17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate * CDDL HEADER START
37c478bd9Sstevel@tonic-gate *
47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the
5aa59c4cbSrsb * Common Development and Distribution License (the "License").
6aa59c4cbSrsb * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate *
87c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate * and limitations under the License.
127c478bd9Sstevel@tonic-gate *
137c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate *
197c478bd9Sstevel@tonic-gate * CDDL HEADER END
207c478bd9Sstevel@tonic-gate */
217c478bd9Sstevel@tonic-gate /*
225010b7f7SLori Alt * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
237c478bd9Sstevel@tonic-gate */
247c478bd9Sstevel@tonic-gate
257c478bd9Sstevel@tonic-gate #include <sys/file.h>
267c478bd9Sstevel@tonic-gate #include <sys/stat.h>
277c478bd9Sstevel@tonic-gate #include <sys/atomic.h>
287c478bd9Sstevel@tonic-gate #include <sys/mntio.h>
297c478bd9Sstevel@tonic-gate #include <sys/mnttab.h>
307c478bd9Sstevel@tonic-gate #include <sys/mount.h>
317c478bd9Sstevel@tonic-gate #include <sys/sunddi.h>
327c478bd9Sstevel@tonic-gate #include <sys/sysmacros.h>
337c478bd9Sstevel@tonic-gate #include <sys/systm.h>
347c478bd9Sstevel@tonic-gate #include <sys/vfs.h>
35aa59c4cbSrsb #include <sys/vfs_opreg.h>
367c478bd9Sstevel@tonic-gate #include <sys/fs/mntdata.h>
377c478bd9Sstevel@tonic-gate #include <fs/fs_subr.h>
387c478bd9Sstevel@tonic-gate #include <sys/vmsystm.h>
397c478bd9Sstevel@tonic-gate #include <vm/seg_vn.h>
40835ee219SRobert Harris #include <sys/time.h>
41835ee219SRobert Harris #include <sys/ksynch.h>
42835ee219SRobert Harris #include <sys/sdt.h>
437c478bd9Sstevel@tonic-gate
447c478bd9Sstevel@tonic-gate #define MNTROOTINO 2
457c478bd9Sstevel@tonic-gate
467c478bd9Sstevel@tonic-gate static mntnode_t *mntgetnode(vnode_t *);
477c478bd9Sstevel@tonic-gate
487c478bd9Sstevel@tonic-gate vnodeops_t *mntvnodeops;
49df2381bfSpraks extern void vfs_mnttab_readop(void);
507c478bd9Sstevel@tonic-gate
517c478bd9Sstevel@tonic-gate /*
527c478bd9Sstevel@tonic-gate * Design of kernel mnttab accounting.
537c478bd9Sstevel@tonic-gate *
54835ee219SRobert Harris * mntfs provides two methods of reading the in-kernel mnttab, i.e. the state of
55835ee219SRobert Harris * the mounted resources: the read-only file /etc/mnttab, and a collection of
56835ee219SRobert Harris * ioctl() commands. Most of these interfaces are public and are described in
57*bbf21555SRichard Lowe * mnttab(5). Three private ioctl() commands, MNTIOC_GETMNTENT,
58835ee219SRobert Harris * MNTIOC_GETEXTMNTENT and MNTIOC_GETMNTANY, provide for the getmntent(3C)
59835ee219SRobert Harris * family of functions, allowing them to support white space in mount names.
607c478bd9Sstevel@tonic-gate *
61835ee219SRobert Harris * A significant feature of mntfs is that it provides a file descriptor with a
62835ee219SRobert Harris * snapshot once it begins to consume mnttab data. Thus, as the process
63835ee219SRobert Harris * continues to consume data, its view of the in-kernel mnttab does not change
64835ee219SRobert Harris * even if resources are mounted or unmounted. The intent is to ensure that
65835ee219SRobert Harris * processes are guaranteed to read self-consistent data even as the system
66835ee219SRobert Harris * changes.
67835ee219SRobert Harris *
68835ee219SRobert Harris * The snapshot is implemented by a "database", unique to each zone, that
69835ee219SRobert Harris * comprises a linked list of mntelem_ts. The database is identified by
70835ee219SRobert Harris * zone_mntfs_db and is protected by zone_mntfs_db_lock. Each element contains
71835ee219SRobert Harris * the text entry in /etc/mnttab for a mounted resource, i.e. a vfs_t, and is
72835ee219SRobert Harris * marked with its time of "birth", i.e. creation. An element is "killed", and
73835ee219SRobert Harris * marked with its time of death, when it is found to be out of date, e.g. when
74835ee219SRobert Harris * the corresponding resource has been unmounted.
75835ee219SRobert Harris *
76835ee219SRobert Harris * When a process performs the first read() or ioctl() for a file descriptor for
77835ee219SRobert Harris * /etc/mnttab, the database is updated by a call to mntfs_snapshot() to ensure
78835ee219SRobert Harris * that an element exists for each currently mounted resource. Following this,
79835ee219SRobert Harris * the current time is written into a snapshot structure, a mntsnap_t, embedded
80835ee219SRobert Harris * in the descriptor's mntnode_t.
81835ee219SRobert Harris *
82835ee219SRobert Harris * mntfs is able to enumerate the /etc/mnttab entries corresponding to a
83835ee219SRobert Harris * particular file descriptor by searching the database for entries that were
84835ee219SRobert Harris * born before the appropriate snapshot and that either are still alive or died
85835ee219SRobert Harris * after the snapshot was created. Consumers use the iterator function
86835ee219SRobert Harris * mntfs_get_next_elem() to identify the next suitable element in the database.
87835ee219SRobert Harris *
88835ee219SRobert Harris * Each snapshot has a hold on its corresponding database elements, effected by
89835ee219SRobert Harris * a per-element reference count. At last close(), a snapshot is destroyed in
90835ee219SRobert Harris * mntfs_freesnap() by releasing all of its holds; an element is destroyed if
91835ee219SRobert Harris * its reference count becomes zero. Therefore the database never exists unless
92835ee219SRobert Harris * there is at least one active consumer of /etc/mnttab.
93835ee219SRobert Harris *
94835ee219SRobert Harris * getmntent(3C) et al. "do not open, close or rewind the file." This implies
95835ee219SRobert Harris * that getmntent() and read() must be able to operate without interaction on
96835ee219SRobert Harris * the same file descriptor; this is accomplished by the use of separate
97835ee219SRobert Harris * mntsnap_ts for both read() and ioctl().
987c478bd9Sstevel@tonic-gate *
995545576aSRobert Harris * mntfs observes the following lock-ordering:
1005545576aSRobert Harris *
1015545576aSRobert Harris * mnp->mnt_contents -> vfslist -> zonep->zone_mntfs_db_lock
1025545576aSRobert Harris *
1037c478bd9Sstevel@tonic-gate * NOTE: The following variable enables the generation of the "dev=xxx"
1047c478bd9Sstevel@tonic-gate * in the option string for a mounted file system. Really this should
1057c478bd9Sstevel@tonic-gate * be gotten rid of altogether, but for the sake of backwards compatibility
1067c478bd9Sstevel@tonic-gate * we had to leave it in. It is defined as a 32-bit device number. This
1077c478bd9Sstevel@tonic-gate * means that when 64-bit device numbers are in use, if either the major or
1087c478bd9Sstevel@tonic-gate * minor part of the device number will not fit in a 16 bit quantity, the
1097c478bd9Sstevel@tonic-gate * "dev=" will be set to NODEV (0x7fffffff). See PSARC 1999/566 and
1107c478bd9Sstevel@tonic-gate * 1999/131 for details. The cmpldev() function used to generate the 32-bit
1117c478bd9Sstevel@tonic-gate * device number handles this check and assigns the proper value.
1127c478bd9Sstevel@tonic-gate */
1137c478bd9Sstevel@tonic-gate int mntfs_enabledev = 1; /* enable old "dev=xxx" option */
1147c478bd9Sstevel@tonic-gate
115835ee219SRobert Harris extern void vfs_mono_time(timespec_t *);
116835ee219SRobert Harris enum { MNTFS_FIRST, MNTFS_SECOND, MNTFS_NEITHER };
117835ee219SRobert Harris
118835ee219SRobert Harris /*
119835ee219SRobert Harris * Determine whether a field within a line from /etc/mnttab contains actual
120835ee219SRobert Harris * content or simply the marker string "-". This never applies to the time,
121835ee219SRobert Harris * therefore the delimiter must be a tab.
122835ee219SRobert Harris */
123835ee219SRobert Harris #define MNTFS_REAL_FIELD(x) (*(x) != '-' || *((x) + 1) != '\t')
124835ee219SRobert Harris
1257c478bd9Sstevel@tonic-gate static int
mntfs_devsize(struct vfs * vfsp)1267c478bd9Sstevel@tonic-gate mntfs_devsize(struct vfs *vfsp)
1277c478bd9Sstevel@tonic-gate {
1287c478bd9Sstevel@tonic-gate dev32_t odev;
1297c478bd9Sstevel@tonic-gate
1307c478bd9Sstevel@tonic-gate (void) cmpldev(&odev, vfsp->vfs_dev);
1317c478bd9Sstevel@tonic-gate return (snprintf(NULL, 0, "dev=%x", odev));
1327c478bd9Sstevel@tonic-gate }
1337c478bd9Sstevel@tonic-gate
1347c478bd9Sstevel@tonic-gate static int
mntfs_devprint(struct vfs * vfsp,char * buf)1357c478bd9Sstevel@tonic-gate mntfs_devprint(struct vfs *vfsp, char *buf)
1367c478bd9Sstevel@tonic-gate {
1377c478bd9Sstevel@tonic-gate dev32_t odev;
1387c478bd9Sstevel@tonic-gate
1397c478bd9Sstevel@tonic-gate (void) cmpldev(&odev, vfsp->vfs_dev);
1407c478bd9Sstevel@tonic-gate return (snprintf(buf, MAX_MNTOPT_STR, "dev=%x", odev));
1417c478bd9Sstevel@tonic-gate }
1427c478bd9Sstevel@tonic-gate
143835ee219SRobert Harris /* Identify which, if either, of two supplied timespec structs is newer. */
144835ee219SRobert Harris static int
mntfs_newest(timespec_t * a,timespec_t * b)145835ee219SRobert Harris mntfs_newest(timespec_t *a, timespec_t *b)
146835ee219SRobert Harris {
147835ee219SRobert Harris if (a->tv_sec == b->tv_sec &&
148835ee219SRobert Harris a->tv_nsec == b->tv_nsec) {
149835ee219SRobert Harris return (MNTFS_NEITHER);
150835ee219SRobert Harris } else if (b->tv_sec > a->tv_sec ||
151835ee219SRobert Harris (b->tv_sec == a->tv_sec &&
152835ee219SRobert Harris b->tv_nsec > a->tv_nsec)) {
153835ee219SRobert Harris return (MNTFS_SECOND);
154835ee219SRobert Harris } else {
155835ee219SRobert Harris return (MNTFS_FIRST);
156835ee219SRobert Harris }
157835ee219SRobert Harris }
158835ee219SRobert Harris
1597c478bd9Sstevel@tonic-gate static int
mntfs_optsize(struct vfs * vfsp)1607c478bd9Sstevel@tonic-gate mntfs_optsize(struct vfs *vfsp)
1617c478bd9Sstevel@tonic-gate {
1627c478bd9Sstevel@tonic-gate int i, size = 0;
1637c478bd9Sstevel@tonic-gate mntopt_t *mop;
1647c478bd9Sstevel@tonic-gate
1657c478bd9Sstevel@tonic-gate for (i = 0; i < vfsp->vfs_mntopts.mo_count; i++) {
1667c478bd9Sstevel@tonic-gate mop = &vfsp->vfs_mntopts.mo_list[i];
1677c478bd9Sstevel@tonic-gate if (mop->mo_flags & MO_NODISPLAY)
1687c478bd9Sstevel@tonic-gate continue;
1697c478bd9Sstevel@tonic-gate if (mop->mo_flags & MO_SET) {
1707c478bd9Sstevel@tonic-gate if (size)
1717c478bd9Sstevel@tonic-gate size++; /* space for comma */
1727c478bd9Sstevel@tonic-gate size += strlen(mop->mo_name);
1737c478bd9Sstevel@tonic-gate /*
1747c478bd9Sstevel@tonic-gate * count option value if there is one
1757c478bd9Sstevel@tonic-gate */
1767c478bd9Sstevel@tonic-gate if (mop->mo_arg != NULL) {
1777c478bd9Sstevel@tonic-gate size += strlen(mop->mo_arg) + 1;
1787c478bd9Sstevel@tonic-gate }
1797c478bd9Sstevel@tonic-gate }
1807c478bd9Sstevel@tonic-gate }
1817c478bd9Sstevel@tonic-gate if (vfsp->vfs_zone != NULL && vfsp->vfs_zone != global_zone) {
1827c478bd9Sstevel@tonic-gate /*
1837c478bd9Sstevel@tonic-gate * Add space for "zone=<zone_name>" if required.
1847c478bd9Sstevel@tonic-gate */
1857c478bd9Sstevel@tonic-gate if (size)
1867c478bd9Sstevel@tonic-gate size++; /* space for comma */
1877c478bd9Sstevel@tonic-gate size += sizeof ("zone=") - 1;
1887c478bd9Sstevel@tonic-gate size += strlen(vfsp->vfs_zone->zone_name);
1897c478bd9Sstevel@tonic-gate }
1907c478bd9Sstevel@tonic-gate if (mntfs_enabledev) {
1917c478bd9Sstevel@tonic-gate if (size != 0)
1927c478bd9Sstevel@tonic-gate size++; /* space for comma */
1937c478bd9Sstevel@tonic-gate size += mntfs_devsize(vfsp);
1947c478bd9Sstevel@tonic-gate }
1957c478bd9Sstevel@tonic-gate if (size == 0)
1967c478bd9Sstevel@tonic-gate size = strlen("-");
1977c478bd9Sstevel@tonic-gate return (size);
1987c478bd9Sstevel@tonic-gate }
1997c478bd9Sstevel@tonic-gate
2007c478bd9Sstevel@tonic-gate static int
mntfs_optprint(struct vfs * vfsp,char * buf)2017c478bd9Sstevel@tonic-gate mntfs_optprint(struct vfs *vfsp, char *buf)
2027c478bd9Sstevel@tonic-gate {
2037c478bd9Sstevel@tonic-gate int i, optinbuf = 0;
2047c478bd9Sstevel@tonic-gate mntopt_t *mop;
2057c478bd9Sstevel@tonic-gate char *origbuf = buf;
2067c478bd9Sstevel@tonic-gate
2077c478bd9Sstevel@tonic-gate for (i = 0; i < vfsp->vfs_mntopts.mo_count; i++) {
2087c478bd9Sstevel@tonic-gate mop = &vfsp->vfs_mntopts.mo_list[i];
2097c478bd9Sstevel@tonic-gate if (mop->mo_flags & MO_NODISPLAY)
2107c478bd9Sstevel@tonic-gate continue;
2117c478bd9Sstevel@tonic-gate if (mop->mo_flags & MO_SET) {
2127c478bd9Sstevel@tonic-gate if (optinbuf)
2137c478bd9Sstevel@tonic-gate *buf++ = ',';
2147c478bd9Sstevel@tonic-gate else
2157c478bd9Sstevel@tonic-gate optinbuf = 1;
2167c478bd9Sstevel@tonic-gate buf += snprintf(buf, MAX_MNTOPT_STR,
21760946fe0Smec "%s", mop->mo_name);
2187c478bd9Sstevel@tonic-gate /*
2197c478bd9Sstevel@tonic-gate * print option value if there is one
2207c478bd9Sstevel@tonic-gate */
2217c478bd9Sstevel@tonic-gate if (mop->mo_arg != NULL) {
2227c478bd9Sstevel@tonic-gate buf += snprintf(buf, MAX_MNTOPT_STR, "=%s",
22360946fe0Smec mop->mo_arg);
2247c478bd9Sstevel@tonic-gate }
2257c478bd9Sstevel@tonic-gate }
2267c478bd9Sstevel@tonic-gate }
2277c478bd9Sstevel@tonic-gate if (vfsp->vfs_zone != NULL && vfsp->vfs_zone != global_zone) {
2287c478bd9Sstevel@tonic-gate if (optinbuf)
2297c478bd9Sstevel@tonic-gate *buf++ = ',';
2307c478bd9Sstevel@tonic-gate else
2317c478bd9Sstevel@tonic-gate optinbuf = 1;
2327c478bd9Sstevel@tonic-gate buf += snprintf(buf, MAX_MNTOPT_STR, "zone=%s",
2337c478bd9Sstevel@tonic-gate vfsp->vfs_zone->zone_name);
2347c478bd9Sstevel@tonic-gate }
2357c478bd9Sstevel@tonic-gate if (mntfs_enabledev) {
2367c478bd9Sstevel@tonic-gate if (optinbuf++)
2377c478bd9Sstevel@tonic-gate *buf++ = ',';
2387c478bd9Sstevel@tonic-gate buf += mntfs_devprint(vfsp, buf);
2397c478bd9Sstevel@tonic-gate }
2407c478bd9Sstevel@tonic-gate if (!optinbuf) {
2417c478bd9Sstevel@tonic-gate buf += snprintf(buf, MAX_MNTOPT_STR, "-");
2427c478bd9Sstevel@tonic-gate }
2437c478bd9Sstevel@tonic-gate return (buf - origbuf);
2447c478bd9Sstevel@tonic-gate }
2457c478bd9Sstevel@tonic-gate
246835ee219SRobert Harris void
mntfs_populate_text(vfs_t * vfsp,zone_t * zonep,mntelem_t * elemp)247835ee219SRobert Harris mntfs_populate_text(vfs_t *vfsp, zone_t *zonep, mntelem_t *elemp)
248835ee219SRobert Harris {
249835ee219SRobert Harris struct extmnttab *tabp = &elemp->mnte_tab;
250835ee219SRobert Harris const char *resource, *mntpt;
251835ee219SRobert Harris char *cp = elemp->mnte_text;
252835ee219SRobert Harris mntpt = refstr_value(vfsp->vfs_mntpt);
253835ee219SRobert Harris resource = refstr_value(vfsp->vfs_resource);
254835ee219SRobert Harris
255835ee219SRobert Harris tabp->mnt_special = 0;
256835ee219SRobert Harris if (resource != NULL && resource[0] != '\0') {
257835ee219SRobert Harris if (resource[0] != '/') {
258835ee219SRobert Harris cp += snprintf(cp, MAXPATHLEN, "%s\t", resource);
259835ee219SRobert Harris } else if (!ZONE_PATH_VISIBLE(resource, zonep)) {
260835ee219SRobert Harris /*
261835ee219SRobert Harris * Use the mount point as the resource.
262835ee219SRobert Harris */
263835ee219SRobert Harris cp += snprintf(cp, MAXPATHLEN, "%s\t",
264835ee219SRobert Harris ZONE_PATH_TRANSLATE(mntpt, zonep));
265835ee219SRobert Harris } else {
266835ee219SRobert Harris cp += snprintf(cp, MAXPATHLEN, "%s\t",
267835ee219SRobert Harris ZONE_PATH_TRANSLATE(resource, zonep));
268835ee219SRobert Harris }
269835ee219SRobert Harris } else {
270835ee219SRobert Harris cp += snprintf(cp, MAXPATHLEN, "-\t");
271835ee219SRobert Harris }
272835ee219SRobert Harris
273835ee219SRobert Harris tabp->mnt_mountp = (char *)(cp - elemp->mnte_text);
274835ee219SRobert Harris if (mntpt != NULL && mntpt[0] != '\0') {
275835ee219SRobert Harris /*
276835ee219SRobert Harris * We know the mount point is visible from within the zone,
277835ee219SRobert Harris * otherwise it wouldn't be on the zone's vfs list.
278835ee219SRobert Harris */
279835ee219SRobert Harris cp += snprintf(cp, MAXPATHLEN, "%s\t",
280835ee219SRobert Harris ZONE_PATH_TRANSLATE(mntpt, zonep));
281835ee219SRobert Harris } else {
282835ee219SRobert Harris cp += snprintf(cp, MAXPATHLEN, "-\t");
283835ee219SRobert Harris }
284835ee219SRobert Harris
285835ee219SRobert Harris tabp->mnt_fstype = (char *)(cp - elemp->mnte_text);
286835ee219SRobert Harris cp += snprintf(cp, MAXPATHLEN, "%s\t",
287835ee219SRobert Harris vfssw[vfsp->vfs_fstype].vsw_name);
288835ee219SRobert Harris
289835ee219SRobert Harris tabp->mnt_mntopts = (char *)(cp - elemp->mnte_text);
290835ee219SRobert Harris cp += mntfs_optprint(vfsp, cp);
291835ee219SRobert Harris *cp++ = '\t';
292835ee219SRobert Harris
293835ee219SRobert Harris tabp->mnt_time = (char *)(cp - elemp->mnte_text);
294835ee219SRobert Harris cp += snprintf(cp, MAX_MNTOPT_STR, "%ld", vfsp->vfs_mtime);
295835ee219SRobert Harris *cp++ = '\n'; /* over-write snprintf's trailing null-byte */
296835ee219SRobert Harris
297835ee219SRobert Harris tabp->mnt_major = getmajor(vfsp->vfs_dev);
298835ee219SRobert Harris tabp->mnt_minor = getminor(vfsp->vfs_dev);
299835ee219SRobert Harris
300835ee219SRobert Harris elemp->mnte_text_size = cp - elemp->mnte_text;
301835ee219SRobert Harris elemp->mnte_vfs_ctime = vfsp->vfs_hrctime;
302835ee219SRobert Harris elemp->mnte_hidden = vfsp->vfs_flag & VFS_NOMNTTAB;
303835ee219SRobert Harris }
304835ee219SRobert Harris
305835ee219SRobert Harris /* Determine the length of the /etc/mnttab entry for this vfs_t. */
3067c478bd9Sstevel@tonic-gate static size_t
mntfs_text_len(vfs_t * vfsp,zone_t * zone)307835ee219SRobert Harris mntfs_text_len(vfs_t *vfsp, zone_t *zone)
3087c478bd9Sstevel@tonic-gate {
3097c478bd9Sstevel@tonic-gate size_t size = 0;
3107c478bd9Sstevel@tonic-gate const char *resource, *mntpt;
311835ee219SRobert Harris size_t mntsize;
3127c478bd9Sstevel@tonic-gate
3137c478bd9Sstevel@tonic-gate mntpt = refstr_value(vfsp->vfs_mntpt);
3147c478bd9Sstevel@tonic-gate if (mntpt != NULL && mntpt[0] != '\0') {
315835ee219SRobert Harris mntsize = strlen(ZONE_PATH_TRANSLATE(mntpt, zone)) + 1;
3167c478bd9Sstevel@tonic-gate } else {
317835ee219SRobert Harris mntsize = 2; /* "-\t" */
3187c478bd9Sstevel@tonic-gate }
319835ee219SRobert Harris size += mntsize;
3207c478bd9Sstevel@tonic-gate
3217c478bd9Sstevel@tonic-gate resource = refstr_value(vfsp->vfs_resource);
3227c478bd9Sstevel@tonic-gate if (resource != NULL && resource[0] != '\0') {
3237c478bd9Sstevel@tonic-gate if (resource[0] != '/') {
3247c478bd9Sstevel@tonic-gate size += strlen(resource) + 1;
3257c478bd9Sstevel@tonic-gate } else if (!ZONE_PATH_VISIBLE(resource, zone)) {
3267c478bd9Sstevel@tonic-gate /*
3277c478bd9Sstevel@tonic-gate * Same as the zone's view of the mount point.
3287c478bd9Sstevel@tonic-gate */
329835ee219SRobert Harris size += mntsize;
3307c478bd9Sstevel@tonic-gate } else {
3317c478bd9Sstevel@tonic-gate size += strlen(ZONE_PATH_TRANSLATE(resource, zone)) + 1;
3327c478bd9Sstevel@tonic-gate }
3337c478bd9Sstevel@tonic-gate } else {
334835ee219SRobert Harris size += 2; /* "-\t" */
3357c478bd9Sstevel@tonic-gate }
3367c478bd9Sstevel@tonic-gate size += strlen(vfssw[vfsp->vfs_fstype].vsw_name) + 1;
3377c478bd9Sstevel@tonic-gate size += mntfs_optsize(vfsp);
3387c478bd9Sstevel@tonic-gate size += snprintf(NULL, 0, "\t%ld\n", vfsp->vfs_mtime);
3397c478bd9Sstevel@tonic-gate return (size);
3407c478bd9Sstevel@tonic-gate }
3417c478bd9Sstevel@tonic-gate
342835ee219SRobert Harris /* Destroy the resources associated with a snapshot element. */
3437c478bd9Sstevel@tonic-gate static void
mntfs_destroy_elem(mntelem_t * elemp)344835ee219SRobert Harris mntfs_destroy_elem(mntelem_t *elemp)
3457c478bd9Sstevel@tonic-gate {
346835ee219SRobert Harris kmem_free(elemp->mnte_text, elemp->mnte_text_size);
347835ee219SRobert Harris kmem_free(elemp, sizeof (mntelem_t));
3487c478bd9Sstevel@tonic-gate }
3497c478bd9Sstevel@tonic-gate
350835ee219SRobert Harris /*
351835ee219SRobert Harris * Return 1 if the given snapshot is in the range of the given element; return
352835ee219SRobert Harris * 0 otherwise.
353835ee219SRobert Harris */
354835ee219SRobert Harris static int
mntfs_elem_in_range(mntsnap_t * snapp,mntelem_t * elemp)355835ee219SRobert Harris mntfs_elem_in_range(mntsnap_t *snapp, mntelem_t *elemp)
3567c478bd9Sstevel@tonic-gate {
357835ee219SRobert Harris timespec_t *stimep = &snapp->mnts_time;
358835ee219SRobert Harris timespec_t *btimep = &elemp->mnte_birth;
359835ee219SRobert Harris timespec_t *dtimep = &elemp->mnte_death;
3607c478bd9Sstevel@tonic-gate
3617c478bd9Sstevel@tonic-gate /*
362835ee219SRobert Harris * If a snapshot is in range of an element then the snapshot must have
363835ee219SRobert Harris * been created after the birth of the element, and either the element
364835ee219SRobert Harris * is still alive or it died after the snapshot was created.
3657c478bd9Sstevel@tonic-gate */
366835ee219SRobert Harris if (mntfs_newest(btimep, stimep) == MNTFS_SECOND &&
367835ee219SRobert Harris (MNTFS_ELEM_IS_ALIVE(elemp) ||
368835ee219SRobert Harris mntfs_newest(stimep, dtimep) == MNTFS_SECOND))
369835ee219SRobert Harris return (1);
370835ee219SRobert Harris else
371835ee219SRobert Harris return (0);
3727c478bd9Sstevel@tonic-gate }
3737c478bd9Sstevel@tonic-gate
374835ee219SRobert Harris /*
375835ee219SRobert Harris * Return the next valid database element, after the one provided, for a given
376835ee219SRobert Harris * snapshot; return NULL if none exists. The caller must hold the zone's
377835ee219SRobert Harris * database lock as a reader before calling this function.
378835ee219SRobert Harris */
379835ee219SRobert Harris static mntelem_t *
mntfs_get_next_elem(mntsnap_t * snapp,mntelem_t * elemp)380835ee219SRobert Harris mntfs_get_next_elem(mntsnap_t *snapp, mntelem_t *elemp)
3817c478bd9Sstevel@tonic-gate {
382835ee219SRobert Harris int show_hidden = snapp->mnts_flags & MNTS_SHOWHIDDEN;
3837c478bd9Sstevel@tonic-gate
3847c478bd9Sstevel@tonic-gate do {
385835ee219SRobert Harris elemp = elemp->mnte_next;
386835ee219SRobert Harris } while (elemp &&
387835ee219SRobert Harris (!mntfs_elem_in_range(snapp, elemp) ||
388835ee219SRobert Harris (!show_hidden && elemp->mnte_hidden)));
389835ee219SRobert Harris return (elemp);
3907c478bd9Sstevel@tonic-gate }
3917c478bd9Sstevel@tonic-gate
392835ee219SRobert Harris /*
393835ee219SRobert Harris * This function frees the resources associated with a mntsnap_t. It walks
394835ee219SRobert Harris * through the database, decrementing the reference count of any element that
395835ee219SRobert Harris * satisfies the snapshot. If the reference count of an element becomes zero
396835ee219SRobert Harris * then it is removed from the database.
397835ee219SRobert Harris */
3987c478bd9Sstevel@tonic-gate static void
mntfs_freesnap(mntnode_t * mnp,mntsnap_t * snapp)399835ee219SRobert Harris mntfs_freesnap(mntnode_t *mnp, mntsnap_t *snapp)
4007c478bd9Sstevel@tonic-gate {
401a19609f8Sjv zone_t *zonep = MTOD(mnp)->mnt_zone_ref.zref_zone;
402835ee219SRobert Harris krwlock_t *dblockp = &zonep->zone_mntfs_db_lock;
403835ee219SRobert Harris mntelem_t **elempp = &zonep->zone_mntfs_db;
404835ee219SRobert Harris mntelem_t *elemp;
405835ee219SRobert Harris int show_hidden = snapp->mnts_flags & MNTS_SHOWHIDDEN;
406835ee219SRobert Harris size_t number_decremented = 0;
4077c478bd9Sstevel@tonic-gate
408835ee219SRobert Harris ASSERT(RW_WRITE_HELD(&mnp->mnt_contents));
4097c478bd9Sstevel@tonic-gate
410835ee219SRobert Harris /* Ignore an uninitialised snapshot. */
411835ee219SRobert Harris if (snapp->mnts_nmnts == 0)
412835ee219SRobert Harris return;
413835ee219SRobert Harris
414835ee219SRobert Harris /* Drop the holds on any matching database elements. */
415835ee219SRobert Harris rw_enter(dblockp, RW_WRITER);
416835ee219SRobert Harris while ((elemp = *elempp) != NULL) {
417835ee219SRobert Harris if (mntfs_elem_in_range(snapp, elemp) &&
418835ee219SRobert Harris (!elemp->mnte_hidden || show_hidden) &&
419835ee219SRobert Harris ++number_decremented && --elemp->mnte_refcnt == 0) {
420835ee219SRobert Harris if ((*elempp = elemp->mnte_next) != NULL)
421835ee219SRobert Harris (*elempp)->mnte_prev = elemp->mnte_prev;
422835ee219SRobert Harris mntfs_destroy_elem(elemp);
4237c478bd9Sstevel@tonic-gate } else {
424835ee219SRobert Harris elempp = &elemp->mnte_next;
4257c478bd9Sstevel@tonic-gate }
4267c478bd9Sstevel@tonic-gate }
427835ee219SRobert Harris rw_exit(dblockp);
428835ee219SRobert Harris ASSERT(number_decremented == snapp->mnts_nmnts);
4297c478bd9Sstevel@tonic-gate
430835ee219SRobert Harris /* Clear the snapshot data. */
431835ee219SRobert Harris bzero(snapp, sizeof (mntsnap_t));
4327c478bd9Sstevel@tonic-gate }
4337c478bd9Sstevel@tonic-gate
434835ee219SRobert Harris /* Insert the new database element newp after the existing element prevp. */
4357c478bd9Sstevel@tonic-gate static void
mntfs_insert_after(mntelem_t * newp,mntelem_t * prevp)436835ee219SRobert Harris mntfs_insert_after(mntelem_t *newp, mntelem_t *prevp)
4377c478bd9Sstevel@tonic-gate {
438835ee219SRobert Harris newp->mnte_prev = prevp;
439835ee219SRobert Harris newp->mnte_next = prevp->mnte_next;
440835ee219SRobert Harris prevp->mnte_next = newp;
441835ee219SRobert Harris if (newp->mnte_next != NULL)
442835ee219SRobert Harris newp->mnte_next->mnte_prev = newp;
4437c478bd9Sstevel@tonic-gate }
4447c478bd9Sstevel@tonic-gate
445835ee219SRobert Harris /* Create and return a copy of a given database element. */
446835ee219SRobert Harris static mntelem_t *
mntfs_copy(mntelem_t * origp)447835ee219SRobert Harris mntfs_copy(mntelem_t *origp)
4487c478bd9Sstevel@tonic-gate {
449835ee219SRobert Harris mntelem_t *copyp;
4507c478bd9Sstevel@tonic-gate
451835ee219SRobert Harris copyp = kmem_zalloc(sizeof (mntelem_t), KM_SLEEP);
452835ee219SRobert Harris copyp->mnte_vfs_ctime = origp->mnte_vfs_ctime;
453835ee219SRobert Harris copyp->mnte_text_size = origp->mnte_text_size;
454835ee219SRobert Harris copyp->mnte_text = kmem_alloc(copyp->mnte_text_size, KM_SLEEP);
455835ee219SRobert Harris bcopy(origp->mnte_text, copyp->mnte_text, copyp->mnte_text_size);
456835ee219SRobert Harris copyp->mnte_tab = origp->mnte_tab;
457835ee219SRobert Harris copyp->mnte_hidden = origp->mnte_hidden;
4587c478bd9Sstevel@tonic-gate
459835ee219SRobert Harris return (copyp);
4607c478bd9Sstevel@tonic-gate }
4617c478bd9Sstevel@tonic-gate
462835ee219SRobert Harris /*
463835ee219SRobert Harris * Compare two database elements and determine whether or not the vfs_t payload
464835ee219SRobert Harris * data of each are the same. Return 1 if so and 0 otherwise.
465835ee219SRobert Harris */
466835ee219SRobert Harris static int
mntfs_is_same_element(mntelem_t * a,mntelem_t * b)467835ee219SRobert Harris mntfs_is_same_element(mntelem_t *a, mntelem_t *b)
4687c478bd9Sstevel@tonic-gate {
469835ee219SRobert Harris if (a->mnte_hidden == b->mnte_hidden &&
470835ee219SRobert Harris a->mnte_text_size == b->mnte_text_size &&
471835ee219SRobert Harris bcmp(a->mnte_text, b->mnte_text, a->mnte_text_size) == 0 &&
472835ee219SRobert Harris bcmp(&a->mnte_tab, &b->mnte_tab, sizeof (struct extmnttab)) == 0)
473835ee219SRobert Harris return (1);
474835ee219SRobert Harris else
475835ee219SRobert Harris return (0);
4767c478bd9Sstevel@tonic-gate }
4777c478bd9Sstevel@tonic-gate
4787c478bd9Sstevel@tonic-gate /*
479835ee219SRobert Harris * mntfs_snapshot() updates the database, creating it if necessary, so that it
480835ee219SRobert Harris * accurately reflects the state of the in-kernel mnttab. It also increments
481835ee219SRobert Harris * the reference count on all database elements that correspond to currently-
482835ee219SRobert Harris * mounted resources. Finally, it initialises the appropriate snapshot
483835ee219SRobert Harris * structure.
4847c478bd9Sstevel@tonic-gate *
485835ee219SRobert Harris * Each vfs_t is given a high-resolution time stamp, for the benefit of mntfs,
486835ee219SRobert Harris * when it is inserted into the in-kernel mnttab. This time stamp is copied into
487835ee219SRobert Harris * the corresponding database element when it is created, allowing the element
488835ee219SRobert Harris * and the vfs_t to be identified as a pair. It is possible that some file
489835ee219SRobert Harris * systems may make unadvertised changes to, for example, a resource's mount
490835ee219SRobert Harris * options. Therefore, in order to determine whether a database element is an
491835ee219SRobert Harris * up-to-date representation of a given vfs_t, it is compared with a temporary
492835ee219SRobert Harris * element generated for this purpose. Although less efficient, this is safer
493835ee219SRobert Harris * than implementing an mtime for a vfs_t.
494835ee219SRobert Harris *
495835ee219SRobert Harris * Some mounted resources are marked as "hidden" with a VFS_NOMNTTAB flag. These
496835ee219SRobert Harris * are considered invisible unless the user has already set the MNT_SHOWHIDDEN
497835ee219SRobert Harris * flag in the vnode using the MNTIOC_SHOWHIDDEN ioctl.
4987c478bd9Sstevel@tonic-gate */
499835ee219SRobert Harris static void
mntfs_snapshot(mntnode_t * mnp,mntsnap_t * snapp)500835ee219SRobert Harris mntfs_snapshot(mntnode_t *mnp, mntsnap_t *snapp)
5017c478bd9Sstevel@tonic-gate {
5025545576aSRobert Harris mntdata_t *mnd = MTOD(mnp);
503a19609f8Sjv zone_t *zonep = mnd->mnt_zone_ref.zref_zone;
504835ee219SRobert Harris int is_global_zone = (zonep == global_zone);
505835ee219SRobert Harris int show_hidden = mnp->mnt_flags & MNT_SHOWHIDDEN;
506835ee219SRobert Harris vfs_t *vfsp, *firstvfsp, *lastvfsp;
507835ee219SRobert Harris vfs_t dummyvfs;
508835ee219SRobert Harris vfs_t *dummyvfsp = NULL;
509835ee219SRobert Harris krwlock_t *dblockp = &zonep->zone_mntfs_db_lock;
510835ee219SRobert Harris mntelem_t **headpp = &zonep->zone_mntfs_db;
511835ee219SRobert Harris mntelem_t *elemp;
512835ee219SRobert Harris mntelem_t *prevp = NULL;
513835ee219SRobert Harris int order;
514835ee219SRobert Harris mntelem_t *tempelemp;
515835ee219SRobert Harris mntelem_t *newp;
516835ee219SRobert Harris mntelem_t *firstp = NULL;
517835ee219SRobert Harris size_t nmnts = 0;
5185545576aSRobert Harris size_t total_text_size = 0;
5195545576aSRobert Harris size_t normal_text_size = 0;
520835ee219SRobert Harris int insert_before;
521835ee219SRobert Harris timespec_t last_mtime;
522835ee219SRobert Harris size_t entry_length, new_entry_length;
523835ee219SRobert Harris
524835ee219SRobert Harris
525835ee219SRobert Harris ASSERT(RW_WRITE_HELD(&mnp->mnt_contents));
5267c478bd9Sstevel@tonic-gate vfs_list_read_lock();
527835ee219SRobert Harris vfs_mnttab_modtime(&last_mtime);
528835ee219SRobert Harris
5297c478bd9Sstevel@tonic-gate /*
530835ee219SRobert Harris * If this snapshot already exists then we must have been asked to
531835ee219SRobert Harris * rewind the file, i.e. discard the snapshot and create a new one in
532835ee219SRobert Harris * its place. In this case we first see if the in-kernel mnttab has
533835ee219SRobert Harris * advertised a change; if not then we simply reinitialise the metadata.
5347c478bd9Sstevel@tonic-gate */
535835ee219SRobert Harris if (snapp->mnts_nmnts) {
536835ee219SRobert Harris if (mntfs_newest(&last_mtime, &snapp->mnts_last_mtime) ==
537835ee219SRobert Harris MNTFS_NEITHER) {
538835ee219SRobert Harris /*
539835ee219SRobert Harris * An unchanged mtime is no guarantee that the
540835ee219SRobert Harris * in-kernel mnttab is unchanged; for example, a
541835ee219SRobert Harris * concurrent remount may be between calls to
542835ee219SRobert Harris * vfs_setmntopt_nolock() and vfs_mnttab_modtimeupd().
543835ee219SRobert Harris * It follows that the database may have changed, and
544835ee219SRobert Harris * in particular that some elements in this snapshot
545835ee219SRobert Harris * may have been killed by another call to
546835ee219SRobert Harris * mntfs_snapshot(). It is therefore not merely
547835ee219SRobert Harris * unnecessary to update the snapshot's time but in
548835ee219SRobert Harris * fact dangerous; it needs to be left alone.
549835ee219SRobert Harris */
550835ee219SRobert Harris snapp->mnts_next = snapp->mnts_first;
551835ee219SRobert Harris snapp->mnts_flags &= ~MNTS_REWIND;
552835ee219SRobert Harris snapp->mnts_foffset = snapp->mnts_ieoffset = 0;
553835ee219SRobert Harris vfs_list_unlock();
554835ee219SRobert Harris return;
555835ee219SRobert Harris } else {
556835ee219SRobert Harris mntfs_freesnap(mnp, snapp);
557835ee219SRobert Harris }
5587c478bd9Sstevel@tonic-gate }
5597c478bd9Sstevel@tonic-gate
5607c478bd9Sstevel@tonic-gate /*
561835ee219SRobert Harris * Create a temporary database element. For each vfs_t, the temporary
562835ee219SRobert Harris * element will be populated with the corresponding text. If the vfs_t
563835ee219SRobert Harris * does not have a corresponding element within the database, or if
564835ee219SRobert Harris * there is such an element but it is stale, a copy of the temporary
565835ee219SRobert Harris * element is inserted into the database at the appropriate location.
5667c478bd9Sstevel@tonic-gate */
567835ee219SRobert Harris tempelemp = kmem_alloc(sizeof (mntelem_t), KM_SLEEP);
568835ee219SRobert Harris entry_length = MNT_LINE_MAX;
569835ee219SRobert Harris tempelemp->mnte_text = kmem_alloc(entry_length, KM_SLEEP);
570835ee219SRobert Harris
571835ee219SRobert Harris /* Find the first and last vfs_t for the given zone. */
572835ee219SRobert Harris if (is_global_zone) {
573835ee219SRobert Harris firstvfsp = rootvfs;
574835ee219SRobert Harris lastvfsp = firstvfsp->vfs_prev;
575835ee219SRobert Harris } else {
576835ee219SRobert Harris firstvfsp = zonep->zone_vfslist;
577835ee219SRobert Harris /*
578835ee219SRobert Harris * If there isn't already a vfs_t for root then we create a
579835ee219SRobert Harris * dummy which will be used as the head of the list (which will
580835ee219SRobert Harris * therefore no longer be circular).
581835ee219SRobert Harris */
582835ee219SRobert Harris if (firstvfsp == NULL ||
583835ee219SRobert Harris strcmp(refstr_value(firstvfsp->vfs_mntpt),
584835ee219SRobert Harris zonep->zone_rootpath) != 0) {
585835ee219SRobert Harris /*
586835ee219SRobert Harris * The zone's vfs_ts will have mount points relative to
587835ee219SRobert Harris * the zone's root path. The vfs_t for the zone's
588835ee219SRobert Harris * root file system would therefore have a mount point
589835ee219SRobert Harris * equal to the zone's root path. Since the zone's root
590835ee219SRobert Harris * path isn't a mount point, we copy the vfs_t of the
591835ee219SRobert Harris * zone's root vnode, and provide it with a fake mount
5925010b7f7SLori Alt * and resource. However, if the zone's root is a
5935010b7f7SLori Alt * zfs dataset, use the dataset name as the resource.
594835ee219SRobert Harris *
595835ee219SRobert Harris * Note that by cloning another vfs_t we also acquire
596835ee219SRobert Harris * its high-resolution ctime. This might appear to
597835ee219SRobert Harris * violate the requirement that the ctimes in the list
598835ee219SRobert Harris * of vfs_ts are unique and monotonically increasing;
599835ee219SRobert Harris * this is not the case. The dummy vfs_t appears in only
600835ee219SRobert Harris * a non-global zone's vfs_t list, where the cloned
601835ee219SRobert Harris * vfs_t would not ordinarily be visible; the ctimes are
602835ee219SRobert Harris * therefore unique. The zone's root path must be
603835ee219SRobert Harris * available before the zone boots, and so its root
604835ee219SRobert Harris * vnode's vfs_t's ctime must be lower than those of any
605835ee219SRobert Harris * resources subsequently mounted by the zone. The
606835ee219SRobert Harris * ctimes are therefore monotonically increasing.
607835ee219SRobert Harris */
608835ee219SRobert Harris dummyvfs = *zonep->zone_rootvp->v_vfsp;
609835ee219SRobert Harris dummyvfs.vfs_mntpt = refstr_alloc(zonep->zone_rootpath);
6105010b7f7SLori Alt if (strcmp(vfssw[dummyvfs.vfs_fstype].vsw_name, "zfs")
6115010b7f7SLori Alt != 0)
6125010b7f7SLori Alt dummyvfs.vfs_resource = dummyvfs.vfs_mntpt;
613835ee219SRobert Harris dummyvfsp = &dummyvfs;
614835ee219SRobert Harris if (firstvfsp == NULL) {
615835ee219SRobert Harris lastvfsp = dummyvfsp;
616835ee219SRobert Harris } else {
617835ee219SRobert Harris lastvfsp = firstvfsp->vfs_zone_prev;
618835ee219SRobert Harris dummyvfsp->vfs_zone_next = firstvfsp;
6197c478bd9Sstevel@tonic-gate }
620835ee219SRobert Harris firstvfsp = dummyvfsp;
621835ee219SRobert Harris } else {
622835ee219SRobert Harris lastvfsp = firstvfsp->vfs_zone_prev;
623835ee219SRobert Harris }
624835ee219SRobert Harris }
6257c478bd9Sstevel@tonic-gate
626835ee219SRobert Harris /*
627835ee219SRobert Harris * Now walk through all the vfs_ts for this zone. For each one, find the
628835ee219SRobert Harris * corresponding database element, creating it first if necessary, and
629835ee219SRobert Harris * increment its reference count.
630835ee219SRobert Harris */
631835ee219SRobert Harris rw_enter(dblockp, RW_WRITER);
632835ee219SRobert Harris elemp = zonep->zone_mntfs_db;
633835ee219SRobert Harris /* CSTYLED */
634835ee219SRobert Harris for (vfsp = firstvfsp;;
635835ee219SRobert Harris vfsp = is_global_zone ? vfsp->vfs_next : vfsp->vfs_zone_next) {
636835ee219SRobert Harris DTRACE_PROBE1(new__vfs, vfs_t *, vfsp);
637835ee219SRobert Harris /* Consider only visible entries. */
638835ee219SRobert Harris if ((vfsp->vfs_flag & VFS_NOMNTTAB) == 0 || show_hidden) {
639835ee219SRobert Harris /*
640835ee219SRobert Harris * Walk through the existing database looking for either
641835ee219SRobert Harris * an element that matches the current vfs_t, or for the
642835ee219SRobert Harris * correct place in which to insert a new element.
643835ee219SRobert Harris */
644835ee219SRobert Harris insert_before = 0;
645835ee219SRobert Harris for (; elemp; prevp = elemp, elemp = elemp->mnte_next) {
646835ee219SRobert Harris DTRACE_PROBE1(considering__elem, mntelem_t *,
647835ee219SRobert Harris elemp);
648835ee219SRobert Harris
649835ee219SRobert Harris /* Compare the vfs_t with the element. */
650835ee219SRobert Harris order = mntfs_newest(&elemp->mnte_vfs_ctime,
651835ee219SRobert Harris &vfsp->vfs_hrctime);
652835ee219SRobert Harris
653835ee219SRobert Harris /*
654835ee219SRobert Harris * If we encounter a database element newer than
655835ee219SRobert Harris * this vfs_t then we've stepped over a gap
656835ee219SRobert Harris * where the element for this vfs_t must be
657835ee219SRobert Harris * inserted.
658835ee219SRobert Harris */
659835ee219SRobert Harris if (order == MNTFS_FIRST) {
660835ee219SRobert Harris insert_before = 1;
661835ee219SRobert Harris break;
662835ee219SRobert Harris }
663835ee219SRobert Harris
664835ee219SRobert Harris /* Dead elements no longer interest us. */
665835ee219SRobert Harris if (MNTFS_ELEM_IS_DEAD(elemp))
666835ee219SRobert Harris continue;
667835ee219SRobert Harris
668835ee219SRobert Harris /*
669835ee219SRobert Harris * If the time stamps are the same then the
670835ee219SRobert Harris * element is potential match for the vfs_t,
671835ee219SRobert Harris * although it may later prove to be stale.
672835ee219SRobert Harris */
673835ee219SRobert Harris if (order == MNTFS_NEITHER)
674835ee219SRobert Harris break;
6757c478bd9Sstevel@tonic-gate
676835ee219SRobert Harris /*
677835ee219SRobert Harris * This element must be older than the vfs_t.
678835ee219SRobert Harris * It must, therefore, correspond to a vfs_t
679835ee219SRobert Harris * that has been unmounted. Since the element is
680835ee219SRobert Harris * still alive, we kill it if it is visible.
681835ee219SRobert Harris */
682835ee219SRobert Harris if (!elemp->mnte_hidden || show_hidden)
683835ee219SRobert Harris vfs_mono_time(&elemp->mnte_death);
684835ee219SRobert Harris }
685835ee219SRobert Harris DTRACE_PROBE2(possible__match, vfs_t *, vfsp,
686835ee219SRobert Harris mntelem_t *, elemp);
687835ee219SRobert Harris
688835ee219SRobert Harris /* Create a new database element if required. */
689835ee219SRobert Harris new_entry_length = mntfs_text_len(vfsp, zonep);
690835ee219SRobert Harris if (new_entry_length > entry_length) {
691835ee219SRobert Harris kmem_free(tempelemp->mnte_text, entry_length);
692835ee219SRobert Harris tempelemp->mnte_text =
693835ee219SRobert Harris kmem_alloc(new_entry_length, KM_SLEEP);
694835ee219SRobert Harris entry_length = new_entry_length;
695835ee219SRobert Harris }
696835ee219SRobert Harris mntfs_populate_text(vfsp, zonep, tempelemp);
697835ee219SRobert Harris ASSERT(tempelemp->mnte_text_size == new_entry_length);
698835ee219SRobert Harris if (elemp == NULL) {
699835ee219SRobert Harris /*
700835ee219SRobert Harris * We ran off the end of the database. Insert a
701835ee219SRobert Harris * new element at the end.
702835ee219SRobert Harris */
703835ee219SRobert Harris newp = mntfs_copy(tempelemp);
704835ee219SRobert Harris vfs_mono_time(&newp->mnte_birth);
705835ee219SRobert Harris if (prevp) {
706835ee219SRobert Harris mntfs_insert_after(newp, prevp);
707835ee219SRobert Harris } else {
708835ee219SRobert Harris newp->mnte_next = NULL;
709835ee219SRobert Harris newp->mnte_prev = NULL;
710835ee219SRobert Harris ASSERT(*headpp == NULL);
711835ee219SRobert Harris *headpp = newp;
712835ee219SRobert Harris }
713835ee219SRobert Harris elemp = newp;
714835ee219SRobert Harris } else if (insert_before) {
715835ee219SRobert Harris /*
716835ee219SRobert Harris * Insert a new element before the current one.
717835ee219SRobert Harris */
718835ee219SRobert Harris newp = mntfs_copy(tempelemp);
719835ee219SRobert Harris vfs_mono_time(&newp->mnte_birth);
720835ee219SRobert Harris if (prevp) {
721835ee219SRobert Harris mntfs_insert_after(newp, prevp);
722835ee219SRobert Harris } else {
723835ee219SRobert Harris newp->mnte_next = elemp;
724835ee219SRobert Harris newp->mnte_prev = NULL;
725835ee219SRobert Harris elemp->mnte_prev = newp;
726835ee219SRobert Harris ASSERT(*headpp == elemp);
727835ee219SRobert Harris *headpp = newp;
728835ee219SRobert Harris }
729835ee219SRobert Harris elemp = newp;
730835ee219SRobert Harris } else if (!mntfs_is_same_element(elemp, tempelemp)) {
731835ee219SRobert Harris /*
732835ee219SRobert Harris * The element corresponds to the vfs_t, but the
733835ee219SRobert Harris * vfs_t has changed; it must have been
734835ee219SRobert Harris * remounted. Kill the old element and insert a
735835ee219SRobert Harris * new one after it.
736835ee219SRobert Harris */
737835ee219SRobert Harris vfs_mono_time(&elemp->mnte_death);
738835ee219SRobert Harris newp = mntfs_copy(tempelemp);
739835ee219SRobert Harris vfs_mono_time(&newp->mnte_birth);
740835ee219SRobert Harris mntfs_insert_after(newp, elemp);
741835ee219SRobert Harris elemp = newp;
7427c478bd9Sstevel@tonic-gate }
7437c478bd9Sstevel@tonic-gate
744835ee219SRobert Harris /* We've found the corresponding element. Hold it. */
745835ee219SRobert Harris DTRACE_PROBE1(incrementing, mntelem_t *, elemp);
746835ee219SRobert Harris elemp->mnte_refcnt++;
747835ee219SRobert Harris
748835ee219SRobert Harris /*
749835ee219SRobert Harris * Update the parameters used to initialise the
750835ee219SRobert Harris * snapshot.
751835ee219SRobert Harris */
752835ee219SRobert Harris nmnts++;
7535545576aSRobert Harris total_text_size += elemp->mnte_text_size;
7545545576aSRobert Harris if (!elemp->mnte_hidden)
7555545576aSRobert Harris normal_text_size += elemp->mnte_text_size;
756835ee219SRobert Harris if (!firstp)
757835ee219SRobert Harris firstp = elemp;
758835ee219SRobert Harris
759835ee219SRobert Harris prevp = elemp;
760835ee219SRobert Harris elemp = elemp->mnte_next;
7617c478bd9Sstevel@tonic-gate }
7627c478bd9Sstevel@tonic-gate
763835ee219SRobert Harris if (vfsp == lastvfsp)
764835ee219SRobert Harris break;
7657c478bd9Sstevel@tonic-gate }
7667c478bd9Sstevel@tonic-gate
767835ee219SRobert Harris /*
768835ee219SRobert Harris * Any remaining visible database elements that are still alive must be
769835ee219SRobert Harris * killed now, because their corresponding vfs_ts must have been
770835ee219SRobert Harris * unmounted.
771835ee219SRobert Harris */
772835ee219SRobert Harris for (; elemp; elemp = elemp->mnte_next) {
773835ee219SRobert Harris if (MNTFS_ELEM_IS_ALIVE(elemp) &&
774835ee219SRobert Harris (!elemp->mnte_hidden || show_hidden))
775835ee219SRobert Harris vfs_mono_time(&elemp->mnte_death);
7767c478bd9Sstevel@tonic-gate }
777835ee219SRobert Harris
778835ee219SRobert Harris /* Initialise the snapshot. */
779835ee219SRobert Harris vfs_mono_time(&snapp->mnts_time);
780835ee219SRobert Harris snapp->mnts_last_mtime = last_mtime;
781835ee219SRobert Harris snapp->mnts_first = snapp->mnts_next = firstp;
782835ee219SRobert Harris snapp->mnts_flags = show_hidden ? MNTS_SHOWHIDDEN : 0;
783835ee219SRobert Harris snapp->mnts_nmnts = nmnts;
7845545576aSRobert Harris snapp->mnts_text_size = total_text_size;
785835ee219SRobert Harris snapp->mnts_foffset = snapp->mnts_ieoffset = 0;
786835ee219SRobert Harris
7875545576aSRobert Harris /*
7885545576aSRobert Harris * Record /etc/mnttab's current size and mtime for possible future use
7895545576aSRobert Harris * by mntgetattr().
7905545576aSRobert Harris */
7915545576aSRobert Harris mnd->mnt_size = normal_text_size;
7925545576aSRobert Harris mnd->mnt_mtime = last_mtime;
7935545576aSRobert Harris if (show_hidden) {
7945545576aSRobert Harris mnd->mnt_hidden_size = total_text_size;
7955545576aSRobert Harris mnd->mnt_hidden_mtime = last_mtime;
7965545576aSRobert Harris }
7975545576aSRobert Harris
798835ee219SRobert Harris /* Clean up. */
799835ee219SRobert Harris rw_exit(dblockp);
800835ee219SRobert Harris vfs_list_unlock();
801835ee219SRobert Harris if (dummyvfsp != NULL)
802835ee219SRobert Harris refstr_rele(dummyvfsp->vfs_mntpt);
803835ee219SRobert Harris kmem_free(tempelemp->mnte_text, entry_length);
804835ee219SRobert Harris kmem_free(tempelemp, sizeof (mntelem_t));
8057c478bd9Sstevel@tonic-gate }
8067c478bd9Sstevel@tonic-gate
8077c478bd9Sstevel@tonic-gate /*
8087c478bd9Sstevel@tonic-gate * Public function to convert vfs_mntopts into a string.
8097c478bd9Sstevel@tonic-gate * A buffer of sufficient size is allocated, which is returned via bufp,
8107c478bd9Sstevel@tonic-gate * and whose length is returned via lenp.
8117c478bd9Sstevel@tonic-gate */
8127c478bd9Sstevel@tonic-gate void
mntfs_getmntopts(struct vfs * vfsp,char ** bufp,size_t * lenp)8137c478bd9Sstevel@tonic-gate mntfs_getmntopts(struct vfs *vfsp, char **bufp, size_t *lenp)
8147c478bd9Sstevel@tonic-gate {
8157c478bd9Sstevel@tonic-gate size_t len;
8167c478bd9Sstevel@tonic-gate char *buf;
8177c478bd9Sstevel@tonic-gate
8187c478bd9Sstevel@tonic-gate vfs_list_read_lock();
8197c478bd9Sstevel@tonic-gate
8207c478bd9Sstevel@tonic-gate len = mntfs_optsize(vfsp) + 1;
8217c478bd9Sstevel@tonic-gate buf = kmem_alloc(len, KM_NOSLEEP);
8227c478bd9Sstevel@tonic-gate if (buf == NULL) {
8237c478bd9Sstevel@tonic-gate *bufp = NULL;
8247c478bd9Sstevel@tonic-gate vfs_list_unlock();
8257c478bd9Sstevel@tonic-gate return;
8267c478bd9Sstevel@tonic-gate }
8277c478bd9Sstevel@tonic-gate buf[len - 1] = '\0';
8287c478bd9Sstevel@tonic-gate (void) mntfs_optprint(vfsp, buf);
8297c478bd9Sstevel@tonic-gate ASSERT(buf[len - 1] == '\0');
8307c478bd9Sstevel@tonic-gate
8317c478bd9Sstevel@tonic-gate vfs_list_unlock();
8327c478bd9Sstevel@tonic-gate *bufp = buf;
8337c478bd9Sstevel@tonic-gate *lenp = len;
8347c478bd9Sstevel@tonic-gate }
8357c478bd9Sstevel@tonic-gate
8367c478bd9Sstevel@tonic-gate /* ARGSUSED */
8377c478bd9Sstevel@tonic-gate static int
mntopen(vnode_t ** vpp,int flag,cred_t * cr,caller_context_t * ct)838da6c28aaSamw mntopen(vnode_t **vpp, int flag, cred_t *cr, caller_context_t *ct)
8397c478bd9Sstevel@tonic-gate {
8407c478bd9Sstevel@tonic-gate vnode_t *vp = *vpp;
8417c478bd9Sstevel@tonic-gate mntnode_t *nmnp;
8427c478bd9Sstevel@tonic-gate
8437c478bd9Sstevel@tonic-gate /*
8447c478bd9Sstevel@tonic-gate * Not allowed to open for writing, return error.
8457c478bd9Sstevel@tonic-gate */
8467c478bd9Sstevel@tonic-gate if (flag & FWRITE)
8477c478bd9Sstevel@tonic-gate return (EPERM);
8487c478bd9Sstevel@tonic-gate /*
8497c478bd9Sstevel@tonic-gate * Create a new mnt/vnode for each open, this will give us a handle to
8507c478bd9Sstevel@tonic-gate * hang the snapshot on.
8517c478bd9Sstevel@tonic-gate */
8527c478bd9Sstevel@tonic-gate nmnp = mntgetnode(vp);
8537c478bd9Sstevel@tonic-gate
8547c478bd9Sstevel@tonic-gate *vpp = MTOV(nmnp);
8551a5e258fSJosef 'Jeff' Sipek atomic_inc_32(&MTOD(nmnp)->mnt_nopen);
8567c478bd9Sstevel@tonic-gate VN_RELE(vp);
8577c478bd9Sstevel@tonic-gate return (0);
8587c478bd9Sstevel@tonic-gate }
8597c478bd9Sstevel@tonic-gate
8607c478bd9Sstevel@tonic-gate /* ARGSUSED */
8617c478bd9Sstevel@tonic-gate static int
mntclose(vnode_t * vp,int flag,int count,offset_t offset,cred_t * cr,caller_context_t * ct)862da6c28aaSamw mntclose(vnode_t *vp, int flag, int count, offset_t offset, cred_t *cr,
863da6c28aaSamw caller_context_t *ct)
8647c478bd9Sstevel@tonic-gate {
8657c478bd9Sstevel@tonic-gate mntnode_t *mnp = VTOM(vp);
8667c478bd9Sstevel@tonic-gate
8677c478bd9Sstevel@tonic-gate /* Clean up any locks or shares held by the current process */
8687c478bd9Sstevel@tonic-gate cleanlocks(vp, ttoproc(curthread)->p_pid, 0);
8697c478bd9Sstevel@tonic-gate cleanshares(vp, ttoproc(curthread)->p_pid);
8707c478bd9Sstevel@tonic-gate
8717c478bd9Sstevel@tonic-gate if (count > 1)
8727c478bd9Sstevel@tonic-gate return (0);
8737c478bd9Sstevel@tonic-gate if (vp->v_count == 1) {
874835ee219SRobert Harris rw_enter(&mnp->mnt_contents, RW_WRITER);
875835ee219SRobert Harris mntfs_freesnap(mnp, &mnp->mnt_read);
876835ee219SRobert Harris mntfs_freesnap(mnp, &mnp->mnt_ioctl);
877835ee219SRobert Harris rw_exit(&mnp->mnt_contents);
8781a5e258fSJosef 'Jeff' Sipek atomic_dec_32(&MTOD(mnp)->mnt_nopen);
8797c478bd9Sstevel@tonic-gate }
8807c478bd9Sstevel@tonic-gate return (0);
8817c478bd9Sstevel@tonic-gate }
8827c478bd9Sstevel@tonic-gate
8837c478bd9Sstevel@tonic-gate /* ARGSUSED */
8847c478bd9Sstevel@tonic-gate static int
mntread(vnode_t * vp,uio_t * uio,int ioflag,cred_t * cred,caller_context_t * ct)8857c478bd9Sstevel@tonic-gate mntread(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cred, caller_context_t *ct)
8867c478bd9Sstevel@tonic-gate {
887835ee219SRobert Harris mntnode_t *mnp = VTOM(vp);
888a19609f8Sjv zone_t *zonep = MTOD(mnp)->mnt_zone_ref.zref_zone;
889835ee219SRobert Harris mntsnap_t *snapp = &mnp->mnt_read;
8907c478bd9Sstevel@tonic-gate off_t off = uio->uio_offset;
8917c478bd9Sstevel@tonic-gate size_t len = uio->uio_resid;
892835ee219SRobert Harris char *bufferp;
893835ee219SRobert Harris size_t available, copylen;
894835ee219SRobert Harris size_t written = 0;
895835ee219SRobert Harris mntelem_t *elemp;
896835ee219SRobert Harris krwlock_t *dblockp = &zonep->zone_mntfs_db_lock;
897835ee219SRobert Harris int error = 0;
898835ee219SRobert Harris off_t ieoffset;
8997c478bd9Sstevel@tonic-gate
900835ee219SRobert Harris rw_enter(&mnp->mnt_contents, RW_WRITER);
901835ee219SRobert Harris if (snapp->mnts_nmnts == 0 || (off == (off_t)0))
902835ee219SRobert Harris mntfs_snapshot(mnp, snapp);
903835ee219SRobert Harris
904835ee219SRobert Harris if ((size_t)(off + len) > snapp->mnts_text_size)
905835ee219SRobert Harris len = snapp->mnts_text_size - off;
9067c478bd9Sstevel@tonic-gate
907835ee219SRobert Harris if (off < 0 || len > snapp->mnts_text_size) {
90854c529d4SViswanathan Kannappan rw_exit(&mnp->mnt_contents);
9097c478bd9Sstevel@tonic-gate return (EFAULT);
91054c529d4SViswanathan Kannappan }
9117c478bd9Sstevel@tonic-gate
91254c529d4SViswanathan Kannappan if (len == 0) {
91354c529d4SViswanathan Kannappan rw_exit(&mnp->mnt_contents);
9147c478bd9Sstevel@tonic-gate return (0);
91554c529d4SViswanathan Kannappan }
9167c478bd9Sstevel@tonic-gate
9177c478bd9Sstevel@tonic-gate /*
918835ee219SRobert Harris * For the file offset provided, locate the corresponding database
919835ee219SRobert Harris * element and calculate the corresponding offset within its text. If
920835ee219SRobert Harris * the file offset is the same as that reached during the last read(2)
921835ee219SRobert Harris * then use the saved element and intra-element offset.
9227c478bd9Sstevel@tonic-gate */
923835ee219SRobert Harris rw_enter(dblockp, RW_READER);
924835ee219SRobert Harris if (off == 0 || (off == snapp->mnts_foffset)) {
925835ee219SRobert Harris elemp = snapp->mnts_next;
926835ee219SRobert Harris ieoffset = snapp->mnts_ieoffset;
927835ee219SRobert Harris } else {
928835ee219SRobert Harris off_t total_off;
929835ee219SRobert Harris /*
930835ee219SRobert Harris * Find the element corresponding to the requested file offset
931835ee219SRobert Harris * by walking through the database and summing the text sizes
932835ee219SRobert Harris * of the individual elements. If the requested file offset is
933835ee219SRobert Harris * greater than that reached on the last visit then we can start
934835ee219SRobert Harris * at the last seen element; otherwise, we have to start at the
935835ee219SRobert Harris * beginning.
936835ee219SRobert Harris */
937835ee219SRobert Harris if (off > snapp->mnts_foffset) {
938835ee219SRobert Harris elemp = snapp->mnts_next;
939835ee219SRobert Harris total_off = snapp->mnts_foffset - snapp->mnts_ieoffset;
940835ee219SRobert Harris } else {
941835ee219SRobert Harris elemp = snapp->mnts_first;
942835ee219SRobert Harris total_off = 0;
943835ee219SRobert Harris }
944835ee219SRobert Harris while (off > total_off + elemp->mnte_text_size) {
945835ee219SRobert Harris total_off += elemp->mnte_text_size;
946835ee219SRobert Harris elemp = mntfs_get_next_elem(snapp, elemp);
947835ee219SRobert Harris ASSERT(elemp != NULL);
948835ee219SRobert Harris }
949835ee219SRobert Harris /* Calculate the intra-element offset. */
950835ee219SRobert Harris if (off > total_off)
951835ee219SRobert Harris ieoffset = off - total_off;
952835ee219SRobert Harris else
953835ee219SRobert Harris ieoffset = 0;
954835ee219SRobert Harris }
955835ee219SRobert Harris
956835ee219SRobert Harris /*
957835ee219SRobert Harris * Create a buffer and populate it with the text from successive
958835ee219SRobert Harris * database elements until it is full.
959835ee219SRobert Harris */
960835ee219SRobert Harris bufferp = kmem_alloc(len, KM_SLEEP);
961835ee219SRobert Harris while (written < len) {
962835ee219SRobert Harris available = elemp->mnte_text_size - ieoffset;
963835ee219SRobert Harris copylen = MIN(len - written, available);
964835ee219SRobert Harris bcopy(elemp->mnte_text + ieoffset, bufferp + written, copylen);
965835ee219SRobert Harris written += copylen;
966835ee219SRobert Harris if (copylen == available) {
967835ee219SRobert Harris elemp = mntfs_get_next_elem(snapp, elemp);
968835ee219SRobert Harris ASSERT(elemp != NULL || written == len);
969835ee219SRobert Harris ieoffset = 0;
970835ee219SRobert Harris } else {
971835ee219SRobert Harris ieoffset += copylen;
972835ee219SRobert Harris }
973835ee219SRobert Harris }
974835ee219SRobert Harris rw_exit(dblockp);
975835ee219SRobert Harris
976835ee219SRobert Harris /*
977835ee219SRobert Harris * Write the populated buffer, update the snapshot's state if
978835ee219SRobert Harris * successful and then advertise our read.
979835ee219SRobert Harris */
980835ee219SRobert Harris error = uiomove(bufferp, len, UIO_READ, uio);
981835ee219SRobert Harris if (error == 0) {
982835ee219SRobert Harris snapp->mnts_next = elemp;
983835ee219SRobert Harris snapp->mnts_foffset = off + len;
984835ee219SRobert Harris snapp->mnts_ieoffset = ieoffset;
9857c478bd9Sstevel@tonic-gate }
986df2381bfSpraks vfs_mnttab_readop();
98754c529d4SViswanathan Kannappan rw_exit(&mnp->mnt_contents);
988835ee219SRobert Harris
989835ee219SRobert Harris /* Clean up. */
990835ee219SRobert Harris kmem_free(bufferp, len);
9917c478bd9Sstevel@tonic-gate return (error);
9927c478bd9Sstevel@tonic-gate }
9937c478bd9Sstevel@tonic-gate
9947c478bd9Sstevel@tonic-gate static int
mntgetattr(vnode_t * vp,vattr_t * vap,int flags,cred_t * cr,caller_context_t * ct)995da6c28aaSamw mntgetattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
996da6c28aaSamw caller_context_t *ct)
9977c478bd9Sstevel@tonic-gate {
9985545576aSRobert Harris int mask = vap->va_mask;
9997c478bd9Sstevel@tonic-gate int error;
10005545576aSRobert Harris mntnode_t *mnp = VTOM(vp);
10015545576aSRobert Harris timespec_t mtime, old_mtime;
10025545576aSRobert Harris size_t size, old_size;
10037c478bd9Sstevel@tonic-gate mntdata_t *mntdata = MTOD(VTOM(vp));
10045545576aSRobert Harris mntsnap_t *rsnapp, *isnapp;
10055545576aSRobert Harris extern timespec_t vfs_mnttab_ctime;
10065545576aSRobert Harris
10075545576aSRobert Harris
10085545576aSRobert Harris /* AT_MODE, AT_UID and AT_GID are derived from the underlying file. */
10095545576aSRobert Harris if (mask & AT_MODE|AT_UID|AT_GID) {
10105545576aSRobert Harris if (error = VOP_GETATTR(mnp->mnt_mountvp, vap, flags, cr, ct))
10115545576aSRobert Harris return (error);
10125545576aSRobert Harris }
10137c478bd9Sstevel@tonic-gate
10147c478bd9Sstevel@tonic-gate /*
10155545576aSRobert Harris * There are some minor subtleties in the determination of
10165545576aSRobert Harris * /etc/mnttab's size and mtime. We wish to avoid any condition in
10175545576aSRobert Harris * which, in the vicinity of a change to the in-kernel mnttab, we
10185545576aSRobert Harris * return an old value for one but a new value for the other. We cannot
10195545576aSRobert Harris * simply hold vfslist for the entire calculation because we might need
10205545576aSRobert Harris * to call mntfs_snapshot(), which calls vfs_list_read_lock().
10217c478bd9Sstevel@tonic-gate */
10225545576aSRobert Harris if (mask & AT_SIZE|AT_NBLOCKS) {
10235545576aSRobert Harris rw_enter(&mnp->mnt_contents, RW_WRITER);
10245545576aSRobert Harris
10255545576aSRobert Harris vfs_list_read_lock();
10265545576aSRobert Harris vfs_mnttab_modtime(&mtime);
10275545576aSRobert Harris if (mnp->mnt_flags & MNT_SHOWHIDDEN) {
10285545576aSRobert Harris old_mtime = mntdata->mnt_hidden_mtime;
10295545576aSRobert Harris old_size = mntdata->mnt_hidden_size;
10305545576aSRobert Harris } else {
10315545576aSRobert Harris old_mtime = mntdata->mnt_mtime;
10325545576aSRobert Harris old_size = mntdata->mnt_size;
10335545576aSRobert Harris }
10345545576aSRobert Harris vfs_list_unlock();
10355545576aSRobert Harris
10365545576aSRobert Harris rsnapp = &mnp->mnt_read;
10375545576aSRobert Harris isnapp = &mnp->mnt_ioctl;
10385545576aSRobert Harris if (rsnapp->mnts_nmnts || isnapp->mnts_nmnts) {
10395545576aSRobert Harris /*
10405545576aSRobert Harris * The mntnode already has at least one snapshot from
10415545576aSRobert Harris * which to take the size; the user will understand from
1042*bbf21555SRichard Lowe * mnttab(5) that the current size of the in-kernel
10435545576aSRobert Harris * mnttab is irrelevant.
10445545576aSRobert Harris */
10455545576aSRobert Harris size = rsnapp->mnts_nmnts ? rsnapp->mnts_text_size :
10465545576aSRobert Harris isnapp->mnts_text_size;
10475545576aSRobert Harris } else if (mntfs_newest(&mtime, &old_mtime) == MNTFS_NEITHER) {
10485545576aSRobert Harris /*
10495545576aSRobert Harris * There is no existing valid snapshot but the in-kernel
10505545576aSRobert Harris * mnttab has not changed since the time that the last
10515545576aSRobert Harris * one was generated. Use the old file size; note that
10525545576aSRobert Harris * it is guaranteed to be consistent with mtime, which
10535545576aSRobert Harris * may be returned to the user later.
10545545576aSRobert Harris */
10555545576aSRobert Harris size = old_size;
10565545576aSRobert Harris } else {
10575545576aSRobert Harris /*
10585545576aSRobert Harris * There is no snapshot and the in-kernel mnttab has
10595545576aSRobert Harris * changed since the last one was created. We generate a
10605545576aSRobert Harris * new snapshot which we use for not only the size but
10615545576aSRobert Harris * also the mtime, thereby ensuring that the two are
10625545576aSRobert Harris * consistent.
10635545576aSRobert Harris */
10645545576aSRobert Harris mntfs_snapshot(mnp, rsnapp);
10655545576aSRobert Harris size = rsnapp->mnts_text_size;
10665545576aSRobert Harris mtime = rsnapp->mnts_last_mtime;
10675545576aSRobert Harris mntfs_freesnap(mnp, rsnapp);
10685545576aSRobert Harris }
10695545576aSRobert Harris
1070835ee219SRobert Harris rw_exit(&mnp->mnt_contents);
10715545576aSRobert Harris } else if (mask & AT_ATIME|AT_MTIME) {
10725545576aSRobert Harris vfs_list_read_lock();
10735545576aSRobert Harris vfs_mnttab_modtime(&mtime);
10745545576aSRobert Harris vfs_list_unlock();
1075835ee219SRobert Harris }
10767c478bd9Sstevel@tonic-gate
10775545576aSRobert Harris /* Always look like a regular file. */
10785545576aSRobert Harris if (mask & AT_TYPE)
10795545576aSRobert Harris vap->va_type = VREG;
10805545576aSRobert Harris /* Mode should basically be read only. */
10815545576aSRobert Harris if (mask & AT_MODE)
10825545576aSRobert Harris vap->va_mode &= 07444;
10835545576aSRobert Harris if (mask & AT_FSID)
10845545576aSRobert Harris vap->va_fsid = vp->v_vfsp->vfs_dev;
10855545576aSRobert Harris /* Nodeid is always ROOTINO. */
10865545576aSRobert Harris if (mask & AT_NODEID)
10875545576aSRobert Harris vap->va_nodeid = (ino64_t)MNTROOTINO;
10887c478bd9Sstevel@tonic-gate /*
10897c478bd9Sstevel@tonic-gate * Set nlink to the number of open vnodes for mnttab info
10907c478bd9Sstevel@tonic-gate * plus one for existing.
10917c478bd9Sstevel@tonic-gate */
10925545576aSRobert Harris if (mask & AT_NLINK)
10935545576aSRobert Harris vap->va_nlink = mntdata->mnt_nopen + 1;
10945545576aSRobert Harris if (mask & AT_SIZE)
10955545576aSRobert Harris vap->va_size = size;
10965545576aSRobert Harris if (mask & AT_ATIME)
10975545576aSRobert Harris vap->va_atime = mtime;
10985545576aSRobert Harris if (mask & AT_MTIME)
10995545576aSRobert Harris vap->va_mtime = mtime;
11005545576aSRobert Harris if (mask & AT_CTIME)
11015545576aSRobert Harris vap->va_ctime = vfs_mnttab_ctime;
11025545576aSRobert Harris if (mask & AT_RDEV)
11035545576aSRobert Harris vap->va_rdev = 0;
11045545576aSRobert Harris if (mask & AT_BLKSIZE)
11055545576aSRobert Harris vap->va_blksize = DEV_BSIZE;
11065545576aSRobert Harris if (mask & AT_NBLOCKS)
11075545576aSRobert Harris vap->va_nblocks = btod(size);
11085545576aSRobert Harris if (mask & AT_SEQ)
11095545576aSRobert Harris vap->va_seq = 0;
11105545576aSRobert Harris
11117c478bd9Sstevel@tonic-gate return (0);
11127c478bd9Sstevel@tonic-gate }
11137c478bd9Sstevel@tonic-gate
11147c478bd9Sstevel@tonic-gate static int
mntaccess(vnode_t * vp,int mode,int flags,cred_t * cr,caller_context_t * ct)1115da6c28aaSamw mntaccess(vnode_t *vp, int mode, int flags, cred_t *cr,
1116da6c28aaSamw caller_context_t *ct)
11177c478bd9Sstevel@tonic-gate {
11187c478bd9Sstevel@tonic-gate mntnode_t *mnp = VTOM(vp);
11197c478bd9Sstevel@tonic-gate
11207c478bd9Sstevel@tonic-gate if (mode & (VWRITE|VEXEC))
11217c478bd9Sstevel@tonic-gate return (EROFS);
11227c478bd9Sstevel@tonic-gate
11237c478bd9Sstevel@tonic-gate /*
11247c478bd9Sstevel@tonic-gate * Do access check on the underlying directory vnode.
11257c478bd9Sstevel@tonic-gate */
1126da6c28aaSamw return (VOP_ACCESS(mnp->mnt_mountvp, mode, flags, cr, ct));
11277c478bd9Sstevel@tonic-gate }
11287c478bd9Sstevel@tonic-gate
11297c478bd9Sstevel@tonic-gate
11307c478bd9Sstevel@tonic-gate /*
11317c478bd9Sstevel@tonic-gate * New /mntfs vnode required; allocate it and fill in most of the fields.
11327c478bd9Sstevel@tonic-gate */
11337c478bd9Sstevel@tonic-gate static mntnode_t *
mntgetnode(vnode_t * dp)11347c478bd9Sstevel@tonic-gate mntgetnode(vnode_t *dp)
11357c478bd9Sstevel@tonic-gate {
11367c478bd9Sstevel@tonic-gate mntnode_t *mnp;
11377c478bd9Sstevel@tonic-gate vnode_t *vp;
11387c478bd9Sstevel@tonic-gate
11397c478bd9Sstevel@tonic-gate mnp = kmem_zalloc(sizeof (mntnode_t), KM_SLEEP);
11407c478bd9Sstevel@tonic-gate mnp->mnt_vnode = vn_alloc(KM_SLEEP);
11417c478bd9Sstevel@tonic-gate mnp->mnt_mountvp = VTOM(dp)->mnt_mountvp;
114254c529d4SViswanathan Kannappan rw_init(&mnp->mnt_contents, NULL, RW_DEFAULT, NULL);
11437c478bd9Sstevel@tonic-gate vp = MTOV(mnp);
11447c478bd9Sstevel@tonic-gate vp->v_flag = VNOCACHE|VNOMAP|VNOSWAP|VNOMOUNT;
11457c478bd9Sstevel@tonic-gate vn_setops(vp, mntvnodeops);
11467c478bd9Sstevel@tonic-gate vp->v_vfsp = dp->v_vfsp;
11477c478bd9Sstevel@tonic-gate vp->v_type = VREG;
11487c478bd9Sstevel@tonic-gate vp->v_data = (caddr_t)mnp;
11497c478bd9Sstevel@tonic-gate
11507c478bd9Sstevel@tonic-gate return (mnp);
11517c478bd9Sstevel@tonic-gate }
11527c478bd9Sstevel@tonic-gate
11537c478bd9Sstevel@tonic-gate /*
11547c478bd9Sstevel@tonic-gate * Free the storage obtained from mntgetnode().
11557c478bd9Sstevel@tonic-gate */
11567c478bd9Sstevel@tonic-gate static void
mntfreenode(mntnode_t * mnp)11577c478bd9Sstevel@tonic-gate mntfreenode(mntnode_t *mnp)
11587c478bd9Sstevel@tonic-gate {
11597c478bd9Sstevel@tonic-gate vnode_t *vp = MTOV(mnp);
11607c478bd9Sstevel@tonic-gate
116154c529d4SViswanathan Kannappan rw_destroy(&mnp->mnt_contents);
11627c478bd9Sstevel@tonic-gate vn_invalid(vp);
11637c478bd9Sstevel@tonic-gate vn_free(vp);
11647c478bd9Sstevel@tonic-gate kmem_free(mnp, sizeof (*mnp));
11657c478bd9Sstevel@tonic-gate }
11667c478bd9Sstevel@tonic-gate
11677c478bd9Sstevel@tonic-gate
11687c478bd9Sstevel@tonic-gate /* ARGSUSED */
11697c478bd9Sstevel@tonic-gate static int
mntfsync(vnode_t * vp,int syncflag,cred_t * cr,caller_context_t * ct)1170da6c28aaSamw mntfsync(vnode_t *vp, int syncflag, cred_t *cr, caller_context_t *ct)
11717c478bd9Sstevel@tonic-gate {
11727c478bd9Sstevel@tonic-gate return (0);
11737c478bd9Sstevel@tonic-gate }
11747c478bd9Sstevel@tonic-gate
11757c478bd9Sstevel@tonic-gate /* ARGSUSED */
11767c478bd9Sstevel@tonic-gate static void
mntinactive(vnode_t * vp,cred_t * cr,caller_context_t * ct)1177da6c28aaSamw mntinactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
11787c478bd9Sstevel@tonic-gate {
11797c478bd9Sstevel@tonic-gate mntnode_t *mnp = VTOM(vp);
11807c478bd9Sstevel@tonic-gate
11817c478bd9Sstevel@tonic-gate mntfreenode(mnp);
11827c478bd9Sstevel@tonic-gate }
11837c478bd9Sstevel@tonic-gate
1184835ee219SRobert Harris /*
11855545576aSRobert Harris * lseek(2) is supported only to rewind the file by resetmnttab(3C). Rewinding
11865545576aSRobert Harris * has a special meaning for /etc/mnttab: it forces mntfs to refresh the
11875545576aSRobert Harris * snapshot at the next ioctl().
1188835ee219SRobert Harris *
1189*bbf21555SRichard Lowe * mnttab(5) explains that "the snapshot...is taken any time a read(2) is
11905545576aSRobert Harris * performed at offset 0". We therefore ignore the read snapshot here.
