We use add_root_meta_rsv and sub_root_meta_rsv to track prealloc and
pertrans reservations for subvolumes when quotas are enabled. The
convert function does not properly increment pertrans after decrementing
prealloc, so the count is not accurate.

Note: we check that the fs is not read-only to mirror the logic in
qgroup_convert_meta, which checks that before adding to the pertrans rsv.

Fixes: 8287475a

 ("btrfs: qgroup: Use root::qgroup_meta_rsv_* to record qgroup meta reserved space")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>

There are reports from tree-checker that detects corrupted nodes,
without any obvious pattern so possibly an overwrite in memory.
After some debugging it turns out there's a race when reading an extent
buffer the uptodate status can be missed.

To prevent concurrent reads for the same extent buffer,
read_extent_buffer_pages() performs these checks:

    /* (1) */
    if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
        return 0;

    /* (2) */
    if (test_and_set_bit(EXTENT_BUFFER_READING, &eb->bflags))
        goto done;

At this point, it seems safe to start the actual read operation. Once
that completes, end_bbio_meta_read() does

    /* (3) */
    set_extent_buffer_uptodate(eb);

    /* (4) */
    clear_bit(EXTENT_BUFFER_READING, &eb->bflags);

Normally, this is enough to ensure only one read happens, and all other
callers wait for it to finish before returning.  Unfortunately, there is
a racey interleaving:

    Thread A | Thread B | Thread C
    ---------+----------+---------
       (1)   |          |
             |    (1)   |
       (2)   |          |
       (3)   |          |
       (4)   |          |
             |    (2)   |
             |          |    (1)

When this happens, thread B kicks of an unnecessary read. Worse, thread
C will see UPTODATE set and return immediately, while the read from
thread B is still in progress.  This race could result in tree-checker
errors like this as the extent buffer is concurrently modified:

    BTRFS critical (device dm-0): corrupted node, root=256
    block=8550954455682405139 owner mismatch, have 11858205567642294356
    expect [256, 18446744073709551360]

Fix it by testing UPTODATE again after setting the READING bit, and if
it's been set, skip the unnecessary read.

Fixes: d7172f52

 ("btrfs: use per-buffer locking for extent_buffer reading")
Link: https://lore.kernel.org/linux-btrfs/CAHk-=whNdMaN9ntZ47XRKP6DBes2E5w7fi-0U3H2+PS18p+Pzw@mail.gmail.com/
Link: https://lore.kernel.org/linux-btrfs/f51a6d5d7432455a6a858d51b49ecac183e0bbc9.1706312914.git.wqu@suse.com/
Link: https://lore.kernel.org/linux-btrfs/c7241ea4-fcc6-48d2-98c8-b5ea790d6c89@gmx.com/
CC: stable@vger.kernel.org # 6.5+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tavian Barnes <tavianator@tavianator.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor update of changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>

When attempting to exclusive open a device which has no exclusive open
permission, such as a physical device associated with the flakey dm
device, the open operation will fail, resulting in a mount failure.

In this particular scenario, we erroneously return -EINVAL instead of the
correct error code provided by the bdev_open_by_path() function, which is
-EBUSY.

Fix this, by returning error code from the bdev_open_by_path() function.
With this correction, the mount error message will align with that of
ext4 and xfs.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Commit f4a9f219 ("btrfs: do not delete unused block group if it may be
used soon") changed the behaviour of deleting unused block-groups on zoned
filesystems. Starting with this commit, we're using
btrfs_space_info_used() to calculate the number of used bytes in a
space_info. But btrfs_space_info_used() also accounts
btrfs_space_info::bytes_zone_unusable as used bytes.

So if a block group is 100% zone_unusable it is skipped from the deletion
step.

In order not to skip fully zone_unusable block-groups, also check if the
block-group has bytes left that can be used on a zoned filesystem.

