ldiskfs/kernel_patches/patches/linux-5.4/ext4-lookup-dotdot.patch

   1 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
   2 index cd01c4a..0aefa8e 100644
   3 --- a/fs/ext4/namei.c
   4 +++ b/fs/ext4/namei.c
   5 @@ -1663,6 +1663,32 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
   6                         return ERR_PTR(-EPERM);
   7                 }
   8         }
   9 +       /* ".." shouldn't go into dcache to preserve dcache hierarchy
  10 +        * otherwise we'll get parent being a child of actual child.
  11 +        * see bug 10458 for details -bzzz */
  12 +       if (inode && (dentry->d_name.name[0] == '.' &&
  13 +                     (dentry->d_name.len == 1 || (dentry->d_name.len == 2 &&
  14 +                                            dentry->d_name.name[1] == '.')))) {
  15 +               struct dentry *goal = NULL;
  16 +
  17 +               /* first, look for an existing dentry - any one is good */
  18 +               goal = d_find_any_alias(inode);
  19 +               if (goal == NULL) {
  20 +                       spin_lock(&dentry->d_lock);
  21 +                       /* there is no alias, we need to make current dentry:
  22 +                        *  a) inaccessible for __d_lookup()
  23 +                        *  b) inaccessible for iopen */
  24 +                       J_ASSERT(hlist_unhashed(&dentry->d_u.d_alias));
  25 +                       dentry->d_flags |= DCACHE_NFSFS_RENAMED;
  26 +                       /* this is d_instantiate() ... */
  27 +                       hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry);
  28 +                       dentry->d_inode = inode;
  29 +                       spin_unlock(&dentry->d_lock);
  30 +               }
  31 +               if (goal)
  32 +                       iput(inode);
  33 +               return goal;
  34 +       }
  35
  36  #ifdef CONFIG_UNICODE
  37         if (!inode && IS_CASEFOLDED(dir)) {