Messages in this thread | | | Date | Sun, 11 Jul 2004 01:25:49 +1000 | From | Greg Banks <> | Subject | Re: [autofs] Re: umount() and NFS races in 2.4.26 |
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On Sat, Jul 10, 2004 at 02:57:46PM +0800, raven@themaw.net wrote: > On Thu, 8 Jul 2004, Thomas Moestl wrote: > > I believe that I have found two problems: > > > > - The NFS async unlink code (fs/nfs/unlink.c) does keep a dentry for > > later asynchronous processing, but the mount point is unbusied via > > path_release() once sys_unlink() returns (fs/namei.c). [...]
This used to be a bug. It was fixed in 2.4.26 with
http://linux.bkbits.net:8080/linux-2.4/diffs/fs/nfs/dir.c@1.13
What happens now is that the dentry and its inode are cleaned up when the async unlink task is deleted in nfs_put_super() between the first and second calls to invalidate_inodes() in kill_super().
> > - There is a SMP race between the shrink_dcache_parent() (fs/dcache.c) > > called from kill_super() and prune_dache() called via > > shrink_dache_memory() (called by kswapd), as follows: [...]
Your scenario sounds plausible and might explain at least some of the autofs unmount races we've been seeing.
> > In the attached patch, I have used a semaphore to serialize purging > > accesses to the dentry_unused list. [...]
Can we see the patch please?
Greg. -- Greg Banks, R&D Software Engineer, SGI Australian Software Group. I don't speak for SGI. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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