[PATCH] Vectorize aio_read/aio_write fileop methods

This patch vectorizes aio_read() and aio_write() methods to prepare for
collapsing all aio & vectored operations into one interface - which is
aio_read()/aio_write().

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Michael Holzheu <HOLZHEU@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 55 insertions, 25 deletions

diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index 4a000d846a93..86924f9cdd7e 100644
--- a/drivers/usb/gadget/inode.c
+++ b/drivers/usb/gadget/inode.c
@@ -533,7 +533,8 @@ struct kiocb_priv {
 	struct usb_request	*req;
 	struct ep_data		*epdata;
 	void			*buf;
-	char __user		*ubuf;		/* NULL for writes */
+	const struct iovec	*iv;
+	unsigned long		nr_segs;
 	unsigned		actual;
 };
 
@@ -561,17 +562,32 @@ static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
 {
 	struct kiocb_priv	*priv = iocb->private;
-	ssize_t			status = priv->actual;
-
-	/* we "retry" to get the right mm context for this: */
-	status = copy_to_user(priv->ubuf, priv->buf, priv->actual);
-	if (unlikely(0 != status))
-		status = -EFAULT;
-	else
-		status = priv->actual;
-	kfree(priv->buf);
-	kfree(priv);
-	return status;
+	ssize_t			len, total;
+	int			i;
+
+  	/* we "retry" to get the right mm context for this: */
+
+ 	/* copy stuff into user buffers */
+ 	total = priv->actual;
+ 	len = 0;
+ 	for (i=0; i < priv->nr_segs; i++) {
+ 		ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
+
+ 		if (copy_to_user(priv->iv[i].iov_base, priv->buf, this)) {
+ 			if (len == 0)
+ 				len = -EFAULT;
+ 			break;
+ 		}
+
+ 		total -= this;
+ 		len += this;
+ 		if (total == 0)
+ 			break;
+ 	}
+  	kfree(priv->buf);
+  	kfree(priv);
+  	aio_put_req(iocb);
+ 	return len;
 }
 
 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
@@ -584,7 +600,7 @@ static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
 	spin_lock(&epdata->dev->lock);
 	priv->req = NULL;
 	priv->epdata = NULL;
-	if (priv->ubuf == NULL
+	if (priv->iv == NULL
 			|| unlikely(req->actual == 0)
 			|| unlikely(kiocbIsCancelled(iocb))) {
 		kfree(req->buf);
@@ -619,7 +635,8 @@ ep_aio_rwtail(
 	char		*buf,
 	size_t		len,
 	struct ep_data	*epdata,
-	char __user	*ubuf
+	const struct iovec *iv,
+	unsigned long 	nr_segs
 )
 {
 	struct kiocb_priv	*priv;
@@ -634,7 +651,8 @@ fail:
 		return value;
 	}
 	iocb->private = priv;
-	priv->ubuf = ubuf;
+	priv->iv = iv;
+	priv->nr_segs = nr_segs;
 
 	value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
 	if (unlikely(value < 0)) {
@@ -674,41 +692,53 @@ fail:
 		kfree(priv);
 		put_ep(epdata);
 	} else
-		value = (ubuf ? -EIOCBRETRY : -EIOCBQUEUED);
+		value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
 	return value;
 }
 
 static ssize_t
-ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
+ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
+		unsigned long nr_segs, loff_t o)
 {
 	struct ep_data		*epdata = iocb->ki_filp->private_data;
 	char			*buf;
 
 	if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
 		return -EINVAL;
-	buf = kmalloc(len, GFP_KERNEL);
+
+	buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 	if (unlikely(!buf))
 		return -ENOMEM;
+
 	iocb->ki_retry = ep_aio_read_retry;
-	return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
+	return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
 }
 
 static ssize_t
-ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
+ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
+		unsigned long nr_segs, loff_t o)
 {
 	struct ep_data		*epdata = iocb->ki_filp->private_data;
 	char			*buf;
+	size_t			len = 0;
+	int			i = 0;
 
 	if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
 		return -EINVAL;
-	buf = kmalloc(len, GFP_KERNEL);
+
+	buf = kmalloc(iocb->ki_left, GFP_KERNEL);
 	if (unlikely(!buf))
 		return -ENOMEM;
-	if (unlikely(copy_from_user(buf, ubuf, len) != 0)) {
-		kfree(buf);
-		return -EFAULT;
+
+	for (i=0; i < nr_segs; i++) {
+		if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
+				iov[i].iov_len) != 0)) {
+			kfree(buf);
+			return -EFAULT;
+		}
+		len += iov[i].iov_len;
 	}
-	return ep_aio_rwtail(iocb, buf, len, epdata, NULL);
+	return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
 }
 
 /*----------------------------------------------------------------------*/