Fixes: f4a9f219

 ("btrfs: do not delete unused block group if it may be used soon")
CC: stable@vger.kernel.org # 6.1+
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>

At btrfs_add_extent_mapping(), if we failed to merge the extent map, which
is unexpected and theoretically should never happen, we use WARN_ONCE() to
log a message which is not great because we don't get information about
which filesystem it relates to in case we have multiple btrfs filesystems
mounted. So change this to use btrfs_warn() and surround the error check
with WARN_ON() so we always get a useful stack trace and the condition is
flagged as "unlikely" since it's not expected to ever happen.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

At btrfs_add_extent_mapping(), if we are unable to merge the existing
extent map, we print a warning message that suggests interval ranges in
the form "[X, Y)", where the first element is the inclusive start offset
of a range and the second element is the exclusive end offset. However
we end up printing the length of the ranges instead of the exclusive end
offsets. So fix this by printing the range end offsets.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

At unpin_extent_range() we print warning messages that are supposed to
print an interval in the form "[X, Y)", with the first element being an
inclusive start offset and the second element being the exclusive end
offset of a range. However we end up printing the range's length instead
of the range's exclusive end offset, so fix that to avoid having confusing
and non-sense messages in case we hit one of these unexpected scenarios.

Fixes: 00deaf04

 ("btrfs: log messages at unpin_extent_range() during unexpected cases")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

At unpin_extent_cache() if we happen to find an extent map with an
unexpected start offset, we jump to the 'out' label and never release the
reference we added to the extent map through the call to
lookup_extent_mapping(), therefore resulting in a leak. So fix this by
moving the free_extent_map() under the 'out' label.

Fixes: c03c89f8

 ("btrfs: handle errors returned from unpin_extent_cache()")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Boris managed to create a device capable of changing its maj:min without
altering its device path.

Only multi-devices can be scanned. A device that gets scanned and remains
in the btrfs kernel cache might end up with an incorrect maj:min.

Despite the temp-fsid feature patch did not introduce this bug, it could
lead to issues if the above multi-device is converted to a single device
with a stale maj:min. Subsequently, attempting to mount the same device
with the correct maj:min might mistake it for another device with the same
fsid, potentially resulting in wrongly auto-enabling the temp-fsid feature.

To address this, this patch validates the device's maj:min at the time of
device open and updates it if it has changed since the last scan.

CC: stable@vger.kernel.org # 6.7+
Fixes: a5b8a5f9

 ("btrfs: support cloned-device mount capability")
Reported-by: Boris Burkov <boris@bur.io>
Co-developed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Boris Burkov <boris@bur.io&gt;#>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Shinichiro reported the following use-after-free triggered by the device
replace operation in fstests btrfs/070.

 BTRFS info (device nullb1): scrub: finished on devid 1 with status: 0
 ==================================================================
 BUG: KASAN: slab-use-after-free in do_zone_finish+0x91a/0xb90 [btrfs]
 Read of size 8 at addr ffff8881543c8060 by task btrfs-cleaner/3494007

 CPU: 0 PID: 3494007 Comm: btrfs-cleaner Tainted: G        W          6.8.0-rc5-kts #1
 Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020
 Call Trace:
  <TASK>
  dump_stack_lvl+0x5b/0x90
  print_report+0xcf/0x670
  ? __virt_addr_valid+0x200/0x3e0
  kasan_report+0xd8/0x110
  ? do_zone_finish+0x91a/0xb90 [btrfs]
  ? do_zone_finish+0x91a/0xb90 [btrfs]
  do_zone_finish+0x91a/0xb90 [btrfs]
  btrfs_delete_unused_bgs+0x5e1/0x1750 [btrfs]
  ? __pfx_btrfs_delete_unused_bgs+0x10/0x10 [btrfs]
  ? btrfs_put_root+0x2d/0x220 [btrfs]
  ? btrfs_clean_one_deleted_snapshot+0x299/0x430 [btrfs]
  cleaner_kthread+0x21e/0x380 [btrfs]
  ? __pfx_cleaner_kthread+0x10/0x10 [btrfs]
  kthread+0x2e3/0x3c0
  ? __pfx_kthread+0x10/0x10
  ret_from_fork+0x31/0x70
  ? __pfx_kthread+0x10/0x10
  ret_from_fork_asm+0x1b/0x30
  </TASK>

 Allocated by task 3493983:
  kasan_save_stack+0x33/0x60
  kasan_save_track+0x14/0x30
  __kasan_kmalloc+0xaa/0xb0
  btrfs_alloc_device+0xb3/0x4e0 [btrfs]
  device_list_add.constprop.0+0x993/0x1630 [btrfs]
  btrfs_scan_one_device+0x219/0x3d0 [btrfs]
  btrfs_control_ioctl+0x26e/0x310 [btrfs]
  __x64_sys_ioctl+0x134/0x1b0
  do_syscall_64+0x99/0x190
  entry_SYSCALL_64_after_hwframe+0x6e/0x76

