block: convert to pos and nr_sectors accessors

With recent cleanups, there is no place where low level driver
directly manipulates request fields.  This means that the 'hard'
request fields always equal the !hard fields.  Convert all
rq->sectors, nr_sectors and current_nr_sectors references to
accessors.

While at it, drop superflous blk_rq_pos() < 0 test in swim.c.

[ Impact: use pos and nr_sectors accessors ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Tested-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Acked-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Acked-by: Mike Miller <mike.miller@hp.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Tim Waugh <tim@cyberelk.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Dario Ballabio <ballabio_dario@emc.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: unsik Kim <donari75@gmail.com>
Cc: Laurent Vivier <Laurent@lvivier.info>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

7 files changed, 45 insertions, 44 deletions

diff --git a/block/as-iosched.c b/block/as-iosched.c
index 45bd07059c28..7a12cf6ee1d3 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -306,8 +306,8 @@ as_choose_req(struct as_data *ad, struct request *rq1, struct request *rq2)
         data_dir = rq_is_sync(rq1);
 
         last = ad->last_sector[data_dir];
-        s1 = rq1->sector;
-        s2 = rq2->sector;
+        s1 = blk_rq_pos(rq1);
+        s2 = blk_rq_pos(rq2);
 
         BUG_ON(data_dir != rq_is_sync(rq2));
 
@@ -566,13 +566,15 @@ static void as_update_iohist(struct as_data *ad, struct as_io_context *aic,
                         as_update_thinktime(ad, aic, thinktime);
 
                         /* Calculate read -> read seek distance */
-                        if (aic->last_request_pos < rq->sector)
-                                seek_dist = rq->sector - aic->last_request_pos;
+                        if (aic->last_request_pos < blk_rq_pos(rq))
+                                seek_dist = blk_rq_pos(rq) -
+                                            aic->last_request_pos;
                         else
-                                seek_dist = aic->last_request_pos - rq->sector;
+                                seek_dist = aic->last_request_pos -
+                                            blk_rq_pos(rq);
                         as_update_seekdist(ad, aic, seek_dist);
                 }
-                aic->last_request_pos = rq->sector + rq->nr_sectors;
+                aic->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq);
                 set_bit(AS_TASK_IOSTARTED, &aic->state);
                 spin_unlock(&aic->lock);
         }
@@ -587,7 +589,7 @@ static int as_close_req(struct as_data *ad, struct as_io_context *aic,
 {
         unsigned long delay;    /* jiffies */
         sector_t last = ad->last_sector[ad->batch_data_dir];
-        sector_t next = rq->sector;
+        sector_t next = blk_rq_pos(rq);
         sector_t delta; /* acceptable close offset (in sectors) */
         sector_t s;
 
@@ -981,7 +983,7 @@ static void as_move_to_dispatch(struct as_data *ad, struct request *rq)
          * This has to be set in order to be correctly updated by
          * as_find_next_rq
          */
-        ad->last_sector[data_dir] = rq->sector + rq->nr_sectors;
+        ad->last_sector[data_dir] = blk_rq_pos(rq) + blk_rq_sectors(rq);
 
         if (data_dir == BLK_RW_SYNC) {
                 struct io_context *ioc = RQ_IOC(rq);
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index c167de5b9eff..8713c2fbc4f6 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -324,7 +324,7 @@ int blkdev_issue_flush(struct block_device *bdev, sector_t *error_sector)
         /*
          * The driver must store the error location in ->bi_sector, if
          * it supports it. For non-stacked drivers, this should be copied
-         * from rq->sector.
+         * from blk_rq_pos(rq).
          */
         if (error_sector)
                 *error_sector = bio->bi_sector;
diff --git a/block/blk-core.c b/block/blk-core.c
index 895e55b74a40..82dc20621c06 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -72,7 +72,7 @@ static void drive_stat_acct(struct request *rq, int new_io)
                 return;
 
         cpu = part_stat_lock();
-        part = disk_map_sector_rcu(rq->rq_disk, rq->sector);
+        part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
 
         if (!new_io)
                 part_stat_inc(cpu, part, merges[rw]);
@@ -185,10 +185,9 @@ void blk_dump_rq_flags(struct request *rq, char *msg)
                 rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->cmd_type,
                 rq->cmd_flags);
 
-        printk(KERN_INFO "  sector %llu, nr/cnr %lu/%u\n",
-                                                (unsigned long long)rq->sector,
-                                                rq->nr_sectors,
-                                                rq->current_nr_sectors);
+        printk(KERN_INFO "  sector %llu, nr/cnr %u/%u\n",
+               (unsigned long long)blk_rq_pos(rq),
+               blk_rq_sectors(rq), blk_rq_cur_sectors(rq));
         printk(KERN_INFO "  bio %p, biotail %p, buffer %p, len %u\n",
                                                 rq->bio, rq->biotail,
                                                 rq->buffer, rq->data_len);
@@ -1557,7 +1556,7 @@ EXPORT_SYMBOL(submit_bio);
  */
 int blk_rq_check_limits(struct request_queue *q, struct request *rq)
 {
-        if (rq->nr_sectors > q->max_sectors ||
+        if (blk_rq_sectors(rq) > q->max_sectors ||
             rq->data_len > q->max_hw_sectors << 9) {
                 printk(KERN_ERR "%s: over max size limit.\n", __func__);
                 return -EIO;
@@ -1645,7 +1644,7 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes)
                 int cpu;
 
                 cpu = part_stat_lock();
-                part = disk_map_sector_rcu(req->rq_disk, req->sector);
+                part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
                 part_stat_add(cpu, part, sectors[rw], bytes >> 9);
                 part_stat_unlock();
         }
@@ -1665,7 +1664,7 @@ static void blk_account_io_done(struct request *req)
                 int cpu;
 
                 cpu = part_stat_lock();
-                part = disk_map_sector_rcu(req->rq_disk, req->sector);
+                part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
 
                 part_stat_inc(cpu, part, ios[rw]);
                 part_stat_add(cpu, part, ticks[rw], duration);
@@ -1846,7 +1845,7 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
         if (error && (blk_fs_request(req) && !(req->cmd_flags & REQ_QUIET))) {
                 printk(KERN_ERR "end_request: I/O error, dev %s, sector %llu\n",
                                 req->rq_disk ? req->rq_disk->disk_name : "?",
-                                (unsigned long long)req->sector);
+                                (unsigned long long)blk_rq_pos(req));
         }
 
         blk_account_io_completion(req, nr_bytes);
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 23d2a6fe34a3..bf62a87a9da2 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -259,7 +259,7 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req,
         else
                 max_sectors = q->max_sectors;
 
-        if (req->nr_sectors + bio_sectors(bio) > max_sectors) {
+        if (blk_rq_sectors(req) + bio_sectors(bio) > max_sectors) {
                 req->cmd_flags |= REQ_NOMERGE;
                 if (req == q->last_merge)
                         q->last_merge = NULL;
@@ -284,7 +284,7 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req,
                 max_sectors = q->max_sectors;
 
 
-        if (req->nr_sectors + bio_sectors(bio) > max_sectors) {
+        if (blk_rq_sectors(req) + bio_sectors(bio) > max_sectors) {
                 req->cmd_flags |= REQ_NOMERGE;
                 if (req == q->last_merge)
                         q->last_merge = NULL;
@@ -315,7 +315,7 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
         /*
          * Will it become too large?
          */
-        if ((req->nr_sectors + next->nr_sectors) > q->max_sectors)
+        if ((blk_rq_sectors(req) + blk_rq_sectors(next)) > q->max_sectors)
                 return 0;
 
         total_phys_segments = req->nr_phys_segments + next->nr_phys_segments;
@@ -345,7 +345,7 @@ static void blk_account_io_merge(struct request *req)
                 int cpu;
 
                 cpu = part_stat_lock();
-                part = disk_map_sector_rcu(req->rq_disk, req->sector);
+                part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
 
                 part_round_stats(cpu, part);
                 part_dec_in_flight(part);
@@ -366,7 +366,7 @@ static int attempt_merge(struct request_queue *q, struct request *req,
         /*
          * not contiguous
          */
-        if (req->sector + req->nr_sectors != next->sector)
+        if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next))
                 return 0;
 
         if (rq_data_dir(req) != rq_data_dir(next)
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 575083a9ffe4..db4d990a66bf 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -349,8 +349,8 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2)
         else if (rq_is_meta(rq2) && !rq_is_meta(rq1))
                 return rq2;
 
-        s1 = rq1->sector;
-        s2 = rq2->sector;
+        s1 = blk_rq_pos(rq1);
+        s2 = blk_rq_pos(rq2);
 
         last = cfqd->last_position;
 
@@ -949,10 +949,10 @@ static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd,
 static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd,
                                           struct request *rq)
 {
-        if (rq->sector >= cfqd->last_position)
-                return rq->sector - cfqd->last_position;
+        if (blk_rq_pos(rq) >= cfqd->last_position)
+                return blk_rq_pos(rq) - cfqd->last_position;
         else
-                return cfqd->last_position - rq->sector;
+                return cfqd->last_position - blk_rq_pos(rq);
 }
 
 #define CIC_SEEK_THR    8 * 1024
@@ -1918,10 +1918,10 @@ cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic,
 
         if (!cic->last_request_pos)
                 sdist = 0;
-        else if (cic->last_request_pos < rq->sector)
-                sdist = rq->sector - cic->last_request_pos;
+        else if (cic->last_request_pos < blk_rq_pos(rq))
+                sdist = blk_rq_pos(rq) - cic->last_request_pos;
         else
-                sdist = cic->last_request_pos - rq->sector;
+                sdist = cic->last_request_pos - blk_rq_pos(rq);
 
         /*
          * Don't allow the seek distance to get too large from the
@@ -2071,7 +2071,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
         cfq_update_io_seektime(cfqd, cic, rq);
         cfq_update_idle_window(cfqd, cfqq, cic);
 
-        cic->last_request_pos = rq->sector + rq->nr_sectors;
+        cic->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq);
 
         if (cfqq == cfqd->active_queue) {
                 /*
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index c4d991d4adef..b547cbca7b23 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -138,7 +138,7 @@ deadline_merge(struct request_queue *q, struct request **req, struct bio *bio)
 
                 __rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector);
                 if (__rq) {
-                        BUG_ON(sector != __rq->sector);
+                        BUG_ON(sector != blk_rq_pos(__rq));
 
                         if (elv_rq_merge_ok(__rq, bio)) {
                                 ret = ELEVATOR_FRONT_MERGE;
diff --git a/block/elevator.c b/block/elevator.c
index 1af5d9f04aff..918920056e42 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -52,7 +52,7 @@ static const int elv_hash_shift = 6;
 #define ELV_HASH_FN(sec)        \
                 (hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift))
 #define ELV_HASH_ENTRIES        (1 << elv_hash_shift)
-#define rq_hash_key(rq)         ((rq)->sector + (rq)->nr_sectors)
+#define rq_hash_key(rq)         (blk_rq_pos(rq) + blk_rq_sectors(rq))
 
 DEFINE_TRACE(block_rq_insert);
 DEFINE_TRACE(block_rq_issue);
@@ -119,9 +119,9 @@ static inline int elv_try_merge(struct request *__rq, struct bio *bio)
          * we can merge and sequence is ok, check if it's possible
          */
         if (elv_rq_merge_ok(__rq, bio)) {
-                if (__rq->sector + __rq->nr_sectors == bio->bi_sector)
+                if (blk_rq_pos(__rq) + blk_rq_sectors(__rq) == bio->bi_sector)
                         ret = ELEVATOR_BACK_MERGE;
-                else if (__rq->sector - bio_sectors(bio) == bio->bi_sector)
+                else if (blk_rq_pos(__rq) - bio_sectors(bio) == bio->bi_sector)
                         ret = ELEVATOR_FRONT_MERGE;
         }
 
@@ -370,9 +370,9 @@ struct request *elv_rb_add(struct rb_root *root, struct request *rq)
                 parent = *p;
                 __rq = rb_entry(parent, struct request, rb_node);
 
-                if (rq->sector < __rq->sector)
+                if (blk_rq_pos(rq) < blk_rq_pos(__rq))
                         p = &(*p)->rb_left;
-                else if (rq->sector > __rq->sector)
+                else if (blk_rq_pos(rq) > blk_rq_pos(__rq))
                         p = &(*p)->rb_right;
                 else
                         return __rq;
@@ -400,9 +400,9 @@ struct request *elv_rb_find(struct rb_root *root, sector_t sector)
         while (n) {
                 rq = rb_entry(n, struct request, rb_node);
 
-                if (sector < rq->sector)
+                if (sector < blk_rq_pos(rq))
                         n = n->rb_left;
-                else if (sector > rq->sector)
+                else if (sector > blk_rq_pos(rq))
                         n = n->rb_right;
                 else
                         return rq;
@@ -441,14 +441,14 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
                         break;
                 if (pos->cmd_flags & stop_flags)
                         break;
-                if (rq->sector >= boundary) {
-                        if (pos->sector < boundary)
+                if (blk_rq_pos(rq) >= boundary) {
+                        if (blk_rq_pos(pos) < boundary)
                                 continue;
                 } else {
-                        if (pos->sector >= boundary)
+                        if (blk_rq_pos(pos) >= boundary)
                                 break;
                 }
-                if (rq->sector >= pos->sector)
+                if (blk_rq_pos(rq) >= blk_rq_pos(pos))
                         break;
         }