[PATCH 4/6] gadget/function/f_fs.c: switch to ->{read,write}_iter()

[Al Viro <viro@ZenIV.linux.org.uk>]

From: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 drivers/usb/gadget/function/f_fs.c | 136 ++++++++++++++++---------------------
 1 file changed, 58 insertions(+), 78 deletions(-)

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 11704e7..04c6542 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -856,38 +856,6 @@ error:
 	return ret;
 }
 
-static ssize_t
-ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
-		 loff_t *ptr)
-{
-	struct ffs_io_data io_data;
-	struct iovec iov = {.iov_base = buf, .iov_len = len};
-
-	ENTER();
-
-	io_data.aio = false;
-	io_data.read = false;
-	iov_iter_init(&io_data.data, WRITE, &iov, 1, len);
-
-	return ffs_epfile_io(file, &io_data);
-}
-
-static ssize_t
-ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
-{
-	struct ffs_io_data io_data;
-	struct iovec iov = {.iov_base = buf, .iov_len = len};
-
-	ENTER();
-
-	io_data.aio = false;
-	io_data.read = true;
-	io_data.to_free = NULL;
-	iov_iter_init(&io_data.data, READ, &iov, 1, len);
-
-	return ffs_epfile_io(file, &io_data);
-}
-
 static int
 ffs_epfile_open(struct inode *inode, struct file *file)
 {
@@ -924,72 +892,84 @@ static int ffs_aio_cancel(struct kiocb *kiocb)
 	return value;
 }
 
-static ssize_t ffs_epfile_aio_write(struct kiocb *kiocb,
-				    const struct iovec *iovec,
-				    unsigned long nr_segs, loff_t loff)
+static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
 {
-	struct ffs_io_data *io_data;
+	struct ffs_io_data io_data, *p = &io_data;
 	ssize_t res;
 
 	ENTER();
 
-	io_data = kmalloc(sizeof(*io_data), GFP_KERNEL);
-	if (unlikely(!io_data))
-		return -ENOMEM;
+	if (!is_sync_kiocb(kiocb)) {
+		p = kmalloc(sizeof(io_data), GFP_KERNEL);
+		if (unlikely(!p))
+			return -ENOMEM;
+		p->aio = true;
+	} else {
+		p->aio = false;
+	}
 
-	io_data->aio = true;
-	io_data->read = false;
-	io_data->kiocb = kiocb;
-	iov_iter_init(&io_data->data, WRITE, iovec, nr_segs, kiocb->ki_nbytes);
-	io_data->mm = current->mm;
+	p->read = false;
+	p->kiocb = kiocb;
+	p->data = *from;
+	p->mm = current->mm;
 
-	kiocb->private = io_data;
+	kiocb->private = p;
 
 	kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
 
-	res = ffs_epfile_io(kiocb->ki_filp, io_data);
-	if (res != -EIOCBQUEUED)
-		kfree(io_data);
+	res = ffs_epfile_io(kiocb->ki_filp, p);
+	if (res == -EIOCBQUEUED)
+		return res;
+	if (p->aio)
+		kfree(p);
+	else
+		*from = p->data;
 	return res;
 }
 
-static ssize_t ffs_epfile_aio_read(struct kiocb *kiocb,
-				   const struct iovec *iovec,
-				   unsigned long nr_segs, loff_t loff)
+static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
 {
-	struct ffs_io_data *io_data;
-	struct iovec *iovec_copy;
+	struct ffs_io_data io_data, *p = &io_data;
 	ssize_t res;
 
 	ENTER();
 
-	iovec_copy = kmalloc_array(nr_segs, sizeof(*iovec_copy), GFP_KERNEL);
-	if (unlikely(!iovec_copy))
-		return -ENOMEM;
-
-	memcpy(iovec_copy, iovec, sizeof(struct iovec)*nr_segs);
-
-	io_data = kmalloc(sizeof(*io_data), GFP_KERNEL);
-	if (unlikely(!io_data)) {
-		kfree(iovec_copy);
-		return -ENOMEM;
+	if (!is_sync_kiocb(kiocb)) {
+		p = kmalloc(sizeof(io_data), GFP_KERNEL);
+		if (unlikely(!p))
+			return -ENOMEM;
+		p->aio = true;
+	} else {
+		p->aio = false;
 	}
 
-	io_data->aio = true;
-	io_data->read = true;
-	io_data->kiocb = kiocb;
-	io_data->to_free = iovec_copy;
-	iov_iter_init(&io_data->data, READ, iovec_copy, nr_segs, kiocb->ki_nbytes);
-	io_data->mm = current->mm;
+	p->read = true;
+	p->kiocb = kiocb;
+	if (p->aio) {
+		p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
+		if (!p->to_free) {
+			kfree(p);
+			return -ENOMEM;
+		}
+	} else {
+		p->data = *to;
+		p->to_free = NULL;
+	}
+	p->mm = current->mm;
 
-	kiocb->private = io_data;
+	kiocb->private = p;
 
 	kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
 
-	res = ffs_epfile_io(kiocb->ki_filp, io_data);
-	if (res != -EIOCBQUEUED) {
-		kfree(io_data->to_free);
-		kfree(io_data);
+	res = ffs_epfile_io(kiocb->ki_filp, p);
+	if (res == -EIOCBQUEUED)
+		return res;
+
+	if (p->aio) {
+		kfree(p->to_free);
+		kfree(p);
+	} else {
+		*to = p->data;
 	}
 	return res;
 }
@@ -1071,10 +1051,10 @@ static const struct file_operations ffs_epfile_operations = {
 	.llseek =	no_llseek,
 
 	.open =		ffs_epfile_open,
-	.write =	ffs_epfile_write,
-	.read =		ffs_epfile_read,
-	.aio_write =	ffs_epfile_aio_write,
-	.aio_read =	ffs_epfile_aio_read,
+	.write =	new_sync_write,
+	.read =		new_sync_read,
+	.write_iter =	ffs_epfile_write_iter,
+	.read_iter =	ffs_epfile_read_iter,
 	.release =	ffs_epfile_release,
 	.unlocked_ioctl =	ffs_epfile_ioctl,
 };
-- 
2.1.4

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