From e02119d5a7b4396c5a872582fddc8bd6d305a70a Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Fri, 5 Sep 2008 16:13:11 -0400 Subject: Btrfs: Add a write ahead tree log to optimize synchronous operations File syncs and directory syncs are optimized by copying their items into a special (copy-on-write) log tree. There is one log tree per subvolume and the btrfs super block points to a tree of log tree roots. After a crash, items are copied out of the log tree and back into the subvolume. See tree-log.c for all the details. Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 73 +++++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 54 insertions(+), 19 deletions(-) (limited to 'fs/btrfs/ctree.c') diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 7114faafa9d4..579124043d9b 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -60,7 +60,7 @@ void btrfs_free_path(struct btrfs_path *p) kmem_cache_free(btrfs_path_cachep, p); } -void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) +void noinline btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) { int i; @@ -176,7 +176,7 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans, return 0; } -int __btrfs_cow_block(struct btrfs_trans_handle *trans, +int noinline __btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, struct extent_buffer *parent, int parent_slot, @@ -294,7 +294,7 @@ int __btrfs_cow_block(struct btrfs_trans_handle *trans, return 0; } -int btrfs_cow_block(struct btrfs_trans_handle *trans, +int noinline btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, struct extent_buffer *parent, int parent_slot, struct extent_buffer **cow_ret, u64 prealloc_dest) @@ -677,9 +677,10 @@ static int noinline check_block(struct btrfs_root *root, * * slot may point to max if the key is bigger than all of the keys */ -static int generic_bin_search(struct extent_buffer *eb, unsigned long p, - int item_size, struct btrfs_key *key, - int max, int *slot) +static noinline int generic_bin_search(struct extent_buffer *eb, + unsigned long p, + int item_size, struct btrfs_key *key, + int max, int *slot) { int low = 0; int high = max; @@ -765,7 +766,7 @@ static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, return -1; } -static struct extent_buffer *read_node_slot(struct btrfs_root *root, +static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, struct extent_buffer *parent, int slot) { int level = btrfs_header_level(parent); @@ -781,7 +782,7 @@ static struct extent_buffer *read_node_slot(struct btrfs_root *root, btrfs_node_ptr_generation(parent, slot)); } -static int balance_level(struct btrfs_trans_handle *trans, +static noinline int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int level) { @@ -1128,8 +1129,9 @@ static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans, /* * readahead one full node of leaves */ -static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path, - int level, int slot, u64 objectid) +static noinline void reada_for_search(struct btrfs_root *root, + struct btrfs_path *path, + int level, int slot, u64 objectid) { struct extent_buffer *node; struct btrfs_disk_key disk_key; @@ -1201,7 +1203,8 @@ static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path, } } -static void unlock_up(struct btrfs_path *path, int level, int lowest_unlock) +static noinline void unlock_up(struct btrfs_path *path, int level, + int lowest_unlock) { int i; int skip_level = level; @@ -1759,8 +1762,9 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root * * returns 0 on success and < 0 on failure */ -static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root - *root, struct btrfs_path *path, int level) +static noinline int split_node(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, int level) { u64 root_gen; struct extent_buffer *c; @@ -1874,7 +1878,8 @@ static int leaf_space_used(struct extent_buffer *l, int start, int nr) * the start of the leaf data. IOW, how much room * the leaf has left for both items and data */ -int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf) +int noinline btrfs_leaf_free_space(struct btrfs_root *root, + struct extent_buffer *leaf) { int nritems = btrfs_header_nritems(leaf); int ret; @@ -2283,9 +2288,11 @@ out: * * returns 0 if all went well and < 0 on failure. */ -static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root - *root, struct btrfs_key *ins_key, - struct btrfs_path *path, int data_size, int extend) +static noinline int split_leaf(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_key *ins_key, + struct btrfs_path *path, int data_size, + int extend) { u64 root_gen; struct extent_buffer *l; @@ -3079,6 +3086,7 @@ int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) * was nothing in the tree that matched the search criteria. */ int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, + struct btrfs_key *max_key, struct btrfs_path *path, int cache_only, u64 min_trans) { @@ -3093,6 +3101,7 @@ int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, again: cur = btrfs_lock_root_node(root); level = btrfs_header_level(cur); + WARN_ON(path->nodes[level]); path->nodes[level] = cur; path->locks[level] = 1; @@ -3107,6 +3116,8 @@ again: /* at level = 0, we're done, setup the path and exit */ if (level == 0) { + if (slot >= nritems) + goto find_next_key; ret = 0; path->slots[level] = slot; btrfs_item_key_to_cpu(cur, &found_key, slot); @@ -3123,6 +3134,8 @@ again: u64 blockptr; u64 gen; struct extent_buffer *tmp; + struct btrfs_disk_key disk_key; + blockptr = btrfs_node_blockptr(cur, slot); gen = btrfs_node_ptr_generation(cur, slot); if (gen < min_trans) { @@ -3132,6 +3145,14 @@ again: if (!cache_only) break; + if (max_key) { + btrfs_node_key(cur, &disk_key, slot); + if (comp_keys(&disk_key, max_key) >= 0) { + ret = 1; + goto out; + } + } + tmp = btrfs_find_tree_block(root, blockptr, btrfs_level_size(root, level - 1)); @@ -3143,14 +3164,16 @@ again: free_extent_buffer(tmp); slot++; } +find_next_key: /* * we didn't find a candidate key in this node, walk forward * and find another one */ if (slot >= nritems) { - ret = btrfs_find_next_key(root, path, min_key, level, + path->slots[level] = slot; + sret = btrfs_find_next_key(root, path, min_key, level, cache_only, min_trans); - if (ret == 0) { + if (sret == 0) { btrfs_release_path(root, path); goto again; } else { @@ -3351,6 +3374,7 @@ int btrfs_previous_item(struct btrfs_root *root, { struct btrfs_key found_key; struct extent_buffer *leaf; + u32 nritems; int ret; while(1) { @@ -3362,9 +3386,20 @@ int btrfs_previous_item(struct btrfs_root *root, path->slots[0]--; } leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + if (nritems == 0) + return 1; + if (path->slots[0] == nritems) + path->slots[0]--; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.type == type) return 0; + if (found_key.objectid < min_objectid) + break; + if (found_key.objectid == min_objectid && + found_key.type < type) + break; } return 1; } -- cgit v1.2.3