dblist.c revision 00eb0eee0addfd3b7ede98b85e00dff1547838a0 
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
23static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b);
24static EXT2_QSORT_TYPE dir_block_cmp2(const void *a, const void *b);
25static EXT2_QSORT_TYPE (*sortfunc32)(const void *a, const void *b);
26
27/*
28 * Returns the number of directories in the filesystem as reported by
29 * the group descriptors.  Of course, the group descriptors could be
30 * wrong!
31 */
32errcode_t ext2fs_get_num_dirs(ext2_filsys fs, ext2_ino_t *ret_num_dirs)
33{
34	dgrp_t	i;
35	ext2_ino_t	num_dirs, max_dirs;
36
37	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
38
39	num_dirs = 0;
40	max_dirs = fs->super->s_inodes_per_group;
41	for (i = 0; i < fs->group_desc_count; i++) {
42		if (ext2fs_bg_used_dirs_count(fs, i) > max_dirs)
43			num_dirs += max_dirs / 8;
44		else
45			num_dirs += ext2fs_bg_used_dirs_count(fs, i);
46	}
47	if (num_dirs > fs->super->s_inodes_count)
48		num_dirs = fs->super->s_inodes_count;
49
50	*ret_num_dirs = num_dirs;
51
52	return 0;
53}
54
55/*
56 * helper function for making a new directory block list (for
57 * initialize and copy).
58 */
59static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size,
60			     ext2_ino_t count,
61			     struct ext2_db_entry2 *list,
62			     ext2_dblist *ret_dblist)
63{
64	ext2_dblist	dblist = NULL;
65	errcode_t	retval;
66	ext2_ino_t	num_dirs;
67	size_t		len;
68
69	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
70
71	if ((ret_dblist == 0) && fs->dblist &&
72	    (fs->dblist->magic == EXT2_ET_MAGIC_DBLIST))
73		return 0;
74
75	retval = ext2fs_get_mem(sizeof(struct ext2_struct_dblist), &dblist);
76	if (retval)
77		goto cleanup;
78	memset(dblist, 0, sizeof(struct ext2_struct_dblist));
79
80	dblist->magic = EXT2_ET_MAGIC_DBLIST;
81	dblist->fs = fs;
82	if (size)
83		dblist->size = size;
84	else {
85		retval = ext2fs_get_num_dirs(fs, &num_dirs);
86		if (retval)
87			goto cleanup;
88		dblist->size = (num_dirs * 2) + 12;
89	}
90	len = (size_t) sizeof(struct ext2_db_entry2) * dblist->size;
91	dblist->count = count;
92	retval = ext2fs_get_array(dblist->size, sizeof(struct ext2_db_entry2),
93		&dblist->list);
94	if (retval)
95		goto cleanup;
96
97	if (list)
98		memcpy(dblist->list, list, len);
99	else
100		memset(dblist->list, 0, len);
101	if (ret_dblist)
102		*ret_dblist = dblist;
103	else
104		fs->dblist = dblist;
105	return 0;
106cleanup:
107	if (dblist)
108		ext2fs_free_mem(&dblist);
109	return retval;
110}
111
112/*
113 * Initialize a directory block list
114 */
115errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist)
116{
117	ext2_dblist	dblist;
118	errcode_t	retval;
119
120	retval = make_dblist(fs, 0, 0, 0, &dblist);
121	if (retval)
122		return retval;
123
124	dblist->sorted = 1;
125	if (ret_dblist)
126		*ret_dblist = dblist;
127	else
128		fs->dblist = dblist;
129
130	return 0;
131}
132
133/*
134 * Copy a directory block list
135 */
136errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist *dest)
137{
138	ext2_dblist	dblist;
139	errcode_t	retval;
140
141	retval = make_dblist(src->fs, src->size, src->count, src->list,
142			     &dblist);
143	if (retval)
144		return retval;
145	dblist->sorted = src->sorted;
146	*dest = dblist;
147	return 0;
148}
149
150/*
151 * Close a directory block list
152 *
153 * (moved to closefs.c)
