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 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25 /*
26 * Copyright (c) 2012 by Delphix. All rights reserved.
27 */
28
29 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
30 /* All Rights Reserved */
31
32 /*
33 * University Copyright- Copyright (c) 1982, 1986, 1988
34 * The Regents of the University of California
35 * All Rights Reserved
36 *
37 * University Acknowledgment- Portions of this document are derived from
38 * software developed by the University of California, Berkeley, and its
39 * contributors.
40 */
41
42
43 #include <sys/types.h>
44 #include <sys/t_lock.h>
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/buf.h>
48 #include <sys/conf.h>
49 #include <sys/cred.h>
50 #include <sys/kmem.h>
51 #include <sys/sysmacros.h>
52 #include <sys/vfs.h>
53 #include <sys/vfs_opreg.h>
54 #include <sys/vnode.h>
55 #include <sys/fs/snode.h>
56 #include <sys/fs/fifonode.h>
57 #include <sys/debug.h>
58 #include <sys/errno.h>
59 #include <sys/time.h>
60 #include <sys/file.h>
61 #include <sys/open.h>
62 #include <sys/user.h>
63 #include <sys/termios.h>
64 #include <sys/stream.h>
65 #include <sys/strsubr.h>
66 #include <sys/autoconf.h>
67 #include <sys/esunddi.h>
68 #include <sys/flock.h>
69 #include <sys/modctl.h>
70
71 struct vfs spec_vfs;
72 static dev_t specdev;
73 struct kmem_cache *snode_cache;
74 int spec_debug = 0;
75
76 static struct snode *sfind(dev_t, vtype_t, struct vnode *);
77 static struct vnode *get_cvp(dev_t, vtype_t, struct snode *, int *);
78 static void sinsert(struct snode *);
79
80 struct vnode *
81 specvp_devfs(
82 struct vnode *realvp,
83 dev_t dev,
84 vtype_t vtyp,
85 struct cred *cr,
86 dev_info_t *dip)
87 {
88 struct vnode *vp;
89
90 ASSERT(realvp && dip);
91 vp = specvp(realvp, dev, vtyp, cr);
92 ASSERT(vp);
93
94 /* associate a dip hold with the common snode's s_dip pointer */
95 spec_assoc_vp_with_devi(vp, dip);
96 return (vp);
97 }
98
99 /*
100 * Return a shadow special vnode for the given dev.
101 * If no snode exists for this dev create one and put it
102 * in a table hashed by <dev, realvp>. If the snode for
103 * this dev is already in the table return it (ref count is
104 * incremented by sfind). The snode will be flushed from the
105 * table when spec_inactive calls sdelete.
106 *
107 * The fsid is inherited from the real vnode so that clones
108 * can be found.
109 *
110 */
111 struct vnode *
112 specvp(
113 struct vnode *vp,
114 dev_t dev,
115 vtype_t type,
116 struct cred *cr)
117 {
118 struct snode *sp;
119 struct snode *nsp;
120 struct snode *csp;
121 struct vnode *svp;
122 struct vattr va;
123 int rc;
124 int used_csp = 0; /* Did we use pre-allocated csp */
125
126 if (vp == NULL)
127 return (NULL);
128 if (vp->v_type == VFIFO)
129 return (fifovp(vp, cr));
130
131 ASSERT(vp->v_type == type);
132 ASSERT(vp->v_rdev == dev);
133
134 /*
135 * Pre-allocate snodes before holding any locks in case we block
136 */
137 nsp = kmem_cache_alloc(snode_cache, KM_SLEEP);
138 csp = kmem_cache_alloc(snode_cache, KM_SLEEP);
139
140 /*
141 * Get the time attributes outside of the stable lock since
142 * this operation may block. Unfortunately, it may not have
143 * been required if the snode is in the cache.
144 */
145 va.va_mask = AT_FSID | AT_TIMES;
146 rc = VOP_GETATTR(vp, &va, 0, cr, NULL); /* XXX may block! */
147
148 mutex_enter(&stable_lock);
149 if ((sp = sfind(dev, type, vp)) == NULL) {
150 struct vnode *cvp;
151
152 sp = nsp; /* Use pre-allocated snode */
153 svp = STOV(sp);
154
155 sp->s_realvp = vp;
156 VN_HOLD(vp);
157 sp->s_commonvp = NULL;
158 sp->s_dev = dev;
159 sp->s_dip = NULL;
160 sp->s_nextr = NULL;
161 sp->s_list = NULL;
162 sp->s_plcy = NULL;
163 sp->s_size = 0;
164 sp->s_flag = 0;
165 if (rc == 0) {
166 /*
167 * Set times in snode to those in the vnode.
168 */
169 sp->s_fsid = va.va_fsid;
170 sp->s_atime = va.va_atime.tv_sec;
171 sp->s_mtime = va.va_mtime.tv_sec;
172 sp->s_ctime = va.va_ctime.tv_sec;
173 } else {
174 sp->s_fsid = specdev;
175 sp->s_atime = 0;
176 sp->s_mtime = 0;
177 sp->s_ctime = 0;
178 }
179 sp->s_count = 0;
180 sp->s_mapcnt = 0;
181
182 vn_reinit(svp);
183 svp->v_flag = (vp->v_flag & VROOT);
184 svp->v_vfsp = vp->v_vfsp;
185 VFS_HOLD(svp->v_vfsp);
186 svp->v_type = type;
187 svp->v_rdev = dev;
188 (void) vn_copypath(vp, svp);
189 if (type == VBLK || type == VCHR) {
190 cvp = get_cvp(dev, type, csp, &used_csp);
191 svp->v_stream = cvp->v_stream;
192
193 sp->s_commonvp = cvp;
194 }
195 vn_exists(svp);
196 sinsert(sp);
197 mutex_exit(&stable_lock);
198 if (used_csp == 0) {
199 /* Didn't use pre-allocated snode so free it */
200 kmem_cache_free(snode_cache, csp);
201 }
202 } else {
203 mutex_exit(&stable_lock);
204 /* free unused snode memory */
205 kmem_cache_free(snode_cache, nsp);
206 kmem_cache_free(snode_cache, csp);
207 }
208 return (STOV(sp));
209 }
210
211 /*
212 * Return a special vnode for the given dev; no vnode is supplied
213 * for it to shadow. Always create a new snode and put it in the
214 * table hashed by <dev, NULL>. The snode will be flushed from the
215 * table when spec_inactive() calls sdelete(). The association of
216 * this node with a attached instance of hardware is not made until
217 * spec_open time.
218 *
219 * N.B. Assumes caller takes on responsibility of making sure no one
220 * else is creating a snode for (dev, type) at this time.
221 */
222 struct vnode *
223 makespecvp(dev_t dev, vtype_t type)
224 {
225 struct snode *sp;
226 struct vnode *svp, *cvp;
227 time_t now;
228
229 sp = kmem_cache_alloc(snode_cache, KM_SLEEP);
230 svp = STOV(sp);
231 cvp = commonvp(dev, type);
232 now = gethrestime_sec();
233
234 sp->s_realvp = NULL;
235 sp->s_commonvp = cvp;
236 sp->s_dev = dev;
237 sp->s_dip = NULL;
238 sp->s_nextr = NULL;
239 sp->s_list = NULL;
240 sp->s_plcy = NULL;
241 sp->s_size = 0;
242 sp->s_flag = 0;
243 sp->s_fsid = specdev;
244 sp->s_atime = now;
245 sp->s_mtime = now;
246 sp->s_ctime = now;
247 sp->s_count = 0;
248 sp->s_mapcnt = 0;
249
250 vn_reinit(svp);
251 svp->v_vfsp = &spec_vfs;
252 svp->v_stream = cvp->v_stream;
253 svp->v_type = type;
254 svp->v_rdev = dev;
255
256 vn_exists(svp);
257 mutex_enter(&stable_lock);
258 sinsert(sp);
259 mutex_exit(&stable_lock);
260
261 return (svp);
262 }
263
264
265 /*
266 * This function is called from spec_assoc_vp_with_devi(). That function
267 * associates a "new" dip with a common snode, releasing (any) old dip
268 * in the process. This function (spec_assoc_fence()) looks at the "new dip"
269 * and determines whether the snode should be fenced of or not. As the table
270 * below indicates, the value of old-dip is a don't care for all cases.
271 *
272 * old-dip new-dip common-snode
273 * =========================================
274 * Don't care NULL unfence
275 * Don't care retired fence
276 * Don't care not-retired unfence
277 *
278 * Since old-dip value is a "don't care", it is not passed into this function.
279 */
280 static void
281 spec_assoc_fence(dev_info_t *ndip, vnode_t *vp)
282 {
283 int fence;
284 struct snode *csp;
285
286 ASSERT(vp);
287 ASSERT(vn_matchops(vp, spec_getvnodeops()));
288
289 fence = 0;
290 if (ndip != NULL) {
291 mutex_enter(&DEVI(ndip)->devi_lock);
292 if (DEVI(ndip)->devi_flags & DEVI_RETIRED)
293 fence = 1;
294 mutex_exit(&DEVI(ndip)->devi_lock);
295 }
296
297 csp = VTOCS(vp);
298 ASSERT(csp);
299
300 /* SFENCED flag only set on common snode */
301 mutex_enter(&csp->s_lock);
302 if (fence)
303 csp->s_flag |= SFENCED;
304 else
305 csp->s_flag &= ~SFENCED;
306 mutex_exit(&csp->s_lock);
307
308 FENDBG((CE_NOTE, "%sfenced common snode (%p) for new dip=%p",
309 fence ? "" : "un", (void *)csp, (void *)ndip));
310 }
311
312 /*
313 * Associate the common snode with a devinfo node. This is called from:
314 *
315 * 1) specvp_devfs to associate a specfs node with the dip attached
316 * by devfs.
317 *
318 * 2) spec_open after path reconstruction and attach.
319 *
320 * 3) From dacf processing to associate a makespecvp node with
321 * the dip that dacf postattach processing is being performed on.
322 * This association is made prior to open to avoid recursion issues.
323 *
324 * 4) From ddi_assoc_queue_with_devi to change vnode association as part of
325 * DL_ATTACH/DL_DETACH processing (SDIPSET already set). The call
326 * from ddi_assoc_queue_with_devi may specify a NULL dip.
327 *
328 * We put an extra hold on the devinfo node passed in as we establish it as
329 * the new s_dip pointer. Any hold associated with the prior s_dip pointer
330 * is released. The new hold will stay active until another call to
331 * spec_assoc_vp_with_devi or until the common snode is destroyed by
332 * spec_inactive after the last VN_RELE of the common node. This devinfo hold
333 * transfers across a clone open except in the clone_dev case, where the clone
334 * driver is no longer required after open.
335 *
336 * When SDIPSET is set and s_dip is NULL, the vnode has an association with
337 * the driver even though there is currently no association with a specific
338 * hardware instance.
339 */
340 void
341 spec_assoc_vp_with_devi(struct vnode *vp, dev_info_t *dip)
342 {
343 struct snode *csp;
344 dev_info_t *olddip;
345
346 ASSERT(vp);
347
348 /*
349 * Don't establish a NULL association for a vnode associated with the
350 * clone driver. The qassociate(, -1) call from a streams driver's
351 * open implementation to indicate support for qassociate has the
352 * side-effect of this type of spec_assoc_vp_with_devi call. This
353 * call should not change the the association of the pre-clone
354 * vnode associated with the clone driver, the post-clone newdev
355 * association will be established later by spec_clone().
356 */
357 if ((dip == NULL) && (getmajor(vp->v_rdev) == clone_major))
358 return;
359
360 /* hold the new */
361 if (dip)
362 e_ddi_hold_devi(dip);
363
364 csp = VTOS(VTOS(vp)->s_commonvp);
365 mutex_enter(&csp->s_lock);
366 olddip = csp->s_dip;
367 csp->s_dip = dip;
368 csp->s_flag |= SDIPSET;
369
370 /* If association changes then invalidate cached size */
371 if (olddip != dip)
372 csp->s_flag &= ~SSIZEVALID;
373 mutex_exit(&csp->s_lock);
374
375 spec_assoc_fence(dip, vp);
376
377 /* release the old */
378 if (olddip)
379 ddi_release_devi(olddip);
380 }
381
382 /*
383 * Return the held dip associated with the specified snode.
384 */
385 dev_info_t *
386 spec_hold_devi_by_vp(struct vnode *vp)
387 {
388 struct snode *csp;
389 dev_info_t *dip;
390
391 ASSERT(vn_matchops(vp, spec_getvnodeops()));
392
393 csp = VTOS(VTOS(vp)->s_commonvp);
394 dip = csp->s_dip;
395 if (dip)
396 e_ddi_hold_devi(dip);
397 return (dip);
398 }
399
400 /*
401 * Find a special vnode that refers to the given device
402 * of the given type. Never return a "common" vnode.
403 * Return NULL if a special vnode does not exist.
404 * HOLD the vnode before returning it.
405 */
406 struct vnode *
407 specfind(dev_t dev, vtype_t type)
408 {
409 struct snode *st;
410 struct vnode *nvp;
411
412 mutex_enter(&stable_lock);
413 st = stable[STABLEHASH(dev)];
414 while (st != NULL) {
415 if (st->s_dev == dev) {
416 nvp = STOV(st);
417 if (nvp->v_type == type && st->s_commonvp != nvp) {
418 VN_HOLD(nvp);
419 mutex_exit(&stable_lock);
420 return (nvp);
421 }
422 }
423 st = st->s_next;
424 }
425 mutex_exit(&stable_lock);
426 return (NULL);
427 }
428
429 /*
430 * Loop through the snode cache looking for snodes referencing dip.
431 *
432 * This function determines if a devinfo node is "BUSY" from the perspective
433 * of having an active vnode associated with the device, which represents a
434 * dependency on the device's services. This function is needed because a
435 * devinfo node can have a non-zero devi_ref and still NOT be "BUSY" when,
436 * for instance, the framework is manipulating the node (has an open
437 * ndi_hold_devi).
438 *
439 * Returns:
440 * DEVI_REFERENCED - if dip is referenced
441 * DEVI_NOT_REFERENCED - if dip is not referenced
442 */
443 int
444 devi_stillreferenced(dev_info_t *dip)
445 {
446 struct snode *sp;
447 int i;
448
449 /* if no hold then there can't be an snode with s_dip == dip */
450 if (e_ddi_devi_holdcnt(dip) == 0)
451 return (DEVI_NOT_REFERENCED);
452
453 mutex_enter(&stable_lock);
454 for (i = 0; i < STABLESIZE; i++) {
455 for (sp = stable[i]; sp != NULL; sp = sp->s_next) {
456 if (sp->s_dip == dip) {
457 mutex_exit(&stable_lock);
458 return (DEVI_REFERENCED);
459 }
460 }
461 }
462 mutex_exit(&stable_lock);
463 return (DEVI_NOT_REFERENCED);
464 }
465
466 /*
467 * Given an snode, returns the open count and the dip
468 * associated with that snode
469 * Assumes the caller holds the appropriate locks
470 * to prevent snode and/or dip from going away.
471 * Returns:
472 * -1 No associated dip
473 * >= 0 Number of opens.
474 */
475 int
476 spec_devi_open_count(struct snode *sp, dev_info_t **dipp)
477 {
478 dev_info_t *dip;
479 uint_t count;
480 struct vnode *vp;
481
482 ASSERT(sp);
483 ASSERT(dipp);
484
485 vp = STOV(sp);
486
487 *dipp = NULL;
488
489 /*
490 * We are only interested in common snodes. Only common snodes
491 * get their s_count fields bumped up on opens.
492 */
493 if (sp->s_commonvp != vp || (dip = sp->s_dip) == NULL)
494 return (-1);
495
496 mutex_enter(&sp->s_lock);
497 count = sp->s_count + sp->s_mapcnt;
498 if (sp->s_flag & SLOCKED)
499 count++;
500 mutex_exit(&sp->s_lock);
501
502 *dipp = dip;
503
504 return (count);
505 }
506
507 /*
508 * Given a device vnode, return the common
509 * vnode associated with it.
510 */
511 struct vnode *
512 common_specvp(struct vnode *vp)
513 {
514 struct snode *sp;
515
516 if ((vp->v_type != VBLK) && (vp->v_type != VCHR) ||
517 !vn_matchops(vp, spec_getvnodeops()))
518 return (vp);
519 sp = VTOS(vp);
520 return (sp->s_commonvp);
521 }
522
523 /*
524 * Returns a special vnode for the given dev. The vnode is the
525 * one which is "common" to all the snodes which represent the
526 * same device.
527 * Similar to commonvp() but doesn't acquire the stable_lock, and
528 * may use a pre-allocated snode provided by caller.
529 */
530 static struct vnode *
531 get_cvp(
532 dev_t dev,
533 vtype_t type,
534 struct snode *nsp, /* pre-allocated snode */
535 int *used_nsp) /* flag indicating if we use nsp */
536 {
537 struct snode *sp;
538 struct vnode *svp;
539
540 ASSERT(MUTEX_HELD(&stable_lock));
541 if ((sp = sfind(dev, type, NULL)) == NULL) {
542 sp = nsp; /* Use pre-allocated snode */
543 *used_nsp = 1; /* return value */
544 svp = STOV(sp);
545
546 sp->s_realvp = NULL;
547 sp->s_commonvp = svp; /* points to itself */
548 sp->s_dev = dev;
549 sp->s_dip = NULL;
550 sp->s_nextr = NULL;
551 sp->s_list = NULL;
552 sp->s_plcy = NULL;
553 sp->s_size = UNKNOWN_SIZE;
554 sp->s_flag = 0;
555 sp->s_fsid = specdev;
556 sp->s_atime = 0;
557 sp->s_mtime = 0;
558 sp->s_ctime = 0;
559 sp->s_count = 0;
560 sp->s_mapcnt = 0;
561
562 vn_reinit(svp);
563 svp->v_vfsp = &spec_vfs;
564 svp->v_type = type;
565 svp->v_rdev = dev;
566 vn_exists(svp);
567 sinsert(sp);
568 } else
569 *used_nsp = 0;
570 return (STOV(sp));
571 }
572
573 /*
574 * Returns a special vnode for the given dev. The vnode is the
575 * one which is "common" to all the snodes which represent the
576 * same device. For use ONLY by SPECFS.
577 */
578 struct vnode *
579 commonvp(dev_t dev, vtype_t type)
580 {
581 struct snode *sp, *nsp;
582 struct vnode *svp;
583
584 /* Pre-allocate snode in case we might block */
585 nsp = kmem_cache_alloc(snode_cache, KM_SLEEP);
586
587 mutex_enter(&stable_lock);
588 if ((sp = sfind(dev, type, NULL)) == NULL) {
589 sp = nsp; /* Use pre-alloced snode */
590 svp = STOV(sp);
591
592 sp->s_realvp = NULL;
593 sp->s_commonvp = svp; /* points to itself */
594 sp->s_dev = dev;
595 sp->s_dip = NULL;
596 sp->s_nextr = NULL;
597 sp->s_list = NULL;
598 sp->s_plcy = NULL;
599 sp->s_size = UNKNOWN_SIZE;
600 sp->s_flag = 0;
601 sp->s_fsid = specdev;
602 sp->s_atime = 0;
603 sp->s_mtime = 0;
604 sp->s_ctime = 0;
605 sp->s_count = 0;
606 sp->s_mapcnt = 0;
607
608 vn_reinit(svp);
609 svp->v_vfsp = &spec_vfs;
610 svp->v_type = type;
611 svp->v_rdev = dev;
612 vn_exists(svp);
613 sinsert(sp);
614 mutex_exit(&stable_lock);
615 } else {
616 mutex_exit(&stable_lock);
617 /* Didn't need the pre-allocated snode */
618 kmem_cache_free(snode_cache, nsp);
619 }
620 return (STOV(sp));
621 }
622
623 /*
624 * Snode lookup stuff.
625 * These routines maintain a table of snodes hashed by dev so
626 * that the snode for an dev can be found if it already exists.
627 */
628 struct snode *stable[STABLESIZE];
629 int stablesz = STABLESIZE;
630 kmutex_t stable_lock;
631
632 /*
633 * Put a snode in the table.
634 */
635 static void
636 sinsert(struct snode *sp)
637 {
638 ASSERT(MUTEX_HELD(&stable_lock));
639 sp->s_next = stable[STABLEHASH(sp->s_dev)];
640 stable[STABLEHASH(sp->s_dev)] = sp;
641 }
642
643 /*
644 * Remove an snode from the hash table.
645 * The realvp is not released here because spec_inactive() still
646 * needs it to do a spec_fsync().
647 */
648 void
649 sdelete(struct snode *sp)
650 {
651 struct snode *st;
652 struct snode *stprev = NULL;
653
654 ASSERT(MUTEX_HELD(&stable_lock));
655 st = stable[STABLEHASH(sp->s_dev)];
656 while (st != NULL) {
657 if (st == sp) {
658 if (stprev == NULL)
659 stable[STABLEHASH(sp->s_dev)] = st->s_next;
660 else
661 stprev->s_next = st->s_next;
662 break;
663 }
664 stprev = st;
665 st = st->s_next;
666 }
667 }
668
669 /*
670 * Lookup an snode by <dev, type, vp>.
671 * ONLY looks for snodes with non-NULL s_realvp members and
672 * common snodes (with s_commonvp pointing to its vnode).
673 *
674 * If vp is NULL, only return commonvp. Otherwise return
675 * shadow vp with both shadow and common vp's VN_HELD.
676 */
677 static struct snode *
678 sfind(
679 dev_t dev,
680 vtype_t type,
681 struct vnode *vp)
682 {
683 struct snode *st;
684 struct vnode *svp;
685
686 ASSERT(MUTEX_HELD(&stable_lock));
687 st = stable[STABLEHASH(dev)];
688 while (st != NULL) {
689 svp = STOV(st);
690 if (st->s_dev == dev && svp->v_type == type &&
691 VN_CMP(st->s_realvp, vp) &&
692 (vp != NULL || st->s_commonvp == svp) &&
693 (vp == NULL || st->s_realvp->v_vfsp == vp->v_vfsp)) {
694 VN_HOLD(svp);
695 return (st);
696 }
697 st = st->s_next;
698 }
699 return (NULL);
700 }
701
702 /*
703 * Mark the accessed, updated, or changed times in an snode
704 * with the current time.
705 */
706 void
707 smark(struct snode *sp, int flag)
708 {
709 time_t now = gethrestime_sec();
710
711 /* check for change to avoid unnecessary locking */
712 ASSERT((flag & ~(SACC|SUPD|SCHG)) == 0);
713 if (((flag & sp->s_flag) != flag) ||
714 ((flag & SACC) && (sp->s_atime != now)) ||
715 ((flag & SUPD) && (sp->s_mtime != now)) ||
716 ((flag & SCHG) && (sp->s_ctime != now))) {
717 /* lock and update */
718 mutex_enter(&sp->s_lock);
719 sp->s_flag |= flag;
720 if (flag & SACC)
721 sp->s_atime = now;
722 if (flag & SUPD)
723 sp->s_mtime = now;
724 if (flag & SCHG)
725 sp->s_ctime = now;
726 mutex_exit(&sp->s_lock);
727 }
728 }
729
730 /*
731 * Return the maximum file offset permitted for this device.
732 * -1 means unrestricted. SLOFFSET is associated with D_64BIT.
733 *
734 * On a 32-bit kernel this will limit:
735 * o D_64BIT devices to SPEC_MAXOFFSET_T.
736 * o non-D_64BIT character drivers to a 32-bit offset (MAXOFF_T).
737 */
738 offset_t
739 spec_maxoffset(struct vnode *vp)
740 {
741 struct snode *sp = VTOS(vp);
742 struct snode *csp = VTOS(sp->s_commonvp);
743
744 if (vp->v_stream)
745 return ((offset_t)-1);
746 else if (csp->s_flag & SANYOFFSET) /* D_U64BIT */
747 return ((offset_t)-1);
748 #ifdef _ILP32
749 if (csp->s_flag & SLOFFSET) /* D_64BIT */
750 return (SPEC_MAXOFFSET_T);
751 #endif /* _ILP32 */
752 return (MAXOFF_T);
753 }
754
755 /*ARGSUSED*/
756 static int
757 snode_constructor(void *buf, void *cdrarg, int kmflags)
758 {
759 struct snode *sp = buf;
760 struct vnode *vp;
761
762 vp = sp->s_vnode = vn_alloc(kmflags);
763 if (vp == NULL) {
764 return (-1);
765 }
766 vn_setops(vp, spec_getvnodeops());
767 vp->v_data = sp;
768
769 mutex_init(&sp->s_lock, NULL, MUTEX_DEFAULT, NULL);
770 cv_init(&sp->s_cv, NULL, CV_DEFAULT, NULL);
771 return (0);
772 }
773
774 /*ARGSUSED1*/
775 static void
776 snode_destructor(void *buf, void *cdrarg)
777 {
778 struct snode *sp = buf;
779 struct vnode *vp = STOV(sp);
780
781 mutex_destroy(&sp->s_lock);
782 cv_destroy(&sp->s_cv);
783
784 vn_free(vp);
785 }
786
787
788 int
789 specinit(int fstype, char *name)
790 {
791 static const fs_operation_def_t spec_vfsops_template[] = {
792 VFSNAME_SYNC, { .vfs_sync = spec_sync },
793 NULL, NULL
794 };
795 extern struct vnodeops *spec_vnodeops;
796 extern const fs_operation_def_t spec_vnodeops_template[];
797 struct vfsops *spec_vfsops;
798 int error;
799 dev_t dev;
800
801 /*
802 * Associate vfs and vnode operations.
803 */
804 error = vfs_setfsops(fstype, spec_vfsops_template, &spec_vfsops);
805 if (error != 0) {
806 cmn_err(CE_WARN, "specinit: bad vfs ops template");
807 return (error);
808 }
809
810 error = vn_make_ops(name, spec_vnodeops_template, &spec_vnodeops);
811 if (error != 0) {
812 (void) vfs_freevfsops_by_type(fstype);
813 cmn_err(CE_WARN, "specinit: bad vnode ops template");
814 return (error);
815 }
816
817 mutex_init(&stable_lock, NULL, MUTEX_DEFAULT, NULL);
818 mutex_init(&spec_syncbusy, NULL, MUTEX_DEFAULT, NULL);
819
820 /*
821 * Create snode cache
822 */
823 snode_cache = kmem_cache_create("snode_cache", sizeof (struct snode),
824 0, snode_constructor, snode_destructor, NULL, NULL, NULL, 0);
825
826 /*
827 * Associate vfs operations with spec_vfs
828 */
829 VFS_INIT(&spec_vfs, spec_vfsops, (caddr_t)NULL);
830 if ((dev = getudev()) == -1)
831 dev = 0;
832 specdev = makedevice(dev, 0);
833 return (0);
834 }
835
836 int
837 device_close(struct vnode *vp, int flag, struct cred *cr)
838 {
839 struct snode *sp = VTOS(vp);
840 enum vtype type = vp->v_type;
841 struct vnode *cvp;
842 dev_t dev;
843 int error;
844
845 dev = sp->s_dev;
846 cvp = sp->s_commonvp;
847
848 switch (type) {
849
850 case VCHR:
851 if (vp->v_stream) {
852 if (cvp->v_stream != NULL)
853 error = strclose(cvp, flag, cr);
854 vp->v_stream = NULL;
855 } else
856 error = dev_close(dev, flag, OTYP_CHR, cr);
857 break;
858
859 case VBLK:
860 /*
861 * On last close a block device we must
862 * invalidate any in-core blocks so that we
863 * can, for example, change floppy disks.
864 */
865 (void) spec_putpage(cvp, (offset_t)0,
866 (size_t)0, B_INVAL|B_FORCE, cr, NULL);
867 bflush(dev);
868 binval(dev);
869 error = dev_close(dev, flag, OTYP_BLK, cr);
870 break;
871 default:
872 panic("device_close: not a device");
873 /*NOTREACHED*/
874 }
875
876 return (error);
877 }
878
879 struct vnode *
880 makectty(vnode_t *ovp)
881 {
882 vnode_t *vp;
883
884 if (vp = makespecvp(ovp->v_rdev, VCHR)) {
885 struct snode *sp;
886 struct snode *csp;
887 struct vnode *cvp;
888
889 sp = VTOS(vp);
890 cvp = sp->s_commonvp;
891 csp = VTOS(cvp);
892 mutex_enter(&csp->s_lock);
893 csp->s_count++;
894 mutex_exit(&csp->s_lock);
895 }
896
897 return (vp);
898 }
899
900 void
901 spec_snode_walk(int (*callback)(struct snode *sp, void *arg), void *arg)
902 {
903 struct snode *sp;
904 int i;
905
906 ASSERT(callback);
907
908 mutex_enter(&stable_lock);
909 for (i = 0; i < STABLESIZE; i++) {
910 for (sp = stable[i]; sp; sp = sp->s_next) {
911 if (callback(sp, arg) != DDI_WALK_CONTINUE)
912 goto out;
913 }
914 }
915 out:
916 mutex_exit(&stable_lock);
917 }
918
919 int
920 spec_is_clone(vnode_t *vp)
921 {
922 struct snode *sp;
923
924 if (vn_matchops(vp, spec_getvnodeops())) {
925 sp = VTOS(vp);
926 return ((sp->s_flag & SCLONE) ? 1 : 0);
927 }
928
929 return (0);
930 }
931
932 int
933 spec_is_selfclone(vnode_t *vp)
934 {
935 struct snode *sp;
936
937 if (vn_matchops(vp, spec_getvnodeops())) {
