diff options
| author | David Sterba <dsterba@suse.com> | 2022-09-05 19:32:23 +0300 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2022-09-26 13:28:02 +0300 |
| commit | 748f553c3c4c4f175c6c834358632aff802d72cf (patch) | |
| tree | cab7b8594b9c01f5c6e656dd9f60ba5cdb12c406 /fs/btrfs/transaction.c | |
| parent | b0b47a38596f32130cb6cbdd4f7be80778fc359a (diff) | |
| download | linux-748f553c3c4c4f175c6c834358632aff802d72cf.tar.xz | |
btrfs: add KCSAN annotations for unlocked access to block_rsv->full
KCSAN reports that there's unlocked access mixed with locked access,
which is technically correct but is not a bug. To avoid false alerts at
least from KCSAN, add annotation and use a wrapper whenever ->full is
accessed for read outside of lock.
It is used as a fast check and only advisory. In the worst case the
block reserve is found !full and becomes full in the meantime, but
properly handled.
Depending on the value of ->full, btrfs_block_rsv_release decides
where to return the reservation, and block_rsv_release_bytes handles a
NULL pointer for block_rsv and if it's not NULL then it double checks
the full status under a lock.
Link: https://lore.kernel.org/linux-btrfs/CAAwBoOJDjei5Hnem155N_cJwiEkVwJYvgN-tQrwWbZQGhFU=cA@mail.gmail.com/
Link: https://lore.kernel.org/linux-btrfs/YvHU/vsXd7uz5V6j@hungrycats.org
Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/transaction.c')
| -rw-r--r-- | fs/btrfs/transaction.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index d9e608935e64..9d7563df81a0 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -594,7 +594,7 @@ start_transaction(struct btrfs_root *root, unsigned int num_items, */ num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items); if (flush == BTRFS_RESERVE_FLUSH_ALL && - delayed_refs_rsv->full == 0) { + btrfs_block_rsv_full(delayed_refs_rsv) == 0) { delayed_refs_bytes = num_bytes; num_bytes <<= 1; } @@ -619,7 +619,7 @@ start_transaction(struct btrfs_root *root, unsigned int num_items, if (rsv->space_info->force_alloc) do_chunk_alloc = true; } else if (num_items == 0 && flush == BTRFS_RESERVE_FLUSH_ALL && - !delayed_refs_rsv->full) { + !btrfs_block_rsv_full(delayed_refs_rsv)) { /* * Some people call with btrfs_start_transaction(root, 0) * because they can be throttled, but have some other mechanism |