From 6961cd4d0fde97f1cdb798ba21cf124ecfa0bf95 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 7 Nov 2018 14:34:05 -0700 Subject: ubd: fix missing lock around request issue We need to hold the device lock (and disable interrupts) while writing new commands, or we could be interrupted while that is happening and read invalid requests in the completion path. Fixes: 4e6da0fe8058 ("um: Convert ubd driver to blk-mq") Tested-by: Richard Weinberger Signed-off-by: Jens Axboe --- arch/um/drivers/ubd_kern.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 74c002ddc0ce..08831f5d83db 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -1341,11 +1341,14 @@ static int ubd_queue_one_vec(struct blk_mq_hw_ctx *hctx, struct request *req, static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) { + struct ubd *ubd_dev = hctx->queue->queuedata; struct request *req = bd->rq; int ret = 0; blk_mq_start_request(req); + spin_lock_irq(&ubd_dev->lock); + if (req_op(req) == REQ_OP_FLUSH) { ret = ubd_queue_one_vec(hctx, req, 0, NULL); } else { @@ -1361,9 +1364,11 @@ static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, } } out: - if (ret < 0) { + spin_unlock_irq(&ubd_dev->lock); + + if (ret < 0) blk_mq_requeue_request(req, true); - } + return BLK_STS_OK; } -- cgit v1.2.3 From 0033dfd92a5646a78025e86f8df4d5b18181ba2c Mon Sep 17 00:00:00 2001 From: Anton Ivanov Date: Thu, 8 Nov 2018 13:07:23 +0000 Subject: ubd: fix missing initialization of io_req The SYNC path doesn't initialize io_req->error, which can cause random errors. Before the conversion to blk-mq, we always completed requests with BLK_STS_OK status, but now we actually look at the error field and this issue becomes apparent. Signed-off-by: Anton Ivanov [axboe: fixed up commit message to explain what is actually going on] Signed-off-by: Jens Axboe --- arch/um/drivers/ubd_kern.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 08831f5d83db..28c40624bcb6 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -1305,6 +1305,7 @@ static int ubd_queue_one_vec(struct blk_mq_hw_ctx *hctx, struct request *req, io_req->fds[0] = dev->cow.fd; else io_req->fds[0] = dev->fd; + io_req->error = 0; if (req_op(req) == REQ_OP_FLUSH) { io_req->op = UBD_FLUSH; @@ -1313,9 +1314,7 @@ static int ubd_queue_one_vec(struct blk_mq_hw_ctx *hctx, struct request *req, io_req->cow_offset = -1; io_req->offset = off; io_req->length = bvec->bv_len; - io_req->error = 0; io_req->sector_mask = 0; - io_req->op = rq_data_dir(req) == READ ? UBD_READ : UBD_WRITE; io_req->offsets[0] = 0; io_req->offsets[1] = dev->cow.data_offset; -- cgit v1.2.3