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1/*
2 * linux/fs/ext4/ialloc.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * BSD ufs-inspired inode and directory allocation by
10 * Stephen Tweedie (sct@redhat.com), 1993
11 * Big-endian to little-endian byte-swapping/bitmaps by
12 * David S. Miller (davem@caip.rutgers.edu), 1995
13 */
14
15#include <linux/time.h>
16#include <linux/fs.h>
17#include <linux/jbd2.h>
18#include <linux/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 <asm/byteorder.h>
26
27#include "ext4.h"
28#include "ext4_jbd2.h"
29#include "xattr.h"
30#include "acl.h"
31
32#include <trace/events/ext4.h>
33
34/*
35 * ialloc.c contains the inodes allocation and deallocation routines
36 */
37
38/*
39 * The free inodes are managed by bitmaps. A file system contains several
40 * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
41 * block for inodes, N blocks for the inode table and data blocks.
42 *
43 * The file system contains group descriptors which are located after the
44 * super block. Each descriptor contains the number of the bitmap block and
45 * the free blocks count in the block.
46 */
47
48/*
49 * To avoid calling the atomic setbit hundreds or thousands of times, we only
50 * need to use it within a single byte (to ensure we get endianness right).
51 * We can use memset for the rest of the bitmap as there are no other users.
52 */
53void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
54{
55 int i;
56
57 if (start_bit >= end_bit)
58 return;
59
60 ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
61 for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
62 ext4_set_bit(i, bitmap);
63 if (i < end_bit)
64 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
65}
66
67/* Initializes an uninitialized inode bitmap */
68static unsigned ext4_init_inode_bitmap(struct super_block *sb,
69 struct buffer_head *bh,
70 ext4_group_t block_group,
71 struct ext4_group_desc *gdp)
72{
73 J_ASSERT_BH(bh, buffer_locked(bh));
74
75 /* If checksum is bad mark all blocks and inodes use to prevent
76 * allocation, essentially implementing a per-group read-only flag. */
77 if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
78 ext4_error(sb, "Checksum bad for group %u", block_group);
79 ext4_free_group_clusters_set(sb, gdp, 0);
80 ext4_free_inodes_set(sb, gdp, 0);
81 ext4_itable_unused_set(sb, gdp, 0);
82 memset(bh->b_data, 0xff, sb->s_blocksize);
83 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
84 EXT4_INODES_PER_GROUP(sb) / 8);
85 return 0;
86 }
87
88 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
89 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
90 bh->b_data);
91 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
92 EXT4_INODES_PER_GROUP(sb) / 8);
93 ext4_group_desc_csum_set(sb, block_group, gdp);
94
95 return EXT4_INODES_PER_GROUP(sb);
96}
97
98void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
99{
100 if (uptodate) {
101 set_buffer_uptodate(bh);
102 set_bitmap_uptodate(bh);
103 }
104 unlock_buffer(bh);
105 put_bh(bh);
106}
107
108/*
109 * Read the inode allocation bitmap for a given block_group, reading
110 * into the specified slot in the superblock's bitmap cache.
111 *
112 * Return buffer_head of bitmap on success or NULL.
113 */
114static struct buffer_head *
115ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
116{
117 struct ext4_group_desc *desc;
118 struct buffer_head *bh = NULL;
119 ext4_fsblk_t bitmap_blk;
120
121 desc = ext4_get_group_desc(sb, block_group, NULL);
122 if (!desc)
123 return NULL;
124
125 bitmap_blk = ext4_inode_bitmap(sb, desc);
126 bh = sb_getblk(sb, bitmap_blk);
127 if (unlikely(!bh)) {
128 ext4_error(sb, "Cannot read inode bitmap - "
129 "block_group = %u, inode_bitmap = %llu",
130 block_group, bitmap_blk);
131 return NULL;
132 }
133 if (bitmap_uptodate(bh))
134 goto verify;
135
136 lock_buffer(bh);
137 if (bitmap_uptodate(bh)) {
138 unlock_buffer(bh);
139 goto verify;
140 }
141
142 ext4_lock_group(sb, block_group);
143 if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
144 ext4_init_inode_bitmap(sb, bh, block_group, desc);
145 set_bitmap_uptodate(bh);
146 set_buffer_uptodate(bh);
147 set_buffer_verified(bh);
148 ext4_unlock_group(sb, block_group);
149 unlock_buffer(bh);
150 return bh;
151 }
152 ext4_unlock_group(sb, block_group);
153
154 if (buffer_uptodate(bh)) {
155 /*
156 * if not uninit if bh is uptodate,
157 * bitmap is also uptodate
158 */
159 set_bitmap_uptodate(bh);
160 unlock_buffer(bh);
161 goto verify;
162 }
163 /*
164 * submit the buffer_head for reading
165 */
166 trace_ext4_load_inode_bitmap(sb, block_group);
167 bh->b_end_io = ext4_end_bitmap_read;
168 get_bh(bh);
169 submit_bh(READ, bh);
170 wait_on_buffer(bh);
171 if (!buffer_uptodate(bh)) {
172 put_bh(bh);
173 ext4_error(sb, "Cannot read inode bitmap - "
174 "block_group = %u, inode_bitmap = %llu",
175 block_group, bitmap_blk);
176 return NULL;
177 }
178
179verify:
180 ext4_lock_group(sb, block_group);
181 if (!buffer_verified(bh) &&
182 !ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
183 EXT4_INODES_PER_GROUP(sb) / 8)) {
184 ext4_unlock_group(sb, block_group);
185 put_bh(bh);
186 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
187 "inode_bitmap = %llu", block_group, bitmap_blk);
188 return NULL;
189 }
190 ext4_unlock_group(sb, block_group);
191 set_buffer_verified(bh);
192 return bh;
193}
194
195/*
196 * NOTE! When we get the inode, we're the only people
197 * that have access to it, and as such there are no
198 * race conditions we have to worry about. The inode
199 * is not on the hash-lists, and it cannot be reached
200 * through the filesystem because the directory entry
201 * has been deleted earlier.
202 *
203 * HOWEVER: we must make sure that we get no aliases,
204 * which means that we have to call "clear_inode()"
205 * _before_ we mark the inode not in use in the inode
206 * bitmaps. Otherwise a newly created file might use
207 * the same inode number (not actually the same pointer
208 * though), and then we'd have two inodes sharing the
209 * same inode number and space on the harddisk.
210 */
211void ext4_free_inode(handle_t *handle, struct inode *inode)
212{
213 struct super_block *sb = inode->i_sb;
214 int is_directory;
215 unsigned long ino;
216 struct buffer_head *bitmap_bh = NULL;
217 struct buffer_head *bh2;
218 ext4_group_t block_group;
219 unsigned long bit;
220 struct ext4_group_desc *gdp;
221 struct ext4_super_block *es;
222 struct ext4_sb_info *sbi;
223 int fatal = 0, err, count, cleared;
224
225 if (!sb) {
226 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
227 "nonexistent device\n", __func__, __LINE__);
228 return;
229 }
230 if (atomic_read(&inode->i_count) > 1) {
231 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
232 __func__, __LINE__, inode->i_ino,
233 atomic_read(&inode->i_count));
234 return;
235 }
236 if (inode->i_nlink) {
237 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
238 __func__, __LINE__, inode->i_ino, inode->i_nlink);
239 return;
240 }
241 sbi = EXT4_SB(sb);
242
243 ino = inode->i_ino;
244 ext4_debug("freeing inode %lu\n", ino);
245 trace_ext4_free_inode(inode);
246
247 /*
248 * Note: we must free any quota before locking the superblock,
249 * as writing the quota to disk may need the lock as well.
250 */
251 dquot_initialize(inode);
252 ext4_xattr_delete_inode(handle, inode);
253 dquot_free_inode(inode);
254 dquot_drop(inode);
255
256 is_directory = S_ISDIR(inode->i_mode);
257
258 /* Do this BEFORE marking the inode not in use or returning an error */
259 ext4_clear_inode(inode);
260
261 es = EXT4_SB(sb)->s_es;
262 if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
263 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
264 goto error_return;
265 }
266 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
267 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
268 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
269 if (!bitmap_bh)
270 goto error_return;
271
272 BUFFER_TRACE(bitmap_bh, "get_write_access");
273 fatal = ext4_journal_get_write_access(handle, bitmap_bh);
274 if (fatal)
275 goto error_return;
276
277 fatal = -ESRCH;
278 gdp = ext4_get_group_desc(sb, block_group, &bh2);
279 if (gdp) {
280 BUFFER_TRACE(bh2, "get_write_access");
281 fatal = ext4_journal_get_write_access(handle, bh2);
282 }
283 ext4_lock_group(sb, block_group);
284 cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
285 if (fatal || !cleared) {
286 ext4_unlock_group(sb, block_group);
287 goto out;
288 }
289
290 count = ext4_free_inodes_count(sb, gdp) + 1;
291 ext4_free_inodes_set(sb, gdp, count);
292 if (is_directory) {
293 count = ext4_used_dirs_count(sb, gdp) - 1;
294 ext4_used_dirs_set(sb, gdp, count);
295 percpu_counter_dec(&sbi->s_dirs_counter);
296 }
297 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
298 EXT4_INODES_PER_GROUP(sb) / 8);
299 ext4_group_desc_csum_set(sb, block_group, gdp);
300 ext4_unlock_group(sb, block_group);
301
302 percpu_counter_inc(&sbi->s_freeinodes_counter);
303 if (sbi->s_log_groups_per_flex) {
304 ext4_group_t f = ext4_flex_group(sbi, block_group);
305
306 atomic_inc(&sbi->s_flex_groups[f].free_inodes);
307 if (is_directory)
308 atomic_dec(&sbi->s_flex_groups[f].used_dirs);
309 }
310 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
311 fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
312out:
313 if (cleared) {
314 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
315 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
316 if (!fatal)
317 fatal = err;
318 ext4_mark_super_dirty(sb);
319 } else
320 ext4_error(sb, "bit already cleared for inode %lu", ino);
321
322error_return:
323 brelse(bitmap_bh);
324 ext4_std_error(sb, fatal);
325}
326
327struct orlov_stats {
328 __u32 free_inodes;
329 __u32 free_clusters;
330 __u32 used_dirs;
331};
332
333/*
334 * Helper function for Orlov's allocator; returns critical information
335 * for a particular block group or flex_bg. If flex_size is 1, then g
336 * is a block group number; otherwise it is flex_bg number.
337 */
338static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
339 int flex_size, struct orlov_stats *stats)
340{
341 struct ext4_group_desc *desc;
342 struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups;
343
344 if (flex_size > 1) {
345 stats->free_inodes = atomic_read(&flex_group[g].free_inodes);
346 stats->free_clusters = atomic_read(&flex_group[g].free_clusters);
347 stats->used_dirs = atomic_read(&flex_group[g].used_dirs);
348 return;
349 }
350
351 desc = ext4_get_group_desc(sb, g, NULL);
352 if (desc) {
353 stats->free_inodes = ext4_free_inodes_count(sb, desc);
354 stats->free_clusters = ext4_free_group_clusters(sb, desc);
355 stats->used_dirs = ext4_used_dirs_count(sb, desc);
356 } else {
357 stats->free_inodes = 0;
358 stats->free_clusters = 0;
359 stats->used_dirs = 0;
360 }
361}
362
363/*
364 * Orlov's allocator for directories.
365 *
366 * We always try to spread first-level directories.
367 *
368 * If there are blockgroups with both free inodes and free blocks counts
369 * not worse than average we return one with smallest directory count.
370 * Otherwise we simply return a random group.
371 *
372 * For the rest rules look so:
373 *
374 * It's OK to put directory into a group unless
375 * it has too many directories already (max_dirs) or
376 * it has too few free inodes left (min_inodes) or
377 * it has too few free blocks left (min_blocks) or
378 * Parent's group is preferred, if it doesn't satisfy these
379 * conditions we search cyclically through the rest. If none
380 * of the groups look good we just look for a group with more
381 * free inodes than average (starting at parent's group).
382 */
383
384static int find_group_orlov(struct super_block *sb, struct inode *parent,
385 ext4_group_t *group, umode_t mode,
386 const struct qstr *qstr)
387{
388 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
389 struct ext4_sb_info *sbi = EXT4_SB(sb);
390 ext4_group_t real_ngroups = ext4_get_groups_count(sb);
391 int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
392 unsigned int freei, avefreei, grp_free;
393 ext4_fsblk_t freeb, avefreec;
394 unsigned int ndirs;
395 int max_dirs, min_inodes;
396 ext4_grpblk_t min_clusters;
397 ext4_group_t i, grp, g, ngroups;
398 struct ext4_group_desc *desc;
399 struct orlov_stats stats;
400 int flex_size = ext4_flex_bg_size(sbi);
401 struct dx_hash_info hinfo;
402
403 ngroups = real_ngroups;
404 if (flex_size > 1) {
405 ngroups = (real_ngroups + flex_size - 1) >>
406 sbi->s_log_groups_per_flex;
407 parent_group >>= sbi->s_log_groups_per_flex;
408 }
409
410 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
411 avefreei = freei / ngroups;
412 freeb = EXT4_C2B(sbi,
413 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
414 avefreec = freeb;
415 do_div(avefreec, ngroups);
416 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
417
418 if (S_ISDIR(mode) &&
419 ((parent == sb->s_root->d_inode) ||
420 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
421 int best_ndir = inodes_per_group;
422 int ret = -1;
423
424 if (qstr) {
425 hinfo.hash_version = DX_HASH_HALF_MD4;
426 hinfo.seed = sbi->s_hash_seed;
427 ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
428 grp = hinfo.hash;
429 } else
430 get_random_bytes(&grp, sizeof(grp));
431 parent_group = (unsigned)grp % ngroups;
432 for (i = 0; i < ngroups; i++) {
433 g = (parent_group + i) % ngroups;
434 get_orlov_stats(sb, g, flex_size, &stats);
435 if (!stats.free_inodes)
436 continue;
437 if (stats.used_dirs >= best_ndir)
438 continue;
439 if (stats.free_inodes < avefreei)
440 continue;
441 if (stats.free_clusters < avefreec)
442 continue;
443 grp = g;
444 ret = 0;
445 best_ndir = stats.used_dirs;
446 }
447 if (ret)
448 goto fallback;
449 found_flex_bg:
450 if (flex_size == 1) {
451 *group = grp;
452 return 0;
453 }
454
455 /*
456 * We pack inodes at the beginning of the flexgroup's
457 * inode tables. Block allocation decisions will do
458 * something similar, although regular files will
459 * start at 2nd block group of the flexgroup. See
460 * ext4_ext_find_goal() and ext4_find_near().
461 */
462 grp *= flex_size;
463 for (i = 0; i < flex_size; i++) {
464 if (grp+i >= real_ngroups)
465 break;
466 desc = ext4_get_group_desc(sb, grp+i, NULL);
467 if (desc && ext4_free_inodes_count(sb, desc)) {
468 *group = grp+i;
469 return 0;
470 }
471 }
472 goto fallback;
473 }
474
475 max_dirs = ndirs / ngroups + inodes_per_group / 16;
476 min_inodes = avefreei - inodes_per_group*flex_size / 4;
477 if (min_inodes < 1)
478 min_inodes = 1;
479 min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
480
481 /*
482 * Start looking in the flex group where we last allocated an
483 * inode for this parent directory
484 */
485 if (EXT4_I(parent)->i_last_alloc_group != ~0) {
486 parent_group = EXT4_I(parent)->i_last_alloc_group;
487 if (flex_size > 1)
488 parent_group >>= sbi->s_log_groups_per_flex;
489 }
490
491 for (i = 0; i < ngroups; i++) {
492 grp = (parent_group + i) % ngroups;
493 get_orlov_stats(sb, grp, flex_size, &stats);
494 if (stats.used_dirs >= max_dirs)
495 continue;
496 if (stats.free_inodes < min_inodes)
497 continue;
498 if (stats.free_clusters < min_clusters)
499 continue;
500 goto found_flex_bg;
501 }
502
503fallback:
504 ngroups = real_ngroups;
505 avefreei = freei / ngroups;
506fallback_retry:
507 parent_group = EXT4_I(parent)->i_block_group;
508 for (i = 0; i < ngroups; i++) {
509 grp = (parent_group + i) % ngroups;
510 desc = ext4_get_group_desc(sb, grp, NULL);
511 if (desc) {
512 grp_free = ext4_free_inodes_count(sb, desc);
513 if (grp_free && grp_free >= avefreei) {
514 *group = grp;
515 return 0;
516 }
517 }
518 }
519
520 if (avefreei) {
521 /*
522 * The free-inodes counter is approximate, and for really small
523 * filesystems the above test can fail to find any blockgroups
524 */
525 avefreei = 0;
526 goto fallback_retry;
527 }
528
529 return -1;
530}
531
532static int find_group_other(struct super_block *sb, struct inode *parent,
533 ext4_group_t *group, umode_t mode)
534{
535 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
536 ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
537 struct ext4_group_desc *desc;
538 int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
539
540 /*
541 * Try to place the inode is the same flex group as its
542 * parent. If we can't find space, use the Orlov algorithm to
543 * find another flex group, and store that information in the
544 * parent directory's inode information so that use that flex
545 * group for future allocations.
546 */
547 if (flex_size > 1) {
548 int retry = 0;
549
550 try_again:
551 parent_group &= ~(flex_size-1);
552 last = parent_group + flex_size;
553 if (last > ngroups)
554 last = ngroups;
555 for (i = parent_group; i < last; i++) {
556 desc = ext4_get_group_desc(sb, i, NULL);
557 if (desc && ext4_free_inodes_count(sb, desc)) {
558 *group = i;
559 return 0;
560 }
561 }
562 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
563 retry = 1;
564 parent_group = EXT4_I(parent)->i_last_alloc_group;
565 goto try_again;
566 }
567 /*
568 * If this didn't work, use the Orlov search algorithm
569 * to find a new flex group; we pass in the mode to
570 * avoid the topdir algorithms.
571 */
572 *group = parent_group + flex_size;
573 if (*group > ngroups)
574 *group = 0;
575 return find_group_orlov(sb, parent, group, mode, NULL);
576 }
577
578 /*
579 * Try to place the inode in its parent directory
580 */
581 *group = parent_group;
582 desc = ext4_get_group_desc(sb, *group, NULL);
583 if (desc && ext4_free_inodes_count(sb, desc) &&
584 ext4_free_group_clusters(sb, desc))
585 return 0;
586
587 /*
588 * We're going to place this inode in a different blockgroup from its
589 * parent. We want to cause files in a common directory to all land in
590 * the same blockgroup. But we want files which are in a different
591 * directory which shares a blockgroup with our parent to land in a
592 * different blockgroup.
593 *
594 * So add our directory's i_ino into the starting point for the hash.
595 */
596 *group = (*group + parent->i_ino) % ngroups;
597
598 /*
599 * Use a quadratic hash to find a group with a free inode and some free
600 * blocks.
601 */
602 for (i = 1; i < ngroups; i <<= 1) {
603 *group += i;
604 if (*group >= ngroups)
605 *group -= ngroups;
606 desc = ext4_get_group_desc(sb, *group, NULL);
607 if (desc && ext4_free_inodes_count(sb, desc) &&
608 ext4_free_group_clusters(sb, desc))
609 return 0;
610 }
611
612 /*
613 * That failed: try linear search for a free inode, even if that group
614 * has no free blocks.
615 */
616 *group = parent_group;
617 for (i = 0; i < ngroups; i++) {
618 if (++*group >= ngroups)
619 *group = 0;
620 desc = ext4_get_group_desc(sb, *group, NULL);
621 if (desc && ext4_free_inodes_count(sb, desc))
622 return 0;
623 }
624
625 return -1;
626}
627
628/*
629 * There are two policies for allocating an inode. If the new inode is
630 * a directory, then a forward search is made for a block group with both
631 * free space and a low directory-to-inode ratio; if that fails, then of
632 * the groups with above-average free space, that group with the fewest
633 * directories already is chosen.
