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>
41 #include "mount_constants.h"
45 #include "parse_opt.h"
47 #include "parse_dev.h"
51 #define NFS_PROGRAM (100003)
55 #define NFS_PORT (2049)
58 #ifndef NFS_MAXHOSTNAME
59 #define NFS_MAXHOSTNAME (255)
62 #ifndef NFS_MAXPATHNAME
63 #define NFS_MAXPATHNAME (1024)
66 #ifndef NFS_DEF_FG_TIMEOUT_MINUTES
67 #define NFS_DEF_FG_TIMEOUT_MINUTES (2u)
70 #ifndef NFS_DEF_BG_TIMEOUT_MINUTES
71 #define NFS_DEF_BG_TIMEOUT_MINUTES (10000u)
74 extern int nfs_mount_data_version;
75 extern char *progname;
79 struct nfsmount_info {
80 const char *spec, /* server:/path */
81 *node, /* mounted-on dir */
82 *type; /* "nfs" or "nfs4" */
83 char *hostname; /* server's hostname */
84 struct sockaddr_storage address; /* server's address */
85 socklen_t salen; /* size of server's address */
87 struct mount_options *options; /* parsed mount options */
88 char **extra_opts; /* string for /etc/mtab */
90 unsigned long version; /* NFS version */
91 int flags, /* MS_ flags */
92 fake, /* actually do the mount? */
93 child; /* forked bg child? */
96 inline void set_default_version(struct nfsmount_info *mi);
98 inline void set_default_version(struct nfsmount_info *mi)
100 extern unsigned long config_default_vers;
102 * Use the default value set in the config file when
103 * the version has not been explicitly set.
105 if (mi->version == 0 && config_default_vers) {
106 if (config_default_vers < 4)
107 mi->version = config_default_vers;
111 inline void set_default_version(struct nfsmount_info *mi) {}
112 #endif /* MOUNT_CONFIG */
115 * Obtain a retry timeout value based on the value of the "retry=" option.
117 * Returns a time_t timeout timestamp, in seconds.
119 static time_t nfs_parse_retry_option(struct mount_options *options,
120 unsigned int timeout_minutes)
124 switch (po_get_numeric(options, "retry", &tmp)) {
129 timeout_minutes = tmp;
134 nfs_error(_("%s: invalid retry timeout was specified; "
135 "using default timeout"), progname);
139 return time(NULL) + (time_t)(timeout_minutes * 60);
143 * Convert the passed-in sockaddr-style address to presentation
144 * format, then append an option of the form "keyword=address".
146 * Returns 1 if the option was appended successfully; otherwise zero.
148 static int nfs_append_generic_address_option(const struct sockaddr *sap,
149 const socklen_t salen,
151 struct mount_options *options)
153 char address[NI_MAXHOST];
154 char new_option[512];
157 if (!nfs_present_sockaddr(sap, salen, address, sizeof(address)))
160 len = snprintf(new_option, sizeof(new_option), "%s=%s",
162 if (len < 0 || (size_t)len >= sizeof(new_option))
165 if (po_append(options, new_option) != PO_SUCCEEDED)
171 nfs_error(_("%s: failed to construct %s option"), progname, keyword);
176 * Append the 'addr=' option to the options string to pass a resolved
177 * server address to the kernel. After a successful mount, this address
178 * is also added to /etc/mtab for use when unmounting.
180 * If 'addr=' is already present, we strip it out. This prevents users
181 * from setting a bogus 'addr=' option themselves, and also allows bg
182 * retries to recompute the server's address, in case it has changed.
184 * Returns 1 if 'addr=' option appended successfully;
187 static int nfs_append_addr_option(const struct sockaddr *sap,
189 struct mount_options *options)
191 po_remove_all(options, "addr");
192 return nfs_append_generic_address_option(sap, salen, "addr", options);
196 * Called to discover our address and append an appropriate 'clientaddr='
197 * option to the options string.
199 * Returns 1 if 'clientaddr=' option created successfully or if
200 * 'clientaddr=' option is already present; otherwise zero.
202 static int nfs_append_clientaddr_option(const struct sockaddr *sap,
204 struct mount_options *options)
206 struct sockaddr_storage dummy;
207 struct sockaddr *my_addr = (struct sockaddr *)&dummy;
208 socklen_t my_len = sizeof(dummy);
210 if (po_contains(options, "clientaddr") == PO_FOUND)
213 nfs_callback_address(sap, salen, my_addr, &my_len);
215 return nfs_append_generic_address_option(my_addr, my_len,
216 "clientaddr", options);
220 * Resolve the 'mounthost=' hostname and append a new option using
221 * the resulting address.
223 static int nfs_fix_mounthost_option(struct mount_options *options)
225 struct sockaddr_storage dummy;
226 struct sockaddr *sap = (struct sockaddr *)&dummy;
227 socklen_t salen = sizeof(dummy);
230 mounthost = po_get(options, "mounthost");
234 if (!nfs_name_to_address(mounthost, sap, &salen)) {
235 nfs_error(_("%s: unable to determine mount server's address"),
240 return nfs_append_generic_address_option(sap, salen,
241 "mountaddr", options);
245 * Returns zero if the "lock" option is in effect, but statd
246 * can't be started. Otherwise, returns 1.
248 static const char *nfs_lock_opttbl[] = {
254 static int nfs_verify_lock_option(struct mount_options *options)
256 if (po_rightmost(options, nfs_lock_opttbl) == 0)
259 if (!start_statd()) {
260 nfs_error(_("%s: rpc.statd is not running but is "
261 "required for remote locking."), progname);
262 nfs_error(_("%s: Either use '-o nolock' to keep "
263 "locks local, or start statd."), progname);
270 static int nfs_append_sloppy_option(struct mount_options *options)
272 if (!sloppy || linux_version_code() < MAKE_VERSION(2, 6, 27))
275 if (po_append(options, "sloppy") == PO_FAILED)
280 * Set up mandatory non-version specific NFS mount options.
282 * Returns 1 if successful; otherwise zero.
284 static int nfs_validate_options(struct nfsmount_info *mi)
286 struct sockaddr *sap = (struct sockaddr *)&mi->address;
288 if (!nfs_parse_devname(mi->spec, &mi->hostname, NULL))
291 mi->salen = sizeof(mi->address);
292 if (!nfs_name_to_address(mi->hostname, sap, &mi->salen))
295 if (!nfs_nfs_version(mi->options, &mi->version))
297 if (strncmp(mi->type, "nfs4", 4) == 0)
300 char *option = po_get(mi->options, "proto");
301 if (option && strcmp(option, "rdma") == 0)
306 * If enabled, see if the default version was
307 * set in the config file
309 set_default_version(mi);
311 if (!nfs_append_sloppy_option(mi->options))
314 if (!nfs_append_addr_option(sap, mi->salen, mi->options))
321 * Get NFS/mnt server addresses from mount options
323 * Returns 1 and fills in @nfs_saddr, @nfs_salen, @mnt_saddr, and @mnt_salen
324 * if all goes well; otherwise zero.
326 static int nfs_extract_server_addresses(struct mount_options *options,
327 struct sockaddr *nfs_saddr,
328 socklen_t *nfs_salen,
329 struct sockaddr *mnt_saddr,
330 socklen_t *mnt_salen)
334 option = po_get(options, "addr");
337 if (!nfs_string_to_sockaddr(option, nfs_saddr, nfs_salen))
340 option = po_get(options, "mountaddr");
341 if (option == NULL) {
342 memcpy(mnt_saddr, nfs_saddr, *nfs_salen);
343 *mnt_salen = *nfs_salen;
344 } else if (!nfs_string_to_sockaddr(option, mnt_saddr, mnt_salen))
350 static int nfs_construct_new_options(struct mount_options *options,
351 struct pmap *nfs_pmap,
352 struct pmap *mnt_pmap)
356 po_remove_all(options, "nfsprog");
357 po_remove_all(options, "mountprog");
359 po_remove_all(options, "v2");
360 po_remove_all(options, "v3");
361 po_remove_all(options, "vers");
362 po_remove_all(options, "nfsvers");
363 snprintf(new_option, sizeof(new_option) - 1,
364 "vers=%lu", nfs_pmap->pm_vers);
365 if (po_append(options, new_option) == PO_FAILED)
368 po_remove_all(options, "proto");
369 po_remove_all(options, "udp");
370 po_remove_all(options, "tcp");
371 switch (nfs_pmap->pm_prot) {
373 snprintf(new_option, sizeof(new_option) - 1,
375 if (po_append(options, new_option) == PO_FAILED)
379 snprintf(new_option, sizeof(new_option) - 1,
381 if (po_append(options, new_option) == PO_FAILED)
386 po_remove_all(options, "port");
387 if (nfs_pmap->pm_port != NFS_PORT) {
388 snprintf(new_option, sizeof(new_option) - 1,
389 "port=%lu", nfs_pmap->pm_port);
390 if (po_append(options, new_option) == PO_FAILED)
394 po_remove_all(options, "mountvers");
395 snprintf(new_option, sizeof(new_option) - 1,
396 "mountvers=%lu", mnt_pmap->pm_vers);
397 if (po_append(options, new_option) == PO_FAILED)
400 po_remove_all(options, "mountproto");
401 switch (mnt_pmap->pm_prot) {
403 snprintf(new_option, sizeof(new_option) - 1,
405 if (po_append(options, new_option) == PO_FAILED)
409 snprintf(new_option, sizeof(new_option) - 1,
411 if (po_append(options, new_option) == PO_FAILED)
416 po_remove_all(options, "mountport");
417 snprintf(new_option, sizeof(new_option) - 1,
418 "mountport=%lu", mnt_pmap->pm_port);
419 if (po_append(options, new_option) == PO_FAILED)
426 * Reconstruct the mount option string based on a portmapper probe
427 * of the server. Returns one if the server's portmapper returned
428 * something we can use, otherwise zero.
430 * To handle version and transport protocol fallback properly, we
431 * need to parse some of the mount options in order to set up a
432 * portmap probe. Mount options that nfs_rewrite_pmap_mount_options()
433 * doesn't recognize are left alone.
435 * Returns TRUE if rewriting was successful; otherwise
436 * FALSE is returned if some failure occurred.
439 nfs_rewrite_pmap_mount_options(struct mount_options *options)
441 struct sockaddr_storage nfs_address;
442 struct sockaddr *nfs_saddr = (struct sockaddr *)&nfs_address;
443 socklen_t nfs_salen = sizeof(nfs_address);
444 struct pmap nfs_pmap;
445 struct sockaddr_storage mnt_address;
446 struct sockaddr *mnt_saddr = (struct sockaddr *)&mnt_address;
447 socklen_t mnt_salen = sizeof(mnt_address);
448 struct pmap mnt_pmap;
452 * Skip option negotiation for proto=rdma mounts.
454 option = po_get(options, "proto");
455 if (option && strcmp(option, "rdma") == 0)
459 * Extract just the options needed to contact server.
460 * Bail now if any of these have bad values.
462 if (!nfs_extract_server_addresses(options, nfs_saddr, &nfs_salen,
463 mnt_saddr, &mnt_salen)) {
467 if (!nfs_options2pmap(options, &nfs_pmap, &mnt_pmap)) {
473 * The kernel NFS client doesn't support changing the RPC
474 * program number for these services, so force the value of
475 * these fields before probing the server's ports.
477 nfs_pmap.pm_prog = NFS_PROGRAM;
478 mnt_pmap.pm_prog = MOUNTPROG;
481 * If the server's rpcbind service isn't available, we can't
482 * negotiate. Bail now if we can't contact it.
484 if (!nfs_probe_bothports(mnt_saddr, mnt_salen, &mnt_pmap,
485 nfs_saddr, nfs_salen, &nfs_pmap)) {
490 if (!nfs_construct_new_options(options, &nfs_pmap, &mnt_pmap)) {
501 * Do the mount(2) system call.
503 * Returns TRUE if successful, otherwise FALSE.
504 * "errno" is set to reflect the individual error.
506 static int nfs_sys_mount(struct nfsmount_info *mi, struct mount_options *opts)
508 char *options = NULL;
511 if (po_join(opts, &options) == PO_FAILED) {
517 printf(_("%s: trying text-based options '%s'\n"),
523 result = mount(mi->spec, mi->node, mi->type,
524 mi->flags & ~(MS_USER|MS_USERS), options);
525 if (verbose && result) {
527 nfs_error(_("%s: mount(2): %s"), progname, strerror(save));
534 * For "-t nfs vers=2" or "-t nfs vers=3" mounts.
536 static int nfs_try_mount_v3v2(struct nfsmount_info *mi)
538 struct mount_options *options = po_dup(mi->options);
546 if (!nfs_fix_mounthost_option(options)) {
550 if (!mi->fake && !nfs_verify_lock_option(options)) {
556 * Options we negotiate below may be stale by the time this
557 * file system is unmounted. In order to force umount.nfs
558 * to renegotiate with the server, only write the user-
559 * specified options, and not negotiated options, to /etc/mtab.
561 if (po_join(options, mi->extra_opts) == PO_FAILED) {
566 if (!nfs_rewrite_pmap_mount_options(options))
569 result = nfs_sys_mount(mi, options);
577 * For "-t nfs -o vers=4" or "-t nfs4" mounts.
579 static int nfs_try_mount_v4(struct nfsmount_info *mi)
581 struct sockaddr *sap = (struct sockaddr *)&mi->address;
582 struct mount_options *options = po_dup(mi->options);
590 if (mi->version == 0) {
591 if (po_append(options, "vers=4") == PO_FAILED) {
597 if (!nfs_append_clientaddr_option(sap, mi->salen, options)) {
602 * Update option string to be recorded in /etc/mtab.
604 if (po_join(options, mi->extra_opts) == PO_FAILED) {
609 result = nfs_sys_mount(mi, options);
617 * This is a single pass through the fg/bg loop.
619 * Returns TRUE if successful, otherwise FALSE.
620 * "errno" is set to reflect the individual error.
622 static int nfs_try_mount(struct nfsmount_info *mi)
626 switch (mi->version) {
628 if (linux_version_code() > MAKE_VERSION(2, 6, 31)) {
630 result = nfs_try_mount_v4(mi);
631 if (errno != EPROTONOSUPPORT)
636 result = nfs_try_mount_v3v2(mi);
639 result = nfs_try_mount_v4(mi);
649 * Distinguish between permanent and temporary errors.
651 * Basically, we retry if communication with the server has
652 * failed so far, but fail immediately if there is a local
653 * error (like a bad mount option).
655 * ESTALE is also a temporary error because some servers
656 * return ESTALE when a share is temporarily offline.
658 * Returns 1 if we should fail immediately, or 0 if we
661 static int nfs_is_permanent_error(int error)
667 return 0; /* temporary */
669 return 1; /* permanent */
674 * Handle "foreground" NFS mounts.
676 * Retry the mount request for as long as the 'retry=' option says.
678 * Returns a valid mount command exit code.
680 static int nfsmount_fg(struct nfsmount_info *mi)
682 unsigned int secs = 1;
685 timeout = nfs_parse_retry_option(mi->options,
686 NFS_DEF_FG_TIMEOUT_MINUTES);
688 printf(_("%s: timeout set for %s"),
689 progname, ctime(&timeout));
692 if (nfs_try_mount(mi))
695 if (nfs_is_permanent_error(errno))
698 if (time(NULL) > timeout) {
703 if (errno != ETIMEDOUT) {
712 mount_error(mi->spec, mi->node, errno);
717 * Handle "background" NFS mount [first try]
719 * Returns a valid mount command exit code.
721 * EX_BG should cause the caller to fork and invoke nfsmount_child.
723 static int nfsmount_parent(struct nfsmount_info *mi)
725 if (nfs_try_mount(mi))
728 if (nfs_is_permanent_error(errno)) {
729 mount_error(mi->spec, mi->node, errno);
733 sys_mount_errors(mi->hostname, errno, 1, 1);
738 * Handle "background" NFS mount [retry daemon]
740 * Returns a valid mount command exit code: EX_SUCCESS if successful,
741 * EX_FAIL if a failure occurred. There's nothing to catch the
742 * error return, though, so we use sys_mount_errors to log the
745 static int nfsmount_child(struct nfsmount_info *mi)
747 unsigned int secs = 1;
750 timeout = nfs_parse_retry_option(mi->options,
751 NFS_DEF_BG_TIMEOUT_MINUTES);
760 if (nfs_try_mount(mi))
763 if (nfs_is_permanent_error(errno))
766 if (time(NULL) > timeout)
769 sys_mount_errors(mi->hostname, errno, 1, 1);
772 sys_mount_errors(mi->hostname, errno, 1, 0);
777 * Handle "background" NFS mount
779 * Returns a valid mount command exit code.
781 static int nfsmount_bg(struct nfsmount_info *mi)
784 return nfsmount_parent(mi);
786 return nfsmount_child(mi);
790 * Process mount options and try a mount system call.
792 * Returns a valid mount command exit code.
794 static const char *nfs_background_opttbl[] = {
800 static int nfsmount_start(struct nfsmount_info *mi)
802 if (!nfs_validate_options(mi))
805 if (po_rightmost(mi->options, nfs_background_opttbl) == 0)
806 return nfsmount_bg(mi);
808 return nfsmount_fg(mi);
812 * nfsmount_string - Mount an NFS file system using C string options
813 * @spec: C string specifying remote share to mount ("hostname:path")
814 * @node: C string pathname of local mounted-on directory
815 * @type: C string that represents file system type ("nfs" or "nfs4")
816 * @flags: MS_ style mount flags
817 * @extra_opts: pointer to C string containing fs-specific mount options
818 * (input and output argument)
819 * @fake: flag indicating whether to carry out the whole operation
820 * @child: one if this is a mount daemon (bg)
822 int nfsmount_string(const char *spec, const char *node, const char *type,
823 int flags, char **extra_opts, int fake, int child)
825 struct nfsmount_info mi = {
829 .extra_opts = extra_opts,
834 int retval = EX_FAIL;
836 mi.options = po_split(*extra_opts);
838 retval = nfsmount_start(&mi);
839 po_destroy(mi.options);
841 nfs_error(_("%s: internal option parsing error"), progname);