Now when everything is prepared, add support in xfs to accept MAP_SYNC
as an mmap(2) flag.
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/ext4/file.c | 1 +
fs/xfs/xfs_file.c | 23 +++++++++++++++++++++++
2 files changed, 24 insertions(+)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index f013cda84b3d..6b597cc6b29d 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -26,6 +26,7 @@
#include <linux/quotaops.h>
#include <linux/pagevec.h>
#include <linux/uio.h>
+#include <linux/mman.h>
#include "ext4.h"
#include "ext4_jbd2.h"
#include "xattr.h"
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index c45f24ffab22..fb135224476d 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -44,6 +44,7 @@
#include <linux/falloc.h>
#include <linux/pagevec.h>
#include <linux/backing-dev.h>
+#include <linux/mman.h>
static const struct vm_operations_struct xfs_file_vm_ops;
@@ -1142,6 +1143,27 @@ xfs_file_mmap(
return 0;
}
+#define XFS_MAP_SUPPORTED (LEGACY_MAP_MASK | MAP_SYNC)
+
+static int
+xfs_file_mmap_validate(
+ struct file *filp,
+ struct vm_area_struct *vma,
+ unsigned long map_flags)
+{
+ if (map_flags & ~XFS_MAP_SUPPORTED)
+ return -EOPNOTSUPP;
+
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(filp)) && (map_flags & MAP_SYNC))
+ return -EOPNOTSUPP;
+
+ return xfs_file_mmap(filp, vma);
+}
+
const struct file_operations xfs_file_operations = {
.llseek = xfs_file_llseek,
.read_iter = xfs_file_read_iter,
@@ -1153,6 +1175,7 @@ const struct file_operations xfs_file_operations = {
.compat_ioctl = xfs_file_compat_ioctl,
#endif
.mmap = xfs_file_mmap,
+ .mmap_validate = xfs_file_mmap_validate,
.open = xfs_file_open,
.release = xfs_file_release,
.fsync = xfs_file_fsync,
--
2.12.3
