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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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#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; unsigned int reply_len;};
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_set *bset = container_of(q->tag_set, struct bsg_set, tag_set); 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 = bset->reply_len; 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_teardown_job - routine to teardown a bsg job * @kref: kref inside bsg_job that is to be torn down */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);
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 * @job: bsg_job that is complete * @result: job reply result * @reply_payload_rcv_len: length of payload recvd * * The LLD should call this when the bsg job has completed. */void bsg_job_done(struct bsg_job *job, int result, unsigned int reply_payload_rcv_len){ struct request *rq = blk_mq_rq_from_pdu(job);
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_complete - softirq done routine for destroying the bsg requests * @rq: BSG request that holds the job to be destroyed */static void bsg_complete(struct request *rq){ struct bsg_job *job = blk_mq_rq_to_pdu(rq);
bsg_job_put(job);}
static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req){ size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
BUG_ON(!req->nr_phys_segments);
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, buf->sg_list); buf->payload_len = blk_rq_bytes(req); return 0;}
/** * 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 bool bsg_prepare_job(struct device *dev, struct request *req){ struct bsg_job *job = blk_mq_rq_to_pdu(req); int ret;
job->timeout = req->timeout;
if (req->bio) { ret = bsg_map_buffer(&job->request_payload, req); if (ret) goto failjob_rls_job; } 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); kref_init(&job->kref); return true;
failjob_rls_rqst_payload: kfree(job->request_payload.sg_list);failjob_rls_job: job->result = -ENOMEM; return false;}
/** * 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 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 = 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 BLK_STS_IOERR;
if (!bsg_prepare_job(dev, req)) goto out;
ret = bset->job_fn(blk_mq_rq_to_pdu(req)); if (!ret) sts = BLK_STS_OK;
out: put_device(dev); 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, int numa_node){ struct bsg_set *bset = container_of(set, struct bsg_set, tag_set); struct bsg_job *job = blk_mq_rq_to_pdu(req);
job->reply = kzalloc(bset->reply_len, GFP_KERNEL); if (!job->reply) return -ENOMEM; return 0;}
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 * @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 * @reply_len: size of the reply buffer needed for each job */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, unsigned int reply_len){ struct bsg_set *bset; struct blk_mq_tag_set *set; struct request_queue *q; int ret = -ENOMEM;
bset = kzalloc_obj(*bset); if (!bset) return ERR_PTR(-ENOMEM);
bset->job_fn = job_fn; bset->timeout_fn = timeout; bset->reply_len = reply_len;
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; }
blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
bset->bd = bsg_register_queue(q, dev, name, bsg_transport_sg_io_fn, NULL); if (IS_ERR(bset->bd)) { ret = PTR_ERR(bset->bd); goto out_cleanup_queue; }
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);