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defconfig: exynos9610: Re-add dropped Wi-Fi AP options lost
[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / fs / ext4 / ialloc.c
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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/ext4/ialloc.c
4 *
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
9 *
10 * BSD ufs-inspired inode and directory allocation by
11 * Stephen Tweedie (sct@redhat.com), 1993
12 * Big-endian to little-endian byte-swapping/bitmaps by
13 * David S. Miller (davem@caip.rutgers.edu), 1995
14 */
15
16#include <linux/time.h>
17#include <linux/fs.h>
18#include <linux/stat.h>
19#include <linux/string.h>
20#include <linux/quotaops.h>
21#include <linux/buffer_head.h>
22#include <linux/random.h>
23#include <linux/bitops.h>
24#include <linux/blkdev.h>
25#include <linux/cred.h>
26
27#include <asm/byteorder.h>
28
29#include "ext4.h"
30#include "ext4_jbd2.h"
31#include "xattr.h"
32#include "acl.h"
33
34#include <trace/events/ext4.h>
35
36/*
37 * ialloc.c contains the inodes allocation and deallocation routines
38 */
39
40/*
41 * The free inodes are managed by bitmaps. A file system contains several
42 * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
43 * block for inodes, N blocks for the inode table and data blocks.
44 *
45 * The file system contains group descriptors which are located after the
46 * super block. Each descriptor contains the number of the bitmap block and
47 * the free blocks count in the block.
48 */
49
50/*
51 * To avoid calling the atomic setbit hundreds or thousands of times, we only
52 * need to use it within a single byte (to ensure we get endianness right).
53 * We can use memset for the rest of the bitmap as there are no other users.
54 */
55void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
56{
57 int i;
58
59 if (start_bit >= end_bit)
60 return;
61
62 ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
63 for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
64 ext4_set_bit(i, bitmap);
65 if (i < end_bit)
66 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
67}
68
69void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
70{
71 if (uptodate) {
72 set_buffer_uptodate(bh);
73 set_bitmap_uptodate(bh);
74 }
75 unlock_buffer(bh);
76 put_bh(bh);
77}
78
79static int ext4_validate_inode_bitmap(struct super_block *sb,
80 struct ext4_group_desc *desc,
81 ext4_group_t block_group,
82 struct buffer_head *bh)
83{
84 ext4_fsblk_t blk;
85 struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
86 struct ext4_sb_info *sbi = EXT4_SB(sb);
87
88 if (buffer_verified(bh))
89 return 0;
90 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
91 return -EFSCORRUPTED;
92
93 ext4_lock_group(sb, block_group);
94 if (buffer_verified(bh))
95 goto verified;
96 blk = ext4_inode_bitmap(sb, desc);
97 if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
98 EXT4_INODES_PER_GROUP(sb) / 8)) {
99 ext4_unlock_group(sb, block_group);
100 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
101 "inode_bitmap = %llu", block_group, blk);
102 grp = ext4_get_group_info(sb, block_group);
103 if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
104 int count;
105 count = ext4_free_inodes_count(sb, desc);
106 percpu_counter_sub(&sbi->s_freeinodes_counter,
107 count);
108 }
109 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
110 return -EFSBADCRC;
111 }
112 set_buffer_verified(bh);
113verified:
114 ext4_unlock_group(sb, block_group);
115 return 0;
116}
117
118/*
119 * Read the inode allocation bitmap for a given block_group, reading
120 * into the specified slot in the superblock's bitmap cache.
121 *
122 * Return buffer_head of bitmap on success or NULL.
123 */
124static struct buffer_head *
125ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
126{
127 struct ext4_group_desc *desc;
128 struct ext4_sb_info *sbi = EXT4_SB(sb);
129 struct buffer_head *bh = NULL;
130 ext4_fsblk_t bitmap_blk;
131 int err;
132
133 desc = ext4_get_group_desc(sb, block_group, NULL);
134 if (!desc)
135 return ERR_PTR(-EFSCORRUPTED);
136
137 bitmap_blk = ext4_inode_bitmap(sb, desc);
138 if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
139 (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
140 ext4_error(sb, "Invalid inode bitmap blk %llu in "
141 "block_group %u", bitmap_blk, block_group);
142 return ERR_PTR(-EFSCORRUPTED);
143 }
144 bh = sb_getblk(sb, bitmap_blk);
145 if (unlikely(!bh)) {
146 ext4_error(sb, "Cannot read inode bitmap - "
147 "block_group = %u, inode_bitmap = %llu",
148 block_group, bitmap_blk);
149 return ERR_PTR(-EIO);
150 }
151 if (bitmap_uptodate(bh))
152 goto verify;
153
154 lock_buffer(bh);
155 if (bitmap_uptodate(bh)) {
156 unlock_buffer(bh);
157 goto verify;
158 }
159
160 ext4_lock_group(sb, block_group);
161 if (ext4_has_group_desc_csum(sb) &&
162 (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
163 if (block_group == 0) {
164 ext4_unlock_group(sb, block_group);
165 unlock_buffer(bh);
166 ext4_error(sb, "Inode bitmap for bg 0 marked "
167 "uninitialized");
168 err = -EFSCORRUPTED;
169 goto out;
170 }
171 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
172 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
173 sb->s_blocksize * 8, bh->b_data);
174 set_bitmap_uptodate(bh);
175 set_buffer_uptodate(bh);
176 set_buffer_verified(bh);
177 ext4_unlock_group(sb, block_group);
178 unlock_buffer(bh);
179 return bh;
180 }
181 ext4_unlock_group(sb, block_group);
182
183 if (buffer_uptodate(bh)) {
184 /*
185 * if not uninit if bh is uptodate,
186 * bitmap is also uptodate
187 */
188 set_bitmap_uptodate(bh);
189 unlock_buffer(bh);
190 goto verify;
191 }
192 /*
193 * submit the buffer_head for reading
194 */
195 trace_ext4_load_inode_bitmap(sb, block_group);
196 bh->b_end_io = ext4_end_bitmap_read;
197 get_bh(bh);
198 submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
199 wait_on_buffer(bh);
200 if (!buffer_uptodate(bh)) {
201 put_bh(bh);
202 ext4_error(sb, "Cannot read inode bitmap - "
203 "block_group = %u, inode_bitmap = %llu",
204 block_group, bitmap_blk);
205 return ERR_PTR(-EIO);
206 }
207
208verify:
209 err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
210 if (err)
211 goto out;
212 return bh;
213out:
214 put_bh(bh);
215 return ERR_PTR(err);
216}
217
218/*
219 * NOTE! When we get the inode, we're the only people
220 * that have access to it, and as such there are no
221 * race conditions we have to worry about. The inode
222 * is not on the hash-lists, and it cannot be reached
223 * through the filesystem because the directory entry
224 * has been deleted earlier.
225 *
226 * HOWEVER: we must make sure that we get no aliases,
227 * which means that we have to call "clear_inode()"
228 * _before_ we mark the inode not in use in the inode
229 * bitmaps. Otherwise a newly created file might use
230 * the same inode number (not actually the same pointer
231 * though), and then we'd have two inodes sharing the
232 * same inode number and space on the harddisk.
233 */
234void ext4_free_inode(handle_t *handle, struct inode *inode)
235{
236 struct super_block *sb = inode->i_sb;
237 int is_directory;
238 unsigned long ino;
239 struct buffer_head *bitmap_bh = NULL;
240 struct buffer_head *bh2;
241 ext4_group_t block_group;
242 unsigned long bit;
243 struct ext4_group_desc *gdp;
244 struct ext4_super_block *es;
245 struct ext4_sb_info *sbi;
246 int fatal = 0, err, count, cleared;
247 struct ext4_group_info *grp;
248
249 if (!sb) {
250 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
251 "nonexistent device\n", __func__, __LINE__);
252 return;
253 }
254 if (atomic_read(&inode->i_count) > 1) {
255 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
256 __func__, __LINE__, inode->i_ino,
257 atomic_read(&inode->i_count));
258 return;
259 }
260 if (inode->i_nlink) {
261 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
262 __func__, __LINE__, inode->i_ino, inode->i_nlink);
263 return;
264 }
265 sbi = EXT4_SB(sb);
266
267 ino = inode->i_ino;
268 ext4_debug("freeing inode %lu\n", ino);
269 trace_ext4_free_inode(inode);
270
271 /*
272 * Note: we must free any quota before locking the superblock,
273 * as writing the quota to disk may need the lock as well.
274 */
275 dquot_initialize(inode);
276 dquot_free_inode(inode);
277 dquot_drop(inode);
278
279 is_directory = S_ISDIR(inode->i_mode);
280
281 /* Do this BEFORE marking the inode not in use or returning an error */
282 ext4_clear_inode(inode);
283
284 es = EXT4_SB(sb)->s_es;
285 if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
286 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
287 goto error_return;
288 }
289 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
290 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
291 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
292 /* Don't bother if the inode bitmap is corrupt. */
293 grp = ext4_get_group_info(sb, block_group);
294 if (IS_ERR(bitmap_bh)) {
295 fatal = PTR_ERR(bitmap_bh);
296 bitmap_bh = NULL;
297 goto error_return;
298 }
299 if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
300 fatal = -EFSCORRUPTED;
301 goto error_return;
302 }
303
304 BUFFER_TRACE(bitmap_bh, "get_write_access");
305 fatal = ext4_journal_get_write_access(handle, bitmap_bh);
306 if (fatal)
307 goto error_return;
308
309 fatal = -ESRCH;
310 gdp = ext4_get_group_desc(sb, block_group, &bh2);
311 if (gdp) {
312 BUFFER_TRACE(bh2, "get_write_access");
313 fatal = ext4_journal_get_write_access(handle, bh2);
314 }
315 ext4_lock_group(sb, block_group);
316 cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
317 if (fatal || !cleared) {
318 ext4_unlock_group(sb, block_group);
319 goto out;
320 }
321
322 count = ext4_free_inodes_count(sb, gdp) + 1;
323 ext4_free_inodes_set(sb, gdp, count);
324 if (is_directory) {
325 count = ext4_used_dirs_count(sb, gdp) - 1;
326 ext4_used_dirs_set(sb, gdp, count);
327 percpu_counter_dec(&sbi->s_dirs_counter);
328 }
329 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
330 EXT4_INODES_PER_GROUP(sb) / 8);
331 ext4_group_desc_csum_set(sb, block_group, gdp);
332 ext4_unlock_group(sb, block_group);
333
334 percpu_counter_inc(&sbi->s_freeinodes_counter);
335 if (sbi->s_log_groups_per_flex) {
336 ext4_group_t f = ext4_flex_group(sbi, block_group);
337
338 atomic_inc(&sbi->s_flex_groups[f].free_inodes);
339 if (is_directory)
340 atomic_dec(&sbi->s_flex_groups[f].used_dirs);
341 }
342 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
343 fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
344out:
345 if (cleared) {
346 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
347 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
348 if (!fatal)
349 fatal = err;
350 } else {
351 ext4_error(sb, "bit already cleared for inode %lu", ino);
352 if (gdp && !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
353 int count;
354 count = ext4_free_inodes_count(sb, gdp);
355 percpu_counter_sub(&sbi->s_freeinodes_counter,
356 count);
357 }
358 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
359 }
360
361error_return:
362 brelse(bitmap_bh);
363 ext4_std_error(sb, fatal);
364}
365
366struct orlov_stats {
367 __u64 free_clusters;
368 __u32 free_inodes;
369 __u32 used_dirs;
370};
371
372/*
373 * Helper function for Orlov's allocator; returns critical information
374 * for a particular block group or flex_bg. If flex_size is 1, then g
375 * is a block group number; otherwise it is flex_bg number.
