Merge tag 'regmap-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie...
[sfrench/cifs-2.6.git] / 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/stat.h>
18 #include <linux/string.h>
19 #include <linux/quotaops.h>
20 #include <linux/buffer_head.h>
21 #include <linux/random.h>
22 #include <linux/bitops.h>
23 #include <linux/blkdev.h>
24 #include <asm/byteorder.h>
25
26 #include "ext4.h"
27 #include "ext4_jbd2.h"
28 #include "xattr.h"
29 #include "acl.h"
30
31 #include <trace/events/ext4.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 ext4_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 static int ext4_init_inode_bitmap(struct super_block *sb,
68                                        struct buffer_head *bh,
69                                        ext4_group_t block_group,
70                                        struct ext4_group_desc *gdp)
71 {
72         struct ext4_group_info *grp;
73         struct ext4_sb_info *sbi = EXT4_SB(sb);
74         J_ASSERT_BH(bh, buffer_locked(bh));
75
76         /* If checksum is bad mark all blocks and inodes use to prevent
77          * allocation, essentially implementing a per-group read-only flag. */
78         if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
79                 grp = ext4_get_group_info(sb, block_group);
80                 if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
81                         percpu_counter_sub(&sbi->s_freeclusters_counter,
82                                            grp->bb_free);
83                 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
84                 if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
85                         int count;
86                         count = ext4_free_inodes_count(sb, gdp);
87                         percpu_counter_sub(&sbi->s_freeinodes_counter,
88                                            count);
89                 }
90                 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
91                 return -EFSBADCRC;
92         }
93
94         memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
95         ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
96                         bh->b_data);
97         ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
98                                    EXT4_INODES_PER_GROUP(sb) / 8);
99         ext4_group_desc_csum_set(sb, block_group, gdp);
100
101         return 0;
102 }
103
104 void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
105 {
106         if (uptodate) {
107                 set_buffer_uptodate(bh);
108                 set_bitmap_uptodate(bh);
109         }
110         unlock_buffer(bh);
111         put_bh(bh);
112 }
113
114 static int ext4_validate_inode_bitmap(struct super_block *sb,
115                                       struct ext4_group_desc *desc,
116                                       ext4_group_t block_group,
117                                       struct buffer_head *bh)
118 {
119         ext4_fsblk_t    blk;
120         struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
121         struct ext4_sb_info *sbi = EXT4_SB(sb);
122
123         if (buffer_verified(bh))
124                 return 0;
125         if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
126                 return -EFSCORRUPTED;
127
128         ext4_lock_group(sb, block_group);
129         blk = ext4_inode_bitmap(sb, desc);
130         if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
131                                            EXT4_INODES_PER_GROUP(sb) / 8)) {
132                 ext4_unlock_group(sb, block_group);
133                 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
134                            "inode_bitmap = %llu", block_group, blk);
135                 grp = ext4_get_group_info(sb, block_group);
136                 if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
137                         int count;
138                         count = ext4_free_inodes_count(sb, desc);
139                         percpu_counter_sub(&sbi->s_freeinodes_counter,
140                                            count);
141                 }
142                 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
143                 return -EFSBADCRC;
144         }
145         set_buffer_verified(bh);
146         ext4_unlock_group(sb, block_group);
147         return 0;
148 }
149
150 /*
151  * Read the inode allocation bitmap for a given block_group, reading
152  * into the specified slot in the superblock's bitmap cache.
153  *
154  * Return buffer_head of bitmap on success or NULL.
155  */
156 static struct buffer_head *
157 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
158 {
159         struct ext4_group_desc *desc;
160         struct buffer_head *bh = NULL;
161         ext4_fsblk_t bitmap_blk;
162         int err;
163
164         desc = ext4_get_group_desc(sb, block_group, NULL);
165         if (!desc)
166                 return ERR_PTR(-EFSCORRUPTED);
167
168         bitmap_blk = ext4_inode_bitmap(sb, desc);
169         bh = sb_getblk(sb, bitmap_blk);
170         if (unlikely(!bh)) {
171                 ext4_error(sb, "Cannot read inode bitmap - "
172                             "block_group = %u, inode_bitmap = %llu",
173                             block_group, bitmap_blk);
174                 return ERR_PTR(-EIO);
175         }
176         if (bitmap_uptodate(bh))
177                 goto verify;
178
179         lock_buffer(bh);
180         if (bitmap_uptodate(bh)) {
181                 unlock_buffer(bh);
182                 goto verify;
183         }
184
185         ext4_lock_group(sb, block_group);
186         if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
187                 err = ext4_init_inode_bitmap(sb, bh, block_group, desc);
188                 set_bitmap_uptodate(bh);
189                 set_buffer_uptodate(bh);
190                 set_buffer_verified(bh);
191                 ext4_unlock_group(sb, block_group);
192                 unlock_buffer(bh);
193                 if (err) {
194                         ext4_error(sb, "Failed to init inode bitmap for group "
195                                    "%u: %d", block_group, err);
196                         goto out;
197                 }
198                 return bh;
199         }
200         ext4_unlock_group(sb, block_group);
201
202         if (buffer_uptodate(bh)) {
203                 /*
204                  * if not uninit if bh is uptodate,
205                  * bitmap is also uptodate
206                  */
207                 set_bitmap_uptodate(bh);
208                 unlock_buffer(bh);
209                 goto verify;
210         }
211         /*
212          * submit the buffer_head for reading
213          */
214         trace_ext4_load_inode_bitmap(sb, block_group);
215         bh->b_end_io = ext4_end_bitmap_read;
216         get_bh(bh);
217         submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
218         wait_on_buffer(bh);
219         if (!buffer_uptodate(bh)) {
220                 put_bh(bh);
221                 ext4_error(sb, "Cannot read inode bitmap - "
222                            "block_group = %u, inode_bitmap = %llu",
223                            block_group, bitmap_blk);
224                 return ERR_PTR(-EIO);
225         }
226
227 verify:
228         err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
229         if (err)
230                 goto out;
231         return bh;
232 out:
233         put_bh(bh);
234         return ERR_PTR(err);
235 }
236
237 /*
238  * NOTE! When we get the inode, we're the only people
239  * that have access to it, and as such there are no
240  * race conditions we have to worry about. The inode
241  * is not on the hash-lists, and it cannot be reached
242  * through the filesystem because the directory entry
243  * has been deleted earlier.
