btrfs: handle errors while updating refcounts in update_ref_for_cow

Since commit fb235dc06f (btrfs: qgroup: Move half of the qgroup
accounting time out of commit trans) the assumption that
btrfs_add_delayed_{data,tree}_ref can only return 0 or -ENOMEM has
been false.  The qgroup operations call into btrfs_search_slot
and friends and can now return the full spectrum of error codes.

Fortunately, the fix here is easy since update_ref_for_cow failing
is already handled so we just need to bail early with the error
code.

Fixes: fb235dc06f (btrfs: qgroup: Move half of the qgroup accounting ...)
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Edmund Nadolski <enadolski@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Jeff Mahoney 2017-11-21 13:58:49 -05:00 committed by David Sterba
parent b430b77512
commit 692826b273

View File

@ -1032,14 +1032,17 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) &&
!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
ret = btrfs_inc_ref(trans, root, buf, 1);
BUG_ON(ret); /* -ENOMEM */
if (ret)
return ret;
if (root->root_key.objectid ==
BTRFS_TREE_RELOC_OBJECTID) {
ret = btrfs_dec_ref(trans, root, buf, 0);
BUG_ON(ret); /* -ENOMEM */
if (ret)
return ret;
ret = btrfs_inc_ref(trans, root, cow, 1);
BUG_ON(ret); /* -ENOMEM */
if (ret)
return ret;
}
new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
} else {
@ -1049,7 +1052,8 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
ret = btrfs_inc_ref(trans, root, cow, 1);
else
ret = btrfs_inc_ref(trans, root, cow, 0);
BUG_ON(ret); /* -ENOMEM */
if (ret)
return ret;
}
if (new_flags != 0) {
int level = btrfs_header_level(buf);
@ -1068,9 +1072,11 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
ret = btrfs_inc_ref(trans, root, cow, 1);
else
ret = btrfs_inc_ref(trans, root, cow, 0);
BUG_ON(ret); /* -ENOMEM */
if (ret)
return ret;
ret = btrfs_dec_ref(trans, root, buf, 1);
BUG_ON(ret); /* -ENOMEM */
if (ret)
return ret;
}
clean_tree_block(fs_info, buf);
*last_ref = 1;