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;
86
87 if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)
88 return 0;
89
90 grp = ext4_get_group_info(sb, block_group);
91
92 if (buffer_verified(bh))
93 return 0;
94 if (!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, block_group, desc, bh,
102 EXT4_INODES_PER_GROUP(sb) / 8) ||
103 ext4_simulate_fail(sb, EXT4_SIM_IBITMAP_CRC)) {
104 ext4_unlock_group(sb, block_group);
105 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
106 "inode_bitmap = %llu", block_group, blk);
107 ext4_mark_group_bitmap_corrupted(sb, block_group,
108 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
109 return -EFSBADCRC;
110 }
111 set_buffer_verified(bh);
112 verified:
113 ext4_unlock_group(sb, block_group);
114 return 0;
115 }
116
117 /*
118 * Read the inode allocation bitmap for a given block_group, reading
119 * into the specified slot in the superblock's bitmap cache.
120 *
121 * Return buffer_head of bitmap on success, or an ERR_PTR on error.
122 */
123 static struct buffer_head *
ext4_read_inode_bitmap(struct super_block * sb,ext4_group_t block_group)124 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
125 {
126 struct ext4_group_desc *desc;
127 struct ext4_sb_info *sbi = EXT4_SB(sb);
128 struct buffer_head *bh = NULL;
129 ext4_fsblk_t bitmap_blk;
130 int err;
131
132 desc = ext4_get_group_desc(sb, block_group, NULL);
133 if (!desc)
134 return ERR_PTR(-EFSCORRUPTED);
135
136 bitmap_blk = ext4_inode_bitmap(sb, desc);
137 if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
138 (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
139 ext4_error(sb, "Invalid inode bitmap blk %llu in "
140 "block_group %u", bitmap_blk, block_group);
141 ext4_mark_group_bitmap_corrupted(sb, block_group,
142 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
143 return ERR_PTR(-EFSCORRUPTED);
144 }
145 bh = sb_getblk(sb, bitmap_blk);
146 if (unlikely(!bh)) {
147 ext4_warning(sb, "Cannot read inode bitmap - "
148 "block_group = %u, inode_bitmap = %llu",
149 block_group, bitmap_blk);
150 return ERR_PTR(-ENOMEM);
151 }
152 if (bitmap_uptodate(bh))
153 goto verify;
154
155 lock_buffer(bh);
156 if (bitmap_uptodate(bh)) {
157 unlock_buffer(bh);
158 goto verify;
159 }
160
161 ext4_lock_group(sb, block_group);
162 if (ext4_has_group_desc_csum(sb) &&
163 (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
164 if (block_group == 0) {
165 ext4_unlock_group(sb, block_group);
166 unlock_buffer(bh);
167 ext4_error(sb, "Inode bitmap for bg 0 marked "
168 "uninitialized");
169 err = -EFSCORRUPTED;
170 goto out;
171 }
172 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
173 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
174 sb->s_blocksize * 8, bh->b_data);
175 set_bitmap_uptodate(bh);
176 set_buffer_uptodate(bh);
177 set_buffer_verified(bh);
178 ext4_unlock_group(sb, block_group);
179 unlock_buffer(bh);
180 return bh;
181 }
182 ext4_unlock_group(sb, block_group);
183
184 if (buffer_uptodate(bh)) {
185 /*
186 * if not uninit if bh is uptodate,
187 * bitmap is also uptodate
188 */
189 set_bitmap_uptodate(bh);
190 unlock_buffer(bh);
191 goto verify;
192 }
193 /*
194 * submit the buffer_head for reading
195 */
196 trace_ext4_load_inode_bitmap(sb, block_group);
197 ext4_read_bh(bh, REQ_META | REQ_PRIO, ext4_end_bitmap_read);
198 ext4_simulate_fail_bh(sb, bh, EXT4_SIM_IBITMAP_EIO);
199 if (!buffer_uptodate(bh)) {
200 put_bh(bh);
201 ext4_error_err(sb, EIO, "Cannot read inode bitmap - "
202 "block_group = %u, inode_bitmap = %llu",
203 block_group, bitmap_blk);
204 ext4_mark_group_bitmap_corrupted(sb, block_group,
205 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
206 return ERR_PTR(-EIO);
207 }
208
209 verify:
210 err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
211 if (err)
212 goto out;
213 return bh;
214 out:
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 */
ext4_free_inode(handle_t * handle,struct inode * inode)235 void 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, block_group, gdp, bitmap_bh,
331 EXT4_INODES_PER_GROUP(sb) / 8);
332 ext4_group_desc_csum_set(sb, block_group, gdp);
333 ext4_unlock_group(sb, block_group);
334
335 if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
336 percpu_counter_inc(&sbi->s_freeinodes_counter);
337 if (sbi->s_log_groups_per_flex) {
338 struct flex_groups *fg;
339
340 fg = sbi_array_rcu_deref(sbi, s_flex_groups,
341 ext4_flex_group(sbi, block_group));
342 atomic_inc(&fg->free_inodes);
343 if (is_directory)
344 atomic_dec(&fg->used_dirs);
345 }
346 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
347 fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
348 out:
349 if (cleared) {
350 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
351 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
352 if (!fatal)
353 fatal = err;
354 } else {
355 ext4_error(sb, "bit already cleared for inode %lu", ino);
356 ext4_mark_group_bitmap_corrupted(sb, block_group,
357 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
358 }
359
360 error_return:
361 brelse(bitmap_bh);
362 ext4_std_error(sb, fatal);
363 }
364
365 struct orlov_stats {
366 __u64 free_clusters;
367 __u32 free_inodes;
368 __u32 used_dirs;
369 };
370
371 /*
372 * Helper function for Orlov's allocator; returns critical information
373 * for a particular block group or flex_bg. If flex_size is 1, then g
374 * is a block group number; otherwise it is flex_bg number.
375 */
get_orlov_stats(struct super_block * sb,ext4_group_t g,int flex_size,struct orlov_stats * stats)376 static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
377 int flex_size, struct orlov_stats *stats)
378 {
379 struct ext4_group_desc *desc;
380
381 if (flex_size > 1) {
382 struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),
383 s_flex_groups, g);
384 stats->free_inodes = atomic_read(&fg->free_inodes);
385 stats->free_clusters = atomic64_read(&fg->free_clusters);
386 stats->used_dirs = atomic_read(&fg->used_dirs);
387 return;
388 }
389
390 desc = ext4_get_group_desc(sb, g, NULL);
391 if (desc) {
392 stats->free_inodes = ext4_free_inodes_count(sb, desc);
393 stats->free_clusters = ext4_free_group_clusters(sb, desc);
394 stats->used_dirs = ext4_used_dirs_count(sb, desc);
395 } else {
396 stats->free_inodes = 0;
397 stats->free_clusters = 0;
398 stats->used_dirs = 0;
399 }
400 }
401
402 /*
403 * Orlov's allocator for directories.
404 *
405 * We always try to spread first-level directories.
406 *
407 * If there are blockgroups with both free inodes and free clusters counts
408 * not worse than average we return one with smallest directory count.
409 * Otherwise we simply return a random group.
410 *
411 * For the rest rules look so:
412 *
413 * It's OK to put directory into a group unless
414 * it has too many directories already (max_dirs) or
415 * it has too few free inodes left (min_inodes) or
416 * it has too few free clusters left (min_clusters) or
417 * Parent's group is preferred, if it doesn't satisfy these
418 * conditions we search cyclically through the rest. If none
419 * of the groups look good we just look for a group with more
420 * free inodes than average (starting at parent's group).
421 */
422
find_group_orlov(struct super_block * sb,struct inode * parent,ext4_group_t * group,umode_t mode,const struct qstr * qstr)423 static int find_group_orlov(struct super_block *sb, struct inode *parent,
424 ext4_group_t *group, umode_t mode,
425 const struct qstr *qstr)
426 {
427 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
428 struct ext4_sb_info *sbi = EXT4_SB(sb);
429 ext4_group_t real_ngroups = ext4_get_groups_count(sb);
430 int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
431 unsigned int freei, avefreei, grp_free;
432 ext4_fsblk_t freec, avefreec;
433 unsigned int ndirs;
434 int max_dirs, min_inodes;
435 ext4_grpblk_t min_clusters;
436 ext4_group_t i, grp, g, ngroups;
437 struct ext4_group_desc *desc;
438 struct orlov_stats stats;
439 int flex_size = ext4_flex_bg_size(sbi);
440 struct dx_hash_info hinfo;
441
442 ngroups = real_ngroups;
443 if (flex_size > 1) {
444 ngroups = (real_ngroups + flex_size - 1) >>
445 sbi->s_log_groups_per_flex;
446 parent_group >>= sbi->s_log_groups_per_flex;
447 }
448
449 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
450 avefreei = freei / ngroups;
451 freec = percpu_counter_read_positive(&sbi->s_freeclusters_counter);
452 avefreec = freec;
453 do_div(avefreec, ngroups);
454 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
455
456 if (S_ISDIR(mode) &&
457 ((parent == d_inode(sb->s_root)) ||
458 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
459 int best_ndir = inodes_per_group;
460 int ret = -1;
461
462 if (qstr) {
463 hinfo.hash_version = DX_HASH_HALF_MD4;
464 hinfo.seed = sbi->s_hash_seed;
465 ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);
466 grp = hinfo.hash;
467 } else
468 grp = prandom_u32();
469 parent_group = (unsigned)grp % ngroups;
470 for (i = 0; i < ngroups; i++) {
471 g = (parent_group + i) % ngroups;
472 get_orlov_stats(sb, g, flex_size, &stats);
473 if (!stats.free_inodes)
474 continue;
475 if (stats.used_dirs >= best_ndir)
476 continue;
477 if (stats.free_inodes < avefreei)
478 continue;
479 if (stats.free_clusters < avefreec)
480 continue;
481 grp = g;
482 ret = 0;
483 best_ndir = stats.used_dirs;
484 }
485 if (ret)
486 goto fallback;
487 found_flex_bg:
488 if (flex_size == 1) {
489 *group = grp;
490 return 0;
491 }
492
493 /*
494 * We pack inodes at the beginning of the flexgroup's
495 * inode tables. Block allocation decisions will do
496 * something similar, although regular files will
497 * start at 2nd block group of the flexgroup. See
498 * ext4_ext_find_goal() and ext4_find_near().
