writeback: Fix periodic writeback after fs mount
Code in blkdev.c moves a device inode to default_backing_dev_info when the last reference to the device is put and moves the device inode back to its bdi when the first reference is acquired. This includes moving to wb.b_dirty list if the device inode is dirty. The code however doesn't setup timer to wake corresponding flusher thread and while wb.b_dirty list is non-empty __mark_inode_dirty() will not set it up either. Thus periodic writeback is effectively disabled until a sync(2) call which can lead to unexpected data loss in case of crash or power failure. Fix the problem by setting up a timer for periodic writeback in case we add the first dirty inode to wb.b_dirty list in bdev_inode_switch_bdi(). Reported-by: NBert De Jonghe <Bert.DeJonghe@amplidata.com> CC: stable@vger.kernel.org # >= 3.0 Signed-off-by: NJan Kara <jack@suse.cz> Signed-off-by: NJens Axboe <axboe@kernel.dk>
Showing
想要评论请 注册 或 登录