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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;
86
87 if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)
88 return 0;
89
90 grp = ext4_get_group_info(sb, block_group);
91
92 if (buffer_verified(bh))
93 return 0;
94 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
95 return -EFSCORRUPTED;
96
97 ext4_lock_group(sb, block_group);
98 if (buffer_verified(bh))
99 goto verified;
100 blk = ext4_inode_bitmap(sb, desc);
101 if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
102 EXT4_INODES_PER_GROUP(sb) / 8) ||
103 ext4_simulate_fail(sb, EXT4_SIM_IBITMAP_CRC)) {
104 ext4_unlock_group(sb, block_group);
105 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
106 "inode_bitmap = %llu", block_group, blk);
107 ext4_mark_group_bitmap_corrupted(sb, block_group,
108 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
109 return -EFSBADCRC;
110 }
111 set_buffer_verified(bh);
112verified:
113 ext4_unlock_group(sb, block_group);
114 return 0;
115}
116
117/*
118 * Read the inode allocation bitmap for a given block_group, reading
119 * into the specified slot in the superblock's bitmap cache.
120 *
121 * Return buffer_head of bitmap on success, or an ERR_PTR on error.
122 */
123static struct buffer_head *
124ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
125{
126 struct ext4_group_desc *desc;
127 struct ext4_sb_info *sbi = EXT4_SB(sb);
128 struct buffer_head *bh = NULL;
129 ext4_fsblk_t bitmap_blk;
130 int err;
131
132 desc = ext4_get_group_desc(sb, block_group, NULL);
133 if (!desc)
134 return ERR_PTR(-EFSCORRUPTED);
135
136 bitmap_blk = ext4_inode_bitmap(sb, desc);
137 if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
138 (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
139 ext4_error(sb, "Invalid inode bitmap blk %llu in "
140 "block_group %u", bitmap_blk, block_group);
141 ext4_mark_group_bitmap_corrupted(sb, block_group,
142 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
143 return ERR_PTR(-EFSCORRUPTED);
144 }
145 bh = sb_getblk(sb, bitmap_blk);
146 if (unlikely(!bh)) {
147 ext4_warning(sb, "Cannot read inode bitmap - "
148 "block_group = %u, inode_bitmap = %llu",
149 block_group, bitmap_blk);
150 return ERR_PTR(-ENOMEM);
151 }
152 if (bitmap_uptodate(bh))
153 goto verify;
154
155 lock_buffer(bh);
156 if (bitmap_uptodate(bh)) {
157 unlock_buffer(bh);
158 goto verify;
159 }
160
161 ext4_lock_group(sb, block_group);
162 if (ext4_has_group_desc_csum(sb) &&
163 (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
164 if (block_group == 0) {
165 ext4_unlock_group(sb, block_group);
166 unlock_buffer(bh);
167 ext4_error(sb, "Inode bitmap for bg 0 marked "
168 "uninitialized");
169 err = -EFSCORRUPTED;
170 goto out;
171 }
172 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
173 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
174 sb->s_blocksize * 8, bh->b_data);
175 set_bitmap_uptodate(bh);
176 set_buffer_uptodate(bh);
177 set_buffer_verified(bh);
178 ext4_unlock_group(sb, block_group);
179 unlock_buffer(bh);
180 return bh;
181 }
182 ext4_unlock_group(sb, block_group);
183
184 if (buffer_uptodate(bh)) {
185 /*
186 * if not uninit if bh is uptodate,
187 * bitmap is also uptodate
188 */
189 set_bitmap_uptodate(bh);
190 unlock_buffer(bh);
191 goto verify;
192 }
193 /*
194 * submit the buffer_head for reading
195 */
196 trace_ext4_load_inode_bitmap(sb, block_group);
197 ext4_read_bh(bh, REQ_META | REQ_PRIO, ext4_end_bitmap_read);
198 ext4_simulate_fail_bh(sb, bh, EXT4_SIM_IBITMAP_EIO);
199 if (!buffer_uptodate(bh)) {
200 put_bh(bh);
201 ext4_error_err(sb, EIO, "Cannot read inode bitmap - "
202 "block_group = %u, inode_bitmap = %llu",
203 block_group, bitmap_blk);
204 ext4_mark_group_bitmap_corrupted(sb, block_group,
205 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
206 return ERR_PTR(-EIO);
207 }
208
209verify:
210 err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
211 if (err)
212 goto out;
213 return bh;
214out:
215 put_bh(bh);
216 return ERR_PTR(err);
217}
218
219/*
220 * NOTE! When we get the inode, we're the only people
221 * that have access to it, and as such there are no
222 * race conditions we have to worry about. The inode
223 * is not on the hash-lists, and it cannot be reached
224 * through the filesystem because the directory entry
225 * has been deleted earlier.
226 *
227 * HOWEVER: we must make sure that we get no aliases,
228 * which means that we have to call "clear_inode()"
229 * _before_ we mark the inode not in use in the inode
230 * bitmaps. Otherwise a newly created file might use
231 * the same inode number (not actually the same pointer
232 * though), and then we'd have two inodes sharing the
233 * same inode number and space on the harddisk.
234 */
235void ext4_free_inode(handle_t *handle, struct inode *inode)
236{
237 struct super_block *sb = inode->i_sb;
238 int is_directory;
239 unsigned long ino;
240 struct buffer_head *bitmap_bh = NULL;
241 struct buffer_head *bh2;
242 ext4_group_t block_group;
243 unsigned long bit;
244 struct ext4_group_desc *gdp;
245 struct ext4_super_block *es;
246 struct ext4_sb_info *sbi;
247 int fatal = 0, err, count, cleared;
248 struct ext4_group_info *grp;
249
250 if (!sb) {
251 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
252 "nonexistent device\n", __func__, __LINE__);
253 return;
254 }
255 if (atomic_read(&inode->i_count) > 1) {
256 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
257 __func__, __LINE__, inode->i_ino,
258 atomic_read(&inode->i_count));
259 return;
260 }
261 if (inode->i_nlink) {
262 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
263 __func__, __LINE__, inode->i_ino, inode->i_nlink);
264 return;
265 }
266 sbi = EXT4_SB(sb);
267
268 ino = inode->i_ino;
269 ext4_debug("freeing inode %lu\n", ino);
270 trace_ext4_free_inode(inode);
271
272 dquot_initialize(inode);
273 dquot_free_inode(inode);
274
275 is_directory = S_ISDIR(inode->i_mode);
276
277 /* Do this BEFORE marking the inode not in use or returning an error */
278 ext4_clear_inode(inode);
279
280 es = sbi->s_es;
281 if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
282 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
283 goto error_return;
284 }
285 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
286 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
287 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
288 /* Don't bother if the inode bitmap is corrupt. */
289 if (IS_ERR(bitmap_bh)) {
290 fatal = PTR_ERR(bitmap_bh);
291 bitmap_bh = NULL;
292 goto error_return;
293 }
294 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
295 grp = ext4_get_group_info(sb, block_group);
296 if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
297 fatal = -EFSCORRUPTED;
298 goto error_return;
299 }
300 }
301
302 BUFFER_TRACE(bitmap_bh, "get_write_access");
303 fatal = ext4_journal_get_write_access(handle, bitmap_bh);
304 if (fatal)
305 goto error_return;
306
307 fatal = -ESRCH;
308 gdp = ext4_get_group_desc(sb, block_group, &bh2);
309 if (gdp) {
310 BUFFER_TRACE(bh2, "get_write_access");
311 fatal = ext4_journal_get_write_access(handle, bh2);
312 }
313 ext4_lock_group(sb, block_group);
314 cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
315 if (fatal || !cleared) {
316 ext4_unlock_group(sb, block_group);
317 goto out;
318 }
319
320 count = ext4_free_inodes_count(sb, gdp) + 1;
321 ext4_free_inodes_set(sb, gdp, count);
322 if (is_directory) {
323 count = ext4_used_dirs_count(sb, gdp) - 1;
324 ext4_used_dirs_set(sb, gdp, count);
325 if (percpu_counter_initialized(&sbi->s_dirs_counter))
326 percpu_counter_dec(&sbi->s_dirs_counter);
327 }
328 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
329 EXT4_INODES_PER_GROUP(sb) / 8);
330 ext4_group_desc_csum_set(sb, block_group, gdp);
331 ext4_unlock_group(sb, block_group);
332
333 if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
334 percpu_counter_inc(&sbi->s_freeinodes_counter);
335 if (sbi->s_log_groups_per_flex) {
336 struct flex_groups *fg;
337
338 fg = sbi_array_rcu_deref(sbi, s_flex_groups,
339 ext4_flex_group(sbi, block_group));
340 atomic_inc(&fg->free_inodes);
341 if (is_directory)
342 atomic_dec(&fg->used_dirs);
343 }
344 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
345 fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
346out:
347 if (cleared) {
348 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
349 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
350 if (!fatal)
351 fatal = err;
352 } else {
353 ext4_error(sb, "bit already cleared for inode %lu", ino);
354 ext4_mark_group_bitmap_corrupted(sb, block_group,
355 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
356 }
357
358error_return:
359 brelse(bitmap_bh);
360 ext4_std_error(sb, fatal);
361}
362
363struct orlov_stats {
364 __u64 free_clusters;
365 __u32 free_inodes;
366 __u32 used_dirs;
367};
368
369/*
370 * Helper function for Orlov's allocator; returns critical information
371 * for a particular block group or flex_bg. If flex_size is 1, then g
372 * is a block group number; otherwise it is flex_bg number.
