2 * stropts.c -- NFS mount using C string to pass options to kernel
4 * Copyright (C) 2007 Oracle. All rights reserved.
5 * Copyright (C) 2007 Chuck Lever <chuck.lever@oracle.com>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public
18 * License along with this program; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 021110-1307, USA.
33 #include <sys/socket.h>
34 #include <sys/mount.h>
35 #include <netinet/in.h>
36 #include <arpa/inet.h>
43 #include "mount_constants.h"
47 #include "parse_opt.h"
49 #include "parse_dev.h"
53 #define NFS_PROGRAM (100003)
57 #define NFS_PORT (2049)
60 #ifndef NFS_MAXHOSTNAME
61 #define NFS_MAXHOSTNAME (255)
64 #ifndef NFS_MAXPATHNAME
65 #define NFS_MAXPATHNAME (1024)
68 #ifndef NFS_DEF_FG_TIMEOUT_MINUTES
69 #define NFS_DEF_FG_TIMEOUT_MINUTES (2u)
72 #ifndef NFS_DEF_BG_TIMEOUT_MINUTES
73 #define NFS_DEF_BG_TIMEOUT_MINUTES (10000u)
76 extern int nfs_mount_data_version;
77 extern char *progname;
81 struct nfsmount_info {
82 const char *spec, /* server:/path */
83 *node, /* mounted-on dir */
84 *type; /* "nfs" or "nfs4" */
85 char *hostname; /* server's hostname */
86 struct addrinfo *address; /* server's addresses */
88 struct mount_options *options; /* parsed mount options */
89 char **extra_opts; /* string for /etc/mtab */
91 unsigned long version; /* NFS version */
92 int flags, /* MS_ flags */
93 fake, /* actually do the mount? */
94 child; /* forked bg child? */
98 static void nfs_default_version(struct nfsmount_info *mi);
100 static void nfs_default_version(struct nfsmount_info *mi)
102 extern unsigned long config_default_vers;
104 * Use the default value set in the config file when
105 * the version has not been explicitly set.
107 if (mi->version == 0 && config_default_vers) {
108 if (config_default_vers < 4)
109 mi->version = config_default_vers;
113 inline void nfs_default_version(struct nfsmount_info *mi) {}
114 #endif /* MOUNT_CONFIG */
117 * Obtain a retry timeout value based on the value of the "retry=" option.
119 * Returns a time_t timeout timestamp, in seconds.
121 static time_t nfs_parse_retry_option(struct mount_options *options,
122 unsigned int timeout_minutes)
126 switch (po_get_numeric(options, "retry", &tmp)) {
131 timeout_minutes = tmp;
136 nfs_error(_("%s: invalid retry timeout was specified; "
137 "using default timeout"), progname);
141 return time(NULL) + (time_t)(timeout_minutes * 60);
145 * Convert the passed-in sockaddr-style address to presentation
146 * format, then append an option of the form "keyword=address".
148 * Returns 1 if the option was appended successfully; otherwise zero.
150 static int nfs_append_generic_address_option(const struct sockaddr *sap,
151 const socklen_t salen,
153 struct mount_options *options)
155 char address[NI_MAXHOST];
156 char new_option[512];
159 if (!nfs_present_sockaddr(sap, salen, address, sizeof(address)))
162 len = snprintf(new_option, sizeof(new_option), "%s=%s",
164 if (len < 0 || (size_t)len >= sizeof(new_option))
167 if (po_append(options, new_option) != PO_SUCCEEDED)
173 nfs_error(_("%s: failed to construct %s option"), progname, keyword);
178 * Append the 'addr=' option to the options string to pass a resolved
179 * server address to the kernel. After a successful mount, this address
180 * is also added to /etc/mtab for use when unmounting.
182 * If 'addr=' is already present, we strip it out. This prevents users
183 * from setting a bogus 'addr=' option themselves, and also allows bg
184 * retries to recompute the server's address, in case it has changed.
186 * Returns 1 if 'addr=' option appended successfully;
189 static int nfs_append_addr_option(const struct sockaddr *sap,
191 struct mount_options *options)
193 po_remove_all(options, "addr");
194 return nfs_append_generic_address_option(sap, salen, "addr", options);
198 * Called to discover our address and append an appropriate 'clientaddr='
199 * option to the options string.
201 * Returns 1 if 'clientaddr=' option created successfully or if
202 * 'clientaddr=' option is already present; otherwise zero.
204 static int nfs_append_clientaddr_option(const struct sockaddr *sap,
206 struct mount_options *options)
208 union nfs_sockaddr address;
209 struct sockaddr *my_addr = &address.sa;
210 socklen_t my_len = sizeof(address);
212 if (po_contains(options, "clientaddr") == PO_FOUND)
215 nfs_callback_address(sap, salen, my_addr, &my_len);
217 return nfs_append_generic_address_option(my_addr, my_len,
218 "clientaddr", options);
222 * Determine whether to append a 'mountaddr=' option. The option is needed if:
224 * 1. "mounthost=" was specified, or
225 * 2. The address families for proto= and mountproto= are different.
227 static int nfs_fix_mounthost_option(struct mount_options *options,
228 const char *nfs_hostname)
230 union nfs_sockaddr address;
231 struct sockaddr *sap = &address.sa;
232 socklen_t salen = sizeof(address);
233 sa_family_t nfs_family, mnt_family;
236 if (!nfs_nfs_proto_family(options, &nfs_family))
238 if (!nfs_mount_proto_family(options, &mnt_family))
241 mounthost = po_get(options, "mounthost");
242 if (mounthost == NULL) {
243 if (nfs_family == mnt_family)
245 mounthost = (char *)nfs_hostname;
248 if (!nfs_lookup(mounthost, mnt_family, sap, &salen)) {
249 nfs_error(_("%s: unable to determine mount server's address"),
254 return nfs_append_generic_address_option(sap, salen,
255 "mountaddr", options);
259 * Returns zero if the "lock" option is in effect, but statd
260 * can't be started. Otherwise, returns 1.
262 static const char *nfs_lock_opttbl[] = {
268 static int nfs_verify_lock_option(struct mount_options *options)
270 if (po_rightmost(options, nfs_lock_opttbl) == 0)
273 if (!start_statd()) {
274 nfs_error(_("%s: rpc.statd is not running but is "
275 "required for remote locking."), progname);
276 nfs_error(_("%s: Either use '-o nolock' to keep "
277 "locks local, or start statd."), progname);
284 static int nfs_append_sloppy_option(struct mount_options *options)
286 if (!sloppy || linux_version_code() < MAKE_VERSION(2, 6, 27))
289 if (po_append(options, "sloppy") == PO_FAILED)
294 static int nfs_set_version(struct nfsmount_info *mi)
296 if (!nfs_nfs_version(mi->options, &mi->version))
299 if (strncmp(mi->type, "nfs4", 4) == 0)
303 * Before 2.6.32, the kernel NFS client didn't
304 * support "-t nfs vers=4" mounts, so NFS version
305 * 4 cannot be included when autonegotiating
306 * while running on those kernels.
308 if (mi->version == 0 &&
309 linux_version_code() <= MAKE_VERSION(2, 6, 31))
313 * If we still don't know, check for version-specific
316 if (mi->version == 0) {
317 if (po_contains(mi->options, "mounthost") ||
318 po_contains(mi->options, "mountaddr") ||
319 po_contains(mi->options, "mountvers") ||
320 po_contains(mi->options, "mountproto"))
325 * If enabled, see if the default version was
326 * set in the config file
328 nfs_default_version(mi);
334 * Set up mandatory non-version specific NFS mount options.
336 * Returns 1 if successful; otherwise zero.
338 static int nfs_validate_options(struct nfsmount_info *mi)
340 struct addrinfo hint = {
341 .ai_protocol = (int)IPPROTO_UDP,
346 if (!nfs_parse_devname(mi->spec, &mi->hostname, NULL))
349 if (!nfs_nfs_proto_family(mi->options, &family))
352 hint.ai_family = (int)family;
353 error = getaddrinfo(mi->hostname, NULL, &hint, &mi->address);
355 nfs_error(_("%s: Failed to resolve server %s: %s"),
356 progname, mi->hostname, gai_strerror(error));
361 if (!nfs_set_version(mi))
364 if (!nfs_append_sloppy_option(mi->options))
367 if (!nfs_append_addr_option(mi->address->ai_addr,
368 mi->address->ai_addrlen, mi->options))
375 * Get NFS/mnt server addresses from mount options
377 * Returns 1 and fills in @nfs_saddr, @nfs_salen, @mnt_saddr, and @mnt_salen
378 * if all goes well; otherwise zero.
380 static int nfs_extract_server_addresses(struct mount_options *options,
381 struct sockaddr *nfs_saddr,
382 socklen_t *nfs_salen,
383 struct sockaddr *mnt_saddr,
384 socklen_t *mnt_salen)
388 option = po_get(options, "addr");
391 if (!nfs_string_to_sockaddr(option, nfs_saddr, nfs_salen))
394 option = po_get(options, "mountaddr");
395 if (option == NULL) {
396 memcpy(mnt_saddr, nfs_saddr, *nfs_salen);
397 *mnt_salen = *nfs_salen;
398 } else if (!nfs_string_to_sockaddr(option, mnt_saddr, mnt_salen))
404 static int nfs_construct_new_options(struct mount_options *options,
405 struct sockaddr *nfs_saddr,
406 struct pmap *nfs_pmap,
407 struct sockaddr *mnt_saddr,
408 struct pmap *mnt_pmap)
413 po_remove_all(options, "nfsprog");
414 po_remove_all(options, "mountprog");
416 po_remove_all(options, "v2");
417 po_remove_all(options, "v3");
418 po_remove_all(options, "vers");
419 po_remove_all(options, "nfsvers");
420 snprintf(new_option, sizeof(new_option) - 1,
421 "vers=%lu", nfs_pmap->pm_vers);
422 if (po_append(options, new_option) == PO_FAILED)
425 po_remove_all(options, "proto");
426 po_remove_all(options, "udp");
427 po_remove_all(options, "tcp");
428 netid = nfs_get_netid(nfs_saddr->sa_family, nfs_pmap->pm_prot);
431 snprintf(new_option, sizeof(new_option) - 1,
434 if (po_append(options, new_option) == PO_FAILED)
437 po_remove_all(options, "port");
438 if (nfs_pmap->pm_port != NFS_PORT) {
439 snprintf(new_option, sizeof(new_option) - 1,
440 "port=%lu", nfs_pmap->pm_port);
441 if (po_append(options, new_option) == PO_FAILED)
445 po_remove_all(options, "mountvers");
446 snprintf(new_option, sizeof(new_option) - 1,
447 "mountvers=%lu", mnt_pmap->pm_vers);
448 if (po_append(options, new_option) == PO_FAILED)
451 po_remove_all(options, "mountproto");
452 netid = nfs_get_netid(mnt_saddr->sa_family, mnt_pmap->pm_prot);
455 snprintf(new_option, sizeof(new_option) - 1,
456 "mountproto=%s", netid);
458 if (po_append(options, new_option) == PO_FAILED)
461 po_remove_all(options, "mountport");
462 snprintf(new_option, sizeof(new_option) - 1,
463 "mountport=%lu", mnt_pmap->pm_port);
464 if (po_append(options, new_option) == PO_FAILED)
471 * Reconstruct the mount option string based on a portmapper probe
472 * of the server. Returns one if the server's portmapper returned
473 * something we can use, otherwise zero.
475 * To handle version and transport protocol fallback properly, we
476 * need to parse some of the mount options in order to set up a
477 * portmap probe. Mount options that nfs_rewrite_pmap_mount_options()
478 * doesn't recognize are left alone.
480 * Returns TRUE if rewriting was successful; otherwise
481 * FALSE is returned if some failure occurred.
484 nfs_rewrite_pmap_mount_options(struct mount_options *options)
486 union nfs_sockaddr nfs_address;
487 struct sockaddr *nfs_saddr = &nfs_address.sa;
488 socklen_t nfs_salen = sizeof(nfs_address);
489 struct pmap nfs_pmap;
490 union nfs_sockaddr mnt_address;
491 struct sockaddr *mnt_saddr = &mnt_address.sa;
492 socklen_t mnt_salen = sizeof(mnt_address);
493 unsigned long protocol;
494 struct pmap mnt_pmap;
497 * Version and transport negotiation is not required
498 * and does not work for RDMA mounts.
500 if (!nfs_nfs_protocol(options, &protocol)) {
504 if (protocol == NFSPROTO_RDMA)
508 * Extract just the options needed to contact server.
509 * Bail now if any of these have bad values.
511 if (!nfs_extract_server_addresses(options, nfs_saddr, &nfs_salen,
512 mnt_saddr, &mnt_salen)) {
516 if (!nfs_options2pmap(options, &nfs_pmap, &mnt_pmap)) {
522 * The kernel NFS client doesn't support changing the RPC
523 * program number for these services, so force the value of
524 * these fields before probing the server's ports.
526 nfs_pmap.pm_prog = NFS_PROGRAM;
527 mnt_pmap.pm_prog = MOUNTPROG;
530 * If the server's rpcbind service isn't available, we can't
531 * negotiate. Bail now if we can't contact it.
533 if (!nfs_probe_bothports(mnt_saddr, mnt_salen, &mnt_pmap,
534 nfs_saddr, nfs_salen, &nfs_pmap)) {
536 if (rpc_createerr.cf_stat == RPC_PROGNOTREGISTERED)
538 else if (rpc_createerr.cf_error.re_errno != 0)
539 errno = rpc_createerr.cf_error.re_errno;
543 if (!nfs_construct_new_options(options, nfs_saddr, &nfs_pmap,
544 mnt_saddr, &mnt_pmap)) {
545 if (rpc_createerr.cf_stat == RPC_UNKNOWNPROTO)
546 errno = EPROTONOSUPPORT;
558 * Do the mount(2) system call.
560 * Returns TRUE if successful, otherwise FALSE.
561 * "errno" is set to reflect the individual error.
563 static int nfs_sys_mount(struct nfsmount_info *mi, struct mount_options *opts)
565 char *options = NULL;
568 if (po_join(opts, &options) == PO_FAILED) {
576 result = mount(mi->spec, mi->node, mi->type,
577 mi->flags & ~(MS_USER|MS_USERS), options);
578 if (verbose && result) {
580 nfs_error(_("%s: mount(2): %s"), progname, strerror(save));
586 static int nfs_do_mount_v3v2(struct nfsmount_info *mi,
587 struct sockaddr *sap, socklen_t salen)
589 struct mount_options *options = po_dup(mi->options);
597 if (!nfs_append_addr_option(sap, salen, options)) {
603 if (!nfs_fix_mounthost_option(options, mi->hostname)) {
608 if (!mi->fake && !nfs_verify_lock_option(options)) {
615 * Options we negotiate below may be stale by the time this
616 * file system is unmounted. In order to force umount.nfs
617 * to renegotiate with the server, only write the user-
618 * specified options, and not negotiated options, to /etc/mtab.
620 if (po_join(options, mi->extra_opts) == PO_FAILED) {
626 printf(_("%s: trying text-based options '%s'\n"),
627 progname, *mi->extra_opts);
629 if (!nfs_rewrite_pmap_mount_options(options))
632 result = nfs_sys_mount(mi, options);
640 * Attempt a "-t nfs vers=2" or "-t nfs vers=3" mount.
642 * Returns TRUE if successful, otherwise FALSE.
643 * "errno" is set to reflect the individual error.
645 static int nfs_try_mount_v3v2(struct nfsmount_info *mi)
650 for (ai = mi->address; ai != NULL; ai = ai->ai_next) {
651 ret = nfs_do_mount_v3v2(mi, ai->ai_addr, ai->ai_addrlen);
667 static int nfs_do_mount_v4(struct nfsmount_info *mi,
668 struct sockaddr *sap, socklen_t salen)
670 struct mount_options *options = po_dup(mi->options);
678 if (mi->version == 0) {
679 if (po_contains(options, "mounthost") ||
680 po_contains(options, "mountaddr") ||
681 po_contains(options, "mountvers") ||
682 po_contains(options, "mountproto")) {
684 * Since these mountd options are set assume version 3
685 * is wanted so error out with EPROTONOSUPPORT so the
686 * protocol negation starts with v3.
688 errno = EPROTONOSUPPORT;
691 if (po_append(options, "vers=4") == PO_FAILED) {
697 if (!nfs_append_addr_option(sap, salen, options)) {
702 if (!nfs_append_clientaddr_option(sap, salen, options)) {
708 * Update option string to be recorded in /etc/mtab.
710 if (po_join(options, mi->extra_opts) == PO_FAILED) {
716 printf(_("%s: trying text-based options '%s'\n"),
717 progname, *mi->extra_opts);
719 result = nfs_sys_mount(mi, options);
727 * Attempt a "-t nfs -o vers=4" or "-t nfs4" mount.
729 * Returns TRUE if successful, otherwise FALSE.
730 * "errno" is set to reflect the individual error.
732 static int nfs_try_mount_v4(struct nfsmount_info *mi)
737 for (ai = mi->address; ai != NULL; ai = ai->ai_next) {
738 ret = nfs_do_mount_v4(mi, ai->ai_addr, ai->ai_addrlen);
754 * Handle NFS version and transport protocol
757 * When no version or protocol is specified on the
758 * command line, mount.nfs negotiates with the server
759 * to determine appropriate settings for the new
762 * Returns TRUE if successful, otherwise FALSE.
763 * "errno" is set to reflect the individual error.
765 static int nfs_autonegotiate(struct nfsmount_info *mi)
769 result = nfs_try_mount_v4(mi);
774 case EPROTONOSUPPORT:
775 /* A clear indication that the server or our
776 * client does not support NFS version 4. */
779 /* Legacy Linux servers don't export an NFS
780 * version 4 pseudoroot. */
783 /* Linux servers prior to 2.6.25 may return
784 * EPERM when NFS version 4 is not supported. */
791 return nfs_try_mount_v3v2(mi);
795 * This is a single pass through the fg/bg loop.
797 * Returns TRUE if successful, otherwise FALSE.
798 * "errno" is set to reflect the individual error.
800 static int nfs_try_mount(struct nfsmount_info *mi)
804 switch (mi->version) {
806 result = nfs_autonegotiate(mi);
810 result = nfs_try_mount_v3v2(mi);
813 result = nfs_try_mount_v4(mi);
823 * Distinguish between permanent and temporary errors.
825 * Basically, we retry if communication with the server has
826 * failed so far, but fail immediately if there is a local
827 * error (like a bad mount option).
829 * ESTALE is also a temporary error because some servers
830 * return ESTALE when a share is temporarily offline.
832 * Returns 1 if we should fail immediately, or 0 if we
835 static int nfs_is_permanent_error(int error)
842 return 0; /* temporary */
844 return 1; /* permanent */
849 * Handle "foreground" NFS mounts.
851 * Retry the mount request for as long as the 'retry=' option says.
853 * Returns a valid mount command exit code.
855 static int nfsmount_fg(struct nfsmount_info *mi)
857 unsigned int secs = 1;
860 timeout = nfs_parse_retry_option(mi->options,
861 NFS_DEF_FG_TIMEOUT_MINUTES);
863 printf(_("%s: timeout set for %s"),
864 progname, ctime(&timeout));
867 if (nfs_try_mount(mi))
870 if (nfs_is_permanent_error(errno))
873 if (time(NULL) > timeout) {
878 if (errno != ETIMEDOUT) {
887 mount_error(mi->spec, mi->node, errno);
892 * Handle "background" NFS mount [first try]
894 * Returns a valid mount command exit code.
896 * EX_BG should cause the caller to fork and invoke nfsmount_child.
898 static int nfsmount_parent(struct nfsmount_info *mi)
900 if (nfs_try_mount(mi))
903 if (nfs_is_permanent_error(errno)) {
904 mount_error(mi->spec, mi->node, errno);
908 sys_mount_errors(mi->hostname, errno, 1, 1);
913 * Handle "background" NFS mount [retry daemon]
915 * Returns a valid mount command exit code: EX_SUCCESS if successful,
916 * EX_FAIL if a failure occurred. There's nothing to catch the
917 * error return, though, so we use sys_mount_errors to log the
920 static int nfsmount_child(struct nfsmount_info *mi)
922 unsigned int secs = 1;
925 timeout = nfs_parse_retry_option(mi->options,
926 NFS_DEF_BG_TIMEOUT_MINUTES);
935 if (nfs_try_mount(mi))
938 if (nfs_is_permanent_error(errno))
941 if (time(NULL) > timeout)
944 sys_mount_errors(mi->hostname, errno, 1, 1);
947 sys_mount_errors(mi->hostname, errno, 1, 0);
952 * Handle "background" NFS mount
954 * Returns a valid mount command exit code.
956 static int nfsmount_bg(struct nfsmount_info *mi)
959 return nfsmount_parent(mi);
961 return nfsmount_child(mi);
965 * Usually all that is needed for an NFS remount is to change
966 * generic mount options like "sync" or "ro". These generic
967 * options are controlled by mi->flags, not by text-based
968 * options, and no contact with the server is needed.
970 * Take care with the /etc/mtab entry for this mount; just
971 * calling update_mtab() will change an "-t nfs -o vers=4"
972 * mount to an "-t nfs -o remount" mount, and that will
973 * confuse umount.nfs.
975 * Returns a valid mount command exit code.
977 static int nfs_remount(struct nfsmount_info *mi)
979 if (nfs_sys_mount(mi, mi->options))
985 * Process mount options and try a mount system call.
987 * Returns a valid mount command exit code.
989 static const char *nfs_background_opttbl[] = {
995 static int nfsmount_start(struct nfsmount_info *mi)
997 if (!nfs_validate_options(mi))
1001 * Avoid retry and negotiation logic when remounting
1003 if (mi->flags & MS_REMOUNT)
1004 return nfs_remount(mi);
1006 if (po_rightmost(mi->options, nfs_background_opttbl) == 0)
1007 return nfsmount_bg(mi);
1009 return nfsmount_fg(mi);
1013 * nfsmount_string - Mount an NFS file system using C string options
1014 * @spec: C string specifying remote share to mount ("hostname:path")
1015 * @node: C string pathname of local mounted-on directory
1016 * @type: C string that represents file system type ("nfs" or "nfs4")
1017 * @flags: MS_ style mount flags
1018 * @extra_opts: pointer to C string containing fs-specific mount options
1019 * (input and output argument)
1020 * @fake: flag indicating whether to carry out the whole operation
1021 * @child: one if this is a mount daemon (bg)
1023 * Returns a valid mount command exit code.
1025 int nfsmount_string(const char *spec, const char *node, const char *type,
1026 int flags, char **extra_opts, int fake, int child)
1028 struct nfsmount_info mi = {
1033 .extra_opts = extra_opts,
1038 int retval = EX_FAIL;
1040 mi.options = po_split(*extra_opts);
1042 retval = nfsmount_start(&mi);
1043 po_destroy(mi.options);
1045 nfs_error(_("%s: internal option parsing error"), progname);
1047 freeaddrinfo(mi.address);