[PATCH 157/437] usb: class: convert to read/write iterators

[Jens Axboe]

Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
 drivers/usb/class/cdc-wdm.c | 18 +++++++++---------
 drivers/usb/class/usblp.c   |  6 ++++--
 drivers/usb/class/usbtmc.c  |  6 ++++--
 3 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index c8262e2f2917..a811000b5eb2 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -476,6 +476,7 @@ static ssize_t wdm_write
 	kfree(buf);
 	return rv;
 }
+FOPS_WRITE_ITER_HELPER(wdm_write);
 
 /*
  * Submit the read urb if resp_count is non-zero.
@@ -520,13 +521,12 @@ static int service_outstanding_interrupt(struct wdm_device *desc)
 	return rv;
 }
 
-static ssize_t wdm_read
-(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
+static ssize_t wdm_read(struct kiocb *iocb, struct iov_iter *to)
 {
 	int rv, cntr;
 	int i = 0;
-	struct wdm_device *desc = file->private_data;
-
+	struct wdm_device *desc = iocb->ki_filp->private_data;
+	size_t count = iov_iter_count(to);
 
 	rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 	if (rv < 0)
@@ -546,7 +546,7 @@ static ssize_t wdm_read
 			goto err;
 		}
 		i++;
-		if (file->f_flags & O_NONBLOCK) {
+		if (iocb->ki_filp->f_flags & O_NONBLOCK) {
 			if (!test_bit(WDM_READ, &desc->flags)) {
 				rv = -EAGAIN;
 				goto err;
@@ -604,8 +604,8 @@ static ssize_t wdm_read
 
 	if (cntr > count)
 		cntr = count;
-	rv = copy_to_user(buffer, desc->ubuf, cntr);
-	if (rv > 0) {
+	rv = !copy_to_iter_full(desc->ubuf, cntr, to);
+	if (rv) {
 		rv = -EFAULT;
 		goto err;
 	}
@@ -810,8 +810,8 @@ static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
 static const struct file_operations wdm_fops = {
 	.owner =	THIS_MODULE,
-	.read =		wdm_read,
-	.write =	wdm_write,
+	.read_iter =	wdm_read,
+	.write_iter =	wdm_write_iter,
 	.fsync =	wdm_fsync,
 	.open =		wdm_open,
 	.flush =	wdm_flush,
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index 5a2e43331064..2f16b7916963 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -832,6 +832,7 @@ static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t
 raise_biglock:
 	return writecount ? writecount : rv;
 }
+FOPS_WRITE_ITER_HELPER(usblp_write);
 
 /*
  * Notice that we fail to restart in a few cases: on EFAULT, on restart
@@ -885,6 +886,7 @@ static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, lo
 	mutex_unlock(&usblp->mut);
 	return count;
 }
+FOPS_READ_ITER_HELPER(usblp_read);
 
 /*
  * Wait for the write path to come idle.
@@ -1080,8 +1082,8 @@ static unsigned int usblp_quirks(__u16 vendor, __u16 product)
 
 static const struct file_operations usblp_fops = {
 	.owner =	THIS_MODULE,
-	.read =		usblp_read,
-	.write =	usblp_write,
+	.read_iter =	usblp_read_iter,
+	.write_iter =	usblp_write_iter,
 	.poll =		usblp_poll,
 	.unlocked_ioctl =	usblp_ioctl,
 	.compat_ioctl =		usblp_ioctl,
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 311007b1d904..281eeb29cf7f 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -1506,6 +1506,7 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 	kfree(buffer);
 	return retval;
 }
+FOPS_READ_ITER_HELPER(usbtmc_read);
 
 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 			    size_t count, loff_t *f_pos)
@@ -1644,6 +1645,7 @@ static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 	mutex_unlock(&data->io_mutex);
 	return retval;
 }
+FOPS_WRITE_ITER_HELPER(usbtmc_write);
 
 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 {
@@ -2261,8 +2263,8 @@ static __poll_t usbtmc_poll(struct file *file, poll_table *wait)
 
 static const struct file_operations fops = {
 	.owner		= THIS_MODULE,
-	.read		= usbtmc_read,
-	.write		= usbtmc_write,
+	.read_iter	= usbtmc_read_iter,
+	.write_iter	= usbtmc_write_iter,
 	.open		= usbtmc_open,
 	.release	= usbtmc_release,
 	.flush		= usbtmc_flush,
-- 
2.43.0