373 */
374static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
375 int flex_size, struct orlov_stats *stats)
376{
377 struct ext4_group_desc *desc;
378
379 if (flex_size > 1) {
380 struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),
381 s_flex_groups, g);
382 stats->free_inodes = atomic_read(&fg->free_inodes);
383 stats->free_clusters = atomic64_read(&fg->free_clusters);
384 stats->used_dirs = atomic_read(&fg->used_dirs);
385 return;
386 }
387
388 desc = ext4_get_group_desc(sb, g, NULL);
389 if (desc) {
390 stats->free_inodes = ext4_free_inodes_count(sb, desc);
391 stats->free_clusters = ext4_free_group_clusters(sb, desc);
392 stats->used_dirs = ext4_used_dirs_count(sb, desc);
393 } else {
394 stats->free_inodes = 0;
395 stats->free_clusters = 0;
396 stats->used_dirs = 0;
397 }
398}
399
400/*
401 * Orlov's allocator for directories.
402 *
403 * We always try to spread first-level directories.
404 *
405 * If there are blockgroups with both free inodes and free clusters counts
406 * not worse than average we return one with smallest directory count.
407 * Otherwise we simply return a random group.
408 *
409 * For the rest rules look so:
410 *
411 * It's OK to put directory into a group unless
412 * it has too many directories already (max_dirs) or
413 * it has too few free inodes left (min_inodes) or
414 * it has too few free clusters left (min_clusters) or
415 * Parent's group is preferred, if it doesn't satisfy these
416 * conditions we search cyclically through the rest. If none
417 * of the groups look good we just look for a group with more
418 * free inodes than average (starting at parent's group).
419 */
420
421static int find_group_orlov(struct super_block *sb, struct inode *parent,
422 ext4_group_t *group, umode_t mode,
423 const struct qstr *qstr)
424{
425 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
426 struct ext4_sb_info *sbi = EXT4_SB(sb);
427 ext4_group_t real_ngroups = ext4_get_groups_count(sb);
428 int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
429 unsigned int freei, avefreei, grp_free;
430 ext4_fsblk_t freec, avefreec;
431 unsigned int ndirs;
432 int max_dirs, min_inodes;
433 ext4_grpblk_t min_clusters;
434 ext4_group_t i, grp, g, ngroups;
435 struct ext4_group_desc *desc;
436 struct orlov_stats stats;
437 int flex_size = ext4_flex_bg_size(sbi);
438 struct dx_hash_info hinfo;
439
440 ngroups = real_ngroups;
441 if (flex_size > 1) {
442 ngroups = (real_ngroups + flex_size - 1) >>
443 sbi->s_log_groups_per_flex;
444 parent_group >>= sbi->s_log_groups_per_flex;
445 }
446
447 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
448 avefreei = freei / ngroups;
449 freec = percpu_counter_read_positive(&sbi->s_freeclusters_counter);
450 avefreec = freec;
451 do_div(avefreec, ngroups);
452 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
453
454 if (S_ISDIR(mode) &&
455 ((parent == d_inode(sb->s_root)) ||
456 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
457 int best_ndir = inodes_per_group;
458 int ret = -1;
459
460 if (qstr) {
461 hinfo.hash_version = DX_HASH_HALF_MD4;
462 hinfo.seed = sbi->s_hash_seed;
463 ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);
464 grp = hinfo.hash;
465 } else
466 grp = prandom_u32();
467 parent_group = (unsigned)grp % ngroups;
468 for (i = 0; i < ngroups; i++) {
469 g = (parent_group + i) % ngroups;
470 get_orlov_stats(sb, g, flex_size, &stats);
471 if (!stats.free_inodes)
472 continue;
473 if (stats.used_dirs >= best_ndir)
474 continue;
475 if (stats.free_inodes < avefreei)
476 continue;
477 if (stats.free_clusters < avefreec)
478 continue;
479 grp = g;
480 ret = 0;
481 best_ndir = stats.used_dirs;
482 }
483 if (ret)
484 goto fallback;
485 found_flex_bg:
486 if (flex_size == 1) {
487 *group = grp;
488 return 0;
489 }
490
491 /*
492 * We pack inodes at the beginning of the flexgroup's
493 * inode tables. Block allocation decisions will do
494 * something similar, although regular files will
495 * start at 2nd block group of the flexgroup. See
496 * ext4_ext_find_goal() and ext4_find_near().
