From 0c9d5b127f695818c2c5a3868c1f28ca2969e905 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 6 Apr 2017 12:06:37 +1000 Subject: [PATCH] md/raid1: avoid reusing a resync bio after error handling. fix_sync_read_error() modifies a bio on a newly faulty device by setting bi_end_io to end_sync_write. This ensure that put_buf() will still call rdev_dec_pending() as required, but makes sure that subsequent code in fix_sync_read_error() doesn't try to read from the device. Unfortunately this interacts badly with sync_request_write() which assumes that any bio with bi_end_io set to non-NULL other than end_sync_read is safe to write to. As the device is now faulty it doesn't make sense to write. As the bio was recently used for a read, it is "dirty" and not suitable for immediate submission. In particular, ->bi_next might be non-NULL, which will cause generic_make_request() to complain. Break this interaction by refusing to write to devices which are marked as Faulty. Reported-and-tested-by: Michael Wang Fixes: 2e52d449bcec ("md/raid1: add failfast handling for reads.") Cc: stable@vger.kernel.org (v4.10+) Signed-off-by: NeilBrown Signed-off-by: Shaohua Li --- drivers/md/raid1.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 7d6723558fd8..70278b9a3c43 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -2218,6 +2218,8 @@ static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio) (i == r1_bio->read_disk || !test_bit(MD_RECOVERY_SYNC, &mddev->recovery)))) continue; + if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) + continue; bio_set_op_attrs(wbio, REQ_OP_WRITE, 0); if (test_bit(FailFast, &conf->mirrors[i].rdev->flags)) -- 2.20.1