block: add blk_rq_set_block_pc()

With the optimizations around not clearing the full request at alloc
time, we are leaving some of the needed init for REQ_TYPE_BLOCK_PC
up to the user allocating the request.

Add a blk_rq_set_block_pc() that sets the command type to
REQ_TYPE_BLOCK_PC, and properly initializes the members associated
with this type of request. Update callers to use this function instead
of manipulating rq->cmd_type directly.

Includes fixes from Christoph Hellwig <hch@lst.de> for my half-assed
attempt.

Signed-off-by: Jens Axboe <axboe@fb.com>

17 files changed, 41 insertions, 20 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 40d654861c33..9aca8c71e70b 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1218,6 +1218,8 @@ struct request *blk_make_request(struct request_queue *q, struct bio *bio,
         if (unlikely(!rq))
                 return ERR_PTR(-ENOMEM);
 
+        blk_rq_set_block_pc(rq);
+
         for_each_bio(bio) {
                 struct bio *bounce_bio = bio;
                 int ret;
@@ -1235,6 +1237,22 @@ struct request *blk_make_request(struct request_queue *q, struct bio *bio,
 EXPORT_SYMBOL(blk_make_request);
 
 /**
+ * blk_rq_set_block_pc - initialize a requeest to type BLOCK_PC
+ * @rq:         request to be initialized
+ *
+ */
+void blk_rq_set_block_pc(struct request *rq)
+{
+        rq->cmd_type = REQ_TYPE_BLOCK_PC;
+        rq->__data_len = 0;
+        rq->__sector = (sector_t) -1;
+        rq->bio = rq->biotail = NULL;
+        memset(rq->__cmd, 0, sizeof(rq->__cmd));
+        rq->cmd = rq->__cmd;
+}
+EXPORT_SYMBOL(blk_rq_set_block_pc);
+
+/**
  * blk_requeue_request - put a request back on queue
  * @q:          request queue where request should be inserted
  * @rq:         request to be inserted
diff --git a/block/bsg.c b/block/bsg.c
index e5214c148096..ff46addde5d8 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -196,7 +196,6 @@ static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
          * fill in request structure
          */
         rq->cmd_len = hdr->request_len;
-        rq->cmd_type = REQ_TYPE_BLOCK_PC;
 
         rq->timeout = msecs_to_jiffies(hdr->timeout);
         if (!rq->timeout)
@@ -273,6 +272,8 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
         rq = blk_get_request(q, rw, GFP_KERNEL);
         if (!rq)
                 return ERR_PTR(-ENOMEM);
+        blk_rq_set_block_pc(rq);
+
         ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
         if (ret)
                 goto out;
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 9c28a5b38042..14695c6221c8 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -229,7 +229,6 @@ static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
          * fill in request structure
          */
         rq->cmd_len = hdr->cmd_len;
-        rq->cmd_type = REQ_TYPE_BLOCK_PC;
 
         rq->timeout = msecs_to_jiffies(hdr->timeout);
         if (!rq->timeout)
@@ -311,6 +310,7 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
         rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
         if (!rq)
                 return -ENOMEM;
+        blk_rq_set_block_pc(rq);
 
         if (blk_fill_sghdr_rq(q, rq, hdr, mode)) {
                 blk_put_request(rq);
@@ -491,7 +491,7 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
         memset(sense, 0, sizeof(sense));
         rq->sense = sense;
         rq->sense_len = 0;
-        rq->cmd_type = REQ_TYPE_BLOCK_PC;
+        blk_rq_set_block_pc(rq);
 
         blk_execute_rq(q, disk, rq, 0);
 
@@ -524,7 +524,7 @@ static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
         int err;
 
         rq = blk_get_request(q, WRITE, __GFP_WAIT);
-        rq->cmd_type = REQ_TYPE_BLOCK_PC;
+        blk_rq_set_block_pc(rq);
         rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
         rq->cmd[0] = cmd;
         rq->cmd[4] = data;
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index ef166ad2dbad..758ac442c5b5 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -704,6 +704,7 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
 
         rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
                              WRITE : READ, __GFP_WAIT);
+        blk_rq_set_block_pc(rq);
 
         if (cgc->buflen) {
                 ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
@@ -716,7 +717,6 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
         memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
 
         rq->timeout = 60*HZ;
-        rq->cmd_type = REQ_TYPE_BLOCK_PC;
         if (cgc->quiet)
                 rq->cmd_flags |= REQ_QUIET;
 
