the path, but before it searches again the
tree for the next key/leaf, the ordered extent for the single page
range at file offset 315392 completes. That results in trimming the
file extent item we processed before, adjusting its key offset from
315392 to 319488, reducing its length from 61440 to 57344 and inserting
a new file extent item for that single page range, with a key offset of
315392 and a length of 4096.
Leaf A now looks like:
(...)
item 132 key (143616 108 315392) itemoff 4995 itemsize 53
extent data disk bytenr 1801666560 nr 4096
extent data offset 0 nr 4096 ram 4096
item 133 key (143616 108 319488) itemoff 4942 itemsize 53
extent data disk bytenr 1903988736 nr 73728
extent data offset 16384 nr 57344 ram 73728
9) When btrfs_next_leaf() returns, it gives us a path pointing to leaf A
at slot 133, since it's the first key that follows what was the last
key we saw (143616 108 315392). In fact it's the same item we processed
before, but its key offset was changed, so it counts as a new key;
10) So now we have:
@key.offset == 319488
@datal == 57344
@off (372736) is > key.offset (319488), so @new_key.offset is set to
208896 (@destoff value).
@new_key.offset (208896) != @last_dest_end (212992), so @drop_start
is set to 212992 (@last_dest_end value).
@datal is adjusted to 4096 because @off > @key.offset.
So in this iteration we call btrfs_replace_file_extents() for the
invalid range of [212992, 212991] (which is
[@drop_start, @new_key.offset + @datal - 1]).
This range is empty, the end offset is smaller than the start offset
so btrfs_replace_file_extents() returns -EINVAL, which we end up
returning to user space and fail the reflink operation.
This all happens because the range of this file extent item was
already processed in the previous iteration.
This scenario can be triggered very sporadically by fsx from fstests, for
example with test case generic/522.
So fix this by having btrfs_clone() skip file extent items that cover a
file range that we have already processed.
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Almost none of the errors stemming from a valid mount option but wrong
value prints a descriptive message which would help to identify why
mount failed. Like in the linked report:
$ uname -r
v4.19
$ mount -o compress=zstd /dev/sdb /mnt
mount: /mnt: wrong fs type, bad option, bad superblock on
/dev/sdb, missing codepage or helper program, or other error.
$ dmesg
...
BTRFS error (device sdb): open_ctree failed
Errors caused by memory allocation failures are left out as it's not a
user error so reporting that would be confusing.
Link: https://lore.kernel.org/linux-btrfs/9c3fec36-fc61-3a33-4977-a7e207c3fa4e@gmx.de/
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Upstream commit 9f73f1aef9 ("btrfs: force v2 space cache usage for
subpage mount") forces subpage mount to use v2 cache, to avoid
deprecated v1 cache which doesn't support subpage properly.
But there is a loophole that user can still remount to v1 cache.
The existing check will only give users a warning, but does not really
prevent to do the remount.
Although remounting to v1 will not cause any problems since the v1 cache
will always be marked invalid when mounted with a different page size,
it's still better to prevent v1 cache at all for subpage mounts.
Fixes: 9f73f1aef9 ("btrfs: force v2 space cache usage for subpage mount")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When we start an unmount, at close_ctree(), if we have the reclaim task
running and in the middle of a data block group relocation, we can trigger
a deadlock when stopping an async reclaim task, producing a trace like the
following:
[629724.498185] task:kworker/u16:7 state:D stack: 0 pid:681170 ppid: 2 flags:0x00004000
[629724.499760] Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs]
[629724.501267] Call Trace:
[629724.501759] <TASK>
[629724.502174] __schedule+0x3cb/0xed0
[629724.502842] schedule+0x4e/0xb0
[629724.503447] btrfs_wait_on_delayed_iputs+0x7c/0xc0 [btrfs]
[629724.504534] ? prepare_to_wait_exclusive+0xc0/0xc0
[629724.505442] flush_space+0x423/0x630 [btrfs]
[629724.506296] ? rcu_read_unlock_trace_special+0x20/0x50
[629724.507259] ? lock_release+0x220/0x4a0
[629724.507932] ? btrfs_get_alloc_profile+0xb3/0x290 [btrfs]
