nilfs2: get rid of BUG_ON use in btree lookup routines
The current btree lookup routines make a kernel oops when detected
inconsistency in btree blocks. These routines should instead return a
proper error code because the inconsistency usually comes from
corruption of on-disk metadata.
This fixes the issue by converting BUG_ON calls to proper error
handlings.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index e25b507..420c9ec 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -444,6 +444,18 @@
nilfs_btree_get_nonroot_node(path, level);
}
+static inline int
+nilfs_btree_bad_node(struct nilfs_btree_node *node, int level)
+{
+ if (unlikely(nilfs_btree_node_get_level(node) != level)) {
+ dump_stack();
+ printk(KERN_CRIT "NILFS: btree level mismatch: %d != %d\n",
+ nilfs_btree_node_get_level(node), level);
+ return 1;
+ }
+ return 0;
+}
+
static int nilfs_btree_do_lookup(const struct nilfs_btree *btree,
struct nilfs_btree_path *path,
__u64 key, __u64 *ptrp, int minlevel)
@@ -467,7 +479,8 @@
if (ret < 0)
return ret;
node = nilfs_btree_get_nonroot_node(path, level);
- BUG_ON(level != nilfs_btree_node_get_level(node));
+ if (nilfs_btree_bad_node(node, level))
+ return -EINVAL;
if (!found)
found = nilfs_btree_node_lookup(node, key, &index);
else
@@ -512,7 +525,8 @@
if (ret < 0)
return ret;
node = nilfs_btree_get_nonroot_node(path, level);
- BUG_ON(level != nilfs_btree_node_get_level(node));
+ if (nilfs_btree_bad_node(node, level))
+ return -EINVAL;
index = nilfs_btree_node_get_nchildren(node) - 1;
ptr = nilfs_btree_node_get_ptr(btree, node, index);
path[level].bp_index = index;