blk-mq: make the sysfs mq/ layout reflect current mappings
Currently blk-mq registers all the hardware queues in sysfs,
regardless of whether it uses them (e.g. they have CPU mappings)
or not. The unused hardware queues lack the cpux/ directories,
and the other sysfs entries (like active, pending, etc) are all
zeroes.
Change this so that sysfs correctly reflects the current mappings
of the hardware queues.
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index 99a60a8..e5f575f 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -327,6 +327,42 @@
.release = blk_mq_sysfs_release,
};
+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))
+ return;
+
+ hctx_for_each_ctx(hctx, ctx, i)
+ kobject_del(&ctx->kobj);
+
+ kobject_del(&hctx->kobj);
+}
+
+int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ struct request_queue *q = hctx->queue;
+ struct blk_mq_ctx *ctx;
+ int i, ret;
+
+ if (!hctx->nr_ctx || !(hctx->flags & BLK_MQ_F_SYSFS_UP))
+ return 0;
+
+ ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num);
+ if (ret)
+ return ret;
+
+ hctx_for_each_ctx(hctx, ctx, i) {
+ ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
void blk_mq_unregister_disk(struct gendisk *disk)
{
struct request_queue *q = disk->queue;
@@ -335,11 +371,11 @@
int i, j;
queue_for_each_hw_ctx(q, hctx, i) {
- hctx_for_each_ctx(hctx, ctx, j) {
- kobject_del(&ctx->kobj);
+ blk_mq_unregister_hctx(hctx);
+
+ hctx_for_each_ctx(hctx, ctx, j)
kobject_put(&ctx->kobj);
- }
- kobject_del(&hctx->kobj);
+
kobject_put(&hctx->kobj);
}
@@ -350,15 +386,30 @@
kobject_put(&disk_to_dev(disk)->kobj);
}
+static void blk_mq_sysfs_init(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ struct blk_mq_ctx *ctx;
+ int i, j;
+
+ kobject_init(&q->mq_kobj, &blk_mq_ktype);
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
+
+ hctx_for_each_ctx(hctx, ctx, j)
+ kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
+ }
+}
+
int blk_mq_register_disk(struct gendisk *disk)
{
struct device *dev = disk_to_dev(disk);
struct request_queue *q = disk->queue;
struct blk_mq_hw_ctx *hctx;
- struct blk_mq_ctx *ctx;
- int ret, i, j;
+ int ret, i;
- kobject_init(&q->mq_kobj, &blk_mq_ktype);
+ blk_mq_sysfs_init(q);
ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq");
if (ret < 0)
@@ -367,20 +418,10 @@
kobject_uevent(&q->mq_kobj, KOBJ_ADD);
queue_for_each_hw_ctx(q, hctx, i) {
- kobject_init(&hctx->kobj, &blk_mq_hw_ktype);
- ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", i);
+ hctx->flags |= BLK_MQ_F_SYSFS_UP;
+ ret = blk_mq_register_hctx(hctx);
if (ret)
break;
-
- if (!hctx->nr_ctx)
- continue;
-
- hctx_for_each_ctx(hctx, ctx, j) {
- kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);
- ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
- if (ret)
- break;
- }
}
if (ret) {
@@ -390,3 +431,26 @@
return 0;
}
+
+void blk_mq_sysfs_unregister(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ blk_mq_unregister_hctx(hctx);
+}
+
+int blk_mq_sysfs_register(struct request_queue *q)
+{
+ struct blk_mq_hw_ctx *hctx;
+ int i, ret = 0;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ ret = blk_mq_register_hctx(hctx);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}