497 */
498 grp *= flex_size;
499 for (i = 0; i < flex_size; i++) {
500 if (grp+i >= real_ngroups)
501 break;
502 desc = ext4_get_group_desc(sb, grp+i, NULL);
503 if (desc && ext4_free_inodes_count(sb, desc)) {
504 *group = grp+i;
505 return 0;
506 }
507 }
508 goto fallback;
509 }
510
511 max_dirs = ndirs / ngroups + inodes_per_group / 16;
512 min_inodes = avefreei - inodes_per_group*flex_size / 4;
513 if (min_inodes < 1)
514 min_inodes = 1;
515 min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
516
517 /*
518 * Start looking in the flex group where we last allocated an
519 * inode for this parent directory
520 */
521 if (EXT4_I(parent)->i_last_alloc_group != ~0) {
522 parent_group = EXT4_I(parent)->i_last_alloc_group;
523 if (flex_size > 1)
524 parent_group >>= sbi->s_log_groups_per_flex;
525 }
526
527 for (i = 0; i < ngroups; i++) {
528 grp = (parent_group + i) % ngroups;
529 get_orlov_stats(sb, grp, flex_size, &stats);
530 if (stats.used_dirs >= max_dirs)
531 continue;
532 if (stats.free_inodes < min_inodes)
533 continue;
534 if (stats.free_clusters < min_clusters)
535 continue;
536 goto found_flex_bg;
537 }
538
539fallback:
540 ngroups = real_ngroups;
541 avefreei = freei / ngroups;
542fallback_retry:
543 parent_group = EXT4_I(parent)->i_block_group;
544 for (i = 0; i < ngroups; i++) {
545 grp = (parent_group + i) % ngroups;
546 desc = ext4_get_group_desc(sb, grp, NULL);
547 if (desc) {
548 grp_free = ext4_free_inodes_count(sb, desc);
549 if (grp_free && grp_free >= avefreei) {
550 *group = grp;
551 return 0;
552 }
553 }
554 }
555
556 if (avefreei) {
557 /*
558 * The free-inodes counter is approximate, and for really small
559 * filesystems the above test can fail to find any blockgroups
560 */
561 avefreei = 0;
562 goto fallback_retry;
563 }
564
565 return -1;
566}
567
568static int find_group_other(struct super_block *sb, struct inode *parent,
569 ext4_group_t *group, umode_t mode)
570{
571 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
572 ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
573 struct ext4_group_desc *desc;
574 int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
575
576 /*
577 * Try to place the inode is the same flex group as its
578 * parent. If we can't find space, use the Orlov algorithm to
579 * find another flex group, and store that information in the
580 * parent directory's inode information so that use that flex
581 * group for future allocations.
582 */
583 if (flex_size > 1) {
584 int retry = 0;
585
586 try_again:
587 parent_group &= ~(flex_size-1);
588 last = parent_group + flex_size;
589 if (last > ngroups)
590 last = ngroups;
591 for (i = parent_group; i < last; i++) {
592 desc = ext4_get_group_desc(sb, i, NULL);
593 if (desc && ext4_free_inodes_count(sb, desc)) {
594 *group = i;
595 return 0;
596 }
597 }
598 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
599 retry = 1;
600 parent_group = EXT4_I(parent)->i_last_alloc_group;
601 goto try_again;
602 }
603 /*
604 * If this didn't work, use the Orlov search algorithm
605 * to find a new flex group; we pass in the mode to
606 * avoid the topdir algorithms.
607 */
608 *group = parent_group + flex_size;
609 if (*group > ngroups)
610 *group = 0;
611 return find_group_orlov(sb, parent, group, mode, NULL);
612 }
613
614 /*
615 * Try to place the inode in its parent directory
616 */
617 *group = parent_group;
618 desc = ext4_get_group_desc(sb, *group, NULL);
619 if (desc && ext4_free_inodes_count(sb, desc) &&
620 ext4_free_group_clusters(sb, desc))
621 return 0;
622
623 /*
624 * We're going to place this inode in a different blockgroup from its
625 * parent. We want to cause files in a common directory to all land in
626 * the same blockgroup. But we want files which are in a different
627 * directory which shares a blockgroup with our parent to land in a
628 * different blockgroup.
629 *
630 * So add our directory's i_ino into the starting point for the hash.
631 */
632 *group = (*group + parent->i_ino) % ngroups;
633
634 /*
635 * Use a quadratic hash to find a group with a free inode and some free
636 * blocks.
637 */
638 for (i = 1; i < ngroups; i <<= 1) {
639 *group += i;
640 if (*group >= ngroups)
641 *group -= ngroups;
642 desc = ext4_get_group_desc(sb, *group, NULL);
643 if (desc && ext4_free_inodes_count(sb, desc) &&
644 ext4_free_group_clusters(sb, desc))
645 return 0;
646 }
647
648 /*
649 * That failed: try linear search for a free inode, even if that group
650 * has no free blocks.
651 */
652 *group = parent_group;
653 for (i = 0; i < ngroups; i++) {
654 if (++*group >= ngroups)
655 *group = 0;
656 desc = ext4_get_group_desc(sb, *group, NULL);
657 if (desc && ext4_free_inodes_count(sb, desc))
658 return 0;
659 }
660
661 return -1;
662}
663
664/*
665 * In no journal mode, if an inode has recently been deleted, we want
666 * to avoid reusing it until we're reasonably sure the inode table
667 * block has been written back to disk. (Yes, these values are
668 * somewhat arbitrary...)
669 */
670#define RECENTCY_MIN 60
671#define RECENTCY_DIRTY 300
672
673static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
674{
675 struct ext4_group_desc *gdp;
676 struct ext4_inode *raw_inode;
677 struct buffer_head *bh;
678 int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
679 int offset, ret = 0;
680 int recentcy = RECENTCY_MIN;
681 u32 dtime, now;
682
683 gdp = ext4_get_group_desc(sb, group, NULL);
684 if (unlikely(!gdp))
685 return 0;
686
687 bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
688 (ino / inodes_per_block));
689 if (!bh || !buffer_uptodate(bh))
690 /*
691 * If the block is not in the buffer cache, then it
692 * must have been written out.
693 */
694 goto out;
695
696 offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
697 raw_inode = (struct ext4_inode *) (bh->b_data + offset);
698
699 /* i_dtime is only 32 bits on disk, but we only care about relative
700 * times in the range of a few minutes (i.e. long enough to sync a
701 * recently-deleted inode to disk), so using the low 32 bits of the
702 * clock (a 68 year range) is enough, see time_before32() */
703 dtime = le32_to_cpu(raw_inode->i_dtime);
704 now = ktime_get_real_seconds();
705 if (buffer_dirty(bh))
706 recentcy += RECENTCY_DIRTY;
707
708 if (dtime && time_before32(dtime, now) &&
709 time_before32(now, dtime + recentcy))
710 ret = 1;
711out:
712 brelse(bh);
713 return ret;
714}
715
716static int find_inode_bit(struct super_block *sb, ext4_group_t group,
717 struct buffer_head *bitmap, unsigned long *ino)
718{
719 bool check_recently_deleted = EXT4_SB(sb)->s_journal == NULL;
720 unsigned long recently_deleted_ino = EXT4_INODES_PER_GROUP(sb);
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 goto not_found;
728
729 if (check_recently_deleted && recently_deleted(sb, group, *ino)) {
730 recently_deleted_ino = *ino;
731 *ino = *ino + 1;
732 if (*ino < EXT4_INODES_PER_GROUP(sb))
733 goto next;
734 goto not_found;
735 }
736 return 1;
737not_found:
738 if (recently_deleted_ino >= EXT4_INODES_PER_GROUP(sb))
739 return 0;
740 /*
741 * Not reusing recently deleted inodes is mostly a preference. We don't
742 * want to report ENOSPC or skew allocation patterns because of that.
743 * So return even recently deleted inode if we could find better in the
744 * given range.
745 */
746 *ino = recently_deleted_ino;
747 return 1;
748}
749
750int ext4_mark_inode_used(struct super_block *sb, int ino)
751{
752 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
753 struct buffer_head *inode_bitmap_bh = NULL, *group_desc_bh = NULL;
754 struct ext4_group_desc *gdp;
755 ext4_group_t group;
756 int bit;
757 int err = -EFSCORRUPTED;
758
759 if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
760 goto out;
761
762 group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
763 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
764 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
765 if (IS_ERR(inode_bitmap_bh))
766 return PTR_ERR(inode_bitmap_bh);
767
768 if (ext4_test_bit(bit, inode_bitmap_bh->b_data)) {
769 err = 0;
770 goto out;
771 }
772
773 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
774 if (!gdp || !group_desc_bh) {
775 err = -EINVAL;
776 goto out;
777 }
778
779 ext4_set_bit(bit, inode_bitmap_bh->b_data);
780
781 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
782 err = ext4_handle_dirty_metadata(NULL, NULL, inode_bitmap_bh);
783 if (err) {
784 ext4_std_error(sb, err);
785 goto out;
786 }
787 err = sync_dirty_buffer(inode_bitmap_bh);
788 if (err) {
789 ext4_std_error(sb, err);
790 goto out;
791 }
792
793 /* We may have to initialize the block bitmap if it isn't already */
794 if (ext4_has_group_desc_csum(sb) &&
795 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
796 struct buffer_head *block_bitmap_bh;
797
798 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
799 if (IS_ERR(block_bitmap_bh)) {
800 err = PTR_ERR(block_bitmap_bh);
801 goto out;
802 }
803
804 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
805 err = ext4_handle_dirty_metadata(NULL, NULL, block_bitmap_bh);
806 sync_dirty_buffer(block_bitmap_bh);
807
808 /* recheck and clear flag under lock if we still need to */
809 ext4_lock_group(sb, group);
810 if (ext4_has_group_desc_csum(sb) &&
811 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
812 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
813 ext4_free_group_clusters_set(sb, gdp,
814 ext4_free_clusters_after_init(sb, group, gdp));
815 ext4_block_bitmap_csum_set(sb, group, gdp,
816 block_bitmap_bh);
817 ext4_group_desc_csum_set(sb, group, gdp);
818 }
819 ext4_unlock_group(sb, group);
820 brelse(block_bitmap_bh);
821
822 if (err) {
823 ext4_std_error(sb, err);
824 goto out;
825 }
826 }
827
828 /* Update the relevant bg descriptor fields */
829 if (ext4_has_group_desc_csum(sb)) {
830 int free;
831
832 ext4_lock_group(sb, group); /* while we modify the bg desc */
833 free = EXT4_INODES_PER_GROUP(sb) -
834 ext4_itable_unused_count(sb, gdp);
835 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
836 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
837 free = 0;
838 }
839
840 /*
841 * Check the relative inode number against the last used
842 * relative inode number in this group. if it is greater
843 * we need to update the bg_itable_unused count
844 */
845 if (bit >= free)
846 ext4_itable_unused_set(sb, gdp,
847 (EXT4_INODES_PER_GROUP(sb) - bit - 1));
848 } else {
849 ext4_lock_group(sb, group);
850 }
851
852 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
853 if (ext4_has_group_desc_csum(sb)) {
854 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
855 EXT4_INODES_PER_GROUP(sb) / 8);
856 ext4_group_desc_csum_set(sb, group, gdp);
857 }
858
859 ext4_unlock_group(sb, group);
860 err = ext4_handle_dirty_metadata(NULL, NULL, group_desc_bh);
861 sync_dirty_buffer(group_desc_bh);
862out:
863 return err;
864}
865
866static int ext4_xattr_credits_for_new_inode(struct inode *dir, mode_t mode,
867 bool encrypt)
868{
869 struct super_block *sb = dir->i_sb;
870 int nblocks = 0;
871#ifdef CONFIG_EXT4_FS_POSIX_ACL
872 struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
873
874 if (IS_ERR(p))
875 return PTR_ERR(p);
876 if (p) {
877 int acl_size = p->a_count * sizeof(ext4_acl_entry);
878
879 nblocks += (S_ISDIR(mode) ? 2 : 1) *
880 __ext4_xattr_set_credits(sb, NULL /* inode */,
881 NULL /* block_bh */, acl_size,
882 true /* is_create */);
883 posix_acl_release(p);
884 }
885#endif
886
887#ifdef CONFIG_SECURITY
888 {
889 int num_security_xattrs = 1;
890
891#ifdef CONFIG_INTEGRITY
892 num_security_xattrs++;
893#endif
894 /*
895 * We assume that security xattrs are never more than 1k.
896 * In practice they are under 128 bytes.
897 */
898 nblocks += num_security_xattrs *
899 __ext4_xattr_set_credits(sb, NULL /* inode */,
900 NULL /* block_bh */, 1024,
901 true /* is_create */);
902 }
903#endif
904 if (encrypt)
905 nblocks += __ext4_xattr_set_credits(sb,
906 NULL /* inode */,
907 NULL /* block_bh */,
908 FSCRYPT_SET_CONTEXT_MAX_SIZE,
909 true /* is_create */);
910 return nblocks;
911}
912
913/*
914 * There are two policies for allocating an inode. If the new inode is
915 * a directory, then a forward search is made for a block group with both
916 * free space and a low directory-to-inode ratio; if that fails, then of
917 * the groups with above-average free space, that group with the fewest
918 * directories already is chosen.
919 *
920 * For other inodes, search forward from the parent directory's block
921 * group to find a free inode.
922 */
923struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
924 handle_t *handle, struct inode *dir,
925 umode_t mode, const struct qstr *qstr,
926 __u32 goal, uid_t *owner, __u32 i_flags,
927 int handle_type, unsigned int line_no,
928 int nblocks)
929{
930 struct super_block *sb;
931 struct buffer_head *inode_bitmap_bh = NULL;
932 struct buffer_head *group_desc_bh;
933 ext4_group_t ngroups, group = 0;
934 unsigned long ino = 0;
935 struct inode *inode;
936 struct ext4_group_desc *gdp = NULL;
937 struct ext4_inode_info *ei;
938 struct ext4_sb_info *sbi;
939 int ret2, err;
940 struct inode *ret;
941 ext4_group_t i;
942 ext4_group_t flex_group;
943 struct ext4_group_info *grp = NULL;
944 bool encrypt = false;
945
946 /* Cannot create files in a deleted directory */
947 if (!dir || !dir->i_nlink)
948 return ERR_PTR(-EPERM);
949
950 sb = dir->i_sb;
951 sbi = EXT4_SB(sb);
952
953 if (unlikely(ext4_forced_shutdown(sbi)))
954 return ERR_PTR(-EIO);
955
956 ngroups = ext4_get_groups_count(sb);
957 trace_ext4_request_inode(dir, mode);
958 inode = new_inode(sb);
959 if (!inode)
960 return ERR_PTR(-ENOMEM);
961 ei = EXT4_I(inode);
962
963 /*
964 * Initialize owners and quota early so that we don't have to account
965 * for quota initialization worst case in standard inode creating
966 * transaction
967 */
968 if (owner) {
969 inode->i_mode = mode;
970 i_uid_write(inode, owner[0]);
971 i_gid_write(inode, owner[1]);
972 } else if (test_opt(sb, GRPID)) {
973 inode->i_mode = mode;
974 inode_fsuid_set(inode, mnt_userns);
975 inode->i_gid = dir->i_gid;
976 } else
977 inode_init_owner(mnt_userns, inode, dir, mode);
978
979 if (ext4_has_feature_project(sb) &&
980 ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
981 ei->i_projid = EXT4_I(dir)->i_projid;
982 else
983 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
984
985 if (!(i_flags & EXT4_EA_INODE_FL)) {
986 err = fscrypt_prepare_new_inode(dir, inode, &encrypt);
987 if (err)
988 goto out;
989 }
990
991 err = dquot_initialize(inode);
992 if (err)
993 goto out;
994
995 if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
996 ret2 = ext4_xattr_credits_for_new_inode(dir, mode, encrypt);
997 if (ret2 < 0) {
998 err = ret2;
999 goto out;
1000 }
1001 nblocks += ret2;
1002 }
1003
1004 if (!goal)
1005 goal = sbi->s_inode_goal;
1006
1007 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
1008 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
1009 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
1010 ret2 = 0;
1011 goto got_group;
1012 }
1013
1014 if (S_ISDIR(mode))
1015 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
1016 else
1017 ret2 = find_group_other(sb, dir, &group, mode);
1018
1019got_group:
1020 EXT4_I(dir)->i_last_alloc_group = group;
1021 err = -ENOSPC;
1022 if (ret2 == -1)
1023 goto out;
1024
1025 /*
1026 * Normally we will only go through one pass of this loop,
1027 * unless we get unlucky and it turns out the group we selected
1028 * had its last inode grabbed by someone else.
