relay: update relay to use mmap_prepare

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.

Link: https://lkml.kernel.org/r/7c9e82cdddf8b573ea3edb8cdb697363e3ccb5d7.1760959442.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Pedro Falcato <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andreas Larsson <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Baolin Wang <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Chatre, Reinette <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Dave Martin <[email protected]>
Cc: Dave Young <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: James Morse <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Kevin Tian <[email protected]>
Cc: Konstantin Komarov <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Nicolas Pitre <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Robin Murohy <[email protected]>
Cc: Sumanth Korikkar <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: "Uladzislau Rezki (Sony)" <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Vivek Goyal <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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,
 };