diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 7c99bf112960f01291366084ff4f85283f9fe27f..71e3fa30082c888677162c4c2fc7a30ec7eb4944 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2875,7 +2875,8 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, } else { if (!btrfs_tree_read_lock_atomic(b)) { btrfs_set_path_blocking(p); - __btrfs_tree_read_lock(b, p->recurse); + __btrfs_tree_read_lock(b, BTRFS_NESTING_NORMAL, + p->recurse); } p->locks[level] = BTRFS_READ_LOCK; } @@ -5453,7 +5454,9 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, } if (!ret) { btrfs_set_path_blocking(path); - __btrfs_tree_read_lock(next, path->recurse); + __btrfs_tree_read_lock(next, + BTRFS_NESTING_NORMAL, + path->recurse); } next_rw_lock = BTRFS_READ_LOCK; } @@ -5488,7 +5491,9 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, ret = btrfs_try_tree_read_lock(next); if (!ret) { btrfs_set_path_blocking(path); - __btrfs_tree_read_lock(next, path->recurse); + __btrfs_tree_read_lock(next, + BTRFS_NESTING_NORMAL, + path->recurse); } next_rw_lock = BTRFS_READ_LOCK; } diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index 740a0cde57314e8104caf82e8142a56982bf223f..66e02ebdd340890affc90063b12dd687ad995a0a 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -244,7 +244,8 @@ void btrfs_set_lock_blocking_write(struct extent_buffer *eb) * * The rwlock is held upon exit. */ -void __btrfs_tree_read_lock(struct extent_buffer *eb, bool recurse) +void __btrfs_tree_read_lock(struct extent_buffer *eb, enum btrfs_lock_nesting nest, + bool recurse) { u64 start_ns = 0; @@ -282,7 +283,7 @@ void __btrfs_tree_read_lock(struct extent_buffer *eb, bool recurse) void btrfs_tree_read_lock(struct extent_buffer *eb) { - __btrfs_tree_read_lock(eb, false); + __btrfs_tree_read_lock(eb, BTRFS_NESTING_NORMAL, false); } /* @@ -415,7 +416,7 @@ void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb) * * The rwlock is held for write upon exit. */ -void btrfs_tree_lock(struct extent_buffer *eb) +void __btrfs_tree_lock(struct extent_buffer *eb, enum btrfs_lock_nesting nest) __acquires(&eb->lock) { u64 start_ns = 0; @@ -440,6 +441,11 @@ void btrfs_tree_lock(struct extent_buffer *eb) trace_btrfs_tree_lock(eb, start_ns); } +void btrfs_tree_lock(struct extent_buffer *eb) +{ + __btrfs_tree_lock(eb, BTRFS_NESTING_NORMAL); +} + /* * Release the write lock, either blocking or spinning (ie. there's no need * for an explicit blocking unlock, like btrfs_tree_read_unlock_blocking). @@ -565,7 +571,7 @@ struct extent_buffer *__btrfs_read_lock_root_node(struct btrfs_root *root, while (1) { eb = btrfs_root_node(root); - __btrfs_tree_read_lock(eb, recurse); + __btrfs_tree_read_lock(eb, BTRFS_NESTING_NORMAL, recurse); if (eb == root->node) break; btrfs_tree_read_unlock(eb); diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h index 31f6d6405c1de104fb656b0e9678f0185befc601..5fabda8f0a80f8ab766137f88715299ed0f32a41 100644 --- a/fs/btrfs/locking.h +++ b/fs/btrfs/locking.h @@ -16,12 +16,35 @@ #define BTRFS_WRITE_LOCK_BLOCKING 3 #define BTRFS_READ_LOCK_BLOCKING 4 +/* + * We are limited in number of subclasses by MAX_LOCKDEP_SUBCLASSES, which at + * the time of this patch is 8, which is how many we use. Keep this in mind if + * you decide you want to add another subclass. + */ +enum btrfs_lock_nesting { + BTRFS_NESTING_NORMAL, + + /* + * We are limited to MAX_LOCKDEP_SUBLCLASSES number of subclasses, so + * add this in here and add a static_assert to keep us from going over + * the limit. As of this writing we're limited to 8, and we're + * definitely using 8, hence this check to keep us from messing up in + * the future. + */ + BTRFS_NESTING_MAX, +}; + +static_assert(BTRFS_NESTING_MAX <= MAX_LOCKDEP_SUBCLASSES, + "too many lock subclasses defined"); + struct btrfs_path; +void __btrfs_tree_lock(struct extent_buffer *eb, enum btrfs_lock_nesting nest); void btrfs_tree_lock(struct extent_buffer *eb); void btrfs_tree_unlock(struct extent_buffer *eb); -void __btrfs_tree_read_lock(struct extent_buffer *eb, bool recurse); +void __btrfs_tree_read_lock(struct extent_buffer *eb, enum btrfs_lock_nesting nest, + bool recurse); void btrfs_tree_read_lock(struct extent_buffer *eb); void btrfs_tree_read_unlock(struct extent_buffer *eb); void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb);