ublk: defer disk allocation
Defer allocating the gendisk and request_queue until UBLK_CMD_START_DEV is called. This avoids funky life times where a disk is allocated and then can be added and removed multiple times, which has never been supported by the block layer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20220721130916.1869719-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig
Jens Axboe
Родитель
c50061f0f1
Коммит
6d9e6dfdf3
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@ -112,7 +112,6 @@ struct ublk_queue {
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struct ublk_device {
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struct gendisk *ub_disk;
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struct request_queue *ub_queue;
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char *__queues;
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@ -126,6 +125,7 @@ struct ublk_device {
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struct device cdev_dev;
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#define UB_STATE_OPEN (1 << 0)
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#define UB_STATE_USED (1 << 1)
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unsigned long state;
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int ub_number;
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@ -156,8 +156,6 @@ static DEFINE_MUTEX(ublk_ctl_mutex);
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static struct miscdevice ublk_misc;
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static struct lock_class_key ublk_bio_compl_lkclass;
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static inline bool ublk_can_use_task_work(const struct ublk_queue *ubq)
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{
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if (IS_BUILTIN(CONFIG_BLK_DEV_UBLK) &&
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@ -209,8 +207,17 @@ static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id)
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PAGE_SIZE);
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}
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static void ublk_free_disk(struct gendisk *disk)
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{
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struct ublk_device *ub = disk->private_data;
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clear_bit(UB_STATE_USED, &ub->state);
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put_device(&ub->cdev_dev);
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}
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static const struct block_device_operations ub_fops = {
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.owner = THIS_MODULE,
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.free_disk = ublk_free_disk,
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};
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#define UBLK_MAX_PIN_PAGES 32
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@ -801,13 +808,15 @@ static void ublk_cancel_dev(struct ublk_device *ub)
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static void ublk_stop_dev(struct ublk_device *ub)
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{
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mutex_lock(&ub->mutex);
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if (!disk_live(ub->ub_disk))
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if (ub->dev_info.state != UBLK_S_DEV_LIVE)
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goto unlock;
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del_gendisk(ub->ub_disk);
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ub->dev_info.state = UBLK_S_DEV_DEAD;
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ub->dev_info.ublksrv_pid = -1;
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ublk_cancel_dev(ub);
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put_disk(ub->ub_disk);
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ub->ub_disk = NULL;
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unlock:
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mutex_unlock(&ub->mutex);
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cancel_delayed_work_sync(&ub->monitor_work);
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@ -1033,12 +1042,7 @@ static void ublk_cdev_rel(struct device *dev)
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{
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struct ublk_device *ub = container_of(dev, struct ublk_device, cdev_dev);
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blk_mq_destroy_queue(ub->ub_queue);
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put_disk(ub->ub_disk);
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blk_mq_free_tag_set(&ub->tag_set);
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ublk_deinit_queues(ub);
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__ublk_destroy_dev(ub);
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@ -1078,31 +1082,24 @@ static void ublk_stop_work_fn(struct work_struct *work)
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ublk_stop_dev(ub);
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}
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static void ublk_update_capacity(struct ublk_device *ub)
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/* align maximum I/O size to PAGE_SIZE */
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static void ublk_align_max_io_size(struct ublk_device *ub)
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{
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unsigned int max_rq_bytes;
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unsigned int max_rq_bytes = ub->dev_info.rq_max_blocks << ub->bs_shift;
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/* make max request buffer size aligned with PAGE_SIZE */
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max_rq_bytes = round_down(ub->dev_info.rq_max_blocks <<
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ub->bs_shift, PAGE_SIZE);
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ub->dev_info.rq_max_blocks = max_rq_bytes >> ub->bs_shift;
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set_capacity(ub->ub_disk, ub->dev_info.dev_blocks << (ub->bs_shift - 9));
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ub->dev_info.rq_max_blocks =
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round_down(max_rq_bytes, PAGE_SIZE) >> ub->bs_shift;
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}
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/* add disk & cdev, cleanup everything in case of failure */
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/* add tag_set & cdev, cleanup everything in case of failure */
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static int ublk_add_dev(struct ublk_device *ub)
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{
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struct gendisk *disk;
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int err = -ENOMEM;
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int bsize;
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/* We are not ready to support zero copy */
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ub->dev_info.flags[0] &= ~UBLK_F_SUPPORT_ZERO_COPY;
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bsize = ub->dev_info.block_size;
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ub->bs_shift = ilog2(bsize);
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ub->bs_shift = ilog2(ub->dev_info.block_size);
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ub->dev_info.nr_hw_queues = min_t(unsigned int,
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ub->dev_info.nr_hw_queues, nr_cpu_ids);
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@ -1119,59 +1116,16 @@ static int ublk_add_dev(struct ublk_device *ub)
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ub->tag_set.cmd_size = sizeof(struct ublk_rq_data);
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ub->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
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ub->tag_set.driver_data = ub;
