diff options
| -rw-r--r-- | fs/btrfs/ctree.h | 18 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.c | 4 | ||||
| -rw-r--r-- | fs/btrfs/transaction.h | 2 | ||||
| -rw-r--r-- | fs/btrfs/tree-log.c | 2 |
4 files changed, 22 insertions, 4 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 3ebb5229660a..c8f1d2d7c46c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -191,6 +191,14 @@ struct btrfs_root { atomic_t log_commit[2]; /* Used only for log trees of subvolumes, not for the log root tree */ atomic_t log_batch; + /* + * Protected by the 'log_mutex' lock but can be read without holding + * that lock to avoid unnecessary lock contention, in which case it + * should be read using btrfs_get_root_log_transid() except if it's a + * log tree in which case it can be directly accessed. Updates to this + * field should always use btrfs_set_root_log_transid(), except for log + * trees where the field can be updated directly. + */ int log_transid; /* No matter the commit succeeds or not*/ int log_transid_committed; @@ -332,6 +340,16 @@ static inline u64 btrfs_root_id(const struct btrfs_root *root) return root->root_key.objectid; } +static inline int btrfs_get_root_log_transid(const struct btrfs_root *root) +{ + return READ_ONCE(root->log_transid); +} + +static inline void btrfs_set_root_log_transid(struct btrfs_root *root, int log_transid) +{ + WRITE_ONCE(root->log_transid, log_transid); +} + static inline int btrfs_get_root_last_log_commit(const struct btrfs_root *root) { return READ_ONCE(root->last_log_commit); diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index fe18c54cec10..c84d32951b26 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -675,7 +675,7 @@ static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info, refcount_set(&root->refs, 1); atomic_set(&root->snapshot_force_cow, 0); atomic_set(&root->nr_swapfiles, 0); - root->log_transid = 0; + btrfs_set_root_log_transid(root, 0); root->log_transid_committed = -1; btrfs_set_root_last_log_commit(root, 0); root->anon_dev = 0; @@ -1004,7 +1004,7 @@ int btrfs_add_log_tree(struct btrfs_trans_handle *trans, WARN_ON(root->log_root); root->log_root = log_root; - root->log_transid = 0; + btrfs_set_root_log_transid(root, 0); root->log_transid_committed = -1; btrfs_set_root_last_log_commit(root, 0); return 0; diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index 365c0654890e..18c4f6e83b78 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -175,7 +175,7 @@ static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans, { spin_lock(&inode->lock); inode->last_trans = trans->transaction->transid; - inode->last_sub_trans = inode->root->log_transid; + inode->last_sub_trans = btrfs_get_root_log_transid(inode->root); inode->last_log_commit = inode->last_sub_trans - 1; spin_unlock(&inode->lock); } diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 28a61a7dd371..958bb23d3d99 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -2958,7 +2958,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, btrfs_set_root_node(&log->root_item, log->node); memcpy(&new_root_item, &log->root_item, sizeof(new_root_item)); - root->log_transid++; + btrfs_set_root_log_transid(root, root->log_transid + 1); log->log_transid = root->log_transid; root->log_start_pid = 0; /* |