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Commit cfa913a5 authored by Ryusuke Konishi's avatar Ryusuke Konishi
Browse files

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: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
parent 7c017457

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;