drivers/scsi/scsi_bsg.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/bsg.h>
   3 #include <scsi/scsi.h>
   4 #include <scsi/scsi_ioctl.h>
   5 #include <scsi/scsi_cmnd.h>
   6 #include <scsi/scsi_device.h>
   7 #include <scsi/sg.h>
   8 #include "scsi_priv.h"
   9
  10 #define uptr64(val) ((void __user *)(uintptr_t)(val))
  11
  12 static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
  13                 fmode_t mode, unsigned int timeout)
  14 {
  15         struct scsi_request *sreq;
  16         struct request *rq;
  17         struct bio *bio;
  18         int ret;
  19
  20         if (hdr->protocol != BSG_PROTOCOL_SCSI  ||
  21             hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_CMD)
  22                 return -EINVAL;
  23         if (hdr->dout_xfer_len && hdr->din_xfer_len) {
  24                 pr_warn_once("BIDI support in bsg has been removed.\n");
  25                 return -EOPNOTSUPP;
  26         }
  27
  28         rq = blk_get_request(q, hdr->dout_xfer_len ?
  29                              REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
  30         if (IS_ERR(rq))
  31                 return PTR_ERR(rq);
  32         rq->timeout = timeout;
  33
  34         ret = -ENOMEM;
  35         sreq = scsi_req(rq);
  36         sreq->cmd_len = hdr->request_len;
  37         if (sreq->cmd_len > BLK_MAX_CDB) {
  38                 sreq->cmd = kzalloc(sreq->cmd_len, GFP_KERNEL);
  39                 if (!sreq->cmd)
  40                         goto out_put_request;
  41         }
  42
  43         ret = -EFAULT;
  44         if (copy_from_user(sreq->cmd, uptr64(hdr->request), sreq->cmd_len))
  45                 goto out_free_cmd;
  46         ret = -EPERM;
  47         if (!scsi_cmd_allowed(sreq->cmd, mode))
  48                 goto out_free_cmd;
  49
  50         ret = 0;
  51         if (hdr->dout_xfer_len) {
  52                 ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp),
  53                                 hdr->dout_xfer_len, GFP_KERNEL);
  54         } else if (hdr->din_xfer_len) {
  55                 ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp),
  56                                 hdr->din_xfer_len, GFP_KERNEL);
  57         }
  58
  59         if (ret)
  60                 goto out_free_cmd;
  61
  62         bio = rq->bio;
  63         blk_execute_rq(NULL, rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL));
  64
  65         /*
  66          * fill in all the output members
  67          */
  68         hdr->device_status = sreq->result & 0xff;
  69         hdr->transport_status = host_byte(sreq->result);
  70         hdr->driver_status = 0;
  71         if (scsi_status_is_check_condition(sreq->result))
  72                 hdr->driver_status = DRIVER_SENSE;
  73         hdr->info = 0;
  74         if (hdr->device_status || hdr->transport_status || hdr->driver_status)
  75                 hdr->info |= SG_INFO_CHECK;
  76         hdr->response_len = 0;
  77
  78         if (sreq->sense_len && hdr->response) {
  79                 int len = min_t(unsigned int, hdr->max_response_len,
  80                                         sreq->sense_len);
  81
  82                 if (copy_to_user(uptr64(hdr->response), sreq->sense, len))
  83                         ret = -EFAULT;
  84                 else
  85                         hdr->response_len = len;
  86         }
  87
  88         if (rq_data_dir(rq) == READ)
  89                 hdr->din_resid = sreq->resid_len;
  90         else
  91                 hdr->dout_resid = sreq->resid_len;
  92
  93         blk_rq_unmap_user(bio);
  94
  95 out_free_cmd:
  96         scsi_req_free_cmd(scsi_req(rq));
  97 out_put_request:
  98         blk_put_request(rq);
  99         return ret;
 100 }
 101
 102 struct bsg_device *scsi_bsg_register_queue(struct scsi_device *sdev)
 103 {
 104         return bsg_register_queue(sdev->request_queue, &sdev->sdev_gendev,
 105                         dev_name(&sdev->sdev_gendev), scsi_bsg_sg_io_fn);
 106 }