block: Remove "dying" checks from sysfs callbacks

Block drivers must call del_gendisk() before blk_cleanup_queue().
del_gendisk() calls kobject_del() and kobject_del() waits until any
ongoing sysfs callback functions have finished. In other words, the
sysfs callback functions won't be called for a queue in the dying
state. Hence remove the "dying" checks from the sysfs callback
functions.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-core.c b/block/blk-core.c
index d5e668e..8b51d9e 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -336,6 +336,8 @@ EXPORT_SYMBOL_GPL(blk_set_queue_dying);
  */
 void blk_cleanup_queue(struct request_queue *q)
 {
+       WARN_ON_ONCE(blk_queue_registered(q));
+
        /* mark @q DYING, no new request or merges will be allowed afterwards */
        mutex_lock(&q->sysfs_lock);
        blk_set_queue_dying(q);

diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index a0d3ce3..81a273b 100644 (file)
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -74,10 +74,8 @@ static ssize_t blk_mq_sysfs_show(struct kobject *kobj, struct attribute *attr,
        if (!entry->show)
                return -EIO;
 
-       res = -ENOENT;
        mutex_lock(&q->sysfs_lock);
-       if (!blk_queue_dying(q))
-               res = entry->show(ctx, page);
+       res = entry->show(ctx, page);
        mutex_unlock(&q->sysfs_lock);
        return res;
 }
@@ -97,10 +95,8 @@ static ssize_t blk_mq_sysfs_store(struct kobject *kobj, struct attribute *attr,
        if (!entry->store)
                return -EIO;
 
-       res = -ENOENT;
        mutex_lock(&q->sysfs_lock);
-       if (!blk_queue_dying(q))
-               res = entry->store(ctx, page, length);
+       res = entry->store(ctx, page, length);
        mutex_unlock(&q->sysfs_lock);
        return res;
 }
@@ -120,10 +116,8 @@ static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
        if (!entry->show)
                return -EIO;
 
-       res = -ENOENT;
        mutex_lock(&q->sysfs_lock);
-       if (!blk_queue_dying(q))
-               res = entry->show(hctx, page);
+       res = entry->show(hctx, page);
        mutex_unlock(&q->sysfs_lock);
        return res;
 }
@@ -144,10 +138,8 @@ static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
        if (!entry->store)
                return -EIO;
 
-       res = -ENOENT;
        mutex_lock(&q->sysfs_lock);
-       if (!blk_queue_dying(q))
-               res = entry->store(hctx, page, length);
+       res = entry->store(hctx, page, length);
        mutex_unlock(&q->sysfs_lock);
        return res;
 }

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 46f5198..fca9b15 100644 (file)
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -801,10 +801,6 @@ queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
        if (!entry->show)
                return -EIO;
        mutex_lock(&q->sysfs_lock);
-       if (blk_queue_dying(q)) {
-               mutex_unlock(&q->sysfs_lock);
-               return -ENOENT;
-       }
        res = entry->show(q, page);
        mutex_unlock(&q->sysfs_lock);
        return res;
@@ -823,10 +819,6 @@ queue_attr_store(struct kobject *kobj, struct attribute *attr,
 
        q = container_of(kobj, struct request_queue, kobj);
        mutex_lock(&q->sysfs_lock);
-       if (blk_queue_dying(q)) {
-               mutex_unlock(&q->sysfs_lock);
-               return -ENOENT;
-       }
        res = entry->store(q, page, length);
        mutex_unlock(&q->sysfs_lock);
        return res;