Merge tag 'spi-fix-v5.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/brooni...
[linux-2.6-microblaze.git] / fs / ext4 / ialloc.c
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  */
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
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
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 (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 *
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  */
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 (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  */
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
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 / 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
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
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
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
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
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  */
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 (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                         down_read(&grp->alloc_sem); /*
1190                                                      * protect vs itable
1191                                                      * lazyinit
1192                                                      */
1193                 }
1194                 ext4_lock_group(sb, group); /* while we modify the bg desc */
1195                 free = EXT4_INODES_PER_GROUP(sb) -
1196                         ext4_itable_unused_count(sb, gdp);
1197                 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
1198                         gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
1199                         free = 0;
1200                 }
1201                 /*
1202                  * Check the relative inode number against the last used
1203                  * relative inode number in this group. if it is greater
1204                  * we need to update the bg_itable_unused count
1205                  */
1206                 if (ino > free)
1207                         ext4_itable_unused_set(sb, gdp,
1208                                         (EXT4_INODES_PER_GROUP(sb) - ino));
1209                 if (!(sbi->s_mount_state & EXT4_FC_REPLAY))
1210                         up_read(&grp->alloc_sem);
1211         } else {
1212                 ext4_lock_group(sb, group);
1213         }
1214
1215         ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
1216         if (S_ISDIR(mode)) {
1217                 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
1218                 if (sbi->s_log_groups_per_flex) {
1219                         ext4_group_t f = ext4_flex_group(sbi, group);
1220
1221                         atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,
1222                                                         f)->used_dirs);
1223                 }
1224         }
1225         if (ext4_has_group_desc_csum(sb)) {
1226                 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
1227                                            EXT4_INODES_PER_GROUP(sb) / 8);
1228                 ext4_group_desc_csum_set(sb, group, gdp);
1229         }
1230         ext4_unlock_group(sb, group);
1231
1232         BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
1233         err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
1234         if (err) {
1235                 ext4_std_error(sb, err);
1236                 goto out;
1237         }
1238
1239         percpu_counter_dec(&sbi->s_freeinodes_counter);
1240         if (S_ISDIR(mode))
1241                 percpu_counter_inc(&sbi->s_dirs_counter);
1242
1243         if (sbi->s_log_groups_per_flex) {
1244                 flex_group = ext4_flex_group(sbi, group);
1245                 atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,
1246                                                 flex_group)->free_inodes);
1247         }
1248
1249         inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
1250         /* This is the optimal IO size (for stat), not the fs block size */
1251         inode->i_blocks = 0;
1252         inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1253         ei->i_crtime = inode->i_mtime;
1254
1255         memset(ei->i_data, 0, sizeof(ei->i_data));
1256         ei->i_dir_start_lookup = 0;
1257         ei->i_disksize = 0;
1258
1259         /* Don't inherit extent flag from directory, amongst others. */
1260         ei->i_flags =
1261                 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
1262         ei->i_flags |= i_flags;
1263         ei->i_file_acl = 0;
1264         ei->i_dtime = 0;
1265         ei->i_block_group = group;
1266         ei->i_last_alloc_group = ~0;
1267
1268         ext4_set_inode_flags(inode, true);
1269         if (IS_DIRSYNC(inode))
1270                 ext4_handle_sync(handle);
1271         if (insert_inode_locked(inode) < 0) {
1272                 /*
1273                  * Likely a bitmap corruption causing inode to be allocated
1274                  * twice.