376 */
377static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
378 int flex_size, struct orlov_stats *stats)
379{
380 struct ext4_group_desc *desc;
381 struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups;
382
383 if (flex_size > 1) {
384 stats->free_inodes = atomic_read(&flex_group[g].free_inodes);
385 stats->free_clusters = atomic64_read(&flex_group[g].free_clusters);
386 stats->used_dirs = atomic_read(&flex_group[g].used_dirs);
387 return;
388 }
389
390 desc = ext4_get_group_desc(sb, g, NULL);
391 if (desc) {
392 stats->free_inodes = ext4_free_inodes_count(sb, desc);
393 stats->free_clusters = ext4_free_group_clusters(sb, desc);
394 stats->used_dirs = ext4_used_dirs_count(sb, desc);
395 } else {
396 stats->free_inodes = 0;
397 stats->free_clusters = 0;
398 stats->used_dirs = 0;
399 }
400}
401
402/*
403 * Orlov's allocator for directories.
404 *
405 * We always try to spread first-level directories.
406 *
407 * If there are blockgroups with both free inodes and free blocks counts
408 * not worse than average we return one with smallest directory count.
409 * Otherwise we simply return a random group.
410 *
411 * For the rest rules look so:
412 *
413 * It's OK to put directory into a group unless
414 * it has too many directories already (max_dirs) or
415 * it has too few free inodes left (min_inodes) or
416 * it has too few free blocks left (min_blocks) or
417 * Parent's group is preferred, if it doesn't satisfy these
418 * conditions we search cyclically through the rest. If none
419 * of the groups look good we just look for a group with more
420 * free inodes than average (starting at parent's group).
421 */
422
423static int find_group_orlov(struct super_block *sb, struct inode *parent,
424 ext4_group_t *group, umode_t mode,
425 const struct qstr *qstr)
426{
427 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
428 struct ext4_sb_info *sbi = EXT4_SB(sb);
429 ext4_group_t real_ngroups = ext4_get_groups_count(sb);
430 int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
431 unsigned int freei, avefreei, grp_free;
432 ext4_fsblk_t freeb, avefreec;
433 unsigned int ndirs;
434 int max_dirs, min_inodes;
435 ext4_grpblk_t min_clusters;
436 ext4_group_t i, grp, g, ngroups;
437 struct ext4_group_desc *desc;
438 struct orlov_stats stats;
439 int flex_size = ext4_flex_bg_size(sbi);
440 struct dx_hash_info hinfo;
441
442 ngroups = real_ngroups;
443 if (flex_size > 1) {
444 ngroups = (real_ngroups + flex_size - 1) >>
445 sbi->s_log_groups_per_flex;
446 parent_group >>= sbi->s_log_groups_per_flex;
447 }
448
449 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
450 avefreei = freei / ngroups;
451 freeb = EXT4_C2B(sbi,
452 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
453 avefreec = freeb;
454 do_div(avefreec, ngroups);
455 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
456
457 if (S_ISDIR(mode) &&
458 ((parent == d_inode(sb->s_root)) ||
459 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
460 int best_ndir = inodes_per_group;
461 int ret = -1;
462
463 if (qstr) {
464 hinfo.hash_version = DX_HASH_HALF_MD4;
465 hinfo.seed = sbi->s_hash_seed;
466 ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
467 grp = hinfo.hash;
468 } else
469 grp = prandom_u32();
470 parent_group = (unsigned)grp % ngroups;
471 for (i = 0; i < ngroups; i++) {
472 g = (parent_group + i) % ngroups;
473 get_orlov_stats(sb, g, flex_size, &stats);
474 if (!stats.free_inodes)
475 continue;
476 if (stats.used_dirs >= best_ndir)
477 continue;
478 if (stats.free_inodes < avefreei)
479 continue;
480 if (stats.free_clusters < avefreec)
481 continue;
482 grp = g;
483 ret = 0;
484 best_ndir = stats.used_dirs;
485 }
486 if (ret)
487 goto fallback;
488 found_flex_bg:
489 if (flex_size == 1) {
490 *group = grp;
491 return 0;
492 }
493
494 /*
495 * We pack inodes at the beginning of the flexgroup's
496 * inode tables. Block allocation decisions will do
497 * something similar, although regular files will
498 * start at 2nd block group of the flexgroup. See
499 * ext4_ext_find_goal() and ext4_find_near().
