ldiskfs/kernel_patches/patches/sles11sp2/ext4-lookup-dotdot.patch

   1 ---
   2  fs/ext4/namei.c |   42 ++++++++++++++++++++++++++++++++++++++++++
   3  1 file changed, 42 insertions(+)
   4
   5 --- a/fs/ext4/namei.c
   6 +++ b/fs/ext4/namei.c
   7 @@ -1031,6 +1031,16 @@ errout:
   8         return NULL;
   9  }
  10
  11 +static inline int
  12 +is_dot_or_dot_dot(const struct qstr *name)
  13 +{
  14 +       if (name->name[0] != '.')
  15 +               return 0;
  16 +       if (name->len == 1 || (name->len == 2 && name->name[1] == '.'))
  17 +               return 1;
  18 +       return 0;
  19 +}
  20 +
  21  static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
  22  {
  23         struct inode *inode;
  24 @@ -1061,6 +1071,38 @@ static struct dentry *ext4_lookup(struct
  25                         }
  26                 }
  27         }
  28 +
  29 +       /* ".." shouldn't go into dcache to preserve dcache hierarchy
  30 +        * otherwise we'll get parent being a child of actual child.
  31 +        * see bug 10458 for details -bzzz */
  32 +       if (inode && is_dot_or_dot_dot(&dentry->d_name)) {
  33 +               struct dentry *tmp, *goal = NULL;
  34 +               struct list_head *lp;
  35 +
  36 +               /* first, look for an existing dentry - any one is good */
  37 +               spin_lock(&inode->i_lock);
  38 +               list_for_each(lp, &inode->i_dentry) {
  39 +                       tmp = list_entry(lp, struct dentry, d_alias);
  40 +                       goal = tmp;
  41 +                       dget(goal);
  42 +                       break;
  43 +               }
  44 +               if (goal == NULL) {
  45 +                       /* there is no alias, we need to make current dentry:
  46 +                        *  a) inaccessible for __d_lookup()
  47 +                        *  b) inaccessible for iopen */
  48 +                       J_ASSERT(list_empty(&dentry->d_alias));
  49 +                       dentry->d_flags |= DCACHE_NFSFS_RENAMED;
  50 +                       /* this is d_instantiate() ... */
  51 +                       list_add(&dentry->d_alias, &inode->i_dentry);
  52 +                       dentry->d_inode = inode;
  53 +               }
  54 +               spin_unlock(&inode->i_lock);
  55 +               if (goal)
  56 +                       iput(inode);
  57 +               return goal;
  58 +       }
  59 +
  60         return d_splice_alias(inode, dentry);
  61  }
  62