[629724.508940] ? do_raw_spin_unlock+0x4b/0xa0
[629724.509688] btrfs_async_reclaim_metadata_space+0x139/0x320 [btrfs]
[629724.510922] process_one_work+0x252/0x5a0
[629724.511694] ? process_one_work+0x5a0/0x5a0
[629724.512508] worker_thread+0x52/0x3b0
[629724.513220] ? process_one_work+0x5a0/0x5a0
[629724.514021] kthread+0xf2/0x120
[629724.514627] ? kthread_complete_and_exit+0x20/0x20
[629724.515526] ret_from_fork+0x22/0x30
[629724.516236] </TASK>
[629724.516694] task:umount state:D stack: 0 pid:719055 ppid:695412 flags:0x00004000
[629724.518269] Call Trace:
[629724.518746] <TASK>
[629724.519160] __schedule+0x3cb/0xed0
[629724.519835] schedule+0x4e/0xb0
[629724.520467] schedule_timeout+0xed/0x130
[629724.521221] ? lock_release+0x220/0x4a0
[629724.521946] ? lock_acquired+0x19c/0x420
[629724.522662] ? trace_hardirqs_on+0x1b/0xe0
[629724.523411] __wait_for_common+0xaf/0x1f0
[629724.524189] ? usleep_range_state+0xb0/0xb0
[629724.524997] __flush_work+0x26d/0x530
[629724.525698] ? flush_workqueue_prep_pwqs+0x140/0x140
[629724.526580] ? lock_acquire+0x1a0/0x310
[629724.527324] __cancel_work_timer+0x137/0x1c0
[629724.528190] close_ctree+0xfd/0x531 [btrfs]
[629724.529000] ? evict_inodes+0x166/0x1c0
[629724.529510] generic_shutdown_super+0x74/0x120
[629724.530103] kill_anon_super+0x14/0x30
[629724.530611] btrfs_kill_super+0x12/0x20 [btrfs]
[629724.531246] deactivate_locked_super+0x31/0xa0
[629724.531817] cleanup_mnt+0x147/0x1c0
[629724.532319] task_work_run+0x5c/0xa0
[629724.532984] exit_to_user_mode_prepare+0x1a6/0x1b0
[629724.533598] syscall_exit_to_user_mode+0x16/0x40
[629724.534200] do_syscall_64+0x48/0x90
[629724.534667] entry_SYSCALL_64_after_hwframe+0x44/0xae
[629724.535318] RIP: 0033:0x7fa2b90437a7
[629724.535804] RSP: 002b:00007ffe0b7e4458 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[629724.536912] RAX: 0000000000000000 RBX: 00007fa2b9182264 RCX: 00007fa2b90437a7
[629724.538156] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000555d6cf20dd0
[629724.539053] RBP: 0000555d6cf20ba0 R08: 0000000000000000 R09: 00007ffe0b7e3200
[629724.539956] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[629724.540883] R13: 0000555d6cf20dd0 R14: 0000555d6cf20cb0 R15: 0000000000000000
[629724.541796] </TASK>
This happens because:
1) Before entering close_ctree() we have the async block group reclaim
task running and relocating a data block group;
2) There's an async metadata (or data) space reclaim task running;
3) We enter close_ctree() and park the cleaner kthread;
4) The async space reclaim task is at flush_space() and runs all the
existing delayed iputs;
5) Before the async space reclaim task calls
btrfs_wait_on_delayed_iputs(), the block group reclaim task which is
doing the data block group relocation, creates a delayed iput at
replace_file_extents() (called when COWing leaves that have file extent
items pointing to relocated data extents, during the merging phase
of relocation roots);
6) The async reclaim space reclaim task blocks at
btrfs_wait_on_delayed_iputs(), since we have a new delayed iput;
7) The task at close_ctree() then calls cancel_work_sync() to stop the
async space reclaim task, but it blocks since that task is waiting for
the delayed iput to be run;
8) The delayed iput is never run because the cleaner kthread is parked,
and no one else runs delayed iputs, resulting in a hang.
So fix this by stopping the async block group reclaim task before we
park the cleaner kthread.
Fixes: 18bb8bbf13 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Zoned devices are expected to have zone sizes in the range of 1-2GB for
ZNS SSDs and SMR HDDs have zone sizes of 256MB, so there is no need to
allow arbitrarily small zone sizes on btrfs.
But for testing purposes with emulated devices it is sometimes desirable
to create devices with as small as 4MB zone size to uncover errors.
So use 4MB as the smallest possible zone size and reject mounts of devices
with a smaller zone size.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Btrfs defaults to max_inline=2K to make small writes inlined into
metadata.
The default value is always a win, as even DUP/RAID1/RAID10 doubles the
metadata usage, it should still cause less physical space used compared
to a 4K regular extents.
