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Subject[PATCH 27/28] ovl: Do not do metacopy only for ioctl modifying file attr
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From: Vivek Goyal <vgoyal@redhat.com>

ovl_copy_up() by default will only do metadata only copy up (if enabled).
That means when ovl_real_ioctl() calls ovl_real_file(), it will still get
the lower file (as ovl_real_file() opens data file and not metacopy). And
that means "chattr +i" will end up modifying lower inode.

There seem to be two ways to solve this.
A. Open metacopy file in ovl_real_ioctl() and do operations on that
B. Force full copy up when FS_IOC_SETFLAGS is called.

I am resorting to option B for now as it feels little safer option. If
there are performance issues due to this, we can revisit it.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/overlayfs/file.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 953295774471..31f32fc1004b 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -389,7 +389,7 @@ static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
if (ret)
return ret;

- ret = ovl_copy_up(file_dentry(file));
+ ret = ovl_copy_up_with_data(file_dentry(file));
if (!ret) {
ret = ovl_real_ioctl(file, cmd, arg);

--
2.14.3
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