btrfs: handle failure of add_pending_csums

add_pending_csums was added as part of the new data=ordered
implementation in e6dcd2dc9c48 ("Btrfs: New data=ordered
implementation"). Even back then it called the btrfs_csum_file_blocks
which can fail but it never bothered handling the failure. In ENOMEM
situation this could lead to the filesystem failing to write the
checksums for a particular extent and not detect this. On read this
could lead to the filesystem erroring out due to crc mismatch. Fix it by
propagating failure from add_pending_csums and handling them.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 29b4913..8f7d41f 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2042,12 +2042,15 @@ static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
                             struct inode *inode, struct list_head *list)
 {
        struct btrfs_ordered_sum *sum;
+       int ret;
 
        list_for_each_entry(sum, list, list) {
                trans->adding_csums = true;
-               btrfs_csum_file_blocks(trans,
+               ret = btrfs_csum_file_blocks(trans,
                       BTRFS_I(inode)->root->fs_info->csum_root, sum);
                trans->adding_csums = false;
+               if (ret)
+                       return ret;
        }
        return 0;
 }
@@ -3061,7 +3064,11 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
                goto out;
        }
 
-       add_pending_csums(trans, inode, &ordered_extent->list);
+       ret = add_pending_csums(trans, inode, &ordered_extent->list);
+       if (ret) {
+               btrfs_abort_transaction(trans, ret);
+               goto out;
+       }
 
        btrfs_ordered_update_i_size(inode, 0, ordered_extent);
        ret = btrfs_update_inode_fallback(trans, root, inode);