io_uring: add helper to free all request caches

We have three different ones, put it in a helper for easy calling. This
is in preparation for doing it outside of ring freeing as well. With
that in mind, also ensure that we do the proper locking for safe calling
from a context where the ring it still live.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 9cd7b03a6f34c00bdc0bee49fd345879253dda42..1895fc1322527e9d88f9c577821aa6937eb4f562 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8693,10 +8693,27 @@ static void io_req_cache_free(struct list_head *list, struct task_struct *tsk)
        }
 }
 
-static void io_ring_ctx_free(struct io_ring_ctx *ctx)
+static void io_req_caches_free(struct io_ring_ctx *ctx, struct task_struct *tsk)
 {
        struct io_submit_state *submit_state = &ctx->submit_state;
 
+       mutex_lock(&ctx->uring_lock);
+
+       if (submit_state->free_reqs)
+               kmem_cache_free_bulk(req_cachep, submit_state->free_reqs,
+                                    submit_state->reqs);
+
+       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);
+       spin_unlock_irq(&ctx->completion_lock);
+
+       mutex_unlock(&ctx->uring_lock);
+}
+
+static void io_ring_ctx_free(struct io_ring_ctx *ctx)
+{
        /*
         * Some may use context even when all refs and requests have been put,
         * and they are free to do so while still holding uring_lock, see
@@ -8715,10 +8732,6 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
                ctx->mm_account = NULL;
        }
 
-       if (submit_state->free_reqs)
-               kmem_cache_free_bulk(req_cachep, submit_state->free_reqs,
-                                    submit_state->reqs);
-
 #ifdef CONFIG_BLK_CGROUP
        if (ctx->sqo_blkcg_css)
                css_put(ctx->sqo_blkcg_css);
@@ -8742,9 +8755,8 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
        percpu_ref_exit(&ctx->refs);
        free_uid(ctx->user);
        put_cred(ctx->creds);
+       io_req_caches_free(ctx, NULL);
        kfree(ctx->cancel_hash);
-       io_req_cache_free(&ctx->submit_state.comp.free_list, NULL);
-       io_req_cache_free(&ctx->submit_state.comp.locked_free_list, NULL);
        kfree(ctx);
 }