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) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
23 */
24
25 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
26 /* All Rights Reserved */
27
28
29 /*
30 * This file supports the vfs operations for the NAMEFS file system.
31 */
32
33 #include <sys/types.h>
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/debug.h>
37 #include <sys/errno.h>
38 #include <sys/kmem.h>
39 #include <sys/inline.h>
40 #include <sys/file.h>
41 #include <sys/proc.h>
42 #include <sys/stat.h>
43 #include <sys/statvfs.h>
44 #include <sys/mount.h>
45 #include <sys/sysmacros.h>
46 #include <sys/var.h>
47 #include <sys/vfs.h>
48 #include <sys/vfs_opreg.h>
49 #include <sys/vnode.h>
50 #include <sys/mode.h>
51 #include <sys/pcb.h>
52 #include <sys/signal.h>
53 #include <sys/user.h>
54 #include <sys/uio.h>
55 #include <sys/cred.h>
56 #include <sys/fs/namenode.h>
57 #include <sys/stream.h>
58 #include <sys/strsubr.h>
59 #include <sys/cmn_err.h>
60 #include <sys/modctl.h>
61 #include <fs/fs_subr.h>
62 #include <sys/policy.h>
63 #include <sys/vmem.h>
64 #include <sys/fs/sdev_impl.h>
65
66 #define NM_INOQUANT (64 * 1024)
67
68 /*
69 * Define global data structures.
70 */
71 dev_t namedev;
72 int namefstype;
73 struct namenode *nm_filevp_hash[NM_FILEVP_HASH_SIZE];
74 struct vfs namevfs;
75 kmutex_t ntable_lock;
76
77 static vmem_t *nm_inoarena; /* vmem arena to allocate inode no's from */
78 static kmutex_t nm_inolock;
79
80 vfsops_t *namefs_vfsops;
81 /*
82 * Functions to allocate node id's starting from 1. Based on vmem routines.
83 * The vmem arena is extended in NM_INOQUANT chunks.
84 */
85 uint64_t
namenodeno_alloc(void)86 namenodeno_alloc(void)
87 {
88 uint64_t nno;
89
90 mutex_enter(&nm_inolock);
91 nno = (uint64_t)(uintptr_t)
92 vmem_alloc(nm_inoarena, 1, VM_NOSLEEP + VM_FIRSTFIT);
93 if (nno == 0) {
94 (void) vmem_add(nm_inoarena, (void *)(vmem_size(nm_inoarena,
95 VMEM_ALLOC | VMEM_FREE) + 1), NM_INOQUANT, VM_SLEEP);
96 nno = (uint64_t)(uintptr_t)
97 vmem_alloc(nm_inoarena, 1, VM_SLEEP + VM_FIRSTFIT);
98 ASSERT(nno != 0);
99 }
100 mutex_exit(&nm_inolock);
101 ASSERT32(nno <= ULONG_MAX);
102 return (nno);
103 }
104
105 static void
namenodeno_init(void)106 namenodeno_init(void)
107 {
108 nm_inoarena = vmem_create("namefs_inodes", (void *)1, NM_INOQUANT, 1,
109 NULL, NULL, NULL, 1, VM_SLEEP);
110 mutex_init(&nm_inolock, NULL, MUTEX_DEFAULT, NULL);
111 }
112
113 void
namenodeno_free(uint64_t nn)114 namenodeno_free(uint64_t nn)
115 {
116 void *vaddr = (void *)(uintptr_t)nn;
117
118 ASSERT32((uint64_t)(uintptr_t)vaddr == nn);
119
120 mutex_enter(&nm_inolock);
121 vmem_free(nm_inoarena, vaddr, 1);
122 mutex_exit(&nm_inolock);
123 }
124
125 /*
126 * Insert a namenode into the nm_filevp_hash table.
127 *
128 * Each link has a unique namenode with a unique nm_mountvp field.
129 * The nm_filevp field of the namenode need not be unique, since a
130 * file descriptor may be mounted to multiple nodes at the same time.
131 * We hash on nm_filevp since that's what discriminates the searches
132 * in namefind() and nm_unmountall().
133 */
134 void
nameinsert(struct namenode * nodep)135 nameinsert(struct namenode *nodep)
136 {
137 struct namenode **bucket;
138
139 ASSERT(MUTEX_HELD(&ntable_lock));
140
141 bucket = NM_FILEVP_HASH(nodep->nm_filevp);
142 nodep->nm_nextp = *bucket;
143 *bucket = nodep;
144 }
145
146 /*
147 * Remove a namenode from the hash table, if present.
148 */
149 void
nameremove(struct namenode * nodep)150 nameremove(struct namenode *nodep)
151 {
152 struct namenode *np, **npp;
153
154 ASSERT(MUTEX_HELD(&ntable_lock));
155
156 for (npp = NM_FILEVP_HASH(nodep->nm_filevp); (np = *npp) != NULL;
157 npp = &np->nm_nextp) {
158 if (np == nodep) {
159 *npp = np->nm_nextp;
160 return;
161 }
162 }
163 }
164
165 /*
166 * Search for a namenode that has a nm_filevp == vp and nm_mountpt == mnt.
167 * If mnt is NULL, return the first link with nm_filevp of vp.
168 * Returns namenode pointer on success, NULL on failure.
169 */
170 struct namenode *
namefind(vnode_t * vp,vnode_t * mnt)171 namefind(vnode_t *vp, vnode_t *mnt)
172 {
173 struct namenode *np;
174
175 ASSERT(MUTEX_HELD(&ntable_lock));
176 for (np = *NM_FILEVP_HASH(vp); np != NULL; np = np->nm_nextp)
177 if (np->nm_filevp == vp &&
178 (mnt == NULL || np->nm_mountpt == mnt))
179 break;
180 return (np);
181 }
182
183 /*
184 * Force the unmouting of a file descriptor from ALL of the nodes
185 * that it was mounted to.
186 * At the present time, the only usage for this routine is in the
187 * event one end of a pipe was mounted. At the time the unmounted
188 * end gets closed down, the mounted end is forced to be unmounted.
189 *
190 * This routine searches the namenode hash list for all namenodes
191 * that have a nm_filevp field equal to vp. Each time one is found,
192 * the dounmount() routine is called. This causes the nm_unmount()
193 * routine to be called and thus, the file descriptor is unmounted
194 * from the node.
195 *
196 * At the start of this routine, the reference count for vp is
197 * incremented to protect the vnode from being released in the
198 * event the mount was the only thing keeping the vnode active.
199 * If that is the case, the VOP_CLOSE operation is applied to
200 * the vnode, prior to it being released.
201 */
202 static int
nm_umountall(vnode_t * vp,cred_t * crp)203 nm_umountall(vnode_t *vp, cred_t *crp)
204 {
205 vfs_t *vfsp;
206 struct namenode *nodep;
207 int error = 0;
208 int realerr = 0;
209
210 /*
211 * For each namenode that is associated with the file:
212 * If the v_vfsp field is not namevfs, dounmount it. Otherwise,
213 * it was created in nm_open() and will be released in time.
214 * The following loop replicates some code from nm_find. That
215 * routine can't be used as is since the list isn't strictly
216 * consumed as it is traversed.
217 */
218 mutex_enter(&ntable_lock);
219 nodep = *NM_FILEVP_HASH(vp);
220 while (nodep) {
221 if (nodep->nm_filevp == vp &&
222 (vfsp = NMTOV(nodep)->v_vfsp) != NULL &&
223 vfsp != &namevfs && (NMTOV(nodep)->v_flag & VROOT)) {
224
225 /*
226 * If the vn_vfswlock fails, skip the vfs since
227 * somebody else may be unmounting it.
228 */
229 if (vn_vfswlock(vfsp->vfs_vnodecovered)) {
230 realerr = EBUSY;
231 nodep = nodep->nm_nextp;
232 continue;
233 }
234
235 /*
236 * Can't hold ntable_lock across call to do_unmount
237 * because nm_unmount tries to acquire it. This means
238 * there is a window where another mount of vp can
239 * happen so it is possible that after nm_unmountall
240 * there are still some mounts. This situation existed
241 * without MT locking because dounmount can sleep
242 * so another mount could happen during that time.
243 * This situation is unlikely and doesn't really cause
244 * any problems.
245 */
246 mutex_exit(&ntable_lock);
247 if ((error = dounmount(vfsp, 0, crp)) != 0)
248 realerr = error;
249 mutex_enter(&ntable_lock);
250 /*
251 * Since we dropped the ntable_lock, we
252 * have to start over from the beginning.
253 * If for some reasons dounmount() fails,
254 * start from beginning means that we will keep on
255 * trying unless another thread unmounts it for us.
256 */
257 nodep = *NM_FILEVP_HASH(vp);
258 } else
259 nodep = nodep->nm_nextp;
260 }
261 mutex_exit(&ntable_lock);
262 return (realerr);
263 }
264
265 /*
266 * Force the unmouting of a file descriptor from ALL of the nodes
267 * that it was mounted to. XXX: fifo_close() calls this routine.
268 *
269 * nm_umountall() may return EBUSY.
270 * nm_unmountall() will keep on trying until it succeeds.
271 */
272 int
nm_unmountall(vnode_t * vp,cred_t * crp)273 nm_unmountall(vnode_t *vp, cred_t *crp)
274 {
275 int error;
276
277 /*
278 * Nm_umuontall() returns only if it succeeds or
279 * return with error EBUSY. If EBUSY, that means
280 * it cannot acquire the lock on the covered vnode,
281 * and we will keep on trying.
282 */
283 for (;;) {
284 error = nm_umountall(vp, crp);
285 if (error != EBUSY)
286 break;
287 delay(1); /* yield cpu briefly, then try again */
288 }
289 return (error);
290 }
291
292 /*
293 * Mount a file descriptor onto the node in the file system.
294 * Create a new vnode, update the attributes with info from the
295 * file descriptor and the mount point. The mask, mode, uid, gid,
296 * atime, mtime and ctime are taken from the mountpt. Link count is
297 * set to one, the file system id is namedev and nodeid is unique
298 * for each mounted object. Other attributes are taken from mount point.
299 * Make sure user is owner (or root) with write permissions on mount point.
300 * Hash the new vnode and return 0.
301 * Upon entry to this routine, the file descriptor is in the
302 * fd field of a struct namefd. Copy that structure from user
303 * space and retrieve the file descriptor.
304 */
305 static int
nm_mount(vfs_t * vfsp,vnode_t * mvp,struct mounta * uap,cred_t * crp)306 nm_mount(vfs_t *vfsp, vnode_t *mvp, struct mounta *uap, cred_t *crp)
307 {
308 struct namefd namefdp;
309 struct vnode *filevp; /* file descriptor vnode */
310 struct file *fp;
311 struct vnode *newvp; /* vnode representing this mount */
312 struct vnode *rvp; /* realvp (if any) for the mountpt */
313 struct namenode *nodep; /* namenode for this mount */
314 struct vattr filevattr; /* attributes of file dec. */
315 struct vattr *vattrp; /* attributes of this mount */
316 char *resource_name;
317 char *resource_nodetype;
318 statvfs64_t *svfsp;
319 int error = 0;
320
321 /*
322 * Get the file descriptor from user space.
323 * Make sure the file descriptor is valid and has an
324 * associated file pointer.
325 * If so, extract the vnode from the file pointer.
326 */
327 if (uap->datalen != sizeof (struct namefd))
328 return (EINVAL);
329
330 if (copyin(uap->dataptr, &namefdp, uap->datalen))
331 return (EFAULT);
332
333 if ((fp = getf(namefdp.fd)) == NULL)
334 return (EBADF);
335
336 /*
337 * If the mount point already has something mounted
338 * on it, disallow this mount. (This restriction may
339 * be removed in a later release).
340 * Or unmount has completed but the namefs ROOT vnode
341 * count has not decremented to zero, disallow this mount.
342 */
343
344 mutex_enter(&mvp->v_lock);
345 if ((mvp->v_flag & VROOT) ||
346 vfs_matchops(mvp->v_vfsp, namefs_vfsops)) {
347 mutex_exit(&mvp->v_lock);
348 releasef(namefdp.fd);
349 return (EBUSY);
350 }
351 mutex_exit(&mvp->v_lock);
352
353 /*
354 * Cannot allow users to fattach() in /dev/pts.
355 * First, there is no need for doing so and secondly
356 * we cannot allow arbitrary users to park on a node in
357 * /dev/pts or /dev/vt.
358 */
359 rvp = NULLVP;
360 if (vn_matchops(mvp, spec_getvnodeops()) &&
361 VOP_REALVP(mvp, &rvp, NULL) == 0 && rvp &&
362 (vn_matchops(rvp, devpts_getvnodeops()) ||
363 vn_matchops(rvp, devvt_getvnodeops()))) {
364 releasef(namefdp.fd);
365 return (ENOTSUP);
366 }
367
368 filevp = fp->f_vnode;
369 if (filevp->v_type == VDIR || filevp->v_type == VPORT) {
370 releasef(namefdp.fd);
371 return (EINVAL);
372 }
373
374 /*
375 * If the fd being mounted refers to neither a door nor a stream,
376 * make sure the caller is privileged.
377 */
378 if (filevp->v_type != VDOOR && filevp->v_stream == NULL) {
379 if (secpolicy_fs_mount(crp, filevp, vfsp) != 0) {
380 /* fd is neither a stream nor a door */
381 releasef(namefdp.fd);
382 return (EINVAL);
383 }
384 }
385
386 /*
387 * Make sure the file descriptor is not the root of some
388 * file system.
389 * If it's not, create a reference and allocate a namenode
390 * to represent this mount request.
391 */
392 if (filevp->v_flag & VROOT) {
393 releasef(namefdp.fd);
394 return (EBUSY);
395 }
396
397 nodep = kmem_zalloc(sizeof (struct namenode), KM_SLEEP);
398
399 mutex_init(&nodep->nm_lock, NULL, MUTEX_DEFAULT, NULL);
400 vattrp = &nodep->nm_vattr;
401 vattrp->va_mask = AT_ALL;
402 if (error = VOP_GETATTR(mvp, vattrp, 0, crp, NULL))
403 goto out;
404
405 filevattr.va_mask = AT_ALL;
406 if (error = VOP_GETATTR(filevp, &filevattr, 0, crp, NULL))
407 goto out;
408 /*
409 * Make sure the user is the owner of the mount point
410 * or has sufficient privileges.
411 */
412 if (error = secpolicy_vnode_owner(crp, vattrp->va_uid))
413 goto out;
414
415 /*
416 * Make sure the user has write permissions on the
417 * mount point (or has sufficient privileges).
418 */
419 if (secpolicy_vnode_access2(crp, mvp, vattrp->va_uid, vattrp->va_mode,
420 VWRITE) != 0) {
421 error = EACCES;
422 goto out;
423 }
424
425 /*
426 * If the file descriptor has file/record locking, don't
427 * allow the mount to succeed.
428 */
429 if (vn_has_flocks(filevp)) {
430 error = EACCES;
431 goto out;
432 }
433
434 /*
435 * Initialize the namenode.
436 */
437 if (filevp->v_stream) {
438 struct stdata *stp = filevp->v_stream;
439 mutex_enter(&stp->sd_lock);
440 stp->sd_flag |= STRMOUNT;
441 mutex_exit(&stp->sd_lock);
442 }
443 nodep->nm_filevp = filevp;
444 mutex_enter(&fp->f_tlock);
445 fp->f_count++;
446 mutex_exit(&fp->f_tlock);
447
448 releasef(namefdp.fd);
449 nodep->nm_filep = fp;
450 nodep->nm_mountpt = mvp;
451
452 /*
453 * The attributes for the mounted file descriptor were initialized
454 * above by applying VOP_GETATTR to the mount point. Some of
455 * the fields of the attributes structure will be overwritten
456 * by the attributes from the file descriptor.
457 */
458 vattrp->va_type = filevattr.va_type;
459 vattrp->va_fsid = namedev;
460 vattrp->va_nodeid = namenodeno_alloc();
461 vattrp->va_nlink = 1;
462 vattrp->va_size = filevattr.va_size;
463 vattrp->va_rdev = filevattr.va_rdev;
464 vattrp->va_blksize = filevattr.va_blksize;
465 vattrp->va_nblocks = filevattr.va_nblocks;
466 vattrp->va_seq = 0;
467
468 /*
469 * Initialize new vnode structure for the mounted file descriptor.
470 */
471 nodep->nm_vnode = vn_alloc(KM_SLEEP);
472 newvp = NMTOV(nodep);
473
474 newvp->v_flag = filevp->v_flag | VROOT | VNOMAP | VNOSWAP;
475 vn_setops(newvp, nm_vnodeops);
476 newvp->v_vfsp = vfsp;
477 newvp->v_stream = filevp->v_stream;
478 newvp->v_type = filevp->v_type;
479 newvp->v_rdev = filevp->v_rdev;
480 newvp->v_data = (caddr_t)nodep;
481 VFS_HOLD(vfsp);
482 vn_exists(newvp);
483
484 /*
485 * Initialize the vfs structure.
486 */
487 vfsp->vfs_vnodecovered = NULL;
488 vfsp->vfs_flag |= VFS_UNLINKABLE;
489 vfsp->vfs_bsize = 1024;
490 vfsp->vfs_fstype = namefstype;
491 vfs_make_fsid(&vfsp->vfs_fsid, namedev, namefstype);
492 vfsp->vfs_data = (caddr_t)nodep;
493 vfsp->vfs_dev = namedev;
494 vfsp->vfs_bcount = 0;
495
496 /*
497 * Set the name we mounted from.
498 */
499 switch (filevp->v_type) {
500 case VPROC: /* VOP_GETATTR() translates this to VREG */
501 case VREG: resource_nodetype = "file"; break;
502 case VDIR: resource_nodetype = "directory"; break;
503 case VBLK: resource_nodetype = "device"; break;
504 case VCHR: resource_nodetype = "device"; break;
505 case VLNK: resource_nodetype = "link"; break;
506 case VFIFO: resource_nodetype = "fifo"; break;
507 case VDOOR: resource_nodetype = "door"; break;
508 case VSOCK: resource_nodetype = "socket"; break;
509 default: resource_nodetype = "resource"; break;
510 }
511
512 #define RESOURCE_NAME_SZ 128 /* Maximum length of the resource name */
513 resource_name = kmem_alloc(RESOURCE_NAME_SZ, KM_SLEEP);
514 svfsp = kmem_alloc(sizeof (statvfs64_t), KM_SLEEP);
515
516 error = VFS_STATVFS(filevp->v_vfsp, svfsp);
517 if (error == 0) {
518 (void) snprintf(resource_name, RESOURCE_NAME_SZ,
519 "unspecified_%s_%s", svfsp->f_basetype, resource_nodetype);
520 } else {
521 (void) snprintf(resource_name, RESOURCE_NAME_SZ,
522 "unspecified_%s", resource_nodetype);
523 }
524
525 vfs_setresource(vfsp, resource_name, 0);
526
527 kmem_free(svfsp, sizeof (statvfs64_t));
528 kmem_free(resource_name, RESOURCE_NAME_SZ);
529 #undef RESOURCE_NAME_SZ
530
531 /*
532 * Insert the namenode.
533 */
534 mutex_enter(&ntable_lock);
535 nameinsert(nodep);
536 mutex_exit(&ntable_lock);
537 return (0);
538 out:
539 releasef(namefdp.fd);
540 kmem_free(nodep, sizeof (struct namenode));
541 return (error);
542 }
543
544 /*
545 * Unmount a file descriptor from a node in the file system.
546 * If the user is not the owner of the file and is not privileged,
547 * the request is denied.
548 * Otherwise, remove the namenode from the hash list.
549 * If the mounted file descriptor was that of a stream and this
550 * was the last mount of the stream, turn off the STRMOUNT flag.
551 * If the rootvp is referenced other than through the mount,
552 * nm_inactive will clean up.
553 */
554 static int
nm_unmount(vfs_t * vfsp,int flag,cred_t * crp)555 nm_unmount(vfs_t *vfsp, int flag, cred_t *crp)
556 {
557 struct namenode *nodep = (struct namenode *)vfsp->vfs_data;
558 vnode_t *vp, *thisvp;
559 struct file *fp = NULL;
560
561 ASSERT((nodep->nm_flag & NMNMNT) == 0);
562
563 /*
564 * forced unmount is not supported by this file system
565 * and thus, ENOTSUP, is being returned.
566 */
567 if (flag & MS_FORCE) {
568 return (ENOTSUP);
569 }
570
571 vp = nodep->nm_filevp;
572 mutex_enter(&nodep->nm_lock);
573 if (secpolicy_vnode_owner(crp, nodep->nm_vattr.va_uid) != 0) {
574 mutex_exit(&nodep->nm_lock);
575 return (EPERM);
576 }
577
578 mutex_exit(&nodep->nm_lock);
579
580 mutex_enter(&ntable_lock);
581 nameremove(nodep);
582 thisvp = NMTOV(nodep);
583 mutex_enter(&thisvp->v_lock);
584 if (thisvp->v_count-- == 1) {
585 fp = nodep->nm_filep;
586 mutex_exit(&thisvp->v_lock);
587 vn_invalid(thisvp);
588 vn_free(thisvp);
589 VFS_RELE(vfsp);
590 namenodeno_free(nodep->nm_vattr.va_nodeid);
591 kmem_free(nodep, sizeof (struct namenode));
592 } else {
593 thisvp->v_flag &= ~VROOT;
594 mutex_exit(&thisvp->v_lock);
595 }
596 if (namefind(vp, NULLVP) == NULL && vp->v_stream) {
597 struct stdata *stp = vp->v_stream;
598 mutex_enter(&stp->sd_lock);
599 stp->sd_flag &= ~STRMOUNT;
600 mutex_exit(&stp->sd_lock);
601 }
602 mutex_exit(&ntable_lock);
603 if (fp != NULL)
604 (void) closef(fp);
605 return (0);
606 }
607
608 /*
609 * Create a reference to the root of a mounted file descriptor.
610 * This routine is called from lookupname() in the event a path
611 * is being searched that has a mounted file descriptor in it.
612 */
613 static int
nm_root(vfs_t * vfsp,vnode_t ** vpp)614 nm_root(vfs_t *vfsp, vnode_t **vpp)
615 {
616 struct namenode *nodep = (struct namenode *)vfsp->vfs_data;
617 struct vnode *vp = NMTOV(nodep);
618
619 VN_HOLD(vp);
620 *vpp = vp;
621 return (0);
622 }
623
624 /*
625 * Return in sp the status of this file system.
626 */
627 static int
nm_statvfs(vfs_t * vfsp,struct statvfs64 * sp)628 nm_statvfs(vfs_t *vfsp, struct statvfs64 *sp)
629 {
630 dev32_t d32;
631
632 bzero(sp, sizeof (*sp));
633 sp->f_bsize = 1024;
634 sp->f_frsize = 1024;
635 (void) cmpldev(&d32, vfsp->vfs_dev);
636 sp->f_fsid = d32;
637 (void) strcpy(sp->f_basetype, vfssw[vfsp->vfs_fstype].vsw_name);
638 sp->f_flag = vf_to_stf(vfsp->vfs_flag);
639 return (0);
640 }
641
642 /*
643 * Since this file system has no disk blocks of its own, apply
644 * the VOP_FSYNC operation on the mounted file descriptor.