1191835ee219SRobert Harris */
11927c478bd9Sstevel@tonic-gate /* ARGSUSED */
11937c478bd9Sstevel@tonic-gate static int
mntseek(vnode_t * vp,offset_t ooff,offset_t * noffp,caller_context_t * ct)1194835ee219SRobert Harris mntseek(vnode_t *vp, offset_t ooff, offset_t *noffp, caller_context_t *ct)
11957c478bd9Sstevel@tonic-gate {
119654c529d4SViswanathan Kannappan mntnode_t *mnp = VTOM(vp);
119754c529d4SViswanathan Kannappan
119854c529d4SViswanathan Kannappan if (*noffp == 0) {
119954c529d4SViswanathan Kannappan rw_enter(&mnp->mnt_contents, RW_WRITER);
1200835ee219SRobert Harris mnp->mnt_ioctl.mnts_flags |= MNTS_REWIND;
120154c529d4SViswanathan Kannappan rw_exit(&mnp->mnt_contents);
120254c529d4SViswanathan Kannappan }
12037c478bd9Sstevel@tonic-gate
12047c478bd9Sstevel@tonic-gate return (0);
12057c478bd9Sstevel@tonic-gate }
12067c478bd9Sstevel@tonic-gate
12077c478bd9Sstevel@tonic-gate /*
12087c478bd9Sstevel@tonic-gate * Return the answer requested to poll().
12097c478bd9Sstevel@tonic-gate * POLLRDBAND will return when the mtime of the mnttab
12107c478bd9Sstevel@tonic-gate * information is newer than the latest one read for this open.
12117c478bd9Sstevel@tonic-gate */
12127c478bd9Sstevel@tonic-gate /* ARGSUSED */
12137c478bd9Sstevel@tonic-gate static int
mntpoll(vnode_t * vp,short ev,int any,short * revp,pollhead_t ** phpp,caller_context_t * ct)1214da6c28aaSamw mntpoll(vnode_t *vp, short ev, int any, short *revp, pollhead_t **phpp,
1215da6c28aaSamw caller_context_t *ct)
12167c478bd9Sstevel@tonic-gate {
12177c478bd9Sstevel@tonic-gate mntnode_t *mnp = VTOM(vp);
1218835ee219SRobert Harris mntsnap_t *snapp;
12197c478bd9Sstevel@tonic-gate
122054c529d4SViswanathan Kannappan rw_enter(&mnp->mnt_contents, RW_READER);
1221835ee219SRobert Harris if (mntfs_newest(&mnp->mnt_ioctl.mnts_last_mtime,
1222835ee219SRobert Harris &mnp->mnt_read.mnts_last_mtime) == MNTFS_FIRST)
1223835ee219SRobert Harris snapp = &mnp->mnt_ioctl;
1224835ee219SRobert Harris else
1225835ee219SRobert Harris snapp = &mnp->mnt_read;
12267c478bd9Sstevel@tonic-gate
12277c478bd9Sstevel@tonic-gate *revp = 0;
12287c478bd9Sstevel@tonic-gate *phpp = (pollhead_t *)NULL;
12297c478bd9Sstevel@tonic-gate if (ev & POLLIN)
12307c478bd9Sstevel@tonic-gate *revp |= POLLIN;
12317c478bd9Sstevel@tonic-gate
12327c478bd9Sstevel@tonic-gate if (ev & POLLRDNORM)
12337c478bd9Sstevel@tonic-gate *revp |= POLLRDNORM;
12347c478bd9Sstevel@tonic-gate
12357c478bd9Sstevel@tonic-gate if (ev & POLLRDBAND) {
1236835ee219SRobert Harris vfs_mnttab_poll(&snapp->mnts_last_mtime, phpp);
12377c478bd9Sstevel@tonic-gate if (*phpp == (pollhead_t *)NULL)
12387c478bd9Sstevel@tonic-gate *revp |= POLLRDBAND;
12397c478bd9Sstevel@tonic-gate }
124054c529d4SViswanathan Kannappan rw_exit(&mnp->mnt_contents);
124154c529d4SViswanathan Kannappan
12427c478bd9Sstevel@tonic-gate if (*revp || *phpp != NULL || any) {
12437c478bd9Sstevel@tonic-gate return (0);
12447c478bd9Sstevel@tonic-gate }
12457c478bd9Sstevel@tonic-gate /*
12467c478bd9Sstevel@tonic-gate * If someone is polling an unsupported poll events (e.g.
12477c478bd9Sstevel@tonic-gate * POLLOUT, POLLPRI, etc.), just return POLLERR revents.
12487c478bd9Sstevel@tonic-gate * That way we will ensure that we don't return a 0
12497c478bd9Sstevel@tonic-gate * revents with a NULL pollhead pointer.
12507c478bd9Sstevel@tonic-gate */
12517c478bd9Sstevel@tonic-gate *revp = POLLERR;
12527c478bd9Sstevel@tonic-gate return (0);
12537c478bd9Sstevel@tonic-gate }
1254835ee219SRobert Harris
1255835ee219SRobert Harris /*
1256835ee219SRobert Harris * mntfs_same_word() returns 1 if two words are the same in the context of
1257835ee219SRobert Harris * MNTIOC_GETMNTANY and 0 otherwise.
1258835ee219SRobert Harris *
1259835ee219SRobert Harris * worda is a memory address that lies somewhere in the buffer bufa; it cannot
1260835ee219SRobert Harris * be NULL since this is used to indicate to getmntany(3C) that the user does
1261835ee219SRobert Harris * not wish to match a particular field. The text to which worda points is
1262835ee219SRobert Harris * supplied by the user; if it is not null-terminated then it cannot match.
1263835ee219SRobert Harris *
1264835ee219SRobert Harris * Buffer bufb contains a line from /etc/mnttab, in which the fields are
1265835ee219SRobert Harris * delimited by tab or new-line characters. offb is the offset of the second
1266835ee219SRobert Harris * word within this buffer.
1267835ee219SRobert Harris *
1268835ee219SRobert Harris * mntfs_same_word() returns 1 if the words are the same and 0 otherwise.
1269835ee219SRobert Harris */
1270835ee219SRobert Harris int
mntfs_same_word(char * worda,char * bufa,size_t sizea,off_t offb,char * bufb,size_t sizeb)1271835ee219SRobert Harris mntfs_same_word(char *worda, char *bufa, size_t sizea, off_t offb, char *bufb,
1272835ee219SRobert Harris size_t sizeb)
1273835ee219SRobert Harris {
1274835ee219SRobert Harris char *wordb = bufb + offb;
1275835ee219SRobert Harris int bytes_remaining;
1276835ee219SRobert Harris
1277835ee219SRobert Harris ASSERT(worda != NULL);
1278835ee219SRobert Harris
1279835ee219SRobert Harris bytes_remaining = MIN(((bufa + sizea) - worda),
1280835ee219SRobert Harris ((bufb + sizeb) - wordb));
1281835ee219SRobert Harris while (bytes_remaining && *worda == *wordb) {
1282835ee219SRobert Harris worda++;
1283835ee219SRobert Harris wordb++;
1284835ee219SRobert Harris bytes_remaining--;
1285835ee219SRobert Harris }
1286835ee219SRobert Harris if (bytes_remaining &&
1287835ee219SRobert Harris *worda == '\0' && (*wordb == '\t' || *wordb == '\n'))
1288835ee219SRobert Harris return (1);
1289835ee219SRobert Harris else
1290835ee219SRobert Harris return (0);
1291835ee219SRobert Harris }
1292835ee219SRobert Harris
1293835ee219SRobert Harris /*
1294835ee219SRobert Harris * mntfs_special_info_string() returns which, if either, of VBLK or VCHR
1295835ee219SRobert Harris * corresponds to a supplied path. If the path is a special device then the
1296835ee219SRobert Harris * function optionally sets the major and minor numbers.
1297835ee219SRobert Harris */
1298835ee219SRobert Harris vtype_t
mntfs_special_info_string(char * path,uint_t * major,uint_t * minor,cred_t * cr)1299835ee219SRobert Harris mntfs_special_info_string(char *path, uint_t *major, uint_t *minor, cred_t *cr)
1300835ee219SRobert Harris {
1301835ee219SRobert Harris vattr_t vattr;
1302835ee219SRobert Harris vnode_t *vp;
1303835ee219SRobert Harris vtype_t type;
1304835ee219SRobert Harris int error;
1305835ee219SRobert Harris
1306835ee219SRobert Harris if (path == NULL || *path != '/' ||
1307835ee219SRobert Harris lookupnameat(path + 1, UIO_SYSSPACE, FOLLOW, NULLVPP, &vp, rootdir))
1308835ee219SRobert Harris return (0);
1309835ee219SRobert Harris
1310835ee219SRobert Harris vattr.va_mask = AT_TYPE | AT_RDEV;
1311835ee219SRobert Harris error = VOP_GETATTR(vp, &vattr, ATTR_REAL, cr, NULL);
1312835ee219SRobert Harris VN_RELE(vp);
1313835ee219SRobert Harris
1314835ee219SRobert Harris if (error == 0 && ((type = vattr.va_type) == VBLK || type == VCHR)) {
1315835ee219SRobert Harris if (major && minor) {
1316835ee219SRobert Harris *major = getmajor(vattr.va_rdev);
1317835ee219SRobert Harris *minor = getminor(vattr.va_rdev);
1318835ee219SRobert Harris }
1319835ee219SRobert Harris return (type);
1320835ee219SRobert Harris } else {
1321835ee219SRobert Harris return (0);
1322835ee219SRobert Harris }
1323835ee219SRobert Harris }
1324835ee219SRobert Harris
1325835ee219SRobert Harris /*
1326835ee219SRobert Harris * mntfs_special_info_element() extracts the name of the mounted resource
1327835ee219SRobert Harris * for a given element and copies it into a null-terminated string, which it
1328835ee219SRobert Harris * then passes to mntfs_special_info_string().
1329835ee219SRobert Harris */
1330835ee219SRobert Harris vtype_t
mntfs_special_info_element(mntelem_t * elemp,cred_t * cr)1331835ee219SRobert Harris mntfs_special_info_element(mntelem_t *elemp, cred_t *cr)
1332835ee219SRobert Harris {
1333835ee219SRobert Harris char *newpath;
1334835ee219SRobert Harris vtype_t type;
1335835ee219SRobert Harris
1336835ee219SRobert Harris newpath = kmem_alloc(elemp->mnte_text_size, KM_SLEEP);
1337835ee219SRobert Harris bcopy(elemp->mnte_text, newpath, (off_t)(elemp->mnte_tab.mnt_mountp));
1338835ee219SRobert Harris *(newpath + (off_t)elemp->mnte_tab.mnt_mountp - 1) = '\0';
1339835ee219SRobert Harris type = mntfs_special_info_string(newpath, NULL, NULL, cr);
1340835ee219SRobert Harris kmem_free(newpath, elemp->mnte_text_size);
1341835ee219SRobert Harris
1342835ee219SRobert Harris return (type);
1343835ee219SRobert Harris }
1344835ee219SRobert Harris
1345835ee219SRobert Harris /*
1346835ee219SRobert Harris * Convert an address that points to a byte within a user buffer into an
1347835ee219SRobert Harris * address that points to the corresponding offset within a kernel buffer. If
1348835ee219SRobert Harris * the user address is NULL then make no conversion. If the address does not
1349835ee219SRobert Harris * lie within the buffer then reset it to NULL.
1350835ee219SRobert Harris */
1351835ee219SRobert Harris char *
mntfs_import_addr(char * uaddr,char * ubufp,char * kbufp,size_t bufsize)1352835ee219SRobert Harris mntfs_import_addr(char *uaddr, char *ubufp, char *kbufp, size_t bufsize)
1353835ee219SRobert Harris {
1354835ee219SRobert Harris if (uaddr < ubufp || uaddr >= ubufp + bufsize)
1355835ee219SRobert Harris return (NULL);
1356835ee219SRobert Harris else
1357835ee219SRobert Harris return (kbufp + (uaddr - ubufp));
1358835ee219SRobert Harris }
1359835ee219SRobert Harris
1360835ee219SRobert Harris /*
1361835ee219SRobert Harris * These 32-bit versions are to support STRUCT_DECL(9F) etc. in
1362835ee219SRobert Harris * mntfs_copyout_element() and mntioctl().
1363835ee219SRobert Harris */
1364835ee219SRobert Harris #ifdef _SYSCALL32_IMPL
1365835ee219SRobert Harris typedef struct extmnttab32 {
1366835ee219SRobert Harris uint32_t mnt_special;
1367835ee219SRobert Harris uint32_t mnt_mountp;
1368835ee219SRobert Harris uint32_t mnt_fstype;
1369835ee219SRobert Harris uint32_t mnt_mntopts;
1370835ee219SRobert Harris uint32_t mnt_time;
1371835ee219SRobert Harris uint_t mnt_major;
1372835ee219SRobert Harris uint_t mnt_minor;
1373835ee219SRobert Harris } extmnttab32_t;
1374835ee219SRobert Harris
1375835ee219SRobert Harris typedef struct mnttab32 {
1376835ee219SRobert Harris uint32_t mnt_special;
1377835ee219SRobert Harris uint32_t mnt_mountp;
1378835ee219SRobert Harris uint32_t mnt_fstype;
1379835ee219SRobert Harris uint32_t mnt_mntopts;
1380835ee219SRobert Harris uint32_t mnt_time;
1381835ee219SRobert Harris } mnttab32_t;
1382835ee219SRobert Harris
1383835ee219SRobert Harris struct mntentbuf32 {
1384835ee219SRobert Harris uint32_t mbuf_emp;
1385835ee219SRobert Harris uint_t mbuf_bufsize;
1386835ee219SRobert Harris uint32_t mbuf_buf;
1387835ee219SRobert Harris };
1388835ee219SRobert Harris #endif
1389835ee219SRobert Harris
1390835ee219SRobert Harris /*
1391835ee219SRobert Harris * mntfs_copyout_element() is common code for the MNTIOC_GETMNTENT,
1392835ee219SRobert Harris * MNTIOC_GETEXTMNTENT and MNTIOC_GETMNTANY ioctls. Having identifed the
1393835ee219SRobert Harris * database element desired by the user, this function copies out the text and
1394835ee219SRobert Harris * the pointers to the relevant userland addresses. It returns 0 on success
1395835ee219SRobert Harris * and non-zero otherwise.
1396835ee219SRobert Harris */
1397835ee219SRobert Harris int
mntfs_copyout_elem(mntelem_t * elemp,struct extmnttab * uemp,char * ubufp,int cmd,int datamodel)1398835ee219SRobert Harris mntfs_copyout_elem(mntelem_t *elemp, struct extmnttab *uemp,
1399835ee219SRobert Harris char *ubufp, int cmd, int datamodel)
1400835ee219SRobert Harris {
1401835ee219SRobert Harris STRUCT_DECL(extmnttab, ktab);
1402835ee219SRobert Harris char *dbbufp = elemp->mnte_text;
1403835ee219SRobert Harris size_t dbbufsize = elemp->mnte_text_size;
1404835ee219SRobert Harris struct extmnttab *dbtabp = &elemp->mnte_tab;
1405835ee219SRobert Harris size_t ssize;
1406835ee219SRobert Harris char *kbufp;
1407835ee219SRobert Harris int error = 0;
1408835ee219SRobert Harris
1409835ee219SRobert Harris
1410835ee219SRobert Harris /*
1411835ee219SRobert Harris * We create a struct extmnttab within the kernel of the size
1412835ee219SRobert Harris * determined by the user's data model. We then populate its
1413835ee219SRobert Harris * fields by combining the start address of the text buffer
1414835ee219SRobert Harris * supplied by the user, ubufp, with the offsets stored for
1415835ee219SRobert Harris * this database element within dbtabp, a pointer to a struct
1416835ee219SRobert Harris * extmnttab.
1417835ee219SRobert Harris *
1418835ee219SRobert Harris * Note that if the corresponding field is "-" this signifies
1419835ee219SRobert Harris * no real content, and we set the address to NULL. This does
1420835ee219SRobert Harris * not apply to mnt_time.
1421835ee219SRobert Harris */
1422835ee219SRobert Harris STRUCT_INIT(ktab, datamodel);
1423835ee219SRobert Harris STRUCT_FSETP(ktab, mnt_special,
1424835ee219SRobert Harris MNTFS_REAL_FIELD(dbbufp) ? ubufp : NULL);
1425835ee219SRobert Harris STRUCT_FSETP(ktab, mnt_mountp,
1426835ee219SRobert Harris MNTFS_REAL_FIELD(dbbufp + (off_t)dbtabp->mnt_mountp) ?
1427835ee219SRobert Harris ubufp + (off_t)dbtabp->mnt_mountp : NULL);
1428835ee219SRobert Harris STRUCT_FSETP(ktab, mnt_fstype,
1429835ee219SRobert Harris MNTFS_REAL_FIELD(dbbufp + (off_t)dbtabp->mnt_fstype) ?
1430835ee219SRobert Harris ubufp + (off_t)dbtabp->mnt_fstype : NULL);
1431835ee219SRobert Harris STRUCT_FSETP(ktab, mnt_mntopts,
1432835ee219SRobert Harris MNTFS_REAL_FIELD(dbbufp + (off_t)dbtabp->mnt_mntopts) ?