499 */
500 grp *= flex_size;
501 for (i = 0; i < flex_size; i++) {
502 if (grp+i >= real_ngroups)
503 break;
504 desc = ext4_get_group_desc(sb, grp+i, NULL);
505 if (desc && ext4_free_inodes_count(sb, desc)) {
506 *group = grp+i;
507 return 0;
508 }
509 }
510 goto fallback;
511 }
512
513 max_dirs = ndirs / ngroups + inodes_per_group*flex_size / 16;
514 min_inodes = avefreei - inodes_per_group*flex_size / 4;
515 if (min_inodes < 1)
516 min_inodes = 1;
517 min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
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
541 fallback:
542 ngroups = real_ngroups;
543 avefreei = freei / ngroups;
544 fallback_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
find_group_other(struct super_block * sb,struct inode * parent,ext4_group_t * group,umode_t mode)570 static 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
recently_deleted(struct super_block * sb,ext4_group_t group,int ino)675 static 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;
713 out:
714 brelse(bh);
715 return ret;
716 }
717
find_inode_bit(struct super_block * sb,ext4_group_t group,struct buffer_head * bitmap,unsigned long * ino)718 static 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
724 next:
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;
739 not_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
ext4_mark_inode_used(struct super_block * sb,int ino)752 int 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 = -EFSCORRUPTED;
760
761 if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
762 goto out;
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 || !group_desc_bh) {
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, group, gdp,
818 block_bitmap_bh);
819 ext4_group_desc_csum_set(sb, group, gdp);
820 }
821 ext4_unlock_group(sb, group);
822 brelse(block_bitmap_bh);
823
824 if (err) {
825 ext4_std_error(sb, err);
826 goto out;
827 }
828 }
829
830 /* Update the relevant bg descriptor fields */
831 if (ext4_has_group_desc_csum(sb)) {
832 int free;
833
834 ext4_lock_group(sb, group); /* while we modify the bg desc */
835 free = EXT4_INODES_PER_GROUP(sb) -
836 ext4_itable_unused_count(sb, gdp);
837 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
838 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
839 free = 0;
840 }
841
842 /*
843 * Check the relative inode number against the last used
844 * relative inode number in this group. if it is greater
845 * we need to update the bg_itable_unused count
846 */
847 if (bit >= free)
848 ext4_itable_unused_set(sb, gdp,
849 (EXT4_INODES_PER_GROUP(sb) - bit - 1));
850 } else {
851 ext4_lock_group(sb, group);
852 }
853
854 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
855 if (ext4_has_group_desc_csum(sb)) {
856 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
857 EXT4_INODES_PER_GROUP(sb) / 8);
858 ext4_group_desc_csum_set(sb, group, gdp);
859 }
860
861 ext4_unlock_group(sb, group);
862 err = ext4_handle_dirty_metadata(NULL, NULL, group_desc_bh);
863 sync_dirty_buffer(group_desc_bh);
864 out:
865 return err;
866 }
867
ext4_xattr_credits_for_new_inode(struct inode * dir,mode_t mode,bool encrypt)868 static int ext4_xattr_credits_for_new_inode(struct inode *dir, mode_t mode,
869 bool encrypt)
870 {
871 struct super_block *sb = dir->i_sb;
872 int nblocks = 0;
873 #ifdef CONFIG_EXT4_FS_POSIX_ACL
874 struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);
875
876 if (IS_ERR(p))
877 return PTR_ERR(p);
878 if (p) {
879 int acl_size = p->a_count * sizeof(ext4_acl_entry);
880
881 nblocks += (S_ISDIR(mode) ? 2 : 1) *
882 __ext4_xattr_set_credits(sb, NULL /* inode */,
883 NULL /* block_bh */, acl_size,
884 true /* is_create */);
885 posix_acl_release(p);
886 }
887 #endif
888
889 #ifdef CONFIG_SECURITY
890 {
891 int num_security_xattrs = 1;
892
893 #ifdef CONFIG_INTEGRITY
894 num_security_xattrs++;
895 #endif
896 /*
897 * We assume that security xattrs are never more than 1k.
898 * In practice they are under 128 bytes.
