Currently if the range to trim is too small, for example on 1K fs
the request to trim the first block, then the 'range->len' is not set
reporting wrong number of discarded block to the caller.

Fix this by always setting the 'range->len' before we return. Note that
when there is a failure (-EINVAL) caller can not depend on 'range->len'
being set properly.

Signed-off-by: Lukas Czerner <redacted>
---
v2: nothing changed

 fs/ext4/mballoc.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index f20688e..8f817f2 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c

@@ -5092,11 +5092,11 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
 		 */
 		first_cluster = 0;
 	}
-	range->len = trimmed * sb->s_blocksize;
 
 	if (!ret)
 		atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen);
 
 out:
+	range->len = trimmed * sb->s_blocksize;
 	return ret;
 }

-- 
1.7.4.4