[PATCH v2 04/16] relay: update relay to use mmap_prepare

[Lorenzo Stoakes <lorenzo.stoakes@oracle.com>]

It is relatively trivial to update this code to use the f_op->mmap_prepare
hook in favour of the deprecated f_op->mmap hook, so do so.

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
 kernel/relay.c | 33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/kernel/relay.c b/kernel/relay.c
index 8d915fe98198..e36f6b926f7f 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -72,17 +72,18 @@ static void relay_free_page_array(struct page **array)
 }
 
 /**
- *	relay_mmap_buf: - mmap channel buffer to process address space
- *	@buf: relay channel buffer
- *	@vma: vm_area_struct describing memory to be mapped
+ *	relay_mmap_prepare_buf: - mmap channel buffer to process address space
+ *	@buf: the relay channel buffer
+ *	@desc: describing what to map
  *
  *	Returns 0 if ok, negative on error
  *
  *	Caller should already have grabbed mmap_lock.
  */
-static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
+static int relay_mmap_prepare_buf(struct rchan_buf *buf,
+				  struct vm_area_desc *desc)
 {
-	unsigned long length = vma->vm_end - vma->vm_start;
+	unsigned long length = vma_desc_size(desc);
 
 	if (!buf)
 		return -EBADF;
@@ -90,9 +91,9 @@ static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
 	if (length != (unsigned long)buf->chan->alloc_size)
 		return -EINVAL;
 
-	vma->vm_ops = &relay_file_mmap_ops;
-	vm_flags_set(vma, VM_DONTEXPAND);
-	vma->vm_private_data = buf;
+	desc->vm_ops = &relay_file_mmap_ops;
+	desc->vm_flags |= VM_DONTEXPAND;
+	desc->private_data = buf;
 
 	return 0;
 }
@@ -749,16 +750,16 @@ static int relay_file_open(struct inode *inode, struct file *filp)
 }
 
 /**
- *	relay_file_mmap - mmap file op for relay files
- *	@filp: the file
- *	@vma: the vma describing what to map
+ *	relay_file_mmap_prepare - mmap file op for relay files
+ *	@desc: describing what to map
  *
- *	Calls upon relay_mmap_buf() to map the file into user space.
+ *	Calls upon relay_mmap_prepare_buf() to map the file into user space.
  */
-static int relay_file_mmap(struct file *filp, struct vm_area_struct *vma)
+static int relay_file_mmap_prepare(struct vm_area_desc *desc)
 {
-	struct rchan_buf *buf = filp->private_data;
-	return relay_mmap_buf(buf, vma);
+	struct rchan_buf *buf = desc->file->private_data;
+
+	return relay_mmap_prepare_buf(buf, desc);
 }
 
 /**
@@ -1006,7 +1007,7 @@ static ssize_t relay_file_read(struct file *filp,
 const struct file_operations relay_file_operations = {
 	.open		= relay_file_open,
 	.poll		= relay_file_poll,
-	.mmap		= relay_file_mmap,
+	.mmap_prepare	= relay_file_mmap_prepare,
 	.read		= relay_file_read,
 	.release	= relay_file_release,
 };
-- 
2.51.0