scsi: add a scsi_alloc_request helper

Add a new helper that calls blk_get_request and initializes the
scsi_request to avoid the indirect call through ->.initialize_rq_fn.

Note that this makes the pktcdvd driver depend on the SCSI core, but
given that only SCSI devices support SCSI passthrough requests that
is not a functional change.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20211021060607.264371-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index ab3e37a..9151e8f 100644 (file)
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -304,8 +304,8 @@ config BLK_DEV_RAM_SIZE
 config CDROM_PKTCDVD
        tristate "Packet writing on CD/DVD media (DEPRECATED)"
        depends on !UML
+       depends on SCSI
        select CDROM
-       select SCSI_COMMON
        help
          Note: This driver is deprecated and will be removed from the
          kernel in the near future!

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index cb52cce..ea2262e 100644 (file)
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -703,7 +703,7 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
        struct request *rq;
        int ret = 0;
 
-       rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
+       rq = scsi_alloc_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
                             REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
        if (IS_ERR(rq))
                return PTR_ERR(rq);

diff --git a/drivers/scsi/scsi_bsg.c b/drivers/scsi/scsi_bsg.c
index 81c3853..551727a 100644 (file)
--- a/drivers/scsi/scsi_bsg.c
+++ b/drivers/scsi/scsi_bsg.c
@@ -25,8 +25,8 @@ static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
                return -EOPNOTSUPP;
        }
 
-       rq = blk_get_request(q, hdr->dout_xfer_len ?
-                            REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
+       rq = scsi_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;

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index b6c86cc..71d027b 100644 (file)
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1998,7 +1998,7 @@ static void scsi_eh_lock_door(struct scsi_device *sdev)
        struct request *req;
        struct scsi_request *rq;
 
-       req = blk_get_request(sdev->request_queue, REQ_OP_DRV_IN, 0);
+       req = scsi_alloc_request(sdev->request_queue, REQ_OP_DRV_IN, 0);
        if (IS_ERR(req))
                return;
        rq = scsi_req(req);

diff --git a/drivers/scsi/scsi_ioctl.c b/drivers/scsi/scsi_ioctl.c
index 6ff2207..0078975 100644 (file)
--- a/drivers/scsi/scsi_ioctl.c
+++ b/drivers/scsi/scsi_ioctl.c
@@ -438,7 +438,7 @@ static int sg_io(struct scsi_device *sdev, struct gendisk *disk,
                at_head = 1;
 
        ret = -ENOMEM;
-       rq = blk_get_request(sdev->request_queue, writing ?
+       rq = scsi_alloc_request(sdev->request_queue, writing ?
                             REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
        if (IS_ERR(rq))
                return PTR_ERR(rq);
@@ -561,7 +561,7 @@ static int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk,
 
        }
 
-       rq = blk_get_request(q, in_len ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
+       rq = scsi_alloc_request(q, in_len ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
        if (IS_ERR(rq)) {
                err = PTR_ERR(rq);
                goto error_free_buffer;

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 30f7d0b..a0f801f 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -216,7 +216,7 @@ int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
        struct scsi_request *rq;
        int ret;
 
-       req = blk_get_request(sdev->request_queue,
+       req = scsi_alloc_request(sdev->request_queue,
                        data_direction == DMA_TO_DEVICE ?
                        REQ_OP_DRV_OUT : REQ_OP_DRV_IN,
                        rq_flags & RQF_PM ? BLK_MQ_REQ_PM : 0);
@@ -1079,9 +1079,6 @@ EXPORT_SYMBOL(scsi_alloc_sgtables);
  * This function initializes the members of struct scsi_cmnd that must be
  * initialized before request processing starts and that won't be
  * reinitialized if a SCSI command is requeued.
- *
- * Called from inside blk_get_request() for pass-through requests and from
- * inside scsi_init_command() for filesystem requests.
  */
 static void scsi_initialize_rq(struct request *rq)
 {
@@ -1098,6 +1095,18 @@ static void scsi_initialize_rq(struct request *rq)
        cmd->retries = 0;
 }
 
