Commit graph

74 commits

Author SHA1 Message Date
Linus Torvalds
eabcdba3ad for-6.13-rc3-tag
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Merge tag 'for-6.13-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - tree-checker catches invalid number of inline extent references

 - zoned mode fixes:
    - enhance zone append IO command so it also detects emulated writes
    - handle bio splitting at sectorsize boundary

 - when deleting a snapshot, fix a condition for visiting nodes in reloc
   trees

* tag 'for-6.13-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: tree-checker: reject inline extent items with 0 ref count
  btrfs: split bios to the fs sector size boundary
  btrfs: use bio_is_zone_append() in the completion handler
  btrfs: fix improper generation check in snapshot delete
2024-12-18 14:17:21 -08:00
Christoph Hellwig
be691b5e59 btrfs: split bios to the fs sector size boundary
Btrfs like other file systems can't really deal with I/O not aligned to
it's internal block size (which strangely is called sector size in
btrfs, for historical reasons), but the block layer split helper doesn't
even know about that.

Round down the split boundary so that all I/Os are aligned.

Fixes: d5e4377d50 ("btrfs: split zone append bios in btrfs_submit_bio")
CC: stable@vger.kernel.org # 6.12
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-17 19:54:32 +01:00
Christoph Hellwig
6c3864e055 btrfs: use bio_is_zone_append() in the completion handler
Otherwise it won't catch bios turned into regular writes by the block
level zone write plugging. The additional test it adds is for emulated
zone append.

Fixes: 9b1ce7f0c6 ("block: Implement zone append emulation")
CC: stable@vger.kernel.org # 6.12
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-17 19:54:32 +01:00
Johannes Thumshirn
c7c97ceff9 btrfs: handle bio_split() errors
Commit e546fe1da9 ("block: Rework bio_split() return value") changed
bio_split() so that it can return errors.

Add error handling for it in btrfs_split_bio() and ultimately
btrfs_submit_chunk(). As the bio is not submitted, the bio counter must
be decremented to pair btrfs_bio_counter_inc_blocked().

Reviewed-by: John Garry <john.g.garry@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>
2024-12-06 15:04:13 +01:00
Qu Wenruo
67cd3f2217 btrfs: split out CONFIG_BTRFS_EXPERIMENTAL from CONFIG_BTRFS_DEBUG
Currently CONFIG_BTRFS_EXPERIMENTAL is not only for the extra debugging
output, but also for experimental features.

This is not ideal to distinguish planned but not yet stable features
from those purely designed for debugging.

This patch splits the following features into CONFIG_BTRFS_EXPERIMENTAL:

- Extent map shrinker
  This seems to be the first one to exit experimental.

- Extent tree v2
  This seems to be the last one to graduate from experimental.

- Raid stripe tree
- Csum offload mode
- Send protocol v3

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>
2024-11-11 14:34:12 +01:00
Linus Torvalds
6b4926494e for-6.12-rc5-tag
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Merge tag 'for-6.12-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more stability fixes. There's one patch adding export of MIPS
  cmpxchg helper, used in the error propagation fix.

   - fix error propagation from split bios to the original btrfs bio

   - fix merging of adjacent extents (normal operation, defragmentation)

   - fix potential use after free after freeing btrfs device structures"

* tag 'for-6.12-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix defrag not merging contiguous extents due to merged extent maps
  btrfs: fix extent map merging not happening for adjacent extents
  btrfs: fix use-after-free of block device file in __btrfs_free_extra_devids()
  btrfs: fix error propagation of split bios
  MIPS: export __cmpxchg_small()
2024-11-01 07:31:47 -10:00
Naohiro Aota
d48e1dea39 btrfs: fix error propagation of split bios
The purpose of btrfs_bbio_propagate_error() shall be propagating an error
of split bio to its original btrfs_bio, and tell the error to the upper
layer. However, it's not working well on some cases.

* Case 1. Immediate (or quick) end_bio with an error

When btrfs sends btrfs_bio to mirrored devices, btrfs calls
btrfs_bio_end_io() when all the mirroring bios are completed. If that
btrfs_bio was split, it is from btrfs_clone_bioset and its end_io function
is btrfs_orig_write_end_io. For this case, btrfs_bbio_propagate_error()
accesses the orig_bbio's bio context to increase the error count.

That works well in most cases. However, if the end_io is called enough
fast, orig_bbio's (remaining part after split) bio context may not be
properly set at that time. Since the bio context is set when the orig_bbio
(the last btrfs_bio) is sent to devices, that might be too late for earlier
split btrfs_bio's completion.  That will result in NULL pointer
dereference.

That bug is easily reproducible by running btrfs/146 on zoned devices [1]
and it shows the following trace.

[1] You need raid-stripe-tree feature as it create "-d raid0 -m raid1" FS.

