On Fri, 11 Nov 2022, NeilBrown wrote: > NFSv4.1 and later require the server to report a "scope". Servers with > the same scope are expected to understand each other's state ids etc, > though may not accept them - this ensure there can be no > misunderstanding. This is helpful for migration. > > Servers with different scope are known to be different and if a server > appears to change scope on a restart, lock recovery must not be > attempted. > > It is important for fail-over configurations to have the same scope for > all server instances. Linux NFSD sets scope to host name. It is common > for fail-over configurations to use different host names on different > server nodes. So the default is not good for these configurations and > must be over-ridden. > > As discussed in > https://github.com/ClusterLabs/resource-agents/issues/1644 > some HA management tools attempt to address this with calls to "unshare" > and "hostname" before running "rpc.nfsd". This is unnecessarily > cumbersome. > > This patch adds a "-S" command-line option and nfsd.scope config value > so that the scope can be set easily for nfsd. > > Signed-off-by: NeilBrown <neilb@xxxxxxx> > --- > systemd/nfs.conf.man | 1 + > utils/nfsd/nfsd.c | 19 ++++++++++++++++++- > utils/nfsd/nfsd.man | 13 ++++++++++++- > 3 files changed, 31 insertions(+), 2 deletions(-) > > diff --git a/systemd/nfs.conf.man b/systemd/nfs.conf.man > index b95c05a68759..bfd3380ff081 100644 > --- a/systemd/nfs.conf.man > +++ b/systemd/nfs.conf.man > @@ -172,6 +172,7 @@ for details. > Recognized values: > .BR threads , > .BR host , > +.BR scope , > .BR port , > .BR grace-time , > .BR lease-time , > diff --git a/utils/nfsd/nfsd.c b/utils/nfsd/nfsd.c > index 4016a761293b..169e02a84f7b 100644 > --- a/utils/nfsd/nfsd.c > +++ b/utils/nfsd/nfsd.c > @@ -23,6 +23,7 @@ > #include <sys/socket.h> > #include <netinet/in.h> > #include <arpa/inet.h> > +#include <sched.h> > > #include "conffile.h" > #include "nfslib.h" > @@ -39,6 +40,7 @@ static void usage(const char *); > static struct option longopts[] = > { > { "host", 1, 0, 'H' }, > + { "scope", 1, 0, 'S'}, > { "help", 0, 0, 'h' }, > { "no-nfs-version", 1, 0, 'N' }, > { "nfs-version", 1, 0, 'V' }, > @@ -69,6 +71,7 @@ main(int argc, char **argv) > int count = NFSD_NPROC, c, i, error = 0, portnum, fd, found_one; > char *p, *progname, *port, *rdma_port = NULL; > char **haddr = NULL; > + char *scope = NULL; > int hcounter = 0; > struct conf_list *hosts; > int socket_up = 0; > @@ -168,8 +171,9 @@ main(int argc, char **argv) > hcounter++; > } > } > + scope = conf_get_str("nfsd", "scope"); > > - while ((c = getopt_long(argc, argv, "dH:hN:V:p:P:stTuUrG:L:", longopts, NULL)) != EOF) { > + while ((c = getopt_long(argc, argv, "dH:S:hN:V:p:P:stTuUrG:L:", longopts, NULL)) != EOF) { > switch(c) { > case 'd': > xlog_config(D_ALL, 1); > @@ -190,6 +194,9 @@ main(int argc, char **argv) > haddr[hcounter] = optarg; > hcounter++; > break; > + case 'S': > + scope = optarg; > + break; > case 'P': /* XXX for nfs-server compatibility */ > case 'p': > /* only the last -p option has any effect */ > @@ -367,6 +374,16 @@ main(int argc, char **argv) > if (lease > 0) > nfssvc_set_time("lease", lease); > > + if (!scope && hcounter == 1) > + scope = haddr[0]; Sorry, I didn't mean to leave the bit in. I had originally thought that if -S wasn't given but -H was, then the first named given to -H would be used as the scope. But I subsequently realised that could cause a regression of anyone who explictly sets a hostname (in a namespace) but gives something else to -H (e.g. an IP address). So I removed it... or meant to. I will resend. NeilBrown > + if (scope) { > + if (unshare(CLONE_NEWUTS) < 0 || > + sethostname(scope, strlen(scope)) < 0) { > + xlog(L_ERROR, "Unable to set server scope: %m"); > + error = -1; > + goto out; > + } > + } > i = 0; > do { > error = nfssvc_set_sockets(protobits, haddr[i], port); > diff --git a/utils/nfsd/nfsd.man b/utils/nfsd/nfsd.man > index bb99fe2b1d89..dc05f3623465 100644 > --- a/utils/nfsd/nfsd.man > +++ b/utils/nfsd/nfsd.man > @@ -35,9 +35,17 @@ Note that > .B lockd > (which performs file locking services for NFS) may still accept > request on all known network addresses. This may change in future > -releases of the Linux Kernel. This option can be used multiple time > +releases of the Linux Kernel. This option can be used multiple times > to listen to more than one interface. > .TP > +.B \S " or " \-\-scope scope > +NFSv4.1 and later require the server to report a "scope" which is used > +by the clients to detect if two connections are to the same server. > +By default Linux NFSD uses the host name as the scope. > +.sp > +It is particularly important for high-availablity configurations to ensure > +that all potential server nodes report the same server scope. > +.TP > .B \-p " or " \-\-port port > specify a different port to listen on for NFS requests. By default, > .B rpc.nfsd > @@ -134,6 +142,9 @@ will listen on. Use of the > .B --host > option replaces all host names listed here. > .TP > +.B scope > +Set the server scope. > +.TP > .B grace-time > The grace time, for both NFSv4 and NLM, in seconds. > .TP > -- > 2.38.1 > >
