diff options
| author | Chengming Zhou <zhouchengming@bytedance.com> | 2023-08-21 17:56:00 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-08-22 08:58:05 -0600 |
| commit | e1dd7bc93029024af5688253b0c05181d6e01f8e (patch) | |
| tree | af06f25bebaedcb4b34985f4cb4da87c88baa240 /block/blk-mq.c | |
| parent | 851e06297f20bbd85c93bbf09469f2150d1db218 (diff) | |
| download | lwn-e1dd7bc93029024af5688253b0c05181d6e01f8e.tar.gz lwn-e1dd7bc93029024af5688253b0c05181d6e01f8e.zip | |
blk-mq: fix tags leak when shrink nr_hw_queues
Although we don't need to realloc set->tags[] when shrink nr_hw_queues,
we need to free them. Or these tags will be leaked.
How to reproduce:
1. mount -t configfs configfs /mnt
2. modprobe null_blk nr_devices=0 submit_queues=8
3. mkdir /mnt/nullb/nullb0
4. echo 1 > /mnt/nullb/nullb0/power
5. echo 4 > /mnt/nullb/nullb0/submit_queues
6. rmdir /mnt/nullb/nullb0
In step 4, will alloc 9 tags (8 submit queues and 1 poll queue), then
in step 5, new_nr_hw_queues = 5 (4 submit queues and 1 poll queue).
At last in step 6, only these 5 tags are freed, the other 4 tags leaked.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230821095602.70742-1-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq.c')
| -rw-r--r-- | block/blk-mq.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 687ec3f4f10d..afad6d06eaf7 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4379,9 +4379,13 @@ static int blk_mq_realloc_tag_set_tags(struct blk_mq_tag_set *set, int new_nr_hw_queues) { struct blk_mq_tags **new_tags; + int i; - if (set->nr_hw_queues >= new_nr_hw_queues) + if (set->nr_hw_queues >= new_nr_hw_queues) { + for (i = new_nr_hw_queues; i < set->nr_hw_queues; i++) + __blk_mq_free_map_and_rqs(set, i); goto done; + } new_tags = kcalloc_node(new_nr_hw_queues, sizeof(struct blk_mq_tags *), GFP_KERNEL, set->numa_node); |