[PATCH v1 5/7] xfs: Add device retry

Allison Henderson
2018-11-28T14:52:44Z

Check to see if the _xfs_buf_read fails. If so loop over the
available mirrors and retry the read

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
---
fs/xfs/xfs_buf.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index dd8ba59..f102d01 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -21,6 +21,7 @@
#include <linux/migrate.h>
#include <linux/backing-dev.h>
#include <linux/freezer.h>
+#include <linux/blkdev.h>

#include "xfs_format.h"
#include "xfs_log_format.h"
@@ -808,6 +809,8 @@ xfs_buf_read_map(
const struct xfs_buf_ops *ops)
{
struct xfs_buf *bp;
+ struct request_queue *q;
+ unsigned short i;

flags |= XBF_READ;

@@ -820,7 +823,30 @@ xfs_buf_read_map(
if (!(bp->b_flags & XBF_DONE)) {
XFS_STATS_INC(target->bt_mount, xb_get_read);
bp->b_ops = ops;
- _xfs_buf_read(bp, flags);
+ q = bdev_get_queue(bp->b_target->bt_bdev);
+
+ /*
+ * Mirrors are indexed 1 - n, specified through the rw_hint.
+ * Setting the hint to 0 is unspecified and allows the block
+ * layer to decide.
+ */
+ for (i = 0; i <= blk_queue_get_mirrors(q); i++) {
+ bp->b_error = 0;
+ bp->b_rw_hint = i;
+ _xfs_buf_read(bp, flags);
+
+ switch (bp->b_error) {
+ case -EIO:
+ case -EFSCORRUPTED:
+ case -EFSBADCRC:
+ /* loop again */
+ continue;
+ default:
+ goto retry_done;
+ }
+
+ }
+retry_done:
return bp;
}

--
2.7.4