634 *
635 * For other inodes, search forward from the parent directory's block
636 * group to find a free inode.
637 */
638struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, umode_t mode,
639 const struct qstr *qstr, __u32 goal, uid_t *owner)
640{
641 struct super_block *sb;
642 struct buffer_head *inode_bitmap_bh = NULL;
643 struct buffer_head *group_desc_bh;
644 ext4_group_t ngroups, group = 0;
645 unsigned long ino = 0;
646 struct inode *inode;
647 struct ext4_group_desc *gdp = NULL;
648 struct ext4_inode_info *ei;
649 struct ext4_sb_info *sbi;
650 int ret2, err = 0;
651 struct inode *ret;
652 ext4_group_t i;
653 ext4_group_t flex_group;
654
655 /* Cannot create files in a deleted directory */
656 if (!dir || !dir->i_nlink)
657 return ERR_PTR(-EPERM);
658
659 sb = dir->i_sb;
660 ngroups = ext4_get_groups_count(sb);
661 trace_ext4_request_inode(dir, mode);
662 inode = new_inode(sb);
663 if (!inode)
664 return ERR_PTR(-ENOMEM);
665 ei = EXT4_I(inode);
666 sbi = EXT4_SB(sb);
667
668 if (!goal)
669 goal = sbi->s_inode_goal;
670
671 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
672 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
673 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
674 ret2 = 0;
675 goto got_group;
676 }
677
678 if (S_ISDIR(mode))
679 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
680 else
681 ret2 = find_group_other(sb, dir, &group, mode);
682
683got_group:
684 EXT4_I(dir)->i_last_alloc_group = group;
685 err = -ENOSPC;
686 if (ret2 == -1)
687 goto out;
688
689 /*
690 * Normally we will only go through one pass of this loop,
691 * unless we get unlucky and it turns out the group we selected
692 * had its last inode grabbed by someone else.
693 */
694 for (i = 0; i < ngroups; i++, ino = 0) {
695 err = -EIO;
696
697 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
698 if (!gdp)
699 goto fail;
700
701 brelse(inode_bitmap_bh);
702 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
703 if (!inode_bitmap_bh)
704 goto fail;
705
706repeat_in_this_group:
707 ino = ext4_find_next_zero_bit((unsigned long *)
708 inode_bitmap_bh->b_data,
709 EXT4_INODES_PER_GROUP(sb), ino);
710 if (ino >= EXT4_INODES_PER_GROUP(sb)) {
711 if (++group == ngroups)
712 group = 0;
713 continue;
714 }
715 if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) {
716 ext4_error(sb, "reserved inode found cleared - "
717 "inode=%lu", ino + 1);
718 continue;
719 }
720 ext4_lock_group(sb, group);
721 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
722 ext4_unlock_group(sb, group);
723 ino++; /* the inode bitmap is zero-based */
724 if (!ret2)
725 goto got; /* we grabbed the inode! */
726 if (ino < EXT4_INODES_PER_GROUP(sb))
727 goto repeat_in_this_group;
728 }
729 err = -ENOSPC;
730 goto out;
731
732got:
733 /* We may have to initialize the block bitmap if it isn't already */
734 if (ext4_has_group_desc_csum(sb) &&
735 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
736 struct buffer_head *block_bitmap_bh;
737
738 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
739 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
740 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
741 if (err) {
742 brelse(block_bitmap_bh);
743 goto fail;
744 }
745
746 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
747 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
748 brelse(block_bitmap_bh);
749
750 /* recheck and clear flag under lock if we still need to */
751 ext4_lock_group(sb, group);
752 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
753 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
754 ext4_free_group_clusters_set(sb, gdp,
755 ext4_free_clusters_after_init(sb, group, gdp));
756 ext4_block_bitmap_csum_set(sb, group, gdp,
757 block_bitmap_bh,
758 EXT4_BLOCKS_PER_GROUP(sb) /
759 8);
760 ext4_group_desc_csum_set(sb, group, gdp);
761 }
762 ext4_unlock_group(sb, group);
763
764 if (err)
765 goto fail;
766 }
767
768 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
769 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
770 if (err)
771 goto fail;
772
773 BUFFER_TRACE(group_desc_bh, "get_write_access");
774 err = ext4_journal_get_write_access(handle, group_desc_bh);
775 if (err)
776 goto fail;
777
778 /* Update the relevant bg descriptor fields */
779 if (ext4_has_group_desc_csum(sb)) {
780 int free;
781 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
782
783 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
784 ext4_lock_group(sb, group); /* while we modify the bg desc */
785 free = EXT4_INODES_PER_GROUP(sb) -
786 ext4_itable_unused_count(sb, gdp);
787 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
788 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
789 free = 0;
790 }
791 /*
792 * Check the relative inode number against the last used
793 * relative inode number in this group. if it is greater
794 * we need to update the bg_itable_unused count
795 */
796 if (ino > free)
797 ext4_itable_unused_set(sb, gdp,
798 (EXT4_INODES_PER_GROUP(sb) - ino));
799 up_read(&grp->alloc_sem);
800 } else {
801 ext4_lock_group(sb, group);
802 }
803
804 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
805 if (S_ISDIR(mode)) {
806 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
807 if (sbi->s_log_groups_per_flex) {
808 ext4_group_t f = ext4_flex_group(sbi, group);
809
810 atomic_inc(&sbi->s_flex_groups[f].used_dirs);
811 }
812 }
813 if (ext4_has_group_desc_csum(sb)) {
814 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
815 EXT4_INODES_PER_GROUP(sb) / 8);
816 ext4_group_desc_csum_set(sb, group, gdp);
817 }
818 ext4_unlock_group(sb, group);
819
820 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
821 err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
822 if (err)
823 goto fail;
824
825 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
826 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
827 if (err)
828 goto fail;
829
830 percpu_counter_dec(&sbi->s_freeinodes_counter);
831 if (S_ISDIR(mode))
832 percpu_counter_inc(&sbi->s_dirs_counter);
833 ext4_mark_super_dirty(sb);
834
835 if (sbi->s_log_groups_per_flex) {
836 flex_group = ext4_flex_group(sbi, group);
837 atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes);
838 }
839 if (owner) {
840 inode->i_mode = mode;
841 i_uid_write(inode, owner[0]);
842 i_gid_write(inode, owner[1]);
843 } else if (test_opt(sb, GRPID)) {
844 inode->i_mode = mode;
845 inode->i_uid = current_fsuid();
846 inode->i_gid = dir->i_gid;
847 } else
848 inode_init_owner(inode, dir, mode);
849
850 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
851 /* This is the optimal IO size (for stat), not the fs block size */
852 inode->i_blocks = 0;
853 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
854 ext4_current_time(inode);
855
856 memset(ei->i_data, 0, sizeof(ei->i_data));
857 ei->i_dir_start_lookup = 0;
858 ei->i_disksize = 0;
859
860 /* Don't inherit extent flag from directory, amongst others. */
861 ei->i_flags =
862 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
863 ei->i_file_acl = 0;
864 ei->i_dtime = 0;
865 ei->i_block_group = group;
866 ei->i_last_alloc_group = ~0;
867
868 ext4_set_inode_flags(inode);
869 if (IS_DIRSYNC(inode))
870 ext4_handle_sync(handle);
871 if (insert_inode_locked(inode) < 0) {
872 /*
873 * Likely a bitmap corruption causing inode to be allocated
874 * twice.
875 */
876 err = -EIO;
877 goto fail;
878 }
879 spin_lock(&sbi->s_next_gen_lock);
880 inode->i_generation = sbi->s_next_generation++;
881 spin_unlock(&sbi->s_next_gen_lock);
882
883 /* Precompute checksum seed for inode metadata */
884 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
885 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
886 __u32 csum;
887 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
888 __le32 inum = cpu_to_le32(inode->i_ino);
889 __le32 gen = cpu_to_le32(inode->i_generation);
890 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
891 sizeof(inum));
892 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
893 sizeof(gen));
894 }
895
896 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
897 ext4_set_inode_state(inode, EXT4_STATE_NEW);
898
899 ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
900
901 ret = inode;
902 dquot_initialize(inode);
903 err = dquot_alloc_inode(inode);
904 if (err)
905 goto fail_drop;
906
907 err = ext4_init_acl(handle, inode, dir);
908 if (err)
909 goto fail_free_drop;
910
911 err = ext4_init_security(handle, inode, dir, qstr);
912 if (err)
913 goto fail_free_drop;
914
915 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
916 /* set extent flag only for directory, file and normal symlink*/
917 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
918 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
919 ext4_ext_tree_init(handle, inode);
920 }
921 }
922
923 if (ext4_handle_valid(handle)) {
924 ei->i_sync_tid = handle->h_transaction->t_tid;
925 ei->i_datasync_tid = handle->h_transaction->t_tid;
926 }
927
928 err = ext4_mark_inode_dirty(handle, inode);
929 if (err) {
930 ext4_std_error(sb, err);
931 goto fail_free_drop;
932 }
933
934 ext4_debug("allocating inode %lu\n", inode->i_ino);
935 trace_ext4_allocate_inode(inode, dir, mode);
936 goto really_out;
937fail:
938 ext4_std_error(sb, err);
939out:
940 iput(inode);
941 ret = ERR_PTR(err);
942really_out:
943 brelse(inode_bitmap_bh);
944 return ret;
945
946fail_free_drop:
947 dquot_free_inode(inode);
948
949fail_drop:
950 dquot_drop(inode);
951 inode->i_flags |= S_NOQUOTA;
952 clear_nlink(inode);
953 unlock_new_inode(inode);
954 iput(inode);
955 brelse(inode_bitmap_bh);
956 return ERR_PTR(err);
957}
958
959/* Verify that we are loading a valid orphan from disk */
960struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
961{
962 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
963 ext4_group_t block_group;
964 int bit;
965 struct buffer_head *bitmap_bh;
966 struct inode *inode = NULL;
967 long err = -EIO;
968
969 /* Error cases - e2fsck has already cleaned up for us */
970 if (ino > max_ino) {
971 ext4_warning(sb, "bad orphan ino %lu! e2fsck was run?", ino);
972 goto error;
973 }
974
975 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
976 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
977 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
978 if (!bitmap_bh) {
979 ext4_warning(sb, "inode bitmap error for orphan %lu", ino);
980 goto error;
981 }
982
983 /* Having the inode bit set should be a 100% indicator that this
984 * is a valid orphan (no e2fsck run on fs). Orphans also include
985 * inodes that were being truncated, so we can't check i_nlink==0.
986 */
987 if (!ext4_test_bit(bit, bitmap_bh->b_data))
988 goto bad_orphan;
989
990 inode = ext4_iget(sb, ino);
991 if (IS_ERR(inode))
992 goto iget_failed;
993
994 /*
995 * If the orphans has i_nlinks > 0 then it should be able to be
996 * truncated, otherwise it won't be removed from the orphan list
997 * during processing and an infinite loop will result.
998 */
999 if (inode->i_nlink && !ext4_can_truncate(inode))
1000 goto bad_orphan;
1001
1002 if (NEXT_ORPHAN(inode) > max_ino)
1003 goto bad_orphan;
1004 brelse(bitmap_bh);
1005 return inode;
1006
1007iget_failed:
1008 err = PTR_ERR(inode);
1009 inode = NULL;
1010bad_orphan:
1011 ext4_warning(sb, "bad orphan inode %lu! e2fsck was run?", ino);
1012 printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1013 bit, (unsigned long long)bitmap_bh->b_blocknr,
1014 ext4_test_bit(bit, bitmap_bh->b_data));
1015 printk(KERN_NOTICE "inode=%p\n", inode);
1016 if (inode) {
1017 printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
1018 is_bad_inode(inode));
1019 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
1020 NEXT_ORPHAN(inode));
1021 printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
1022 printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink);
1023 /* Avoid freeing blocks if we got a bad deleted inode */
1024 if (inode->i_nlink == 0)
1025 inode->i_blocks = 0;
1026 iput(inode);
1027 }
1028 brelse(bitmap_bh);
1029error:
1030 return ERR_PTR(err);
1031}
1032
1033unsigned long ext4_count_free_inodes(struct super_block *sb)
1034{
1035 unsigned long desc_count;
1036 struct ext4_group_desc *gdp;
1037 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1038#ifdef EXT4FS_DEBUG
1039 struct ext4_super_block *es;
1040 unsigned long bitmap_count, x;
1041 struct buffer_head *bitmap_bh = NULL;
1042
1043 es = EXT4_SB(sb)->s_es;
1044 desc_count = 0;
1045 bitmap_count = 0;
1046 gdp = NULL;
1047 for (i = 0; i < ngroups; i++) {
1048 gdp = ext4_get_group_desc(sb, i, NULL);
1049 if (!gdp)
1050 continue;
1051 desc_count += ext4_free_inodes_count(sb, gdp);
1052 brelse(bitmap_bh);
1053 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1054 if (!bitmap_bh)
1055 continue;
1056
1057 x = ext4_count_free(bitmap_bh->b_data,
1058 EXT4_INODES_PER_GROUP(sb) / 8);
1059 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1060 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1061 bitmap_count += x;
1062 }
1063 brelse(bitmap_bh);
1064 printk(KERN_DEBUG "ext4_count_free_inodes: "
1065 "stored = %u, computed = %lu, %lu\n",
1066 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1067 return desc_count;
1068#else
1069 desc_count = 0;
1070 for (i = 0; i < ngroups; i++) {
1071 gdp = ext4_get_group_desc(sb, i, NULL);
1072 if (!gdp)
1073 continue;
1074 desc_count += ext4_free_inodes_count(sb, gdp);
1075 cond_resched();
1076 }
1077 return desc_count;
1078#endif
1079}
1080
1081/* Called at mount-time, super-block is locked */
1082unsigned long ext4_count_dirs(struct super_block * sb)
1083{
1084 unsigned long count = 0;
1085 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1086
1087 for (i = 0; i < ngroups; i++) {
1088 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1089 if (!gdp)
1090 continue;
1091 count += ext4_used_dirs_count(sb, gdp);
1092 }
1093 return count;
1094}
1095
1096/*
1097 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1098 * inode table. Must be called without any spinlock held. The only place
1099 * where it is called from on active part of filesystem is ext4lazyinit
1100 * thread, so we do not need any special locks, however we have to prevent
1101 * inode allocation from the current group, so we take alloc_sem lock, to
1102 * block ext4_new_inode() until we are finished.
1103 */
1104int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1105 int barrier)
1106{
1107 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1108 struct ext4_sb_info *sbi = EXT4_SB(sb);
1109 struct ext4_group_desc *gdp = NULL;
1110 struct buffer_head *group_desc_bh;
1111 handle_t *handle;
1112 ext4_fsblk_t blk;
1113 int num, ret = 0, used_blks = 0;
1114
1115 /* This should not happen, but just to be sure check this */
1116 if (sb->s_flags & MS_RDONLY) {
1117 ret = 1;
1118 goto out;
1119 }
1120
1121 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1122 if (!gdp)
1123 goto out;
1124
1125 /*
1126 * We do not need to lock this, because we are the only one
1127 * handling this flag.
1128 */
1129 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1130 goto out;
1131
1132 handle = ext4_journal_start_sb(sb, 1);
1133 if (IS_ERR(handle)) {
1134 ret = PTR_ERR(handle);
1135 goto out;
1136 }
1137
1138 down_write(&grp->alloc_sem);
1139 /*
1140 * If inode bitmap was already initialized there may be some
1141 * used inodes so we need to skip blocks with used inodes in
1142 * inode table.
1143 */
1144 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
1145 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
1146 ext4_itable_unused_count(sb, gdp)),
1147 sbi->s_inodes_per_block);
1148
1149 if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) {
1150 ext4_error(sb, "Something is wrong with group %u: "
1151 "used itable blocks: %d; "
1152 "itable unused count: %u",
1153 group, used_blks,
1154 ext4_itable_unused_count(sb, gdp));
1155 ret = 1;
1156 goto err_out;
1157 }
1158
1159 blk = ext4_inode_table(sb, gdp) + used_blks;
1160 num = sbi->s_itb_per_group - used_blks;
1161
1162 BUFFER_TRACE(group_desc_bh, "get_write_access");
1163 ret = ext4_journal_get_write_access(handle,
1164 group_desc_bh);
1165 if (ret)
1166 goto err_out;
1167
1168 /*
1169 * Skip zeroout if the inode table is full. But we set the ZEROED
1170 * flag anyway, because obviously, when it is full it does not need
1171 * further zeroing.
1172 */
1173 if (unlikely(num == 0))
1174 goto skip_zeroout;
1175
1176 ext4_debug("going to zero out inode table in group %d\n",
1177 group);
1178 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1179 if (ret < 0)
1180 goto err_out;
1181 if (barrier)
1182 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1183
1184skip_zeroout:
1185 ext4_lock_group(sb, group);
1186 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1187 ext4_group_desc_csum_set(sb, group, gdp);
1188 ext4_unlock_group(sb, group);
1189
1190 BUFFER_TRACE(group_desc_bh,
1191 "call ext4_handle_dirty_metadata");
1192 ret = ext4_handle_dirty_metadata(handle, NULL,
1193 group_desc_bh);
1194
1195err_out:
1196 up_write(&grp->alloc_sem);
1197 ext4_journal_stop(handle);
1198out:
1199 return ret;
1200}
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 if (buffer_verified(bh))
91 return 0;
92
93 grp = ext4_get_group_info(sb, block_group);
94 if (!grp || 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, desc, bh) ||
102 ext4_simulate_fail(sb, EXT4_SIM_IBITMAP_CRC)) {
103 ext4_unlock_group(sb, block_group);
104 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
105 "inode_bitmap = %llu", block_group, blk);
106 ext4_mark_group_bitmap_corrupted(sb, block_group,
107 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
108 return -EFSBADCRC;
109 }
110 set_buffer_verified(bh);
111verified:
112 ext4_unlock_group(sb, block_group);
113 return 0;
114}
115
116/*
117 * Read the inode allocation bitmap for a given block_group, reading
118 * into the specified slot in the superblock's bitmap cache.
119 *
120 * Return buffer_head of bitmap on success, or an ERR_PTR on error.
121 */
122static struct buffer_head *
123ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
124{
125 struct ext4_group_desc *desc;
126 struct ext4_sb_info *sbi = EXT4_SB(sb);
127 struct buffer_head *bh = NULL;
128 ext4_fsblk_t bitmap_blk;
129 int err;
130
131 desc = ext4_get_group_desc(sb, block_group, NULL);
132 if (!desc)
133 return ERR_PTR(-EFSCORRUPTED);
134
135 bitmap_blk = ext4_inode_bitmap(sb, desc);
136 if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
137 (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
138 ext4_error(sb, "Invalid inode bitmap blk %llu in "
139 "block_group %u", bitmap_blk, block_group);
140 ext4_mark_group_bitmap_corrupted(sb, block_group,
141 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
142 return ERR_PTR(-EFSCORRUPTED);
143 }
144 bh = sb_getblk(sb, bitmap_blk);
145 if (unlikely(!bh)) {
146 ext4_warning(sb, "Cannot read inode bitmap - "
147 "block_group = %u, inode_bitmap = %llu",
148 block_group, bitmap_blk);
149 return ERR_PTR(-ENOMEM);
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 ext4_read_bh(bh, REQ_META | REQ_PRIO,
197 ext4_end_bitmap_read,
198 ext4_simulate_fail(sb, 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 (!grp || 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, sb, bitmap_bh,
304 EXT4_JTR_NONE);
305 if (fatal)
306 goto error_return;
307
308 fatal = -ESRCH;
309 gdp = ext4_get_group_desc(sb, block_group, &bh2);
310 if (gdp) {
311 BUFFER_TRACE(bh2, "get_write_access");
312 fatal = ext4_journal_get_write_access(handle, sb, bh2,
313 EXT4_JTR_NONE);
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 if (percpu_counter_initialized(&sbi->s_dirs_counter))
328 percpu_counter_dec(&sbi->s_dirs_counter);
329 }
330 ext4_inode_bitmap_csum_set(sb, gdp, bitmap_bh);
331 ext4_group_desc_csum_set(sb, block_group, gdp);
332 ext4_unlock_group(sb, block_group);
333
334 if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
335 percpu_counter_inc(&sbi->s_freeinodes_counter);
336 if (sbi->s_log_groups_per_flex) {
337 struct flex_groups *fg;
338
339 fg = sbi_array_rcu_deref(sbi, s_flex_groups,
340 ext4_flex_group(sbi, block_group));
341 atomic_inc(&fg->free_inodes);
342 if (is_directory)
343 atomic_dec(&fg->used_dirs);
344 }
345 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
346 fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
347out:
348 if (cleared) {
349 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
350 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
351 if (!fatal)
352 fatal = err;
353 } else {
354 ext4_error(sb, "bit already cleared for inode %lu", ino);
355 ext4_mark_group_bitmap_corrupted(sb, block_group,
356 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
357 }
358
359error_return:
360 brelse(bitmap_bh);
361 ext4_std_error(sb, fatal);
362}
363
364struct orlov_stats {
365 __u64 free_clusters;
366 __u32 free_inodes;
367 __u32 used_dirs;
368};
369
370/*
371 * Helper function for Orlov's allocator; returns critical information
372 * for a particular block group or flex_bg. If flex_size is 1, then g
373 * is a block group number; otherwise it is flex_bg number.
