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 */
ext4_mark_bitmap_end(int start_bit,int end_bit,char * bitmap)55 void 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
ext4_end_bitmap_read(struct buffer_head * bh,int uptodate)69 void 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
ext4_validate_inode_bitmap(struct super_block * sb,struct ext4_group_desc * desc,ext4_group_t block_group,struct buffer_head * bh)79 static int ext4_validate_inode_bitmap(struct super_block *sb,
80 struct ext4_group_desc *desc,
81 ext4_group_t block_group,
82 struct buffer_head *bh)
83 {
84 ext4_fsblk_t blk;
85 struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
86
87 if (buffer_verified(bh))
88 return 0;
89 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
90 return -EFSCORRUPTED;
91
92 ext4_lock_group(sb, block_group);
93 if (buffer_verified(bh))
94 goto verified;
95 blk = ext4_inode_bitmap(sb, desc);
96 if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
97 EXT4_INODES_PER_GROUP(sb) / 8)) {
98 ext4_unlock_group(sb, block_group);
99 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
100 "inode_bitmap = %llu", block_group, blk);
101 ext4_mark_group_bitmap_corrupted(sb, block_group,
102 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
103 return -EFSBADCRC;
104 }
105 set_buffer_verified(bh);
106 verified:
107 ext4_unlock_group(sb, block_group);
108 return 0;
109 }
110
111 /*
112 * Read the inode allocation bitmap for a given block_group, reading
113 * into the specified slot in the superblock's bitmap cache.
114 *
115 * Return buffer_head of bitmap on success or NULL.
116 */
117 static struct buffer_head *
ext4_read_inode_bitmap(struct super_block * sb,ext4_group_t block_group)118 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
119 {
120 struct ext4_group_desc *desc;
121 struct ext4_sb_info *sbi = EXT4_SB(sb);
122 struct buffer_head *bh = NULL;
123 ext4_fsblk_t bitmap_blk;
124 int err;
125
126 desc = ext4_get_group_desc(sb, block_group, NULL);
127 if (!desc)
128 return ERR_PTR(-EFSCORRUPTED);
129
130 bitmap_blk = ext4_inode_bitmap(sb, desc);
131 if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
132 (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
133 ext4_error(sb, "Invalid inode bitmap blk %llu in "
134 "block_group %u", bitmap_blk, block_group);
135 ext4_mark_group_bitmap_corrupted(sb, block_group,
136 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
137 return ERR_PTR(-EFSCORRUPTED);
138 }
139 bh = sb_getblk(sb, bitmap_blk);
140 if (unlikely(!bh)) {
141 ext4_warning(sb, "Cannot read inode bitmap - "
142 "block_group = %u, inode_bitmap = %llu",
143 block_group, bitmap_blk);
144 return ERR_PTR(-ENOMEM);
145 }
146 if (bitmap_uptodate(bh))
147 goto verify;
148
149 lock_buffer(bh);
150 if (bitmap_uptodate(bh)) {
151 unlock_buffer(bh);
152 goto verify;
153 }
154
155 ext4_lock_group(sb, block_group);
156 if (ext4_has_group_desc_csum(sb) &&
157 (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
158 if (block_group == 0) {
159 ext4_unlock_group(sb, block_group);
160 unlock_buffer(bh);
161 ext4_error(sb, "Inode bitmap for bg 0 marked "
162 "uninitialized");
163 err = -EFSCORRUPTED;
164 goto out;
165 }
166 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
167 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
168 sb->s_blocksize * 8, bh->b_data);
169 set_bitmap_uptodate(bh);
170 set_buffer_uptodate(bh);
171 set_buffer_verified(bh);
172 ext4_unlock_group(sb, block_group);
173 unlock_buffer(bh);
174 return bh;
175 }
176 ext4_unlock_group(sb, block_group);
177
178 if (buffer_uptodate(bh)) {
179 /*
180 * if not uninit if bh is uptodate,
181 * bitmap is also uptodate
182 */
183 set_bitmap_uptodate(bh);
184 unlock_buffer(bh);
185 goto verify;
186 }
187 /*
188 * submit the buffer_head for reading
189 */
190 trace_ext4_load_inode_bitmap(sb, block_group);
191 bh->b_end_io = ext4_end_bitmap_read;
192 get_bh(bh);
193 submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
194 wait_on_buffer(bh);
195 if (!buffer_uptodate(bh)) {
196 put_bh(bh);
197 ext4_error(sb, "Cannot read inode bitmap - "
198 "block_group = %u, inode_bitmap = %llu",
199 block_group, bitmap_blk);
200 ext4_mark_group_bitmap_corrupted(sb, block_group,
201 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
202 return ERR_PTR(-EIO);
203 }
204
205 verify:
206 err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
207 if (err)
208 goto out;
209 return bh;
210 out:
211 put_bh(bh);
212 return ERR_PTR(err);
213 }
214
215 /*
216 * NOTE! When we get the inode, we're the only people
217 * that have access to it, and as such there are no
218 * race conditions we have to worry about. The inode
219 * is not on the hash-lists, and it cannot be reached
220 * through the filesystem because the directory entry
221 * has been deleted earlier.
222 *
223 * HOWEVER: we must make sure that we get no aliases,
224 * which means that we have to call "clear_inode()"
225 * _before_ we mark the inode not in use in the inode
226 * bitmaps. Otherwise a newly created file might use
227 * the same inode number (not actually the same pointer
228 * though), and then we'd have two inodes sharing the
229 * same inode number and space on the harddisk.
230 */
ext4_free_inode(handle_t * handle,struct inode * inode)231 void ext4_free_inode(handle_t *handle, struct inode *inode)
232 {
233 struct super_block *sb = inode->i_sb;
234 int is_directory;
235 unsigned long ino;
236 struct buffer_head *bitmap_bh = NULL;
237 struct buffer_head *bh2;
238 ext4_group_t block_group;
239 unsigned long bit;
240 struct ext4_group_desc *gdp;
241 struct ext4_super_block *es;
242 struct ext4_sb_info *sbi;
243 int fatal = 0, err, count, cleared;
244 struct ext4_group_info *grp;
245
246 if (!sb) {
247 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
248 "nonexistent device\n", __func__, __LINE__);
249 return;
250 }
251 if (atomic_read(&inode->i_count) > 1) {
252 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
253 __func__, __LINE__, inode->i_ino,
254 atomic_read(&inode->i_count));
255 return;
256 }
257 if (inode->i_nlink) {
258 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
259 __func__, __LINE__, inode->i_ino, inode->i_nlink);
260 return;
261 }
262 sbi = EXT4_SB(sb);
263
264 ino = inode->i_ino;
265 ext4_debug("freeing inode %lu\n", ino);
266 trace_ext4_free_inode(inode);
267
268 dquot_initialize(inode);
269 dquot_free_inode(inode);
270
271 is_directory = S_ISDIR(inode->i_mode);
272
273 /* Do this BEFORE marking the inode not in use or returning an error */
274 ext4_clear_inode(inode);
275
276 es = sbi->s_es;
277 if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
278 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
279 goto error_return;
280 }
281 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
282 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
283 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
284 /* Don't bother if the inode bitmap is corrupt. */
285 grp = ext4_get_group_info(sb, block_group);
286 if (IS_ERR(bitmap_bh)) {
287 fatal = PTR_ERR(bitmap_bh);
288 bitmap_bh = NULL;
289 goto error_return;
290 }
291 if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
292 fatal = -EFSCORRUPTED;
293 goto error_return;
294 }
295
296 BUFFER_TRACE(bitmap_bh, "get_write_access");
297 fatal = ext4_journal_get_write_access(handle, bitmap_bh);
298 if (fatal)
299 goto error_return;
300
301 fatal = -ESRCH;
302 gdp = ext4_get_group_desc(sb, block_group, &bh2);
303 if (gdp) {
304 BUFFER_TRACE(bh2, "get_write_access");
305 fatal = ext4_journal_get_write_access(handle, bh2);
306 }
307 ext4_lock_group(sb, block_group);
308 cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
309 if (fatal || !cleared) {
310 ext4_unlock_group(sb, block_group);
311 goto out;
312 }
313
314 count = ext4_free_inodes_count(sb, gdp) + 1;
315 ext4_free_inodes_set(sb, gdp, count);
316 if (is_directory) {
317 count = ext4_used_dirs_count(sb, gdp) - 1;
318 ext4_used_dirs_set(sb, gdp, count);
319 percpu_counter_dec(&sbi->s_dirs_counter);
320 }
321 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
322 EXT4_INODES_PER_GROUP(sb) / 8);
323 ext4_group_desc_csum_set(sb, block_group, gdp);
324 ext4_unlock_group(sb, block_group);
325
326 percpu_counter_inc(&sbi->s_freeinodes_counter);
327 if (sbi->s_log_groups_per_flex) {
328 struct flex_groups *fg;
329
330 fg = sbi_array_rcu_deref(sbi, s_flex_groups,
331 ext4_flex_group(sbi, block_group));
332 atomic_inc(&fg->free_inodes);
333 if (is_directory)
334 atomic_dec(&fg->used_dirs);
335 }
336 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
337 fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
338 out:
339 if (cleared) {
340 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
341 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
342 if (!fatal)
343 fatal = err;
344 } else {
345 ext4_error(sb, "bit already cleared for inode %lu", ino);
346 ext4_mark_group_bitmap_corrupted(sb, block_group,
347 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
348 }
349
350 error_return:
351 brelse(bitmap_bh);
352 ext4_std_error(sb, fatal);
353 }
354
355 struct orlov_stats {
356 __u64 free_clusters;
357 __u32 free_inodes;
358 __u32 used_dirs;
359 };
360
361 /*
362 * Helper function for Orlov's allocator; returns critical information
363 * for a particular block group or flex_bg. If flex_size is 1, then g
364 * is a block group number; otherwise it is flex_bg number.
365 */
get_orlov_stats(struct super_block * sb,ext4_group_t g,int flex_size,struct orlov_stats * stats)366 static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
367 int flex_size, struct orlov_stats *stats)
368 {
369 struct ext4_group_desc *desc;
370
371 if (flex_size > 1) {
372 struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),
373 s_flex_groups, g);
374 stats->free_inodes = atomic_read(&fg->free_inodes);
375 stats->free_clusters = atomic64_read(&fg->free_clusters);
376 stats->used_dirs = atomic_read(&fg->used_dirs);
377 return;
378 }
379
380 desc = ext4_get_group_desc(sb, g, NULL);
381 if (desc) {
382 stats->free_inodes = ext4_free_inodes_count(sb, desc);
383 stats->free_clusters = ext4_free_group_clusters(sb, desc);
384 stats->used_dirs = ext4_used_dirs_count(sb, desc);
385 } else {
386 stats->free_inodes = 0;
387 stats->free_clusters = 0;
388 stats->used_dirs = 0;
389 }
390 }
391
392 /*
393 * Orlov's allocator for directories.
394 *
395 * We always try to spread first-level directories.
396 *
397 * If there are blockgroups with both free inodes and free clusters counts
398 * not worse than average we return one with smallest directory count.
399 * Otherwise we simply return a random group.
400 *
401 * For the rest rules look so:
402 *
403 * It's OK to put directory into a group unless
404 * it has too many directories already (max_dirs) or
405 * it has too few free inodes left (min_inodes) or
406 * it has too few free clusters left (min_clusters) or
407 * Parent's group is preferred, if it doesn't satisfy these
408 * conditions we search cyclically through the rest. If none
409 * of the groups look good we just look for a group with more
410 * free inodes than average (starting at parent's group).
