blk-mq: make blk_mq_alloc_request_hctx() allocate a scheduler request
blk_mq_alloc_request_hctx() allocates a driver request directly, unlike
its blk_mq_alloc_request() counterpart. It also crashes because it
doesn't update the tags->rqs map.
Fix it by making it allocate a scheduler request.
Reported-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Tested-by: Sagi Grimberg <sagi@grimberg.me>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 4df5fb4..85a7047 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -273,10 +273,9 @@ EXPORT_SYMBOL(blk_mq_alloc_request);
struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw,
unsigned int flags, unsigned int hctx_idx)
{
- struct blk_mq_hw_ctx *hctx;
- struct blk_mq_ctx *ctx;
+ struct blk_mq_alloc_data alloc_data = { .flags = flags };
struct request *rq;
- struct blk_mq_alloc_data alloc_data;
+ unsigned int cpu;
int ret;
/*
@@ -299,25 +298,23 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw,
* Check if the hardware context is actually mapped to anything.
* If not tell the caller that it should skip this queue.
*/
- hctx = q->queue_hw_ctx[hctx_idx];
- if (!blk_mq_hw_queue_mapped(hctx)) {
- ret = -EXDEV;
- goto out_queue_exit;
+ alloc_data.hctx = q->queue_hw_ctx[hctx_idx];
+ if (!blk_mq_hw_queue_mapped(alloc_data.hctx)) {
+ blk_queue_exit(q);
+ return ERR_PTR(-EXDEV);
}
- ctx = __blk_mq_get_ctx(q, cpumask_first(hctx->cpumask));
+ cpu = cpumask_first(alloc_data.hctx->cpumask);
+ alloc_data.ctx = __blk_mq_get_ctx(q, cpu);
- blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
- rq = __blk_mq_alloc_request(&alloc_data, rw);
- if (!rq) {
- ret = -EWOULDBLOCK;
- goto out_queue_exit;
- }
+ rq = blk_mq_sched_get_request(q, NULL, rw, &alloc_data);
+
+ blk_mq_put_ctx(alloc_data.ctx);
+ blk_queue_exit(q);
+
+ if (!rq)
+ return ERR_PTR(-EWOULDBLOCK);
return rq;
-
-out_queue_exit:
- blk_queue_exit(q);
- return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
