ocfs2: local mounts

This allows users to format an ocfs2 file system with a special flag,
OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT. When the file system sees this flag, it
will not use any cluster services, nor will it require a cluster
configuration, thus acting like a 'local' file system.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c
index 69f85ae392dc..51b020447683 100644
--- a/fs/ocfs2/mmap.c
+++ b/fs/ocfs2/mmap.c
@@ -83,10 +83,12 @@ static struct vm_operations_struct ocfs2_file_vm_ops = {
 int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
 {
         int ret = 0, lock_level = 0;
+        struct ocfs2_super *osb = OCFS2_SB(file->f_dentry->d_inode->i_sb);
 
         /* We don't want to support shared writable mappings yet. */
-        if (((vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_MAYSHARE))
-            && ((vma->vm_flags & VM_WRITE) || (vma->vm_flags & VM_MAYWRITE))) {
+        if (!ocfs2_mount_local(osb) &&
+            ((vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_MAYSHARE)) &&
+            ((vma->vm_flags & VM_WRITE) || (vma->vm_flags & VM_MAYWRITE))) {
                 mlog(0, "disallow shared writable mmaps %lx\n", vma->vm_flags);
                 /* This is -EINVAL because generic_file_readonly_mmap
                  * returns it in a similar situation. */