500 */
501 grp *= flex_size;
502 for (i = 0; i < flex_size; i++) {
503 if (grp+i >= real_ngroups)
504 break;
505 desc = ext4_get_group_desc(sb, grp+i, NULL);
506 if (desc && ext4_free_inodes_count(sb, desc)) {
507 *group = grp+i;
508 return 0;
509 }
510 }
511 goto fallback;
512 }
513
514 max_dirs = ndirs / ngroups + inodes_per_group / 16;
515 min_inodes = avefreei - inodes_per_group*flex_size / 4;
516 if (min_inodes < 1)
517 min_inodes = 1;
518 min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
519
520 /*
521 * Start looking in the flex group where we last allocated an
522 * inode for this parent directory
523 */
524 if (EXT4_I(parent)->i_last_alloc_group != ~0) {
525 parent_group = EXT4_I(parent)->i_last_alloc_group;
526 if (flex_size > 1)
527 parent_group >>= sbi->s_log_groups_per_flex;
528 }
529
530 for (i = 0; i < ngroups; i++) {
531 grp = (parent_group + i) % ngroups;
532 get_orlov_stats(sb, grp, flex_size, &stats);
533 if (stats.used_dirs >= max_dirs)
534 continue;
535 if (stats.free_inodes < min_inodes)
536 continue;
537 if (stats.free_clusters < min_clusters)
538 continue;
539 goto found_flex_bg;
540 }
541
542fallback:
543 ngroups = real_ngroups;
544 avefreei = freei / ngroups;
545fallback_retry:
546 parent_group = EXT4_I(parent)->i_block_group;
547 for (i = 0; i < ngroups; i++) {
548 grp = (parent_group + i) % ngroups;
549 desc = ext4_get_group_desc(sb, grp, NULL);
550 if (desc) {
551 grp_free = ext4_free_inodes_count(sb, desc);
552 if (grp_free && grp_free >= avefreei) {
553 *group = grp;
554 return 0;
555 }
556 }
557 }
558
559 if (avefreei) {
560 /*
561 * The free-inodes counter is approximate, and for really small
562 * filesystems the above test can fail to find any blockgroups
563 */
564 avefreei = 0;
565 goto fallback_retry;
566 }
567
568 return -1;
569}
570
571static int find_group_other(struct super_block *sb, struct inode *parent,
572 ext4_group_t *group, umode_t mode)
573{
574 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
575 ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
576 struct ext4_group_desc *desc;
577 int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
578
579 /*
580 * Try to place the inode is the same flex group as its
581 * parent. If we can't find space, use the Orlov algorithm to
582 * find another flex group, and store that information in the
583 * parent directory's inode information so that use that flex
584 * group for future allocations.
585 */
586 if (flex_size > 1) {
587 int retry = 0;
588
589 try_again:
590 parent_group &= ~(flex_size-1);
591 last = parent_group + flex_size;
592 if (last > ngroups)
593 last = ngroups;
594 for (i = parent_group; i < last; i++) {
595 desc = ext4_get_group_desc(sb, i, NULL);
596 if (desc && ext4_free_inodes_count(sb, desc)) {
597 *group = i;
598 return 0;
599 }
600 }
601 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
602 retry = 1;
603 parent_group = EXT4_I(parent)->i_last_alloc_group;
604 goto try_again;
605 }
606 /*
607 * If this didn't work, use the Orlov search algorithm
608 * to find a new flex group; we pass in the mode to
609 * avoid the topdir algorithms.
610 */
611 *group = parent_group + flex_size;
612 if (*group > ngroups)
613 *group = 0;
614 return find_group_orlov(sb, parent, group, mode, NULL);
615 }
616
617 /*
618 * Try to place the inode in its parent directory
619 */
620 *group = parent_group;
621 desc = ext4_get_group_desc(sb, *group, NULL);
622 if (desc && ext4_free_inodes_count(sb, desc) &&
623 ext4_free_group_clusters(sb, desc))
624 return 0;
625
626 /*
627 * We're going to place this inode in a different blockgroup from its
628 * parent. We want to cause files in a common directory to all land in
629 * the same blockgroup. But we want files which are in a different
630 * directory which shares a blockgroup with our parent to land in a
631 * different blockgroup.
632 *
633 * So add our directory's i_ino into the starting point for the hash.
634 */
635 *group = (*group + parent->i_ino) % ngroups;
636
637 /*
638 * Use a quadratic hash to find a group with a free inode and some free
639 * blocks.
640 */
641 for (i = 1; i < ngroups; i <<= 1) {
642 *group += i;
643 if (*group >= ngroups)
644 *group -= ngroups;
645 desc = ext4_get_group_desc(sb, *group, NULL);
646 if (desc && ext4_free_inodes_count(sb, desc) &&
647 ext4_free_group_clusters(sb, desc))
648 return 0;
649 }
650
651 /*
652 * That failed: try linear search for a free inode, even if that group
653 * has no free blocks.
654 */
655 *group = parent_group;
656 for (i = 0; i < ngroups; i++) {
657 if (++*group >= ngroups)
658 *group = 0;
659 desc = ext4_get_group_desc(sb, *group, NULL);
660 if (desc && ext4_free_inodes_count(sb, desc))
661 return 0;
662 }
663
664 return -1;
665}
666
667/*
668 * In no journal mode, if an inode has recently been deleted, we want
669 * to avoid reusing it until we're reasonably sure the inode table
670 * block has been written back to disk. (Yes, these values are
671 * somewhat arbitrary...)
672 */
673#define RECENTCY_MIN 5
674#define RECENTCY_DIRTY 300
675
676static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
677{
678 struct ext4_group_desc *gdp;
679 struct ext4_inode *raw_inode;
680 struct buffer_head *bh;
681 int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
682 int offset, ret = 0;
683 int recentcy = RECENTCY_MIN;
684 u32 dtime, now;
685
686 gdp = ext4_get_group_desc(sb, group, NULL);
687 if (unlikely(!gdp))
688 return 0;
689
690 bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
691 (ino / inodes_per_block));
692 if (!bh || !buffer_uptodate(bh))
693 /*
694 * If the block is not in the buffer cache, then it
695 * must have been written out.
696 */
697 goto out;
698
699 offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
700 raw_inode = (struct ext4_inode *) (bh->b_data + offset);
701
702 /* i_dtime is only 32 bits on disk, but we only care about relative
703 * times in the range of a few minutes (i.e. long enough to sync a
704 * recently-deleted inode to disk), so using the low 32 bits of the
705 * clock (a 68 year range) is enough, see time_before32() */
706 dtime = le32_to_cpu(raw_inode->i_dtime);
707 now = ktime_get_real_seconds();
708 if (buffer_dirty(bh))
709 recentcy += RECENTCY_DIRTY;
710
711 if (dtime && time_before32(dtime, now) &&
712 time_before32(now, dtime + recentcy))
713 ret = 1;
714out:
715 brelse(bh);
716 return ret;
717}
718
719static int find_inode_bit(struct super_block *sb, ext4_group_t group,
720 struct buffer_head *bitmap, unsigned long *ino)
721{
722next:
723 *ino = ext4_find_next_zero_bit((unsigned long *)
724 bitmap->b_data,
725 EXT4_INODES_PER_GROUP(sb), *ino);
726 if (*ino >= EXT4_INODES_PER_GROUP(sb))
727 return 0;
728
729 if ((EXT4_SB(sb)->s_journal == NULL) &&
730 recently_deleted(sb, group, *ino)) {
731 *ino = *ino + 1;
732 if (*ino < EXT4_INODES_PER_GROUP(sb))
733 goto next;
734 return 0;
735 }
736
737 return 1;
738}
739
740/*
741 * There are two policies for allocating an inode. If the new inode is
742 * a directory, then a forward search is made for a block group with both
743 * free space and a low directory-to-inode ratio; if that fails, then of
744 * the groups with above-average free space, that group with the fewest
745 * directories already is chosen.