1029 */
1030 for (i = 0; i < ngroups; i++, ino = 0) {
1031 err = -EIO;
1032
1033 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1034 if (!gdp)
1035 goto out;
1036
1037 /*
1038 * Check free inodes count before loading bitmap.
1039 */
1040 if (ext4_free_inodes_count(sb, gdp) == 0)
1041 goto next_group;
1042
1043 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1044 grp = ext4_get_group_info(sb, group);
1045 /*
1046 * Skip groups with already-known suspicious inode
1047 * tables
1048 */
1049 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
1050 goto next_group;
1051 }
1052
1053 brelse(inode_bitmap_bh);
1054 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
1055 /* Skip groups with suspicious inode tables */
1056 if (((!(sbi->s_mount_state & EXT4_FC_REPLAY))
1057 && EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) ||
1058 IS_ERR(inode_bitmap_bh)) {
1059 inode_bitmap_bh = NULL;
1060 goto next_group;
1061 }
1062
1063repeat_in_this_group:
1064 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
1065 if (!ret2)
1066 goto next_group;
1067
1068 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
1069 ext4_error(sb, "reserved inode found cleared - "
1070 "inode=%lu", ino + 1);
1071 ext4_mark_group_bitmap_corrupted(sb, group,
1072 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1073 goto next_group;
1074 }
1075
1076 if ((!(sbi->s_mount_state & EXT4_FC_REPLAY)) && !handle) {
1077 BUG_ON(nblocks <= 0);
1078 handle = __ext4_journal_start_sb(dir->i_sb, line_no,
1079 handle_type, nblocks, 0,
1080 ext4_trans_default_revoke_credits(sb));
1081 if (IS_ERR(handle)) {
1082 err = PTR_ERR(handle);
1083 ext4_std_error(sb, err);
1084 goto out;
1085 }
1086 }
1087 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
1088 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
1089 if (err) {
1090 ext4_std_error(sb, err);
1091 goto out;
1092 }
1093 ext4_lock_group(sb, group);
1094 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
1095 if (ret2) {
1096 /* Someone already took the bit. Repeat the search
1097 * with lock held.
1098 */
1099 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
1100 if (ret2) {
1101 ext4_set_bit(ino, inode_bitmap_bh->b_data);
1102 ret2 = 0;
1103 } else {
1104 ret2 = 1; /* we didn't grab the inode */
1105 }
1106 }
1107 ext4_unlock_group(sb, group);
1108 ino++; /* the inode bitmap is zero-based */
1109 if (!ret2)
1110 goto got; /* we grabbed the inode! */
1111
1112 if (ino < EXT4_INODES_PER_GROUP(sb))
1113 goto repeat_in_this_group;
1114next_group:
1115 if (++group == ngroups)
1116 group = 0;
1117 }
1118 err = -ENOSPC;
1119 goto out;
1120
1121got:
1122 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
1123 err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
1124 if (err) {
1125 ext4_std_error(sb, err);
1126 goto out;
1127 }
1128
1129 BUFFER_TRACE(group_desc_bh, "get_write_access");
1130 err = ext4_journal_get_write_access(handle, group_desc_bh);
1131 if (err) {
1132 ext4_std_error(sb, err);
1133 goto out;
1134 }
1135
1136 /* We may have to initialize the block bitmap if it isn't already */
1137 if (ext4_has_group_desc_csum(sb) &&
1138 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
1139 struct buffer_head *block_bitmap_bh;
1140
1141 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
1142 if (IS_ERR(block_bitmap_bh)) {
1143 err = PTR_ERR(block_bitmap_bh);
1144 goto out;
1145 }
1146 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
1147 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
1148 if (err) {
1149 brelse(block_bitmap_bh);
1150 ext4_std_error(sb, err);
1151 goto out;
1152 }
1153
1154 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1155 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1156
1157 /* recheck and clear flag under lock if we still need to */
1158 ext4_lock_group(sb, group);
1159 if (ext4_has_group_desc_csum(sb) &&
1160 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1161 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1162 ext4_free_group_clusters_set(sb, gdp,
1163 ext4_free_clusters_after_init(sb, group, gdp));
1164 ext4_block_bitmap_csum_set(sb, group, gdp,
1165 block_bitmap_bh);
1166 ext4_group_desc_csum_set(sb, group, gdp);
1167 }
1168 ext4_unlock_group(sb, group);
1169 brelse(block_bitmap_bh);
1170
1171 if (err) {
1172 ext4_std_error(sb, err);
1173 goto out;
1174 }
1175 }
1176
1177 /* Update the relevant bg descriptor fields */
1178 if (ext4_has_group_desc_csum(sb)) {
1179 int free;
1180 struct ext4_group_info *grp = NULL;
1181
1182 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1183 grp = ext4_get_group_info(sb, group);
1184 down_read(&grp->alloc_sem); /*
1185 * protect vs itable
1186 * lazyinit
1187 */
1188 }
1189 ext4_lock_group(sb, group); /* while we modify the bg desc */
1190 free = EXT4_INODES_PER_GROUP(sb) -
1191 ext4_itable_unused_count(sb, gdp);
1192 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1193 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1194 free = 0;
1195 }
1196 /*
1197 * Check the relative inode number against the last used
1198 * relative inode number in this group. if it is greater
1199 * we need to update the bg_itable_unused count
1200 */
1201 if (ino > free)
1202 ext4_itable_unused_set(sb, gdp,
1203 (EXT4_INODES_PER_GROUP(sb) - ino));
1204 if (!(sbi->s_mount_state & EXT4_FC_REPLAY))
1205 up_read(&grp->alloc_sem);
1206 } else {
1207 ext4_lock_group(sb, group);
1208 }
1209
1210 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1211 if (S_ISDIR(mode)) {
1212 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1213 if (sbi->s_log_groups_per_flex) {
1214 ext4_group_t f = ext4_flex_group(sbi, group);
1215
1216 atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1217 f)->used_dirs);
1218 }
1219 }
1220 if (ext4_has_group_desc_csum(sb)) {
1221 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1222 EXT4_INODES_PER_GROUP(sb) / 8);
1223 ext4_group_desc_csum_set(sb, group, gdp);
1224 }
1225 ext4_unlock_group(sb, group);
1226
1227 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1228 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1229 if (err) {
1230 ext4_std_error(sb, err);
1231 goto out;
1232 }
1233
1234 percpu_counter_dec(&sbi->s_freeinodes_counter);
1235 if (S_ISDIR(mode))
1236 percpu_counter_inc(&sbi->s_dirs_counter);
1237
1238 if (sbi->s_log_groups_per_flex) {
1239 flex_group = ext4_flex_group(sbi, group);
1240 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1241 flex_group)->free_inodes);
1242 }
1243
1244 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1245 /* This is the optimal IO size (for stat), not the fs block size */
1246 inode->i_blocks = 0;
1247 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1248 ei->i_crtime = inode->i_mtime;
1249
1250 memset(ei->i_data, 0, sizeof(ei->i_data));
1251 ei->i_dir_start_lookup = 0;
1252 ei->i_disksize = 0;
1253
1254 /* Don't inherit extent flag from directory, amongst others. */
1255 ei->i_flags =
1256 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1257 ei->i_flags |= i_flags;
1258 ei->i_file_acl = 0;
1259 ei->i_dtime = 0;
1260 ei->i_block_group = group;
1261 ei->i_last_alloc_group = ~0;
1262
1263 ext4_set_inode_flags(inode, true);
1264 if (IS_DIRSYNC(inode))
1265 ext4_handle_sync(handle);
1266 if (insert_inode_locked(inode) < 0) {
1267 /*
1268 * Likely a bitmap corruption causing inode to be allocated
1269 * twice.
