Граф коммитов

11133 Коммитов

Автор SHA1 Сообщение Дата
Christoph Hellwig ff18a4afeb btrfs: raid56: use fixed stripe length everywhere
The raid56 code assumes a fixed stripe length BTRFS_STRIPE_LEN but there
are functions passing it as arguments, this is not necessary. The fixed
value has been used for a long time and though the stripe length should
be configurable by super block member stripesize, this hasn't been
implemented and would require more changes so we don't need to keep this
code around until then.

Partially based on a patch from Qu Wenruo.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[ update changelog ]
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:39 +02:00
Filipe Manana 0201fceb9f btrfs: remove the inode cache check at btrfs_is_free_space_inode()
The inode cache feature was removed in kernel 5.11, and we no longer have
any code that reads from or writes to inode caches. We may still mount a
filesystem that has inode caches, but they are ignored.

Remove the check for an inode cache from btrfs_is_free_space_inode(),
since we no longer have code to trigger reads from an inode cache or
writes to an inode cache. The check at send.c is still needed, because
in case we find a filesystem with an inode cache, we must ignore it.
Also leave the checks at tree-checker.c, as they are sanity checks.

This eliminates a dead branch and reduces the amount of code since it's
in an inline function.

Before:

$ size fs/btrfs/btrfs.ko
   text	   data	    bss	    dec	    hex	filename
1620662	 189240	  29032	1838934	 1c0f56	fs/btrfs/btrfs.ko

After:

$ size fs/btrfs/btrfs.ko
   text	   data	    bss	    dec	    hex	filename
1620502	 189240	  29032	1838774	 1c0eb6	fs/btrfs/btrfs.ko

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:39 +02:00
Nikolay Borisov 74860816e8 btrfs: sysfs: remove BIG_METADATA feature files
This flag has been merged in 3.10 and is effectively always-on. Its
status depends on the host page size so there's another way to guarantee
compatibility with old kernels.

Due to a bug introduced in 6f93e834fa ("btrfs: fix upper limit for
max_inline for page size 64K") the flag is not persisted among features
in the superblock so it's not reliable.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:39 +02:00
Nikolay Borisov 0766837b0d btrfs: sysfs: remove MIXED_BACKREF feature file
This feature has been the default for about 13 year. At this point it's
safe to consider it an indispensable feature of BTRFS as such there's
no need to advertise it in sysfs. Remove the global sysfs feature file,
the per-filesystem feature file has never been there.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:39 +02:00
Nikolay Borisov 49f468c938 btrfs: don't print 'has skinny extents' anymore on mount
Skinny extents have been a default mkfs feature since version 3.18 i
(introduced in btrfs-progs commit 6715de04d9a7 ("btrfs-progs: mkfs:
make skinny-metadata default") ). It really doesn't bring any value to
users to simply remove it.

Reviewed-by: Qu Wenruo <wqu@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>
2022-07-25 17:45:39 +02:00
Nikolay Borisov 6b769dac21 btrfs: don't print 'flagging with big metadata' anymore on mount
Added in commit 727011e07c ("Btrfs: allow metadata blocks larger than
the page size") in 2010 and it's been default for mkfs since 3.12
(2013).  The message doesn't really convey any useful information to
users. Remove it.

Reviewed-by: Qu Wenruo <wqu@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>
2022-07-25 17:45:39 +02:00
David Sterba c1867eb33e btrfs: clean up chained assignments
The chained assignments may be convenient to write, but make readability
a bit worse as it's too easy to overlook that there are several values
set on the same line while this is rather an exception.  Making it
consistent everywhere avoids surprises.

The pattern where inode times are initialized reuses the first value and
the order is mtime, ctime. In other blocks the assignments are expanded
so the order of variables is similar to the neighboring code.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:39 +02:00
David Sterba ac0677348f btrfs: merge calculations for simple striped profiles in btrfs_rmap_block
Use the same expression for stripe_nr for RAID0 (map->sub_stripes is 1)
and RAID10 (map->sub_stripes is 2), with equivalent results.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:38 +02:00
David Sterba d09cb9e188 btrfs: use mask for all RAID1* profiles in btrfs_calc_avail_data_space
There's a sequence of hard coded values for RAID1 profiles that are
already stored in the raid_attr table that should be used instead.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:38 +02:00
Nikolay Borisov e26b04c4c9 btrfs: properly flag filesystem with BTRFS_FEATURE_INCOMPAT_BIG_METADATA
Commit 6f93e834fa seemingly inadvertently moved the code responsible
for flagging the filesystem as having BIG_METADATA to a place where
setting the flag was essentially lost. This means that
filesystems created with kernels containing this bug (starting with 5.15)
can potentially be mounted by older (pre-3.4) kernels. In reality
chances for this happening are low because there are other incompat
flags introduced in the mean time. Still the correct behavior is to set
INCOMPAT_BIG_METADATA flag and persist this in the superblock.

Fixes: 6f93e834fa ("btrfs: fix upper limit for max_inline for page size 64K")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@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>
2022-07-25 17:45:38 +02:00
David Sterba c8a5f8ca9a btrfs: print checksum type and implementation at mount time
Per user request, print the checksum type and implementation at mount
time among the messages. The checksum is user configurable and the
actual crypto implementation is useful to see for performance reasons.
The same information is also available after mount in
/sys/fs/FSID/checksum file.

Example:

  [25.323662] BTRFS info (device vdb): using sha256 (sha256-generic) checksum algorithm

Link: https://github.com/kdave/btrfs-progs/issues/483
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:38 +02:00
Josef Bacik 1314ca78b2 btrfs: reset block group chunk force if we have to wait
If you try to force a chunk allocation, but you race with another chunk
allocation, you will end up waiting on the chunk allocation that just
occurred and then allocate another chunk.  If you have many threads all
doing this at once you can way over-allocate chunks.

Fix this by resetting force to NO_FORCE, that way if we think we need to
allocate we can, otherwise we don't force another chunk allocation if
one is already happening.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:38 +02:00
David Sterba 4824735918 btrfs: send: add new command FILEATTR for file attributes
There are file attributes inherited from previous ext2 SETFLAGS/GETFLAGS
and later from XFLAGS interfaces, now commonly found under the
'fileattr' API. This corresponds to the individual inode bits and that's
part of the on-disk format, so this is suitable for the protocol. The
other interfaces contain a lot of cruft or bits that btrfs does not
support yet.

Currently the value is u64 and matches btrfs_inode_item. Not all the
bits can be set by ioctls (like NODATASUM or READONLY), but we can send
them over the protocol and leave it up to the receiving side what and
how to apply.

As some of the flags, eg. IMMUTABLE, can prevent any further changes,
the receiving side needs to understand that and apply the changes in the
right order, or possibly with some intermediate steps. This should be
easier, future proof and simpler on the protocol layer than implementing
in kernel.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:38 +02:00
David Sterba 22a5b2abb7 btrfs: send: add OTIME as utimes attribute for proto 2+ by default
When send v1 was introduced the otime (inode creation time) was not
available, however the attribute in btrfs send protocol exists. Though
it would be possible to add it for v1 too as the attribute would be
ignored by v1 receive, let's not change the layout of v1 and only add
that to v2+.  The otime cannot be changed and is only informative.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:38 +02:00
Qu Wenruo 8f0ed7d4e7 btrfs: output mirror number for bad metadata
When handling a real world transid mismatch image, it's hard to know
which copy is corrupted, as the error messages just look like this:

  BTRFS warning (device dm-3): checksum verify failed on 30408704 wanted 0xcdcdcdcd found 0x3c0adc8e level 0
  BTRFS warning (device dm-3): checksum verify failed on 30408704 wanted 0xcdcdcdcd found 0x3c0adc8e level 0
  BTRFS warning (device dm-3): checksum verify failed on 30408704 wanted 0xcdcdcdcd found 0x3c0adc8e level 0
  BTRFS warning (device dm-3): checksum verify failed on 30408704 wanted 0xcdcdcdcd found 0x3c0adc8e level 0

We don't even know if the retry is caused by btrfs or the VFS retry.

To make things a little easier to read, add mirror number for all
related tree block read errors.