244  *
245  * HOWEVER: we must make sure that we get no aliases,
246  * which means that we have to call "clear_inode()"
247  * _before_ we mark the inode not in use in the inode
248  * bitmaps. Otherwise a newly created file might use
249  * the same inode number (not actually the same pointer
250  * though), and then we'd have two inodes sharing the
251  * same inode number and space on the harddisk.
252  */
253 void ext4_free_inode(handle_t *handle, struct inode *inode)
254 {
255         struct super_block *sb = inode->i_sb;
256         int is_directory;
257         unsigned long ino;
258         struct buffer_head *bitmap_bh = NULL;
259         struct buffer_head *bh2;
260         ext4_group_t block_group;
261         unsigned long bit;
262         struct ext4_group_desc *gdp;
263         struct ext4_super_block *es;
264         struct ext4_sb_info *sbi;
265         int fatal = 0, err, count, cleared;
266         struct ext4_group_info *grp;
267
268         if (!sb) {
269                 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
270                        "nonexistent device\n", __func__, __LINE__);
271                 return;
272         }
273         if (atomic_read(&inode->i_count) > 1) {
274                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
275                          __func__, __LINE__, inode->i_ino,
276                          atomic_read(&inode->i_count));
277                 return;
278         }
279         if (inode->i_nlink) {
280                 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
281                          __func__, __LINE__, inode->i_ino, inode->i_nlink);
282                 return;
283         }
284         sbi = EXT4_SB(sb);
285
286         ino = inode->i_ino;
287         ext4_debug("freeing inode %lu\n", ino);
288         trace_ext4_free_inode(inode);
289
290         /*
291          * Note: we must free any quota before locking the superblock,
292          * as writing the quota to disk may need the lock as well.
293          */
294         dquot_initialize(inode);
295         ext4_xattr_delete_inode(handle, inode);
296         dquot_free_inode(inode);
297         dquot_drop(inode);
298
299         is_directory = S_ISDIR(inode->i_mode);
300
301         /* Do this BEFORE marking the inode not in use or returning an error */
302         ext4_clear_inode(inode);
303
304         es = EXT4_SB(sb)->s_es;
305         if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
306                 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
307                 goto error_return;
308         }
309         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
310         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
311         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
312         /* Don't bother if the inode bitmap is corrupt. */
313         grp = ext4_get_group_info(sb, block_group);
314         if (IS_ERR(bitmap_bh)) {
315                 fatal = PTR_ERR(bitmap_bh);
316                 bitmap_bh = NULL;
317                 goto error_return;
318         }
319         if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
320                 fatal = -EFSCORRUPTED;
321                 goto error_return;
322         }
323
324         BUFFER_TRACE(bitmap_bh, "get_write_access");
325         fatal = ext4_journal_get_write_access(handle, bitmap_bh);
326         if (fatal)
327                 goto error_return;
328
329         fatal = -ESRCH;
330         gdp = ext4_get_group_desc(sb, block_group, &bh2);
331         if (gdp) {
332                 BUFFER_TRACE(bh2, "get_write_access");
333                 fatal = ext4_journal_get_write_access(handle, bh2);
334         }
335         ext4_lock_group(sb, block_group);
336         cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
337         if (fatal || !cleared) {
338                 ext4_unlock_group(sb, block_group);
339                 goto out;
340         }
341
342         count = ext4_free_inodes_count(sb, gdp) + 1;
343         ext4_free_inodes_set(sb, gdp, count);
344         if (is_directory) {
345                 count = ext4_used_dirs_count(sb, gdp) - 1;
346                 ext4_used_dirs_set(sb, gdp, count);
347                 percpu_counter_dec(&sbi->s_dirs_counter);
348         }
349         ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
350                                    EXT4_INODES_PER_GROUP(sb) / 8);
351         ext4_group_desc_csum_set(sb, block_group, gdp);
352         ext4_unlock_group(sb, block_group);
353
354         percpu_counter_inc(&sbi->s_freeinodes_counter);
355         if (sbi->s_log_groups_per_flex) {
356                 ext4_group_t f = ext4_flex_group(sbi, block_group);
357
358                 atomic_inc(&sbi->s_flex_groups[f].free_inodes);
359                 if (is_directory)
360                         atomic_dec(&sbi->s_flex_groups[f].used_dirs);
361         }
362         BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
363         fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
364 out:
365         if (cleared) {
366                 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
367                 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
368                 if (!fatal)
369                         fatal = err;
370         } else {
371                 ext4_error(sb, "bit already cleared for inode %lu", ino);
372                 if (gdp && !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
373                         int count;
374                         count = ext4_free_inodes_count(sb, gdp);
375                         percpu_counter_sub(&sbi->s_freeinodes_counter,
376                                            count);
377                 }
378                 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
379         }
380
381 error_return:
382         brelse(bitmap_bh);
383         ext4_std_error(sb, fatal);
384 }
385
386 struct orlov_stats {
387         __u64 free_clusters;
388         __u32 free_inodes;
389         __u32 used_dirs;
390 };
391
392 /*
393  * Helper function for Orlov's allocator; returns critical information
394  * for a particular block group or flex_bg.  If flex_size is 1, then g
395  * is a block group number; otherwise it is flex_bg number.
