xref: /illumos-gate/usr/src/cmd/zfs/zfs_iter.c (revision fa9e4066f08beec538e775443c5be79dd423fcab)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <libintl.h>
30 #include <libuutil.h>
31 #include <stddef.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <strings.h>
35 
36 #include <libzfs.h>
37 
38 #include "zfs_util.h"
39 
40 /*
41  * This is a private interface used to gather up all the datasets specified on
42  * the command line so that we can iterate over them in order.
43  *
44  * First, we iterate over all filesystems, gathering them together into an
45  * AVL tree sorted by name.  For snapshots, we order them according to
46  * creation time.  We report errors for any explicitly specified datasets
47  * that we couldn't open.
48  *
49  * When finished, we have an AVL tree of ZFS handles.  We go through and execute
50  * the provided callback for each one, passing whatever data the user supplied.
51  */
52 
53 typedef struct zfs_node {
54 	zfs_handle_t	*zn_handle;
55 	uu_avl_node_t	zn_avlnode;
56 } zfs_node_t;
57 
58 typedef struct callback_data {
59 	uu_avl_t	*cb_avl;
60 	int		cb_recurse;
61 	zfs_type_t	cb_types;
62 } callback_data_t;
63 
64 uu_avl_pool_t *avl_pool;
65 
66 /*
67  * Called for each dataset.  If the object the object is of an appropriate type,
68  * add it to the avl tree and recurse over any children as necessary.
69  */
70 int
71 zfs_callback(zfs_handle_t *zhp, void *data)
72 {
73 	callback_data_t *cb = data;
74 	int dontclose = 0;
75 
76 	/*
77 	 * If this object is of the appropriate type, add it to the AVL tree.
78 	 */
79 	if (zfs_get_type(zhp) & cb->cb_types) {
80 		uu_avl_index_t idx;
81 		zfs_node_t *node = safe_malloc(sizeof (zfs_node_t));
82 
83 		node->zn_handle = zhp;
84 		uu_avl_node_init(node, &node->zn_avlnode, avl_pool);
85 		if (uu_avl_find(cb->cb_avl, node, NULL, &idx) == NULL) {
86 			uu_avl_insert(cb->cb_avl, node, idx);
87 			dontclose = 1;
88 		} else {
89 			free(node);
90 		}
91 	}
92 
93 	/*
94 	 * If 'recurse' is set, and the datasets can have datasets of the
95 	 * appropriate type, then recurse over its children.
96 	 */
97 	if (cb->cb_recurse && (zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM ||
98 	    (cb->cb_types & ZFS_TYPE_SNAPSHOT)))
99 		(void) zfs_iter_children(zhp, zfs_callback, data);
100 
101 	if (!dontclose)
102 		zfs_close(zhp);
103 
104 	return (0);
105 }
106 
107 /* ARGSUSED */
108 static int
109 zfs_compare(const void *larg, const void *rarg, void *unused)
110 {
111 	zfs_handle_t *l = ((zfs_node_t *)larg)->zn_handle;
112 	zfs_handle_t *r = ((zfs_node_t *)rarg)->zn_handle;
113 	const char *lname = zfs_get_name(l);
114 	const char *rname = zfs_get_name(r);
115 	char *lat, *rat;
116 	uint64_t lcreate, rcreate;
117 	int ret;
118 
119 	lat = (char *)strchr(lname, '@');
120 	rat = (char *)strchr(rname, '@');
121 
122 	if (lat != NULL)
123 		*lat = '\0';
124 	if (rat != NULL)
125 		*rat = '\0';
126 
127 	ret = strcmp(lname, rname);
128 	if (ret == 0) {
129 		/*
130 		 * If we're comparing a dataset to one of its snapshots, we
131 		 * always make the full dataset first.
132 		 */
133 		if (lat == NULL) {
134 			ret = -1;
135 		} else if (rat == NULL) {
136 			ret = 1;
137 		} else {
138 			/*
139 			 * If we have two snapshots from the same dataset, then
140 			 * we want to sort them according to creation time.  We
141 			 * use the hidden CREATETXG property to get an absolute
142 			 * ordering of snapshots.
143 			 */
144 			lcreate = zfs_prop_get_int(l, ZFS_PROP_CREATETXG);
145 			rcreate = zfs_prop_get_int(r, ZFS_PROP_CREATETXG);
146 
147 			if (lcreate < rcreate)
148 				ret = -1;
149 			else if (lcreate > rcreate)
150 				ret = 1;
151 		}
152 	}
153 
154 	if (lat != NULL)
155 		*lat = '@';
156 	if (rat != NULL)
157 		*rat = '@';
158 
159 	return (ret);
160 }
161 
162 int
163 zfs_for_each(int argc, char **argv, int recurse, zfs_type_t types,
164     zfs_iter_f callback, void *data)
165 {
166 	callback_data_t cb;
167 	int ret = 0;
168 	zfs_node_t *node;
169 	uu_avl_walk_t *walk;
170 
171 	avl_pool = uu_avl_pool_create("zfs_pool", sizeof (zfs_node_t),
172 	    offsetof(zfs_node_t, zn_avlnode), zfs_compare, UU_DEFAULT);
173 
174 	if (avl_pool == NULL) {
175 		(void) fprintf(stderr,
176 		    gettext("internal error: out of memory\n"));
177 		exit(1);
178 	}
179 
180 	cb.cb_recurse = recurse;
181 	cb.cb_types = types;
182 	if ((cb.cb_avl = uu_avl_create(avl_pool, NULL, UU_DEFAULT)) == NULL) {
183 		(void) fprintf(stderr,
184 		    gettext("internal error: out of memory\n"));
185 		exit(1);
186 	}
187 
188 	if (argc == 0) {
189 		/*
190 		 * If given no arguments, iterate over all datasets.
191 		 */
192 		cb.cb_recurse = 1;
193 		ret = zfs_iter_root(zfs_callback, &cb);
194 	} else {
195 		int i;
196 		zfs_handle_t *zhp;
197 		zfs_type_t argtype;
198 
199 		/*
200 		 * If we're recursive, then we always allow filesystems as
201 		 * arguments.  If we also are interested in snapshots, then we
202 		 * can take volumes as well.
203 		 */
204 		argtype = types;
205 		if (recurse) {
206 			argtype |= ZFS_TYPE_FILESYSTEM;
207 			if (types & ZFS_TYPE_SNAPSHOT)
208 				argtype |= ZFS_TYPE_VOLUME;
209 		}
210 
211 		for (i = 0; i < argc; i++) {
212 			if ((zhp = zfs_open(argv[i], argtype)) != NULL)
213 				ret = zfs_callback(zhp, &cb);
214 			else
215 				ret = 1;
216 		}
217 	}
218 
219 	/*
220 	 * At this point we've got our AVL tree full of zfs handles, so iterate
221 	 * over each one and execute the real user callback.
222 	 */
223 	for (node = uu_avl_first(cb.cb_avl); node != NULL;
224 	    node = uu_avl_next(cb.cb_avl, node))
225 		ret |= callback(node->zn_handle, data);
226 
227 	/*
228 	 * Finally, clean up the AVL tree.
229 	 */
230 	if ((walk = uu_avl_walk_start(cb.cb_avl, UU_WALK_ROBUST)) == NULL) {
231 		(void) fprintf(stderr,
232 		    gettext("internal error: out of memory"));
233 		exit(1);
234 	}
235 
236 	while ((node = uu_avl_walk_next(walk)) != NULL) {
237 		uu_avl_remove(cb.cb_avl, node);
238 		zfs_close(node->zn_handle);
239 		free(node);
240 	}
241 
242 	uu_avl_walk_end(walk);
243 	uu_avl_destroy(cb.cb_avl);
244 	uu_avl_pool_destroy(avl_pool);
245 
246 	return (ret);
247 }
248