Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs fixes from Miklos Szeredi:
 "This contains two regression fixes: one for the xattr API update and
  one for using the mounter's creds in file creation in overlayfs.

  There's also a fix for a bug in handling hard linked AF_UNIX sockets
  that's been there from day one.  This fix is overlayfs only despite
  the fact that it touches code outside the overlay filesystem: d_real()
  is an identity function for all except overlay dentries"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fix uid/gid when creating over whiteout
  ovl: xattr filter fix
  af_unix: fix hard linked sockets on overlay
  vfs: add d_real_inode() helper

2 files changed, 17 insertions, 22 deletions

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 22f0253a3567..c2a6b0894022 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -405,12 +405,21 @@ static int ovl_create_or_link(struct dentry *dentry, int mode, dev_t rdev,
                 err = ovl_create_upper(dentry, inode, &stat, link, hardlink);
         } else {
                 const struct cred *old_cred;
+                struct cred *override_cred;
 
                 old_cred = ovl_override_creds(dentry->d_sb);
 
-                err = ovl_create_over_whiteout(dentry, inode, &stat, link,
-                                               hardlink);
+                err = -ENOMEM;
+                override_cred = prepare_creds();
+                if (override_cred) {
+                        override_cred->fsuid = old_cred->fsuid;
+                        override_cred->fsgid = old_cred->fsgid;
+                        put_cred(override_creds(override_cred));
+                        put_cred(override_cred);
 
+                        err = ovl_create_over_whiteout(dentry, inode, &stat,
+                                                       link, hardlink);
+                }
                 revert_creds(old_cred);
         }
 
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 0ed7c4012437..1dbeab6cf96e 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -238,41 +238,27 @@ out:
         return err;
 }
 
-static bool ovl_need_xattr_filter(struct dentry *dentry,
-                                  enum ovl_path_type type)
-{
-        if ((type & (__OVL_PATH_PURE | __OVL_PATH_UPPER)) == __OVL_PATH_UPPER)
-                return S_ISDIR(dentry->d_inode->i_mode);
-        else
-                return false;
-}
-
 ssize_t ovl_getxattr(struct dentry *dentry, struct inode *inode,
                      const char *name, void *value, size_t size)
 {
-        struct path realpath;
-        enum ovl_path_type type = ovl_path_real(dentry, &realpath);
+        struct dentry *realdentry = ovl_dentry_real(dentry);
 
-        if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
+        if (ovl_is_private_xattr(name))
                 return -ENODATA;
 
-        return vfs_getxattr(realpath.dentry, name, value, size);
+        return vfs_getxattr(realdentry, name, value, size);
 }
 
 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
 {
-        struct path realpath;
-        enum ovl_path_type type = ovl_path_real(dentry, &realpath);
+        struct dentry *realdentry = ovl_dentry_real(dentry);
         ssize_t res;
         int off;
 
-        res = vfs_listxattr(realpath.dentry, list, size);
+        res = vfs_listxattr(realdentry, list, size);
         if (res <= 0 || size == 0)
                 return res;
 
-        if (!ovl_need_xattr_filter(dentry, type))
-                return res;
-
         /* filter out private xattrs */
         for (off = 0; off < res;) {
                 char *s = list + off;
@@ -302,7 +288,7 @@ int ovl_removexattr(struct dentry *dentry, const char *name)
                 goto out;
 
         err = -ENODATA;
-        if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
+        if (ovl_is_private_xattr(name))
                 goto out_drop_write;
 
         if (!OVL_TYPE_UPPER(type)) {