411 */
412
find_group_orlov(struct super_block * sb,struct inode * parent,ext4_group_t * group,umode_t mode,const struct qstr * qstr)413 static int find_group_orlov(struct super_block *sb, struct inode *parent,
414 ext4_group_t *group, umode_t mode,
415 const struct qstr *qstr)
416 {
417 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
418 struct ext4_sb_info *sbi = EXT4_SB(sb);
419 ext4_group_t real_ngroups = ext4_get_groups_count(sb);
420 int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
421 unsigned int freei, avefreei, grp_free;
422 ext4_fsblk_t freec, avefreec;
423 unsigned int ndirs;
424 int max_dirs, min_inodes;
425 ext4_grpblk_t min_clusters;
426 ext4_group_t i, grp, g, ngroups;
427 struct ext4_group_desc *desc;
428 struct orlov_stats stats;
429 int flex_size = ext4_flex_bg_size(sbi);
430 struct dx_hash_info hinfo;
431
432 ngroups = real_ngroups;
433 if (flex_size > 1) {
434 ngroups = (real_ngroups + flex_size - 1) >>
435 sbi->s_log_groups_per_flex;
436 parent_group >>= sbi->s_log_groups_per_flex;
437 }
438
439 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
440 avefreei = freei / ngroups;
441 freec = percpu_counter_read_positive(&sbi->s_freeclusters_counter);
442 avefreec = freec;
443 do_div(avefreec, ngroups);
444 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
445
446 if (S_ISDIR(mode) &&
447 ((parent == d_inode(sb->s_root)) ||
448 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
449 int best_ndir = inodes_per_group;
450 int ret = -1;
451
452 if (qstr) {
453 hinfo.hash_version = DX_HASH_HALF_MD4;
454 hinfo.seed = sbi->s_hash_seed;
455 ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);
456 grp = hinfo.hash;
457 } else
458 grp = prandom_u32();
459 parent_group = (unsigned)grp % ngroups;
460 for (i = 0; i < ngroups; i++) {
461 g = (parent_group + i) % ngroups;
462 get_orlov_stats(sb, g, flex_size, &stats);
463 if (!stats.free_inodes)
464 continue;
465 if (stats.used_dirs >= best_ndir)
466 continue;
467 if (stats.free_inodes < avefreei)
468 continue;
469 if (stats.free_clusters < avefreec)
470 continue;
471 grp = g;
472 ret = 0;
473 best_ndir = stats.used_dirs;
474 }
475 if (ret)
476 goto fallback;
477 found_flex_bg:
478 if (flex_size == 1) {
479 *group = grp;
480 return 0;
481 }
482
483 /*
484 * We pack inodes at the beginning of the flexgroup's
485 * inode tables. Block allocation decisions will do
486 * something similar, although regular files will
487 * start at 2nd block group of the flexgroup. See
488 * ext4_ext_find_goal() and ext4_find_near().
489 */
490 grp *= flex_size;
491 for (i = 0; i < flex_size; i++) {
492 if (grp+i >= real_ngroups)
493 break;
494 desc = ext4_get_group_desc(sb, grp+i, NULL);
495 if (desc && ext4_free_inodes_count(sb, desc)) {
496 *group = grp+i;
497 return 0;
498 }
499 }
500 goto fallback;
501 }
502
503 max_dirs = ndirs / ngroups + inodes_per_group*flex_size / 16;
504 min_inodes = avefreei - inodes_per_group*flex_size / 4;
505 if (min_inodes < 1)
506 min_inodes = 1;
507 min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
508
509 /*
510 * Start looking in the flex group where we last allocated an
511 * inode for this parent directory
512 */
513 if (EXT4_I(parent)->i_last_alloc_group != ~0) {
514 parent_group = EXT4_I(parent)->i_last_alloc_group;
515 if (flex_size > 1)
516 parent_group >>= sbi->s_log_groups_per_flex;
517 }
518
519 for (i = 0; i < ngroups; i++) {
520 grp = (parent_group + i) % ngroups;
521 get_orlov_stats(sb, grp, flex_size, &stats);
522 if (stats.used_dirs >= max_dirs)
523 continue;
524 if (stats.free_inodes < min_inodes)
525 continue;
526 if (stats.free_clusters < min_clusters)
527 continue;
528 goto found_flex_bg;
529 }
530
531 fallback:
532 ngroups = real_ngroups;
533 avefreei = freei / ngroups;
534 fallback_retry:
535 parent_group = EXT4_I(parent)->i_block_group;
536 for (i = 0; i < ngroups; i++) {
537 grp = (parent_group + i) % ngroups;
538 desc = ext4_get_group_desc(sb, grp, NULL);
539 if (desc) {
540 grp_free = ext4_free_inodes_count(sb, desc);
541 if (grp_free && grp_free >= avefreei) {
542 *group = grp;
543 return 0;
544 }
545 }
546 }
547
548 if (avefreei) {
549 /*
550 * The free-inodes counter is approximate, and for really small
551 * filesystems the above test can fail to find any blockgroups
552 */
553 avefreei = 0;
554 goto fallback_retry;
555 }
556
557 return -1;
558 }
559
find_group_other(struct super_block * sb,struct inode * parent,ext4_group_t * group,umode_t mode)560 static int find_group_other(struct super_block *sb, struct inode *parent,
561 ext4_group_t *group, umode_t mode)
562 {
563 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
564 ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
565 struct ext4_group_desc *desc;
566 int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
567
568 /*
569 * Try to place the inode is the same flex group as its
570 * parent. If we can't find space, use the Orlov algorithm to
571 * find another flex group, and store that information in the
572 * parent directory's inode information so that use that flex
573 * group for future allocations.
574 */
575 if (flex_size > 1) {
576 int retry = 0;
577
578 try_again:
579 parent_group &= ~(flex_size-1);
580 last = parent_group + flex_size;
581 if (last > ngroups)
582 last = ngroups;
583 for (i = parent_group; i < last; i++) {
584 desc = ext4_get_group_desc(sb, i, NULL);
585 if (desc && ext4_free_inodes_count(sb, desc)) {
586 *group = i;
587 return 0;
588 }
589 }
590 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
591 retry = 1;
592 parent_group = EXT4_I(parent)->i_last_alloc_group;
593 goto try_again;
594 }
595 /*
596 * If this didn't work, use the Orlov search algorithm
597 * to find a new flex group; we pass in the mode to
598 * avoid the topdir algorithms.
599 */
600 *group = parent_group + flex_size;
601 if (*group > ngroups)
602 *group = 0;
603 return find_group_orlov(sb, parent, group, mode, NULL);
604 }
605
606 /*
607 * Try to place the inode in its parent directory
608 */
609 *group = parent_group;
610 desc = ext4_get_group_desc(sb, *group, NULL);
611 if (desc && ext4_free_inodes_count(sb, desc) &&
612 ext4_free_group_clusters(sb, desc))
613 return 0;
614
615 /*
616 * We're going to place this inode in a different blockgroup from its
617 * parent. We want to cause files in a common directory to all land in
618 * the same blockgroup. But we want files which are in a different
619 * directory which shares a blockgroup with our parent to land in a
620 * different blockgroup.
621 *
622 * So add our directory's i_ino into the starting point for the hash.
623 */
624 *group = (*group + parent->i_ino) % ngroups;
625
626 /*
627 * Use a quadratic hash to find a group with a free inode and some free
628 * blocks.
629 */
630 for (i = 1; i < ngroups; i <<= 1) {
631 *group += i;
632 if (*group >= ngroups)
633 *group -= ngroups;
634 desc = ext4_get_group_desc(sb, *group, NULL);
635 if (desc && ext4_free_inodes_count(sb, desc) &&
636 ext4_free_group_clusters(sb, desc))
637 return 0;
638 }
639
640 /*
641 * That failed: try linear search for a free inode, even if that group
642 * has no free blocks.
643 */
644 *group = parent_group;
645 for (i = 0; i < ngroups; i++) {
646 if (++*group >= ngroups)
647 *group = 0;
648 desc = ext4_get_group_desc(sb, *group, NULL);
649 if (desc && ext4_free_inodes_count(sb, desc))
650 return 0;
651 }
652
653 return -1;
654 }
655
656 /*
657 * In no journal mode, if an inode has recently been deleted, we want
658 * to avoid reusing it until we're reasonably sure the inode table
659 * block has been written back to disk. (Yes, these values are
660 * somewhat arbitrary...)
661 */
662 #define RECENTCY_MIN 60
663 #define RECENTCY_DIRTY 300
664
recently_deleted(struct super_block * sb,ext4_group_t group,int ino)665 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
666 {
667 struct ext4_group_desc *gdp;
668 struct ext4_inode *raw_inode;
669 struct buffer_head *bh;
670 int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
671 int offset, ret = 0;
672 int recentcy = RECENTCY_MIN;
673 u32 dtime, now;
674
675 gdp = ext4_get_group_desc(sb, group, NULL);
676 if (unlikely(!gdp))
677 return 0;
678
679 bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
680 (ino / inodes_per_block));
681 if (!bh || !buffer_uptodate(bh))
682 /*
683 * If the block is not in the buffer cache, then it
684 * must have been written out.
685 */
686 goto out;
687
688 offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
689 raw_inode = (struct ext4_inode *) (bh->b_data + offset);
690
691 /* i_dtime is only 32 bits on disk, but we only care about relative
692 * times in the range of a few minutes (i.e. long enough to sync a
693 * recently-deleted inode to disk), so using the low 32 bits of the
694 * clock (a 68 year range) is enough, see time_before32() */
695 dtime = le32_to_cpu(raw_inode->i_dtime);
696 now = ktime_get_real_seconds();
697 if (buffer_dirty(bh))
698 recentcy += RECENTCY_DIRTY;
699
700 if (dtime && time_before32(dtime, now) &&
701 time_before32(now, dtime + recentcy))
702 ret = 1;
703 out:
704 brelse(bh);
705 return ret;
706 }
707
find_inode_bit(struct super_block * sb,ext4_group_t group,struct buffer_head * bitmap,unsigned long * ino)708 static int find_inode_bit(struct super_block *sb, ext4_group_t group,
709 struct buffer_head *bitmap, unsigned long *ino)
710 {
711 next:
712 *ino = ext4_find_next_zero_bit((unsigned long *)
713 bitmap->b_data,
714 EXT4_INODES_PER_GROUP(sb), *ino);
715 if (*ino >= EXT4_INODES_PER_GROUP(sb))
716 return 0;
717
718 if ((EXT4_SB(sb)->s_journal == NULL) &&
719 recently_deleted(sb, group, *ino)) {
720 *ino = *ino + 1;
721 if (*ino < EXT4_INODES_PER_GROUP(sb))
722 goto next;
723 return 0;
724 }
725
726 return 1;
727 }
728
729 /*
730 * There are two policies for allocating an inode. If the new inode is
731 * a directory, then a forward search is made for a block group with both
732 * free space and a low directory-to-inode ratio; if that fails, then of
733 * the groups with above-average free space, that group with the fewest
734 * directories already is chosen.
735 *
736 * For other inodes, search forward from the parent directory's block
737 * group to find a free inode.
