ovl: fix corner case of non-unique st_dev;st_ino
commit9c6d8f13e9
upstream. On non-samefs overlay without xino, non pure upper inodes should use a pseudo_dev assigned to each unique lower fs and pure upper inodes use the real upper st_dev. It is fine for an overlay pure upper inode to use the same st_dev;st_ino values as the real upper inode, because the content of those two different filesystem objects is always the same. In this case, however: - two filesystems, A and B - upper layer is on A - lower layer 1 is also on A - lower layer 2 is on B Non pure upper overlay inode, whose origin is in layer 1 will have the same st_dev;st_ino values as the real lower inode. This may result with a false positive results of 'diff' between the real lower and copied up overlay inode. Fix this by using the upper st_dev;st_ino values in this case. This breaks the property of constant st_dev;st_ino across copy up of this case. This breakage will be fixed by a later patch. Fixes:5148626b80
("ovl: allocate anon bdev per unique lower fs") Cc: stable@vger.kernel.org # v4.17+ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
84514aa3c0
commit
f96384a621
|
@ -200,8 +200,14 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
|
|||
if (ovl_test_flag(OVL_INDEX, d_inode(dentry)) ||
|
||||
(!ovl_verify_lower(dentry->d_sb) &&
|
||||
(is_dir || lowerstat.nlink == 1))) {
|
||||
stat->ino = lowerstat.ino;
|
||||
lower_layer = ovl_layer_lower(dentry);
|
||||
/*
|
||||
* Cannot use origin st_dev;st_ino because
|
||||
* origin inode content may differ from overlay
|
||||
* inode content.
|
||||
*/
|
||||
if (samefs || lower_layer->fsid)
|
||||
stat->ino = lowerstat.ino;
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
Loading…
Reference in New Issue