From 6407bf6d7c449cbfb0a39d985194e265eda3baf4 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 27 Mar 2007 06:33:00 -0400 Subject: Btrfs: reference counts on data extents Signed-off-by: Chris Mason diff --git a/fs/btrfs/TODO b/fs/btrfs/TODO index 2ca301b..7aec75e 100644 --- a/fs/btrfs/TODO +++ b/fs/btrfs/TODO @@ -8,7 +8,10 @@ * Add block mapping tree (simple dm layer) * Add simple tree locking (semaphore per tree) * Make allocator smarter +* make level a field in header +* add a block group to struct inode * Make directory hashing work on 32 bit +* Make sure nobh stuff is working properly for cows * Do actual block accounting * Check compat and incompat flags on the inode * Add virtual filesystems, mountable snapshots diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 7b7120d..1a98952 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -9,10 +9,11 @@ struct btrfs_transaction; #define BTRFS_MAGIC "_BtRfS_M" -#define BTRFS_ROOT_TREE_OBJECTID 1 -#define BTRFS_EXTENT_TREE_OBJECTID 2 -#define BTRFS_INODE_MAP_OBJECTID 3 -#define BTRFS_FS_TREE_OBJECTID 4 +#define BTRFS_ROOT_TREE_OBJECTID 1ULL +#define BTRFS_EXTENT_TREE_OBJECTID 2ULL +#define BTRFS_INODE_MAP_OBJECTID 3ULL +#define BTRFS_FS_TREE_OBJECTID 4ULL +#define BTRFS_FIRST_FREE_OBJECTID 5ULL /* * we can actually store much bigger names, but lets not confuse the rest diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 82f6e9e..4d4fc48 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -13,7 +13,7 @@ static int del_pending_extents(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root); static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root - *root, u64 blocknr) + *root, u64 blocknr, u64 num_blocks) { struct btrfs_path path; int ret; @@ -29,7 +29,7 @@ static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root key.objectid = blocknr; key.flags = 0; btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); - key.offset = 1; + key.offset = num_blocks; ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path, 0, 1); if (ret != 0) @@ -48,7 +48,7 @@ static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root } static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root - *root, u64 blocknr, u32 *refs) + *root, u64 blocknr, u64 num_blocks, u32 *refs) { struct btrfs_path path; int ret; @@ -57,7 +57,7 @@ static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root struct btrfs_extent_item *item; btrfs_init_path(&path); key.objectid = blocknr; - key.offset = 1; + key.offset = num_blocks; key.flags = 0; btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path, @@ -76,17 +76,34 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, { u64 blocknr; struct btrfs_node *buf_node; + struct btrfs_leaf *buf_leaf; + struct btrfs_disk_key *key; + struct btrfs_file_extent_item *fi; int i; + int leaf; + int ret; if (!root->ref_cows) return 0; buf_node = btrfs_buffer_node(buf); - if (btrfs_is_leaf(buf_node)) - return 0; - + leaf = btrfs_is_leaf(buf_node); + buf_leaf = btrfs_buffer_leaf(buf); for (i = 0; i < btrfs_header_nritems(&buf_node->header); i++) { - blocknr = btrfs_node_blockptr(buf_node, i); - inc_block_ref(trans, root, blocknr); + if (leaf) { + key = &buf_leaf->items[i].key; + if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(buf_leaf, i, + struct btrfs_file_extent_item); + ret = inc_block_ref(trans, root, + btrfs_file_extent_disk_blocknr(fi), + btrfs_file_extent_disk_num_blocks(fi)); + BUG_ON(ret); + } else { + blocknr = btrfs_node_blockptr(buf_node, i); + ret = inc_block_ref(trans, root, blocknr, 1); + BUG_ON(ret); + } } return 0; } @@ -469,6 +486,37 @@ struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, return buf; } +static int drop_leaf_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct buffer_head *cur) +{ + struct btrfs_disk_key *key; + struct btrfs_leaf *leaf; + struct btrfs_file_extent_item *fi; + int i; + int nritems; + int