So the above messages would look like this:

  BTRFS warning (device dm-3): checksum verify failed on logical 30408704 mirror 1 wanted 0xcdcdcdcd found 0x3c0adc8e level 0
  BTRFS warning (device dm-3): checksum verify failed on logical 30408704 mirror 2 wanted 0xcdcdcdcd found 0x3c0adc8e level 0
  BTRFS warning (device dm-3): checksum verify failed on logical 30408704 mirror 1 wanted 0xcdcdcdcd found 0x3c0adc8e level 0
  BTRFS warning (device dm-3): checksum verify failed on logical 30408704 mirror 2 wanted 0xcdcdcdcd found 0x3c0adc8e level 0

Signed-off-by: Qu Wenruo <wqu@suse.com>
[ update messages, add "logical" ]
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:38 +02:00
Naohiro Aota aaafa1ebd6 btrfs: replace unnecessary goto with direct return at cow_file_range()
The 'goto out' in cow_file_range() in the exit block are not necessary
and jump back. Replace them with return, while still keeping 'goto out'
in the main code.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ keep goto in the main code, update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:38 +02:00
Naohiro Aota 71aa147b4d btrfs: fix error handling of fallback uncompress write
When cow_file_range() fails in the middle of the allocation loop, it
unlocks the pages but leaves the ordered extents intact. Thus, we need
to call btrfs_cleanup_ordered_extents() to finish the created ordered
extents.

Also, we need to call end_extent_writepage() if locked_page is available
because btrfs_cleanup_ordered_extents() never processes the region on
the locked_page.

Furthermore, we need to set the mapping as error if locked_page is
unavailable before unlocking the pages, so that the errno is properly
propagated to the user space.

CC: stable@vger.kernel.org # 5.18+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:38 +02:00
Naohiro Aota 99826e4cab btrfs: extend btrfs_cleanup_ordered_extents for NULL locked_page
btrfs_cleanup_ordered_extents() assumes locked_page to be non-NULL, so it
is not usable for submit_uncompressed_range() which can have NULL
locked_page.

Add support supports locked_page == NULL case. Also, it rewrites
redundant "page_offset(locked_page)".

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:38 +02:00
Naohiro Aota 9ce7466f37 btrfs: ensure pages are unlocked on cow_file_range() failure
There is a hung_task report on zoned btrfs like below.

https://github.com/naota/linux/issues/59

  [726.328648] INFO: task rocksdb:high0:11085 blocked for more than 241 seconds.
  [726.329839]       Not tainted 5.16.0-rc1+ #1
  [726.330484] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [726.331603] task:rocksdb:high0   state:D stack:    0 pid:11085 ppid: 11082 flags:0x00000000
  [726.331608] Call Trace:
  [726.331611]  <TASK>
  [726.331614]  __schedule+0x2e5/0x9d0
  [726.331622]  schedule+0x58/0xd0
  [726.331626]  io_schedule+0x3f/0x70
  [726.331629]  __folio_lock+0x125/0x200
  [726.331634]  ? find_get_entries+0x1bc/0x240
  [726.331638]  ? filemap_invalidate_unlock_two+0x40/0x40
  [726.331642]  truncate_inode_pages_range+0x5b2/0x770
  [726.331649]  truncate_inode_pages_final+0x44/0x50
  [726.331653]  btrfs_evict_inode+0x67/0x480
  [726.331658]  evict+0xd0/0x180
  [726.331661]  iput+0x13f/0x200
  [726.331664]  do_unlinkat+0x1c0/0x2b0
  [726.331668]  __x64_sys_unlink+0x23/0x30
  [726.331670]  do_syscall_64+0x3b/0xc0
  [726.331674]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [726.331677] RIP: 0033:0x7fb9490a171b
  [726.331681] RSP: 002b:00007fb943ffac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
  [726.331684] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb9490a171b
  [726.331686] RDX: 00007fb943ffb040 RSI: 000055a6bbe6ec20 RDI: 00007fb94400d300
  [726.331687] RBP: 00007fb943ffad00 R08: 0000000000000000 R09: 0000000000000000
  [726.331688] R10: 0000000000000031 R11: 0000000000000246 R12: 00007fb943ffb000
  [726.331690] R13: 00007fb943ffb040 R14: 0000000000000000 R15: 00007fb943ffd260
  [726.331693]  </TASK>

While we debug the issue, we found running fstests generic/551 on 5GB
non-zoned null_blk device in the emulated zoned mode also had a
similar hung issue.

Also, we can reproduce the same symptom with an error injected
cow_file_range() setup.

The hang occurs when cow_file_range() fails in the middle of
allocation. cow_file_range() called from do_allocation_zoned() can
split the give region ([start, end]) for allocation depending on
current block group usages. When btrfs can allocate bytes for one part
of the split regions but fails for the other region (e.g. because of
-ENOSPC), we return the error leaving the pages in the succeeded regions
locked. Technically, this occurs only when @unlock == 0. Otherwise, we
unlock the pages in an allocated region after creating an ordered
extent.

Considering the callers of cow_file_range(unlock=0) won't write out
the pages, we can unlock the pages on error exit from
cow_file_range(). So, we can ensure all the pages except @locked_page
are unlocked on error case.

In summary, cow_file_range now behaves like this:

- page_started == 1 (return value)
  - All the pages are unlocked. IO is started.
- unlock == 1
  - All the pages except @locked_page are unlocked in any case
- unlock == 0
  - On success, all the pages are locked for writing out them
  - On failure, all the pages except @locked_page are unlocked

Fixes: 42c0110009 ("btrfs: zoned: introduce dedicated data write path for zoned filesystems")
CC: stable@vger.kernel.org # 5.12+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:38 +02:00
Ioannis Angelakopoulos 140a8ff765 btrfs: sysfs: export commit stats
Export commit stats in file

  /sys/fs/btrfs/UUID/commit_stats

with example output like:

  commits 123
  last_commit_ms 11
  max_commit_ms 150
  total_commit_ms 2000

The values are in one file so reading them at a single time will give a
more consistent view. The stats are internally tracked in nanoseconds so
the cumulative values should not suffer from rounding errors.

Writing 0 to the file 'commit_stats' will reset max_commit_ms.
Initial values are set at first mount of the filesystem.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Ioannis Angelakopoulos <iangelak@fb.com>
[ update changelog ]
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:37 +02:00
Ioannis Angelakopoulos e55958c8a0 btrfs: collect commit stats, count, duration
Track several stats about transaction commit, to be later exported via
sysfs:

- number of commits so far
- duration of the last commit in ns
- maximum commit duration seen so far in ns
- total duration for all commits so far in ns

The update of the commit stats occurs after the commit thread has gone
through all the logic that checks if there is another thread committing
at the same time. This means that we only account for actual commit work
in the commit stats we report and not the time the thread spends waiting
until it is ready to do the commit work.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Ioannis Angelakopoulos <iangelak@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:37 +02:00
Christoph Hellwig f3e90c1ca9 btrfs: remove extent writepage address space operation
Same as in commit 21b4ee7029 ("xfs: drop ->writepage completely"): we
can remove the callback as it's only used in one place - single page
writeback from memory reclaim and is not called for cgroup writeback at
all.

We only allow such writeback from kswapd, not from direct memory
reclaim, and so it is rarely used. When it comes from kswapd, it is
effectively random dirty page shoot-down, which is horrible for IO
patterns. We can rely on background writeback to clean all dirty pages
in an efficient way and not let it be interrupted by kswapd.

Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:37 +02:00
David Sterba 9555e1f188 btrfs: send: use boolean types for current inode status
The new, new_gen and deleted indicate a status, use boolean type instead
of int.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:37 +02:00
David Sterba cec3dad943 btrfs: send: remove old TODO regarding ERESTARTSYS
The whole send operation is restartable and handling properly a buffer
write may not be easy. We can't know what caused that and if a short
delay and retry will fix it or how many retries should be performed in
case it's a temporary condition.

The error value is returned to the ioctl caller so in case it's
transient problem, the user would be notified about the reason. Remove
the TODO note as there's no plan to handle ERESTARTSYS.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:37 +02:00
David Sterba 8234d3f658 btrfs: send: simplify includes
We don't need the whole ctree.h in send.h, none of the data types
defined there are used.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:37 +02:00
David Sterba e3b4b9040b btrfs: send: drop __KERNEL__ ifdef from send.h
We don't need this ifdef as the header file is not shared, the protocol
definition used by userspace should be from libbtrfs or libbtrfsutil.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:37 +02:00
Christoph Hellwig ee5b46a353 btrfs: increase direct io read size limit to 256 sectors
Btrfs currently limits direct I/O reads to a single sector, which goes
back to commit c329861da4 ("Btrfs: don't allocate a separate csums
array for direct reads") from Josef.  That commit changes the direct I/O
code to ".. use the private part of the io_tree for our csums.", but ten
years later that isn't how checksums for direct reads work, instead they
use a csums allocation on a per-btrfs_dio_private basis (which have their
own performance problem for small I/O, but that will be addressed later).