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 49ac5662585b..0f40c95049c0 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2184,6 +2184,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
                         ret = -ENOMEM;
                         break;
                 }
+                blk_rq_set_block_pc(rq);
 
                 ret = blk_rq_map_user(q, rq, NULL, ubuf, len, GFP_KERNEL);
                 if (ret) {
@@ -2203,7 +2204,6 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
                 rq->cmd[9] = 0xf8;
 
                 rq->cmd_len = 12;
-                rq->cmd_type = REQ_TYPE_BLOCK_PC;
                 rq->timeout = 60 * HZ;
                 bio = rq->bio;
 
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 5248c888552b..7bcf67eec921 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -120,6 +120,7 @@ static struct request *get_alua_req(struct scsi_device *sdev,
                             "%s: blk_get_request failed\n", __func__);
                 return NULL;
         }
+        blk_rq_set_block_pc(rq);
 
         if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
                 blk_put_request(rq);
@@ -128,7 +129,6 @@ static struct request *get_alua_req(struct scsi_device *sdev,
                 return NULL;
         }
 
-        rq->cmd_type = REQ_TYPE_BLOCK_PC;
         rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
                          REQ_FAILFAST_DRIVER;
         rq->retries = ALUA_FAILOVER_RETRIES;
diff --git a/drivers/scsi/device_handler/scsi_dh_emc.c b/drivers/scsi/device_handler/scsi_dh_emc.c
index e1c8be06de9d..6f07f7fe3aa1 100644
--- a/drivers/scsi/device_handler/scsi_dh_emc.c
+++ b/drivers/scsi/device_handler/scsi_dh_emc.c
@@ -280,6 +280,7 @@ static struct request *get_req(struct scsi_device *sdev, int cmd,
                 return NULL;
         }
 
+        blk_rq_set_block_pc(rq);
         rq->cmd_len = COMMAND_SIZE(cmd);
         rq->cmd[0] = cmd;
 
@@ -304,7 +305,6 @@ static struct request *get_req(struct scsi_device *sdev, int cmd,
                 break;
         }
 
-        rq->cmd_type = REQ_TYPE_BLOCK_PC;
         rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
                          REQ_FAILFAST_DRIVER;
         rq->timeout = CLARIION_TIMEOUT;
diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
index 084062bb8ee9..e9d9fea9e272 100644
--- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c
+++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
@@ -120,7 +120,7 @@ retry:
         if (!req)
                 return SCSI_DH_RES_TEMP_UNAVAIL;
 
-        req->cmd_type = REQ_TYPE_BLOCK_PC;
+        blk_rq_set_block_pc(req);
         req->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
                           REQ_FAILFAST_DRIVER;
         req->cmd_len = COMMAND_SIZE(TEST_UNIT_READY);
@@ -250,7 +250,7 @@ static int hp_sw_start_stop(struct hp_sw_dh_data *h)
         if (!req)
                 return SCSI_DH_RES_TEMP_UNAVAIL;
 
-        req->cmd_type = REQ_TYPE_BLOCK_PC;
+        blk_rq_set_block_pc(req);
         req->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
                           REQ_FAILFAST_DRIVER;
         req->cmd_len = COMMAND_SIZE(START_STOP);
diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
index 4b9cf93f3fb6..826069db9848 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -279,6 +279,7 @@ static struct request *get_rdac_req(struct scsi_device *sdev,
                                 "get_rdac_req: blk_get_request failed.\n");
                 return NULL;
         }
+        blk_rq_set_block_pc(rq);
 
         if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
                 blk_put_request(rq);
@@ -287,7 +288,6 @@ static struct request *get_rdac_req(struct scsi_device *sdev,
                 return NULL;
         }
 
-        rq->cmd_type = REQ_TYPE_BLOCK_PC;
         rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
                          REQ_FAILFAST_DRIVER;
         rq->retries = RDAC_RETRIES;
diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
index bac04c2335aa..5f4cbf0c4759 100644
--- a/drivers/scsi/osd/osd_initiator.c
+++ b/drivers/scsi/osd/osd_initiator.c
@@ -1570,6 +1570,7 @@ static struct request *_make_request(struct request_queue *q, bool has_write,
                 if (unlikely(!req))
                         return ERR_PTR(-ENOMEM);
 
+                blk_rq_set_block_pc(req);
                 return req;
         }
 }
@@ -1590,7 +1591,6 @@ static int _init_blk_request(struct osd_request *or,
         }
 
         or->request = req;
-        req->cmd_type = REQ_TYPE_BLOCK_PC;
         req->cmd_flags |= REQ_QUIET;
 
         req->timeout = or->timeout;
@@ -1608,7 +1608,7 @@ static int _init_blk_request(struct osd_request *or,
                                 ret = PTR_ERR(req);
                                 goto out;
                         }
-                        req->cmd_type = REQ_TYPE_BLOCK_PC;
+                        blk_rq_set_block_pc(req);
                         or->in.req = or->request->next_rq = req;
                 }
         } else if (has_in)
diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c
index 21883a2d6324..0727ea7cc387 100644
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@@ -365,7 +365,7 @@ static int osst_execute(struct osst_request *SRpnt, const unsigned char *cmd,
         if (!req)
                 return DRIVER_ERROR << 24;
 
-        req->cmd_type = REQ_TYPE_BLOCK_PC;
+        blk_rq_set_block_pc(req);
         req->cmd_flags |= REQ_QUIET;
 
         SRpnt->bio = NULL;
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index f17aa7aa7879..af624619d547 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1951,6 +1951,8 @@ static void scsi_eh_lock_door(struct scsi_device *sdev)
          */
         req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL);
 
+        blk_rq_set_block_pc(req);
+
         req->cmd[0] = ALLOW_MEDIUM_REMOVAL;
         req->cmd[1] = 0;
         req->cmd[2] = 0;
@@ -1960,7 +1962,6 @@ static void scsi_eh_lock_door(struct scsi_device *sdev)
 
         req->cmd_len = COMMAND_SIZE(req->cmd[0]);
 
-        req->cmd_type = REQ_TYPE_BLOCK_PC;
         req->cmd_flags |= REQ_QUIET;
         req->timeout = 10 * HZ;
         req->retries = 5;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index a0c95cac91f0..c3c1697b143e 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -195,6 +195,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
         req = blk_get_request(sdev->request_queue, write, __GFP_WAIT);
         if (!req)
                 return ret;
+        blk_rq_set_block_pc(req);
 
         if (bufflen &&  blk_rq_map_kern(sdev->request_queue, req,
                                         buffer, bufflen, __GFP_WAIT))
@@ -206,7 +207,6 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
         req->sense_len = 0;
         req->retries = retries;
         req->timeout = timeout;
-        req->cmd_type = REQ_TYPE_BLOCK_PC;
         req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT;
 
         /*
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index df5e961484e1..53268aaba559 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1653,10 +1653,9 @@ static int sg_start_req(Sg_request *srp, unsigned char *cmd)
         if (!rq)
                 return -ENOMEM;
 
+        blk_rq_set_block_pc(rq);
         memcpy(rq->cmd, cmd, hp->cmd_len);
-
         rq->cmd_len = hp->cmd_len;
-        rq->cmd_type = REQ_TYPE_BLOCK_PC;
 
         srp->rq = rq;
         rq->end_io_data = srp;
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index afc834e172c6..14eb4b256a03 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -484,7 +484,7 @@ static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
         if (!req)
                 return DRIVER_ERROR << 24;
 
-        req->cmd_type = REQ_TYPE_BLOCK_PC;
+        blk_rq_set_block_pc(req);
         req->cmd_flags |= REQ_QUIET;
 
         mdata->null_mapped = 1;
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 0f199f6a0738..94d00df28f39 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -1055,6 +1055,8 @@ pscsi_execute_cmd(struct se_cmd *cmd)
                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
                         goto fail;
                 }
+
+                blk_rq_set_block_pc(req);
         } else {
                 BUG_ON(!cmd->data_length);
 
@@ -1071,7 +1073,6 @@ pscsi_execute_cmd(struct se_cmd *cmd)
                 }
         }
 
-        req->cmd_type = REQ_TYPE_BLOCK_PC;
         req->end_io = pscsi_req_done;
         req->end_io_data = cmd;
         req->cmd_len = scsi_command_size(pt->pscsi_cdb);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index dc2c703f05fd..31e11051f1ba 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -796,6 +796,7 @@ extern void __blk_put_request(struct request_queue *, struct request *);
 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
 extern struct request *blk_make_request(struct request_queue *, struct bio *,
                                         gfp_t);
+extern void blk_rq_set_block_pc(struct request *);
 extern void blk_requeue_request(struct request_queue *, struct request *);
 extern void blk_add_request_payload(struct request *rq, struct page *page,
                 unsigned int len);