738 */
__ext4_new_inode(handle_t * handle,struct inode * dir,umode_t mode,const struct qstr * qstr,__u32 goal,uid_t * owner,__u32 i_flags,int handle_type,unsigned int line_no,int nblocks)739 struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
740 umode_t mode, const struct qstr *qstr,
741 __u32 goal, uid_t *owner, __u32 i_flags,
742 int handle_type, unsigned int line_no,
743 int nblocks)
744 {
745 struct super_block *sb;
746 struct buffer_head *inode_bitmap_bh = NULL;
747 struct buffer_head *group_desc_bh;
748 ext4_group_t ngroups, group = 0;
749 unsigned long ino = 0;
750 struct inode *inode;
751 struct ext4_group_desc *gdp = NULL;
752 struct ext4_inode_info *ei;
753 struct ext4_sb_info *sbi;
754 int ret2, err;
755 struct inode *ret;
756 ext4_group_t i;
757 ext4_group_t flex_group;
758 struct ext4_group_info *grp;
759 int encrypt = 0;
760
761 /* Cannot create files in a deleted directory */
762 if (!dir || !dir->i_nlink)
763 return ERR_PTR(-EPERM);
764
765 sb = dir->i_sb;
766 sbi = EXT4_SB(sb);
767
768 if (unlikely(ext4_forced_shutdown(sbi)))
769 return ERR_PTR(-EIO);
770
771 if ((IS_ENCRYPTED(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) &&
772 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) &&
773 !(i_flags & EXT4_EA_INODE_FL)) {
774 err = fscrypt_get_encryption_info(dir);
775 if (err)
776 return ERR_PTR(err);
777 if (!fscrypt_has_encryption_key(dir))
778 return ERR_PTR(-ENOKEY);
779 encrypt = 1;
780 }
781
782 if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
783 #ifdef CONFIG_EXT4_FS_POSIX_ACL
784 struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
785
786 if (IS_ERR(p))
787 return ERR_CAST(p);
788 if (p) {
789 int acl_size = p->a_count * sizeof(ext4_acl_entry);
790
791 nblocks += (S_ISDIR(mode) ? 2 : 1) *
792 __ext4_xattr_set_credits(sb, NULL /* inode */,
793 NULL /* block_bh */, acl_size,
794 true /* is_create */);
795 posix_acl_release(p);
796 }
797 #endif
798
799 #ifdef CONFIG_SECURITY
800 {
801 int num_security_xattrs = 1;
802
803 #ifdef CONFIG_INTEGRITY
804 num_security_xattrs++;
805 #endif
806 /*
807 * We assume that security xattrs are never
808 * more than 1k. In practice they are under
809 * 128 bytes.
810 */
811 nblocks += num_security_xattrs *
812 __ext4_xattr_set_credits(sb, NULL /* inode */,
813 NULL /* block_bh */, 1024,
814 true /* is_create */);
815 }
816 #endif
817 if (encrypt)
818 nblocks += __ext4_xattr_set_credits(sb,
819 NULL /* inode */, NULL /* block_bh */,
820 FSCRYPT_SET_CONTEXT_MAX_SIZE,
821 true /* is_create */);
822 }
823
824 ngroups = ext4_get_groups_count(sb);
825 trace_ext4_request_inode(dir, mode);
826 inode = new_inode(sb);
827 if (!inode)
828 return ERR_PTR(-ENOMEM);
829 ei = EXT4_I(inode);
830
831 /*
832 * Initialize owners and quota early so that we don't have to account
833 * for quota initialization worst case in standard inode creating
834 * transaction
835 */
836 if (owner) {
837 inode->i_mode = mode;
838 i_uid_write(inode, owner[0]);
839 i_gid_write(inode, owner[1]);
840 } else if (test_opt(sb, GRPID)) {
841 inode->i_mode = mode;
842 inode->i_uid = current_fsuid();
843 inode->i_gid = dir->i_gid;
844 } else
845 inode_init_owner(inode, dir, mode);
846
847 if (ext4_has_feature_project(sb) &&
848 ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
849 ei->i_projid = EXT4_I(dir)->i_projid;
850 else
851 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
852
853 err = dquot_initialize(inode);
854 if (err)
855 goto out;
856
857 if (!goal)
858 goal = sbi->s_inode_goal;
859
860 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
861 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
862 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
863 ret2 = 0;
864 goto got_group;
865 }
866
867 if (S_ISDIR(mode))
868 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
869 else
870 ret2 = find_group_other(sb, dir, &group, mode);
871
872 got_group:
873 EXT4_I(dir)->i_last_alloc_group = group;
874 err = -ENOSPC;
875 if (ret2 == -1)
876 goto out;
877
878 /*
879 * Normally we will only go through one pass of this loop,
880 * unless we get unlucky and it turns out the group we selected
881 * had its last inode grabbed by someone else.
882 */
883 for (i = 0; i < ngroups; i++, ino = 0) {
884 err = -EIO;
885
886 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
887 if (!gdp)
888 goto out;
889
890 /*
891 * Check free inodes count before loading bitmap.
892 */
893 if (ext4_free_inodes_count(sb, gdp) == 0)
894 goto next_group;
895
896 grp = ext4_get_group_info(sb, group);
897 /* Skip groups with already-known suspicious inode tables */
898 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
899 goto next_group;
900
901 brelse(inode_bitmap_bh);
902 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
903 /* Skip groups with suspicious inode tables */
904 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
905 IS_ERR(inode_bitmap_bh)) {
906 inode_bitmap_bh = NULL;
907 goto next_group;
908 }
909
910 repeat_in_this_group:
911 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
912 if (!ret2)
913 goto next_group;
914
915 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
916 ext4_error(sb, "reserved inode found cleared - "
917 "inode=%lu", ino + 1);
918 ext4_mark_group_bitmap_corrupted(sb, group,
919 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
920 goto next_group;
921 }
922
923 if (!handle) {
924 BUG_ON(nblocks <= 0);
925 handle = __ext4_journal_start_sb(dir->i_sb, line_no,
926 handle_type, nblocks,
927 0);
928 if (IS_ERR(handle)) {
929 err = PTR_ERR(handle);
930 ext4_std_error(sb, err);
931 goto out;
932 }
933 }
934 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
935 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
936 if (err) {
937 ext4_std_error(sb, err);
938 goto out;
939 }
940 ext4_lock_group(sb, group);
941 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
942 if (ret2) {
943 /* Someone already took the bit. Repeat the search
944 * with lock held.
