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 /*
269 * Note: we must free any quota before locking the superblock,
270 * as writing the quota to disk may need the lock as well.
271 */
272 dquot_initialize(inode);
273 dquot_free_inode(inode);
274 dquot_drop(inode);
275
276 is_directory = S_ISDIR(inode->i_mode);
277
278 /* Do this BEFORE marking the inode not in use or returning an error */
279 ext4_clear_inode(inode);
280
281 es = sbi->s_es;
282 if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
283 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
284 goto error_return;
285 }
286 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
287 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
288 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
289 /* Don't bother if the inode bitmap is corrupt. */
290 grp = ext4_get_group_info(sb, block_group);
291 if (IS_ERR(bitmap_bh)) {
292 fatal = PTR_ERR(bitmap_bh);
293 bitmap_bh = NULL;
294 goto error_return;
295 }
296 if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
297 fatal = -EFSCORRUPTED;
298 goto error_return;
299 }
300
301 BUFFER_TRACE(bitmap_bh, "get_write_access");
302 fatal = ext4_journal_get_write_access(handle, bitmap_bh);
303 if (fatal)
304 goto error_return;
305
306 fatal = -ESRCH;
307 gdp = ext4_get_group_desc(sb, block_group, &bh2);
308 if (gdp) {
309 BUFFER_TRACE(bh2, "get_write_access");
310 fatal = ext4_journal_get_write_access(handle, bh2);
311 }
312 ext4_lock_group(sb, block_group);
313 cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
314 if (fatal || !cleared) {
315 ext4_unlock_group(sb, block_group);
316 goto out;
317 }
318
319 count = ext4_free_inodes_count(sb, gdp) + 1;
320 ext4_free_inodes_set(sb, gdp, count);
321 if (is_directory) {
322 count = ext4_used_dirs_count(sb, gdp) - 1;
323 ext4_used_dirs_set(sb, gdp, count);
324 percpu_counter_dec(&sbi->s_dirs_counter);
325 }
326 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
327 EXT4_INODES_PER_GROUP(sb) / 8);
328 ext4_group_desc_csum_set(sb, block_group, gdp);
329 ext4_unlock_group(sb, block_group);
330
331 percpu_counter_inc(&sbi->s_freeinodes_counter);
332 if (sbi->s_log_groups_per_flex) {
333 struct flex_groups *fg;
334
335 fg = sbi_array_rcu_deref(sbi, s_flex_groups,
336 ext4_flex_group(sbi, block_group));
337 atomic_inc(&fg->free_inodes);
338 if (is_directory)
339 atomic_dec(&fg->used_dirs);
340 }
341 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
342 fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
343 out:
344 if (cleared) {
345 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
346 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
347 if (!fatal)
348 fatal = err;
349 } else {
350 ext4_error(sb, "bit already cleared for inode %lu", ino);
351 ext4_mark_group_bitmap_corrupted(sb, block_group,
352 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
353 }
354
355 error_return:
356 brelse(bitmap_bh);
357 ext4_std_error(sb, fatal);
358 }
359
360 struct orlov_stats {
361 __u64 free_clusters;
362 __u32 free_inodes;
363 __u32 used_dirs;
364 };
365
366 /*
367 * Helper function for Orlov's allocator; returns critical information
368 * for a particular block group or flex_bg. If flex_size is 1, then g
369 * is a block group number; otherwise it is flex_bg number.
370 */
get_orlov_stats(struct super_block * sb,ext4_group_t g,int flex_size,struct orlov_stats * stats)371 static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
372 int flex_size, struct orlov_stats *stats)
373 {
374 struct ext4_group_desc *desc;
375
376 if (flex_size > 1) {
377 struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),
378 s_flex_groups, g);
379 stats->free_inodes = atomic_read(&fg->free_inodes);
380 stats->free_clusters = atomic64_read(&fg->free_clusters);
381 stats->used_dirs = atomic_read(&fg->used_dirs);
382 return;
383 }
384
385 desc = ext4_get_group_desc(sb, g, NULL);
386 if (desc) {
387 stats->free_inodes = ext4_free_inodes_count(sb, desc);
388 stats->free_clusters = ext4_free_group_clusters(sb, desc);
389 stats->used_dirs = ext4_used_dirs_count(sb, desc);
390 } else {
391 stats->free_inodes = 0;
392 stats->free_clusters = 0;
393 stats->used_dirs = 0;
394 }
395 }
396
397 /*
398 * Orlov's allocator for directories.
399 *
400 * We always try to spread first-level directories.
401 *
402 * If there are blockgroups with both free inodes and free clusters counts
403 * not worse than average we return one with smallest directory count.
404 * Otherwise we simply return a random group.
405 *
406 * For the rest rules look so:
407 *
408 * It's OK to put directory into a group unless
409 * it has too many directories already (max_dirs) or
410 * it has too few free inodes left (min_inodes) or
411 * it has too few free clusters left (min_clusters) or
412 * Parent's group is preferred, if it doesn't satisfy these
413 * conditions we search cyclically through the rest. If none
414 * of the groups look good we just look for a group with more
415 * free inodes than average (starting at parent's group).
416 */
417
find_group_orlov(struct super_block * sb,struct inode * parent,ext4_group_t * group,umode_t mode,const struct qstr * qstr)418 static int find_group_orlov(struct super_block *sb, struct inode *parent,
419 ext4_group_t *group, umode_t mode,
420 const struct qstr *qstr)
421 {
422 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
423 struct ext4_sb_info *sbi = EXT4_SB(sb);
424 ext4_group_t real_ngroups = ext4_get_groups_count(sb);
425 int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
426 unsigned int freei, avefreei, grp_free;
427 ext4_fsblk_t freec, avefreec;
428 unsigned int ndirs;
429 int max_dirs, min_inodes;
430 ext4_grpblk_t min_clusters;
431 ext4_group_t i, grp, g, ngroups;
432 struct ext4_group_desc *desc;
433 struct orlov_stats stats;
434 int flex_size = ext4_flex_bg_size(sbi);
435 struct dx_hash_info hinfo;
436
437 ngroups = real_ngroups;
438 if (flex_size > 1) {
439 ngroups = (real_ngroups + flex_size - 1) >>
440 sbi->s_log_groups_per_flex;
441 parent_group >>= sbi->s_log_groups_per_flex;
442 }
443
444 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
445 avefreei = freei / ngroups;
446 freec = percpu_counter_read_positive(&sbi->s_freeclusters_counter);
447 avefreec = freec;
448 do_div(avefreec, ngroups);
449 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
450
451 if (S_ISDIR(mode) &&
452 ((parent == d_inode(sb->s_root)) ||
453 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
454 int best_ndir = inodes_per_group;
455 int ret = -1;
456
457 if (qstr) {
458 hinfo.hash_version = DX_HASH_HALF_MD4;
459 hinfo.seed = sbi->s_hash_seed;
460 ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
461 grp = hinfo.hash;
462 } else
463 grp = prandom_u32();
464 parent_group = (unsigned)grp % ngroups;
465 for (i = 0; i < ngroups; i++) {
466 g = (parent_group + i) % ngroups;
467 get_orlov_stats(sb, g, flex_size, &stats);
468 if (!stats.free_inodes)
469 continue;
470 if (stats.used_dirs >= best_ndir)
471 continue;
472 if (stats.free_inodes < avefreei)
473 continue;
474 if (stats.free_clusters < avefreec)
475 continue;
476 grp = g;
477 ret = 0;
478 best_ndir = stats.used_dirs;
479 }
480 if (ret)
481 goto fallback;
482 found_flex_bg:
483 if (flex_size == 1) {
484 *group = grp;
485 return 0;
486 }
487
488 /*
489 * We pack inodes at the beginning of the flexgroup's
490 * inode tables. Block allocation decisions will do
491 * something similar, although regular files will
492 * start at 2nd block group of the flexgroup. See
493 * ext4_ext_find_goal() and ext4_find_near().
494 */
495 grp *= flex_size;
496 for (i = 0; i < flex_size; i++) {
497 if (grp+i >= real_ngroups)
498 break;
499 desc = ext4_get_group_desc(sb, grp+i, NULL);
500 if (desc && ext4_free_inodes_count(sb, desc)) {
501 *group = grp+i;
502 return 0;
503 }
504 }
505 goto fallback;
506 }
507
508 max_dirs = ndirs / ngroups + inodes_per_group*flex_size / 16;
509 min_inodes = avefreei - inodes_per_group*flex_size / 4;
510 if (min_inodes < 1)
511 min_inodes = 1;
512 min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
513
514 /*
515 * Start looking in the flex group where we last allocated an
516 * inode for this parent directory
517 */
518 if (EXT4_I(parent)->i_last_alloc_group != ~0) {
519 parent_group = EXT4_I(parent)->i_last_alloc_group;
520 if (flex_size > 1)
521 parent_group >>= sbi->s_log_groups_per_flex;
522 }
523
524 for (i = 0; i < ngroups; i++) {
525 grp = (parent_group + i) % ngroups;
526 get_orlov_stats(sb, grp, flex_size, &stats);
527 if (stats.used_dirs >= max_dirs)
528 continue;
529 if (stats.free_inodes < min_inodes)
530 continue;
531 if (stats.free_clusters < min_clusters)
532 continue;
533 goto found_flex_bg;
534 }
535
536 fallback:
537 ngroups = real_ngroups;
538 avefreei = freei / ngroups;
539 fallback_retry:
540 parent_group = EXT4_I(parent)->i_block_group;
541 for (i = 0; i < ngroups; i++) {
542 grp = (parent_group + i) % ngroups;
543 desc = ext4_get_group_desc(sb, grp, NULL);
544 if (desc) {
545 grp_free = ext4_free_inodes_count(sb, desc);
546 if (grp_free && grp_free >= avefreei) {
547 *group = grp;
548 return 0;
549 }
550 }
551 }
552
553 if (avefreei) {
554 /*
555 * The free-inodes counter is approximate, and for really small
556 * filesystems the above test can fail to find any blockgroups
557 */
558 avefreei = 0;
559 goto fallback_retry;
560 }
561
562 return -1;
563 }
564
find_group_other(struct super_block * sb,struct inode * parent,ext4_group_t * group,umode_t mode)565 static int find_group_other(struct super_block *sb, struct inode *parent,
566 ext4_group_t *group, umode_t mode)
567 {
568 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
569 ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
570 struct ext4_group_desc *desc;
571 int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
572
573 /*
574 * Try to place the inode is the same flex group as its
575 * parent. If we can't find space, use the Orlov algorithm to
576 * find another flex group, and store that information in the
577 * parent directory's inode information so that use that flex
578 * group for future allocations.
