diff options
Diffstat (limited to 'fs/btrfs/ctree.c')
-rw-r--r-- | fs/btrfs/ctree.c | 74 |
1 files changed, 37 insertions, 37 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index dff4da0..1b756fa 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -63,7 +63,6 @@ void btrfs_free_path(struct btrfs_path *p) void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) { int i; - int skip = p->skip_locking; int keep = p->keep_locks; for (i = 0; i < BTRFS_MAX_LEVEL; i++) { @@ -76,7 +75,6 @@ void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) free_extent_buffer(p->nodes[i]); } memset(p, 0, sizeof(*p)); - p->skip_locking = skip; p->keep_locks = keep; } @@ -1137,7 +1135,6 @@ static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path, return; node = path->nodes[level]; - WARN_ON(!path->skip_locking && !btrfs_tree_locked(node)); search = btrfs_node_blockptr(node, slot); blocksize = btrfs_level_size(root, level - 1); @@ -1192,6 +1189,7 @@ static void unlock_up(struct btrfs_path *path, int level, int lowest_unlock) { int i; int skip_level = level; + int no_skips = 0; struct extent_buffer *t; for (i = level; i < BTRFS_MAX_LEVEL; i++) { @@ -1199,27 +1197,24 @@ static void unlock_up(struct btrfs_path *path, int level, int lowest_unlock) break; if (!path->locks[i]) break; - if (path->slots[i] == 0) { + if (!no_skips && path->slots[i] == 0) { skip_level = i + 1; continue; } - if (path->keep_locks) { + if (!no_skips && path->keep_locks) { u32 nritems; t = path->nodes[i]; nritems = btrfs_header_nritems(t); - if (nritems < 2 || path->slots[i] >= nritems - 2) { -if (path->keep_locks) { -//printk("path %p skip level now %d\n", path, skip_level); -} + if (nritems < 1 || path->slots[i] >= nritems - 1) { skip_level = i + 1; continue; } } + if (skip_level < i && i >= lowest_unlock) + no_skips = 1; + t = path->nodes[i]; if (i >= lowest_unlock && i > skip_level && path->locks[i]) { -if (path->keep_locks) { -//printk("path %p unlocking level %d slot %d nritems %d skip_level %d\n", path, i, path->slots[i], btrfs_header_nritems(t), skip_level); -} btrfs_tree_unlock(t); path->locks[i] = 0; } @@ -1244,6 +1239,7 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root ins_len, int cow) { struct extent_buffer *b; + struct extent_buffer *tmp; int slot; int ret; int level; @@ -1263,10 +1259,7 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root if (ins_len < 0) lowest_unlock = 2; again: - if (!p->skip_locking) - b = btrfs_lock_root_node(root); - else - b = btrfs_root_node(root); + b = btrfs_lock_root_node(root); while (b) { level = btrfs_header_level(b); @@ -1286,8 +1279,7 @@ again: WARN_ON(1); level = btrfs_header_level(b); p->nodes[level] = b; - if (!p->skip_locking) - p->locks[level] = 1; + p->locks[level] = 1; ret = check_block(root, p, level); if (ret) return -1; @@ -1328,10 +1320,29 @@ again: reada_for_search(root, p, level, slot, key->objectid); - b = read_node_slot(root, b, slot); - if (!p->skip_locking) - btrfs_tree_lock(b); - unlock_up(p, level + 1, lowest_unlock); + tmp = btrfs_find_tree_block(root, + btrfs_node_blockptr(b, slot), + btrfs_level_size(root, level - 1)); + if (tmp && btrfs_buffer_uptodate(tmp, + btrfs_node_ptr_generation(b, slot))) { + b = tmp; + } else { + /* + * reduce lock contention at high levels + * of the btree by dropping locks before + * we read. + */ + if (level > 1) { + btrfs_release_path(NULL, p); + if (tmp) + free_extent_buffer(tmp); + goto again; + } else { + b = read_node_slot(root, b, slot); + } + } + btrfs_tree_lock(b); + unlock_up(p, level, lowest_unlock); } else { p->slots[level] = slot; if (ins_len > 0 && btrfs_leaf_free_space(root, b) < @@ -3007,17 +3018,8 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) reada_for_search(root, path, level, slot, 0); next = read_node_slot(root, c, slot); - if (!path->skip_locking) { - if (!btrfs_tree_locked(c)) { - int i; - WARN_ON(1); -printk("path %p no lock on level %d\n", path, level); -for (i = 0; i < BTRFS_MAX_LEVEL; i++) { -printk("path %p level %d slot %d nritems %d\n", path, i, path->slots[i], btrfs_header_nritems(path->nodes[i])); -} - } - btrfs_tree_lock(next); - } + WARN_ON(!btrfs_tree_locked(c)); + btrfs_tree_lock(next); break; } path->slots[level] = slot; @@ -3035,10 +3037,8 @@ printk("path %p level %d slot %d nritems %d\n", path, i, path->slots[i], btrfs_h if (level == 1 && path->locks[1] && path->reada) reada_for_search(root, path, level, slot, 0); next = read_node_slot(root, next, 0); - if (!path->skip_locking) { - WARN_ON(!btrfs_tree_locked(path->nodes[level])); - btrfs_tree_lock(next); - } + WARN_ON(!btrfs_tree_locked(path->nodes[level])); + btrfs_tree_lock(next); } done: unlock_up(path, 0, 1); |