But since the introduction of RAID1C3 and RAID1C4 it's no longer the case,
users may find inlined extents causing too much space wasted, and want
to convert those inlined extents back to regular extents.
Unfortunately defrag will unconditionally skip all inline extents, no
matter if the user is trying to converting them back to regular extents.
So this patch will add a small exception for defrag_collect_targets() to
allow defragging inline extents, if and only if the inlined extents are
larger than max_inline, allowing users to convert them to regular ones.
This also allows us to defrag extents like the following:
item 6 key (257 EXTENT_DATA 0) itemoff 15794 itemsize 69
generation 7 type 0 (inline)
inline extent data size 48 ram_bytes 4096 compression 1 (zlib)
item 7 key (257 EXTENT_DATA 4096) itemoff 15741 itemsize 53
generation 7 type 1 (regular)
extent data disk byte 13631488 nr 4096
extent data offset 0 nr 16384 ram 16384
extent compression 1 (zlib)
Previously we're unable to do any defrag, since the first extent is
inlined, and the second one has no extent to merge.
Now we can defrag it to just one single extent, saving 48 bytes metadata
space.
item 6 key (257 EXTENT_DATA 0) itemoff 15810 itemsize 53
generation 8 type 1 (regular)
extent data disk byte 13635584 nr 4096
extent data offset 0 nr 20480 ram 20480
extent compression 1 (zlib)
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The following error message lack the "0x" obviously:
cannot mount because of unsupported optional features (4000)
Add the prefix to make it less confusing. This can happen on older
kernels that try to mount a filesystem with newer features so it makes
sense to backport to older trees.
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When reserving metadata units for creating an inode, we don't need to
reserve one extra unit for the inode ref item because when creating the
inode, at btrfs_create_new_inode(), we always insert the inode item and
the inode ref item in a single batch (a single btree insert operation,
and both ending up in the same leaf).
As we have accounted already one unit for the inode item, the extra unit
for the inode ref item is superfluous, it only makes us reserve more
metadata than necessary and often adding more reclaim pressure if we are
low on available metadata space.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The block_group->alloc_offset is an offset from the start of the block
group. OTOH, the ->meta_write_pointer is an address in the logical
space. So, we should compare the alloc_offset shifted with the
block_group->start.
Fixes: afba2bc036 ("btrfs: zoned: implement active zone tracking")
CC: stable@vger.kernel.org # 5.16+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
A send operation reads extent data using the buffered IO path for getting
extent data to send in write commands and this is both because it's simple
and to make use of the generic readahead infrastructure, which results in
a massive speedup.
However this fills the page cache with data that, most of the time, is
really only used by the send operation - once the write commands are sent,
it's not useful to have the data in the page cache anymore. For large
snapshots, bringing all data into the page cache eventually leads to the
need to evict other data from the page cache that may be more useful for
applications (and kernel subsystems).
Even if extents are shared with the subvolume on which a snapshot is based
on and the data is currently on the page cache due to being read through
the subvolume, attempting to read the data through the snapshot will
always result in bringing a new copy of the data into another location in
the page cache (there's currently no shared memory for shared extents).
So make send evict the data it has read before if when it first opened
the inode, its mapping had no pages currently loaded: when
inode->i_mapping->nr_pages has a value of 0. Do this instead of deciding
based on the return value of filemap_range_has_page() before reading an
extent because the generic readahead mechanism may read pages beyond the
range we request (and it very often does it), which means a call to
filemap_range_has_page() will return true due to the readahead that was
triggered when processing a previous extent - we don't have a simple way
to distinguish this case from the case where the data was brought into
the page cache through someone else. So checking for the mapping number
of pages being 0 when we first open the inode is simple, cheap and it
generally accomplishes the goal of not trashing the page cache - the
only exception is if part of data was previously loaded into the page
cache through the snapshot by some other process, in that case we end
up not evicting any data send brings into the page cache, just like
before this change - but that however is not the common case.
Example scenario, on a box with 32G of RAM:
$ btrfs subvolume create /mnt/sv1
$ xfs_io -f -c "pwrite 0 4G" /mnt/sv1/file1
$ btrfs subvolume snapshot -r /mnt/sv1 /mnt/snap1
$ free -m
total used free shared buff/cache available
Mem: 31937 186 26866 0 4883 31297
Swap: 8188 0 8188
# After this we get less 4G of free memory.
$ btrfs send /mnt/snap1 >/dev/null
$ free -m
total used free shared buff/cache available
Mem: 31937 186 22814 0 8935 31297
Swap: 8188 0 8188
The same, obviously, applies to an incremental send.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Every time we send a write command, we open the inode, read some data to
a buffer and then close the inode. The amount of data we read for each
write command is at most 48K, returned by max_send_read_size(), and that
corresponds to: BTRFS_SEND_BUF_SIZE - 16K = 48K. In practice this does
not add any significant overhead, because the time elapsed between every
close (iput()) and open (btrfs_iget()) is very short, so the inode is kept
in the VFS's cache after the iput() and it's still there by the time we
do the next btrfs_iget().