  BUG: kernel NULL pointer dereference, address: 0000000000000020
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: Oops: 0000 [#1] PREEMPT SMP PTI
  CPU: 1 UID: 0 PID: 13 Comm: kworker/u32:1 Not tainted 6.11.0-rc7-BTRFS-ZNS+ #474
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  Workqueue: writeback wb_workfn (flush-btrfs-5)
  RIP: 0010:btrfs_bio_end_io+0xae/0xc0 [btrfs]
  BTRFS error (device dm-0): bdev /dev/mapper/error-test errs: wr 2, rd 0, flush 0, corrupt 0, gen 0
  RSP: 0018:ffffc9000006f248 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff888005a7f080 RCX: ffffc9000006f1dc
  RDX: 0000000000000000 RSI: 000000000000000a RDI: ffff888005a7f080
  RBP: ffff888011dfc540 R08: 0000000000000000 R09: 0000000000000001
  R10: ffffffff82e508e0 R11: 0000000000000005 R12: ffff88800ddfbe58
  R13: ffff888005a7f080 R14: ffff888005a7f158 R15: ffff888005a7f158
  FS:  0000000000000000(0000) GS:ffff88803ea80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000020 CR3: 0000000002e22006 CR4: 0000000000370ef0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   ? __die_body.cold+0x19/0x26
   ? page_fault_oops+0x13e/0x2b0
   ? _printk+0x58/0x73
   ? do_user_addr_fault+0x5f/0x750
   ? exc_page_fault+0x76/0x240
   ? asm_exc_page_fault+0x22/0x30
   ? btrfs_bio_end_io+0xae/0xc0 [btrfs]
   ? btrfs_log_dev_io_error+0x7f/0x90 [btrfs]
   btrfs_orig_write_end_io+0x51/0x90 [btrfs]
   dm_submit_bio+0x5c2/0xa50 [dm_mod]
   ? find_held_lock+0x2b/0x80
   ? blk_try_enter_queue+0x90/0x1e0
   __submit_bio+0xe0/0x130
   ? ktime_get+0x10a/0x160
   ? lockdep_hardirqs_on+0x74/0x100
   submit_bio_noacct_nocheck+0x199/0x410
   btrfs_submit_bio+0x7d/0x150 [btrfs]
   btrfs_submit_chunk+0x1a1/0x6d0 [btrfs]
   ? lockdep_hardirqs_on+0x74/0x100
   ? __folio_start_writeback+0x10/0x2c0
   btrfs_submit_bbio+0x1c/0x40 [btrfs]
   submit_one_bio+0x44/0x60 [btrfs]
   submit_extent_folio+0x13f/0x330 [btrfs]
   ? btrfs_set_range_writeback+0xa3/0xd0 [btrfs]
   extent_writepage_io+0x18b/0x360 [btrfs]
   extent_write_locked_range+0x17c/0x340 [btrfs]
   ? __pfx_end_bbio_data_write+0x10/0x10 [btrfs]
   run_delalloc_cow+0x71/0xd0 [btrfs]
   btrfs_run_delalloc_range+0x176/0x500 [btrfs]
   ? find_lock_delalloc_range+0x119/0x260 [btrfs]
   writepage_delalloc+0x2ab/0x480 [btrfs]
   extent_write_cache_pages+0x236/0x7d0 [btrfs]
   btrfs_writepages+0x72/0x130 [btrfs]
   do_writepages+0xd4/0x240
   ? find_held_lock+0x2b/0x80
   ? wbc_attach_and_unlock_inode+0x12c/0x290
   ? wbc_attach_and_unlock_inode+0x12c/0x290
   __writeback_single_inode+0x5c/0x4c0
   ? do_raw_spin_unlock+0x49/0xb0
   writeback_sb_inodes+0x22c/0x560
   __writeback_inodes_wb+0x4c/0xe0
   wb_writeback+0x1d6/0x3f0
   wb_workfn+0x334/0x520
   process_one_work+0x1ee/0x570
   ? lock_is_held_type+0xc6/0x130
   worker_thread+0x1d1/0x3b0
   ? __pfx_worker_thread+0x10/0x10
   kthread+0xee/0x120
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x30/0x50
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>
  Modules linked in: dm_mod btrfs blake2b_generic xor raid6_pq rapl
  CR2: 0000000000000020

* Case 2. Earlier completion of orig_bbio for mirrored btrfs_bios

btrfs_bbio_propagate_error() assumes the end_io function for orig_bbio is
called last among split bios. In that case, btrfs_orig_write_end_io() sets
the bio->bi_status to BLK_STS_IOERR by seeing the bioc->error [2].
Otherwise, the increased orig_bio's bioc->error is not checked by anyone
and return BLK_STS_OK to the upper layer.

[2] Actually, this is not true. Because we only increases orig_bioc->errors
by max_errors, the condition "atomic_read(&bioc->error) > bioc->max_errors"
is still not met if only one split btrfs_bio fails.

* Case 3. Later completion of orig_bbio for un-mirrored btrfs_bios

In contrast to the above case, btrfs_bbio_propagate_error() is not working
well if un-mirrored orig_bbio is completed last. It sets
orig_bbio->bio.bi_status to the btrfs_bio's error. But, that is easily
over-written by orig_bbio's completion status. If the status is BLK_STS_OK,
the upper layer would not know the failure.

* Solution

Considering the above cases, we can only save the error status in the
orig_bbio (remaining part after split) itself as it is always
available. Also, the saved error status should be propagated when all the
split btrfs_bios are finished (i.e, bbio->pending_ios == 0).

This commit introduces "status" to btrfs_bbio and saves the first error of
split bios to original btrfs_bio's "status" variable. When all the split
bios are finished, the saved status is loaded into original btrfs_bio's
status.

With this commit, btrfs/146 on zoned devices does not hit the NULL pointer
dereference anymore.

Fixes: 852eee62d3 ("btrfs: allow btrfs_submit_bio to split bios")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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>
2024-10-23 18:17:43 +02:00
Linus Torvalds
26bb0d3f38 for-6.12/block-20240913
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Merge tag 'for-6.12/block-20240913' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - MD changes via Song:
      - md-bitmap refactoring (Yu Kuai)
      - raid5 performance optimization (Artur Paszkiewicz)
      - Other small fixes (Yu Kuai, Chen Ni)
      - Add a sysfs entry 'new_level' (Xiao Ni)
      - Improve information reported in /proc/mdstat (Mateusz Kusiak)

 - NVMe changes via Keith:
      - Asynchronous namespace scanning (Stuart)
      - TCP TLS updates (Hannes)
      - RDMA queue controller validation (Niklas)
      - Align field names to the spec (Anuj)
      - Metadata support validation (Puranjay)
      - A syntax cleanup (Shen)
      - Fix a Kconfig linking error (Arnd)
      - New queue-depth quirk (Keith)

 - Add missing unplug trace event (Keith)

 - blk-iocost fixes (Colin, Konstantin)

 - t10-pi modular removal and fixes (Alexey)

 - Fix for potential BLKSECDISCARD overflow (Alexey)

 - bio splitting cleanups and fixes (Christoph)

 - Deal with folios rather than rather than pages, speeding up how the
   block layer handles bigger IOs (Kundan)

 - Use spinlocks rather than bit spinlocks in zram (Sebastian, Mike)

 - Reduce zoned device overhead in ublk (Ming)

 - Add and use sendpages_ok() for drbd and nvme-tcp (Ofir)

 - Fix regression in partition error pointer checking (Riyan)

 - Add support for write zeroes and rotational status in nbd (Wouter)

 - Add Yu Kuai as new BFQ maintainer. The scheduler has been
   unmaintained for quite a while.