899 */
900 nblocks += num_security_xattrs *
901 __ext4_xattr_set_credits(sb, NULL /* inode */,
902 NULL /* block_bh */, 1024,
903 true /* is_create */);
904 }
905 #endif
906 if (encrypt)
907 nblocks += __ext4_xattr_set_credits(sb,
908 NULL /* inode */,
909 NULL /* block_bh */,
910 FSCRYPT_SET_CONTEXT_MAX_SIZE,
911 true /* is_create */);
912 return nblocks;
913 }
914
915 /*
916 * There are two policies for allocating an inode. If the new inode is
917 * a directory, then a forward search is made for a block group with both
918 * free space and a low directory-to-inode ratio; if that fails, then of
919 * the groups with above-average free space, that group with the fewest
920 * directories already is chosen.
921 *
922 * For other inodes, search forward from the parent directory's block
923 * group to find a free inode.
924 */
__ext4_new_inode(struct user_namespace * mnt_userns,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)925 struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
926 handle_t *handle, struct inode *dir,
927 umode_t mode, const struct qstr *qstr,
928 __u32 goal, uid_t *owner, __u32 i_flags,
929 int handle_type, unsigned int line_no,
930 int nblocks)
931 {
932 struct super_block *sb;
933 struct buffer_head *inode_bitmap_bh = NULL;
934 struct buffer_head *group_desc_bh;
935 ext4_group_t ngroups, group = 0;
936 unsigned long ino = 0;
937 struct inode *inode;
938 struct ext4_group_desc *gdp = NULL;
939 struct ext4_inode_info *ei;
940 struct ext4_sb_info *sbi;
941 int ret2, err;
942 struct inode *ret;
943 ext4_group_t i;
944 ext4_group_t flex_group;
945 struct ext4_group_info *grp = NULL;
946 bool encrypt = false;
947
948 /* Cannot create files in a deleted directory */
949 if (!dir || !dir->i_nlink)
950 return ERR_PTR(-EPERM);
951
952 sb = dir->i_sb;
953 sbi = EXT4_SB(sb);
954
955 if (unlikely(ext4_forced_shutdown(sbi)))
956 return ERR_PTR(-EIO);
957
958 ngroups = ext4_get_groups_count(sb);
959 trace_ext4_request_inode(dir, mode);
960 inode = new_inode(sb);
961 if (!inode)
962 return ERR_PTR(-ENOMEM);
963 ei = EXT4_I(inode);
964
965 /*
966 * Initialize owners and quota early so that we don't have to account
967 * for quota initialization worst case in standard inode creating
968 * transaction
969 */
970 if (owner) {
971 inode->i_mode = mode;
972 i_uid_write(inode, owner[0]);
973 i_gid_write(inode, owner[1]);
974 } else if (test_opt(sb, GRPID)) {
975 inode->i_mode = mode;
976 inode_fsuid_set(inode, mnt_userns);
977 inode->i_gid = dir->i_gid;
978 } else
979 inode_init_owner(mnt_userns, inode, dir, mode);
980
981 if (ext4_has_feature_project(sb) &&
982 ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
983 ei->i_projid = EXT4_I(dir)->i_projid;
984 else
985 ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
986
987 if (!(i_flags & EXT4_EA_INODE_FL)) {
988 err = fscrypt_prepare_new_inode(dir, inode, &encrypt);
989 if (err)
990 goto out;
991 }
992
993 err = dquot_initialize(inode);
994 if (err)
995 goto out;
996
997 if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {
998 ret2 = ext4_xattr_credits_for_new_inode(dir, mode, encrypt);
999 if (ret2 < 0) {
1000 err = ret2;
1001 goto out;
1002 }
1003 nblocks += ret2;
1004 }
1005
1006 if (!goal)
1007 goal = sbi->s_inode_goal;
1008
1009 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
1010 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
1011 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
1012 ret2 = 0;
1013 goto got_group;
1014 }
1015
1016 if (S_ISDIR(mode))
1017 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
1018 else
1019 ret2 = find_group_other(sb, dir, &group, mode);
1020
1021 got_group:
1022 EXT4_I(dir)->i_last_alloc_group = group;
1023 err = -ENOSPC;
1024 if (ret2 == -1)
1025 goto out;
1026
1027 /*
1028 * Normally we will only go through one pass of this loop,
1029 * unless we get unlucky and it turns out the group we selected
1030 * had its last inode grabbed by someone else.
1031 */
1032 for (i = 0; i < ngroups; i++, ino = 0) {
1033 err = -EIO;
1034
1035 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1036 if (!gdp)
1037 goto out;
1038
1039 /*
1040 * Check free inodes count before loading bitmap.
1041 */
1042 if (ext4_free_inodes_count(sb, gdp) == 0)
1043 goto next_group;
1044
1045 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1046 grp = ext4_get_group_info(sb, group);
1047 /*
1048 * Skip groups with already-known suspicious inode
1049 * tables
1050 */
1051 if (!grp || EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
1052 goto next_group;
1053 }
1054
1055 brelse(inode_bitmap_bh);
1056 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
1057 /* Skip groups with suspicious inode tables */
1058 if (((!(sbi->s_mount_state & EXT4_FC_REPLAY))
1059 && EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) ||
1060 IS_ERR(inode_bitmap_bh)) {
1061 inode_bitmap_bh = NULL;
1062 goto next_group;
1063 }
1064
1065 repeat_in_this_group:
1066 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
1067 if (!ret2)
1068 goto next_group;
1069
1070 if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
1071 ext4_error(sb, "reserved inode found cleared - "
1072 "inode=%lu", ino + 1);
1073 ext4_mark_group_bitmap_corrupted(sb, group,
1074 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1075 goto next_group;
1076 }
1077
1078 if ((!(sbi->s_mount_state & EXT4_FC_REPLAY)) && !handle) {
1079 BUG_ON(nblocks <= 0);
1080 handle = __ext4_journal_start_sb(dir->i_sb, line_no,
1081 handle_type, nblocks, 0,
1082 ext4_trans_default_revoke_credits(sb));
1083 if (IS_ERR(handle)) {
1084 err = PTR_ERR(handle);
1085 ext4_std_error(sb, err);
1086 goto out;
1087 }
1088 }
1089 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
1090 err = ext4_journal_get_write_access(handle, sb, inode_bitmap_bh,
1091 EXT4_JTR_NONE);
1092 if (err) {
1093 ext4_std_error(sb, err);
1094 goto out;
1095 }
1096 ext4_lock_group(sb, group);
1097 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
1098 if (ret2) {
1099 /* Someone already took the bit. Repeat the search
1100 * with lock held.
1101 */
1102 ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
1103 if (ret2) {
1104 ext4_set_bit(ino, inode_bitmap_bh->b_data);
1105 ret2 = 0;
1106 } else {
1107 ret2 = 1; /* we didn't grab the inode */
1108 }
1109 }
1110 ext4_unlock_group(sb, group);
1111 ino++; /* the inode bitmap is zero-based */
1112 if (!ret2)
1113 goto got; /* we grabbed the inode! */
1114
1115 if (ino < EXT4_INODES_PER_GROUP(sb))
1116 goto repeat_in_this_group;
1117 next_group:
1118 if (++group == ngroups)
1119 group = 0;
1120 }
1121 err = -ENOSPC;
1122 goto out;
1123
1124 got:
1125 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
1126 err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
1127 if (err) {
1128 ext4_std_error(sb, err);
1129 goto out;
1130 }
1131
1132 BUFFER_TRACE(group_desc_bh, "get_write_access");
1133 err = ext4_journal_get_write_access(handle, sb, group_desc_bh,
1134 EXT4_JTR_NONE);
1135 if (err) {
1136 ext4_std_error(sb, err);
1137 goto out;
1138 }
1139
1140 /* We may have to initialize the block bitmap if it isn't already */
1141 if (ext4_has_group_desc_csum(sb) &&
1142 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
1143 struct buffer_head *block_bitmap_bh;
1144
1145 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
1146 if (IS_ERR(block_bitmap_bh)) {
1147 err = PTR_ERR(block_bitmap_bh);
1148 goto out;
1149 }
1150 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
1151 err = ext4_journal_get_write_access(handle, sb, block_bitmap_bh,
1152 EXT4_JTR_NONE);
1153 if (err) {
1154 brelse(block_bitmap_bh);
1155 ext4_std_error(sb, err);
1156 goto out;
1157 }
1158
1159 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
1160 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
1161
1162 /* recheck and clear flag under lock if we still need to */
1163 ext4_lock_group(sb, group);
1164 if (ext4_has_group_desc_csum(sb) &&
1165 (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
1166 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
1167 ext4_free_group_clusters_set(sb, gdp,
1168 ext4_free_clusters_after_init(sb, group, gdp));
1169 ext4_block_bitmap_csum_set(sb, group, gdp,
1170 block_bitmap_bh);
1171 ext4_group_desc_csum_set(sb, group, gdp);
1172 }
1173 ext4_unlock_group(sb, group);
1174 brelse(block_bitmap_bh);
1175
1176 if (err) {
1177 ext4_std_error(sb, err);
1178 goto out;
1179 }
1180 }
1181
1182 /* Update the relevant bg descriptor fields */
