1 /* vi: set sw=4 ts=4: */
3 * tag.c - allocation/initialization/free routines for tag structs
5 * Copyright (C) 2001 Andreas Dilger
6 * Copyright (C) 2003 Theodore Ts'o
9 * This file may be redistributed under the terms of the
10 * GNU Lesser General Public License.
20 static blkid_tag blkid_new_tag(void)
24 tag = xzalloc(sizeof(struct blkid_struct_tag));
26 INIT_LIST_HEAD(&tag->bit_tags);
27 INIT_LIST_HEAD(&tag->bit_names);
32 #ifdef CONFIG_BLKID_DEBUG
33 void blkid_debug_dump_tag(blkid_tag tag)
36 printf(" tag: NULL\n");
40 printf(" tag: %s=\"%s\"\n", tag->bit_name, tag->bit_val);
44 void blkid_free_tag(blkid_tag tag)
49 DBG(DEBUG_TAG, printf(" freeing tag %s=%s\n", tag->bit_name,
50 tag->bit_val ? tag->bit_val : "(NULL)"));
51 DBG(DEBUG_TAG, blkid_debug_dump_tag(tag));
53 list_del(&tag->bit_tags); /* list of tags for this device */
54 list_del(&tag->bit_names); /* list of tags with this type */
62 * Find the desired tag on a device. If value is NULL, then the
63 * first such tag is returned, otherwise return only exact tag if found.
65 blkid_tag blkid_find_tag_dev(blkid_dev dev, const char *type)
72 list_for_each(p, &dev->bid_tags) {
73 blkid_tag tmp = list_entry(p, struct blkid_struct_tag,
76 if (!strcmp(tmp->bit_name, type))
83 * Find the desired tag type in the cache.
84 * We return the head tag for this tag type.
86 static blkid_tag blkid_find_head_cache(blkid_cache cache, const char *type)
88 blkid_tag head = NULL, tmp;
94 list_for_each(p, &cache->bic_tags) {
95 tmp = list_entry(p, struct blkid_struct_tag, bit_tags);
96 if (!strcmp(tmp->bit_name, type)) {
98 printf(" found cache tag head %s\n", type));
107 * Set a tag on an existing device.
109 * If value is NULL, then delete the tagsfrom the device.
111 int blkid_set_tag(blkid_dev dev, const char *name,
112 const char *value, const int vlength)
114 blkid_tag t = 0, head = 0;
118 return -BLKID_ERR_PARAM;
120 if (!(val = blkid_strndup(value, vlength)) && value)
121 return -BLKID_ERR_MEM;
122 t = blkid_find_tag_dev(dev, name);
126 if (!strcmp(t->bit_val, val)) {
127 /* Same thing, exit */
134 /* Existing tag not present, add to device */
135 if (!(t = blkid_new_tag()))
137 t->bit_name = blkid_strdup(name);
141 list_add_tail(&t->bit_tags, &dev->bid_tags);
143 if (dev->bid_cache) {
144 head = blkid_find_head_cache(dev->bid_cache,
147 head = blkid_new_tag();
152 printf(" creating new cache tag head %s\n", name));
153 head->bit_name = blkid_strdup(name);
156 list_add_tail(&head->bit_tags,
157 &dev->bid_cache->bic_tags);
159 list_add_tail(&t->bit_names, &head->bit_names);
163 /* Link common tags directly to the device struct */
164 if (!strcmp(name, "TYPE"))
166 else if (!strcmp(name, "LABEL"))
167 dev->bid_label = val;
168 else if (!strcmp(name, "UUID"))
172 dev->bid_cache->bic_flags |= BLKID_BIC_FL_CHANGED;
179 blkid_free_tag(head);
180 return -BLKID_ERR_MEM;
185 * Parse a "NAME=value" string. This is slightly different than
186 * parse_token, because that will end an unquoted value at a space, while
187 * this will assume that an unquoted value is the rest of the token (e.g.
188 * if we are passed an already quoted string from the command-line we don't
189 * have to both quote and escape quote so that the quotes make it to
192 * Returns 0 on success, and -1 on failure.
194 int blkid_parse_tag_string(const char *token, char **ret_type, char **ret_val)
196 char *name, *value, *cp;
198 DBG(DEBUG_TAG, printf("trying to parse '%s' as a tag\n", token));
200 if (!token || !(cp = strchr(token, '=')))
203 name = blkid_strdup(token);
206 value = name + (cp - token);
208 if (*value == '"' || *value == '\'') {
210 if (!(cp = strrchr(value, c)))
211 goto errout; /* missing closing quote */
214 value = blkid_strdup(value);
229 * Tag iteration routines for the public libblkid interface.
231 * These routines do not expose the list.h implementation, which are a
232 * contamination of the namespace, and which force us to reveal far, far
233 * too much of our internal implemenation. I'm not convinced I want
234 * to keep list.h in the long term, anyway. It's fine for kernel
235 * programming, but performance is not the #1 priority for this
236 * library, and I really don't like the tradeoff of type-safety for
237 * performance for this application. [tytso:20030125.2007EST]
241 * This series of functions iterate over all tags in a device
243 #define TAG_ITERATE_MAGIC 0x01a5284c
245 struct blkid_struct_tag_iterate {
251 blkid_tag_iterate blkid_tag_iterate_begin(blkid_dev dev)
253 blkid_tag_iterate iter;
255 iter = xmalloc(sizeof(struct blkid_struct_tag_iterate));
256 iter->magic = TAG_ITERATE_MAGIC;
258 iter->p = dev->bid_tags.next;
263 * Return 0 on success, -1 on error
265 extern int blkid_tag_next(blkid_tag_iterate iter,
266 const char **type, const char **value)
272 if (!iter || iter->magic != TAG_ITERATE_MAGIC ||
273 iter->p == &iter->dev->bid_tags)
275 tag = list_entry(iter->p, struct blkid_struct_tag, bit_tags);
276 *type = tag->bit_name;
277 *value = tag->bit_val;
278 iter->p = iter->p->next;
282 void blkid_tag_iterate_end(blkid_tag_iterate iter)
284 if (!iter || iter->magic != TAG_ITERATE_MAGIC)
291 * This function returns a device which matches a particular
292 * type/value pair. If there is more than one device that matches the
293 * search specification, it returns the one with the highest priority
294 * value. This allows us to give preference to EVMS or LVM devices.
296 * XXX there should also be an interface which uses an iterator so we
297 * can get all of the devices which match a type/value search parameter.
299 extern blkid_dev blkid_find_dev_with_tag(blkid_cache cache,
308 if (!cache || !type || !value)
311 blkid_read_cache(cache);
313 DBG(DEBUG_TAG, printf("looking for %s=%s in cache\n", type, value));
318 head = blkid_find_head_cache(cache, type);
321 list_for_each(p, &head->bit_names) {
322 blkid_tag tmp = list_entry(p, struct blkid_struct_tag,
325 if (!strcmp(tmp->bit_val, value) &&
326 tmp->bit_dev->bid_pri > pri) {
332 if (dev && !(dev->bid_flags & BLKID_BID_FL_VERIFIED)) {
333 dev = blkid_verify(cache, dev);
334 if (dev && (dev->bid_flags & BLKID_BID_FL_VERIFIED))
338 if (!dev && !(cache->bic_flags & BLKID_BIC_FL_PROBED)) {
339 if (blkid_probe_all(cache) < 0)
354 void usage(char *prog)
356 fprintf(stderr, "Usage: %s [-f blkid_file] [-m debug_mask] device "
359 fprintf(stderr, "\tList all tags for a device and exit\n");
363 int main(int argc, char **argv)
365 blkid_tag_iterate iter;
366 blkid_cache cache = NULL;
369 int flags = BLKID_DEV_FIND;
372 char *devname = NULL;
373 char *search_type = NULL;
374 char *search_value = NULL;
375 const char *type, *value;
377 while ((c = getopt (argc, argv, "m:f:")) != EOF)
383 blkid_debug_mask = strtoul (optarg, &tmp, 0);
385 fprintf(stderr, "Invalid debug mask: %s\n",
394 devname = argv[optind++];
396 search_type = argv[optind++];
398 search_value = argv[optind++];
399 if (!devname || (argc != optind))
402 if ((ret = blkid_get_cache(&cache, file)) != 0) {
403 fprintf(stderr, "%s: error creating cache (%d)\n",
408 dev = blkid_get_dev(cache, devname, flags);
410 fprintf(stderr, "%s: cannot find device in blkid cache\n", devname);
414 found = blkid_dev_has_tag(dev, search_type, search_value);
415 printf("Device %s: (%s, %s) %s\n", blkid_dev_devname(dev),
416 search_type, search_value ? search_value : "NULL",
417 found ? "FOUND" : "NOT FOUND");
420 printf("Device %s...\n", blkid_dev_devname(dev));
422 iter = blkid_tag_iterate_begin(dev);
423 while (blkid_tag_next(iter, &type, &value) == 0) {
424 printf("\tTag %s has value %s\n", type, value);
426 blkid_tag_iterate_end(iter);
428 blkid_put_cache(cache);