As between processing extents of the current inode we don't do anything
else, it makes sense to keep the inode open after we process its first
extent that needs to be sent and keep it open until we start processing
the next inode. This serves to facilitate the next change, which aims
to avoid having send operations trash the page cache with data extents.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Create a new bio_set that contains all the per-bio private data needed
by btrfs for direct I/O and tell the iomap code to use that instead
of separately allocation the btrfs_dio_private structure.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The btrfs_dio_private structure is only used in inode.c, so move the
definition there.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This field is never used, so remove it. Last use was probably in
23ea8e5a07 ("Btrfs: load checksum data once when submitting a direct
read io").
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Make use of the new iomap_iter->private field to avoid a memory
allocation per iomap range.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Allow the file system to keep state for all iterations. For now only
wire it up for direct I/O as there is an immediate need for it there.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Allow the file system to provide a specific bio_set for allocating
direct I/O bios. This will allow file systems that use the
->submit_io hook to stash away additional information for file system
use.
To make use of this additional space for information in the completion
path, the file system needs to override the ->bi_end_io callback and
then call back into iomap, so export iomap_dio_bio_end_io for that.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a wrapper around iomap_dio_rw that keeps the direct I/O internals
isolated in inode.c.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
While the active zones within an active block group are reset, and their
active resource is released, the block group itself is kept in the active
block group list and marked as active. As a result, the list will contain
more than max_active_zones block groups. That itself is not fatal for the
device as the zones are properly reset.
However, that inflated list is, of course, strange. Also, a to-appear
patch series, which deactivates an active block group on demand, gets
confused with the wrong list.
So, fix the issue by finishing the unused block group once it gets
read-only, so that we can release the active resource in an early stage.
Fixes: be1a1d7a5d ("btrfs: zoned: finish fully written block group")
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit be1a1d7a5d ("btrfs: zoned: finish fully written block group")
introduced zone finishing code both for data and metadata end_io path.
However, the metadata side is not working as it should. First, it
compares logical address (eb->start + eb->len) with offset within a
block group (cache->zone_capacity) in submit_eb_page(). That essentially
disabled zone finishing on metadata end_io path.
Furthermore, fixing the issue above revealed we cannot call
btrfs_zone_finish_endio() in end_extent_buffer_writeback(). We cannot
call btrfs_lookup_block_group() which require spin lock inside end_io
context.
Introduce btrfs_schedule_zone_finish_bg() to wait for the extent buffer
writeback and do the zone finish IO in a workqueue.
Also, drop EXTENT_BUFFER_ZONE_FINISH as it is no longer used.
Fixes: be1a1d7a5d ("btrfs: zoned: finish fully written block group")
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently, btrfs_zone_finish_endio() finishes a block group only when the
written region reaches the end of the block group. We can also finish the
block group when no more allocation is possible.
Fixes: be1a1d7a5d ("btrfs: zoned: finish fully written block group")
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_zone_finish() and btrfs_zone_finish_endio() have similar code.
Introduce do_zone_finish() to factor out the common code.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce a wrapper to check if all the space in a block group is
allocated or not.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When iterating the backrefs in an extent item if the ptr to the
'current' backref record goes beyond the extent item a warning is
generated and -ENOENT is returned. However what's more appropriate to
debug such cases would be to return EUCLEAN and also print identifying
information about the performed search as well as the current content of
the leaf containing the possibly corrupted extent item.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The bio_ctrl is the last use of bio_flags that has been converted to
compress type everywhere else.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Several functions take parameter bio_flags that was simplified to just
compress type, unify it and change the type accordingly.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The bio_flags is now used to store unchanged compress type, so unify
that.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helpers extent_set_compress_type and extent_compress_type have
become trivial after previous cleanups and can be removed.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The bio_flags are used only to encode the compression and there are no
other EXTENT_BIO_* flags, so the compress type can be stored directly.
