target/linux/generic/pending-4.9/140-jffs2-use-.rename2-and-add-RENAME_WHITEOUT-support.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Subject: jffs2: use .rename2 and add RENAME_WHITEOUT support
   3
   4 It is required for renames on overlayfs
   5
   6 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   7 ---
   8
   9 --- a/fs/jffs2/dir.c
  10 +++ b/fs/jffs2/dir.c
  11 @@ -752,6 +752,24 @@ static int jffs2_mknod (struct inode *di
  12         return ret;
  13  }
  14
  15 +static int jffs2_whiteout (struct inode *old_dir, struct dentry *old_dentry)
  16 +{
  17 +       struct dentry *wh;
  18 +       int err;
  19 +
  20 +       wh = d_alloc(old_dentry->d_parent, &old_dentry->d_name);
  21 +       if (!wh)
  22 +               return -ENOMEM;
  23 +
  24 +       err = jffs2_mknod(old_dir, wh, S_IFCHR | WHITEOUT_MODE,
  25 +                         WHITEOUT_DEV);
  26 +       if (err)
  27 +               return err;
  28 +
  29 +       d_rehash(wh);
  30 +       return 0;
  31 +}
  32 +
  33  static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
  34                          struct inode *new_dir_i, struct dentry *new_dentry,
  35                          unsigned int flags)
  36 @@ -762,7 +780,7 @@ static int jffs2_rename (struct inode *o
  37         uint8_t type;
  38         uint32_t now;
  39
  40 -       if (flags & ~RENAME_NOREPLACE)
  41 +       if (flags & ~(RENAME_NOREPLACE|RENAME_WHITEOUT))
  42                 return -EINVAL;
  43
  44         /* The VFS will check for us and prevent trying to rename a
  45 @@ -828,9 +846,14 @@ static int jffs2_rename (struct inode *o
  46         if (d_is_dir(old_dentry) && !victim_f)
  47                 inc_nlink(new_dir_i);
  48
  49 -       /* Unlink the original */
  50 -       ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
  51 -                             old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
  52 +       if (flags & RENAME_WHITEOUT)
  53 +               /* Replace with whiteout */
  54 +               ret = jffs2_whiteout(old_dir_i, old_dentry);
  55 +       else
  56 +               /* Unlink the original */
  57 +               ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
  58 +                                     old_dentry->d_name.name,
  59 +                                     old_dentry->d_name.len, NULL, now);
  60
  61         /* We don't touch inode->i_nlink */
  62