There is no fundamental limit in btrfs itself to limit the I/O size
except for the size of the checksum array that scales linearly with
the number of sectors in an I/O.  Pick a somewhat arbitrary limit of
256 limits, which matches what the buffered reads typically see as
the upper limit as the limit for direct I/O as well.

This significantly improves direct read performance.  For example a fio
run doing 1 MiB aio reads with a queue depth of 1 roughly triples the
throughput:

Baseline:

READ: bw=65.3MiB/s (68.5MB/s), 65.3MiB/s-65.3MiB/s (68.5MB/s-68.5MB/s), io=19.1GiB (20.6GB), run=300013-300013msec

With this patch:

READ: bw=196MiB/s (206MB/s), 196MiB/s-196MiB/s (206MB/s-206MB/s), io=57.5GiB (61.7GB), run=300006-300006msc

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:37 +02:00
Qu Wenruo f6065f8ede btrfs: raid56: don't trust any cached sector in __raid56_parity_recover()
[BUG]
There is a small workload which will always fail with recent kernel:
(A simplified version from btrfs/125 test case)

  mkfs.btrfs -f -m raid5 -d raid5 -b 1G $dev1 $dev2 $dev3
  mount $dev1 $mnt
  xfs_io -f -c "pwrite -S 0xee 0 1M" $mnt/file1
  sync
  umount $mnt
  btrfs dev scan -u $dev3
  mount -o degraded $dev1 $mnt
  xfs_io -f -c "pwrite -S 0xff 0 128M" $mnt/file2
  umount $mnt
  btrfs dev scan
  mount $dev1 $mnt
  btrfs balance start --full-balance $mnt
  umount $mnt

The failure is always failed to read some tree blocks:

  BTRFS info (device dm-4): relocating block group 217710592 flags data|raid5
  BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7
  BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7
  ...

[CAUSE]
With the recently added debug output, we can see all RAID56 operations
related to full stripe 38928384:

  56.1183: raid56_read_partial: full_stripe=38928384 devid=2 type=DATA1 offset=0 opf=0x0 physical=9502720 len=65536
  56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=16384 opf=0x0 physical=9519104 len=16384
  56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x0 physical=9551872 len=16384
  56.1187: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=0 opf=0x1 physical=9502720 len=16384
  56.1188: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=32768 opf=0x1 physical=9535488 len=16384
  56.1188: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=0 opf=0x1 physical=30474240 len=16384
  56.1189: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=32768 opf=0x1 physical=30507008 len=16384
  56.1218: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x1 physical=9551872 len=16384
  56.1219: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=49152 opf=0x1 physical=30523392 len=16384
  56.2721: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2
  56.2723: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2
  56.2724: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2

Before we enter raid56_parity_recover(), we have triggered some metadata
write for the full stripe 38928384, this leads to us to read all the
sectors from disk.

Furthermore, btrfs raid56 write will cache its calculated P/Q sectors to
avoid unnecessary read.

This means, for that full stripe, after any partial write, we will have
stale data, along with P/Q calculated using that stale data.

Thankfully due to patch "btrfs: only write the sectors in the vertical stripe
which has data stripes" we haven't submitted all the corrupted P/Q to disk.

When we really need to recover certain range, aka in
raid56_parity_recover(), we will use the cached rbio, along with its
cached sectors (the full stripe is all cached).

This explains why we have no event raid56_scrub_read_recover()
triggered.

Since we have the cached P/Q which is calculated using the stale data,
the recovered one will just be stale.

In our particular test case, it will always return the same incorrect
metadata, thus causing the same error message "parent transid verify
failed on 39010304 wanted 9 found 7" again and again.

[BTRFS DESTRUCTIVE RMW PROBLEM]

Test case btrfs/125 (and above workload) always has its trouble with
the destructive read-modify-write (RMW) cycle:

        0       32K     64K
Data1:  | Good  | Good  |
Data2:  | Bad   | Bad   |
Parity: | Good  | Good  |

In above case, if we trigger any write into Data1, we will use the bad
data in Data2 to re-generate parity, killing the only chance to recovery
Data2, thus Data2 is lost forever.

This destructive RMW cycle is not specific to btrfs RAID56, but there
are some btrfs specific behaviors making the case even worse:

- Btrfs will cache sectors for unrelated vertical stripes.

  In above example, if we're only writing into 0~32K range, btrfs will
  still read data range (32K ~ 64K) of Data1, and (64K~128K) of Data2.
  This behavior is to cache sectors for later update.

  Incidentally commit d4e28d9b5f ("btrfs: raid56: make steal_rbio()
  subpage compatible") has a bug which makes RAID56 to never trust the
  cached sectors, thus slightly improve the situation for recovery.

  Unfortunately, follow up fix "btrfs: update stripe_sectors::uptodate in
  steal_rbio" will revert the behavior back to the old one.

- Btrfs raid56 partial write will update all P/Q sectors and cache them

  This means, even if data at (64K ~ 96K) of Data2 is free space, and
  only (96K ~ 128K) of Data2 is really stale data.
  And we write into that (96K ~ 128K), we will update all the parity
  sectors for the full stripe.

  This unnecessary behavior will completely kill the chance of recovery.

  Thankfully, an unrelated optimization "btrfs: only write the sectors
  in the vertical stripe which has data stripes" will prevent
  submitting the write bio for untouched vertical sectors.

  That optimization will keep the on-disk P/Q untouched for a chance for
  later recovery.

[FIX]
Although we have no good way to completely fix the destructive RMW
(unless we go full scrub for each partial write), we can still limit the
damage.

With patch "btrfs: only write the sectors in the vertical stripe which
has data stripes" now we won't really submit the P/Q of unrelated
vertical stripes, so the on-disk P/Q should still be fine.

Now we really need to do is just drop all the cached sectors when doing
recovery.

By this, we have a chance to read the original P/Q from disk, and have a
chance to recover the stale data, while still keep the cache to speed up
regular write path.

In fact, just dropping all the cache for recovery path is good enough to
allow the test case btrfs/125 along with the small script to pass
reliably.

The lack of metadata write after the degraded mount, and forced metadata
COW is saving us this time.

So this patch will fix the behavior by not trust any cache in
__raid56_parity_recover(), to solve the problem while still keep the
cache useful.

But please note that this test pass DOES NOT mean we have solved the
destructive RMW problem, we just do better damage control a little
better.

Related patches:

- btrfs: only write the sectors in the vertical stripe
- d4e28d9b5f ("btrfs: raid56: make steal_rbio() subpage compatible")
- btrfs: update stripe_sectors::uptodate in steal_rbio

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:37 +02:00
Christoph Hellwig 711f447b4f btrfs: remove the finish_func argument to btrfs_mark_ordered_io_finished
finish_func is always set to finish_ordered_fn, so remove it and also
the now pointless and somewhat confusingly named
__endio_write_update_ordered wrapper.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:37 +02:00
Nikolay Borisov 1f4f639fe7 btrfs: batch up release of reserved metadata for delayed items used for deletion
With Filipe's recent rework of the delayed inode code one aspect which
isn't batched is the release of the reserved metadata of delayed inode's
delete items. With this patch on top of Filipe's rework and running the
same test as provided in the description of a patch titled
"btrfs: improve batch deletion of delayed dir index items" I observe
the following change of the number of calls to btrfs_block_rsv_release:

Before this change:
- block_rsv_release:                      1004
- btrfs_delete_delayed_items_total_time: 14602
- delete_batches:                          505

After:
- block_rsv_release:                       510
- btrfs_delete_delayed_items_total_time: 13643
- delete_batches:                          507

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:37 +02:00
Qu Wenruo 3613249a1b btrfs: warn about dev extents that are inside the reserved range
Btrfs on-disk format has reserved the first 1MiB for the primary super
block (at 64KiB offset) and bootloaders may also use this space.

This behavior is only introduced since v4.1 btrfs-progs release,
although kernel can ensure we never touch the reserved range of super
blocks, it's better to inform the end users, and a balance will resolve
the problem.

Signed-off-by: Qu Wenruo <wqu@suse.com>
[ update changelog and message ]
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:36 +02:00
Qu Wenruo 37f85ec320 btrfs: use named constant for reserved device space
There's a reserved space on each device of size 1MiB that can be used by
bootloaders or to avoid accidental overwrite. Use a symbolic constant
with the explaining comment instead of hard coding the value and
multiple comments.

