diff mbox series

[15/18] io_uring: add io_kiocb ref count

Message ID 20190207195552.22770-16-axboe@kernel.dk (mailing list archive)
State New, archived
Headers show
Series [01/18] fs: add an iopoll method to struct file_operations | expand

Commit Message

Jens Axboe Feb. 7, 2019, 7:55 p.m. UTC 
We'll use this for the POLL implementation. Regular requests will
NOT be using references, so initialize it to 0. Any real use of
the io_kiocb ref will initialize it to at least 2.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 200631cf3955..b54c70f8f8af 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -160,6 +160,7 @@  struct io_kiocb {
 	struct io_ring_ctx	*ctx;
 	struct list_head	list;
 	unsigned int		flags;
+	refcount_t		refs;
 #define REQ_F_FORCE_NONBLOCK	1	/* inline submission attempt */
 #define REQ_F_IOPOLL_COMPLETED	2	/* polled IO has completed */
 #define REQ_F_FIXED_FILE	4	/* ctx owns file */
@@ -345,6 +346,7 @@  static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx,
 
 	req->ctx = ctx;
 	req->flags = 0;
+	refcount_set(&req->refs, 0);
 	return req;
 out:
 	io_ring_drop_ctx_refs(ctx, 1);
@@ -362,8 +364,10 @@  static void io_free_req_many(struct io_ring_ctx *ctx, void **reqs, int *nr)
 
 static void io_free_req(struct io_kiocb *req)
 {
-	io_ring_drop_ctx_refs(req->ctx, 1);
-	kmem_cache_free(req_cachep, req);
+	if (!refcount_read(&req->refs) || refcount_dec_and_test(&req->refs)) {
+		io_ring_drop_ctx_refs(req->ctx, 1);
+		kmem_cache_free(req_cachep, req);
+	}
 }
 
 /*