Re: Please backport shrink dentry list fixes to stable

["Holger Hoffstätte" <holger.hoffstaette@googlemail.com>]

On Thu, 02 Oct 2014 13:50:24 -0700, Cong Wang wrote:

> Hello,
> 
> 
> Sorry to request for backporting another large fixes to stable.
> 
> We have seen a list corruption on 3.14 stable kernel (see the end of
> this email), which I think is probably fixed by the following list of
> patches from Al:
> 
> fe91522a7ba82ca1a51b07e19954b3825e4aaa22 don't remove from shrink list in select_collect()
> 41edf278fc2f042f4e22a12ed87d19c5201210e1 dentry_kill(): don't try to remove from shrink list
> 01b6035190b024240a43ac1d8e9c6f964f5f1c63 expand the call of dentry_lru_del() in dentry_kill()
> b4f0354e968f5fabd39bc85b99fedae4a97589fe new helper: dentry_free()
> 5c47e6d0ad608987b91affbcf7d1fc12dfbe8fb4 fold try_prune_one_dentry()
> 03b3b889e79cdb6b806fc0ba9be0d71c186bbfaa fold d_kill() and d_free()
> 
> And there are 7 patches to fix the above patches:
> 
> 00fe425bc28f0ccba034a77783c09c15af4 dcache: add missing lockdep annotation

This commit does not exist and seems to be the truncated hash of the
last one (9f12600f..). I guess copypasta salad.

> 8cbf74da435d1bd13dbb790f94c7ff67b2fb6af4 dentry_kill() doesn't need the second argument now
> b2b80195d8829921506880f6dccd21cabd163d0d dealing with the rest of shrink_dentry_list() livelock
> 046b961b45f93a92e4c70525a12f3d378bced130 shrink_dentry_list(): take parent's ->d_lock earlier
> ff2fde9929feb2aef45377ce56b8b12df85dda69 expand dentry_kill(dentry, 0) in shrink_dentry_list()
> e55fd011549eae01a230e3cace6f4d031b6a3453 split dentry_kill()
> 64fd72e0a44bdd62c5ca277cb24d0d02b2d8e9dc lift the "already marked killed" case into shrink_dentry_list()
> 
> ...and one more to fix up from Linus:
> 
> 9f12600fe425bc28f0ccba034a77783c09c15af4    dcache: add missing lockdep annotation
> 
> I don't follow vfs development so could easily miss something here, Al
> should know much better than I do and may come up with a much easier
> way to fix it. Please evaluate this.

I can confirm that these apply correctly (in reverse order per paragraph) over
3.14.19 and that it still compiles.

-h