ret; + + BUG_ON(!btrfs_is_leaf(btrfs_buffer_node(cur))); + leaf = btrfs_buffer_leaf(cur); + nritems = btrfs_header_nritems(&leaf->header); + for (i = 0; i < nritems; i++) { + key = &leaf->items[i].key; + if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); + /* + * FIXME make sure to insert a trans record that + * repeats the snapshot del on crash + */ + ret = btrfs_free_extent(trans, root, + btrfs_file_extent_disk_blocknr(fi), + btrfs_file_extent_disk_num_blocks(fi), + 0); + BUG_ON(ret); + } + return 0; +} + /* * helper function for drop_snapshot, this walks down the tree dropping ref * counts as it goes. @@ -483,28 +531,33 @@ static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root u32 refs; ret = lookup_block_ref(trans, root, path->nodes[*level]->b_blocknr, - &refs); + 1, &refs); BUG_ON(ret); if (refs > 1) goto out; /* * walk down to the last node level and free all the leaves */ - while(*level > 0) { + while(*level >= 0) { cur = path->nodes[*level]; if (path->slots[*level] >= btrfs_header_nritems(btrfs_buffer_header(cur))) break; + if (*level == 0) { + ret = drop_leaf_ref(trans, root, cur); + BUG_ON(ret); + break; + } blocknr = btrfs_node_blockptr(btrfs_buffer_node(cur), path->slots[*level]); - ret = lookup_block_ref(trans, root, blocknr, &refs); - if (refs != 1 || *level == 1) { + ret = lookup_block_ref(trans, root, blocknr, 1, &refs); + BUG_ON(ret); + if (refs != 1) { path->slots[*level]++; ret = btrfs_free_extent(trans, root, blocknr, 1, 1); BUG_ON(ret); continue; } - BUG_ON(ret); next = read_tree_block(root, blocknr); if (path->nodes[*level-1]) btrfs_block_release(root, path->nodes[*level-1]); @@ -513,8 +566,8 @@ static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root path->slots[*level] = 0; } out: - ret = btrfs_free_extent(trans, root, path->nodes[*level]->b_blocknr, - 1, 1); + ret = btrfs_free_extent(trans, root, + path->nodes[*level]->b_blocknr, 1, 1); btrfs_block_release(root, path->nodes[*level]); path->nodes[*level] = NULL; *level += 1; @@ -544,10 +597,10 @@ static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root ret = btrfs_free_extent(trans, root, path->nodes[*level]->b_blocknr, 1, 1); + BUG_ON(ret); btrfs_block_release(root, path->nodes[*level]); path->nodes[*level] = NULL; *level = i + 1; - BUG_ON(ret); } } return 1; diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c index ad2d375..1b2c5e0 100644 --- a/fs/btrfs/inode-map.c +++ b/fs/btrfs/inode-map.c @@ -25,6 +25,7 @@ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans, if (fs_root->fs_info->last_inode_alloc_dirid == dirid) search_start = fs_root->fs_info->last_inode_alloc; + search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID); search_key.objectid = search_start; search_key.flags = 0; btrfs_set_key_type(&search_key, BTRFS_INODE_MAP_ITEM_KEY); diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 2c2883f..487da5a 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -700,7 +700,7 @@ out: static int btrfs_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to) { - return block_prepare_write(page, from, to, btrfs_get_block); + return nobh_prepare_write(page, from, to, btrfs_get_block); } static void btrfs_write_super(struct super_block *sb) @@ -721,7 +721,7 @@ static int btrfs_readpages(struct file *file, struct address_space *mapping, static int btrfs_writepage(struct page *page, struct writeback_control *wbc) { - return block_write_full_page(page, btrfs_get_block, wbc); + return nobh_writepage(page, btrfs_get_block, wbc); } static int btrfs_get_sb(struct file_system_type *fs_type, @@ -768,7 +768,7 @@ static struct address_space_operations btrfs_aops = { .writepage = btrfs_writepage, .sync_page = block_sync_page, .prepare_write = btrfs_prepare_write, - .commit_write = generic_commit_write, + .commit_write = nobh_commit_write, }; static struct inode_operations btrfs_file_inode_operations = { -- cgit v0.10.2