drivers/scsi/scsi_bsg.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <linux/bsg.h>
0003 #include <scsi/scsi.h>
0004 #include <scsi/scsi_ioctl.h>
0005 #include <scsi/scsi_cmnd.h>
0006 #include <scsi/scsi_device.h>
0007 #include <scsi/sg.h>
0008 #include "scsi_priv.h"
0009
0010 #define uptr64(val) ((void __user *)(uintptr_t)(val))
0011
0012 static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
0013         fmode_t mode, unsigned int timeout)
0014 {
0015     struct scsi_cmnd *scmd;
0016     struct request *rq;
0017     struct bio *bio;
0018     int ret;
0019
0020     if (hdr->protocol != BSG_PROTOCOL_SCSI  ||
0021         hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_CMD)
0022         return -EINVAL;
0023     if (hdr->dout_xfer_len && hdr->din_xfer_len) {
0024         pr_warn_once("BIDI support in bsg has been removed.\n");
0025         return -EOPNOTSUPP;
0026     }
0027
0028     rq = scsi_alloc_request(q, hdr->dout_xfer_len ?
0029                 REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
0030     if (IS_ERR(rq))
0031         return PTR_ERR(rq);
0032     rq->timeout = timeout;
0033
0034     scmd = blk_mq_rq_to_pdu(rq);
0035     scmd->cmd_len = hdr->request_len;
0036     if (scmd->cmd_len > sizeof(scmd->cmnd)) {
0037         ret = -EINVAL;
0038         goto out_put_request;
0039     }
0040
0041     ret = -EFAULT;
0042     if (copy_from_user(scmd->cmnd, uptr64(hdr->request), scmd->cmd_len))
0043         goto out_put_request;
0044     ret = -EPERM;
0045     if (!scsi_cmd_allowed(scmd->cmnd, mode))
0046         goto out_put_request;
0047
0048     ret = 0;
0049     if (hdr->dout_xfer_len) {
0050         ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp),
0051                 hdr->dout_xfer_len, GFP_KERNEL);
0052     } else if (hdr->din_xfer_len) {
0053         ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp),
0054                 hdr->din_xfer_len, GFP_KERNEL);
0055     }
0056
0057     if (ret)
0058         goto out_put_request;
0059
0060     bio = rq->bio;
0061     blk_execute_rq(rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL));
0062
0063     /*
0064      * fill in all the output members
0065      */
0066     hdr->device_status = scmd->result & 0xff;
0067     hdr->transport_status = host_byte(scmd->result);
0068     hdr->driver_status = 0;
0069     if (scsi_status_is_check_condition(scmd->result))
0070         hdr->driver_status = DRIVER_SENSE;
0071     hdr->info = 0;
0072     if (hdr->device_status || hdr->transport_status || hdr->driver_status)
0073         hdr->info |= SG_INFO_CHECK;
0074     hdr->response_len = 0;
0075
0076     if (scmd->sense_len && hdr->response) {
0077         int len = min_t(unsigned int, hdr->max_response_len,
0078                 scmd->sense_len);
0079
0080         if (copy_to_user(uptr64(hdr->response), scmd->sense_buffer,
0081                  len))
0082             ret = -EFAULT;
0083         else
0084             hdr->response_len = len;
0085     }
0086
0087     if (rq_data_dir(rq) == READ)
0088         hdr->din_resid = scmd->resid_len;
0089     else
0090         hdr->dout_resid = scmd->resid_len;
0091
0092     blk_rq_unmap_user(bio);
0093
0094 out_put_request:
0095     blk_mq_free_request(rq);
0096     return ret;
0097 }
0098
0099 struct bsg_device *scsi_bsg_register_queue(struct scsi_device *sdev)
0100 {
0101     return bsg_register_queue(sdev->request_queue, &sdev->sdev_gendev,
0102             dev_name(&sdev->sdev_gendev), scsi_bsg_sg_io_fn);
0103 }