746 *
747 * For other inodes, search forward from the parent directory's block
748 * group to find a free inode.
749 */
750struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
751 umode_t mode, const struct qstr *qstr,
752 __u32 goal, uid_t *owner, __u32 i_flags,
753 int handle_type, unsigned int line_no,
754 int nblocks)
755{
756 struct super_block *sb;
757 struct buffer_head *inode_bitmap_bh = NULL;
758 struct buffer_head *group_desc_bh;
759 ext4_group_t ngroups, group = 0;
760 unsigned long ino = 0;
761 struct inode *inode;
762 struct ext4_group_desc *gdp = NULL;
763 struct ext4_inode_info *ei;
764 struct ext4_sb_info *sbi;
765 int ret2, err;
766 struct inode *ret;
767 ext4_group_t i;
768 ext4_group_t flex_group;
769 struct ext4_group_info *grp;
770 int encrypt = 0;
771
772 /* Cannot create files in a deleted directory */
773 if (!dir || !dir->i_nlink)
774 return ERR_PTR(-EPERM);
775
776 sb = dir->i_sb;
777 sbi = EXT4_SB(sb);
778
779 if (unlikely(ext4_forced_shutdown(sbi)))
780 return ERR_PTR(-EIO);
781
782 if ((ext4_encrypted_inode(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) &&
783 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) &&
784 !(i_flags & EXT4_EA_INODE_FL)) {
785 err = fscrypt_get_encryption_info(dir);
786 if (err)
787 return ERR_PTR(err);
788 if (!fscrypt_has_encryption_key(dir))
789 return ERR_PTR(-ENOKEY);
790 encrypt = 1;
791 }
792
793 if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
794#ifdef CONFIG_EXT4_FS_POSIX_ACL
795 struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
796
797 if (IS_ERR(p))
798 return ERR_CAST(p);
799 if (p) {
800 int acl_size = p->a_count * sizeof(ext4_acl_entry);
801
802 nblocks += (S_ISDIR(mode) ? 2 : 1) *
803 __ext4_xattr_set_credits(sb, NULL /* inode */,
804 NULL /* block_bh */, acl_size,
805 true /* is_create */);
806 posix_acl_release(p);
807 }
808#endif
809
810#ifdef CONFIG_SECURITY
811 {
812 int num_security_xattrs = 1;
813
814#ifdef CONFIG_INTEGRITY
815 num_security_xattrs++;
816#endif
817 /*
818 * We assume that security xattrs are never
819 * more than 1k. In practice they are under
820 * 128 bytes.
821 */
822 nblocks += num_security_xattrs *
823 __ext4_xattr_set_credits(sb, NULL /* inode */,
824 NULL /* block_bh */, 1024,
825 true /* is_create */);
826 }
827#endif
828 if (encrypt)
829 nblocks += __ext4_xattr_set_credits(sb,
830 NULL /* inode */, NULL /* block_bh */,
831 FSCRYPT_SET_CONTEXT_MAX_SIZE,
832 true /* is_create */);
833 }
834
835 ngroups = ext4_get_groups_count(sb);
836 trace_ext4_request_inode(dir, mode);
837 inode = new_inode(sb);
838 if (!inode)
839 return ERR_PTR(-ENOMEM);
840 ei = EXT4_I(inode);
841
842 /*
843 * Initialize owners and quota early so that we don't have to account
844 * for quota initialization worst case in standard inode creating
845 * transaction
846 */
847 if (owner) {
848 inode->i_mode = mode;
849 i_uid_write(inode, owner[0]);
850 i_gid_write(inode, owner[1]);
851 } else if (test_opt(sb, GRPID)) {
852 inode->i_mode = mode;
853 inode->i_uid = current_fsuid();
854 inode->i_gid = dir->i_gid;
855 } else
856 inode_init_owner(inode, dir, mode);
857
858 if (ext4_has_feature_project(sb) &&
859 ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
860 ei->i_projid = EXT4_I(dir)->i_projid;
861 else
862 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
863
864 err = dquot_initialize(inode);
865 if (err)
866 goto out;
867
868 if (!goal)
869 goal = sbi->s_inode_goal;
870
871 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
872 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
873 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
874 ret2 = 0;
875 goto got_group;
876 }
877
878 if (S_ISDIR(mode))
879 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
880 else
881 ret2 = find_group_other(sb, dir, &group, mode);
882
883got_group:
884 EXT4_I(dir)->i_last_alloc_group = group;
885 err = -ENOSPC;
886 if (ret2 == -1)
887 goto out;
888
889 /*
890 * Normally we will only go through one pass of this loop,
891 * unless we get unlucky and it turns out the group we selected
892 * had its last inode grabbed by someone else.
893 */
894 for (i = 0; i < ngroups; i++, ino = 0) {
895 err = -EIO;
896
897 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
898 if (!gdp)
899 goto out;
900
901 /*
902 * Check free inodes count before loading bitmap.
