xref: /titanic_41/usr/src/uts/common/fs/dev/sdev_zvolops.c (revision 726fad2a65f16c200a03969c29cb5c86c2d427db)
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 /* vnode ops for the /dev/zvol directory */
27 
28 #include <sys/types.h>
29 #include <sys/param.h>
30 #include <sys/sysmacros.h>
31 #include <sys/ddi.h>
32 #include <sys/sunndi.h>
33 #include <sys/sunldi.h>
34 #include <fs/fs_subr.h>
35 #include <sys/fs/dv_node.h>
36 #include <sys/fs/sdev_impl.h>
37 #include <sys/zfs_ioctl.h>
38 #include <sys/policy.h>
39 #include <sys/stat.h>
40 #include <sys/vfs_opreg.h>
41 
42 struct vnodeops	*devzvol_vnodeops;
43 static uint64_t devzvol_gen = 0;
44 static uint64_t devzvol_zclist;
45 static size_t devzvol_zclist_size;
46 static ldi_ident_t devzvol_li;
47 static ldi_handle_t devzvol_lh;
48 static kmutex_t devzvol_mtx;
49 static boolean_t devzvol_isopen;
50 
51 /*
52  * we need to use ddi_mod* since fs/dev gets loaded early on in
53  * startup(), and linking fs/dev to fs/zfs would drag in a lot of
54  * other stuff (like drv/random) before the rest of the system is
55  * ready to go
56  */
57 ddi_modhandle_t zfs_mod;
58 int (*szcm)(char *);
59 int (*szn2m)(char *, minor_t *);
60 
61 int
62 sdev_zvol_create_minor(char *dsname)
63 {
64 	return ((*szcm)(dsname));
65 }
66 
67 int
68 sdev_zvol_name2minor(char *dsname, minor_t *minor)
69 {
70 	return ((*szn2m)(dsname, minor));
71 }
72 
73 int
74 devzvol_open_zfs()
75 {
76 	int rc;
77 
78 	devzvol_li = ldi_ident_from_anon();
79 	if (ldi_open_by_name("/dev/zfs", FREAD | FWRITE, kcred,
80 	    &devzvol_lh, devzvol_li))
81 		return (-1);
82 	if (zfs_mod == NULL && ((zfs_mod = ddi_modopen("fs/zfs",
83 	    KRTLD_MODE_FIRST, &rc)) == NULL)) {
84 		return (rc);
85 	}
86 	ASSERT(szcm == NULL && szn2m == NULL);
87 	if ((szcm = (int (*)(char *))
88 	    ddi_modsym(zfs_mod, "zvol_create_minor", &rc)) == NULL) {
89 		cmn_err(CE_WARN, "couldn't resolve zvol_create_minor");
90 		return (rc);
91 	}
92 	if ((szn2m = (int(*)(char *, minor_t *))
93 	    ddi_modsym(zfs_mod, "zvol_name2minor", &rc)) == NULL) {
94 		cmn_err(CE_WARN, "couldn't resolve zvol_name2minor");
95 		return (rc);
96 	}
97 	return (0);
98 }
99 
100 void
101 devzvol_close_zfs()
102 {
103 	szcm = NULL;
104 	szn2m = NULL;
105 	(void) ldi_close(devzvol_lh, FREAD|FWRITE, kcred);
106 	ldi_ident_release(devzvol_li);
107 	if (zfs_mod != NULL) {
108 		(void) ddi_modclose(zfs_mod);
109 		zfs_mod = NULL;
110 	}
111 }
112 
113 int
114 devzvol_handle_ioctl(int cmd, zfs_cmd_t *zc, size_t *alloc_size)
115 {
116 	uint64_t cookie;
117 	int size = 8000;
118 	int unused;
119 	int rc;
120 
121 	if (cmd != ZFS_IOC_POOL_CONFIGS)
122 		mutex_enter(&devzvol_mtx);
123 	if (!devzvol_isopen) {
124 		if ((rc = devzvol_open_zfs()) == 0) {
125 			devzvol_isopen = B_TRUE;
126 		} else {
127 			if (cmd != ZFS_IOC_POOL_CONFIGS)
128 				mutex_exit(&devzvol_mtx);
129 			return (ENXIO);
130 		}
131 	}
132 	cookie = zc->zc_cookie;
133 again:
134 	zc->zc_nvlist_dst = (uint64_t)(intptr_t)kmem_alloc(size,
135 	    KM_SLEEP);
136 	zc->zc_nvlist_dst_size = size;
137 	rc = ldi_ioctl(devzvol_lh, cmd, (intptr_t)zc, FKIOCTL, kcred,