 Freed by task 3494056:
  kasan_save_stack+0x33/0x60
  kasan_save_track+0x14/0x30
  kasan_save_free_info+0x3f/0x60
  poison_slab_object+0x102/0x170
  __kasan_slab_free+0x32/0x70
  kfree+0x11b/0x320
  btrfs_rm_dev_replace_free_srcdev+0xca/0x280 [btrfs]
  btrfs_dev_replace_finishing+0xd7e/0x14f0 [btrfs]
  btrfs_dev_replace_by_ioctl+0x1286/0x25a0 [btrfs]
  btrfs_ioctl+0xb27/0x57d0 [btrfs]
  __x64_sys_ioctl+0x134/0x1b0
  do_syscall_64+0x99/0x190
  entry_SYSCALL_64_after_hwframe+0x6e/0x76

 The buggy address belongs to the object at ffff8881543c8000
  which belongs to the cache kmalloc-1k of size 1024
 The buggy address is located 96 bytes inside of
  freed 1024-byte region [ffff8881543c8000, ffff8881543c8400)

 The buggy address belongs to the physical page:
 page:00000000fe2c1285 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1543c8
 head:00000000fe2c1285 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
 flags: 0x17ffffc0000840(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
 page_type: 0xffffffff()
 raw: 0017ffffc0000840 ffff888100042dc0 ffffea0019e8f200 dead000000000002
 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff8881543c7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffff8881543c7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 >ffff8881543c8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                        ^
  ffff8881543c8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8881543c8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

This UAF happens because we're accessing stale zone information of a
already removed btrfs_device in do_zone_finish().

The sequence of events is as follows:

btrfs_dev_replace_start
  btrfs_scrub_dev
   btrfs_dev_replace_finishing
    btrfs_dev_replace_update_device_in_mapping_tree <-- devices replaced
    btrfs_rm_dev_replace_free_srcdev
     btrfs_free_device                              <-- device freed

cleaner_kthread
 btrfs_delete_unused_bgs
  btrfs_zone_finish
   do_zone_finish              <-- refers the freed device

The reason for this is that we're using a cached pointer to the chunk_map
from the block group, but on device replace this cached pointer can
contain stale device entries.

The staleness comes from the fact, that btrfs_block_group::physical_map is
not a pointer to a btrfs_chunk_map but a memory copy of it.

Also take the fs_info::dev_replace::rwsem to prevent
btrfs_dev_replace_update_device_in_mapping_tree() from changing the device
underneath us again.

Note: btrfs_dev_replace_update_device_in_mapping_tree() is holding
fs_info::mapping_tree_lock, but as this is a spinning read/write lock we
cannot take it as the call to blkdev_zone_mgmt() requires a memory
allocation which may not sleep.
But btrfs_dev_replace_update_device_in_mapping_tree() is always called with
the fs_info::dev_replace::rwsem held in write mode.

Many thanks to Shinichiro for analyzing the bug.

Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
CC: stable@vger.kernel.org # 6.8
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>

At the moment scrub_supers() doesn't grab the super block's location via
the zoned device aware btrfs_sb_log_location() but via btrfs_sb_offset().

This leads to checksum errors on 'scrub' as we're not accessing the
correct location of the super block.

So use btrfs_sb_log_location() for getting the super blocks location on
scrub.

Reported-by: WA AM <waautomata@gmail.com>
Link: http://lore.kernel.org/linux-btrfs/CANU2Z0EvUzfYxczLgGUiREoMndE9WdQnbaawV5Fv5gNXptPUKw@mail.gmail.com
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Qu Wenruo <wqu@suse.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>

During fiemap we may have to visit multiple leaves of the subvolume's
inode tree, and each time we are freeing and allocating an extent buffer
to use as a clone of each visited leaf. Optimize this by reusing cloned
extent buffers, to avoid the freeing and re-allocation both of the extent
buffer structure itself and more importantly of the pages attached to the
extent buffer.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

For fiemap we recently stopped locking the target extent range for the
whole duration of the fiemap call, in order to avoid a deadlock in a
scenario where the fiemap buffer happens to be a memory mapped range of
the same file. This use case is very unlikely to be useful in practice but
it may be triggered by fuzz testing (syzbot, etc).