903 */
904 if (ext4_free_inodes_count(sb, gdp) == 0)
905 goto next_group;
906
907 grp = ext4_get_group_info(sb, group);
908 /* Skip groups with already-known suspicious inode tables */
909 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
910 goto next_group;
911
912 brelse(inode_bitmap_bh);
913 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
914 /* Skip groups with suspicious inode tables */
915 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
916 IS_ERR(inode_bitmap_bh)) {
917 inode_bitmap_bh = NULL;
918 goto next_group;
919 }
920
921repeat_in_this_group:
922 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
923 if (!ret2)
924 goto next_group;
925
926 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
927 ext4_error(sb, "reserved inode found cleared - "
928 "inode=%lu", ino + 1);
929 goto next_group;
930 }
931
932 if (!handle) {
933 BUG_ON(nblocks <= 0);
934 handle = __ext4_journal_start_sb(dir->i_sb, line_no,
935 handle_type, nblocks,
936 0);
937 if (IS_ERR(handle)) {
938 err = PTR_ERR(handle);
939 ext4_std_error(sb, err);
940 goto out;
941 }
942 }
943 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
944 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
945 if (err) {
946 ext4_std_error(sb, err);
947 goto out;
948 }
949 ext4_lock_group(sb, group);
950 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
951 if (ret2) {
952 /* Someone already took the bit. Repeat the search
953 * with lock held.
954 */
955 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
956 if (ret2) {
957 ext4_set_bit(ino, inode_bitmap_bh->b_data);
958 ret2 = 0;
959 } else {
960 ret2 = 1; /* we didn't grab the inode */
961 }
962 }
963 ext4_unlock_group(sb, group);
964 ino++; /* the inode bitmap is zero-based */
965 if (!ret2)
966 goto got; /* we grabbed the inode! */
967
968 if (ino < EXT4_INODES_PER_GROUP(sb))
969 goto repeat_in_this_group;
970next_group:
971 if (++group == ngroups)
972 group = 0;
973 }
974 err = -ENOSPC;
975 goto out;
976
977got:
978 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
979 err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
980 if (err) {
981 ext4_std_error(sb, err);
982 goto out;
983 }
984
985 BUFFER_TRACE(group_desc_bh, "get_write_access");
986 err = ext4_journal_get_write_access(handle, group_desc_bh);
987 if (err) {
988 ext4_std_error(sb, err);
989 goto out;
990 }
991
992 /* We may have to initialize the block bitmap if it isn't already */
993 if (ext4_has_group_desc_csum(sb) &&
994 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
995 struct buffer_head *block_bitmap_bh;
996
997 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
998 if (IS_ERR(block_bitmap_bh)) {
999 err = PTR_ERR(block_bitmap_bh);
1000 goto out;
1001 }
1002 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
1003 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
1004 if (err) {
1005 brelse(block_bitmap_bh);
1006 ext4_std_error(sb, err);
1007 goto out;
1008 }
1009
1010 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1011 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1012
1013 /* recheck and clear flag under lock if we still need to */
1014 ext4_lock_group(sb, group);
1015 if (ext4_has_group_desc_csum(sb) &&
1016 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1017 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1018 ext4_free_group_clusters_set(sb, gdp,
1019 ext4_free_clusters_after_init(sb, group, gdp));
1020 ext4_block_bitmap_csum_set(sb, group, gdp,
1021 block_bitmap_bh);
1022 ext4_group_desc_csum_set(sb, group, gdp);
1023 }
1024 ext4_unlock_group(sb, group);
1025 brelse(block_bitmap_bh);
1026
1027 if (err) {
1028 ext4_std_error(sb, err);
1029 goto out;
1030 }
1031 }
1032
1033 /* Update the relevant bg descriptor fields */
1034 if (ext4_has_group_desc_csum(sb)) {
1035 int free;
1036 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1037
1038 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
1039 ext4_lock_group(sb, group); /* while we modify the bg desc */
1040 free = EXT4_INODES_PER_GROUP(sb) -
1041 ext4_itable_unused_count(sb, gdp);
1042 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1043 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1044 free = 0;
1045 }
1046 /*
1047 * Check the relative inode number against the last used
1048 * relative inode number in this group. if it is greater
1049 * we need to update the bg_itable_unused count
1050 */
1051 if (ino > free)
1052 ext4_itable_unused_set(sb, gdp,
1053 (EXT4_INODES_PER_GROUP(sb) - ino));
1054 up_read(&grp->alloc_sem);
1055 } else {
1056 ext4_lock_group(sb, group);
1057 }
1058
1059 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1060 if (S_ISDIR(mode)) {
1061 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1062 if (sbi->s_log_groups_per_flex) {
1063 ext4_group_t f = ext4_flex_group(sbi, group);
1064
1065 atomic_inc(&sbi->s_flex_groups[f].used_dirs);
1066 }
1067 }
1068 if (ext4_has_group_desc_csum(sb)) {
1069 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1070 EXT4_INODES_PER_GROUP(sb) / 8);
1071 ext4_group_desc_csum_set(sb, group, gdp);
1072 }
1073 ext4_unlock_group(sb, group);
1074
1075 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1076 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1077 if (err) {
1078 ext4_std_error(sb, err);
1079 goto out;
1080 }
1081
1082 percpu_counter_dec(&sbi->s_freeinodes_counter);
1083 if (S_ISDIR(mode))
1084 percpu_counter_inc(&sbi->s_dirs_counter);
1085
1086 if (sbi->s_log_groups_per_flex) {
1087 flex_group = ext4_flex_group(sbi, group);
1088 atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes);
1089 }
1090
1091 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1092 /* This is the optimal IO size (for stat), not the fs block size */
1093 inode->i_blocks = 0;
1094 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
1095 current_time(inode);
1096
1097 memset(ei->i_data, 0, sizeof(ei->i_data));
1098 ei->i_dir_start_lookup = 0;
1099 ei->i_disksize = 0;
1100
1101 /* Don't inherit extent flag from directory, amongst others. */
1102 ei->i_flags =
1103 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1104 ei->i_flags |= i_flags;
1105 ei->i_file_acl = 0;
1106 ei->i_dtime = 0;
1107 ei->i_block_group = group;
1108 ei->i_last_alloc_group = ~0;
1109
1110 ext4_set_inode_flags(inode);
1111 if (IS_DIRSYNC(inode))
1112 ext4_handle_sync(handle);
1113 if (insert_inode_locked(inode) < 0) {
1114 /*
1115 * Likely a bitmap corruption causing inode to be allocated
1116 * twice.