 - Various sets of fixes for BFQ (Yu Kuai)

 - Misc fixes and cleanups (Alvaro, Christophe, Li, Md Haris, Mikhail,
   Yang)

* tag 'for-6.12/block-20240913' of git://git.kernel.dk/linux: (120 commits)
  nvme-pci: qdepth 1 quirk
  block: fix potential invalid pointer dereference in blk_add_partition
  blk_iocost: make read-only static array vrate_adj_pct const
  block: unpin user pages belonging to a folio at once
  mm: release number of pages of a folio
  block: introduce folio awareness and add a bigger size from folio
  block: Added folio-ized version of bio_add_hw_page()
  block, bfq: factor out a helper to split bfqq in bfq_init_rq()
  block, bfq: remove local variable 'bfqq_already_existing' in bfq_init_rq()
  block, bfq: remove local variable 'split' in bfq_init_rq()
  block, bfq: remove bfq_log_bfqg()
  block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()
  block, bfq: fix procress reference leakage for bfqq in merge chain
  block, bfq: fix uaf for accessing waker_bfqq after splitting
  blk-throttle: support prioritized processing of metadata
  blk-throttle: remove last_low_overflow_time
  drbd: Add NULL check for net_conf to prevent dereference in state validation
  nvme-tcp: fix link failure for TCP auth
  blk-mq: add missing unplug trace event
  mtip32xx: Remove redundant null pointer checks in mtip_hw_debugfs_init()
  ...
2024-09-16 13:33:06 +02:00
Qu Wenruo
9ca0e58cb7 btrfs: merge btrfs_orig_bbio_end_io() into btrfs_bio_end_io()
There are only two differences between the two functions:

- btrfs_orig_bbio_end_io() does extra error propagation
  This is mostly to allow tolerance for write errors.

- btrfs_orig_bbio_end_io() does extra pending_ios check
  This check can handle both the original bio, or the cloned one.
  (All accounting happens in the original one).

This makes btrfs_orig_bbio_end_io() a much safer call.
In fact we already had a double freeing error due to usage of
btrfs_bio_end_io() in the error path of btrfs_submit_chunk().

So just move the whole content of btrfs_orig_bbio_end_io() into
btrfs_bio_end_io().

For normal paths this brings no change, because they are already calling
btrfs_orig_bbio_end_io() in the first place.

For error paths (not only inside bio.c but also external callers), this
change will introduce extra checks, especially for external callers, as
they will error out without submitting the btrfs bio.

But considering it's already in the error path, such slower but much
safer checks are still an overall win.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10 16:51:20 +02:00
David Sterba
22b4ef50dc btrfs: rename __btrfs_submit_bio() and drop double underscores
Previous patch freed the function name btrfs_submit_bio() so we can use
it for a helper that submits struct bio.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10 16:51:19 +02:00
David Sterba
792e86ef31 btrfs: rename btrfs_submit_bio() to btrfs_submit_bbio()
The function name is a bit misleading as it submits the btrfs_bio
(bbio), rename it so we can use btrfs_submit_bio() when an actual bio is
submitted.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10 16:51:19 +02:00
Johannes Thumshirn
f4d39cf1ce btrfs: set search_commit_root on stripe io in case of relocation
Set rst_search_commit_root in the btrfs_io_stripe we're passing to
btrfs_map_block() in case we're doing data relocation.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10 16:51:17 +02:00
Johannes Thumshirn
d6106f0dc5 btrfs: rename btrfs_io_stripe::is_scrub to rst_search_commit_root
Rename 'btrfs_io_stripe::is_scrub' to 'rst_search_commit_root'. While
'is_scrub' describes the state of the io_stripe (it is a stripe submitted
by scrub) it does not describe the purpose, namely looking at the commit
root when searching RAID stripe-tree entries.

Renaming the stripe to rst_search_commit_root describes this purpose.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@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>
2024-09-10 16:51:17 +02:00
Christoph Hellwig
b35243a447 block: rework bio splitting
The current setup with bio_may_exceed_limit and __bio_split_to_limits
is a bit of a mess.

Change it so that __bio_split_to_limits does all the work and is just
a variant of bio_split_to_limits that returns nr_segs.  This is done
by inlining it and instead have the various bio_split_* helpers directly
submit the potentially split bios.

To support btrfs, the rw version has a lower level helper split out
that just returns the offset to split.  This turns out to nicely clean
up the btrfs flow as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com>
Link: https://lore.kernel.org/r/20240826173820.1690925-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-08-29 04:32:32 -06:00
Qu Wenruo
10d9d8c351 btrfs: fix a use-after-free when hitting errors inside btrfs_submit_chunk()
[BUG]
There is an internal report that KASAN is reporting use-after-free, with
the following backtrace:

  BUG: KASAN: slab-use-after-free in btrfs_check_read_bio+0xa68/0xb70 [btrfs]
  Read of size 4 at addr ffff8881117cec28 by task kworker/u16:2/45
  CPU: 1 UID: 0 PID: 45 Comm: kworker/u16:2 Not tainted 6.11.0-rc2-next-20240805-default+ #76
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
  Workqueue: btrfs-endio btrfs_end_bio_work [btrfs]
  Call Trace:
   dump_stack_lvl+0x61/0x80
   print_address_description.constprop.0+0x5e/0x2f0
   print_report+0x118/0x216
   kasan_report+0x11d/0x1f0
   btrfs_check_read_bio+0xa68/0xb70 [btrfs]
   process_one_work+0xce0/0x12a0
   worker_thread+0x717/0x1250
   kthread+0x2e3/0x3c0
   ret_from_fork+0x2d/0x70
   ret_from_fork_asm+0x11/0x20

  Allocated by task 20917:
   kasan_save_stack+0x37/0x60
   kasan_save_track+0x10/0x30
   __kasan_slab_alloc+0x7d/0x80
   kmem_cache_alloc_noprof+0x16e/0x3e0
   mempool_alloc_noprof+0x12e/0x310
   bio_alloc_bioset+0x3f0/0x7a0
   btrfs_bio_alloc+0x2e/0x50 [btrfs]
   submit_extent_page+0x4d1/0xdb0 [btrfs]
   btrfs_do_readpage+0x8b4/0x12a0 [btrfs]
   btrfs_readahead+0x29a/0x430 [btrfs]
   read_pages+0x1a7/0xc60
   page_cache_ra_unbounded+0x2ad/0x560
   filemap_get_pages+0x629/0xa20
   filemap_read+0x335/0xbf0
   vfs_read+0x790/0xcb0
   ksys_read+0xfd/0x1d0
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x4b/0x53

  Freed by task 20917:
   kasan_save_stack+0x37/0x60
   kasan_save_track+0x10/0x30
   kasan_save_free_info+0x37/0x50
   __kasan_slab_free+0x4b/0x60
   kmem_cache_free+0x214/0x5d0
   bio_free+0xed/0x180
   end_bbio_data_read+0x1cc/0x580 [btrfs]
   btrfs_submit_chunk+0x98d/0x1880 [btrfs]
   btrfs_submit_bio+0x33/0x70 [btrfs]
   submit_one_bio+0xd4/0x130 [btrfs]
   submit_extent_page+0x3ea/0xdb0 [btrfs]
   btrfs_do_readpage+0x8b4/0x12a0 [btrfs]
   btrfs_readahead+0x29a/0x430 [btrfs]
   read_pages+0x1a7/0xc60
   page_cache_ra_unbounded+0x2ad/0x560
   filemap_get_pages+0x629/0xa20
   filemap_read+0x335/0xbf0
   vfs_read+0x790/0xcb0
   ksys_read+0xfd/0x1d0
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x4b/0x53

[CAUSE]
Although I cannot reproduce the error, the report itself is good enough
to pin down the cause.