374 */
375static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
376 int flex_size, struct orlov_stats *stats)
377{
378 struct ext4_group_desc *desc;
379
380 if (flex_size > 1) {
381 struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),
382 s_flex_groups, g);
383 stats->free_inodes = atomic_read(&fg->free_inodes);
384 stats->free_clusters = atomic64_read(&fg->free_clusters);
385 stats->used_dirs = atomic_read(&fg->used_dirs);
386 return;
387 }
388
389 desc = ext4_get_group_desc(sb, g, NULL);
390 if (desc) {
391 stats->free_inodes = ext4_free_inodes_count(sb, desc);
392 stats->free_clusters = ext4_free_group_clusters(sb, desc);
393 stats->used_dirs = ext4_used_dirs_count(sb, desc);
394 } else {
395 stats->free_inodes = 0;
396 stats->free_clusters = 0;
397 stats->used_dirs = 0;
398 }
399}
400
401/*
402 * Orlov's allocator for directories.
403 *
404 * We always try to spread first-level directories.
405 *
406 * If there are blockgroups with both free inodes and free clusters counts
407 * not worse than average we return one with smallest directory count.
408 * Otherwise we simply return a random group.
409 *
410 * For the rest rules look so:
411 *
412 * It's OK to put directory into a group unless
413 * it has too many directories already (max_dirs) or
414 * it has too few free inodes left (min_inodes) or
415 * it has too few free clusters left (min_clusters) or
416 * Parent's group is preferred, if it doesn't satisfy these
417 * conditions we search cyclically through the rest. If none
418 * of the groups look good we just look for a group with more
419 * free inodes than average (starting at parent's group).
420 */
421
422static int find_group_orlov(struct super_block *sb, struct inode *parent,
423 ext4_group_t *group, umode_t mode,
424 const struct qstr *qstr)
425{
426 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
427 struct ext4_sb_info *sbi = EXT4_SB(sb);
428 ext4_group_t real_ngroups = ext4_get_groups_count(sb);
429 int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
430 unsigned int freei, avefreei, grp_free;
431 ext4_fsblk_t freec, avefreec;
432 unsigned int ndirs;
433 int max_dirs, min_inodes;
434 ext4_grpblk_t min_clusters;
435 ext4_group_t i, grp, g, ngroups;
436 struct ext4_group_desc *desc;
437 struct orlov_stats stats;
438 int flex_size = ext4_flex_bg_size(sbi);
439 struct dx_hash_info hinfo;
440
441 ngroups = real_ngroups;
442 if (flex_size > 1) {
443 ngroups = (real_ngroups + flex_size - 1) >>
444 sbi->s_log_groups_per_flex;
445 parent_group >>= sbi->s_log_groups_per_flex;
446 }
447
448 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
449 avefreei = freei / ngroups;
450 freec = percpu_counter_read_positive(&sbi->s_freeclusters_counter);
451 avefreec = freec;
452 do_div(avefreec, ngroups);
453 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
454
455 if (S_ISDIR(mode) &&
456 ((parent == d_inode(sb->s_root)) ||
457 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
458 int best_ndir = inodes_per_group;
459 int ret = -1;
460
461 if (qstr) {
462 hinfo.hash_version = DX_HASH_HALF_MD4;
463 hinfo.seed = sbi->s_hash_seed;
464 ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);
465 parent_group = hinfo.hash % ngroups;
466 } else
467 parent_group = get_random_u32_below(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*flex_size / 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 if (min_clusters < 0)
517 min_clusters = 0;
518
519 /*
520 * Start looking in the flex group where we last allocated an
521 * inode for this parent directory
522 */
523 if (EXT4_I(parent)->i_last_alloc_group != ~0) {
524 parent_group = EXT4_I(parent)->i_last_alloc_group;
525 if (flex_size > 1)
526 parent_group >>= sbi->s_log_groups_per_flex;
527 }
528
529 for (i = 0; i < ngroups; i++) {
530 grp = (parent_group + i) % ngroups;
531 get_orlov_stats(sb, grp, flex_size, &stats);
532 if (stats.used_dirs >= max_dirs)
533 continue;
534 if (stats.free_inodes < min_inodes)
535 continue;
536 if (stats.free_clusters < min_clusters)
537 continue;
538 goto found_flex_bg;
539 }
540
541fallback:
542 ngroups = real_ngroups;
543 avefreei = freei / ngroups;
544fallback_retry:
545 parent_group = EXT4_I(parent)->i_block_group;
546 for (i = 0; i < ngroups; i++) {
547 grp = (parent_group + i) % ngroups;
548 desc = ext4_get_group_desc(sb, grp, NULL);
549 if (desc) {
550 grp_free = ext4_free_inodes_count(sb, desc);
551 if (grp_free && grp_free >= avefreei) {
552 *group = grp;
553 return 0;
554 }
555 }
556 }
557
558 if (avefreei) {
559 /*
560 * The free-inodes counter is approximate, and for really small
561 * filesystems the above test can fail to find any blockgroups
562 */
563 avefreei = 0;
564 goto fallback_retry;
565 }
566
567 return -1;
568}
569
570static int find_group_other(struct super_block *sb, struct inode *parent,
571 ext4_group_t *group, umode_t mode)
572{
573 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
574 ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
575 struct ext4_group_desc *desc;
576 int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
577
578 /*
579 * Try to place the inode is the same flex group as its
580 * parent. If we can't find space, use the Orlov algorithm to
581 * find another flex group, and store that information in the
582 * parent directory's inode information so that use that flex
583 * group for future allocations.
584 */
585 if (flex_size > 1) {
586 int retry = 0;
587
588 try_again:
589 parent_group &= ~(flex_size-1);
590 last = parent_group + flex_size;
591 if (last > ngroups)
592 last = ngroups;
593 for (i = parent_group; i < last; i++) {
594 desc = ext4_get_group_desc(sb, i, NULL);
595 if (desc && ext4_free_inodes_count(sb, desc)) {
596 *group = i;
597 return 0;
598 }
599 }
600 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
601 retry = 1;
602 parent_group = EXT4_I(parent)->i_last_alloc_group;
603 goto try_again;
604 }
605 /*
606 * If this didn't work, use the Orlov search algorithm
607 * to find a new flex group; we pass in the mode to
608 * avoid the topdir algorithms.
609 */
610 *group = parent_group + flex_size;
611 if (*group > ngroups)
612 *group = 0;
613 return find_group_orlov(sb, parent, group, mode, NULL);
614 }
615
616 /*
617 * Try to place the inode in its parent directory
618 */
619 *group = parent_group;
620 desc = ext4_get_group_desc(sb, *group, NULL);
621 if (desc && ext4_free_inodes_count(sb, desc) &&
622 ext4_free_group_clusters(sb, desc))
623 return 0;
624
625 /*
626 * We're going to place this inode in a different blockgroup from its
627 * parent. We want to cause files in a common directory to all land in
628 * the same blockgroup. But we want files which are in a different
629 * directory which shares a blockgroup with our parent to land in a
630 * different blockgroup.
631 *
632 * So add our directory's i_ino into the starting point for the hash.
633 */
634 *group = (*group + parent->i_ino) % ngroups;
635
636 /*
637 * Use a quadratic hash to find a group with a free inode and some free
638 * blocks.
639 */
640 for (i = 1; i < ngroups; i <<= 1) {
641 *group += i;
642 if (*group >= ngroups)
643 *group -= ngroups;
644 desc = ext4_get_group_desc(sb, *group, NULL);
645 if (desc && ext4_free_inodes_count(sb, desc) &&
646 ext4_free_group_clusters(sb, desc))
647 return 0;
648 }
649
650 /*
651 * That failed: try linear search for a free inode, even if that group
652 * has no free blocks.
653 */
654 *group = parent_group;
655 for (i = 0; i < ngroups; i++) {
656 if (++*group >= ngroups)
657 *group = 0;
658 desc = ext4_get_group_desc(sb, *group, NULL);
659 if (desc && ext4_free_inodes_count(sb, desc))
660 return 0;
661 }
662
663 return -1;
664}
665
666/*
667 * In no journal mode, if an inode has recently been deleted, we want
668 * to avoid reusing it until we're reasonably sure the inode table
669 * block has been written back to disk. (Yes, these values are
670 * somewhat arbitrary...)