1433835ee219SRobert Harris ubufp + (off_t)dbtabp->mnt_mntopts : NULL);
1434835ee219SRobert Harris STRUCT_FSETP(ktab, mnt_time,
1435835ee219SRobert Harris ubufp + (off_t)dbtabp->mnt_time);
1436835ee219SRobert Harris if (cmd == MNTIOC_GETEXTMNTENT) {
1437835ee219SRobert Harris STRUCT_FSETP(ktab, mnt_major, dbtabp->mnt_major);
1438835ee219SRobert Harris STRUCT_FSETP(ktab, mnt_minor, dbtabp->mnt_minor);
1439835ee219SRobert Harris ssize = SIZEOF_STRUCT(extmnttab, datamodel);
1440835ee219SRobert Harris } else {
1441835ee219SRobert Harris ssize = SIZEOF_STRUCT(mnttab, datamodel);
1442835ee219SRobert Harris }
1443835ee219SRobert Harris if (copyout(STRUCT_BUF(ktab), uemp, ssize))
1444835ee219SRobert Harris return (EFAULT);
1445835ee219SRobert Harris
1446835ee219SRobert Harris /*
1447835ee219SRobert Harris * We create a text buffer in the kernel into which we copy the
1448835ee219SRobert Harris * /etc/mnttab entry for this element. We change the tab and
1449835ee219SRobert Harris * new-line delimiters to null bytes before copying out the
1450835ee219SRobert Harris * buffer.
1451835ee219SRobert Harris */
1452835ee219SRobert Harris kbufp = kmem_alloc(dbbufsize, KM_SLEEP);
1453835ee219SRobert Harris bcopy(elemp->mnte_text, kbufp, dbbufsize);
1454835ee219SRobert Harris *(kbufp + (off_t)dbtabp->mnt_mountp - 1) =
1455835ee219SRobert Harris *(kbufp + (off_t)dbtabp->mnt_fstype - 1) =
1456835ee219SRobert Harris *(kbufp + (off_t)dbtabp->mnt_mntopts - 1) =
1457835ee219SRobert Harris *(kbufp + (off_t)dbtabp->mnt_time - 1) =
1458835ee219SRobert Harris *(kbufp + dbbufsize - 1) = '\0';
1459835ee219SRobert Harris if (copyout(kbufp, ubufp, dbbufsize))
1460835ee219SRobert Harris error = EFAULT;
1461835ee219SRobert Harris
1462835ee219SRobert Harris kmem_free(kbufp, dbbufsize);
1463835ee219SRobert Harris return (error);
1464835ee219SRobert Harris }
1465835ee219SRobert Harris
14667c478bd9Sstevel@tonic-gate /* ARGSUSED */
14677c478bd9Sstevel@tonic-gate static int
mntioctl(struct vnode * vp,int cmd,intptr_t arg,int flag,cred_t * cr,int * rvalp,caller_context_t * ct)1468835ee219SRobert Harris mntioctl(struct vnode *vp, int cmd, intptr_t arg, int flag, cred_t *cr,
1469835ee219SRobert Harris int *rvalp, caller_context_t *ct)
14707c478bd9Sstevel@tonic-gate {
14717c478bd9Sstevel@tonic-gate uint_t *up = (uint_t *)arg;
14727c478bd9Sstevel@tonic-gate mntnode_t *mnp = VTOM(vp);
1473835ee219SRobert Harris mntsnap_t *snapp = &mnp->mnt_ioctl;
1474835ee219SRobert Harris int error = 0;
1475a19609f8Sjv zone_t *zonep = MTOD(mnp)->mnt_zone_ref.zref_zone;
1476835ee219SRobert Harris krwlock_t *dblockp = &zonep->zone_mntfs_db_lock;
1477835ee219SRobert Harris model_t datamodel = flag & DATAMODEL_MASK;
14787c478bd9Sstevel@tonic-gate
14797c478bd9Sstevel@tonic-gate switch (cmd) {
14807c478bd9Sstevel@tonic-gate
1481835ee219SRobert Harris case MNTIOC_NMNTS: /* get no. of mounted resources */
1482835ee219SRobert Harris {
1483835ee219SRobert Harris rw_enter(&mnp->mnt_contents, RW_READER);
1484835ee219SRobert Harris if (snapp->mnts_nmnts == 0 ||
1485835ee219SRobert Harris (snapp->mnts_flags & MNTS_REWIND)) {
148654c529d4SViswanathan Kannappan if (!rw_tryupgrade(&mnp->mnt_contents)) {
148754c529d4SViswanathan Kannappan rw_exit(&mnp->mnt_contents);
148854c529d4SViswanathan Kannappan rw_enter(&mnp->mnt_contents, RW_WRITER);
148954c529d4SViswanathan Kannappan }
1490835ee219SRobert Harris if (snapp->mnts_nmnts == 0 ||
1491835ee219SRobert Harris (snapp->mnts_flags & MNTS_REWIND))
1492835ee219SRobert Harris mntfs_snapshot(mnp, snapp);
14937c478bd9Sstevel@tonic-gate }
1494835ee219SRobert Harris rw_exit(&mnp->mnt_contents);
1495835ee219SRobert Harris
1496835ee219SRobert Harris if (suword32(up, snapp->mnts_nmnts) != 0)
14977c478bd9Sstevel@tonic-gate error = EFAULT;
14987c478bd9Sstevel@tonic-gate break;
14997c478bd9Sstevel@tonic-gate }
15007c478bd9Sstevel@tonic-gate
1501835ee219SRobert Harris case MNTIOC_GETDEVLIST: /* get mounted device major/minor nos */
1502835ee219SRobert Harris {
15037c478bd9Sstevel@tonic-gate size_t len;
1504835ee219SRobert Harris uint_t *devlist;
1505835ee219SRobert Harris mntelem_t *elemp;
1506835ee219SRobert Harris int i = 0;
15077c478bd9Sstevel@tonic-gate
1508835ee219SRobert Harris rw_enter(&mnp->mnt_contents, RW_READER);
1509835ee219SRobert Harris if (snapp->mnts_nmnts == 0 ||
1510835ee219SRobert Harris (snapp->mnts_flags & MNTS_REWIND)) {
151154c529d4SViswanathan Kannappan if (!rw_tryupgrade(&mnp->mnt_contents)) {
151254c529d4SViswanathan Kannappan rw_exit(&mnp->mnt_contents);
151354c529d4SViswanathan Kannappan rw_enter(&mnp->mnt_contents, RW_WRITER);
151454c529d4SViswanathan Kannappan }
1515835ee219SRobert Harris if (snapp->mnts_nmnts == 0 ||
1516835ee219SRobert Harris (snapp->mnts_flags & MNTS_REWIND))
1517835ee219SRobert Harris mntfs_snapshot(mnp, snapp);
151854c529d4SViswanathan Kannappan rw_downgrade(&mnp->mnt_contents);
15197c478bd9Sstevel@tonic-gate }
15207c478bd9Sstevel@tonic-gate
1521835ee219SRobert Harris /* Create a local buffer to hold the device numbers. */
1522835ee219SRobert Harris len = 2 * snapp->mnts_nmnts * sizeof (uint_t);
15237c478bd9Sstevel@tonic-gate devlist = kmem_alloc(len, KM_SLEEP);
15247c478bd9Sstevel@tonic-gate
1525835ee219SRobert Harris /*
1526835ee219SRobert Harris * Walk the database elements for this snapshot and add their
1527835ee219SRobert Harris * major and minor numbers.
1528835ee219SRobert Harris */
1529835ee219SRobert Harris rw_enter(dblockp, RW_READER);
1530835ee219SRobert Harris for (elemp = snapp->mnts_first; elemp;
1531835ee219SRobert Harris elemp = mntfs_get_next_elem(snapp, elemp)) {
1532835ee219SRobert Harris devlist[2 * i] = elemp->mnte_tab.mnt_major;
1533835ee219SRobert Harris devlist[2 * i + 1] = elemp->mnte_tab.mnt_minor;
1534835ee219SRobert Harris i++;
15357c478bd9Sstevel@tonic-gate }
1536835ee219SRobert Harris rw_exit(dblockp);
1537835ee219SRobert Harris ASSERT(i == snapp->mnts_nmnts);
1538835ee219SRobert Harris rw_exit(&mnp->mnt_contents);
15397c478bd9Sstevel@tonic-gate
1540835ee219SRobert Harris error = xcopyout(devlist, up, len);
15417c478bd9Sstevel@tonic-gate kmem_free(devlist, len);
15427c478bd9Sstevel@tonic-gate break;
15437c478bd9Sstevel@tonic-gate }
15447c478bd9Sstevel@tonic-gate
15457c478bd9Sstevel@tonic-gate case MNTIOC_SETTAG: /* set tag on mounted file system */
15467c478bd9Sstevel@tonic-gate case MNTIOC_CLRTAG: /* clear tag on mounted file system */
15477c478bd9Sstevel@tonic-gate {
15487c478bd9Sstevel@tonic-gate struct mnttagdesc *dp = (struct mnttagdesc *)arg;
15497c478bd9Sstevel@tonic-gate STRUCT_DECL(mnttagdesc, tagdesc);
15507c478bd9Sstevel@tonic-gate char *cptr;
15517c478bd9Sstevel@tonic-gate uint32_t major, minor;
15527c478bd9Sstevel@tonic-gate char tagbuf[MAX_MNTOPT_TAG];
15537c478bd9Sstevel@tonic-gate char *pbuf;
15547c478bd9Sstevel@tonic-gate size_t len;
15557c478bd9Sstevel@tonic-gate uint_t start = 0;
15567c478bd9Sstevel@tonic-gate mntdata_t *mntdata = MTOD(mnp);
1557a19609f8Sjv zone_t *zone = mntdata->mnt_zone_ref.zref_zone;
15587c478bd9Sstevel@tonic-gate
15597c478bd9Sstevel@tonic-gate STRUCT_INIT(tagdesc, flag & DATAMODEL_MASK);
15607c478bd9Sstevel@tonic-gate if (copyin(dp, STRUCT_BUF(tagdesc), STRUCT_SIZE(tagdesc))) {
15617c478bd9Sstevel@tonic-gate error = EFAULT;
15627c478bd9Sstevel@tonic-gate break;
15637c478bd9Sstevel@tonic-gate }
15647c478bd9Sstevel@tonic-gate pbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
15657c478bd9Sstevel@tonic-gate if (zone != global_zone) {
15667c478bd9Sstevel@tonic-gate (void) strcpy(pbuf, zone->zone_rootpath);
15677c478bd9Sstevel@tonic-gate /* truncate "/" and nul */
15687c478bd9Sstevel@tonic-gate start = zone->zone_rootpathlen - 2;
15697c478bd9Sstevel@tonic-gate ASSERT(pbuf[start] == '/');
15707c478bd9Sstevel@tonic-gate }
15717c478bd9Sstevel@tonic-gate cptr = STRUCT_FGETP(tagdesc, mtd_mntpt);
15727c478bd9Sstevel@tonic-gate error = copyinstr(cptr, pbuf + start, MAXPATHLEN - start, &len);
15737c478bd9Sstevel@tonic-gate if (error) {
15747c478bd9Sstevel@tonic-gate kmem_free(pbuf, MAXPATHLEN);
15757c478bd9Sstevel@tonic-gate break;
15767c478bd9Sstevel@tonic-gate }
15777c478bd9Sstevel@tonic-gate if (start != 0 && pbuf[start] != '/') {
15787c478bd9Sstevel@tonic-gate kmem_free(pbuf, MAXPATHLEN);
15797c478bd9Sstevel@tonic-gate error = EINVAL;
15807c478bd9Sstevel@tonic-gate break;
15817c478bd9Sstevel@tonic-gate }
15827c478bd9Sstevel@tonic-gate cptr = STRUCT_FGETP(tagdesc, mtd_tag);
15837c478bd9Sstevel@tonic-gate if ((error = copyinstr(cptr, tagbuf, MAX_MNTOPT_TAG, &len))) {
15847c478bd9Sstevel@tonic-gate kmem_free(pbuf, MAXPATHLEN);
15857c478bd9Sstevel@tonic-gate break;
15867c478bd9Sstevel@tonic-gate }
15877c478bd9Sstevel@tonic-gate major = STRUCT_FGET(tagdesc, mtd_major);
15887c478bd9Sstevel@tonic-gate minor = STRUCT_FGET(tagdesc, mtd_minor);
15897c478bd9Sstevel@tonic-gate if (cmd == MNTIOC_SETTAG)
15907c478bd9Sstevel@tonic-gate error = vfs_settag(major, minor, pbuf, tagbuf, cr);
15917c478bd9Sstevel@tonic-gate else
15927c478bd9Sstevel@tonic-gate error = vfs_clrtag(major, minor, pbuf, tagbuf, cr);
15937c478bd9Sstevel@tonic-gate kmem_free(pbuf, MAXPATHLEN);
15947c478bd9Sstevel@tonic-gate break;
15957c478bd9Sstevel@tonic-gate }
15967c478bd9Sstevel@tonic-gate
15977c478bd9Sstevel@tonic-gate case MNTIOC_SHOWHIDDEN:
15987c478bd9Sstevel@tonic-gate {
15995545576aSRobert Harris rw_enter(&mnp->mnt_contents, RW_WRITER);
16007c478bd9Sstevel@tonic-gate mnp->mnt_flags |= MNT_SHOWHIDDEN;
16015545576aSRobert Harris rw_exit(&mnp->mnt_contents);
16027c478bd9Sstevel@tonic-gate break;
16037c478bd9Sstevel@tonic-gate }
16047c478bd9Sstevel@tonic-gate
1605835ee219SRobert Harris case MNTIOC_GETMNTANY:
16067c478bd9Sstevel@tonic-gate {
1607835ee219SRobert Harris STRUCT_DECL(mntentbuf, embuf); /* Our copy of user's embuf */
1608835ee219SRobert Harris STRUCT_DECL(extmnttab, ktab); /* Out copy of user's emp */
1609835ee219SRobert Harris struct extmnttab *uemp; /* uaddr of user's emp */
1610835ee219SRobert Harris char *ubufp; /* uaddr of user's text buf */
1611835ee219SRobert Harris size_t ubufsize; /* size of the above */
1612835ee219SRobert Harris struct extmnttab preftab; /* our version of user's emp */
1613835ee219SRobert Harris char *prefbuf; /* our copy of user's text */
1614835ee219SRobert Harris mntelem_t *elemp; /* a database element */
1615835ee219SRobert Harris struct extmnttab *dbtabp; /* element's extmnttab */
1616835ee219SRobert Harris char *dbbufp; /* element's text buf */
1617835ee219SRobert Harris size_t dbbufsize; /* size of the above */
1618835ee219SRobert Harris vtype_t type; /* type, if any, of special */
16197c478bd9Sstevel@tonic-gate
1620835ee219SRobert Harris
1621835ee219SRobert Harris /*
1622835ee219SRobert Harris * embuf is a struct embuf within the kernel. We copy into it
1623835ee219SRobert Harris * the struct embuf supplied by the user.
1624835ee219SRobert Harris */
1625835ee219SRobert Harris STRUCT_INIT(embuf, datamodel);
1626835ee219SRobert Harris if (copyin((void *) arg, STRUCT_BUF(embuf),
1627835ee219SRobert Harris STRUCT_SIZE(embuf))) {
1628835ee219SRobert Harris error = EFAULT;
1629835ee219SRobert Harris break;
163054c529d4SViswanathan Kannappan }
1631835ee219SRobert Harris uemp = STRUCT_FGETP(embuf, mbuf_emp);
1632835ee219SRobert Harris ubufp = STRUCT_FGETP(embuf, mbuf_buf);
1633835ee219SRobert Harris ubufsize = STRUCT_FGET(embuf, mbuf_bufsize);
1634835ee219SRobert Harris
1635835ee219SRobert Harris /*
1636835ee219SRobert Harris * Check that the text buffer offered by the user is the
1637835ee219SRobert Harris * agreed size.