1270 */
1271 err = -EIO;
1272 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1273 inode->i_ino);
1274 ext4_mark_group_bitmap_corrupted(sb, group,
1275 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1276 goto out;
1277 }
1278 inode->i_generation = prandom_u32();
1279
1280 /* Precompute checksum seed for inode metadata */
1281 if (ext4_has_metadata_csum(sb)) {
1282 __u32 csum;
1283 __le32 inum = cpu_to_le32(inode->i_ino);
1284 __le32 gen = cpu_to_le32(inode->i_generation);
1285 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1286 sizeof(inum));
1287 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1288 sizeof(gen));
1289 }
1290
1291 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1292 ext4_set_inode_state(inode, EXT4_STATE_NEW);
1293
1294 ei->i_extra_isize = sbi->s_want_extra_isize;
1295 ei->i_inline_off = 0;
1296 if (ext4_has_feature_inline_data(sb) &&
1297 (!(ei->i_flags & EXT4_DAX_FL) || S_ISDIR(mode)))
1298 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1299 ret = inode;
1300 err = dquot_alloc_inode(inode);
1301 if (err)
1302 goto fail_drop;
1303
1304 /*
1305 * Since the encryption xattr will always be unique, create it first so
1306 * that it's less likely to end up in an external xattr block and
1307 * prevent its deduplication.
1308 */
1309 if (encrypt) {
1310 err = fscrypt_set_context(inode, handle);
1311 if (err)
1312 goto fail_free_drop;
1313 }
1314
1315 if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1316 err = ext4_init_acl(handle, inode, dir);
1317 if (err)
1318 goto fail_free_drop;
1319
1320 err = ext4_init_security(handle, inode, dir, qstr);
1321 if (err)
1322 goto fail_free_drop;
1323 }
1324
1325 if (ext4_has_feature_extents(sb)) {
1326 /* set extent flag only for directory, file and normal symlink*/
1327 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1328 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1329 ext4_ext_tree_init(handle, inode);
1330 }
1331 }
1332
1333 if (ext4_handle_valid(handle)) {
1334 ei->i_sync_tid = handle->h_transaction->t_tid;
1335 ei->i_datasync_tid = handle->h_transaction->t_tid;
1336 }
1337
1338 err = ext4_mark_inode_dirty(handle, inode);
1339 if (err) {
1340 ext4_std_error(sb, err);
1341 goto fail_free_drop;
1342 }
1343
1344 ext4_debug("allocating inode %lu\n", inode->i_ino);
1345 trace_ext4_allocate_inode(inode, dir, mode);
1346 brelse(inode_bitmap_bh);
1347 return ret;
1348
1349fail_free_drop:
1350 dquot_free_inode(inode);
1351fail_drop:
1352 clear_nlink(inode);
1353 unlock_new_inode(inode);
1354out:
1355 dquot_drop(inode);
1356 inode->i_flags |= S_NOQUOTA;
1357 iput(inode);
1358 brelse(inode_bitmap_bh);
1359 return ERR_PTR(err);
1360}
1361
1362/* Verify that we are loading a valid orphan from disk */
1363struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1364{
1365 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1366 ext4_group_t block_group;
1367 int bit;
1368 struct buffer_head *bitmap_bh = NULL;
1369 struct inode *inode = NULL;
1370 int err = -EFSCORRUPTED;
1371
1372 if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1373 goto bad_orphan;
1374
1375 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1376 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1377 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1378 if (IS_ERR(bitmap_bh))
1379 return ERR_CAST(bitmap_bh);
1380
1381 /* Having the inode bit set should be a 100% indicator that this
1382 * is a valid orphan (no e2fsck run on fs). Orphans also include
1383 * inodes that were being truncated, so we can't check i_nlink==0.
1384 */
1385 if (!ext4_test_bit(bit, bitmap_bh->b_data))
1386 goto bad_orphan;
1387
1388 inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1389 if (IS_ERR(inode)) {
1390 err = PTR_ERR(inode);
1391 ext4_error_err(sb, -err,
1392 "couldn't read orphan inode %lu (err %d)",
1393 ino, err);
1394 brelse(bitmap_bh);
1395 return inode;
1396 }
1397
1398 /*
1399 * If the orphans has i_nlinks > 0 then it should be able to
1400 * be truncated, otherwise it won't be removed from the orphan
1401 * list during processing and an infinite loop will result.
1402 * Similarly, it must not be a bad inode.
1403 */
1404 if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1405 is_bad_inode(inode))
1406 goto bad_orphan;
1407
1408 if (NEXT_ORPHAN(inode) > max_ino)
1409 goto bad_orphan;
1410 brelse(bitmap_bh);
1411 return inode;
1412
1413bad_orphan:
1414 ext4_error(sb, "bad orphan inode %lu", ino);
1415 if (bitmap_bh)
1416 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1417 bit, (unsigned long long)bitmap_bh->b_blocknr,
1418 ext4_test_bit(bit, bitmap_bh->b_data));
1419 if (inode) {
1420 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1421 is_bad_inode(inode));
1422 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1423 NEXT_ORPHAN(inode));
1424 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1425 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1426 /* Avoid freeing blocks if we got a bad deleted inode */
1427 if (inode->i_nlink == 0)
1428 inode->i_blocks = 0;
1429 iput(inode);
1430 }
1431 brelse(bitmap_bh);
1432 return ERR_PTR(err);
1433}
1434
1435unsigned long ext4_count_free_inodes(struct super_block *sb)
1436{
1437 unsigned long desc_count;
1438 struct ext4_group_desc *gdp;
1439 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1440#ifdef EXT4FS_DEBUG
1441 struct ext4_super_block *es;
1442 unsigned long bitmap_count, x;
1443 struct buffer_head *bitmap_bh = NULL;
1444
1445 es = EXT4_SB(sb)->s_es;
1446 desc_count = 0;
1447 bitmap_count = 0;
1448 gdp = NULL;
1449 for (i = 0; i < ngroups; i++) {
1450 gdp = ext4_get_group_desc(sb, i, NULL);
1451 if (!gdp)
1452 continue;
1453 desc_count += ext4_free_inodes_count(sb, gdp);
1454 brelse(bitmap_bh);
1455 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1456 if (IS_ERR(bitmap_bh)) {
1457 bitmap_bh = NULL;
1458 continue;
1459 }
1460
1461 x = ext4_count_free(bitmap_bh->b_data,
1462 EXT4_INODES_PER_GROUP(sb) / 8);
1463 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1464 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1465 bitmap_count += x;
1466 }
1467 brelse(bitmap_bh);
1468 printk(KERN_DEBUG "ext4_count_free_inodes: "
1469 "stored = %u, computed = %lu, %lu\n",
1470 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1471 return desc_count;
1472#else
1473 desc_count = 0;
1474 for (i = 0; i < ngroups; i++) {
1475 gdp = ext4_get_group_desc(sb, i, NULL);
1476 if (!gdp)
1477 continue;
1478 desc_count += ext4_free_inodes_count(sb, gdp);
1479 cond_resched();
1480 }
1481 return desc_count;
1482#endif
1483}
1484
1485/* Called at mount-time, super-block is locked */
1486unsigned long ext4_count_dirs(struct super_block * sb)
1487{
1488 unsigned long count = 0;
1489 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1490
1491 for (i = 0; i < ngroups; i++) {
1492 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1493 if (!gdp)
1494 continue;
1495 count += ext4_used_dirs_count(sb, gdp);
1496 }
1497 return count;
1498}
1499
1500/*
1501 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1502 * inode table. Must be called without any spinlock held. The only place
1503 * where it is called from on active part of filesystem is ext4lazyinit
1504 * thread, so we do not need any special locks, however we have to prevent
1505 * inode allocation from the current group, so we take alloc_sem lock, to
1506 * block ext4_new_inode() until we are finished.
