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 2010 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 *
25 * Copyright (c) 1983,1984,1985,1986,1987,1988,1989 AT&T.
26 * All rights reserved.
27 */
28 /*
29 * Copyright (c) 2017 by Delphix. All rights reserved.
30 */
31
32 /*
33 * Node hash implementation initially borrowed from NFS (nfs_subr.c)
34 * but then heavily modified. It's no longer an array of hash lists,
35 * but an AVL tree per mount point. More on this below.
36 */
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/time.h>
41 #include <sys/vnode.h>
42 #include <sys/bitmap.h>
43 #include <sys/dnlc.h>
44 #include <sys/kmem.h>
45 #include <sys/sunddi.h>
46 #include <sys/sysmacros.h>
47
48 #include <netsmb/smb_osdep.h>
49
50 #include <netsmb/smb.h>
51 #include <netsmb/smb_conn.h>
52 #include <netsmb/smb_subr.h>
53 #include <netsmb/smb_rq.h>
54
55 #include <smbfs/smbfs.h>
56 #include <smbfs/smbfs_node.h>
57 #include <smbfs/smbfs_subr.h>
58
59 /*
60 * The AVL trees (now per-mount) allow finding an smbfs node by its
61 * full remote path name. It also allows easy traversal of all nodes
62 * below (path wise) any given node. A reader/writer lock for each
63 * (per mount) AVL tree is used to control access and to synchronize
64 * lookups, additions, and deletions from that AVL tree.
65 *
66 * Previously, this code use a global array of hash chains, each with
67 * its own rwlock. A few struct members, functions, and comments may
68 * still refer to a "hash", and those should all now be considered to
69 * refer to the per-mount AVL tree that replaced the old hash chains.
70 * (i.e. member smi_hash_lk, function sn_hashfind, etc.)
71 *
72 * The smbnode freelist is organized as a doubly linked list with
73 * a head pointer. Additions and deletions are synchronized via
74 * a single mutex.
75 *
76 * In order to add an smbnode to the free list, it must be linked into
77 * the mount's AVL tree and the exclusive lock for the AVL must be held.
78 * If an smbnode is not linked into the AVL tree, then it is destroyed
79 * because it represents no valuable information that can be reused
80 * about the file. The exclusive lock for the AVL tree must be held
81 * in order to prevent a lookup in the AVL tree from finding the
82 * smbnode and using it and assuming that the smbnode is not on the
83 * freelist. The lookup in the AVL tree will have the AVL tree lock
84 * held, either exclusive or shared.
85 *
86 * The vnode reference count for each smbnode is not allowed to drop
87 * below 1. This prevents external entities, such as the VM
88 * subsystem, from acquiring references to vnodes already on the
89 * freelist and then trying to place them back on the freelist
90 * when their reference is released. This means that the when an
91 * smbnode is looked up in the AVL tree, then either the smbnode
92 * is removed from the freelist and that reference is tranfered to
93 * the new reference or the vnode reference count must be incremented
94 * accordingly. The mutex for the freelist must be held in order to
95 * accurately test to see if the smbnode is on the freelist or not.
96 * The AVL tree lock might be held shared and it is possible that
97 * two different threads may race to remove the smbnode from the
98 * freelist. This race can be resolved by holding the mutex for the
99 * freelist. Please note that the mutex for the freelist does not
100 * need to held if the smbnode is not on the freelist. It can not be
101 * placed on the freelist due to the requirement that the thread
102 * putting the smbnode on the freelist must hold the exclusive lock
103 * for the AVL tree and the thread doing the lookup in the AVL tree
104 * is holding either a shared or exclusive lock for the AVL tree.
105 *
106 * The lock ordering is:
107 *
108 * AVL tree lock -> vnode lock
109 * AVL tree lock -> freelist lock
110 */
111
112 static kmutex_t smbfreelist_lock;
113 static smbnode_t *smbfreelist = NULL;
114 static ulong_t smbnodenew = 0;
115 long nsmbnode = 0;
116
117 static struct kmem_cache *smbnode_cache;
118
119 static const vsecattr_t smbfs_vsa0 = { 0 };
120
121 /*
122 * Mutex to protect the following variables:
123 * smbfs_major
124 * smbfs_minor
125 */
126 kmutex_t smbfs_minor_lock;
127 int smbfs_major;
128 int smbfs_minor;
129
130 /* See smbfs_node_findcreate() */
131 struct smbfattr smbfs_fattr0;
132
133 /*
134 * Local functions.
135 * SN for Smb Node
136 */
137 static void sn_rmfree(smbnode_t *);
138 static void sn_inactive(smbnode_t *);
139 static void sn_addhash_locked(smbnode_t *, avl_index_t);
140 static void sn_rmhash_locked(smbnode_t *);
141 static void sn_destroy_node(smbnode_t *);
142 void smbfs_kmem_reclaim(void *cdrarg);
143
144 static smbnode_t *
145 sn_hashfind(smbmntinfo_t *, const char *, int, avl_index_t *);
146
147 static smbnode_t *
148 make_smbnode(smbmntinfo_t *, const char *, int, int *);
149
150 /*
151 * Free the resources associated with an smbnode.
