block: Use accessor functions for queue limits

Convert all external users of queue limits to using wrapper functions
instead of poking the request queue variables directly.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

9 files changed, 54 insertions, 44 deletions

diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index 0d98054cdbd7..30022b4e2f63 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -388,10 +388,10 @@ int blkdev_issue_discard(struct block_device *bdev,
 
                 bio->bi_sector = sector;
 
-                if (nr_sects > q->max_hw_sectors) {
-                        bio->bi_size = q->max_hw_sectors << 9;
-                        nr_sects -= q->max_hw_sectors;
-                        sector += q->max_hw_sectors;
+                if (nr_sects > queue_max_hw_sectors(q)) {
+                        bio->bi_size = queue_max_hw_sectors(q) << 9;
+                        nr_sects -= queue_max_hw_sectors(q);
+                        sector += queue_max_hw_sectors(q);
                 } else {
                         bio->bi_size = nr_sects << 9;
                         nr_sects = 0;
diff --git a/block/blk-core.c b/block/blk-core.c
index 59c4af523112..7a4c40184a64 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1437,11 +1437,11 @@ static inline void __generic_make_request(struct bio *bio)
                         goto end_io;
                 }
 
-                if (unlikely(nr_sectors > q->max_hw_sectors)) {
+                if (unlikely(nr_sectors > queue_max_hw_sectors(q))) {
                         printk(KERN_ERR "bio too big device %s (%u > %u)\n",
-                                bdevname(bio->bi_bdev, b),
-                                bio_sectors(bio),
-                                q->max_hw_sectors);
+                               bdevname(bio->bi_bdev, b),
+                               bio_sectors(bio),
+                               queue_max_hw_sectors(q));
                         goto end_io;
                 }
 
@@ -1608,8 +1608,8 @@ EXPORT_SYMBOL(submit_bio);
  */
 int blk_rq_check_limits(struct request_queue *q, struct request *rq)
 {
-        if (blk_rq_sectors(rq) > q->max_sectors ||
-            blk_rq_bytes(rq) > q->max_hw_sectors << 9) {
+        if (blk_rq_sectors(rq) > queue_max_sectors(q) ||
+            blk_rq_bytes(rq) > queue_max_hw_sectors(q) << 9) {
                 printk(KERN_ERR "%s: over max size limit.\n", __func__);
                 return -EIO;
         }
@@ -1621,8 +1621,8 @@ int blk_rq_check_limits(struct request_queue *q, struct request *rq)
          * limitation.
          */
         blk_recalc_rq_segments(rq);
-        if (rq->nr_phys_segments > q->max_phys_segments ||
-            rq->nr_phys_segments > q->max_hw_segments) {
+        if (rq->nr_phys_segments > queue_max_phys_segments(q) ||
+            rq->nr_phys_segments > queue_max_hw_segments(q)) {
                 printk(KERN_ERR "%s: over max segments limit.\n", __func__);
                 return -EIO;
         }
diff --git a/block/blk-map.c b/block/blk-map.c
index ef2492adca7e..9083cf0180cc 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -115,7 +115,7 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
         struct bio *bio = NULL;
         int ret;
 
-        if (len > (q->max_hw_sectors << 9))
+        if (len > (queue_max_hw_sectors(q) << 9))
                 return -EINVAL;
         if (!len)
                 return -EINVAL;
@@ -292,7 +292,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
         struct bio *bio;
         int ret;
 
-        if (len > (q->max_hw_sectors << 9))
+        if (len > (queue_max_hw_sectors(q) << 9))
                 return -EINVAL;
         if (!len || !kbuf)
                 return -EINVAL;
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 4974dd5767e5..39ce64432ba6 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -32,11 +32,12 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
                          * never considered part of another segment, since that
                          * might change with the bounce page.
                          */
-                        high = page_to_pfn(bv->bv_page) > q->bounce_pfn;
+                        high = page_to_pfn(bv->bv_page) > queue_bounce_pfn(q);
                         if (high || highprv)
                                 goto new_segment;
                         if (cluster) {
-                                if (seg_size + bv->bv_len > q->max_segment_size)
+                                if (seg_size + bv->bv_len
+                                    > queue_max_segment_size(q))
                                         goto new_segment;
                                 if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv))
                                         goto new_segment;
@@ -91,7 +92,7 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
                 return 0;
 
         if (bio->bi_seg_back_size + nxt->bi_seg_front_size >
-            q->max_segment_size)
+            queue_max_segment_size(q))
                 return 0;
 
         if (!bio_has_data(bio))
@@ -134,7 +135,7 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
                 int nbytes = bvec->bv_len;
 
                 if (bvprv && cluster) {
-                        if (sg->length + nbytes > q->max_segment_size)
+                        if (sg->length + nbytes > queue_max_segment_size(q))
                                 goto new_segment;
 
                         if (!BIOVEC_PHYS_MERGEABLE(bvprv, bvec))
@@ -205,8 +206,8 @@ static inline int ll_new_hw_segment(struct request_queue *q,
 {
         int nr_phys_segs = bio_phys_segments(q, bio);
 
-        if (req->nr_phys_segments + nr_phys_segs > q->max_hw_segments
-            || req->nr_phys_segments + nr_phys_segs > q->max_phys_segments) {
+        if (req->nr_phys_segments + nr_phys_segs > queue_max_hw_segments(q) ||
+            req->nr_phys_segments + nr_phys_segs > queue_max_phys_segments(q)) {
                 req->cmd_flags |= REQ_NOMERGE;
                 if (req == q->last_merge)
                         q->last_merge = NULL;
@@ -227,9 +228,9 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req,
         unsigned short max_sectors;
 
         if (unlikely(blk_pc_request(req)))
-                max_sectors = q->max_hw_sectors;
+                max_sectors = queue_max_hw_sectors(q);
         else
-                max_sectors = q->max_sectors;
+                max_sectors = queue_max_sectors(q);
 
         if (blk_rq_sectors(req) + bio_sectors(bio) > max_sectors) {
                 req->cmd_flags |= REQ_NOMERGE;
@@ -251,9 +252,9 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req,
         unsigned short max_sectors;
 
         if (unlikely(blk_pc_request(req)))
-                max_sectors = q->max_hw_sectors;
+                max_sectors = queue_max_hw_sectors(q);
         else
-                max_sectors = q->max_sectors;
+                max_sectors = queue_max_sectors(q);
 
 
         if (blk_rq_sectors(req) + bio_sectors(bio) > max_sectors) {
@@ -287,7 +288,7 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
         /*
          * Will it become too large?
          */
-        if ((blk_rq_sectors(req) + blk_rq_sectors(next)) > q->max_sectors)
+        if ((blk_rq_sectors(req) + blk_rq_sectors(next)) > queue_max_sectors(q))
                 return 0;
 
         total_phys_segments = req->nr_phys_segments + next->nr_phys_segments;
@@ -299,10 +300,10 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
                 total_phys_segments--;
         }
 
-        if (total_phys_segments > q->max_phys_segments)
+        if (total_phys_segments > queue_max_phys_segments(q))
                 return 0;
 
-        if (total_phys_segments > q->max_hw_segments)
+        if (total_phys_segments > queue_max_hw_segments(q))
                 return 0;
 
         /* Merge is OK... */
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 15c3164537b8..0b32f984eed2 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -219,6 +219,15 @@ void blk_queue_max_sectors(struct request_queue *q, unsigned int max_sectors)
 }
 EXPORT_SYMBOL(blk_queue_max_sectors);
 
+void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_sectors)
+{
+        if (BLK_DEF_MAX_SECTORS > max_sectors)
+                q->max_hw_sectors = BLK_DEF_MAX_SECTORS;
+        else
+                q->max_hw_sectors = max_sectors;
+}
+EXPORT_SYMBOL(blk_queue_max_hw_sectors);
+
 /**
  * blk_queue_max_phys_segments - set max phys segments for a request for this queue
  * @q:  the request queue for the device
@@ -395,11 +404,11 @@ int blk_queue_dma_drain(struct request_queue *q,
                                dma_drain_needed_fn *dma_drain_needed,
                                void *buf, unsigned int size)
 {
-        if (q->max_hw_segments < 2 || q->max_phys_segments < 2)
+        if (queue_max_hw_segments(q) < 2 || queue_max_phys_segments(q) < 2)
                 return -EINVAL;
         /* make room for appending the drain */
-        --q->max_hw_segments;
-        --q->max_phys_segments;
+        blk_queue_max_hw_segments(q, queue_max_hw_segments(q) - 1);
+        blk_queue_max_phys_segments(q, queue_max_phys_segments(q) - 1);
         q->dma_drain_needed = dma_drain_needed;
         q->dma_drain_buffer = buf;
         q->dma_drain_size = size;
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 13d38b7e4d0f..142a4acddd43 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -95,7 +95,7 @@ queue_ra_store(struct request_queue *q, const char *page, size_t count)
 
 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
 {
-        int max_sectors_kb = q->max_sectors >> 1;
+        int max_sectors_kb = queue_max_sectors(q) >> 1;
 
         return queue_var_show(max_sectors_kb, (page));
 }
@@ -109,7 +109,7 @@ static ssize_t
 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
 {
         unsigned long max_sectors_kb,
-                        max_hw_sectors_kb = q->max_hw_sectors >> 1,
+                max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
                         page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
         ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
 
@@ -117,7 +117,7 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
                 return -EINVAL;
 
         spin_lock_irq(q->queue_lock);
-        q->max_sectors = max_sectors_kb << 1;
+        blk_queue_max_sectors(q, max_sectors_kb << 1);
         spin_unlock_irq(q->queue_lock);
 
         return ret;
@@ -125,7 +125,7 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
 
 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
 {
-        int max_hw_sectors_kb = q->max_hw_sectors >> 1;
+        int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
 
         return queue_var_show(max_hw_sectors_kb, (page));
 }
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index 9eaa1940273a..df18a156d011 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -766,7 +766,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
                 return compat_put_int(arg, bdev_logical_block_size(bdev));
         case BLKSECTGET:
                 return compat_put_ushort(arg,
-                                         bdev_get_queue(bdev)->max_sectors);
+                                         queue_max_sectors(bdev_get_queue(bdev)));
         case BLKRASET: /* compatible, but no compat_ptr (!) */
         case BLKFRASET:
                 if (!capable(CAP_SYS_ADMIN))
diff --git a/block/ioctl.c b/block/ioctl.c
index 7aa97f65da82..500e4c73cc52 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -152,10 +152,10 @@ static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
                 bio->bi_private = &wait;
                 bio->bi_sector = start;
 
-                if (len > q->max_hw_sectors) {
-                        bio->bi_size = q->max_hw_sectors << 9;
-                        len -= q->max_hw_sectors;
-                        start += q->max_hw_sectors;
+                if (len > queue_max_hw_sectors(q)) {
+                        bio->bi_size = queue_max_hw_sectors(q) << 9;
+                        len -= queue_max_hw_sectors(q);
+                        start += queue_max_hw_sectors(q);
                 } else {
                         bio->bi_size = len << 9;
                         len = 0;
@@ -313,7 +313,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
         case BLKSSZGET: /* get block device hardware sector size */
                 return put_int(arg, bdev_logical_block_size(bdev));
         case BLKSECTGET:
-                return put_ushort(arg, bdev_get_queue(bdev)->max_sectors);
+                return put_ushort(arg, queue_max_sectors(bdev_get_queue(bdev)));
         case BLKRASET:
         case BLKFRASET:
                 if(!capable(CAP_SYS_ADMIN))
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index a9670dd4b5de..5f8e798ede4e 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -75,7 +75,7 @@ static int sg_set_timeout(struct request_queue *q, int __user *p)
 
 static int sg_get_reserved_size(struct request_queue *q, int __user *p)
 {
-        unsigned val = min(q->sg_reserved_size, q->max_sectors << 9);
+        unsigned val = min(q->sg_reserved_size, queue_max_sectors(q) << 9);
 
         return put_user(val, p);
 }
@@ -89,8 +89,8 @@ static int sg_set_reserved_size(struct request_queue *q, int __user *p)
 
         if (size < 0)
                 return -EINVAL;
-        if (size > (q->max_sectors << 9))
-                size = q->max_sectors << 9;
+        if (size > (queue_max_sectors(q) << 9))
+                size = queue_max_sectors(q) << 9;
 
         q->sg_reserved_size = size;
         return 0;
@@ -264,7 +264,7 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
         if (hdr->cmd_len > BLK_MAX_CDB)
                 return -EINVAL;
 
-        if (hdr->dxfer_len > (q->max_hw_sectors << 9))
+        if (hdr->dxfer_len > (queue_max_hw_sectors(q) << 9))
                 return -EIO;
 
         if (hdr->dxfer_len)