Note: since btrfs-progs v4.1, mkfs.btrfs will reserve the first 1MiB for
the primary super block (at offset 64KiB), until then the range could
have been used by mistake. Kernel has been always respecting the 1MiB
range for writes.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:36 +02:00
David Sterba bfceac7fd3 btrfs: remove unused typedefs get_extent_t and btrfs_work_func_t
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:36 +02:00
David Sterba e3059ec06b btrfs: sink iterator parameter to btrfs_ioctl_logical_to_ino
There's only one function we pass to iterate_inodes_from_logical as
iterator, so we can drop the indirection and call it directly, after
moving the function to backref.c

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:36 +02:00
David Sterba 875d1daa7b btrfs: simplify parameters of backref iterators
The inode reference iterator interface takes parameters that are derived
from the context parameter, but as it's a void* type the values are
passed individually.

Change the ctx type to inode_fs_path as it's the only thing we pass and
drop any parameters that are derived from that.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:36 +02:00
David Sterba ad6240f662 btrfs: call inode_to_path directly and drop indirection
The functions for iterating inode reference take a function parameter
but there's only one value, inode_to_path(). Remove the indirection and
call the function. As paths_from_inode would become just an alias for
iterate_irefs(), merge the two into one function.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:36 +02:00
Qu Wenruo 6d322b4839 btrfs: use ncopies from btrfs_raid_array in btrfs_num_copies()
For all non-RAID56 profiles, we can use btrfs_raid_array[].ncopies
directly, only for RAID5 and RAID6 we need some extra handling as
there's no table value for that.

For RAID10 there's a change from sub_stripes to ncopies. The values are
the same but semantically we want to use number of copies, as this is
what btrfs_num_copies does.

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>
2022-07-25 17:45:36 +02:00
Qu Wenruo 0b30f71945 btrfs: use btrfs_raid_array to calculate number of parity stripes
Use the raid table instead of hard coded values and rename the helper as
it is exported.  This could make later extension on RAID56 based
profiles easier.

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>
2022-07-25 17:45:36 +02:00
Qu Wenruo 6dead96c1a btrfs: use btrfs_chunk_max_errors() to replace tolerance calculation
In __btrfs_map_block() we have an assignment to @max_errors using
nr_parity_stripes().

Although it works for RAID56 it's confusing.  Replace it with
btrfs_chunk_max_errors().

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>
2022-07-25 17:45:36 +02:00
Qu Wenruo bc88b486d5 btrfs: remove parameter dev_extent_len from scrub_stripe()
For scrub_stripe() we can easily calculate the dev extent length as we
have the full info of the chunk.

Thus there is no need to pass @dev_extent_len from the caller, and we
introduce a helper, btrfs_calc_stripe_length(), to do the calculation
from extent_map structure.

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>
2022-07-25 17:45:36 +02:00
David Sterba 9db33891c7 btrfs: unify tree search helper returning prev and next nodes
Simplify helper to return only next and prev pointers, we don't need all
the node/parent/prev/next pointers of __etree_search as there are now
other specialized helpers. Rename parameters so they follow the naming.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:36 +02:00
David Sterba ec60c76f53 btrfs: make tree search for insert more generic and use it for tree_search
With a slight extension of tree_search_for_insert (fill the return node
and parent return parameters) we can avoid calling __etree_search from
tree_search, that could be removed eventually in followup patches.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
David Sterba bebb22c13d btrfs: open code inexact rbtree search in tree_search
The call chain from

tree_search
  tree_search_for_insert
    __etree_search

can be open coded and allow further simplifications, here we need a tree
search with fallback to the next node in case it's not found. This is
represented as __etree_search parameters next_ret=valid, prev_ret=NULL.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
David Sterba c367602a78 btrfs: remove node and parent parameters from insert_state
There's no caller left that would pass valid pointers to insert_state so
we can drop them.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
David Sterba fb8f07d2d8 btrfs: add fast path for extent_state insertion
In two cases the exact location where to insert the extent state is
known at the call time so we don't need to pass it to insert_state that
takes the fast path.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
David Sterba 6d92b304ec btrfs: pass bits by value not by pointer for extent_state helpers
The bits are passed to all extent state helpers for no apparent reason,
the value only read and never updated so remove the indirection and pass
it directly. Also unify the type to u32 where needed.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
David Sterba cee5126825 btrfs: lift start and end parameters to callers of insert_state
Let callers of insert_state to set up the extent state to allow further
simplifications of the parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
David Sterba c7e118cf98 btrfs: open code rbtree search in insert_state
The rbtree search is a known pattern and can be open coded, allowing to
remove the tree_insert and further cleanups.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
David Sterba 12c9cdda62 btrfs: open code rbtree search in split_state
Preparatory work to remove tree_insert from extent_io.c, the rbtree
search loop is a known and simple so it can be open coded.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
Qu Wenruo 1c10702e7c btrfs: raid56: avoid double for loop inside raid56_parity_scrub_stripe()
Originally it's iterating all the sectors which has dbitmap sector for
the vertical stripe.

It can be easily converted to sector bytenr iteration with an test_bit()
call.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
Qu Wenruo 550cdeb3e0 btrfs: raid56: avoid double for loop inside raid56_rmw_stripe()
This function doesn't even utilize full stripe skip, just iterate all
the data sectors is definitely enough.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
Qu Wenruo aee35e4bcc btrfs: raid56: avoid double for loop inside alloc_rbio_essential_pages()
The double loop is just checking if the page for the vertical stripe
is allocated.

We can easily convert it to single loop and get rid of @stripe variable.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
Qu Wenruo ef340fccbe btrfs: raid56: avoid double for loop inside __raid56_parity_recover()
The double for loop can be easily converted to single for loop as we're
really iterating the sectors in their bytenr order.

The only exception is the full stripe skip, however that can also easily
be done inside the loop.  Add an ASSERT() along with a comment for that
specific case.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:35 +02:00
Qu Wenruo 3692004465 btrfs: raid56: avoid double for loop inside finish_rmw()
We can easily calculate the stripe number and sector number inside the
stripe.  Thus there is not much need for a double for loop.

For the only case we want to skip the whole stripe, we can manually
increase @total_sector_nr.
This is not a recommended behavior, thus every time the iterator gets
modified there will be a comment along with an ASSERT() for it.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:34 +02:00
Josef Bacik f31f09f6be btrfs: tree-log: make the return value for log syncing consistent
Currently we will return 1 or -EAGAIN if we decide we need to commit
the transaction rather than sync the log.  In practice this doesn't
really matter, we interpret any !0 and !BTRFS_NO_LOG_SYNC as needing to
commit the transaction.  However this makes it hard to figure out what
the correct thing to do is.

Fix this up by defining BTRFS_LOG_FORCE_COMMIT and using this in all the
places where we want to force the transaction to be committed.

CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@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>
2022-07-25 17:45:34 +02:00
Johannes Thumshirn 5bea250881 btrfs: add tracepoints for ordered extents
When debugging a reference counting issue with ordered extents, I've found
we're lacking a lot of tracepoint coverage in the ordered extent code.

Close these gaps by adding tracepoints after every refcount_inc() in the
ordered extent code.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.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>
2022-07-25 17:45:34 +02:00
David Sterba 15dcccdb8b btrfs: sysfs: advertise zoned support among features
We've hidden the zoned support in sysfs under debug config for the first
releases but now the stability is reasonable, though not all features
have been implemented.

Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:34 +02:00
Christoph Hellwig a4012f06f1 btrfs: split discard handling out of btrfs_map_block
Mapping block for discard doesn't really share any code with the regular
block mapping case.  Split it out into an entirely separate helper
that just returns an array of btrfs_discard_stripe structures and the
number of stripes.

This removes the need for the length field in the btrfs_io_context
structure, so remove tht.

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>
2022-07-25 17:45:34 +02:00
Christoph Hellwig 5eecef7108 btrfs: stop looking at btrfs_bio->iter in index_one_bio
All the bios that index_one_bio operates on are the bios submitted by the
upper layer.  These are never resubmitted to an actual device by the
raid56 code, and thus the iter never changes from the initial state.
Thus we can always just use bi_iter directly as it will be the same as
the saved copy.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:34 +02:00
Qu Wenruo dc4d316849 btrfs: reject log replay if there is unsupported RO compat flag
[BUG]
If we have a btrfs image with dirty log, along with an unsupported RO
compatible flag:

log_root		30474240
...
compat_flags		0x0
compat_ro_flags		0x40000003
			( FREE_SPACE_TREE |
			  FREE_SPACE_TREE_VALID |
			  unknown flag: 0x40000000 )

Then even if we can only mount it RO, we will still cause metadata
update for log replay:

  BTRFS info (device dm-1): flagging fs with big metadata feature
  BTRFS info (device dm-1): using free space tree
  BTRFS info (device dm-1): has skinny extents
  BTRFS info (device dm-1): start tree-log replay

This is definitely against RO compact flag requirement.

[CAUSE]
RO compact flag only forces us to do RO mount, but we will still do log
replay for plain RO mount.

Thus this will result us to do log replay and update metadata.

This can be very problematic for new RO compat flag, for example older
kernel can not understand v2 cache, and if we allow metadata update on
RO mount and invalidate/corrupt v2 cache.

[FIX]
Just reject the mount unless rescue=nologreplay is provided:

  BTRFS error (device dm-1): cannot replay dirty log with unsupport optional features (0x40000000), try rescue=nologreplay instead

We don't want to set rescue=nologreply directly, as this would make the
end user to read the old data, and cause confusion.

Since the such case is really rare, we're mostly fine to just reject the
mount with an error message, which also includes the proper workaround.

CC: stable@vger.kernel.org #4.9+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:34 +02:00
Qu Wenruo 97f09d55f1 btrfs: make btrfs_super_block::log_root_transid deprecated
When using "btrfs inspect-internal dump-super" to inspect an fs with
dirty log, it always shows the log_root_transid as 0:

  log_root                30474240
  log_root_transid        0 <<<
  log_root_level          0

It turns out that, btrfs_super_block::log_root_transid is never really
utilized (even no read for it).

This can date back to the introduction of btrfs into upstream kernel.

In fact, when reading log tree root, we always use
btrfs_super_block::generation + 1 as the expected generation.
So here we're completely safe to mark this member deprecated.

In theory we can easily reuse this member for other purposes, but to be
extra safe, here we follow the leafsize way, by adding "__unused_" for
log_root_transid.
And we can safely remove the accessors, since there is no such callers
from the very beginning.

Reviewed-by: Filipe Manana <fdmanana@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>
2022-07-25 17:45:34 +02:00
Christoph Hellwig 722c82ac9e btrfs: pass the btrfs_bio_ctrl to submit_one_bio
submit_one_bio always works on the bio and compression flags from a
btrfs_bio_ctrl structure.  Pass the explicitly and clean up the
calling conventions by handling a NULL bio in submit_one_bio, and
using the btrfs_bio_ctrl to pass the mirror number as well.

Reviewed-by: Qu Wenruo <wqu@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>
2022-07-25 17:45:34 +02:00
Christoph Hellwig 9845e5ddcb btrfs: merge end_write_bio and flush_write_bio
Merge end_write_bio and flush_write_bio into a single submit_write_bio
helper, that either submits the bio or ends it if a negative errno was
passed in.  This consolidates a lot of duplicated checks in the callers.

Reviewed-by: Qu Wenruo <wqu@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>
2022-07-25 17:45:34 +02:00
Christoph Hellwig 2d5ac130fa btrfs: don't use bio->bi_private to pass the inode to submit_one_bio
submit_one_bio is only used for page cache I/O, so the inode can be
trivially derived from the first page in the bio.

Reviewed-by: Qu Wenruo <wqu@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>
2022-07-25 17:45:34 +02:00
David Sterba 234fdd2815 btrfs: remove redundant check in up check_setget_bounds
There are two separate checks in the bounds checker, the first one being
a special case of the second. As this function is performance critical
due to checking access to any eb member, reducing the size can slightly
improve performance.

On a release build on x86_64 the helper is completely inlined so the
function call overhead is also gone.

There was a report of 5% performance drop on metadata heavy workload,
that disappeared after disabling asserts. The most significant part of
that is the bounds checker.

https://lore.kernel.org/linux-btrfs/20200724164147.39925-1-josef@toxicpanda.com/

After the analysis, the optimized code removes the worst overhead which
is the function call and the performance was restored.

https://lore.kernel.org/linux-btrfs/20200730110943.GE3703@twin.jikos.cz/

1. baseline, asserts on, setget check on

run time:		46s
run time with perf:	48s

2. asserts on, comment out setget check

run time:		44s
run time with perf:	47s

So this is confirms the 5% difference

3. asserts on, optimized seget check

run time:		44s
run time with perf:	47s

The optimizations are reducing the number of ifs to 1 and inlining the
hot path. Low-level stuff, gets the performance back. Patch below.

4. asserts off, no setget check

run time:		44s
run time with perf:	45s

This verifies that asserts other than the setget check have negligible
impact on performance and it's not harmful to keep them on.

Analysis where the performance is lost:

* check_setget_bounds is short function, but it's still a function call,
  changing the flow of instructions and given how many times it's
  called the overhead adds up

* there are two conditions, one to check if the range is
  completely outside (member_offset > eb->len) or partially inside
  (member_offset + size > eb->len)

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:33 +02:00
Fabio M. De Francesco 51c0674a56 btrfs: replace kmap() with kmap_local_page() in lzo.c
The use of kmap() is being deprecated in favor of kmap_local_page() where
it is feasible. With kmap_local_page(), the mapping is per thread, CPU
local and not globally visible.

Therefore, use kmap_local_page() / kunmap_local() in lzo.c wherever the
mappings are per thread and not globally visible.

Tested on QEMU + KVM 32 bits VM with 4GB of RAM and HIGHMEM64G enabled.

Suggested-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:33 +02:00
Fabio M. De Francesco 70826b6bd5 btrfs: replace kmap() with kmap_local_page() in inode.c
The use of kmap() is being deprecated in favor of kmap_local_page() where
it is feasible. With kmap_local_page(), the mapping is per thread, CPU
local and not globally visible.

Therefore, use kmap_local_page() / kunmap_local() in inode.c wherever the
mappings are per thread and not globally visible.

Tested on QEMU + KVM 32 bits VM with 4GB of RAM and HIGHMEM64G enabled.

Suggested-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:33 +02:00
Christoph Hellwig 9ff7ddd3c7 btrfs: do not allocate a btrfs_bio for low-level bios
The bios submitted from btrfs_map_bio don't really interact with the
rest of btrfs and the only btrfs_bio member actually used in the
low-level bios is the pointer to the btrfs_io_context used for endio
handler.

Use a union in struct btrfs_io_stripe that allows the endio handler to
find the btrfs_io_context and remove the spurious ->device assignment
so that a plain fs_bio_set bio can be used for the low-level bios
allocated inside btrfs_map_bio.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:33 +02:00
Christoph Hellwig a316a25991 btrfs: factor stripe submission logic out of btrfs_map_bio
Move all per-stripe handling into submit_stripe_bio and use a label to
cleanup instead of duplicating the logic.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:33 +02:00
Christoph Hellwig d7b9416fe5 btrfs: remove btrfs_end_io_wq
All reads bio that go through btrfs_map_bio need to be completed in
user context.  And read I/Os are the most common and timing critical
in almost any file system workloads.

Embed a work_struct into struct btrfs_bio and use it to complete all
read bios submitted through btrfs_map, using the REQ_META flag to decide
which workqueue they are placed on.

This removes the need for a separate 128 byte allocation (typically
rounded up to 192 bytes by slab) for all reads with a size increase
of 24 bytes for struct btrfs_bio.  Future patches will reorganize
struct btrfs_bio to make use of this extra space for writes as well.

(All sizes are based a on typical 64-bit non-debug build)

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:33 +02:00
Christoph Hellwig 08a6f46434 btrfs: centralize setting REQ_META
Set REQ_META in btrfs_submit_metadata_bio instead of the various callers.
We'll start relying on this flag inside of btrfs in a bit, and this
ensures it is always set correctly.

Reviewed-by: Qu Wenruo <wqu@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>
2022-07-25 17:45:33 +02:00
Christoph Hellwig fed8a72df1 btrfs: don't use btrfs_bio_wq_end_io for compressed writes
Compressed write bio completion is the only user of btrfs_bio_wq_end_io
for writes, and the use of btrfs_bio_wq_end_io is a little suboptimal
here as we only real need user context for the final completion of a
compressed_bio structure, and not every single bio completion.

