forked from luck/tmp_suning_uos_patched
nbd: use an idr to keep track of nbd devices
To prepare for dynamically adding new nbd devices to the system switch from using an array for the nbd devices and instead use an idr. This copies what loop does for keeping track of its devices. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Josef Bacik
Jens Axboe
parent
124d6db07c
commit
b0d9111a2d
@ -41,6 +41,9 @@
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#include <linux/nbd.h>
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static DEFINE_IDR(nbd_index_idr);
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static DEFINE_MUTEX(nbd_index_mutex);
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struct nbd_sock {
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struct socket *sock;
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struct mutex tx_lock;
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@ -89,9 +92,9 @@ static struct dentry *nbd_dbg_dir;
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#define NBD_MAGIC 0x68797548
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static unsigned int nbds_max = 16;
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static struct nbd_device *nbd_dev;
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static int max_part;
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static struct workqueue_struct *recv_workqueue;
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static int part_shift;
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static inline struct device *nbd_to_dev(struct nbd_device *nbd)
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{
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@ -993,6 +996,103 @@ static struct blk_mq_ops nbd_mq_ops = {
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.timeout = nbd_xmit_timeout,
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};
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static void nbd_dev_remove(struct nbd_device *nbd)
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{
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struct gendisk *disk = nbd->disk;
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nbd->magic = 0;
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if (disk) {
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del_gendisk(disk);
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blk_cleanup_queue(disk->queue);
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blk_mq_free_tag_set(&nbd->tag_set);
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put_disk(disk);
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}
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kfree(nbd);
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}
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static int nbd_dev_add(int index)
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{
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struct nbd_device *nbd;
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struct gendisk *disk;
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struct request_queue *q;
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int err = -ENOMEM;
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nbd = kzalloc(sizeof(struct nbd_device), GFP_KERNEL);
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if (!nbd)
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goto out;
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disk = alloc_disk(1 << part_shift);
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if (!disk)
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goto out_free_nbd;
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if (index >= 0) {
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err = idr_alloc(&nbd_index_idr, nbd, index, index + 1,
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GFP_KERNEL);
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if (err == -ENOSPC)
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err = -EEXIST;
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} else {
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err = idr_alloc(&nbd_index_idr, nbd, 0, 0, GFP_KERNEL);
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if (err >= 0)
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index = err;
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}
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if (err < 0)
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goto out_free_disk;
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nbd->disk = disk;
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nbd->tag_set.ops = &nbd_mq_ops;
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nbd->tag_set.nr_hw_queues = 1;
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nbd->tag_set.queue_depth = 128;
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nbd->tag_set.numa_node = NUMA_NO_NODE;
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nbd->tag_set.cmd_size = sizeof(struct nbd_cmd);
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nbd->tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
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BLK_MQ_F_SG_MERGE | BLK_MQ_F_BLOCKING;
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nbd->tag_set.driver_data = nbd;
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err = blk_mq_alloc_tag_set(&nbd->tag_set);
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if (err)
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goto out_free_idr;
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q = blk_mq_init_queue(&nbd->tag_set);
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if (IS_ERR(q)) {
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err = PTR_ERR(q);
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goto out_free_tags;
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}
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disk->queue = q;
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/*
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* Tell the block layer that we are not a rotational device
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*/
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queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue);
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queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, disk->queue);
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disk->queue->limits.discard_granularity = 512;
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blk_queue_max_discard_sectors(disk->queue, UINT_MAX);
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disk->queue->limits.discard_zeroes_data = 0;
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blk_queue_max_hw_sectors(disk->queue, 65536);
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disk->queue->limits.max_sectors = 256;
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nbd->magic = NBD_MAGIC;
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mutex_init(&nbd->config_lock);
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disk->major = NBD_MAJOR;
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disk->first_minor = index << part_shift;
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disk->fops = &nbd_fops;
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disk->private_data = nbd;
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sprintf(disk->disk_name, "nbd%d", index);
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init_waitqueue_head(&nbd->recv_wq);
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nbd_reset(nbd);
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add_disk(disk);
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return index;
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out_free_tags:
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blk_mq_free_tag_set(&nbd->tag_set);
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out_free_idr:
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idr_remove(&nbd_index_idr, index);
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out_free_disk:
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put_disk(disk);
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out_free_nbd:
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kfree(nbd);
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out:
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return err;
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}
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/*
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* And here should be modules and kernel interface
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* (Just smiley confuses emacs :-)
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@ -1000,9 +1100,7 @@ static struct blk_mq_ops nbd_mq_ops = {
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static int __init nbd_init(void)
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{
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int err = -ENOMEM;
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int i;
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int part_shift;
