From 483f4afc421435b7cfe5e88f74eea0b73a476d75 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 18 Mar 2006 18:34:37 -0500 Subject: [PATCH] [PATCH] fix sysfs interaction and lifetime rules handling for queues --- block/ll_rw_blk.c | 83 +++++++++++++++++++++++++++++------------- include/linux/blkdev.h | 6 +-- 2 files changed, 61 insertions(+), 28 deletions(-) diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 6dc769182052..6c793b196aa9 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -1740,16 +1740,11 @@ EXPORT_SYMBOL(blk_run_queue); * 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 @@ void blk_cleanup_queue(request_queue_t * q) 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 @@ request_queue_t *blk_alloc_queue(gfp_t gfp_mask) } 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 @@ request_queue_t *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) 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 @@ EXPORT_SYMBOL(blk_init_queue_node); 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 @@ static ssize_t 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 @@ queue_attr_store(struct kobject *kobj, struct attribute *attr, 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); + + ssize_t res; - q = container_of(kobj, struct request_queue, kobj); 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 sysfs_ops queue_sysfs_ops = { 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 @@ int blk_register_queue(struct gendisk *disk) 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 @@ void blk_unregister_queue(struct gendisk *disk) 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); } } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 80518f703538..56bb6a4e15f3 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -406,8 +406,6 @@ struct request_queue struct blk_queue_tag *queue_tags; - atomic_t refcnt; - unsigned int nr_sorted; unsigned int in_flight; @@ -426,6 +424,8 @@ struct request_queue struct request pre_flush_rq, bar_rq, post_flush_rq; struct request *orig_bar_rq; unsigned int bi_size; + + struct mutex sysfs_lock; }; #define RQ_INACTIVE (-1) @@ -727,7 +727,7 @@ extern long nr_blockdev_pages(void); int blk_get_queue(request_queue_t *); request_queue_t *blk_alloc_queue(gfp_t); request_queue_t *blk_alloc_queue_node(gfp_t, int); -#define blk_put_queue(q) blk_cleanup_queue((q)) +extern void blk_put_queue(request_queue_t *); /* * tag stuff