396  */
397 static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
398                             int flex_size, struct orlov_stats *stats)
399 {
400         struct ext4_group_desc *desc;
401         struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups;
402
403         if (flex_size > 1) {
404                 stats->free_inodes = atomic_read(&flex_group[g].free_inodes);
405                 stats->free_clusters = atomic64_read(&flex_group[g].free_clusters);
406                 stats->used_dirs = atomic_read(&flex_group[g].used_dirs);
407                 return;
408         }
409
410         desc = ext4_get_group_desc(sb, g, NULL);
411         if (desc) {
412                 stats->free_inodes = ext4_free_inodes_count(sb, desc);
413                 stats->free_clusters = ext4_free_group_clusters(sb, desc);
414                 stats->used_dirs = ext4_used_dirs_count(sb, desc);
415         } else {
416                 stats->free_inodes = 0;
417                 stats->free_clusters = 0;
418                 stats->used_dirs = 0;
419         }
420 }
421
422 /*
423  * Orlov's allocator for directories.
424  *
425  * We always try to spread first-level directories.
426  *
427  * If there are blockgroups with both free inodes and free blocks counts
428  * not worse than average we return one with smallest directory count.
429  * Otherwise we simply return a random group.
430  *
431  * For the rest rules look so:
432  *
433  * It's OK to put directory into a group unless
434  * it has too many directories already (max_dirs) or
435  * it has too few free inodes left (min_inodes) or
436  * it has too few free blocks left (min_blocks) or
437  * Parent's group is preferred, if it doesn't satisfy these
438  * conditions we search cyclically through the rest. If none
439  * of the groups look good we just look for a group with more
440  * free inodes than average (starting at parent's group).
441  */
442
443 static int find_group_orlov(struct super_block *sb, struct inode *parent,
444                             ext4_group_t *group, umode_t mode,
445                             const struct qstr *qstr)
446 {
447         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
448         struct ext4_sb_info *sbi = EXT4_SB(sb);
449         ext4_group_t real_ngroups = ext4_get_groups_count(sb);
450         int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
451         unsigned int freei, avefreei, grp_free;
452         ext4_fsblk_t freeb, avefreec;
453         unsigned int ndirs;
454         int max_dirs, min_inodes;
455         ext4_grpblk_t min_clusters;
456         ext4_group_t i, grp, g, ngroups;
457         struct ext4_group_desc *desc;
458         struct orlov_stats stats;
459         int flex_size = ext4_flex_bg_size(sbi);
460         struct dx_hash_info hinfo;
461
462         ngroups = real_ngroups;
463         if (flex_size > 1) {
464                 ngroups = (real_ngroups + flex_size - 1) >>
465                         sbi->s_log_groups_per_flex;
466                 parent_group >>= sbi->s_log_groups_per_flex;
467         }
468
469         freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
470         avefreei = freei / ngroups;
471         freeb = EXT4_C2B(sbi,
472                 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
473         avefreec = freeb;
474         do_div(avefreec, ngroups);
475         ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
476
477         if (S_ISDIR(mode) &&
478             ((parent == d_inode(sb->s_root)) ||
479              (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
480                 int best_ndir = inodes_per_group;
481                 int ret = -1;
482
483                 if (qstr) {
484                         hinfo.hash_version = DX_HASH_HALF_MD4;
485                         hinfo.seed = sbi->s_hash_seed;
486                         ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
487                         grp = hinfo.hash;
488                 } else
489                         grp = prandom_u32();
490                 parent_group = (unsigned)grp % ngroups;
491                 for (i = 0; i < ngroups; i++) {
492                         g = (parent_group + i) % ngroups;
493                         get_orlov_stats(sb, g, flex_size, &stats);
494                         if (!stats.free_inodes)
495                                 continue;
496                         if (stats.used_dirs >= best_ndir)
497                                 continue;
498                         if (stats.free_inodes < avefreei)
499                                 continue;
500                         if (stats.free_clusters < avefreec)
501                                 continue;
502                         grp = g;
503                         ret = 0;
504                         best_ndir = stats.used_dirs;
505                 }
506                 if (ret)
507                         goto fallback;
508         found_flex_bg:
509                 if (flex_size == 1) {
510                         *group = grp;
511                         return 0;
512                 }
513
514                 /*
515                  * We pack inodes at the beginning of the flexgroup's
516                  * inode tables.  Block allocation decisions will do
517                  * something similar, although regular files will
518                  * start at 2nd block group of the flexgroup.  See
519                  * ext4_ext_find_goal() and ext4_find_near().
520                  */
521                 grp *= flex_size;
522                 for (i = 0; i < flex_size; i++) {
523                         if (grp+i >= real_ngroups)
524                                 break;
525                         desc = ext4_get_group_desc(sb, grp+i, NULL);
526                         if (desc && ext4_free_inodes_count(sb, desc)) {
527                                 *group = grp+i;
528                                 return 0;
529                         }
530                 }
531                 goto fallback;
532         }
533
534         max_dirs = ndirs / ngroups + inodes_per_group / 16;
535         min_inodes = avefreei - inodes_per_group*flex_size / 4;
536         if (min_inodes < 1)
537                 min_inodes = 1;
538         min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
539
540         /*
541          * Start looking in the flex group where we last allocated an
542          * inode for this parent directory
543          */
544         if (EXT4_I(parent)->i_last_alloc_group != ~0) {
545                 parent_group = EXT4_I(parent)->i_last_alloc_group;
546                 if (flex_size > 1)
547                         parent_group >>= sbi->s_log_groups_per_flex;
548         }
549
550         for (i = 0; i < ngroups; i++) {
551                 grp = (parent_group + i) % ngroups;
552                 get_orlov_stats(sb, grp, flex_size, &stats);
553                 if (stats.used_dirs >= max_dirs)
554                         continue;
555                 if (stats.free_inodes < min_inodes)
556                         continue;
557                 if (stats.free_clusters < min_clusters)
558                         continue;
559                 goto found_flex_bg;
560         }
561
562 fallback:
563         ngroups = real_ngroups;
564         avefreei = freei / ngroups;
565 fallback_retry:
566         parent_group = EXT4_I(parent)->i_block_group;
567         for (i = 0; i < ngroups; i++) {
568                 grp = (parent_group + i) % ngroups;
569                 desc = ext4_get_group_desc(sb, grp, NULL);
570                 if (desc) {
571                         grp_free = ext4_free_inodes_count(sb, desc);
572                         if (grp_free && grp_free >= avefreei) {
573                                 *group = grp;
574                                 return 0;
575                         }
576                 }
577         }
578
579         if (avefreei) {
580                 /*
581                  * The free-inodes counter is approximate, and for really small
582                  * filesystems the above test can fail to find any blockgroups
583                  */
584                 avefreei = 0;
585                 goto fallback_retry;
586         }
587
588         return -1;
589 }
590
591 static int find_group_other(struct super_block *sb, struct inode *parent,
592                             ext4_group_t *group, umode_t mode)
593 {
594         ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
595         ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
596         struct ext4_group_desc *desc;
597         int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
598
599         /*
600          * Try to place the inode is the same flex group as its
601          * parent.  If we can't find space, use the Orlov algorithm to
602          * find another flex group, and store that information in the
603          * parent directory's inode information so that use that flex
604          * group for future allocations.
605          */
606         if (flex_size > 1) {
607                 int retry = 0;
608
609         try_again:
610                 parent_group &= ~(flex_size-1);
611                 last = parent_group + flex_size;
612                 if (last > ngroups)
613                         last = ngroups;
614                 for  (i = parent_group; i < last; i++) {
615                         desc = ext4_get_group_desc(sb, i, NULL);
616                         if (desc && ext4_free_inodes_count(sb, desc)) {
617                                 *group = i;
618                                 return 0;
619                         }
620                 }
621                 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
622                         retry = 1;
623                         parent_group = EXT4_I(parent)->i_last_alloc_group;
624                         goto try_again;
625                 }
626                 /*
627                  * If this didn't work, use the Orlov search algorithm
628                  * to find a new flex group; we pass in the mode to
629                  * avoid the topdir algorithms.
630                  */
631                 *group = parent_group + flex_size;
632                 if (*group > ngroups)
633                         *group = 0;
634                 return find_group_orlov(sb, parent, group, mode, NULL);
635         }
636
637         /*
638          * Try to place the inode in its parent directory
639          */
640         *group = parent_group;
641         desc = ext4_get_group_desc(sb, *group, NULL);
642         if (desc && ext4_free_inodes_count(sb, desc) &&
643             ext4_free_group_clusters(sb, desc))
644                 return 0;
645
646         /*
647          * We're going to place this inode in a different blockgroup from its
648          * parent.  We want to cause files in a common directory to all land in
649          * the same blockgroup.  But we want files which are in a different
650          * directory which shares a blockgroup with our parent to land in a
651          * different blockgroup.
652          *
653          * So add our directory's i_ino into the starting point for the hash.
654          */
655         *group = (*group + parent->i_ino) % ngroups;
656
657         /*
658          * Use a quadratic hash to find a group with a free inode and some free
659          * blocks.
660          */
661         for (i = 1; i < ngroups; i <<= 1) {
662                 *group += i;
663                 if (*group >= ngroups)
664                         *group -= ngroups;
665                 desc = ext4_get_group_desc(sb, *group, NULL);
666                 if (desc && ext4_free_inodes_count(sb, desc) &&
667                     ext4_free_group_clusters(sb, desc))
668                         return 0;
669         }
670
671         /*
672          * That failed: try linear search for a free inode, even if that group
673          * has no free blocks.
674          */
675         *group = parent_group;
676         for (i = 0; i < ngroups; i++) {
677                 if (++*group >= ngroups)
678                         *group = 0;
679                 desc = ext4_get_group_desc(sb, *group, NULL);
680                 if (desc && ext4_free_inodes_count(sb, desc))
681                         return 0;
682         }
683
684         return -1;
685 }
686
687 /*
688  * In no journal mode, if an inode has recently been deleted, we want
689  * to avoid reusing it until we're reasonably sure the inode table
690  * block has been written back to disk.  (Yes, these values are
691  * somewhat arbitrary...)
692  */
693 #define RECENTCY_MIN    5
694 #define RECENTCY_DIRTY  30
695
696 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
697 {
698         struct ext4_group_desc  *gdp;
699         struct ext4_inode       *raw_inode;
700         struct buffer_head      *bh;
701         unsigned long           dtime, now;
702         int     inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
703         int     offset, ret = 0, recentcy = RECENTCY_MIN;
704
705         gdp = ext4_get_group_desc(sb, group, NULL);
706         if (unlikely(!gdp))
707                 return 0;
708
709         bh = sb_getblk(sb, ext4_inode_table(sb, gdp) +
710                        (ino / inodes_per_block));
711         if (unlikely(!bh) || !buffer_uptodate(bh))
712                 /*
713                  * If the block is not in the buffer cache, then it
714                  * must have been written out.
715                  */
716                 goto out;
717
718         offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
719         raw_inode = (struct ext4_inode *) (bh->b_data + offset);
720         dtime = le32_to_cpu(raw_inode->i_dtime);
721         now = get_seconds();
722         if (buffer_dirty(bh))
723                 recentcy += RECENTCY_DIRTY;
724
725         if (dtime && (dtime < now) && (now < dtime + recentcy))
726                 ret = 1;
727 out:
728         brelse(bh);
729         return ret;
730 }
731
732 /*
733  * There are two policies for allocating an inode.  If the new inode is
734  * a directory, then a forward search is made for a block group with both
735  * free space and a low directory-to-inode ratio; if that fails, then of
736  * the groups with above-average free space, that group with the fewest
737  * directories already is chosen.
738  *
739  * For other inodes, search forward from the parent directory's block
740  * group to find a free inode.
741  */
742 struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
743                                umode_t mode, const struct qstr *qstr,
744                                __u32 goal, uid_t *owner, int handle_type,
745                                unsigned int line_no, int nblocks)
746 {
747         struct super_block *sb;
748         struct buffer_head *inode_bitmap_bh = NULL;
749         struct buffer_head *group_desc_bh;
750         ext4_group_t ngroups, group = 0;
751         unsigned long ino = 0;
752         struct inode *inode;
753         struct ext4_group_desc *gdp = NULL;
754         struct ext4_inode_info *ei;
755         struct ext4_sb_info *sbi;
756         int ret2, err;
757         struct inode *ret;
758         ext4_group_t i;
759         ext4_group_t flex_group;
760         struct ext4_group_info *grp;
761         int encrypt = 0;
762
763         /* Cannot create files in a deleted directory */
764         if (!dir || !dir->i_nlink)
765                 return ERR_PTR(-EPERM);
766
767         if ((ext4_encrypted_inode(dir) ||
768              DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) &&
769             (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
770                 err = fscrypt_get_encryption_info(dir);
771                 if (err)
772                         return ERR_PTR(err);
773                 if (!fscrypt_has_encryption_key(dir))
774                         return ERR_PTR(-EPERM);
775                 if (!handle)
776                         nblocks += EXT4_DATA_TRANS_BLOCKS(dir->i_sb);
777                 encrypt = 1;
778         }
779
780         sb = dir->i_sb;
781         ngroups = ext4_get_groups_count(sb);
782         trace_ext4_request_inode(dir, mode);
783         inode = new_inode(sb);
784         if (!inode)
785                 return ERR_PTR(-ENOMEM);
786         ei = EXT4_I(inode);
787         sbi = EXT4_SB(sb);
788
789         /*
790          * Initialize owners and quota early so that we don't have to account
791          * for quota initialization worst case in standard inode creating
792          * transaction
793          */
794         if (owner) {
795                 inode->i_mode = mode;
796                 i_uid_write(inode, owner[0]);
797                 i_gid_write(inode, owner[1]);
798         } else if (test_opt(sb, GRPID)) {
799                 inode->i_mode = mode;
800                 inode->i_uid = current_fsuid();
801                 inode->i_gid = dir->i_gid;
802         } else
803                 inode_init_owner(inode, dir, mode);
804
805         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_PROJECT) &&
806             ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
807                 ei->i_projid = EXT4_I(dir)->i_projid;
808         else
809                 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
810
811         err = dquot_initialize(inode);
812         if (err)
813                 goto out;
814
815         if (!goal)
816                 goal = sbi->s_inode_goal;
817
818         if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
819                 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
820                 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
821                 ret2 = 0;
822                 goto got_group;
823         }
824
825         if (S_ISDIR(mode))
826                 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
827         else
828                 ret2 = find_group_other(sb, dir, &group, mode);
829
830 got_group:
831         EXT4_I(dir)->i_last_alloc_group = group;
832         err = -ENOSPC;
833         if (ret2 == -1)
834                 goto out;
835
836         /*
837          * Normally we will only go through one pass of this loop,
838          * unless we get unlucky and it turns out the group we selected
839          * had its last inode grabbed by someone else.
840          */
841         for (i = 0; i < ngroups; i++, ino = 0) {
842                 err = -EIO;
843
844                 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
845                 if (!gdp)
846                         goto out;
847
848                 /*
849                  * Check free inodes count before loading bitmap.
