[PATCH -next] io_uring: Remove unneeded if-null-free check

[PATCH -next] io_uring: Remove unneeded if-null-free check

[Zheng Yongjun]

Eliminate the following coccicheck warning:

fs/io_uring.c:6056:4-9: WARNING: NULL check before some freeing functions is not needed.
fs/io_uring.c:1744:2-7: WARNING: NULL check before some freeing functions is not needed.
fs/io_uring.c:3340:2-7: WARNING: NULL check before some freeing functions is not needed.
fs/io_uring.c:4612:2-7: WARNING: NULL check before some freeing functions is not needed.
fs/io_uring.c:4375:2-7: WARNING: NULL check before some freeing functions is not needed.
fs/io_uring.c:3441:2-7: WARNING: NULL check before some freeing functions is not needed.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
---
 fs/io_uring.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 5f82954004f6..6d0b3d09d92d 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1740,8 +1740,7 @@ static void io_dismantle_req(struct io_kiocb *req)
 		io_put_file(req->file);
 	if (req->fixed_rsrc_refs)
 		percpu_ref_put(req->fixed_rsrc_refs);
-	if (req->async_data)
-		kfree(req->async_data);
+	kfree(req->async_data);
 	if (req->work.creds) {
 		put_cred(req->work.creds);
 		req->work.creds = NULL;
@@ -3336,8 +3335,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
 	kiocb_done(kiocb, ret, issue_flags);
 out_free:
 	/* it's faster to check here then delegate to kfree */
-	if (iovec)
-		kfree(iovec);
+	kfree(iovec);
 	return 0;
 }
 
@@ -3437,8 +3435,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
 	}
 out_free:
 	/* it's reportedly faster than delegating the null check to kfree() */
-	if (iovec)
-		kfree(iovec);
+	kfree(iovec);
 	return ret;
 }
 
@@ -4371,8 +4368,7 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
 		ret = -EINTR;
 
 	/* fast path, check for non-NULL to avoid function call */
-	if (kmsg->free_iov)
-		kfree(kmsg->free_iov);
+	kfree(kmsg->free_iov);
 	req->flags &= ~REQ_F_NEED_CLEANUP;
 	if (ret < min_ret)
 		req_set_fail_links(req);
@@ -4608,8 +4604,7 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
 	if (req->flags & REQ_F_BUFFER_SELECTED)
 		cflags = io_put_recv_kbuf(req);
 	/* fast path, check for non-NULL to avoid function call */
-	if (kmsg->free_iov)
-		kfree(kmsg->free_iov);
+	kfree(kmsg->free_iov);
 	req->flags &= ~REQ_F_NEED_CLEANUP;
 	if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
 		req_set_fail_links(req);
@@ -6052,8 +6047,7 @@ static void io_clean_op(struct io_kiocb *req)
 		case IORING_OP_WRITE_FIXED:
 		case IORING_OP_WRITE: {
 			struct io_async_rw *io = req->async_data;
-			if (io->free_iovec)
-				kfree(io->free_iovec);
+			kfree(io->free_iovec);
 			break;
 			}
 		case IORING_OP_RECVMSG:
-- 
2.25.1

Re: [PATCH -next] io_uring: Remove unneeded if-null-free check

[Pavel Begunkov]

On 6/2/21 7:54 AM, Zheng Yongjun wrote:
> Eliminate the following coccicheck warning:
> 
> fs/io_uring.c:6056:4-9: WARNING: NULL check before some freeing functions is not needed.
> fs/io_uring.c:1744:2-7: WARNING: NULL check before some freeing functions is not needed.
> fs/io_uring.c:3340:2-7: WARNING: NULL check before some freeing functions is not needed.
> fs/io_uring.c:4612:2-7: WARNING: NULL check before some freeing functions is not needed.
> fs/io_uring.c:4375:2-7: WARNING: NULL check before some freeing functions is not needed.
> fs/io_uring.c:3441:2-7: WARNING: NULL check before some freeing functions is not needed.

Take a look at the comments right above changed lines.

> 
> Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
> ---
>  fs/io_uring.c | 18 ++++++------------
>  1 file changed, 6 insertions(+), 12 deletions(-)
[...]
>  	/* it's reportedly faster than delegating the null check to kfree() */
> -	if (iovec)
> -		kfree(iovec);
> +	kfree(iovec);
[...]

-- 
Pavel Begunkov