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authorAlex Lyakas <alex.bolshoy@gmail.com>2016-03-10 13:10:15 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-05-18 18:35:17 -0700
commitb96513cce7b82c66f6d1ff87261d65d7cda08861 (patch)
tree4574f12e1bb2799009cb017dd5550de52fa900ca
parent342da5cefddbf818e1cb59537e021cdad9744e93 (diff)
downloadlwn-b96513cce7b82c66f6d1ff87261d65d7cda08861.tar.gz
lwn-b96513cce7b82c66f6d1ff87261d65d7cda08861.zip
btrfs: do not write corrupted metadata blocks to disk
commit 0f805531daa2ebfb5706422dc2ead1cff9e53e65 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/btrfs/disk-io.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 87946c69c68f..ae6e3e36fdf0 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -513,9 +513,20 @@ 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);
}