[PATCH AUTOSEL 5.6 21/68] null_blk: fix spurious IO errors after failed past-wp access

Sasha Levin
2020-04-10T04:02:41Z

From: Alexey Dobriyan <adobriyan@gmail.com>

[ Upstream commit ff77042296d0a54535ddf74412c5ae92cb4ec76a ]

Steps to reproduce:

BLKRESETZONE zone 0

// force EIO
pwrite(fd, buf, 4096, 4096);

[issue more IO including zone ioctls]

It will start failing randomly including IO to unrelated zones because of
->error "reuse". Trigger can be partition detection as well if test is not
run immediately which is even more entertaining.

The fix is of course to clear ->error where necessary.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alexey Dobriyan (SK hynix) <adobriyan@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/block/null_blk_main.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index 2b8b4cb447cfb..d6a8d66e98036 100644
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -605,6 +605,7 @@ static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
if (tag != -1U) {
cmd = &nq->cmds[tag];
cmd->tag = tag;
+ cmd->error = BLK_STS_OK;
cmd->nq = nq;
if (nq->dev->irqmode == NULL_IRQ_TIMER) {
hrtimer_init(&cmd->timer, CLOCK_MONOTONIC,
@@ -1385,6 +1386,7 @@ static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
cmd->timer.function = null_cmd_timer_expired;
}
cmd->rq = bd->rq;
+ cmd->error = BLK_STS_OK;
cmd->nq = nq;

blk_mq_start_request(bd->rq);
--
2.20.1