1507 */
1508int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1509 int barrier)
1510{
1511 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1512 struct ext4_sb_info *sbi = EXT4_SB(sb);
1513 struct ext4_group_desc *gdp = NULL;
1514 struct buffer_head *group_desc_bh;
1515 handle_t *handle;
1516 ext4_fsblk_t blk;
1517 int num, ret = 0, used_blks = 0;
1518 unsigned long used_inos = 0;
1519
1520 /* This should not happen, but just to be sure check this */
1521 if (sb_rdonly(sb)) {
1522 ret = 1;
1523 goto out;
1524 }
1525
1526 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1527 if (!gdp)
1528 goto out;
1529
1530 /*
1531 * We do not need to lock this, because we are the only one
1532 * handling this flag.
1533 */
1534 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1535 goto out;
1536
1537 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1538 if (IS_ERR(handle)) {
1539 ret = PTR_ERR(handle);
1540 goto out;
1541 }
1542
1543 down_write(&grp->alloc_sem);
1544 /*
1545 * If inode bitmap was already initialized there may be some
1546 * used inodes so we need to skip blocks with used inodes in
1547 * inode table.
1548 */
1549 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
1550 used_inos = EXT4_INODES_PER_GROUP(sb) -
1551 ext4_itable_unused_count(sb, gdp);
1552 used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
1553
1554 /* Bogus inode unused count? */
1555 if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
1556 ext4_error(sb, "Something is wrong with group %u: "
1557 "used itable blocks: %d; "
1558 "itable unused count: %u",
1559 group, used_blks,
1560 ext4_itable_unused_count(sb, gdp));
1561 ret = 1;
1562 goto err_out;
1563 }
1564
1565 used_inos += group * EXT4_INODES_PER_GROUP(sb);
1566 /*
1567 * Are there some uninitialized inodes in the inode table
1568 * before the first normal inode?
1569 */
1570 if ((used_blks != sbi->s_itb_per_group) &&
1571 (used_inos < EXT4_FIRST_INO(sb))) {
1572 ext4_error(sb, "Something is wrong with group %u: "
1573 "itable unused count: %u; "
1574 "itables initialized count: %ld",
1575 group, ext4_itable_unused_count(sb, gdp),
1576 used_inos);
1577 ret = 1;
1578 goto err_out;
1579 }
1580 }
1581
1582 blk = ext4_inode_table(sb, gdp) + used_blks;
1583 num = sbi->s_itb_per_group - used_blks;
1584
1585 BUFFER_TRACE(group_desc_bh, "get_write_access");
1586 ret = ext4_journal_get_write_access(handle,
1587 group_desc_bh);
1588 if (ret)
1589 goto err_out;
1590
1591 /*
1592 * Skip zeroout if the inode table is full. But we set the ZEROED
1593 * flag anyway, because obviously, when it is full it does not need
1594 * further zeroing.
1595 */
1596 if (unlikely(num == 0))
1597 goto skip_zeroout;
1598
1599 ext4_debug("going to zero out inode table in group %d\n",
1600 group);
1601 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1602 if (ret < 0)
1603 goto err_out;
1604 if (barrier)
1605 blkdev_issue_flush(sb->s_bdev);
1606
1607skip_zeroout:
1608 ext4_lock_group(sb, group);
1609 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1610 ext4_group_desc_csum_set(sb, group, gdp);
1611 ext4_unlock_group(sb, group);
1612
1613 BUFFER_TRACE(group_desc_bh,
1614 "call ext4_handle_dirty_metadata");
1615 ret = ext4_handle_dirty_metadata(handle, NULL,
1616 group_desc_bh);
1617
1618err_out:
1619 up_write(&grp->alloc_sem);
1620 ext4_journal_stop(handle);
1621out:
1622 return ret;
1623}
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 */
52void 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 */
67static 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
104void 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
114static 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 */
156static struct buffer_head *
157ext4_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(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
227verify:
228 err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
229 if (err)
230 goto out;
231 return bh;
232out:
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 */
253void 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);
364out:
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
381error_return:
382 brelse(bitmap_bh);
383 ext4_std_error(sb, fatal);
384}
385
386struct 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 */
397static 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
443static 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
562fallback:
563 ngroups = real_ngroups;
564 avefreei = freei / ngroups;
565fallback_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
591static 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
696static 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;
727out:
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 */
742struct 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 = ext4_get_encryption_info(dir);
771 if (err)
772 return ERR_PTR(err);
773 if (ext4_encryption_info(dir) == NULL)
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
830got_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
876repeat_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! */
915next_inode:
916 if (ino < EXT4_INODES_PER_GROUP(sb))
917 goto repeat_in_this_group;
918next_group:
919 if (++group == ngroups)
920 group = 0;
921 }
922 err = -ENOSPC;
923 goto out;
924
925got:
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 err = ext4_inherit_context(dir, inode);
1119 if (err)
1120 goto fail_free_drop;
1121 }
1122
1123 err = ext4_mark_inode_dirty(handle, inode);
1124 if (err) {
1125 ext4_std_error(sb, err);
1126 goto fail_free_drop;
1127 }
1128
1129 ext4_debug("allocating inode %lu\n", inode->i_ino);
1130 trace_ext4_allocate_inode(inode, dir, mode);
1131 brelse(inode_bitmap_bh);
1132 return ret;
1133
1134fail_free_drop:
1135 dquot_free_inode(inode);
1136fail_drop:
1137 clear_nlink(inode);
1138 unlock_new_inode(inode);
1139out:
1140 dquot_drop(inode);
1141 inode->i_flags |= S_NOQUOTA;
1142 iput(inode);
1143 brelse(inode_bitmap_bh);
1144 return ERR_PTR(err);
1145}
1146
1147/* Verify that we are loading a valid orphan from disk */
1148struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1149{
1150 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1151 ext4_group_t block_group;
1152 int bit;
1153 struct buffer_head *bitmap_bh;
1154 struct inode *inode = NULL;
1155 long err = -EIO;
1156
1157 /* Error cases - e2fsck has already cleaned up for us */
1158 if (ino > max_ino) {
1159 ext4_warning(sb, "bad orphan ino %lu! e2fsck was run?", ino);
1160 err = -EFSCORRUPTED;
1161 goto error;
1162 }
1163
1164 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1165 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1166 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1167 if (IS_ERR(bitmap_bh)) {
1168 err = PTR_ERR(bitmap_bh);
1169 ext4_warning(sb, "inode bitmap error %ld for orphan %lu",
1170 ino, err);
1171 goto error;
1172 }
1173
1174 /* Having the inode bit set should be a 100% indicator that this
1175 * is a valid orphan (no e2fsck run on fs). Orphans also include
1176 * inodes that were being truncated, so we can't check i_nlink==0.