671 */
672#define RECENTCY_MIN 60
673#define RECENTCY_DIRTY 300
674
675static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
676{
677 struct ext4_group_desc *gdp;
678 struct ext4_inode *raw_inode;
679 struct buffer_head *bh;
680 int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
681 int offset, ret = 0;
682 int recentcy = RECENTCY_MIN;
683 u32 dtime, now;
684
685 gdp = ext4_get_group_desc(sb, group, NULL);
686 if (unlikely(!gdp))
687 return 0;
688
689 bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
690 (ino / inodes_per_block));
691 if (!bh || !buffer_uptodate(bh))
692 /*
693 * If the block is not in the buffer cache, then it
694 * must have been written out.
695 */
696 goto out;
697
698 offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
699 raw_inode = (struct ext4_inode *) (bh->b_data + offset);
700
701 /* i_dtime is only 32 bits on disk, but we only care about relative
702 * times in the range of a few minutes (i.e. long enough to sync a
703 * recently-deleted inode to disk), so using the low 32 bits of the
704 * clock (a 68 year range) is enough, see time_before32() */
705 dtime = le32_to_cpu(raw_inode->i_dtime);
706 now = ktime_get_real_seconds();
707 if (buffer_dirty(bh))
708 recentcy += RECENTCY_DIRTY;
709
710 if (dtime && time_before32(dtime, now) &&
711 time_before32(now, dtime + recentcy))
712 ret = 1;
713out:
714 brelse(bh);
715 return ret;
716}
717
718static int find_inode_bit(struct super_block *sb, ext4_group_t group,
719 struct buffer_head *bitmap, unsigned long *ino)
720{
721 bool check_recently_deleted = EXT4_SB(sb)->s_journal == NULL;
722 unsigned long recently_deleted_ino = EXT4_INODES_PER_GROUP(sb);
723
724next:
725 *ino = ext4_find_next_zero_bit((unsigned long *)
726 bitmap->b_data,
727 EXT4_INODES_PER_GROUP(sb), *ino);
728 if (*ino >= EXT4_INODES_PER_GROUP(sb))
729 goto not_found;
730
731 if (check_recently_deleted && recently_deleted(sb, group, *ino)) {
732 recently_deleted_ino = *ino;
733 *ino = *ino + 1;
734 if (*ino < EXT4_INODES_PER_GROUP(sb))
735 goto next;
736 goto not_found;
737 }
738 return 1;
739not_found:
740 if (recently_deleted_ino >= EXT4_INODES_PER_GROUP(sb))
741 return 0;
742 /*
743 * Not reusing recently deleted inodes is mostly a preference. We don't
744 * want to report ENOSPC or skew allocation patterns because of that.
745 * So return even recently deleted inode if we could find better in the
746 * given range.
747 */
748 *ino = recently_deleted_ino;
749 return 1;
750}
751
752int ext4_mark_inode_used(struct super_block *sb, int ino)
753{
754 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
755 struct buffer_head *inode_bitmap_bh = NULL, *group_desc_bh = NULL;
756 struct ext4_group_desc *gdp;
757 ext4_group_t group;
758 int bit;
759 int err;
760
761 if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
762 return -EFSCORRUPTED;
763
764 group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
765 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
766 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
767 if (IS_ERR(inode_bitmap_bh))
768 return PTR_ERR(inode_bitmap_bh);
769
770 if (ext4_test_bit(bit, inode_bitmap_bh->b_data)) {
771 err = 0;
772 goto out;
773 }
774
775 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
776 if (!gdp) {
777 err = -EINVAL;
778 goto out;
779 }
780
781 ext4_set_bit(bit, inode_bitmap_bh->b_data);
782
783 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
784 err = ext4_handle_dirty_metadata(NULL, NULL, inode_bitmap_bh);
785 if (err) {
786 ext4_std_error(sb, err);
787 goto out;
788 }
789 err = sync_dirty_buffer(inode_bitmap_bh);
790 if (err) {
791 ext4_std_error(sb, err);
792 goto out;
793 }
794
795 /* We may have to initialize the block bitmap if it isn't already */
796 if (ext4_has_group_desc_csum(sb) &&
797 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
798 struct buffer_head *block_bitmap_bh;
799
800 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
801 if (IS_ERR(block_bitmap_bh)) {
802 err = PTR_ERR(block_bitmap_bh);
803 goto out;
804 }
805
806 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
807 err = ext4_handle_dirty_metadata(NULL, NULL, block_bitmap_bh);
808 sync_dirty_buffer(block_bitmap_bh);
809
810 /* recheck and clear flag under lock if we still need to */
811 ext4_lock_group(sb, group);
812 if (ext4_has_group_desc_csum(sb) &&
813 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
814 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
815 ext4_free_group_clusters_set(sb, gdp,
816 ext4_free_clusters_after_init(sb, group, gdp));
817 ext4_block_bitmap_csum_set(sb, gdp, block_bitmap_bh);
818 ext4_group_desc_csum_set(sb, group, gdp);
819 }
820 ext4_unlock_group(sb, group);
821 brelse(block_bitmap_bh);
822
823 if (err) {
824 ext4_std_error(sb, err);
825 goto out;
826 }
827 }
828
829 /* Update the relevant bg descriptor fields */
830 if (ext4_has_group_desc_csum(sb)) {
831 int free;
832
833 ext4_lock_group(sb, group); /* while we modify the bg desc */
834 free = EXT4_INODES_PER_GROUP(sb) -
835 ext4_itable_unused_count(sb, gdp);
836 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
837 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
838 free = 0;
839 }
840
841 /*
842 * Check the relative inode number against the last used
843 * relative inode number in this group. if it is greater
844 * we need to update the bg_itable_unused count
845 */
846 if (bit >= free)
847 ext4_itable_unused_set(sb, gdp,
848 (EXT4_INODES_PER_GROUP(sb) - bit - 1));
849 } else {
850 ext4_lock_group(sb, group);
851 }
852
853 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
854 if (ext4_has_group_desc_csum(sb)) {
855 ext4_inode_bitmap_csum_set(sb, gdp, inode_bitmap_bh);
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 brelse(inode_bitmap_bh);
864 return err;
865}
866
867static int ext4_xattr_credits_for_new_inode(struct inode *dir, mode_t mode,
868 bool encrypt)
869{
870 struct super_block *sb = dir->i_sb;
871 int nblocks = 0;
872#ifdef CONFIG_EXT4_FS_POSIX_ACL
873 struct posix_acl *p = get_inode_acl(dir, ACL_TYPE_DEFAULT);
874
875 if (IS_ERR(p))
876 return PTR_ERR(p);
877 if (p) {
878 int acl_size = p->a_count * sizeof(ext4_acl_entry);
879
880 nblocks += (S_ISDIR(mode) ? 2 : 1) *
881 __ext4_xattr_set_credits(sb, NULL /* inode */,
882 NULL /* block_bh */, acl_size,
883 true /* is_create */);
884 posix_acl_release(p);
885 }
886#endif
887
888#ifdef CONFIG_SECURITY
889 {
890 int num_security_xattrs = 1;
891
892#ifdef CONFIG_INTEGRITY
893 num_security_xattrs++;
894#endif
895 /*
896 * We assume that security xattrs are never more than 1k.
897 * In practice they are under 128 bytes.
898 */
899 nblocks += num_security_xattrs *
900 __ext4_xattr_set_credits(sb, NULL /* inode */,
901 NULL /* block_bh */, 1024,
902 true /* is_create */);
903 }
904#endif
905 if (encrypt)
906 nblocks += __ext4_xattr_set_credits(sb,
907 NULL /* inode */,
908 NULL /* block_bh */,
909 FSCRYPT_SET_CONTEXT_MAX_SIZE,
910 true /* is_create */);
911 return nblocks;
912}
913
914/*
915 * There are two policies for allocating an inode. If the new inode is
916 * a directory, then a forward search is made for a block group with both
917 * free space and a low directory-to-inode ratio; if that fails, then of
918 * the groups with above-average free space, that group with the fewest
919 * directories already is chosen.
920 *
921 * For other inodes, search forward from the parent directory's block
922 * group to find a free inode.
923 */
924struct inode *__ext4_new_inode(struct mnt_idmap *idmap,
925 handle_t *handle, struct inode *dir,
926 umode_t mode, const struct qstr *qstr,
927 __u32 goal, uid_t *owner, __u32 i_flags,
928 int handle_type, unsigned int line_no,
929 int nblocks)
930{
931 struct super_block *sb;
932 struct buffer_head *inode_bitmap_bh = NULL;
933 struct buffer_head *group_desc_bh;
934 ext4_group_t ngroups, group = 0;
935 unsigned long ino = 0;
936 struct inode *inode;
937 struct ext4_group_desc *gdp = NULL;
938 struct ext4_inode_info *ei;
939 struct ext4_sb_info *sbi;
940 int ret2, err;
941 struct inode *ret;
942 ext4_group_t i;
943 ext4_group_t flex_group;
944 struct ext4_group_info *grp = NULL;
945 bool encrypt = false;
946
947 /* Cannot create files in a deleted directory */
948 if (!dir || !dir->i_nlink)
949 return ERR_PTR(-EPERM);
950
951 sb = dir->i_sb;
952 sbi = EXT4_SB(sb);
953
954 if (unlikely(ext4_forced_shutdown(sb)))
955 return ERR_PTR(-EIO);
956
957 ngroups = ext4_get_groups_count(sb);
958 trace_ext4_request_inode(dir, mode);
959 inode = new_inode(sb);
960 if (!inode)
961 return ERR_PTR(-ENOMEM);
962 ei = EXT4_I(inode);
963
964 /*
965 * Initialize owners and quota early so that we don't have to account
966 * for quota initialization worst case in standard inode creating
967 * transaction
968 */
969 if (owner) {
970 inode->i_mode = mode;
971 i_uid_write(inode, owner[0]);
972 i_gid_write(inode, owner[1]);
973 } else if (test_opt(sb, GRPID)) {
974 inode->i_mode = mode;
975 inode_fsuid_set(inode, idmap);
976 inode->i_gid = dir->i_gid;
977 } else
978 inode_init_owner(idmap, inode, dir, mode);
979
980 if (ext4_has_feature_project(sb) &&
981 ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
982 ei->i_projid = EXT4_I(dir)->i_projid;
983 else
984 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
985
986 if (!(i_flags & EXT4_EA_INODE_FL)) {
987 err = fscrypt_prepare_new_inode(dir, inode, &encrypt);
988 if (err)
989 goto out;
990 }
991
992 err = dquot_initialize(inode);
993 if (err)
994 goto out;
995
996 if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
997 ret2 = ext4_xattr_credits_for_new_inode(dir, mode, encrypt);
998 if (ret2 < 0) {
999 err = ret2;
1000 goto out;
1001 }
1002 nblocks += ret2;
1003 }
1004
1005 if (!goal)
1006 goal = sbi->s_inode_goal;
1007
1008 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
1009 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
1010 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
1011 ret2 = 0;
1012 goto got_group;
1013 }
1014
1015 if (S_ISDIR(mode))
1016 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
1017 else
1018 ret2 = find_group_other(sb, dir, &group, mode);
1019
1020got_group:
1021 EXT4_I(dir)->i_last_alloc_group = group;
1022 err = -ENOSPC;
1023 if (ret2 == -1)
1024 goto out;
1025
1026 /*
1027 * Normally we will only go through one pass of this loop,
1028 * unless we get unlucky and it turns out the group we selected
1029 * had its last inode grabbed by someone else.