945 */
946 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
947 if (ret2) {
948 ext4_set_bit(ino, inode_bitmap_bh->b_data);
949 ret2 = 0;
950 } else {
951 ret2 = 1; /* we didn't grab the inode */
952 }
953 }
954 ext4_unlock_group(sb, group);
955 ino++; /* the inode bitmap is zero-based */
956 if (!ret2)
957 goto got; /* we grabbed the inode! */
958
959 if (ino < EXT4_INODES_PER_GROUP(sb))
960 goto repeat_in_this_group;
961 next_group:
962 if (++group == ngroups)
963 group = 0;
964 }
965 err = -ENOSPC;
966 goto out;
967
968 got:
969 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
970 err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
971 if (err) {
972 ext4_std_error(sb, err);
973 goto out;
974 }
975
976 BUFFER_TRACE(group_desc_bh, "get_write_access");
977 err = ext4_journal_get_write_access(handle, group_desc_bh);
978 if (err) {
979 ext4_std_error(sb, err);
980 goto out;
981 }
982
983 /* We may have to initialize the block bitmap if it isn't already */
984 if (ext4_has_group_desc_csum(sb) &&
985 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
986 struct buffer_head *block_bitmap_bh;
987
988 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
989 if (IS_ERR(block_bitmap_bh)) {
990 err = PTR_ERR(block_bitmap_bh);
991 goto out;
992 }
993 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
994 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
995 if (err) {
996 brelse(block_bitmap_bh);
997 ext4_std_error(sb, err);
998 goto out;
999 }
1000
1001 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1002 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1003
1004 /* recheck and clear flag under lock if we still need to */
1005 ext4_lock_group(sb, group);
1006 if (ext4_has_group_desc_csum(sb) &&
1007 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1008 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1009 ext4_free_group_clusters_set(sb, gdp,
1010 ext4_free_clusters_after_init(sb, group, gdp));
1011 ext4_block_bitmap_csum_set(sb, group, gdp,
1012 block_bitmap_bh);
1013 ext4_group_desc_csum_set(sb, group, gdp);
1014 }
1015 ext4_unlock_group(sb, group);
1016 brelse(block_bitmap_bh);
1017
1018 if (err) {
1019 ext4_std_error(sb, err);
1020 goto out;
1021 }
1022 }
1023
1024 /* Update the relevant bg descriptor fields */
1025 if (ext4_has_group_desc_csum(sb)) {
1026 int free;
1027 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1028
1029 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
1030 ext4_lock_group(sb, group); /* while we modify the bg desc */
1031 free = EXT4_INODES_PER_GROUP(sb) -
1032 ext4_itable_unused_count(sb, gdp);
1033 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1034 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1035 free = 0;
1036 }
1037 /*
1038 * Check the relative inode number against the last used
1039 * relative inode number in this group. if it is greater
1040 * we need to update the bg_itable_unused count
1041 */
1042 if (ino > free)
1043 ext4_itable_unused_set(sb, gdp,
1044 (EXT4_INODES_PER_GROUP(sb) - ino));
1045 up_read(&grp->alloc_sem);
1046 } else {
1047 ext4_lock_group(sb, group);
1048 }
1049
1050 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1051 if (S_ISDIR(mode)) {
1052 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1053 if (sbi->s_log_groups_per_flex) {
1054 ext4_group_t f = ext4_flex_group(sbi, group);
1055
1056 atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1057 f)->used_dirs);
1058 }
1059 }
1060 if (ext4_has_group_desc_csum(sb)) {
1061 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1062 EXT4_INODES_PER_GROUP(sb) / 8);
1063 ext4_group_desc_csum_set(sb, group, gdp);
1064 }
1065 ext4_unlock_group(sb, group);
1066
1067 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1068 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1069 if (err) {
1070 ext4_std_error(sb, err);
1071 goto out;
1072 }
1073
1074 percpu_counter_dec(&sbi->s_freeinodes_counter);
1075 if (S_ISDIR(mode))
1076 percpu_counter_inc(&sbi->s_dirs_counter);
1077
1078 if (sbi->s_log_groups_per_flex) {
1079 flex_group = ext4_flex_group(sbi, group);
1080 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1081 flex_group)->free_inodes);
1082 }
1083
1084 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1085 /* This is the optimal IO size (for stat), not the fs block size */
1086 inode->i_blocks = 0;
1087 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1088 ei->i_crtime = inode->i_mtime;
1089
1090 memset(ei->i_data, 0, sizeof(ei->i_data));
1091 ei->i_dir_start_lookup = 0;
1092 ei->i_disksize = 0;
1093
1094 /* Don't inherit extent flag from directory, amongst others. */
1095 ei->i_flags =
1096 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1097 ei->i_flags |= i_flags;
1098 ei->i_file_acl = 0;
1099 ei->i_dtime = 0;
1100 ei->i_block_group = group;
1101 ei->i_last_alloc_group = ~0;
1102
1103 ext4_set_inode_flags(inode);
1104 if (IS_DIRSYNC(inode))
1105 ext4_handle_sync(handle);
1106 if (insert_inode_locked(inode) < 0) {
1107 /*
1108 * Likely a bitmap corruption causing inode to be allocated
1109 * twice.