The struct member name is left unchanged and will be cleaned in later
patches.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helper used to do more with the wbc state but now it's just one
subtraction, no need to have a special helper.
It became trivial in a91326679f ("Btrfs: make mapping->writeback_index
point to the last written page").
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The value of btrfs_delayed_extent_op::is_data is always false, we can
cascade the change and simplify code that depends on it, removing the
structure member eventually.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The parameter has been added in 2009 in the infamous monster commit
5d4f98a28c ("Btrfs: Mixed back reference (FORWARD ROLLING FORMAT
CHANGE)") but not used ever since. We can sink it and allow further
simplifications.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When reserving data space for a direct IO write we can end up deadlocking
if we have multiple tasks attempting a write to the same file range, there
are multiple extents covered by that file range, we are low on available
space for data and the writes don't expand the inode's i_size.
The deadlock can happen like this:
1) We have a file with an i_size of 1M, at offset 0 it has an extent with
a size of 128K and at offset 128K it has another extent also with a
size of 128K;
2) Task A does a direct IO write against file range [0, 256K), and because
the write is within the i_size boundary, it takes the inode's lock (VFS
level) in shared mode;
3) Task A locks the file range [0, 256K) at btrfs_dio_iomap_begin(), and
then gets the extent map for the extent covering the range [0, 128K).
At btrfs_get_blocks_direct_write(), it creates an ordered extent for
that file range ([0, 128K));
4) Before returning from btrfs_dio_iomap_begin(), it unlocks the file
range [0, 256K);
5) Task A executes btrfs_dio_iomap_begin() again, this time for the file
range [128K, 256K), and locks the file range [128K, 256K);
6) Task B starts a direct IO write against file range [0, 256K) as well.
It also locks the inode in shared mode, as it's within the i_size limit,
and then tries to lock file range [0, 256K). It is able to lock the
subrange [0, 128K) but then blocks waiting for the range [128K, 256K),
as it is currently locked by task A;
7) Task A enters btrfs_get_blocks_direct_write() and tries to reserve data
space. Because we are low on available free space, it triggers the
async data reclaim task, and waits for it to reserve data space;
8) The async reclaim task decides to wait for all existing ordered extents
to complete (through btrfs_wait_ordered_roots()).
It finds the ordered extent previously created by task A for the file
range [0, 128K) and waits for it to complete;
9) The ordered extent for the file range [0, 128K) can not complete
because it blocks at btrfs_finish_ordered_io() when trying to lock the
file range [0, 128K).
This results in a deadlock, because:
- task B is holding the file range [0, 128K) locked, waiting for the
range [128K, 256K) to be unlocked by task A;
- task A is holding the file range [128K, 256K) locked and it's waiting
for the async data reclaim task to satisfy its space reservation
request;
- the async data reclaim task is waiting for ordered extent [0, 128K)
to complete, but the ordered extent can not complete because the
file range [0, 128K) is currently locked by task B, which is waiting
on task A to unlock file range [128K, 256K) and task A waiting
on the async data reclaim task.
This results in a deadlock between 4 task: task A, task B, the async
data reclaim task and the task doing ordered extent completion (a work
queue task).
This type of deadlock can sporadically be triggered by the test case
generic/300 from fstests, and results in a stack trace like the following:
[12084.033689] INFO: task kworker/u16:7:123749 blocked for more than 241 seconds.
[12084.034877] Not tainted 5.18.0-rc2-btrfs-next-115 #1
[12084.035562] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[12084.036548] task:kworker/u16:7 state:D stack: 0 pid:123749 ppid: 2 flags:0x00004000
[12084.036554] Workqueue: btrfs-flush_delalloc btrfs_work_helper [btrfs]
[12084.036599] Call Trace:
[12084.036601] <TASK>
[12084.036606] __schedule+0x3cb/0xed0
[12084.036616] schedule+0x4e/0xb0
[12084.036620] btrfs_start_ordered_extent+0x109/0x1c0 [btrfs]
[12084.036651] ? prepare_to_wait_exclusive+0xc0/0xc0
[12084.036659] btrfs_run_ordered_extent_work+0x1a/0x30 [btrfs]
[12084.036688] btrfs_work_helper+0xf8/0x400 [btrfs]
[12084.036719] ? lock_is_held_type+0xe8/0x140
[12084.036727] process_one_work+0x252/0x5a0
[12084.036736] ? process_one_work+0x5a0/0x5a0
[12084.036738] worker_thread+0x52/0x3b0
[12084.036743] ? process_one_work+0x5a0/0x5a0
[12084.036745] kthread+0xf2/0x120
[12084.036747] ? kthread_complete_and_exit+0x20/0x20
[12084.036751] ret_from_fork+0x22/0x30
[12084.036765] </TASK>
[12084.036769] INFO: task kworker/u16:11:153787 blocked for more than 241 seconds.