154 */
155
156
157/*
158 * Add a directory block to the directory block list
159 */
160errcode_t ext2fs_add_dir_block2(ext2_dblist dblist, ext2_ino_t ino,
161				blk64_t blk, e2_blkcnt_t blockcnt)
162{
163	struct ext2_db_entry2 	*new_entry;
164	errcode_t		retval;
165	unsigned long		old_size;
166
167	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
168
169	if (dblist->count >= dblist->size) {
170		old_size = dblist->size * sizeof(struct ext2_db_entry2);
171		dblist->size += dblist->size > 200 ? dblist->size / 2 : 100;
172		retval = ext2fs_resize_mem(old_size, (size_t) dblist->size *
173					   sizeof(struct ext2_db_entry2),
174					   &dblist->list);
175		if (retval) {
176			dblist->size = old_size / sizeof(struct ext2_db_entry2);
177			return retval;
178		}
179	}
180	new_entry = dblist->list + ( dblist->count++);
181	new_entry->blk = blk;
182	new_entry->ino = ino;
183	new_entry->blockcnt = blockcnt;
184
185	dblist->sorted = 0;
186
187	return 0;
188}
189
190/*
191 * Change the directory block to the directory block list
192 */
193errcode_t ext2fs_set_dir_block2(ext2_dblist dblist, ext2_ino_t ino,
194				blk64_t blk, e2_blkcnt_t blockcnt)
195{
196	dgrp_t			i;
197
198	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
199
200	for (i=0; i < dblist->count; i++) {
201		if ((dblist->list[i].ino != ino) ||
202		    (dblist->list[i].blockcnt != blockcnt))
203			continue;
204		dblist->list[i].blk = blk;
205		dblist->sorted = 0;
206		return 0;
207	}
208	return EXT2_ET_DB_NOT_FOUND;
209}
210
211void ext2fs_dblist_sort2(ext2_dblist dblist,
212			 EXT2_QSORT_TYPE (*sortfunc)(const void *,
213						     const void *))
214{
215	if (!sortfunc)
216		sortfunc = dir_block_cmp2;
217	qsort(dblist->list, (size_t) dblist->count,
218	      sizeof(struct ext2_db_entry2), sortfunc);
219	dblist->sorted = 1;
220}
221
222/*
223 * This function iterates over the directory block list
224 */
225errcode_t ext2fs_dblist_iterate2(ext2_dblist dblist,
226				 int (*func)(ext2_filsys fs,
227					     struct ext2_db_entry2 *db_info,
228					     void	*priv_data),
229				 void *priv_data)
230{
231	unsigned long long	i;
232	int		ret;
233
234	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
235
236	if (!dblist->sorted)
237		ext2fs_dblist_sort2(dblist, 0);
238	for (i=0; i < dblist->count; i++) {
239		ret = (*func)(dblist->fs, &dblist->list[i], priv_data);
240		if (ret & DBLIST_ABORT)
241			return 0;
242	}
243	return 0;
244}
245
246static EXT2_QSORT_TYPE dir_block_cmp2(const void *a, const void *b)
247{
248	const struct ext2_db_entry2 *db_a =
249		(const struct ext2_db_entry2 *) a;
250	const struct ext2_db_entry2 *db_b =
251		(const struct ext2_db_entry2 *) b;
252
253	if (db_a->blk != db_b->blk)
254		return (int) (db_a->blk - db_b->blk);
255
256	if (db_a->ino != db_b->ino)
257		return (int) (db_a->ino - db_b->ino);
258
259	return (db_a->blockcnt - db_b->blockcnt);
260}
261
262blk64_t ext2fs_dblist_count2(ext2_dblist dblist)
263{
264	return dblist->count;
265}
266
267errcode_t ext2fs_dblist_get_last2(ext2_dblist dblist,
268				  struct ext2_db_entry2 **entry)
269{
270	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
271
272	if (dblist->count == 0)
273		return EXT2_ET_DBLIST_EMPTY;
274
275	if (entry)
276		*entry = dblist->list + ( dblist->count-1);
277	return 0;
278}
279
280errcode_t ext2fs_dblist_drop_last(ext2_dblist dblist)
281{
282	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
283
284	if (dblist->count == 0)
285		return EXT2_ET_DBLIST_EMPTY;
286
287	dblist->count--;
288	return 0;
289}
290
291/*
292 * Legacy 32-bit versions
293 */
294
295/*
296 * Add a directory block to the directory block list
297 */
298errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
299			       int blockcnt)
300{
301	return ext2fs_add_dir_block2(dblist, ino, blk, blockcnt);
302}
303
304/*
305 * Change the directory block to the directory block list
306 */
307errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
308			       int blockcnt)
309{
310	return ext2fs_set_dir_block2(dblist, ino, blk, blockcnt);
311}
312
313void ext2fs_dblist_sort(ext2_dblist dblist,
314			EXT2_QSORT_TYPE (*sortfunc)(const void *,
315						    const void *))
316{
317	if (sortfunc) {
318		sortfunc32 = sortfunc;
319		sortfunc = dir_block_cmp;
320	} else
321		sortfunc = dir_block_cmp2;
322	qsort(dblist->list, (size_t) dblist->count,
323	      sizeof(struct ext2_db_entry2), sortfunc);
324	dblist->sorted = 1;
325}
326
327/*
328 * This function iterates over the directory block list
329 */
330struct iterate_passthrough {
331	int (*func)(ext2_filsys fs,
332		    struct ext2_db_entry *db_info,
333		    void	*priv_data);
334	void *priv_data;
335};
336
337static int passthrough_func(ext2_filsys fs,
338			    struct ext2_db_entry2 *db_info,
339			    void	*priv_data)
340{
341	struct iterate_passthrough *p = priv_data;
342	struct ext2_db_entry db;
343	int ret;
344
345	db.ino = db_info->ino;
346	db.blk = (blk_t) db_info->blk;
347	db.blockcnt = (int) db_info->blockcnt;
348	ret = (p->func)(fs, &db, p->priv_data);
349	db_info->ino = db.ino;
350	db_info->blk = db.blk;
351	db_info->blockcnt = db.blockcnt;
352	return ret;
353}
354
355errcode_t ext2fs_dblist_iterate(ext2_dblist dblist,
356				int (*func)(ext2_filsys fs,
357					    struct ext2_db_entry *db_info,
358					    void	*priv_data),
359				void *priv_data)
360{
361	struct iterate_passthrough pass;
362
363	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
364	pass.func = func;
365	pass.priv_data = priv_data;
366
367	return ext2fs_dblist_iterate2(dblist, passthrough_func, &pass);
368}
369
370static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b)
371{
372	const struct ext2_db_entry2 *db_a =
373		(const struct ext2_db_entry2 *) a;
374	const struct ext2_db_entry2 *db_b =
375		(const struct ext2_db_entry2 *) b;
376
377	struct ext2_db_entry a32, b32;
378
379	a32.ino = db_a->ino;  a32.blk = db_a->blk;
380	a32.blockcnt = db_a->blockcnt;
381
382	b32.ino = db_b->ino;  b32.blk = db_b->blk;
383	b32.blockcnt = db_b->blockcnt;
384
385	return sortfunc32(&a32, &b32);
386}
387
388int ext2fs_dblist_count(ext2_dblist dblist)
389{
390	return dblist->count;
391}
392
393errcode_t ext2fs_dblist_get_last(ext2_dblist dblist,
394				 struct ext2_db_entry **entry)
395{
396	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
397	static struct ext2_db_entry ret_entry;
398	struct ext2_db_entry2 *last;
399
400	if (dblist->count == 0)
401		return EXT2_ET_DBLIST_EMPTY;
402
403	if (!entry)
404		return 0;
405
406	last = dblist->list + dblist->count -1;
407
408	ret_entry.ino = last->ino;
409	ret_entry.blk = last->blk;
410	ret_entry.blockcnt = last->blockcnt;
411	*entry = &ret_entry;
412
413	return 0;
414}
415
416