• Joonwoo Park's avatar
    configfs: file.c fix possible recursive locking · 116ba5d5
    Joonwoo Park authored
    configfs_register_subsystem() with default_groups triggers recursive locking.
    it seems that mutex_lock_nested is needed.
    
    =============================================
    [ INFO: possible recursive locking detected ]
    2.6.24-rc6 #145
    ---------------------------------------------
    swapper/1 is trying to acquire lock:
     (&sb->s_type->i_mutex_key#3){--..}, at: [<c40c9a9e>] configfs_add_file+0x2e/0x70
    
    but task is already holding lock:
     (&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca985>] configfs_register_subsystem+0x55/0x130
    
    other info that might help us debug this:
    1 lock held by swapper/1:
     #0:  (&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca985>] configfs_register_subsystem+0x55/0x130
    
    stack backtrace:
    Pid: 1, comm: swapper Not tainted 2.6.24-rc6 #145
     [<c40053ba>] show_trace_log_lvl+0x1a/0x30
     [<c4005e82>] show_trace+0x12/0x20
     [<c400687e>] dump_stack+0x6e/0x80
     [<c404ec72>] __lock_acquire+0xe62/0x1120
     [<c404efb2>] lock_acquire+0x82/0xa0
     [<c43fda88>] mutex_lock_nested+0x98/0x2e0
     [<c40c9a9e>] configfs_add_file+0x2e/0x70
     [<c40c9b0c>] configfs_create_file+0x2c/0x40
     [<c40ca639>] configfs_attach_item+0x139/0x220
     [<c40ca734>] configfs_attach_group+0x14/0x140
     [<c40ca7e9>] configfs_attach_group+0xc9/0x140
     [<c40ca9f6>] configfs_register_subsystem+0xc6/0x130
     [<c45c8186>] init_netconsole+0x2b6/0x300
     [<c45a75f2>] kernel_init+0x142/0x320
     [<c4004fb3>] kernel_thread_helper+0x7/0x14
     =======================
    Signed-off-by: default avatarJoonwoo Park <joonwpark81@gmail.com>
    Signed-off-by: default avatarJoel Becker <joel.becker@oracle.com>
    Signed-off-by: default avatarMark Fasheh <mark.fasheh@oracle.com>
    116ba5d5
file.c 9.43 KB