block: implement blk_rq_pos/[cur_]sectors() and convert obvious ones

Implement accessors - blk_rq_pos(), blk_rq_sectors() and
blk_rq_cur_sectors() which return rq->hard_sector, rq->hard_nr_sectors
and rq->hard_cur_sectors respectively and convert direct references of
the said fields to the accessors.

This is in preparation of request data length handling cleanup.

Geert	: suggested adding const to struct request * parameter to accessors
Sergei	: spotted error in patch description

[ Impact: cleanup ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Tested-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Ackec-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

12 files changed, 42 insertions, 25 deletions

diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index c8d087655eff..c167de5b9eff 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -163,7 +163,7 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp)
          * For an empty barrier, there's no actual BAR request, which
          * in turn makes POSTFLUSH unnecessary.  Mask them off.
          */
-        if (!rq->hard_nr_sectors) {
+        if (!blk_rq_sectors(rq)) {
                 q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
                                 QUEUE_ORDERED_DO_POSTFLUSH);
                 /*
diff --git a/block/blk-core.c b/block/blk-core.c
index 394c5bd81271..895e55b74a40 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1683,7 +1683,7 @@ static void blk_account_io_done(struct request *req)
 unsigned int blk_rq_bytes(struct request *rq)
 {
         if (blk_fs_request(rq))
-                return rq->hard_nr_sectors << 9;
+                return blk_rq_sectors(rq) << 9;
 
         return rq->data_len;
 }
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index def0c698a4bc..575083a9ffe4 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -760,7 +760,7 @@ static void cfq_activate_request(struct request_queue *q, struct request *rq)
         cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d",
                                                 cfqd->rq_in_driver);
 
-        cfqd->last_position = rq->hard_sector + rq->hard_nr_sectors;
+        cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq);
 }
 
 static void cfq_deactivate_request(struct request_queue *q, struct request *rq)
diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c
index f6586e4d351c..c2388673684e 100644
--- a/drivers/block/ps3disk.c
+++ b/drivers/block/ps3disk.c
@@ -136,7 +136,7 @@ static int ps3disk_submit_request_sg(struct ps3_storage_device *dev,
         dev_dbg(&dev->sbd.core,
                 "%s:%u: %s req has %u bvecs for %lu sectors %lu hard sectors\n",
                 __func__, __LINE__, op, n, req->nr_sectors,
-                req->hard_nr_sectors);
+                blk_rq_sectors(req));
 #endif
 
         start_sector = req->sector * priv->blocking_factor;
diff --git a/drivers/block/viodasd.c b/drivers/block/viodasd.c
index ecccf65dce2f..e821eed7132f 100644
--- a/drivers/block/viodasd.c
+++ b/drivers/block/viodasd.c
@@ -368,12 +368,12 @@ static void do_viodasd_request(struct request_queue *q)
                 blkdev_dequeue_request(req);
                 /* check that request contains a valid command */
                 if (!blk_fs_request(req)) {
-                        viodasd_end_request(req, -EIO, req->hard_nr_sectors);
+                        viodasd_end_request(req, -EIO, blk_rq_sectors(req));
                         continue;
                 }
                 /* Try sending the request */
                 if (send_request(req) != 0)
-                        viodasd_end_request(req, -EIO, req->hard_nr_sectors);
+                        viodasd_end_request(req, -EIO, blk_rq_sectors(req));
         }
 }
 
@@ -590,7 +590,7 @@ static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
                 err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
                 printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
                                 event->xRc, bevent->sub_result, err->msg);
-                num_sect = req->hard_nr_sectors;
+                num_sect = blk_rq_sectors(req);
         }
         qlock = req->q->queue_lock;
         spin_lock_irqsave(qlock, irq_flags);
diff --git a/drivers/block/xsysace.c b/drivers/block/xsysace.c
index b1e1d7e5ab1e..5722931d14c5 100644
--- a/drivers/block/xsysace.c
+++ b/drivers/block/xsysace.c
@@ -645,8 +645,8 @@ static void ace_fsm_dostate(struct ace_device *ace)
 
                 /* Okay, it's a data request, set it up for transfer */
                 dev_dbg(ace->dev,
-                        "request: sec=%llx hcnt=%lx, ccnt=%x, dir=%i\n",
-                        (unsigned long long) req->sector, req->hard_nr_sectors,
+                        "request: sec=%llx hcnt=%x, ccnt=%x, dir=%i\n",
+                        (unsigned long long) req->sector, blk_rq_sectors(req),
                         req->current_nr_sectors, rq_data_dir(req));
 
                 ace->req = req;
@@ -654,7 +654,7 @@ static void ace_fsm_dostate(struct ace_device *ace)
                 ace->data_count = req->current_nr_sectors * ACE_BUF_PER_SECTOR;
                 ace_out32(ace, ACE_MPULBA, req->sector & 0x0FFFFFFF);
 
