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1 /*
2  * dblist.c -- directory block list functions
3  *
4  * Copyright 1997 by Theodore Ts'o
5  *
6  * %Begin-Header%
7  * This file may be redistributed under the terms of the GNU Library
8  * General Public License, version 2.
9  * %End-Header%
10  */
11 
12 #include "config.h"
13 #include <stdio.h>
14 #if HAVE_UNISTD_H
15 #include <unistd.h>
16 #endif
17 #include <string.h>
18 #include <time.h>
19 
20 #include "ext2_fs.h"
21 #include "ext2fsP.h"
22 
23 static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b);
24 static EXT2_QSORT_TYPE dir_block_cmp2(const void *a, const void *b);
25 static EXT2_QSORT_TYPE (*sortfunc32)(const void *a, const void *b);
26 
27 /*
28  * helper function for making a new directory block list (for
29  * initialize and copy).
30  */
make_dblist(ext2_filsys fs,ext2_ino_t size,ext2_ino_t count,struct ext2_db_entry2 * list,ext2_dblist * ret_dblist)31 static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size,
32 			     ext2_ino_t count,
33 			     struct ext2_db_entry2 *list,
34 			     ext2_dblist *ret_dblist)
35 {
36 	ext2_dblist	dblist = NULL;
37 	errcode_t	retval;
38 	ext2_ino_t	num_dirs;
39 	size_t		len;
40 
41 	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
42 
43 	if ((ret_dblist == 0) && fs->dblist &&
44 	    (fs->dblist->magic == EXT2_ET_MAGIC_DBLIST))
45 		return 0;
46 
47 	retval = ext2fs_get_mem(sizeof(struct ext2_struct_dblist), &dblist);
48 	if (retval)
49 		goto cleanup;
50 	memset(dblist, 0, sizeof(struct ext2_struct_dblist));
51 
52 	dblist->magic = EXT2_ET_MAGIC_DBLIST;
53 	dblist->fs = fs;
54 	if (size)
55 		dblist->size = size;
56 	else {
57 		retval = ext2fs_get_num_dirs(fs, &num_dirs);
58 		if (retval)
59 			goto cleanup;
60 		dblist->size = (num_dirs * 2) + 12;
61 	}
62 	len = (size_t) sizeof(struct ext2_db_entry2) * dblist->size;
63 	dblist->count = count;
64 	retval = ext2fs_get_array(dblist->size, sizeof(struct ext2_db_entry2),
65 		&dblist->list);
66 	if (retval)
67 		goto cleanup;
68 
69 	if (list)
70 		memcpy(dblist->list, list, len);
71 	else
72 		memset(dblist->list, 0, len);
73 	if (ret_dblist)
74 		*ret_dblist = dblist;
75 	else
76 		fs->dblist = dblist;
77 	return 0;
78 cleanup:
79 	if (dblist)
80 		ext2fs_free_mem(&dblist);
81 	return retval;
82 }
83 
84 /*
85  * Initialize a directory block list
86  */
ext2fs_init_dblist(ext2_filsys fs,ext2_dblist * ret_dblist)87 errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist)
88 {
89 	ext2_dblist	dblist;
90 	errcode_t	retval;
91 
92 	retval = make_dblist(fs, 0, 0, 0, &dblist);
93 	if (retval)
94 		return retval;
95 
96 	dblist->sorted = 1;
97 	if (ret_dblist)
98 		*ret_dblist = dblist;
99 	else
100 		fs->dblist = dblist;
101 
102 	return 0;
103 }
104 
105 /*
106  * Copy a directory block list
107  */
ext2fs_copy_dblist(ext2_dblist src,ext2_dblist * dest)108 errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist *dest)
109 {
110 	ext2_dblist	dblist;
111 	errcode_t	retval;
112 
113 	retval = make_dblist(src->fs, src->size, src->count, src->list,
114 			     &dblist);
115 	if (retval)
116 		return retval;
117 	dblist->sorted = src->sorted;
118 	*dest = dblist;
119 	return 0;
120 }
121 
122 /*
123  * Close a directory block list
124  *
125  * (moved to closefs.c)
126  */
127 
128 
129 /*
130  * Add a directory block to the directory block list
131  */
ext2fs_add_dir_block2(ext2_dblist dblist,ext2_ino_t ino,blk64_t blk,e2_blkcnt_t blockcnt)132 errcode_t ext2fs_add_dir_block2(ext2_dblist dblist, ext2_ino_t ino,
133 				blk64_t blk, e2_blkcnt_t blockcnt)
134 {
135 	struct ext2_db_entry2 	*new_entry;
136 	errcode_t		retval;
137 	unsigned long		old_size;
138 
139 	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
140 
141 	if (dblist->count >= dblist->size) {
142 		old_size = dblist->size * sizeof(struct ext2_db_entry2);
143 		dblist->size += dblist->size > 200 ? dblist->size / 2 : 100;
144 		retval = ext2fs_resize_mem(old_size, (size_t) dblist->size *
145 					   sizeof(struct ext2_db_entry2),
146 					   &dblist->list);
147 		if (retval) {
148 			dblist->size = old_size / sizeof(struct ext2_db_entry2);
149 			return retval;
150 		}
151 	}
152 	new_entry = dblist->list + ( dblist->count++);
153 	new_entry->blk = blk;
154 	new_entry->ino = ino;
155 	new_entry->blockcnt = blockcnt;
156 
157 	dblist->sorted = 0;
158 
159 	return 0;
160 }
161 
162 /*
163  * Change the directory block to the directory block list
164  */
ext2fs_set_dir_block2(ext2_dblist dblist,ext2_ino_t ino,blk64_t blk,e2_blkcnt_t blockcnt)165 errcode_t ext2fs_set_dir_block2(ext2_dblist dblist, ext2_ino_t ino,
166 				blk64_t blk, e2_blkcnt_t blockcnt)
167 {
168 	dgrp_t			i;
169 
170 	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
171 
172 	for (i=0; i < dblist->count; i++) {
173 		if ((dblist->list[i].ino != ino) ||
174 		    (dblist->list[i].blockcnt != blockcnt))
175 			continue;
176 		dblist->list[i].blk = blk;
177 		dblist->sorted = 0;
178 		return 0;
179 	}
180 	return EXT2_ET_DB_NOT_FOUND;
181 }
182 
ext2fs_dblist_sort2(ext2_dblist dblist,EXT2_QSORT_TYPE (* sortfunc)(const void *,const void *))183 void ext2fs_dblist_sort2(ext2_dblist dblist,
184 			 EXT2_QSORT_TYPE (*sortfunc)(const void *,
185 						     const void *))
186 {
187 	if (!sortfunc)
188 		sortfunc = dir_block_cmp2;
189 	qsort(dblist->list, (size_t) dblist->count,
190 	      sizeof(struct ext2_db_entry2), sortfunc);
191 	dblist->sorted = 1;
192 }
193 
194 /*
195  * This function iterates over the directory block list
196  */
ext2fs_dblist_iterate3(ext2_dblist dblist,int (* func)(ext2_filsys fs,struct ext2_db_entry2 * db_info,void * priv_data),unsigned long long start,unsigned long long count,void * priv_data)197 errcode_t ext2fs_dblist_iterate3(ext2_dblist dblist,
198 				 int (*func)(ext2_filsys fs,
199 					     struct ext2_db_entry2 *db_info,
200 					     void	*priv_data),
201 				 unsigned long long start,
202 				 unsigned long long count,
203 				 void *priv_data)
204 {
205 	unsigned long long	i, end;
206 	int		ret;
207 
208 	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
209 
210 	end = start + count;
211 	if (!dblist->sorted)
212 		ext2fs_dblist_sort2(dblist, 0);
213 	if (end > dblist->count)
214 		end = dblist->count;
215 	for (i = start; i < end; i++) {
216 		ret = (*func)(dblist->fs, &dblist->list[i], priv_data);
217 		if (ret & DBLIST_ABORT)
218 			return 0;
219 	}
220 	return 0;
221 }
222 
ext2fs_dblist_iterate2(ext2_dblist dblist,int (* func)(ext2_filsys fs,struct ext2_db_entry2 * db_info,void * priv_data),void * priv_data)223 errcode_t ext2fs_dblist_iterate2(ext2_dblist dblist,
224 				 int (*func)(ext2_filsys fs,
225 					     struct ext2_db_entry2 *db_info,
226 					     void	*priv_data),
227 				 void *priv_data)
228 {
229 	return ext2fs_dblist_iterate3(dblist, func, 0, dblist->count,
230 				      priv_data);
231 }
232 
dir_block_cmp2(const void * a,const void * b)233 static EXT2_QSORT_TYPE dir_block_cmp2(const void *a, const void *b)
234 {
235 	const struct ext2_db_entry2 *db_a =
236 		(const struct ext2_db_entry2 *) a;
237 	const struct ext2_db_entry2 *db_b =
238 		(const struct ext2_db_entry2 *) b;
239 
240 	if (db_a->blk != db_b->blk)
241 		return (int) (db_a->blk - db_b->blk);
242 
243 	if (db_a->ino != db_b->ino)
244 		return (int) (db_a->ino - db_b->ino);
245 
246 	return (db_a->blockcnt - db_b->blockcnt);
247 }
248 
ext2fs_dblist_count2(ext2_dblist dblist)249 blk64_t ext2fs_dblist_count2(ext2_dblist dblist)
250 {
251 	return dblist->count;
252 }
253 
ext2fs_dblist_get_last2(ext2_dblist dblist,struct ext2_db_entry2 ** entry)254 errcode_t ext2fs_dblist_get_last2(ext2_dblist dblist,
255 				  struct ext2_db_entry2 **entry)
256 {
257 	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
258 
259 	if (dblist->count == 0)
260 		return EXT2_ET_DBLIST_EMPTY;
261 
262 	if (entry)
263 		*entry = dblist->list + ( dblist->count-1);
264 	return 0;
265 }
266 
ext2fs_dblist_drop_last(ext2_dblist dblist)267 errcode_t ext2fs_dblist_drop_last(ext2_dblist dblist)
268 {
269 	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
270 
271 	if (dblist->count == 0)
272 		return EXT2_ET_DBLIST_EMPTY;
273 
274 	dblist->count--;
275 	return 0;
276 }
277 
278 /*
279  * Legacy 32-bit versions
280  */
281 
282 /*
283  * Add a directory block to the directory block list
284  */
ext2fs_add_dir_block(ext2_dblist dblist,ext2_ino_t ino,blk_t blk,int blockcnt)285 errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
286 			       int blockcnt)
287 {
288 	return ext2fs_add_dir_block2(dblist, ino, blk, blockcnt);
289 }
290 
291 /*
292  * Change the directory block to the directory block list
293  */
ext2fs_set_dir_block(ext2_dblist dblist,ext2_ino_t ino,blk_t blk,int blockcnt)294 errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
295 			       int blockcnt)
296 {
297 	return ext2fs_set_dir_block2(dblist, ino, blk, blockcnt);
298 }
299 
ext2fs_dblist_sort(ext2_dblist dblist,EXT2_QSORT_TYPE (* sortfunc)(const void *,const void *))300 void ext2fs_dblist_sort(ext2_dblist dblist,
301 			EXT2_QSORT_TYPE (*sortfunc)(const void *,
302 						    const void *))
303 {
304 	if (sortfunc) {
305 		sortfunc32 = sortfunc;
306 		sortfunc = dir_block_cmp;
307 	} else
308 		sortfunc = dir_block_cmp2;
309 	qsort(dblist->list, (size_t) dblist->count,
310 	      sizeof(struct ext2_db_entry2), sortfunc);
311 	dblist->sorted = 1;
312 }
313 
314 /*
315  * This function iterates over the directory block list
316  */
317 struct iterate_passthrough {
318 	int (*func)(ext2_filsys fs,
319 		    struct ext2_db_entry *db_info,
320 		    void	*priv_data);
321 	void *priv_data;
322 };
323 
passthrough_func(ext2_filsys fs,struct ext2_db_entry2 * db_info,void * priv_data)324 static int passthrough_func(ext2_filsys fs,
325 			    struct ext2_db_entry2 *db_info,
326 			    void	*priv_data)
327 {
328 	struct iterate_passthrough *p = priv_data;
329 	struct ext2_db_entry db;
330 	int ret;
331 
332 	db.ino = db_info->ino;
333 	db.blk = (blk_t) db_info->blk;
334 	db.blockcnt = (int) db_info->blockcnt;
335 	ret = (p->func)(fs, &db, p->priv_data);
336 	db_info->ino = db.ino;
337 	db_info->blk = db.blk;
338 	db_info->blockcnt = db.blockcnt;
339 	return ret;
340 }
341 
ext2fs_dblist_iterate(ext2_dblist dblist,int (* func)(ext2_filsys fs,struct ext2_db_entry * db_info,void * priv_data),void * priv_data)342 errcode_t ext2fs_dblist_iterate(ext2_dblist dblist,
343 				int (*func)(ext2_filsys fs,
344 					    struct ext2_db_entry *db_info,
345 					    void	*priv_data),
346 				void *priv_data)
347 {
348 	struct iterate_passthrough pass;
349 
350 	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
351 	pass.func = func;
352 	pass.priv_data = priv_data;
353 
354 	return ext2fs_dblist_iterate2(dblist, passthrough_func, &pass);
355 }
356 
dir_block_cmp(const void * a,const void * b)357 static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b)
358 {
359 	const struct ext2_db_entry2 *db_a =
360 		(const struct ext2_db_entry2 *) a;
361 	const struct ext2_db_entry2 *db_b =
362 		(const struct ext2_db_entry2 *) b;
363 
364 	struct ext2_db_entry a32, b32;
365 
366 	a32.ino = db_a->ino;  a32.blk = db_a->blk;
367 	a32.blockcnt = db_a->blockcnt;
368 
369 	b32.ino = db_b->ino;  b32.blk = db_b->blk;
370 	b32.blockcnt = db_b->blockcnt;
371 
372 	return sortfunc32(&a32, &b32);
373 }
374 
ext2fs_dblist_count(ext2_dblist dblist)375 int ext2fs_dblist_count(ext2_dblist dblist)
376 {
377 	return dblist->count;
378 }
379 
ext2fs_dblist_get_last(ext2_dblist dblist,struct ext2_db_entry ** entry)380 errcode_t ext2fs_dblist_get_last(ext2_dblist dblist,
381 				 struct ext2_db_entry **entry)
382 {
383 	static struct ext2_db_entry ret_entry;
384 	struct ext2_db_entry2 *last;
385 
386 	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
387 
388 	if (dblist->count == 0)
389 		return EXT2_ET_DBLIST_EMPTY;
390 
391 	if (!entry)
392 		return 0;
393 
394 	last = dblist->list + dblist->count -1;
395 
396 	ret_entry.ino = last->ino;
397 	ret_entry.blk = last->blk;
398 	ret_entry.blockcnt = last->blockcnt;
399 	*entry = &ret_entry;
400 
401 	return 0;
402 }
403 
404