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1/*
2 * linux/fs/ext4/ialloc.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * BSD ufs-inspired inode and directory allocation by
10 * Stephen Tweedie (sct@redhat.com), 1993
11 * Big-endian to little-endian byte-swapping/bitmaps by
12 * David S. Miller (davem@caip.rutgers.edu), 1995
13 */
14
15#include <linux/time.h>
16#include <linux/fs.h>
17#include <linux/jbd2.h>
18#include <linux/stat.h>
19#include <linux/string.h>
20#include <linux/quotaops.h>
21#include <linux/buffer_head.h>
22#include <linux/random.h>
23#include <linux/bitops.h>
24#include <linux/blkdev.h>
25#include <asm/byteorder.h>
26
27#include "ext4.h"
28#include "ext4_jbd2.h"
29#include "xattr.h"
30#include "acl.h"
31
32#include <trace/events/ext4.h>
33
34/*
35 * ialloc.c contains the inodes allocation and deallocation routines
36 */
37
38/*
39 * The free inodes are managed by bitmaps. A file system contains several
40 * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
41 * block for inodes, N blocks for the inode table and data blocks.
42 *
43 * The file system contains group descriptors which are located after the
44 * super block. Each descriptor contains the number of the bitmap block and
45 * the free blocks count in the block.
46 */
47
48/*
49 * To avoid calling the atomic setbit hundreds or thousands of times, we only
50 * need to use it within a single byte (to ensure we get endianness right).
51 * We can use memset for the rest of the bitmap as there are no other users.
52 */
53void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
54{
55 int i;
56
57 if (start_bit >= end_bit)
58 return;
59
60 ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
61 for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
62 ext4_set_bit(i, bitmap);
63 if (i < end_bit)
64 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
65}
66
67/* Initializes an uninitialized inode bitmap */
68static unsigned ext4_init_inode_bitmap(struct super_block *sb,
69 struct buffer_head *bh,
70 ext4_group_t block_group,
71 struct ext4_group_desc *gdp)
72{
73 J_ASSERT_BH(bh, buffer_locked(bh));
74
75 /* If checksum is bad mark all blocks and inodes use to prevent
76 * allocation, essentially implementing a per-group read-only flag. */
77 if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
78 ext4_error(sb, "Checksum bad for group %u", block_group);
79 ext4_free_group_clusters_set(sb, gdp, 0);
80 ext4_free_inodes_set(sb, gdp, 0);
81 ext4_itable_unused_set(sb, gdp, 0);
82 memset(bh->b_data, 0xff, sb->s_blocksize);
83 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
84 EXT4_INODES_PER_GROUP(sb) / 8);
85 return 0;
86 }
87
88 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
89 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
90 bh->b_data);
91 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
92 EXT4_INODES_PER_GROUP(sb) / 8);
93 ext4_group_desc_csum_set(sb, block_group, gdp);
94
95 return EXT4_INODES_PER_GROUP(sb);
96}
97
98void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
99{
100 if (uptodate) {
101 set_buffer_uptodate(bh);
102 set_bitmap_uptodate(bh);
103 }
104 unlock_buffer(bh);
105 put_bh(bh);
106}
107
108/*
109 * Read the inode allocation bitmap for a given block_group, reading
110 * into the specified slot in the superblock's bitmap cache.
111 *
112 * Return buffer_head of bitmap on success or NULL.
113 */
114static struct buffer_head *
115ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
116{
117 struct ext4_group_desc *desc;
118 struct buffer_head *bh = NULL;
119 ext4_fsblk_t bitmap_blk;
120
121 desc = ext4_get_group_desc(sb, block_group, NULL);
122 if (!desc)
123 return NULL;
124
125 bitmap_blk = ext4_inode_bitmap(sb, desc);
126 bh = sb_getblk(sb, bitmap_blk);
127 if (unlikely(!bh)) {
128 ext4_error(sb, "Cannot read inode bitmap - "
129 "block_group = %u, inode_bitmap = %llu",
130 block_group, bitmap_blk);
131 return NULL;
132 }
133 if (bitmap_uptodate(bh))
134 goto verify;
135
136 lock_buffer(bh);
137 if (bitmap_uptodate(bh)) {
138 unlock_buffer(bh);
139 goto verify;
140 }
141
142 ext4_lock_group(sb, block_group);
143 if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
144 ext4_init_inode_bitmap(sb, bh, block_group, desc);
145 set_bitmap_uptodate(bh);
146 set_buffer_uptodate(bh);
147 set_buffer_verified(bh);
148 ext4_unlock_group(sb, block_group);
149 unlock_buffer(bh);
150 return bh;
151 }
152 ext4_unlock_group(sb, block_group);
153
154 if (buffer_uptodate(bh)) {
155 /*
156 * if not uninit if bh is uptodate,
157 * bitmap is also uptodate
158 */
159 set_bitmap_uptodate(bh);
160 unlock_buffer(bh);
161 goto verify;
162 }
163 /*
164 * submit the buffer_head for reading
165 */
166 trace_ext4_load_inode_bitmap(sb, block_group);
167 bh->b_end_io = ext4_end_bitmap_read;
168 get_bh(bh);
169 submit_bh(READ, bh);
170 wait_on_buffer(bh);
171 if (!buffer_uptodate(bh)) {
172 put_bh(bh);
173 ext4_error(sb, "Cannot read inode bitmap - "
174 "block_group = %u, inode_bitmap = %llu",
175 block_group, bitmap_blk);
176 return NULL;
177 }
178
179verify:
180 ext4_lock_group(sb, block_group);
181 if (!buffer_verified(bh) &&
182 !ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
183 EXT4_INODES_PER_GROUP(sb) / 8)) {
184 ext4_unlock_group(sb, block_group);
185 put_bh(bh);
186 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
187 "inode_bitmap = %llu", block_group, bitmap_blk);
188 return NULL;
189 }
190 ext4_unlock_group(sb, block_group);
191 set_buffer_verified(bh);
192 return bh;
193}
194
195/*
196 * NOTE! When we get the inode, we're the only people
197 * that have access to it, and as such there are no
198 * race conditions we have to worry about. The inode
199 * is not on the hash-lists, and it cannot be reached
200 * through the filesystem because the directory entry
201 * has been deleted earlier.
202 *
203 * HOWEVER: we must make sure that we get no aliases,
204 * which means that we have to call "clear_inode()"
205 * _before_ we mark the inode not in use in the inode
206 * bitmaps. Otherwise a newly created file might use
207 * the same inode number (not actually the same pointer
208 * though), and then we'd have two inodes sharing the
209 * same inode number and space on the harddisk.
210 */
211void ext4_free_inode(handle_t *handle, struct inode *inode)
212{
213 struct super_block *sb = inode->i_sb;
214 int is_directory;
215 unsigned long ino;
216 struct buffer_head *bitmap_bh = NULL;
217 struct buffer_head *bh2;
218 ext4_group_t block_group;
219 unsigned long bit;
220 struct ext4_group_desc *gdp;
221 struct ext4_super_block *es;
222 struct ext4_sb_info *sbi;
223 int fatal = 0, err, count, cleared;
224
225 if (!sb) {
226 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
227 "nonexistent device\n", __func__, __LINE__);
228 return;
229 }
230 if (atomic_read(&inode->i_count) > 1) {
231 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
232 __func__, __LINE__, inode->i_ino,
233 atomic_read(&inode->i_count));
234 return;
235 }
236 if (inode->i_nlink) {
237 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
238 __func__, __LINE__, inode->i_ino, inode->i_nlink);
239 return;
240 }
241 sbi = EXT4_SB(sb);
242
243 ino = inode->i_ino;
244 ext4_debug("freeing inode %lu\n", ino);
245 trace_ext4_free_inode(inode);
246
247 /*
248 * Note: we must free any quota before locking the superblock,
249 * as writing the quota to disk may need the lock as well.
250 */
251 dquot_initialize(inode);
252 ext4_xattr_delete_inode(handle, inode);
253 dquot_free_inode(inode);
254 dquot_drop(inode);
255
256 is_directory = S_ISDIR(inode->i_mode);
257
258 /* Do this BEFORE marking the inode not in use or returning an error */
259 ext4_clear_inode(inode);
260
261 es = EXT4_SB(sb)->s_es;
262 if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
263 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
264 goto error_return;
265 }
266 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
267 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
268 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
269 if (!bitmap_bh)
270 goto error_return;
271
272 BUFFER_TRACE(bitmap_bh, "get_write_access");
273 fatal = ext4_journal_get_write_access(handle, bitmap_bh);
274 if (fatal)
275 goto error_return;
276
277 fatal = -ESRCH;
278 gdp = ext4_get_group_desc(sb, block_group, &bh2);
279 if (gdp) {
280 BUFFER_TRACE(bh2, "get_write_access");
281 fatal = ext4_journal_get_write_access(handle, bh2);
282 }
283 ext4_lock_group(sb, block_group);
284 cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
285 if (fatal || !cleared) {
286 ext4_unlock_group(sb, block_group);
287 goto out;
288 }
289
290 count = ext4_free_inodes_count(sb, gdp) + 1;
291 ext4_free_inodes_set(sb, gdp, count);
292 if (is_directory) {
293 count = ext4_used_dirs_count(sb, gdp) - 1;
294 ext4_used_dirs_set(sb, gdp, count);
295 percpu_counter_dec(&sbi->s_dirs_counter);
296 }
297 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
298 EXT4_INODES_PER_GROUP(sb) / 8);
299 ext4_group_desc_csum_set(sb, block_group, gdp);
300 ext4_unlock_group(sb, block_group);
301
302 percpu_counter_inc(&sbi->s_freeinodes_counter);
303 if (sbi->s_log_groups_per_flex) {
304 ext4_group_t f = ext4_flex_group(sbi, block_group);
305
306 atomic_inc(&sbi->s_flex_groups[f].free_inodes);
307 if (is_directory)
308 atomic_dec(&sbi->s_flex_groups[f].used_dirs);
309 }
310 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
311 fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
312out:
313 if (cleared) {
314 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
315 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
316 if (!fatal)
317 fatal = err;
318 ext4_mark_super_dirty(sb);
319 } else
320 ext4_error(sb, "bit already cleared for inode %lu", ino);
321
322error_return:
323 brelse(bitmap_bh);
324 ext4_std_error(sb, fatal);
325}
326
327struct orlov_stats {
328 __u32 free_inodes;
329 __u32 free_clusters;
330 __u32 used_dirs;
331};
332
333/*
334 * Helper function for Orlov's allocator; returns critical information
335 * for a particular block group or flex_bg. If flex_size is 1, then g
336 * is a block group number; otherwise it is flex_bg number.
337 */
338static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
339 int flex_size, struct orlov_stats *stats)
340{
341 struct ext4_group_desc *desc;
342 struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups;
343
344 if (flex_size > 1) {
345 stats->free_inodes = atomic_read(&flex_group[g].free_inodes);
346 stats->free_clusters = atomic_read(&flex_group[g].free_clusters);
347 stats->used_dirs = atomic_read(&flex_group[g].used_dirs);
348 return;
349 }
350
351 desc = ext4_get_group_desc(sb, g, NULL);
352 if (desc) {
353 stats->free_inodes = ext4_free_inodes_count(sb, desc);
354 stats->free_clusters = ext4_free_group_clusters(sb, desc);
355 stats->used_dirs = ext4_used_dirs_count(sb, desc);
356 } else {
357 stats->free_inodes = 0;
358 stats->free_clusters = 0;
359 stats->used_dirs = 0;
360 }
361}
362
363/*
364 * Orlov's allocator for directories.
365 *
366 * We always try to spread first-level directories.
367 *
368 * If there are blockgroups with both free inodes and free blocks counts
369 * not worse than average we return one with smallest directory count.
370 * Otherwise we simply return a random group.
371 *
372 * For the rest rules look so:
373 *
374 * It's OK to put directory into a group unless
375 * it has too many directories already (max_dirs) or
376 * it has too few free inodes left (min_inodes) or
377 * it has too few free blocks left (min_blocks) or
378 * Parent's group is preferred, if it doesn't satisfy these
379 * conditions we search cyclically through the rest. If none
380 * of the groups look good we just look for a group with more
381 * free inodes than average (starting at parent's group).
382 */
383
384static int find_group_orlov(struct super_block *sb, struct inode *parent,
385 ext4_group_t *group, umode_t mode,
386 const struct qstr *qstr)
387{
388 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
389 struct ext4_sb_info *sbi = EXT4_SB(sb);
390 ext4_group_t real_ngroups = ext4_get_groups_count(sb);
391 int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
392 unsigned int freei, avefreei, grp_free;
393 ext4_fsblk_t freeb, avefreec;
394 unsigned int ndirs;
395 int max_dirs, min_inodes;
396 ext4_grpblk_t min_clusters;
397 ext4_group_t i, grp, g, ngroups;
398 struct ext4_group_desc *desc;
399 struct orlov_stats stats;
400 int flex_size = ext4_flex_bg_size(sbi);
401 struct dx_hash_info hinfo;
402
403 ngroups = real_ngroups;
404 if (flex_size > 1) {
405 ngroups = (real_ngroups + flex_size - 1) >>
406 sbi->s_log_groups_per_flex;
407 parent_group >>= sbi->s_log_groups_per_flex;
408 }
409
410 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
411 avefreei = freei / ngroups;
412 freeb = EXT4_C2B(sbi,
413 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
414 avefreec = freeb;
415 do_div(avefreec, ngroups);
416 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
417
418 if (S_ISDIR(mode) &&
419 ((parent == sb->s_root->d_inode) ||
420 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
421 int best_ndir = inodes_per_group;
422 int ret = -1;
423
424 if (qstr) {
425 hinfo.hash_version = DX_HASH_HALF_MD4;
426 hinfo.seed = sbi->s_hash_seed;
427 ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
428 grp = hinfo.hash;
429 } else
430 get_random_bytes(&grp, sizeof(grp));
431 parent_group = (unsigned)grp % ngroups;
432 for (i = 0; i < ngroups; i++) {
433 g = (parent_group + i) % ngroups;
434 get_orlov_stats(sb, g, flex_size, &stats);
435 if (!stats.free_inodes)
436 continue;
437 if (stats.used_dirs >= best_ndir)
438 continue;
439 if (stats.free_inodes < avefreei)
440 continue;
441 if (stats.free_clusters < avefreec)
442 continue;
443 grp = g;
444 ret = 0;
445 best_ndir = stats.used_dirs;
446 }
447 if (ret)
448 goto fallback;
449 found_flex_bg:
450 if (flex_size == 1) {
451 *group = grp;
452 return 0;
453 }
454
455 /*
456 * We pack inodes at the beginning of the flexgroup's
457 * inode tables. Block allocation decisions will do
458 * something similar, although regular files will
459 * start at 2nd block group of the flexgroup. See
460 * ext4_ext_find_goal() and ext4_find_near().
461 */
462 grp *= flex_size;
463 for (i = 0; i < flex_size; i++) {
464 if (grp+i >= real_ngroups)
465 break;
466 desc = ext4_get_group_desc(sb, grp+i, NULL);
467 if (desc && ext4_free_inodes_count(sb, desc)) {
468 *group = grp+i;
469 return 0;
470 }
471 }
472 goto fallback;
473 }
474
475 max_dirs = ndirs / ngroups + inodes_per_group / 16;
476 min_inodes = avefreei - inodes_per_group*flex_size / 4;
477 if (min_inodes < 1)
478 min_inodes = 1;
479 min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
480
481 /*
482 * Start looking in the flex group where we last allocated an
483 * inode for this parent directory
484 */
485 if (EXT4_I(parent)->i_last_alloc_group != ~0) {
486 parent_group = EXT4_I(parent)->i_last_alloc_group;
487 if (flex_size > 1)
488 parent_group >>= sbi->s_log_groups_per_flex;
489 }
490
491 for (i = 0; i < ngroups; i++) {
492 grp = (parent_group + i) % ngroups;
493 get_orlov_stats(sb, grp, flex_size, &stats);
494 if (stats.used_dirs >= max_dirs)
495 continue;
496 if (stats.free_inodes < min_inodes)
497 continue;
498 if (stats.free_clusters < min_clusters)
499 continue;
500 goto found_flex_bg;
501 }
502
503fallback:
504 ngroups = real_ngroups;
505 avefreei = freei / ngroups;
506fallback_retry:
507 parent_group = EXT4_I(parent)->i_block_group;
508 for (i = 0; i < ngroups; i++) {
509 grp = (parent_group + i) % ngroups;
510 desc = ext4_get_group_desc(sb, grp, NULL);
511 if (desc) {
512 grp_free = ext4_free_inodes_count(sb, desc);
513 if (grp_free && grp_free >= avefreei) {
514 *group = grp;
515 return 0;
516 }
517 }
518 }
519
520 if (avefreei) {
521 /*
522 * The free-inodes counter is approximate, and for really small
523 * filesystems the above test can fail to find any blockgroups
524 */
525 avefreei = 0;
526 goto fallback_retry;
527 }
528
529 return -1;
530}
531
532static int find_group_other(struct super_block *sb, struct inode *parent,
533 ext4_group_t *group, umode_t mode)
534{
535 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
536 ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
537 struct ext4_group_desc *desc;
538 int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
539
540 /*
541 * Try to place the inode is the same flex group as its
542 * parent. If we can't find space, use the Orlov algorithm to
543 * find another flex group, and store that information in the
544 * parent directory's inode information so that use that flex
545 * group for future allocations.
546 */
547 if (flex_size > 1) {
548 int retry = 0;
549
550 try_again:
551 parent_group &= ~(flex_size-1);
552 last = parent_group + flex_size;
553 if (last > ngroups)
554 last = ngroups;
555 for (i = parent_group; i < last; i++) {
556 desc = ext4_get_group_desc(sb, i, NULL);
557 if (desc && ext4_free_inodes_count(sb, desc)) {
558 *group = i;
559 return 0;
560 }
561 }
562 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
563 retry = 1;
564 parent_group = EXT4_I(parent)->i_last_alloc_group;
565 goto try_again;
566 }
567 /*
568 * If this didn't work, use the Orlov search algorithm
569 * to find a new flex group; we pass in the mode to
570 * avoid the topdir algorithms.
571 */
572 *group = parent_group + flex_size;
573 if (*group > ngroups)
574 *group = 0;
575 return find_group_orlov(sb, parent, group, mode, NULL);
576 }
577
578 /*
579 * Try to place the inode in its parent directory
580 */
581 *group = parent_group;
582 desc = ext4_get_group_desc(sb, *group, NULL);
583 if (desc && ext4_free_inodes_count(sb, desc) &&
584 ext4_free_group_clusters(sb, desc))
585 return 0;
586
587 /*
588 * We're going to place this inode in a different blockgroup from its
589 * parent. We want to cause files in a common directory to all land in
590 * the same blockgroup. But we want files which are in a different
591 * directory which shares a blockgroup with our parent to land in a
592 * different blockgroup.
593 *
594 * So add our directory's i_ino into the starting point for the hash.
595 */
596 *group = (*group + parent->i_ino) % ngroups;
597
598 /*
599 * Use a quadratic hash to find a group with a free inode and some free
600 * blocks.
601 */
602 for (i = 1; i < ngroups; i <<= 1) {
603 *group += i;
604 if (*group >= ngroups)
605 *group -= ngroups;
606 desc = ext4_get_group_desc(sb, *group, NULL);
607 if (desc && ext4_free_inodes_count(sb, desc) &&
608 ext4_free_group_clusters(sb, desc))
609 return 0;
610 }
611
612 /*
613 * That failed: try linear search for a free inode, even if that group
614 * has no free blocks.
615 */
616 *group = parent_group;
617 for (i = 0; i < ngroups; i++) {
618 if (++*group >= ngroups)
619 *group = 0;
620 desc = ext4_get_group_desc(sb, *group, NULL);
621 if (desc && ext4_free_inodes_count(sb, desc))
622 return 0;
623 }
624
625 return -1;
626}
627
628/*
629 * There are two policies for allocating an inode. If the new inode is
630 * a directory, then a forward search is made for a block group with both
631 * free space and a low directory-to-inode ratio; if that fails, then of
632 * the groups with above-average free space, that group with the fewest
633 * directories already is chosen.
634 *
635 * For other inodes, search forward from the parent directory's block
636 * group to find a free inode.
637 */
638struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, umode_t mode,
639 const struct qstr *qstr, __u32 goal, uid_t *owner)
640{
641 struct super_block *sb;
642 struct buffer_head *inode_bitmap_bh = NULL;
643 struct buffer_head *group_desc_bh;
644 ext4_group_t ngroups, group = 0;
645 unsigned long ino = 0;
646 struct inode *inode;
647 struct ext4_group_desc *gdp = NULL;
648 struct ext4_inode_info *ei;
649 struct ext4_sb_info *sbi;
650 int ret2, err = 0;
651 struct inode *ret;
652 ext4_group_t i;
653 ext4_group_t flex_group;
654
655 /* Cannot create files in a deleted directory */
656 if (!dir || !dir->i_nlink)
657 return ERR_PTR(-EPERM);
658
659 sb = dir->i_sb;
660 ngroups = ext4_get_groups_count(sb);
661 trace_ext4_request_inode(dir, mode);
662 inode = new_inode(sb);
663 if (!inode)
664 return ERR_PTR(-ENOMEM);
665 ei = EXT4_I(inode);
666 sbi = EXT4_SB(sb);
667
668 if (!goal)
669 goal = sbi->s_inode_goal;
670
671 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
672 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
673 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
674 ret2 = 0;
675 goto got_group;
676 }
677
678 if (S_ISDIR(mode))
679 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
680 else
681 ret2 = find_group_other(sb, dir, &group, mode);
682
683got_group:
684 EXT4_I(dir)->i_last_alloc_group = group;
685 err = -ENOSPC;
686 if (ret2 == -1)
687 goto out;
688
689 /*
690 * Normally we will only go through one pass of this loop,
691 * unless we get unlucky and it turns out the group we selected
692 * had its last inode grabbed by someone else.
693 */
694 for (i = 0; i < ngroups; i++, ino = 0) {
695 err = -EIO;
696
697 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
698 if (!gdp)
699 goto fail;
700
701 brelse(inode_bitmap_bh);
702 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
703 if (!inode_bitmap_bh)
704 goto fail;
705
706repeat_in_this_group:
707 ino = ext4_find_next_zero_bit((unsigned long *)
708 inode_bitmap_bh->b_data,
709 EXT4_INODES_PER_GROUP(sb), ino);
710 if (ino >= EXT4_INODES_PER_GROUP(sb)) {
711 if (++group == ngroups)
712 group = 0;
713 continue;
714 }
715 if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) {
716 ext4_error(sb, "reserved inode found cleared - "
717 "inode=%lu", ino + 1);
718 continue;
719 }
720 ext4_lock_group(sb, group);
721 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
722 ext4_unlock_group(sb, group);
723 ino++; /* the inode bitmap is zero-based */
724 if (!ret2)
725 goto got; /* we grabbed the inode! */
726 if (ino < EXT4_INODES_PER_GROUP(sb))
727 goto repeat_in_this_group;
728 }
729 err = -ENOSPC;
730 goto out;
731
732got:
733 /* We may have to initialize the block bitmap if it isn't already */
734 if (ext4_has_group_desc_csum(sb) &&
735 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
736 struct buffer_head *block_bitmap_bh;
737
738 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
739 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
740 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
741 if (err) {
742 brelse(block_bitmap_bh);
743 goto fail;
744 }
745
746 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
747 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
748 brelse(block_bitmap_bh);
749
750 /* recheck and clear flag under lock if we still need to */
751 ext4_lock_group(sb, group);
752 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