1117 */
1118 err = -EIO;
1119 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1120 inode->i_ino);
1121 goto out;
1122 }
1123 spin_lock(&sbi->s_next_gen_lock);
1124 inode->i_generation = sbi->s_next_generation++;
1125 spin_unlock(&sbi->s_next_gen_lock);
1126
1127 /* Precompute checksum seed for inode metadata */
1128 if (ext4_has_metadata_csum(sb)) {
1129 __u32 csum;
1130 __le32 inum = cpu_to_le32(inode->i_ino);
1131 __le32 gen = cpu_to_le32(inode->i_generation);
1132 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1133 sizeof(inum));
1134 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1135 sizeof(gen));
1136 }
1137
1138 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1139 ext4_set_inode_state(inode, EXT4_STATE_NEW);
1140
1141 ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
1142 ei->i_inline_off = 0;
1143 if (ext4_has_feature_inline_data(sb))
1144 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1145 ret = inode;
1146 err = dquot_alloc_inode(inode);
1147 if (err)
1148 goto fail_drop;
1149
1150 /*
1151 * Since the encryption xattr will always be unique, create it first so
1152 * that it's less likely to end up in an external xattr block and
1153 * prevent its deduplication.
1154 */
1155 if (encrypt) {
1156 err = fscrypt_inherit_context(dir, inode, handle, true);
1157 if (err)
1158 goto fail_free_drop;
1159 }
1160
1161 if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1162 err = ext4_init_acl(handle, inode, dir);
1163 if (err)
1164 goto fail_free_drop;
1165
1166 err = ext4_init_security(handle, inode, dir, qstr);
1167 if (err)
1168 goto fail_free_drop;
1169 }
1170
1171 if (ext4_has_feature_extents(sb)) {
1172 /* set extent flag only for directory, file and normal symlink*/
1173 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1174 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1175 ext4_ext_tree_init(handle, inode);
1176 }
1177 }
1178
1179 if (ext4_handle_valid(handle)) {
1180 ei->i_sync_tid = handle->h_transaction->t_tid;
1181 ei->i_datasync_tid = handle->h_transaction->t_tid;
1182 }
1183
1184 err = ext4_mark_inode_dirty(handle, inode);
1185 if (err) {
1186 ext4_std_error(sb, err);
1187 goto fail_free_drop;
1188 }
1189
1190 ext4_debug("allocating inode %lu\n", inode->i_ino);
1191 trace_ext4_allocate_inode(inode, dir, mode);
1192 brelse(inode_bitmap_bh);
1193 return ret;
1194
1195fail_free_drop:
1196 dquot_free_inode(inode);
1197fail_drop:
1198 clear_nlink(inode);
1199 unlock_new_inode(inode);
1200out:
1201 dquot_drop(inode);
1202 inode->i_flags |= S_NOQUOTA;
1203 iput(inode);
1204 brelse(inode_bitmap_bh);
1205 return ERR_PTR(err);
1206}
1207
1208/* Verify that we are loading a valid orphan from disk */
1209struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1210{
1211 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1212 ext4_group_t block_group;
1213 int bit;
1214 struct buffer_head *bitmap_bh = NULL;
1215 struct inode *inode = NULL;
1216 int err = -EFSCORRUPTED;
1217
1218 if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1219 goto bad_orphan;
1220
1221 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1222 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1223 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1224 if (IS_ERR(bitmap_bh)) {
1225 ext4_error(sb, "inode bitmap error %ld for orphan %lu",
1226 ino, PTR_ERR(bitmap_bh));
1227 return (struct inode *) bitmap_bh;
1228 }
1229
1230 /* Having the inode bit set should be a 100% indicator that this
1231 * is a valid orphan (no e2fsck run on fs). Orphans also include
1232 * inodes that were being truncated, so we can't check i_nlink==0.
1233 */
1234 if (!ext4_test_bit(bit, bitmap_bh->b_data))
1235 goto bad_orphan;
1236
1237 inode = ext4_iget(sb, ino);
1238 if (IS_ERR(inode)) {
1239 err = PTR_ERR(inode);
1240 ext4_error(sb, "couldn't read orphan inode %lu (err %d)",
1241 ino, err);
1242 return inode;
1243 }
1244
1245 /*
1246 * If the orphans has i_nlinks > 0 then it should be able to
1247 * be truncated, otherwise it won't be removed from the orphan
1248 * list during processing and an infinite loop will result.
1249 * Similarly, it must not be a bad inode.
