From c53839fc3217085c210e1a62022016f199ae7b5a Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn Date: Mon, 25 Feb 2019 14:24:16 +0100 Subject: [PATCH] btrfs: warn if extent buffer mapping crosses a page boundary in csum_tree_block Since commit d2e174d5d3ee ("btrfs: document extent mapping assumptions in checksum") we have a comment in place why map_private_extent_buffer() can't return 1 in the csum_tree_block() case. Make this a bit more explicit and WARN_ON() in case this this assumption breaks. Signed-off-by: Johannes Thumshirn Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 4f11a83304ae..c4404e1e9cfb 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -285,7 +285,7 @@ static int csum_tree_block(struct extent_buffer *buf, u8 *result) */ err = map_private_extent_buffer(buf, offset, 32, &kaddr, &map_start, &map_len); - if (err) + if (WARN_ON(err)) return err; cur_len = min(len, map_len - (offset - map_start)); crc = btrfs_csum_data(kaddr + offset - map_start, -- 2.30.2