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dm: make sure create and remove dm device won't race with open and close table

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open_table_device() and close_table_device() is protected by
table_devices_lock, hence use it to protect add_disk() and
del_gendisk().

Prepare to track per-add_disk holder relations in dm.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221115141054.1051801-6-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Yu Kuai 2022-11-15 22:10:49 +08:00 committed by Jens Axboe
parent 7b5865831c
commit d563792c89
1 changed files with 16 additions and 0 deletions
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16
drivers/md/dm.c
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@ -1952,7 +1952,14 @@ static void cleanup_mapped_device(struct mapped_device *md)
spin_unlock(&_minor_lock);
if (dm_get_md_type(md) != DM_TYPE_NONE) {
dm_sysfs_exit(md);
/*
* Hold lock to make sure del_gendisk() won't concurrent
* with open/close_table_device().
*/
mutex_lock(&md->table_devices_lock);
del_gendisk(md->disk);
mutex_unlock(&md->table_devices_lock);
}
dm_queue_destroy_crypto_profile(md->queue);
put_disk(md->disk);
@ -2312,15 +2319,24 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
if (r)
return r;
/*
* Hold lock to make sure add_disk() and del_gendisk() won't concurrent
* with open_table_device() and close_table_device().
*/
mutex_lock(&md->table_devices_lock);
r = add_disk(md->disk);
mutex_unlock(&md->table_devices_lock);
if (r)
return r;
r = dm_sysfs_init(md);
if (r) {
mutex_lock(&md->table_devices_lock);
del_gendisk(md->disk);
mutex_unlock(&md->table_devices_lock);
return r;
}
md->type = type;
return 0;
}