afs: Implement shared-writeable mmap
Implement shared-writeable mmap for AFS.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/fs/afs/file.c b/fs/afs/file.c
index c3a7bc1..675c5c2 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -19,6 +19,7 @@
#include <linux/task_io_accounting_ops.h>
#include "internal.h"
+static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
static int afs_readpage(struct file *file, struct page *page);
static void afs_invalidatepage(struct page *page, unsigned int offset,
unsigned int length);
@@ -34,7 +35,7 @@ const struct file_operations afs_file_operations = {
.llseek = generic_file_llseek,
.read_iter = generic_file_read_iter,
.write_iter = afs_file_write,
- .mmap = generic_file_readonly_mmap,
+ .mmap = afs_file_mmap,
.splice_read = generic_file_splice_read,
.fsync = afs_fsync,
.lock = afs_lock,
@@ -61,6 +62,12 @@ const struct address_space_operations afs_fs_aops = {
.writepages = afs_writepages,
};
+static const struct vm_operations_struct afs_vm_ops = {
+ .fault = filemap_fault,
+ .map_pages = filemap_map_pages,
+ .page_mkwrite = afs_page_mkwrite,
+};
+
/*
* Discard a pin on a writeback key.
*/
@@ -629,3 +636,16 @@ static int afs_releasepage(struct page *page, gfp_t gfp_flags)
_leave(" = T");
return 1;
}
+
+/*
+ * Handle setting up a memory mapping on an AFS file.
+ */
+static int afs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ int ret;
+
+ ret = generic_file_mmap(file, vma);
+ if (ret == 0)
+ vma->vm_ops = &afs_vm_ops;
+ return ret;
+}