block: add block polling support

[cascardo/linux.git] / block / blk-sysfs.c

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 31849e3..565b8da 100644 (file)
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -317,6 +317,34 @@ queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
        return ret;
 }
 
+static ssize_t queue_poll_show(struct request_queue *q, char *page)
+{
+       return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
+}
+
+static ssize_t queue_poll_store(struct request_queue *q, const char *page,
+                               size_t count)
+{
+       unsigned long poll_on;
+       ssize_t ret;
+
+       if (!q->mq_ops || !q->mq_ops->poll)
+               return -EINVAL;
+
+       ret = queue_var_store(&poll_on, page, count);
+       if (ret < 0)
+               return ret;
+
+       spin_lock_irq(q->queue_lock);
+       if (poll_on)
+               queue_flag_set(QUEUE_FLAG_POLL, q);
+       else
+               queue_flag_clear(QUEUE_FLAG_POLL, 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 },
        .show = queue_requests_show,
@@ -442,6 +470,12 @@ static struct queue_sysfs_entry queue_random_entry = {
        .store = queue_store_random,
 };
 
+static struct queue_sysfs_entry queue_poll_entry = {
+       .attr = {.name = "io_poll", .mode = S_IRUGO | S_IWUSR },
+       .show = queue_poll_show,
+       .store = queue_poll_store,
+};
+
 static struct attribute *default_attrs[] = {
        &queue_requests_entry.attr,
        &queue_ra_entry.attr,
@@ -466,6 +500,7 @@ static struct attribute *default_attrs[] = {
        &queue_rq_affinity_entry.attr,
        &queue_iostats_entry.attr,
        &queue_random_entry.attr,
+       &queue_poll_entry.attr,
        NULL,
 };