1183 if (ext4_has_group_desc_csum(sb)) {
1184 int free;
1185 struct ext4_group_info *grp = NULL;
1186
1187 if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {
1188 grp = ext4_get_group_info(sb, group);
1189 if (!grp) {
1190 err = -EFSCORRUPTED;
1191 goto out;
1192 }
1193 down_read(&grp->alloc_sem); /*
1194 * protect vs itable
1195 * lazyinit
1196 */
1197 }
1198 ext4_lock_group(sb, group); /* while we modify the bg desc */
1199 free = EXT4_INODES_PER_GROUP(sb) -
1200 ext4_itable_unused_count(sb, gdp);
1201 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1202 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1203 free = 0;
1204 }
1205 /*
1206 * Check the relative inode number against the last used
1207 * relative inode number in this group. if it is greater
1208 * we need to update the bg_itable_unused count
1209 */
1210 if (ino > free)
1211 ext4_itable_unused_set(sb, gdp,
1212 (EXT4_INODES_PER_GROUP(sb) - ino));
1213 if (!(sbi->s_mount_state & EXT4_FC_REPLAY))
1214 up_read(&grp->alloc_sem);
1215 } else {
1216 ext4_lock_group(sb, group);
1217 }
1218
1219 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1220 if (S_ISDIR(mode)) {
1221 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1222 if (sbi->s_log_groups_per_flex) {
1223 ext4_group_t f = ext4_flex_group(sbi, group);
1224
1225 atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1226 f)->used_dirs);
1227 }
1228 }
1229 if (ext4_has_group_desc_csum(sb)) {
1230 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1231 EXT4_INODES_PER_GROUP(sb) / 8);
1232 ext4_group_desc_csum_set(sb, group, gdp);
1233 }
1234 ext4_unlock_group(sb, group);
1235
1236 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1237 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1238 if (err) {
1239 ext4_std_error(sb, err);
1240 goto out;
1241 }
1242
1243 percpu_counter_dec(&sbi->s_freeinodes_counter);
1244 if (S_ISDIR(mode))
1245 percpu_counter_inc(&sbi->s_dirs_counter);
1246
1247 if (sbi->s_log_groups_per_flex) {
1248 flex_group = ext4_flex_group(sbi, group);
1249 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1250 flex_group)->free_inodes);
1251 }
1252
1253 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1254 /* This is the optimal IO size (for stat), not the fs block size */
1255 inode->i_blocks = 0;
1256 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1257 ei->i_crtime = inode->i_mtime;
1258
1259 memset(ei->i_data, 0, sizeof(ei->i_data));
1260 ei->i_dir_start_lookup = 0;
1261 ei->i_disksize = 0;
1262
1263 /* Don't inherit extent flag from directory, amongst others. */
1264 ei->i_flags =
1265 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1266 ei->i_flags |= i_flags;
1267 ei->i_file_acl = 0;
1268 ei->i_dtime = 0;
1269 ei->i_block_group = group;
1270 ei->i_last_alloc_group = ~0;
1271
1272 ext4_set_inode_flags(inode, true);
1273 if (IS_DIRSYNC(inode))
1274 ext4_handle_sync(handle);
1275 if (insert_inode_locked(inode) < 0) {
1276 /*
1277 * Likely a bitmap corruption causing inode to be allocated
1278 * twice.
1279 */
1280 err = -EIO;
1281 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1282 inode->i_ino);
1283 ext4_mark_group_bitmap_corrupted(sb, group,
1284 EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1285 goto out;
1286 }
1287 inode->i_generation = prandom_u32();
1288
1289 /* Precompute checksum seed for inode metadata */
1290 if (ext4_has_metadata_csum(sb)) {
1291 __u32 csum;
1292 __le32 inum = cpu_to_le32(inode->i_ino);
1293 __le32 gen = cpu_to_le32(inode->i_generation);
1294 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1295 sizeof(inum));
1296 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1297 sizeof(gen));
1298 }
1299
1300 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1301 ext4_set_inode_state(inode, EXT4_STATE_NEW);
1302
1303 ei->i_extra_isize = sbi->s_want_extra_isize;
1304 ei->i_inline_off = 0;
1305 if (ext4_has_feature_inline_data(sb) &&
1306 (!(ei->i_flags & EXT4_DAX_FL) || S_ISDIR(mode)))
1307 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1308 ret = inode;
1309 err = dquot_alloc_inode(inode);
1310 if (err)
1311 goto fail_drop;
1312
1313 /*
1314 * Since the encryption xattr will always be unique, create it first so
1315 * that it's less likely to end up in an external xattr block and
1316 * prevent its deduplication.
