1 /*
2  *  linux/fs/ext3/ialloc.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  BSD ufs-inspired inode and directory allocation by
10  *  Stephen Tweedie (sct@redhat.com), 1993
11  *  Big-endian to little-endian byte-swapping/bitmaps by
12  *        David S. Miller (davem@caip.rutgers.edu), 1995
13  */
14 
15 #include <linux/time.h>
16 #include <linux/fs.h>
17 #include <linux/jbd.h>
18 #include <linux/ext3_fs.h>
19 #include <linux/ext3_jbd.h>
20 #include <linux/stat.h>
21 #include <linux/string.h>
22 #include <linux/quotaops.h>
23 #include <linux/buffer_head.h>
24 #include <linux/random.h>
25 #include <linux/bitops.h>
26 
27 #include <asm/byteorder.h>
28 
29 #include "xattr.h"
30 #include "acl.h"
31 
32 /*
33  * ialloc.c contains the inodes allocation and deallocation routines
34  */
35 
36 /*
37  * The free inodes are managed by bitmaps.  A file system contains several
38  * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
39  * block for inodes, N blocks for the inode table and data blocks.
40  *
41  * The file system contains group descriptors which are located after the
42  * super block.  Each descriptor contains the number of the bitmap block and
43  * the free blocks count in the block.
44  */
45 
46 
47 /*
48  * Read the inode allocation bitmap for a given block_group, reading
49  * into the specified slot in the superblock's bitmap cache.
50  *
51  * Return buffer_head of bitmap on success or NULL.
52  */
53 static struct buffer_head *
read_inode_bitmap(struct super_block * sb,unsigned long block_group)54 read_inode_bitmap(struct super_block * sb, unsigned long block_group)
55 {
56 	struct ext3_group_desc *desc;
57 	struct buffer_head *bh = NULL;
58 
59 	desc = ext3_get_group_desc(sb, block_group, NULL);
60 	if (!desc)
61 		goto error_out;
62 
63 	bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
64 	if (!bh)
65 		ext3_error(sb, "read_inode_bitmap",
66 			    "Cannot read inode bitmap - "
67 			    "block_group = %lu, inode_bitmap = %u",
68 			    block_group, le32_to_cpu(desc->bg_inode_bitmap));
69 error_out:
70 	return bh;
71 }
72 
73 /*
74  * NOTE! When we get the inode, we're the only people
75  * that have access to it, and as such there are no
76  * race conditions we have to worry about. The inode
77  * is not on the hash-lists, and it cannot be reached
78  * through the filesystem because the directory entry
79  * has been deleted earlier.
80  *
81  * HOWEVER: we must make sure that we get no aliases,
82  * which means that we have to call "clear_inode()"
83  * _before_ we mark the inode not in use in the inode
84  * bitmaps. Otherwise a newly created file might use
85  * the same inode number (not actually the same pointer
86  * though), and then we'd have two inodes sharing the
87  * same inode number and space on the harddisk.
88  */
ext3_free_inode(handle_t * handle,struct inode * inode)89 void ext3_free_inode (handle_t *handle, struct inode * inode)
90 {
91 	struct super_block * sb = inode->i_sb;
92 	int is_directory;
93 	unsigned long ino;
94 	struct buffer_head *bitmap_bh = NULL;
95 	struct buffer_head *bh2;
96 	unsigned long block_group;
97 	unsigned long bit;
98 	struct ext3_group_desc * gdp;
99 	struct ext3_super_block * es;
100 	struct ext3_sb_info *sbi;
101 	int fatal = 0, err;
102 
103 	if (atomic_read(&inode->i_count) > 1) {
104 		printk ("ext3_free_inode: inode has count=%d\n",
105 					atomic_read(&inode->i_count));
106 		return;
107 	}
108 	if (inode->i_nlink) {
109 		printk ("ext3_free_inode: inode has nlink=%d\n",
110 			inode->i_nlink);
111 		return;
112 	}
113 	if (!sb) {
114 		printk("ext3_free_inode: inode on nonexistent device\n");
115 		return;
116 	}
117 	sbi = EXT3_SB(sb);
118 
119 	ino = inode->i_ino;
120 	ext3_debug ("freeing inode %lu\n", ino);
121 
122 	is_directory = S_ISDIR(inode->i_mode);
123 
124 	es = EXT3_SB(sb)->s_es;
125 	if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
126 		ext3_error (sb, "ext3_free_inode",
127 			    "reserved or nonexistent inode %lu", ino);
128 		goto error_return;
129 	}
130 	block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
131 	bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
132 	bitmap_bh = read_inode_bitmap(sb, block_group);
133 	if (!bitmap_bh)
134 		goto error_return;
135 
136 	BUFFER_TRACE(bitmap_bh, "get_write_access");
137 	fatal = ext3_journal_get_write_access(handle, bitmap_bh);
138 	if (fatal)
139 		goto error_return;
140 
141 	/* Ok, now we can actually update the inode bitmaps.. */
142 	if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
143 					bit, bitmap_bh->b_data))
144 		ext3_error (sb, "ext3_free_inode",
145 			      "bit already cleared for inode %lu", ino);
146 	else {
147 		gdp = ext3_get_group_desc (sb, block_group, &bh2);
148 
149 		BUFFER_TRACE(bh2, "get_write_access");
150 		fatal = ext3_journal_get_write_access(handle, bh2);
151 		if (fatal) goto error_return;
152 
153 		if (gdp) {
154 			spin_lock(sb_bgl_lock(sbi, block_group));
155 			le16_add_cpu(&gdp->bg_free_inodes_count, 1);
156 			if (is_directory)
157 				le16_add_cpu(&gdp->bg_used_dirs_count, -1);
158 			spin_unlock(sb_bgl_lock(sbi, block_group));
159 			percpu_counter_inc(&sbi->s_freeinodes_counter);
160 			if (is_directory)
161 				percpu_counter_dec(&sbi->s_dirs_counter);
162 
163 		}
164 		BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
165 		err = ext3_journal_dirty_metadata(handle, bh2);
166 		if (!fatal) fatal = err;
167 	}
168 	BUFFER_TRACE(bitmap_bh, "call ext3_journal_dirty_metadata");
169 	err = ext3_journal_dirty_metadata(handle, bitmap_bh);
170 	if (!fatal)
171 		fatal = err;
172 
173 error_return:
174 	brelse(bitmap_bh);
175 	ext3_std_error(sb, fatal);
176 }
177 
178 /*
179  * There are two policies for allocating an inode.  If the new inode is
180  * a directory, then a forward search is made for a block group with both
181  * free space and a low directory-to-inode ratio; if that fails, then of
182  * the groups with above-average free space, that group with the fewest
183  * directories already is chosen.
184  *
185  * For other inodes, search forward from the parent directory\'s block
186  * group to find a free inode.
187  */
find_group_dir(struct super_block * sb,struct inode * parent)188 static int find_group_dir(struct super_block *sb, struct inode *parent)
189 {
190 	int ngroups = EXT3_SB(sb)->s_groups_count;
191 	unsigned int freei, avefreei;
192 	struct ext3_group_desc *desc, *best_desc = NULL;
193 	int group, best_group = -1;
194 
195 	freei = percpu_counter_read_positive(&EXT3_SB(sb)->s_freeinodes_counter);
196 	avefreei = freei / ngroups;
197 
198 	for (group = 0; group < ngroups; group++) {
199 		desc = ext3_get_group_desc (sb, group, NULL);
200 		if (!desc || !desc->bg_free_inodes_count)
201 			continue;
202 		if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
203 			continue;
204 		if (!best_desc ||
205 		    (le16_to_cpu(desc->bg_free_blocks_count) >
206 		     le16_to_cpu(best_desc->bg_free_blocks_count))) {
207 			best_group = group;
208 			best_desc = desc;
209 		}
210 	}
211 	return best_group;
212 }
213 
214 /*
215  * Orlov's allocator for directories.
216  *
217  * We always try to spread first-level directories.
218  *
219  * If there are blockgroups with both free inodes and free blocks counts
220  * not worse than average we return one with smallest directory count.
221  * Otherwise we simply return a random group.
222  *
223  * For the rest rules look so:
224  *
225  * It's OK to put directory into a group unless
226  * it has too many directories already (max_dirs) or
227  * it has too few free inodes left (min_inodes) or
228  * it has too few free blocks left (min_blocks) or
229  * it's already running too large debt (max_debt).
230  * Parent's group is preferred, if it doesn't satisfy these
231  * conditions we search cyclically through the rest. If none
232  * of the groups look good we just look for a group with more
233  * free inodes than average (starting at parent's group).
234  *
235  * Debt is incremented each time we allocate a directory and decremented
236  * when we allocate an inode, within 0--255.
237  */
238 
239 #define INODE_COST 64
240 #define BLOCK_COST 256
241 
find_group_orlov(struct super_block * sb,struct inode * parent)242 static int find_group_orlov(struct super_block *sb, struct inode *parent)
243 {
244 	int parent_group = EXT3_I(parent)->i_block_group;
245 	struct ext3_sb_info *sbi = EXT3_SB(sb);
246 	struct ext3_super_block *es = sbi->s_es;
247 	int ngroups = sbi->s_groups_count;
248 	int inodes_per_group = EXT3_INODES_PER_GROUP(sb);
249 	unsigned int freei, avefreei;
250 	ext3_fsblk_t freeb, avefreeb;
251 	ext3_fsblk_t blocks_per_dir;
252 	unsigned int ndirs;
253 	int max_debt, max_dirs, min_inodes;
254 	ext3_grpblk_t min_blocks;
255 	int group = -1, i;
256 	struct ext3_group_desc *desc;
257 
258 	freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
259 	avefreei = freei / ngroups;
260 	freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
261 	avefreeb = freeb / ngroups;
262 	ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
263 
264 	if ((parent == sb->s_root->d_inode) ||
265 	    (EXT3_I(parent)->i_flags & EXT3_TOPDIR_FL)) {
266 		int best_ndir = inodes_per_group;
267 		int best_group = -1;
268 
269 		get_random_bytes(&group, sizeof(group));
270 		parent_group = (unsigned)group % ngroups;
271 		for (i = 0; i < ngroups; i++) {
272 			group = (parent_group + i) % ngroups;
273 			desc = ext3_get_group_desc (sb, group, NULL);
274 			if (!desc || !desc->bg_free_inodes_count)
275 				continue;
276 			if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
277 				continue;
278 			if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
279 				continue;
280 			if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
281 				continue;
282 			best_group = group;
283 			best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
284 		}
285 		if (best_group >= 0)
286 			return best_group;
287 		goto fallback;
288 	}
289 
290 	blocks_per_dir = (le32_to_cpu(es->s_blocks_count) - freeb) / ndirs;
291 
292 	max_dirs = ndirs / ngroups + inodes_per_group / 16;
293 	min_inodes = avefreei - inodes_per_group / 4;
294 	min_blocks = avefreeb - EXT3_BLOCKS_PER_GROUP(sb) / 4;
295 
296 	max_debt = EXT3_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, (ext3_fsblk_t)BLOCK_COST);
297 	if (max_debt * INODE_COST > inodes_per_group)
298 		max_debt = inodes_per_group / INODE_COST;
299 	if (max_debt > 255)
300 		max_debt = 255;
301 	if (max_debt == 0)
302 		max_debt = 1;
303 
304 	for (i = 0; i < ngroups; i++) {
305 		group = (parent_group + i) % ngroups;
306 		desc = ext3_get_group_desc (sb, group, NULL);
307 		if (!desc || !desc->bg_free_inodes_count)
308 			continue;
309 		if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
310 			continue;
311 		if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
312 			continue;
313 		if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
314 			continue;
315 		return group;
316 	}
317 
318 fallback:
319 	for (i = 0; i < ngroups; i++) {
320 		group = (parent_group + i) % ngroups;
321 		desc = ext3_get_group_desc (sb, group, NULL);
322 		if (!desc || !desc->bg_free_inodes_count)
323 			continue;
324 		if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
325 			return group;
326 	}
327 
328 	if (avefreei) {
329 		/*
330 		 * The free-inodes counter is approximate, and for really small
331 		 * filesystems the above test can fail to find any blockgroups
332 		 */
333 		avefreei = 0;
334 		goto fallback;
335 	}
336 
337 	return -1;
338 }
339 
find_group_other(struct super_block * sb,struct inode * parent)340 static int find_group_other(struct super_block *sb, struct inode *parent)
341 {
342 	int parent_group = EXT3_I(parent)->i_block_group;
343 	int ngroups = EXT3_SB(sb)->s_groups_count;
344 	struct ext3_group_desc *desc;
345 	int group, i;
346 
347 	/*
348 	 * Try to place the inode in its parent directory
349 	 */
350 	group = parent_group;
351 	desc = ext3_get_group_desc (sb, group, NULL);
352 	if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
353 			le16_to_cpu(desc->bg_free_blocks_count))
354 		return group;
355 
356 	/*
357 	 * We're going to place this inode in a different blockgroup from its
358 	 * parent.  We want to cause files in a common directory to all land in
359 	 * the same blockgroup.  But we want files which are in a different
360 	 * directory which shares a blockgroup with our parent to land in a
361 	 * different blockgroup.
362 	 *
363 	 * So add our directory's i_ino into the starting point for the hash.
364 	 */
365 	group = (group + parent->i_ino) % ngroups;
366 
367 	/*
368 	 * Use a quadratic hash to find a group with a free inode and some free
369 	 * blocks.
370 	 */
371 	for (i = 1; i < ngroups; i <<= 1) {
372 		group += i;
373 		if (group >= ngroups)
374 			group -= ngroups;
375 		desc = ext3_get_group_desc (sb, group, NULL);
376 		if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
377 				le16_to_cpu(desc->bg_free_blocks_count))
378 			return group;
379 	}
380 
381 	/*
382 	 * That failed: try linear search for a free inode, even if that group
383 	 * has no free blocks.
384 	 */
385 	group = parent_group;
386 	for (i = 0; i < ngroups; i++) {
387 		if (++group >= ngroups)
388 			group = 0;
389 		desc = ext3_get_group_desc (sb, group, NULL);
390 		if (desc && le16_to_cpu(desc->bg_free_inodes_count))
391 			return group;
392 	}
393 
394 	return -1;
395 }
396 
397 /*
398  * There are two policies for allocating an inode.  If the new inode is
399  * a directory, then a forward search is made for a block group with both
400  * free space and a low directory-to-inode ratio; if that fails, then of
401  * the groups with above-average free space, that group with the fewest
402  * directories already is chosen.
403  *
404  * For other inodes, search forward from the parent directory's block
405  * group to find a free inode.
406  */
ext3_new_inode(handle_t * handle,struct inode * dir,const struct qstr * qstr,int mode)407 struct inode *ext3_new_inode(handle_t *handle, struct inode * dir,
408 			     const struct qstr *qstr, int mode)
409 {
410 	struct super_block *sb;
411 	struct buffer_head *bitmap_bh = NULL;
412 	struct buffer_head *bh2;
413 	int group;
414 	unsigned long ino = 0;
415 	struct inode * inode;
416 	struct ext3_group_desc * gdp = NULL;
417 	struct ext3_super_block * es;
418 	struct ext3_inode_info *ei;
419 	struct ext3_sb_info *sbi;
420 	int err = 0;
421 	struct inode *ret;
422 	int i;
423 
424 	/* Cannot create files in a deleted directory */
425 	if (!dir || !dir->i_nlink)
426 		return ERR_PTR(-EPERM);
427 
428 	sb = dir->i_sb;
429 	inode = new_inode(sb);
430 	if (!inode)
431 		return ERR_PTR(-ENOMEM);
432 	ei = EXT3_I(inode);
433 
434 	sbi = EXT3_SB(sb);
435 	es = sbi->s_es;
436 	if (S_ISDIR(mode)) {
437 		if (test_opt (sb, OLDALLOC))
438 			group = find_group_dir(sb, dir);
439 		else
440 			group = find_group_orlov(sb, dir);
441 	} else
442 		group = find_group_other(sb, dir);
443 
444 	err = -ENOSPC;
445 	if (group == -1)
446 		goto out;
447 
448 	for (i = 0; i < sbi->s_groups_count; i++) {
449 		err = -EIO;
450 
451 		gdp = ext3_get_group_desc(sb, group, &bh2);
452 		if (!gdp)
453 			goto fail;
454 
455 		brelse(bitmap_bh);
456 		bitmap_bh = read_inode_bitmap(sb, group);
457 		if (!bitmap_bh)
458 			goto fail;
459 
460 		ino = 0;
461 
462 repeat_in_this_group:
463 		ino = ext3_find_next_zero_bit((unsigned long *)
464 				bitmap_bh->b_data, EXT3_INODES_PER_GROUP(sb), ino);
465 		if (ino < EXT3_INODES_PER_GROUP(sb)) {
466 
467 			BUFFER_TRACE(bitmap_bh, "get_write_access");
468 			err = ext3_journal_get_write_access(handle, bitmap_bh);
469 			if (err)
470 				goto fail;
471 
472 			if (!ext3_set_bit_atomic(sb_bgl_lock(sbi, group),
473 						ino, bitmap_bh->b_data)) {
474 				/* we won it */
475 				BUFFER_TRACE(bitmap_bh,
476 					"call ext3_journal_dirty_metadata");
477 				err = ext3_journal_dirty_metadata(handle,
478 								bitmap_bh);
479 				if (err)
480 					goto fail;
481 				goto got;
482 			}
483 			/* we lost it */
484 			journal_release_buffer(handle, bitmap_bh);
485 
486 			if (++ino < EXT3_INODES_PER_GROUP(sb))
487 				goto repeat_in_this_group;
488 		}
489 
490 		/*
491 		 * This case is possible in concurrent environment.  It is very
492 		 * rare.  We cannot repeat the find_group_xxx() call because
493 		 * that will simply return the same blockgroup, because the
494 		 * group descriptor metadata has not yet been updated.
495 		 * So we just go onto the next blockgroup.
496 		 */
497 		if (++group == sbi->s_groups_count)
498 			group = 0;
499 	}
500 	err = -ENOSPC;
501 	goto out;
502 
503 got:
504 	ino += group * EXT3_INODES_PER_GROUP(sb) + 1;
505 	if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
506 		ext3_error (sb, "ext3_new_inode",
507 			    "reserved inode or inode > inodes count - "
508 			    "block_group = %d, inode=%lu", group, ino);
509 		err = -EIO;
510 		goto fail;
511 	}
512 
513 	BUFFER_TRACE(bh2, "get_write_access");
514 	err = ext3_journal_get_write_access(handle, bh2);
515 	if (err) goto fail;
516 	spin_lock(sb_bgl_lock(sbi, group));
517 	le16_add_cpu(&gdp->bg_free_inodes_count, -1);
518 	if (S_ISDIR(mode)) {
519 		le16_add_cpu(&gdp->bg_used_dirs_count, 1);
520 	}
521 	spin_unlock(sb_bgl_lock(sbi, group));
522 	BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
523 	err = ext3_journal_dirty_metadata(handle, bh2);
524 	if (err) goto fail;
525 
526 	percpu_counter_dec(&sbi->s_freeinodes_counter);
527 	if (S_ISDIR(mode))
528 		percpu_counter_inc(&sbi->s_dirs_counter);
529 
530 
531 	if (test_opt(sb, GRPID)) {
532 		inode->i_mode = mode;
533 		inode->i_uid = current_fsuid();
534 		inode->i_gid = dir->i_gid;
535 	} else
536 		inode_init_owner(inode, dir, mode);
537 
538 	inode->i_ino = ino;
539 	/* This is the optimal IO size (for stat), not the fs block size */
540 	inode->i_blocks = 0;
541 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
542 
543 	memset(ei->i_data, 0, sizeof(ei->i_data));
544 	ei->i_dir_start_lookup = 0;
545 	ei->i_disksize = 0;
546 
547 	ei->i_flags =
548 		ext3_mask_flags(mode, EXT3_I(dir)->i_flags & EXT3_FL_INHERITED);
549 #ifdef EXT3_FRAGMENTS
550 	ei->i_faddr = 0;
551 	ei->i_frag_no = 0;
552 	ei->i_frag_size = 0;
553 #endif
554 	ei->i_file_acl = 0;
555 	ei->i_dir_acl = 0;
556 	ei->i_dtime = 0;
557 	ei->i_block_alloc_info = NULL;
558 	ei->i_block_group = group;
559 
560 	ext3_set_inode_flags(inode);
561 	if (IS_DIRSYNC(inode))
562 		handle->h_sync = 1;
563 	if (insert_inode_locked(inode) < 0) {
564 		err = -EINVAL;
565 		goto fail_drop;
566 	}
567 	spin_lock(&sbi->s_next_gen_lock);
568 	inode->i_generation = sbi->s_next_generation++;
569 	spin_unlock(&sbi->s_next_gen_lock);
570 
571 	ei->i_state_flags = 0;
572 	ext3_set_inode_state(inode, EXT3_STATE_NEW);
573 
574 	/* See comment in ext3_iget for explanation */
575 	if (ino >= EXT3_FIRST_INO(sb) + 1 &&
576 	    EXT3_INODE_SIZE(sb) > EXT3_GOOD_OLD_INODE_SIZE) {
577 		ei->i_extra_isize =
578 			sizeof(struct ext3_inode) - EXT3_GOOD_OLD_INODE_SIZE;
579 	} else {
580 		ei->i_extra_isize = 0;
581 	}
582 
583 	ret = inode;
584 	dquot_initialize(inode);
585 	err = dquot_alloc_inode(inode);
586 	if (err)
587 		goto fail_drop;
588 
589 	err = ext3_init_acl(handle, inode, dir);
590 	if (err)
591 		goto fail_free_drop;
592 
593 	err = ext3_init_security(handle, inode, dir, qstr);
594 	if (err)
595 		goto fail_free_drop;
596 
597 	err = ext3_mark_inode_dirty(handle, inode);
598 	if (err) {
599 		ext3_std_error(sb, err);
600 		goto fail_free_drop;
601 	}
602 
603 	ext3_debug("allocating inode %lu\n", inode->i_ino);
604 	goto really_out;
605 fail:
606 	ext3_std_error(sb, err);
607 out:
608 	iput(inode);
609 	ret = ERR_PTR(err);
610 really_out:
611 	brelse(bitmap_bh);
612 	return ret;
613 
614 fail_free_drop:
615 	dquot_free_inode(inode);
616 
617 fail_drop:
618 	dquot_drop(inode);
619 	inode->i_flags |= S_NOQUOTA;
620 	inode->i_nlink = 0;
621 	unlock_new_inode(inode);
622 	iput(inode);
623 	brelse(bitmap_bh);
624 	return ERR_PTR(err);
625 }
626 
627 /* Verify that we are loading a valid orphan from disk */
ext3_orphan_get(struct super_block * sb,unsigned long ino)628 struct inode *ext3_orphan_get(struct super_block *sb, unsigned long ino)
629 {
630 	unsigned long max_ino = le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count);
631 	unsigned long block_group;
632 	int bit;
633 	struct buffer_head *bitmap_bh;
634 	struct inode *inode = NULL;
635 	long err = -EIO;
636 
637 	/* Error cases - e2fsck has already cleaned up for us */
638 	if (ino > max_ino) {
639 		ext3_warning(sb, __func__,
640 			     "bad orphan ino %lu!  e2fsck was run?", ino);
641 		goto error;
642 	}
643 
644 	block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
645 	bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
646 	bitmap_bh = read_inode_bitmap(sb, block_group);
647 	if (!bitmap_bh) {
648 		ext3_warning(sb, __func__,
649 			     "inode bitmap error for orphan %lu", ino);
650 		goto error;
651 	}
652 
653 	/* Having the inode bit set should be a 100% indicator that this
654 	 * is a valid orphan (no e2fsck run on fs).  Orphans also include
655 	 * inodes that were being truncated, so we can't check i_nlink==0.
656 	 */
657 	if (!ext3_test_bit(bit, bitmap_bh->b_data))
658 		goto bad_orphan;
659 
660 	inode = ext3_iget(sb, ino);
661 	if (IS_ERR(inode))
662 		goto iget_failed;
663 
664 	/*
665 	 * If the orphans has i_nlinks > 0 then it should be able to be
666 	 * truncated, otherwise it won't be removed from the orphan list
667 	 * during processing and an infinite loop will result.
668 	 */
669 	if (inode->i_nlink && !ext3_can_truncate(inode))
670 		goto bad_orphan;
671 
672 	if (NEXT_ORPHAN(inode) > max_ino)
673 		goto bad_orphan;
674 	brelse(bitmap_bh);
675 	return inode;
676 
677 iget_failed:
678 	err = PTR_ERR(inode);
679 	inode = NULL;
680 bad_orphan:
681 	ext3_warning(sb, __func__,
682 		     "bad orphan inode %lu!  e2fsck was run?", ino);
683 	printk(KERN_NOTICE "ext3_test_bit(bit=%d, block=%llu) = %d\n",
684 	       bit, (unsigned long long)bitmap_bh->b_blocknr,
685 	       ext3_test_bit(bit, bitmap_bh->b_data));
686 	printk(KERN_NOTICE "inode=%p\n", inode);
687 	if (inode) {
688 		printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
689 		       is_bad_inode(inode));
690 		printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
691 		       NEXT_ORPHAN(inode));
692 		printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
693 		printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink);
694 		/* Avoid freeing blocks if we got a bad deleted inode */
695 		if (inode->i_nlink == 0)
696 			inode->i_blocks = 0;
697 		iput(inode);
698 	}
699 	brelse(bitmap_bh);
700 error:
701 	return ERR_PTR(err);
702 }
703 
ext3_count_free_inodes(struct super_block * sb)704 unsigned long ext3_count_free_inodes (struct super_block * sb)
705 {
706 	unsigned long desc_count;
707 	struct ext3_group_desc *gdp;
708 	int i;
709 #ifdef EXT3FS_DEBUG
710 	struct ext3_super_block *es;
711 	unsigned long bitmap_count, x;
712 	struct buffer_head *bitmap_bh = NULL;
713 
714 	es = EXT3_SB(sb)->s_es;
715 	desc_count = 0;
716 	bitmap_count = 0;
717 	gdp = NULL;
718 	for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
719 		gdp = ext3_get_group_desc (sb, i, NULL);
720 		if (!gdp)
721 			continue;
722 		desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
723 		brelse(bitmap_bh);
724 		bitmap_bh = read_inode_bitmap(sb, i);
725 		if (!bitmap_bh)
726 			continue;
727 
728 		x = ext3_count_free(bitmap_bh, EXT3_INODES_PER_GROUP(sb) / 8);
729 		printk("group %d: stored = %d, counted = %lu\n",
730 			i, le16_to_cpu(gdp->bg_free_inodes_count), x);
731 		bitmap_count += x;
732 	}
733 	brelse(bitmap_bh);
734 	printk("ext3_count_free_inodes: stored = %u, computed = %lu, %lu\n",
735 		le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
736 	return desc_count;
737 #else
738 	desc_count = 0;
739 	for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
740 		gdp = ext3_get_group_desc (sb, i, NULL);
741 		if (!gdp)
742 			continue;
743 		desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
744 		cond_resched();
745 	}
746 	return desc_count;
747 #endif
748 }
749 
750 /* Called at mount-time, super-block is locked */
ext3_count_dirs(struct super_block * sb)751 unsigned long ext3_count_dirs (struct super_block * sb)
752 {
753 	unsigned long count = 0;
754 	int i;
755 
756 	for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) {
757 		struct ext3_group_desc *gdp = ext3_get_group_desc (sb, i, NULL);
758 		if (!gdp)
759 			continue;
760 		count += le16_to_cpu(gdp->bg_used_dirs_count);
761 	}
762 	return count;
763 }
764 
765