Btrfs: Use map_private_extent_buffer during generic_bin_search
It is possible that generic_bin_search will be called on a tree block
that has not been locked. This happens because cache_block_block skips
locking on the tree blocks.
Since the tree block isn't locked, we aren't allowed to change
the extent_buffer->map_token field. Using map_private_extent_buffer
avoids any changes to the internal extent buffer fields.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index a83cbdf..19c0dd3 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -813,7 +813,8 @@
unmap_extent_buffer(eb, map_token, KM_USER0);
map_token = NULL;
}
- err = map_extent_buffer(eb, offset,
+
+ err = map_private_extent_buffer(eb, offset,
sizeof(struct btrfs_disk_key),
&map_token, &kaddr,
&map_start, &map_len, KM_USER0);
@@ -3585,6 +3586,7 @@
int level;
int ret = 1;
+ WARN_ON(!path->keep_locks);
again:
cur = btrfs_lock_root_node(root);
level = btrfs_header_level(cur);
@@ -3708,6 +3710,7 @@
int slot;
struct extent_buffer *c;
+ WARN_ON(!path->keep_locks);
while(level < BTRFS_MAX_LEVEL) {
if (!path->nodes[level])
return 1;