1110 */
1111 err = -EIO;
1112 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1113 inode->i_ino);
1114 ext4_mark_group_bitmap_corrupted(sb, group,
1115 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1116 goto out;
1117 }
1118 inode->i_generation = prandom_u32();
1119
1120 /* Precompute checksum seed for inode metadata */
1121 if (ext4_has_metadata_csum(sb)) {
1122 __u32 csum;
1123 __le32 inum = cpu_to_le32(inode->i_ino);
1124 __le32 gen = cpu_to_le32(inode->i_generation);
1125 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1126 sizeof(inum));
1127 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1128 sizeof(gen));
1129 }
1130
1131 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1132 ext4_set_inode_state(inode, EXT4_STATE_NEW);
1133
1134 ei->i_extra_isize = sbi->s_want_extra_isize;
1135 ei->i_inline_off = 0;
1136 if (ext4_has_feature_inline_data(sb))
1137 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1138 ret = inode;
1139 err = dquot_alloc_inode(inode);
1140 if (err)
1141 goto fail_drop;
1142
1143 /*
1144 * Since the encryption xattr will always be unique, create it first so
1145 * that it's less likely to end up in an external xattr block and
1146 * prevent its deduplication.
1147 */
1148 if (encrypt) {
1149 err = fscrypt_inherit_context(dir, inode, handle, true);
1150 if (err)
1151 goto fail_free_drop;
1152 }
1153
1154 if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1155 err = ext4_init_acl(handle, inode, dir);
1156 if (err)
1157 goto fail_free_drop;
1158
1159 err = ext4_init_security(handle, inode, dir, qstr);
1160 if (err)
1161 goto fail_free_drop;
1162 }
1163
1164 if (ext4_has_feature_extents(sb)) {
1165 /* set extent flag only for directory, file and normal symlink*/
1166 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1167 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1168 ext4_ext_tree_init(handle, inode);
1169 }
1170 }
1171
1172 if (ext4_handle_valid(handle)) {
1173 ei->i_sync_tid = handle->h_transaction->t_tid;
1174 ei->i_datasync_tid = handle->h_transaction->t_tid;
1175 }
1176
1177 err = ext4_mark_inode_dirty(handle, inode);
1178 if (err) {
1179 ext4_std_error(sb, err);
1180 goto fail_free_drop;
1181 }
1182
1183 ext4_debug("allocating inode %lu\n", inode->i_ino);
1184 trace_ext4_allocate_inode(inode, dir, mode);
1185 brelse(inode_bitmap_bh);
1186 return ret;
1187
1188 fail_free_drop:
1189 dquot_free_inode(inode);
1190 fail_drop:
1191 clear_nlink(inode);
1192 unlock_new_inode(inode);
1193 out:
1194 dquot_drop(inode);
1195 inode->i_flags |= S_NOQUOTA;
1196 iput(inode);
1197 brelse(inode_bitmap_bh);
1198 return ERR_PTR(err);
1199 }
1200
1201 /* Verify that we are loading a valid orphan from disk */
ext4_orphan_get(struct super_block * sb,unsigned long ino)1202 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1203 {
1204 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1205 ext4_group_t block_group;
1206 int bit;
1207 struct buffer_head *bitmap_bh = NULL;
1208 struct inode *inode = NULL;
1209 int err = -EFSCORRUPTED;
1210
1211 if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1212 goto bad_orphan;
1213
1214 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1215 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1216 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1217 if (IS_ERR(bitmap_bh))
1218 return ERR_CAST(bitmap_bh);
1219
1220 /* Having the inode bit set should be a 100% indicator that this
1221 * is a valid orphan (no e2fsck run on fs). Orphans also include
1222 * inodes that were being truncated, so we can't check i_nlink==0.
1223 */
1224 if (!ext4_test_bit(bit, bitmap_bh->b_data))
1225 goto bad_orphan;
1226
1227 inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1228 if (IS_ERR(inode)) {
1229 err = PTR_ERR(inode);
1230 ext4_error(sb, "couldn't read orphan inode %lu (err %d)",
1231 ino, err);
1232 return inode;
1233 }
1234
1235 /*
1236 * If the orphans has i_nlinks > 0 then it should be able to
1237 * be truncated, otherwise it won't be removed from the orphan
1238 * list during processing and an infinite loop will result.
1239 * Similarly, it must not be a bad inode.