[12084.037702] Not tainted 5.18.0-rc2-btrfs-next-115 #1
[12084.038540] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[12084.039506] task:kworker/u16:11 state:D stack: 0 pid:153787 ppid: 2 flags:0x00004000
[12084.039511] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
[12084.039551] Call Trace:
[12084.039553] <TASK>
[12084.039557] __schedule+0x3cb/0xed0
[12084.039566] schedule+0x4e/0xb0
[12084.039569] schedule_timeout+0xed/0x130
[12084.039573] ? mark_held_locks+0x50/0x80
[12084.039578] ? _raw_spin_unlock_irq+0x24/0x50
[12084.039580] ? lockdep_hardirqs_on+0x7d/0x100
[12084.039585] __wait_for_common+0xaf/0x1f0
[12084.039587] ? usleep_range_state+0xb0/0xb0
[12084.039596] btrfs_wait_ordered_extents+0x3d6/0x470 [btrfs]
[12084.039636] btrfs_wait_ordered_roots+0x175/0x240 [btrfs]
[12084.039670] flush_space+0x25b/0x630 [btrfs]
[12084.039712] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs]
[12084.039747] process_one_work+0x252/0x5a0
[12084.039756] ? process_one_work+0x5a0/0x5a0
[12084.039758] worker_thread+0x52/0x3b0
[12084.039762] ? process_one_work+0x5a0/0x5a0
[12084.039765] kthread+0xf2/0x120
[12084.039766] ? kthread_complete_and_exit+0x20/0x20
[12084.039770] ret_from_fork+0x22/0x30
[12084.039783] </TASK>
[12084.039800] INFO: task kworker/u16:17:217907 blocked for more than 241 seconds.
[12084.040709] Not tainted 5.18.0-rc2-btrfs-next-115 #1
[12084.041398] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[12084.042404] task:kworker/u16:17 state:D stack: 0 pid:217907 ppid: 2 flags:0x00004000
[12084.042411] Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
[12084.042461] Call Trace:
[12084.042463] <TASK>
[12084.042471] __schedule+0x3cb/0xed0
[12084.042485] schedule+0x4e/0xb0
[12084.042490] wait_extent_bit.constprop.0+0x1eb/0x260 [btrfs]
[12084.042539] ? prepare_to_wait_exclusive+0xc0/0xc0
[12084.042551] lock_extent_bits+0x37/0x90 [btrfs]
[12084.042601] btrfs_finish_ordered_io.isra.0+0x3fd/0x960 [btrfs]
[12084.042656] ? lock_is_held_type+0xe8/0x140
[12084.042667] btrfs_work_helper+0xf8/0x400 [btrfs]
[12084.042716] ? lock_is_held_type+0xe8/0x140
[12084.042727] process_one_work+0x252/0x5a0
[12084.042742] worker_thread+0x52/0x3b0
[12084.042750] ? process_one_work+0x5a0/0x5a0
[12084.042754] kthread+0xf2/0x120
[12084.042757] ? kthread_complete_and_exit+0x20/0x20
[12084.042763] ret_from_fork+0x22/0x30
[12084.042783] </TASK>
[12084.042798] INFO: task fio:234517 blocked for more than 241 seconds.