1638835ee219SRobert Harris */
1639835ee219SRobert Harris if (ubufsize != MNT_LINE_MAX) {
1640835ee219SRobert Harris error = EINVAL;
1641835ee219SRobert Harris break;
1642835ee219SRobert Harris }
1643835ee219SRobert Harris
1644835ee219SRobert Harris /* Copy the user-supplied entry into a local buffer. */
1645835ee219SRobert Harris prefbuf = kmem_alloc(MNT_LINE_MAX, KM_SLEEP);
1646835ee219SRobert Harris if (copyin(ubufp, prefbuf, MNT_LINE_MAX)) {
1647835ee219SRobert Harris kmem_free(prefbuf, MNT_LINE_MAX);
1648835ee219SRobert Harris error = EFAULT;
1649835ee219SRobert Harris break;
1650835ee219SRobert Harris }
1651835ee219SRobert Harris
1652835ee219SRobert Harris /* Ensure that any string within it is null-terminated. */
1653835ee219SRobert Harris *(prefbuf + MNT_LINE_MAX - 1) = 0;
1654835ee219SRobert Harris
1655835ee219SRobert Harris /* Copy in the user-supplied mpref */
1656835ee219SRobert Harris STRUCT_INIT(ktab, datamodel);
1657835ee219SRobert Harris if (copyin(uemp, STRUCT_BUF(ktab),
1658835ee219SRobert Harris SIZEOF_STRUCT(mnttab, datamodel))) {
1659835ee219SRobert Harris kmem_free(prefbuf, MNT_LINE_MAX);
1660835ee219SRobert Harris error = EFAULT;
1661835ee219SRobert Harris break;
1662835ee219SRobert Harris }
1663835ee219SRobert Harris
1664835ee219SRobert Harris /*
1665835ee219SRobert Harris * Copy the members of the user's pref struct into a local
1666835ee219SRobert Harris * struct. The pointers need to be offset and verified to
1667835ee219SRobert Harris * ensure that they lie within the bounds of the buffer.
1668835ee219SRobert Harris */
1669835ee219SRobert Harris preftab.mnt_special = mntfs_import_addr(STRUCT_FGETP(ktab,
1670835ee219SRobert Harris mnt_special), ubufp, prefbuf, MNT_LINE_MAX);
1671835ee219SRobert Harris preftab.mnt_mountp = mntfs_import_addr(STRUCT_FGETP(ktab,
1672835ee219SRobert Harris mnt_mountp), ubufp, prefbuf, MNT_LINE_MAX);
1673835ee219SRobert Harris preftab.mnt_fstype = mntfs_import_addr(STRUCT_FGETP(ktab,
1674835ee219SRobert Harris mnt_fstype), ubufp, prefbuf, MNT_LINE_MAX);
1675835ee219SRobert Harris preftab.mnt_mntopts = mntfs_import_addr(STRUCT_FGETP(ktab,
1676835ee219SRobert Harris mnt_mntopts), ubufp, prefbuf, MNT_LINE_MAX);
1677835ee219SRobert Harris preftab.mnt_time = mntfs_import_addr(STRUCT_FGETP(ktab,
1678835ee219SRobert Harris mnt_time), ubufp, prefbuf, MNT_LINE_MAX);
1679835ee219SRobert Harris
1680835ee219SRobert Harris /*
1681835ee219SRobert Harris * If the user specifies a mounted resource that is a special
1682835ee219SRobert Harris * device then we capture its mode and major and minor numbers;
16835545576aSRobert Harris * cf. the block comment below.
1684835ee219SRobert Harris */
1685835ee219SRobert Harris type = mntfs_special_info_string(preftab.mnt_special,
1686835ee219SRobert Harris &preftab.mnt_major, &preftab.mnt_minor, cr);
1687835ee219SRobert Harris
1688835ee219SRobert Harris rw_enter(&mnp->mnt_contents, RW_WRITER);
1689835ee219SRobert Harris if (snapp->mnts_nmnts == 0 ||
1690835ee219SRobert Harris (snapp->mnts_flags & MNTS_REWIND))
1691835ee219SRobert Harris mntfs_snapshot(mnp, snapp);
1692835ee219SRobert Harris
1693835ee219SRobert Harris /*
1694835ee219SRobert Harris * This is the core functionality that implements getmntany().
1695835ee219SRobert Harris * We walk through the mntfs database until we find an element
1696835ee219SRobert Harris * matching the user's preferences that are contained in
1697835ee219SRobert Harris * preftab. Typically, this means checking that the text
1698835ee219SRobert Harris * matches. However, the mounted resource is special: if the
1699835ee219SRobert Harris * user is looking for a special device then we must find a
1700835ee219SRobert Harris * database element with the same major and minor numbers and
1701835ee219SRobert Harris * the same type, i.e. VBLK or VCHR. The type is not recorded
1702835ee219SRobert Harris * in the element because it cannot be inferred from the vfs_t.
1703835ee219SRobert Harris * We therefore check the type of suitable candidates via
1704835ee219SRobert Harris * mntfs_special_info_element(); since this calls into the
1705835ee219SRobert Harris * underlying file system we make sure to drop the database lock
1706835ee219SRobert Harris * first.
1707835ee219SRobert Harris */
1708835ee219SRobert Harris elemp = snapp->mnts_next;
1709835ee219SRobert Harris rw_enter(dblockp, RW_READER);
1710835ee219SRobert Harris for (;;) {
1711835ee219SRobert Harris for (; elemp; elemp = mntfs_get_next_elem(snapp,
1712835ee219SRobert Harris elemp)) {
1713835ee219SRobert Harris dbtabp = &elemp->mnte_tab;
1714835ee219SRobert Harris dbbufp = elemp->mnte_text;
1715835ee219SRobert Harris dbbufsize = elemp->mnte_text_size;
1716835ee219SRobert Harris
1717835ee219SRobert Harris if (((type &&
1718835ee219SRobert Harris dbtabp->mnt_major == preftab.mnt_major &&
1719835ee219SRobert Harris dbtabp->mnt_minor == preftab.mnt_minor &&
1720835ee219SRobert Harris MNTFS_REAL_FIELD(dbbufp)) ||
1721835ee219SRobert Harris (!type && (!preftab.mnt_special ||
1722835ee219SRobert Harris mntfs_same_word(preftab.mnt_special,
1723835ee219SRobert Harris prefbuf, MNT_LINE_MAX, (off_t)0, dbbufp,
1724835ee219SRobert Harris dbbufsize)))) &&
1725835ee219SRobert Harris
1726835ee219SRobert Harris (!preftab.mnt_mountp || mntfs_same_word(
1727835ee219SRobert Harris preftab.mnt_mountp, prefbuf, MNT_LINE_MAX,
1728835ee219SRobert Harris (off_t)dbtabp->mnt_mountp, dbbufp,
1729835ee219SRobert Harris dbbufsize)) &&
1730835ee219SRobert Harris
1731835ee219SRobert Harris (!preftab.mnt_fstype || mntfs_same_word(
1732835ee219SRobert Harris preftab.mnt_fstype, prefbuf, MNT_LINE_MAX,
1733835ee219SRobert Harris (off_t)dbtabp->mnt_fstype, dbbufp,
1734835ee219SRobert Harris dbbufsize)) &&
1735835ee219SRobert Harris
1736835ee219SRobert Harris (!preftab.mnt_mntopts || mntfs_same_word(
1737835ee219SRobert Harris preftab.mnt_mntopts, prefbuf, MNT_LINE_MAX,
1738835ee219SRobert Harris (off_t)dbtabp->mnt_mntopts, dbbufp,
1739835ee219SRobert Harris dbbufsize)) &&
1740835ee219SRobert Harris
1741835ee219SRobert Harris (!preftab.mnt_time || mntfs_same_word(
1742835ee219SRobert Harris preftab.mnt_time, prefbuf, MNT_LINE_MAX,
1743835ee219SRobert Harris (off_t)dbtabp->mnt_time, dbbufp,
1744835ee219SRobert Harris dbbufsize)))
1745835ee219SRobert Harris break;
174654c529d4SViswanathan Kannappan }
1747835ee219SRobert Harris rw_exit(dblockp);
1748835ee219SRobert Harris
1749835ee219SRobert Harris if (elemp == NULL || type == 0 ||
1750835ee219SRobert Harris type == mntfs_special_info_element(elemp, cr))
1751835ee219SRobert Harris break;
1752835ee219SRobert Harris
1753835ee219SRobert Harris rw_enter(dblockp, RW_READER);
1754835ee219SRobert Harris elemp = mntfs_get_next_elem(snapp, elemp);
1755835ee219SRobert Harris }
1756835ee219SRobert Harris
1757835ee219SRobert Harris kmem_free(prefbuf, MNT_LINE_MAX);
1758835ee219SRobert Harris
1759835ee219SRobert Harris /* If we failed to find a match then return EOF. */
1760835ee219SRobert Harris if (elemp == NULL) {
1761835ee219SRobert Harris rw_exit(&mnp->mnt_contents);
1762835ee219SRobert Harris *rvalp = MNTFS_EOF;
1763835ee219SRobert Harris break;
17647c478bd9Sstevel@tonic-gate }
1765835ee219SRobert Harris
17667c478bd9Sstevel@tonic-gate /*
1767835ee219SRobert Harris * Check that the text buffer offered by the user will be large
1768835ee219SRobert Harris * enough to accommodate the text for this entry.
17697c478bd9Sstevel@tonic-gate */
1770835ee219SRobert Harris if (elemp->mnte_text_size > MNT_LINE_MAX) {
177154c529d4SViswanathan Kannappan rw_exit(&mnp->mnt_contents);
1772835ee219SRobert Harris *rvalp = MNTFS_TOOLONG;
1773835ee219SRobert Harris break;
17747c478bd9Sstevel@tonic-gate }
17757c478bd9Sstevel@tonic-gate
1776835ee219SRobert Harris /*
1777835ee219SRobert Harris * Populate the user's struct mnttab and text buffer using the
1778835ee219SRobert Harris * element's contents.
1779835ee219SRobert Harris */
1780835ee219SRobert Harris if (mntfs_copyout_elem(elemp, uemp, ubufp, cmd, datamodel)) {
1781835ee219SRobert Harris error = EFAULT;
17827c478bd9Sstevel@tonic-gate } else {
1783835ee219SRobert Harris rw_enter(dblockp, RW_READER);
1784835ee219SRobert Harris elemp = mntfs_get_next_elem(snapp, elemp);
1785835ee219SRobert Harris rw_exit(dblockp);
1786835ee219SRobert Harris snapp->mnts_next = elemp;
17877c478bd9Sstevel@tonic-gate }
1788835ee219SRobert Harris rw_exit(&mnp->mnt_contents);
1789835ee219SRobert Harris break;
1790835ee219SRobert Harris }
1791835ee219SRobert Harris
1792835ee219SRobert Harris case MNTIOC_GETMNTENT:
1793835ee219SRobert Harris case MNTIOC_GETEXTMNTENT:
1794835ee219SRobert Harris {
1795835ee219SRobert Harris STRUCT_DECL(mntentbuf, embuf); /* Our copy of user's embuf */
1796835ee219SRobert Harris struct extmnttab *uemp; /* uaddr of user's emp */
1797835ee219SRobert Harris char *ubufp; /* uaddr of user's text buf */
1798835ee219SRobert Harris size_t ubufsize; /* size of the above */
1799835ee219SRobert Harris mntelem_t *elemp; /* a database element */
1800835ee219SRobert Harris
1801835ee219SRobert Harris
1802835ee219SRobert Harris rw_enter(&mnp->mnt_contents, RW_WRITER);
1803835ee219SRobert Harris if (snapp->mnts_nmnts == 0 ||
1804835ee219SRobert Harris (snapp->mnts_flags & MNTS_REWIND))
1805835ee219SRobert Harris mntfs_snapshot(mnp, snapp);
1806835ee219SRobert Harris if ((elemp = snapp->mnts_next) == NULL) {
1807835ee219SRobert Harris rw_exit(&mnp->mnt_contents);
1808835ee219SRobert Harris *rvalp = MNTFS_EOF;
1809835ee219SRobert Harris break;
1810835ee219SRobert Harris }
1811835ee219SRobert Harris
1812835ee219SRobert Harris /*
1813835ee219SRobert Harris * embuf is a struct embuf within the kernel. We copy into it
1814835ee219SRobert Harris * the struct embuf supplied by the user.
1815835ee219SRobert Harris */
1816835ee219SRobert Harris STRUCT_INIT(embuf, datamodel);
1817835ee219SRobert Harris if (copyin((void *) arg, STRUCT_BUF(embuf),
1818835ee219SRobert Harris STRUCT_SIZE(embuf))) {
1819835ee219SRobert Harris rw_exit(&mnp->mnt_contents);
1820835ee219SRobert Harris error = EFAULT;
1821835ee219SRobert Harris break;
1822835ee219SRobert Harris }
1823835ee219SRobert Harris uemp = STRUCT_FGETP(embuf, mbuf_emp);
1824835ee219SRobert Harris ubufp = STRUCT_FGETP(embuf, mbuf_buf);
1825835ee219SRobert Harris ubufsize = STRUCT_FGET(embuf, mbuf_bufsize);
18267c478bd9Sstevel@tonic-gate
1827835ee219SRobert Harris /*
1828835ee219SRobert Harris * Check that the text buffer offered by the user will be large
1829835ee219SRobert Harris * enough to accommodate the text for this entry.
1830835ee219SRobert Harris */
1831835ee219SRobert Harris if (elemp->mnte_text_size > ubufsize) {
183254c529d4SViswanathan Kannappan rw_exit(&mnp->mnt_contents);
1833835ee219SRobert Harris *rvalp = MNTFS_TOOLONG;
1834835ee219SRobert Harris break;
183554c529d4SViswanathan Kannappan }
18367c478bd9Sstevel@tonic-gate
1837835ee219SRobert Harris /*
1838835ee219SRobert Harris * Populate the user's struct mnttab and text buffer using the
1839835ee219SRobert Harris * element's contents.
1840835ee219SRobert Harris */
1841835ee219SRobert Harris if (mntfs_copyout_elem(elemp, uemp, ubufp, cmd, datamodel)) {
1842835ee219SRobert Harris error = EFAULT;
1843835ee219SRobert Harris } else {
1844835ee219SRobert Harris rw_enter(dblockp, RW_READER);
1845835ee219SRobert Harris elemp = mntfs_get_next_elem(snapp, elemp);
1846835ee219SRobert Harris rw_exit(dblockp);
1847835ee219SRobert Harris snapp->mnts_next = elemp;
1848835ee219SRobert Harris }
1849835ee219SRobert Harris rw_exit(&mnp->mnt_contents);
18507c478bd9Sstevel@tonic-gate break;
18517c478bd9Sstevel@tonic-gate }
18527c478bd9Sstevel@tonic-gate
18537c478bd9Sstevel@tonic-gate default:
18547c478bd9Sstevel@tonic-gate error = EINVAL;
18557c478bd9Sstevel@tonic-gate break;
18567c478bd9Sstevel@tonic-gate }
18577c478bd9Sstevel@tonic-gate
18587c478bd9Sstevel@tonic-gate return (error);
18597c478bd9Sstevel@tonic-gate }
18607c478bd9Sstevel@tonic-gate
18615545576aSRobert Harris /*
18625545576aSRobert Harris * mntfs provides a new vnode for each open(2). Two vnodes will represent the
18635545576aSRobert Harris * same instance of /etc/mnttab if they share the same (zone-specific) vfs.
18645545576aSRobert Harris */
18655545576aSRobert Harris /* ARGSUSED */
18665545576aSRobert Harris int
mntcmp(vnode_t * vp1,vnode_t * vp2,caller_context_t * ct)18675545576aSRobert Harris mntcmp(vnode_t *vp1, vnode_t *vp2, caller_context_t *ct)
18685545576aSRobert Harris {
18695545576aSRobert Harris return (vp1 != NULL && vp2 != NULL && vp1->v_vfsp == vp2->v_vfsp);
18705545576aSRobert Harris }
18715545576aSRobert Harris
18727c478bd9Sstevel@tonic-gate /*
18737c478bd9Sstevel@tonic-gate * /mntfs vnode operations vector
18747c478bd9Sstevel@tonic-gate */
18757c478bd9Sstevel@tonic-gate const fs_operation_def_t mnt_vnodeops_template[] = {
1876aa59c4cbSrsb VOPNAME_OPEN, { .vop_open = mntopen },
1877aa59c4cbSrsb VOPNAME_CLOSE, { .vop_close = mntclose },
1878aa59c4cbSrsb VOPNAME_READ, { .vop_read = mntread },
1879aa59c4cbSrsb VOPNAME_IOCTL, { .vop_ioctl = mntioctl },
1880aa59c4cbSrsb VOPNAME_GETATTR, { .vop_getattr = mntgetattr },
1881aa59c4cbSrsb VOPNAME_ACCESS, { .vop_access = mntaccess },
1882aa59c4cbSrsb VOPNAME_FSYNC, { .vop_fsync = mntfsync },
1883aa59c4cbSrsb VOPNAME_INACTIVE, { .vop_inactive = mntinactive },
1884aa59c4cbSrsb VOPNAME_SEEK, { .vop_seek = mntseek },
1885aa59c4cbSrsb VOPNAME_POLL, { .vop_poll = mntpoll },
18865545576aSRobert Harris VOPNAME_CMP, { .vop_cmp = mntcmp },
1887aa59c4cbSrsb VOPNAME_DISPOSE, { .error = fs_error },
1888aa59c4cbSrsb VOPNAME_SHRLOCK, { .error = fs_error },
1889aa59c4cbSrsb NULL, NULL
18907c478bd9Sstevel@tonic-gate };
1891