645 */
646 static int
nm_sync(vfs_t * vfsp,short flag,cred_t * crp)647 nm_sync(vfs_t *vfsp, short flag, cred_t *crp)
648 {
649 struct namenode *nodep;
650
651 if (vfsp == NULL)
652 return (0);
653
654 nodep = (struct namenode *)vfsp->vfs_data;
655 if (flag & SYNC_CLOSE)
656 return (nm_umountall(nodep->nm_filevp, crp));
657
658 return (VOP_FSYNC(nodep->nm_filevp, FSYNC, crp, NULL));
659 }
660
661 /*
662 * File system initialization routine. Save the file system type,
663 * establish a file system device number and initialize nm_filevp_hash[].
664 */
665 int
nameinit(int fstype,char * name)666 nameinit(int fstype, char *name)
667 {
668 static const fs_operation_def_t nm_vfsops_template[] = {
669 VFSNAME_MOUNT, { .vfs_mount = nm_mount },
670 VFSNAME_UNMOUNT, { .vfs_unmount = nm_unmount },
671 VFSNAME_ROOT, { .vfs_root = nm_root },
672 VFSNAME_STATVFS, { .vfs_statvfs = nm_statvfs },
673 VFSNAME_SYNC, { .vfs_sync = nm_sync },
674 NULL, NULL
675 };
676 static const fs_operation_def_t nm_dummy_vfsops_template[] = {
677 VFSNAME_STATVFS, { .vfs_statvfs = nm_statvfs },
678 VFSNAME_SYNC, { .vfs_sync = nm_sync },
679 NULL, NULL
680 };
681 int error;
682 int dev;
683 vfsops_t *dummy_vfsops;
684
685 error = vfs_setfsops(fstype, nm_vfsops_template, &namefs_vfsops);
686 if (error != 0) {
687 cmn_err(CE_WARN, "nameinit: bad vfs ops template");
688 return (error);
689 }
690
691 error = vfs_makefsops(nm_dummy_vfsops_template, &dummy_vfsops);
692 if (error != 0) {
693 (void) vfs_freevfsops_by_type(fstype);
694 cmn_err(CE_WARN, "nameinit: bad dummy vfs ops template");
695 return (error);
696 }
697
698 error = vn_make_ops(name, nm_vnodeops_template, &nm_vnodeops);
699 if (error != 0) {
700 (void) vfs_freevfsops_by_type(fstype);
701 vfs_freevfsops(dummy_vfsops);
702 cmn_err(CE_WARN, "nameinit: bad vnode ops template");
703 return (error);
704 }
705
706 namefstype = fstype;
707
708 if ((dev = getudev()) == (major_t)-1) {
709 cmn_err(CE_WARN, "nameinit: can't get unique device");
710 dev = 0;
711 }
712 mutex_init(&ntable_lock, NULL, MUTEX_DEFAULT, NULL);
713 namedev = makedevice(dev, 0);
714 bzero(nm_filevp_hash, sizeof (nm_filevp_hash));
715 vfs_setops(&namevfs, dummy_vfsops);
716 namevfs.vfs_vnodecovered = NULL;
717 namevfs.vfs_bsize = 1024;
718 namevfs.vfs_fstype = namefstype;
719 vfs_make_fsid(&namevfs.vfs_fsid, namedev, namefstype);
720 namevfs.vfs_dev = namedev;
721 return (0);
722 }
723
724 static mntopts_t nm_mntopts = {
725 NULL,
726 0
727 };
728
729 static vfsdef_t vfw = {
730 VFSDEF_VERSION,
731 "namefs",
732 nameinit,
733 VSW_HASPROTO | VSW_ZMOUNT,
734 &nm_mntopts
735 };
736
737 /*
738 * Module linkage information for the kernel.
739 */
740 static struct modlfs modlfs = {
741 &mod_fsops, "filesystem for namefs", &vfw
742 };
743
744 static struct modlinkage modlinkage = {
745 MODREV_1, (void *)&modlfs, NULL
746 };
747
748 int
_init(void)749 _init(void)
750 {
751 namenodeno_init();
752 return (mod_install(&modlinkage));
753 }
754
755 int
_fini(void)756 _fini(void)
757 {
758 return (EBUSY);
759 }
760
761 int
_info(struct modinfo * modinfop)762 _info(struct modinfo *modinfop)
763 {
764 return (mod_info(&modlinkage, modinfop));
765 }
766