From: Al Viro <viro@ZenIV.linux.org.uk>
To: Jeff Layton <jeff.layton@primarydata.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Bruce Fields <bfields@fieldses.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
Tejun Heo <tj@kernel.org>, NeilBrown <neilb@suse.de>
Subject: Re: [PATCH v2 00/16] nfsd/sunrpc: add support for a workqueue-based nfsd
Date: Fri, 12 Dec 2014 16:59:52 +0000 [thread overview]
Message-ID: <20141212165952.GD22149@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20141212065408.2f76c41e@tlielax.poochiereds.net>
On Fri, Dec 12, 2014 at 06:54:08AM -0500, Jeff Layton wrote:
> > Umm... I would be very surprised if it turned out to be a problem.
> > nfsd really doesn't give a fuck about its cwd and root - not in the
> > thread side of things. And (un)exporting is (a) not on a hot path
> > and (b) not done from a kernel thread anyway. fh_to_dentry and friends
> > doesn't care about root/cwd, etc.
> >
> > I don't see anything that could cause that kind of issues.
>
> I like the change overall -- it would certainly make my patch series
> simpler, but what about pathwalking? We do take the fs->lock in
> unlazy_walk. Is it possible we'd end up with more contention there?
That would take a pathname lookup in kernel thread side of nfsd that
* isn't single-component
* isn't LOOKUP_ROOT one (i.e. vfs_path_lookup() or file_open_root())
and I would really hope we don't have such things. Any such a beast would
allow probing the tree layout outside of what we export, to start with...
AFAICS, we really don't have anything of that sort. Note that e.g.
lookup_one_len() doesn't go anywhere near ->fs->lock...
next prev parent reply other threads:[~2014-12-12 16:59 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-10 19:07 [PATCH v2 00/16] nfsd/sunrpc: add support for a workqueue-based nfsd Jeff Layton
2014-12-10 19:07 ` [PATCH v2 01/16] sunrpc: add a new svc_serv_ops struct and move sv_shutdown into it Jeff Layton
2014-12-10 19:07 ` [PATCH v2 02/16] sunrpc: move sv_function into sv_ops Jeff Layton
2014-12-10 19:07 ` [PATCH v2 03/16] sunrpc: move sv_module parm " Jeff Layton
2014-12-10 19:07 ` [PATCH v2 04/16] sunrpc: turn enqueueing a svc_xprt into a svc_serv operation Jeff Layton
2014-12-10 19:07 ` [PATCH v2 05/16] sunrpc: abstract out svc_set_num_threads to sv_ops Jeff Layton
2014-12-10 19:07 ` [PATCH v2 06/16] sunrpc: move pool_mode definitions into svc.h Jeff Layton
2014-12-10 19:07 ` [PATCH v2 07/16] sunrpc: factor svc_rqst allocation and freeing from sv_nrthreads refcounting Jeff Layton
2014-12-10 19:07 ` [PATCH v2 08/16] sunrpc: set up workqueue function in svc_xprt Jeff Layton
2014-12-10 19:07 ` [PATCH v2 09/16] sunrpc: set up svc_rqst work if it's defined Jeff Layton
2014-12-10 19:07 ` [PATCH v2 10/16] sunrpc: add basic support for workqueue-based services Jeff Layton
2014-12-10 19:07 ` [PATCH v2 11/16] nfsd: keep a reference to the fs_struct in svc_rqst Jeff Layton
2014-12-10 19:07 ` [PATCH v2 12/16] nfsd: add support for workqueue based service processing Jeff Layton
2014-12-10 19:07 ` [PATCH v2 13/16] sunrpc: keep a cache of svc_rqsts for each NUMA node Jeff Layton
2014-12-10 19:07 ` [PATCH v2 14/16] sunrpc: add more tracepoints around svc_xprt handling Jeff Layton
2014-12-10 19:07 ` [PATCH v2 15/16] sunrpc: print the svc_rqst pointer value in svc_process tracepoint Jeff Layton
2014-12-10 19:08 ` [PATCH v2 16/16] sunrpc: add tracepoints around svc_sock handling Jeff Layton
2014-12-10 22:31 ` [PATCH v2 00/16] nfsd/sunrpc: add support for a workqueue-based nfsd Chuck Lever
2014-12-10 23:13 ` Jeff Layton
2014-12-12 2:12 ` Al Viro
2014-12-12 2:29 ` Linus Torvalds
2014-12-12 3:02 ` Al Viro
2014-12-12 3:06 ` Al Viro
2014-12-12 11:54 ` Jeff Layton
2014-12-12 16:59 ` Al Viro [this message]
2014-12-13 14:06 ` Jeff Layton
2014-12-13 17:29 ` Al Viro
2014-12-12 2:52 ` Al Viro
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