Commit e5547d2c authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: fix locked_free_list caches_free() 



Don't forget to zero locked_free_nr, it's not a disaster but makes it
attempting to flush it with extra locking when there is nothing in the
list. Also, don't traverse a potentially long list freeing requests
under spinlock, splice the list and do it afterwards.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 7c977a58

fs/io_uring.c

+5 −3
Original line number Diff line number Diff line
@@ -8708,6 +8708,7 @@ static void io_req_cache_free(struct list_head *list, struct task_struct *tsk) 
static void io_req_caches_free(struct io_ring_ctx *ctx, struct task_struct *tsk)

{

	struct io_submit_state *submit_state = &ctx->submit_state;

	struct io_comp_state *cs = &ctx->submit_state.comp;



	mutex_lock(&ctx->uring_lock);
@@ -8717,12 +8718,13 @@ static void io_req_caches_free(struct io_ring_ctx *ctx, struct task_struct *tsk) 
		submit_state->free_reqs = 0;

	}



	io_req_cache_free(&submit_state->comp.free_list, NULL);



	spin_lock_irq(&ctx->completion_lock);

	io_req_cache_free(&submit_state->comp.locked_free_list, NULL);

	list_splice_init(&cs->locked_free_list, &cs->free_list);

	cs->locked_free_nr = 0;

	spin_unlock_irq(&ctx->completion_lock);



	io_req_cache_free(&cs->free_list, NULL);



	mutex_unlock(&ctx->uring_lock);

}