[PATCH v2 05/15] btrfs: don't do repair validation for checksum errors

[Omar Sandoval <osandov@osandov.com>]

From: Omar Sandoval <osandov@fb.com>

The purpose of the validation step is to distinguish between good and
bad sectors in a failed multi-sector read. If a multi-sector read
succeeded but some of those sectors had checksum errors, we don't need
to validate anything; we know the sectors with bad checksums need to be
repaired.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/extent_io.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 712f49607d3a..25dd42437cbd 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2640,6 +2640,14 @@ static bool btrfs_io_needs_validation(struct inode *inode, struct bio *bio)
 	u64 len = 0;
 	int i;
 
+	/*
+	 * If bi_status is BLK_STS_OK, then this was a checksum error, not an
+	 * I/O error. In this case, we already know exactly which sector was
+	 * bad, so we don't need to validate.
+	 */
+	if (bio->bi_status == BLK_STS_OK)
+		return false;
+
 	/*
 	 * We need to validate each sector individually if the failed I/O was
 	 * for multiple sectors.
-- 
2.26.1