Date: Mon, 15 Oct 2012 00:17:16 +0000 (UTC) From: Rick Macklem <rmacklem@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r241568 - head/usr.sbin/mountd Message-ID: <201210150017.q9F0HGOl072847@svn.freebsd.org>
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Author: rmacklem Date: Mon Oct 15 00:17:16 2012 New Revision: 241568 URL: http://svn.freebsd.org/changeset/base/241568 Log: Add a new '-S' option to mountd, which tells it to suspend execution of the nfsd threads while it is reloading the exports. This avoids clients from getting intermittent access errors when the exports are being reloaded non-atomically. It is not an ideal solution, since requests will back up while the nfsd threads are suspended. Also, when this option is used, if mountd crashes while reloading exports, mountd will have to be restarted to get the nfsd threads to resume execution. This has been tested by Vincent Hoffman (vince at unsane.co.uk) and John Hickey (jh at deterlab.net). The nfse patch offers a more comprehensive solution for this issue. PR: kern/9619, kern/131342 Reviewed by: kib MFC after: 2 weeks Modified: head/usr.sbin/mountd/mountd.c Modified: head/usr.sbin/mountd/mountd.c ============================================================================== --- head/usr.sbin/mountd/mountd.c Mon Oct 15 00:07:18 2012 (r241567) +++ head/usr.sbin/mountd/mountd.c Mon Oct 15 00:17:16 2012 (r241568) @@ -246,6 +246,7 @@ static int mallocd_svcport = 0; static int *sock_fd; static int sock_fdcnt; static int sock_fdpos; +static int suspend_nfsd = 0; int opt_flags; static int have_v6 = 1; @@ -311,7 +312,7 @@ main(int argc, char **argv) else close(s); - while ((c = getopt(argc, argv, "2deh:lnop:r")) != -1) + while ((c = getopt(argc, argv, "2deh:lnop:rS")) != -1) switch (c) { case '2': force_v2 = 1; @@ -363,6 +364,9 @@ main(int argc, char **argv) out_of_mem(); } break; + case 'S': + suspend_nfsd = 1; + break; default: usage(); }; @@ -921,7 +925,7 @@ usage(void) { fprintf(stderr, "usage: mountd [-2] [-d] [-e] [-l] [-n] [-p <port>] [-r] " - "[-h <bindip>] [export_file ...]\n"); + "[-S] [-h <bindip>] [export_file ...]\n"); exit(1); } @@ -1659,6 +1663,8 @@ get_exportlist(void) int done; struct nfsex_args eargs; + if (suspend_nfsd != 0) + (void)nfssvc(NFSSVC_SUSPENDNFSD, NULL); v4root_dirpath[0] = '\0'; bzero(&export, sizeof(export)); export.ex_flags = MNT_DELEXPORT; @@ -1787,6 +1793,9 @@ get_exportlist(void) */ if (run_v4server > 0 && has_publicfh == 0) (void) nfssvc(NFSSVC_NOPUBLICFH, NULL); + + /* Resume the nfsd. If they weren't suspended, this is harmless. */ + (void)nfssvc(NFSSVC_RESUMENFSD, NULL); } /*
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