+struct request *scsi_alloc_request(struct request_queue *q,
+               unsigned int op, blk_mq_req_flags_t flags)
+{
+       struct request *rq;
+
+       rq = blk_get_request(q, op, flags);
+       if (!IS_ERR(rq))
+               scsi_initialize_rq(rq);
+       return rq;
+}
+EXPORT_SYMBOL_GPL(scsi_alloc_request);
+
 /*
  * Only called when the request isn't completed by SCSI, and not freed by
  * SCSI
@@ -1864,7 +1873,6 @@ static const struct blk_mq_ops scsi_mq_ops_no_commit = {
 #endif
        .init_request   = scsi_mq_init_request,
        .exit_request   = scsi_mq_exit_request,
-       .initialize_rq_fn = scsi_initialize_rq,
        .cleanup_rq     = scsi_cleanup_rq,
        .busy           = scsi_mq_lld_busy,
        .map_queues     = scsi_map_queues,
@@ -1894,7 +1902,6 @@ static const struct blk_mq_ops scsi_mq_ops = {
 #endif
        .init_request   = scsi_mq_init_request,
        .exit_request   = scsi_mq_exit_request,
-       .initialize_rq_fn = scsi_initialize_rq,
        .cleanup_rq     = scsi_cleanup_rq,
        .busy           = scsi_mq_lld_busy,
        .map_queues     = scsi_map_queues,

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 3c98f08..85f57ac 100644 (file)
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1718,13 +1718,13 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
         *
         * With scsi-mq enabled, there are a fixed number of preallocated
         * requests equal in number to shost->can_queue.  If all of the
-        * preallocated requests are already in use, then blk_get_request()
+        * preallocated requests are already in use, then scsi_alloc_request()
         * will sleep until an active command completes, freeing up a request.
         * Although waiting in an asynchronous interface is less than ideal, we
         * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
         * not expect an EWOULDBLOCK from this condition.
         */
-       rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
+       rq = scsi_alloc_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
                        REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
        if (IS_ERR(rq)) {
                kfree(long_cmdp);

diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 115f7ef..7c4d9a9 100644 (file)
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -967,7 +967,7 @@ static int sr_read_cdda_bpc(struct cdrom_device_info *cdi, void __user *ubuf,
        struct bio *bio;
        int ret;
 
-       rq = blk_get_request(disk->queue, REQ_OP_DRV_IN, 0);
+       rq = scsi_alloc_request(disk->queue, REQ_OP_DRV_IN, 0);
        if (IS_ERR(rq))
                return PTR_ERR(rq);
        req = scsi_req(rq);

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 9933722..1275299 100644 (file)
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -543,7 +543,7 @@ static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
        int err = 0;
        struct scsi_tape *STp = SRpnt->stp;
 
-       req = blk_get_request(SRpnt->stp->device->request_queue,
+       req = scsi_alloc_request(SRpnt->stp->device->request_queue,
                        data_direction == DMA_TO_DEVICE ?
                        REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
        if (IS_ERR(req))

diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 75ef52f..b5705a2 100644 (file)
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -980,11 +980,10 @@ pscsi_execute_cmd(struct se_cmd *cmd)
        memcpy(pt->pscsi_cdb, cmd->t_task_cdb,
                scsi_command_size(cmd->t_task_cdb));
 
-       req = blk_get_request(pdv->pdv_sd->request_queue,
+       req = scsi_alloc_request(pdv->pdv_sd->request_queue,
                        cmd->data_direction == DMA_TO_DEVICE ?
                        REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
        if (IS_ERR(req)) {
-               pr_err("PSCSI: blk_get_request() failed\n");
                ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
                goto fail;
        }

diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index eaf04c9..3107806 100644 (file)
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -396,4 +396,7 @@ static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
                             u8 key, u8 asc, u8 ascq);
 
+struct request *scsi_alloc_request(struct request_queue *q,
+               unsigned int op, blk_mq_req_flags_t flags);
+
 #endif /* _SCSI_SCSI_CMND_H */