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@xxxxxx>
---
drivers/block/ublk_drv.c | 127 ++++++++++++++++-----------------------
1 file changed, 53 insertions(+), 74 deletions(-)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 748247c0435be..81bfdda0f1af4 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -112,7 +112,6 @@ struct ublk_queue {
struct ublk_device {
struct gendisk *ub_disk;
- struct request_queue *ub_queue;
char *__queues;
@@ -126,6 +125,7 @@ struct ublk_device {
struct device cdev_dev;
#define UB_STATE_OPEN (1 << 0)
+#define UB_STATE_USED (1 << 1)
unsigned long state;
int ub_number;
@@ -156,8 +156,6 @@ static DEFINE_MUTEX(ublk_ctl_mutex);
static struct miscdevice ublk_misc;
-static struct lock_class_key ublk_bio_compl_lkclass;
-
static inline bool ublk_can_use_task_work(const struct ublk_queue *ubq)
{
if (IS_BUILTIN(CONFIG_BLK_DEV_UBLK) &&
@@ -209,8 +207,17 @@ static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id)
PAGE_SIZE);
}
+static void ublk_free_disk(struct gendisk *disk)
+{
+ struct ublk_device *ub = disk->private_data;
+
+ clear_bit(UB_STATE_USED, &ub->state);
+ put_device(&ub->cdev_dev);
+}
+
static const struct block_device_operations ub_fops = {
.owner = THIS_MODULE,
+ .free_disk = ublk_free_disk,
};
#define UBLK_MAX_PIN_PAGES 32
@@ -801,13 +808,15 @@ static void ublk_cancel_dev(struct ublk_device *ub)
static void ublk_stop_dev(struct ublk_device *ub)
{
mutex_lock(&ub->mutex);
- if (!disk_live(ub->ub_disk))
+ if (ub->dev_info.state != UBLK_S_DEV_LIVE)
goto unlock;
del_gendisk(ub->ub_disk);
ub->dev_info.state = UBLK_S_DEV_DEAD;
ub->dev_info.ublksrv_pid = -1;
ublk_cancel_dev(ub);
+ put_disk(ub->ub_disk);
+ ub->ub_disk = NULL;
unlock:
mutex_unlock(&ub->mutex);
cancel_delayed_work_sync(&ub->monitor_work);
@@ -1033,12 +1042,7 @@ static void ublk_cdev_rel(struct device *dev)
{
struct ublk_device *ub = container_of(dev, struct ublk_device, cdev_dev);
- blk_mq_destroy_queue(ub->ub_queue);
-
- put_disk(ub->ub_disk);
-
blk_mq_free_tag_set(&ub->tag_set);
-
ublk_deinit_queues(ub);
__ublk_destroy_dev(ub);
@@ -1078,31 +1082,24 @@ static void ublk_stop_work_fn(struct work_struct *work)
ublk_stop_dev(ub);
}
-static void ublk_update_capacity(struct ublk_device *ub)
+/* align maximum I/O size to PAGE_SIZE */
+static void ublk_align_max_io_size(struct ublk_device *ub)
{
- unsigned int max_rq_bytes;
+ unsigned int max_rq_bytes = ub->dev_info.rq_max_blocks << ub->bs_shift;
- /* make max request buffer size aligned with PAGE_SIZE */
- max_rq_bytes = round_down(ub->dev_info.rq_max_blocks <<
- ub->bs_shift, PAGE_SIZE);
- ub->dev_info.rq_max_blocks = max_rq_bytes >> ub->bs_shift;
-
- set_capacity(ub->ub_disk, ub->dev_info.dev_blocks << (ub->bs_shift - 9));
+ ub->dev_info.rq_max_blocks =
+ round_down(max_rq_bytes, PAGE_SIZE) >> ub->bs_shift;
}
-/* add disk & cdev, cleanup everything in case of failure */
+/* add tag_set & cdev, cleanup everything in case of failure */
static int ublk_add_dev(struct ublk_device *ub)
{
- struct gendisk *disk;
int err = -ENOMEM;
- int bsize;
/* We are not ready to support zero copy */
ub->dev_info.flags[0] &= ~UBLK_F_SUPPORT_ZERO_COPY;
- bsize = ub->dev_info.block_size;
- ub->bs_shift = ilog2(bsize);
-
+ ub->bs_shift = ilog2(ub->dev_info.block_size);
ub->dev_info.nr_hw_queues = min_t(unsigned int,
ub->dev_info.nr_hw_queues, nr_cpu_ids);
@@ -1119,59 +1116,16 @@ static int ublk_add_dev(struct ublk_device *ub)