Add a work_struct to struct compressed_bio instead and use that to call
finish_compressed_bio_write.  This allows to remove all handling of
write bios in the btrfs_bio_wq_end_io infrastructure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:33 +02:00
Christoph Hellwig 02bb5b7247 btrfs: don't double-defer bio completions for compressed reads
The bio completion handler of the bio used for the compressed data is
already run in a workqueue using btrfs_bio_wq_end_io, so don't schedule
the completion of the original bio to the same workqueue again but just
execute it directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:33 +02:00
Christoph Hellwig d34e123de1 btrfs: defer I/O completion based on the btrfs_raid_bio
Instead of attaching an extra allocation an indirect call to each
low-level bio issued by the RAID code, add a work_struct to struct
btrfs_raid_bio and only defer the per-rbio completion action.  The
per-bio action for all the I/Os are trivial and can be safely done
from interrupt context.

As a nice side effect this also allows sharing the boilerplate code
for the per-bio completions

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:33 +02:00
Christoph Hellwig c93104e758 btrfs: split btrfs_submit_data_bio to read and write parts
Split btrfs_submit_data_bio into one helper for reads and one for writes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:33 +02:00
Christoph Hellwig e6484bd488 btrfs: simplify code flow in btrfs_submit_dio_bio
There is no exit block and cleanup and the function is reasonably short
so we can use inline return and not the goto. This makes the function
more straight forward.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@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>
2022-07-25 17:45:33 +02:00
Christoph Hellwig b4c46bdea9 btrfs: move more work into btrfs_end_bioc
Assign ->mirror_num and ->bi_status in btrfs_end_bioc instead of
duplicating the logic in the callers.  Also remove the bio argument as
it always must be bioc->orig_bio and the now pointless bioc_error that
did nothing but assign bi_sector to the same value just sampled in the
caller.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@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>
2022-07-25 17:45:32 +02:00
Omar Sandoval d681559280 btrfs: send: enable support for stream v2 and compressed writes
Now that the new support is implemented, allow the ioctl to accept v2
and the compressed flag, and update the version in sysfs.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:32 +02:00
Omar Sandoval 3ea4dc5bf0 btrfs: send: send compressed extents with encoded writes
Now that all of the pieces are in place, we can use the ENCODED_WRITE
command to send compressed extents when appropriate.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:32 +02:00
Omar Sandoval a4b333f227 btrfs: send: get send buffer pages for protocol v2
For encoded writes in send v2, we will get the encoded data with
btrfs_encoded_read_regular_fill_pages(), which expects a list of raw
pages. To avoid extra buffers and copies, we should read directly into
the send buffer. Therefore, we need the raw pages for the send buffer.

We currently allocate the send buffer with kvmalloc(), which may return
a kmalloc'd buffer or a vmalloc'd buffer. For vmalloc, we can get the
pages with vmalloc_to_page(). For kmalloc, we could use virt_to_page().
However, the buffer size we use (144K) is not a power of two, which in
theory is not guaranteed to return a page-aligned buffer, and in
practice would waste a lot of memory due to rounding up to the next
power of two. 144K is large enough that it usually gets allocated with
vmalloc(), anyways. So, for send v2, replace kvmalloc() with vmalloc()
and save the pages in an array.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:32 +02:00
Omar Sandoval 356bbbb66b btrfs: send: write larger chunks when using stream v2
The length field of the send stream TLV header is 16 bits. This means
that the maximum amount of data that can be sent for one write is 64K
minus one. However, encoded writes must be able to send the maximum
compressed extent (128K) in one command, or more. To support this, send
stream version 2 encodes the DATA attribute differently: it has no
length field, and the length is implicitly up to the end of containing
command (which has a 32bit length field). Although this is necessary
for encoded writes, normal writes can benefit from it, too.

Also add a check to enforce that the DATA attribute is last. It is only
strictly necessary for v2, but we might as well make v1 consistent with
it.

For v2, let's bump up the send buffer to the maximum compressed extent
size plus 16K for the other metadata (144K total). Since this will most
likely be vmalloc'd (and always will be after the next commit), we round
it up to the next page since we might as well use the rest of the page
on systems with >16K pages.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:32 +02:00
Omar Sandoval b7c14f23fb btrfs: send: add stream v2 definitions
This adds the definitions of the new commands for send stream version 2
and their respective attributes: fallocate, FS_IOC_SETFLAGS (a.k.a.
chattr), and encoded writes. It also documents two changes to the send
stream format in v2: the receiver shouldn't assume a maximum command
size, and the DATA attribute is encoded differently to allow for writes
larger than 64k. These will be implemented in subsequent changes, and
then the ioctl will accept the new version and flag.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:32 +02:00
Omar Sandoval 54cab6aff8 btrfs: send: explicitly number commands and attributes
Commit e77fbf9903 ("btrfs: send: prepare for v2 protocol") added
_BTRFS_SEND_C_MAX_V* macros equal to the maximum command number for the
version plus 1, but as written this creates gaps in the number space.

The maximum command number is currently 22, and __BTRFS_SEND_C_MAX_V1 is
accordingly 23. But then __BTRFS_SEND_C_MAX_V2 is 24, suggesting that v2
has a command numbered 23, and __BTRFS_SEND_C_MAX is 25, suggesting that
23 and 24 are valid commands.

Instead, let's explicitly number all of the commands, attributes, and
sentinel MAX constants.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:32 +02:00
Omar Sandoval ca182acc53 btrfs: send: remove unused send_ctx::{total,cmd}_send_size
We collect these statistics but have never exposed them in any way. I
also didn't find any patches that ever attempted to make use of them.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:32 +02:00
Stefan Roesch 22c55e3bbb btrfs: sysfs: add force_chunk_alloc trigger to force allocation
Adds write-only trigger to force new chunk allocation for a given block
group type. It is at

  /sys/fs/btrfs/<uuid>/allocation/<type>/force_chunk_alloc

Note: this is now only for debugging and testing and is enabled with the
      CONFIG_BTRFS_DEBUG configuration option. The transaction is
      started from sysfs context and can be problematic in some cases.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ Changes from the original submission:
  - update changelog
  - drop unnecessary error messages
  - switch value to bool and use kstrtobool
  - move BTRFS_ATTR_W definition
  - add comment for using transaction
]
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:32 +02:00
Stefan Roesch 19fc516a51 btrfs: sysfs: export chunk size in space infos
Add new sysfs knob

  /sys/fs/btrfs/<uuid>/allocation/<type>/chunk_size.

This allows to query the chunk size and also set the chunk size.

Constraints:

- can be changed by root only
- system chunk size can't be set
- maximum chunk size is 10% of the filesystem size
- final value is rounded down to a multiple of 256M
- cannot be set on zoned filesystem

Note, that rounding and the 10% clamp will result to a different value
on filesystems smaller than 10G, typically 768M.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ Changes to original submission:
  - document setting constraints
  - drop read-only requirement
  - drop unnecessary error messages
  - fix return values of _store callback
  - use memparse for the value
  - fix rounding down to 256M
]
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:32 +02:00
Stefan Roesch f6fca3917b btrfs: store chunk size in space-info struct
The chunk size is stored in the btrfs_space_info structure.  It is
initialized at the start and is then used.

A new API is added to update the current chunk size.  This API is used
to be able to expose the chunk_size as a sysfs setting.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ rename and merge helpers, switch atomic type to u64, style fixes ]
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:32 +02:00
Josef Bacik 71b68e9e35 btrfs: do not batch insert non-consecutive dir indexes during log replay
While running generic/475 in a loop I got the following error

BTRFS critical (device dm-11): corrupt leaf: root=5 block=31096832 slot=69, bad key order, prev (263 96 531) current (263 96 524)
<snip>
 item 65 key (263 96 517) itemoff 14132 itemsize 33
 item 66 key (263 96 523) itemoff 14099 itemsize 33
 item 67 key (263 96 525) itemoff 14066 itemsize 33
 item 68 key (263 96 531) itemoff 14033 itemsize 33
 item 69 key (263 96 524) itemoff 14000 itemsize 33

As you can see here we have 3 dir index keys with the dir index value of
523, 524, and 525 inserted between 517 and 524.  This occurs because our
dir index insertion code will bulk insert all dir index items on the
node regardless of their actual key value.

This makes sense on a normally running system, because if there's a gap
in between the items there was a deletion before the item was inserted,
so there's not going to be an overlap of the dir index items that need
to be inserted and what exists on disk.

However during log replay this isn't necessarily true, we could have any
number of dir indexes in the tree already.

Fix this by seeing if we're replaying the log, and if we are simply skip
batching if there's a gap in the key space.

