From: Chen Zhongjin chenzhongjin@huawei.com
[ Upstream commit fa81cbafbf5764ad5053512152345fab37a1fe18 ]
kmemleak reported memory leaks in device_add_disk():
kmemleak: 3 new suspected memory leaks
unreferenced object 0xffff88800f420800 (size 512): comm "modprobe", pid 4275, jiffies 4295639067 (age 223.512s) hex dump (first 32 bytes): 04 00 00 00 08 00 00 00 01 00 00 00 00 00 00 00 ................ 00 e1 f5 05 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000d3662699>] kmalloc_trace+0x26/0x60 [<00000000edc7aadc>] wbt_init+0x50/0x6f0 [<0000000069601d16>] wbt_enable_default+0x157/0x1c0 [<0000000028fc393f>] blk_register_queue+0x2a4/0x420 [<000000007345a042>] device_add_disk+0x6fd/0xe40 [<0000000060e6aab0>] nbd_dev_add+0x828/0xbf0 [nbd] ...
It is because the memory allocated in wbt_enable_default() is not released in device_add_disk() error path. Normally, these memory are freed in:
del_gendisk() rq_qos_exit() rqos->ops->exit(rqos); wbt_exit()
So rq_qos_exit() is called to free the rq_wb memory for wbt_init(). However in the error path of device_add_disk(), only blk_unregister_queue() is called and make rq_wb memory leaked.
Add rq_qos_exit() to the error path to fix it.
Fixes: 83cbce957446 ("block: add error handling for device_add_disk / add_disk") Signed-off-by: Chen Zhongjin chenzhongjin@huawei.com Reviewed-by: Christoph Hellwig hch@lst.de Link: https://lore.kernel.org/r/20221029071355.35462-1-chenzhongjin@huawei.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- block/genhd.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/block/genhd.c b/block/genhd.c index 988ba52fd331..044ff97381e3 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -519,6 +519,7 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk, bdi_unregister(disk->bdi); out_unregister_queue: blk_unregister_queue(disk); + rq_qos_exit(disk->queue); out_put_slave_dir: kobject_put(disk->slave_dir); out_put_holder_dir: