* [PATCH] mount: Add automounter program map for FedFS
2011-05-26 16:39 [PATCH] FedFS file system client support Chuck Lever
@ 2011-05-26 16:39 ` Chuck Lever
2011-05-30 4:15 ` [PATCH] FedFS file system client support Ian Kent
1 sibling, 0 replies; 5+ messages in thread
From: Chuck Lever @ 2011-05-26 16:39 UTC (permalink / raw)
To: fedfs-utils-devel, autofs
This new utility interprets the passed-in key as a FedFS domain,
performs a DNS SRV lookup, and generates the mount.nfs parameters
needed to mount the domain. It can handle multiple read-only and
read-write domain root replicas using support already built into the
automounter.
The FedFS entry in the master map might look like this:
/nfs4 /usr/sbin/fedfs-map-nfs4
To support other file system protocols, additional lines in the master
map and another program map utility (or options for this one) would be
needed.
Benefits:
o Simple to configure
o The TLD can be placed anywhere on the client
o No additional build or package dependencies on nfs-utils or
autofs
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
.gitignore | 1
INSTALL | 10 +-
README | 14 ++-
doc/man/Makefile.am | 2
doc/man/fedfs-map-nfs4.8 | 154 ++++++++++++++++++++++++++++
doc/man/fedfs.7 | 4 +
src/mount/Makefile.am | 5 +
src/mount/fedfs-map-nfs4.c | 242 ++++++++++++++++++++++++++++++++++++++++++++
8 files changed, 422 insertions(+), 10 deletions(-)
create mode 100644 doc/man/fedfs-map-nfs4.8
create mode 100644 src/mount/fedfs-map-nfs4.c
diff --git a/.gitignore b/.gitignore
index ce06ff1..41daf0f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,6 +9,7 @@ src/fedfsd/fedfsd
src/resolve-junction/resolve-junction
src/nsdbparams/nsdbparams
src/mount/mount.fedfs
+src/mount/fedfs-map-nfs4
libadmin.a
libjunction.a
libnsdb.a
diff --git a/INSTALL b/INSTALL
index 8cb8e9e..548381b 100644
--- a/INSTALL
+++ b/INSTALL
@@ -143,12 +143,14 @@ FedFS file server
FedFS client
- o Install mount.fedfs
+ o Install /usr/sbin/fedfs-map-nfs4
- o Create a local /nfs4 directory, and subdirectories for the FedFS
- domains you want to mount
+ o Create a local /nfs4 directory
- o Add lines to /etc/fstab to mount the domains
+ o Install and configure autofs
+
+ o Add an entry to the master map (usually /etc/auto.master) for
+ the /nfs4 directory and restart autofs
FedFS admin client
diff --git a/README b/README
index 0067ac2..78b9647 100644
--- a/README
+++ b/README
@@ -59,7 +59,10 @@ changed over time.
Installable components include:
- o A mount command to mount the top of a FedFS domain namespace
+ o An automounter program map to manage the FedFS domain namespace
+ on FedFS-enabled clients
+
+ o A mount command to mount parts of a FedFS domain namespace
o An ONC RPC service daemon that runs on file servers enabling the
management by remote FedFS ADMIN clients of FedFS junctions
@@ -81,9 +84,14 @@ Installable components include:
o HTML Doxygen style documentation with built-in source browser
+The automounter program map is a subcommand invoked by the automounter
+to locate FedFS domains and construct appropriate mount options for
+mounting domain roots. It is used in conjunction with the Linux
+autofs facility.
+
The mount command is a subcommand invoked by mount(8) to handle the
-housekeeping needed to find and mount FedFS domains at the top of the
-client's FedFS namespace (usually /nfs4 for NFSv4 servers).
+housekeeping needed to find and mount part or all of FedFS domain
+name spaces.
The fedfsd program is an RPC server that allows remote administrators to
create FedFS junctions in local file systems. FedFS ADMIN requests that
diff --git a/doc/man/Makefile.am b/doc/man/Makefile.am
index 7f92ebf..83c6d03 100644
--- a/doc/man/Makefile.am
+++ b/doc/man/Makefile.am
@@ -24,6 +24,6 @@
##
dist_man7_MANS = fedfs.7
-dist_man8_MANS = rpc.fedfsd.8 mount.fedfs.8
+dist_man8_MANS = rpc.fedfsd.8 mount.fedfs.8 fedfs-map-nfs4.8
CLEANFILES = cscope.in.out cscope.out cscope.po.out
DISTCLEANFILES = Makefile.in
diff --git a/doc/man/fedfs-map-nfs4.8 b/doc/man/fedfs-map-nfs4.8
new file mode 100644
index 0000000..ffc5b6a
--- /dev/null
+++ b/doc/man/fedfs-map-nfs4.8
@@ -0,0 +1,154 @@
+.\"@(#)fedfs-map-nfs4.8"
+.\"
+.\" @file doc/man/fedfs-map-nfs4.8
+.\" @brief man page for fedfs-map-nfs4 command
+.\"
+
+.\"
+.\" Copyright 2011 Oracle. All rights reserved.
