[PATCH 14/30] bsg: convert to use blk-mq

Jens Axboe
2018-10-31T17:59:06Z

Requires a few changes to the FC transport class as well.

Cc: linux-scsi@vger.kernel.org
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Tested-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
block/bsg-lib.c | 123 +++++++++++++++++++------------
drivers/scsi/scsi_transport_fc.c | 59 +++++++++------
2 files changed, 110 insertions(+), 72 deletions(-)

diff --git a/block/bsg-lib.c b/block/bsg-lib.c
index 3f2e9a1bae44..faf20f4500c9 100644
--- a/block/bsg-lib.c
+++ b/block/bsg-lib.c
@@ -21,7 +21,7 @@
*
*/
#include <linux/slab.h>
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
#include <linux/delay.h>
#include <linux/scatterlist.h>
#include <linux/bsg-lib.h>
@@ -129,7 +129,7 @@ static void bsg_teardown_job(struct kref *kref)
kfree(job->request_payload.sg_list);
kfree(job->reply_payload.sg_list);

- blk_end_request_all(rq, BLK_STS_OK);
+ blk_mq_end_request(rq, BLK_STS_OK);
}

void bsg_job_put(struct bsg_job *job)
@@ -157,15 +157,15 @@ void bsg_job_done(struct bsg_job *job, int result,
{
job->result = result;
job->reply_payload_rcv_len = reply_payload_rcv_len;
- blk_complete_request(blk_mq_rq_from_pdu(job));
+ blk_mq_complete_request(blk_mq_rq_from_pdu(job));
}
EXPORT_SYMBOL_GPL(bsg_job_done);

/**
- * bsg_softirq_done - softirq done routine for destroying the bsg requests
+ * bsg_complete - softirq done routine for destroying the bsg requests
* @rq: BSG request that holds the job to be destroyed
*/
-static void bsg_softirq_done(struct request *rq)
+static void bsg_complete(struct request *rq)
{
struct bsg_job *job = blk_mq_rq_to_pdu(rq);

@@ -224,54 +224,46 @@ static bool bsg_prepare_job(struct device *dev, struct request *req)
}

/**
- * bsg_request_fn - generic handler for bsg requests
- * @q: request queue to manage
+ * bsg_queue_rq - generic handler for bsg requests
+ * @hctx: hardware queue
+ * @bd: queue data
*
* On error the create_bsg_job function should return a -Exyz error value
* that will be set to ->result.
*
* Drivers/subsys should pass this to the queue init function.
*/
-static void bsg_request_fn(struct request_queue *q)
- __releases(q->queue_lock)
- __acquires(q->queue_lock)
+static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
{
+ struct request_queue *q = hctx->queue;
struct device *dev = q->queuedata;
- struct request *req;
+ struct request *req = bd->rq;
int ret;

+ blk_mq_start_request(req);
+
if (!get_device(dev))
- return;
-
- while (1) {
- req = blk_fetch_request(q);
- if (!req)
- break;
- spin_unlock_irq(q->queue_lock);
-
- if (!bsg_prepare_job(dev, req)) {
- blk_end_request_all(req, BLK_STS_OK);
- spin_lock_irq(q->queue_lock);
- continue;
- }
-
- ret = q->bsg_job_fn(blk_mq_rq_to_pdu(req));
- spin_lock_irq(q->queue_lock);
- if (ret)
- break;
- }
+ return BLK_STS_IOERR;
+
+ if (!bsg_prepare_job(dev, req))
+ return BLK_STS_IOERR;
+
+ ret = q->bsg_job_fn(blk_mq_rq_to_pdu(req));
+ if (ret)
+ return BLK_STS_IOERR;

- spin_unlock_irq(q->queue_lock);
put_device(dev);
- spin_lock_irq(q->queue_lock);
+ return BLK_STS_OK;
}

/* called right after the request is allocated for the request_queue */
-static int bsg_init_rq(struct request_queue *q, struct request *req, gfp_t gfp)
+static int bsg_init_rq(struct blk_mq_tag_set *set, struct request *req,
+ unsigned int hctx_idx, unsigned int numa_node)
{
struct bsg_job *job = blk_mq_rq_to_pdu(req);

- job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, gfp);
+ job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
if (!job->reply)
return -ENOMEM;
return 0;
@@ -289,7 +281,8 @@ static void bsg_initialize_rq(struct request *req)
job->dd_data = job + 1;
}

-static void bsg_exit_rq(struct request_queue *q, struct request *req)
+static void bsg_exit_rq(struct blk_mq_tag_set *set, struct request *req,
+ unsigned int hctx_idx)
{
struct bsg_job *job = blk_mq_rq_to_pdu(req);

@@ -299,12 +292,36 @@ static void bsg_exit_rq(struct request_queue *q, struct request *req)
void bsg_remove_queue(struct request_queue *q)
{
if (q) {
+ struct blk_mq_tag_set *set = q->tag_set;
+
bsg_unregister_queue(q);
blk_cleanup_queue(q);
+ blk_mq_free_tag_set(set);
+ kfree(set);
}
}
EXPORT_SYMBOL_GPL(bsg_remove_queue);

+static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved)
+{
+ enum blk_eh_timer_return ret = BLK_EH_DONE;
+ struct request_queue *q = rq->q;
+
+ if (q->rq_timed_out_fn)
+ ret = q->rq_timed_out_fn(rq);
+
+ return ret;
+}
+
+static const struct blk_mq_ops bsg_mq_ops = {
+ .queue_rq = bsg_queue_rq,
+ .init_request = bsg_init_rq,
+ .exit_request = bsg_exit_rq,
+ .initialize_rq_fn = bsg_initialize_rq,
+ .complete = bsg_complete,
+ .timeout = bsg_timeout,
+};
+
/**
* bsg_setup_queue - Create and add the bsg hooks so we can receive requests
* @dev: device to attach bsg device to
@@ -315,28 +332,34 @@ EXPORT_SYMBOL_GPL(bsg_remove_queue);
struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
bsg_job_fn *job_fn, rq_timed_out_fn *timeout, int dd_job_size)
{
+ struct blk_mq_tag_set *set;
struct request_queue *q;
- int ret;
+ int ret = -ENOMEM;

- q = blk_alloc_queue(GFP_KERNEL);
- if (!q)
+ set = kzalloc(sizeof(*set), GFP_KERNEL);
+ if (!set)
return ERR_PTR(-ENOMEM);
- q->cmd_size = sizeof(struct bsg_job) + dd_job_size;
- q->init_rq_fn = bsg_init_rq;
- q->exit_rq_fn = bsg_exit_rq;
- q->initialize_rq_fn = bsg_initialize_rq;
- q->request_fn = bsg_request_fn;

- ret = blk_init_allocated_queue(q);
- if (ret)
- goto out_cleanup_queue;
+ set->ops = &bsg_mq_ops,
+ set->nr_hw_queues = 1;
+ set->queue_depth = 128;
+ set->numa_node = NUMA_NO_NODE;
+ set->cmd_size = sizeof(struct bsg_job) + dd_job_size;
+ set->flags = BLK_MQ_F_NO_SCHED | BLK_MQ_F_BLOCKING;
+ if (blk_mq_alloc_tag_set(set))
+ goto out_tag_set;
+
+ q = blk_mq_init_queue(set);
+ if (IS_ERR(q)) {
+ ret = PTR_ERR(q);
+ goto out_queue;
+ }

q->queuedata = dev;
q->bsg_job_fn = job_fn;
blk_queue_flag_set(QUEUE_FLAG_BIDI, q);
- blk_queue_softirq_done(q, bsg_softirq_done);
blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
- blk_queue_rq_timed_out(q, timeout);
+ q->rq_timed_out_fn = timeout;

ret = bsg_register_queue(q, dev, name, &bsg_transport_ops);
if (ret) {
@@ -348,6 +371,10 @@ struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
return q;
out_cleanup_queue:
blk_cleanup_queue(q);
+out_queue:
+ blk_mq_free_tag_set(set);
+out_tag_set:
+ kfree(set);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(bsg_setup_queue);
diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 638f83ab04b2..d7035270d274 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -3592,7 +3592,7 @@ fc_bsg_job_timeout(struct request *req)

