xref: /illumos-gate/usr/src/common/zfs/zfs_prop.c (revision 08516594b0e540dc0f415fa7ae31f54d943a0913)
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * Master property table.
30  *
31  * This table keeps track of all the properties supported by ZFS, and their
32  * various attributes.  Not all of these are needed by the kernel, and several
33  * are only used by a single libzfs client.  But having them here centralizes
34  * all property information in one location.
35  *
36  * 	name		The human-readable string representing this property
37  * 	proptype	Basic type (string, boolean, number)
38  * 	default		Default value for the property.  Sadly, C only allows
39  * 			you to initialize the first member of a union, so we
40  * 			have two default members for each property.
41  * 	attr		Attributes (readonly, inheritable) for the property
42  * 	types		Valid dataset types to which this applies
43  * 	values		String describing acceptable values for the property
44  * 	colname		The column header for 'zfs list'
45  *	colfmt		The column formatting for 'zfs list'
46  *
47  * This table must match the order of property types in libzfs.h.
48  */
49 
50 #include <sys/zio.h>
51 #include <sys/spa.h>
52 #include <sys/zfs_acl.h>
53 #include <sys/zfs_ioctl.h>
54 
55 #include "zfs_prop.h"
56 
57 #if defined(_KERNEL)
58 #include <sys/systm.h>
59 #else
60 #include <stdlib.h>
61 #include <string.h>
62 #include <ctype.h>
63 #endif
64 
65 typedef enum {
66 	prop_default,
67 	prop_readonly,
68 	prop_inherit
69 } prop_attr_t;
70 
71 typedef struct {
72 	const char	*pd_name;
73 	zfs_proptype_t	pd_proptype;
74 	uint64_t	pd_numdefault;
75 	const char	*pd_strdefault;
76 	prop_attr_t	pd_attr;
77 	int		pd_types;
78 	const char	*pd_values;
79 	const char	*pd_colname;
80 	boolean_t	pd_rightalign;
81 	boolean_t	pd_visible;
82 } prop_desc_t;
83 
84 static prop_desc_t zfs_prop_table[] = {
85 	{ "type",	prop_type_string,	0,	NULL,	prop_readonly,
86 	    ZFS_TYPE_ANY, "filesystem | volume | snapshot", "TYPE", B_TRUE,
87 	    B_TRUE },
88 	{ "creation",	prop_type_number,	0,	NULL,	prop_readonly,
89 	    ZFS_TYPE_ANY, "<date>", "CREATION", B_FALSE, B_TRUE },
90 	{ "used",	prop_type_number,	0,	NULL,	prop_readonly,
91 	    ZFS_TYPE_ANY, "<size>",	"USED", B_TRUE, B_TRUE },
92 	{ "available",	prop_type_number,	0,	NULL,	prop_readonly,
93 	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME, "<size>", "AVAIL", B_TRUE,
94 	    B_TRUE },
95 	{ "referenced",	prop_type_number,	0,	NULL,	prop_readonly,
96 	    ZFS_TYPE_ANY,
97 	    "<size>", "REFER", B_TRUE, B_TRUE },
98 	{ "compressratio", prop_type_number,	0,	NULL,	prop_readonly,
99 	    ZFS_TYPE_ANY, "<1.00x or higher if compressed>", "RATIO", B_TRUE,
100 	    B_TRUE },
101 	{ "mounted",	prop_type_boolean,	0,	NULL,	prop_readonly,
102 	    ZFS_TYPE_FILESYSTEM, "yes | no | -", "MOUNTED", B_TRUE, B_TRUE },
103 	{ "origin",	prop_type_string,	0,	NULL,	prop_readonly,
104 	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME, "<snapshot>", "ORIGIN",
105 	    B_FALSE, B_TRUE },
106 	{ "quota",	prop_type_number,	0,	NULL,	prop_default,
107 	    ZFS_TYPE_FILESYSTEM, "<size> | none", "QUOTA", B_TRUE, B_TRUE },
108 	{ "reservation", prop_type_number,	0,	NULL,	prop_default,
109 	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME,
110 	    "<size> | none", "RESERV", B_TRUE, B_TRUE },
111 	{ "volsize",	prop_type_number,	0,	NULL,	prop_default,
112 	    ZFS_TYPE_VOLUME, "<size>", "VOLSIZE", B_TRUE, B_TRUE },
113 	{ "volblocksize", prop_type_number,	8192,	NULL,	prop_readonly,
114 	    ZFS_TYPE_VOLUME, "512 to 128k, power of 2",	"VOLBLOCK", B_TRUE,
115 	    B_TRUE },
116 	{ "recordsize",	prop_type_number,	SPA_MAXBLOCKSIZE,	NULL,
117 	    prop_inherit,
118 	    ZFS_TYPE_FILESYSTEM,
119 	    "512 to 128k, power of 2", "RECSIZE", B_TRUE, B_TRUE },
120 	{ "mountpoint",	prop_type_string,	0,	"/",	prop_inherit,
121 	    ZFS_TYPE_FILESYSTEM,
122 	    "<path> | legacy | none", "MOUNTPOINT", B_FALSE, B_TRUE },
123 	{ "sharenfs",	prop_type_string,	0,	"off",	prop_inherit,
124 	    ZFS_TYPE_FILESYSTEM,
125 	    "on | off | share(1M) options", "SHARENFS", B_FALSE, B_TRUE },
126 	{ "checksum",	prop_type_index,	ZIO_CHECKSUM_DEFAULT,	"on",
127 	    prop_inherit,	ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME,
128 	    "on | off | fletcher2 | fletcher4 | sha256", "CHECKSUM", B_TRUE,
129 	    B_TRUE },
130 	{ "compression", prop_type_index,	ZIO_COMPRESS_DEFAULT,	"off",
131 	    prop_inherit,	ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME,
132 	    "on | off | lzjb | gzip | gzip-[1-9]", "COMPRESS", B_TRUE, B_TRUE },
133 	{ "atime",	prop_type_boolean,	1,	NULL,	prop_inherit,
134 	    ZFS_TYPE_FILESYSTEM,
135 	    "on | off", "ATIME", B_TRUE, B_TRUE },
136 	{ "devices",	prop_type_boolean,	1,	NULL,	prop_inherit,
137 	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_SNAPSHOT,
138 	    "on | off", "DEVICES", B_TRUE, B_TRUE },
139 	{ "exec",	prop_type_boolean,	1,	NULL,	prop_inherit,
140 	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_SNAPSHOT,
141 	    "on | off", "EXEC", B_TRUE, B_TRUE },
142 	{ "setuid",	prop_type_boolean,	1,	NULL,	prop_inherit,
143 	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_SNAPSHOT, "on | off", "SETUID",
144 	    B_TRUE, B_TRUE },
145 	{ "readonly",	prop_type_boolean,	0,	NULL,	prop_inherit,
146 	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME,
147 	    "on | off", "RDONLY", B_TRUE, B_TRUE },
148 	{ "zoned",	prop_type_boolean,	0,	NULL,	prop_inherit,
149 	    ZFS_TYPE_FILESYSTEM,
150 	    "on | off", "ZONED", B_TRUE, B_TRUE },
151 	{ "snapdir",	prop_type_index,	ZFS_SNAPDIR_HIDDEN, "hidden",
152 	    prop_inherit,
153 	    ZFS_TYPE_FILESYSTEM,
154 	    "hidden | visible", "SNAPDIR", B_TRUE, B_TRUE },
155 	{ "aclmode", prop_type_index,	ZFS_ACL_GROUPMASK, "groupmask",
156 	    prop_inherit, ZFS_TYPE_FILESYSTEM,
157 	    "discard | groupmask | passthrough", "ACLMODE", B_TRUE, B_TRUE },
158 	{ "aclinherit", prop_type_index,	ZFS_ACL_SECURE,	"secure",
159 	    prop_inherit, ZFS_TYPE_FILESYSTEM,
160 	    "discard | noallow | secure | passthrough", "ACLINHERIT", B_TRUE,
161 	    B_TRUE },
162 	{ "createtxg",	prop_type_number,	0,	NULL,	prop_readonly,
163 	    ZFS_TYPE_ANY, NULL, NULL, B_FALSE, B_FALSE },
164 	{ "name",	prop_type_string,	0,	NULL,	prop_readonly,
165 	    ZFS_TYPE_ANY, NULL, "NAME", B_FALSE, B_FALSE },
166 	{ "canmount",	prop_type_boolean,	1,	NULL,	prop_default,
167 	    ZFS_TYPE_FILESYSTEM,
168 	    "on | off", "CANMOUNT", B_TRUE, B_TRUE },
169 	{ "shareiscsi",	prop_type_string,	0,	"off",	prop_inherit,
170 	    ZFS_TYPE_ANY,
171 	    "on | off | type=<type>", "SHAREISCSI", B_FALSE, B_TRUE },
172 	{ "iscsioptions", prop_type_string,	0,	NULL,	prop_inherit,
173 	    ZFS_TYPE_VOLUME, NULL, "ISCSIOPTIONS", B_FALSE, B_FALSE },
174 	{ "xattr",	prop_type_boolean,	1,	NULL,	prop_inherit,
175 	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_SNAPSHOT,
176 	    "on | off", "XATTR", B_TRUE, B_TRUE },
177 	{ "numclones", prop_type_number,	0,	NULL,	prop_readonly,
178 	    ZFS_TYPE_SNAPSHOT, NULL, NULL, B_FALSE, B_FALSE },
179 	{ "copies",	prop_type_index,	1,	"1",	prop_inherit,
180 	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME,
181 	    "1 | 2 | 3", "COPIES", B_TRUE, B_TRUE },
182 	{ "bootfs", prop_type_string,	0,	NULL,	prop_default,
183 	    ZFS_TYPE_POOL, "<filesystem>", "BOOTFS", B_FALSE, B_TRUE },
184 };
185 
186 #define	ZFS_PROP_COUNT	((sizeof (zfs_prop_table))/(sizeof (prop_desc_t)))
187 
188 /*
189  * Returns TRUE if the property applies to the given dataset types.
190  */
191 int
192 zfs_prop_valid_for_type(zfs_prop_t prop, int types)
193 {
194 	return ((zfs_prop_table[prop].pd_types & types) != 0);
195 }
196 
197 /*
198  * Determine if the specified property is visible or not.
199  */
200 boolean_t
201 zfs_prop_is_visible(zfs_prop_t prop)
202 {
203 	if (prop < 0)
204 		return (B_FALSE);
205 
206 	return (zfs_prop_table[prop].pd_visible);
207 }
208 
209 /*
210  * Iterate over all properties, calling back into the specified function
211  * for each property. We will continue to iterate until we either
212  * reach the end or the callback function something other than
213  * ZFS_PROP_CONT.
214  */
215 zfs_prop_t
216 zfs_prop_iter_common(zfs_prop_f func, void *cb, zfs_type_t type,
217     boolean_t show_all)
218 {
219 	int i;
220 
221 	for (i = 0; i < ZFS_PROP_COUNT; i++) {
222 		if (zfs_prop_valid_for_type(i, type) &&
223 		    (zfs_prop_is_visible(i) || show_all)) {
224 			if (func(i, cb) != ZFS_PROP_CONT)
225 				return (i);
226 		}
227 	}
228 	return (ZFS_PROP_CONT);
229 }
230 
231 zfs_prop_t
232 zfs_prop_iter(zfs_prop_f func, void *cb, boolean_t show_all)
233 {
234 	return (zfs_prop_iter_common(func, cb, ZFS_TYPE_ANY, show_all));
235 }
236 
237 zpool_prop_t
238 zpool_prop_iter(zpool_prop_f func, void *cb, boolean_t show_all)
239 {
240 	return (zfs_prop_iter_common(func, cb, ZFS_TYPE_POOL, show_all));
241 }
242 
243 zfs_proptype_t
244 zfs_prop_get_type(zfs_prop_t prop)
245 {
246 	return (zfs_prop_table[prop].pd_proptype);
247 }
248 
249 static boolean_t
250 propname_match(const char *p, zfs_prop_t prop, size_t len)
251 {
252 	const char *propname = zfs_prop_table[prop].pd_name;
253 #ifndef _KERNEL
254 	const char *colname = zfs_prop_table[prop].pd_colname;
255 	int c;
256 #endif
257 
258 #ifndef _KERNEL
259 	if (colname == NULL)
260 		return (B_FALSE);
261 #endif
262 
263 	if (len == strlen(propname) &&
264 	    strncmp(p, propname, len) == 0)
265 		return (B_TRUE);
266 
267 #ifndef _KERNEL
268 	if (len != strlen(colname))
269 		return (B_FALSE);
270 
271 	for (c = 0; c < len; c++)
272 		if (p[c] != tolower(colname[c]))
273 			break;
274 
275 	return (colname[c] == '\0');
276 #else
277 	return (B_FALSE);
278 #endif
279 }
280 
281 zfs_prop_t
282 zfs_name_to_prop_cb(zfs_prop_t prop, void *cb_data)
283 {
284 	const char *propname = cb_data;
285 
286 	if (propname_match(propname, prop, strlen(propname)))
287 		return (prop);
288 
289 	return (ZFS_PROP_CONT);
290 }
291 
292 /*
293  * Given a property name and its type, returns the corresponding property ID.
294  */
295 zfs_prop_t
296 zfs_name_to_prop_common(const char *propname, zfs_type_t type)
297 {
298 	zfs_prop_t prop;
299 
300 	prop = zfs_prop_iter_common(zfs_name_to_prop_cb, (void *)propname,
301 	    type, B_TRUE);
302 	return (prop == ZFS_PROP_CONT ? ZFS_PROP_INVAL : prop);
303 }
304 
305 /*
306  * Given a zfs dataset property name, returns the corresponding property ID.
307  */
308 zfs_prop_t
309 zfs_name_to_prop(const char *propname)
310 {
311 	return (zfs_name_to_prop_common(propname, ZFS_TYPE_ANY));
312 }
313 
314 /*
315  * Given a pool property name, returns the corresponding property ID.
316  */
317 zpool_prop_t
318 zpool_name_to_prop(const char *propname)
319 {
320 	return (zfs_name_to_prop_common(propname, ZFS_TYPE_POOL));
321 }
322 
323 /*
324  * For user property names, we allow all lowercase alphanumeric characters, plus
325  * a few useful punctuation characters.
326  */
327 static int
328 valid_char(char c)
329 {
330 	return ((c >= 'a' && c <= 'z') ||
331 	    (c >= '0' && c <= '9') ||
332 	    c == '-' || c == '_' || c == '.' || c == ':');
333 }
334 
335 /*
336  * Returns true if this is a valid user-defined property (one with a ':').
337  */
338 boolean_t
339 zfs_prop_user(const char *name)
340 {
341 	int i;
342 	char c;
343 	boolean_t foundsep = B_FALSE;
344 
345 	for (i = 0; i < strlen(name); i++) {
346 		c = name[i];
347 		if (!valid_char(c))
348 			return (B_FALSE);
349 		if (c == ':')
350 			foundsep = B_TRUE;
351 	}
352 
353 	if (!foundsep)
354 		return (B_FALSE);
355 
356 	return (B_TRUE);
357 }
358 
359 /*
360  * Return the default value for the given property.
361  */
362 const char *
363 zfs_prop_default_string(zfs_prop_t prop)
364 {
365 	return (zfs_prop_table[prop].pd_strdefault);
366 }
367 
368 uint64_t
369 zfs_prop_default_numeric(zfs_prop_t prop)
370 {
371 	return (zfs_prop_table[prop].pd_numdefault);
372 }
373 
374 /*
375  * Returns TRUE if the property is readonly.
376  */
377 int
378 zfs_prop_readonly(zfs_prop_t prop)
379 {
380 	return (zfs_prop_table[prop].pd_attr == prop_readonly);
381 }
382 
383 /*
384  * Given a dataset property ID, returns the corresponding name.
385  * Assuming the zfs dataset propety ID is valid.
386  */
387 const char *
388 zfs_prop_to_name(zfs_prop_t prop)
389 {
390 	return (zfs_prop_table[prop].pd_name);
391 }
392 
393 /*
394  * Given a pool property ID, returns the corresponding name.
395  * Assuming the pool propety ID is valid.
396  */
397 const char *
398 zpool_prop_to_name(zpool_prop_t prop)
399 {
400 	return (zfs_prop_table[prop].pd_name);
401 }
402 
403 /*
404  * Returns TRUE if the property is inheritable.
405  */
406 int
407 zfs_prop_inheritable(zfs_prop_t prop)
408 {
409 	return (zfs_prop_table[prop].pd_attr == prop_inherit);
410 }
411 
412 typedef struct zfs_index {
413 	const char *name;
414 	uint64_t index;
415 } zfs_index_t;
416 
417 static zfs_index_t checksum_table[] = {
418 	{ "on",		ZIO_CHECKSUM_ON },
419 	{ "off",	ZIO_CHECKSUM_OFF },
420 	{ "fletcher2",	ZIO_CHECKSUM_FLETCHER_2 },
421 	{ "fletcher4",	ZIO_CHECKSUM_FLETCHER_4 },
422 	{ "sha256",	ZIO_CHECKSUM_SHA256 },
423 	{ NULL }
424 };
425 
426 static zfs_index_t compress_table[] = {
427 	{ "on",		ZIO_COMPRESS_ON },
428 	{ "off",	ZIO_COMPRESS_OFF },
429 	{ "lzjb",	ZIO_COMPRESS_LZJB },
430 	{ "gzip",	ZIO_COMPRESS_GZIP_6 },	/* the default gzip level */
431 	{ "gzip-1",	ZIO_COMPRESS_GZIP_1 },
432 	{ "gzip-2",	ZIO_COMPRESS_GZIP_2 },
433 	{ "gzip-3",	ZIO_COMPRESS_GZIP_3 },
434 	{ "gzip-4",	ZIO_COMPRESS_GZIP_4 },
435 	{ "gzip-5",	ZIO_COMPRESS_GZIP_5 },
436 	{ "gzip-6",	ZIO_COMPRESS_GZIP_6 },
437 	{ "gzip-7",	ZIO_COMPRESS_GZIP_7 },
438 	{ "gzip-8",	ZIO_COMPRESS_GZIP_8 },
439 	{ "gzip-9",	ZIO_COMPRESS_GZIP_9 },
440 	{ NULL }
441 };
442 
443 static zfs_index_t snapdir_table[] = {
444 	{ "hidden",	ZFS_SNAPDIR_HIDDEN },
445 	{ "visible",	ZFS_SNAPDIR_VISIBLE },
446 	{ NULL }
447 };
448 
449 static zfs_index_t acl_mode_table[] = {
450 	{ "discard",	ZFS_ACL_DISCARD },
451 	{ "groupmask",	ZFS_ACL_GROUPMASK },
452 	{ "passthrough", ZFS_ACL_PASSTHROUGH },
453 	{ NULL }
454 };
455 
456 static zfs_index_t acl_inherit_table[] = {
457 	{ "discard",	ZFS_ACL_DISCARD },
458 	{ "noallow",	ZFS_ACL_NOALLOW },
459 	{ "secure",	ZFS_ACL_SECURE },
460 	{ "passthrough", ZFS_ACL_PASSTHROUGH },
461 	{ NULL }
462 };
463 
464 static zfs_index_t copies_table[] = {
465 	{ "1",	1 },
466 	{ "2",	2 },
467 	{ "3",	3 },
468 	{ NULL }
469 };
470 
471 static zfs_index_t *
472 zfs_prop_index_table(zfs_prop_t prop)
473 {
474 	switch (prop) {
475 	case ZFS_PROP_CHECKSUM:
476 		return (checksum_table);
477 	case ZFS_PROP_COMPRESSION:
478 		return (compress_table);
479 	case ZFS_PROP_SNAPDIR:
480 		return (snapdir_table);
481 	case ZFS_PROP_ACLMODE:
482 		return (acl_mode_table);
483 	case ZFS_PROP_ACLINHERIT:
484 		return (acl_inherit_table);
485 	case ZFS_PROP_COPIES:
486 		return (copies_table);
487 	default:
488 		return (NULL);
489 	}
490 }
491 
492 
493 /*
494  * Tables of index types, plus functions to convert between the user view
495  * (strings) and internal representation (uint64_t).
496  */
497 int
498 zfs_prop_string_to_index(zfs_prop_t prop, const char *string, uint64_t *index)
499 {
500 	zfs_index_t *table;
501 	int i;
502 
503 	if ((table = zfs_prop_index_table(prop)) == NULL)
504 		return (-1);
505 
506 	for (i = 0; table[i].name != NULL; i++) {
507 		if (strcmp(string, table[i].name) == 0) {
508 			*index = table[i].index;
509 			return (0);
510 		}
511 	}
512 
513 	return (-1);
514 }
515 
516 int
517 zfs_prop_index_to_string(zfs_prop_t prop, uint64_t index, const char **string)
518 {
519 	zfs_index_t *table;
520 	int i;
521 
522 	if ((table = zfs_prop_index_table(prop)) == NULL)
523 		return (-1);
524 
525 	for (i = 0; table[i].name != NULL; i++) {
526 		if (table[i].index == index) {
527 			*string = table[i].name;
528 			return (0);
529 		}
530 	}
531 
532 	return (-1);
533 }
534 
535 #ifndef _KERNEL
536 
537 /*
538  * Returns a string describing the set of acceptable values for the given
539  * zfs property, or NULL if it cannot be set.
540  */
541 const char *
542 zfs_prop_values(zfs_prop_t prop)
543 {
544 	if (zfs_prop_table[prop].pd_types == ZFS_TYPE_POOL)
545 		return (NULL);
546 
547 	return (zfs_prop_table[prop].pd_values);
548 }
549 
550 /*
551  * Returns a string describing the set of acceptable values for the given
552  * zpool property, or NULL if it cannot be set.
553  */
554 const char *
555 zpool_prop_values(zfs_prop_t prop)
556 {
557 	if (zfs_prop_table[prop].pd_types != ZFS_TYPE_POOL)
558 		return (NULL);
559 
560 	return (zfs_prop_table[prop].pd_values);
561 }
562 
563 /*
564  * Returns TRUE if this property is a string type.  Note that index types
565  * (compression, checksum) are treated as strings in userland, even though they
566  * are stored numerically on disk.
567  */
568 int
569 zfs_prop_is_string(zfs_prop_t prop)
570 {
571 	return (zfs_prop_table[prop].pd_proptype == prop_type_string ||
572 	    zfs_prop_table[prop].pd_proptype == prop_type_index);
573 }
574 
575 /*
576  * Returns the column header for the given property.  Used only in
577  * 'zfs list -o', but centralized here with the other property information.
578  */
579 const char *
580 zfs_prop_column_name(zfs_prop_t prop)
581 {
582 	return (zfs_prop_table[prop].pd_colname);
583 }
584 
585 /*
586  * Returns whether the given property should be displayed right-justified for
587  * 'zfs list'.
588  */
589 boolean_t
590 zfs_prop_align_right(zfs_prop_t prop)
591 {
592 	return (zfs_prop_table[prop].pd_rightalign);
593 }
594 
595 /*
596  * Determines the minimum width for the column, and indicates whether it's fixed
597  * or not.  Only string columns are non-fixed.
598  */
599 size_t
600 zfs_prop_width(zfs_prop_t prop, boolean_t *fixed)
601 {
602 	prop_desc_t *pd = &zfs_prop_table[prop];
603 	zfs_index_t *idx;
604 	size_t ret;
605 	int i;
606 
607 	*fixed = B_TRUE;
608 
609 	/*
610 	 * Start with the width of the column name.
611 	 */
612 	ret = strlen(pd->pd_colname);
613 
614 	/*
615 	 * For fixed-width values, make sure the width is large enough to hold
616 	 * any possible value.
617 	 */
618 	switch (pd->pd_proptype) {
619 	case prop_type_number:
620 		/*
621 		 * The maximum length of a human-readable number is 5 characters
622 		 * ("20.4M", for example).
623 		 */
624 		if (ret < 5)
625 			ret = 5;
626 		/*
627 		 * 'creation' is handled specially because it's a number
628 		 * internally, but displayed as a date string.
629 		 */
630 		if (prop == ZFS_PROP_CREATION)
631 			*fixed = B_FALSE;
632 		break;
633 	case prop_type_boolean:
634 		/*
635 		 * The maximum length of a boolean value is 3 characters, for
636 		 * "off".
637 		 */
638 		if (ret < 3)
639 			ret = 3;
640 		break;
641 	case prop_type_index:
642 		idx = zfs_prop_index_table(prop);
643 		for (i = 0; idx[i].name != NULL; i++) {
644 			if (strlen(idx[i].name) > ret)
645 				ret = strlen(idx[i].name);
646 		}
647 		break;
648 
649 	case prop_type_string:
650 		*fixed = B_FALSE;
651 		break;
652 	}
653 
654 	return (ret);
655 }
656 
657 #endif
658