Hello,
During the descent through the tree, if path->slots[...] points to an
intermediate slot in the current node, we release upper level node's
lock. When cache_only is true, btrfs_find_next_key may advance
path->slots[] several times. Therefore, when we found path->slots[...]
>= btrfs_header_nritems(...), upper level node may be not locked.
Note: this patch wasn't tested.
Regards
YZ
---
diff -r 3f0eee804974 ctree.c
--- a/ctree.c Thu Jun 26 10:34:20 2008 -0400
+++ b/ctree.c Wed Jul 16 00:15:09 2008 +0800
@@ -3114,10 +3114,39 @@ int btrfs_find_next_key(struct btrfs_roo
c = path->nodes[level];
next:
if (slot >= btrfs_header_nritems(c)) {
- level++;
- if (level == BTRFS_MAX_LEVEL) {
+ int ret;
+ int orig_lowest;
+ struct btrfs_key last_key;
+
+ if (!path->nodes[level + 1] ||
+ level + 1 == BTRFS_MAX_LEVEL) {
return 1;
}
+ if (path->locks[level + 1]) {
+ level++;
+ continue;
+ }
+
+ /*
+ * Upper level node isn't locked, this can happen
+ * when cache_only is true.
+ */
+ slot = btrfs_header_nritems(c) - 1;
+ if (level == 0)
+ btrfs_item_key_to_cpu(c, &last_key, slot);
+ else
+ btrfs_node_key_to_cpu(c, &last_key, slot);
+
+ btrfs_release_path(root, path);
+ orig_lowest = path->lowest_level;
+ path->lowest_level = level;
+ ret = btrfs_search_slot(NULL, root, &last_key, path,
+ 0, 0);
+ path->lowest_level = orig_lowest;
+ if (ret < 0)
+ return ret;
+ if (ret == 0)
+ path->slots[level]++;
continue;
}
if (level == 0)
--
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