@@ -880,13 +880,16 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info,
* indirect refs to their parent bytenr.
* When roots are found, they're added to the roots list
*
+ * If nolock is set, it will consider the ref_head already locked and don't
+ * try to lock it.
+ *
* FIXME some caching might speed things up
*/
static int find_parent_nodes(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
u64 time_seq, struct ulist *refs,
struct ulist *roots, const u64 *extent_item_pos,
- u64 root_objectid, u64 inum)
+ u64 root_objectid, u64 inum, int nolock)
{
struct btrfs_key key;
struct btrfs_path *path;
@@ -944,7 +947,7 @@ again:
spin_lock(&delayed_refs->lock);
head = btrfs_find_delayed_ref_head(trans, bytenr);
if (head) {
- if (!mutex_trylock(&head->mutex)) {
+ if (!nolock && !mutex_trylock(&head->mutex)) {
atomic_inc(&head->node.refs);
spin_unlock(&delayed_refs->lock);
@@ -963,7 +966,8 @@ again:
ret = __add_delayed_refs(head, time_seq,
&prefs_delayed, &total_refs,
inum);
- mutex_unlock(&head->mutex);
+ if (!nolock)
+ mutex_unlock(&head->mutex);
if (ret)
goto out;
} else {
@@ -1124,7 +1128,8 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
return -ENOMEM;
ret = find_parent_nodes(trans, fs_info, bytenr,
- time_seq, *leafs, NULL, extent_item_pos, 0, 0);
+ time_seq, *leafs, NULL, extent_item_pos,
+ 0, 0, 0);
if (ret < 0 && ret != -ENOENT) {
free_leaf_list(*leafs);
return ret;
@@ -1148,7 +1153,8 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
*/
static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
- u64 time_seq, struct ulist **roots)
+ u64 time_seq, struct ulist **roots,
+ int nolock)
{
struct ulist *tmp;
struct ulist_node *node = NULL;
@@ -1167,7 +1173,8 @@ static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans,
ULIST_ITER_INIT(&uiter);
while (1) {
ret = find_parent_nodes(trans, fs_info, bytenr,
- time_seq, tmp, *roots, NULL, 0, 0);
+ time_seq, tmp, *roots, NULL, 0, 0,
+ nolock);
if (ret < 0 && ret != -ENOENT) {
ulist_free(tmp);
ulist_free(*roots);
@@ -1186,13 +1193,14 @@ static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans,
int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
- u64 time_seq, struct ulist **roots)
+ u64 time_seq, struct ulist **roots, int nolock)
{
int ret;
if (!trans)
down_read(&fs_info->commit_root_sem);
- ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots);
+ ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots,
+ nolock);
if (!trans)
up_read(&fs_info->commit_root_sem);
return ret;
@@ -1224,7 +1232,7 @@ int btrfs_check_shared(struct btrfs_trans_handle *trans,
ULIST_ITER_INIT(&uiter);
while (1) {
ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp,
- roots, NULL, root_objectid, inum);
+ roots, NULL, root_objectid, inum, 0);
if (ret == BACKREF_FOUND_SHARED) {
ret = 1;
break;
@@ -1635,7 +1643,7 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
ULIST_ITER_INIT(&ref_uiter);
while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) {
ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val,
- tree_mod_seq_elem.seq, &roots);
+ tree_mod_seq_elem.seq, &roots, 0);
if (ret)
break;
ULIST_ITER_INIT(&root_uiter);
@@ -53,7 +53,7 @@ int paths_from_inode(u64 inum, struct inode_fs_paths *ipath);
int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
- u64 time_seq, struct ulist **roots);
+ u64 time_seq, struct ulist **roots, int nolock);
char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
u32 name_len, unsigned long name_off,
struct extent_buffer *eb_in, u64 parent,
@@ -3050,7 +3050,7 @@ static int check_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
btrfs_get_tree_mod_seq(root->fs_info, &tree_mod_seq_elem);
ret = btrfs_find_all_roots(trans, root->fs_info, disko,
- tree_mod_seq_elem.seq, &roots);
+ tree_mod_seq_elem.seq, &roots, 0);
if (ret < 0)
goto out;
ret = 0;
@@ -1788,7 +1788,7 @@ static int check_existing_refs(struct btrfs_trans_handle *trans,
int ret = 0;
ret = btrfs_find_all_roots(trans, fs_info, oper->bytenr,
- oper->elem.seq, &roots);
+ oper->elem.seq, &roots, 0);
if (ret < 0)
return ret;
ret = 0;
@@ -1879,7 +1879,7 @@ static int qgroup_shared_accounting(struct btrfs_trans_handle *trans,
btrfs_get_tree_mod_seq(fs_info, &elem);
ret = btrfs_find_all_roots(trans, fs_info, oper->bytenr, elem.seq,
- &roots);
+ &roots, 0);
btrfs_put_tree_mod_seq(fs_info, &elem);
if (ret < 0) {
ulist_free(qgroups);
@@ -1988,7 +1988,7 @@ static int qgroup_subtree_accounting(struct btrfs_trans_handle *trans,
btrfs_get_tree_mod_seq(fs_info, &elem);
ret = btrfs_find_all_roots(trans, fs_info, oper->bytenr,
- elem.seq, &roots);
+ elem.seq, &roots, 0);
btrfs_put_tree_mod_seq(fs_info, &elem);
if (ret < 0)
goto out;
@@ -2590,7 +2590,7 @@ qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
ulist_reinit(qgroups);
ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
- &roots);
+ &roots, 0);
if (ret < 0)
goto out;
spin_lock(&fs_info->qgroup_lock);
Add the "nolock" option for btrfs_find_all_roots(). This will allow btrfs_find_all_roots() to be called in btrfs_qgroup_record_ref(), which will provide the basis for coming qgroup patches. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> --- fs/btrfs/backref.c | 28 ++++++++++++++++++---------- fs/btrfs/backref.h | 2 +- fs/btrfs/ioctl.c | 2 +- fs/btrfs/qgroup.c | 8 ++++---- 4 files changed, 24 insertions(+), 16 deletions(-)