579 */
580 if (flex_size > 1) {
581 int retry = 0;
582
583 try_again:
584 parent_group &= ~(flex_size-1);
585 last = parent_group + flex_size;
586 if (last > ngroups)
587 last = ngroups;
588 for (i = parent_group; i < last; i++) {
589 desc = ext4_get_group_desc(sb, i, NULL);
590 if (desc && ext4_free_inodes_count(sb, desc)) {
591 *group = i;
592 return 0;
593 }
594 }
595 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
596 retry = 1;
597 parent_group = EXT4_I(parent)->i_last_alloc_group;
598 goto try_again;
599 }
600 /*
601 * If this didn't work, use the Orlov search algorithm
602 * to find a new flex group; we pass in the mode to
603 * avoid the topdir algorithms.
604 */
605 *group = parent_group + flex_size;
606 if (*group > ngroups)
607 *group = 0;
608 return find_group_orlov(sb, parent, group, mode, NULL);
609 }
610
611 /*
612 * Try to place the inode in its parent directory
613 */
614 *group = parent_group;
615 desc = ext4_get_group_desc(sb, *group, NULL);
616 if (desc && ext4_free_inodes_count(sb, desc) &&
617 ext4_free_group_clusters(sb, desc))
618 return 0;
619
620 /*
621 * We're going to place this inode in a different blockgroup from its
622 * parent. We want to cause files in a common directory to all land in
623 * the same blockgroup. But we want files which are in a different
624 * directory which shares a blockgroup with our parent to land in a
625 * different blockgroup.
626 *
627 * So add our directory's i_ino into the starting point for the hash.
628 */
629 *group = (*group + parent->i_ino) % ngroups;
630
631 /*
632 * Use a quadratic hash to find a group with a free inode and some free
633 * blocks.
634 */
635 for (i = 1; i < ngroups; i <<= 1) {
636 *group += i;
637 if (*group >= ngroups)
638 *group -= ngroups;
639 desc = ext4_get_group_desc(sb, *group, NULL);
640 if (desc && ext4_free_inodes_count(sb, desc) &&
641 ext4_free_group_clusters(sb, desc))
642 return 0;
643 }
644
645 /*
646 * That failed: try linear search for a free inode, even if that group
647 * has no free blocks.
648 */
649 *group = parent_group;
650 for (i = 0; i < ngroups; i++) {
651 if (++*group >= ngroups)
652 *group = 0;
653 desc = ext4_get_group_desc(sb, *group, NULL);
654 if (desc && ext4_free_inodes_count(sb, desc))
655 return 0;
656 }
657
658 return -1;
659 }
660
661 /*
662 * In no journal mode, if an inode has recently been deleted, we want
663 * to avoid reusing it until we're reasonably sure the inode table
664 * block has been written back to disk. (Yes, these values are
665 * somewhat arbitrary...)
666 */
667 #define RECENTCY_MIN 60
668 #define RECENTCY_DIRTY 300
669
recently_deleted(struct super_block * sb,ext4_group_t group,int ino)670 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
671 {
672 struct ext4_group_desc *gdp;
673 struct ext4_inode *raw_inode;
674 struct buffer_head *bh;
675 int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
676 int offset, ret = 0;
677 int recentcy = RECENTCY_MIN;
678 u32 dtime, now;
679
680 gdp = ext4_get_group_desc(sb, group, NULL);
681 if (unlikely(!gdp))
682 return 0;
683
684 bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
685 (ino / inodes_per_block));
686 if (!bh || !buffer_uptodate(bh))
687 /*
688 * If the block is not in the buffer cache, then it
689 * must have been written out.
690 */
691 goto out;
692
693 offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
694 raw_inode = (struct ext4_inode *) (bh->b_data + offset);
695
696 /* i_dtime is only 32 bits on disk, but we only care about relative
697 * times in the range of a few minutes (i.e. long enough to sync a
698 * recently-deleted inode to disk), so using the low 32 bits of the
699 * clock (a 68 year range) is enough, see time_before32() */
700 dtime = le32_to_cpu(raw_inode->i_dtime);
701 now = ktime_get_real_seconds();
702 if (buffer_dirty(bh))
703 recentcy += RECENTCY_DIRTY;
704
705 if (dtime && time_before32(dtime, now) &&
706 time_before32(now, dtime + recentcy))
707 ret = 1;
708 out:
709 brelse(bh);
710 return ret;
711 }
712
find_inode_bit(struct super_block * sb,ext4_group_t group,struct buffer_head * bitmap,unsigned long * ino)713 static int find_inode_bit(struct super_block *sb, ext4_group_t group,
714 struct buffer_head *bitmap, unsigned long *ino)
715 {
716 next:
717 *ino = ext4_find_next_zero_bit((unsigned long *)
718 bitmap->b_data,
719 EXT4_INODES_PER_GROUP(sb), *ino);
720 if (*ino >= EXT4_INODES_PER_GROUP(sb))
721 return 0;
722
723 if ((EXT4_SB(sb)->s_journal == NULL) &&
724 recently_deleted(sb, group, *ino)) {
725 *ino = *ino + 1;
726 if (*ino < EXT4_INODES_PER_GROUP(sb))
727 goto next;
728 return 0;
729 }
730
731 return 1;
732 }
733
734 /*
735 * There are two policies for allocating an inode. If the new inode is
736 * a directory, then a forward search is made for a block group with both
737 * free space and a low directory-to-inode ratio; if that fails, then of
738 * the groups with above-average free space, that group with the fewest
739 * directories already is chosen.
740 *
741 * For other inodes, search forward from the parent directory's block
742 * group to find a free inode.
743 */
__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)744 struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
745 umode_t mode, const struct qstr *qstr,
746 __u32 goal, uid_t *owner, __u32 i_flags,
747 int handle_type, unsigned int line_no,
748 int nblocks)
749 {
750 struct super_block *sb;
751 struct buffer_head *inode_bitmap_bh = NULL;
752 struct buffer_head *group_desc_bh;
753 ext4_group_t ngroups, group = 0;
754 unsigned long ino = 0;
755 struct inode *inode;
756 struct ext4_group_desc *gdp = NULL;
757 struct ext4_inode_info *ei;
758 struct ext4_sb_info *sbi;
759 int ret2, err;
760 struct inode *ret;
761 ext4_group_t i;
762 ext4_group_t flex_group;
763 struct ext4_group_info *grp;
764 int encrypt = 0;
765
766 /* Cannot create files in a deleted directory */
767 if (!dir || !dir->i_nlink)
768 return ERR_PTR(-EPERM);
769
770 sb = dir->i_sb;
771 sbi = EXT4_SB(sb);
772
773 if (unlikely(ext4_forced_shutdown(sbi)))
774 return ERR_PTR(-EIO);
775
776 if ((ext4_encrypted_inode(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) &&
777 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) &&
778 !(i_flags & EXT4_EA_INODE_FL)) {
779 err = fscrypt_get_encryption_info(dir);
780 if (err)
781 return ERR_PTR(err);
782 if (!fscrypt_has_encryption_key(dir))
783 return ERR_PTR(-ENOKEY);
784 encrypt = 1;
785 }
786
787 if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
788 #ifdef CONFIG_EXT4_FS_POSIX_ACL
789 struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
790
791 if (IS_ERR(p))
792 return ERR_CAST(p);
793 if (p) {
794 int acl_size = p->a_count * sizeof(ext4_acl_entry);
795
796 nblocks += (S_ISDIR(mode) ? 2 : 1) *
797 __ext4_xattr_set_credits(sb, NULL /* inode */,
798 NULL /* block_bh */, acl_size,
799 true /* is_create */);
800 posix_acl_release(p);
801 }
802 #endif
803
804 #ifdef CONFIG_SECURITY
805 {
806 int num_security_xattrs = 1;
807
808 #ifdef CONFIG_INTEGRITY
809 num_security_xattrs++;
810 #endif
811 /*
812 * We assume that security xattrs are never
813 * more than 1k. In practice they are under
814 * 128 bytes.
815 */
816 nblocks += num_security_xattrs *
817 __ext4_xattr_set_credits(sb, NULL /* inode */,
818 NULL /* block_bh */, 1024,
819 true /* is_create */);
820 }
821 #endif
822 if (encrypt)
823 nblocks += __ext4_xattr_set_credits(sb,
824 NULL /* inode */, NULL /* block_bh */,
825 FSCRYPT_SET_CONTEXT_MAX_SIZE,
826 true /* is_create */);
827 }
828
829 ngroups = ext4_get_groups_count(sb);
830 trace_ext4_request_inode(dir, mode);
831 inode = new_inode(sb);
832 if (!inode)
833 return ERR_PTR(-ENOMEM);
834 ei = EXT4_I(inode);
835
836 /*
837 * Initialize owners and quota early so that we don't have to account
838 * for quota initialization worst case in standard inode creating
839 * transaction
840 */
841 if (owner) {
842 inode->i_mode = mode;
843 i_uid_write(inode, owner[0]);
844 i_gid_write(inode, owner[1]);
845 } else if (test_opt(sb, GRPID)) {
846 inode->i_mode = mode;
847 inode->i_uid = current_fsuid();
848 inode->i_gid = dir->i_gid;
849 } else
850 inode_init_owner(inode, dir, mode);
851
852 if (ext4_has_feature_project(sb) &&
853 ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
854 ei->i_projid = EXT4_I(dir)->i_projid;
855 else
856 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
857
858 err = dquot_initialize(inode);
859 if (err)
860 goto out;
861
862 if (!goal)
863 goal = sbi->s_inode_goal;
864
865 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
866 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
867 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
868 ret2 = 0;
869 goto got_group;
870 }
871
872 if (S_ISDIR(mode))
873 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
874 else
875 ret2 = find_group_other(sb, dir, &group, mode);
876
877 got_group:
878 EXT4_I(dir)->i_last_alloc_group = group;
879 err = -ENOSPC;
880 if (ret2 == -1)
881 goto out;
882
883 /*
884 * Normally we will only go through one pass of this loop,
885 * unless we get unlucky and it turns out the group we selected
886 * had its last inode grabbed by someone else.
887 */
888 for (i = 0; i < ngroups; i++, ino = 0) {
889 err = -EIO;
890
891 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
892 if (!gdp)
893 goto out;
894
895 /*
896 * Check free inodes count before loading bitmap.
897 */
898 if (ext4_free_inodes_count(sb, gdp) == 0)
899 goto next_group;
900
901 grp = ext4_get_group_info(sb, group);
902 /* Skip groups with already-known suspicious inode tables */
903 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
904 goto next_group;
905
906 brelse(inode_bitmap_bh);
907 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
908 /* Skip groups with suspicious inode tables */
909 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
910 IS_ERR(inode_bitmap_bh)) {
911 inode_bitmap_bh = NULL;
912 goto next_group;
913 }
914
915 repeat_in_this_group:
916 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
917 if (!ret2)
918 goto next_group;
919
920 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
921 ext4_error(sb, "reserved inode found cleared - "
922 "inode=%lu", ino + 1);
923 ext4_mark_group_bitmap_corrupted(sb, group,
924 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
925 goto next_group;
926 }
927
928 if (!handle) {
929 BUG_ON(nblocks <= 0);
930 handle = __ext4_journal_start_sb(dir->i_sb, line_no,
931 handle_type, nblocks,
932 0);
933 if (IS_ERR(handle)) {
934 err = PTR_ERR(handle);
935 ext4_std_error(sb, err);
936 goto out;
937 }
938 }
939 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
940 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
941 if (err) {
942 ext4_std_error(sb, err);
943 goto out;
944 }
945 ext4_lock_group(sb, group);
946 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
947 if (ret2) {
948 /* Someone already took the bit. Repeat the search
949 * with lock held.
950 */
951 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
952 if (ret2) {
953 ext4_set_bit(ino, inode_bitmap_bh->b_data);
954 ret2 = 0;
955 } else {
956 ret2 = 1; /* we didn't grab the inode */
957 }
958 }
959 ext4_unlock_group(sb, group);
960 ino++; /* the inode bitmap is zero-based */
961 if (!ret2)
962 goto got; /* we grabbed the inode! */
963
964 if (ino < EXT4_INODES_PER_GROUP(sb))
965 goto repeat_in_this_group;
966 next_group:
967 if (++group == ngroups)
968 group = 0;
969 }
970 err = -ENOSPC;
971 goto out;
972
973 got:
974 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
975 err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
976 if (err) {
977 ext4_std_error(sb, err);
978 goto out;
979 }
980
981 BUFFER_TRACE(group_desc_bh, "get_write_access");
982 err = ext4_journal_get_write_access(handle, group_desc_bh);
983 if (err) {
984 ext4_std_error(sb, err);
985 goto out;
986 }
987
988 /* We may have to initialize the block bitmap if it isn't already */
989 if (ext4_has_group_desc_csum(sb) &&
990 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
991 struct buffer_head *block_bitmap_bh;
992
993 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
994 if (IS_ERR(block_bitmap_bh)) {
995 err = PTR_ERR(block_bitmap_bh);
996 goto out;