1317 */
1318 if (encrypt) {
1319 err = fscrypt_set_context(inode, handle);
1320 if (err)
1321 goto fail_free_drop;
1322 }
1323
1324 if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1325 err = ext4_init_acl(handle, inode, dir);
1326 if (err)
1327 goto fail_free_drop;
1328
1329 err = ext4_init_security(handle, inode, dir, qstr);
1330 if (err)
1331 goto fail_free_drop;
1332 }
1333
1334 if (ext4_has_feature_extents(sb)) {
1335 /* set extent flag only for directory, file and normal symlink*/
1336 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1337 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1338 ext4_ext_tree_init(handle, inode);
1339 }
1340 }
1341
1342 if (ext4_handle_valid(handle)) {
1343 ei->i_sync_tid = handle->h_transaction->t_tid;
1344 ei->i_datasync_tid = handle->h_transaction->t_tid;
1345 }
1346
1347 err = ext4_mark_inode_dirty(handle, inode);
1348 if (err) {
1349 ext4_std_error(sb, err);
1350 goto fail_free_drop;
1351 }
1352
1353 ext4_debug("allocating inode %lu\n", inode->i_ino);
1354 trace_ext4_allocate_inode(inode, dir, mode);
1355 brelse(inode_bitmap_bh);
1356 return ret;
1357
1358 fail_free_drop:
1359 dquot_free_inode(inode);
1360 fail_drop:
1361 clear_nlink(inode);
1362 unlock_new_inode(inode);
1363 out:
1364 dquot_drop(inode);
1365 inode->i_flags |= S_NOQUOTA;
1366 iput(inode);
1367 brelse(inode_bitmap_bh);
1368 return ERR_PTR(err);
1369 }
1370
1371 /* Verify that we are loading a valid orphan from disk */
ext4_orphan_get(struct super_block * sb,unsigned long ino)1372 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1373 {
1374 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1375 ext4_group_t block_group;
1376 int bit;
1377 struct buffer_head *bitmap_bh = NULL;
1378 struct inode *inode = NULL;
1379 int err = -EFSCORRUPTED;
1380
1381 if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1382 goto bad_orphan;
1383
1384 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1385 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1386 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1387 if (IS_ERR(bitmap_bh))
1388 return ERR_CAST(bitmap_bh);
1389
1390 /* Having the inode bit set should be a 100% indicator that this
1391 * is a valid orphan (no e2fsck run on fs). Orphans also include
1392 * inodes that were being truncated, so we can't check i_nlink==0.
1393 */
1394 if (!ext4_test_bit(bit, bitmap_bh->b_data))
1395 goto bad_orphan;
1396
1397 inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1398 if (IS_ERR(inode)) {
1399 err = PTR_ERR(inode);
1400 ext4_error_err(sb, -err,
1401 "couldn't read orphan inode %lu (err %d)",
1402 ino, err);
1403 brelse(bitmap_bh);
1404 return inode;
1405 }
1406
1407 /*
1408 * If the orphans has i_nlinks > 0 then it should be able to
1409 * be truncated, otherwise it won't be removed from the orphan
1410 * list during processing and an infinite loop will result.
1411 * Similarly, it must not be a bad inode.
1412 */
1413 if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1414 is_bad_inode(inode))
1415 goto bad_orphan;
1416
1417 if (NEXT_ORPHAN(inode) > max_ino)
1418 goto bad_orphan;
1419 brelse(bitmap_bh);
1420 return inode;
1421
1422 bad_orphan:
1423 ext4_error(sb, "bad orphan inode %lu", ino);
1424 if (bitmap_bh)
1425 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1426 bit, (unsigned long long)bitmap_bh->b_blocknr,
1427 ext4_test_bit(bit, bitmap_bh->b_data));
1428 if (inode) {
1429 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1430 is_bad_inode(inode));
1431 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1432 NEXT_ORPHAN(inode));
1433 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1434 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1435 /* Avoid freeing blocks if we got a bad deleted inode */
1436 if (inode->i_nlink == 0)
1437 inode->i_blocks = 0;
1438 iput(inode);
1439 }
1440 brelse(bitmap_bh);
1441 return ERR_PTR(err);
1442 }
1443
ext4_count_free_inodes(struct super_block * sb)1444 unsigned long ext4_count_free_inodes(struct super_block *sb)
1445 {
1446 unsigned long desc_count;
1447 struct ext4_group_desc *gdp;
1448 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1449 #ifdef EXT4FS_DEBUG
1450 struct ext4_super_block *es;
1451 unsigned long bitmap_count, x;
1452 struct buffer_head *bitmap_bh = NULL;
1453
1454 es = EXT4_SB(sb)->s_es;
1455 desc_count = 0;
1456 bitmap_count = 0;
1457 gdp = NULL;
1458 for (i = 0; i < ngroups; i++) {
1459 gdp = ext4_get_group_desc(sb, i, NULL);
1460 if (!gdp)
1461 continue;
1462 desc_count += ext4_free_inodes_count(sb, gdp);
1463 brelse(bitmap_bh);
1464 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1465 if (IS_ERR(bitmap_bh)) {
1466 bitmap_bh = NULL;
1467 continue;
1468 }
1469
1470 x = ext4_count_free(bitmap_bh->b_data,
1471 EXT4_INODES_PER_GROUP(sb) / 8);
1472 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1473 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1474 bitmap_count += x;
1475 }
1476 brelse(bitmap_bh);
1477 printk(KERN_DEBUG "ext4_count_free_inodes: "
1478 "stored = %u, computed = %lu, %lu\n",
1479 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1480 return desc_count;
1481 #else
1482 desc_count = 0;
1483 for (i = 0; i < ngroups; i++) {
1484 gdp = ext4_get_group_desc(sb, i, NULL);
1485 if (!gdp)
1486 continue;
1487 desc_count += ext4_free_inodes_count(sb, gdp);
1488 cond_resched();
1489 }
1490 return desc_count;
1491 #endif
1492 }
1493
1494 /* Called at mount-time, super-block is locked */
ext4_count_dirs(struct super_block * sb)1495 unsigned long ext4_count_dirs(struct super_block * sb)
1496 {
1497 unsigned long count = 0;
1498 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1499
1500 for (i = 0; i < ngroups; i++) {
1501 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1502 if (!gdp)
1503 continue;
1504 count += ext4_used_dirs_count(sb, gdp);
1505 }
1506 return count;
1507 }
1508
1509 /*
1510 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1511 * inode table. Must be called without any spinlock held. The only place
1512 * where it is called from on active part of filesystem is ext4lazyinit
1513 * thread, so we do not need any special locks, however we have to prevent
1514 * inode allocation from the current group, so we take alloc_sem lock, to
1515 * block ext4_new_inode() until we are finished.
