btrfs: do not write corrupted metadata blocks to disk

csum_dirty_buffer was issuing a warning in case the extent buffer
did not look alright, but was still returning success.
Let's return error in this case, and also add an additional sanity
check on the extent buffer header.
The caller up the chain may BUG_ON on this, for example flush_epd_write_bio will,
but it is better than to have a silent metadata corruption on disk.

Signed-off-by: Alex Lyakas <alex@zadarastorage.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Alex Lyakas 2016-03-10 13:10:15 +02:00 committed by David Sterba
parent 8bd98f0e6b
commit 0f805531da

View file

@ -512,9 +512,20 @@ static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
eb = (struct extent_buffer *)page->private;
if (page != eb->pages[0])
return 0;
found_start = btrfs_header_bytenr(eb);
if (WARN_ON(found_start != start || !PageUptodate(page)))
return 0;
/*
* Please do not consolidate these warnings into a single if.
* It is useful to know what went wrong.
*/
if (WARN_ON(found_start != start))
return -EUCLEAN;
if (WARN_ON(!PageUptodate(page)))
return -EUCLEAN;
ASSERT(memcmp_extent_buffer(eb, fs_info->fsid,
btrfs_header_fsid(), BTRFS_FSID_SIZE) == 0);
return csum_tree_block(fs_info, eb, 0);
}