dblist.c revision 624e8ebe3058bad9af6e719b7f9e7afab7d3fe30 
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 <stdio.h>
13#if HAVE_UNISTD_H
14#include <unistd.h>
15#endif
16#include <string.h>
17#include <time.h>
18
19#include "ext2_fs.h"
20#include "ext2fsP.h"
21
22static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b);
23static EXT2_QSORT_TYPE dir_block_cmp2(const void *a, const void *b);
24static EXT2_QSORT_TYPE (*sortfunc32)(const void *a, const void *b);
25
26/*
27 * Returns the number of directories in the filesystem as reported by
28 * the group descriptors.  Of course, the group descriptors could be
29 * wrong!
30 */
31errcode_t ext2fs_get_num_dirs(ext2_filsys fs, ext2_ino_t *ret_num_dirs)
32{
33	dgrp_t	i;
34	ext2_ino_t	num_dirs, max_dirs;
35
36	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
37
38	num_dirs = 0;
39	max_dirs = fs->super->s_inodes_per_group;
40	for (i = 0; i < fs->group_desc_count; i++) {
41		if (ext2fs_bg_used_dirs_count(fs, i) > max_dirs)
42			num_dirs += max_dirs / 8;
43		else
44			num_dirs += ext2fs_bg_used_dirs_count(fs, i);
45	}
46	if (num_dirs > fs->super->s_inodes_count)
47		num_dirs = fs->super->s_inodes_count;
48
49	*ret_num_dirs = num_dirs;
50
51	return 0;
52}
53
54/*
55 * helper function for making a new directory block list (for
56 * initialize and copy).
57 */
58static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size,
59			     ext2_ino_t count,
60			     struct ext2_db_entry2 *list,
61			     ext2_dblist *ret_dblist)
62{
63	ext2_dblist	dblist;
64	errcode_t	retval;
65	ext2_ino_t	num_dirs;
66	size_t		len;
67
68	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
69
70	if ((ret_dblist == 0) && fs->dblist &&
71	    (fs->dblist->magic == EXT2_ET_MAGIC_DBLIST))
72		return 0;
73
74	retval = ext2fs_get_mem(sizeof(struct ext2_struct_dblist), &dblist);
75	if (retval)
76		goto cleanup;
77	memset(dblist, 0, sizeof(struct ext2_struct_dblist));
78
79	dblist->magic = EXT2_ET_MAGIC_DBLIST;
80	dblist->fs = fs;
81	if (size)
82		dblist->size = size;
83	else {
84		retval = ext2fs_get_num_dirs(fs, &num_dirs);
85		if (retval)
86			goto cleanup;
87		dblist->size = (num_dirs * 2) + 12;
88	}
89	len = (size_t) sizeof(struct ext2_db_entry2) * dblist->size;
90	dblist->count = count;
91	retval = ext2fs_get_array(dblist->size, sizeof(struct ext2_db_entry2),
92		&dblist->list);
93	if (retval)
94		goto cleanup;
95
96	if (list)
97		memcpy(dblist->list, list, len);
98	else
99		memset(dblist->list, 0, len);
100	if (ret_dblist)
101		*ret_dblist = dblist;
102	else
103		fs->dblist = dblist;
104	return 0;
105cleanup:
106	if (dblist)
107		ext2fs_free_mem(&dblist);
108	return retval;
109}
110
111/*
112 * Initialize a directory block list
113 */
114errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist)
115{
116	ext2_dblist	dblist;
117	errcode_t	retval;
118
119	retval = make_dblist(fs, 0, 0, 0, &dblist);
120	if (retval)
121		return retval;
122
123	dblist->sorted = 1;
124	if (ret_dblist)
125		*ret_dblist = dblist;
126	else
127		fs->dblist = dblist;
128
129	return 0;
130}
131
132/*
133 * Copy a directory block list
134 */
135errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist *dest)
136{
137	ext2_dblist	dblist;
138	errcode_t	retval;
139
140	retval = make_dblist(src->fs, src->size, src->count, src->list,
141			     &dblist);
142	if (retval)
143		return retval;
144	dblist->sorted = src->sorted;
145	*dest = dblist;
146	return 0;
147}
148
149/*
150 * Close a directory block list
151 *
152 * (moved to closefs.c)
153 */
154
155
156/*
157 * Add a directory block to the directory block list
158 */
159errcode_t ext2fs_add_dir_block2(ext2_dblist dblist, ext2_ino_t ino,
160				blk64_t blk, e2_blkcnt_t blockcnt)
161{
162	struct ext2_db_entry2 	*new_entry;
163	errcode_t		retval;
164	unsigned long		old_size;
165
166	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
167
168	if (dblist->count >= dblist->size) {
169		old_size = dblist->size * sizeof(struct ext2_db_entry2);
170		dblist->size += dblist->size > 200 ? dblist->size / 2 : 100;
171		retval = ext2fs_resize_mem(old_size, (size_t) dblist->size *
172					   sizeof(struct ext2_db_entry2),
173					   &dblist->list);
174		if (retval) {
175			dblist->size = old_size / sizeof(struct ext2_db_entry2);
176			return retval;
177		}
178	}
179	new_entry = dblist->list + ( dblist->count++);
180	new_entry->blk = blk;
181	new_entry->ino = ino;
182	new_entry->blockcnt = blockcnt;
183
184	dblist->sorted = 0;
185
186	return 0;
187}
188
189/*
190 * Change the directory block to the directory block list
191 */
192errcode_t ext2fs_set_dir_block2(ext2_dblist dblist, ext2_ino_t ino,
193				blk64_t blk, e2_blkcnt_t blockcnt)
194{
195	dgrp_t			i;
196
197	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
198
199	for (i=0; i < dblist->count; i++) {
200		if ((dblist->list[i].ino != ino) ||
201		    (dblist->list[i].blockcnt != blockcnt))
202			continue;
203		dblist->list[i].blk = blk;
204		dblist->sorted = 0;
205		return 0;
206	}
207	return EXT2_ET_DB_NOT_FOUND;
208}
209
210void ext2fs_dblist_sort2(ext2_dblist dblist,
211			 EXT2_QSORT_TYPE (*sortfunc)(const void *,
212						     const void *))
213{
214	if (!sortfunc)
215		sortfunc = dir_block_cmp2;
216	qsort(dblist->list, (size_t) dblist->count,
217	      sizeof(struct ext2_db_entry2), sortfunc);
218	dblist->sorted = 1;
219}
220
221/*
222 * This function iterates over the directory block list
223 */
224errcode_t ext2fs_dblist_iterate2(ext2_dblist dblist,
225				 int (*func)(ext2_filsys fs,
226					     struct ext2_db_entry2 *db_info,
227					     void	*priv_data),
228				 void *priv_data)
229{
230	unsigned long long	i;
231	int		ret;
232
233	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
234
235	if (!dblist->sorted)
236		ext2fs_dblist_sort2(dblist, 0);
237	for (i=0; i < dblist->count; i++) {
238		ret = (*func)(dblist->fs, &dblist->list[i], priv_data);
239		if (ret & DBLIST_ABORT)
240			return 0;
241	}
242	return 0;
243}
244
245static EXT2_QSORT_TYPE dir_block_cmp2(const void *a, const void *b)
246{
247	const struct ext2_db_entry2 *db_a =
248		(const struct ext2_db_entry2 *) a;
249	const struct ext2_db_entry2 *db_b =
250		(const struct ext2_db_entry2 *) b;
251
252	if (db_a->blk != db_b->blk)
253		return (int) (db_a->blk - db_b->blk);
254
255	if (db_a->ino != db_b->ino)
256		return (int) (db_a->ino - db_b->ino);
257
258	return (db_a->blockcnt - db_b->blockcnt);
259}
260
261blk64_t ext2fs_dblist_count2(ext2_dblist dblist)
262{
263	return dblist->count;
264}
265
266errcode_t ext2fs_dblist_get_last2(ext2_dblist dblist,
267				  struct ext2_db_entry2 **entry)
268{
269	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
270
271	if (dblist->count == 0)
272		return EXT2_ET_DBLIST_EMPTY;
273
274	if (entry)
275		*entry = dblist->list + ( dblist->count-1);
276	return 0;
277}
278
279errcode_t ext2fs_dblist_drop_last(ext2_dblist dblist)
280{
281	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
282
283	if (dblist->count == 0)
284		return EXT2_ET_DBLIST_EMPTY;
285
286	dblist->count--;
287	return 0;
288}
289
290/*
291 * Legacy 32-bit versions
292 */
293
294/*
295 * Add a directory block to the directory block list
296 */
297errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
298			       int blockcnt)
299{
300	return ext2fs_add_dir_block2(dblist, ino, blk, blockcnt);
301}
302
303/*
304 * Change the directory block to the directory block list
305 */
306errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
307			       int blockcnt)
308{
309	return ext2fs_set_dir_block2(dblist, ino, blk, blockcnt);
310}
311
312void ext2fs_dblist_sort(ext2_dblist dblist,
313			EXT2_QSORT_TYPE (*sortfunc)(const void *,
314						    const void *))
315{
316	if (sortfunc) {
317		sortfunc32 = sortfunc;
318		sortfunc = dir_block_cmp;
319	} else
320		sortfunc = dir_block_cmp2;
321	qsort(dblist->list, (size_t) dblist->count,
322	      sizeof(struct ext2_db_entry2), sortfunc);
323	dblist->sorted = 1;
324}
325
326/*
327 * This function iterates over the directory block list
328 */
329struct iterate_passthrough {
330	int (*func)(ext2_filsys fs,
331		    struct ext2_db_entry *db_info,
332		    void	*priv_data);
333	void *priv_data;
334};
335
336static int passthrough_func(ext2_filsys fs,
337			    struct ext2_db_entry2 *db_info,
338			    void	*priv_data)
339{
340	struct iterate_passthrough *p = priv_data;
341	struct ext2_db_entry db;
342	int ret;
343
344	db.ino = db_info->ino;
345	db.blk = (blk_t) db_info->blk;
346	db.blockcnt = (int) db_info->blockcnt;
347	ret = (p->func)(fs, &db, p->priv_data);
348	db_info->ino = db.ino;
349	db_info->blk = db.blk;
350	db_info->blockcnt = db.blockcnt;
351	return ret;
352}
353
354errcode_t ext2fs_dblist_iterate(ext2_dblist dblist,
355				int (*func)(ext2_filsys fs,
356					    struct ext2_db_entry *db_info,
357					    void	*priv_data),
358				void *priv_data)
359{
360	struct iterate_passthrough pass;
361
362	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
363	pass.func = func;
364	pass.priv_data = priv_data;
365
366	return ext2fs_dblist_iterate2(dblist, passthrough_func, &pass);
367}
368
369static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b)
370{
371	const struct ext2_db_entry2 *db_a =
372		(const struct ext2_db_entry2 *) a;
373	const struct ext2_db_entry2 *db_b =
374		(const struct ext2_db_entry2 *) b;
375
376	struct ext2_db_entry a32, b32;
377
378	a32.ino = db_a->ino;  a32.blk = db_a->blk;
379	a32.blockcnt = db_a->blockcnt;
380
381	b32.ino = db_b->ino;  b32.blk = db_b->blk;
382	b32.blockcnt = db_b->blockcnt;
383
384	return sortfunc32(&a32, &b32);
385}
386
387int ext2fs_dblist_count(ext2_dblist dblist)
388{
389	return dblist->count;
390}
391
392errcode_t ext2fs_dblist_get_last(ext2_dblist dblist,
393				 struct ext2_db_entry **entry)
394{
395	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
396	static struct ext2_db_entry ret_entry;
397	struct ext2_db_entry2 *last;
398
399	if (dblist->count == 0)
400		return EXT2_ET_DBLIST_EMPTY;
401
402	if (!entry)
403		return 0;
404
405	last = dblist->list + dblist->count -1;
406
407	ret_entry.ino = last->ino;
408	ret_entry.blk = last->blk;
409	ret_entry.blockcnt = last->blockcnt;
410	*entry = &ret_entry;
411
412	return 0;
413}
414
415