diff options
| -rw-r--r-- | fs/btrfs/ctree.c | 198 | ||||
| -rw-r--r-- | fs/btrfs/ctree.h | 4 |
2 files changed, 143 insertions, 59 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index ec96f3a6d536..9d4ba3470c17 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -37,6 +37,11 @@ static int balance_node_right(struct btrfs_trans_handle *trans, struct extent_buffer *src_buf); static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int level, int slot); +static int setup_items_for_insert(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct btrfs_path *path, + struct btrfs_key *cpu_key, u32 *data_size, + u32 total_data, u32 total_size, int nr); + struct btrfs_path *btrfs_alloc_path(void) { @@ -2997,75 +3002,85 @@ again: return ret; } -/* - * This function splits a single item into two items, - * giving 'new_key' to the new item and splitting the - * old one at split_offset (from the start of the item). - * - * The path may be released by this operation. After - * the split, the path is pointing to the old item. The - * new item is going to be in the same node as the old one. - * - * Note, the item being split must be smaller enough to live alone on - * a tree block with room for one extra struct btrfs_item - * - * This allows us to split the item in place, keeping a lock on the - * leaf the entire time. - */ -int btrfs_split_item(struct btrfs_trans_handle *trans, - struct btrfs_root *root, - struct btrfs_path *path, - struct btrfs_key *new_key, - unsigned long split_offset) +static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, int ins_len) { - u32 item_size; + struct btrfs_key key; struct extent_buffer *leaf; - struct btrfs_key orig_key; - struct btrfs_item *item; - struct btrfs_item *new_item; - int ret = 0; - int slot; - u32 nritems; - u32 orig_offset; - struct btrfs_disk_key disk_key; - char *buf; + struct btrfs_file_extent_item *fi; + u64 extent_len = 0; + u32 item_size; + int ret; leaf = path->nodes[0]; - btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]); - if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item)) - goto split; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + + BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && + key.type != BTRFS_EXTENT_CSUM_KEY); + + if (btrfs_leaf_free_space(root, leaf) >= ins_len) + return 0; item_size = btrfs_item_size_nr(leaf, path->slots[0]); + if (key.type == BTRFS_EXTENT_DATA_KEY) { + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + extent_len = btrfs_file_extent_num_bytes(leaf, fi); + } btrfs_release_path(root, path); - path->search_for_split = 1; path->keep_locks = 1; - - ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1); + path->search_for_split = 1; + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); path->search_for_split = 0; + if (ret < 0) + goto err; + ret = -EAGAIN; + leaf = path->nodes[0]; /* if our item isn't there or got smaller, return now */ - if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0], - path->slots[0])) { - path->keep_locks = 0; - return -EAGAIN; + if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) + goto err; + + if (key.type == BTRFS_EXTENT_DATA_KEY) { + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) + goto err; } btrfs_set_path_blocking(path); - ret = split_leaf(trans, root, &orig_key, path, - sizeof(struct btrfs_item), 1); - path->keep_locks = 0; + ret = split_leaf(trans, root, &key, path, ins_len, 1); BUG_ON(ret); + path->keep_locks = 0; btrfs_unlock_up_safe(path, 1); + return 0; +err: + path->keep_locks = 0; + return ret; +} + +static noinline int split_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *new_key, + unsigned long split_offset) +{ + struct extent_buffer *leaf; + struct btrfs_item *item; + struct btrfs_item *new_item; + int slot; + char *buf; + u32 nritems; + u32 item_size; + u32 orig_offset; + struct btrfs_disk_key disk_key; + leaf = path->nodes[0]; BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); -split: - /* - * make sure any changes to the path from split_leaf leave it - * in a blocking state - */ btrfs_set_path_blocking(path); item = btrfs_item_nr(leaf, path->slots[0]); @@ -3073,19 +3088,19 @@ split: item_size = btrfs_item_size(leaf, item); buf = kmalloc(item_size, GFP_NOFS); + if (!buf) + return -ENOMEM; + read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, path->slots[0]), item_size); - slot = path->slots[0] + 1; - leaf = path->nodes[0]; + slot = path->slots[0] + 1; nritems = btrfs_header_nritems(leaf); - if (slot != nritems) { /* shift the items */ memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), - btrfs_item_nr_offset(slot), - (nritems - slot) * sizeof(struct btrfs_item)); - + btrfs_item_nr_offset(slot), + (nritems - slot) * sizeof(struct btrfs_item)); } btrfs_cpu_key_to_disk(&disk_key, new_key); @@ -3113,16 +3128,81 @@ split: item_size - split_offset); btrfs_mark_buffer_dirty(leaf); - ret = 0; - if (btrfs_leaf_free_space(root, leaf) < 0) { - btrfs_print_leaf(root, leaf); - BUG(); - } + BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); kfree(buf); + return 0; +} + +/* + * This function splits a single item into two items, + * giving 'new_key' to the new item and splitting the + * old one at split_offset (from the start of the item). + * + * The path may be released by this operation. After + * the split, the path is pointing to the old item. The + * new item is going to be in the same node as the old one. + * + * Note, the item being split must be smaller enough to live alone on + * a tree block with room for one extra struct btrfs_item + * + * This allows us to split the item in place, keeping a lock on the + * leaf the entire time. + */ +int btrfs_split_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *new_key, + unsigned long split_offset) +{ + int ret; + ret = setup_leaf_for_split(trans, root, path, + sizeof(struct btrfs_item)); + if (ret) + return ret; + + ret = split_item(trans, root, path, new_key, split_offset); return ret; } /* + * This function duplicate a item, giving 'new_key' to the new item. + * It guarantees both items live in the same tree leaf and the new item + * is contiguous with the original item. + * + * This allows us to split file extent in place, keeping a lock on the + * leaf the entire time. + */ +int btrfs_duplicate_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *new_key) +{ + struct extent_buffer *leaf; + int ret; + u32 item_size; + + leaf = path->nodes[0]; + item_size = btrfs_item_size_nr(leaf, path->slots[0]); + ret = setup_leaf_for_split(trans, root, path, + item_size + sizeof(struct btrfs_item)); + if (ret) + return ret; + + path->slots[0]++; + ret = setup_items_for_insert(trans, root, path, new_key, &item_size, + item_size, item_size + + sizeof(struct btrfs_item), 1); + BUG_ON(ret); + + leaf = path->nodes[0]; + memcpy_extent_buffer(leaf, + btrfs_item_ptr_offset(leaf, path->slots[0]), + btrfs_item_ptr_offset(leaf, path->slots[0] - 1), + item_size); + return 0; +} + +/* * make the item pointed to by the path smaller. new_size indicates * how small to make it, and from_end tells us if we just chop bytes * off the end of the item or if we shift the item to chop bytes off diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 444b3e9b92a4..e3b58001162d 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2089,6 +2089,10 @@ int btrfs_split_item(struct btrfs_trans_handle *trans, struct btrfs_path *path, struct btrfs_key *new_key, unsigned long split_offset); +int btrfs_duplicate_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *new_key); int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key, struct btrfs_path *p, int ins_len, int cow); |