ldiskfs/kernel_patches/patches/ubuntu18/ext4-hash-indexed-dir-dotdot-update.patch

   1 Index: linux-4.15.0/fs/ext4/namei.c
   2 ===================================================================
   3 --- linux-4.15.0.orig/fs/ext4/namei.c
   4 +++ linux-4.15.0/fs/ext4/namei.c
   5 @@ -2043,6 +2043,74 @@ out_frames:
   6         return retval;
   7  }
   8
   9 +/* update ".." for hash-indexed directory, split the item "." if necessary */
  10 +static int ext4_update_dotdot(handle_t *handle, struct dentry *dentry,
  11 +                             struct inode *inode)
  12 +{
  13 +       struct inode *dir = dentry->d_parent->d_inode;
  14 +       struct buffer_head *dir_block;
  15 +       struct ext4_dir_entry_2 *de;
  16 +       int len, journal = 0, err = 0;
  17 +
  18 +       if (IS_ERR(handle))
  19 +               return PTR_ERR(handle);
  20 +
  21 +       if (IS_DIRSYNC(dir))
  22 +               handle->h_sync = 1;
  23 +
  24 +       dir_block = ext4_bread(handle, dir, 0, 0);
  25 +       if (IS_ERR(dir_block)) {
  26 +               err = PTR_ERR(dir_block);
  27 +               goto out;
  28 +       }
  29 +
  30 +       de = (struct ext4_dir_entry_2 *)dir_block->b_data;
  31 +       /* the first item must be "." */
  32 +       assert(de->name_len == 1 && de->name[0] == '.');
  33 +       len = le16_to_cpu(de->rec_len);
  34 +       assert(len >= EXT4_DIR_REC_LEN(1));
  35 +       if (len > EXT4_DIR_REC_LEN(1)) {
  36 +               BUFFER_TRACE(dir_block, "get_write_access");
  37 +               err = ext4_journal_get_write_access(handle, dir_block);
  38 +               if (err)
  39 +                       goto out_journal;
  40 +
  41 +               journal = 1;
  42 +               de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(1));
  43 +       }
  44 +
  45 +       len -= EXT4_DIR_REC_LEN(1);
  46 +       assert(len == 0 || len >= EXT4_DIR_REC_LEN(2));
  47 +       de = (struct ext4_dir_entry_2 *)
  48 +                       ((char *) de + le16_to_cpu(de->rec_len));
  49 +       if (!journal) {
  50 +               BUFFER_TRACE(dir_block, "get_write_access");
  51 +               err = ext4_journal_get_write_access(handle, dir_block);
  52 +               if (err)
  53 +                       goto out_journal;
  54 +       }
  55 +
  56 +       de->inode = cpu_to_le32(inode->i_ino);
  57 +       if (len > 0)
  58 +               de->rec_len = cpu_to_le16(len);
  59 +       else
  60 +               assert(le16_to_cpu(de->rec_len) >= EXT4_DIR_REC_LEN(2));
  61 +       de->name_len = 2;
  62 +       strcpy(de->name, "..");
  63 +       ext4_set_de_type(dir->i_sb, de, S_IFDIR);
  64 +
  65 +out_journal:
  66 +       if (journal) {
  67 +               BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
  68 +               err = ext4_handle_dirty_dirent_node(handle, dir, dir_block);
  69 +               ext4_mark_inode_dirty(handle, dir);
  70 +       }
  71 +       brelse(dir_block);
  72 +
  73 +out:
  74 +       return err;
  75 +}
  76 +
  77  /*
  78   *     ext4_add_entry()
  79   *
  80 @@ -2091,6 +2159,9 @@ static int ext4_add_entry(handle_t *hand
  81         }
  82
  83         if (is_dx(dir)) {
  84 +               if (dentry->d_name.len == 2 &&
  85 +                   memcmp(dentry->d_name.name, "..", 2) == 0)
  86 +                       return ext4_update_dotdot(handle, dentry, inode);
  87                 retval = ext4_dx_add_entry(handle, &fname, dir, inode);
  88                 if (!retval || (retval != ERR_BAD_DX_DIR))
  89                         goto out;