Messages in this thread | | | From | Jeff Layton <> | Date | Sat, 13 Dec 2014 09:06:45 -0500 | Subject | Re: [PATCH v2 00/16] nfsd/sunrpc: add support for a workqueue-based nfsd |
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On Fri, 12 Dec 2014 16:59:52 +0000 Al Viro <viro@ZenIV.linux.org.uk> wrote:
> 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...
Ahh right. Ok, then I don't see any issue with this so far. Maybe worth letting it stew in -next once -rc1 ships? Thanks!
Acked-by: Jeff Layton <jlayton@primarydata.com>
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