lkml.org 
[lkml]   [2010]   [Oct]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 04/19] fs: Implement lazy LRU updates for inodes.
On Sun, Oct 17, 2010 at 04:29:24AM +1100, Nick Piggin wrote:
> > I don't think the pointer check will work either. By the time we retake
> > the lru lock the inode might already have been reaped through a call
> > to invalidate_inodes. There's no way we can do anything with it after
>
> I don't think you're right. If we re take inode_lock, ensure it is on
> the LRU, and call the can_unuse checks, there is no more problem than
> the regular loop taking items from the LRU, AFAIKS.

As long as we have the global inode lock it should indeed be safe.
But once we have a separate lru lock (global or per-zone, with or
without i_lock during the addition) there is nothing preventing the
inode from getting reused and re-added to the lru in the meantime.
Sure this is an extremly unlikely case, but there is no locking to
prevent it once inode_lock is gone.



\
 
 \ /
  Last update: 2010-10-17 02:49    [W:0.128 / U:0.140 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site