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: Jan Schmidt <list.btrfs@jan-o-sch.net>
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 579131d..8f7d123 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -179,7 +179,8 @@
static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
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)
{
int ret;
@@ -212,7 +213,7 @@
*/
while (1) {
eie = NULL;
- ret = btrfs_next_leaf(root, path);
+ ret = btrfs_next_old_leaf(root, path, time_seq);
if (ret < 0)
return ret;
if (ret)
@@ -297,7 +298,7 @@
if (level == 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);
out:
btrfs_free_path(path);
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 50d7c99..cb76b2a 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -5017,6 +5017,12 @@
*/
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 level;
struct extent_buffer *c;
@@ -5041,7 +5047,10 @@
path->keep_locks = 1;
path->leave_spinning = 1;
- ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (time_seq)
+ ret = btrfs_search_old_slot(root, &key, path, time_seq);
+ else
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
path->keep_locks = 0;
if (ret < 0)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0151ca1..db15e9e 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2753,6 +2753,8 @@
}
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)
{
++p->slots[0];