linux-stable.git/fs/btrfs/delalloc-space.c, branch linux-rolling-stable

btrfs: zoned: fix deadlock waiting for ticket during data relocation

2026-07-24T14:19:42+00:00

[ Upstream commit 814c3b4ea357297c507158bceb07bcdc5fbe9808 ]

When performing data relocation on a zoned filesystem, BTRFS can deadlock
in handle_reserve_tickets(). The relocation process is waiting on a space
reservation ticket that can never be fulfilled, because the relocation
itself is the operation responsible for freeing up that space.

Fix this by introducing a new flush state,
BTRFS_RESERVE_FLUSH_ZONED_RELOCATION, specifically for data chunk
allocation during zoned relocation. Like
BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE, this state uses
priority_reclaim_data_space() instead of the normal flushing path, which
avoids re-entering the relocation code and breaking the deadlock cycle.

In btrfs_alloc_data_chunk_ondemand(), select this new flush state when the
inode belongs to a data relocation root on a zoned filesystem.

Fixes: e2a7fd22378f ("btrfs: zoned: add zone reclaim flush state for DATA space_info")
Reviewed-by: Boris Burkov 
Reviewed-by: Naohiro Aota 
Signed-off-by: Johannes Thumshirn 
Signed-off-by: David Sterba 
Signed-off-by: Sasha Levin

btrfs: remove fs_info argument from btrfs_reserve_metadata_bytes()

2025-11-24T20:59:11+00:00

We don't need it since we can grab fs_info from the given space_info.
So remove the fs_info argument.

Reviewed-by: Qu Wenruo 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Anand Jain 
Signed-off-by: Filipe Manana 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: add block reserve for treelog

2025-05-15T12:30:53+00:00

We need to add a dedicated block_rsv for tree-log, because the block_rsv
serves for a tree node allocation in btrfs_alloc_tree_block(). Currently,
tree-log tree uses fs_info->empty_block_rsv, which is shared across trees
and points to the normal metadata space_info. Instead, we add a dedicated
block_rsv and that block_rsv can use the dedicated sub-space_info.

Reviewed-by: Johannes Thumshirn 
Signed-off-by: Naohiro Aota 
Signed-off-by: David Sterba

btrfs: use proper data space_info for zoned mode

2025-05-15T12:30:53+00:00

Now that, we have data sub-space for the zoned mode. Tweak some space_info
functions to use proper space_info for a file.

Reviewed-by: Johannes Thumshirn 
Signed-off-by: Naohiro Aota 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: pass struct btrfs_inode to btrfs_free_reserved_data_space_noquota()

2025-05-15T12:30:52+00:00

As well as the last patch, pass struct btrfs_inode to the function and
let it distinguish which data space it is working on in a later patch.
There is no functional change with this commit.

Reviewed-by: Johannes Thumshirn 
Signed-off-by: Naohiro Aota 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: pass btrfs_space_info to btrfs_reserve_data_bytes()

2025-05-15T12:30:52+00:00

Pass struct btrfs_space_info to btrfs_reserve_data_bytes() to allow
reserving the data from multiple data space_info candidates.

This is a preparation for the following commits and there is no functional
change.

Reviewed-by: Johannes Thumshirn 
Signed-off-by: Naohiro Aota 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: refactor how we handle reserved space inside copy_one_range()

2025-05-15T12:30:40+00:00

There are several things not ideal in copy_one_range():

- Unnecessary temporary variables
  * block_offset
  * reserve_bytes
  * dirty_blocks
  * num_blocks
  * release_bytes
  These are utilized to handle short-copy cases.

- Inconsistent handling of btrfs_delalloc_release_extents()
  There is a hidden behavior that, after reserving metadata for X bytes
  of data write, we have to call btrfs_delalloc_release_extents() with X
  once and only once.

  Calling btrfs_delalloc_release_extents(X - 4K) and
  btrfs_delalloc_release_extents(4K) will cause outstanding extents
  accounting to go wrong.

  This is because the outstanding extents mechanism is not designed to
  handle shrinking of reserved space.

Improve above situations by:

- Use a single @reserved_start and @reserved_len pair
  Now we reserve space for the initial range, and if a short copy
  happened and we need to shrink the reserved space, we can easily
  calculate the new length, and update @reserved_len.

- Introduce helpers to shrink reserved data and metadata space
  This is done by two new helpers, shrink_reserved_space() and
  btrfs_delalloc_shrink_extents().

  The later will do a better calculation if we need to modify the
  outstanding extents, and the first one will be utilized inside
  copy_one_range().

- Manually unlock, release reserved space and return if no byte is
  copied

Reviewed-by: Filipe Manana 
Signed-off-by: Qu Wenruo 
Signed-off-by: David Sterba

btrfs: drop fs_info argument from btrfs_update_space_info_*()

2025-01-13T13:53:14+00:00

Since commit e1e577aafe41 ("btrfs: store fs_info in space_info"), we have
the fs_info in a space_info. So, we can drop fs_info argument from
btrfs_update_space_info_*. There is no behavior change.

Reviewed-by: Johannes Thumshirn 
Signed-off-by: Naohiro Aota 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: constify pointer parameters where applicable

2024-07-11T13:33:22+00:00

We can add const to many parameters, this is for clarity and minor
addition to safety. There are some minor effects, in the assembly
code and .ko measured on release config. This patch does not cover all
possible conversions.

Signed-off-by: David Sterba

btrfs: remove unused included headers

2024-03-04T15:24:46+00:00

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 
Signed-off-by: David Sterba