1030 */
1031 for (i = 0; i < ngroups; i++, ino = 0) {
1032 err = -EIO;
1033
1034 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1035 if (!gdp)
1036 goto out;
1037
1038 /*
1039 * Check free inodes count before loading bitmap.
1040 */
1041 if (ext4_free_inodes_count(sb, gdp) == 0)
1042 goto next_group;
1043
1044 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1045 grp = ext4_get_group_info(sb, group);
1046 /*
1047 * Skip groups with already-known suspicious inode
1048 * tables
1049 */
1050 if (!grp || EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
1051 goto next_group;
1052 }
1053
1054 brelse(inode_bitmap_bh);
1055 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
1056 /* Skip groups with suspicious inode tables */
1057 if (IS_ERR(inode_bitmap_bh)) {
1058 inode_bitmap_bh = NULL;
1059 goto next_group;
1060 }
1061 if (!(sbi->s_mount_state & EXT4_FC_REPLAY) &&
1062 EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
1063 goto next_group;
1064
1065 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
1066 if (!ret2)
1067 goto next_group;
1068
1069 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
1070 ext4_error(sb, "reserved inode found cleared - "
1071 "inode=%lu", ino + 1);
1072 ext4_mark_group_bitmap_corrupted(sb, group,
1073 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1074 goto next_group;
1075 }
1076
1077 if ((!(sbi->s_mount_state & EXT4_FC_REPLAY)) && !handle) {
1078 BUG_ON(nblocks <= 0);
1079 handle = __ext4_journal_start_sb(NULL, dir->i_sb,
1080 line_no, handle_type, nblocks, 0,
1081 ext4_trans_default_revoke_credits(sb));
1082 if (IS_ERR(handle)) {
1083 err = PTR_ERR(handle);
1084 ext4_std_error(sb, err);
1085 goto out;
1086 }
1087 }
1088 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
1089 err = ext4_journal_get_write_access(handle, sb, inode_bitmap_bh,
1090 EXT4_JTR_NONE);
1091 if (err) {
1092 ext4_std_error(sb, err);
1093 goto out;
1094 }
1095 ext4_lock_group(sb, group);
1096 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
1097 if (ret2) {
1098 /* Someone already took the bit. Repeat the search
1099 * with lock held.
1100 */
1101 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
1102 if (ret2) {
1103 ext4_set_bit(ino, inode_bitmap_bh->b_data);
1104 ret2 = 0;
1105 } else {
1106 ret2 = 1; /* we didn't grab the inode */
1107 }
1108 }
1109 ext4_unlock_group(sb, group);
1110 ino++; /* the inode bitmap is zero-based */
1111 if (!ret2)
1112 goto got; /* we grabbed the inode! */
1113
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, sb, group_desc_bh,
1131 EXT4_JTR_NONE);
1132 if (err) {
1133 ext4_std_error(sb, err);
1134 goto out;
1135 }
1136
1137 /* We may have to initialize the block bitmap if it isn't already */
1138 if (ext4_has_group_desc_csum(sb) &&
1139 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
1140 struct buffer_head *block_bitmap_bh;
1141
1142 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
1143 if (IS_ERR(block_bitmap_bh)) {
1144 err = PTR_ERR(block_bitmap_bh);
1145 goto out;
1146 }
1147 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
1148 err = ext4_journal_get_write_access(handle, sb, block_bitmap_bh,
1149 EXT4_JTR_NONE);
1150 if (err) {
1151 brelse(block_bitmap_bh);
1152 ext4_std_error(sb, err);
1153 goto out;
1154 }
1155
1156 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1157 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1158
1159 /* recheck and clear flag under lock if we still need to */
1160 ext4_lock_group(sb, group);
1161 if (ext4_has_group_desc_csum(sb) &&
1162 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1163 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1164 ext4_free_group_clusters_set(sb, gdp,
1165 ext4_free_clusters_after_init(sb, group, gdp));
1166 ext4_block_bitmap_csum_set(sb, gdp, block_bitmap_bh);
1167 ext4_group_desc_csum_set(sb, group, gdp);
1168 }
1169 ext4_unlock_group(sb, group);
1170 brelse(block_bitmap_bh);
1171
1172 if (err) {
1173 ext4_std_error(sb, err);
1174 goto out;
1175 }
1176 }
1177
1178 /* Update the relevant bg descriptor fields */
1179 if (ext4_has_group_desc_csum(sb)) {
1180 int free;
1181 struct ext4_group_info *grp = NULL;
1182
1183 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1184 grp = ext4_get_group_info(sb, group);
1185 if (!grp) {
1186 err = -EFSCORRUPTED;
1187 goto out;
1188 }
1189 down_read(&grp->alloc_sem); /*
1190 * protect vs itable
1191 * lazyinit
1192 */
1193 }
1194 ext4_lock_group(sb, group); /* while we modify the bg desc */
1195 free = EXT4_INODES_PER_GROUP(sb) -
1196 ext4_itable_unused_count(sb, gdp);
1197 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1198 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1199 free = 0;
1200 }
1201 /*
1202 * Check the relative inode number against the last used
1203 * relative inode number in this group. if it is greater
1204 * we need to update the bg_itable_unused count
1205 */
1206 if (ino > free)
1207 ext4_itable_unused_set(sb, gdp,
1208 (EXT4_INODES_PER_GROUP(sb) - ino));
1209 if (!(sbi->s_mount_state & EXT4_FC_REPLAY))
1210 up_read(&grp->alloc_sem);
1211 } else {
1212 ext4_lock_group(sb, group);
1213 }
1214
1215 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1216 if (S_ISDIR(mode)) {
1217 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1218 if (sbi->s_log_groups_per_flex) {
1219 ext4_group_t f = ext4_flex_group(sbi, group);
1220
1221 atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1222 f)->used_dirs);
1223 }
1224 }
1225 if (ext4_has_group_desc_csum(sb)) {
1226 ext4_inode_bitmap_csum_set(sb, gdp, inode_bitmap_bh);
1227 ext4_group_desc_csum_set(sb, group, gdp);
1228 }
1229 ext4_unlock_group(sb, group);
1230
1231 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1232 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1233 if (err) {
1234 ext4_std_error(sb, err);
1235 goto out;
1236 }
1237
1238 percpu_counter_dec(&sbi->s_freeinodes_counter);
1239 if (S_ISDIR(mode))
1240 percpu_counter_inc(&sbi->s_dirs_counter);
1241
1242 if (sbi->s_log_groups_per_flex) {
1243 flex_group = ext4_flex_group(sbi, group);
1244 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1245 flex_group)->free_inodes);
1246 }
1247
1248 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1249 /* This is the optimal IO size (for stat), not the fs block size */
1250 inode->i_blocks = 0;
1251 simple_inode_init_ts(inode);
1252 ei->i_crtime = inode_get_mtime(inode);
1253
1254 memset(ei->i_data, 0, sizeof(ei->i_data));
1255 ei->i_dir_start_lookup = 0;
1256 ei->i_disksize = 0;
1257
1258 /* Don't inherit extent flag from directory, amongst others. */
1259 ei->i_flags =
1260 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1261 ei->i_flags |= i_flags;
1262 ei->i_file_acl = 0;
1263 ei->i_dtime = 0;
1264 ei->i_block_group = group;
1265 ei->i_last_alloc_group = ~0;
1266
1267 ext4_set_inode_flags(inode, true);
1268 if (IS_DIRSYNC(inode))
1269 ext4_handle_sync(handle);
1270 if (insert_inode_locked(inode) < 0) {
1271 /*
1272 * Likely a bitmap corruption causing inode to be allocated
1273 * twice.
1274 */
1275 err = -EIO;
1276 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1277 inode->i_ino);
1278 ext4_mark_group_bitmap_corrupted(sb, group,
1279 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1280 goto out;
1281 }
1282 inode->i_generation = get_random_u32();
1283
1284 /* Precompute checksum seed for inode metadata */
1285 if (ext4_has_metadata_csum(sb)) {
1286 __u32 csum;
1287 __le32 inum = cpu_to_le32(inode->i_ino);
1288 __le32 gen = cpu_to_le32(inode->i_generation);
1289 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1290 sizeof(inum));
1291 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1292 sizeof(gen));
1293 }
1294
1295 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1296 ext4_set_inode_state(inode, EXT4_STATE_NEW);
1297
1298 ei->i_extra_isize = sbi->s_want_extra_isize;
1299 ei->i_inline_off = 0;
1300 if (ext4_has_feature_inline_data(sb) &&
1301 (!(ei->i_flags & EXT4_DAX_FL) || S_ISDIR(mode)))
1302 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1303 ret = inode;
1304 err = dquot_alloc_inode(inode);
1305 if (err)
1306 goto fail_drop;
1307
1308 /*
1309 * Since the encryption xattr will always be unique, create it first so
1310 * that it's less likely to end up in an external xattr block and
1311 * prevent its deduplication.