This however introduced a race that makes us miss delalloc ranges for
file regions that are currently holes, so the caller of fiemap will not
be aware that there's data for some file regions. This can be quite
serious for some use cases - for example in coreutils versions before 9.0,
the cp program used fiemap to detect holes and data in the source file,
copying only regions with data (extents or delalloc) from the source file
to the destination file in order to preserve holes (see the documentation
for its --sparse command line option). This means that if cp was used
with a source file that had delalloc in a hole, the destination file could
end up without that data, which is effectively a data loss issue, if it
happened to hit the race described below.

The race happens like this:

1) Fiemap is called, without the FIEMAP_FLAG_SYNC flag, for a file that
   has delalloc in the file range [64M, 65M[, which is currently a hole;

2) Fiemap locks the inode in shared mode, then starts iterating the
   inode's subvolume tree searching for file extent items, without having
   the whole fiemap target range locked in the inode's io tree - the
   change introduced recently by commit b0ad381f ("btrfs: fix
   deadlock with fiemap and extent locking"). It only locks ranges in
   the io tree when it finds a hole or prealloc extent since that
   commit;

3) Note that fiemap clones each leaf before using it, and this is to
   avoid deadlocks when locking a file range in the inode's io tree and
   the fiemap buffer is memory mapped to some file, because writing
   to the page with btrfs_page_mkwrite() will wait on any ordered extent
   for the page's range and the ordered extent needs to lock the range
   and may need to modify the same leaf, therefore leading to a deadlock
   on the leaf;

4) While iterating the file extent items in the cloned leaf before
   finding the hole in the range [64M, 65M[, the delalloc in that range
   is flushed and its ordered extent completes - meaning the corresponding
   file extent item is in the inode's subvolume tree, but not present in
   the cloned leaf that fiemap is iterating over;

5) When fiemap finds the hole in the [64M, 65M[ range by seeing the gap in
   the cloned leaf (or a file extent item with disk_bytenr == 0 in case
   the NO_HOLES feature is not enabled), it will lock that file range in
   the inode's io tree and then search for delalloc by checking for the
   EXTENT_DELALLOC bit in the io tree for that range and ordered extents
   (with btrfs_find_delalloc_in_range()). But it finds nothing since the
   delalloc in that range was already flushed and the ordered extent
   completed and is gone - as a result fiemap will not report that there's
   delalloc or an extent for the range [64M, 65M[, so user space will be
   mislead into thinking that there's a hole in that range.

This could actually be sporadically triggered with test case generic/094
from fstests, which reports a missing extent/delalloc range like this:

  generic/094 2s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//generic/094.out.bad)
      --- tests/generic/094.out	2020-06-10 19:29:03.830519425 +0100
      +++ /home/fdmanana/git/hub/xfstests/results//generic/094.out.bad	2024-02-28 11:00:00.381071525 +0000
      @@ -1,3 +1,9 @@
       QA output created by 094
       fiemap run with sync
       fiemap run without sync
      +ERROR: couldn't find extent at 7
      +map is 'HHDDHPPDPHPH'
      +logical: [       5..       6] phys:   301517..  301518 flags: 0x800 tot: 2
      +logical: [       8..       8] phys:   301520..  301520 flags: 0x800 tot: 1
      ...
      (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/generic/094.out /home/fdmanana/git/hub/xfstests/results//generic/094.out.bad'  to see the entire diff)

So in order to fix this, while still avoiding deadlocks in the case where
the fiemap buffer is memory mapped to the same file, change fiemap to work
like the following:

1) Always lock the whole range in the inode's io tree before starting to
   iterate the inode's subvolume tree searching for file extent items,
   just like we did before commit b0ad381f ("btrfs: fix deadlock with
   fiemap and extent locking");

2) Now instead of writing to the fiemap buffer every time we have an extent
   to report, write instead to a temporary buffer (1 page), and when that
   buffer becomes full, stop iterating the file extent items, unlock the
   range in the io tree, release the search path, submit all the entries
   kept in that buffer to the fiemap buffer, and then resume the search
   for file extent items after locking again the remainder of the range in
   the io tree.

   The buffer having a size of a page, allows for 146 entries in a system
   with 4K pages. This is a large enough value to have a good performance
   by avoiding too many restarts of the search for file extent items.
   In other words this preserves the huge performance gains made in the
   last two years to fiemap, while avoiding the deadlocks in case the
   fiemap buffer is memory mapped to the same file (useless in practice,
   but possible and exercised by fuzz testing and syzbot).

