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authorMiao Xie <miaox@cn.fujitsu.com>2013-05-15 07:48:19 +0000
committerJosef Bacik <jbacik@fusionio.com>2013-06-14 11:29:37 -0400
commitcb517eabba4f109810dba2e5f37b0dcf22103065 (patch)
tree5c553813bf6fdc41df3912a1146828cba64d3b17 /fs/btrfs/root-tree.c
parentbabbf170c781f24095336c82ebf18ad272ddb773 (diff)
downloadlinux-cb517eabba4f109810dba2e5f37b0dcf22103065.tar.bz2
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.c170
1 files changed, 53 insertions, 117 deletions
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 5bf1ed57f178..79e683273de5 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;
}
}