The call trace is the regular endio workqueue context, but the
free-by-task trace is showing that during btrfs_submit_chunk() we
already hit a critical error, and is calling btrfs_bio_end_io() to error
out.  And the original endio function called bio_put() to free the whole
bio.

This means a double freeing thus causing use-after-free, e.g.:

1. Enter btrfs_submit_bio() with a read bio
   The read bio length is 128K, crossing two 64K stripes.

2. The first run of btrfs_submit_chunk()

2.1 Call btrfs_map_block(), which returns 64K
2.2 Call btrfs_split_bio()
    Now there are two bios, one referring to the first 64K, the other
    referring to the second 64K.
2.3 The first half is submitted.

3. The second run of btrfs_submit_chunk()

3.1 Call btrfs_map_block(), which by somehow failed
    Now we call btrfs_bio_end_io() to handle the error

3.2 btrfs_bio_end_io() calls the original endio function
    Which is end_bbio_data_read(), and it calls bio_put() for the
    original bio.

    Now the original bio is freed.

4. The submitted first 64K bio finished
   Now we call into btrfs_check_read_bio() and tries to advance the bio
   iter.
   But since the original bio (thus its iter) is already freed, we
   trigger the above use-after free.

   And even if the memory is not poisoned/corrupted, we will later call
   the original endio function, causing a double freeing.

[FIX]
Instead of calling btrfs_bio_end_io(), call btrfs_orig_bbio_end_io(),
which has the extra check on split bios and do the proper refcounting
for cloned bios.

Furthermore there is already one extra btrfs_cleanup_bio() call, but
that is duplicated to btrfs_orig_bbio_end_io() call, so remove that
label completely.

Reported-by: David Sterba <dsterba@suse.com>
Fixes: 852eee62d3 ("btrfs: allow btrfs_submit_bio to split bios")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-27 01:34:08 +02:00
Qu Wenruo
169aaaf2e0 btrfs: introduce new "rescue=ignoremetacsums" mount option
Introduce "rescue=ignoremetacsums" to ignore metadata csums, all the
other metadata sanity checks are still kept as is.

This new mount option is mostly to allow the kernel to mount an
interrupted checksum conversion (at the metadata csum overwrite stage).

And since the main part of metadata sanity checks is inside
tree-checker, we shouldn't lose much safety, and the new mount option is
rescue mount option it requires full read-only mount.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-11 15:33:29 +02:00
David Sterba
8610ba7eab btrfs: pass a btrfs_inode to is_data_inode()
Pass a struct btrfs_inode to is_data_inode() as it's an
internal interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-11 15:33:28 +02:00
Johannes Thumshirn
cebae292e0 btrfs: zoned: allocate dummy checksums for zoned NODATASUM writes
Shin'ichiro reported that when he's running fstests' test-case
btrfs/167 on emulated zoned devices, he's seeing the following NULL
pointer dereference in 'btrfs_zone_finish_endio()':

  Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] PREEMPT SMP KASAN NOPTI
  KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
  CPU: 4 PID: 2332440 Comm: kworker/u80:15 Tainted: G        W          6.10.0-rc2-kts+ #4
  Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020
  Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
  RIP: 0010:btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]

  RSP: 0018:ffff88867f107a90 EFLAGS: 00010206
  RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff893e5534
  RDX: 0000000000000011 RSI: 0000000000000004 RDI: 0000000000000088
  RBP: 0000000000000002 R08: 0000000000000001 R09: ffffed1081696028
  R10: ffff88840b4b0143 R11: ffff88834dfff600 R12: ffff88840b4b0000
  R13: 0000000000020000 R14: 0000000000000000 R15: ffff888530ad5210
  FS:  0000000000000000(0000) GS:ffff888e3f800000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f87223fff38 CR3: 00000007a7c6a002 CR4: 00000000007706f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  PKRU: 55555554
  Call Trace:
   <TASK>
   ? __die_body.cold+0x19/0x27
   ? die_addr+0x46/0x70
   ? exc_general_protection+0x14f/0x250
   ? asm_exc_general_protection+0x26/0x30
   ? do_raw_read_unlock+0x44/0x70
   ? btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]
   btrfs_finish_one_ordered+0x5d9/0x19a0 [btrfs]
   ? __pfx_lock_release+0x10/0x10
   ? do_raw_write_lock+0x90/0x260
   ? __pfx_do_raw_write_lock+0x10/0x10
   ? __pfx_btrfs_finish_one_ordered+0x10/0x10 [btrfs]
   ? _raw_write_unlock+0x23/0x40
   ? btrfs_finish_ordered_zoned+0x5a9/0x850 [btrfs]
   ? lock_acquire+0x435/0x500
   btrfs_work_helper+0x1b1/0xa70 [btrfs]
   ? __schedule+0x10a8/0x60b0
   ? __pfx___might_resched+0x10/0x10
   process_one_work+0x862/0x1410
   ? __pfx_lock_acquire+0x10/0x10
   ? __pfx_process_one_work+0x10/0x10
   ? assign_work+0x16c/0x240
   worker_thread+0x5e6/0x1010
   ? __pfx_worker_thread+0x10/0x10
   kthread+0x2c3/0x3a0
   ? trace_irq_enable.constprop.0+0xce/0x110
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x31/0x70
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>

Enabling CONFIG_BTRFS_ASSERT revealed the following assertion to
trigger:

  assertion failed: !list_empty(&ordered->list), in fs/btrfs/zoned.c:1815

This indicates, that we're missing the checksums list on the
ordered_extent. As btrfs/167 is doing a NOCOW write this is to be
expected.

Further analysis with drgn confirmed the assumption:

  >>> inode = prog.crashed_thread().stack_trace()[11]['ordered'].inode
  >>> btrfs_inode = drgn.container_of(inode, "struct btrfs_inode", \
         				"vfs_inode")
  >>> print(btrfs_inode.flags)
  (u32)1

As zoned emulation mode simulates conventional zones on regular devices,
we cannot use zone-append for writing. But we're only attaching dummy
checksums if we're doing a zone-append write.

So for NOCOW zoned data writes on conventional zones, also attach a
dummy checksum.

Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: cbfce4c7fb ("btrfs: optimize the logical to physical mapping for zoned writes")
CC: Naohiro Aota <Naohiro.Aota@wdc.com> # 6.6+
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.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>
2024-06-13 20:43:55 +02:00
Naohiro Aota
2761ece893 btrfs: introduce offload_csum_mode to tweak checksum offloading behavior
We disable offloading checksum to workqueues and do it synchronously when
the checksum algorithm is fast. However, as reported in the link below,
RAID0 with multiple devices may suffer from the sync checksum, because
"fast checksum" is still not fast enough to catch up with RAID0 writing.

We don't have an effective way to determine whether to offload or not,
for now add a sysfs knob so this can be debugged. This is intentionally
under CONFIG_BTRFS_DEBUG so ti's not exposed to users as it may be
removed in the future agin.

Introduce fs_devices->offload_csum_mode, so that a btrfs developer can
change the behavior by writing to /sys/fs/btrfs/<uuid>/offload_csum. The
default is "auto" which is the same as the previous behavior. Or, you
can set "on" or "off" (or "y" or "n" whatever kstrtobool() accepts) to
always/never offload checksum.

More benchmark need to be collected with this knob to implement a proper
criteria to enable/disable checksum offloading.

Link: https://lore.kernel.org/linux-btrfs/20230731152223.4EFB.409509F4@e16-tech.com/
Link: https://lore.kernel.org/linux-btrfs/p3vo3g7pqn664mhmdhlotu5dzcna6vjtcoc2hb2lsgo2fwct7k@xzaxclba5tae/
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>
2024-03-04 16:24:52 +01:00
David Sterba
2b712e3bb2 btrfs: remove unused included headers
With help of neovim, LSP and clangd we can identify header files that
are not actually needed to be included in the .c files. This is focused
only on removal (with minor fixups), further cleanups are possible but
will require doing the header files properly with forward declarations,
minimized includes and include-what-you-use care.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-03-04 16:24:46 +01:00
Johannes Thumshirn
c4e5b7470a btrfs: remove duplicate recording of physical address
Remove the duplicate physical recording of the original write physical
address in case of a single device write.

This duplicated code is most likely present due to a rebase error.

Reviewed-by: Filipe Manana <fdmanana@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>
2024-03-04 16:24:45 +01:00
Qu Wenruo
96c36eaa77 btrfs: migrate btrfs_repair_io_failure() to folio interfaces
[BUG]
Test case btrfs/124 failed if larger metadata folio is enabled, the
dying message looks like this:

 BTRFS error (device dm-2): bad tree block start, mirror 2 want 31686656 have 0
 BTRFS info (device dm-2): read error corrected: ino 0 off 31686656 (dev /dev/mapper/test-scratch2 sector 20928)
 BUG: kernel NULL pointer dereference, address: 0000000000000020
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 CPU: 6 PID: 350881 Comm: btrfs Tainted: G           OE      6.7.0-rc3-custom+ #128
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 2/2/2022
 RIP: 0010:btrfs_read_extent_buffer+0x106/0x180 [btrfs]
 PKRU: 55555554
 Call Trace:
  <TASK>
  read_tree_block+0x33/0xb0 [btrfs]
  read_block_for_search+0x23e/0x340 [btrfs]
  btrfs_search_slot+0x2f9/0xe60 [btrfs]
  btrfs_lookup_csum+0x75/0x160 [btrfs]
  btrfs_lookup_bio_sums+0x21a/0x560 [btrfs]
  btrfs_submit_chunk+0x152/0x680 [btrfs]
  btrfs_submit_bio+0x1c/0x50 [btrfs]
  submit_one_bio+0x40/0x80 [btrfs]
  submit_extent_page+0x158/0x390 [btrfs]
  btrfs_do_readpage+0x330/0x740 [btrfs]
  extent_readahead+0x38d/0x6c0 [btrfs]
  read_pages+0x94/0x2c0
  page_cache_ra_unbounded+0x12d/0x190
  relocate_file_extent_cluster+0x7c1/0x9d0 [btrfs]
  relocate_block_group+0x2d3/0x560 [btrfs]
  btrfs_relocate_block_group+0x2c7/0x4b0 [btrfs]
  btrfs_relocate_chunk+0x4c/0x1a0 [btrfs]
  btrfs_balance+0x925/0x13c0 [btrfs]
  btrfs_ioctl+0x19f1/0x25d0 [btrfs]
  __x64_sys_ioctl+0x90/0xd0
  do_syscall_64+0x3f/0xf0
  entry_SYSCALL_64_after_hwframe+0x6e/0x76

[CAUSE]
The dying line is at btrfs_repair_io_failure() call inside
btrfs_repair_eb_io_failure().

The function is still relying on the extent buffer using page sized
folios.
When the extent buffer is using larger folio, we go into the 2nd slot of
folios[], and triggered the NULL pointer dereference.

[FIX]
Migrate btrfs_repair_io_failure() to folio interfaces.

So that when we hit a larger folio, we just submit the whole folio in
one go.

This also affects data repair path through btrfs_end_repair_bio(),
thankfully data is still fully page based, we can just add an
ASSERT(), and use page_folio() to convert the page to folio.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-12-15 23:03:58 +01:00
David Sterba
eefaf0a1a6 btrfs: fix typos found by codespell
Signed-off-by: David Sterba <dsterba@suse.com>
2023-12-15 23:00:04 +01:00
David Sterba
078b8b90b8 btrfs: merge ordered work callbacks in btrfs_work into one
There are two callbacks defined in btrfs_work but only two actually make
use of them, otherwise there are NULLs. We can get rid of the freeing
callback making it a special case of the normal work. This reduces the
size of btrfs_work by 8 bytes, final layout:

struct btrfs_work {
        btrfs_func_t               func;                 /*     0     8 */
        btrfs_ordered_func_t       ordered_func;         /*     8     8 */
        struct work_struct         normal_work;          /*    16    32 */
        struct list_head           ordered_list;         /*    48    16 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        struct btrfs_workqueue *   wq;                   /*    64     8 */
        long unsigned int          flags;                /*    72     8 */

        /* size: 80, cachelines: 2, members: 6 */
        /* last cacheline: 16 bytes */
};

This in turn reduces size of other structures (on a release config):

- async_chunk			 160 ->  152
- async_submit_bio		 152 ->  144
- btrfs_async_delayed_work	 104 ->   96
- btrfs_caching_control		 176 ->  168
- btrfs_delalloc_work		 144 ->  136
- btrfs_fs_info			3608 -> 3600
- btrfs_ordered_extent		 440 ->  424
- btrfs_writepage_fixup		 104 ->   96

Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12 16:44:10 +02:00
Johannes Thumshirn
9acaa64187 btrfs: scrub: implement raid stripe tree support
A filesystem that uses the raid stripe tree for logical to physical
address translation can't use the regular scrub path, that reads all
stripes and then checks if a sector is unused afterwards.