Fixes: b0ad381f

 ("btrfs: fix deadlock with fiemap and extent locking")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

At contains_pending_extent() the value of the end offset of a chunk we
found in the device's allocation state io tree is inclusive, so when
we calculate the length we pass to the in_range() macro, we must sum
1 to the expression "physical_end - physical_offset".

In practice the wrong calculation should be harmless as chunks sizes
are never 1 byte and we should never have 1 byte ranges of unallocated
space. Nevertheless fix the wrong calculation.

Reported-by: Alex Lyakas <alex.lyakas@zadara.com>
Link: https://lore.kernel.org/linux-btrfs/CAOcd+r30e-f4R-5x-S7sV22RJPe7+pgwherA6xqN2_qe7o4XTg@mail.gmail.com/
Fixes: 1c11b63e

 ("btrfs: replace pending/pinned chunks lists with io tree")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Currently "btrfs subvolume snapshot -i <qgroupid>" would always mark the
qgroup inconsistent.

This can be annoying if the fs has a lot of snapshots, and needs qgroup
to get the accounting for the amount of bytes it can free for each
snapshot.

Although we have the new simple quote as a solution, there is also a
case where we can skip the full scan, if all the following conditions
are met:

- The source subvolume belongs to a higher level parent qgroup
- The parent qgroup already owns all its bytes exclusively
- The new snapshot is also added to the same parent qgroup

In that case, we only need to add nodesize to the parent qgroup and
avoid a full rescan.

This patch would add the extra quick accounting update for such inherit.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

[BUG]
Currently btrfs can create subvolume with an invalid qgroup inherit
without triggering any error:

  # mkfs.btrfs -O quota -f $dev
  # mount $dev $mnt
  # btrfs subvolume create -i 2/0 $mnt/subv1
  # btrfs qgroup show -prce --sync $mnt
  Qgroupid    Referenced    Exclusive   Path
  --------    ----------    ---------   ----
  0/5           16.00KiB     16.00KiB   <toplevel>
  0/256         16.00KiB     16.00KiB   subv1

[CAUSE]
We only do a very basic size check for btrfs_qgroup_inherit structure,
but never really verify if the values are correct.

Thus in btrfs_qgroup_inherit() function, we have to skip non-existing
qgroups, and never return any error.

[FIX]
Fix the behavior and introduce extra checks:

- Introduce early check for btrfs_qgroup_inherit structure
  Not only the size, but also all the qgroup ids would be verified.

  And the timing is very early, so we can return error early.
  This early check is very important for snapshot creation, as snapshot
  is delayed to transaction commit.

- Drop support for btrfs_qgroup_inherit::num_ref_copies and
  num_excl_copies
  Those two members are used to specify to copy refr/excl numbers from
  other qgroups.
  This would definitely mark qgroup inconsistent, and btrfs-progs has
  dropped the support for them for a long time.
  It's time to drop the support for kernel.

- Verify the supported btrfs_qgroup_inherit::flags
  Just in case we want to add extra flags for btrfs_qgroup_inherit.

Now above subvolume creation would fail with -ENOENT other than silently
ignore the non-existing qgroup.

CC: stable@vger.kernel.org # 6.7+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

To better debug issues surrounding device scans, include the device's
major and minor numbers in the device scan notice for btrfs.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

btrfs_put_caching_control() is only used in block-group.c, so mark it
static.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Lijuan Li <lilijuan@iscas.ac.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

The SLAB_MEM_SPREAD flag used to be implemented in SLAB, which was
removed as of v6.8-rc1, so it became a dead flag since the commit
16a1d968

 ("mm/slab: remove mm/slab.c and slab_def.h"). And the
series[1] went on to mark it obsolete to avoid confusion for users.
Here we can just remove all its users, which has no functional change.

[1] https://lore.kernel.org/all/20240223-slab-cleanup-flags-v2-1-02f1753e8303@suse.cz/

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

[BUG]
If qgroup is marked inconsistent (e.g. caused by operations needing full
subtree rescan, like creating a snapshot and assign to a higher level
qgroup), btrfs would immediately start leaking its data reserved space.

