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]; + 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
