From: Neil Brown Subject: Re: [PATCH 1/5] knfsd: Replace lock_kernel with a mutex for nfsd thread startup/shutdown locking. Date: Thu, 12 Jun 2008 13:38:42 +1000 Message-ID: <18512.39490.36187.783761@notabene.brown> References: <1213101639-26423-1-git-send-email-jlayton@redhat.com> <1213101639-26423-2-git-send-email-jlayton@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: linux-nfs@vger.kernel.org, nfsv4@linux-nfs.org, gnb@melbourne.sgi.com To: Jeff Layton Return-path: In-Reply-To: message from Jeff Layton on Tuesday June 10 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfsv4-bounces@linux-nfs.org Errors-To: nfsv4-bounces@linux-nfs.org List-ID: On Tuesday June 10, jlayton@redhat.com wrote: > From: Neil Brown > > This removes the BKL from the RPC service creation codepath. The BKL > really isn't adequate for this job since some of this info needs > protection across sleeps. > > Also, add some comments to try and clarify how the locking should work > and to make it clear that the BKL isn't necessary as long as there is > adequate locking between tasks when touching the svc_serv fields. > > Signed-off-by: Neil Brown > Signed-off-by: Jeff Layton Thanks for proceeding with this. As well as the fixes for this that you included in 2/5, you need this patch as well for correctness.... Well, you need the first hunk. The second is unrelated but probably should be fixed. The rest all looks good. NeilBrown --------------------------------- Signed-off-by: Neil Brown ### Diffstat output ./fs/nfsd/nfssvc.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff .prev/fs/nfsd/nfssvc.c ./fs/nfsd/nfssvc.c --- .prev/fs/nfsd/nfssvc.c 2008-06-12 13:27:47.000000000 +1000 +++ ./fs/nfsd/nfssvc.c 2008-06-12 13:32:14.000000000 +1000 @@ -169,10 +169,12 @@ int nfsd_vers(int vers, enum vers_op cha int nfsd_nrthreads(void) { - if (nfsd_serv == NULL) - return 0; - else - return nfsd_serv->sv_nrthreads; + int rv = 0; + mutex_lock(&nfsd_mutex); + if (nfsd_serv) + rv = nfsd_serv->sv_nrthreads; + mutex_unlock(&nfsd_mutex); + return rv; } static int killsig; /* signal that was used to kill last nfsd */ @@ -275,7 +277,7 @@ static int nfsd_init_socks(int port) SVC_SOCK_DEFAULTS); if (error < 0) lockd_down(); -} + } if (error < 0) return error; return 0;