ub->tag_set.cmd_size = sizeof(struct ublk_rq_data);
ub->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
ub->tag_set.driver_data = ub;
-
err = blk_mq_alloc_tag_set(&ub->tag_set);
if (err)
goto out_deinit_queues;
- ub->ub_queue = blk_mq_init_queue(&ub->tag_set);
- if (IS_ERR(ub->ub_queue)) {
- err = PTR_ERR(ub->ub_queue);
- goto out_cleanup_tags;
- }
- ub->ub_queue->queuedata = ub;
-
- disk = ub->ub_disk = blk_mq_alloc_disk_for_queue(ub->ub_queue,
- &ublk_bio_compl_lkclass);
- if (!disk) {
- err = -ENOMEM;
- goto out_free_request_queue;
- }
-
- blk_queue_logical_block_size(ub->ub_queue, bsize);
- blk_queue_physical_block_size(ub->ub_queue, bsize);
- blk_queue_io_min(ub->ub_queue, bsize);
-
- blk_queue_max_hw_sectors(ub->ub_queue, ub->dev_info.rq_max_blocks <<
- (ub->bs_shift - 9));
-
- ub->ub_queue->limits.discard_granularity = PAGE_SIZE;
-
- blk_queue_max_discard_sectors(ub->ub_queue, UINT_MAX >> 9);
- blk_queue_max_write_zeroes_sectors(ub->ub_queue, UINT_MAX >> 9);
-
- ublk_update_capacity(ub);
-
- disk->fops = &ub_fops;
- disk->private_data = ub;
- disk->queue = ub->ub_queue;
- sprintf(disk->disk_name, "ublkb%d", ub->ub_number);
-
+ ublk_align_max_io_size(ub);
mutex_init(&ub->mutex);
/* add char dev so that ublksrv daemon can be setup */
- err = ublk_add_chdev(ub);
- if (err)
- return err;
-
- /* don't expose disk now until we got start command from cdev */
+ return ublk_add_chdev(ub);
- return 0;
-
-out_free_request_queue:
- blk_mq_destroy_queue(ub->ub_queue);
-out_cleanup_tags:
- blk_mq_free_tag_set(&ub->tag_set);
out_deinit_queues:
ublk_deinit_queues(ub);
out_destroy_dev:
@@ -1209,6 +1163,7 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
int ublksrv_pid = (int)header->data[0];
unsigned long dev_blocks = header->data[1];
struct ublk_device *ub;
+ struct gendisk *disk;
int ret = -EINVAL;
if (ublksrv_pid <= 0)
@@ -1223,21 +1178,45 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd)
schedule_delayed_work(&ub->monitor_work, UBLK_DAEMON_MONITOR_PERIOD);
mutex_lock(&ub->mutex);
- if (disk_live(ub->ub_disk)) {
+ if (ub->dev_info.state == UBLK_S_DEV_LIVE ||
+ test_bit(UB_STATE_USED, &ub->state)) {
ret = -EEXIST;
goto out_unlock;
}
/* We may get disk size updated */
- if (dev_blocks) {
+ if (dev_blocks)
ub->dev_info.dev_blocks = dev_blocks;
- ublk_update_capacity(ub);
+
+ disk = blk_mq_alloc_disk(&ub->tag_set, ub);
+ if (IS_ERR(disk)) {
+ ret = PTR_ERR(disk);
+ goto out_unlock;
}
+ sprintf(disk->disk_name, "ublkb%d", ub->ub_number);
+ disk->fops = &ub_fops;
+ disk->private_data = ub;
+
+ blk_queue_logical_block_size(disk->queue, ub->dev_info.block_size);
+ blk_queue_physical_block_size(disk->queue, ub->dev_info.block_size);
+ blk_queue_io_min(disk->queue, ub->dev_info.block_size);
+ blk_queue_max_hw_sectors(disk->queue,
+ ub->dev_info.rq_max_blocks << (ub->bs_shift - 9));
+ disk->queue->limits.discard_granularity = PAGE_SIZE;
+ blk_queue_max_discard_sectors(disk->queue, UINT_MAX >> 9);
+ blk_queue_max_write_zeroes_sectors(disk->queue, UINT_MAX >> 9);
+
+ set_capacity(disk, ub->dev_info.dev_blocks << (ub->bs_shift - 9));
+
ub->dev_info.ublksrv_pid = ublksrv_pid;
- ret = add_disk(ub->ub_disk);
- if (ret)
+ ub->ub_disk = disk;
+ get_device(&ub->cdev_dev);
+ ret = add_disk(disk);
+ if (ret) {
+ put_disk(disk);
goto out_unlock;
-
+ }
+ set_bit(UB_STATE_USED, &ub->state);
ub->dev_info.state = UBLK_S_DEV_LIVE;
out_unlock:
mutex_unlock(&ub->mutex);
--
2.30.2