138 	    &unused);
139 	if (rc == ENOMEM) {
140 		int newsize;
141 		newsize = zc->zc_nvlist_dst_size;
142 		ASSERT(newsize > size);
143 		kmem_free((void *)(uintptr_t)zc->zc_nvlist_dst, size);
144 		size = newsize;
145 		zc->zc_cookie = cookie;
146 		goto again;
147 	}
148 	if (alloc_size == NULL)
149 		kmem_free((void *)(uintptr_t)zc->zc_nvlist_dst, size);
150 	else
151 		*alloc_size = size;
152 	if (cmd != ZFS_IOC_POOL_CONFIGS)
153 		mutex_exit(&devzvol_mtx);
154 	return (rc);
155 }
156 
157 /* figures out if the objset exists and returns its type */
158 int
159 devzvol_objset_check(char *dsname, dmu_objset_type_t *type)
160 {
161 	boolean_t	ispool;
162 	zfs_cmd_t	*zc;
163 	int rc;
164 
165 	zc = kmem_zalloc(sizeof (zfs_cmd_t), KM_SLEEP);
166 	(void) strlcpy(zc->zc_name, dsname, MAXPATHLEN);
167 
168 	ispool = (strchr(dsname, '/') == NULL) ? B_TRUE : B_FALSE;
169 	if (!ispool && sdev_zvol_name2minor(dsname, NULL) == 0) {
170 		sdcmn_err13(("found cached minor node"));
171 		if (type)
172 			*type = DMU_OST_ZVOL;
173 		kmem_free(zc, sizeof (zfs_cmd_t));
174 		return (0);
175 	}
176 	rc = devzvol_handle_ioctl(ispool ? ZFS_IOC_POOL_STATS :
177 	    ZFS_IOC_OBJSET_STATS, zc, NULL);
178 	if (type && rc == 0)
179 		*type = (ispool) ? DMU_OST_ZFS :
180 		    zc->zc_objset_stats.dds_type;
181 	kmem_free(zc, sizeof (zfs_cmd_t));
182 	return (rc);
183 }
184 
185 /*
186  * returns what the zfs dataset name should be, given the /dev/zvol
187  * path and an optional name; otherwise NULL
188  */
189 char *
190 devzvol_make_dsname(const char *path, const char *name)
191 {
192 	char *dsname;
193 	const char *ptr;
194 	int dslen;
195 
196 	if (strcmp(path, ZVOL_DIR) == 0)
197 		return (NULL);
198 	if (name && (strcmp(name, ".") == 0 || strcmp(name, "..") == 0))
199 		return (NULL);
200 	ptr = path + strlen(ZVOL_DIR);
201 	if (strncmp(ptr, "/dsk", 4) == 0)
202 		ptr += strlen("/dsk");
203 	else if (strncmp(ptr, "/rdsk", 5) == 0)
204 		ptr += strlen("/rdsk");
205 	else
206 		return (NULL);
207 	if (*ptr == '/')
208 		ptr++;
209 
210 	dslen = strlen(ptr);
211 	if (dslen)
212 		dslen++;			/* plus null */
213 	if (name)
214 		dslen += strlen(name) + 1;	/* plus slash */
215 	dsname = kmem_zalloc(dslen, KM_SLEEP);
216 	if (*ptr) {
217 		(void) strlcpy(dsname, ptr, dslen);
218 		if (name)
219 			(void) strlcat(dsname, "/", dslen);
220 	}
221 	if (name)
222 		(void) strlcat(dsname, name, dslen);
223 	return (dsname);
224 }
225 
226 /*
227  * check if the zvol's sdev_node is still valid, which means make
228  * sure the zvol is still valid.  zvol minors aren't proactively
229  * destroyed when the zvol is destroyed, so we use a validator to clean
230  * these up (in other words, when such nodes are encountered during
231  * subsequent lookup() and readdir() operations) so that only valid
232  * nodes are returned.  The ordering between devname_lookup_func and
233  * devzvol_validate is a little inefficient in the case of invalid
234  * or stale nodes because devname_lookup_func calls
235  * devzvol_create_{dir, link}, then the validator says it's invalid,
236  * and then the node gets cleaned up.
237  */
238 int
239 devzvol_validate(struct sdev_node *dv)
240 {
241 	dmu_objset_type_t do_type;
242 	char *dsname;
243 	char *nm = dv->sdev_name;
244 	int rc;
245 
246 	sdcmn_err13(("validating ('%s' '%s')", dv->sdev_path, nm));
247 	/*
248 	 * validate only READY nodes; if someone is sitting on the
249 	 * directory of a dataset that just got destroyed we could
250 	 * get a zombie node which we just skip.
251 	 */
252 	if (dv->sdev_state != SDEV_READY) {
253 		sdcmn_err13(("skipping '%s'", nm));
254 		return (SDEV_VTOR_SKIP);
255 	}
256 
257 	if ((strcmp(dv->sdev_path, ZVOL_DIR "/dsk") == 0) ||
258 	    (strcmp(dv->sdev_path, ZVOL_DIR "/rdsk") == 0))
259 		return (SDEV_VTOR_VALID);
260 	dsname = devzvol_make_dsname(dv->sdev_path, NULL);
261 	if (dsname == NULL)
262 		return (SDEV_VTOR_INVALID);
263 
264 	rc = devzvol_objset_check(dsname, &do_type);
265 	sdcmn_err13(("  '%s' rc %d", dsname, rc));
266 	if (rc != 0) {
267 		kmem_free(dsname, strlen(dsname) + 1);
268 		return (SDEV_VTOR_INVALID);
269 	}
270 	sdcmn_err13(("  v_type %d do_type %d",
271 	    SDEVTOV(dv)->v_type, do_type));
272 	if ((SDEVTOV(dv)->v_type == VLNK && do_type != DMU_OST_ZVOL) ||
273 	    (SDEVTOV(dv)->v_type == VDIR && do_type == DMU_OST_ZVOL)) {
274 		kmem_free(dsname, strlen(dsname) + 1);
275 		return (SDEV_VTOR_STALE);
276 	}
277 	if (SDEVTOV(dv)->v_type == VLNK) {
278 		char *ptr, *link;
279 		long val = 0;
280 		minor_t lminor, ominor;
281 
282 		rc = sdev_getlink(SDEVTOV(dv), &link);
283 		ASSERT(rc == 0);
284 
285 		ptr = strrchr(link, ':') + 1;
286 		rc = ddi_strtol(ptr, NULL, 10, &val);
287 		kmem_free(link, strlen(link) + 1);
288 		ASSERT(rc == 0 && val != 0);
289 		lminor = (minor_t)val;
290 		if (sdev_zvol_name2minor(dsname, &ominor) < 0 ||
291 		    ominor != lminor) {
292 			kmem_free(dsname, strlen(dsname) + 1);
293 			return (SDEV_VTOR_STALE);
294 		}
295 	}
296 	kmem_free(dsname, strlen(dsname) + 1);
297 	return (SDEV_VTOR_VALID);
298 }
299 
300 /*
301  * creates directories as needed in response to a readdir
302  */
303 void
304 devzvol_create_pool_dirs(struct vnode *dvp)
305 {
306 	zfs_cmd_t	*zc;
307 	nvlist_t *nv = NULL;
308 	nvpair_t *elem = NULL;
309 	size_t size;
310 	int pools = 0;
311 	int rc;
312 
313 	sdcmn_err13(("devzvol_create_pool_dirs"));
314 	zc = kmem_zalloc(sizeof (zfs_cmd_t), KM_SLEEP);
315 	mutex_enter(&devzvol_mtx);
316 	zc->zc_cookie = devzvol_gen;
317 
318 	rc = devzvol_handle_ioctl(ZFS_IOC_POOL_CONFIGS, zc, &size);
319 	switch (rc) {
320 		case 0:
321 			/* new generation */
322 			ASSERT(devzvol_gen != zc->zc_cookie);
323 			devzvol_gen = zc->zc_cookie;
324 			if (devzvol_zclist)
325 				kmem_free((void *)(uintptr_t)devzvol_zclist,
326 				    devzvol_zclist_size);
327 			devzvol_zclist = zc->zc_nvlist_dst;
328 			devzvol_zclist_size = size;
329 			break;
330 		case EEXIST:
331 			/*
332 			 * no change in the configuration; still need
333 			 * to do lookups in case we did a lookup in
334 			 * zvol/rdsk but not zvol/dsk (or vice versa)
335 			 */
336 			kmem_free((void *)(uintptr_t)zc->zc_nvlist_dst,
337 			    size);
338 			break;
339 		default:
340 			kmem_free((void *)(uintptr_t)zc->zc_nvlist_dst,
341 			    size);
342 			goto out;
343 	}
344 	rc = nvlist_unpack((char *)(uintptr_t)devzvol_zclist,
345 	    devzvol_zclist_size, &nv, 0);
346 	if (rc) {
347 		ASSERT(rc == 0);
348 		kmem_free((void *)(uintptr_t)devzvol_zclist,
349 		    devzvol_zclist_size);
350 		devzvol_gen = 0;
351 		devzvol_zclist = NULL;
352 		devzvol_zclist_size = 0;
353 		goto out;
354 	}
355 	mutex_exit(&devzvol_mtx);
356 	while ((elem = nvlist_next_nvpair(nv, elem)) != NULL) {
357 		struct vnode *vp;
358 		ASSERT(dvp->v_count > 0);
359 		rc = VOP_LOOKUP(dvp, nvpair_name(elem), &vp, NULL, 0,
360 		    NULL, kcred, NULL, 0, NULL);
361 		/* should either work, or not be visible from a zone */
362 		ASSERT(rc == 0 || rc == ENOENT);
363 		if (rc == 0)
364 			VN_RELE(vp);
365 		pools++;
366 	}
367 	nvlist_free(nv);
368 	mutex_enter(&devzvol_mtx);
369 	if (devzvol_isopen && pools == 0) {
370 		/* clean up so zfs can be unloaded */
371 		devzvol_close_zfs();
372 		devzvol_isopen = B_FALSE;
373 	}
374 out:
375 	mutex_exit(&devzvol_mtx);
376 	kmem_free(zc, sizeof (zfs_cmd_t));
377 }
378 
379 /*ARGSUSED3*/
380 static int
381 devzvol_create_dir(struct sdev_node *ddv, char *nm, void **arg,
382     cred_t *cred, void *whatever, char *whichever)
383 {
384 	timestruc_t now;
385 	struct vattr *vap = (struct vattr *)arg;
386 
387 	sdcmn_err13(("create_dir (%s) (%s) '%s'", ddv->sdev_name,
388 	    ddv->sdev_path, nm));
389 	ASSERT(strncmp(ddv->sdev_path, ZVOL_DIR,
390 	    strlen(ZVOL_DIR)) == 0);
391 	*vap = *sdev_getdefault_attr(VDIR);
392 	gethrestime(&now);
393 	vap->va_atime = now;
394 	vap->va_mtime = now;
395 	vap->va_ctime = now;
396 	return (0);
397 }
398 
399 /*ARGSUSED3*/
400 static int
401 devzvol_create_link(struct sdev_node *ddv, char *nm,
402     void **arg, cred_t *cred, void *whatever, char *whichever)
403 {
404 	minor_t minor;
405 	char *pathname = (char *)*arg;
406 	int rc;
407 	char *dsname;
408 	char *x;
409 	char str[MAXNAMELEN];
410 	sdcmn_err13(("create_link (%s) (%s) '%s'", ddv->sdev_name,
411 	    ddv->sdev_path, nm));
412 	dsname = devzvol_make_dsname(ddv->sdev_path, nm);
413 	rc = sdev_zvol_create_minor(dsname);
414 	if ((rc != 0 && rc != EEXIST && rc != EBUSY) ||
415 	    sdev_zvol_name2minor(dsname, &minor)) {
416 		sdcmn_err13(("devzvol_create_link %d", rc));
417 		kmem_free(dsname, strlen(dsname) + 1);
418 		return (-1);
419 	}
420 	kmem_free(dsname, strlen(dsname) + 1);
421 
422 	/*
423 	 * This is a valid zvol; create a symlink that points to the
424 	 * minor which was created under /devices/pseudo/zfs@0
425 	 */
426 	*pathname = '\0';
427 	for (x = ddv->sdev_path; x = strchr(x, '/'); x++)
428 		(void) strcat(pathname, "../");
429 	(void) snprintf(str, sizeof (str), ZVOL_PSEUDO_DEV "%u", minor);
430 	(void) strncat(pathname, str, MAXPATHLEN);
431 	if (strncmp(ddv->sdev_path, ZVOL_FULL_RDEV_DIR,
432 	    strlen(ZVOL_FULL_RDEV_DIR)) == 0)
433 		(void) strcat(pathname, ",raw");
434 	return (0);
435 }
436 
437 /* Clean zvol sdev_nodes that are no longer valid.  */
438 static void
439 devzvol_prunedir(struct sdev_node *ddv)
440 {
441 	struct sdev_node *dv;
442 
443 	ASSERT(RW_READ_HELD(&ddv->sdev_contents));
444 
445 	sdcmn_err13(("prunedir '%s'", ddv->sdev_name));
446 	ASSERT(strncmp(ddv->sdev_path, ZVOL_DIR, strlen(ZVOL_DIR)) == 0);
447 	if (rw_tryupgrade(&ddv->sdev_contents) == 0) {
448 		rw_exit(&ddv->sdev_contents);
449 		rw_enter(&ddv->sdev_contents, RW_WRITER);
450 	}
451 
452 	dv = SDEV_FIRST_ENTRY(ddv);
453 	while (dv) {
454 		sdcmn_err13(("sdev_name '%s'", dv->sdev_name));
455 		/* skip stale nodes */
456 		if (dv->sdev_flags & SDEV_STALE) {
457 			sdcmn_err13(("  stale"));
458 			dv = SDEV_NEXT_ENTRY(ddv, dv);
459 			continue;
460 		}
461 
462 		switch (devzvol_validate(dv)) {
463 		case SDEV_VTOR_VALID:
464 		case SDEV_VTOR_SKIP:
465 			dv = SDEV_NEXT_ENTRY(ddv, dv);
466 			continue;
467 		case SDEV_VTOR_INVALID:
468 			sdcmn_err7(("prunedir: destroy invalid "
469 			    "node: %s\n", dv->sdev_name));
470 			break;
471 		}
472 
473 		if ((SDEVTOV(dv)->v_type == VDIR) &&
474 		    (sdev_cleandir(dv, NULL, 0) != 0)) {
475 			dv = SDEV_NEXT_ENTRY(ddv, dv);
476 			continue;
477 		}
478 		SDEV_HOLD(dv);
479 		/* remove the cache node */
480 		if (sdev_cache_update(ddv, &dv, dv->sdev_name,
481 		    SDEV_CACHE_DELETE) == 0)
482 			dv = SDEV_FIRST_ENTRY(ddv);
483 		else
484 			dv = SDEV_NEXT_ENTRY(ddv, dv);
485 	}
486 	rw_downgrade(&ddv->sdev_contents);
487 }
488 
489 /*ARGSUSED*/
490 static int
491 devzvol_lookup(struct vnode *dvp, char *nm, struct vnode **vpp,
492     struct pathname *pnp, int flags, struct vnode *rdir, struct cred *cred,
493     caller_context_t *ct, int *direntflags, pathname_t *realpnp)
494 {
495 	enum vtype expected_type = VDIR;
496 	struct sdev_node *parent = VTOSDEV(dvp);
497 	char *dsname;
498 	dmu_objset_type_t do_type;
499 	int error;
500 
501 	sdcmn_err13(("devzvol_lookup '%s' '%s'", parent->sdev_path, nm));
502 	*vpp = NULL;
503 	/* execute access is required to search the directory */
504 	if ((error = VOP_ACCESS(dvp, VEXEC, 0, cred, ct)) != 0)
505 		return (error);
506 
507 	rw_enter(&parent->sdev_contents, RW_READER);
508 	if (!SDEV_IS_GLOBAL(parent)) {
509 		rw_exit(&parent->sdev_contents);
510 		return (prof_lookup(dvp, nm, vpp, cred));
511 	}
512 
513 	dsname = devzvol_make_dsname(parent->sdev_path, nm);
514 	rw_exit(&parent->sdev_contents);
515 	sdcmn_err13(("rvp dsname %s", dsname ? dsname : "(null)"));
516 	if (dsname) {
517 		error = devzvol_objset_check(dsname, &do_type);
518 		if (error != 0) {
519 			error = ENOENT;
520 			goto out;
521 		}
522 		if (do_type == DMU_OST_ZVOL)
523 			expected_type = VLNK;
524 	}
525 	/*
526 	 * the callbacks expect:
527 	 *
528 	 * parent->sdev_path		   nm
529 	 * /dev/zvol			   {r}dsk
530 	 * /dev/zvol/{r}dsk		   <pool name>
531 	 * /dev/zvol/{r}dsk/<dataset name> <last ds component>
532 	 *
533 	 * sdev_name is always last path component of sdev_path
534 	 */
535 	if (expected_type == VDIR) {
536 		error = devname_lookup_func(parent, nm, vpp, cred,
537 		    devzvol_create_dir, SDEV_VATTR);
538 	} else {
539 		error = devname_lookup_func(parent, nm, vpp, cred,
540 		    devzvol_create_link, SDEV_VLINK);
541 	}
542 	sdcmn_err13(("devzvol_lookup %d %d", expected_type, error));
543 	ASSERT(error || ((*vpp)->v_type == expected_type));
544 out:
545 	if (dsname)
546 		kmem_free(dsname, strlen(dsname) + 1);
547 	sdcmn_err13(("devzvol_lookup %d", error));
548 	return (error);
549 }
550 
551 /*
552  * We allow create to find existing nodes
553  *	- if the node doesn't exist - EROFS
554  *	- creating an existing dir read-only succeeds, otherwise EISDIR
555  *	- exclusive creates fail - EEXIST
556  */
557 /*ARGSUSED2*/
558 static int
559 devzvol_create(struct vnode *dvp, char *nm, struct vattr *vap, vcexcl_t excl,
560     int mode, struct vnode **vpp, struct cred *cred, int flag,
561     caller_context_t *ct, vsecattr_t *vsecp)
562 {
563 	int error;
564 	struct vnode *vp;
565 
566 	*vpp = NULL;
567 
568 	error = devzvol_lookup(dvp, nm, &vp, NULL, 0, NULL, cred, ct, NULL,
569 	    NULL);
570 	if (error == 0) {
571 		if (excl == EXCL)
572 			error = EEXIST;
573 		else if (vp->v_type == VDIR && (mode & VWRITE))
574 			error = EISDIR;
575 		else
576 			error = VOP_ACCESS(vp, mode, 0, cred, ct);
577 
578 		if (error) {
579 			VN_RELE(vp);
580 		} else
581 			*vpp = vp;
582 	} else if (error == ENOENT) {
583 		error = EROFS;
584 	}
585 
586 	return (error);
587 }
588 
589 void sdev_iter_snapshots(struct vnode *dvp, char *name);
590 
591 void
592 sdev_iter_datasets(struct vnode *dvp, int arg, char *name)
593 {
594 	zfs_cmd_t	*zc;
595 	int rc;
596 
597 	sdcmn_err13(("iter name is '%s' (arg %x)", name, arg));
598 	zc = kmem_zalloc(sizeof (zfs_cmd_t), KM_SLEEP);
599 	(void) strcpy(zc->zc_name, name);
600 
601 	while ((rc = devzvol_handle_ioctl(arg, zc, B_FALSE)) == 0) {
602 		struct vnode *vpp;
603 		char *ptr;
604 
