On Wed, Apr 03, 2019 at 06:19:21PM +0100, Al Viro wrote: > On Wed, Apr 03, 2019 at 06:08:11PM +0100, Al Viro wrote: > > > Oh, *brilliant* > > > > Let's do d_invalidate() on random dentries and hope they go away. > > With convoluted and brittle logics for deciding which ones to > > spare, which is actually wrong. This will pick mountpoints > > and tear them out, to start with. > > > > NAKed-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> > > > > And this is a NAK for the entire approach; if it has a positive refcount, > > LEAVE IT ALONE. Period. Don't play this kind of games, they are wrong. > > d_invalidate() is not something that can be done to an arbitrary dentry. > > PS: "try to evict what can be evicted out of this set" can be done, but > you want something like > start with empty list > go through your array of references > grab dentry->d_lock > if dentry->d_lockref.count is not zero > unlock and continue > if dentry->d_flags & DCACHE_SHRINK_LIST > ditto, it's not for us to play with > if (dentry->d_flags & DCACHE_LRU_LIST) > d_lru_del(dentry); > d_shrink_add(dentry, &list); > unlock > > on the collection phase and > if the list is not empty by the end of that loop > shrink_dentry_list(&list); > on the disposal. Implemented as suggested, thanks. RFCv3 to come when we have some stats for you :) thanks, Tobin.