1177 */
1178 if (!ext4_test_bit(bit, bitmap_bh->b_data))
1179 goto bad_orphan;
1180
1181 inode = ext4_iget(sb, ino);
1182 if (IS_ERR(inode))
1183 goto iget_failed;
1184
1185 /*
1186 * If the orphans has i_nlinks > 0 then it should be able to be
1187 * truncated, otherwise it won't be removed from the orphan list
1188 * during processing and an infinite loop will result.
1189 */
1190 if (inode->i_nlink && !ext4_can_truncate(inode))
1191 goto bad_orphan;
1192
1193 if (NEXT_ORPHAN(inode) > max_ino)
1194 goto bad_orphan;
1195 brelse(bitmap_bh);
1196 return inode;
1197
1198iget_failed:
1199 err = PTR_ERR(inode);
1200 inode = NULL;
1201bad_orphan:
1202 ext4_warning(sb, "bad orphan inode %lu! e2fsck was run?", ino);
1203 printk(KERN_WARNING "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 printk(KERN_WARNING "inode=%p\n", inode);
1207 if (inode) {
1208 printk(KERN_WARNING "is_bad_inode(inode)=%d\n",
1209 is_bad_inode(inode));
1210 printk(KERN_WARNING "NEXT_ORPHAN(inode)=%u\n",
1211 NEXT_ORPHAN(inode));
1212 printk(KERN_WARNING "max_ino=%lu\n", max_ino);
1213 printk(KERN_WARNING "i_nlink=%u\n", inode->i_nlink);
1214 /* Avoid freeing blocks if we got a bad deleted inode */
1215 if (inode->i_nlink == 0)
1216 inode->i_blocks = 0;
1217 iput(inode);
1218 }
1219 brelse(bitmap_bh);
1220error:
1221 return ERR_PTR(err);
1222}
1223
1224unsigned long ext4_count_free_inodes(struct super_block *sb)
1225{
1226 unsigned long desc_count;
1227 struct ext4_group_desc *gdp;
1228 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1229#ifdef EXT4FS_DEBUG
1230 struct ext4_super_block *es;
1231 unsigned long bitmap_count, x;
1232 struct buffer_head *bitmap_bh = NULL;
1233
1234 es = EXT4_SB(sb)->s_es;
1235 desc_count = 0;
1236 bitmap_count = 0;
1237 gdp = NULL;
1238 for (i = 0; i < ngroups; i++) {
1239 gdp = ext4_get_group_desc(sb, i, NULL);
1240 if (!gdp)
1241 continue;
1242 desc_count += ext4_free_inodes_count(sb, gdp);
1243 brelse(bitmap_bh);
1244 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1245 if (IS_ERR(bitmap_bh)) {
1246 bitmap_bh = NULL;
1247 continue;
1248 }
1249
1250 x = ext4_count_free(bitmap_bh->b_data,
1251 EXT4_INODES_PER_GROUP(sb) / 8);
1252 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1253 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1254 bitmap_count += x;
1255 }
1256 brelse(bitmap_bh);
1257 printk(KERN_DEBUG "ext4_count_free_inodes: "
1258 "stored = %u, computed = %lu, %lu\n",
1259 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1260 return desc_count;
1261#else
1262 desc_count = 0;
1263 for (i = 0; i < ngroups; i++) {
1264 gdp = ext4_get_group_desc(sb, i, NULL);
1265 if (!gdp)
1266 continue;
1267 desc_count += ext4_free_inodes_count(sb, gdp);
1268 cond_resched();
1269 }
1270 return desc_count;
1271#endif
1272}
1273
1274/* Called at mount-time, super-block is locked */
1275unsigned long ext4_count_dirs(struct super_block * sb)
1276{
1277 unsigned long count = 0;
1278 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1279
1280 for (i = 0; i < ngroups; i++) {
1281 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1282 if (!gdp)
1283 continue;
1284 count += ext4_used_dirs_count(sb, gdp);
1285 }
1286 return count;
1287}
1288
1289/*
1290 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1291 * inode table. Must be called without any spinlock held. The only place
1292 * where it is called from on active part of filesystem is ext4lazyinit
1293 * thread, so we do not need any special locks, however we have to prevent
1294 * inode allocation from the current group, so we take alloc_sem lock, to
1295 * block ext4_new_inode() until we are finished.
1296 */
1297int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1298 int barrier)
1299{
1300 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1301 struct ext4_sb_info *sbi = EXT4_SB(sb);
1302 struct ext4_group_desc *gdp = NULL;
1303 struct buffer_head *group_desc_bh;
1304 handle_t *handle;
1305 ext4_fsblk_t blk;
1306 int num, ret = 0, used_blks = 0;
1307
1308 /* This should not happen, but just to be sure check this */
1309 if (sb->s_flags & MS_RDONLY) {
1310 ret = 1;
1311 goto out;
1312 }
1313
1314 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1315 if (!gdp)
1316 goto out;
1317
1318 /*
1319 * We do not need to lock this, because we are the only one
1320 * handling this flag.
1321 */
1322 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1323 goto out;
1324
1325 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1326 if (IS_ERR(handle)) {
1327 ret = PTR_ERR(handle);
1328 goto out;
1329 }
1330
1331 down_write(&grp->alloc_sem);
1332 /*
1333 * If inode bitmap was already initialized there may be some
1334 * used inodes so we need to skip blocks with used inodes in
1335 * inode table.
1336 */
1337 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
1338 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
1339 ext4_itable_unused_count(sb, gdp)),
1340 sbi->s_inodes_per_block);
1341
1342 if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) {
1343 ext4_error(sb, "Something is wrong with group %u: "
1344 "used itable blocks: %d; "
1345 "itable unused count: %u",
1346 group, used_blks,
1347 ext4_itable_unused_count(sb, gdp));
1348 ret = 1;
1349 goto err_out;
1350 }
1351
1352 blk = ext4_inode_table(sb, gdp) + used_blks;
1353 num = sbi->s_itb_per_group - used_blks;
1354
1355 BUFFER_TRACE(group_desc_bh, "get_write_access");
1356 ret = ext4_journal_get_write_access(handle,
1357 group_desc_bh);
1358 if (ret)
1359 goto err_out;
1360
1361 /*
1362 * Skip zeroout if the inode table is full. But we set the ZEROED
1363 * flag anyway, because obviously, when it is full it does not need
1364 * further zeroing.
1365 */
1366 if (unlikely(num == 0))
1367 goto skip_zeroout;
1368
1369 ext4_debug("going to zero out inode table in group %d\n",
1370 group);
1371 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1372 if (ret < 0)
1373 goto err_out;
1374 if (barrier)
1375 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1376
1377skip_zeroout:
1378 ext4_lock_group(sb, group);
1379 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1380 ext4_group_desc_csum_set(sb, group, gdp);
1381 ext4_unlock_group(sb, group);
1382
1383 BUFFER_TRACE(group_desc_bh,
1384 "call ext4_handle_dirty_metadata");
1385 ret = ext4_handle_dirty_metadata(handle, NULL,
1386 group_desc_bh);
1387
1388err_out:
1389 up_write(&grp->alloc_sem);
1390 ext4_journal_stop(handle);
1391out:
1392 return ret;
1393}