605 		sdcmn_err13(("  name %s", zc->zc_name));
606 		if (strchr(zc->zc_name, '$') || strchr(zc->zc_name, '%'))
607 			goto skip;
608 		ptr = strrchr(zc->zc_name, '/') + 1;
609 		rc = devzvol_lookup(dvp, ptr, &vpp, NULL, 0, NULL,
610 		    kcred, NULL, NULL, NULL);
611 		if (rc == 0) {
612 			VN_RELE(vpp);
613 		} else if (rc == ENOENT) {
614 			goto skip;
615 		} else {
616 			/* EBUSY == problem with zvols's dmu holds? */
617 			ASSERT(0);
618 			goto skip;
619 		}
620 		if (arg == ZFS_IOC_DATASET_LIST_NEXT &&
621 		    zc->zc_objset_stats.dds_type != DMU_OST_ZFS)
622 			sdev_iter_snapshots(dvp, zc->zc_name);
623 skip:
624 		(void) strcpy(zc->zc_name, name);
625 	}
626 	kmem_free(zc, sizeof (zfs_cmd_t));
627 }
628 
629 void
630 sdev_iter_snapshots(struct vnode *dvp, char *name)
631 {
632 	sdev_iter_datasets(dvp, ZFS_IOC_SNAPSHOT_LIST_NEXT, name);
633 }
634 
635 /*ARGSUSED4*/
636 static int
637 devzvol_readdir(struct vnode *dvp, struct uio *uiop, struct cred *cred,
638     int *eofp, caller_context_t *ct_unused, int flags_unused)
639 {
640 	struct sdev_node *sdvp = VTOSDEV(dvp);
641 	char *ptr;
642 
643 	sdcmn_err13(("zv readdir of '%s' %s'", sdvp->sdev_path,
644 	    sdvp->sdev_name));
645 
646 	if (strcmp(sdvp->sdev_path, ZVOL_DIR) == 0) {
647 		struct vnode *vp;
648 
649 		rw_exit(&sdvp->sdev_contents);
650 		(void) devname_lookup_func(sdvp, "dsk", &vp, cred,
651 		    devzvol_create_dir, SDEV_VATTR);
652 		VN_RELE(vp);
653 		(void) devname_lookup_func(sdvp, "rdsk", &vp, cred,
654 		    devzvol_create_dir, SDEV_VATTR);
655 		VN_RELE(vp);
656 		rw_enter(&sdvp->sdev_contents, RW_READER);
657 		return (devname_readdir_func(dvp, uiop, cred, eofp, 0));
658 	}
659 	if (uiop->uio_offset == 0)
660 		devzvol_prunedir(sdvp);
661 	ptr = sdvp->sdev_path + strlen(ZVOL_DIR);
662 	if ((strcmp(ptr, "/dsk") == 0) || (strcmp(ptr, "/rdsk") == 0)) {
663 		rw_exit(&sdvp->sdev_contents);
664 		devzvol_create_pool_dirs(dvp);
665 		rw_enter(&sdvp->sdev_contents, RW_READER);
666 		return (devname_readdir_func(dvp, uiop, cred, eofp, 0));
667 	}
668 
669 	ptr = strchr(ptr + 1, '/') + 1;
670 	rw_exit(&sdvp->sdev_contents);
671 	sdev_iter_datasets(dvp, ZFS_IOC_DATASET_LIST_NEXT, ptr);
672 	rw_enter(&sdvp->sdev_contents, RW_READER);
673 	return (devname_readdir_func(dvp, uiop, cred, eofp, 0));
674 }
675 
676 const fs_operation_def_t devzvol_vnodeops_tbl[] = {
677 	VOPNAME_READDIR,	{ .vop_readdir = devzvol_readdir },
678 	VOPNAME_LOOKUP,		{ .vop_lookup = devzvol_lookup },
679 	VOPNAME_CREATE,		{ .vop_create = devzvol_create },
680 	VOPNAME_RENAME,		{ .error = fs_nosys },
681 	VOPNAME_MKDIR,		{ .error = fs_nosys },
682 	VOPNAME_RMDIR,		{ .error = fs_nosys },
683 	VOPNAME_REMOVE,		{ .error = fs_nosys },
684 	VOPNAME_SYMLINK,	{ .error = fs_nosys },
685 	NULL,			NULL
686 };
687