From 72ae199db4be7bf0092e15adaa8a43ce2434bf9f Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Thu, 16 Sep 2010 14:34:39 -0400 Subject: [PATCH] rpc.nfsd: mount up nfsdfs is it doesn't appear to be mounted yet There's a bit of a chicken and egg problem when nfsd is run the first time. On Fedora/RHEL at least, /proc/fs/nfsd is mounted up whenever nfsd is plugged in via a modprobe.conf "install" directive. If someone runs rpc.nfsd without plugging in nfsd.ko first, /proc/fs/nfsd won't be mounted and rpc.nfsd will end up using the legacy nfsctl interface. After that, nfsd will be plugged in and subsequent rpc.nfsd invocations will use that instead. This is a problem as some nfsd command-line options are ignored when the legacy interface is used. It'll also be a problem for people who want IPv6 enabled servers. The upshot is that we really don't want to use the legacy interface unless there is no other option. To avoid this situation, have rpc.nfsd check to see if the "threads" file is already present. If it's not, then make an attempt to mount /proc/fs/nfsd. This is a "best-effort" sort of thing, however so we just ignore the return code from the mount attempt and fall back to using nfsctl() if it fails. Signed-off-by: Jeff Layton Signed-off-by: Steve Dickson --- utils/nfsd/nfsd.c | 3 +++ utils/nfsd/nfssvc.c | 52 ++++++++++++++++++++++++++++++++++++++++++--- utils/nfsd/nfssvc.h | 1 + 3 files changed, 53 insertions(+), 3 deletions(-) diff --git a/utils/nfsd/nfsd.c b/utils/nfsd/nfsd.c index 1cda1e5..658b8fa 100644 --- a/utils/nfsd/nfsd.c +++ b/utils/nfsd/nfsd.c @@ -246,6 +246,9 @@ main(int argc, char **argv) exit(1); } + /* make sure nfsdfs is mounted if it's available */ + nfssvc_mount_nfsdfs(progname); + /* can only change number of threads if nfsd is already up */ if (nfssvc_inuse()) { socket_up = 1; diff --git a/utils/nfsd/nfssvc.c b/utils/nfsd/nfssvc.c index 34c67ca..7693626 100644 --- a/utils/nfsd/nfssvc.c +++ b/utils/nfsd/nfssvc.c @@ -15,9 +15,11 @@ #include #include #include +#include #include #include #include +#include #include "nfslib.h" #include "xlog.h" @@ -31,9 +33,13 @@ */ #undef IPV6_SUPPORTED -#define NFSD_PORTS_FILE "/proc/fs/nfsd/portlist" -#define NFSD_VERS_FILE "/proc/fs/nfsd/versions" -#define NFSD_THREAD_FILE "/proc/fs/nfsd/threads" +#ifndef NFSD_FS_DIR +#define NFSD_FS_DIR "/proc/fs/nfsd" +#endif + +#define NFSD_PORTS_FILE NFSD_FS_DIR "/portlist" +#define NFSD_VERS_FILE NFSD_FS_DIR "/versions" +#define NFSD_THREAD_FILE NFSD_FS_DIR "/threads" /* * declaring a common static scratch buffer here keeps us from having to @@ -43,6 +49,46 @@ */ char buf[128]; +/* + * Using the "new" interfaces for nfsd requires that /proc/fs/nfsd is + * actually mounted. Make an attempt to mount it here if it doesn't appear + * to be. If the mount attempt fails, no big deal -- fall back to using nfsctl + * instead. + */ +void +nfssvc_mount_nfsdfs(char *progname) +{ + int err; + struct stat statbuf; + + err = stat(NFSD_THREAD_FILE, &statbuf); + if (err == 0) + return; + + if (errno != ENOENT) { + xlog(L_ERROR, "Unable to stat %s: errno %d (%m)", + NFSD_THREAD_FILE, errno); + return; + } + + /* + * this call can return an error if modprobe is set up to automatically + * mount nfsdfs when nfsd.ko is plugged in. So, ignore the return + * code from it and just check for the "threads" file afterward. + */ + system("/bin/mount -t nfsd nfsd " NFSD_FS_DIR " >/dev/null 2>&1"); + + err = stat(NFSD_THREAD_FILE, &statbuf); + if (err == 0) + return; + + xlog(L_WARNING, "Unable to access " NFSD_FS_DIR " errno %d (%m)." + "\nPlease try, as root, 'mount -t nfsd nfsd " NFSD_FS_DIR + "' and then restart %s to correct the problem", errno, progname); + + return; +} + /* * Are there already sockets configured? If not, then it is safe to try to * open some and pass them through. diff --git a/utils/nfsd/nfssvc.h b/utils/nfsd/nfssvc.h index 0c69bd6..1a01cec 100644 --- a/utils/nfsd/nfssvc.h +++ b/utils/nfsd/nfssvc.h @@ -20,6 +20,7 @@ * */ +void nfssvc_mount_nfsdfs(char *progname); int nfssvc_inuse(void); int nfssvc_set_sockets(const int family, const unsigned int protobits, const char *host, const char *port); -- 2.39.2