152 * Note: This is different from smbfs_inactive
153 *
154 * NFS: nfs_subr.c:rinactive
155 */
156 static void
157 sn_inactive(smbnode_t *np)
158 {
159 vsecattr_t ovsa;
160 cred_t *oldcr;
161 char *orpath;
162 int orplen;
163
164 /*
165 * Flush and invalidate all pages (todo)
166 * Free any held credentials and caches...
167 * etc. (See NFS code)
168 */
169 mutex_enter(&np->r_statelock);
170
171 ovsa = np->r_secattr;
172 np->r_secattr = smbfs_vsa0;
173 np->r_sectime = 0;
174
175 oldcr = np->r_cred;
176 np->r_cred = NULL;
177
178 orpath = np->n_rpath;
179 orplen = np->n_rplen;
180 np->n_rpath = NULL;
181 np->n_rplen = 0;
182
183 mutex_exit(&np->r_statelock);
184
185 if (ovsa.vsa_aclentp != NULL)
186 kmem_free(ovsa.vsa_aclentp, ovsa.vsa_aclentsz);
187
188 if (oldcr != NULL)
189 crfree(oldcr);
190
191 if (orpath != NULL)
192 kmem_free(orpath, orplen + 1);
193 }
194
195 /*
196 * Find and optionally create an smbnode for the passed
197 * mountinfo, directory, separator, and name. If the
198 * desired smbnode already exists, return a reference.
199 * If the file attributes pointer is non-null, the node
200 * is created if necessary and linked into the AVL tree.
201 *
202 * Callers that need a node created but don't have the
203 * real attributes pass smbfs_fattr0 to force creation.
204 *
205 * Note: make_smbnode() may upgrade the "hash" lock to exclusive.
206 *
207 * NFS: nfs_subr.c:makenfsnode
208 */
209 smbnode_t *
210 smbfs_node_findcreate(
211 smbmntinfo_t *mi,
212 const char *dirnm,
213 int dirlen,
214 const char *name,
215 int nmlen,
216 char sep,
217 struct smbfattr *fap)
218 {
219 char tmpbuf[256];
220 size_t rpalloc;
221 char *p, *rpath;
222 int rplen;
223 smbnode_t *np;
224 vnode_t *vp;
225 int newnode;
226
227 /*
228 * Build the search string, either in tmpbuf or
229 * in allocated memory if larger than tmpbuf.
230 */
231 rplen = dirlen;
232 if (sep != '\0')
233 rplen++;
234 rplen += nmlen;
235 if (rplen < sizeof (tmpbuf)) {
236 /* use tmpbuf */
237 rpalloc = 0;
238 rpath = tmpbuf;
239 } else {
240 rpalloc = rplen + 1;
241 rpath = kmem_alloc(rpalloc, KM_SLEEP);
242 }
243 p = rpath;
244 bcopy(dirnm, p, dirlen);
245 p += dirlen;
246 if (sep != '\0')
247 *p++ = sep;
248 if (name != NULL) {
249 bcopy(name, p, nmlen);
250 p += nmlen;
251 }
252 ASSERT(p == rpath + rplen);
253
254 /*
255 * Find or create a node with this path.
256 */
257 rw_enter(&mi->smi_hash_lk, RW_READER);
258 if (fap == NULL)
259 np = sn_hashfind(mi, rpath, rplen, NULL);
260 else
261 np = make_smbnode(mi, rpath, rplen, &newnode);
262 rw_exit(&mi->smi_hash_lk);
263
264 if (rpalloc)
265 kmem_free(rpath, rpalloc);
266
267 if (fap == NULL) {
268 /*
269 * Caller is "just looking" (no create)
270 * so np may or may not be NULL here.
271 * Either way, we're done.
272 */
273 return (np);
274 }
275
276 /*
277 * We should have a node, possibly created.
278 * Do we have (real) attributes to apply?
279 */
280 ASSERT(np != NULL);
281 if (fap == &smbfs_fattr0)
282 return (np);
283
284 /*
285 * Apply the given attributes to this node,
286 * dealing with any cache impact, etc.
287 */
288 vp = SMBTOV(np);
289 if (!newnode) {
290 /*
291 * Found an existing node.
292 * Maybe purge caches...
293 */
294 smbfs_cache_check(vp, fap);
295 }
296 smbfs_attrcache_fa(vp, fap);
297
298 /*
299 * Note NFS sets vp->v_type here, assuming it
300 * can never change for the life of a node.
301 * We allow v_type to change, and set it in
302 * smbfs_attrcache(). Also: mode, uid, gid
303 */
304 return (np);
305 }
306
307 /*
308 * NFS: nfs_subr.c:rtablehash
309 * We use smbfs_hash().
310 */
311
312 /*
313 * Find or create an smbnode.
