Overlayfs cannot be notified when mmapped area gets dirty,
so we need to proactively mark inode dirty in ->mmap operation.
Signed-off-by: Chengguang Xu <cgxu519@xxxxxxxxxxxx>
---
fs/overlayfs/file.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index efccb7c1f9bc..cd6fcdfd81a9 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -486,6 +486,10 @@ static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
/* Drop reference count from new vm_file value */
fput(realfile);
} else {
+ if (vma->vm_flags & (VM_SHARED|VM_MAYSHARE) &&
+ vma->vm_flags & (VM_WRITE|VM_MAYWRITE))
+ ovl_mark_inode_dirty(file_inode(file));
+
/* Drop reference count from previous vm_file value */
fput(file);
}
--
2.26.2
