[B][PATCH 07/11] bcache: count backing device I/O error for writeback I/O

[Mauricio Faria de Oliveira]

From: Coly Li <colyli at suse.de>

BugLink: https://bugs.launchpad.net/bugs/1829563

Commit c7b7bd07404c5 ("bcache: add io_disable to struct cached_dev")
counts backing device I/O requets and set dc->io_disable to true if error
counters exceeds dc->io_error_limit. But it only counts I/O errors for
regular I/O request, neglects errors of write back I/Os when backing device
is offline.

This patch counts the errors of writeback I/Os, in dirty_endio() if
bio->bi_status is  not 0, it means error happens when writing dirty keys
to backing device, then bch_count_backing_io_errors() is called.

By this fix, even there is no reqular I/O request coming, if writeback I/O
errors exceed dc->io_error_limit, the bcache device may still be stopped
for the broken backing device.

Fixes: c7b7bd07404c5 ("bcache: add io_disable to struct cached_dev")
Signed-off-by: Coly Li <colyli at suse.de>
Reviewed-by: Hannes Reinecke <hare at suse.com>
Signed-off-by: Jens Axboe <axboe at kernel.dk>
(cherry picked from commit bf78980fcc58bad2d61858ce342153a3dd097aa0)
Signed-off-by: Mauricio Faria de Oliveira <mfo at canonical.com>
---
 drivers/md/bcache/writeback.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index 8ee82acf2c3a..993dcc5cd97a 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -220,8 +220,10 @@ static void dirty_endio(struct bio *bio)
 	struct keybuf_key *w = bio->bi_private;
 	struct dirty_io *io = w->private;
 
-	if (bio->bi_status)
+	if (bio->bi_status) {
 		SET_KEY_DIRTY(&w->key, false);
+		bch_count_backing_io_errors(io->dc, bio);
+	}
 
 	closure_put(&io->cl);
 }
-- 
2.17.1