[patch] fix the ext3 data=journal unmount bug

[Ken Moffat]

Here's mine:

/usr/src/linux/fs/ext3/super.c.rej


***************
*** 47,54 ****
  static void ext3_clear_journal_err(struct super_block * sb,
                     struct ext3_super_block * es);
 
- static int ext3_sync_fs(struct super_block * sb);
-
  #ifdef CONFIG_JBD_DEBUG
  int journal_no_write[2];
 
--- 47,52 ----
  static void ext3_clear_journal_err(struct super_block * sb,
                     struct ext3_super_block * es);
 
  #ifdef CONFIG_JBD_DEBUG
  int journal_no_write[2];
 
***************
*** 456,462 ****
      delete_inode:    ext3_delete_inode,    /* BKL not held.  We take it */
      put_super:    ext3_put_super,        /* BKL held */
      write_super:    ext3_write_super,    /* BKL held */
-     sync_fs:    ext3_sync_fs,
      write_super_lockfs: ext3_write_super_lockfs, /* BKL not held. Take 
it */
      unlockfs:    ext3_unlockfs,        /* BKL not held.  We take it */
      statfs:        ext3_statfs,        /* BKL held */
--- 454,459 ----
      delete_inode:    ext3_delete_inode,    /* BKL not held.  We take it */
      put_super:    ext3_put_super,        /* BKL held */
      write_super:    ext3_write_super,    /* BKL held */
      write_super_lockfs: ext3_write_super_lockfs, /* BKL not held. Take 
it */
      unlockfs:    ext3_unlockfs,        /* BKL not held.  We take it */
      statfs:        ext3_statfs,        /* BKL held */
***************
*** 1580,1601 ****
   * This implicitly triggers the writebehind on sync().
   */
 
  void ext3_write_super (struct super_block * sb)
  {
-     if (down_trylock(&sb->s_lock) == 0)
-         BUG();
-     sb->s_dirt = 0;
-     log_start_commit(EXT3_SB(sb)->s_journal, NULL);
- }
-
- static int ext3_sync_fs(struct super_block *sb)
- {
      tid_t target;
 
      sb->s_dirt = 0;
      target = log_start_commit(EXT3_SB(sb)->s_journal, NULL);
-     log_wait_commit(EXT3_SB(sb)->s_journal, target);
-     return 0;
  }
 
  /*
--- 1577,1600 ----
   * This implicitly triggers the writebehind on sync().
   */
 
+ static int do_sync_supers = 0;
+ MODULE_PARM(do_sync_supers, "i");
+ MODULE_PARM_DESC(do_sync_supers, "Write superblocks synchronously");
+
  void ext3_write_super (struct super_block * sb)
  {
      tid_t target;
 
+     if (down_trylock(&sb->s_lock) == 0)
+         BUG();        /* aviro detector */
      sb->s_dirt = 0;
      target = log_start_commit(EXT3_SB(sb)->s_journal, NULL);
+
+     if (do_sync_supers) {
+         unlock_super(sb);
+         log_wait_commit(EXT3_SB(sb)->s_journal, target);
+         lock_super(sb);
+     }
  }
 
  /*

-- 
Ken Moffat
kmoffat at drizzle.com