When using the raid stripe tree, this will result in lookup errors, as
the stripe tree doesn't know the requested logical addresses.

In case we're scrubbing a filesystem which uses the RAID stripe tree for
multi-device logical to physical address translation, perform an extra
block mapping step to get the real on-disk stripe length from the stripe
tree when scrubbing the sectors.

This prevents a double completion of the btrfs_bio caused by splitting the
underlying bio and ultimately a use-after-free.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12 16:44:09 +02:00
Johannes Thumshirn
02c372e1f0 btrfs: add support for inserting raid stripe extents
Add support for inserting stripe extents into the raid stripe tree on
completion of every write that needs an extra logical-to-physical
translation when using RAID.

Inserting the stripe extents happens after the data I/O has completed,
this is done to

  a) support zone-append and
  b) rule out the possibility of a RAID-write-hole.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12 16:44:09 +02:00
Qu Wenruo
9fb2acc2fe btrfs: remove the need_raid_map parameter from btrfs_map_block()
The parameter @need_raid_map is mostly a legacy from the old days where
we don't yet have a solid definition on the @mirror_num, and only
check-integrity was using that parameter, while all other call sites
just pass 1 for that parameter.

Now since we have removed check-integrity functionality, we can also
remove the @need_raid_map parameter.

This change will also remove the ability to read P/Q stripe directly
when passing 0 as @need_raid_map.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12 16:44:05 +02:00
Qu Wenruo
fb2a836da4 btrfs: check-integrity: remove btrfsic_unmount() function
The function btrfsic_mount() is part of the deprecated check-integrity
functionality.

Now let's remove the main entry point of check-integrity, and thankfully
most of the check-integrity code is self-contained inside
check-integrity.c, we can safely remove the function without huge
changes to btrfs code base.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12 16:44:05 +02:00
Qu Wenruo
51cf580c23 btrfs: check-integrity: remove btrfsic_check_bio() function
The function btrfsic_check_bio() is part of the deprecated
check-integrity functionality.

Now let's remove the main entry point of check-integrity, and thankfully
most of the check-integrity code is self-contained inside
check-integrity.c, we can safely remove the function without huge
changes to btrfs code base.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12 16:44:05 +02:00
Christoph Hellwig
ec63b84d46 btrfs: add an ordered_extent pointer to struct btrfs_bio
Add a pointer to the ordered_extent to the existing union in struct
btrfs_bio, so all code dealing with data write bios can just use a
pointer dereference to retrieve the ordered_extent instead of doing
multiple rbtree lookups per I/O.

The reference to this ordered_extent is dropped at end I/O time,
which implies that an extra one must be acquired when the bio is split.
This also requires moving the btrfs_extract_ordered_extent call into
btrfs_split_bio so that the invariant of always having a valid
ordered_extent reference for the btrfs_bio is kept.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:36 +02:00
Christoph Hellwig
fbe960877b btrfs: add a is_data_bbio helper
Add a helper to check for that a btrfs_bio has a valid inode, and that
it is a data inode to key off all the special handling for data path
checksumming.  Note that this uses is_data_inode instead of REQ_META as
REQ_META is only set directly before submission in submit_one_bio and
we'll also want to use this helper for error handling where REQ_META
isn't set yet.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:36 +02:00
Christoph Hellwig
a39da514eb btrfs: limit write bios to a single ordered extent
Currently buffered writeback bios are allowed to span multiple
ordered_extents, although that basically never actually happens since
commit 4a445b7b61 ("btrfs: don't merge pages into bio if their page
offset is not contiguous").

Supporting bios than span ordered_extents complicates the file
checksumming code, and prevents us from adding an ordered_extent pointer
to the btrfs_bio structure.  Use the existing code to limit a bio to
single ordered_extent for zoned device writes for all writes.

This allows to remove the REQ_BTRFS_ONE_ORDERED flags, and the
handling of multiple ordered_extents in btrfs_csum_one_bio.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:36 +02:00
Christoph Hellwig
c731cd0b6d btrfs: fix file_offset for REQ_BTRFS_ONE_ORDERED bios that get split
If a bio gets split, it needs to have a proper file_offset for checksum
validation and repair to work properly.

Based on feedback from Josef, commit 852eee62d3 ("btrfs: allow
btrfs_submit_bio to split bios") skipped this adjustment for ONE_ORDERED
bios.  But if we actually ever need to split a ONE_ORDERED read bio, this
will lead to a wrong file offset in the repair code.  Right now the only
user of the file_offset is logging of an error message so this is mostly
harmless, but the wrong offset might be more problematic for additional
users in the future.

Fixes: 852eee62d3 ("btrfs: allow btrfs_submit_bio to split bios")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:36 +02:00
Christoph Hellwig
cd4efd210e btrfs: rename __btrfs_map_block to btrfs_map_block
Now that the old btrfs_map_block is gone, drop the leading underscores
from __btrfs_map_block.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:34 +02:00
Christoph Hellwig
71df088c1c btrfs: defer splitting of ordered extents until I/O completion
The btrfs zoned completion code currently needs an ordered_extent and
extent_map per bio so that it can account for the non-predictable
write location from Zone Append.  To archive that it currently splits
the ordered_extent and extent_map at I/O submission time, and then
records the actual physical address in the ->physical field of the
ordered_extent.

This patch instead switches to record the "original" physical address
that the btrfs allocator assigned in spare space in the btrfs_bio,
and then rewrites the logical address in the btrfs_ordered_sum
structure at I/O completion time.  This allows the ordered extent
completion handler to simply walk the list of ordered csums and
split the ordered extent as needed.  This removes an extra ordered
extent and extent_map lookup and manipulation during the I/O
submission path, and instead batches it in the I/O completion path
where we need to touch these anyway.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:33 +02:00
Christoph Hellwig
3887653c44 btrfs: record orig_physical only for the original bio
btrfs_submit_dev_bio is also called for clone bios that aren't embedded
into a btrfs_bio structure, but previous commit "btrfs: optimize the
logical to physical mapping for zoned writes" added code to assign
btrfs_bio.orig_physical in it.

