[PATCH v2 09/35] ovl: copy up file size as well

From: Miklos Szeredi
Date: Mon May 07 2018 - 04:38:48 EST


Copy i_size of the underlying inode to the overlay inode in ovl_copyattr().

This is in preparation for stacking I/O operations on overlay files.

This patch shouldn't have any observable effect.

Remove stale comment from ovl_setattr() [spotted by Vivek Goyal].

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
fs/overlayfs/inode.c | 9 ---------
fs/overlayfs/overlayfs.h | 2 ++
2 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index f7b1910bb9d4..ba3f832cc39a 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -22,15 +22,6 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
struct dentry *upperdentry;
const struct cred *old_cred;

- /*
- * Check for permissions before trying to copy-up. This is redundant
- * since it will be rechecked later by ->setattr() on upper dentry. But
- * without this, copy-up can be triggered by just about anybody.
- *
- * We don't initialize inode->size, which just means that
- * inode_newsize_ok() will always check against MAX_LFS_FILESIZE and not
- * check for a swapfile (which this won't be anyway).
- */
err = setattr_prepare(dentry, attr);
if (err)
return err;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 4e26778774c3..b9f7c632ab9c 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -9,6 +9,7 @@

#include <linux/kernel.h>
#include <linux/uuid.h>
+#include <linux/fs.h>
#include "ovl_entry.h"

enum ovl_path_type {
@@ -348,6 +349,7 @@ static inline void ovl_copyattr(struct inode *from, struct inode *to)
to->i_atime = from->i_atime;
to->i_mtime = from->i_mtime;
to->i_ctime = from->i_ctime;
+ i_size_write(to, i_size_read(from));
}

static inline void ovl_copyflags(struct inode *from, struct inode *to)
--
2.14.3