The following script can easily reproduce it:

  mkfs.btrfs -O quota -f $dev
  mount $dev $mnt
  btrfs subvolume create $mnt/subv1
  btrfs qgroup create 1/0 $mnt

  # This snapshot creation would mark qgroup inconsistent,
  # as the ownership involves different higher level qgroup, thus
  # we have to rescan both source and snapshot, which can be very
  # time consuming, thus here btrfs just choose to mark qgroup
  # inconsistent, and let users to determine when to do the rescan.
  btrfs subv snapshot -i 1/0 $mnt/subv1 $mnt/snap1

  # Now this write would lead to qgroup rsv leak.
  xfs_io -f -c "pwrite 0 64k" $mnt/file1

  # And at unmount time, btrfs would report 64K DATA rsv space leaked.
  umount $mnt

And we would have the following dmesg output for the unmount:

  BTRFS info (device dm-1): last unmount of filesystem 14a3d84e-f47b-4f72-b053-a8a36eef74d3
  BTRFS warning (device dm-1): qgroup 0/5 has unreleased space, type 0 rsv 65536

[CAUSE]
Since commit e15e9f43

 ("btrfs: introduce
BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING to skip qgroup accounting"),
we introduce a mode for btrfs qgroup to skip the timing consuming
backref walk, if the qgroup is already inconsistent.

But this skip also covered the data reserved freeing, thus the qgroup
reserved space for each newly created data extent would not be freed,
thus cause the leakage.

[FIX]
Make the data extent reserved space freeing mandatory.

The qgroup reserved space handling is way cheaper compared to the
backref walking part, and we always have the super sensitive leak
detector, thus it's definitely worth to always free the qgroup
reserved data space.

Reported-by: Fabian Vogt <fvogt@suse.com>
Fixes: e15e9f43

 ("btrfs: introduce BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING to skip qgroup accounting")
CC: stable@vger.kernel.org # 6.1+
Link: https://bugzilla.suse.com/show_bug.cgi?id=1216196
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

[BUG]
There is a bug report about very suspicious tree-checker got triggered:

  BTRFS critical (device dm-0): corrupted node, root=256
block=8550954455682405139 owner mismatch, have 11858205567642294356
expect [256, 18446744073709551360]
  BTRFS critical (device dm-0): corrupted node, root=256
block=8550954455682405139 owner mismatch, have 11858205567642294356
expect [256, 18446744073709551360]
  BTRFS critical (device dm-0): corrupted node, root=256
block=8550954455682405139 owner mismatch, have 11858205567642294356
expect [256, 18446744073709551360]
  SELinux: inode_doinit_use_xattr:  getxattr returned 117 for dev=dm-0
ino=5737268

[ANALYZE]
The root cause is still unclear, but there are some clues already:

- Unaligned eb bytenr
  The block bytenr is 8550954455682405139, which is not even aligned to
  2.
  This bytenr is fetched from extent buffer header, not from eb->start.

  This means, at the initial time of read, eb header bytenr is still
  correct (the very basis check to continue read), but later something
  wrong happened, got at least the first page corrupted.
  Thus we got such obviously incorrect value.

- Invalid extent buffer header owner
  The read itself is triggered for subvolume 256, but the eb header
  owner is 11858205567642294356, which is not really possible.
  The problem here is, subvolume id is limited to (1 << 48 - 1),
  and this one definitely goes beyond that limit.

  So this value is another garbage.

We already got two garbage from an extent buffer, which passed the
initial bytenr and csum checks, but later the contents become garbage at
some point.

This looks like a page lifespan problem (e.g. we didn't properly hold the
page).

[ENHANCEMENT]
The current tree-checker only outputs things from the extent buffer,
nothing with the page status.

So this patch would enhance the tree-checker output by also dumping the
first page, which would look like this:

  page:00000000aa9f3ce8 refcount:4 mapcount:0 mapping:00000000169aa6b6 index:0x1d0c pfn:0x1022e5
  memcg:ffff888103456000
  aops:btree_aops [btrfs] ino:1
  flags: 0x2ffff0000008000(private|node=0|zone=2|lastcpupid=0xffff)
  page_type: 0xffffffff()
  raw: 02ffff0000008000 0000000000000000 dead000000000122 ffff88811e06e220
  raw: 0000000000001d0c ffff888102fdb1d8 00000004ffffffff ffff888103456000
  page dumped because: eb page dump
  BTRFS critical (device dm-3): corrupt leaf: root=5 block=30457856 slot=6 ino=257 file_offset=0, invalid disk_bytenr for file extent, have 10617606235235216665, should be aligned to 4096
  BTRFS error (device dm-3): read time tree block corruption detected on logical 30457856 mirror 1

From the dump we can see some extra info, something can help us to do
extra cross-checks:

- Page refcount
  if it's too low, it definitely means something bad.