938 sp = VTOS(vp);
939 return ((sp->s_flag & SSELFCLONE) ? 1 : 0);
940 }
941
942 return (0);
943 }
944
945 /*
946 * We may be invoked with a NULL vp in which case we fence off
947 * all snodes associated with dip
948 */
949 int
950 spec_fence_snode(dev_info_t *dip, struct vnode *vp)
951 {
952 struct snode *sp;
953 struct snode *csp;
954 int retired;
955 int i;
956 char *path;
957 int emitted;
958
959 ASSERT(dip);
960
961 retired = 0;
962 mutex_enter(&DEVI(dip)->devi_lock);
963 if (DEVI(dip)->devi_flags & DEVI_RETIRED)
964 retired = 1;
965 mutex_exit(&DEVI(dip)->devi_lock);
966
967 if (!retired)
968 return (0);
969
970 path = kmem_alloc(MAXPATHLEN, KM_SLEEP);
971 (void) ddi_pathname(dip, path);
972
973
974 if (vp != NULL) {
975 ASSERT(vn_matchops(vp, spec_getvnodeops()));
976 csp = VTOCS(vp);
977 ASSERT(csp);
978 mutex_enter(&csp->s_lock);
979 csp->s_flag |= SFENCED;
980 mutex_exit(&csp->s_lock);
981 FENDBG((CE_NOTE, "fenced off snode(%p) for dip: %s",
982 (void *)csp, path));
983 kmem_free(path, MAXPATHLEN);
984 return (0);
985 }
986
987 emitted = 0;
988 mutex_enter(&stable_lock);
989 for (i = 0; i < STABLESIZE; i++) {
990 for (sp = stable[i]; sp != NULL; sp = sp->s_next) {
991 ASSERT(sp->s_commonvp);
992 csp = VTOS(sp->s_commonvp);
993 if (csp->s_dip == dip) {
994 /* fence off the common snode */
995 mutex_enter(&csp->s_lock);
996 csp->s_flag |= SFENCED;
997 mutex_exit(&csp->s_lock);
998 if (!emitted) {
999 FENDBG((CE_NOTE, "fenced 1 of N"));
1000 emitted++;
1001 }
1002 }
1003 }
1004 }
1005 mutex_exit(&stable_lock);
1006
1007 FENDBG((CE_NOTE, "fenced off all snodes for dip: %s", path));
1008 kmem_free(path, MAXPATHLEN);
1009
1010 return (0);
1011 }
1012
1013
1014 int
1015 spec_unfence_snode(dev_info_t *dip)
1016 {
1017 struct snode *sp;
1018 struct snode *csp;
1019 int i;
1020 char *path;
1021 int emitted;
1022
1023 ASSERT(dip);
1024
1025 path = kmem_alloc(MAXPATHLEN, KM_SLEEP);
1026 (void) ddi_pathname(dip, path);
1027
1028 emitted = 0;
1029 mutex_enter(&stable_lock);
1030 for (i = 0; i < STABLESIZE; i++) {
1031 for (sp = stable[i]; sp != NULL; sp = sp->s_next) {
1032 ASSERT(sp->s_commonvp);
1033 csp = VTOS(sp->s_commonvp);
1034 ASSERT(csp);
1035 if (csp->s_dip == dip) {
1036 /* unfence the common snode */
1037 mutex_enter(&csp->s_lock);
1038 csp->s_flag &= ~SFENCED;
1039 mutex_exit(&csp->s_lock);
1040 if (!emitted) {
1041 FENDBG((CE_NOTE, "unfenced 1 of N"));
1042 emitted++;
1043 }
1044 }
1045 }
1046 }
1047 mutex_exit(&stable_lock);
1048
1049 FENDBG((CE_NOTE, "unfenced all snodes for dip: %s", path));
1050 kmem_free(path, MAXPATHLEN);
1051
1052 return (0);
1053 }
1054
1055 void
1056 spec_size_invalidate(dev_t dev, vtype_t type)
1057 {
1058
1059 struct snode *csp;
1060
1061 mutex_enter(&stable_lock);
1062 if ((csp = sfind(dev, type, NULL)) != NULL) {
1063 mutex_enter(&csp->s_lock);
1064 csp->s_flag &= ~SSIZEVALID;
1065 VN_RELE_ASYNC(STOV(csp), system_taskq);
1066 mutex_exit(&csp->s_lock);
1067 }
1068 mutex_exit(&stable_lock);
1069 }