nilfs2: add sanity check in nilfs_btree_add_dirty_buffer (cfa913a5) · Commits · 戴 / test

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 <konishi.ryusuke@lab.ntt.co.jp>

fs/nilfs2/btree.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -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;

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