997 }
998 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
999 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
1000 if (err) {
1001 brelse(block_bitmap_bh);
1002 ext4_std_error(sb, err);
1003 goto out;
1004 }
1005
1006 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1007 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1008
1009 /* recheck and clear flag under lock if we still need to */
1010 ext4_lock_group(sb, group);
1011 if (ext4_has_group_desc_csum(sb) &&
1012 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1013 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1014 ext4_free_group_clusters_set(sb, gdp,
1015 ext4_free_clusters_after_init(sb, group, gdp));
1016 ext4_block_bitmap_csum_set(sb, group, gdp,
1017 block_bitmap_bh);
1018 ext4_group_desc_csum_set(sb, group, gdp);
1019 }
1020 ext4_unlock_group(sb, group);
1021 brelse(block_bitmap_bh);
1022
1023 if (err) {
1024 ext4_std_error(sb, err);
1025 goto out;
1026 }
1027 }
1028
1029 /* Update the relevant bg descriptor fields */
1030 if (ext4_has_group_desc_csum(sb)) {
1031 int free;
1032 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1033
1034 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
1035 ext4_lock_group(sb, group); /* while we modify the bg desc */
1036 free = EXT4_INODES_PER_GROUP(sb) -
1037 ext4_itable_unused_count(sb, gdp);
1038 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1039 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1040 free = 0;
1041 }
1042 /*
1043 * Check the relative inode number against the last used
1044 * relative inode number in this group. if it is greater
1045 * we need to update the bg_itable_unused count
1046 */
1047 if (ino > free)
1048 ext4_itable_unused_set(sb, gdp,
1049 (EXT4_INODES_PER_GROUP(sb) - ino));
1050 up_read(&grp->alloc_sem);
1051 } else {
1052 ext4_lock_group(sb, group);
1053 }
1054
1055 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1056 if (S_ISDIR(mode)) {
1057 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1058 if (sbi->s_log_groups_per_flex) {
1059 ext4_group_t f = ext4_flex_group(sbi, group);
1060
1061 atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1062 f)->used_dirs);
1063 }
1064 }
1065 if (ext4_has_group_desc_csum(sb)) {
1066 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1067 EXT4_INODES_PER_GROUP(sb) / 8);
1068 ext4_group_desc_csum_set(sb, group, gdp);
1069 }
1070 ext4_unlock_group(sb, group);
1071
1072 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1073 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1074 if (err) {
1075 ext4_std_error(sb, err);
1076 goto out;
1077 }
1078
1079 percpu_counter_dec(&sbi->s_freeinodes_counter);
1080 if (S_ISDIR(mode))
1081 percpu_counter_inc(&sbi->s_dirs_counter);
1082
1083 if (sbi->s_log_groups_per_flex) {
1084 flex_group = ext4_flex_group(sbi, group);
1085 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1086 flex_group)->free_inodes);
1087 }
1088
1089 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1090 /* This is the optimal IO size (for stat), not the fs block size */
1091 inode->i_blocks = 0;
1092 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1093 ei->i_crtime = inode->i_mtime;
1094
1095 memset(ei->i_data, 0, sizeof(ei->i_data));
1096 ei->i_dir_start_lookup = 0;
1097 ei->i_disksize = 0;
1098
1099 /* Don't inherit extent flag from directory, amongst others. */
1100 ei->i_flags =
1101 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1102 ei->i_flags |= i_flags;
1103 ei->i_file_acl = 0;
1104 ei->i_dtime = 0;
1105 ei->i_block_group = group;
1106 ei->i_last_alloc_group = ~0;
1107
1108 ext4_set_inode_flags(inode);
1109 if (IS_DIRSYNC(inode))
1110 ext4_handle_sync(handle);
1111 if (insert_inode_locked(inode) < 0) {
1112 /*
1113 * Likely a bitmap corruption causing inode to be allocated
1114 * twice.
1115 */
1116 err = -EIO;
1117 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1118 inode->i_ino);
1119 ext4_mark_group_bitmap_corrupted(sb, group,
1120 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1121 goto out;
1122 }
1123 inode->i_generation = prandom_u32();
1124
1125 /* Precompute checksum seed for inode metadata */
1126 if (ext4_has_metadata_csum(sb)) {
1127 __u32 csum;
1128 __le32 inum = cpu_to_le32(inode->i_ino);
1129 __le32 gen = cpu_to_le32(inode->i_generation);
1130 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1131 sizeof(inum));
1132 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1133 sizeof(gen));
1134 }
1135
1136 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1137 ext4_set_inode_state(inode, EXT4_STATE_NEW);
1138
1139 ei->i_extra_isize = sbi->s_want_extra_isize;
1140 ei->i_inline_off = 0;
1141 if (ext4_has_feature_inline_data(sb))
1142 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1143 ret = inode;
1144 err = dquot_alloc_inode(inode);
1145 if (err)
1146 goto fail_drop;
1147
1148 /*
1149 * Since the encryption xattr will always be unique, create it first so
1150 * that it's less likely to end up in an external xattr block and
1151 * prevent its deduplication.