1275                  */
1276                 err = -EIO;
1277                 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
1278                            inode->i_ino);
1279                 ext4_mark_group_bitmap_corrupted(sb, group,
1280                                         EXT4_GROUP_INFO_IBITMAP_CORRUPT);
1281                 goto out;
1282         }
1283         inode->i_generation = prandom_u32();
1284
1285         /* Precompute checksum seed for inode metadata */
1286         if (ext4_has_metadata_csum(sb)) {
1287                 __u32 csum;
1288                 __le32 inum = cpu_to_le32(inode->i_ino);
1289                 __le32 gen = cpu_to_le32(inode->i_generation);
1290                 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
1291                                    sizeof(inum));
1292                 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
1293                                               sizeof(gen));
1294         }
1295
1296         ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1297         ext4_set_inode_state(inode, EXT4_STATE_NEW);
1298
1299         ei->i_extra_isize = sbi->s_want_extra_isize;
1300         ei->i_inline_off = 0;
1301         if (ext4_has_feature_inline_data(sb) &&
1302             (!(ei->i_flags & EXT4_DAX_FL) || S_ISDIR(mode)))
1303                 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1304         ret = inode;
1305         err = dquot_alloc_inode(inode);
1306         if (err)
1307                 goto fail_drop;
1308
1309         /*
1310          * Since the encryption xattr will always be unique, create it first so
1311          * that it's less likely to end up in an external xattr block and
1312          * prevent its deduplication.
1313          */
1314         if (encrypt) {
1315                 err = fscrypt_set_context(inode, handle);
1316                 if (err)
1317                         goto fail_free_drop;
1318         }
1319
1320         if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
1321                 err = ext4_init_acl(handle, inode, dir);
1322                 if (err)
1323                         goto fail_free_drop;
1324
1325                 err = ext4_init_security(handle, inode, dir, qstr);
1326                 if (err)
1327                         goto fail_free_drop;
1328         }
1329
1330         if (ext4_has_feature_extents(sb)) {
1331                 /* set extent flag only for directory, file and normal symlink*/
1332                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1333                         ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1334                         ext4_ext_tree_init(handle, inode);
1335                 }
1336         }
1337
1338         if (ext4_handle_valid(handle)) {
1339                 ei->i_sync_tid = handle->h_transaction->t_tid;
1340                 ei->i_datasync_tid = handle->h_transaction->t_tid;
1341         }
1342
1343         err = ext4_mark_inode_dirty(handle, inode);
1344         if (err) {
1345                 ext4_std_error(sb, err);
1346                 goto fail_free_drop;
1347         }
1348
1349         ext4_debug("allocating inode %lu\n", inode->i_ino);
1350         trace_ext4_allocate_inode(inode, dir, mode);
1351         brelse(inode_bitmap_bh);
1352         return ret;
1353
1354 fail_free_drop:
1355         dquot_free_inode(inode);
1356 fail_drop:
1357         clear_nlink(inode);
1358         unlock_new_inode(inode);
1359 out:
1360         dquot_drop(inode);
1361         inode->i_flags |= S_NOQUOTA;
1362         iput(inode);
1363         brelse(inode_bitmap_bh);
1364         return ERR_PTR(err);
1365 }
1366
1367 /* Verify that we are loading a valid orphan from disk */
1368 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1369 {
1370         unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1371         ext4_group_t block_group;
1372         int bit;
1373         struct buffer_head *bitmap_bh = NULL;
1374         struct inode *inode = NULL;
1375         int err = -EFSCORRUPTED;
1376
1377         if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
1378                 goto bad_orphan;
1379
1380         block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1381         bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1382         bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1383         if (IS_ERR(bitmap_bh))
1384                 return ERR_CAST(bitmap_bh);
1385
1386         /* Having the inode bit set should be a 100% indicator that this
1387          * is a valid orphan (no e2fsck run on fs).  Orphans also include
1388          * inodes that were being truncated, so we can't check i_nlink==0.
1389          */
1390         if (!ext4_test_bit(bit, bitmap_bh->b_data))
1391                 goto bad_orphan;
1392
1393         inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);
1394         if (IS_ERR(inode)) {
1395                 err = PTR_ERR(inode);
1396                 ext4_error_err(sb, -err,
1397                                "couldn't read orphan inode %lu (err %d)",
1398                                ino, err);
1399                 brelse(bitmap_bh);
1400                 return inode;
1401         }
1402
1403         /*
1404          * If the orphans has i_nlinks > 0 then it should be able to
1405          * be truncated, otherwise it won't be removed from the orphan
1406          * list during processing and an infinite loop will result.