+.\"
+.\" This file is part of fedfs-utils.
+.\"
+.\" fedfs-utils is free software; you can redistribute it and/or modify
+.\" it under the terms of the GNU General Public License version 2.0 as
+.\" published by the Free Software Foundation.
+.\"
+.\" fedfs-utils is distributed in the hope that it will be useful, but
+.\" WITHOUT ANY WARRANTY; without even the implied warranty of
+.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+.\" GNU General Public License version 2.0 for more details.
+.\"
+.\" You should have received a copy of the GNU General Public License
+.\" version 2.0 along with fedfs-utils. If not, see:
+.\"
+.\" http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
+.\"
+.TH FEDFS-MAP-NFS4 8 "30 Apr 2011"
+.SH NAME
+fedfs-map-nfs4 \- generate automounter program map entries for FedFS
+.SH SYNOPSIS
+.B fedfs-map-nfs4
+.I domainname
+.SH INTRODUCTION
+RFC 5716 introduces the Federated File System (FedFS, for short).
+FedFS is an extensible standardized mechanism
+by which system administrators construct
+a coherent namespace across multiple file servers using
+.IR "file system referrals" .
+For further details, see
+.BR fedfs (7).
+.SH DESCRIPTION
+The
+.BR fedfs-map-nfs4 (8)
+command provides a FedFS program map for the local system's automounter.
+Although it is typically intended to be invoked by the automounter,
+it is also safe to invoke directly for scripting or debugging purposes.
+See
+.BR autofs (5)
+for information about how program maps work.
+.SS Operation
+The
+.BR fedfs-map-nfs4 (8)
+command locates FedFS domains by looking for DNS SRV records
+that advertise file servers exporting domain root replicas.
+The
+.I domainname
+argument determines what FedFS domain is to be mounted.
+.P
+It retrieves and sorts the domain root replica records
+according to SRV record sorting rules outlined in RFC 2782.
+It then generates a sun format map entry on
+.I stdout
+representing the set of servers contained in the SRV record,
+a standard export path to the domain root,
+and appropriate NFS mount options.
+Error messages are output on
+.IR stderr .
+.SS Globally useful names
+Across all FedFS-enabled file system clients,
+a unique file object in a FedFS domain is always accessed
+via the same pathname.
+Such pathnames are referred to as
+.IR "globally useful names" .
+See
+.BR fedfs (7)
+for a full discussion.
+.P
+The top-level directory of a globally useful name is always
+the networked file system type (NFS version 4, CIFS, and so on).
+A
+.BR fedfs-map-nfs4 (8)
+program map entry is used with the NFS version 4 top-level directory
+to provide globally useful names via the NFS version 4 protocol.
+.SH EXAMPLES
+Typically, a
+.BR fedfs-map-nfs4 (8)
+entry in
+.I /etc/auto.master
+looks like this:
+.P
+.NF
+.TA 2.5i +0.7i +0.7i
+ /nfs4 /usr/sbin/fedfs-map-nfs4
+.FI
+.P
+Under the /nfs4 directory on the local system, the automounter uses
+.BR fedfs-map-nfs4 (8)
+to convert a FedFS domain name to a set of servers and an export path,
+which are then passed to
+.BR mount.nfs (8).
+.P
+The automounter mounts this FedFS domain on the directory
+.IR /nfs4/domainname .
+Note that this also works for dot-prefixed domain names, in order to
+support mounting read-write domain root replicas.
+.P
+After configuring and restarting
+.BR autofs ,
+to access files in the
+.I example.net
+FedFS domain, for instance, you can start with:
+.RS
+.sp
+cd /nfs4/example.net
+.sp
+.RE
+The automounter uses the
+.BR fedfs-map-nfs4 (8)
+command to look up the file servers that provide the domain root for the
+.I example.net
+domain. It then mounts one of these servers on
+.IR /nfs4/example.net .
+.P
+If the
+.BR fedfs-map-nfs4 (8)
+command cannot find the requested domain, no local directory is created
+and no mount operation is performed. Applications receive an ENOENT
+error in this case.
+.P
+While these mounted domains remain active on the local system,
+the mounted-on directories remain visible.
+After a period of inactivity, the automounter automatically unmounts
+a FedFS domain.
+Local applications browsing the top-level directory
+do not see all available FedFS domains. They see only the ones that
+are mounted and active.
+.SH FILES
+.TP 18n
+.I /etc/auto.master
+master automounter map
+.SH "SEE ALSO"
+.BR fedfs (7),
+.BR nfs (5),
+.BR autofs (5),
+.sp
+RFC 2782 for a discussion of DNS SRV records
+.sp
+RFC 5716 for FedFS requirements and overview
+.SH COLOPHON
+This page is part of the fedfs-utils package.
