blk-cgroup: refactor blkcg_print_stat

[linux-2.6-microblaze.git] / block / blk-sysfs.c

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 370d83c..1832587 100644 (file)
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -88,9 +88,11 @@ queue_requests_store(struct request_queue *q, const char *page, size_t count)
 
 static ssize_t queue_ra_show(struct request_queue *q, char *page)
 {
-       unsigned long ra_kb = q->backing_dev_info->ra_pages <<
-                                       (PAGE_SHIFT - 10);
+       unsigned long ra_kb;
 
+       if (!queue_has_disk(q))
+               return -EINVAL;
+       ra_kb = queue_to_disk(q)->bdi->ra_pages << (PAGE_SHIFT - 10);
        return queue_var_show(ra_kb, page);
 }
 
@@ -98,13 +100,14 @@ static ssize_t
 queue_ra_store(struct request_queue *q, const char *page, size_t count)
 {
        unsigned long ra_kb;
-       ssize_t ret = queue_var_store(&ra_kb, page, count);
+       ssize_t ret;
 
+       if (!queue_has_disk(q))
+               return -EINVAL;
+       ret = queue_var_store(&ra_kb, page, count);
        if (ret < 0)
                return ret;
-
-       q->backing_dev_info->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
-
+       queue_to_disk(q)->bdi->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
        return ret;
 }
 
@@ -251,7 +254,9 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
 
        spin_lock_irq(&q->queue_lock);
        q->limits.max_sectors = max_sectors_kb << 1;
-       q->backing_dev_info->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10);
+       if (queue_has_disk(q))
+               queue_to_disk(q)->bdi->io_pages =
+                       max_sectors_kb >> (PAGE_SHIFT - 10);
        spin_unlock_irq(&q->queue_lock);
 
        return ret;
@@ -766,13 +771,6 @@ static void blk_exit_queue(struct request_queue *q)
         * e.g. blkcg_print_blkgs() to crash.
         */
        blkcg_exit_queue(q);
-
-       /*
-        * Since the cgroup code may dereference the @q->backing_dev_info
-        * pointer, only decrease its reference count after having removed the
-        * association with the block cgroup controller.
-        */
-       bdi_put(q->backing_dev_info);
 }
 
 /**
@@ -866,7 +864,7 @@ int blk_register_queue(struct gendisk *disk)
                  "%s is registering an already registered queue\n",
                  kobject_name(&dev->kobj));
 
-       blk_queue_update_readahead(q);
+       disk_update_readahead(disk);
 
        ret = blk_trace_init_sysfs(dev);
        if (ret)