850                  */
851                 if (ext4_free_inodes_count(sb, gdp) == 0) {
852                         if (++group == ngroups)
853                                 group = 0;
854                         continue;
855                 }
856
857                 grp = ext4_get_group_info(sb, group);
858                 /* Skip groups with already-known suspicious inode tables */
859                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
860                         if (++group == ngroups)
861                                 group = 0;
862                         continue;
863                 }
864
865                 brelse(inode_bitmap_bh);
866                 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
867                 /* Skip groups with suspicious inode tables */
868                 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
869                     IS_ERR(inode_bitmap_bh)) {
870                         inode_bitmap_bh = NULL;
871                         if (++group == ngroups)
872                                 group = 0;
873                         continue;
874                 }
875
876 repeat_in_this_group:
877                 ino = ext4_find_next_zero_bit((unsigned long *)
878                                               inode_bitmap_bh->b_data,
879                                               EXT4_INODES_PER_GROUP(sb), ino);
880                 if (ino >= EXT4_INODES_PER_GROUP(sb))
881                         goto next_group;
882                 if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) {
883                         ext4_error(sb, "reserved inode found cleared - "
884                                    "inode=%lu", ino + 1);
885                         continue;
886                 }
887                 if ((EXT4_SB(sb)->s_journal == NULL) &&
888                     recently_deleted(sb, group, ino)) {
889                         ino++;
890                         goto next_inode;
891                 }
892                 if (!handle) {
893                         BUG_ON(nblocks <= 0);
894                         handle = __ext4_journal_start_sb(dir->i_sb, line_no,
895                                                          handle_type, nblocks,
896                                                          0);
897                         if (IS_ERR(handle)) {
898                                 err = PTR_ERR(handle);
899                                 ext4_std_error(sb, err);
900                                 goto out;
901                         }
902                 }
903                 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
904                 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
905                 if (err) {
906                         ext4_std_error(sb, err);
907                         goto out;
908                 }
909                 ext4_lock_group(sb, group);
910                 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
911                 ext4_unlock_group(sb, group);
912                 ino++;          /* the inode bitmap is zero-based */
913                 if (!ret2)
914                         goto got; /* we grabbed the inode! */
915 next_inode:
916                 if (ino < EXT4_INODES_PER_GROUP(sb))
917                         goto repeat_in_this_group;
918 next_group:
919                 if (++group == ngroups)
920                         group = 0;
921         }
922         err = -ENOSPC;
923         goto out;
924
925 got:
926         BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
927         err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
928         if (err) {
929                 ext4_std_error(sb, err);
930                 goto out;
931         }
932
933         BUFFER_TRACE(group_desc_bh, "get_write_access");
934         err = ext4_journal_get_write_access(handle, group_desc_bh);
935         if (err) {
936                 ext4_std_error(sb, err);
937                 goto out;
938         }
939
940         /* We may have to initialize the block bitmap if it isn't already */
941         if (ext4_has_group_desc_csum(sb) &&
942             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
943                 struct buffer_head *block_bitmap_bh;
944
945                 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
946                 if (IS_ERR(block_bitmap_bh)) {
947                         err = PTR_ERR(block_bitmap_bh);
948                         goto out;
949                 }
950                 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
951                 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
952                 if (err) {
953                         brelse(block_bitmap_bh);
954                         ext4_std_error(sb, err);
955                         goto out;
956                 }
957
958                 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
959                 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
960
961                 /* recheck and clear flag under lock if we still need to */
962                 ext4_lock_group(sb, group);
963                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
964                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
965                         ext4_free_group_clusters_set(sb, gdp,
966                                 ext4_free_clusters_after_init(sb, group, gdp));
967                         ext4_block_bitmap_csum_set(sb, group, gdp,
968                                                    block_bitmap_bh);
969                         ext4_group_desc_csum_set(sb, group, gdp);
970                 }
971                 ext4_unlock_group(sb, group);
972                 brelse(block_bitmap_bh);
973
974                 if (err) {
975                         ext4_std_error(sb, err);
976                         goto out;
977                 }
978         }
979
980         /* Update the relevant bg descriptor fields */
981         if (ext4_has_group_desc_csum(sb)) {
982                 int free;
983                 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
984
985                 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
986                 ext4_lock_group(sb, group); /* while we modify the bg desc */
987                 free = EXT4_INODES_PER_GROUP(sb) -
988                         ext4_itable_unused_count(sb, gdp);
989                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
990                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
991                         free = 0;
992                 }
993                 /*
994                  * Check the relative inode number against the last used
995                  * relative inode number in this group. if it is greater
996                  * we need to update the bg_itable_unused count
997                  */
998                 if (ino > free)
999                         ext4_itable_unused_set(sb, gdp,
1000                                         (EXT4_INODES_PER_GROUP(sb) - ino));
1001                 up_read(&grp->alloc_sem);
1002         } else {
1003                 ext4_lock_group(sb, group);
1004         }
1005
1006         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1007         if (S_ISDIR(mode)) {
1008                 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1009                 if (sbi->s_log_groups_per_flex) {
1010                         ext4_group_t f = ext4_flex_group(sbi, group);
1011
1012                         atomic_inc(&sbi->s_flex_groups[f].used_dirs);
1013                 }
1014         }
1015         if (ext4_has_group_desc_csum(sb)) {
1016                 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1017                                            EXT4_INODES_PER_GROUP(sb) / 8);
1018                 ext4_group_desc_csum_set(sb, group, gdp);
1019         }
1020         ext4_unlock_group(sb, group);
1021
1022         BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1023         err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1024         if (err) {
1025                 ext4_std_error(sb, err);
1026                 goto out;
1027         }
1028
1029         percpu_counter_dec(&sbi->s_freeinodes_counter);
1030         if (S_ISDIR(mode))
1031                 percpu_counter_inc(&sbi->s_dirs_counter);
1032
1033         if (sbi->s_log_groups_per_flex) {
1034                 flex_group = ext4_flex_group(sbi, group);
1035                 atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes);
1036         }
1037
1038         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1039         /* This is the optimal IO size (for stat), not the fs block size */
1040         inode->i_blocks = 0;
1041         inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
1042                                                        ext4_current_time(inode);
1043
1044         memset(ei->i_data, 0, sizeof(ei->i_data));
1045         ei->i_dir_start_lookup = 0;
1046         ei->i_disksize = 0;
1047
1048         /* Don't inherit extent flag from directory, amongst others. */
1049         ei->i_flags =
1050                 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1051         ei->i_file_acl = 0;
1052         ei->i_dtime = 0;
1053         ei->i_block_group = group;
1054         ei->i_last_alloc_group = ~0;
1055
1056         ext4_set_inode_flags(inode);
1057         if (IS_DIRSYNC(inode))
1058                 ext4_handle_sync(handle);
1059         if (insert_inode_locked(inode) < 0) {
1060                 /*
1061                  * Likely a bitmap corruption causing inode to be allocated
1062                  * twice.
1063                  */
1064                 err = -EIO;
1065                 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1066                            inode->i_ino);
1067                 goto out;
1068         }
1069         spin_lock(&sbi->s_next_gen_lock);
1070         inode->i_generation = sbi->s_next_generation++;
1071         spin_unlock(&sbi->s_next_gen_lock);
1072
1073         /* Precompute checksum seed for inode metadata */
1074         if (ext4_has_metadata_csum(sb)) {
1075                 __u32 csum;
1076                 __le32 inum = cpu_to_le32(inode->i_ino);
1077                 __le32 gen = cpu_to_le32(inode->i_generation);
1078                 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1079                                    sizeof(inum));
1080                 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1081                                               sizeof(gen));
1082         }
1083
1084         ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1085         ext4_set_inode_state(inode, EXT4_STATE_NEW);
1086
1087         ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
1088         ei->i_inline_off = 0;
1089         if (ext4_has_feature_inline_data(sb))
1090                 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1091         ret = inode;
1092         err = dquot_alloc_inode(inode);
1093         if (err)
1094                 goto fail_drop;
1095
1096         err = ext4_init_acl(handle, inode, dir);
1097         if (err)
1098                 goto fail_free_drop;
1099
1100         err = ext4_init_security(handle, inode, dir, qstr);
1101         if (err)
1102                 goto fail_free_drop;
1103
1104         if (ext4_has_feature_extents(sb)) {
1105                 /* set extent flag only for directory, file and normal symlink*/
1106                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1107                         ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1108                         ext4_ext_tree_init(handle, inode);
1109                 }
1110         }
1111
1112         if (ext4_handle_valid(handle)) {
1113                 ei->i_sync_tid = handle->h_transaction->t_tid;
1114                 ei->i_datasync_tid = handle->h_transaction->t_tid;
1115         }
1116
1117         if (encrypt) {
1118                 /* give pointer to avoid set_context with journal ops. */
1119                 err = fscrypt_inherit_context(dir, inode, &encrypt, true);
1120                 if (err)
1121                         goto fail_free_drop;
1122         }
1123
1124         err = ext4_mark_inode_dirty(handle, inode);
1125         if (err) {
1126                 ext4_std_error(sb, err);
1127                 goto fail_free_drop;
1128         }
1129
1130         ext4_debug("allocating inode %lu\n", inode->i_ino);
1131         trace_ext4_allocate_inode(inode, dir, mode);
1132         brelse(inode_bitmap_bh);
1133         return ret;
1134
1135 fail_free_drop:
1136         dquot_free_inode(inode);
1137 fail_drop:
1138         clear_nlink(inode);
1139         unlock_new_inode(inode);
1140 out:
1141         dquot_drop(inode);
1142         inode->i_flags |= S_NOQUOTA;
1143         iput(inode);
1144         brelse(inode_bitmap_bh);
1145         return ERR_PTR(err);
1146 }
1147
1148 /* Verify that we are loading a valid orphan from disk */
1149 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1150 {
1151         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1152         ext4_group_t block_group;
1153         int bit;
1154         struct buffer_head *bitmap_bh = NULL;
1155         struct inode *inode = NULL;
1156         int err = -EFSCORRUPTED;
1157
1158         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1159                 goto bad_orphan;
1160
1161         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1162         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1163         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1164         if (IS_ERR(bitmap_bh)) {
1165                 ext4_error(sb, "inode bitmap error %ld for orphan %lu",
1166                            ino, PTR_ERR(bitmap_bh));
1167                 return (struct inode *) bitmap_bh;
1168         }
1169
1170         /* Having the inode bit set should be a 100% indicator that this
1171          * is a valid orphan (no e2fsck run on fs).  Orphans also include
1172          * inodes that were being truncated, so we can't check i_nlink==0.
1173          */
1174         if (!ext4_test_bit(bit, bitmap_bh->b_data))
1175                 goto bad_orphan;
1176
1177         inode = ext4_iget(sb, ino);
1178         if (IS_ERR(inode)) {
1179                 err = PTR_ERR(inode);
1180                 ext4_error(sb, "couldn't read orphan inode %lu (err %d)",
1181                            ino, err);
1182                 return inode;
1183         }
1184
1185         /*
1186          * If the orphans has i_nlinks > 0 then it should be able to
1187          * be truncated, otherwise it won't be removed from the orphan
1188          * list during processing and an infinite loop will result.
1189          * Similarly, it must not be a bad inode.
