Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland...

[pandora-kernel.git] / block / blk-sysfs.c

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 54d0db1..304ec73 100644 (file)
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -135,6 +135,27 @@ static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
        return queue_var_show(max_hw_sectors_kb, (page));
 }
 
+static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
+{
+       return queue_var_show(blk_queue_nomerges(q), page);
+}
+
+static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
+                                   size_t count)
+{
+       unsigned long nm;
+       ssize_t ret = queue_var_store(&nm, page, count);
+
+       spin_lock_irq(q->queue_lock);
+       if (nm)
+               queue_flag_set(QUEUE_FLAG_NOMERGES, q);
+       else
+               queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
+
+       spin_unlock_irq(q->queue_lock);
+       return ret;
+}
+
 
 static struct queue_sysfs_entry queue_requests_entry = {
        .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
@@ -170,6 +191,12 @@ static struct queue_sysfs_entry queue_hw_sector_size_entry = {
        .show = queue_hw_sector_size_show,
 };
 
+static struct queue_sysfs_entry queue_nomerges_entry = {
+       .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
+       .show = queue_nomerges_show,
+       .store = queue_nomerges_store,
+};
+
 static struct attribute *default_attrs[] = {
        &queue_requests_entry.attr,
        &queue_ra_entry.attr,
@@ -177,6 +204,7 @@ static struct attribute *default_attrs[] = {
        &queue_max_sectors_entry.attr,
        &queue_iosched_entry.attr,
        &queue_hw_sector_size_entry.attr,
+       &queue_nomerges_entry.attr,
        NULL,
 };
 
@@ -276,9 +304,12 @@ int blk_register_queue(struct gendisk *disk)
 
        struct request_queue *q = disk->queue;
 
-       if (!q || !q->request_fn)
+       if (WARN_ON(!q))
                return -ENXIO;
 
+       if (!q->request_fn)
+               return 0;
+
        ret = kobject_add(&q->kobj, kobject_get(&disk->dev.kobj),
                          "%s", "queue");
        if (ret < 0)
@@ -300,7 +331,10 @@ void blk_unregister_queue(struct gendisk *disk)
 {
        struct request_queue *q = disk->queue;
 
-       if (q && q->request_fn) {
+       if (WARN_ON(!q))
+               return;
+
+       if (q->request_fn) {
                elv_unregister_queue(q);
 
                kobject_uevent(&q->kobj, KOBJ_REMOVE);