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Commit 053ab70f authored by Liu Bo's avatar Liu Bo Committed by Chris Mason
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Btrfs: check btree node's nritems 



When btree node (level = 1) has nritems which equals to zero,
we can end up with panic due to insert_ptr()'s

BUG_ON(slot > nritems);

where slot is 1 and nritems is 0, as copy_for_split() calls
insert_ptr(.., path->slots[1] + 1, ...);

A invalid value results in the whole mess, this adds the check
for btree's node nritems so that we stop reading block when
when something is wrong.

Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent 35bbb97f

fs/btrfs/disk-io.c

+16 −0
Original line number Diff line number Diff line
@@ -613,6 +613,19 @@ static noinline int check_leaf(struct btrfs_root *root, 
	return 0;

}



static int check_node(struct btrfs_root *root, struct extent_buffer *node)

{

	unsigned long nr = btrfs_header_nritems(node);



	if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(root)) {

		btrfs_crit(root->fs_info,

			   "corrupt node: block %llu root %llu nritems %lu",

			   node->start, root->objectid, nr);

		return -EIO;

	}

	return 0;

}



static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,

				      u64 phy_offset, struct page *page,

				      u64 start, u64 end, int mirror)
@@ -683,6 +696,9 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio, 
		ret = -EIO;

	}



	if (found_level > 0 && check_node(root, eb))

		ret = -EIO;



	if (!ret)

		set_extent_buffer_uptodate(eb);

err: