Merge branch 'fixes-jgarzik' of git://git.kernel.org/pub/scm/linux/kernel/git/linvill...
[linux-2.6] / fs / ext4 / ialloc.c
1 /*
2  *  linux/fs/ext4/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/jbd2.h>
18 #include <linux/ext4_fs.h>
19 #include <linux/ext4_jbd2.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 #include <linux/blkdev.h>
27 #include <asm/byteorder.h>
28
29 #include "xattr.h"
30 #include "acl.h"
31 #include "group.h"
32
33 /*
34  * ialloc.c contains the inodes allocation and deallocation routines
35  */
36
37 /*
38  * The free inodes are managed by bitmaps.  A file system contains several
39  * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
40  * block for inodes, N blocks for the inode table and data blocks.
41  *
42  * The file system contains group descriptors which are located after the
43  * super block.  Each descriptor contains the number of the bitmap block and
44  * the free blocks count in the block.
45  */
46
47 /*
48  * To avoid calling the atomic setbit hundreds or thousands of times, we only
49  * need to use it within a single byte (to ensure we get endianness right).
50  * We can use memset for the rest of the bitmap as there are no other users.
51  */
52 void mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
53 {
54         int i;
55
56         if (start_bit >= end_bit)
57                 return;
58
59         ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
60         for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
61                 ext4_set_bit(i, bitmap);
62         if (i < end_bit)
63                 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
64 }
65
66 /* Initializes an uninitialized inode bitmap */
67 unsigned ext4_init_inode_bitmap(struct super_block *sb,
68                                 struct buffer_head *bh, int block_group,
69                                 struct ext4_group_desc *gdp)
70 {
71         struct ext4_sb_info *sbi = EXT4_SB(sb);
72
73         J_ASSERT_BH(bh, buffer_locked(bh));
74
75         /* If checksum is bad mark all blocks and inodes use to prevent
76          * allocation, essentially implementing a per-group read-only flag. */
77         if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
78                 ext4_error(sb, __FUNCTION__, "Checksum bad for group %u\n",
79                            block_group);
80                 gdp->bg_free_blocks_count = 0;
81                 gdp->bg_free_inodes_count = 0;
82                 gdp->bg_itable_unused = 0;
83                 memset(bh->b_data, 0xff, sb->s_blocksize);
84                 return 0;
85         }
86
87         memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
88         mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), EXT4_BLOCKS_PER_GROUP(sb),
89                         bh->b_data);
90
91         return EXT4_INODES_PER_GROUP(sb);
92 }
93
94 /*
95  * Read the inode allocation bitmap for a given block_group, reading
96  * into the specified slot in the superblock's bitmap cache.
97  *
98  * Return buffer_head of bitmap on success or NULL.
99  */
100 static struct buffer_head *
101 read_inode_bitmap(struct super_block * sb, unsigned long block_group)
102 {
103         struct ext4_group_desc *desc;
104         struct buffer_head *bh = NULL;
105
106         desc = ext4_get_group_desc(sb, block_group, NULL);
107         if (!desc)
108                 goto error_out;
109         if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
110                 bh = sb_getblk(sb, ext4_inode_bitmap(sb, desc));
111                 if (!buffer_uptodate(bh)) {
112                         lock_buffer(bh);
113                         if (!buffer_uptodate(bh)) {
114                                 ext4_init_inode_bitmap(sb, bh, block_group,
115                                                        desc);
116                                 set_buffer_uptodate(bh);
117                         }
118                         unlock_buffer(bh);
119                 }
120         } else {
121                 bh = sb_bread(sb, ext4_inode_bitmap(sb, desc));
122         }
123         if (!bh)
124                 ext4_error(sb, "read_inode_bitmap",
125                             "Cannot read inode bitmap - "
126                             "block_group = %lu, inode_bitmap = %llu",
127                             block_group, ext4_inode_bitmap(sb, desc));
128 error_out:
129         return bh;
130 }
131
132 /*
133  * NOTE! When we get the inode, we're the only people
134  * that have access to it, and as such there are no
135  * race conditions we have to worry about. The inode
136  * is not on the hash-lists, and it cannot be reached
137  * through the filesystem because the directory entry
138  * has been deleted earlier.
139  *
140  * HOWEVER: we must make sure that we get no aliases,
141  * which means that we have to call "clear_inode()"
142  * _before_ we mark the inode not in use in the inode
143  * bitmaps. Otherwise a newly created file might use
144  * the same inode number (not actually the same pointer
145  * though), and then we'd have two inodes sharing the
146  * same inode number and space on the harddisk.
147  */
148 void ext4_free_inode (handle_t *handle, struct inode * inode)
149 {
150         struct super_block * sb = inode->i_sb;
151         int is_directory;
152         unsigned long ino;
153         struct buffer_head *bitmap_bh = NULL;
154         struct buffer_head *bh2;
155         unsigned long block_group;
156         unsigned long bit;
157         struct ext4_group_desc * gdp;
158         struct ext4_super_block * es;
159         struct ext4_sb_info *sbi;
160         int fatal = 0, err;
161
162         if (atomic_read(&inode->i_count) > 1) {
163                 printk ("ext4_free_inode: inode has count=%d\n",
164                                         atomic_read(&inode->i_count));
165                 return;
166         }
167         if (inode->i_nlink) {
168                 printk ("ext4_free_inode: inode has nlink=%d\n",
169                         inode->i_nlink);
170                 return;
171         }
172         if (!sb) {
173                 printk("ext4_free_inode: inode on nonexistent device\n");
174                 return;
175         }
176         sbi = EXT4_SB(sb);
177
178         ino = inode->i_ino;
179         ext4_debug ("freeing inode %lu\n", ino);
180
181         /*
182          * Note: we must free any quota before locking the superblock,
183          * as writing the quota to disk may need the lock as well.
184          */
185         DQUOT_INIT(inode);
186         ext4_xattr_delete_inode(handle, inode);
187         DQUOT_FREE_INODE(inode);
188         DQUOT_DROP(inode);
189
190         is_directory = S_ISDIR(inode->i_mode);
191
192         /* Do this BEFORE marking the inode not in use or returning an error */
193         clear_inode (inode);
194
195         es = EXT4_SB(sb)->s_es;
196         if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
197                 ext4_error (sb, "ext4_free_inode",
198                             "reserved or nonexistent inode %lu", ino);
199                 goto error_return;
200         }
201         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
202         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
203         bitmap_bh = read_inode_bitmap(sb, block_group);
204         if (!bitmap_bh)
205                 goto error_return;
206
207         BUFFER_TRACE(bitmap_bh, "get_write_access");
208         fatal = ext4_journal_get_write_access(handle, bitmap_bh);
209         if (fatal)
210                 goto error_return;
211
212         /* Ok, now we can actually update the inode bitmaps.. */
213         if (!ext4_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
214                                         bit, bitmap_bh->b_data))
215                 ext4_error (sb, "ext4_free_inode",
216                               "bit already cleared for inode %lu", ino);
217         else {
218                 gdp = ext4_get_group_desc (sb, block_group, &bh2);
219
220                 BUFFER_TRACE(bh2, "get_write_access");
221                 fatal = ext4_journal_get_write_access(handle, bh2);
222                 if (fatal) goto error_return;
223
224                 if (gdp) {
225                         spin_lock(sb_bgl_lock(sbi, block_group));
226                         gdp->bg_free_inodes_count = cpu_to_le16(
227                                 le16_to_cpu(gdp->bg_free_inodes_count) + 1);
228                         if (is_directory)
229                                 gdp->bg_used_dirs_count = cpu_to_le16(
230                                   le16_to_cpu(gdp->bg_used_dirs_count) - 1);
231                         gdp->bg_checksum = ext4_group_desc_csum(sbi,
232                                                         block_group, gdp);
233                         spin_unlock(sb_bgl_lock(sbi, block_group));
234                         percpu_counter_inc(&sbi->s_freeinodes_counter);
235                         if (is_directory)
236                                 percpu_counter_dec(&sbi->s_dirs_counter);
237
238                 }
239                 BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
240                 err = ext4_journal_dirty_metadata(handle, bh2);
241                 if (!fatal) fatal = err;
242         }
243         BUFFER_TRACE(bitmap_bh, "call ext4_journal_dirty_metadata");
244         err = ext4_journal_dirty_metadata(handle, bitmap_bh);
245         if (!fatal)
246                 fatal = err;
247         sb->s_dirt = 1;
248 error_return:
249         brelse(bitmap_bh);
250         ext4_std_error(sb, fatal);
251 }
252
253 /*
254  * There are two policies for allocating an inode.  If the new inode is
255  * a directory, then a forward search is made for a block group with both
256  * free space and a low directory-to-inode ratio; if that fails, then of
257  * the groups with above-average free space, that group with the fewest
258  * directories already is chosen.
259  *
260  * For other inodes, search forward from the parent directory\'s block
261  * group to find a free inode.
262  */
263 static int find_group_dir(struct super_block *sb, struct inode *parent)
264 {
265         int ngroups = EXT4_SB(sb)->s_groups_count;
266         unsigned int freei, avefreei;
267         struct ext4_group_desc *desc, *best_desc = NULL;
268         int group, best_group = -1;
269
270         freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter);
271         avefreei = freei / ngroups;
272
273         for (group = 0; group < ngroups; group++) {
274                 desc = ext4_get_group_desc (sb, group, NULL);
275                 if (!desc || !desc->bg_free_inodes_count)
276                         continue;
277                 if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
278                         continue;
279                 if (!best_desc ||
280                     (le16_to_cpu(desc->bg_free_blocks_count) >
281                      le16_to_cpu(best_desc->bg_free_blocks_count))) {
282                         best_group = group;
283                         best_desc = desc;
284                 }
285         }
286         return best_group;
287 }
288
289 /*
290  * Orlov's allocator for directories.
291  *
292  * We always try to spread first-level directories.
293  *
294  * If there are blockgroups with both free inodes and free blocks counts
295  * not worse than average we return one with smallest directory count.
296  * Otherwise we simply return a random group.
297  *
298  * For the rest rules look so:
299  *
300  * It's OK to put directory into a group unless
301  * it has too many directories already (max_dirs) or
302  * it has too few free inodes left (min_inodes) or
303  * it has too few free blocks left (min_blocks) or
304  * it's already running too large debt (max_debt).
305  * Parent's group is prefered, if it doesn't satisfy these
306  * conditions we search cyclically through the rest. If none
307  * of the groups look good we just look for a group with more
308  * free inodes than average (starting at parent's group).
309  *
310  * Debt is incremented each time we allocate a directory and decremented
311  * when we allocate an inode, within 0--255.
312  */
313
314 #define INODE_COST 64
315 #define BLOCK_COST 256
316
317 static int find_group_orlov(struct super_block *sb, struct inode *parent)
318 {
319         int parent_group = EXT4_I(parent)->i_block_group;
320         struct ext4_sb_info *sbi = EXT4_SB(sb);
321         struct ext4_super_block *es = sbi->s_es;
322         int ngroups = sbi->s_groups_count;
323         int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
324         unsigned int freei, avefreei;
325         ext4_fsblk_t freeb, avefreeb;
326         ext4_fsblk_t blocks_per_dir;
327         unsigned int ndirs;
328         int max_debt, max_dirs, min_inodes;
329         ext4_grpblk_t min_blocks;
330         int group = -1, i;
331         struct ext4_group_desc *desc;
332
333         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
334         avefreei = freei / ngroups;
335         freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
336         avefreeb = freeb;
337         do_div(avefreeb, ngroups);
338         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
339
340         if ((parent == sb->s_root->d_inode) ||
341             (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) {
342                 int best_ndir = inodes_per_group;
343                 int best_group = -1;
344
345                 get_random_bytes(&group, sizeof(group));
346                 parent_group = (unsigned)group % ngroups;
347                 for (i = 0; i < ngroups; i++) {
348                         group = (parent_group + i) % ngroups;
349                         desc = ext4_get_group_desc (sb, group, NULL);
350                         if (!desc || !desc->bg_free_inodes_count)
351                                 continue;
352                         if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
353                                 continue;
354                         if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
355                                 continue;
356                         if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
357                                 continue;
358                         best_group = group;
359                         best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
360                 }
361                 if (best_group >= 0)
362                         return best_group;
363                 goto fallback;
364         }
365
366         blocks_per_dir = ext4_blocks_count(es) - freeb;
367         do_div(blocks_per_dir, ndirs);
368
369         max_dirs = ndirs / ngroups + inodes_per_group / 16;
370         min_inodes = avefreei - inodes_per_group / 4;
371         min_blocks = avefreeb - EXT4_BLOCKS_PER_GROUP(sb) / 4;
372
373         max_debt = EXT4_BLOCKS_PER_GROUP(sb);
374         max_debt /= max_t(int, blocks_per_dir, BLOCK_COST);
375         if (max_debt * INODE_COST > inodes_per_group)
376                 max_debt = inodes_per_group / INODE_COST;
377         if (max_debt > 255)
378                 max_debt = 255;
379         if (max_debt == 0)
380                 max_debt = 1;
381
382         for (i = 0; i < ngroups; i++) {
383                 group = (parent_group + i) % ngroups;
384                 desc = ext4_get_group_desc (sb, group, NULL);
385                 if (!desc || !desc->bg_free_inodes_count)
386                         continue;
387                 if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
388                         continue;
389                 if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
390                         continue;
391                 if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
392                         continue;
393                 return group;
394         }
395
396 fallback:
397         for (i = 0; i < ngroups; i++) {
398                 group = (parent_group + i) % ngroups;
399                 desc = ext4_get_group_desc (sb, group, NULL);
400                 if (!desc || !desc->bg_free_inodes_count)
401                         continue;
402                 if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
403                         return group;
404         }
405
406         if (avefreei) {
407                 /*
408                  * The free-inodes counter is approximate, and for really small
409                  * filesystems the above test can fail to find any blockgroups
410                  */
411                 avefreei = 0;
412                 goto fallback;
413         }
414
415         return -1;
416 }
417
418 static int find_group_other(struct super_block *sb, struct inode *parent)
419 {
420         int parent_group = EXT4_I(parent)->i_block_group;
421         int ngroups = EXT4_SB(sb)->s_groups_count;
422         struct ext4_group_desc *desc;
423         int group, i;
424
425         /*
426          * Try to place the inode in its parent directory
427          */
428         group = parent_group;
429         desc = ext4_get_group_desc (sb, group, NULL);
430         if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
431                         le16_to_cpu(desc->bg_free_blocks_count))
432                 return group;
433
434         /*
435          * We're going to place this inode in a different blockgroup from its
436          * parent.  We want to cause files in a common directory to all land in
437          * the same blockgroup.  But we want files which are in a different
438          * directory which shares a blockgroup with our parent to land in a
439          * different blockgroup.
440          *
441          * So add our directory's i_ino into the starting point for the hash.
442          */
443         group = (group + parent->i_ino) % ngroups;
444
445         /*
446          * Use a quadratic hash to find a group with a free inode and some free
447          * blocks.
448          */
449         for (i = 1; i < ngroups; i <<= 1) {
450                 group += i;
451                 if (group >= ngroups)
452                         group -= ngroups;
453                 desc = ext4_get_group_desc (sb, group, NULL);
454                 if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
455                                 le16_to_cpu(desc->bg_free_blocks_count))
456                         return group;
457         }
458
459         /*
460          * That failed: try linear search for a free inode, even if that group
461          * has no free blocks.
462          */
463         group = parent_group;
464         for (i = 0; i < ngroups; i++) {
465                 if (++group >= ngroups)
466                         group = 0;
467                 desc = ext4_get_group_desc (sb, group, NULL);
468                 if (desc && le16_to_cpu(desc->bg_free_inodes_count))
469                         return group;
470         }
471
472         return -1;
473 }
474
475 /*
476  * There are two policies for allocating an inode.  If the new inode is
477  * a directory, then a forward search is made for a block group with both
478  * free space and a low directory-to-inode ratio; if that fails, then of
479  * the groups with above-average free space, that group with the fewest
480  * directories already is chosen.
481  *
482  * For other inodes, search forward from the parent directory's block
483  * group to find a free inode.
484  */
485 struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
486 {
487         struct super_block *sb;
488         struct buffer_head *bitmap_bh = NULL;
489         struct buffer_head *bh2;
490         int group;
491         unsigned long ino = 0;
492         struct inode * inode;
493         struct ext4_group_desc * gdp = NULL;
494         struct ext4_super_block * es;
495         struct ext4_inode_info *ei;
496         struct ext4_sb_info *sbi;
497         int err = 0;
498         struct inode *ret;
499         int i, free = 0;
500
501         /* Cannot create files in a deleted directory */
502         if (!dir || !dir->i_nlink)
503                 return ERR_PTR(-EPERM);
504
505         sb = dir->i_sb;
506         inode = new_inode(sb);
507         if (!inode)
508                 return ERR_PTR(-ENOMEM);
509         ei = EXT4_I(inode);
510
511         sbi = EXT4_SB(sb);
512         es = sbi->s_es;
513         if (S_ISDIR(mode)) {
514                 if (test_opt (sb, OLDALLOC))
515                         group = find_group_dir(sb, dir);
516                 else
517                         group = find_group_orlov(sb, dir);
518         } else
519                 group = find_group_other(sb, dir);
520
521         err = -ENOSPC;
522         if (group == -1)
523                 goto out;
524
525         for (i = 0; i < sbi->s_groups_count; i++) {
526                 err = -EIO;
527
528                 gdp = ext4_get_group_desc(sb, group, &bh2);
529                 if (!gdp)
530                         goto fail;
531
532                 brelse(bitmap_bh);
533                 bitmap_bh = read_inode_bitmap(sb, group);
534                 if (!bitmap_bh)
535                         goto fail;
536
537                 ino = 0;
538
539 repeat_in_this_group:
540                 ino = ext4_find_next_zero_bit((unsigned long *)
541                                 bitmap_bh->b_data, EXT4_INODES_PER_GROUP(sb), ino);
542                 if (ino < EXT4_INODES_PER_GROUP(sb)) {
543
544                         BUFFER_TRACE(bitmap_bh, "get_write_access");
545                         err = ext4_journal_get_write_access(handle, bitmap_bh);
546                         if (err)
547                                 goto fail;
548
549                         if (!ext4_set_bit_atomic(sb_bgl_lock(sbi, group),
550                                                 ino, bitmap_bh->b_data)) {
551                                 /* we won it */
552                                 BUFFER_TRACE(bitmap_bh,
553                                         "call ext4_journal_dirty_metadata");
554                                 err = ext4_journal_dirty_metadata(handle,
555                                                                 bitmap_bh);
556                                 if (err)
557                                         goto fail;
558                                 goto got;
559                         }
560                         /* we lost it */
561                         jbd2_journal_release_buffer(handle, bitmap_bh);
562
563                         if (++ino < EXT4_INODES_PER_GROUP(sb))
564                                 goto repeat_in_this_group;
565                 }
566
567                 /*
568                  * This case is possible in concurrent environment.  It is very
569                  * rare.  We cannot repeat the find_group_xxx() call because
570                  * that will simply return the same blockgroup, because the
571                  * group descriptor metadata has not yet been updated.
572                  * So we just go onto the next blockgroup.
573                  */
574                 if (++group == sbi->s_groups_count)
575                         group = 0;
576         }
577         err = -ENOSPC;
578         goto out;
579
580 got:
581         ino++;
582         if ((group == 0 && ino < EXT4_FIRST_INO(sb)) ||
583             ino > EXT4_INODES_PER_GROUP(sb)) {
584                 ext4_error(sb, __FUNCTION__,
585                            "reserved inode or inode > inodes count - "
586                            "block_group = %d, inode=%lu", group,
587                            ino + group * EXT4_INODES_PER_GROUP(sb));
588                 err = -EIO;
589                 goto fail;
590         }
591
592         BUFFER_TRACE(bh2, "get_write_access");
593         err = ext4_journal_get_write_access(handle, bh2);
594         if (err) goto fail;
595
596         /* We may have to initialize the block bitmap if it isn't already */
597         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
598             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
599                 struct buffer_head *block_bh = read_block_bitmap(sb, group);
600
601                 BUFFER_TRACE(block_bh, "get block bitmap access");
602                 err = ext4_journal_get_write_access(handle, block_bh);
603                 if (err) {
604                         brelse(block_bh);
605                         goto fail;
606                 }
607
608                 free = 0;
609                 spin_lock(sb_bgl_lock(sbi, group));
610                 /* recheck and clear flag under lock if we still need to */
611                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
612                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
613                         free = ext4_free_blocks_after_init(sb, group, gdp);
614                         gdp->bg_free_blocks_count = cpu_to_le16(free);
615                 }
616                 spin_unlock(sb_bgl_lock(sbi, group));
617
618                 /* Don't need to dirty bitmap block if we didn't change it */
619                 if (free) {
620                         BUFFER_TRACE(block_bh, "dirty block bitmap");
621                         err = ext4_journal_dirty_metadata(handle, block_bh);
622                 }
623
624                 brelse(block_bh);
625                 if (err)
626                         goto fail;
627         }
628
629         spin_lock(sb_bgl_lock(sbi, group));
630         /* If we didn't allocate from within the initialized part of the inode
631          * table then we need to initialize up to this inode. */
632         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
633                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
634                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
635
636                         /* When marking the block group with
637                          * ~EXT4_BG_INODE_UNINIT we don't want to depend
638                          * on the value of bg_itable_unsed even though
639                          * mke2fs could have initialized the same for us.
640                          * Instead we calculated the value below
641                          */
642
643                         free = 0;
644                 } else {
645                         free = EXT4_INODES_PER_GROUP(sb) -
646                                 le16_to_cpu(gdp->bg_itable_unused);
647                 }
648
649                 /*
650                  * Check the relative inode number against the last used
651                  * relative inode number in this group. if it is greater
652                  * we need to  update the bg_itable_unused count
653                  *
654                  */
655                 if (ino > free)
656                         gdp->bg_itable_unused =
657                                 cpu_to_le16(EXT4_INODES_PER_GROUP(sb) - ino);
658         }
659
660         gdp->bg_free_inodes_count =
661                 cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
662         if (S_ISDIR(mode)) {
663                 gdp->bg_used_dirs_count =
664                         cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1);
665         }
666         gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
667         spin_unlock(sb_bgl_lock(sbi, group));
668         BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
669         err = ext4_journal_dirty_metadata(handle, bh2);
670         if (err) goto fail;
671
672         percpu_counter_dec(&sbi->s_freeinodes_counter);
673         if (S_ISDIR(mode))
674                 percpu_counter_inc(&sbi->s_dirs_counter);
675         sb->s_dirt = 1;
676
677         inode->i_uid = current->fsuid;
678         if (test_opt (sb, GRPID))
679                 inode->i_gid = dir->i_gid;
680         else if (dir->i_mode & S_ISGID) {
681                 inode->i_gid = dir->i_gid;
682                 if (S_ISDIR(mode))
683                         mode |= S_ISGID;
684         } else
685                 inode->i_gid = current->fsgid;
686         inode->i_mode = mode;
687
688         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
689         /* This is the optimal IO size (for stat), not the fs block size */
690         inode->i_blocks = 0;
691         inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
692                                                        ext4_current_time(inode);
693
694         memset(ei->i_data, 0, sizeof(ei->i_data));
695         ei->i_dir_start_lookup = 0;
696         ei->i_disksize = 0;
697
698         ei->i_flags = EXT4_I(dir)->i_flags & ~EXT4_INDEX_FL;
699         if (S_ISLNK(mode))
700                 ei->i_flags &= ~(EXT4_IMMUTABLE_FL|EXT4_APPEND_FL);
701         /* dirsync only applies to directories */
702         if (!S_ISDIR(mode))
703                 ei->i_flags &= ~EXT4_DIRSYNC_FL;
704         ei->i_file_acl = 0;
705         ei->i_dir_acl = 0;
706         ei->i_dtime = 0;
707         ei->i_block_alloc_info = NULL;
708         ei->i_block_group = group;
709
710         ext4_set_inode_flags(inode);
711         if (IS_DIRSYNC(inode))
712                 handle->h_sync = 1;
713         insert_inode_hash(inode);
714         spin_lock(&sbi->s_next_gen_lock);
715         inode->i_generation = sbi->s_next_generation++;
716         spin_unlock(&sbi->s_next_gen_lock);
717
718         ei->i_state = EXT4_STATE_NEW;
719
720         ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
721
722         ret = inode;
723         if(DQUOT_ALLOC_INODE(inode)) {
724                 err = -EDQUOT;
725                 goto fail_drop;
726         }
727
728         err = ext4_init_acl(handle, inode, dir);
729         if (err)
730                 goto fail_free_drop;
731
732         err = ext4_init_security(handle,inode, dir);
733         if (err)
734                 goto fail_free_drop;
735
736         err = ext4_mark_inode_dirty(handle, inode);
737         if (err) {
738                 ext4_std_error(sb, err);
739                 goto fail_free_drop;
740         }
741         if (test_opt(sb, EXTENTS)) {
742                 EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL;
743                 ext4_ext_tree_init(handle, inode);
744                 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
745                         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
746                         if (err) goto fail;
747                         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS);
748                         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "call ext4_journal_dirty_metadata");
749                         err = ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
750                 }
751         }
752
753         ext4_debug("allocating inode %lu\n", inode->i_ino);
754         goto really_out;
755 fail:
756         ext4_std_error(sb, err);
757 out:
758         iput(inode);
759         ret = ERR_PTR(err);
760 really_out:
761         brelse(bitmap_bh);
762         return ret;
763
764 fail_free_drop:
765         DQUOT_FREE_INODE(inode);
766
767 fail_drop:
768         DQUOT_DROP(inode);
769         inode->i_flags |= S_NOQUOTA;
770         inode->i_nlink = 0;
771         iput(inode);
772         brelse(bitmap_bh);
773         return ERR_PTR(err);
774 }
775
776 /* Verify that we are loading a valid orphan from disk */
777 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
778 {
779         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
780         unsigned long block_group;
781         int bit;
782         struct buffer_head *bitmap_bh = NULL;
783         struct inode *inode = NULL;
784
785         /* Error cases - e2fsck has already cleaned up for us */
786         if (ino > max_ino) {
787                 ext4_warning(sb, __FUNCTION__,
788                              "bad orphan ino %lu!  e2fsck was run?", ino);
789                 goto out;
790         }
791
792         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
793         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
794         bitmap_bh = read_inode_bitmap(sb, block_group);
795         if (!bitmap_bh) {
796                 ext4_warning(sb, __FUNCTION__,
797                              "inode bitmap error for orphan %lu", ino);
798                 goto out;
799         }
800
801         /* Having the inode bit set should be a 100% indicator that this
802          * is a valid orphan (no e2fsck run on fs).  Orphans also include
803          * inodes that were being truncated, so we can't check i_nlink==0.
804          */
805         if (!ext4_test_bit(bit, bitmap_bh->b_data) ||
806                         !(inode = iget(sb, ino)) || is_bad_inode(inode) ||
807                         NEXT_ORPHAN(inode) > max_ino) {
808                 ext4_warning(sb, __FUNCTION__,
809                              "bad orphan inode %lu!  e2fsck was run?", ino);
810                 printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n",
811                        bit, (unsigned long long)bitmap_bh->b_blocknr,
812                        ext4_test_bit(bit, bitmap_bh->b_data));
813                 printk(KERN_NOTICE "inode=%p\n", inode);
814                 if (inode) {
815                         printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
816                                is_bad_inode(inode));
817                         printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
818                                NEXT_ORPHAN(inode));
819                         printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
820                 }
821                 /* Avoid freeing blocks if we got a bad deleted inode */
822                 if (inode && inode->i_nlink == 0)
823                         inode->i_blocks = 0;
824                 iput(inode);
825                 inode = NULL;
826         }
827 out:
828         brelse(bitmap_bh);
829         return inode;
830 }
831
832 unsigned long ext4_count_free_inodes (struct super_block * sb)
833 {
834         unsigned long desc_count;
835         struct ext4_group_desc *gdp;
836         int i;
837 #ifdef EXT4FS_DEBUG
838         struct ext4_super_block *es;
839         unsigned long bitmap_count, x;
840         struct buffer_head *bitmap_bh = NULL;
841
842         es = EXT4_SB(sb)->s_es;
843         desc_count = 0;
844         bitmap_count = 0;
845         gdp = NULL;
846         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
847                 gdp = ext4_get_group_desc (sb, i, NULL);
848                 if (!gdp)
849                         continue;
850                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
851                 brelse(bitmap_bh);
852                 bitmap_bh = read_inode_bitmap(sb, i);
853                 if (!bitmap_bh)
854                         continue;
855
856                 x = ext4_count_free(bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8);
857                 printk("group %d: stored = %d, counted = %lu\n",
858                         i, le16_to_cpu(gdp->bg_free_inodes_count), x);
859                 bitmap_count += x;
860         }
861         brelse(bitmap_bh);
862         printk("ext4_count_free_inodes: stored = %u, computed = %lu, %lu\n",
863                 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
864         return desc_count;
865 #else
866         desc_count = 0;
867         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
868                 gdp = ext4_get_group_desc (sb, i, NULL);
869                 if (!gdp)
870                         continue;
871                 desc_count += le16_to_cpu(gdp->bg_free_inodes_count);
872                 cond_resched();
873         }
874         return desc_count;
875 #endif
876 }
877
878 /* Called at mount-time, super-block is locked */
879 unsigned long ext4_count_dirs (struct super_block * sb)
880 {
881         unsigned long count = 0;
882         int i;
883
884         for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
885                 struct ext4_group_desc *gdp = ext4_get_group_desc (sb, i, NULL);
886                 if (!gdp)
887                         continue;
888                 count += le16_to_cpu(gdp->bg_used_dirs_count);
889         }
890         return count;
891 }
892