1 files changed, 298 insertions, 118 deletions

diff --git a/block/bsg-lib.c b/block/bsg-lib.c
index 650f427d915b..9ceb5d0832f5 100644
--- a/block/bsg-lib.c
+++ b/block/bsg-lib.c
@@ -1,45 +1,182 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  BSG helper library
  *
  *  Copyright (C) 2008   James Smart, Emulex Corporation
  *  Copyright (C) 2011   Red Hat, Inc.  All rights reserved.
  *  Copyright (C) 2011   Mike Christie
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- *
  */
+#include <linux/bsg.h>
 #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>
 #include <linux/export.h>
 #include <scsi/scsi_cmnd.h>
+#include <scsi/sg.h>
+
+#define uptr64(val) ((void __user *)(uintptr_t)(val))
+
+struct bsg_set {
+	struct blk_mq_tag_set	tag_set;
+	struct bsg_device	*bd;
+	bsg_job_fn		*job_fn;
+	bsg_timeout_fn		*timeout_fn;
+};
+
+static int bsg_transport_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
+		bool open_for_write, unsigned int timeout)
+{
+	struct bsg_job *job;
+	struct request *rq;
+	struct bio *bio;
+	void *reply;
+	int ret;
+
+	if (hdr->protocol != BSG_PROTOCOL_SCSI  ||
+	    hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT)
+		return -EINVAL;
+	if (!capable(CAP_SYS_RAWIO))
+		return -EPERM;
+
+	rq = blk_mq_alloc_request(q, hdr->dout_xfer_len ?
+			     REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
+	if (IS_ERR(rq))
+		return PTR_ERR(rq);
+	rq->timeout = timeout;
+
+	job = blk_mq_rq_to_pdu(rq);
+	reply = job->reply;
+	memset(job, 0, sizeof(*job));
+	job->reply = reply;
+	job->reply_len = SCSI_SENSE_BUFFERSIZE;
+	job->dd_data = job + 1;
+
+	job->request_len = hdr->request_len;
+	job->request = memdup_user(uptr64(hdr->request), hdr->request_len);
+	if (IS_ERR(job->request)) {
+		ret = PTR_ERR(job->request);
+		goto out_free_rq;
+	}
+
+	if (hdr->dout_xfer_len && hdr->din_xfer_len) {
+		job->bidi_rq = blk_mq_alloc_request(rq->q, REQ_OP_DRV_IN, 0);
+		if (IS_ERR(job->bidi_rq)) {
+			ret = PTR_ERR(job->bidi_rq);
+			goto out_free_job_request;
+		}
+
+		ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL,
+				uptr64(hdr->din_xferp), hdr->din_xfer_len,
+				GFP_KERNEL);
+		if (ret)
+			goto out_free_bidi_rq;
+
+		job->bidi_bio = job->bidi_rq->bio;
+	} else {
+		job->bidi_rq = NULL;
+		job->bidi_bio = NULL;
+	}
+
+	ret = 0;
+	if (hdr->dout_xfer_len) {
+		ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp),
+				hdr->dout_xfer_len, GFP_KERNEL);
+	} else if (hdr->din_xfer_len) {
+		ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp),
+				hdr->din_xfer_len, GFP_KERNEL);
+	}
+
+	if (ret)
+		goto out_unmap_bidi_rq;
+
+	bio = rq->bio;
+	blk_execute_rq(rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL));
+
+	/*
+	 * The assignments below don't make much sense, but are kept for
+	 * bug by bug backwards compatibility:
+	 */
+	hdr->device_status = job->result & 0xff;
+	hdr->transport_status = host_byte(job->result);
+	hdr->driver_status = 0;
+	hdr->info = 0;
+	if (hdr->device_status || hdr->transport_status || hdr->driver_status)
+		hdr->info |= SG_INFO_CHECK;
+	hdr->response_len = 0;
+
+	if (job->result < 0) {
+		/* we're only returning the result field in the reply */
+		job->reply_len = sizeof(u32);
+		ret = job->result;
+	}
+
+	if (job->reply_len && hdr->response) {
+		int len = min(hdr->max_response_len, job->reply_len);
+
+		if (copy_to_user(uptr64(hdr->response), job->reply, len))
+			ret = -EFAULT;
+		else
+			hdr->response_len = len;
+	}
+
+	/* we assume all request payload was transferred, residual == 0 */
+	hdr->dout_resid = 0;
+
+	if (job->bidi_rq) {
+		unsigned int rsp_len = job->reply_payload.payload_len;
+
+		if (WARN_ON(job->reply_payload_rcv_len > rsp_len))
+			hdr->din_resid = 0;
+		else
+			hdr->din_resid = rsp_len - job->reply_payload_rcv_len;
+	} else {
+		hdr->din_resid = 0;
+	}
+
+	blk_rq_unmap_user(bio);
+out_unmap_bidi_rq:
+	if (job->bidi_rq)
+		blk_rq_unmap_user(job->bidi_bio);
+out_free_bidi_rq:
+	if (job->bidi_rq)
+		blk_mq_free_request(job->bidi_rq);
+out_free_job_request:
+	kfree(job->request);
+out_free_rq:
+	blk_mq_free_request(rq);
+	return ret;
+}
 
 /**
- * bsg_destroy_job - routine to teardown/delete a bsg job
- * @job: bsg_job that is to be torn down
+ * bsg_teardown_job - routine to teardown a bsg job
+ * @kref: kref inside bsg_job that is to be torn down
  */
-static void bsg_destroy_job(struct bsg_job *job)
+static void bsg_teardown_job(struct kref *kref)
 {
+	struct bsg_job *job = container_of(kref, struct bsg_job, kref);
+	struct request *rq = blk_mq_rq_from_pdu(job);
+
 	put_device(job->dev);	/* release reference for the request */
 
 	kfree(job->request_payload.sg_list);
 	kfree(job->reply_payload.sg_list);
-	kfree(job);
+
+	blk_mq_end_request(rq, BLK_STS_OK);
+}
+
+void bsg_job_put(struct bsg_job *job)
+{
+	kref_put(&job->kref, bsg_teardown_job);
+}
+EXPORT_SYMBOL_GPL(bsg_job_put);
+
+int bsg_job_get(struct bsg_job *job)
+{
+	return kref_get_unless_zero(&job->kref);
 }
+EXPORT_SYMBOL_GPL(bsg_job_get);
 
 /**
  * bsg_job_done - completion routine for bsg requests
@@ -52,39 +189,24 @@ static void bsg_destroy_job(struct bsg_job *job)
 void bsg_job_done(struct bsg_job *job, int result,
 		  unsigned int reply_payload_rcv_len)
 {
-	struct request *req = job->req;
-	struct request *rsp = req->next_rq;
-	int err;
-
-	err = job->req->errors = result;
-	if (err < 0)
-		/* we're only returning the result field in the reply */
-		job->req->sense_len = sizeof(u32);
-	else
-		job->req->sense_len = job->reply_len;
-	/* we assume all request payload was transferred, residual == 0 */
-	req->resid_len = 0;
-
-	if (rsp) {
-		WARN_ON(reply_payload_rcv_len > rsp->resid_len);
+	struct request *rq = blk_mq_rq_from_pdu(job);
 
-		/* set reply (bidi) residual */
-		rsp->resid_len -= min(reply_payload_rcv_len, rsp->resid_len);
-	}
-	blk_complete_request(req);
+	job->result = result;
+	job->reply_payload_rcv_len = reply_payload_rcv_len;
+	if (likely(!blk_should_fake_timeout(rq->q)))
+		blk_mq_complete_request(rq);
 }
 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 = rq->special;
+	struct bsg_job *job = blk_mq_rq_to_pdu(rq);
 
-	blk_end_request_all(rq, rq->errors);
-	bsg_destroy_job(job);
+	bsg_job_put(job);
 }
 
 static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
@@ -93,140 +215,198 @@ static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
 
 	BUG_ON(!req->nr_phys_segments);
 
-	buf->sg_list = kzalloc(sz, GFP_KERNEL);
+	buf->sg_list = kmalloc(sz, GFP_KERNEL);
 	if (!buf->sg_list)
 		return -ENOMEM;
 	sg_init_table(buf->sg_list, req->nr_phys_segments);
-	buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
+	buf->sg_cnt = blk_rq_map_sg(req, buf->sg_list);
 	buf->payload_len = blk_rq_bytes(req);
 	return 0;
 }
 
 /**
- * bsg_create_job - create the bsg_job structure for the bsg request
+ * bsg_prepare_job - create the bsg_job structure for the bsg request
  * @dev: device that is being sent the bsg request
  * @req: BSG request that needs a job structure
  */
-static int bsg_create_job(struct device *dev, struct request *req)
+static bool bsg_prepare_job(struct device *dev, struct request *req)
 {
-	struct request *rsp = req->next_rq;
-	struct request_queue *q = req->q;
-	struct bsg_job *job;
+	struct bsg_job *job = blk_mq_rq_to_pdu(req);
 	int ret;
 
-	BUG_ON(req->special);
-
-	job = kzalloc(sizeof(struct bsg_job) + q->bsg_job_size, GFP_KERNEL);
-	if (!job)
-		return -ENOMEM;
+	job->timeout = req->timeout;
 
-	req->special = job;
-	job->req = req;
-	if (q->bsg_job_size)
-		job->dd_data = (void *)&job[1];
-	job->request = req->cmd;
-	job->request_len = req->cmd_len;
-	job->reply = req->sense;
-	job->reply_len = SCSI_SENSE_BUFFERSIZE;	/* Size of sense buffer
-						 * allocated */
 	if (req->bio) {
 		ret = bsg_map_buffer(&job->request_payload, req);
 		if (ret)
 			goto failjob_rls_job;
 	}
-	if (rsp && rsp->bio) {
-		ret = bsg_map_buffer(&job->reply_payload, rsp);
+	if (job->bidi_rq) {
+		ret = bsg_map_buffer(&job->reply_payload, job->bidi_rq);
 		if (ret)
 			goto failjob_rls_rqst_payload;
 	}
 	job->dev = dev;
 	/* take a reference for the request */
 	get_device(job->dev);
-	return 0;
+	kref_init(&job->kref);
+	return true;
 
 failjob_rls_rqst_payload:
 	kfree(job->request_payload.sg_list);
 failjob_rls_job:
-	kfree(job);
-	return -ENOMEM;
+	job->result = -ENOMEM;
+	return false;
 }
 
 /**
- * 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 the req->errors.
+ * that will be set to ->result.
  *
  * Drivers/subsys should pass this to the queue init function.
  */
-void bsg_request_fn(struct request_queue *q)
+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 bsg_job *job;
+	struct request *req = bd->rq;
+	struct bsg_set *bset =
+		container_of(q->tag_set, struct bsg_set, tag_set);
+	blk_status_t sts = BLK_STS_IOERR;
 	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);
-
-		ret = bsg_create_job(dev, req);
-		if (ret) {
-			req->errors = ret;
-			blk_end_request_all(req, ret);
-			spin_lock_irq(q->queue_lock);
-			continue;
-		}
+		return BLK_STS_IOERR;
 
-		job = req->special;
-		ret = q->bsg_job_fn(job);
-		spin_lock_irq(q->queue_lock);
-		if (ret)
-			break;
-	}
+	if (!bsg_prepare_job(dev, req))
+		goto out;
+
+	ret = bset->job_fn(blk_mq_rq_to_pdu(req));
+	if (!ret)
+		sts = BLK_STS_OK;
 
