xref: /illumos-gate/usr/src/cmd/zfs/zfs_iter.c (revision 0c44d0008f52b6a42b9c01d3b344661217520a68)
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 2006 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 #include <libintl.h>
29 #include <libuutil.h>
30 #include <stddef.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <strings.h>
34 
35 #include <libzfs.h>
36 
37 #include "zfs_util.h"
38 
39 /*
40  * This is a private interface used to gather up all the datasets specified on
41  * the command line so that we can iterate over them in order.
42  *
43  * First, we iterate over all filesystems, gathering them together into an
44  * AVL tree sorted by name.  For snapshots, we order them according to
45  * creation time.  We report errors for any explicitly specified datasets
46  * that we couldn't open.
47  *
48  * When finished, we have an AVL tree of ZFS handles.  We go through and execute
49  * the provided callback for each one, passing whatever data the user supplied.
50  */
51 
52 typedef struct zfs_node {
53 	zfs_handle_t	*zn_handle;
54 	uu_avl_node_t	zn_avlnode;
55 } zfs_node_t;
56 
57 typedef struct callback_data {
58 	uu_avl_t	*cb_avl;
59 	int		cb_recurse;
60 	zfs_type_t	cb_types;
61 } callback_data_t;
62 
63 uu_avl_pool_t *avl_pool;
64 
65 /*
66  * Called for each dataset.  If the object the object is of an appropriate type,
67  * add it to the avl tree and recurse over any children as necessary.
68  */
69 int
70 zfs_callback(zfs_handle_t *zhp, void *data)
71 {
72 	callback_data_t *cb = data;
73 	int dontclose = 0;
74 
75 	/*
76 	 * If this object is of the appropriate type, add it to the AVL tree.
77 	 */
78 	if (zfs_get_type(zhp) & cb->cb_types) {
79 		uu_avl_index_t idx;
80 		zfs_node_t *node = safe_malloc(sizeof (zfs_node_t));
81 
82 		node->zn_handle = zhp;
83 		uu_avl_node_init(node, &node->zn_avlnode, avl_pool);
84 		if (uu_avl_find(cb->cb_avl, node, NULL, &idx) == NULL) {
85 			uu_avl_insert(cb->cb_avl, node, idx);
86 			dontclose = 1;
87 		} else {
88 			free(node);
89 		}
90 	}
91 
92 	/*
93 	 * Recurse if necessary.
94 	 */
95 	if (cb->cb_recurse && (zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM ||
96 	    (zfs_get_type(zhp) == ZFS_TYPE_VOLUME && (cb->cb_types &
97 	    ZFS_TYPE_SNAPSHOT))))
98 		(void) zfs_iter_children(zhp, zfs_callback, data);
99 
100 	if (!dontclose)
101 		zfs_close(zhp);
102 
103 	return (0);
104 }
105 
106 /* ARGSUSED */
107 static int
108 zfs_compare(const void *larg, const void *rarg, void *unused)
109 {
110 	zfs_handle_t *l = ((zfs_node_t *)larg)->zn_handle;
111 	zfs_handle_t *r = ((zfs_node_t *)rarg)->zn_handle;
112 	const char *lname = zfs_get_name(l);
113 	const char *rname = zfs_get_name(r);
114 	char *lat, *rat;
115 	uint64_t lcreate, rcreate;
116 	int ret;
117 
118 	lat = (char *)strchr(lname, '@');
119 	rat = (char *)strchr(rname, '@');
120 
121 	if (lat != NULL)
122 		*lat = '\0';
123 	if (rat != NULL)
124 		*rat = '\0';
125 
126 	ret = strcmp(lname, rname);
127 	if (ret == 0) {
128 		/*
129 		 * If we're comparing a dataset to one of its snapshots, we
130 		 * always make the full dataset first.
131 		 */
132 		if (lat == NULL) {
133 			ret = -1;
134 		} else if (rat == NULL) {
135 			ret = 1;
136 		} else {
137 			/*
138 			 * If we have two snapshots from the same dataset, then
139 			 * we want to sort them according to creation time.  We
140 			 * use the hidden CREATETXG property to get an absolute
141 			 * ordering of snapshots.
142 			 */
143 			lcreate = zfs_prop_get_int(l, ZFS_PROP_CREATETXG);
144 			rcreate = zfs_prop_get_int(r, ZFS_PROP_CREATETXG);
145 
146 			if (lcreate < rcreate)
147 				ret = -1;
148 			else if (lcreate > rcreate)
149 				ret = 1;
150 		}
151 	}
152 
153 	if (lat != NULL)
154 		*lat = '@';
155 	if (rat != NULL)
156 		*rat = '@';
157 
158 	return (ret);
159 }
160 
161 int
162 zfs_for_each(int argc, char **argv, boolean_t recurse, zfs_type_t types,
163     zfs_iter_f callback, void *data)
164 {
165 	callback_data_t cb;
166 	int ret = 0;
167 	zfs_node_t *node;
168 	uu_avl_walk_t *walk;
169 
170 	avl_pool = uu_avl_pool_create("zfs_pool", sizeof (zfs_node_t),
171 	    offsetof(zfs_node_t, zn_avlnode), zfs_compare, UU_DEFAULT);
172 
173 	if (avl_pool == NULL) {
174 		(void) fprintf(stderr,
175 		    gettext("internal error: out of memory\n"));
176 		exit(1);
177 	}
178 
179 	cb.cb_recurse = recurse;
180 	cb.cb_types = types;
181 	if ((cb.cb_avl = uu_avl_create(avl_pool, NULL, UU_DEFAULT)) == NULL) {
182 		(void) fprintf(stderr,
183 		    gettext("internal error: out of memory\n"));
184 		exit(1);
185 	}
186 
187 	if (argc == 0) {
188 		/*
189 		 * If given no arguments, iterate over all datasets.
190 		 */
191 		cb.cb_recurse = 1;
192 		ret = zfs_iter_root(g_zfs, zfs_callback, &cb);
193 	} else {
194 		int i;
195 		zfs_handle_t *zhp;
196 		zfs_type_t argtype;
197 
198 		/*
199 		 * If we're recursive, then we always allow filesystems as
200 		 * arguments.  If we also are interested in snapshots, then we
201 		 * can take volumes as well.
202 		 */
203 		argtype = types;
204 		if (recurse) {
205 			argtype |= ZFS_TYPE_FILESYSTEM;
206 			if (types & ZFS_TYPE_SNAPSHOT)
207 				argtype |= ZFS_TYPE_VOLUME;
208 		}
209 
210 		for (i = 0; i < argc; i++) {
211 			if ((zhp = zfs_open(g_zfs, argv[i], argtype)) != NULL)
212 				ret |= zfs_callback(zhp, &cb);
213 			else
214 				ret = 1;
215 		}
216 	}
217 
218 	/*
219 	 * At this point we've got our AVL tree full of zfs handles, so iterate
220 	 * over each one and execute the real user callback.
221 	 */
222 	for (node = uu_avl_first(cb.cb_avl); node != NULL;
223 	    node = uu_avl_next(cb.cb_avl, node))
224 		ret |= callback(node->zn_handle, data);
225 
226 	/*
227 	 * Finally, clean up the AVL tree.
228 	 */
229 	if ((walk = uu_avl_walk_start(cb.cb_avl, UU_WALK_ROBUST)) == NULL) {
230 		(void) fprintf(stderr,
231 		    gettext("internal error: out of memory"));
232 		exit(1);
233 	}
234 
235 	while ((node = uu_avl_walk_next(walk)) != NULL) {
236 		uu_avl_remove(cb.cb_avl, node);
237 		zfs_close(node->zn_handle);
238 		free(node);
239 	}
240 
241 	uu_avl_walk_end(walk);
242 	uu_avl_destroy(cb.cb_avl);
243 	uu_avl_pool_destroy(avl_pool);
244 
245 	return (ret);
246 }
247