1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
23 */
24
25 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
26 /* All Rights Reserved */
27
28 /*
29 * University Copyright- Copyright (c) 1982, 1986, 1988
30 * The Regents of the University of California
31 * All Rights Reserved
32 *
33 * University Acknowledgment- Portions of this document are derived from
34 * software developed by the University of California, Berkeley, and its
35 * contributors.
36 */
37
38 #include <sys/types.h>
39 #include <sys/t_lock.h>
40 #include <sys/param.h>
41 #include <sys/errno.h>
42 #include <sys/user.h>
43 #include <sys/fstyp.h>
44 #include <sys/kmem.h>
45 #include <sys/systm.h>
46 #include <sys/proc.h>
47 #include <sys/mount.h>
48 #include <sys/vfs.h>
49 #include <sys/vfs_opreg.h>
50 #include <sys/fem.h>
51 #include <sys/mntent.h>
52 #include <sys/stat.h>
53 #include <sys/statvfs.h>
54 #include <sys/statfs.h>
55 #include <sys/cred.h>
56 #include <sys/vnode.h>
57 #include <sys/rwstlock.h>
58 #include <sys/dnlc.h>
59 #include <sys/file.h>
60 #include <sys/time.h>
61 #include <sys/atomic.h>
62 #include <sys/cmn_err.h>
63 #include <sys/buf.h>
64 #include <sys/swap.h>
65 #include <sys/debug.h>
66 #include <sys/vnode.h>
67 #include <sys/modctl.h>
68 #include <sys/ddi.h>
69 #include <sys/pathname.h>
70 #include <sys/bootconf.h>
71 #include <sys/dumphdr.h>
72 #include <sys/dc_ki.h>
73 #include <sys/poll.h>
74 #include <sys/sunddi.h>
75 #include <sys/sysmacros.h>
76 #include <sys/zone.h>
77 #include <sys/policy.h>
78 #include <sys/ctfs.h>
79 #include <sys/objfs.h>
80 #include <sys/console.h>
81 #include <sys/reboot.h>
82 #include <sys/attr.h>
83 #include <sys/zio.h>
84 #include <sys/spa.h>
85 #include <sys/lofi.h>
86 #include <sys/bootprops.h>
87 #include <sys/fsh.h>
88 #include <sys/fsh_impl.h>
89
90 #include <vm/page.h>
91
92 #include <fs/fs_subr.h>
93 /* Private interfaces to create vopstats-related data structures */
94 extern void initialize_vopstats(vopstats_t *);
95 extern vopstats_t *get_fstype_vopstats(struct vfs *, struct vfssw *);
96 extern vsk_anchor_t *get_vskstat_anchor(struct vfs *);
97
98 static void vfs_clearmntopt_nolock(mntopts_t *, const char *, int);
99 static void vfs_setmntopt_nolock(mntopts_t *, const char *,
100 const char *, int, int);
101 static int vfs_optionisset_nolock(const mntopts_t *, const char *, char **);
102 static void vfs_freemnttab(struct vfs *);
103 static void vfs_freeopt(mntopt_t *);
104 static void vfs_swapopttbl_nolock(mntopts_t *, mntopts_t *);
105 static void vfs_swapopttbl(mntopts_t *, mntopts_t *);
106 static void vfs_copyopttbl_extend(const mntopts_t *, mntopts_t *, int);
107 static void vfs_createopttbl_extend(mntopts_t *, const char *,
108 const mntopts_t *);
109 static char **vfs_copycancelopt_extend(char **const, int);
110 static void vfs_freecancelopt(char **);
111 static void getrootfs(char **, char **);
112 static int getmacpath(dev_info_t *, void *);
113 static void vfs_mnttabvp_setup(void);
114
115 struct ipmnt {
116 struct ipmnt *mip_next;
117 dev_t mip_dev;
118 struct vfs *mip_vfsp;
119 };
120
121 static kmutex_t vfs_miplist_mutex;
122 static struct ipmnt *vfs_miplist = NULL;
123 static struct ipmnt *vfs_miplist_end = NULL;
124
125 static kmem_cache_t *vfs_cache; /* Pointer to VFS kmem cache */
126
127 /*
128 * VFS global data.
129 */
130 vnode_t *rootdir; /* pointer to root inode vnode. */
131 vnode_t *devicesdir; /* pointer to inode of devices root */
132 vnode_t *devdir; /* pointer to inode of dev root */
133
134 char *server_rootpath; /* root path for diskless clients */
135 char *server_hostname; /* hostname of diskless server */
136
137 static struct vfs root;
138 static struct vfs devices;
139 static struct vfs dev;
140 struct vfs *rootvfs = &root; /* pointer to root vfs; head of VFS list. */
141 rvfs_t *rvfs_list; /* array of vfs ptrs for vfs hash list */
142 int vfshsz = 512; /* # of heads/locks in vfs hash arrays */
143 /* must be power of 2! */
144 timespec_t vfs_mnttab_ctime; /* mnttab created time */
145 timespec_t vfs_mnttab_mtime; /* mnttab last modified time */
146 char *vfs_dummyfstype = "\0";
147 struct pollhead vfs_pollhd; /* for mnttab pollers */
148 struct vnode *vfs_mntdummyvp; /* to fake mnttab read/write for file events */
149 int mntfstype; /* will be set once mnt fs is mounted */
150
151 /*
152 * Table for generic options recognized in the VFS layer and acted
153 * on at this level before parsing file system specific options.
154 * The nosuid option is stronger than any of the devices and setuid
155 * options, so those are canceled when nosuid is seen.
156 *
157 * All options which are added here need to be added to the
158 * list of standard options in usr/src/cmd/fs.d/fslib.c as well.
159 */
160 /*
161 * VFS Mount options table
162 */
163 static char *ro_cancel[] = { MNTOPT_RW, NULL };
164 static char *rw_cancel[] = { MNTOPT_RO, NULL };
165 static char *suid_cancel[] = { MNTOPT_NOSUID, NULL };
166 static char *nosuid_cancel[] = { MNTOPT_SUID, MNTOPT_DEVICES, MNTOPT_NODEVICES,
167 MNTOPT_NOSETUID, MNTOPT_SETUID, NULL };
168 static char *devices_cancel[] = { MNTOPT_NODEVICES, NULL };
169 static char *nodevices_cancel[] = { MNTOPT_DEVICES, NULL };
170 static char *setuid_cancel[] = { MNTOPT_NOSETUID, NULL };
171 static char *nosetuid_cancel[] = { MNTOPT_SETUID, NULL };
172 static char *nbmand_cancel[] = { MNTOPT_NONBMAND, NULL };
173 static char *nonbmand_cancel[] = { MNTOPT_NBMAND, NULL };
174 static char *exec_cancel[] = { MNTOPT_NOEXEC, NULL };
175 static char *noexec_cancel[] = { MNTOPT_EXEC, NULL };
176
177 static const mntopt_t mntopts[] = {
178 /*
179 * option name cancel options default arg flags
180 */
181 { MNTOPT_REMOUNT, NULL, NULL,
182 MO_NODISPLAY, (void *)0 },
183 { MNTOPT_RO, ro_cancel, NULL, 0,
184 (void *)0 },
185 { MNTOPT_RW, rw_cancel, NULL, 0,
186 (void *)0 },
187 { MNTOPT_SUID, suid_cancel, NULL, 0,
188 (void *)0 },
189 { MNTOPT_NOSUID, nosuid_cancel, NULL, 0,
190 (void *)0 },
191 { MNTOPT_DEVICES, devices_cancel, NULL, 0,
192 (void *)0 },
193 { MNTOPT_NODEVICES, nodevices_cancel, NULL, 0,
194 (void *)0 },
195 { MNTOPT_SETUID, setuid_cancel, NULL, 0,
196 (void *)0 },
197 { MNTOPT_NOSETUID, nosetuid_cancel, NULL, 0,
198 (void *)0 },
199 { MNTOPT_NBMAND, nbmand_cancel, NULL, 0,
200 (void *)0 },
201 { MNTOPT_NONBMAND, nonbmand_cancel, NULL, 0,
202 (void *)0 },
203 { MNTOPT_EXEC, exec_cancel, NULL, 0,
204 (void *)0 },
205 { MNTOPT_NOEXEC, noexec_cancel, NULL, 0,
206 (void *)0 },
207 };
208
209 const mntopts_t vfs_mntopts = {
210 sizeof (mntopts) / sizeof (mntopt_t),
211 (mntopt_t *)&mntopts[0]
212 };
213
214 /*
215 * File system operation dispatch functions.
216 */
217
218 int
219 fsop_mount(vfs_t *vfsp, vnode_t *mvp, struct mounta *uap, cred_t *cr)
220 {
221 return (fsh_mount(vfsp, mvp, uap, cr));
222 }
223
224 int
225 fsop_unmount(vfs_t *vfsp, int flag, cred_t *cr)
226 {
227 return (fsh_unmount(vfsp, flag, cr));
228 }
229
230 int
231 fsop_root(vfs_t *vfsp, vnode_t **vpp)
232 {
233 refstr_t *mntpt;
234 int ret = (*(vfsp)->vfs_op->vfs_root)(vfsp, vpp);
235 /*
236 * Make sure this root has a path. With lofs, it is possible to have
237 * a NULL mountpoint.
238 */
239 if (ret == 0 && vfsp->vfs_mntpt != NULL && (*vpp)->v_path == NULL) {
240 mntpt = vfs_getmntpoint(vfsp);
241 vn_setpath_str(*vpp, refstr_value(mntpt),
242 strlen(refstr_value(mntpt)));
243 refstr_rele(mntpt);
244 }
245
246 return (ret);
247 }
248
249 int
250 fsop_statfs(vfs_t *vfsp, statvfs64_t *sp)
251 {
252 return (*(vfsp)->vfs_op->vfs_statvfs)(vfsp, sp);
253 }
254
255 int
256 fsop_sync(vfs_t *vfsp, short flag, cred_t *cr)
257 {
258 return (*(vfsp)->vfs_op->vfs_sync)(vfsp, flag, cr);
259 }
260
261 int
262 fsop_vget(vfs_t *vfsp, vnode_t **vpp, fid_t *fidp)
263 {
264 /*
265 * In order to handle system attribute fids in a manner
266 * transparent to the underlying fs, we embed the fid for
267 * the sysattr parent object in the sysattr fid and tack on
268 * some extra bytes that only the sysattr layer knows about.
269 *
270 * This guarantees that sysattr fids are larger than other fids
271 * for this vfs. If the vfs supports the sysattr view interface
272 * (as indicated by VFSFT_SYSATTR_VIEWS), we cannot have a size
273 * collision with XATTR_FIDSZ.
274 */
275 if (vfs_has_feature(vfsp, VFSFT_SYSATTR_VIEWS) &&
276 fidp->fid_len == XATTR_FIDSZ)
277 return (xattr_dir_vget(vfsp, vpp, fidp));
278
279 return (*(vfsp)->vfs_op->vfs_vget)(vfsp, vpp, fidp);
280 }
281
282 int
283 fsop_mountroot(vfs_t *vfsp, enum whymountroot reason)
284 {
285 return (*(vfsp)->vfs_op->vfs_mountroot)(vfsp, reason);
286 }
287
288 void
289 fsop_freefs(vfs_t *vfsp)
290 {
291 (*(vfsp)->vfs_op->vfs_freevfs)(vfsp);
292 }
293
294 int
295 fsop_vnstate(vfs_t *vfsp, vnode_t *vp, vntrans_t nstate)
296 {
297 return ((*(vfsp)->vfs_op->vfs_vnstate)(vfsp, vp, nstate));
298 }
299
300 int
301 fsop_sync_by_kind(int fstype, short flag, cred_t *cr)
302 {
303 ASSERT((fstype >= 0) && (fstype < nfstype));
304
305 if (ALLOCATED_VFSSW(&vfssw[fstype]) && VFS_INSTALLED(&vfssw[fstype]))
306 return (*vfssw[fstype].vsw_vfsops.vfs_sync) (NULL, flag, cr);
307 else
308 return (ENOTSUP);
309 }
310
311 /*
312 * File system initialization. vfs_setfsops() must be called from a file
313 * system's init routine.
314 */
315
316 static int
317 fs_copyfsops(const fs_operation_def_t *template, vfsops_t *actual,
318 int *unused_ops)
319 {
320 static const fs_operation_trans_def_t vfs_ops_table[] = {
321 VFSNAME_MOUNT, offsetof(vfsops_t, vfs_mount),
322 fs_nosys, fs_nosys,
323
324 VFSNAME_UNMOUNT, offsetof(vfsops_t, vfs_unmount),
325 fs_nosys, fs_nosys,
326
327 VFSNAME_ROOT, offsetof(vfsops_t, vfs_root),
328 fs_nosys, fs_nosys,
329
330 VFSNAME_STATVFS, offsetof(vfsops_t, vfs_statvfs),
331 fs_nosys, fs_nosys,
332
333 VFSNAME_SYNC, offsetof(vfsops_t, vfs_sync),
334 (fs_generic_func_p) fs_sync,
335 (fs_generic_func_p) fs_sync, /* No errors allowed */
336
337 VFSNAME_VGET, offsetof(vfsops_t, vfs_vget),
338 fs_nosys, fs_nosys,
339
340 VFSNAME_MOUNTROOT, offsetof(vfsops_t, vfs_mountroot),
341 fs_nosys, fs_nosys,
342
343 VFSNAME_FREEVFS, offsetof(vfsops_t, vfs_freevfs),
344 (fs_generic_func_p)fs_freevfs,
345 (fs_generic_func_p)fs_freevfs, /* Shouldn't fail */
346
347 VFSNAME_VNSTATE, offsetof(vfsops_t, vfs_vnstate),
348 (fs_generic_func_p)fs_nosys,
349 (fs_generic_func_p)fs_nosys,
350
351 NULL, 0, NULL, NULL
352 };
353
354 return (fs_build_vector(actual, unused_ops, vfs_ops_table, template));
355 }
356
357 void
358 zfs_boot_init() {
359
360 if (strcmp(rootfs.bo_fstype, MNTTYPE_ZFS) == 0)
361 spa_boot_init();
362 }
363
364 int
365 vfs_setfsops(int fstype, const fs_operation_def_t *template, vfsops_t **actual)
366 {
367 int error;
368 int unused_ops;
369
370 /*
371 * Verify that fstype refers to a valid fs. Note that
372 * 0 is valid since it's used to set "stray" ops.
373 */
374 if ((fstype < 0) || (fstype >= nfstype))
375 return (EINVAL);
376
377 if (!ALLOCATED_VFSSW(&vfssw[fstype]))
378 return (EINVAL);
379
380 /* Set up the operations vector. */
381
382 error = fs_copyfsops(template, &vfssw[fstype].vsw_vfsops, &unused_ops);
383
384 if (error != 0)
385 return (error);
386
387 vfssw[fstype].vsw_flag |= VSW_INSTALLED;
388
389 if (actual != NULL)
390 *actual = &vfssw[fstype].vsw_vfsops;
391
392 #if DEBUG
393 if (unused_ops != 0)
394 cmn_err(CE_WARN, "vfs_setfsops: %s: %d operations supplied "
395 "but not used", vfssw[fstype].vsw_name, unused_ops);
396 #endif
397
398 return (0);
399 }
400
401 int
402 vfs_makefsops(const fs_operation_def_t *template, vfsops_t **actual)
403 {
404 int error;
405 int unused_ops;
406
407 *actual = (vfsops_t *)kmem_alloc(sizeof (vfsops_t), KM_SLEEP);
408
409 error = fs_copyfsops(template, *actual, &unused_ops);
410 if (error != 0) {
411 kmem_free(*actual, sizeof (vfsops_t));
412 *actual = NULL;
413 return (error);
414 }
415
416 return (0);
417 }
418
419 /*
420 * Free a vfsops structure created as a result of vfs_makefsops().
421 * NOTE: For a vfsops structure initialized by vfs_setfsops(), use
422 * vfs_freevfsops_by_type().
423 */
424 void
425 vfs_freevfsops(vfsops_t *vfsops)
426 {
427 kmem_free(vfsops, sizeof (vfsops_t));
428 }
429
430 /*
431 * Since the vfsops structure is part of the vfssw table and wasn't
432 * really allocated, we're not really freeing anything. We keep
433 * the name for consistency with vfs_freevfsops(). We do, however,
434 * need to take care of a little bookkeeping.
435 * NOTE: For a vfsops structure created by vfs_setfsops(), use
436 * vfs_freevfsops_by_type().
437 */
438 int
439 vfs_freevfsops_by_type(int fstype)
440 {
441
442 /* Verify that fstype refers to a loaded fs (and not fsid 0). */
443 if ((fstype <= 0) || (fstype >= nfstype))
444 return (EINVAL);
445
446 WLOCK_VFSSW();
447 if ((vfssw[fstype].vsw_flag & VSW_INSTALLED) == 0) {
448 WUNLOCK_VFSSW();
449 return (EINVAL);
450 }
451
452 vfssw[fstype].vsw_flag &= ~VSW_INSTALLED;
453 WUNLOCK_VFSSW();
454
455 return (0);
456 }
457
458 /* Support routines used to reference vfs_op */
459
460 /* Set the operations vector for a vfs */
461 void
462 vfs_setops(vfs_t *vfsp, vfsops_t *vfsops)
463 {
464 vfsops_t *op;
465
466 ASSERT(vfsp != NULL);
467 ASSERT(vfsops != NULL);
468
469 op = vfsp->vfs_op;
470 membar_consumer();
471 if (vfsp->vfs_femhead == NULL &&
472 casptr(&vfsp->vfs_op, op, vfsops) == op) {
473 return;
474 }
475 fsem_setvfsops(vfsp, vfsops);
476 }
477
478 /* Retrieve the operations vector for a vfs */
479 vfsops_t *
480 vfs_getops(vfs_t *vfsp)
481 {
482 vfsops_t *op;
483
484 ASSERT(vfsp != NULL);
485
486 op = vfsp->vfs_op;
487 membar_consumer();
488 if (vfsp->vfs_femhead == NULL && op == vfsp->vfs_op) {
489 return (op);
490 } else {
491 return (fsem_getvfsops(vfsp));
492 }
493 }
494
495 /*
496 * Returns non-zero (1) if the vfsops matches that of the vfs.
497 * Returns zero (0) if not.
498 */
499 int
500 vfs_matchops(vfs_t *vfsp, vfsops_t *vfsops)
501 {
502 return (vfs_getops(vfsp) == vfsops);
503 }
504
505 /*
506 * Returns non-zero (1) if the file system has installed a non-default,
507 * non-error vfs_sync routine. Returns zero (0) otherwise.
508 */
509 int
510 vfs_can_sync(vfs_t *vfsp)
511 {
512 /* vfs_sync() routine is not the default/error function */
513 return (vfs_getops(vfsp)->vfs_sync != fs_sync);
514 }
515
516 /*
517 * Initialize a vfs structure.
518 */
519 void
520 vfs_init(vfs_t *vfsp, vfsops_t *op, void *data)
521 {
522 /* Other initialization has been moved to vfs_alloc() */
523 vfsp->vfs_count = 0;
524 vfsp->vfs_next = vfsp;
525 vfsp->vfs_prev = vfsp;
526 vfsp->vfs_zone_next = vfsp;
527 vfsp->vfs_zone_prev = vfsp;
528 vfsp->vfs_lofi_minor = 0;
529 sema_init(&vfsp->vfs_reflock, 1, NULL, SEMA_DEFAULT, NULL);
530 vfsimpl_setup(vfsp);
531 vfsp->vfs_data = (data);
532 vfs_setops((vfsp), (op));
533 }
534
535 /*
536 * Allocate and initialize the vfs implementation private data
537 * structure, vfs_impl_t.
538 */
539 void
540 vfsimpl_setup(vfs_t *vfsp)
541 {
542 int i;
543
544 if (vfsp->vfs_implp != NULL) {
545 return;
546 }
547
548 vfsp->vfs_implp = kmem_alloc(sizeof (vfs_impl_t), KM_SLEEP);
549 /* Note that these are #define'd in vfs.h */
550 vfsp->vfs_vskap = NULL;
551 vfsp->vfs_fstypevsp = NULL;
552
553 /* Set size of counted array, then zero the array */
554 vfsp->vfs_featureset[0] = VFS_FEATURE_MAXSZ - 1;
555 for (i = 1; i < VFS_FEATURE_MAXSZ; i++) {
556 vfsp->vfs_featureset[i] = 0;
557 }
558 }
559
560 /*
561 * Release the vfs_impl_t structure, if it exists. Some unbundled
562 * filesystems may not use the newer version of vfs and thus
563 * would not contain this implementation private data structure.
564 */
565 void
566 vfsimpl_teardown(vfs_t *vfsp)
567 {
568 vfs_impl_t *vip = vfsp->vfs_implp;
569
570 if (vip == NULL)
571 return;
572
573 kmem_free(vfsp->vfs_implp, sizeof (vfs_impl_t));
574 vfsp->vfs_implp = NULL;
575 }
576
577 /*
578 * VFS system calls: mount, umount, syssync, statfs, fstatfs, statvfs,
579 * fstatvfs, and sysfs moved to common/syscall.
580 */
581
582 /*
583 * Update every mounted file system. We call the vfs_sync operation of
584 * each file system type, passing it a NULL vfsp to indicate that all
585 * mounted file systems of that type should be updated.
586 */
587 void
588 vfs_sync(int flag)
589 {
590 struct vfssw *vswp;
591 RLOCK_VFSSW();
592 for (vswp = &vfssw[1]; vswp < &vfssw[nfstype]; vswp++) {
593 if (ALLOCATED_VFSSW(vswp) && VFS_INSTALLED(vswp)) {
594 vfs_refvfssw(vswp);
595 RUNLOCK_VFSSW();
596 (void) (*vswp->vsw_vfsops.vfs_sync)(NULL, flag,
597 CRED());
598 vfs_unrefvfssw(vswp);
599 RLOCK_VFSSW();
600 }
601 }
602 RUNLOCK_VFSSW();
603 }
604
605 void
606 sync(void)
607 {
608 vfs_sync(0);
609 }
610
611 /*
612 * External routines.
613 */
614
615 krwlock_t vfssw_lock; /* lock accesses to vfssw */
616
617 /*
618 * Lock for accessing the vfs linked list. Initialized in vfs_mountroot(),
619 * but otherwise should be accessed only via vfs_list_lock() and
620 * vfs_list_unlock(). Also used to protect the timestamp for mods to the list.
621 */
622 static krwlock_t vfslist;
623
624 /*
625 * Mount devfs on /devices. This is done right after root is mounted
626 * to provide device access support for the system
627 */
628 static void
629 vfs_mountdevices(void)
630 {
631 struct vfssw *vsw;
632 struct vnode *mvp;
633 struct mounta mounta = { /* fake mounta for devfs_mount() */
634 NULL,
635 NULL,
636 MS_SYSSPACE,
637 NULL,
638 NULL,
639 0,
640 NULL,
641 0
642 };
643
644 /*
645 * _init devfs module to fill in the vfssw
646 */
647 if (modload("fs", "devfs") == -1)
648 panic("Cannot _init devfs module");
649
650 /*
651 * Hold vfs
652 */
653 RLOCK_VFSSW();
654 vsw = vfs_getvfsswbyname("devfs");
655 VFS_INIT(&devices, &vsw->vsw_vfsops, NULL);
656 VFS_HOLD(&devices);
657
658 /*
659 * Locate mount point
660 */
661 if (lookupname("/devices", UIO_SYSSPACE, FOLLOW, NULLVPP, &mvp))
662 panic("Cannot find /devices");
663
664 /*
665 * Perform the mount of /devices
666 */
667 if (VFS_MOUNT(&devices, mvp, &mounta, CRED()))
668 panic("Cannot mount /devices");
669
670 RUNLOCK_VFSSW();
671
672 /*
673 * Set appropriate members and add to vfs list for mnttab display
674 */
675 vfs_setresource(&devices, "/devices", 0);
676 vfs_setmntpoint(&devices, "/devices", 0);
677
678 /*
679 * Hold the root of /devices so it won't go away
680 */
681 if (VFS_ROOT(&devices, &devicesdir))
682 panic("vfs_mountdevices: not devices root");
683
684 if (vfs_lock(&devices) != 0) {
685 VN_RELE(devicesdir);
686 cmn_err(CE_NOTE, "Cannot acquire vfs_lock of /devices");
687 return;
688 }
689
690 if (vn_vfswlock(mvp) != 0) {
691 vfs_unlock(&devices);
692 VN_RELE(devicesdir);
693 cmn_err(CE_NOTE, "Cannot acquire vfswlock of /devices");
694 return;
695 }
696
697 vfs_add(mvp, &devices, 0);
698 vn_vfsunlock(mvp);
699 vfs_unlock(&devices);
700 VN_RELE(devicesdir);
701 }
702
703 /*
704 * mount the first instance of /dev to root and remain mounted
705 */
706 static void
707 vfs_mountdev1(void)
708 {
709 struct vfssw *vsw;
710 struct vnode *mvp;
711 struct mounta mounta = { /* fake mounta for sdev_mount() */
712 NULL,
713 NULL,
714 MS_SYSSPACE | MS_OVERLAY,
715 NULL,
716 NULL,
717 0,
718 NULL,
719 0
720 };
721
722 /*
723 * _init dev module to fill in the vfssw
724 */
725 if (modload("fs", "dev") == -1)
726 cmn_err(CE_PANIC, "Cannot _init dev module\n");
727
728 /*
729 * Hold vfs
730 */
731 RLOCK_VFSSW();
732 vsw = vfs_getvfsswbyname("dev");
733 VFS_INIT(&dev, &vsw->vsw_vfsops, NULL);
734 VFS_HOLD(&dev);
735
736 /*
737 * Locate mount point
738 */
739 if (lookupname("/dev", UIO_SYSSPACE, FOLLOW, NULLVPP, &mvp))
740 cmn_err(CE_PANIC, "Cannot find /dev\n");
741
742 /*
743 * Perform the mount of /dev
744 */
745 if (VFS_MOUNT(&dev, mvp, &mounta, CRED()))
746 cmn_err(CE_PANIC, "Cannot mount /dev 1\n");
747
748 RUNLOCK_VFSSW();
749
750 /*
751 * Set appropriate members and add to vfs list for mnttab display
752 */
753 vfs_setresource(&dev, "/dev", 0);
754 vfs_setmntpoint(&dev, "/dev", 0);
755
756 /*
757 * Hold the root of /dev so it won't go away
758 */
759 if (VFS_ROOT(&dev, &devdir))
760 cmn_err(CE_PANIC, "vfs_mountdev1: not dev root");
761
762 if (vfs_lock(&dev) != 0) {
763 VN_RELE(devdir);
764 cmn_err(CE_NOTE, "Cannot acquire vfs_lock of /dev");
765 return;
766 }
767
768 if (vn_vfswlock(mvp) != 0) {
769 vfs_unlock(&dev);
770 VN_RELE(devdir);
771 cmn_err(CE_NOTE, "Cannot acquire vfswlock of /dev");
772 return;
773 }
774
775 vfs_add(mvp, &dev, 0);
776 vn_vfsunlock(mvp);
777 vfs_unlock(&dev);
778 VN_RELE(devdir);
779 }
780
781 /*
782 * Mount required filesystem. This is done right after root is mounted.
783 */
784 static void
785 vfs_mountfs(char *module, char *spec, char *path)
786 {
787 struct vnode *mvp;
788 struct mounta mounta;
789 vfs_t *vfsp;
790
791 mounta.flags = MS_SYSSPACE | MS_DATA;
792 mounta.fstype = module;
793 mounta.spec = spec;
794 mounta.dir = path;
795 if (lookupname(path, UIO_SYSSPACE, FOLLOW, NULLVPP, &mvp)) {
796 cmn_err(CE_WARN, "Cannot find %s", path);
797 return;
798 }
799 if (domount(NULL, &mounta, mvp, CRED(), &vfsp))
800 cmn_err(CE_WARN, "Cannot mount %s", path);
801 else
802 VFS_RELE(vfsp);
803 VN_RELE(mvp);
804 }
805
806 /*
807 * vfs_mountroot is called by main() to mount the root filesystem.
808 */
809 void
810 vfs_mountroot(void)
811 {
812 struct vnode *rvp = NULL;
813 char *path;
814 size_t plen;
815 struct vfssw *vswp;
816 proc_t *p;
817
818 rw_init(&vfssw_lock, NULL, RW_DEFAULT, NULL);
819 rw_init(&vfslist, NULL, RW_DEFAULT, NULL);
820
821 /*
822 * Alloc the vfs hash bucket array and locks
823 */
824 rvfs_list = kmem_zalloc(vfshsz * sizeof (rvfs_t), KM_SLEEP);
825
826 /*
827 * Call machine-dependent routine "rootconf" to choose a root
828 * file system type.
829 */
830 if (rootconf())
831 panic("vfs_mountroot: cannot mount root");
832 /*
833 * Get vnode for '/'. Set up rootdir, u.u_rdir and u.u_cdir
834 * to point to it. These are used by lookuppn() so that it
835 * knows where to start from ('/' or '.').
836 */
837 vfs_setmntpoint(rootvfs, "/", 0);
838 if (VFS_ROOT(rootvfs, &rootdir))
839 panic("vfs_mountroot: no root vnode");
840
841 /*
842 * At this point, the process tree consists of p0 and possibly some
843 * direct children of p0. (i.e. there are no grandchildren)
844 *
845 * Walk through them all, setting their current directory.
846 */
847 mutex_enter(&pidlock);
848 for (p = practive; p != NULL; p = p->p_next) {
849 ASSERT(p == &p0 || p->p_parent == &p0);
850
851 PTOU(p)->u_cdir = rootdir;
852 VN_HOLD(PTOU(p)->u_cdir);
853 PTOU(p)->u_rdir = NULL;
854 }
855 mutex_exit(&pidlock);
856
857 /*
858 * Setup the global zone's rootvp, now that it exists.
859 */
860 global_zone->zone_rootvp = rootdir;
861 VN_HOLD(global_zone->zone_rootvp);
862
863 /*
864 * Notify the module code that it can begin using the
865 * root filesystem instead of the boot program's services.
866 */
867 modrootloaded = 1;
868
869 /*
870 * Special handling for a ZFS root file system.
871 */
872 zfs_boot_init();
873
874 /*
875 * Set up mnttab information for root
876 */
877 vfs_setresource(rootvfs, rootfs.bo_name, 0);
878
879 /*
880 * Notify cluster software that the root filesystem is available.
881 */
882 clboot_mountroot();
883
884 /* Now that we're all done with the root FS, set up its vopstats */
885 if ((vswp = vfs_getvfsswbyvfsops(vfs_getops(rootvfs))) != NULL) {
886 /* Set flag for statistics collection */
887 if (vswp->vsw_flag & VSW_STATS) {
888 initialize_vopstats(&rootvfs->vfs_vopstats);
889 rootvfs->vfs_flag |= VFS_STATS;
890 rootvfs->vfs_fstypevsp =
891 get_fstype_vopstats(rootvfs, vswp);
892 rootvfs->vfs_vskap = get_vskstat_anchor(rootvfs);
893 }
894 vfs_unrefvfssw(vswp);
895 }
896
897 /*
898 * Mount /devices, /dev instance 1, /system/contract, /etc/mnttab,
899 * /etc/svc/volatile, /etc/dfs/sharetab, /system/object, and /proc.
900 */
901 vfs_mountdevices();
902 vfs_mountdev1();
903
904 vfs_mountfs("ctfs", "ctfs", CTFS_ROOT);
905 vfs_mountfs("proc", "/proc", "/proc");
906 vfs_mountfs("mntfs", "/etc/mnttab", "/etc/mnttab");
907 vfs_mountfs("tmpfs", "/etc/svc/volatile", "/etc/svc/volatile");
908 vfs_mountfs("objfs", "objfs", OBJFS_ROOT);
909
910 if (getzoneid() == GLOBAL_ZONEID) {
911 vfs_mountfs("sharefs", "sharefs", "/etc/dfs/sharetab");
912 }
913
914 #ifdef __sparc
915 /*
916 * This bit of magic can go away when we convert sparc to
917 * the new boot architecture based on ramdisk.
918 *
919 * Booting off a mirrored root volume:
920 * At this point, we have booted and mounted root on a
921 * single component of the mirror. Complete the boot
922 * by configuring SVM and converting the root to the
923 * dev_t of the mirrored root device. This dev_t conversion
924 * only works because the underlying device doesn't change.
925 */
926 if (root_is_svm) {
927 if (svm_rootconf()) {
928 panic("vfs_mountroot: cannot remount root");
929 }
930
931 /*
932 * mnttab should reflect the new root device
933 */
934 vfs_lock_wait(rootvfs);
935 vfs_setresource(rootvfs, rootfs.bo_name, 0);
936 vfs_unlock(rootvfs);
937 }
938 #endif /* __sparc */
939
940 if (strcmp(rootfs.bo_fstype, "zfs") != 0) {
941 /*
942 * Look up the root device via devfs so that a dv_node is
943 * created for it. The vnode is never VN_RELE()ed.
944 * We allocate more than MAXPATHLEN so that the
945 * buffer passed to i_ddi_prompath_to_devfspath() is
946 * exactly MAXPATHLEN (the function expects a buffer
947 * of that length).
948 */
949 plen = strlen("/devices");
950 path = kmem_alloc(plen + MAXPATHLEN, KM_SLEEP);
951 (void) strcpy(path, "/devices");
952
953 if (i_ddi_prompath_to_devfspath(rootfs.bo_name, path + plen)
954 != DDI_SUCCESS ||
955 lookupname(path, UIO_SYSSPACE, FOLLOW, NULLVPP, &rvp)) {
956
957 /* NUL terminate in case "path" has garbage */
958 path[plen + MAXPATHLEN - 1] = '\0';
959 #ifdef DEBUG
960 cmn_err(CE_WARN, "!Cannot lookup root device: %s",
961 path);
962 #endif
963 }
964 kmem_free(path, plen + MAXPATHLEN);
965 }
966
967 vfs_mnttabvp_setup();
968 }
969
970 /*
971 * Check to see if our "block device" is actually a file. If so,
972 * automatically add a lofi device, and keep track of this fact.
973 */
974 static int
975 lofi_add(const char *fsname, struct vfs *vfsp,
976 mntopts_t *mntopts, struct mounta *uap)
977 {
978 int fromspace = (uap->flags & MS_SYSSPACE) ?
979 UIO_SYSSPACE : UIO_USERSPACE;
980 struct lofi_ioctl *li = NULL;
981 struct vnode *vp = NULL;
982 struct pathname pn = { NULL };
983 ldi_ident_t ldi_id;
984 ldi_handle_t ldi_hdl;
985 vfssw_t *vfssw;
986 int minor;
987 int err = 0;
988
989 if ((vfssw = vfs_getvfssw(fsname)) == NULL)
990 return (0);
991
992 if (!(vfssw->vsw_flag & VSW_CANLOFI)) {
993 vfs_unrefvfssw(vfssw);
994 return (0);
995 }
996
997 vfs_unrefvfssw(vfssw);
998 vfssw = NULL;
999
1000 if (pn_get(uap->spec, fromspace, &pn) != 0)
1001 return (0);
1002
1003 if (lookupname(uap->spec, fromspace, FOLLOW, NULL, &vp) != 0)
1004 goto out;
1005
1006 if (vp->v_type != VREG)
1007 goto out;
1008
1009 /* OK, this is a lofi mount. */
1010
1011 if ((uap->flags & (MS_REMOUNT|MS_GLOBAL)) ||
1012 vfs_optionisset_nolock(mntopts, MNTOPT_SUID, NULL) ||
1013 vfs_optionisset_nolock(mntopts, MNTOPT_SETUID, NULL) ||
1014 vfs_optionisset_nolock(mntopts, MNTOPT_DEVICES, NULL)) {
1015 err = EINVAL;
1016 goto out;
1017 }
1018
1019 ldi_id = ldi_ident_from_anon();
1020 li = kmem_zalloc(sizeof (*li), KM_SLEEP);
1021 (void) strlcpy(li->li_filename, pn.pn_path, MAXPATHLEN);
1022
1023 err = ldi_open_by_name("/dev/lofictl", FREAD | FWRITE, kcred,
1024 &ldi_hdl, ldi_id);
1025
1026 if (err)
1027 goto out2;
1028
1029 err = ldi_ioctl(ldi_hdl, LOFI_MAP_FILE, (intptr_t)li,
1030 FREAD | FWRITE | FKIOCTL, kcred, &minor);
1031
1032 (void) ldi_close(ldi_hdl, FREAD | FWRITE, kcred);
1033
1034 if (!err)
1035 vfsp->vfs_lofi_minor = minor;
1036
1037 out2:
1038 ldi_ident_release(ldi_id);
1039 out:
1040 if (li != NULL)
1041 kmem_free(li, sizeof (*li));
1042 if (vp != NULL)
1043 VN_RELE(vp);
1044 pn_free(&pn);
1045 return (err);
1046 }
1047
1048 static void
1049 lofi_remove(struct vfs *vfsp)
1050 {
1051 struct lofi_ioctl *li = NULL;
1052 ldi_ident_t ldi_id;
1053 ldi_handle_t ldi_hdl;
1054 int err;
1055
1056 if (vfsp->vfs_lofi_minor == 0)
1057 return;
1058
1059 ldi_id = ldi_ident_from_anon();
1060
1061 li = kmem_zalloc(sizeof (*li), KM_SLEEP);
1062 li->li_minor = vfsp->vfs_lofi_minor;
1063 li->li_cleanup = B_TRUE;
1064
1065 err = ldi_open_by_name("/dev/lofictl", FREAD | FWRITE, kcred,
1066 &ldi_hdl, ldi_id);
1067
1068 if (err)
1069 goto out;
1070
1071 err = ldi_ioctl(ldi_hdl, LOFI_UNMAP_FILE_MINOR, (intptr_t)li,
1072 FREAD | FWRITE | FKIOCTL, kcred, NULL);
1073
1074 (void) ldi_close(ldi_hdl, FREAD | FWRITE, kcred);
1075
1076 if (!err)
1077 vfsp->vfs_lofi_minor = 0;
1078
1079 out:
1080 ldi_ident_release(ldi_id);
1081 if (li != NULL)
1082 kmem_free(li, sizeof (*li));
1083 }
1084
1085 /*
1086 * Common mount code. Called from the system call entry point, from autofs,
1087 * nfsv4 trigger mounts, and from pxfs.
1088 *
1089 * Takes the effective file system type, mount arguments, the mount point
1090 * vnode, flags specifying whether the mount is a remount and whether it
1091 * should be entered into the vfs list, and credentials. Fills in its vfspp
1092 * parameter with the mounted file system instance's vfs.
1093 *
1094 * Note that the effective file system type is specified as a string. It may
1095 * be null, in which case it's determined from the mount arguments, and may
1096 * differ from the type specified in the mount arguments; this is a hook to
1097 * allow interposition when instantiating file system instances.
1098 *
1099 * The caller is responsible for releasing its own hold on the mount point
1100 * vp (this routine does its own hold when necessary).
1101 * Also note that for remounts, the mount point vp should be the vnode for
1102 * the root of the file system rather than the vnode that the file system
1103 * is mounted on top of.
1104 */
1105 int
1106 domount(char *fsname, struct mounta *uap, vnode_t *vp, struct cred *credp,
1107 struct vfs **vfspp)
1108 {
1109 struct vfssw *vswp;
1110 vfsops_t *vfsops;
1111 struct vfs *vfsp;
1112 struct vnode *bvp;
1113 dev_t bdev = 0;
1114 mntopts_t mnt_mntopts;
1115 int error = 0;
1116 int copyout_error = 0;
1117 int ovflags;
1118 char *opts = uap->optptr;
1119 char *inargs = opts;
1120 int optlen = uap->optlen;
1121 int remount;
1122 int rdonly;
1123 int nbmand = 0;
1124 int delmip = 0;
1125 int addmip = 0;
1126 int splice = ((uap->flags & MS_NOSPLICE) == 0);
1127 int fromspace = (uap->flags & MS_SYSSPACE) ?
1128 UIO_SYSSPACE : UIO_USERSPACE;
1129 char *resource = NULL, *mountpt = NULL;
1130 refstr_t *oldresource, *oldmntpt;
1131 struct pathname pn, rpn;
1132 vsk_anchor_t *vskap;
1133 char fstname[FSTYPSZ];
1134
1135 /*
1136 * The v_flag value for the mount point vp is permanently set
1137 * to VVFSLOCK so that no one bypasses the vn_vfs*locks routine
1138 * for mount point locking.
1139 */
1140 mutex_enter(&vp->v_lock);
1141 vp->v_flag |= VVFSLOCK;
1142 mutex_exit(&vp->v_lock);
1143
1144 mnt_mntopts.mo_count = 0;
1145 /*
1146 * Find the ops vector to use to invoke the file system-specific mount
1147 * method. If the fsname argument is non-NULL, use it directly.
1148 * Otherwise, dig the file system type information out of the mount
1149 * arguments.
1150 *
1151 * A side effect is to hold the vfssw entry.
1152 *
1153 * Mount arguments can be specified in several ways, which are
1154 * distinguished by flag bit settings. The preferred way is to set
1155 * MS_OPTIONSTR, indicating an 8 argument mount with the file system
1156 * type supplied as a character string and the last two arguments
1157 * being a pointer to a character buffer and the size of the buffer.
1158 * On entry, the buffer holds a null terminated list of options; on
1159 * return, the string is the list of options the file system
1160 * recognized. If MS_DATA is set arguments five and six point to a
1161 * block of binary data which the file system interprets.
1162 * A further wrinkle is that some callers don't set MS_FSS and MS_DATA
1163 * consistently with these conventions. To handle them, we check to
1164 * see whether the pointer to the file system name has a numeric value
1165 * less than 256. If so, we treat it as an index.
1166 */
1167 if (fsname != NULL) {
1168 if ((vswp = vfs_getvfssw(fsname)) == NULL) {
1169 return (EINVAL);
1170 }
1171 } else if (uap->flags & (MS_OPTIONSTR | MS_DATA | MS_FSS)) {
1172 size_t n;
1173 uint_t fstype;
1174
1175 fsname = fstname;
1176
1177 if ((fstype = (uintptr_t)uap->fstype) < 256) {
1178 RLOCK_VFSSW();
1179 if (fstype == 0 || fstype >= nfstype ||
1180 !ALLOCATED_VFSSW(&vfssw[fstype])) {
1181 RUNLOCK_VFSSW();
1182 return (EINVAL);
1183 }
1184 (void) strcpy(fsname, vfssw[fstype].vsw_name);
1185 RUNLOCK_VFSSW();
1186 if ((vswp = vfs_getvfssw(fsname)) == NULL)
1187 return (EINVAL);
1188 } else {
1189 /*
1190 * Handle either kernel or user address space.
1191 */
1192 if (uap->flags & MS_SYSSPACE) {
1193 error = copystr(uap->fstype, fsname,
1194 FSTYPSZ, &n);
1195 } else {
1196 error = copyinstr(uap->fstype, fsname,
1197 FSTYPSZ, &n);
1198 }
1199 if (error) {
1200 if (error == ENAMETOOLONG)
1201 return (EINVAL);
1202 return (error);
1203 }
1204 if ((vswp = vfs_getvfssw(fsname)) == NULL)
1205 return (EINVAL);
1206 }
1207 } else {
1208 if ((vswp = vfs_getvfsswbyvfsops(vfs_getops(rootvfs))) == NULL)
1209 return (EINVAL);
1210 fsname = vswp->vsw_name;
1211 }
1212 if (!VFS_INSTALLED(vswp))
1213 return (EINVAL);
1214
1215 if ((error = secpolicy_fs_allowed_mount(fsname)) != 0) {
1216 vfs_unrefvfssw(vswp);
1217 return (error);
1218 }
1219
1220 vfsops = &vswp->vsw_vfsops;
1221
1222 vfs_copyopttbl(&vswp->vsw_optproto, &mnt_mntopts);
1223 /*
1224 * Fetch mount options and parse them for generic vfs options
1225 */
1226 if (uap->flags & MS_OPTIONSTR) {
1227 /*
1228 * Limit the buffer size
1229 */
1230 if (optlen < 0 || optlen > MAX_MNTOPT_STR) {
1231 error = EINVAL;
1232 goto errout;
1233 }
1234 if ((uap->flags & MS_SYSSPACE) == 0) {
1235 inargs = kmem_alloc(MAX_MNTOPT_STR, KM_SLEEP);
1236 inargs[0] = '\0';
1237 if (optlen) {
1238 error = copyinstr(opts, inargs, (size_t)optlen,
1239 NULL);
1240 if (error) {
1241 goto errout;
1242 }
1243 }
1244 }
1245 vfs_parsemntopts(&mnt_mntopts, inargs, 0);
1246 }
1247 /*
1248 * Flag bits override the options string.
1249 */
1250 if (uap->flags & MS_REMOUNT)
1251 vfs_setmntopt_nolock(&mnt_mntopts, MNTOPT_REMOUNT, NULL, 0, 0);
1252 if (uap->flags & MS_RDONLY)
1253 vfs_setmntopt_nolock(&mnt_mntopts, MNTOPT_RO, NULL, 0, 0);
1254 if (uap->flags & MS_NOSUID)
1255 vfs_setmntopt_nolock(&mnt_mntopts, MNTOPT_NOSUID, NULL, 0, 0);
1256
1257 /*
1258 * Check if this is a remount; must be set in the option string and
1259 * the file system must support a remount option.
1260 */
1261 if (remount = vfs_optionisset_nolock(&mnt_mntopts,
1262 MNTOPT_REMOUNT, NULL)) {
1263 if (!(vswp->vsw_flag & VSW_CANREMOUNT)) {
1264 error = ENOTSUP;
1265 goto errout;
1266 }
1267 uap->flags |= MS_REMOUNT;
1268 }
1269
1270 /*
1271 * uap->flags and vfs_optionisset() should agree.
1272 */
1273 if (rdonly = vfs_optionisset_nolock(&mnt_mntopts, MNTOPT_RO, NULL)) {
1274 uap->flags |= MS_RDONLY;
1275 }
1276 if (vfs_optionisset_nolock(&mnt_mntopts, MNTOPT_NOSUID, NULL)) {
1277 uap->flags |= MS_NOSUID;
1278 }
1279 nbmand = vfs_optionisset_nolock(&mnt_mntopts, MNTOPT_NBMAND, NULL);
1280 ASSERT(splice || !remount);
1281 /*
1282 * If we are splicing the fs into the namespace,
1283 * perform mount point checks.
1284 *
1285 * We want to resolve the path for the mount point to eliminate
1286 * '.' and ".." and symlinks in mount points; we can't do the
1287 * same for the resource string, since it would turn
1288 * "/dev/dsk/c0t0d0s0" into "/devices/pci@...". We need to do
1289 * this before grabbing vn_vfswlock(), because otherwise we
1290 * would deadlock with lookuppn().
1291 */
1292 if (splice) {
1293 ASSERT(vp->v_count > 0);
1294
1295 /*
1296 * Pick up mount point and device from appropriate space.
1297 */
1298 if (pn_get(uap->spec, fromspace, &pn) == 0) {
1299 resource = kmem_alloc(pn.pn_pathlen + 1,
1300 KM_SLEEP);
1301 (void) strcpy(resource, pn.pn_path);
1302 pn_free(&pn);
1303 }
1304 /*
1305 * Do a lookupname prior to taking the
1306 * writelock. Mark this as completed if
1307 * successful for later cleanup and addition to
1308 * the mount in progress table.
1309 */
1310 if ((uap->flags & MS_GLOBAL) == 0 &&
1311 lookupname(uap->spec, fromspace,
1312 FOLLOW, NULL, &bvp) == 0) {
1313 addmip = 1;
1314 }
1315
1316 if ((error = pn_get(uap->dir, fromspace, &pn)) == 0) {
1317 pathname_t *pnp;
1318
1319 if (*pn.pn_path != '/') {
1320 error = EINVAL;
1321 pn_free(&pn);
1322 goto errout;
1323 }
1324 pn_alloc(&rpn);
1325 /*
1326 * Kludge to prevent autofs from deadlocking with
1327 * itself when it calls domount().
1328 *
1329 * If autofs is calling, it is because it is doing
1330 * (autofs) mounts in the process of an NFS mount. A
1331 * lookuppn() here would cause us to block waiting for
1332 * said NFS mount to complete, which can't since this
1333 * is the thread that was supposed to doing it.
1334 */
1335 if (fromspace == UIO_USERSPACE) {
1336 if ((error = lookuppn(&pn, &rpn, FOLLOW, NULL,
1337 NULL)) == 0) {
1338 pnp = &rpn;
1339 } else {
1340 /*
1341 * The file disappeared or otherwise
1342 * became inaccessible since we opened
1343 * it; might as well fail the mount
1344 * since the mount point is no longer
1345 * accessible.
1346 */
1347 pn_free(&rpn);
1348 pn_free(&pn);
1349 goto errout;
1350 }
1351 } else {
1352 pnp = &pn;
1353 }
1354 mountpt = kmem_alloc(pnp->pn_pathlen + 1, KM_SLEEP);
1355 (void) strcpy(mountpt, pnp->pn_path);
1356
1357 /*
1358 * If the addition of the zone's rootpath
1359 * would push us over a total path length
1360 * of MAXPATHLEN, we fail the mount with
1361 * ENAMETOOLONG, which is what we would have
1362 * gotten if we were trying to perform the same
1363 * mount in the global zone.
1364 *
1365 * strlen() doesn't count the trailing
1366 * '\0', but zone_rootpathlen counts both a
1367 * trailing '/' and the terminating '\0'.
1368 */
1369 if ((curproc->p_zone->zone_rootpathlen - 1 +
1370 strlen(mountpt)) > MAXPATHLEN ||
1371 (resource != NULL &&
1372 (curproc->p_zone->zone_rootpathlen - 1 +
1373 strlen(resource)) > MAXPATHLEN)) {
1374 error = ENAMETOOLONG;
1375 }
1376
1377 pn_free(&rpn);
1378 pn_free(&pn);
1379 }
1380
1381 if (error)
1382 goto errout;
1383
1384 /*
1385 * Prevent path name resolution from proceeding past
1386 * the mount point.
1387 */
1388 if (vn_vfswlock(vp) != 0) {
1389 error = EBUSY;
1390 goto errout;
1391 }
1392
1393 /*
1394 * Verify that it's legitimate to establish a mount on
1395 * the prospective mount point.
1396 */
1397 if (vn_mountedvfs(vp) != NULL) {
1398 /*
1399 * The mount point lock was obtained after some
1400 * other thread raced through and established a mount.
1401 */
1402 vn_vfsunlock(vp);
1403 error = EBUSY;
1404 goto errout;
1405 }
1406 if (vp->v_flag & VNOMOUNT) {
1407 vn_vfsunlock(vp);
1408 error = EINVAL;
1409 goto errout;
1410 }
1411 }
1412 if ((uap->flags & (MS_DATA | MS_OPTIONSTR)) == 0) {
1413 uap->dataptr = NULL;
1414 uap->datalen = 0;
1415 }
1416
1417 /*
1418 * If this is a remount, we don't want to create a new VFS.
1419 * Instead, we pass the existing one with a remount flag.
1420 */
1421 if (remount) {
1422 /*
1423 * Confirm that the mount point is the root vnode of the
1424 * file system that is being remounted.
1425 * This can happen if the user specifies a different
1426 * mount point directory pathname in the (re)mount command.
1427 *
1428 * Code below can only be reached if splice is true, so it's
1429 * safe to do vn_vfsunlock() here.
1430 */
1431 if ((vp->v_flag & VROOT) == 0) {
1432 vn_vfsunlock(vp);
1433 error = ENOENT;
1434 goto errout;
1435 }
1436 /*
1437 * Disallow making file systems read-only unless file system
1438 * explicitly allows it in its vfssw. Ignore other flags.
1439 */
1440 if (rdonly && vn_is_readonly(vp) == 0 &&
1441 (vswp->vsw_flag & VSW_CANRWRO) == 0) {
1442 vn_vfsunlock(vp);
1443 error = EINVAL;
1444 goto errout;
1445 }
1446 /*
1447 * Disallow changing the NBMAND disposition of the file
1448 * system on remounts.
1449 */
1450 if ((nbmand && ((vp->v_vfsp->vfs_flag & VFS_NBMAND) == 0)) ||
1451 (!nbmand && (vp->v_vfsp->vfs_flag & VFS_NBMAND))) {
1452 vn_vfsunlock(vp);
1453 error = EINVAL;
1454 goto errout;
1455 }
1456 vfsp = vp->v_vfsp;
1457 ovflags = vfsp->vfs_flag;
1458 vfsp->vfs_flag |= VFS_REMOUNT;
1459 vfsp->vfs_flag &= ~VFS_RDONLY;
1460 } else {
1461 vfsp = vfs_alloc(KM_SLEEP);
1462 VFS_INIT(vfsp, vfsops, NULL);
1463 }
1464
1465 VFS_HOLD(vfsp);
1466
1467 if ((error = lofi_add(fsname, vfsp, &mnt_mntopts, uap)) != 0) {
1468 if (!remount) {
1469 if (splice)
1470 vn_vfsunlock(vp);
1471 vfs_free(vfsp);
1472 } else {
1473 vn_vfsunlock(vp);
1474 VFS_RELE(vfsp);
1475 }
1476 goto errout;
1477 }
1478
1479 /*
1480 * PRIV_SYS_MOUNT doesn't mean you can become root.
1481 */
1482 if (vfsp->vfs_lofi_minor != 0) {
1483 uap->flags |= MS_NOSUID;
1484 vfs_setmntopt_nolock(&mnt_mntopts, MNTOPT_NOSUID, NULL, 0, 0);
1485 }
1486
1487 /*
1488 * The vfs_reflock is not used anymore the code below explicitly
1489 * holds it preventing others accesing it directly.
1490 */
1491 if ((sema_tryp(&vfsp->vfs_reflock) == 0) &&
1492 !(vfsp->vfs_flag & VFS_REMOUNT))
1493 cmn_err(CE_WARN,
1494 "mount type %s couldn't get vfs_reflock", vswp->vsw_name);
1495
1496 /*
1497 * Lock the vfs. If this is a remount we want to avoid spurious umount
1498 * failures that happen as a side-effect of fsflush() and other mount
1499 * and unmount operations that might be going on simultaneously and
1500 * may have locked the vfs currently. To not return EBUSY immediately
1501 * here we use vfs_lock_wait() instead vfs_lock() for the remount case.
1502 */
1503 if (!remount) {
1504 if (error = vfs_lock(vfsp)) {
1505 vfsp->vfs_flag = ovflags;
1506
1507 lofi_remove(vfsp);
1508
1509 if (splice)
1510 vn_vfsunlock(vp);
1511 vfs_free(vfsp);
1512 goto errout;
1513 }
1514 } else {
1515 vfs_lock_wait(vfsp);
1516 }
1517
1518 /*
1519 * Add device to mount in progress table, global mounts require special
1520 * handling. It is possible that we have already done the lookupname
1521 * on a spliced, non-global fs. If so, we don't want to do it again
1522 * since we cannot do a lookupname after taking the
1523 * wlock above. This case is for a non-spliced, non-global filesystem.
1524 */
1525 if (!addmip) {
1526 if ((uap->flags & MS_GLOBAL) == 0 &&
1527 lookupname(uap->spec, fromspace, FOLLOW, NULL, &bvp) == 0) {
1528 addmip = 1;
1529 }
1530 }
1531
1532 if (addmip) {
1533 vnode_t *lvp = NULL;
1534
1535 error = vfs_get_lofi(vfsp, &lvp);
1536 if (error > 0) {
1537 lofi_remove(vfsp);
1538
1539 if (splice)
1540 vn_vfsunlock(vp);
1541 vfs_unlock(vfsp);
1542
1543 if (remount) {
1544 VFS_RELE(vfsp);
1545 } else {
1546 vfs_free(vfsp);
1547 }
1548
1549 goto errout;
1550 } else if (error == -1) {
1551 bdev = bvp->v_rdev;
1552 VN_RELE(bvp);
1553 } else {
1554 bdev = lvp->v_rdev;
1555 VN_RELE(lvp);
1556 VN_RELE(bvp);
1557 }
1558
1559 vfs_addmip(bdev, vfsp);
1560 addmip = 0;
1561 delmip = 1;
1562 }
1563 /*
1564 * Invalidate cached entry for the mount point.
1565 */
1566 if (splice)
1567 dnlc_purge_vp(vp);
1568
1569 /*
1570 * If have an option string but the filesystem doesn't supply a
1571 * prototype options table, create a table with the global
1572 * options and sufficient room to accept all the options in the
1573 * string. Then parse the passed in option string
1574 * accepting all the options in the string. This gives us an
1575 * option table with all the proper cancel properties for the
1576 * global options.
1577 *
1578 * Filesystems that supply a prototype options table are handled
1579 * earlier in this function.
1580 */
1581 if (uap->flags & MS_OPTIONSTR) {
1582 if (!(vswp->vsw_flag & VSW_HASPROTO)) {
1583 mntopts_t tmp_mntopts;
1584
1585 tmp_mntopts.mo_count = 0;
1586 vfs_createopttbl_extend(&tmp_mntopts, inargs,
1587 &mnt_mntopts);
1588 vfs_parsemntopts(&tmp_mntopts, inargs, 1);
1589 vfs_swapopttbl_nolock(&mnt_mntopts, &tmp_mntopts);
1590 vfs_freeopttbl(&tmp_mntopts);
1591 }
1592 }
1593
1594 /*
1595 * Serialize with zone creations.
1596 */
1597 mount_in_progress();
1598 /*
1599 * Instantiate (or reinstantiate) the file system. If appropriate,
1600 * splice it into the file system name space.
1601 *
1602 * We want VFS_MOUNT() to be able to override the vfs_resource
1603 * string if necessary (ie, mntfs), and also for a remount to
1604 * change the same (necessary when remounting '/' during boot).
1605 * So we set up vfs_mntpt and vfs_resource to what we think they
1606 * should be, then hand off control to VFS_MOUNT() which can
1607 * override this.
1608 *
1609 * For safety's sake, when changing vfs_resource or vfs_mntpt of
1610 * a vfs which is on the vfs list (i.e. during a remount), we must
1611 * never set those fields to NULL. Several bits of code make
1612 * assumptions that the fields are always valid.
1613 */
1614 vfs_swapopttbl(&mnt_mntopts, &vfsp->vfs_mntopts);
1615 if (remount) {
1616 if ((oldresource = vfsp->vfs_resource) != NULL)
1617 refstr_hold(oldresource);
1618 if ((oldmntpt = vfsp->vfs_mntpt) != NULL)
1619 refstr_hold(oldmntpt);
1620 }
1621 vfs_setresource(vfsp, resource, 0);
1622 vfs_setmntpoint(vfsp, mountpt, 0);
1623
1624 /*
1625 * going to mount on this vnode, so notify.
1626 */
1627 vnevent_mountedover(vp, NULL);
1628 error = VFS_MOUNT(vfsp, vp, uap, credp);
1629
1630 if (uap->flags & MS_RDONLY)
1631 vfs_setmntopt(vfsp, MNTOPT_RO, NULL, 0);
1632 if (uap->flags & MS_NOSUID)
1633 vfs_setmntopt(vfsp, MNTOPT_NOSUID, NULL, 0);
1634 if (uap->flags & MS_GLOBAL)
1635 vfs_setmntopt(vfsp, MNTOPT_GLOBAL, NULL, 0);
1636
1637 if (error) {
1638 lofi_remove(vfsp);
1639
1640 if (remount) {
1641 /* put back pre-remount options */
1642 vfs_swapopttbl(&mnt_mntopts, &vfsp->vfs_mntopts);
1643 vfs_setmntpoint(vfsp, refstr_value(oldmntpt),
1644 VFSSP_VERBATIM);
1645 if (oldmntpt)
1646 refstr_rele(oldmntpt);
1647 vfs_setresource(vfsp, refstr_value(oldresource),
1648 VFSSP_VERBATIM);
1649 if (oldresource)
1650 refstr_rele(oldresource);
1651 vfsp->vfs_flag = ovflags;
1652 vfs_unlock(vfsp);
1653 VFS_RELE(vfsp);
1654 } else {
1655 vfs_unlock(vfsp);
1656 vfs_freemnttab(vfsp);
1657 vfs_free(vfsp);
1658 }
1659 } else {
1660 /*
1661 * Set the mount time to now
1662 */
1663 vfsp->vfs_mtime = ddi_get_time();
1664 if (remount) {
1665 vfsp->vfs_flag &= ~VFS_REMOUNT;
1666 if (oldresource)
1667 refstr_rele(oldresource);
1668 if (oldmntpt)
1669 refstr_rele(oldmntpt);
1670 } else if (splice) {
1671 /*
1672 * Link vfsp into the name space at the mount
1673 * point. Vfs_add() is responsible for
1674 * holding the mount point which will be
1675 * released when vfs_remove() is called.
1676 */
1677 vfs_add(vp, vfsp, uap->flags);
1678 } else {
1679 /*
1680 * Hold the reference to file system which is
1681 * not linked into the name space.
1682 */
1683 vfsp->vfs_zone = NULL;
1684 VFS_HOLD(vfsp);
1685 vfsp->vfs_vnodecovered = NULL;
1686 }
1687 /*
1688 * Set flags for global options encountered
1689 */
1690 if (vfs_optionisset(vfsp, MNTOPT_RO, NULL))
1691 vfsp->vfs_flag |= VFS_RDONLY;
1692 else
1693 vfsp->vfs_flag &= ~VFS_RDONLY;
1694 if (vfs_optionisset(vfsp, MNTOPT_NOSUID, NULL)) {
1695 vfsp->vfs_flag |= (VFS_NOSETUID|VFS_NODEVICES);
1696 } else {
1697 if (vfs_optionisset(vfsp, MNTOPT_NODEVICES, NULL))
1698 vfsp->vfs_flag |= VFS_NODEVICES;
1699 else
1700 vfsp->vfs_flag &= ~VFS_NODEVICES;
1701 if (vfs_optionisset(vfsp, MNTOPT_NOSETUID, NULL))
1702 vfsp->vfs_flag |= VFS_NOSETUID;
1703 else
1704 vfsp->vfs_flag &= ~VFS_NOSETUID;
1705 }
1706 if (vfs_optionisset(vfsp, MNTOPT_NBMAND, NULL))
1707 vfsp->vfs_flag |= VFS_NBMAND;
1708 else
1709 vfsp->vfs_flag &= ~VFS_NBMAND;
1710
1711 if (vfs_optionisset(vfsp, MNTOPT_XATTR, NULL))
1712 vfsp->vfs_flag |= VFS_XATTR;
1713 else
1714 vfsp->vfs_flag &= ~VFS_XATTR;
1715
1716 if (vfs_optionisset(vfsp, MNTOPT_NOEXEC, NULL))
1717 vfsp->vfs_flag |= VFS_NOEXEC;
1718 else
1719 vfsp->vfs_flag &= ~VFS_NOEXEC;
1720
1721 /*
1722 * Now construct the output option string of options
1723 * we recognized.
1724 */
1725 if (uap->flags & MS_OPTIONSTR) {
1726 vfs_list_read_lock();
1727 copyout_error = vfs_buildoptionstr(
1728 &vfsp->vfs_mntopts, inargs, optlen);
1729 vfs_list_unlock();
1730 if (copyout_error == 0 &&
1731 (uap->flags & MS_SYSSPACE) == 0) {
1732 copyout_error = copyoutstr(inargs, opts,
1733 optlen, NULL);
1734 }
1735 }
1736
1737 /*
1738 * If this isn't a remount, set up the vopstats before
1739 * anyone can touch this. We only allow spliced file
1740 * systems (file systems which are in the namespace) to
1741 * have the VFS_STATS flag set.
1742 * NOTE: PxFS mounts the underlying file system with
1743 * MS_NOSPLICE set and copies those vfs_flags to its private
1744 * vfs structure. As a result, PxFS should never have
1745 * the VFS_STATS flag or else we might access the vfs
1746 * statistics-related fields prior to them being
1747 * properly initialized.
1748 */
1749 if (!remount && (vswp->vsw_flag & VSW_STATS) && splice) {
1750 initialize_vopstats(&vfsp->vfs_vopstats);
1751 /*
1752 * We need to set vfs_vskap to NULL because there's
1753 * a chance it won't be set below. This is checked
1754 * in teardown_vopstats() so we can't have garbage.
1755 */
1756 vfsp->vfs_vskap = NULL;
1757 vfsp->vfs_flag |= VFS_STATS;
1758 vfsp->vfs_fstypevsp = get_fstype_vopstats(vfsp, vswp);
1759 }
1760
1761 if (vswp->vsw_flag & VSW_XID)
1762 vfsp->vfs_flag |= VFS_XID;
1763
1764 vfs_unlock(vfsp);
1765 }
1766 mount_completed();
1767 if (splice)
1768 vn_vfsunlock(vp);
1769
1770 if ((error == 0) && (copyout_error == 0)) {
1771 if (!remount) {
1772 /*
1773 * Don't call get_vskstat_anchor() while holding
1774 * locks since it allocates memory and calls
1775 * VFS_STATVFS(). For NFS, the latter can generate
1776 * an over-the-wire call.
1777 */
1778 vskap = get_vskstat_anchor(vfsp);
1779 /* Only take the lock if we have something to do */
1780 if (vskap != NULL) {
1781 vfs_lock_wait(vfsp);
1782 if (vfsp->vfs_flag & VFS_STATS) {
1783 vfsp->vfs_vskap = vskap;
1784 }
1785 vfs_unlock(vfsp);
1786 }
1787 }
1788 /* Return vfsp to caller. */
1789 *vfspp = vfsp;
1790 fsh_exec_mount_callbacks(vfsp);
1791 }
1792 errout:
1793 vfs_freeopttbl(&mnt_mntopts);
1794 if (resource != NULL)
1795 kmem_free(resource, strlen(resource) + 1);
1796 if (mountpt != NULL)
1797 kmem_free(mountpt, strlen(mountpt) + 1);
1798 /*
1799 * It is possible we errored prior to adding to mount in progress
1800 * table. Must free vnode we acquired with successful lookupname.
1801 */
1802 if (addmip)
1803 VN_RELE(bvp);
1804 if (delmip)
1805 vfs_delmip(vfsp);
1806 ASSERT(vswp != NULL);
1807 vfs_unrefvfssw(vswp);
1808 if (inargs != opts)
1809 kmem_free(inargs, MAX_MNTOPT_STR);
1810 if (copyout_error) {
1811 lofi_remove(vfsp);
1812 VFS_RELE(vfsp);
1813 error = copyout_error;
1814 }
1815 return (error);
1816 }
1817
1818 static void
1819 vfs_setpath(
1820 struct vfs *vfsp, /* vfs being updated */
1821 refstr_t **refp, /* Ref-count string to contain the new path */
1822 const char *newpath, /* Path to add to refp (above) */
1823 uint32_t flag) /* flag */
1824 {
1825 size_t len;
1826 refstr_t *ref;
1827 zone_t *zone = curproc->p_zone;
1828 char *sp;
1829 int have_list_lock = 0;
1830
1831 ASSERT(!VFS_ON_LIST(vfsp) || vfs_lock_held(vfsp));
1832
1833 /*
1834 * New path must be less than MAXPATHLEN because mntfs
1835 * will only display up to MAXPATHLEN bytes. This is currently
1836 * safe, because domount() uses pn_get(), and other callers
1837 * similarly cap the size to fewer than MAXPATHLEN bytes.
1838 */
1839
1840 ASSERT(strlen(newpath) < MAXPATHLEN);
1841
1842 /* mntfs requires consistency while vfs list lock is held */
1843
1844 if (VFS_ON_LIST(vfsp)) {
1845 have_list_lock = 1;
1846 vfs_list_lock();
1847 }
1848
1849 if (*refp != NULL)
1850 refstr_rele(*refp);
1851
1852 /*
1853 * If we are in a non-global zone then we prefix the supplied path,
1854 * newpath, with the zone's root path, with two exceptions. The first
1855 * is where we have been explicitly directed to avoid doing so; this
1856 * will be the case following a failed remount, where the path supplied
1857 * will be a saved version which must now be restored. The second
1858 * exception is where newpath is not a pathname but a descriptive name,
1859 * e.g. "procfs".
1860 */
1861 if (zone == global_zone || (flag & VFSSP_VERBATIM) || *newpath != '/') {
1862 ref = refstr_alloc(newpath);
1863 goto out;
1864 }
1865
1866 /*
1867 * Truncate the trailing '/' in the zoneroot, and merge
1868 * in the zone's rootpath with the "newpath" (resource
1869 * or mountpoint) passed in.
1870 *
1871 * The size of the required buffer is thus the size of
1872 * the buffer required for the passed-in newpath
1873 * (strlen(newpath) + 1), plus the size of the buffer
1874 * required to hold zone_rootpath (zone_rootpathlen)
1875 * minus one for one of the now-superfluous NUL
1876 * terminations, minus one for the trailing '/'.
1877 *
1878 * That gives us:
1879 *
1880 * (strlen(newpath) + 1) + zone_rootpathlen - 1 - 1
1881 *
1882 * Which is what we have below.
1883 */
1884
1885 len = strlen(newpath) + zone->zone_rootpathlen - 1;
1886 sp = kmem_alloc(len, KM_SLEEP);
1887
1888 /*
1889 * Copy everything including the trailing slash, which
1890 * we then overwrite with the NUL character.
1891 */
1892
1893 (void) strcpy(sp, zone->zone_rootpath);
1894 sp[zone->zone_rootpathlen - 2] = '\0';
1895 (void) strcat(sp, newpath);
1896
1897 ref = refstr_alloc(sp);
1898 kmem_free(sp, len);
1899 out:
1900 *refp = ref;
1901
1902 if (have_list_lock) {
1903 vfs_mnttab_modtimeupd();
1904 vfs_list_unlock();
1905 }
1906 }
1907
1908 /*
1909 * Record a mounted resource name in a vfs structure.
1910 * If vfsp is already mounted, caller must hold the vfs lock.
1911 */
1912 void
1913 vfs_setresource(struct vfs *vfsp, const char *resource, uint32_t flag)
1914 {
1915 if (resource == NULL || resource[0] == '\0')
1916 resource = VFS_NORESOURCE;
1917 vfs_setpath(vfsp, &vfsp->vfs_resource, resource, flag);
1918 }
1919
1920 /*
1921 * Record a mount point name in a vfs structure.
1922 * If vfsp is already mounted, caller must hold the vfs lock.
1923 */
1924 void
1925 vfs_setmntpoint(struct vfs *vfsp, const char *mntpt, uint32_t flag)
1926 {
1927 if (mntpt == NULL || mntpt[0] == '\0')
1928 mntpt = VFS_NOMNTPT;
1929 vfs_setpath(vfsp, &vfsp->vfs_mntpt, mntpt, flag);
1930 }
1931
1932 /* Returns the vfs_resource. Caller must call refstr_rele() when finished. */
1933
1934 refstr_t *
1935 vfs_getresource(const struct vfs *vfsp)
1936 {
1937 refstr_t *resource;
1938
1939 vfs_list_read_lock();
1940 resource = vfsp->vfs_resource;
1941 refstr_hold(resource);
1942 vfs_list_unlock();
1943
1944 return (resource);
1945 }
1946
1947 /* Returns the vfs_mntpt. Caller must call refstr_rele() when finished. */
1948
1949 refstr_t *
1950 vfs_getmntpoint(const struct vfs *vfsp)
1951 {
1952 refstr_t *mntpt;
1953
1954 vfs_list_read_lock();
1955 mntpt = vfsp->vfs_mntpt;
1956 refstr_hold(mntpt);
1957 vfs_list_unlock();
1958
1959 return (mntpt);
1960 }
1961
1962 /*
1963 * Create an empty options table with enough empty slots to hold all
1964 * The options in the options string passed as an argument.
1965 * Potentially prepend another options table.
1966 *
1967 * Note: caller is responsible for locking the vfs list, if needed,
1968 * to protect mops.
1969 */
1970 static void
1971 vfs_createopttbl_extend(mntopts_t *mops, const char *opts,
1972 const mntopts_t *mtmpl)
1973 {
1974 const char *s = opts;
1975 uint_t count;
1976
1977 if (opts == NULL || *opts == '\0') {
1978 count = 0;
1979 } else {
1980 count = 1;
1981
1982 /*
1983 * Count number of options in the string
1984 */
1985 for (s = strchr(s, ','); s != NULL; s = strchr(s, ',')) {
1986 count++;
1987 s++;
1988 }
1989 }
1990 vfs_copyopttbl_extend(mtmpl, mops, count);
1991 }
1992
1993 /*
1994 * Create an empty options table with enough empty slots to hold all
1995 * The options in the options string passed as an argument.
1996 *
1997 * This function is *not* for general use by filesystems.
1998 *
1999 * Note: caller is responsible for locking the vfs list, if needed,
2000 * to protect mops.
2001 */
2002 void
2003 vfs_createopttbl(mntopts_t *mops, const char *opts)
2004 {
2005 vfs_createopttbl_extend(mops, opts, NULL);
2006 }
2007
2008
2009 /*
2010 * Swap two mount options tables
2011 */
2012 static void
2013 vfs_swapopttbl_nolock(mntopts_t *optbl1, mntopts_t *optbl2)
2014 {
2015 uint_t tmpcnt;
2016 mntopt_t *tmplist;
2017
2018 tmpcnt = optbl2->mo_count;
2019 tmplist = optbl2->mo_list;
2020 optbl2->mo_count = optbl1->mo_count;
2021 optbl2->mo_list = optbl1->mo_list;
2022 optbl1->mo_count = tmpcnt;
2023 optbl1->mo_list = tmplist;
2024 }
2025
2026 static void
2027 vfs_swapopttbl(mntopts_t *optbl1, mntopts_t *optbl2)
2028 {
2029 vfs_list_lock();
2030 vfs_swapopttbl_nolock(optbl1, optbl2);
2031 vfs_mnttab_modtimeupd();
2032 vfs_list_unlock();
2033 }
2034
2035 static char **
2036 vfs_copycancelopt_extend(char **const moc, int extend)
2037 {
2038 int i = 0;
2039 int j;
2040 char **result;
2041
2042 if (moc != NULL) {
2043 for (; moc[i] != NULL; i++)
2044 /* count number of options to cancel */;
2045 }
2046
2047 if (i + extend == 0)
2048 return (NULL);
2049
2050 result = kmem_alloc((i + extend + 1) * sizeof (char *), KM_SLEEP);
2051
2052 for (j = 0; j < i; j++) {
2053 result[j] = kmem_alloc(strlen(moc[j]) + 1, KM_SLEEP);
2054 (void) strcpy(result[j], moc[j]);
2055 }
2056 for (; j <= i + extend; j++)
2057 result[j] = NULL;
2058
2059 return (result);
2060 }
2061
2062 static void
2063 vfs_copyopt(const mntopt_t *s, mntopt_t *d)
2064 {
2065 char *sp, *dp;
2066
2067 d->mo_flags = s->mo_flags;
2068 d->mo_data = s->mo_data;
2069 sp = s->mo_name;
2070 if (sp != NULL) {
2071 dp = kmem_alloc(strlen(sp) + 1, KM_SLEEP);
2072 (void) strcpy(dp, sp);
2073 d->mo_name = dp;
2074 } else {
2075 d->mo_name = NULL; /* should never happen */
2076 }
2077
2078 d->mo_cancel = vfs_copycancelopt_extend(s->mo_cancel, 0);
2079
2080 sp = s->mo_arg;
2081 if (sp != NULL) {
2082 dp = kmem_alloc(strlen(sp) + 1, KM_SLEEP);
2083 (void) strcpy(dp, sp);
2084 d->mo_arg = dp;
2085 } else {
2086 d->mo_arg = NULL;
2087 }
2088 }
2089
2090 /*
2091 * Copy a mount options table, possibly allocating some spare
2092 * slots at the end. It is permissible to copy_extend the NULL table.
2093 */
2094 static void
2095 vfs_copyopttbl_extend(const mntopts_t *smo, mntopts_t *dmo, int extra)
2096 {
2097 uint_t i, count;
2098 mntopt_t *motbl;
2099
2100 /*
2101 * Clear out any existing stuff in the options table being initialized
2102 */
2103 vfs_freeopttbl(dmo);
2104 count = (smo == NULL) ? 0 : smo->mo_count;
2105 if ((count + extra) == 0) /* nothing to do */
2106 return;
2107 dmo->mo_count = count + extra;
2108 motbl = kmem_zalloc((count + extra) * sizeof (mntopt_t), KM_SLEEP);
2109 dmo->mo_list = motbl;
2110 for (i = 0; i < count; i++) {
2111 vfs_copyopt(&smo->mo_list[i], &motbl[i]);
2112 }
2113 for (i = count; i < count + extra; i++) {
2114 motbl[i].mo_flags = MO_EMPTY;
2115 }
2116 }
2117
2118 /*
2119 * Copy a mount options table.
2120 *
2121 * This function is *not* for general use by filesystems.
2122 *
2123 * Note: caller is responsible for locking the vfs list, if needed,
2124 * to protect smo and dmo.
2125 */
2126 void
2127 vfs_copyopttbl(const mntopts_t *smo, mntopts_t *dmo)
2128 {
2129 vfs_copyopttbl_extend(smo, dmo, 0);
2130 }
2131
2132 static char **
2133 vfs_mergecancelopts(const mntopt_t *mop1, const mntopt_t *mop2)
2134 {
2135 int c1 = 0;
2136 int c2 = 0;
2137 char **result;
2138 char **sp1, **sp2, **dp;
2139
2140 /*
2141 * First we count both lists of cancel options.
2142 * If either is NULL or has no elements, we return a copy of
2143 * the other.
2144 */
2145 if (mop1->mo_cancel != NULL) {
2146 for (; mop1->mo_cancel[c1] != NULL; c1++)
2147 /* count cancel options in mop1 */;
2148 }
2149
2150 if (c1 == 0)
2151 return (vfs_copycancelopt_extend(mop2->mo_cancel, 0));
2152
2153 if (mop2->mo_cancel != NULL) {
2154 for (; mop2->mo_cancel[c2] != NULL; c2++)
2155 /* count cancel options in mop2 */;
2156 }
2157
2158 result = vfs_copycancelopt_extend(mop1->mo_cancel, c2);
2159
2160 if (c2 == 0)
2161 return (result);
2162
2163 /*
2164 * When we get here, we've got two sets of cancel options;
2165 * we need to merge the two sets. We know that the result
2166 * array has "c1+c2+1" entries and in the end we might shrink
2167 * it.
2168 * Result now has a copy of the c1 entries from mop1; we'll
2169 * now lookup all the entries of mop2 in mop1 and copy it if
2170 * it is unique.
2171 * This operation is O(n^2) but it's only called once per
2172 * filesystem per duplicate option. This is a situation
2173 * which doesn't arise with the filesystems in ON and
2174 * n is generally 1.
2175 */
2176
2177 dp = &result[c1];
2178 for (sp2 = mop2->mo_cancel; *sp2 != NULL; sp2++) {
2179 for (sp1 = mop1->mo_cancel; *sp1 != NULL; sp1++) {
2180 if (strcmp(*sp1, *sp2) == 0)
2181 break;
2182 }
2183 if (*sp1 == NULL) {
2184 /*
2185 * Option *sp2 not found in mop1, so copy it.
2186 * The calls to vfs_copycancelopt_extend()
2187 * guarantee that there's enough room.
2188 */
2189 *dp = kmem_alloc(strlen(*sp2) + 1, KM_SLEEP);
2190 (void) strcpy(*dp++, *sp2);
2191 }
2192 }
2193 if (dp != &result[c1+c2]) {
2194 size_t bytes = (dp - result + 1) * sizeof (char *);
2195 char **nres = kmem_alloc(bytes, KM_SLEEP);
2196
2197 bcopy(result, nres, bytes);
2198 kmem_free(result, (c1 + c2 + 1) * sizeof (char *));
2199 result = nres;
2200 }
2201 return (result);
2202 }
2203
2204 /*
2205 * Merge two mount option tables (outer and inner) into one. This is very
2206 * similar to "merging" global variables and automatic variables in C.
2207 *
2208 * This isn't (and doesn't have to be) fast.
2209 *
2210 * This function is *not* for general use by filesystems.
2211 *
2212 * Note: caller is responsible for locking the vfs list, if needed,
2213 * to protect omo, imo & dmo.
2214 */
2215 void
2216 vfs_mergeopttbl(const mntopts_t *omo, const mntopts_t *imo, mntopts_t *dmo)
2217 {
2218 uint_t i, count;
2219 mntopt_t *mop, *motbl;
2220 uint_t freeidx;
2221
2222 /*
2223 * First determine how much space we need to allocate.
2224 */
2225 count = omo->mo_count;
2226 for (i = 0; i < imo->mo_count; i++) {
2227 if (imo->mo_list[i].mo_flags & MO_EMPTY)
2228 continue;
2229 if (vfs_hasopt(omo, imo->mo_list[i].mo_name) == NULL)
2230 count++;
2231 }
2232 ASSERT(count >= omo->mo_count &&
2233 count <= omo->mo_count + imo->mo_count);
2234 motbl = kmem_alloc(count * sizeof (mntopt_t), KM_SLEEP);
2235 for (i = 0; i < omo->mo_count; i++)
2236 vfs_copyopt(&omo->mo_list[i], &motbl[i]);
2237 freeidx = omo->mo_count;
2238 for (i = 0; i < imo->mo_count; i++) {
2239 if (imo->mo_list[i].mo_flags & MO_EMPTY)
2240 continue;
2241 if ((mop = vfs_hasopt(omo, imo->mo_list[i].mo_name)) != NULL) {
2242 char **newcanp;
2243 uint_t index = mop - omo->mo_list;
2244
2245 newcanp = vfs_mergecancelopts(mop, &motbl[index]);
2246
2247 vfs_freeopt(&motbl[index]);
2248 vfs_copyopt(&imo->mo_list[i], &motbl[index]);
2249
2250 vfs_freecancelopt(motbl[index].mo_cancel);
2251 motbl[index].mo_cancel = newcanp;
2252 } else {
2253 /*
2254 * If it's a new option, just copy it over to the first
2255 * free location.
2256 */
2257 vfs_copyopt(&imo->mo_list[i], &motbl[freeidx++]);
2258 }
2259 }
2260 dmo->mo_count = count;
2261 dmo->mo_list = motbl;
2262 }
2263
2264 /*
2265 * Functions to set and clear mount options in a mount options table.
2266 */
2267
2268 /*
2269 * Clear a mount option, if it exists.
2270 *
2271 * The update_mnttab arg indicates whether mops is part of a vfs that is on
2272 * the vfs list.
2273 */
2274 static void
2275 vfs_clearmntopt_nolock(mntopts_t *mops, const char *opt, int update_mnttab)
2276 {
2277 struct mntopt *mop;
2278 uint_t i, count;
2279
2280 ASSERT(!update_mnttab || RW_WRITE_HELD(&vfslist));
2281
2282 count = mops->mo_count;
2283 for (i = 0; i < count; i++) {
2284 mop = &mops->mo_list[i];
2285
2286 if (mop->mo_flags & MO_EMPTY)
2287 continue;
2288 if (strcmp(opt, mop->mo_name))
2289 continue;
2290 mop->mo_flags &= ~MO_SET;
2291 if (mop->mo_arg != NULL) {
2292 kmem_free(mop->mo_arg, strlen(mop->mo_arg) + 1);
2293 }
2294 mop->mo_arg = NULL;
2295 if (update_mnttab)
2296 vfs_mnttab_modtimeupd();
2297 break;
2298 }
2299 }
2300
2301 void
2302 vfs_clearmntopt(struct vfs *vfsp, const char *opt)
2303 {
2304 int gotlock = 0;
2305
2306 if (VFS_ON_LIST(vfsp)) {
2307 gotlock = 1;
2308 vfs_list_lock();
2309 }
2310 vfs_clearmntopt_nolock(&vfsp->vfs_mntopts, opt, gotlock);
2311 if (gotlock)
2312 vfs_list_unlock();
2313 }
2314
2315
2316 /*
2317 * Set a mount option on. If it's not found in the table, it's silently
2318 * ignored. If the option has MO_IGNORE set, it is still set unless the
2319 * VFS_NOFORCEOPT bit is set in the flags. Also, VFS_DISPLAY/VFS_NODISPLAY flag
2320 * bits can be used to toggle the MO_NODISPLAY bit for the option.
2321 * If the VFS_CREATEOPT flag bit is set then the first option slot with
2322 * MO_EMPTY set is created as the option passed in.
2323 *
2324 * The update_mnttab arg indicates whether mops is part of a vfs that is on
2325 * the vfs list.
2326 */
2327 static void
2328 vfs_setmntopt_nolock(mntopts_t *mops, const char *opt,
2329 const char *arg, int flags, int update_mnttab)
2330 {
2331 mntopt_t *mop;
2332 uint_t i, count;
2333 char *sp;
2334
2335 ASSERT(!update_mnttab || RW_WRITE_HELD(&vfslist));
2336
2337 if (flags & VFS_CREATEOPT) {
2338 if (vfs_hasopt(mops, opt) != NULL) {
2339 flags &= ~VFS_CREATEOPT;
2340 }
2341 }
2342 count = mops->mo_count;
2343 for (i = 0; i < count; i++) {
2344 mop = &mops->mo_list[i];
2345
2346 if (mop->mo_flags & MO_EMPTY) {
2347 if ((flags & VFS_CREATEOPT) == 0)
2348 continue;
2349 sp = kmem_alloc(strlen(opt) + 1, KM_SLEEP);
2350 (void) strcpy(sp, opt);
2351 mop->mo_name = sp;
2352 if (arg != NULL)
2353 mop->mo_flags = MO_HASVALUE;
2354 else
2355 mop->mo_flags = 0;
2356 } else if (strcmp(opt, mop->mo_name)) {
2357 continue;
2358 }
2359 if ((mop->mo_flags & MO_IGNORE) && (flags & VFS_NOFORCEOPT))
2360 break;
2361 if (arg != NULL && (mop->mo_flags & MO_HASVALUE) != 0) {
2362 sp = kmem_alloc(strlen(arg) + 1, KM_SLEEP);
2363 (void) strcpy(sp, arg);
2364 } else {
2365 sp = NULL;
2366 }
2367 if (mop->mo_arg != NULL)
2368 kmem_free(mop->mo_arg, strlen(mop->mo_arg) + 1);
2369 mop->mo_arg = sp;
2370 if (flags & VFS_DISPLAY)
2371 mop->mo_flags &= ~MO_NODISPLAY;
2372 if (flags & VFS_NODISPLAY)
2373 mop->mo_flags |= MO_NODISPLAY;
2374 mop->mo_flags |= MO_SET;
2375 if (mop->mo_cancel != NULL) {
2376 char **cp;
2377
2378 for (cp = mop->mo_cancel; *cp != NULL; cp++)
2379 vfs_clearmntopt_nolock(mops, *cp, 0);
2380 }
2381 if (update_mnttab)
2382 vfs_mnttab_modtimeupd();
2383 break;
2384 }
2385 }
2386
2387 void
2388 vfs_setmntopt(struct vfs *vfsp, const char *opt, const char *arg, int flags)
2389 {
2390 int gotlock = 0;
2391
2392 if (VFS_ON_LIST(vfsp)) {
2393 gotlock = 1;
2394 vfs_list_lock();
2395 }
2396 vfs_setmntopt_nolock(&vfsp->vfs_mntopts, opt, arg, flags, gotlock);
2397 if (gotlock)
2398 vfs_list_unlock();
2399 }
2400
2401
2402 /*
2403 * Add a "tag" option to a mounted file system's options list.
2404 *
2405 * Note: caller is responsible for locking the vfs list, if needed,
2406 * to protect mops.
2407 */
2408 static mntopt_t *
2409 vfs_addtag(mntopts_t *mops, const char *tag)
2410 {
2411 uint_t count;
2412 mntopt_t *mop, *motbl;
2413
2414 count = mops->mo_count + 1;
2415 motbl = kmem_zalloc(count * sizeof (mntopt_t), KM_SLEEP);
2416 if (mops->mo_count) {
2417 size_t len = (count - 1) * sizeof (mntopt_t);
2418
2419 bcopy(mops->mo_list, motbl, len);
2420 kmem_free(mops->mo_list, len);
2421 }
2422 mops->mo_count = count;
2423 mops->mo_list = motbl;
2424 mop = &motbl[count - 1];
2425 mop->mo_flags = MO_TAG;
2426 mop->mo_name = kmem_alloc(strlen(tag) + 1, KM_SLEEP);
2427 (void) strcpy(mop->mo_name, tag);
2428 return (mop);
2429 }
2430
2431 /*
2432 * Allow users to set arbitrary "tags" in a vfs's mount options.
2433 * Broader use within the kernel is discouraged.
2434 */
2435 int
2436 vfs_settag(uint_t major, uint_t minor, const char *mntpt, const char *tag,
2437 cred_t *cr)
2438 {
2439 vfs_t *vfsp;
2440 mntopts_t *mops;
2441 mntopt_t *mop;
2442 int found = 0;
2443 dev_t dev = makedevice(major, minor);
2444 int err = 0;
2445 char *buf = kmem_alloc(MAX_MNTOPT_STR, KM_SLEEP);
2446
2447 /*
2448 * Find the desired mounted file system
2449 */
2450 vfs_list_lock();
2451 vfsp = rootvfs;
2452 do {
2453 if (vfsp->vfs_dev == dev &&
2454 strcmp(mntpt, refstr_value(vfsp->vfs_mntpt)) == 0) {
2455 found = 1;
2456 break;
2457 }
2458 vfsp = vfsp->vfs_next;
2459 } while (vfsp != rootvfs);
2460
2461 if (!found) {
2462 err = EINVAL;
2463 goto out;
2464 }
2465 err = secpolicy_fs_config(cr, vfsp);
2466 if (err != 0)
2467 goto out;
2468
2469 mops = &vfsp->vfs_mntopts;
2470 /*
2471 * Add tag if it doesn't already exist
2472 */
2473 if ((mop = vfs_hasopt(mops, tag)) == NULL) {
2474 int len;
2475
2476 (void) vfs_buildoptionstr(mops, buf, MAX_MNTOPT_STR);
2477 len = strlen(buf);
2478 if (len + strlen(tag) + 2 > MAX_MNTOPT_STR) {
2479 err = ENAMETOOLONG;
2480 goto out;
2481 }
2482 mop = vfs_addtag(mops, tag);
2483 }
2484 if ((mop->mo_flags & MO_TAG) == 0) {
2485 err = EINVAL;
2486 goto out;
2487 }
2488 vfs_setmntopt_nolock(mops, tag, NULL, 0, 1);
2489 out:
2490 vfs_list_unlock();
2491 kmem_free(buf, MAX_MNTOPT_STR);
2492 return (err);
2493 }
2494
2495 /*
2496 * Allow users to remove arbitrary "tags" in a vfs's mount options.
2497 * Broader use within the kernel is discouraged.
2498 */
2499 int
2500 vfs_clrtag(uint_t major, uint_t minor, const char *mntpt, const char *tag,
2501 cred_t *cr)
2502 {
2503 vfs_t *vfsp;
2504 mntopt_t *mop;
2505 int found = 0;
2506 dev_t dev = makedevice(major, minor);
2507 int err = 0;
2508
2509 /*
2510 * Find the desired mounted file system
2511 */
2512 vfs_list_lock();
2513 vfsp = rootvfs;
2514 do {
2515 if (vfsp->vfs_dev == dev &&
2516 strcmp(mntpt, refstr_value(vfsp->vfs_mntpt)) == 0) {
2517 found = 1;
2518 break;
2519 }
2520 vfsp = vfsp->vfs_next;
2521 } while (vfsp != rootvfs);
2522
2523 if (!found) {
2524 err = EINVAL;
2525 goto out;
2526 }
2527 err = secpolicy_fs_config(cr, vfsp);
2528 if (err != 0)
2529 goto out;
2530
2531 if ((mop = vfs_hasopt(&vfsp->vfs_mntopts, tag)) == NULL) {
2532 err = EINVAL;
2533 goto out;
2534 }
2535 if ((mop->mo_flags & MO_TAG) == 0) {
2536 err = EINVAL;
2537 goto out;
2538 }
2539 vfs_clearmntopt_nolock(&vfsp->vfs_mntopts, tag, 1);
2540 out:
2541 vfs_list_unlock();
2542 return (err);
2543 }
2544
2545 /*
2546 * Function to parse an option string and fill in a mount options table.
2547 * Unknown options are silently ignored. The input option string is modified
2548 * by replacing separators with nulls. If the create flag is set, options
2549 * not found in the table are just added on the fly. The table must have
2550 * an option slot marked MO_EMPTY to add an option on the fly.
2551 *
2552 * This function is *not* for general use by filesystems.
2553 *
2554 * Note: caller is responsible for locking the vfs list, if needed,
2555 * to protect mops..
2556 */
2557 void
2558 vfs_parsemntopts(mntopts_t *mops, char *osp, int create)
2559 {
2560 char *s = osp, *p, *nextop, *valp, *cp, *ep;
2561 int setflg = VFS_NOFORCEOPT;
2562
2563 if (osp == NULL)
2564 return;
2565 while (*s != '\0') {
2566 p = strchr(s, ','); /* find next option */
2567 if (p == NULL) {
2568 cp = NULL;
2569 p = s + strlen(s);
2570 } else {
2571 cp = p; /* save location of comma */
2572 *p++ = '\0'; /* mark end and point to next option */
2573 }
2574 nextop = p;
2575 p = strchr(s, '='); /* look for value */
2576 if (p == NULL) {
2577 valp = NULL; /* no value supplied */
2578 } else {
2579 ep = p; /* save location of equals */
2580 *p++ = '\0'; /* end option and point to value */
2581 valp = p;
2582 }
2583 /*
2584 * set option into options table
2585 */
2586 if (create)
2587 setflg |= VFS_CREATEOPT;
2588 vfs_setmntopt_nolock(mops, s, valp, setflg, 0);
2589 if (cp != NULL)
2590 *cp = ','; /* restore the comma */
2591 if (valp != NULL)
2592 *ep = '='; /* restore the equals */
2593 s = nextop;
2594 }
2595 }
2596
2597 /*
2598 * Function to inquire if an option exists in a mount options table.
2599 * Returns a pointer to the option if it exists, else NULL.
2600 *
2601 * This function is *not* for general use by filesystems.
2602 *
2603 * Note: caller is responsible for locking the vfs list, if needed,
2604 * to protect mops.
2605 */
2606 struct mntopt *
2607 vfs_hasopt(const mntopts_t *mops, const char *opt)
2608 {
2609 struct mntopt *mop;
2610 uint_t i, count;
2611
2612 count = mops->mo_count;
2613 for (i = 0; i < count; i++) {
2614 mop = &mops->mo_list[i];
2615
2616 if (mop->mo_flags & MO_EMPTY)
2617 continue;
2618 if (strcmp(opt, mop->mo_name) == 0)
2619 return (mop);
2620 }
2621 return (NULL);
2622 }
2623
2624 /*
2625 * Function to inquire if an option is set in a mount options table.
2626 * Returns non-zero if set and fills in the arg pointer with a pointer to
2627 * the argument string or NULL if there is no argument string.
2628 */
2629 static int
2630 vfs_optionisset_nolock(const mntopts_t *mops, const char *opt, char **argp)
2631 {
2632 struct mntopt *mop;
2633 uint_t i, count;
2634
2635 count = mops->mo_count;
2636 for (i = 0; i < count; i++) {
2637 mop = &mops->mo_list[i];
2638
2639 if (mop->mo_flags & MO_EMPTY)
2640 continue;
2641 if (strcmp(opt, mop->mo_name))
2642 continue;
2643 if ((mop->mo_flags & MO_SET) == 0)
2644 return (0);
2645 if (argp != NULL && (mop->mo_flags & MO_HASVALUE) != 0)
2646 *argp = mop->mo_arg;
2647 return (1);
2648 }
2649 return (0);
2650 }
2651
2652
2653 int
2654 vfs_optionisset(const struct vfs *vfsp, const char *opt, char **argp)
2655 {
2656 int ret;
2657
2658 vfs_list_read_lock();
2659 ret = vfs_optionisset_nolock(&vfsp->vfs_mntopts, opt, argp);
2660 vfs_list_unlock();
2661 return (ret);
2662 }
2663
2664
2665 /*
2666 * Construct a comma separated string of the options set in the given
2667 * mount table, return the string in the given buffer. Return non-zero if
2668 * the buffer would overflow.
2669 *
2670 * This function is *not* for general use by filesystems.
2671 *
2672 * Note: caller is responsible for locking the vfs list, if needed,
2673 * to protect mp.
2674 */
2675 int
2676 vfs_buildoptionstr(const mntopts_t *mp, char *buf, int len)
2677 {
2678 char *cp;
2679 uint_t i;
2680
2681 buf[0] = '\0';
2682 cp = buf;
2683 for (i = 0; i < mp->mo_count; i++) {
2684 struct mntopt *mop;
2685
2686 mop = &mp->mo_list[i];
2687 if (mop->mo_flags & MO_SET) {
2688 int optlen, comma = 0;
2689
2690 if (buf[0] != '\0')
2691 comma = 1;
2692 optlen = strlen(mop->mo_name);
2693 if (strlen(buf) + comma + optlen + 1 > len)
2694 goto err;
2695 if (comma)
2696 *cp++ = ',';
2697 (void) strcpy(cp, mop->mo_name);
2698 cp += optlen;
2699 /*
2700 * Append option value if there is one
2701 */
2702 if (mop->mo_arg != NULL) {
2703 int arglen;
2704
2705 arglen = strlen(mop->mo_arg);
2706 if (strlen(buf) + arglen + 2 > len)
2707 goto err;
2708 *cp++ = '=';
2709 (void) strcpy(cp, mop->mo_arg);
2710 cp += arglen;
2711 }
2712 }
2713 }
2714 return (0);
2715 err:
2716 return (EOVERFLOW);
2717 }
2718
2719 static void
2720 vfs_freecancelopt(char **moc)
2721 {
2722 if (moc != NULL) {
2723 int ccnt = 0;
2724 char **cp;
2725
2726 for (cp = moc; *cp != NULL; cp++) {
2727 kmem_free(*cp, strlen(*cp) + 1);
2728 ccnt++;
2729 }
2730 kmem_free(moc, (ccnt + 1) * sizeof (char *));
2731 }
2732 }
2733
2734 static void
2735 vfs_freeopt(mntopt_t *mop)
2736 {
2737 if (mop->mo_name != NULL)
2738 kmem_free(mop->mo_name, strlen(mop->mo_name) + 1);
2739
2740 vfs_freecancelopt(mop->mo_cancel);
2741
2742 if (mop->mo_arg != NULL)
2743 kmem_free(mop->mo_arg, strlen(mop->mo_arg) + 1);
2744 }
2745
2746 /*
2747 * Free a mount options table
2748 *
2749 * This function is *not* for general use by filesystems.
2750 *
2751 * Note: caller is responsible for locking the vfs list, if needed,
2752 * to protect mp.
2753 */
2754 void
2755 vfs_freeopttbl(mntopts_t *mp)
2756 {
2757 uint_t i, count;
2758
2759 count = mp->mo_count;
2760 for (i = 0; i < count; i++) {
2761 vfs_freeopt(&mp->mo_list[i]);
2762 }
2763 if (count) {
2764 kmem_free(mp->mo_list, sizeof (mntopt_t) * count);
2765 mp->mo_count = 0;
2766 mp->mo_list = NULL;
2767 }
2768 }
2769
2770
2771 /* ARGSUSED */
2772 static int
2773 vfs_mntdummyread(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cred,
2774 caller_context_t *ct)
2775 {
2776 return (0);
2777 }
2778
2779 /* ARGSUSED */
2780 static int
2781 vfs_mntdummywrite(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cred,
2782 caller_context_t *ct)
2783 {
2784 return (0);
2785 }
2786
2787 /*
2788 * The dummy vnode is currently used only by file events notification
2789 * module which is just interested in the timestamps.
2790 */
2791 /* ARGSUSED */
2792 static int
2793 vfs_mntdummygetattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
2794 caller_context_t *ct)
2795 {
2796 bzero(vap, sizeof (vattr_t));
2797 vap->va_type = VREG;
2798 vap->va_nlink = 1;
2799 vap->va_ctime = vfs_mnttab_ctime;
2800 /*
2801 * it is ok to just copy mtime as the time will be monotonically
2802 * increasing.
2803 */
2804 vap->va_mtime = vfs_mnttab_mtime;
2805 vap->va_atime = vap->va_mtime;
2806 return (0);
2807 }
2808
2809 static void
2810 vfs_mnttabvp_setup(void)
2811 {
2812 vnode_t *tvp;
2813 vnodeops_t *vfs_mntdummyvnops;
2814 const fs_operation_def_t mnt_dummyvnodeops_template[] = {
2815 VOPNAME_READ, { .vop_read = vfs_mntdummyread },
2816 VOPNAME_WRITE, { .vop_write = vfs_mntdummywrite },
2817 VOPNAME_GETATTR, { .vop_getattr = vfs_mntdummygetattr },
2818 VOPNAME_VNEVENT, { .vop_vnevent = fs_vnevent_support },
2819 NULL, NULL
2820 };
2821
2822 if (vn_make_ops("mnttab", mnt_dummyvnodeops_template,
2823 &vfs_mntdummyvnops) != 0) {
2824 cmn_err(CE_WARN, "vfs_mnttabvp_setup: vn_make_ops failed");
2825 /* Shouldn't happen, but not bad enough to panic */
2826 return;
2827 }
2828
2829 /*
2830 * A global dummy vnode is allocated to represent mntfs files.
2831 * The mntfs file (/etc/mnttab) can be monitored for file events
2832 * and receive an event when mnttab changes. Dummy VOP calls
2833 * will be made on this vnode. The file events notification module
2834 * intercepts this vnode and delivers relevant events.
2835 */
2836 tvp = vn_alloc(KM_SLEEP);
2837 tvp->v_flag = VNOMOUNT|VNOMAP|VNOSWAP|VNOCACHE;
2838 vn_setops(tvp, vfs_mntdummyvnops);
2839 tvp->v_type = VREG;
2840 /*
2841 * The mnt dummy ops do not reference v_data.
2842 * No other module intercepting this vnode should either.
2843 * Just set it to point to itself.
2844 */
2845 tvp->v_data = (caddr_t)tvp;
2846 tvp->v_vfsp = rootvfs;
2847 vfs_mntdummyvp = tvp;
2848 }
2849
2850 /*
2851 * performs fake read/write ops
2852 */
2853 static void
2854 vfs_mnttab_rwop(int rw)
2855 {
2856 struct uio uio;
2857 struct iovec iov;
2858 char buf[1];
2859
2860 if (vfs_mntdummyvp == NULL)
2861 return;
2862
2863 bzero(&uio, sizeof (uio));
2864 bzero(&iov, sizeof (iov));
2865 iov.iov_base = buf;
2866 iov.iov_len = 0;
2867 uio.uio_iov = &iov;
2868 uio.uio_iovcnt = 1;
2869 uio.uio_loffset = 0;
2870 uio.uio_segflg = UIO_SYSSPACE;
2871 uio.uio_resid = 0;
2872 if (rw) {
2873 (void) VOP_WRITE(vfs_mntdummyvp, &uio, 0, kcred, NULL);
2874 } else {
2875 (void) VOP_READ(vfs_mntdummyvp, &uio, 0, kcred, NULL);
2876 }
2877 }
2878
2879 /*
2880 * Generate a write operation.
2881 */
2882 void
2883 vfs_mnttab_writeop(void)
2884 {
2885 vfs_mnttab_rwop(1);
2886 }
2887
2888 /*
2889 * Generate a read operation.
2890 */
2891 void
2892 vfs_mnttab_readop(void)
2893 {
2894 vfs_mnttab_rwop(0);
2895 }
2896
2897 /*
2898 * Free any mnttab information recorded in the vfs struct.
2899 * The vfs must not be on the vfs list.
2900 */
2901 static void
2902 vfs_freemnttab(struct vfs *vfsp)
2903 {
2904 ASSERT(!VFS_ON_LIST(vfsp));
2905
2906 /*
2907 * Free device and mount point information
2908 */
2909 if (vfsp->vfs_mntpt != NULL) {
2910 refstr_rele(vfsp->vfs_mntpt);
2911 vfsp->vfs_mntpt = NULL;
2912 }
2913 if (vfsp->vfs_resource != NULL) {
2914 refstr_rele(vfsp->vfs_resource);
2915 vfsp->vfs_resource = NULL;
2916 }
2917 /*
2918 * Now free mount options information
2919 */
2920 vfs_freeopttbl(&vfsp->vfs_mntopts);
2921 }
2922
2923 /*
2924 * Return the last mnttab modification time
2925 */
2926 void
2927 vfs_mnttab_modtime(timespec_t *ts)
2928 {
2929 ASSERT(RW_LOCK_HELD(&vfslist));
2930 *ts = vfs_mnttab_mtime;
2931 }
2932
2933 /*
2934 * See if mnttab is changed
2935 */
2936 void
2937 vfs_mnttab_poll(timespec_t *old, struct pollhead **phpp)
2938 {
2939 int changed;
2940
2941 *phpp = (struct pollhead *)NULL;
2942
2943 /*
2944 * Note: don't grab vfs list lock before accessing vfs_mnttab_mtime.
2945 * Can lead to deadlock against vfs_mnttab_modtimeupd(). It is safe
2946 * to not grab the vfs list lock because tv_sec is monotonically
2947 * increasing.
2948 */
2949
2950 changed = (old->tv_nsec != vfs_mnttab_mtime.tv_nsec) ||
2951 (old->tv_sec != vfs_mnttab_mtime.tv_sec);
2952 if (!changed) {
2953 *phpp = &vfs_pollhd;
2954 }
2955 }
2956
2957 /* Provide a unique and monotonically-increasing timestamp. */
2958 void
2959 vfs_mono_time(timespec_t *ts)
2960 {
2961 static volatile hrtime_t hrt; /* The saved time. */
2962 hrtime_t newhrt, oldhrt; /* For effecting the CAS. */
2963 timespec_t newts;
2964
2965 /*
2966 * Try gethrestime() first, but be prepared to fabricate a sensible
2967 * answer at the first sign of any trouble.
2968 */
2969 gethrestime(&newts);
2970 newhrt = ts2hrt(&newts);
2971 for (;;) {
2972 oldhrt = hrt;
2973 if (newhrt <= hrt)
2974 newhrt = hrt + 1;
2975 if (cas64((uint64_t *)&hrt, oldhrt, newhrt) == oldhrt)
2976 break;
2977 }
2978 hrt2ts(newhrt, ts);
2979 }
2980
2981 /*
2982 * Update the mnttab modification time and wake up any waiters for
2983 * mnttab changes
2984 */
2985 void
2986 vfs_mnttab_modtimeupd()
2987 {
2988 hrtime_t oldhrt, newhrt;
2989
2990 ASSERT(RW_WRITE_HELD(&vfslist));
2991 oldhrt = ts2hrt(&vfs_mnttab_mtime);
2992 gethrestime(&vfs_mnttab_mtime);
2993 newhrt = ts2hrt(&vfs_mnttab_mtime);
2994 if (oldhrt == (hrtime_t)0)
2995 vfs_mnttab_ctime = vfs_mnttab_mtime;
2996 /*
2997 * Attempt to provide unique mtime (like uniqtime but not).
2998 */
2999 if (newhrt == oldhrt) {
3000 newhrt++;
3001 hrt2ts(newhrt, &vfs_mnttab_mtime);
3002 }
3003 pollwakeup(&vfs_pollhd, (short)POLLRDBAND);
3004 vfs_mnttab_writeop();
3005 }
3006
3007 int
3008 dounmount(struct vfs *vfsp, int flag, cred_t *cr)
3009 {
3010 vnode_t *coveredvp;
3011 int error;
3012 extern void teardown_vopstats(vfs_t *);
3013
3014 /*
3015 * Get covered vnode. This will be NULL if the vfs is not linked
3016 * into the file system name space (i.e., domount() with MNT_NOSPICE).
3017 */
3018 coveredvp = vfsp->vfs_vnodecovered;
3019 ASSERT(coveredvp == NULL || vn_vfswlock_held(coveredvp));
3020
3021 /*
3022 * Purge all dnlc entries for this vfs.
3023 */
3024 (void) dnlc_purge_vfsp(vfsp, 0);
3025
3026 /* For forcible umount, skip VFS_SYNC() since it may hang */
3027 if ((flag & MS_FORCE) == 0)
3028 (void) VFS_SYNC(vfsp, 0, cr);
3029
3030 /*
3031 * Lock the vfs to maintain fs status quo during unmount. This
3032 * has to be done after the sync because ufs_update tries to acquire
3033 * the vfs_reflock.
3034 */
3035 vfs_lock_wait(vfsp);
3036
3037 if (error = VFS_UNMOUNT(vfsp, flag, cr)) {
3038 vfs_unlock(vfsp);
3039 if (coveredvp != NULL)
3040 vn_vfsunlock(coveredvp);
3041 } else if (coveredvp != NULL) {
3042 teardown_vopstats(vfsp);
3043 /*
3044 * vfs_remove() will do a VN_RELE(vfsp->vfs_vnodecovered)
3045 * when it frees vfsp so we do a VN_HOLD() so we can
3046 * continue to use coveredvp afterwards.
3047 */
3048 VN_HOLD(coveredvp);
3049 vfs_remove(vfsp);
3050 vn_vfsunlock(coveredvp);
3051 VN_RELE(coveredvp);
3052 } else {
3053 teardown_vopstats(vfsp);
3054 /*
3055 * Release the reference to vfs that is not linked
3056 * into the name space.
3057 */
3058 vfs_unlock(vfsp);
3059 VFS_RELE(vfsp);
3060 }
3061 return (error);
3062 }
3063
3064
3065 /*
3066 * Vfs_unmountall() is called by uadmin() to unmount all
3067 * mounted file systems (except the root file system) during shutdown.
3068 * It follows the existing locking protocol when traversing the vfs list
3069 * to sync and unmount vfses. Even though there should be no
3070 * other thread running while the system is shutting down, it is prudent
3071 * to still follow the locking protocol.
3072 */
3073 void
3074 vfs_unmountall(void)
3075 {
3076 struct vfs *vfsp;
3077 struct vfs *prev_vfsp = NULL;
3078 int error;
3079
3080 /*
3081 * Toss all dnlc entries now so that the per-vfs sync
3082 * and unmount operations don't have to slog through
3083 * a bunch of uninteresting vnodes over and over again.
3084 */
3085 dnlc_purge();
3086
3087 vfs_list_lock();
3088 for (vfsp = rootvfs->vfs_prev; vfsp != rootvfs; vfsp = prev_vfsp) {
3089 prev_vfsp = vfsp->vfs_prev;
3090
3091 if (vfs_lock(vfsp) != 0)
3092 continue;
3093 error = vn_vfswlock(vfsp->vfs_vnodecovered);
3094 vfs_unlock(vfsp);
3095 if (error)
3096 continue;
3097
3098 vfs_list_unlock();
3099
3100 (void) VFS_SYNC(vfsp, SYNC_CLOSE, CRED());
3101 (void) dounmount(vfsp, 0, CRED());
3102
3103 /*
3104 * Since we dropped the vfslist lock above we must
3105 * verify that next_vfsp still exists, else start over.
3106 */
3107 vfs_list_lock();
3108 for (vfsp = rootvfs->vfs_prev;
3109 vfsp != rootvfs; vfsp = vfsp->vfs_prev)
3110 if (vfsp == prev_vfsp)
3111 break;
3112 if (vfsp == rootvfs && prev_vfsp != rootvfs)
3113 prev_vfsp = rootvfs->vfs_prev;
3114 }
3115 vfs_list_unlock();
3116 }
3117
3118 /*
3119 * Called to add an entry to the end of the vfs mount in progress list
3120 */
3121 void
3122 vfs_addmip(dev_t dev, struct vfs *vfsp)
3123 {
3124 struct ipmnt *mipp;
3125
3126 mipp = (struct ipmnt *)kmem_alloc(sizeof (struct ipmnt), KM_SLEEP);
3127 mipp->mip_next = NULL;
3128 mipp->mip_dev = dev;
3129 mipp->mip_vfsp = vfsp;
3130 mutex_enter(&vfs_miplist_mutex);
3131 if (vfs_miplist_end != NULL)
3132 vfs_miplist_end->mip_next = mipp;
3133 else
3134 vfs_miplist = mipp;
3135 vfs_miplist_end = mipp;
3136 mutex_exit(&vfs_miplist_mutex);
3137 }
3138
3139 /*
3140 * Called to remove an entry from the mount in progress list
3141 * Either because the mount completed or it failed.
3142 */
3143 void
3144 vfs_delmip(struct vfs *vfsp)
3145 {
3146 struct ipmnt *mipp, *mipprev;
3147
3148 mutex_enter(&vfs_miplist_mutex);
3149 mipprev = NULL;
3150 for (mipp = vfs_miplist;
3151 mipp && mipp->mip_vfsp != vfsp; mipp = mipp->mip_next) {
3152 mipprev = mipp;
3153 }
3154 if (mipp == NULL)
3155 return; /* shouldn't happen */
3156 if (mipp == vfs_miplist_end)
3157 vfs_miplist_end = mipprev;
3158 if (mipprev == NULL)
3159 vfs_miplist = mipp->mip_next;
3160 else
3161 mipprev->mip_next = mipp->mip_next;
3162 mutex_exit(&vfs_miplist_mutex);
3163 kmem_free(mipp, sizeof (struct ipmnt));
3164 }
3165
3166 /*
3167 * vfs_add is called by a specific filesystem's mount routine to add
3168 * the new vfs into the vfs list/hash and to cover the mounted-on vnode.
3169 * The vfs should already have been locked by the caller.
3170 *
3171 * coveredvp is NULL if this is the root.
3172 */
3173 void
3174 vfs_add(vnode_t *coveredvp, struct vfs *vfsp, int mflag)
3175 {
3176 int newflag;
3177
3178 ASSERT(vfs_lock_held(vfsp));
3179 VFS_HOLD(vfsp);
3180 newflag = vfsp->vfs_flag;
3181 if (mflag & MS_RDONLY)
3182 newflag |= VFS_RDONLY;
3183 else
3184 newflag &= ~VFS_RDONLY;
3185 if (mflag & MS_NOSUID)
3186 newflag |= (VFS_NOSETUID|VFS_NODEVICES);
3187 else
3188 newflag &= ~(VFS_NOSETUID|VFS_NODEVICES);
3189 if (mflag & MS_NOMNTTAB)
3190 newflag |= VFS_NOMNTTAB;
3191 else
3192 newflag &= ~VFS_NOMNTTAB;
3193
3194 if (coveredvp != NULL) {
3195 ASSERT(vn_vfswlock_held(coveredvp));
3196 coveredvp->v_vfsmountedhere = vfsp;
3197 VN_HOLD(coveredvp);
3198 }
3199 vfsp->vfs_vnodecovered = coveredvp;
3200 vfsp->vfs_flag = newflag;
3201
3202 vfs_list_add(vfsp);
3203 }
3204
3205 /*
3206 * Remove a vfs from the vfs list, null out the pointer from the
3207 * covered vnode to the vfs (v_vfsmountedhere), and null out the pointer
3208 * from the vfs to the covered vnode (vfs_vnodecovered). Release the
3209 * reference to the vfs and to the covered vnode.
3210 *
3211 * Called from dounmount after it's confirmed with the file system
3212 * that the unmount is legal.
3213 */
3214 void
3215 vfs_remove(struct vfs *vfsp)
3216 {
3217 vnode_t *vp;
3218
3219 ASSERT(vfs_lock_held(vfsp));
3220
3221 /*
3222 * Can't unmount root. Should never happen because fs will
3223 * be busy.
3224 */
3225 if (vfsp == rootvfs)
3226 panic("vfs_remove: unmounting root");
3227
3228 vfs_list_remove(vfsp);
3229
3230 /*
3231 * Unhook from the file system name space.
3232 */
3233 vp = vfsp->vfs_vnodecovered;
3234 ASSERT(vn_vfswlock_held(vp));
3235 vp->v_vfsmountedhere = NULL;
3236 vfsp->vfs_vnodecovered = NULL;
3237 VN_RELE(vp);
3238
3239 /*
3240 * Release lock and wakeup anybody waiting.
3241 */
3242 vfs_unlock(vfsp);
3243 VFS_RELE(vfsp);
3244 }
3245
3246 /*
3247 * Lock a filesystem to prevent access to it while mounting,
3248 * unmounting and syncing. Return EBUSY immediately if lock
3249 * can't be acquired.
3250 */
3251 int
3252 vfs_lock(vfs_t *vfsp)
3253 {
3254 vn_vfslocks_entry_t *vpvfsentry;
3255
3256 vpvfsentry = vn_vfslocks_getlock(vfsp);
3257 if (rwst_tryenter(&vpvfsentry->ve_lock, RW_WRITER))
3258 return (0);
3259
3260 vn_vfslocks_rele(vpvfsentry);
3261 return (EBUSY);
3262 }
3263
3264 int
3265 vfs_rlock(vfs_t *vfsp)
3266 {
3267 vn_vfslocks_entry_t *vpvfsentry;
3268
3269 vpvfsentry = vn_vfslocks_getlock(vfsp);
3270
3271 if (rwst_tryenter(&vpvfsentry->ve_lock, RW_READER))
3272 return (0);
3273
3274 vn_vfslocks_rele(vpvfsentry);
3275 return (EBUSY);
3276 }
3277
3278 void
3279 vfs_lock_wait(vfs_t *vfsp)
3280 {
3281 vn_vfslocks_entry_t *vpvfsentry;
3282
3283 vpvfsentry = vn_vfslocks_getlock(vfsp);
3284 rwst_enter(&vpvfsentry->ve_lock, RW_WRITER);
3285 }
3286
3287 void
3288 vfs_rlock_wait(vfs_t *vfsp)
3289 {
3290 vn_vfslocks_entry_t *vpvfsentry;
3291
3292 vpvfsentry = vn_vfslocks_getlock(vfsp);
3293 rwst_enter(&vpvfsentry->ve_lock, RW_READER);
3294 }
3295
3296 /*
3297 * Unlock a locked filesystem.
3298 */
3299 void
3300 vfs_unlock(vfs_t *vfsp)
3301 {
3302 vn_vfslocks_entry_t *vpvfsentry;
3303
3304 /*
3305 * vfs_unlock will mimic sema_v behaviour to fix 4748018.
3306 * And these changes should remain for the patch changes as it is.
3307 */
3308 if (panicstr)
3309 return;
3310
3311 /*
3312 * ve_refcount needs to be dropped twice here.
3313 * 1. To release refernce after a call to vfs_locks_getlock()
3314 * 2. To release the reference from the locking routines like
3315 * vfs_rlock_wait/vfs_wlock_wait/vfs_wlock etc,.
3316 */
3317
3318 vpvfsentry = vn_vfslocks_getlock(vfsp);
3319 vn_vfslocks_rele(vpvfsentry);
3320
3321 rwst_exit(&vpvfsentry->ve_lock);
3322 vn_vfslocks_rele(vpvfsentry);
3323 }
3324
3325 /*
3326 * Utility routine that allows a filesystem to construct its
3327 * fsid in "the usual way" - by munging some underlying dev_t and
3328 * the filesystem type number into the 64-bit fsid. Note that
3329 * this implicitly relies on dev_t persistence to make filesystem
3330 * id's persistent.
3331 *
3332 * There's nothing to prevent an individual fs from constructing its
3333 * fsid in a different way, and indeed they should.
3334 *
3335 * Since we want fsids to be 32-bit quantities (so that they can be
3336 * exported identically by either 32-bit or 64-bit APIs, as well as
3337 * the fact that fsid's are "known" to NFS), we compress the device
3338 * number given down to 32-bits, and panic if that isn't possible.
3339 */
3340 void
3341 vfs_make_fsid(fsid_t *fsi, dev_t dev, int val)
3342 {
3343 if (!cmpldev((dev32_t *)&fsi->val[0], dev))
3344 panic("device number too big for fsid!");
3345 fsi->val[1] = val;
3346 }
3347
3348 int
3349 vfs_lock_held(vfs_t *vfsp)
3350 {
3351 int held;
3352 vn_vfslocks_entry_t *vpvfsentry;
3353
3354 /*
3355 * vfs_lock_held will mimic sema_held behaviour
3356 * if panicstr is set. And these changes should remain
3357 * for the patch changes as it is.
3358 */
3359 if (panicstr)
3360 return (1);
3361
3362 vpvfsentry = vn_vfslocks_getlock(vfsp);
3363 held = rwst_lock_held(&vpvfsentry->ve_lock, RW_WRITER);
3364
3365 vn_vfslocks_rele(vpvfsentry);
3366 return (held);
3367 }
3368
3369 struct _kthread *
3370 vfs_lock_owner(vfs_t *vfsp)
3371 {
3372 struct _kthread *owner;
3373 vn_vfslocks_entry_t *vpvfsentry;
3374
3375 /*
3376 * vfs_wlock_held will mimic sema_held behaviour
3377 * if panicstr is set. And these changes should remain
3378 * for the patch changes as it is.
3379 */
3380 if (panicstr)
3381 return (NULL);
3382
3383 vpvfsentry = vn_vfslocks_getlock(vfsp);
3384 owner = rwst_owner(&vpvfsentry->ve_lock);
3385
3386 vn_vfslocks_rele(vpvfsentry);
3387 return (owner);
3388 }
3389
3390 /*
3391 * vfs list locking.
3392 *
3393 * Rather than manipulate the vfslist lock directly, we abstract into lock
3394 * and unlock routines to allow the locking implementation to be changed for
3395 * clustering.
3396 *
3397 * Whenever the vfs list is modified through its hash links, the overall list
3398 * lock must be obtained before locking the relevant hash bucket. But to see
3399 * whether a given vfs is on the list, it suffices to obtain the lock for the
3400 * hash bucket without getting the overall list lock. (See getvfs() below.)
3401 */
3402
3403 void
3404 vfs_list_lock()
3405 {
3406 rw_enter(&vfslist, RW_WRITER);
3407 }
3408
3409 void
3410 vfs_list_read_lock()
3411 {
3412 rw_enter(&vfslist, RW_READER);
3413 }
3414
3415 void
3416 vfs_list_unlock()
3417 {
3418 rw_exit(&vfslist);
3419 }
3420
3421 /*
3422 * Low level worker routines for adding entries to and removing entries from
3423 * the vfs list.
3424 */
3425
3426 static void
3427 vfs_hash_add(struct vfs *vfsp, int insert_at_head)
3428 {
3429 int vhno;
3430 struct vfs **hp;
3431 dev_t dev;
3432
3433 ASSERT(RW_WRITE_HELD(&vfslist));
3434
3435 dev = expldev(vfsp->vfs_fsid.val[0]);
3436 vhno = VFSHASH(getmajor(dev), getminor(dev));
3437
3438 mutex_enter(&rvfs_list[vhno].rvfs_lock);
3439
3440 /*
3441 * Link into the hash table, inserting it at the end, so that LOFS
3442 * with the same fsid as UFS (or other) file systems will not hide the
3443 * UFS.
3444 */
3445 if (insert_at_head) {
3446 vfsp->vfs_hash = rvfs_list[vhno].rvfs_head;
3447 rvfs_list[vhno].rvfs_head = vfsp;
3448 } else {
3449 for (hp = &rvfs_list[vhno].rvfs_head; *hp != NULL;
3450 hp = &(*hp)->vfs_hash)
3451 continue;
3452 /*
3453 * hp now contains the address of the pointer to update
3454 * to effect the insertion.
3455 */
3456 vfsp->vfs_hash = NULL;
3457 *hp = vfsp;
3458 }
3459
3460 rvfs_list[vhno].rvfs_len++;
3461 mutex_exit(&rvfs_list[vhno].rvfs_lock);
3462 }
3463
3464
3465 static void
3466 vfs_hash_remove(struct vfs *vfsp)
3467 {
3468 int vhno;
3469 struct vfs *tvfsp;
3470 dev_t dev;
3471
3472 ASSERT(RW_WRITE_HELD(&vfslist));
3473
3474 dev = expldev(vfsp->vfs_fsid.val[0]);
3475 vhno = VFSHASH(getmajor(dev), getminor(dev));
3476
3477 mutex_enter(&rvfs_list[vhno].rvfs_lock);
3478
3479 /*
3480 * Remove from hash.
3481 */
3482 if (rvfs_list[vhno].rvfs_head == vfsp) {
3483 rvfs_list[vhno].rvfs_head = vfsp->vfs_hash;
3484 rvfs_list[vhno].rvfs_len--;
3485 goto foundit;
3486 }
3487 for (tvfsp = rvfs_list[vhno].rvfs_head; tvfsp != NULL;
3488 tvfsp = tvfsp->vfs_hash) {
3489 if (tvfsp->vfs_hash == vfsp) {
3490 tvfsp->vfs_hash = vfsp->vfs_hash;
3491 rvfs_list[vhno].rvfs_len--;
3492 goto foundit;
3493 }
3494 }
3495 cmn_err(CE_WARN, "vfs_list_remove: vfs not found in hash");
3496
3497 foundit:
3498
3499 mutex_exit(&rvfs_list[vhno].rvfs_lock);
3500 }
3501
3502
3503 void
3504 vfs_list_add(struct vfs *vfsp)
3505 {
3506 zone_t *zone;
3507
3508 /*
3509 * Typically, the vfs_t will have been created on behalf of the file
3510 * system in vfs_init, where it will have been provided with a
3511 * vfs_impl_t. This, however, might be lacking if the vfs_t was created
3512 * by an unbundled file system. We therefore check for such an example
3513 * before stamping the vfs_t with its creation time for the benefit of
3514 * mntfs.
3515 */
3516 if (vfsp->vfs_implp == NULL)
3517 vfsimpl_setup(vfsp);
3518 vfs_mono_time(&vfsp->vfs_hrctime);
3519
3520 /*
3521 * The zone that owns the mount is the one that performed the mount.
3522 * Note that this isn't necessarily the same as the zone mounted into.
3523 * The corresponding zone_rele_ref() will be done when the vfs_t
3524 * is being free'd.
3525 */
3526 vfsp->vfs_zone = curproc->p_zone;
3527 zone_init_ref(&vfsp->vfs_implp->vi_zone_ref);
3528 zone_hold_ref(vfsp->vfs_zone, &vfsp->vfs_implp->vi_zone_ref,
3529 ZONE_REF_VFS);
3530
3531 /*
3532 * Find the zone mounted into, and put this mount on its vfs list.
3533 */
3534 zone = zone_find_by_path(refstr_value(vfsp->vfs_mntpt));
3535 ASSERT(zone != NULL);
3536 /*
3537 * Special casing for the root vfs. This structure is allocated
3538 * statically and hooked onto rootvfs at link time. During the
3539 * vfs_mountroot call at system startup time, the root file system's
3540 * VFS_MOUNTROOT routine will call vfs_add with this root vfs struct
3541 * as argument. The code below must detect and handle this special
3542 * case. The only apparent justification for this special casing is
3543 * to ensure that the root file system appears at the head of the
3544 * list.
3545 *
3546 * XXX: I'm assuming that it's ok to do normal list locking when
3547 * adding the entry for the root file system (this used to be
3548 * done with no locks held).
3549 */
3550 vfs_list_lock();
3551 /*
3552 * Link into the vfs list proper.
3553 */
3554 if (vfsp == &root) {
3555 /*
3556 * Assert: This vfs is already on the list as its first entry.
3557 * Thus, there's nothing to do.
3558 */
3559 ASSERT(rootvfs == vfsp);
3560 /*
3561 * Add it to the head of the global zone's vfslist.
3562 */
3563 ASSERT(zone == global_zone);
3564 ASSERT(zone->zone_vfslist == NULL);
3565 zone->zone_vfslist = vfsp;
3566 } else {
3567 /*
3568 * Link to end of list using vfs_prev (as rootvfs is now a
3569 * doubly linked circular list) so list is in mount order for
3570 * mnttab use.
3571 */
3572 rootvfs->vfs_prev->vfs_next = vfsp;
3573 vfsp->vfs_prev = rootvfs->vfs_prev;
3574 rootvfs->vfs_prev = vfsp;
3575 vfsp->vfs_next = rootvfs;
3576
3577 /*
3578 * Do it again for the zone-private list (which may be NULL).
3579 */
3580 if (zone->zone_vfslist == NULL) {
3581 ASSERT(zone != global_zone);
3582 zone->zone_vfslist = vfsp;
3583 } else {
3584 zone->zone_vfslist->vfs_zone_prev->vfs_zone_next = vfsp;
3585 vfsp->vfs_zone_prev = zone->zone_vfslist->vfs_zone_prev;
3586 zone->zone_vfslist->vfs_zone_prev = vfsp;
3587 vfsp->vfs_zone_next = zone->zone_vfslist;
3588 }
3589 }
3590
3591 /*
3592 * Link into the hash table, inserting it at the end, so that LOFS
3593 * with the same fsid as UFS (or other) file systems will not hide
3594 * the UFS.
3595 */
3596 vfs_hash_add(vfsp, 0);
3597
3598 /*
3599 * update the mnttab modification time
3600 */
3601 vfs_mnttab_modtimeupd();
3602 vfs_list_unlock();
3603 zone_rele(zone);
3604 }
3605
3606 void
3607 vfs_list_remove(struct vfs *vfsp)
3608 {
3609 zone_t *zone;
3610
3611 zone = zone_find_by_path(refstr_value(vfsp->vfs_mntpt));
3612 ASSERT(zone != NULL);
3613 /*
3614 * Callers are responsible for preventing attempts to unmount the
3615 * root.
3616 */
3617 ASSERT(vfsp != rootvfs);
3618
3619 vfs_list_lock();
3620
3621 /*
3622 * Remove from hash.
3623 */
3624 vfs_hash_remove(vfsp);
3625
3626 /*
3627 * Remove from vfs list.
3628 */
3629 vfsp->vfs_prev->vfs_next = vfsp->vfs_next;
3630 vfsp->vfs_next->vfs_prev = vfsp->vfs_prev;
3631 vfsp->vfs_next = vfsp->vfs_prev = NULL;
3632
3633 /*
3634 * Remove from zone-specific vfs list.
3635 */
3636 if (zone->zone_vfslist == vfsp)
3637 zone->zone_vfslist = vfsp->vfs_zone_next;
3638
3639 if (vfsp->vfs_zone_next == vfsp) {
3640 ASSERT(vfsp->vfs_zone_prev == vfsp);
3641 ASSERT(zone->zone_vfslist == vfsp);
3642 zone->zone_vfslist = NULL;
3643 }
3644
3645 vfsp->vfs_zone_prev->vfs_zone_next = vfsp->vfs_zone_next;
3646 vfsp->vfs_zone_next->vfs_zone_prev = vfsp->vfs_zone_prev;
3647 vfsp->vfs_zone_next = vfsp->vfs_zone_prev = NULL;
3648
3649 /*
3650 * update the mnttab modification time
3651 */
3652 vfs_mnttab_modtimeupd();
3653 vfs_list_unlock();
3654 zone_rele(zone);
3655 }
3656
3657 struct vfs *
3658 getvfs(fsid_t *fsid)
3659 {
3660 struct vfs *vfsp;
3661 int val0 = fsid->val[0];
3662 int val1 = fsid->val[1];
3663 dev_t dev = expldev(val0);
3664 int vhno = VFSHASH(getmajor(dev), getminor(dev));
3665 kmutex_t *hmp = &rvfs_list[vhno].rvfs_lock;
3666
3667 mutex_enter(hmp);
3668 for (vfsp = rvfs_list[vhno].rvfs_head; vfsp; vfsp = vfsp->vfs_hash) {
3669 if (vfsp->vfs_fsid.val[0] == val0 &&
3670 vfsp->vfs_fsid.val[1] == val1) {
3671 VFS_HOLD(vfsp);
3672 mutex_exit(hmp);
3673 return (vfsp);
3674 }
3675 }
3676 mutex_exit(hmp);
3677 return (NULL);
3678 }
3679
3680 /*
3681 * Search the vfs mount in progress list for a specified device/vfs entry.
3682 * Returns 0 if the first entry in the list that the device matches has the
3683 * given vfs pointer as well. If the device matches but a different vfs
3684 * pointer is encountered in the list before the given vfs pointer then
3685 * a 1 is returned.
3686 */
3687
3688 int
3689 vfs_devmounting(dev_t dev, struct vfs *vfsp)
3690 {
3691 int retval = 0;
3692 struct ipmnt *mipp;
3693
3694 mutex_enter(&vfs_miplist_mutex);
3695 for (mipp = vfs_miplist; mipp != NULL; mipp = mipp->mip_next) {
3696 if (mipp->mip_dev == dev) {
3697 if (mipp->mip_vfsp != vfsp)
3698 retval = 1;
3699 break;
3700 }
3701 }
3702 mutex_exit(&vfs_miplist_mutex);
3703 return (retval);
3704 }
3705
3706 /*
3707 * Search the vfs list for a specified device. Returns 1, if entry is found
3708 * or 0 if no suitable entry is found.
3709 */
3710
3711 int
3712 vfs_devismounted(dev_t dev)
3713 {
3714 struct vfs *vfsp;
3715 int found;
3716
3717 vfs_list_read_lock();
3718 vfsp = rootvfs;
3719 found = 0;
3720 do {
3721 if (vfsp->vfs_dev == dev) {
3722 found = 1;
3723 break;
3724 }
3725 vfsp = vfsp->vfs_next;
3726 } while (vfsp != rootvfs);
3727
3728 vfs_list_unlock();
3729 return (found);
3730 }
3731
3732 /*
3733 * Search the vfs list for a specified device. Returns a pointer to it
3734 * or NULL if no suitable entry is found. The caller of this routine
3735 * is responsible for releasing the returned vfs pointer.
3736 */
3737 struct vfs *
3738 vfs_dev2vfsp(dev_t dev)
3739 {
3740 struct vfs *vfsp;
3741 int found;
3742
3743 vfs_list_read_lock();
3744 vfsp = rootvfs;
3745 found = 0;
3746 do {
3747 /*
3748 * The following could be made more efficient by making
3749 * the entire loop use vfs_zone_next if the call is from
3750 * a zone. The only callers, however, ustat(2) and
3751 * umount2(2), don't seem to justify the added
3752 * complexity at present.
3753 */
3754 if (vfsp->vfs_dev == dev &&
3755 ZONE_PATH_VISIBLE(refstr_value(vfsp->vfs_mntpt),
3756 curproc->p_zone)) {
3757 VFS_HOLD(vfsp);
3758 found = 1;
3759 break;
3760 }
3761 vfsp = vfsp->vfs_next;
3762 } while (vfsp != rootvfs);
3763 vfs_list_unlock();
3764 return (found ? vfsp: NULL);
3765 }
3766
3767 /*
3768 * Search the vfs list for a specified mntpoint. Returns a pointer to it
3769 * or NULL if no suitable entry is found. The caller of this routine
3770 * is responsible for releasing the returned vfs pointer.
3771 *
3772 * Note that if multiple mntpoints match, the last one matching is
3773 * returned in an attempt to return the "top" mount when overlay
3774 * mounts are covering the same mount point. This is accomplished by starting
3775 * at the end of the list and working our way backwards, stopping at the first
3776 * matching mount.
3777 */
3778 struct vfs *
3779 vfs_mntpoint2vfsp(const char *mp)
3780 {
3781 struct vfs *vfsp;
3782 struct vfs *retvfsp = NULL;
3783 zone_t *zone = curproc->p_zone;
3784 struct vfs *list;
3785
3786 vfs_list_read_lock();
3787 if (getzoneid() == GLOBAL_ZONEID) {
3788 /*
3789 * The global zone may see filesystems in any zone.
3790 */
3791 vfsp = rootvfs->vfs_prev;
3792 do {
3793 if (strcmp(refstr_value(vfsp->vfs_mntpt), mp) == 0) {
3794 retvfsp = vfsp;
3795 break;
3796 }
3797 vfsp = vfsp->vfs_prev;
3798 } while (vfsp != rootvfs->vfs_prev);
3799 } else if ((list = zone->zone_vfslist) != NULL) {
3800 const char *mntpt;
3801
3802 vfsp = list->vfs_zone_prev;
3803 do {
3804 mntpt = refstr_value(vfsp->vfs_mntpt);
3805 mntpt = ZONE_PATH_TRANSLATE(mntpt, zone);
3806 if (strcmp(mntpt, mp) == 0) {
3807 retvfsp = vfsp;
3808 break;
3809 }
3810 vfsp = vfsp->vfs_zone_prev;
3811 } while (vfsp != list->vfs_zone_prev);
3812 }
3813 if (retvfsp)
3814 VFS_HOLD(retvfsp);
3815 vfs_list_unlock();
3816 return (retvfsp);
3817 }
3818
3819 /*
3820 * Search the vfs list for a specified vfsops.
3821 * if vfs entry is found then return 1, else 0.
3822 */
3823 int
3824 vfs_opsinuse(vfsops_t *ops)
3825 {
3826 struct vfs *vfsp;
3827 int found;
3828
3829 vfs_list_read_lock();
3830 vfsp = rootvfs;
3831 found = 0;
3832 do {
3833 if (vfs_getops(vfsp) == ops) {
3834 found = 1;
3835 break;
3836 }
3837 vfsp = vfsp->vfs_next;
3838 } while (vfsp != rootvfs);
3839 vfs_list_unlock();
3840 return (found);
3841 }
3842
3843 /*
3844 * Allocate an entry in vfssw for a file system type
3845 */
3846 struct vfssw *
3847 allocate_vfssw(const char *type)
3848 {
3849 struct vfssw *vswp;
3850
3851 if (type[0] == '\0' || strlen(type) + 1 > _ST_FSTYPSZ) {
3852 /*
3853 * The vfssw table uses the empty string to identify an
3854 * available entry; we cannot add any type which has
3855 * a leading NUL. The string length is limited to
3856 * the size of the st_fstype array in struct stat.
3857 */
3858 return (NULL);
3859 }
3860
3861 ASSERT(VFSSW_WRITE_LOCKED());
3862 for (vswp = &vfssw[1]; vswp < &vfssw[nfstype]; vswp++)
3863 if (!ALLOCATED_VFSSW(vswp)) {
3864 vswp->vsw_name = kmem_alloc(strlen(type) + 1, KM_SLEEP);
3865 (void) strcpy(vswp->vsw_name, type);
3866 ASSERT(vswp->vsw_count == 0);
3867 vswp->vsw_count = 1;
3868 mutex_init(&vswp->vsw_lock, NULL, MUTEX_DEFAULT, NULL);
3869 return (vswp);
3870 }
3871 return (NULL);
3872 }
3873
3874 /*
3875 * Impose additional layer of translation between vfstype names
3876 * and module names in the filesystem.
3877 */
3878 static const char *
3879 vfs_to_modname(const char *vfstype)
3880 {
3881 if (strcmp(vfstype, "proc") == 0) {
3882 vfstype = "procfs";
3883 } else if (strcmp(vfstype, "fd") == 0) {
3884 vfstype = "fdfs";
3885 } else if (strncmp(vfstype, "nfs", 3) == 0) {
3886 vfstype = "nfs";
3887 }
3888
3889 return (vfstype);
3890 }
3891
3892 /*
3893 * Find a vfssw entry given a file system type name.
3894 * Try to autoload the filesystem if it's not found.
3895 * If it's installed, return the vfssw locked to prevent unloading.
3896 */
3897 struct vfssw *
3898 vfs_getvfssw(const char *type)
3899 {
3900 struct vfssw *vswp;
3901 const char *modname;
3902
3903 RLOCK_VFSSW();
3904 vswp = vfs_getvfsswbyname(type);
3905 modname = vfs_to_modname(type);
3906
3907 if (rootdir == NULL) {
3908 /*
3909 * If we haven't yet loaded the root file system, then our
3910 * _init won't be called until later. Allocate vfssw entry,
3911 * because mod_installfs won't be called.
3912 */
3913 if (vswp == NULL) {
3914 RUNLOCK_VFSSW();
3915 WLOCK_VFSSW();
3916 if ((vswp = vfs_getvfsswbyname(type)) == NULL) {
3917 if ((vswp = allocate_vfssw(type)) == NULL) {
3918 WUNLOCK_VFSSW();
3919 return (NULL);
3920 }
3921 }
3922 WUNLOCK_VFSSW();
3923 RLOCK_VFSSW();
3924 }
3925 if (!VFS_INSTALLED(vswp)) {
3926 RUNLOCK_VFSSW();
3927 (void) modloadonly("fs", modname);
3928 } else
3929 RUNLOCK_VFSSW();
3930 return (vswp);
3931 }
3932
3933 /*
3934 * Try to load the filesystem. Before calling modload(), we drop
3935 * our lock on the VFS switch table, and pick it up after the
3936 * module is loaded. However, there is a potential race: the
3937 * module could be unloaded after the call to modload() completes
3938 * but before we pick up the lock and drive on. Therefore,
3939 * we keep reloading the module until we've loaded the module
3940 * _and_ we have the lock on the VFS switch table.
3941 */
3942 while (vswp == NULL || !VFS_INSTALLED(vswp)) {
3943 RUNLOCK_VFSSW();
3944 if (modload("fs", modname) == -1)
3945 return (NULL);
3946 RLOCK_VFSSW();
3947 if (vswp == NULL)
3948 if ((vswp = vfs_getvfsswbyname(type)) == NULL)
3949 break;
3950 }
3951 RUNLOCK_VFSSW();
3952
3953 return (vswp);
3954 }
3955
3956 /*
3957 * Find a vfssw entry given a file system type name.
3958 */
3959 struct vfssw *
3960 vfs_getvfsswbyname(const char *type)
3961 {
3962 struct vfssw *vswp;
3963
3964 ASSERT(VFSSW_LOCKED());
3965 if (type == NULL || *type == '\0')
3966 return (NULL);
3967
3968 for (vswp = &vfssw[1]; vswp < &vfssw[nfstype]; vswp++) {
3969 if (strcmp(type, vswp->vsw_name) == 0) {
3970 vfs_refvfssw(vswp);
3971 return (vswp);
3972 }
3973 }
3974
3975 return (NULL);
3976 }
3977
3978 /*
3979 * Find a vfssw entry given a set of vfsops.
3980 */
3981 struct vfssw *
3982 vfs_getvfsswbyvfsops(vfsops_t *vfsops)
3983 {
3984 struct vfssw *vswp;
3985
3986 RLOCK_VFSSW();
3987 for (vswp = &vfssw[1]; vswp < &vfssw[nfstype]; vswp++) {
3988 if (ALLOCATED_VFSSW(vswp) && &vswp->vsw_vfsops == vfsops) {
3989 vfs_refvfssw(vswp);
3990 RUNLOCK_VFSSW();
3991 return (vswp);
3992 }
3993 }
3994 RUNLOCK_VFSSW();
3995
3996 return (NULL);
3997 }
3998
3999 /*
4000 * Reference a vfssw entry.
4001 */
4002 void
4003 vfs_refvfssw(struct vfssw *vswp)
4004 {
4005
4006 mutex_enter(&vswp->vsw_lock);
4007 vswp->vsw_count++;
4008 mutex_exit(&vswp->vsw_lock);
4009 }
4010
4011 /*
4012 * Unreference a vfssw entry.
4013 */
4014 void
4015 vfs_unrefvfssw(struct vfssw *vswp)
4016 {
4017
4018 mutex_enter(&vswp->vsw_lock);
4019 vswp->vsw_count--;
4020 mutex_exit(&vswp->vsw_lock);
4021 }
4022
4023 int sync_timeout = 30; /* timeout for syncing a page during panic */
4024 int sync_timeleft; /* portion of sync_timeout remaining */
4025
4026 static int sync_retries = 20; /* number of retries when not making progress */
4027 static int sync_triesleft; /* portion of sync_retries remaining */
4028
4029 static pgcnt_t old_pgcnt, new_pgcnt;
4030 static int new_bufcnt, old_bufcnt;
4031
4032 /*
4033 * Sync all of the mounted filesystems, and then wait for the actual i/o to
4034 * complete. We wait by counting the number of dirty pages and buffers,
4035 * pushing them out using bio_busy() and page_busy(), and then counting again.
4036 * This routine is used during both the uadmin A_SHUTDOWN code as well as
4037 * the SYNC phase of the panic code (see comments in panic.c). It should only
4038 * be used after some higher-level mechanism has quiesced the system so that
4039 * new writes are not being initiated while we are waiting for completion.
4040 *
4041 * To ensure finite running time, our algorithm uses two timeout mechanisms:
4042 * sync_timeleft (a timer implemented by the omnipresent deadman() cyclic), and
4043 * sync_triesleft (a progress counter used by the vfs_syncall() loop below).
4044 * Together these ensure that syncing completes if our i/o paths are stuck.
4045 * The counters are declared above so they can be found easily in the debugger.
4046 *
4047 * The sync_timeleft counter is reset by bio_busy() and page_busy() using the
4048 * vfs_syncprogress() subroutine whenever we make progress through the lists of
4049 * pages and buffers. It is decremented and expired by the deadman() cyclic.
4050 * When vfs_syncall() decides it is done, we disable the deadman() counter by
4051 * setting sync_timeleft to zero. This timer guards against vfs_syncall()
4052 * deadlocking or hanging inside of a broken filesystem or driver routine.
4053 *
4054 * The sync_triesleft counter is updated by vfs_syncall() itself. If we make
4055 * sync_retries consecutive calls to bio_busy() and page_busy() without
4056 * decreasing either the number of dirty buffers or dirty pages below the
4057 * lowest count we have seen so far, we give up and return from vfs_syncall().
4058 *
4059 * Each loop iteration ends with a call to delay() one second to allow time for
4060 * i/o completion and to permit the user time to read our progress messages.
4061 */
4062 void
4063 vfs_syncall(void)
4064 {
4065 if (rootdir == NULL && !modrootloaded)
4066 return; /* panic during boot - no filesystems yet */
4067
4068 printf("syncing file systems...");
4069 vfs_syncprogress();
4070 sync();
4071
4072 vfs_syncprogress();
4073 sync_triesleft = sync_retries;
4074
4075 old_bufcnt = new_bufcnt = INT_MAX;
4076 old_pgcnt = new_pgcnt = ULONG_MAX;
4077
4078 while (sync_triesleft > 0) {
4079 old_bufcnt = MIN(old_bufcnt, new_bufcnt);
4080 old_pgcnt = MIN(old_pgcnt, new_pgcnt);
4081
4082 new_bufcnt = bio_busy(B_TRUE);
4083 new_pgcnt = page_busy(B_TRUE);
4084 vfs_syncprogress();
4085
4086 if (new_bufcnt == 0 && new_pgcnt == 0)
4087 break;
4088
4089 if (new_bufcnt < old_bufcnt || new_pgcnt < old_pgcnt)
4090 sync_triesleft = sync_retries;
4091 else
4092 sync_triesleft--;
4093
4094 if (new_bufcnt)
4095 printf(" [%d]", new_bufcnt);
4096 if (new_pgcnt)
4097 printf(" %lu", new_pgcnt);
4098
4099 delay(hz);
4100 }
4101
4102 if (new_bufcnt != 0 || new_pgcnt != 0)
4103 printf(" done (not all i/o completed)\n");
4104 else
4105 printf(" done\n");
4106
4107 sync_timeleft = 0;
4108 delay(hz);
4109 }
4110
4111 /*
4112 * If we are in the middle of the sync phase of panic, reset sync_timeleft to
4113 * sync_timeout to indicate that we are making progress and the deadman()
4114 * omnipresent cyclic should not yet time us out. Note that it is safe to
4115 * store to sync_timeleft here since the deadman() is firing at high-level
4116 * on top of us. If we are racing with the deadman(), either the deadman()
4117 * will decrement the old value and then we will reset it, or we will
4118 * reset it and then the deadman() will immediately decrement it. In either
4119 * case, correct behavior results.
4120 */
4121 void
4122 vfs_syncprogress(void)
4123 {
4124 if (panicstr)
4125 sync_timeleft = sync_timeout;
4126 }
4127
4128 /*
4129 * Map VFS flags to statvfs flags. These shouldn't really be separate
4130 * flags at all.
4131 */
4132 uint_t
4133 vf_to_stf(uint_t vf)
4134 {
4135 uint_t stf = 0;
4136
4137 if (vf & VFS_RDONLY)
4138 stf |= ST_RDONLY;
4139 if (vf & VFS_NOSETUID)
4140 stf |= ST_NOSUID;
4141 if (vf & VFS_NOTRUNC)
4142 stf |= ST_NOTRUNC;
4143
4144 return (stf);
4145 }
4146
4147 /*
4148 * Entries for (illegal) fstype 0.
4149 */
4150 /* ARGSUSED */
4151 int
4152 vfsstray_sync(struct vfs *vfsp, short arg, struct cred *cr)
4153 {
4154 cmn_err(CE_PANIC, "stray vfs operation");
4155 return (0);
4156 }
4157
4158 /*
4159 * Entries for (illegal) fstype 0.
4160 */
4161 int
4162 vfsstray(void)
4163 {
4164 cmn_err(CE_PANIC, "stray vfs operation");
4165 return (0);
4166 }
4167
4168 /*
4169 * Support for dealing with forced UFS unmount and its interaction with
4170 * LOFS. Could be used by any filesystem.
4171 * See bug 1203132.
4172 */
4173 int
4174 vfs_EIO(void)
4175 {
4176 return (EIO);
4177 }
4178
4179 /*
4180 * We've gotta define the op for sync separately, since the compiler gets
4181 * confused if we mix and match ANSI and normal style prototypes when
4182 * a "short" argument is present and spits out a warning.
4183 */
4184 /*ARGSUSED*/
4185 int
4186 vfs_EIO_sync(struct vfs *vfsp, short arg, struct cred *cr)
4187 {
4188 return (EIO);
4189 }
4190
4191 vfs_t EIO_vfs;
4192 vfsops_t *EIO_vfsops;
4193
4194 /*
4195 * Called from startup() to initialize all loaded vfs's
4196 */
4197 void
4198 vfsinit(void)
4199 {
4200 struct vfssw *vswp;
4201 int error;
4202 extern int vopstats_enabled;
4203 extern void vopstats_startup();
4204
4205 static const fs_operation_def_t EIO_vfsops_template[] = {
4206 VFSNAME_MOUNT, { .error = vfs_EIO },
4207 VFSNAME_UNMOUNT, { .error = vfs_EIO },
4208 VFSNAME_ROOT, { .error = vfs_EIO },
4209 VFSNAME_STATVFS, { .error = vfs_EIO },
4210 VFSNAME_SYNC, { .vfs_sync = vfs_EIO_sync },
4211 VFSNAME_VGET, { .error = vfs_EIO },
4212 VFSNAME_MOUNTROOT, { .error = vfs_EIO },
4213 VFSNAME_FREEVFS, { .error = vfs_EIO },
4214 VFSNAME_VNSTATE, { .error = vfs_EIO },
4215 NULL, NULL
4216 };
4217
4218 static const fs_operation_def_t stray_vfsops_template[] = {
4219 VFSNAME_MOUNT, { .error = vfsstray },
4220 VFSNAME_UNMOUNT, { .error = vfsstray },
4221 VFSNAME_ROOT, { .error = vfsstray },
4222 VFSNAME_STATVFS, { .error = vfsstray },
4223 VFSNAME_SYNC, { .vfs_sync = vfsstray_sync },
4224 VFSNAME_VGET, { .error = vfsstray },
4225 VFSNAME_MOUNTROOT, { .error = vfsstray },
4226 VFSNAME_FREEVFS, { .error = vfsstray },
4227 VFSNAME_VNSTATE, { .error = vfsstray },
4228 NULL, NULL
4229 };
4230
4231 /* Create vfs cache */
4232 vfs_cache = kmem_cache_create("vfs_cache", sizeof (struct vfs),
4233 sizeof (uintptr_t), NULL, NULL, NULL, NULL, NULL, 0);
4234
4235 /* Initialize the vnode cache (file systems may use it during init). */
4236 vn_create_cache();
4237
4238 /* Setup event monitor framework */
4239 fem_init();
4240
4241 /* Setup filesystem hook framework */
4242 fsh_init();
4243
4244 /* Initialize the dummy stray file system type. */
4245 error = vfs_setfsops(0, stray_vfsops_template, NULL);
4246
4247 /* Initialize the dummy EIO file system. */
4248 error = vfs_makefsops(EIO_vfsops_template, &EIO_vfsops);
4249 if (error != 0) {
4250 cmn_err(CE_WARN, "vfsinit: bad EIO vfs ops template");
4251 /* Shouldn't happen, but not bad enough to panic */
4252 }
4253
4254 VFS_INIT(&EIO_vfs, EIO_vfsops, (caddr_t)NULL);
4255
4256 /*
4257 * Default EIO_vfs.vfs_flag to VFS_UNMOUNTED so a lookup
4258 * on this vfs can immediately notice it's invalid.
4259 */
4260 EIO_vfs.vfs_flag |= VFS_UNMOUNTED;
4261
4262 /*
4263 * Call the init routines of non-loadable filesystems only.
4264 * Filesystems which are loaded as separate modules will be
4265 * initialized by the module loading code instead.
4266 */
4267
4268 for (vswp = &vfssw[1]; vswp < &vfssw[nfstype]; vswp++) {
4269 RLOCK_VFSSW();
4270 if (vswp->vsw_init != NULL)
4271 (*vswp->vsw_init)(vswp - vfssw, vswp->vsw_name);
4272 RUNLOCK_VFSSW();
4273 }
4274
4275 vopstats_startup();
4276
4277 if (vopstats_enabled) {
4278 /* EIO_vfs can collect stats, but we don't retrieve them */
4279 initialize_vopstats(&EIO_vfs.vfs_vopstats);
4280 EIO_vfs.vfs_fstypevsp = NULL;
4281 EIO_vfs.vfs_vskap = NULL;
4282 EIO_vfs.vfs_flag |= VFS_STATS;
4283 }
4284
4285 xattr_init();
4286
4287 reparse_point_init();
4288 }
4289
4290 vfs_t *
4291 vfs_alloc(int kmflag)
4292 {
4293 vfs_t *vfsp;
4294
4295 vfsp = kmem_cache_alloc(vfs_cache, kmflag);
4296
4297 /*
4298 * Do the simplest initialization here.
4299 * Everything else gets done in vfs_init()
4300 */
4301 bzero(vfsp, sizeof (vfs_t));
4302 return (vfsp);
4303 }
4304
4305 void
4306 vfs_free(vfs_t *vfsp)
4307 {
4308 /*
4309 * One would be tempted to assert that "vfsp->vfs_count == 0".
4310 * The problem is that this gets called out of domount() with
4311 * a partially initialized vfs and a vfs_count of 1. This is
4312 * also called from vfs_rele() with a vfs_count of 0. We can't
4313 * call VFS_RELE() from domount() if VFS_MOUNT() hasn't successfully
4314 * returned. This is because VFS_MOUNT() fully initializes the
4315 * vfs structure and its associated data. VFS_RELE() will call
4316 * VFS_FREEVFS() which may panic the system if the data structures
4317 * aren't fully initialized from a successful VFS_MOUNT()).
4318 */
4319
4320 /* If FEM was in use, make sure everything gets cleaned up */
4321 if (vfsp->vfs_femhead) {
4322 ASSERT(vfsp->vfs_femhead->femh_list == NULL);
4323 mutex_destroy(&vfsp->vfs_femhead->femh_lock);
4324 kmem_free(vfsp->vfs_femhead, sizeof (*(vfsp->vfs_femhead)));
4325 vfsp->vfs_femhead = NULL;
4326 }
4327
4328 /*
4329 * fsh cleanup
4330 * There's no need here to use atomic operations on vfs_fshrecord.
4331 */
4332 if (vfsp->vfs_fshrecord != NULL) {
4333 fsh_fsrec_destroy(vfsp->vfs_fshrecord);
4334 vfsp->vfs_fshrecord = NULL;
4335 }
4336
4337 if (vfsp->vfs_implp)
4338 vfsimpl_teardown(vfsp);
4339 sema_destroy(&vfsp->vfs_reflock);
4340 kmem_cache_free(vfs_cache, vfsp);
4341 }
4342
4343 /*
4344 * Increments the vfs reference count by one atomically.
4345 */
4346 void
4347 vfs_hold(vfs_t *vfsp)
4348 {
4349 atomic_add_32(&vfsp->vfs_count, 1);
4350 ASSERT(vfsp->vfs_count != 0);
4351 }
4352
4353 /*
4354 * Decrements the vfs reference count by one atomically. When
4355 * vfs reference count becomes zero, it calls the file system
4356 * specific vfs_freevfs() to free up the resources.
4357 */
4358 void
4359 vfs_rele(vfs_t *vfsp)
4360 {
4361 ASSERT(vfsp->vfs_count != 0);
4362 if (atomic_add_32_nv(&vfsp->vfs_count, -1) == 0) {
4363 fsh_exec_free_callbacks(vfsp);
4364 VFS_FREEVFS(vfsp);
4365 lofi_remove(vfsp);
4366 if (vfsp->vfs_zone)
4367 zone_rele_ref(&vfsp->vfs_implp->vi_zone_ref,
4368 ZONE_REF_VFS);
4369 vfs_freemnttab(vfsp);
4370 vfs_free(vfsp);
4371 }
4372 }
4373
4374 /*
4375 * Generic operations vector support.
4376 *
4377 * This is used to build operations vectors for both the vfs and vnode.
4378 * It's normally called only when a file system is loaded.
4379 *
4380 * There are many possible algorithms for this, including the following:
4381 *
4382 * (1) scan the list of known operations; for each, see if the file system
4383 * includes an entry for it, and fill it in as appropriate.
4384 *
4385 * (2) set up defaults for all known operations. scan the list of ops
4386 * supplied by the file system; for each which is both supplied and
4387 * known, fill it in.
4388 *
4389 * (3) sort the lists of known ops & supplied ops; scan the list, filling
4390 * in entries as we go.
4391 *
4392 * we choose (1) for simplicity, and because performance isn't critical here.
4393 * note that (2) could be sped up using a precomputed hash table on known ops.
4394 * (3) could be faster than either, but only if the lists were very large or
4395 * supplied in sorted order.
4396 *
4397 */
4398
4399 int
4400 fs_build_vector(void *vector, int *unused_ops,
4401 const fs_operation_trans_def_t *translation,
4402 const fs_operation_def_t *operations)
4403 {
4404 int i, num_trans, num_ops, used;
4405
4406 /*
4407 * Count the number of translations and the number of supplied
4408 * operations.
4409 */
4410
4411 {
4412 const fs_operation_trans_def_t *p;
4413
4414 for (num_trans = 0, p = translation;
4415 p->name != NULL;
4416 num_trans++, p++)
4417 ;
4418 }
4419
4420 {
4421 const fs_operation_def_t *p;
4422
4423 for (num_ops = 0, p = operations;
4424 p->name != NULL;
4425 num_ops++, p++)
4426 ;
4427 }
4428
4429 /* Walk through each operation known to our caller. There will be */
4430 /* one entry in the supplied "translation table" for each. */
4431
4432 used = 0;
4433
4434 for (i = 0; i < num_trans; i++) {
4435 int j, found;
4436 char *curname;
4437 fs_generic_func_p result;
4438 fs_generic_func_p *location;
4439
4440 curname = translation[i].name;
4441
4442 /* Look for a matching operation in the list supplied by the */
4443 /* file system. */
4444
4445 found = 0;
4446
4447 for (j = 0; j < num_ops; j++) {
4448 if (strcmp(operations[j].name, curname) == 0) {
4449 used++;
4450 found = 1;
4451 break;
4452 }
4453 }
4454
4455 /*
4456 * If the file system is using a "placeholder" for default
4457 * or error functions, grab the appropriate function out of
4458 * the translation table. If the file system didn't supply
4459 * this operation at all, use the default function.
4460 */
4461
4462 if (found) {
4463 result = operations[j].func.fs_generic;
4464 if (result == fs_default) {
4465 result = translation[i].defaultFunc;
4466 } else if (result == fs_error) {
4467 result = translation[i].errorFunc;
4468 } else if (result == NULL) {
4469 /* Null values are PROHIBITED */
4470 return (EINVAL);
4471 }
4472 } else {
4473 result = translation[i].defaultFunc;
4474 }
4475
4476 /* Now store the function into the operations vector. */
4477
4478 location = (fs_generic_func_p *)
4479 (((char *)vector) + translation[i].offset);
4480
4481 *location = result;
4482 }
4483
4484 *unused_ops = num_ops - used;
4485
4486 return (0);
4487 }
4488
4489 /* Placeholder functions, should never be called. */
4490
4491 int
4492 fs_error(void)
4493 {
4494 cmn_err(CE_PANIC, "fs_error called");
4495 return (0);
4496 }
4497
4498 int
4499 fs_default(void)
4500 {
4501 cmn_err(CE_PANIC, "fs_default called");
4502 return (0);
4503 }
4504
4505 #ifdef __sparc
4506
4507 /*
4508 * Part of the implementation of booting off a mirrored root
4509 * involves a change of dev_t for the root device. To
4510 * accomplish this, first remove the existing hash table
4511 * entry for the root device, convert to the new dev_t,
4512 * then re-insert in the hash table at the head of the list.
4513 */
4514 void
4515 vfs_root_redev(vfs_t *vfsp, dev_t ndev, int fstype)
4516 {
4517 vfs_list_lock();
4518
4519 vfs_hash_remove(vfsp);
4520
4521 vfsp->vfs_dev = ndev;
4522 vfs_make_fsid(&vfsp->vfs_fsid, ndev, fstype);
4523
4524 vfs_hash_add(vfsp, 1);
4525
4526 vfs_list_unlock();
4527 }
4528
4529 #else /* x86 NEWBOOT */
4530
4531 #if defined(__x86)
4532 extern int hvmboot_rootconf();
4533 #endif /* __x86 */
4534
4535 extern ib_boot_prop_t *iscsiboot_prop;
4536
4537 int
4538 rootconf()
4539 {
4540 int error;
4541 struct vfssw *vsw;
4542 extern void pm_init();
4543 char *fstyp, *fsmod;
4544 int ret = -1;
4545
4546 getrootfs(&fstyp, &fsmod);
4547
4548 #if defined(__x86)
4549 /*
4550 * hvmboot_rootconf() is defined in the hvm_bootstrap misc module,
4551 * which lives in /platform/i86hvm, and hence is only available when
4552 * booted in an x86 hvm environment. If the hvm_bootstrap misc module
4553 * is not available then the modstub for this function will return 0.
4554 * If the hvm_bootstrap misc module is available it will be loaded
4555 * and hvmboot_rootconf() will be invoked.
4556 */
4557 if (error = hvmboot_rootconf())
4558 return (error);
4559 #endif /* __x86 */
4560
4561 if (error = clboot_rootconf())
4562 return (error);
4563
4564 if (modload("fs", fsmod) == -1)
4565 panic("Cannot _init %s module", fsmod);
4566
4567 RLOCK_VFSSW();
4568 vsw = vfs_getvfsswbyname(fstyp);
4569 RUNLOCK_VFSSW();
4570 if (vsw == NULL) {
4571 cmn_err(CE_CONT, "Cannot find %s filesystem\n", fstyp);
4572 return (ENXIO);
4573 }
4574 VFS_INIT(rootvfs, &vsw->vsw_vfsops, 0);
4575 VFS_HOLD(rootvfs);
4576
4577 /* always mount readonly first */
4578 rootvfs->vfs_flag |= VFS_RDONLY;
4579
4580 pm_init();
4581
4582 if (netboot && iscsiboot_prop) {
4583 cmn_err(CE_WARN, "NFS boot and iSCSI boot"
4584 " shouldn't happen in the same time");
4585 return (EINVAL);
4586 }
4587
4588 if (netboot || iscsiboot_prop) {
4589 ret = strplumb();
4590 if (ret != 0) {
4591 cmn_err(CE_WARN, "Cannot plumb network device %d", ret);
4592 return (EFAULT);
4593 }
4594 }
4595
4596 if ((ret == 0) && iscsiboot_prop) {
4597 ret = modload("drv", "iscsi");
4598 /* -1 indicates fail */
4599 if (ret == -1) {
4600 cmn_err(CE_WARN, "Failed to load iscsi module");
4601 iscsi_boot_prop_free();
4602 return (EINVAL);
4603 } else {
4604 if (!i_ddi_attach_pseudo_node("iscsi")) {
4605 cmn_err(CE_WARN,
4606 "Failed to attach iscsi driver");
4607 iscsi_boot_prop_free();
4608 return (ENODEV);
4609 }
4610 }
4611 }
4612
4613 error = VFS_MOUNTROOT(rootvfs, ROOT_INIT);
4614 vfs_unrefvfssw(vsw);
4615 rootdev = rootvfs->vfs_dev;
4616
4617 if (error)
4618 cmn_err(CE_CONT, "Cannot mount root on %s fstype %s\n",
4619 rootfs.bo_name, fstyp);
4620 else
4621 cmn_err(CE_CONT, "?root on %s fstype %s\n",
4622 rootfs.bo_name, fstyp);
4623 return (error);
4624 }
4625
4626 /*
4627 * XXX this is called by nfs only and should probably be removed
4628 * If booted with ASKNAME, prompt on the console for a filesystem
4629 * name and return it.
4630 */
4631 void
4632 getfsname(char *askfor, char *name, size_t namelen)
4633 {
4634 if (boothowto & RB_ASKNAME) {
4635 printf("%s name: ", askfor);
4636 console_gets(name, namelen);
4637 }
4638 }
4639
4640 /*
4641 * Init the root filesystem type (rootfs.bo_fstype) from the "fstype"
4642 * property.
4643 *
4644 * Filesystem types starting with the prefix "nfs" are diskless clients;
4645 * init the root filename name (rootfs.bo_name), too.
4646 *
4647 * If we are booting via NFS we currently have these options:
4648 * nfs - dynamically choose NFS V2, V3, or V4 (default)
4649 * nfs2 - force NFS V2
4650 * nfs3 - force NFS V3
4651 * nfs4 - force NFS V4
4652 * Because we need to maintain backward compatibility with the naming
4653 * convention that the NFS V2 filesystem name is "nfs" (see vfs_conf.c)
4654 * we need to map "nfs" => "nfsdyn" and "nfs2" => "nfs". The dynamic
4655 * nfs module will map the type back to either "nfs", "nfs3", or "nfs4".
4656 * This is only for root filesystems, all other uses such as cachefs
4657 * will expect that "nfs" == NFS V2.
4658 */
4659 static void
4660 getrootfs(char **fstypp, char **fsmodp)
4661 {
4662 extern char *strplumb_get_netdev_path(void);
4663 char *propstr = NULL;
4664
4665 /*
4666 * Check fstype property; for diskless it should be one of "nfs",
4667 * "nfs2", "nfs3" or "nfs4".
4668 */
4669 if (ddi_prop_lookup_string(DDI_DEV_T_ANY, ddi_root_node(),
4670 DDI_PROP_DONTPASS, "fstype", &propstr)
4671 == DDI_SUCCESS) {
4672 (void) strncpy(rootfs.bo_fstype, propstr, BO_MAXFSNAME);
4673 ddi_prop_free(propstr);
4674
4675 /*
4676 * if the boot property 'fstype' is not set, but 'zfs-bootfs' is set,
4677 * assume the type of this root filesystem is 'zfs'.
4678 */
4679 } else if (ddi_prop_lookup_string(DDI_DEV_T_ANY, ddi_root_node(),
4680 DDI_PROP_DONTPASS, "zfs-bootfs", &propstr)
4681 == DDI_SUCCESS) {
4682 (void) strncpy(rootfs.bo_fstype, "zfs", BO_MAXFSNAME);
4683 ddi_prop_free(propstr);
4684 }
4685
4686 if (strncmp(rootfs.bo_fstype, "nfs", 3) != 0) {
4687 *fstypp = *fsmodp = rootfs.bo_fstype;
4688 return;
4689 }
4690
4691 ++netboot;
4692
4693 if (strcmp(rootfs.bo_fstype, "nfs2") == 0)
4694 (void) strcpy(rootfs.bo_fstype, "nfs");
4695 else if (strcmp(rootfs.bo_fstype, "nfs") == 0)
4696 (void) strcpy(rootfs.bo_fstype, "nfsdyn");
4697
4698 /*
4699 * check if path to network interface is specified in bootpath
4700 * or by a hypervisor domain configuration file.
4701 * XXPV - enable strlumb_get_netdev_path()
4702 */
4703 if (ddi_prop_exists(DDI_DEV_T_ANY, ddi_root_node(), DDI_PROP_DONTPASS,
4704 "xpv-nfsroot")) {
4705 (void) strcpy(rootfs.bo_name, "/xpvd/xnf@0");
4706 } else if (ddi_prop_lookup_string(DDI_DEV_T_ANY, ddi_root_node(),
4707 DDI_PROP_DONTPASS, "bootpath", &propstr)
4708 == DDI_SUCCESS) {
4709 (void) strncpy(rootfs.bo_name, propstr, BO_MAXOBJNAME);
4710 ddi_prop_free(propstr);
4711 } else {
4712 /* attempt to determine netdev_path via boot_mac address */
4713 netdev_path = strplumb_get_netdev_path();
4714 if (netdev_path == NULL)
4715 panic("cannot find boot network interface");
4716 (void) strncpy(rootfs.bo_name, netdev_path, BO_MAXOBJNAME);
4717 }
4718 *fstypp = rootfs.bo_fstype;
4719 *fsmodp = "nfs";
4720 }
4721 #endif
4722
4723 /*
4724 * VFS feature routines
4725 */
4726
4727 #define VFTINDEX(feature) (((feature) >> 32) & 0xFFFFFFFF)
4728 #define VFTBITS(feature) ((feature) & 0xFFFFFFFFLL)
4729
4730 /* Register a feature in the vfs */
4731 void
4732 vfs_set_feature(vfs_t *vfsp, vfs_feature_t feature)
4733 {
4734 /* Note that vfs_featureset[] is found in *vfsp->vfs_implp */
4735 if (vfsp->vfs_implp == NULL)
4736 return;
4737
4738 vfsp->vfs_featureset[VFTINDEX(feature)] |= VFTBITS(feature);
4739 }
4740
4741 void
4742 vfs_clear_feature(vfs_t *vfsp, vfs_feature_t feature)
4743 {
4744 /* Note that vfs_featureset[] is found in *vfsp->vfs_implp */
4745 if (vfsp->vfs_implp == NULL)
4746 return;
4747 vfsp->vfs_featureset[VFTINDEX(feature)] &= VFTBITS(~feature);
4748 }
4749
4750 /*
4751 * Query a vfs for a feature.
4752 * Returns 1 if feature is present, 0 if not
4753 */
4754 int
4755 vfs_has_feature(vfs_t *vfsp, vfs_feature_t feature)
4756 {
4757 int ret = 0;
4758
4759 /* Note that vfs_featureset[] is found in *vfsp->vfs_implp */
4760 if (vfsp->vfs_implp == NULL)
4761 return (ret);
4762
4763 if (vfsp->vfs_featureset[VFTINDEX(feature)] & VFTBITS(feature))
4764 ret = 1;
4765
4766 return (ret);
4767 }
4768
4769 /*
4770 * Propagate feature set from one vfs to another
4771 */
4772 void
4773 vfs_propagate_features(vfs_t *from, vfs_t *to)
4774 {
4775 int i;
4776
4777 if (to->vfs_implp == NULL || from->vfs_implp == NULL)
4778 return;
4779
4780 for (i = 1; i <= to->vfs_featureset[0]; i++) {
4781 to->vfs_featureset[i] = from->vfs_featureset[i];
4782 }
4783 }
4784
4785 #define LOFINODE_PATH "/dev/lofi/%d"
4786
4787 /*
4788 * Return the vnode for the lofi node if there's a lofi mount in place.
4789 * Returns -1 when there's no lofi node, 0 on success, and > 0 on
4790 * failure.
4791 */
4792 int
4793 vfs_get_lofi(vfs_t *vfsp, vnode_t **vpp)
4794 {
4795 char *path = NULL;
4796 int strsize;
4797 int err;
4798
4799 if (vfsp->vfs_lofi_minor == 0) {
4800 *vpp = NULL;
4801 return (-1);
4802 }
4803
4804 strsize = snprintf(NULL, 0, LOFINODE_PATH, vfsp->vfs_lofi_minor);
4805 path = kmem_alloc(strsize + 1, KM_SLEEP);
4806 (void) snprintf(path, strsize + 1, LOFINODE_PATH, vfsp->vfs_lofi_minor);
4807
4808 /*
4809 * We may be inside a zone, so we need to use the /dev path, but
4810 * it's created asynchronously, so we wait here.
4811 */
4812 for (;;) {
4813 err = lookupname(path, UIO_SYSSPACE, FOLLOW, NULLVPP, vpp);
4814
4815 if (err != ENOENT)
4816 break;
4817
4818 if ((err = delay_sig(hz / 8)) == EINTR)
4819 break;
4820 }
4821
4822 if (err)
4823 *vpp = NULL;
4824
4825 kmem_free(path, strsize + 1);
4826 return (err);
4827 }