-	spin_unlock_irq(q->queue_lock);
+out:
 	put_device(dev);
-	spin_lock_irq(q->queue_lock);
+	return sts;
+}
+
+/* called right after the request is allocated for the request_queue */
+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_KERNEL);
+	if (!job->reply)
+		return -ENOMEM;
+	return 0;
 }
-EXPORT_SYMBOL_GPL(bsg_request_fn);
+
+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);
+
+	kfree(job->reply);
+}
+
+void bsg_remove_queue(struct request_queue *q)
+{
+	if (q) {
+		struct bsg_set *bset =
+			container_of(q->tag_set, struct bsg_set, tag_set);
+
+		bsg_unregister_queue(bset->bd);
+		blk_mq_destroy_queue(q);
+		blk_put_queue(q);
+		blk_mq_free_tag_set(&bset->tag_set);
+		kfree(bset);
+	}
+}
+EXPORT_SYMBOL_GPL(bsg_remove_queue);
+
+static enum blk_eh_timer_return bsg_timeout(struct request *rq)
+{
+	struct bsg_set *bset =
+		container_of(rq->q->tag_set, struct bsg_set, tag_set);
+
+	if (!bset->timeout_fn)
+		return BLK_EH_DONE;
+	return bset->timeout_fn(rq);
+}
+
+static const struct blk_mq_ops bsg_mq_ops = {
+	.queue_rq		= bsg_queue_rq,
+	.init_request		= bsg_init_rq,
+	.exit_request		= bsg_exit_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
- * @q: request queue setup by caller
  * @name: device to give bsg device
+ * @lim: queue limits for the bsg queue
  * @job_fn: bsg job handler
+ * @timeout: timeout handler function pointer
  * @dd_job_size: size of LLD data needed for each job
- *
- * The caller should have setup the reuqest queue with bsg_request_fn
- * as the request_fn.
  */
-int bsg_setup_queue(struct device *dev, struct request_queue *q,
-		    char *name, bsg_job_fn *job_fn, int dd_job_size)
+struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
+		struct queue_limits *lim, bsg_job_fn *job_fn,
+		bsg_timeout_fn *timeout, int dd_job_size)
 {
-	int ret;
+	struct bsg_set *bset;
+	struct blk_mq_tag_set *set;
+	struct request_queue *q;
+	int ret = -ENOMEM;
+
+	bset = kzalloc(sizeof(*bset), GFP_KERNEL);
+	if (!bset)
+		return ERR_PTR(-ENOMEM);
+
+	bset->job_fn = job_fn;
+	bset->timeout_fn = timeout;
+
+	set = &bset->tag_set;
+	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_BLOCKING;
+	if (blk_mq_alloc_tag_set(set))
+		goto out_tag_set;
+
+	q = blk_mq_alloc_queue(set, lim, dev);
+	if (IS_ERR(q)) {
+		ret = PTR_ERR(q);
+		goto out_queue;
+	}
 
-	q->queuedata = dev;
-	q->bsg_job_size = dd_job_size;
-	q->bsg_job_fn = job_fn;
-	queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);
-	blk_queue_softirq_done(q, bsg_softirq_done);
 	blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
 
-	ret = bsg_register_queue(q, dev, name, NULL);
-	if (ret) {
-		printk(KERN_ERR "%s: bsg interface failed to "
-		       "initialize - register queue\n", dev->kobj.name);
-		return ret;
+	bset->bd = bsg_register_queue(q, dev, name, bsg_transport_sg_io_fn);
+	if (IS_ERR(bset->bd)) {
+		ret = PTR_ERR(bset->bd);
+		goto out_cleanup_queue;
 	}
 
-	return 0;
+	return q;
+out_cleanup_queue:
+	blk_mq_destroy_queue(q);
+	blk_put_queue(q);
+out_queue:
+	blk_mq_free_tag_set(set);
+out_tag_set:
+	kfree(bset);
+	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(bsg_setup_queue);