From: Pavel Begunkov <asml.silence@gmail.com>
Date: Fri, 9 May 2025 11:12:53 +0000 (+0100)
Subject: io_uring: count allocated requests
X-Git-Tag: v6.16-rc1~215^2~21
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=63de899cb6220357dea9d0f4e5aa459ff5193bb0;p=thirdparty%2Fkernel%2Flinux.git

io_uring: count allocated requests

Keep track of the number requests a ring currently has allocated (and
not freed), it'll be needed in the next patch.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c8f8308294dc2a1cb8925d984d937d4fc14ab5d4.1746788718.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 7e23e993280ee..73b289b48280d 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -435,6 +435,7 @@ struct io_ring_ctx {
 
 	/* protected by ->completion_lock */
 	unsigned			evfd_last_cq_tail;
+	unsigned			nr_req_allocated;
 
 	/*
 	 * Protection for resize vs mmap races - both the mmap and resize
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 6efecb46c828c..714b66ab34b0e 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -957,6 +957,8 @@ __cold bool __io_alloc_req_refill(struct io_ring_ctx *ctx)
 	}
 
 	percpu_ref_get_many(&ctx->refs, ret);
+	ctx->nr_req_allocated += ret;
+
 	while (ret--) {
 		struct io_kiocb *req = reqs[ret];
 
@@ -2694,8 +2696,10 @@ static void io_req_caches_free(struct io_ring_ctx *ctx)
 		kmem_cache_free(req_cachep, req);
 		nr++;
 	}
-	if (nr)
+	if (nr) {
+		ctx->nr_req_allocated -= nr;
 		percpu_ref_put_many(&ctx->refs, nr);
+	}
 	mutex_unlock(&ctx->uring_lock);
 }
 
@@ -2732,6 +2736,9 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
 	percpu_ref_exit(&ctx->refs);
 	free_uid(ctx->user);
 	io_req_caches_free(ctx);
+
+	WARN_ON_ONCE(ctx->nr_req_allocated);
+
 	if (ctx->hash_map)
 		io_wq_put_hash(ctx->hash_map);
 	io_napi_free(ctx);