1407          * Similarly, it must not be a bad inode.
1408          */
1409         if ((inode->i_nlink && !ext4_can_truncate(inode)) ||
1410             is_bad_inode(inode))
1411                 goto bad_orphan;
1412
1413         if (NEXT_ORPHAN(inode) > max_ino)
1414                 goto bad_orphan;
1415         brelse(bitmap_bh);
1416         return inode;
1417
1418 bad_orphan:
1419         ext4_error(sb, "bad orphan inode %lu", ino);
1420         if (bitmap_bh)
1421                 printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1422                        bit, (unsigned long long)bitmap_bh->b_blocknr,
1423                        ext4_test_bit(bit, bitmap_bh->b_data));
1424         if (inode) {
1425                 printk(KERN_ERR "is_bad_inode(inode)=%d\n",
1426                        is_bad_inode(inode));
1427                 printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
1428                        NEXT_ORPHAN(inode));
1429                 printk(KERN_ERR "max_ino=%lu\n", max_ino);
1430                 printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);
1431                 /* Avoid freeing blocks if we got a bad deleted inode */
1432                 if (inode->i_nlink == 0)
1433                         inode->i_blocks = 0;
1434                 iput(inode);
1435         }
1436         brelse(bitmap_bh);
1437         return ERR_PTR(err);
1438 }
1439
1440 unsigned long ext4_count_free_inodes(struct super_block *sb)
1441 {
1442         unsigned long desc_count;
1443         struct ext4_group_desc *gdp;
1444         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1445 #ifdef EXT4FS_DEBUG
1446         struct ext4_super_block *es;
1447         unsigned long bitmap_count, x;
1448         struct buffer_head *bitmap_bh = NULL;
1449
1450         es = EXT4_SB(sb)->s_es;
1451         desc_count = 0;
1452         bitmap_count = 0;
1453         gdp = NULL;
1454         for (i = 0; i < ngroups; i++) {
1455                 gdp = ext4_get_group_desc(sb, i, NULL);
1456                 if (!gdp)
1457                         continue;
1458                 desc_count += ext4_free_inodes_count(sb, gdp);
1459                 brelse(bitmap_bh);
1460                 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1461                 if (IS_ERR(bitmap_bh)) {
1462                         bitmap_bh = NULL;
1463                         continue;
1464                 }
1465
1466                 x = ext4_count_free(bitmap_bh->b_data,
1467                                     EXT4_INODES_PER_GROUP(sb) / 8);
1468                 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1469                         (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1470                 bitmap_count += x;
1471         }
1472         brelse(bitmap_bh);
1473         printk(KERN_DEBUG "ext4_count_free_inodes: "
1474                "stored = %u, computed = %lu, %lu\n",
1475                le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1476         return desc_count;
1477 #else
1478         desc_count = 0;
1479         for (i = 0; i < ngroups; i++) {
1480                 gdp = ext4_get_group_desc(sb, i, NULL);
1481                 if (!gdp)
1482                         continue;
1483                 desc_count += ext4_free_inodes_count(sb, gdp);
1484                 cond_resched();
1485         }
1486         return desc_count;
1487 #endif
1488 }
1489
1490 /* Called at mount-time, super-block is locked */
1491 unsigned long ext4_count_dirs(struct super_block * sb)
1492 {
1493         unsigned long count = 0;
1494         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1495
1496         for (i = 0; i < ngroups; i++) {
1497                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1498                 if (!gdp)
1499                         continue;
1500                 count += ext4_used_dirs_count(sb, gdp);
1501         }
1502         return count;
1503 }
1504
1505 /*
1506  * Zeroes not yet zeroed inode table - just write zeroes through the whole
1507  * inode table. Must be called without any spinlock held. The only place
1508  * where it is called from on active part of filesystem is ext4lazyinit
1509  * thread, so we do not need any special locks, however we have to prevent
1510  * inode allocation from the current group, so we take alloc_sem lock, to
1511  * block ext4_new_inode() until we are finished.
