diff options
Diffstat (limited to 'fs/btrfs/transaction.h')
| -rw-r--r-- | fs/btrfs/transaction.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index 817fd7c9836b..2762c8d6191c 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -69,6 +69,22 @@ struct btrfs_transaction { struct list_head pending_chunks; struct list_head switch_commits; struct list_head dirty_bgs; + + /* + * There is no explicit lock which protects io_bgs, rather its + * consistency is implied by the fact that all the sites which modify + * it do so under some form of transaction critical section, namely: + * + * - btrfs_start_dirty_block_groups - This function can only ever be + * run by one of the transaction committers. Refer to + * BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction + * + * - btrfs_write_dirty_blockgroups - this is called by + * commit_cowonly_roots from transaction critical section + * (TRANS_STATE_COMMIT_DOING) + * + * - btrfs_cleanup_dirty_bgs - called on transaction abort + */ struct list_head io_bgs; struct list_head dropped_roots; |