---- 在 星期四, 2020-10-15 11:25:01 Al Viro <viro@xxxxxxxxxxxxxxxxxx> 撰写 ---- > On Sat, Oct 10, 2020 at 10:23:51PM +0800, Chengguang Xu wrote: > > Currently there is no notification api for kernel about modification > > of vfs inode, in some use cases like overlayfs, this kind of notification > > will be very helpful to implement containerized syncfs functionality. > > As the first attempt, we introduce marking inode dirty notification so that > > overlay's inode could mark itself dirty as well and then only sync dirty > > overlay inode while syncfs. > > Who's responsible for removing the crap from notifier chain? And how does > that affect the lifetime of inode? In this case, overlayfs unregisters call back from the notifier chain of upper inode when evicting it's own inode. It will not affect the lifetime of upper inode because overlayfs inode holds a reference of upper inode that means upper inode will not be evicted while overlayfs inode is still alive. Thanks, Chengguang