• Miao Xie's avatar
    Btrfs: introduce btrfs_{start, end}_nocow_write() for each subvolume · 8257b2dc
    Miao Xie authored
    If the snapshot creation happened after the nocow write but before the dirty
    data flush, we would fail to flush the dirty data because of no space.
    
    So we must keep track of when those nocow write operations start and when they
    end, if there are nocow writers, the snapshot creators must wait. In order
    to implement this function, I introduce btrfs_{start, end}_nocow_write(),
    which is similar to mnt_{want,drop}_write().
    
    These two functions are only used for nocow file write operations.
    Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
    Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
    8257b2dc
disk-io.c 111 KB