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author | Miao Xie <miaox@cn.fujitsu.com> | 2013-05-15 07:48:19 (GMT) |
---|---|---|
committer | Josef Bacik <jbacik@fusionio.com> | 2013-06-14 15:29:37 (GMT) |
commit | cb517eabba4f109810dba2e5f37b0dcf22103065 (patch) | |
tree | 5c553813bf6fdc41df3912a1146828cba64d3b17 /fs/btrfs/root-tree.c | |
parent | babbf170c781f24095336c82ebf18ad272ddb773 (diff) | |
download | linux-cb517eabba4f109810dba2e5f37b0dcf22103065.tar.xz |
Btrfs: cleanup the similar code of the fs root read
There are several functions whose code is similar, such as
btrfs_find_last_root()
btrfs_read_fs_root_no_radix()
Besides that, some functions are invoked twice, it is unnecessary,
for example, we are sure that all roots which is found in
btrfs_find_orphan_roots()
have their orphan items, so it is unnecessary to check the orphan
item again.
So cleanup it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to 'fs/btrfs/root-tree.c')
-rw-r--r-- | fs/btrfs/root-tree.c | 170 |
1 files changed, 53 insertions, 117 deletions
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index 5bf1ed5..79e6832 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -64,52 +64,59 @@ void btrfs_read_root_item(struct extent_buffer *eb, int slot, } /* - * lookup the root with the highest offset for a given objectid. The key we do - * find is copied into 'key'. If we find something return 0, otherwise 1, < 0 - * on error. + * btrfs_find_root - lookup the root by the key. + * root: the root of the root tree + * search_key: the key to search + * path: the path we search + * root_item: the root item of the tree we look for + * root_key: the reak key of the tree we look for + * + * If ->offset of 'seach_key' is -1ULL, it means we are not sure the offset + * of the search key, just lookup the root with the highest offset for a + * given objectid. + * + * If we find something return 0, otherwise > 0, < 0 on error. */ -int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, - struct btrfs_root_item *item, struct btrfs_key *key) +int btrfs_find_root(struct btrfs_root *root, struct btrfs_key *search_key, + struct btrfs_path *path, struct btrfs_root_item *root_item, + struct btrfs_key *root_key) { - struct btrfs_path *path; - struct btrfs_key search_key; struct btrfs_key found_key; struct extent_buffer *l; int ret; int slot; - search_key.objectid = objectid; - search_key.type = BTRFS_ROOT_ITEM_KEY; - search_key.offset = (u64)-1; - - path = btrfs_alloc_path(); - if (!path) - return -ENOMEM; - ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); + ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0); if (ret < 0) - goto out; + return ret; - BUG_ON(ret == 0); - if (path->slots[0] == 0) { - ret = 1; - goto out; + if (search_key->offset != -1ULL) { /* the search key is exact */ + if (ret > 0) + goto out; + } else { + BUG_ON(ret == 0); /* Logical error */ + if (path->slots[0] == 0) + goto out; + path->slots[0]--; + ret = 0; } + l = path->nodes[0]; - slot = path->slots[0] - 1; + slot = path->slots[0]; + btrfs_item_key_to_cpu(l, &found_key, slot); - if (found_key.objectid != objectid || + if (found_key.objectid != search_key->objectid || found_key.type != BTRFS_ROOT_ITEM_KEY) { ret = 1; goto out; } - if (item) - btrfs_read_root_item(l, slot, item); - if (key) - memcpy(key, &found_key, sizeof(found_key)); - ret = 0; + if (root_item) + btrfs_read_root_item(l, slot, root_item); + if (root_key) + memcpy(root_key, &found_key, sizeof(found_key)); out: - btrfs_free_path(path); + btrfs_release_path(path); return ret; } @@ -212,86 +219,6 @@ int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, return btrfs_insert_item(trans, root, key, item, sizeof(*item)); } -/* - * at mount time we want to find all the old transaction snapshots that were in - * the process of being deleted if we crashed. This is any root item with an - * offset lower than the latest root. They need to be queued for deletion to - * finish what was happening when we crashed. - */ -int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid) -{ - struct btrfs_root *dead_root; - struct btrfs_root_item *ri; - struct btrfs_key key; - struct btrfs_key found_key; - struct btrfs_path *path; - int ret; - u32 nritems; - struct extent_buffer *leaf; - int slot; - - key.objectid = objectid; - btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); - key.offset = 0; - path = btrfs_alloc_path(); - if (!path) - return -ENOMEM; - -again: - ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); - if (ret < 0) - goto err; - while (1) { - leaf = path->nodes[0]; - nritems = btrfs_header_nritems(leaf); - slot = path->slots[0]; - if (slot >= nritems) { - ret = btrfs_next_leaf(root, path); - if (ret) - break; - leaf = path->nodes[0]; - nritems = btrfs_header_nritems(leaf); - slot = path->slots[0]; - } - btrfs_item_key_to_cpu(leaf, &key, slot); - if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY) - goto next; - - if (key.objectid < objectid) - goto next; - - if (key.objectid > objectid) - break; - - ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item); - if (btrfs_disk_root_refs(leaf, ri) != 0) - goto next; - - memcpy(&found_key, &key, sizeof(key)); - key.offset++; - btrfs_release_path(path); - dead_root = - btrfs_read_fs_root_no_radix(root->fs_info->tree_root, - &found_key); - if (IS_ERR(dead_root)) { - ret = PTR_ERR(dead_root); - goto err; - } - - ret = btrfs_add_dead_root(dead_root); - if (ret) - goto err; - goto again; -next: - slot++; - path->slots[0]++; - } - ret = 0; -err: - btrfs_free_path(path); - return ret; -} - int btrfs_find_orphan_roots(struct btrfs_root *tree_root) { struct extent_buffer *leaf; @@ -340,20 +267,29 @@ int btrfs_find_orphan_roots(struct btrfs_root *tree_root) root_key.objectid = key.offset; key.offset++; - root = btrfs_read_fs_root_no_name(tree_root->fs_info, - &root_key); - if (!IS_ERR(root)) + root = btrfs_read_fs_root(tree_root, &root_key); + if (IS_ERR(root)) { + err = PTR_ERR(root); + break; + } + + if (btrfs_root_refs(&root->root_item) == 0) { + btrfs_add_dead_root(root); continue; + } - ret = PTR_ERR(root); - if (ret != -ENOENT) { - err = ret; + err = btrfs_init_fs_root(root); + if (err) { + btrfs_free_fs_root(root); break; } - ret = btrfs_find_dead_roots(tree_root, root_key.objectid); - if (ret) { - err = ret; + root->orphan_item_inserted = 1; + + err = btrfs_insert_fs_root(root->fs_info, root); + if (err) { + BUG_ON(err == -EEXIST); + btrfs_free_fs_root(root); break; } } |