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BUILD_BUG_ON(sizeof(struct nbd_request) != 28);
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@ -1036,114 +1134,33 @@ static int __init nbd_init(void)
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if (!recv_workqueue)
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return -ENOMEM;
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nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL);
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if (!nbd_dev) {
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destroy_workqueue(recv_workqueue);
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return -ENOMEM;
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}
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for (i = 0; i < nbds_max; i++) {
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struct request_queue *q;
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struct gendisk *disk = alloc_disk(1 << part_shift);
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if (!disk)
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goto out;
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nbd_dev[i].disk = disk;
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nbd_dev[i].tag_set.ops = &nbd_mq_ops;
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nbd_dev[i].tag_set.nr_hw_queues = 1;
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nbd_dev[i].tag_set.queue_depth = 128;
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nbd_dev[i].tag_set.numa_node = NUMA_NO_NODE;
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nbd_dev[i].tag_set.cmd_size = sizeof(struct nbd_cmd);
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nbd_dev[i].tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
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BLK_MQ_F_SG_MERGE | BLK_MQ_F_BLOCKING;
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nbd_dev[i].tag_set.driver_data = &nbd_dev[i];
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err = blk_mq_alloc_tag_set(&nbd_dev[i].tag_set);
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if (err) {
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put_disk(disk);
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goto out;
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}
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/*
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* The new linux 2.5 block layer implementation requires
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* every gendisk to have its very own request_queue struct.
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* These structs are big so we dynamically allocate them.
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*/
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q = blk_mq_init_queue(&nbd_dev[i].tag_set);
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if (IS_ERR(q)) {
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blk_mq_free_tag_set(&nbd_dev[i].tag_set);
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put_disk(disk);
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goto out;
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}
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disk->queue = q;
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/*
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* Tell the block layer that we are not a rotational device
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*/
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queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue);
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queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, disk->queue);
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disk->queue->limits.discard_granularity = 512;
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blk_queue_max_discard_sectors(disk->queue, UINT_MAX);
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disk->queue->limits.discard_zeroes_data = 0;
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blk_queue_max_hw_sectors(disk->queue, 65536);
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disk->queue->limits.max_sectors = 256;
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}
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if (register_blkdev(NBD_MAJOR, "nbd")) {
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err = -EIO;
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goto out;
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}
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printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR);
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if (register_blkdev(NBD_MAJOR, "nbd"))
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return -EIO;
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nbd_dbg_init();
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for (i = 0; i < nbds_max; i++) {
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struct gendisk *disk = nbd_dev[i].disk;
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nbd_dev[i].magic = NBD_MAGIC;
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mutex_init(&nbd_dev[i].config_lock);
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disk->major = NBD_MAJOR;
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disk->first_minor = i << part_shift;
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disk->fops = &nbd_fops;
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disk->private_data = &nbd_dev[i];
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sprintf(disk->disk_name, "nbd%d", i);
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init_waitqueue_head(&nbd_dev[i].recv_wq);
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nbd_reset(&nbd_dev[i]);
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add_disk(disk);
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}
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mutex_lock(&nbd_index_mutex);
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for (i = 0; i < nbds_max; i++)
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nbd_dev_add(i);
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mutex_unlock(&nbd_index_mutex);
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return 0;
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}
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static int nbd_exit_cb(int id, void *ptr, void *data)
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{
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struct nbd_device *nbd = ptr;
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nbd_dev_remove(nbd);
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return 0;
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out:
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while (i--) {
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blk_mq_free_tag_set(&nbd_dev[i].tag_set);
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blk_cleanup_queue(nbd_dev[i].disk->queue);
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put_disk(nbd_dev[i].disk);
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}
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kfree(nbd_dev);
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destroy_workqueue(recv_workqueue);
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return err;
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}
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static void __exit nbd_cleanup(void)
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{
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int i;
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nbd_dbg_close();
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for (i = 0; i < nbds_max; i++) {
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struct gendisk *disk = nbd_dev[i].disk;
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nbd_dev[i].magic = 0;
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if (disk) {
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del_gendisk(disk);
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blk_cleanup_queue(disk->queue);
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blk_mq_free_tag_set(&nbd_dev[i].tag_set);
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put_disk(disk);
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}
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}
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idr_for_each(&nbd_index_idr, &nbd_exit_cb, NULL);
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idr_destroy(&nbd_index_idr);
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destroy_workqueue(recv_workqueue);
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unregister_blkdev(NBD_MAJOR, "nbd");
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kfree(nbd_dev);
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printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR);
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}
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module_init(nbd_init);
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