1152 */
1153 if (encrypt) {
1154 err = fscrypt_inherit_context(dir, inode, handle, true);
1155 if (err)
1156 goto fail_free_drop;
1157 }
1158
1159 if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1160 err = ext4_init_acl(handle, inode, dir);
1161 if (err)
1162 goto fail_free_drop;
1163
1164 err = ext4_init_security(handle, inode, dir, qstr);
1165 if (err)
1166 goto fail_free_drop;
1167 }
1168
1169 if (ext4_has_feature_extents(sb)) {
1170 /* set extent flag only for directory, file and normal symlink*/
1171 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1172 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1173 ext4_ext_tree_init(handle, inode);
1174 }
1175 }
1176
1177 if (ext4_handle_valid(handle)) {
1178 ei->i_sync_tid = handle->h_transaction->t_tid;
1179 ei->i_datasync_tid = handle->h_transaction->t_tid;
1180 }
1181
1182 err = ext4_mark_inode_dirty(handle, inode);
1183 if (err) {
1184 ext4_std_error(sb, err);
1185 goto fail_free_drop;
1186 }
1187
1188 ext4_debug("allocating inode %lu\n", inode->i_ino);
1189 trace_ext4_allocate_inode(inode, dir, mode);
1190 brelse(inode_bitmap_bh);
1191 return ret;
1192
1193 fail_free_drop:
1194 dquot_free_inode(inode);
1195 fail_drop:
1196 clear_nlink(inode);
1197 unlock_new_inode(inode);
1198 out:
1199 dquot_drop(inode);
1200 inode->i_flags |= S_NOQUOTA;
1201 iput(inode);
1202 brelse(inode_bitmap_bh);
1203 return ERR_PTR(err);
1204 }
1205
1206 /* Verify that we are loading a valid orphan from disk */
ext4_orphan_get(struct super_block * sb,unsigned long ino)1207 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1208 {
1209 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1210 ext4_group_t block_group;
1211 int bit;
1212 struct buffer_head *bitmap_bh = NULL;
1213 struct inode *inode = NULL;
1214 int err = -EFSCORRUPTED;
1215
1216 if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1217 goto bad_orphan;
1218
1219 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1220 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1221 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1222 if (IS_ERR(bitmap_bh))
1223 return (struct inode *) bitmap_bh;
1224
1225 /* Having the inode bit set should be a 100% indicator that this
1226 * is a valid orphan (no e2fsck run on fs). Orphans also include
1227 * inodes that were being truncated, so we can't check i_nlink==0.
1228 */
1229 if (!ext4_test_bit(bit, bitmap_bh->b_data))
1230 goto bad_orphan;
1231
1232 inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1233 if (IS_ERR(inode)) {
1234 err = PTR_ERR(inode);
1235 ext4_error(sb, "couldn't read orphan inode %lu (err %d)",
1236 ino, err);
1237 return inode;
1238 }
1239
1240 /*
1241 * If the orphans has i_nlinks > 0 then it should be able to
1242 * be truncated, otherwise it won't be removed from the orphan
1243 * list during processing and an infinite loop will result.
1244 * Similarly, it must not be a bad inode.
1245 */
1246 if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1247 is_bad_inode(inode))
1248 goto bad_orphan;
1249
1250 if (NEXT_ORPHAN(inode) > max_ino)
1251 goto bad_orphan;
1252 brelse(bitmap_bh);
1253 return inode;
1254
1255 bad_orphan:
1256 ext4_error(sb, "bad orphan inode %lu", ino);
1257 if (bitmap_bh)
1258 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1259 bit, (unsigned long long)bitmap_bh->b_blocknr,
1260 ext4_test_bit(bit, bitmap_bh->b_data));
1261 if (inode) {
1262 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1263 is_bad_inode(inode));
1264 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1265 NEXT_ORPHAN(inode));
1266 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1267 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1268 /* Avoid freeing blocks if we got a bad deleted inode */
1269 if (inode->i_nlink == 0)
1270 inode->i_blocks = 0;
1271 iput(inode);
1272 }
1273 brelse(bitmap_bh);
1274 return ERR_PTR(err);
1275 }
1276
ext4_count_free_inodes(struct super_block * sb)1277 unsigned long ext4_count_free_inodes(struct super_block *sb)
1278 {
1279 unsigned long desc_count;
1280 struct ext4_group_desc *gdp;
1281 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1282 #ifdef EXT4FS_DEBUG
1283 struct ext4_super_block *es;
1284 unsigned long bitmap_count, x;
1285 struct buffer_head *bitmap_bh = NULL;
1286
1287 es = EXT4_SB(sb)->s_es;
1288 desc_count = 0;
1289 bitmap_count = 0;
1290 gdp = NULL;
1291 for (i = 0; i < ngroups; i++) {
1292 gdp = ext4_get_group_desc(sb, i, NULL);
1293 if (!gdp)
1294 continue;
1295 desc_count += ext4_free_inodes_count(sb, gdp);
1296 brelse(bitmap_bh);
1297 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1298 if (IS_ERR(bitmap_bh)) {
1299 bitmap_bh = NULL;
1300 continue;
1301 }
1302
1303 x = ext4_count_free(bitmap_bh->b_data,
1304 EXT4_INODES_PER_GROUP(sb) / 8);
1305 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1306 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1307 bitmap_count += x;
1308 }
1309 brelse(bitmap_bh);
1310 printk(KERN_DEBUG "ext4_count_free_inodes: "
1311 "stored = %u, computed = %lu, %lu\n",
1312 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1313 return desc_count;
1314 #else
1315 desc_count = 0;
1316 for (i = 0; i < ngroups; i++) {
1317 gdp = ext4_get_group_desc(sb, i, NULL);
1318 if (!gdp)
1319 continue;
1320 desc_count += ext4_free_inodes_count(sb, gdp);
1321 cond_resched();
1322 }
1323 return desc_count;
1324 #endif
1325 }
1326
1327 /* Called at mount-time, super-block is locked */
ext4_count_dirs(struct super_block * sb)1328 unsigned long ext4_count_dirs(struct super_block * sb)
1329 {
1330 unsigned long count = 0;
1331 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1332
1333 for (i = 0; i < ngroups; i++) {
1334 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1335 if (!gdp)
1336 continue;
1337 count += ext4_used_dirs_count(sb, gdp);
1338 }
1339 return count;
1340 }
1341
1342 /*
1343 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1344 * inode table. Must be called without any spinlock held. The only place
1345 * where it is called from on active part of filesystem is ext4lazyinit
1346 * thread, so we do not need any special locks, however we have to prevent
1347 * inode allocation from the current group, so we take alloc_sem lock, to
1348 * block ext4_new_inode() until we are finished.