1190          */
1191         if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1192             is_bad_inode(inode))
1193                 goto bad_orphan;
1194
1195         if (NEXT_ORPHAN(inode) > max_ino)
1196                 goto bad_orphan;
1197         brelse(bitmap_bh);
1198         return inode;
1199
1200 bad_orphan:
1201         ext4_error(sb, "bad orphan inode %lu", ino);
1202         if (bitmap_bh)
1203                 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1204                        bit, (unsigned long long)bitmap_bh->b_blocknr,
1205                        ext4_test_bit(bit, bitmap_bh->b_data));
1206         if (inode) {
1207                 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1208                        is_bad_inode(inode));
1209                 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1210                        NEXT_ORPHAN(inode));
1211                 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1212                 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1213                 /* Avoid freeing blocks if we got a bad deleted inode */
1214                 if (inode->i_nlink == 0)
1215                         inode->i_blocks = 0;
1216                 iput(inode);
1217         }
1218         brelse(bitmap_bh);
1219         return ERR_PTR(err);
1220 }
1221
1222 unsigned long ext4_count_free_inodes(struct super_block *sb)
1223 {
1224         unsigned long desc_count;
1225         struct ext4_group_desc *gdp;
1226         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1227 #ifdef EXT4FS_DEBUG
1228         struct ext4_super_block *es;
1229         unsigned long bitmap_count, x;
1230         struct buffer_head *bitmap_bh = NULL;
1231
1232         es = EXT4_SB(sb)->s_es;
1233         desc_count = 0;
1234         bitmap_count = 0;
1235         gdp = NULL;
1236         for (i = 0; i < ngroups; i++) {
1237                 gdp = ext4_get_group_desc(sb, i, NULL);
1238                 if (!gdp)
1239                         continue;
1240                 desc_count += ext4_free_inodes_count(sb, gdp);
1241                 brelse(bitmap_bh);
1242                 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1243                 if (IS_ERR(bitmap_bh)) {
1244                         bitmap_bh = NULL;
1245                         continue;
1246                 }
1247
1248                 x = ext4_count_free(bitmap_bh->b_data,
1249                                     EXT4_INODES_PER_GROUP(sb) / 8);
1250                 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1251                         (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1252                 bitmap_count += x;
1253         }
1254         brelse(bitmap_bh);
1255         printk(KERN_DEBUG "ext4_count_free_inodes: "
1256                "stored = %u, computed = %lu, %lu\n",
1257                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1258         return desc_count;
1259 #else
1260         desc_count = 0;
1261         for (i = 0; i < ngroups; i++) {
1262                 gdp = ext4_get_group_desc(sb, i, NULL);
1263                 if (!gdp)
1264                         continue;
1265                 desc_count += ext4_free_inodes_count(sb, gdp);
1266                 cond_resched();
1267         }
1268         return desc_count;
1269 #endif
1270 }
1271
1272 /* Called at mount-time, super-block is locked */
1273 unsigned long ext4_count_dirs(struct super_block * sb)
1274 {
1275         unsigned long count = 0;
1276         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1277
1278         for (i = 0; i < ngroups; i++) {
1279                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1280                 if (!gdp)
1281                         continue;
1282                 count += ext4_used_dirs_count(sb, gdp);
1283         }
1284         return count;
1285 }
1286
1287 /*
1288  * Zeroes not yet zeroed inode table - just write zeroes through the whole
1289  * inode table. Must be called without any spinlock held. The only place
1290  * where it is called from on active part of filesystem is ext4lazyinit
1291  * thread, so we do not need any special locks, however we have to prevent
1292  * inode allocation from the current group, so we take alloc_sem lock, to
1293  * block ext4_new_inode() until we are finished.
1294  */
1295 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1296                                  int barrier)
1297 {
1298         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1299         struct ext4_sb_info *sbi = EXT4_SB(sb);
1300         struct ext4_group_desc *gdp = NULL;
1301         struct buffer_head *group_desc_bh;
1302         handle_t *handle;
1303         ext4_fsblk_t blk;
1304         int num, ret = 0, used_blks = 0;
1305
1306         /* This should not happen, but just to be sure check this */
1307         if (sb->s_flags & MS_RDONLY) {
1308                 ret = 1;
1309                 goto out;
1310         }
1311
1312         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1313         if (!gdp)
1314                 goto out;
1315
1316         /*
1317          * We do not need to lock this, because we are the only one
1318          * handling this flag.
1319          */
1320         if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1321                 goto out;
1322
1323         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1324         if (IS_ERR(handle)) {
1325                 ret = PTR_ERR(handle);
1326                 goto out;
1327         }
1328
1329         down_write(&grp->alloc_sem);
1330         /*
1331          * If inode bitmap was already initialized there may be some
1332          * used inodes so we need to skip blocks with used inodes in
1333          * inode table.
1334          */
1335         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
1336                 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
1337                             ext4_itable_unused_count(sb, gdp)),
1338                             sbi->s_inodes_per_block);
1339
1340         if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) {
1341                 ext4_error(sb, "Something is wrong with group %u: "
1342                            "used itable blocks: %d; "
1343                            "itable unused count: %u",
1344                            group, used_blks,
1345                            ext4_itable_unused_count(sb, gdp));
1346                 ret = 1;
1347                 goto err_out;
1348         }
1349
1350         blk = ext4_inode_table(sb, gdp) + used_blks;
1351         num = sbi->s_itb_per_group - used_blks;
1352
1353         BUFFER_TRACE(group_desc_bh, "get_write_access");
1354         ret = ext4_journal_get_write_access(handle,
1355                                             group_desc_bh);
1356         if (ret)
1357                 goto err_out;
1358
1359         /*
1360          * Skip zeroout if the inode table is full. But we set the ZEROED
1361          * flag anyway, because obviously, when it is full it does not need
1362          * further zeroing.
1363          */
1364         if (unlikely(num == 0))
1365                 goto skip_zeroout;
1366
1367         ext4_debug("going to zero out inode table in group %d\n",
1368                    group);
1369         ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1370         if (ret < 0)
1371                 goto err_out;
1372         if (barrier)
1373                 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1374
1375 skip_zeroout:
1376         ext4_lock_group(sb, group);
1377         gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1378         ext4_group_desc_csum_set(sb, group, gdp);
1379         ext4_unlock_group(sb, group);
1380
1381         BUFFER_TRACE(group_desc_bh,
1382                      "call ext4_handle_dirty_metadata");
1383         ret = ext4_handle_dirty_metadata(handle, NULL,
1384                                          group_desc_bh);
1385
1386 err_out:
1387         up_write(&grp->alloc_sem);
1388         ext4_journal_stop(handle);
1389 out:
1390         return ret;
1391 }