/* the blk_end_sync_io() doesn't check the error */
if (inflight)
- __blk_complete_request(req);
+ blk_mq_end_request(req, BLK_STS_IOERR);
return BLK_EH_DONE;
}

@@ -3684,14 +3684,9 @@ static void
fc_bsg_goose_queue(struct fc_rport *rport)
{
struct request_queue *q = rport->rqst_q;
- unsigned long flags;
-
- if (!q)
- return;

- spin_lock_irqsave(q->queue_lock, flags);
- blk_run_queue_async(q);
- spin_unlock_irqrestore(q->queue_lock, flags);
+ if (q)
+ blk_mq_run_hw_queues(q, true);
}

/**
@@ -3759,6 +3754,37 @@ static int fc_bsg_dispatch(struct bsg_job *job)
return fc_bsg_host_dispatch(shost, job);
}

+static blk_status_t fc_bsg_rport_prep(struct fc_rport *rport)
+{
+ if (rport->port_state == FC_PORTSTATE_BLOCKED &&
+ !(rport->flags & FC_RPORT_FAST_FAIL_TIMEDOUT))
+ return BLK_STS_RESOURCE;
+
+ if (rport->port_state != FC_PORTSTATE_ONLINE)
+ return BLK_STS_IOERR;
+
+ return BLK_STS_OK;
+}
+
+
+static int fc_bsg_dispatch_prep(struct bsg_job *job)
+{
+ struct fc_rport *rport = fc_bsg_to_rport(job);
+ blk_status_t ret;
+
+ ret = fc_bsg_rport_prep(rport);
+ switch (ret) {
+ case BLK_STS_OK:
+ break;
+ case BLK_STS_RESOURCE:
+ return -EAGAIN;
+ default:
+ return -EIO;
+ }
+
+ return fc_bsg_dispatch(job);
+}
+
/**
* fc_bsg_hostadd - Create and add the bsg hooks so we can receive requests
* @shost: shost for fc_host
@@ -3794,20 +3820,6 @@ fc_bsg_hostadd(struct Scsi_Host *shost, struct fc_host_attrs *fc_host)
return 0;
}

-static int fc_bsg_rport_prep(struct request_queue *q, struct request *req)
-{
- struct fc_rport *rport = dev_to_rport(q->queuedata);
-
- if (rport->port_state == FC_PORTSTATE_BLOCKED &&
- !(rport->flags & FC_RPORT_FAST_FAIL_TIMEDOUT))
- return BLKPREP_DEFER;
-
- if (rport->port_state != FC_PORTSTATE_ONLINE)
- return BLKPREP_KILL;
-
- return BLKPREP_OK;
-}
-
/**
* fc_bsg_rportadd - Create and add the bsg hooks so we can receive requests
* @shost: shost that rport is attached to
@@ -3825,14 +3837,13 @@ fc_bsg_rportadd(struct Scsi_Host *shost, struct fc_rport *rport)
if (!i->f->bsg_request)
return -ENOTSUPP;

- q = bsg_setup_queue(dev, dev_name(dev), fc_bsg_dispatch,
+ q = bsg_setup_queue(dev, dev_name(dev), fc_bsg_dispatch_prep,
fc_bsg_job_timeout, i->f->dd_bsg_size);
if (IS_ERR(q)) {
dev_err(dev, "failed to setup bsg queue\n");
return PTR_ERR(q);
}
__scsi_init_queue(shost, q);
- blk_queue_prep_rq(q, fc_bsg_rport_prep);
blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
rport->rqst_q = q;
return 0;
--
2.17.1