1312 */
1313 if (encrypt) {
1314 err = fscrypt_set_context(inode, handle);
1315 if (err)
1316 goto fail_free_drop;
1317 }
1318
1319 if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1320 err = ext4_init_acl(handle, inode, dir);
1321 if (err)
1322 goto fail_free_drop;
1323
1324 err = ext4_init_security(handle, inode, dir, qstr);
1325 if (err)
1326 goto fail_free_drop;
1327 }
1328
1329 if (ext4_has_feature_extents(sb)) {
1330 /* set extent flag only for directory, file and normal symlink*/
1331 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1332 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1333 ext4_ext_tree_init(handle, inode);
1334 }
1335 }
1336
1337 ext4_update_inode_fsync_trans(handle, inode, 1);
1338
1339 err = ext4_mark_inode_dirty(handle, inode);
1340 if (err) {
1341 ext4_std_error(sb, err);
1342 goto fail_free_drop;
1343 }
1344
1345 ext4_debug("allocating inode %lu\n", inode->i_ino);
1346 trace_ext4_allocate_inode(inode, dir, mode);
1347 brelse(inode_bitmap_bh);
1348 return ret;
1349
1350fail_free_drop:
1351 dquot_free_inode(inode);
1352fail_drop:
1353 clear_nlink(inode);
1354 unlock_new_inode(inode);
1355out:
1356 dquot_drop(inode);
1357 inode->i_flags |= S_NOQUOTA;
1358 iput(inode);
1359 brelse(inode_bitmap_bh);
1360 return ERR_PTR(err);
1361}
1362
1363/* Verify that we are loading a valid orphan from disk */
1364struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1365{
1366 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1367 ext4_group_t block_group;
1368 int bit;
1369 struct buffer_head *bitmap_bh = NULL;
1370 struct inode *inode = NULL;
1371 int err = -EFSCORRUPTED;
1372
1373 if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1374 goto bad_orphan;
1375
1376 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1377 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1378 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1379 if (IS_ERR(bitmap_bh))
1380 return ERR_CAST(bitmap_bh);
1381
1382 /* Having the inode bit set should be a 100% indicator that this
1383 * is a valid orphan (no e2fsck run on fs). Orphans also include
1384 * inodes that were being truncated, so we can't check i_nlink==0.
1385 */
1386 if (!ext4_test_bit(bit, bitmap_bh->b_data))
1387 goto bad_orphan;
1388
1389 inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1390 if (IS_ERR(inode)) {
1391 err = PTR_ERR(inode);
1392 ext4_error_err(sb, -err,
1393 "couldn't read orphan inode %lu (err %d)",
1394 ino, err);
1395 brelse(bitmap_bh);
1396 return inode;
1397 }
1398
1399 /*
1400 * If the orphans has i_nlinks > 0 then it should be able to
1401 * be truncated, otherwise it won't be removed from the orphan
1402 * list during processing and an infinite loop will result.
1403 * Similarly, it must not be a bad inode.
1404 */
1405 if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1406 is_bad_inode(inode))
1407 goto bad_orphan;
1408
1409 if (NEXT_ORPHAN(inode) > max_ino)
1410 goto bad_orphan;
1411 brelse(bitmap_bh);
1412 return inode;
1413
1414bad_orphan:
1415 ext4_error(sb, "bad orphan inode %lu", ino);
1416 if (bitmap_bh)
1417 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1418 bit, (unsigned long long)bitmap_bh->b_blocknr,
1419 ext4_test_bit(bit, bitmap_bh->b_data));
1420 if (inode) {
1421 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1422 is_bad_inode(inode));
1423 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1424 NEXT_ORPHAN(inode));
1425 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1426 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1427 /* Avoid freeing blocks if we got a bad deleted inode */
1428 if (inode->i_nlink == 0)
1429 inode->i_blocks = 0;
1430 iput(inode);
1431 }
1432 brelse(bitmap_bh);
1433 return ERR_PTR(err);
1434}
1435
1436unsigned long ext4_count_free_inodes(struct super_block *sb)
1437{
1438 unsigned long desc_count;
1439 struct ext4_group_desc *gdp;
1440 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1441#ifdef EXT4FS_DEBUG
1442 struct ext4_super_block *es;
1443 unsigned long bitmap_count, x;
1444 struct buffer_head *bitmap_bh = NULL;
1445
1446 es = EXT4_SB(sb)->s_es;
1447 desc_count = 0;
1448 bitmap_count = 0;
1449 gdp = NULL;
1450 for (i = 0; i < ngroups; i++) {
1451 gdp = ext4_get_group_desc(sb, i, NULL);
1452 if (!gdp)
1453 continue;
1454 desc_count += ext4_free_inodes_count(sb, gdp);
1455 brelse(bitmap_bh);
1456 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1457 if (IS_ERR(bitmap_bh)) {
1458 bitmap_bh = NULL;
1459 continue;
1460 }
1461
1462 x = ext4_count_free(bitmap_bh->b_data,
1463 EXT4_INODES_PER_GROUP(sb) / 8);
1464 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1465 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1466 bitmap_count += x;
1467 }
1468 brelse(bitmap_bh);
1469 printk(KERN_DEBUG "ext4_count_free_inodes: "
1470 "stored = %u, computed = %lu, %lu\n",
1471 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1472 return desc_count;
1473#else
1474 desc_count = 0;
1475 for (i = 0; i < ngroups; i++) {
1476 gdp = ext4_get_group_desc(sb, i, NULL);
1477 if (!gdp)
1478 continue;
1479 desc_count += ext4_free_inodes_count(sb, gdp);
1480 cond_resched();
1481 }
1482 return desc_count;
1483#endif
1484}
1485
1486/* Called at mount-time, super-block is locked */
1487unsigned long ext4_count_dirs(struct super_block * sb)
1488{
1489 unsigned long count = 0;
1490 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1491
1492 for (i = 0; i < ngroups; i++) {
1493 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1494 if (!gdp)
1495 continue;
1496 count += ext4_used_dirs_count(sb, gdp);
1497 }
1498 return count;
1499}
1500
1501/*
1502 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1503 * inode table. Must be called without any spinlock held. The only place
1504 * where it is called from on active part of filesystem is ext4lazyinit
1505 * thread, so we do not need any special locks, however we have to prevent
1506 * inode allocation from the current group, so we take alloc_sem lock, to
1507 * block ext4_new_inode() until we are finished.
1508 */
1509int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1510 int barrier)
1511{
1512 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1513 struct ext4_sb_info *sbi = EXT4_SB(sb);
1514 struct ext4_group_desc *gdp = NULL;
1515 struct buffer_head *group_desc_bh;
1516 handle_t *handle;
1517 ext4_fsblk_t blk;
1518 int num, ret = 0, used_blks = 0;
1519 unsigned long used_inos = 0;
1520
1521 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1522 if (!gdp || !grp)
1523 goto out;
1524
1525 /*
1526 * We do not need to lock this, because we are the only one
1527 * handling this flag.
1528 */
1529 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1530 goto out;
1531
1532 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1533 if (IS_ERR(handle)) {
1534 ret = PTR_ERR(handle);
1535 goto out;
1536 }
1537
1538 down_write(&grp->alloc_sem);
1539 /*
1540 * If inode bitmap was already initialized there may be some
1541 * used inodes so we need to skip blocks with used inodes in
1542 * inode table.
1543 */
1544 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
1545 used_inos = EXT4_INODES_PER_GROUP(sb) -
1546 ext4_itable_unused_count(sb, gdp);
1547 used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
1548
1549 /* Bogus inode unused count? */
1550 if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
1551 ext4_error(sb, "Something is wrong with group %u: "
1552 "used itable blocks: %d; "
1553 "itable unused count: %u",
1554 group, used_blks,
1555 ext4_itable_unused_count(sb, gdp));
1556 ret = 1;
1557 goto err_out;
1558 }
1559
1560 used_inos += group * EXT4_INODES_PER_GROUP(sb);
1561 /*
1562 * Are there some uninitialized inodes in the inode table
1563 * before the first normal inode?
1564 */
1565 if ((used_blks != sbi->s_itb_per_group) &&
1566 (used_inos < EXT4_FIRST_INO(sb))) {
1567 ext4_error(sb, "Something is wrong with group %u: "
1568 "itable unused count: %u; "
1569 "itables initialized count: %ld",
1570 group, ext4_itable_unused_count(sb, gdp),
1571 used_inos);
1572 ret = 1;
1573 goto err_out;
1574 }
1575 }
1576
1577 blk = ext4_inode_table(sb, gdp) + used_blks;
1578 num = sbi->s_itb_per_group - used_blks;
1579
1580 BUFFER_TRACE(group_desc_bh, "get_write_access");
1581 ret = ext4_journal_get_write_access(handle, sb, group_desc_bh,
1582 EXT4_JTR_NONE);
1583 if (ret)
1584 goto err_out;
1585
1586 /*
1587 * Skip zeroout if the inode table is full. But we set the ZEROED
1588 * flag anyway, because obviously, when it is full it does not need
1589 * further zeroing.
1590 */
1591 if (unlikely(num == 0))
1592 goto skip_zeroout;
1593
1594 ext4_debug("going to zero out inode table in group %d\n",
1595 group);
1596 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1597 if (ret < 0)
1598 goto err_out;
1599 if (barrier)
1600 blkdev_issue_flush(sb->s_bdev);
1601
1602skip_zeroout:
1603 ext4_lock_group(sb, group);
1604 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1605 ext4_group_desc_csum_set(sb, group, gdp);
1606 ext4_unlock_group(sb, group);
1607
1608 BUFFER_TRACE(group_desc_bh,
1609 "call ext4_handle_dirty_metadata");
1610 ret = ext4_handle_dirty_metadata(handle, NULL,
1611 group_desc_bh);
1612
1613err_out:
1614 up_write(&grp->alloc_sem);
1615 ext4_journal_stop(handle);
1616out:
1617 return ret;
1618}