1349 */
ext4_init_inode_table(struct super_block * sb,ext4_group_t group,int barrier)1350 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1351 int barrier)
1352 {
1353 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1354 struct ext4_sb_info *sbi = EXT4_SB(sb);
1355 struct ext4_group_desc *gdp = NULL;
1356 struct buffer_head *group_desc_bh;
1357 handle_t *handle;
1358 ext4_fsblk_t blk;
1359 int num, ret = 0, used_blks = 0;
1360 unsigned long used_inos = 0;
1361
1362 /* This should not happen, but just to be sure check this */
1363 if (sb_rdonly(sb)) {
1364 ret = 1;
1365 goto out;
1366 }
1367
1368 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1369 if (!gdp)
1370 goto out;
1371
1372 /*
1373 * We do not need to lock this, because we are the only one
1374 * handling this flag.
1375 */
1376 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1377 goto out;
1378
1379 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1380 if (IS_ERR(handle)) {
1381 ret = PTR_ERR(handle);
1382 goto out;
1383 }
1384
1385 down_write(&grp->alloc_sem);
1386 /*
1387 * If inode bitmap was already initialized there may be some
1388 * used inodes so we need to skip blocks with used inodes in
1389 * inode table.
1390 */
1391 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
1392 used_inos = EXT4_INODES_PER_GROUP(sb) -
1393 ext4_itable_unused_count(sb, gdp);
1394 used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
1395
1396 /* Bogus inode unused count? */
1397 if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
1398 ext4_error(sb, "Something is wrong with group %u: "
1399 "used itable blocks: %d; "
1400 "itable unused count: %u",
1401 group, used_blks,
1402 ext4_itable_unused_count(sb, gdp));
1403 ret = 1;
1404 goto err_out;
1405 }
1406
1407 used_inos += group * EXT4_INODES_PER_GROUP(sb);
1408 /*
1409 * Are there some uninitialized inodes in the inode table
1410 * before the first normal inode?
1411 */
1412 if ((used_blks != sbi->s_itb_per_group) &&
1413 (used_inos < EXT4_FIRST_INO(sb))) {
1414 ext4_error(sb, "Something is wrong with group %u: "
1415 "itable unused count: %u; "
1416 "itables initialized count: %ld",
1417 group, ext4_itable_unused_count(sb, gdp),
1418 used_inos);
1419 ret = 1;
1420 goto err_out;
1421 }
1422 }
1423
1424 blk = ext4_inode_table(sb, gdp) + used_blks;
1425 num = sbi->s_itb_per_group - used_blks;
1426
1427 BUFFER_TRACE(group_desc_bh, "get_write_access");
1428 ret = ext4_journal_get_write_access(handle,
1429 group_desc_bh);
1430 if (ret)
1431 goto err_out;
1432
1433 /*
1434 * Skip zeroout if the inode table is full. But we set the ZEROED
1435 * flag anyway, because obviously, when it is full it does not need
1436 * further zeroing.
1437 */
1438 if (unlikely(num == 0))
1439 goto skip_zeroout;
1440
1441 ext4_debug("going to zero out inode table in group %d\n",
1442 group);
1443 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1444 if (ret < 0)
1445 goto err_out;
1446 if (barrier)
1447 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1448
1449 skip_zeroout:
1450 ext4_lock_group(sb, group);
1451 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1452 ext4_group_desc_csum_set(sb, group, gdp);
1453 ext4_unlock_group(sb, group);
1454
1455 BUFFER_TRACE(group_desc_bh,
1456 "call ext4_handle_dirty_metadata");
1457 ret = ext4_handle_dirty_metadata(handle, NULL,
1458 group_desc_bh);
1459
1460 err_out:
1461 up_write(&grp->alloc_sem);
1462 ext4_journal_stop(handle);
1463 out:
1464 return ret;
1465 }
1466