This file system was left broken from the fstest, I tested this patch
against the broken fs to make sure it replayed the log properly, and
then btrfs checked the file system after the log replay to verify
everything was ok.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:14 +02:00
Filipe Manana 763748b238 btrfs: reduce amount of reserved metadata for delayed item insertion
Whenever we want to create a new dir index item (when creating an inode,
create a hard link, rename a file) we reserve 1 unit of metadata space
for it in a transaction (that's 256K for a node/leaf size of 16K), and
then create a delayed insertion item for it to be added later to the
subvolume's tree. That unit of metadata is kept until the delayed item
is inserted into the subvolume tree, which may take a while to happen
(in the worst case, it's done only when the transaction commits). If we
have multiple dir index items to insert for the same directory, say N
index items, and they all fit in a single leaf of metadata, then we are
holding N units of reserved metadata space when all we need is 1 unit.

This change addresses that, whenever a new delayed dir index item is
added, we release the unit of metadata the caller has reserved when it
started the transaction if adding that new dir index item does not
result in touching one more metadata leaf, otherwise the reservation
is kept by transferring it from the transaction block reserve to the
delayed items block reserve, just like before. Given that with a leaf
size of 16K we can have a few hundred dir index items in a single leaf
(the exact value depends on file name lengths), this reduces pressure on
metadata reservation by releasing unnecessary space much sooner.

The following fs_mark test showed some improvement when creating many
files in parallel on machine running a non debug kernel (debian's default
kernel config) with 12 cores:

  $ cat test.sh
  #!/bin/bash

  DEV=/dev/nvme0n1
  MNT=/mnt/nvme0n1
  MOUNT_OPTIONS="-o ssd"
  FILES=100000
  THREADS=$(nproc --all)

  echo "performance" | \
      tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

  mkfs.btrfs -f $DEV
  mount $MOUNT_OPTIONS $DEV $MNT

  OPTS="-S 0 -L 10 -n $FILES -s 0 -t $THREADS -k"
  for ((i = 1; i <= $THREADS; i++)); do
      OPTS="$OPTS -d $MNT/d$i"
  done

  fs_mark $OPTS

  umount $MNT

Before:

FSUse%        Count         Size    Files/sec     App Overhead
     2      1200000            0     225991.3          5465891
     4      2400000            0     345728.1          5512106
     4      3600000            0     346959.5          5557653
     8      4800000            0     329643.0          5587548
     8      6000000            0     312657.4          5606717
     8      7200000            0     281707.5          5727985
    12      8400000            0      88309.8          5020422
    12      9600000            0      85835.9          5207496
    16     10800000            0      81039.2          5404964
    16     12000000            0      58548.6          5842468

After:

FSUse%        Count         Size    Files/sec     App Overhead
     2      1200000            0     230604.5          5778375
     4      2400000            0     348908.3          5508072
     4      3600000            0     357028.7          5484337
     6      4800000            0     342898.3          5565703
     6      6000000            0     314670.8          5751555
     8      7200000            0     282548.2          5778177
    12      8400000            0      90844.9          5306819
    12      9600000            0      86963.1          5304689
    16     10800000            0      89113.2          5455248
    16     12000000            0      86693.5          5518933

The "after" results are after applying this patch and all the other
patches in the same patchset, which is comprised of the following
changes:

  btrfs: balance btree dirty pages and delayed items after a rename
  btrfs: free the path earlier when creating a new inode
  btrfs: balance btree dirty pages and delayed items after clone and dedupe
  btrfs: add assertions when deleting batches of delayed items
  btrfs: deal with deletion errors when deleting delayed items
  btrfs: refactor the delayed item deletion entry point
  btrfs: improve batch deletion of delayed dir index items
  btrfs: assert that delayed item is a dir index item when adding it
  btrfs: improve batch insertion of delayed dir index items
  btrfs: do not BUG_ON() on failure to reserve metadata for delayed item
  btrfs: set delayed item type when initializing it
  btrfs: reduce amount of reserved metadata for delayed item insertion

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:44:36 +02:00
Filipe Manana c9d02ab4b4 btrfs: set delayed item type when initializing it
Currently we set the type of a delayed item only after successfully
inserting it into its respective rbtree. This is fine, as the type
is not used anywhere before that point, but for the next patch in the
series, there will be the need to check the type of a delayed item
before inserting it into a rbtree.

So set the type of a delayed item immediately after allocating it.
This also makes the trivial wrappers for adding insertion and deletion
useless, so it removes them as well.

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>
2022-07-25 17:44:36 +02:00
Filipe Manana 3bae13e9d4 btrfs: do not BUG_ON() on failure to reserve metadata for delayed item
At btrfs_insert_delayed_dir_index(), we don't expect the metadata
reservation for the delayed dir index item insertion to fail, because the
caller is supposed to have reserved 1 unit of metadata space for that.
All callers are able to deal with an error in case that happens, so there
is no need for something so drastic as a BUG_ON() in case of failure.
Instead just emit a warning, so that's easily noticed during development
(fstests in particular), and return the error to the caller.

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>
2022-07-25 17:44:35 +02:00
Filipe Manana 06ac264f3f btrfs: improve batch insertion of delayed dir index items
Currently we group delayed dir index items for insertion as a single batch
(a single btree operation) as long as their keys are sequential in the key
space.

For example we have delayed index items for the following index keys:

   10, 11, 12, 15, 16, 20, 21

We end up building three batches:

1) First one for index keys 10, 11 and 12;
2) Second one for index keys 15 and 16;
3) Third one for index keys 20 and 21.

However, since the dir index numbers come from a monotonically increasing
counter and are never reused, we could group all these items into a single
batch. The existence of holes in the sequence happens only when we had
delayed dir index items for insertion that got deleted before they were
flushed to the subvolume's tree.

The delayed items are stored in a rbtree based on their key order, so
we can just group items into a batch as long as they all fit in a leaf,
and ignore if there's a gap (key offset, index number) between two
consecutive items. This is more efficient and reduces the amount of
time spent when running delayed items if there are gaps between dir
index items.

For example running the following test script:

  $ cat test.sh
  #!/bin/bash

  DEV=/dev/sdj
  MNT=/mnt/sdj

  mkfs.btrfs -f $DEV
  mount $DEV $MNT

  NUM_FILES=100

  mkdir $MNT/testdir
  for ((i = 1; i <= $NUM_FILES; i++)); do
       echo -n > $MNT/testdir/file_$i
  done

  # Now delete every other file, to create gaps in the dir index keys.
  for ((i = 1; i <= $NUM_FILES; i += 2)); do
      rm -f $MNT/testdir/file_$i
  done

  start=$(date +%s%N)
  sync
  end=$(date +%s%N)
  dur=$(( (end - start) / 1000000 ))

  echo -e "\nsync took $dur milliseconds"

  umount $MNT

While having the following bpftrace script running in another shell:

  $ cat bpf-delayed-items-inserts.sh
  #!/usr/bin/bpftrace

  /* Must add 'noinline' to btrfs_insert_delayed_items(). */
  k:btrfs_insert_delayed_items
  {
      @start_insert_delayed_items[tid] = nsecs;
  }

  k:btrfs_insert_empty_items
  /@start_insert_delayed_items[tid]/
  {
     @insert_batches = count();
  }

  kr:btrfs_insert_delayed_items
  /@start_insert_delayed_items[tid]/
  {
      $dur = (nsecs - @start_insert_delayed_items[tid]) / 1000;
      @btrfs_insert_delayed_items_total_time = sum($dur);
      delete(@start_insert_delayed_items[tid]);
  }

Before this change:

@btrfs_insert_delayed_items_total_time: 576
@insert_batches: 51

After this change:

@btrfs_insert_delayed_items_total_time: 174
@insert_batches: 2

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>
2022-07-25 17:44:35 +02:00
Filipe Manana a176affe54 btrfs: assert that delayed item is a dir index item when adding it
All delayed items are for dir index items, we don't support any other item
types at the moment. So simplify __btrfs_add_delayed_item() and add an
assertion for checking the item's key type. This also allows the next
change to be simpler and avoid to check key types. In case we add support
for different item types in the future, then we'll hit the assertion
during development and be able to adjust any code that is assuming delayed
items are always associated to dir index items.

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>
2022-07-25 17:44:35 +02:00
Filipe Manana 4bd02d9012 btrfs: improve batch deletion of delayed dir index items
Currently we group delayed dir index items for deletion in a single batch
(single btree operation) as long as they all exist in the same leaf and as
long as their keys are sequential in the key space. For example if we have
a leaf that has dir index items with offsets:

    2, 3, 4, 6, 7, 10

And we have delayed dir index items for deleting all these indexes, and
no delayed items for any other index keys in between, then we end up
deleting in 3 batches:

1) First batch for indexes 2, 3 and 4;
2) Second batch for indexes 6 and 7;
3) Third batch for index 10.