1516 */
ext4_init_inode_table(struct super_block * sb,ext4_group_t group,int barrier)1517 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1518 int barrier)
1519 {
1520 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1521 struct ext4_sb_info *sbi = EXT4_SB(sb);
1522 struct ext4_group_desc *gdp = NULL;
1523 struct buffer_head *group_desc_bh;
1524 handle_t *handle;
1525 ext4_fsblk_t blk;
1526 int num, ret = 0, used_blks = 0;
1527 unsigned long used_inos = 0;
1528
1529 /* This should not happen, but just to be sure check this */
1530 if (sb_rdonly(sb)) {
1531 ret = 1;
1532 goto out;
1533 }
1534
1535 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1536 if (!gdp || !grp)
1537 goto out;
1538
1539 /*
1540 * We do not need to lock this, because we are the only one
1541 * handling this flag.
1542 */
1543 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1544 goto out;
1545
1546 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1547 if (IS_ERR(handle)) {
1548 ret = PTR_ERR(handle);
1549 goto out;
1550 }
1551
1552 down_write(&grp->alloc_sem);
1553 /*
1554 * If inode bitmap was already initialized there may be some
1555 * used inodes so we need to skip blocks with used inodes in
1556 * inode table.
1557 */
1558 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
1559 used_inos = EXT4_INODES_PER_GROUP(sb) -
1560 ext4_itable_unused_count(sb, gdp);
1561 used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
1562
1563 /* Bogus inode unused count? */
1564 if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
1565 ext4_error(sb, "Something is wrong with group %u: "
1566 "used itable blocks: %d; "
1567 "itable unused count: %u",
1568 group, used_blks,
1569 ext4_itable_unused_count(sb, gdp));
1570 ret = 1;
1571 goto err_out;
1572 }
1573
1574 used_inos += group * EXT4_INODES_PER_GROUP(sb);
1575 /*
1576 * Are there some uninitialized inodes in the inode table
1577 * before the first normal inode?
1578 */
1579 if ((used_blks != sbi->s_itb_per_group) &&
1580 (used_inos < EXT4_FIRST_INO(sb))) {
1581 ext4_error(sb, "Something is wrong with group %u: "
1582 "itable unused count: %u; "
1583 "itables initialized count: %ld",
1584 group, ext4_itable_unused_count(sb, gdp),
1585 used_inos);
1586 ret = 1;
1587 goto err_out;
1588 }
1589 }
1590
1591 blk = ext4_inode_table(sb, gdp) + used_blks;
1592 num = sbi->s_itb_per_group - used_blks;
1593
1594 BUFFER_TRACE(group_desc_bh, "get_write_access");
1595 ret = ext4_journal_get_write_access(handle, sb, group_desc_bh,
1596 EXT4_JTR_NONE);
1597 if (ret)
1598 goto err_out;
1599
1600 /*
1601 * Skip zeroout if the inode table is full. But we set the ZEROED
1602 * flag anyway, because obviously, when it is full it does not need
1603 * further zeroing.
1604 */
1605 if (unlikely(num == 0))
1606 goto skip_zeroout;
1607
1608 ext4_debug("going to zero out inode table in group %d\n",
1609 group);
1610 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1611 if (ret < 0)
1612 goto err_out;
1613 if (barrier)
1614 blkdev_issue_flush(sb->s_bdev);
1615
1616 skip_zeroout:
1617 ext4_lock_group(sb, group);
1618 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1619 ext4_group_desc_csum_set(sb, group, gdp);
1620 ext4_unlock_group(sb, group);
1621
1622 BUFFER_TRACE(group_desc_bh,
1623 "call ext4_handle_dirty_metadata");
1624 ret = ext4_handle_dirty_metadata(handle, NULL,
1625 group_desc_bh);
1626
1627 err_out:
1628 up_write(&grp->alloc_sem);
1629 ext4_journal_stop(handle);
1630 out:
1631 return ret;
1632 }
1633