1250 */
1251 if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1252 is_bad_inode(inode))
1253 goto bad_orphan;
1254
1255 if (NEXT_ORPHAN(inode) > max_ino)
1256 goto bad_orphan;
1257 brelse(bitmap_bh);
1258 return inode;
1259
1260bad_orphan:
1261 ext4_error(sb, "bad orphan inode %lu", ino);
1262 if (bitmap_bh)
1263 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1264 bit, (unsigned long long)bitmap_bh->b_blocknr,
1265 ext4_test_bit(bit, bitmap_bh->b_data));
1266 if (inode) {
1267 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1268 is_bad_inode(inode));
1269 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1270 NEXT_ORPHAN(inode));
1271 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1272 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1273 /* Avoid freeing blocks if we got a bad deleted inode */
1274 if (inode->i_nlink == 0)
1275 inode->i_blocks = 0;
1276 iput(inode);
1277 }
1278 brelse(bitmap_bh);
1279 return ERR_PTR(err);
1280}
1281
1282unsigned long ext4_count_free_inodes(struct super_block *sb)
1283{
1284 unsigned long desc_count;
1285 struct ext4_group_desc *gdp;
1286 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1287#ifdef EXT4FS_DEBUG
1288 struct ext4_super_block *es;
1289 unsigned long bitmap_count, x;
1290 struct buffer_head *bitmap_bh = NULL;
1291
1292 es = EXT4_SB(sb)->s_es;
1293 desc_count = 0;
1294 bitmap_count = 0;
1295 gdp = NULL;
1296 for (i = 0; i < ngroups; i++) {
1297 gdp = ext4_get_group_desc(sb, i, NULL);
1298 if (!gdp)
1299 continue;
1300 desc_count += ext4_free_inodes_count(sb, gdp);
1301 brelse(bitmap_bh);
1302 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1303 if (IS_ERR(bitmap_bh)) {
1304 bitmap_bh = NULL;
1305 continue;
1306 }
1307
1308 x = ext4_count_free(bitmap_bh->b_data,
1309 EXT4_INODES_PER_GROUP(sb) / 8);
1310 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1311 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1312 bitmap_count += x;
1313 }
1314 brelse(bitmap_bh);
1315 printk(KERN_DEBUG "ext4_count_free_inodes: "
1316 "stored = %u, computed = %lu, %lu\n",
1317 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1318 return desc_count;
1319#else
1320 desc_count = 0;
1321 for (i = 0; i < ngroups; i++) {
1322 gdp = ext4_get_group_desc(sb, i, NULL);
1323 if (!gdp)
1324 continue;
1325 desc_count += ext4_free_inodes_count(sb, gdp);
1326 cond_resched();
1327 }
1328 return desc_count;
1329#endif
1330}
1331
1332/* Called at mount-time, super-block is locked */
1333unsigned long ext4_count_dirs(struct super_block * sb)
1334{
1335 unsigned long count = 0;
1336 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1337
1338 for (i = 0; i < ngroups; i++) {
1339 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1340 if (!gdp)
1341 continue;
1342 count += ext4_used_dirs_count(sb, gdp);
1343 }
1344 return count;
1345}
1346
1347/*
1348 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1349 * inode table. Must be called without any spinlock held. The only place
1350 * where it is called from on active part of filesystem is ext4lazyinit
1351 * thread, so we do not need any special locks, however we have to prevent
1352 * inode allocation from the current group, so we take alloc_sem lock, to
1353 * block ext4_new_inode() until we are finished.
1354 */
1355int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1356 int barrier)
1357{
1358 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1359 struct ext4_sb_info *sbi = EXT4_SB(sb);
1360 struct ext4_group_desc *gdp = NULL;
1361 struct buffer_head *group_desc_bh;
1362 handle_t *handle;
1363 ext4_fsblk_t blk;
1364 int num, ret = 0, used_blks = 0;
1365
1366 /* This should not happen, but just to be sure check this */
1367 if (sb_rdonly(sb)) {
1368 ret = 1;
1369 goto out;
1370 }
1371
1372 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1373 if (!gdp)
1374 goto out;
1375
1376 /*
1377 * We do not need to lock this, because we are the only one
1378 * handling this flag.
1379 */
1380 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1381 goto out;
1382
1383 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1384 if (IS_ERR(handle)) {
1385 ret = PTR_ERR(handle);
1386 goto out;
1387 }
1388
1389 down_write(&grp->alloc_sem);
1390 /*
1391 * If inode bitmap was already initialized there may be some
1392 * used inodes so we need to skip blocks with used inodes in
1393 * inode table.
1394 */
1395 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
1396 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
1397 ext4_itable_unused_count(sb, gdp)),
1398 sbi->s_inodes_per_block);
1399
1400 if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group) ||
1401 ((group == 0) && ((EXT4_INODES_PER_GROUP(sb) -
1402 ext4_itable_unused_count(sb, gdp)) <
1403 EXT4_FIRST_INO(sb)))) {
1404 ext4_error(sb, "Something is wrong with group %u: "
1405 "used itable blocks: %d; "
1406 "itable unused count: %u",
1407 group, used_blks,
1408 ext4_itable_unused_count(sb, gdp));
1409 ret = 1;
1410 goto err_out;
1411 }
1412
1413 blk = ext4_inode_table(sb, gdp) + used_blks;
1414 num = sbi->s_itb_per_group - used_blks;
1415
1416 BUFFER_TRACE(group_desc_bh, "get_write_access");
1417 ret = ext4_journal_get_write_access(handle,
1418 group_desc_bh);
1419 if (ret)
1420 goto err_out;
1421
1422 /*
1423 * Skip zeroout if the inode table is full. But we set the ZEROED
1424 * flag anyway, because obviously, when it is full it does not need
1425 * further zeroing.
1426 */
1427 if (unlikely(num == 0))
1428 goto skip_zeroout;
1429
1430 ext4_debug("going to zero out inode table in group %d\n",
1431 group);
1432 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1433 if (ret < 0)
1434 goto err_out;
1435 if (barrier)
1436 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1437
1438skip_zeroout:
1439 ext4_lock_group(sb, group);
1440 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1441 ext4_group_desc_csum_set(sb, group, gdp);
1442 ext4_unlock_group(sb, group);
1443
1444 BUFFER_TRACE(group_desc_bh,
1445 "call ext4_handle_dirty_metadata");
1446 ret = ext4_handle_dirty_metadata(handle, NULL,
1447 group_desc_bh);
1448
1449err_out:
1450 up_write(&grp->alloc_sem);
1451 ext4_journal_stop(handle);
1452out:
1453 return ret;
1454}