This is harmless right now as only the single data profile can be used
on zoned devices, but will blow up when the RAID stripe tree is added.
Move it out into the single I/O specific branch in the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:32 +02:00
Christoph Hellwig
cbfce4c7fb btrfs: optimize the logical to physical mapping for zoned writes
The current code to store the final logical to physical mapping for a
zone append write in the extent tree is rather inefficient.  It first has
to split the ordered extent so that there is one ordered extent per bio,
so that it can look up the ordered extent on I/O completion in
btrfs_record_physical_zoned and store the physical LBA returned by the
block driver in the ordered extent.

btrfs_rewrite_logical_zoned then has to do a lookup in the chunk tree to
see what physical address the logical address for this bio / ordered
extent is mapped to, and then rewrite it in the extent tree.

To optimize this process, we can store the physical address assigned in
the chunk tree to the original logical address and a pointer to
btrfs_ordered_sum structure the in the btrfs_bio structure, and then use
this information to rewrite the logical address in the btrfs_ordered_sum
structure directly at I/O completion time in btrfs_record_physical_zoned.
btrfs_rewrite_logical_zoned then simply updates the logical address in
the extent tree and the ordered_extent itself.

The code in btrfs_rewrite_logical_zoned now runs for all data I/O
completions in zoned file systems, which is fine as there is no remapping
to do for non-append writes to conventional zones or for relocation, and
the overhead for quickly breaking out of the loop is very low.

Because zoned file systems now need the ordered_sums structure to
record the actual write location returned by zone append, allocate dummy
structures without the csum array for them when the I/O doesn't use
checksums, and free them when completing the ordered_extent.

Note that the btrfs_bio doesn't grow as the new field are places into
a union that is so far not used for data writes and has plenty of space
left in it.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:32 +02:00
Christoph Hellwig
e9cb93b9fb btrfs: don't call btrfs_record_physical_zoned for failed append
When a zoned append command fails there is no written address reported,
so don't try to record it.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:32 +02:00
Christoph Hellwig
8bfec2e426 btrfs: remove hipri_workers workqueue
Now that btrfs_wq_submit_bio is never called for synchronous I/O,
the hipri_workers workqueue is not used anymore and can be removed.

Reviewed-by: Chris Mason <clm@fb.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:23 +02:00
Christoph Hellwig
e917ff56c8 btrfs: determine synchronous writers from bio or writeback control
The writeback_control structure already passes down the information about
a writeback being synchronous from the core VM code, and thus information
is propagated into the bio REQ_SYNC flag through the wbc_to_write_flags
helper.

Use that information to decide if checksums calculation is offloaded to
a workqueue instead of btrfs_inode::sync_writers field that not only
bloats the inode but also has too wide scope, being inode wide instead
of limited to the actual writeback request.

The sync writes were set in:

- btrfs_do_write_iter - regular IO, sync status is set
- start_ordered_ops - ordered write start, writeback with WB_SYNC_ALL
  mode
- btrfs_write_marked_extents - write marked extents, writeback with
  WB_SYNC_ALL mode

Reviewed-by: Chris Mason <clm@fb.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:23 +02:00
Christoph Hellwig
da02361807 btrfs: submit IO synchronously for fast checksum implementations
Most modern hardware supports very fast accelerated crc32c calculation.
If that is supported the CPU overhead of the checksum calculation is
very limited, and offloading the calculation to special worker threads
has a lot of overhead for no gain.

E.g. on an Intel Optane device is actually very much slows down even
1M buffered writes with fio:

Unpatched:

write: IOPS=3316, BW=3316MiB/s (3477MB/s)(200GiB/61757msec); 0 zone resets

With synchronous CRCs:

write: IOPS=4882, BW=4882MiB/s (5119MB/s)(200GiB/41948msec); 0 zone resets

With a lot of variation during the unpatched run going down as low as
1100MB/s, while the synchronous CRC version has about the same peak write
speed but much lower dips, and fewer kworkers churning around.
Both tests had fio saturated at 100% CPU.

(thanks to Jens Axboe via Chris Mason for the benchmarking)

Reviewed-by: Chris Mason <clm@fb.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:23 +02:00
Anand Jain
adbe7e388e btrfs: use SECTOR_SHIFT to convert LBA to physical offset
Using SECTOR_SHIFT to convert LBA to physical address makes it more
readable.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:23 +02:00
Qu Wenruo
b675df0257 btrfs: zoned: fix dev-replace after the scrub rework
[BUG]
After commit e02ee89baa ("btrfs: scrub: switch scrub_simple_mirror()
to scrub_stripe infrastructure"), scrub no longer works for zoned device
at all.

Even an empty zoned btrfs cannot be replaced:

  # mkfs.btrfs -f /dev/nvme0n1
  # mount /dev/nvme0n1 /mnt/btrfs
  # btrfs replace start -Bf 1 /dev/nvme0n2 /mnt/btrfs
  Resetting device zones /dev/nvme1n1 (160 zones) ...
  ERROR: ioctl(DEV_REPLACE_START) failed on "/mnt/btrfs/": Input/output error

And we can hit kernel crash related to that:

  BTRFS info (device nvme1n1): host-managed zoned block device /dev/nvme3n1, 160 zones of 134217728 bytes
  BTRFS info (device nvme1n1): dev_replace from /dev/nvme2n1 (devid 2) to /dev/nvme3n1 started
  nvme3n1: Zone Management Append(0x7d) @ LBA 65536, 4 blocks, Zone Is Full (sct 0x1 / sc 0xb9) DNR
  I/O error, dev nvme3n1, sector 786432 op 0xd:(ZONE_APPEND) flags 0x4000 phys_seg 3 prio class 2
  BTRFS error (device nvme1n1): bdev /dev/nvme3n1 errs: wr 1, rd 0, flush 0, corrupt 0, gen 0
  BUG: kernel NULL pointer dereference, address: 00000000000000a8
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
  RIP: 0010:_raw_spin_lock_irqsave+0x1e/0x40
  Call Trace:
   <IRQ>
   btrfs_lookup_ordered_extent+0x31/0x190
   btrfs_record_physical_zoned+0x18/0x40
   btrfs_simple_end_io+0xaf/0xc0
   blk_update_request+0x153/0x4c0
   blk_mq_end_request+0x15/0xd0
   nvme_poll_cq+0x1d3/0x360
   nvme_irq+0x39/0x80
   __handle_irq_event_percpu+0x3b/0x190
   handle_irq_event+0x2f/0x70
   handle_edge_irq+0x7c/0x210
   __common_interrupt+0x34/0xa0
   common_interrupt+0x7d/0xa0
   </IRQ>
   <TASK>
   asm_common_interrupt+0x22/0x40

[CAUSE]
Dev-replace reuses scrub code to iterate all extents and write the
existing content back to the new device.

And for zoned devices, we call fill_writer_pointer_gap() to make sure
all the writes into the zoned device is sequential, even if there may be
some gaps between the writes.

