From cf8599c33803932b73e00a54785103030a37a4ee Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Fri, 22 Aug 2014 11:42:49 +0800 Subject: btrfs-progs: corrupt-block: fix a delete and use bug corrupting extent tree When corrupting extent tree, corrupt-block will iterate each child node/leaf of a node. However, when a node's child is leaf, btrfs_corrupt_extent_leaf() may delete some item in the leaf, which may cause the children number of the parent node decrease. Before this patch, corrupt-block will read out the nritems only *ONCE* and iterate the 'nritems' times. When btrfs_corrupt_extent_leaf() deletes enough item, causing the nritems of btrfs_header decreased, the last few iteration will access non-existed node, which will cause the delete and use bug like the following: deleting extent record: key 40714240 168 16384 Couldn't map the block 3459802452797161472 btrfs-corrupt-block: volumes.c:1137: btrfs_num_copies: Assertion `!(!ce)' failed. Aborted This patch will update the nritmes in each iteration to avoid the bug. Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- btrfs-corrupt-block.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/btrfs-corrupt-block.c b/btrfs-corrupt-block.c index 1a3ac351..474d48fa 100644 --- a/btrfs-corrupt-block.c +++ b/btrfs-corrupt-block.c @@ -264,12 +264,10 @@ static void btrfs_corrupt_extent_tree(struct btrfs_trans_handle *trans, struct extent_buffer *eb) { int i; - u32 nr; if (!eb) return; - nr = btrfs_header_nritems(eb); if (btrfs_is_leaf(eb)) { btrfs_corrupt_extent_leaf(trans, root, eb); return; @@ -280,7 +278,7 @@ static void btrfs_corrupt_extent_tree(struct btrfs_trans_handle *trans, return; } - for (i = 0; i < nr; i++) { + for (i = 0; i < btrfs_header_nritems(eb); i++) { struct extent_buffer *next; next = read_tree_block(root, btrfs_node_blockptr(eb, i), -- cgit v1.2.3