1240 */
1241 if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1242 is_bad_inode(inode))
1243 goto bad_orphan;
1244
1245 if (NEXT_ORPHAN(inode) > max_ino)
1246 goto bad_orphan;
1247 brelse(bitmap_bh);
1248 return inode;
1249
1250 bad_orphan:
1251 ext4_error(sb, "bad orphan inode %lu", ino);
1252 if (bitmap_bh)
1253 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1254 bit, (unsigned long long)bitmap_bh->b_blocknr,
1255 ext4_test_bit(bit, bitmap_bh->b_data));
1256 if (inode) {
1257 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1258 is_bad_inode(inode));
1259 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1260 NEXT_ORPHAN(inode));
1261 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1262 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1263 /* Avoid freeing blocks if we got a bad deleted inode */
1264 if (inode->i_nlink == 0)
1265 inode->i_blocks = 0;
1266 iput(inode);
1267 }
1268 brelse(bitmap_bh);
1269 return ERR_PTR(err);
1270 }
1271
ext4_count_free_inodes(struct super_block * sb)1272 unsigned long ext4_count_free_inodes(struct super_block *sb)
1273 {
1274 unsigned long desc_count;
1275 struct ext4_group_desc *gdp;
1276 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1277 #ifdef EXT4FS_DEBUG
1278 struct ext4_super_block *es;
1279 unsigned long bitmap_count, x;
1280 struct buffer_head *bitmap_bh = NULL;
1281
1282 es = EXT4_SB(sb)->s_es;
1283 desc_count = 0;
1284 bitmap_count = 0;
1285 gdp = NULL;
1286 for (i = 0; i < ngroups; i++) {
1287 gdp = ext4_get_group_desc(sb, i, NULL);
1288 if (!gdp)
1289 continue;
1290 desc_count += ext4_free_inodes_count(sb, gdp);
1291 brelse(bitmap_bh);
1292 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1293 if (IS_ERR(bitmap_bh)) {
1294 bitmap_bh = NULL;
1295 continue;
1296 }
1297
1298 x = ext4_count_free(bitmap_bh->b_data,
1299 EXT4_INODES_PER_GROUP(sb) / 8);
1300 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1301 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1302 bitmap_count += x;
1303 }
1304 brelse(bitmap_bh);
1305 printk(KERN_DEBUG "ext4_count_free_inodes: "
1306 "stored = %u, computed = %lu, %lu\n",
1307 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1308 return desc_count;
1309 #else
1310 desc_count = 0;
1311 for (i = 0; i < ngroups; i++) {
1312 gdp = ext4_get_group_desc(sb, i, NULL);
1313 if (!gdp)
1314 continue;
1315 desc_count += ext4_free_inodes_count(sb, gdp);
1316 cond_resched();
1317 }
1318 return desc_count;
1319 #endif
1320 }
1321
1322 /* Called at mount-time, super-block is locked */
ext4_count_dirs(struct super_block * sb)1323 unsigned long ext4_count_dirs(struct super_block * sb)
1324 {
1325 unsigned long count = 0;
1326 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1327
1328 for (i = 0; i < ngroups; i++) {
1329 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1330 if (!gdp)
1331 continue;
1332 count += ext4_used_dirs_count(sb, gdp);
1333 }
1334 return count;
1335 }
1336
1337 /*
1338 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1339 * inode table. Must be called without any spinlock held. The only place
1340 * where it is called from on active part of filesystem is ext4lazyinit
1341 * thread, so we do not need any special locks, however we have to prevent
1342 * inode allocation from the current group, so we take alloc_sem lock, to
1343 * block ext4_new_inode() until we are finished.
1344 */
ext4_init_inode_table(struct super_block * sb,ext4_group_t group,int barrier)1345 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1346 int barrier)
1347 {
1348 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1349 struct ext4_sb_info *sbi = EXT4_SB(sb);
1350 struct ext4_group_desc *gdp = NULL;
1351 struct buffer_head *group_desc_bh;
1352 handle_t *handle;
1353 ext4_fsblk_t blk;
1354 int num, ret = 0, used_blks = 0;
1355 unsigned long used_inos = 0;
1356
1357 /* This should not happen, but just to be sure check this */
1358 if (sb_rdonly(sb)) {
1359 ret = 1;
1360 goto out;
1361 }
1362
1363 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1364 if (!gdp)
1365 goto out;
1366
1367 /*
1368 * We do not need to lock this, because we are the only one
1369 * handling this flag.
1370 */
1371 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1372 goto out;
1373
1374 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1375 if (IS_ERR(handle)) {
1376 ret = PTR_ERR(handle);
1377 goto out;
1378 }
1379
1380 down_write(&grp->alloc_sem);
1381 /*
1382 * If inode bitmap was already initialized there may be some
1383 * used inodes so we need to skip blocks with used inodes in
1384 * inode table.
1385 */
1386 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
1387 used_inos = EXT4_INODES_PER_GROUP(sb) -
1388 ext4_itable_unused_count(sb, gdp);
1389 used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
1390
1391 /* Bogus inode unused count? */
1392 if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
1393 ext4_error(sb, "Something is wrong with group %u: "
1394 "used itable blocks: %d; "
1395 "itable unused count: %u",
1396 group, used_blks,
1397 ext4_itable_unused_count(sb, gdp));
1398 ret = 1;
1399 goto err_out;
1400 }
1401
1402 used_inos += group * EXT4_INODES_PER_GROUP(sb);
1403 /*
1404 * Are there some uninitialized inodes in the inode table
1405 * before the first normal inode?
1406 */
1407 if ((used_blks != sbi->s_itb_per_group) &&
1408 (used_inos < EXT4_FIRST_INO(sb))) {
1409 ext4_error(sb, "Something is wrong with group %u: "
1410 "itable unused count: %u; "
1411 "itables initialized count: %ld",
1412 group, ext4_itable_unused_count(sb, gdp),
1413 used_inos);
1414 ret = 1;
1415 goto err_out;
1416 }
1417 }
1418
1419 blk = ext4_inode_table(sb, gdp) + used_blks;
1420 num = sbi->s_itb_per_group - used_blks;
1421
1422 BUFFER_TRACE(group_desc_bh, "get_write_access");
1423 ret = ext4_journal_get_write_access(handle,
1424 group_desc_bh);
1425 if (ret)
1426 goto err_out;
1427
1428 /*
1429 * Skip zeroout if the inode table is full. But we set the ZEROED
1430 * flag anyway, because obviously, when it is full it does not need
1431 * further zeroing.
1432 */
1433 if (unlikely(num == 0))
1434 goto skip_zeroout;
1435
1436 ext4_debug("going to zero out inode table in group %d\n",
1437 group);
1438 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1439 if (ret < 0)
1440 goto err_out;
1441 if (barrier)
1442 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1443
1444 skip_zeroout:
1445 ext4_lock_group(sb, group);
1446 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1447 ext4_group_desc_csum_set(sb, group, gdp);
1448 ext4_unlock_group(sb, group);
1449
1450 BUFFER_TRACE(group_desc_bh,
1451 "call ext4_handle_dirty_metadata");
1452 ret = ext4_handle_dirty_metadata(handle, NULL,
1453 group_desc_bh);
1454
1455 err_out:
1456 up_write(&grp->alloc_sem);
1457 ext4_journal_stop(handle);
1458 out:
1459 return ret;
1460 }
1461