However we have several different bugs all related to zoned dev-replace:

- We are using ZONE_APPEND operation for metadata style write back
  For zoned devices, btrfs has two ways to write data:

  * ZONE_APPEND for data
    This allows higher queue depth, but will not be able to know where
    the write would land.
    Thus needs to grab the real on-disk physical location in it's endio.

  * WRITE for metadata
    This requires single queue depth (new writes can only be submitted
    after previous one finished), and all writes must be sequential.

  For scrub, we go single queue depth, but still goes with ZONE_APPEND,
  which requires btrfs_bio::inode being populated.
  This is the cause of that crash.

- No correct tracing of write_pointer
  After a write finished, we should forward sctx->write_pointer, or
  fill_writer_pointer_gap() would not work properly and cause more
  than necessary zero out, and fill the whole zone prematurely.

- Incorrect physical bytenr passed to fill_writer_pointer_gap()
  In scrub_write_sectors(), one call site passes logical address, which
  is completely wrong.

  The other call site passes physical address of current sector, but
  we should pass the physical address of the btrfs_bio we're submitting.

  This is the cause of the -EIO errors.

[FIX]
- Do not use ZONE_APPEND for btrfs_submit_repair_write().

- Manually forward sctx->write_pointer after successful writeback

- Use the physical address of the to-be-submitted btrfs_bio for
  fill_writer_pointer_gap()

Now zoned device replace would work as expected.

Reported-by: Christoph Hellwig <hch@lst.de>
Fixes: e02ee89baa ("btrfs: scrub: switch scrub_simple_mirror() to scrub_stripe infrastructure")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-01 15:12:02 +02:00
Christoph Hellwig
45c2f36871 btrfs: call btrfs_orig_bbio_end_io in btrfs_end_bio_work
When I implemented the storage layer bio splitting, I was under the
assumption that we'll never split metadata bios.  But Qu reminded me that
this can actually happen with very old file systems with unaligned
metadata chunks and RAID0.

I still haven't seen such a case in practice, but we better handled this
case, especially as it is fairly easily to do not calling the ->end_іo
method directly in btrfs_end_io_work, and using the proper
btrfs_orig_bbio_end_io helper instead.

In addition to the old file system with unaligned metadata chunks case
documented in the commit log, the combination of the new scrub code
with Johannes pending raid-stripe-tree also triggers this case.  We
spent some time debugging it and found that this patch solves
the problem.

Fixes: 103c19723c ("btrfs: split the bio submission path into a separate file")
CC: stable@vger.kernel.org # 6.3+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-05-26 23:24:01 +02:00
Qu Wenruo
4886ff7b50 btrfs: introduce a new helper to submit write bio for repair
Both scrub and read-repair are utilizing a special repair writes that:

- Only writes back to a single device
  Even for read-repair on RAID56, we only update the corrupted data
  stripe itself, not triggering the full RMW path.

- Requires a valid @mirror_num
  For RAID56 case, only @mirror_num == 1 is valid.
  For non-RAID56 cases, we need @mirror_num to locate our stripe.

- No data csum generation needed

These two call sites still have some differences though:

- Read-repair goes plain bio
  It doesn't need a full btrfs_bio, and goes submit_bio_wait().

- New scrub repair would go btrfs_bio
  To simplify both read and write path.

So here this patch would:

- Introduce a common helper, btrfs_map_repair_block()
  Due to the single device nature, we can use an on-stack
  btrfs_io_stripe to pass device and its physical bytenr.

- Introduce a new interface, btrfs_submit_repair_bio(), for later scrub
  code
  This is for the incoming scrub code.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-17 18:01:23 +02:00
Qu Wenruo
4317ff0056 btrfs: introduce btrfs_bio::fs_info member
Currently we're doing a lot of work for btrfs_bio:

- Checksum verification for data read bios
- Bio splits if it crosses stripe boundary
- Read repair for data read bios

However for the incoming scrub patches, we don't want this extra
functionality at all, just plain logical + mirror -> physical mapping
ability.

Thus here we do the following changes:

- Introduce btrfs_bio::fs_info
  This is for the new scrub specific btrfs_bio, which would not populate
  btrfs_bio::inode.
  Thus we need such new member to grab a fs_info

  This new member will always be populated.

- Replace @inode argument with @fs_info for btrfs_bio_init() and its
  caller
  Since @inode is no longer a mandatory member, replace it with
  @fs_info, and let involved users populate @inode.

- Skip checksum verification and generation if @bbio->inode is NULL

- Add extra ASSERT()s
  To make sure:

  * bbio->inode is properly set for involved read repair path
  * if @file_offset is set, bbio->inode is also populated

- Grab @fs_info from @bbio directly
  We can no longer go @bbio->inode->root->fs_info, as bbio->inode can be
  NULL. This involves:

  * btrfs_simple_end_io()
  * should_async_write()
  * btrfs_wq_submit_bio()
  * btrfs_use_zone_append()

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-17 18:01:23 +02:00
Christoph Hellwig
3480373ebd btrfs, block: move REQ_CGROUP_PUNT to btrfs
REQ_CGROUP_PUNT is a bit annoying as it is hard to follow and adds
a branch to the bio submission hot path.  To fix this, export
blkcg_punt_bio_submit and let btrfs call it directly.  Add a new
REQ_FS_PRIVATE flag for btrfs to indicate to it's own low-level
bio submission code that a punt to the cgroup submission helper
is required.

Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-17 18:01:22 +02:00
Christoph Hellwig
7edd339c8a btrfs: pass an ordered_extent to btrfs_extract_ordered_extent
To prepare for a new caller that already has the ordered_extent
available, change btrfs_extract_ordered_extent to take an argument
for it.  Add a wrapper for the bio case that still has to do the
lookup (for now).

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-17 18:01:21 +02:00
Johannes Thumshirn
078e4cf5db btrfs: use __bio_add_page for adding a single page in repair_one_sector
The btrfs repair bio submission code uses bio_add_page() to add a page
to a newly created bio. bio_add_page() can fail, but the return value is
never checked.

Use __bio_add_page() as adding a single page to a newly created bio is
guaranteed to succeed.

This brings us a step closer to marking bio_add_page() as __must_check.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.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>
2023-04-17 18:01:20 +02:00
Christoph Hellwig
2cef0c79bb btrfs: make btrfs_split_bio work on struct btrfs_bio
btrfs_split_bio expects a btrfs_bio as argument and always allocates one.
Type both the orig_bio argument and the return value as struct btrfs_bio
to improve type safety.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-17 18:01:18 +02:00