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Commit 3d7806ec authored by Jan Schmidt's avatar Jan Schmidt
Browse files

Btrfs: add btrfs_next_old_leaf 



To make sense of the tree mod log, the backref walker not only needs
btrfs_search_old_slot, but it also called btrfs_next_leaf, which in turn was
calling btrfs_search_slot. This obviously didn't give the correct result.

This commit adds btrfs_next_old_leaf, a drop-in replacement for
btrfs_next_leaf with a time_seq parameter. If it is zero, it behaves exactly
like btrfs_next_leaf. If it is non-zero, it will use btrfs_search_old_slot
with this time_seq parameter.

Signed-off-by: default avatarJan Schmidt <list.btrfs@jan-o-sch.net>
parent a95236d9

fs/btrfs/backref.c

+4 −3
Original line number Original line Diff line number Diff line
@@ -179,7 +179,8 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id, 




static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,

static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,

				struct ulist *parents, int level,

				struct ulist *parents, int level,

				struct btrfs_key *key, u64 wanted_disk_byte,

				struct btrfs_key *key, u64 time_seq,

				u64 wanted_disk_byte,

				const u64 *extent_item_pos)

				const u64 *extent_item_pos)

{

{

	int ret;

	int ret;
@@ -212,7 +213,7 @@ add_parent: 
	 */

	 */

	while (1) {

	while (1) {

		eie = NULL;

		eie = NULL;

		ret = btrfs_next_leaf(root, path);

		ret = btrfs_next_old_leaf(root, path, time_seq);

		if (ret < 0)

		if (ret < 0)

			return ret;

			return ret;

		if (ret)

		if (ret)
@@ -297,7 +298,7 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, 
	if (level == 0)

	if (level == 0)

		btrfs_item_key_to_cpu(eb, &key, path->slots[0]);

		btrfs_item_key_to_cpu(eb, &key, path->slots[0]);





	ret = add_all_parents(root, path, parents, level, &key,

	ret = add_all_parents(root, path, parents, level, &key, time_seq,

				ref->wanted_disk_byte, extent_item_pos);

				ref->wanted_disk_byte, extent_item_pos);

out:

out:

	btrfs_free_path(path);

	btrfs_free_path(path);

fs/btrfs/ctree.c

+10 −1
Original line number Original line Diff line number Diff line
@@ -5016,6 +5016,12 @@ next: 
 * returns < 0 on io errors.

 * returns < 0 on io errors.

 */

 */

int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)

int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)

{

	return btrfs_next_old_leaf(root, path, 0);

}



int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,

			u64 time_seq)

{

{

	int slot;

	int slot;

	int level;

	int level;
@@ -5041,6 +5047,9 @@ again: 
	path->keep_locks = 1;

	path->keep_locks = 1;

	path->leave_spinning = 1;

	path->leave_spinning = 1;





	if (time_seq)

		ret = btrfs_search_old_slot(root, &key, path, time_seq);

	else

		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);

		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);

	path->keep_locks = 0;

	path->keep_locks = 0;

fs/btrfs/ctree.h

+2 −0
Original line number Original line Diff line number Diff line
@@ -2753,6 +2753,8 @@ static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, 
}

}





int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);

int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);

int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,

			u64 time_seq);

static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)

static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)

{

{

	++p->slots[0];

	++p->slots[0];