314 * NFS: nfs_subr.c:make_rnode
315 */
316 static smbnode_t *
317 make_smbnode(
318 smbmntinfo_t *mi,
319 const char *rpath,
320 int rplen,
321 int *newnode)
322 {
323 smbnode_t *np;
324 smbnode_t *tnp;
325 vnode_t *vp;
326 vfs_t *vfsp;
327 avl_index_t where;
328 char *new_rpath = NULL;
329
330 ASSERT(RW_READ_HELD(&mi->smi_hash_lk));
331 vfsp = mi->smi_vfsp;
332
333 start:
334 np = sn_hashfind(mi, rpath, rplen, NULL);
335 if (np != NULL) {
336 *newnode = 0;
337 return (np);
338 }
339
340 /* Note: will retake this lock below. */
341 rw_exit(&mi->smi_hash_lk);
342
343 /*
344 * see if we can find something on the freelist
345 */
346 mutex_enter(&smbfreelist_lock);
347 if (smbfreelist != NULL && smbnodenew >= nsmbnode) {
348 np = smbfreelist;
349 sn_rmfree(np);
350 mutex_exit(&smbfreelist_lock);
351
352 vp = SMBTOV(np);
353
354 if (np->r_flags & RHASHED) {
355 smbmntinfo_t *tmp_mi = np->n_mount;
356 ASSERT(tmp_mi != NULL);
357 rw_enter(&tmp_mi->smi_hash_lk, RW_WRITER);
358 mutex_enter(&vp->v_lock);
359 if (vp->v_count > 1) {
360 VN_RELE_LOCKED(vp);
361 mutex_exit(&vp->v_lock);
362 rw_exit(&tmp_mi->smi_hash_lk);
363 /* start over */
364 rw_enter(&mi->smi_hash_lk, RW_READER);
365 goto start;
366 }
367 mutex_exit(&vp->v_lock);
368 sn_rmhash_locked(np);
369 rw_exit(&tmp_mi->smi_hash_lk);
370 }
371
372 sn_inactive(np);
373
374 mutex_enter(&vp->v_lock);
375 if (vp->v_count > 1) {
376 VN_RELE_LOCKED(vp);
377 mutex_exit(&vp->v_lock);
378 rw_enter(&mi->smi_hash_lk, RW_READER);
379 goto start;
380 }
381 mutex_exit(&vp->v_lock);
382 vn_invalid(vp);
383 /*
384 * destroy old locks before bzero'ing and
385 * recreating the locks below.
386 */
387 smbfs_rw_destroy(&np->r_rwlock);
388 smbfs_rw_destroy(&np->r_lkserlock);
389 mutex_destroy(&np->r_statelock);
390 cv_destroy(&np->r_cv);
391 /*
392 * Make sure that if smbnode is recycled then
393 * VFS count is decremented properly before
394 * reuse.
395 */
396 VFS_RELE(vp->v_vfsp);
397 vn_reinit(vp);
398 } else {
399 /*
400 * allocate and initialize a new smbnode
401 */
402 vnode_t *new_vp;
403
404 mutex_exit(&smbfreelist_lock);
405
406 np = kmem_cache_alloc(smbnode_cache, KM_SLEEP);
407 new_vp = vn_alloc(KM_SLEEP);
408
409 atomic_inc_ulong((ulong_t *)&smbnodenew);
410 vp = new_vp;
411 }
412
413 /*
414 * Allocate and copy the rpath we'll need below.
415 */
416 new_rpath = kmem_alloc(rplen + 1, KM_SLEEP);
417 bcopy(rpath, new_rpath, rplen);
418 new_rpath[rplen] = '\0';
419
420 /* Initialize smbnode_t */
421 bzero(np, sizeof (*np));
422
423 smbfs_rw_init(&np->r_rwlock, NULL, RW_DEFAULT, NULL);
424 smbfs_rw_init(&np->r_lkserlock, NULL, RW_DEFAULT, NULL);
425 mutex_init(&np->r_statelock, NULL, MUTEX_DEFAULT, NULL);
426 cv_init(&np->r_cv, NULL, CV_DEFAULT, NULL);
427 /* cv_init(&np->r_commit.c_cv, NULL, CV_DEFAULT, NULL); */
428
429 np->r_vnode = vp;
430 np->n_mount = mi;
431
432 np->n_fid = SMB_FID_UNUSED;
433 np->n_uid = mi->smi_uid;
434 np->n_gid = mi->smi_gid;
435 /* Leave attributes "stale." */
436
437 #if 0 /* XXX dircache */
438 /*
439 * We don't know if it's a directory yet.
440 * Let the caller do this? XXX
441 */
442 avl_create(&np->r_dir, compar, sizeof (rddir_cache),
443 offsetof(rddir_cache, tree));
444 #endif
445
446 /* Now fill in the vnode. */
447 vn_setops(vp, smbfs_vnodeops);
448 vp->v_data = (caddr_t)np;
449 VFS_HOLD(vfsp);
450 vp->v_vfsp = vfsp;
451 vp->v_type = VNON;
452
453 /*
454 * We entered with mi->smi_hash_lk held (reader).
455 * Retake it now, (as the writer).
456 * Will return with it held.
457 */
458 rw_enter(&mi->smi_hash_lk, RW_WRITER);
459
460 /*
461 * There is a race condition where someone else
462 * may alloc the smbnode while no locks are held,
463 * so check again and recover if found.
464 */
465 tnp = sn_hashfind(mi, rpath, rplen, &where);
466 if (tnp != NULL) {
467 /*
468 * Lost the race. Put the node we were building
469 * on the free list and return the one we found.
470 */
471 rw_exit(&mi->smi_hash_lk);
472 kmem_free(new_rpath, rplen + 1);
473 smbfs_addfree(np);
474 rw_enter(&mi->smi_hash_lk, RW_READER);
475 *newnode = 0;
476 return (tnp);
477 }
478
479 /*
480 * Hash search identifies nodes by the remote path
481 * (n_rpath) so fill that in now, before linking
482 * this node into the node cache (AVL tree).
483 */
484 np->n_rpath = new_rpath;
485 np->n_rplen = rplen;
486 np->n_ino = smbfs_gethash(new_rpath, rplen);
487
488 sn_addhash_locked(np, where);
489 *newnode = 1;
490 return (np);
491 }
492
493 /*
494 * smbfs_addfree
495 * Put an smbnode on the free list, or destroy it immediately
496 * if it offers no value were it to be reclaimed later. Also
497 * destroy immediately when we have too many smbnodes, etc.
498 *
499 * Normally called by smbfs_inactive, but also
500 * called in here during cleanup operations.
501 *
502 * NFS: nfs_subr.c:rp_addfree
503 */
504 void
505 smbfs_addfree(smbnode_t *np)
506 {
507 vnode_t *vp;
508 struct vfs *vfsp;
509 smbmntinfo_t *mi;
510
511 ASSERT(np->r_freef == NULL && np->r_freeb == NULL);
512
513 vp = SMBTOV(np);
514 ASSERT(vp->v_count >= 1);
515
516 vfsp = vp->v_vfsp;
517 mi = VFTOSMI(vfsp);
518
519 /*
520 * If there are no more references to this smbnode and:
521 * we have too many smbnodes allocated, or if the node
522 * is no longer accessible via the AVL tree (!RHASHED),
523 * or an i/o error occurred while writing to the file,
524 * or it's part of an unmounted FS, then try to destroy
525 * it instead of putting it on the smbnode freelist.
526 */
527 if (np->r_count == 0 && (
528 (np->r_flags & RHASHED) == 0 ||
529 (np->r_error != 0) ||
530 (vfsp->vfs_flag & VFS_UNMOUNTED) ||
531 (smbnodenew > nsmbnode))) {
532
533 /* Try to destroy this node. */
534
535 if (np->r_flags & RHASHED) {
536 rw_enter(&mi->smi_hash_lk, RW_WRITER);
537 mutex_enter(&vp->v_lock);
538 if (vp->v_count > 1) {
539 VN_RELE_LOCKED(vp);
540 mutex_exit(&vp->v_lock);
541 rw_exit(&mi->smi_hash_lk);
542 return;
543 /*
544 * Will get another call later,
545 * via smbfs_inactive.
546 */
547 }
548 mutex_exit(&vp->v_lock);
549 sn_rmhash_locked(np);
550 rw_exit(&mi->smi_hash_lk);
551 }
552
553 sn_inactive(np);
554
555 /*
556 * Recheck the vnode reference count. We need to
557 * make sure that another reference has not been
558 * acquired while we were not holding v_lock. The
559 * smbnode is not in the smbnode "hash" AVL tree, so
560 * the only way for a reference to have been acquired
561 * is for a VOP_PUTPAGE because the smbnode was marked
562 * with RDIRTY or for a modified page. This vnode
563 * reference may have been acquired before our call
564 * to sn_inactive. The i/o may have been completed,
565 * thus allowing sn_inactive to complete, but the
566 * reference to the vnode may not have been released
567 * yet. In any case, the smbnode can not be destroyed
568 * until the other references to this vnode have been
569 * released. The other references will take care of
570 * either destroying the smbnode or placing it on the
571 * smbnode freelist. If there are no other references,
572 * then the smbnode may be safely destroyed.
573 */
574 mutex_enter(&vp->v_lock);
575 if (vp->v_count > 1) {
576 VN_RELE_LOCKED(vp);
577 mutex_exit(&vp->v_lock);
578 return;
579 }
580 mutex_exit(&vp->v_lock);
581
582 sn_destroy_node(np);
583 return;
584 }
585
586 /*
587 * Lock the AVL tree and then recheck the reference count
588 * to ensure that no other threads have acquired a reference
589 * to indicate that the smbnode should not be placed on the
590 * freelist. If another reference has been acquired, then
591 * just release this one and let the other thread complete
592 * the processing of adding this smbnode to the freelist.
593 */
594 rw_enter(&mi->smi_hash_lk, RW_WRITER);
595
596 mutex_enter(&vp->v_lock);
597 if (vp->v_count > 1) {
598 VN_RELE_LOCKED(vp);
599 mutex_exit(&vp->v_lock);
600 rw_exit(&mi->smi_hash_lk);
601 return;
602 }
603 mutex_exit(&vp->v_lock);
604
605 /*
606 * Put this node on the free list.
607 */
608 mutex_enter(&smbfreelist_lock);
609 if (smbfreelist == NULL) {
610 np->r_freef = np;
611 np->r_freeb = np;
612 smbfreelist = np;
613 } else {
614 np->r_freef = smbfreelist;
615 np->r_freeb = smbfreelist->r_freeb;
616 smbfreelist->r_freeb->r_freef = np;
617 smbfreelist->r_freeb = np;
618 }
619 mutex_exit(&smbfreelist_lock);
620
621 rw_exit(&mi->smi_hash_lk);
622 }
623
624 /*
625 * Remove an smbnode from the free list.
626 *
627 * The caller must be holding smbfreelist_lock and the smbnode
628 * must be on the freelist.
629 *
630 * NFS: nfs_subr.c:rp_rmfree
631 */
632 static void
633 sn_rmfree(smbnode_t *np)
634 {
635
636 ASSERT(MUTEX_HELD(&smbfreelist_lock));
637 ASSERT(np->r_freef != NULL && np->r_freeb != NULL);
638
639 if (np == smbfreelist) {
640 smbfreelist = np->r_freef;
641 if (np == smbfreelist)
642 smbfreelist = NULL;
643 }
644
645 np->r_freeb->r_freef = np->r_freef;
646 np->r_freef->r_freeb = np->r_freeb;
647
648 np->r_freef = np->r_freeb = NULL;
649 }
650
651 /*
652 * Put an smbnode in the "hash" AVL tree.
653 *
654 * The caller must be hold the rwlock as writer.
655 *
656 * NFS: nfs_subr.c:rp_addhash
657 */
658 static void
659 sn_addhash_locked(smbnode_t *np, avl_index_t where)
660 {
661 smbmntinfo_t *mi = np->n_mount;
662
663 ASSERT(RW_WRITE_HELD(&mi->smi_hash_lk));
664
665 mutex_enter(&np->r_statelock);
666 if ((np->r_flags & RHASHED) == 0) {
667 avl_insert(&mi->smi_hash_avl, np, where);
668 np->r_flags |= RHASHED;
669 }
670 mutex_exit(&np->r_statelock);
671 }
672
673 /*
674 * Remove an smbnode from the "hash" AVL tree.
675 *
676 * The caller must hold the rwlock as writer.
677 *
678 * NFS: nfs_subr.c:rp_rmhash_locked
679 */
680 static void
681 sn_rmhash_locked(smbnode_t *np)
682 {
683 smbmntinfo_t *mi = np->n_mount;
684
685 ASSERT(RW_WRITE_HELD(&mi->smi_hash_lk));
686
687 mutex_enter(&np->r_statelock);
688 if ((np->r_flags & RHASHED) != 0) {
689 np->r_flags &= ~RHASHED;
690 avl_remove(&mi->smi_hash_avl, np);
691 }
692 mutex_exit(&np->r_statelock);
693 }
694
695 /*
696 * Remove an smbnode from the "hash" AVL tree.
697 *
698 * The caller must not be holding the rwlock.
699 */
700 void
701 smbfs_rmhash(smbnode_t *np)
702 {
703 smbmntinfo_t *mi = np->n_mount;
704
705 rw_enter(&mi->smi_hash_lk, RW_WRITER);
706 sn_rmhash_locked(np);
707 rw_exit(&mi->smi_hash_lk);
708 }
709
710 /*
711 * Lookup an smbnode by remote pathname
712 *
713 * The caller must be holding the AVL rwlock, either shared or exclusive.
714 *
715 * NFS: nfs_subr.c:rfind
716 */
717 static smbnode_t *
718 sn_hashfind(
719 smbmntinfo_t *mi,
720 const char *rpath,
721 int rplen,
722 avl_index_t *pwhere) /* optional */
723 {
724 smbfs_node_hdr_t nhdr;
725 smbnode_t *np;
726 vnode_t *vp;
727
728 ASSERT(RW_LOCK_HELD(&mi->smi_hash_lk));
729
730 bzero(&nhdr, sizeof (nhdr));
731 nhdr.hdr_n_rpath = (char *)rpath;
732 nhdr.hdr_n_rplen = rplen;
733
734 /* See smbfs_node_cmp below. */
735 np = avl_find(&mi->smi_hash_avl, &nhdr, pwhere);
736
737 if (np == NULL)
738 return (NULL);
739
740 /*
741 * Found it in the "hash" AVL tree.
742 * Remove from free list, if necessary.
743 */
744 vp = SMBTOV(np);
745 if (np->r_freef != NULL) {
746 mutex_enter(&smbfreelist_lock);
747 /*
748 * If the smbnode is on the freelist,
749 * then remove it and use that reference
750 * as the new reference. Otherwise,
751 * need to increment the reference count.
752 */
753 if (np->r_freef != NULL) {
754 sn_rmfree(np);
755 mutex_exit(&smbfreelist_lock);
756 } else {
757 mutex_exit(&smbfreelist_lock);
758 VN_HOLD(vp);
759 }
760 } else
761 VN_HOLD(vp);
762
763 return (np);
764 }
765
766 static int
767 smbfs_node_cmp(const void *va, const void *vb)
768 {
769 const smbfs_node_hdr_t *a = va;
770 const smbfs_node_hdr_t *b = vb;
771 int clen, diff;
772
773 /*
774 * Same semantics as strcmp, but does not
775 * assume the strings are null terminated.
776 */
777 clen = (a->hdr_n_rplen < b->hdr_n_rplen) ?
778 a->hdr_n_rplen : b->hdr_n_rplen;
779 diff = strncmp(a->hdr_n_rpath, b->hdr_n_rpath, clen);
780 if (diff < 0)
781 return (-1);
782 if (diff > 0)
783 return (1);
784 /* they match through clen */
785 if (b->hdr_n_rplen > clen)
786 return (-1);
787 if (a->hdr_n_rplen > clen)
788 return (1);
789 return (0);
790 }
791
792 /*
793 * Setup the "hash" AVL tree used for our node cache.
794 * See: smbfs_mount, smbfs_destroy_table.
795 */
796 void
797 smbfs_init_hash_avl(avl_tree_t *avl)
798 {
799 avl_create(avl, smbfs_node_cmp, sizeof (smbnode_t),
800 offsetof(smbnode_t, r_avl_node));
801 }
802
803 /*
804 * Invalidate the cached attributes for all nodes "under" the
805 * passed-in node. Note: the passed-in node is NOT affected by
806 * this call. This is used both for files under some directory
807 * after the directory is deleted or renamed, and for extended
808 * attribute files (named streams) under a plain file after that
809 * file is renamed or deleted.
810 *
811 * Do this by walking the AVL tree starting at the passed in node,
812 * and continuing while the visited nodes have a path prefix matching
813 * the entire path of the passed-in node, and a separator just after
814 * that matching path prefix. Watch out for cases where the AVL tree
815 * order may not exactly match the order of an FS walk, i.e.
816 * consider this sequence:
817 * "foo" (directory)
818 * "foo bar" (name containing a space)
819 * "foo/bar"
820 * The walk needs to skip "foo bar" and keep going until it finds
821 * something that doesn't match the "foo" name prefix.
822 */
823 void
824 smbfs_attrcache_prune(smbnode_t *top_np)
825 {
826 smbmntinfo_t *mi;
827 smbnode_t *np;
828 char *rpath;
829 int rplen;
830
831 mi = top_np->n_mount;
832 rw_enter(&mi->smi_hash_lk, RW_READER);
833
834 np = top_np;
835 rpath = top_np->n_rpath;
836 rplen = top_np->n_rplen;
837 for (;;) {
838 np = avl_walk(&mi->smi_hash_avl, np, AVL_AFTER);
839 if (np == NULL)
840 break;
841 if (np->n_rplen < rplen)
842 break;
843 if (0 != strncmp(np->n_rpath, rpath, rplen))
844 break;
845 if (np->n_rplen > rplen && (
846 np->n_rpath[rplen] == ':' ||
847 np->n_rpath[rplen] == '\\'))
848 smbfs_attrcache_remove(np);
849 }
850
851 rw_exit(&mi->smi_hash_lk);
852 }
853
854 #ifdef SMB_VNODE_DEBUG
855 int smbfs_check_table_debug = 1;
856 #else /* SMB_VNODE_DEBUG */
857 int smbfs_check_table_debug = 0;
858 #endif /* SMB_VNODE_DEBUG */
859
860
861 /*
862 * Return 1 if there is a active vnode belonging to this vfs in the
863 * smbnode cache.
864 *
865 * Several of these checks are done without holding the usual
866 * locks. This is safe because destroy_smbtable(), smbfs_addfree(),
867 * etc. will redo the necessary checks before actually destroying
868 * any smbnodes.
869 *
870 * NFS: nfs_subr.c:check_rtable
871 *
872 * Debugging changes here relative to NFS.
873 * Relatively harmless, so left 'em in.
874 */
875 int
876 smbfs_check_table(struct vfs *vfsp, smbnode_t *rtnp)
877 {
878 smbmntinfo_t *mi;
879 smbnode_t *np;
880 vnode_t *vp;
881 int busycnt = 0;
882
883 mi = VFTOSMI(vfsp);
884 rw_enter(&mi->smi_hash_lk, RW_READER);
885 for (np = avl_first(&mi->smi_hash_avl); np != NULL;
886 np = avl_walk(&mi->smi_hash_avl, np, AVL_AFTER)) {
887
888 if (np == rtnp)
889 continue; /* skip the root */
890 vp = SMBTOV(np);
891
892 /* Now the 'busy' checks: */
893 /* Not on the free list? */
894 if (np->r_freef == NULL) {
895 SMBVDEBUG("!r_freef: node=0x%p, rpath=%s\n",
896 (void *)np, np->n_rpath);
897 busycnt++;
898 }
899
900 /* Has dirty pages? */
901 if (vn_has_cached_data(vp) &&
902 (np->r_flags & RDIRTY)) {
903 SMBVDEBUG("is dirty: node=0x%p, rpath=%s\n",
904 (void *)np, np->n_rpath);
905 busycnt++;
906 }
907
908 /* Other refs? (not reflected in v_count) */
909 if (np->r_count > 0) {
910 SMBVDEBUG("+r_count: node=0x%p, rpath=%s\n",
911 (void *)np, np->n_rpath);
912 busycnt++;
913 }
914
915 if (busycnt && !smbfs_check_table_debug)
916 break;
917
918 }
919 rw_exit(&mi->smi_hash_lk);
920
921 return (busycnt);
922 }
923
924 /*
925 * Destroy inactive vnodes from the AVL tree which belong to this
926 * vfs. It is essential that we destroy all inactive vnodes during a
927 * forced unmount as well as during a normal unmount.
928 *
929 * NFS: nfs_subr.c:destroy_rtable
930 *
931 * In here, we're normally destrying all or most of the AVL tree,
932 * so the natural choice is to use avl_destroy_nodes. However,
933 * there may be a few busy nodes that should remain in the AVL
934 * tree when we're done. The solution: use a temporary tree to
935 * hold the busy nodes until we're done destroying the old tree,
936 * then copy the temporary tree over the (now emtpy) real tree.
937 */
938 void
939 smbfs_destroy_table(struct vfs *vfsp)
940 {
941 avl_tree_t tmp_avl;
942 smbmntinfo_t *mi;
943 smbnode_t *np;
944 smbnode_t *rlist;
945 void *v;
946
947 mi = VFTOSMI(vfsp);
948 rlist = NULL;
949 smbfs_init_hash_avl(&tmp_avl);
950
951 rw_enter(&mi->smi_hash_lk, RW_WRITER);
952 v = NULL;
953 while ((np = avl_destroy_nodes(&mi->smi_hash_avl, &v)) != NULL) {
954
955 mutex_enter(&smbfreelist_lock);
956 if (np->r_freef == NULL) {
957 /*
958 * Busy node (not on the free list).
959 * Will keep in the final AVL tree.
960 */
961 mutex_exit(&smbfreelist_lock);
962 avl_add(&tmp_avl, np);
963 } else {
964 /*
965 * It's on the free list. Remove and
966 * arrange for it to be destroyed.
967 */
968 sn_rmfree(np);
969 mutex_exit(&smbfreelist_lock);
970
971 /*
972 * Last part of sn_rmhash_locked().
973 * NB: avl_destroy_nodes has already
974 * removed this from the "hash" AVL.
975 */
976 mutex_enter(&np->r_statelock);
977 np->r_flags &= ~RHASHED;
978 mutex_exit(&np->r_statelock);
979
980 /*
981 * Add to the list of nodes to destroy.
982 * Borrowing avl_child[0] for this list.
983 */
984 np->r_avl_node.avl_child[0] =
985 (struct avl_node *)rlist;
986 rlist = np;
987 }
988 }
989 avl_destroy(&mi->smi_hash_avl);
990
991 /*
992 * Replace the (now destroyed) "hash" AVL with the
993 * temporary AVL, which restores the busy nodes.
994 */
995 mi->smi_hash_avl = tmp_avl;
996 rw_exit(&mi->smi_hash_lk);
997
998 /*
999 * Now destroy the nodes on our temporary list (rlist).
1000 * This call to smbfs_addfree will end up destroying the
1001 * smbnode, but in a safe way with the appropriate set
1002 * of checks done.
1003 */
1004 while ((np = rlist) != NULL) {
1005 rlist = (smbnode_t *)np->r_avl_node.avl_child[0];
1006 smbfs_addfree(np);
1007 }
1008 }
1009
1010 /*
1011 * This routine destroys all the resources associated with the smbnode
1012 * and then the smbnode itself. Note: sn_inactive has been called.
1013 *
1014 * NFS: nfs_subr.c:destroy_rnode
1015 */
1016 static void
1017 sn_destroy_node(smbnode_t *np)
1018 {
1019 vnode_t *vp;
1020 vfs_t *vfsp;
1021
1022 vp = SMBTOV(np);
1023 vfsp = vp->v_vfsp;
1024
1025 ASSERT(vp->v_count == 1);
1026 ASSERT(np->r_count == 0);
1027 ASSERT(np->r_mapcnt == 0);
1028 ASSERT(np->r_secattr.vsa_aclentp == NULL);
1029 ASSERT(np->r_cred == NULL);
1030 ASSERT(np->n_rpath == NULL);
1031 ASSERT(!(np->r_flags & RHASHED));
1032 ASSERT(np->r_freef == NULL && np->r_freeb == NULL);
1033 atomic_dec_ulong((ulong_t *)&smbnodenew);
1034 vn_invalid(vp);
1035 vn_free(vp);
1036 kmem_cache_free(smbnode_cache, np);
1037 VFS_RELE(vfsp);
1038 }
1039
1040 /*
1041 * Flush all vnodes in this (or every) vfs.
1042 * Used by nfs_sync and by nfs_unmount.
1043 */
1044 /*ARGSUSED*/
1045 void
1046 smbfs_rflush(struct vfs *vfsp, cred_t *cr)
1047 {
1048 /* Todo: mmap support. */
1049 }
1050
1051 /* access cache (nfs_subr.c) not used here */
1052
1053 static kmutex_t smbfs_newnum_lock;
1054 static uint32_t smbfs_newnum_val = 0;
1055
1056 /*
1057 * Return a number 0..0xffffffff that's different from the last
1058 * 0xffffffff numbers this returned. Used for unlinked files.
1059 * (This too was copied from nfs_subr.c)
1060 */
1061 uint32_t
1062 smbfs_newnum(void)
1063 {
1064 uint32_t id;
1065
1066 mutex_enter(&smbfs_newnum_lock);
1067 if (smbfs_newnum_val == 0)
1068 smbfs_newnum_val = (uint32_t)gethrestime_sec();
1069 id = smbfs_newnum_val++;
1070 mutex_exit(&smbfs_newnum_lock);
1071 return (id);
1072 }
1073
1074 /*
1075 * Fill in a temporary name at buf
1076 */
1077 int
1078 smbfs_newname(char *buf, size_t buflen)
1079 {
1080 uint_t id;
1081 int n;
1082
1083 id = smbfs_newnum();
1084 n = snprintf(buf, buflen, "~$smbfs%08X", id);
1085 return (n);
1086 }
1087
1088
1089 /*
1090 * initialize resources that are used by smbfs_subr.c
1091 * this is called from the _init() routine (by the way of smbfs_clntinit())
1092 *
1093 * NFS: nfs_subr.c:nfs_subrinit
1094 */
1095 int
1096 smbfs_subrinit(void)
1097 {
1098 ulong_t nsmbnode_max;
1099
1100 /*
1101 * Allocate and initialize the smbnode cache
1102 */
1103 if (nsmbnode <= 0)
1104 nsmbnode = ncsize; /* dnlc.h */
1105 nsmbnode_max = (ulong_t)((kmem_maxavail() >> 2) /
1106 sizeof (struct smbnode));
1107 if (nsmbnode > nsmbnode_max || (nsmbnode == 0 && ncsize == 0)) {
1108 zcmn_err(GLOBAL_ZONEID, CE_NOTE,
1109 "setting nsmbnode to max value of %ld", nsmbnode_max);
1110 nsmbnode = nsmbnode_max;
1111 }
1112
1113 smbnode_cache = kmem_cache_create("smbnode_cache", sizeof (smbnode_t),
1114 0, NULL, NULL, smbfs_kmem_reclaim, NULL, NULL, 0);
1115
1116 /*
1117 * Initialize the various mutexes and reader/writer locks
1118 */
1119 mutex_init(&smbfreelist_lock, NULL, MUTEX_DEFAULT, NULL);
1120 mutex_init(&smbfs_minor_lock, NULL, MUTEX_DEFAULT, NULL);
1121
1122 /*
1123 * Assign unique major number for all smbfs mounts
1124 */
1125 if ((smbfs_major = getudev()) == -1) {
1126 zcmn_err(GLOBAL_ZONEID, CE_WARN,
1127 "smbfs: init: can't get unique device number");
1128 smbfs_major = 0;
1129 }
1130 smbfs_minor = 0;
1131
1132 return (0);
1133 }
1134
1135 /*
1136 * free smbfs hash table, etc.
1137 * NFS: nfs_subr.c:nfs_subrfini
1138 */
1139 void
1140 smbfs_subrfini(void)
1141 {
1142
1143 /*
1144 * Destroy the smbnode cache
1145 */
1146 kmem_cache_destroy(smbnode_cache);
1147
1148 /*
1149 * Destroy the various mutexes and reader/writer locks
1150 */
1151 mutex_destroy(&smbfreelist_lock);
1152 mutex_destroy(&smbfs_minor_lock);
1153 }
1154
1155 /* rddir_cache ? */
1156
1157 /*
1158 * Support functions for smbfs_kmem_reclaim
1159 */
1160
1161 static void
1162 smbfs_node_reclaim(void)
1163 {
1164 smbmntinfo_t *mi;
1165 smbnode_t *np;
1166 vnode_t *vp;
1167
1168 mutex_enter(&smbfreelist_lock);
1169 while ((np = smbfreelist) != NULL) {
1170 sn_rmfree(np);
1171 mutex_exit(&smbfreelist_lock);
1172 if (np->r_flags & RHASHED) {
1173 vp = SMBTOV(np);
1174 mi = np->n_mount;
1175 rw_enter(&mi->smi_hash_lk, RW_WRITER);
1176 mutex_enter(&vp->v_lock);
1177 if (vp->v_count > 1) {
1178 VN_RELE_LOCKED(vp);
1179 mutex_exit(&vp->v_lock);
1180 rw_exit(&mi->smi_hash_lk);
1181 mutex_enter(&smbfreelist_lock);
1182 continue;
1183 }
1184 mutex_exit(&vp->v_lock);
1185 sn_rmhash_locked(np);
1186 rw_exit(&mi->smi_hash_lk);
1187 }
1188 /*
1189 * This call to smbfs_addfree will end up destroying the
1190 * smbnode, but in a safe way with the appropriate set
1191 * of checks done.
1192 */
1193 smbfs_addfree(np);
1194 mutex_enter(&smbfreelist_lock);
1195 }
1196 mutex_exit(&smbfreelist_lock);
1197 }
1198
1199 /*
1200 * Called by kmem_cache_alloc ask us if we could
1201 * "Please give back some memory!"
1202 *
1203 * Todo: dump nodes from the free list?
1204 */
1205 /*ARGSUSED*/
1206 void
1207 smbfs_kmem_reclaim(void *cdrarg)
1208 {
1209 smbfs_node_reclaim();
1210 }
1211
1212 /* nfs failover stuff */
1213 /* nfs_rw_xxx - see smbfs_rwlock.c */