• Kazuya Mio's avatar
    wake up s_wait_unfrozen when ->freeze_fs fails · e1616300
    Kazuya Mio authored
    dd slept infinitely when fsfeeze failed because of EIO.
    To fix this problem, if ->freeze_fs fails, freeze_super() wakes up
    the tasks waiting for the filesystem to become unfrozen.
    
    When s_frozen isn't SB_UNFROZEN in __generic_file_aio_write(),
    the function sleeps until FITHAW ioctl wakes up s_wait_unfrozen.
    
    However, if ->freeze_fs fails, s_frozen is set to SB_UNFROZEN and then
    freeze_super() returns an error number. In this case, FITHAW ioctl returns
    EINVAL because s_frozen is already SB_UNFROZEN. There is no way to wake up
    s_wait_unfrozen, so __generic_file_aio_write() sleeps infinitely.
    Signed-off-by: default avatarKazuya Mio <k-mio@sx.jp.nec.com>
    Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
    e1616300
super.c 29.2 KB