1512  */
1513 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1514                                  int barrier)
1515 {
1516         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1517         struct ext4_sb_info *sbi = EXT4_SB(sb);
1518         struct ext4_group_desc *gdp = NULL;
1519         struct buffer_head *group_desc_bh;
1520         handle_t *handle;
1521         ext4_fsblk_t blk;
1522         int num, ret = 0, used_blks = 0;
1523         unsigned long used_inos = 0;
1524
1525         /* This should not happen, but just to be sure check this */
1526         if (sb_rdonly(sb)) {
1527                 ret = 1;
1528                 goto out;
1529         }
1530
1531         gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1532         if (!gdp)
1533                 goto out;
1534
1535         /*
1536          * We do not need to lock this, because we are the only one
1537          * handling this flag.
1538          */
1539         if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1540                 goto out;
1541
1542         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1543         if (IS_ERR(handle)) {
1544                 ret = PTR_ERR(handle);
1545                 goto out;
1546         }
1547
1548         down_write(&grp->alloc_sem);
1549         /*
1550          * If inode bitmap was already initialized there may be some
1551          * used inodes so we need to skip blocks with used inodes in
1552          * inode table.
1553          */
1554         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {
1555                 used_inos = EXT4_INODES_PER_GROUP(sb) -
1556                             ext4_itable_unused_count(sb, gdp);
1557                 used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);
1558
1559                 /* Bogus inode unused count? */
1560                 if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {
1561                         ext4_error(sb, "Something is wrong with group %u: "
1562                                    "used itable blocks: %d; "
1563                                    "itable unused count: %u",
1564                                    group, used_blks,
1565                                    ext4_itable_unused_count(sb, gdp));
1566                         ret = 1;
1567                         goto err_out;
1568                 }
1569
1570                 used_inos += group * EXT4_INODES_PER_GROUP(sb);
1571                 /*
1572                  * Are there some uninitialized inodes in the inode table
1573                  * before the first normal inode?
1574                  */
1575                 if ((used_blks != sbi->s_itb_per_group) &&
1576                      (used_inos < EXT4_FIRST_INO(sb))) {
1577                         ext4_error(sb, "Something is wrong with group %u: "
1578                                    "itable unused count: %u; "
1579                                    "itables initialized count: %ld",
1580                                    group, ext4_itable_unused_count(sb, gdp),
1581                                    used_inos);
1582                         ret = 1;
1583                         goto err_out;
1584                 }
1585         }
1586
1587         blk = ext4_inode_table(sb, gdp) + used_blks;
1588         num = sbi->s_itb_per_group - used_blks;
1589
1590         BUFFER_TRACE(group_desc_bh, "get_write_access");
1591         ret = ext4_journal_get_write_access(handle, sb, group_desc_bh,
1592                                             EXT4_JTR_NONE);
1593         if (ret)
1594                 goto err_out;
1595
1596         /*
1597          * Skip zeroout if the inode table is full. But we set the ZEROED
1598          * flag anyway, because obviously, when it is full it does not need
1599          * further zeroing.
1600          */
1601         if (unlikely(num == 0))
1602                 goto skip_zeroout;
1603
1604         ext4_debug("going to zero out inode table in group %d\n",
1605                    group);
1606         ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1607         if (ret < 0)
1608                 goto err_out;
1609         if (barrier)
1610                 blkdev_issue_flush(sb->s_bdev);
1611
1612 skip_zeroout:
1613         ext4_lock_group(sb, group);
1614         gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1615         ext4_group_desc_csum_set(sb, group, gdp);
1616         ext4_unlock_group(sb, group);
1617
1618         BUFFER_TRACE(group_desc_bh,
1619                      "call ext4_handle_dirty_metadata");
1620         ret = ext4_handle_dirty_metadata(handle, NULL,
1621                                          group_desc_bh);
1622
1623 err_out:
1624         up_write(&grp->alloc_sem);
1625         ext4_journal_stop(handle);
1626 out:
1627         return ret;
1628 }