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err = blk_mq_alloc_tag_set(&ub->tag_set);
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if (err)
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goto out_deinit_queues;
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ub->ub_queue = blk_mq_init_queue(&ub->tag_set);
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if (IS_ERR(ub->ub_queue)) {
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err = PTR_ERR(ub->ub_queue);
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goto out_cleanup_tags;
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}
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ub->ub_queue->queuedata = ub;
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disk = ub->ub_disk = blk_mq_alloc_disk_for_queue(ub->ub_queue,
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&ublk_bio_compl_lkclass);
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if (!disk) {
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err = -ENOMEM;
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goto out_free_request_queue;
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}
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blk_queue_logical_block_size(ub->ub_queue, bsize);
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blk_queue_physical_block_size(ub->ub_queue, bsize);
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blk_queue_io_min(ub->ub_queue, bsize);
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blk_queue_max_hw_sectors(ub->ub_queue, ub->dev_info.rq_max_blocks <<
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(ub->bs_shift - 9));
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ub->ub_queue->limits.discard_granularity = PAGE_SIZE;
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blk_queue_max_discard_sectors(ub->ub_queue, UINT_MAX >> 9);
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blk_queue_max_write_zeroes_sectors(ub->ub_queue, UINT_MAX >> 9);
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ublk_update_capacity(ub);
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disk->fops = &ub_fops;
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disk->private_data = ub;
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disk->queue = ub->ub_queue;
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sprintf(disk->disk_name, "ublkb%d", ub->ub_number);
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ublk_align_max_io_size(ub);
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mutex_init(&ub->mutex);
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/* add char dev so that ublksrv daemon can be setup */
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err = ublk_add_chdev(ub);
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if (err)
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return err;
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return ublk_add_chdev(ub);
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/* don't expose disk now until we got start command from cdev */
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return 0;
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out_free_request_queue:
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blk_mq_destroy_queue(ub->ub_queue);
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out_cleanup_tags:
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blk_mq_free_tag_set(&ub->tag_set);
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out_deinit_queues:
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ublk_deinit_queues(ub);
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out_destroy_dev:
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@ -1209,6 +1163,7 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
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int ublksrv_pid = (int)header->data[0];
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unsigned long dev_blocks = header->data[1];
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struct ublk_device *ub;
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struct gendisk *disk;
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int ret = -EINVAL;
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if (ublksrv_pid <= 0)
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@ -1223,21 +1178,45 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
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schedule_delayed_work(&ub->monitor_work, UBLK_DAEMON_MONITOR_PERIOD);
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mutex_lock(&ub->mutex);
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if (disk_live(ub->ub_disk)) {
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if (ub->dev_info.state == UBLK_S_DEV_LIVE ||
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test_bit(UB_STATE_USED, &ub->state)) {
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ret = -EEXIST;
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goto out_unlock;
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}
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/* We may get disk size updated */
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if (dev_blocks) {
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if (dev_blocks)
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ub->dev_info.dev_blocks = dev_blocks;
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ublk_update_capacity(ub);
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}
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ub->dev_info.ublksrv_pid = ublksrv_pid;
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ret = add_disk(ub->ub_disk);
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if (ret)
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goto out_unlock;
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disk = blk_mq_alloc_disk(&ub->tag_set, ub);
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if (IS_ERR(disk)) {
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ret = PTR_ERR(disk);
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goto out_unlock;
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}
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sprintf(disk->disk_name, "ublkb%d", ub->ub_number);
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disk->fops = &ub_fops;
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disk->private_data = ub;
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blk_queue_logical_block_size(disk->queue, ub->dev_info.block_size);
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blk_queue_physical_block_size(disk->queue, ub->dev_info.block_size);
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blk_queue_io_min(disk->queue, ub->dev_info.block_size);
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blk_queue_max_hw_sectors(disk->queue,
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ub->dev_info.rq_max_blocks << (ub->bs_shift - 9));
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disk->queue->limits.discard_granularity = PAGE_SIZE;
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blk_queue_max_discard_sectors(disk->queue, UINT_MAX >> 9);
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blk_queue_max_write_zeroes_sectors(disk->queue, UINT_MAX >> 9);
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set_capacity(disk, ub->dev_info.dev_blocks << (ub->bs_shift - 9));
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ub->dev_info.ublksrv_pid = ublksrv_pid;
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ub->ub_disk = disk;
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get_device(&ub->cdev_dev);
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ret = add_disk(disk);
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if (ret) {
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put_disk(disk);
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goto out_unlock;
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}
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set_bit(UB_STATE_USED, &ub->state);
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ub->dev_info.state = UBLK_S_DEV_LIVE;
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out_unlock:
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mutex_unlock(&ub->mutex);
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