From: Ryusuke Konishi Date: Wed, 7 Jul 2010 08:19:54 +0000 (+0900) Subject: nilfs2: add sanity check in nilfs_btree_add_dirty_buffer X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=cfa913a5077f7619869b2b4d1bf23ccb4f8b3d7b;p=deliverable%2Flinux.git nilfs2: add sanity check in nilfs_btree_add_dirty_buffer According to the report titled "problem with nilfs_cleanerd" from Łukasz Wójcicki, nilfs_btree_lookup_dirty_buffers or nilfs_btree_add_dirty_buffer got memory violation during garbage collection. This could happen if a level field of given btree node buffer is incorrect, which is a crucial internal bug. This inserts a sanity check to figure out the problem. Signed-off-by: Ryusuke Konishi --- diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c index b27a342c5af6..386356707f90 100644 --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -1920,6 +1920,18 @@ static void nilfs_btree_add_dirty_buffer(struct nilfs_btree *btree, node = (struct nilfs_btree_node *)bh->b_data; key = nilfs_btree_node_get_key(node, 0); level = nilfs_btree_node_get_level(node); + if (level < NILFS_BTREE_LEVEL_NODE_MIN || + level >= NILFS_BTREE_LEVEL_MAX) { + dump_stack(); + printk(KERN_WARNING + "%s: invalid btree level: %d (key=%llu, ino=%lu, " + "blocknr=%llu)\n", + __func__, level, (unsigned long long)key, + NILFS_BMAP_I(&btree->bt_bmap)->vfs_inode.i_ino, + (unsigned long long)bh->b_blocknr); + return; + } + list_for_each(head, &lists[level]) { cbh = list_entry(head, struct buffer_head, b_assoc_buffers); cnode = (struct nilfs_btree_node *)cbh->b_data;