- Page aops
  Any mapped eb page should have btree_aops with inode number 1.

- Page index
  Since a mapped eb page should has its bytenr matching the page
  position, (index << PAGE_SHIFT) should match the bytenr of the
  bytenr from the critical line.

- Page Private flags
  A mapped eb page should have Private flag set to indicate it's managed
  by btrfs.

Link: https://lore.kernel.org/linux-btrfs/CAHk-=whNdMaN9ntZ47XRKP6DBes2E5w7fi-0U3H2+PS18p+Pzw@mail.gmail.com/
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Since commit a440d48c

 ("Btrfs: heuristic: implement sampling
logic"), btrfs_compress_heuristic() is no longer a simple "return true",
but more complex to determine if we should compress.

Thus the comment is dead and can be confusing, just remove it.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

For the writer counter, it's pretty much the same as the reader counter,
and they are exclusive.  So move them to the new locked bitmap.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Currently btrfs_subpage utilizes its atomic member @reader to manage the
reader counter.  However it is only utilized to prevent the page to be
released/unlocked when we still have reads underway.

In that use case, we don't really allow multiple readers on the same
subpage sector.  So here we can introduce a new locked bitmap to
represent exactly which subpage range is locked for read.

In theory we can remove btrfs_subpage::reader as it's just the set bits
of the new locked bitmap.  But unfortunately bitmap doesn't provide such
handy API yet, so we still keep the reader counter.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Both functions were introduced in commit 1e1de387

 ("btrfs: make
process_one_page() to handle subpage locking"), but they have never
been utilized out of subpage code.  So just unexport them.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

We can pass a valid em cache pointer down to __get_extent_map() and
drop the validity check. This avoids the special case, the call stacks
are simple:

btrfs_read_folio
  btrfs_do_readpage
    __get_extent_map

extent_readahead
  contiguous_readpages
    btrfs_do_readpage
      __get_extent_map

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

The helpers btrfs_del_delalloc_inode() and __btrfs_del_delalloc_inode()
don't follow the pattern when the "__" helper does a special case and
are in fact reversed regarding the naming. We can merge them into one as
there's only one place that needs to be open coded.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Replace the two parameters bdev and name by one that can be used to get
them both.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Other errors in flush_reservations() are handled and also in the caller.
Ignoring commit might make some sense as it's called right after join so
it's to poke the whole commit machinery to free space.

However for consistency return the error. The caller
btrfs_quota_disable() would try to start the transaction which would
in turn fail too so there's no effective change.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Use the KMEM_CACHE() macro instead of kmem_cache_create() to simplify
the creation of SLAB caches when the default values are used.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Use the KMEM_CACHE() macro instead of kmem_cache_create() to simplify
the creation of SLAB caches related to delayed refs when the default
values are used.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Use the KMEM_CACHE() macro instead of kmem_cache_create() to simplify
the creation of SLAB caches when the default values are used.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Use the KMEM_CACHE() macro instead of kmem_cache_create() to simplify
the creation of SLAB caches when the default values are used.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Use the KMEM_CACHE() macro instead of kmem_cache_create() to simplify
the creation of SLAB caches when the default values are used.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Use the KMEM_CACHE() macro instead of kmem_cache_create() to simplify
the creation of SLAB caches when the default values are used.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

The helpers are doing an initialization or release work, none of which
is performance critical that it would require a static inline, so move
them to the .c file.

Signed-off-by: David Sterba <dsterba@suse.com>

The helper is really trivial, reading a cache size can be done directly.

Signed-off-by: David Sterba <dsterba@suse.com>

The helpers are doing an initialization or release work, none of which
is performance critical that it would require a static inline, so move
them to the .c file.

Signed-off-by: David Sterba <dsterba@suse.com>

Using static inline in a .c file should be justified, e.g. when
functions are on a hot path but none of the affected functions seem to
be. As it's all in one compilation unit let the compiler decide.

Signed-off-by: David Sterba <dsterba@suse.com>

This is a simple initializer and not on any hot path, it does not need
to be static inline.

Signed-off-by: David Sterba <dsterba@suse.com>