This is a waste because we can delete all the index keys in a single
batch. What matters is that each consecutive delayed index key matches
each consecutive dir index key in a leaf.

So update the logic at btrfs_batch_delete_items() to check only for a
key match between delayed dir index items and dir index items in a leaf.
Also avoid the useless first iteration on comparing the key of the
first slot to delete with the key of the first delayed item, as it's
silly since they always match, as the delayed item's key was used for
the btree search that gave us the path we have.

This is more efficient and reduces runtime of running delayed items, as
well as lock contention on the subvolume's tree.

For example, the following test script:

  $ cat test.sh
  #!/bin/bash

  DEV=/dev/sdj
  MNT=/mnt/sdj

  mkfs.btrfs -f $DEV
  mount $DEV $MNT

  NUM_FILES=1000

  mkdir $MNT/testdir
  for ((i = 1; i <= $NUM_FILES; i++)); do
      echo -n > $MNT/testdir/file_$i
  done

  # Now delete every other file, to create gaps in the dir index keys.
  for ((i = 1; i <= $NUM_FILES; i += 2)); do
      rm -f $MNT/testdir/file_$i
  done

  # Sync to force any delayed items to be flushed to the tree.
  sync

  start=$(date +%s%N)
  rm -fr $MNT/testdir
  end=$(date +%s%N)
  dur=$(( (end - start) / 1000000 ))

  echo -e "\nrm -fr took $dur milliseconds"

  umount $MNT

Running that test script while having the following bpftrace script
running in another shell:

  $ cat bpf-measure.sh
  #!/usr/bin/bpftrace

  /* Add 'noinline' to btrfs_delete_delayed_items()'s definition. */
  k:btrfs_delete_delayed_items
  {
      @start_delete_delayed_items[tid] = nsecs;
  }

  k:btrfs_del_items
  /@start_delete_delayed_items[tid]/
  {
      @delete_batches = count();
  }

  kr:btrfs_delete_delayed_items
  /@start_delete_delayed_items[tid]/
  {
      $dur = (nsecs - @start_delete_delayed_items[tid]) / 1000;
      @btrfs_delete_delayed_items_total_time = sum($dur);
      delete(@start_delete_delayed_items[tid]);
  }

Before this change:

@btrfs_delete_delayed_items_total_time: 9563
@delete_batches: 1001

After this change:

@btrfs_delete_delayed_items_total_time: 7328
@delete_batches: 509

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>
2022-07-25 17:44:35 +02:00
Filipe Manana 36baa2c751 btrfs: refactor the delayed item deletion entry point
The delayed item deletion entry point, btrfs_delete_delayed_items(), is a
bit convoluted for a few reasons:

1) It's really a loop disguised with labels and goto statements;

2) There's a 'delete_fail' label which isn't only for error cases, we can
   jump to that label even if no error happened, if we simply don't have
   more delayed items to delete;

3) Unnecessarily keeps track of the current and previous items for no
   good reason, as after getting the next item and releasing the current
   one, it just jumps to the 'again' label just to look again for the
   first delayed item;

4) When a delayed item is not in the tree (because it was already deleted
   before), it releases the item while holding a path locked, which is
   not necessary and adds more contention to the tree, specially taking
   into account that the path came from a deletion search, meaning we have
   write locks for nodes at levels 2, 1 and 0. And releasing the item is
   not computationally trivial (rb tree deletion, a kfree() and some
   trivial things).

So refactor it to use a while loop and add some comments to make it more
obvious why we can have delayed items without a matching item in the tree
as well as why not keep the delayed node locked all the time when running
all its deletion items. This is also a preparation for some upcoming work
involving delayed items.

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>
2022-07-25 17:44:35 +02:00
Filipe Manana 2b1d260de1 btrfs: deal with deletion errors when deleting delayed items
Currently, btrfs_delete_delayed_items() ignores any errors returned from
btrfs_batch_delete_items(). This looks fishy but it's not a problem at
the moment because:

1) Two of the errors returned from btrfs_batch_delete_items() are for
   impossible cases, cases where a delayed item does not match any item
   in the leaf the path points to - btrfs_delete_delayed_items() always
   calls btrfs_batch_delete_items() with a path that points to a leaf
   that contains an item matching a delayed item;

2) btrfs_batch_delete_items() may return an error from btrfs_del_items(),
   in which case it does not release the delayed items of the batch.

   At the moment this is harmless because btrfs_del_items() actually is
   always able to delete items, even if it returns an error - when it
   returns an error it's because it ended up with a leaf mostly empty
   (less than 1/3 full) and failed to migrate items from that leaf into
   its neighbour leaves - this is not critical, as all the items were
   deleted, we just left the tree a bit unbalanced, but it's still a
   valid tree and causes no harm, and future operations on the tree will
   eventually balance it.

   So even if we get an error from btrfs_del_items(), the delayed items
   will not be released but the next time we run delayed items we will
   find out, at btrfs_delete_delayed_items(), that they are not present
   in the tree anymore and then release them.

This is all a bit subtle, and it's certainly prone to be a disaster in
case btrfs_del_items() changes one day and may return errors before being
able to delete all the requested items, in which case we could leave the
filesystem in an inconsistent state as we would commit a transaction
despite a failure from deleting items from the tree.

So make btrfs_delete_delayed_items() check for any errors from the call
to btrfs_batch_delete_items().

Reviewed-by: Anand Jain <anand.jain@oracle.com>
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>
2022-07-25 17:44:35 +02:00
Filipe Manana 659192e668 btrfs: add assertions when deleting batches of delayed items
There are a few impossible cases that btrfs_batch_delete_items() tries to
deal with:

1) Getting a path pointing to a NULL leaf;
2) The leaf slot is pointing beyond the last item in the leaf;
3) We can't find a single item to delete.

The first case is impossible because the given path was returned by a
successful call to btrfs_search_slot(). Replace the BUG_ON() with an
ASSERT for this.

The second case is impossible because we are always called when a delayed
item matches an item in the given leaf. So add an ASSERT() for that and
if that condition is not satisfied, trigger a warning and return an error.

The third case is impossible exactly because of the same reason as the
second case. The given delayed item matches one item in the leaf, so we
know that our batch always has at least one item. Add an ASSERT to check
that, trigger a warning if that expectation fails and return an error.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
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>
2022-07-25 17:44:35 +02:00
Filipe Manana 6fe81a3a3a btrfs: balance btree dirty pages and delayed items after clone and dedupe
When reflinking extents (clone and deduplication), we need to touch the
btree of the destination inode's subvolume, as well as potentially
create a delayed inode for the destination inode (if it was not created
before). However we are neither balancing the btree dirty pages nor the
delayed items after such operations, so if we have a task that is doing
a long series of clone or deduplication operations, it can result in
accumulation of too many btree dirty pages and delayed items.

So just call btrfs_btree_balance_dirty() after clone and deduplication,
just like we do for every other system call that results on modifying a
btree and adding delayed items.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
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>
2022-07-25 17:44:35 +02:00
Filipe Manana 814e77182b btrfs: free the path earlier when creating a new inode
When creating an inode, through btrfs_create_new_inode(), we release the
path we allocated before once we don't need it anymore. But we keep it
allocated until we return from that function, which is wasteful because
after we release the path we do several things that can allocate yet
another path: inheriting properties, setting the xattrs used by ACLs and
secutiry modules, adding an orphan item (O_TMPFILE case) or adding a
dir item (for the non-O_TMPFILE case).

So instead of releasing the path once we don't need it anymore, free it
instead. This way we avoid having two paths allocated until we return
from btrfs_create_new_inode().

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
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>
2022-07-25 17:44:35 +02:00
Filipe Manana ca6dee6b79 btrfs: balance btree dirty pages and delayed items after a rename
A rename operation modifies a subvolume's btree, to remove the old dir
item, add the new dir item, remove an inode ref and add a new inode ref.
It can also create the delayed inode for the inodes involved in the
operation, and it creates two delayed dir index items, one to delete
the old name and another one to add the new name.

However we are neither balancing the btree dirty pages nor the delayed
items after a rename, which can result in accumulation of too many
btree dirty pages and delayed items, specially if a task is doing a
series of rename operations (for example it can happen for package
installations/upgrades through the zypper tool).

So just call btrfs_btree_balance_dirty() after a rename, just like we
do for every other system call that results on modifying a btree and
adding delayed items.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
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>
2022-07-25 17:44:35 +02:00