[12084.043598] Not tainted 5.18.0-rc2-btrfs-next-115 #1
[12084.044282] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[12084.045244] task:fio state:D stack: 0 pid:234517 ppid:234515 flags:0x00004000
[12084.045248] Call Trace:
[12084.045250] <TASK>
[12084.045254] __schedule+0x3cb/0xed0
[12084.045263] schedule+0x4e/0xb0
[12084.045266] wait_extent_bit.constprop.0+0x1eb/0x260 [btrfs]
[12084.045298] ? prepare_to_wait_exclusive+0xc0/0xc0
[12084.045306] lock_extent_bits+0x37/0x90 [btrfs]
[12084.045336] btrfs_dio_iomap_begin+0x336/0xc60 [btrfs]
[12084.045370] ? lock_is_held_type+0xe8/0x140
[12084.045378] iomap_iter+0x184/0x4c0
[12084.045383] __iomap_dio_rw+0x2c6/0x8a0
[12084.045406] iomap_dio_rw+0xa/0x30
[12084.045408] btrfs_do_write_iter+0x370/0x5e0 [btrfs]
[12084.045440] aio_write+0xfa/0x2c0
[12084.045448] ? __might_fault+0x2a/0x70
[12084.045451] ? kvm_sched_clock_read+0x14/0x40
[12084.045455] ? lock_release+0x153/0x4a0
[12084.045463] io_submit_one+0x615/0x9f0
[12084.045467] ? __might_fault+0x2a/0x70
[12084.045469] ? kvm_sched_clock_read+0x14/0x40
[12084.045478] __x64_sys_io_submit+0x83/0x160
[12084.045483] ? syscall_enter_from_user_mode+0x1d/0x50
[12084.045489] do_syscall_64+0x3b/0x90
[12084.045517] entry_SYSCALL_64_after_hwframe+0x44/0xae
[12084.045521] RIP: 0033:0x7fa76511af79
[12084.045525] RSP: 002b:00007ffd6d6b9058 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
[12084.045530] RAX: ffffffffffffffda RBX: 00007fa75ba6e760 RCX: 00007fa76511af79
[12084.045532] RDX: 0000557b304ff3f0 RSI: 0000000000000001 RDI: 00007fa75ba4c000
[12084.045535] RBP: 00007fa75ba4c000 R08: 00007fa751b76000 R09: 0000000000000330
[12084.045537] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
[12084.045540] R13: 0000000000000000 R14: 0000557b304ff3f0 R15: 0000557b30521eb0
[12084.045561] </TASK>
Fix this issue by always reserving data space before locking a file range
at btrfs_dio_iomap_begin(). If we can't reserve the space, then we don't
error out immediately - instead after locking the file range, check if we
can do a NOCOW write, and if we can we don't error out since we don't need
to allocate a data extent, however if we can't NOCOW then error out with
-ENOSPC. This also implies that we may end up reserving space when it's
not needed because the write will end up being done in NOCOW mode - in that
case we just release the space after we noticed we did a NOCOW write - this
is the same type of logic that is done in the path for buffered IO writes.
Fixes: f0bfa76a11 ("btrfs: fix ENOSPC failure when attempting direct IO write into NOCOW range")
CC: stable@vger.kernel.org # 5.17+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Derive the compression type from extent map as opposed to the bio flags
passed. This makes it more precise and not reliant on function
parameters.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[SUSPICIOUS CODE]
When refactoring scrub code, I noticed a very strange behavior around
scrub_remap_extent():
if (sctx->is_dev_replace)
scrub_remap_extent(fs_info, cur_logical, scrub_len,
&cur_physical, &target_dev, &cur_mirror);
As replace target is a 1:1 copy of the source device, thus physical
offset inside the target should be the same as physical inside source,
thus this remap call makes no sense to me.
[REAL FUNCTIONALITY]
After more investigation, the function name scrub_remap_extent()
doesn't tell anything of the truth, nor does its if () condition.
The real story behind this function is that, for scrub_pages() we never
expect missing device, even for replacing missing device.
What scrub_remap_extent() is really doing is to find a live mirror, and
make later scrub_pages() to read data from the good copy, other than
from the missing device and increase error counters unnecessarily.
[IMPROVEMENT]
We have no need to bother scrub_remap_extent() in scrub_simple_mirror()
at all, we only need to call it before we call scrub_pages().
And rename the function to scrub_find_live_copy(), add extra comments on
them.
By this we can remove one parameter from scrub_extent(), and reduce the
unnecessary calls to scrub_remap_extent() for regular replace.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since we have find_first_extent_item() to iterate the extent items of a
certain range, there is no need to use the open-coded version.
Replace the final scrub call site with find_first_extent_item().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently scrub_raid56_parity() has a large double loop, handling the
following things at the same time:
- Iterate each data stripe
- Iterate each extent item in one data stripe
Refactor this by:
- Introduce a new helper to handle data stripe iteration
The new helper is scrub_raid56_data_stripe_for_parity(), which
only has one while() loop handling the extent items inside the
data stripe.
The code is still mostly the same as the old code.
- Call cond_resched() for each extent
Previously we only call cond_resched() under a complex if () check.
I see no special reason to do that, and for other scrub functions,
like scrub_simple_mirror() we're already doing the same cond_resched()
after scrubbing one extent.
- Add more comments
Please note that, this patch is only to address the double loop, there
are incoming patches to do extra cleanup.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Although RAID56 has complex repair mechanism, which involves reading the
whole full stripe, but inside one data stripe, it's in fact no different
than SINGLE/RAID1.
