[PATCH 03/13] aio: for async operations, make the iter argument persistent

@@ -187,6 +187,10 @@ struct aio_kiocb {
 	 * this is the underlying eventfd context to deliver events to.
 	 */
 	struct eventfd_ctx	*ki_eventfd;
+
+	struct iov_iter		ki_iter;
+	struct iovec		*ki_iovec;
+	struct iovec		ki_inline_vecs[UIO_FASTIOV];
 };
 
 /*------ sysctl variables----*/

@@ -1026,6 +1030,7 @@ static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx)
 	percpu_ref_get(&ctx->reqs);
 
 	req->ki_ctx = ctx;
+	req->ki_iovec = req->ki_inline_vecs;
 	return req;
 out_put:
 	put_reqs_available(ctx, 1);

@@ -1038,6 +1043,8 @@ static void kiocb_free(struct aio_kiocb *req)
 		fput(req->common.ki_filp);
 	if (req->ki_eventfd != NULL)
 		eventfd_ctx_put(req->ki_eventfd);
+	if (req->ki_iovec != req->ki_inline_vecs)
+		kfree(req->ki_iovec);
 	kmem_cache_free(kiocb_cachep, req);
 }
 

@@ -1417,16 +1424,14 @@ static int aio_setup_vectored_rw(int rw, char __user *buf, size_t len,
  * aio_run_iocb:
  *	Performs the initial checks and io submission.
  */
-static ssize_t aio_run_iocb(struct kiocb *req, unsigned opcode,
+static ssize_t aio_run_iocb(struct aio_kiocb *req, unsigned opcode,
 			    char __user *buf, size_t len, bool compat)
 {
-	struct file *file = req->ki_filp;
+	struct file *file = req->common.ki_filp;
 	ssize_t ret;
 	int rw;
 	fmode_t mode;
 	rw_iter_op *iter_op;
-	struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
-	struct iov_iter iter;
 
 	switch (opcode) {
 	case IOCB_CMD_PREAD:

@@ -1451,43 +1456,39 @@ rw_common:
 
 		if (opcode == IOCB_CMD_PREADV || opcode == IOCB_CMD_PWRITEV)
 			ret = aio_setup_vectored_rw(rw, buf, len,
-						&iovec, compat, &iter);
+						    &req->ki_iovec, compat,
+						    &req->ki_iter);
 		else {
-			ret = import_single_range(rw, buf, len, iovec, &iter);
-			iovec = NULL;
+			ret = import_single_range(rw, buf, len, req->ki_iovec,
+						  &req->ki_iter);
 		}
 		if (!ret)
-			ret = rw_verify_area(rw, file, &req->ki_pos,
-					     iov_iter_count(&iter));
-		if (ret < 0) {
-			kfree(iovec);
+			ret = rw_verify_area(rw, file, &req->common.ki_pos,
+					     iov_iter_count(&req->ki_iter));
+		if (ret < 0)
 			return ret;
-		}
-
-		len = ret;
 
 		if (rw == WRITE)
 			file_start_write(file);
 
-		ret = iter_op(req, &iter);
+		ret = iter_op(&req->common, &req->ki_iter);
 
 		if (rw == WRITE)
 			file_end_write(file);
-		kfree(iovec);
 		break;
 
 	case IOCB_CMD_FDSYNC:
 		if (!file->f_op->aio_fsync)
 			return -EINVAL;
 
-		ret = file->f_op->aio_fsync(req, 1);
+		ret = file->f_op->aio_fsync(&req->common, 1);
 		break;
 
 	case IOCB_CMD_FSYNC:
 		if (!file->f_op->aio_fsync)
 			return -EINVAL;
 
-		ret = file->f_op->aio_fsync(req, 0);
+		ret = file->f_op->aio_fsync(&req->common, 0);
 		break;
 
 	default:

@@ -1504,7 +1505,7 @@ rw_common:
 			     ret == -ERESTARTNOHAND ||
 			     ret == -ERESTART_RESTARTBLOCK))
 			ret = -EINTR;
-		aio_complete(req, ret, 0);
+		aio_complete(&req->common, ret, 0);
 	}
 
 	return 0;

@@ -1571,7 +1572,7 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
 	req->ki_user_iocb = user_iocb;
 	req->ki_user_data = iocb->aio_data;
 
-	ret = aio_run_iocb(&req->common, iocb->aio_lio_opcode,
+	ret = aio_run_iocb(req, iocb->aio_lio_opcode,
 			   (char __user *)(unsigned long)iocb->aio_buf,
 			   iocb->aio_nbytes,
 			   compat);