+A description of the project and information about reporting bugs
+can be found at
+.IR http://oss.oracle.com/projects/fedfs-utils .
+.SH "AUTHOR"
+Chuck Lever <chuck.lever@oracle.com>
diff --git a/doc/man/fedfs.7 b/doc/man/fedfs.7
index a2d2759..83eb215 100644
--- a/doc/man/fedfs.7
+++ b/doc/man/fedfs.7
@@ -164,7 +164,8 @@ file system below them,
are visible at a different point in a client's name space
than are read-only replicas.
.SS Globally Useful Names
-On FedFS-enabled Linux clients, the
+On FedFS-enabled Linux clients,
+either the automounter, with a special program map, or the
.BR mount.fedfs (8)
command finds and mounts the root of a FedFS domain.
.P
@@ -258,6 +259,7 @@ when administering junctions and filesets,
junctions are created on file servers and
registered with the domain's NSDB in two separate steps.
.SH SEE ALSO
+.BR fedfs-map-nfs4 (8),
.BR mount.fedfs (8),
.BR rpc.fedfsd (8),
.BR rpc.mountd (8),
diff --git a/src/mount/Makefile.am b/src/mount/Makefile.am
index 9338d47..93c6b72 100644
--- a/src/mount/Makefile.am
+++ b/src/mount/Makefile.am
@@ -24,7 +24,10 @@
##
noinst_HEADERS = nls.h
-sbin_PROGRAMS = mount.fedfs
+sbin_PROGRAMS = mount.fedfs fedfs-map-nfs4
+fedfs_map_nfs4_SOURCES = fedfs-map-nfs4.c
+fedfs_map_nfs4_LDADD = -lresolv \
+ $(top_builddir)/src/libsi/libsi.a
mount_fedfs_SOURCES = main.c
mount_fedfs_LDADD = -lresolv \
$(top_builddir)/src/libsi/libsi.a
diff --git a/src/mount/fedfs-map-nfs4.c b/src/mount/fedfs-map-nfs4.c
new file mode 100644
index 0000000..8376b6b
--- /dev/null
+++ b/src/mount/fedfs-map-nfs4.c
@@ -0,0 +1,242 @@
+/**
+ * @file src/mount/fedfs-map-nfs4.c
+ * @brief Convert FedFS domain name key to automounter map entry
+ */
+
+/*
+ * Copyright 2011 Oracle. All rights reserved.
+ *
+ * This file is part of fedfs-utils.
+ *
+ * fedfs-utils is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2.0 as
+ * published by the Free Software Foundation.
+ *
+ * fedfs-utils is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License version 2.0 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2.0 along with fedfs-utils. If not, see:
+ *
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/mount.h>
+#include <sys/wait.h>
+
+#include <stdbool.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <libgen.h>
+#include <errno.h>
+#include <getopt.h>
+#include <locale.h>
+#include <netdb.h>
+#include <langinfo.h>
+
+#include "nls.h"
+#include "getsrvinfo.h"
+#include "token.h"
+#include "gpl-boiler.h"
+
+/**
+ * Name of SRV record containing NFSv4 r/o FedFS root
+ */
+#define FEDFS_NFS4_DOMAINROOT_RO "_nfs4._domainroot._tcp"
+
+/**
+ * Name of SRV record containing NFSv4 r/w FedFS root
+ */
+#define FEDFS_NFS4_DOMAINROOT_RW "_nfs4._write._domainroot._tcp"
+
+/**
+ * Export path of NFSv4 r/o FedFS root
+ */
+#define FEDFS_NFS4_EXPORTPATH_RO "/.domainroot"
+
+/**
+ * Export path of NFSv4 r/w FedFS root
+ */
+#define FEDFS_NFS4_EXPORTPATH_RW "/.domainroot-write"
+
+char *progname;
+
+/**
+ * Display usage message
+ */
+static void
+fedfs_map_usage(void)
+{
+ printf(_("\nUsage: %s [domain]\n\n"), progname);
+
+ printf("%s", fedfs_gpl_boilerplate);
+}
+
+/**
+ * Construct an NFSv4 map entry for "domainname" with one server
+ *
+ * @param si single-entry list of SRV records
+ * @param rw_replica true if a R/W domain root replica was requested
+ * @param domainname NUL-terminated UTF-8 string containing name of FedFS domain
+ * @return command exit status
+ */
+static int fedfs_map_nfs4_oneserver(struct srvinfo *si, _Bool rw_replica,
+ const char *domainname)
+{
+ printf("-fstype=nfs,vers=4,fg");
+ if (si->si_port != 2049)
+ printf(",port=%u", si->si_port);
+ printf(" %s:%s-%s\n", si->si_target,
+ rw_replica ? FEDFS_NFS4_EXPORTPATH_RW :
+ FEDFS_NFS4_EXPORTPATH_RO, domainname);
+ return 0;
+}
+
+/**
+ * Construct an NFSv4 map entry for "domainname" with multiple servers
+ *
+ * @param si list of SRV records for requested FedFS domain
+ * @param rw_replica true if a R/W domain root replica was requested
+ * @param domainname NUL-terminated UTF-8 string containing name of FedFS domain
+ * @return command exit status
+ */
+static int fedfs_map_nfs4_replicas(struct srvinfo *si, _Bool rw_replica,
+ const char *domainname)
+{
+ struct srvinfo *cur;
+ unsigned short port;
+ _Bool comma;
+
+ /*
+ * Unfortunately our automounter can't handle a list of
+ * replicas where the various servers live on different
+ * ports from one another.
+ */
+ port = si->si_port;
+ for (cur = si; cur != NULL; cur = cur->si_next)
+ if (cur->si_port != port) {
+ fprintf(stderr, _("%s: Replicas on different ports not supported\n"),
+ progname);
+ return 1;
+ }
+
+ if (port != 2049)
+ printf("-fstype=nfs,vers=4,fg,port=%u ", port);
+ else
+ printf("-fstype=nfs,vers=4,fg ");
+
+ /*
+ * Note that the export path is required to be indentical
+ * for all domain root servers for this domain.
+ */
+ for (comma = false, cur = si; cur != NULL; cur = cur->si_next) {
+ if (comma)
+ printf(",");
+ printf("%s(%u)", cur->si_target, cur->si_weight);
+ comma = true;
+ }
+ printf(":%s-%s\n", rw_replica ? FEDFS_NFS4_EXPORTPATH_RW :
+ FEDFS_NFS4_EXPORTPATH_RO, domainname);
+
+ return 0;
+}
+
+/**
+ * Construct an NFSv4 map entry for "domainname"
+ *
+ * @param domainname NUL-terminated UTF-8 string containing name of FedFS domain
+ * @return command exit status
+ */
+static int fedfs_map_nfs4(const char *domainname)
+{
+ struct srvinfo *cur, *si = NULL;
+ unsigned int count;
+ int error, result;
+ _Bool rw_replica;
+ char *rr;
+
+ rw_replica = false;
+ if (domainname[0] == '.') {
+ rw_replica = true;
+ domainname++;
+ }
+
+ result = 1;
+ rr = rw_replica ? FEDFS_NFS4_DOMAINROOT_RW : FEDFS_NFS4_DOMAINROOT_RO;
+ error = getsrvinfo(rr, domainname, &si);
+ switch (error) {
+ case ESI_SUCCESS:
+ break;
+ case ESI_NONAME:
+ fprintf(stderr, _("%s: Domain name %s not found\n"),
+ progname, domainname);
+ goto out;
+ case ESI_SERVICE:
+ fprintf(stderr, _("%s: No FedFS domain root available for %s\n"),
+ progname, domainname);
+ goto out;
+ default:
+ fprintf(stderr, _("%s: Failed to resolve %s: %s\n"),
+ progname, domainname, gsi_strerror(error));
+ goto out;
+ }
+
+ for (count = 0, cur = si; cur != NULL; cur = cur->si_next)
+ count++;
+ if (count == 1)
+ result = fedfs_map_nfs4_oneserver(si, rw_replica,
+ domainname);
+ else
+ result = fedfs_map_nfs4_replicas(si, rw_replica,
+ domainname);
+
+out:
+ freesrvinfo(si);
+ return result;
+}
+
+/**
+ * Program entry point
+ *
+ * @param argc count of command line arguments
+ * @param argv array of NUL-terminated C strings containing command line arguments
+ * @return program exit status
+ */
+int main(int argc, char *argv[])
+{
+ /* Ensure UTF-8 strings can be handled transparently */
+ if (setlocale(LC_CTYPE, "") == NULL ||
+ strcmp(nl_langinfo(CODESET), "UTF-8") != 0) {
+ fprintf(stderr, _("Failed to set locale and langinfo\n"));
+ return 1;
+ }
+
+ progname = basename(argv[0]);
+
+ if (argc != 2) {
+ fedfs_map_usage();
+ return 1;
+ }
+
+ if (strcmp(progname, "fedfs-map-nfs4") == 0)
+ return fedfs_map_nfs4(argv[1]);
+#ifdef EXAMPLE
+ /* CIFS support might plug in here */
+ else if (strcmp(progname, "fedfs-map-cifs") == 0)
+ return fedfs_map_cifs(argv[1]);
+#endif
+
+ fprintf(stderr, _("%s: Unsupported file system type\n"), progname);
+ return 1;
+}
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