The point here is, for data stripe we just check the csum for each
extent we hit. Only for csum mismatch case, our repair paths divide.
So we can still reuse scrub_simple_mirror() for RAID56 data stripes,
which saves quite some code.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since we have moved all other profiles handling into their own
functions, now the main body of scrub_stripe() is just handling RAID56
profiles.
There is no need to address other profiles in the main loop of
scrub_stripe(), so we can remove those dead branches.
Since we're here, also slightly change the timing of initialization of
variables like @offset, @increment and @logical.
Especially for @logical, we don't really need to initialize it for
btrfs_extent_root()/btrfs_csum_root(), we can use bg->start for that
purpose.
Now those variables are only initialize for RAID56 branches.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The new entrance will iterate through each data stripe which belongs to
the target device.
And since inside each data stripe, RAID0 is just SINGLE, while RAID10 is
just RAID1, we can reuse scrub_simple_mirror() to do the scrub properly.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The new helper, scrub_simple_mirror(), will scrub all extents inside a
range which only has simple mirror based duplication.
This covers every range of SINGLE/DUP/RAID1/RAID1C*, and inside each
data stripe for RAID0/RAID10.
Currently we will use this function to scrub SINGLE/DUP/RAID1/RAID1C*
profiles. As one can see, the new entrance for those simple-mirror
based profiles can be small enough (with comments, just reach 100
lines).
This function will be the basis for the incoming scrub refactor.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The new helper, find_first_extent_item(), will locate an extent item
(either EXTENT_ITEM or METADATA_ITEM) which covers any byte of the
search range.
This helper will later be used to refactor scrub code.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The variable @physical_end is the exclusive stripe end, currently it's
calculated using @physical + @dev_extent_len / map->stripe_len *
map->stripe_len.
And since at allocation time we ensured dev_extent_len is stripe_len
aligned, the result is the same as @physical + @dev_extent_len.
So this patch will just assign @physical and @physical_end early,
without using @nstripes.
This is especially helpful for any possible out: label user, as now we
only need to initialize @offset before going to out: label.
Since we're here, also make @physical_end constant.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
… rename it to simply fs_roots and adjust all usages of this object to use
the XArray API, because it is notionally easier to use and understand, as
it provides array semantics, and also takes care of locking for us,
further simplifying the code.
Also do some refactoring, esp. where the API change requires largely
rewriting some functions, anyway.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Gabriel Niebler <gniebler@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
… named 'extent_buffers'. Also adjust all usages of this object to use
the XArray API, which greatly simplifies the code as it takes care of
locking and is generally easier to use and understand, providing
notionally simpler array semantics.
Also perform some light refactoring.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Gabriel Niebler <gniebler@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
… and adjust all usages of this object to use the XArray API for the sake
of consistency.
XArray API provides array semantics, so it is notionally easier to use and
understand, and it also takes care of locking for us.
None of this makes a real difference in this particular patch, but it does
in other places where similar replacements are or have been made and we
want to be consistent in our usage of data structures in btrfs.
Signed-off-by: Gabriel Niebler <gniebler@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
… in the btrfs_root struct and adjust all usages of this object to use
the XArray API, because it is notionally easier to use and understand,
as it provides array semantics, and also takes care of locking for us,
further simplifying the code.
Also use the opportunity to do some light refactoring.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Gabriel Niebler <gniebler@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In function btrfs_bg_flags_to_raid_index(), we use quite some if () to
convert the BTRFS_BLOCK_GROUP_* bits to a index number.
But the truth is, there is really no such need for so many branches at
all.
Since all BTRFS_BLOCK_GROUP_* flags are just one single bit set inside
BTRFS_BLOCK_GROUP_PROFILES_MASK, we can easily use ilog2() to calculate
their values.
This calculation has an anchor point, the lowest PROFILE bit, which is
RAID0.
Even it's fixed on-disk format and should never change, here I added
extra compile time checks to make it super safe:
1. Make sure RAID0 is always the lowest bit in PROFILE_MASK
This is done by finding the first (least significant) bit set of
RAID0 and PROFILE_MASK & ~RAID0.
2. Make sure RAID0 bit set beyond the highest bit of TYPE_MASK
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's only internally used as another way to represent btrfs profiles,
it's not exposed through any on-disk format, in fact this
btrfs_raid_types is diverted from the on-disk format values.
Furthermore, since it's internal structure, its definition can change in
the future.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
