• Z
    jbd2: fix assertion 'jh->b_frozen_data == NULL' failure when journal aborted · 4a734f08
    Zhihao Cheng 提交于
    Following process will fail assertion 'jh->b_frozen_data == NULL' in
    jbd2_journal_dirty_metadata():
    
                       jbd2_journal_commit_transaction
    unlink(dir/a)
     jh->b_transaction = trans1
     jh->b_jlist = BJ_Metadata
                        journal->j_running_transaction = NULL
                        trans1->t_state = T_COMMIT
    unlink(dir/b)
     handle->h_trans = trans2
     do_get_write_access
      jh->b_modified = 0
      jh->b_frozen_data = frozen_buffer
      jh->b_next_transaction = trans2
     jbd2_journal_dirty_metadata
      is_handle_aborted
       is_journal_aborted // return false
    
               --> jbd2 abort <--
    
                         while (commit_transaction->t_buffers)
                          if (is_journal_aborted)
                           jbd2_journal_refile_buffer
                            __jbd2_journal_refile_buffer
                             WRITE_ONCE(jh->b_transaction,
    						jh->b_next_transaction)
                             WRITE_ONCE(jh->b_next_transaction, NULL)
                             __jbd2_journal_file_buffer(jh, BJ_Reserved)
            J_ASSERT_JH(jh, jh->b_frozen_data == NULL) // assertion failure !
    
    The reproducer (See detail in [Link]) reports:
     ------------[ cut here ]------------
     kernel BUG at fs/jbd2/transaction.c:1629!
     invalid opcode: 0000 [#1] PREEMPT SMP
     CPU: 2 PID: 584 Comm: unlink Tainted: G        W
     5.19.0-rc6-00115-g4a57a840-dirty #697
     RIP: 0010:jbd2_journal_dirty_metadata+0x3c5/0x470
     RSP: 0018:ffffc90000be7ce0 EFLAGS: 00010202
     Call Trace:
      <TASK>
      __ext4_handle_dirty_metadata+0xa0/0x290
      ext4_handle_dirty_dirblock+0x10c/0x1d0
      ext4_delete_entry+0x104/0x200
      __ext4_unlink+0x22b/0x360
      ext4_unlink+0x275/0x390
      vfs_unlink+0x20b/0x4c0
      do_unlinkat+0x42f/0x4c0
      __x64_sys_unlink+0x37/0x50
      do_syscall_64+0x35/0x80
    
    After journal aborting, __jbd2_journal_refile_buffer() is executed with
    holding @jh->b_state_lock, we can fix it by moving 'is_handle_aborted()'
    into the area protected by @jh->b_state_lock.
    
    Link: https://bugzilla.kernel.org/show_bug.cgi?id=216251
    Fixes: 470decc6 ("[PATCH] jbd2: initial copy of files from jbd")
    Signed-off-by: NZhihao Cheng <chengzhihao1@huawei.com>
    Link: https://lore.kernel.org/r/20220715125152.4022726-1-chengzhihao1@huawei.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
    4a734f08
transaction.c 85.8 KB