Btrfs: adjust btrfs_discard_extent() return errors and trimmed bytes
Callers of btrfs_discard_extent() should check if we are mounted with -o discard,
as we want to make fitrim to work even the fs is not mounted with -o discard.
Also we should use REQ_DISCARD to map the free extent to get a full mapping,
last we only return errors if
1. the error is not a EOPNOTSUPP
2. no device supports discard
Signed-off-by: Li Dongyang <lidongyang@novell.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 125639d..8ecc5419 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3054,7 +3054,10 @@
break;
/* opt_discard */
- ret = btrfs_error_discard_extent(root, start, end + 1 - start);
+ if (btrfs_test_opt(root, DISCARD))
+ ret = btrfs_error_discard_extent(root, start,
+ end + 1 - start,
+ NULL);
clear_extent_dirty(unpin, start, end, GFP_NOFS);
btrfs_error_unpin_extent_range(root, start, end);