-                count = req->hard_nr_sectors;
+                count = blk_rq_sectors(req);
                 if (rq_data_dir(req)) {
                         /* Kick off write request */
                         dev_dbg(ace->dev, "write data\n");
@@ -719,8 +719,8 @@ static void ace_fsm_dostate(struct ace_device *ace)
                 /* bio finished; is there another one? */
                 if (__blk_end_request(ace->req, 0,
                                         blk_rq_cur_bytes(ace->req))) {
-                        /* dev_dbg(ace->dev, "next block; h=%li c=%i\n",
-                         *      ace->req->hard_nr_sectors,
+                        /* dev_dbg(ace->dev, "next block; h=%u c=%u\n",
+                         *      blk_rq_sectors(ace->req),
                          *      ace->req->current_nr_sectors);
                          */
                         ace->data_ptr = ace->req->buffer;
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 8bbe222c5e42..182320dd6ea1 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -730,7 +730,7 @@ out_end:
                 if (blk_pc_request(rq))
                         nsectors = (rq->data_len + 511) >> 9;
                 else
-                        nsectors = rq->hard_nr_sectors;
+                        nsectors = blk_rq_sectors(rq);
 
                 if (nsectors == 0)
                         nsectors = 1;
@@ -875,7 +875,7 @@ static ide_startstop_t ide_cd_do_request(ide_drive_t *drive, struct request *rq,
 
         return ide_issue_pc(drive, &cmd);
 out_end:
-        nsectors = rq->hard_nr_sectors;
+        nsectors = blk_rq_sectors(rq);
 
         if (nsectors == 0)
                 nsectors = 1;
@@ -1359,8 +1359,8 @@ static int ide_cdrom_probe_capabilities(ide_drive_t *drive)
 static int ide_cdrom_prep_fs(struct request_queue *q, struct request *rq)
 {
         int hard_sect = queue_hardsect_size(q);
-        long block = (long)rq->hard_sector / (hard_sect >> 9);
-        unsigned long blocks = rq->hard_nr_sectors / (hard_sect >> 9);
+        long block = (long)blk_rq_pos(rq) / (hard_sect >> 9);
+        unsigned long blocks = blk_rq_sectors(rq) / (hard_sect >> 9);
 
         memset(rq->cmd, 0, BLK_MAX_CDB);
 
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index a0309ea661ac..df23bcbd94b4 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -118,7 +118,7 @@ unsigned int ide_rq_bytes(struct request *rq)
         if (blk_pc_request(rq))
                 return rq->data_len;
         else
-                return rq->hard_cur_sectors << 9;
+                return blk_rq_cur_sectors(rq) << 9;
 }
 EXPORT_SYMBOL_GPL(ide_rq_bytes);
 
@@ -133,7 +133,7 @@ int ide_complete_rq(ide_drive_t *drive, int error, unsigned int nr_bytes)
          * and complete the whole request right now
          */
         if (blk_noretry_request(rq) && error <= 0)
-                nr_bytes = rq->hard_nr_sectors << 9;
+                nr_bytes = blk_rq_sectors(rq) << 9;
 
         rc = ide_end_rq(drive, rq, error, nr_bytes);
         if (rc == 0)
diff --git a/drivers/message/i2o/i2o_block.c b/drivers/message/i2o/i2o_block.c
index 221317e6a006..56e60f0d5312 100644
--- a/drivers/message/i2o/i2o_block.c
+++ b/drivers/message/i2o/i2o_block.c
@@ -427,7 +427,7 @@ static void i2o_block_end_request(struct request *req, int error,
         unsigned long flags;
 
         if (blk_end_request(req, error, nr_bytes)) {
-                int leftover = (req->hard_nr_sectors << KERNEL_SECTOR_SHIFT);
+                int leftover = (blk_rq_sectors(req) << KERNEL_SECTOR_SHIFT);
 
                 if (blk_pc_request(req))
                         leftover = req->data_len;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 7d49ef589f33..9ff0ca9988a9 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -546,7 +546,7 @@ static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
          * to queue the remainder of them.
          */
         if (blk_end_request(req, error, bytes)) {
-                int leftover = (req->hard_nr_sectors << 9);
+                int leftover = blk_rq_sectors(req) << 9;
 
                 if (blk_pc_request(req))
                         leftover = req->resid_len;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6a967cad89fa..4e5f85598728 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -832,13 +832,30 @@ static inline void blk_run_address_space(struct address_space *mapping)
 extern void blkdev_dequeue_request(struct request *req);
 
 /*
- * blk_end_request() takes bytes instead of sectors as a complete size.
- * blk_rq_bytes() returns bytes left to complete in the entire request.
- * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
+ * blk_rq_pos()         : the current sector
+ * blk_rq_bytes()       : bytes left in the entire request
+ * blk_rq_cur_bytes()   : bytes left in the current segment
+ * blk_rq_sectors()     : sectors left in the entire request
+ * blk_rq_cur_sectors() : sectors left in the current segment
  */
+static inline sector_t blk_rq_pos(const struct request *rq)
+{
+        return rq->hard_sector;
+}
+
 extern unsigned int blk_rq_bytes(struct request *rq);
 extern unsigned int blk_rq_cur_bytes(struct request *rq);
 
+static inline unsigned int blk_rq_sectors(const struct request *rq)
+{
+        return rq->hard_nr_sectors;
+}
+
+static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
+{
+        return rq->hard_cur_sectors;
+}
+
 /*
  * Request completion related functions.
  *
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 921ef5d1f0ba..42f1c11e754c 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -646,7 +646,7 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
                                 rq->cmd_len, rq->cmd);
         } else  {
                 what |= BLK_TC_ACT(BLK_TC_FS);
-                __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
+                __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_sectors(rq) << 9,
                                 rw, what, rq->errors, 0, NULL);
         }
 }
@@ -857,7 +857,7 @@ void blk_add_driver_data(struct request_queue *q,
                 __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA,
                                 rq->errors, len, data);
         else
-                __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
+                __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_sectors(rq) << 9,
                                 0, BLK_TA_DRV_DATA, rq->errors, len, data);
 }
 EXPORT_SYMBOL_GPL(blk_add_driver_data);