[PATCH] fix sysfs interaction and lifetime rules handling for queues
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 6dc7691..6c793b1 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -1740,16 +1740,11 @@
* Hopefully the low level driver will have finished any
* outstanding requests first...
**/
-void blk_cleanup_queue(request_queue_t * q)
+static void blk_release_queue(struct kobject *kobj)
{
+ request_queue_t *q = container_of(kobj, struct request_queue, kobj);
struct request_list *rl = &q->rq;
- if (!atomic_dec_and_test(&q->refcnt))
- return;
-
- if (q->elevator)
- elevator_exit(q->elevator);
-
blk_sync_queue(q);
if (rl->rq_pool)
@@ -1761,6 +1756,24 @@
kmem_cache_free(requestq_cachep, q);
}
+void blk_put_queue(request_queue_t *q)
+{
+ kobject_put(&q->kobj);
+}
+EXPORT_SYMBOL(blk_put_queue);
+
+void blk_cleanup_queue(request_queue_t * q)
+{
+ mutex_lock(&q->sysfs_lock);
+ set_bit(QUEUE_FLAG_DEAD, &q->queue_flags);
+ mutex_unlock(&q->sysfs_lock);
+
+ if (q->elevator)
+ elevator_exit(q->elevator);
+
+ blk_put_queue(q);
+}
+
EXPORT_SYMBOL(blk_cleanup_queue);
static int blk_init_free_list(request_queue_t *q)
@@ -1788,6 +1801,8 @@
}
EXPORT_SYMBOL(blk_alloc_queue);
+static struct kobj_type queue_ktype;
+
request_queue_t *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
{
request_queue_t *q;
@@ -1798,11 +1813,16 @@
memset(q, 0, sizeof(*q));
init_timer(&q->unplug_timer);
- atomic_set(&q->refcnt, 1);
+
+ snprintf(q->kobj.name, KOBJ_NAME_LEN, "%s", "queue");
+ q->kobj.ktype = &queue_ktype;
+ kobject_init(&q->kobj);
q->backing_dev_info.unplug_io_fn = blk_backing_dev_unplug;
q->backing_dev_info.unplug_io_data = q;
+ mutex_init(&q->sysfs_lock);
+
return q;
}
EXPORT_SYMBOL(blk_alloc_queue_node);
@@ -1901,7 +1921,7 @@
int blk_get_queue(request_queue_t *q)
{
if (likely(!test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
- atomic_inc(&q->refcnt);
+ kobject_get(&q->kobj);
return 0;
}
@@ -3764,13 +3784,19 @@
queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
{
struct queue_sysfs_entry *entry = to_queue(attr);
- struct request_queue *q;
+ request_queue_t *q = container_of(kobj, struct request_queue, kobj);
+ ssize_t res;
- q = container_of(kobj, struct request_queue, kobj);
if (!entry->show)
return -EIO;
-
- return entry->show(q, page);
+ mutex_lock(&q->sysfs_lock);
+ if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
+ mutex_unlock(&q->sysfs_lock);
+ return -ENOENT;
+ }
+ res = entry->show(q, page);
+ mutex_unlock(&q->sysfs_lock);
+ return res;
}
static ssize_t
@@ -3778,13 +3804,20 @@
const char *page, size_t length)
{
struct queue_sysfs_entry *entry = to_queue(attr);
- struct request_queue *q;
+ request_queue_t *q = container_of(kobj, struct request_queue, kobj);
- q = container_of(kobj, struct request_queue, kobj);
+ ssize_t res;
+
if (!entry->store)
return -EIO;
-
- return entry->store(q, page, length);
+ mutex_lock(&q->sysfs_lock);
+ if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
+ mutex_unlock(&q->sysfs_lock);
+ return -ENOENT;
+ }
+ res = entry->store(q, page, length);
+ mutex_unlock(&q->sysfs_lock);
+ return res;
}
static struct sysfs_ops queue_sysfs_ops = {
@@ -3795,6 +3828,7 @@
static struct kobj_type queue_ktype = {
.sysfs_ops = &queue_sysfs_ops,
.default_attrs = default_attrs,
+ .release = blk_release_queue,
};
int blk_register_queue(struct gendisk *disk)
@@ -3807,19 +3841,17 @@
return -ENXIO;
q->kobj.parent = kobject_get(&disk->kobj);
- if (!q->kobj.parent)
- return -EBUSY;
- snprintf(q->kobj.name, KOBJ_NAME_LEN, "%s", "queue");
- q->kobj.ktype = &queue_ktype;
-
- ret = kobject_register(&q->kobj);
+ ret = kobject_add(&q->kobj);
if (ret < 0)
return ret;
+ kobject_uevent(&q->kobj, KOBJ_ADD);
+
ret = elv_register_queue(q);
if (ret) {
- kobject_unregister(&q->kobj);
+ kobject_uevent(&q->kobj, KOBJ_REMOVE);
+ kobject_del(&q->kobj);
return ret;
}
@@ -3833,7 +3865,8 @@
if (q && q->request_fn) {
elv_unregister_queue(q);
- kobject_unregister(&q->kobj);
+ kobject_uevent(&q->kobj, KOBJ_REMOVE);
+ kobject_del(&q->kobj);
kobject_put(&disk->kobj);
}
}