• Chao Yu's avatar
    f2fs: support data flush in background · 36b35a0d
    Chao Yu authored
    Previously, when finishing a checkpoint, we have persisted all fs meta
    info including meta inode, node inode, dentry page of directory inode, so,
    after a sudden power cut, f2fs can recover from last checkpoint with full
    directory structure.
    But during checkpoint, we didn't flush dirty pages of regular and symlink
    inode, so such dirty datas still in memory will be lost in that moment of
    power off.
    In order to reduce the chance of lost data, this patch enables
    f2fs_balance_fs_bg with the ability of data flushing. It will try to flush
    user data before starting a checkpoint. So user's data written after last
    checkpoint which may not be fsynced could be saved.
    When we mount with data_flush option, after every period of cp_interval
    (could be configured in sysfs: /sys/fs/f2fs/device/cp_interval) seconds
    user data could be flushed into device once f2fs_balance_fs_bg was called
    in kworker thread or gc thread.
    Signed-off-by: default avatarChao Yu <chao2.yu@samsung.com>
    Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
segment.c 62.2 KB