These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / block / blk-mq-sysfs.c

diff --git a/kernel/block/blk-mq-sysfs.c b/kernel/block/blk-mq-sysfs.c
index 279c5d6..1cf1878 100644 (file)
--- a/kernel/block/blk-mq-sysfs.c
+++ b/kernel/block/blk-mq-sysfs.c
@@ -174,6 +174,11 @@ static ssize_t blk_mq_sysfs_rq_list_show(struct blk_mq_ctx *ctx, char *page)
        return ret;
 }
 
+static ssize_t blk_mq_hw_sysfs_poll_show(struct blk_mq_hw_ctx *hctx, char *page)
+{
+       return sprintf(page, "invoked=%lu, success=%lu\n", hctx->poll_invoked, hctx->poll_success);
+}
+
 static ssize_t blk_mq_hw_sysfs_queued_show(struct blk_mq_hw_ctx *hctx,
                                           char *page)
 {
@@ -229,8 +234,6 @@ static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
        unsigned int i, first = 1;
        ssize_t ret = 0;
 
-       blk_mq_disable_hotplug();
-
        for_each_cpu(i, hctx->cpumask) {
                if (first)
                        ret += sprintf(ret + page, "%u", i);
@@ -240,8 +243,6 @@ static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page)
                first = 0;
        }
 
-       blk_mq_enable_hotplug();
-
        ret += sprintf(ret + page, "\n");
        return ret;
 }
@@ -299,6 +300,10 @@ static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = {
        .attr = {.name = "cpu_list", .mode = S_IRUGO },
        .show = blk_mq_hw_sysfs_cpus_show,
 };
+static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_poll = {
+       .attr = {.name = "io_poll", .mode = S_IRUGO },
+       .show = blk_mq_hw_sysfs_poll_show,
+};
 
 static struct attribute *default_hw_ctx_attrs[] = {
        &blk_mq_hw_sysfs_queued.attr,
@@ -308,6 +313,7 @@ static struct attribute *default_hw_ctx_attrs[] = {
        &blk_mq_hw_sysfs_tags.attr,
        &blk_mq_hw_sysfs_cpus.attr,
        &blk_mq_hw_sysfs_active.attr,
+       &blk_mq_hw_sysfs_poll.attr,
        NULL,
 };
 
@@ -343,7 +349,7 @@ static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
        struct blk_mq_ctx *ctx;
        int i;
 
-       if (!hctx->nr_ctx || !(hctx->flags & BLK_MQ_F_SYSFS_UP))
+       if (!hctx->nr_ctx)
                return;
 
        hctx_for_each_ctx(hctx, ctx, i)
@@ -358,7 +364,7 @@ static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
        struct blk_mq_ctx *ctx;
        int i, ret;
 
-       if (!hctx->nr_ctx || !(hctx->flags & BLK_MQ_F_SYSFS_UP))
+       if (!hctx->nr_ctx)
                return 0;
 
        ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
@@ -381,6 +387,8 @@ void blk_mq_unregister_disk(struct gendisk *disk)
        struct blk_mq_ctx *ctx;
        int i, j;
 
+       blk_mq_disable_hotplug();
+
        queue_for_each_hw_ctx(q, hctx, i) {
                blk_mq_unregister_hctx(hctx);
 
@@ -395,6 +403,9 @@ void blk_mq_unregister_disk(struct gendisk *disk)
        kobject_put(&q->mq_kobj);
 
        kobject_put(&disk_to_dev(disk)->kobj);
+
+       q->mq_sysfs_init_done = false;
+       blk_mq_enable_hotplug();
 }
 
 static void blk_mq_sysfs_init(struct request_queue *q)
@@ -412,12 +423,6 @@ static void blk_mq_sysfs_init(struct request_queue *q)
                kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
 }
 
-/* see blk_register_queue() */
-void blk_mq_finish_init(struct request_queue *q)
-{
-       percpu_ref_switch_to_percpu(&q->mq_usage_counter);
-}
-
 int blk_mq_register_disk(struct gendisk *disk)
 {
        struct device *dev = disk_to_dev(disk);
@@ -425,27 +430,30 @@ int blk_mq_register_disk(struct gendisk *disk)
        struct blk_mq_hw_ctx *hctx;
        int ret, i;
 
+       blk_mq_disable_hotplug();
+
        blk_mq_sysfs_init(q);
 
        ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
        if (ret < 0)
-               return ret;
+               goto out;
 
        kobject_uevent(&q->mq_kobj, KOBJ_ADD);
 
        queue_for_each_hw_ctx(q, hctx, i) {
-               hctx->flags |= BLK_MQ_F_SYSFS_UP;
                ret = blk_mq_register_hctx(hctx);
                if (ret)
                        break;
        }
 
-       if (ret) {
+       if (ret)
                blk_mq_unregister_disk(disk);
-               return ret;
-       }
+       else
+               q->mq_sysfs_init_done = true;
+out:
+       blk_mq_enable_hotplug();
 
-       return 0;
+       return ret;
 }
 EXPORT_SYMBOL_GPL(blk_mq_register_disk);
 
@@ -454,6 +462,9 @@ void blk_mq_sysfs_unregister(struct request_queue *q)
        struct blk_mq_hw_ctx *hctx;
        int i;
 
+       if (!q->mq_sysfs_init_done)
+               return;
+
        queue_for_each_hw_ctx(q, hctx, i)
                blk_mq_unregister_hctx(hctx);
 }
@@ -463,6 +474,9 @@ int blk_mq_sysfs_register(struct request_queue *q)
        struct blk_mq_hw_ctx *hctx;
        int i, ret = 0;
 
+       if (!q->mq_sysfs_init_done)
+               return ret;
+
        queue_for_each_hw_ctx(q, hctx, i) {
                ret = blk_mq_register_hctx(hctx);
                if (ret)