753 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
754 ext4_free_group_clusters_set(sb, gdp,
755 ext4_free_clusters_after_init(sb, group, gdp));
756 ext4_block_bitmap_csum_set(sb, group, gdp,
757 block_bitmap_bh,
758 EXT4_BLOCKS_PER_GROUP(sb) /
759 8);
760 ext4_group_desc_csum_set(sb, group, gdp);
761 }
762 ext4_unlock_group(sb, group);
763
764 if (err)
765 goto fail;
766 }
767
768 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
769 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
770 if (err)
771 goto fail;
772
773 BUFFER_TRACE(group_desc_bh, "get_write_access");
774 err = ext4_journal_get_write_access(handle, group_desc_bh);
775 if (err)
776 goto fail;
777
778 /* Update the relevant bg descriptor fields */
779 if (ext4_has_group_desc_csum(sb)) {
780 int free;
781 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
782
783 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
784 ext4_lock_group(sb, group); /* while we modify the bg desc */
785 free = EXT4_INODES_PER_GROUP(sb) -
786 ext4_itable_unused_count(sb, gdp);
787 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
788 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
789 free = 0;
790 }
791 /*
792 * Check the relative inode number against the last used
793 * relative inode number in this group. if it is greater
794 * we need to update the bg_itable_unused count
795 */
796 if (ino > free)
797 ext4_itable_unused_set(sb, gdp,
798 (EXT4_INODES_PER_GROUP(sb) - ino));
799 up_read(&grp->alloc_sem);
800 } else {
801 ext4_lock_group(sb, group);
802 }
803
804 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
805 if (S_ISDIR(mode)) {
806 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
807 if (sbi->s_log_groups_per_flex) {
808 ext4_group_t f = ext4_flex_group(sbi, group);
809
810 atomic_inc(&sbi->s_flex_groups[f].used_dirs);
811 }
812 }
813 if (ext4_has_group_desc_csum(sb)) {
814 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
815 EXT4_INODES_PER_GROUP(sb) / 8);
816 ext4_group_desc_csum_set(sb, group, gdp);
817 }
818 ext4_unlock_group(sb, group);
819
820 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
821 err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
822 if (err)
823 goto fail;
824
825 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
826 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
827 if (err)
828 goto fail;
829
830 percpu_counter_dec(&sbi->s_freeinodes_counter);
831 if (S_ISDIR(mode))
832 percpu_counter_inc(&sbi->s_dirs_counter);
833 ext4_mark_super_dirty(sb);
834
835 if (sbi->s_log_groups_per_flex) {
836 flex_group = ext4_flex_group(sbi, group);
837 atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes);
838 }
839 if (owner) {
840 inode->i_mode = mode;
841 i_uid_write(inode, owner[0]);
842 i_gid_write(inode, owner[1]);
843 } else if (test_opt(sb, GRPID)) {
844 inode->i_mode = mode;
845 inode->i_uid = current_fsuid();
846 inode->i_gid = dir->i_gid;
847 } else
848 inode_init_owner(inode, dir, mode);
849
850 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
851 /* This is the optimal IO size (for stat), not the fs block size */
852 inode->i_blocks = 0;
853 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
854 ext4_current_time(inode);
855
856 memset(ei->i_data, 0, sizeof(ei->i_data));
857 ei->i_dir_start_lookup = 0;
858 ei->i_disksize = 0;
859
860 /* Don't inherit extent flag from directory, amongst others. */
861 ei->i_flags =
862 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
863 ei->i_file_acl = 0;
864 ei->i_dtime = 0;
865 ei->i_block_group = group;
866 ei->i_last_alloc_group = ~0;
867
868 ext4_set_inode_flags(inode);
869 if (IS_DIRSYNC(inode))
870 ext4_handle_sync(handle);
871 if (insert_inode_locked(inode) < 0) {
872 /*
873 * Likely a bitmap corruption causing inode to be allocated
874 * twice.
875 */
876 err = -EIO;
877 goto fail;
878 }
879 spin_lock(&sbi->s_next_gen_lock);
880 inode->i_generation = sbi->s_next_generation++;
881 spin_unlock(&sbi->s_next_gen_lock);
882
883 /* Precompute checksum seed for inode metadata */
884 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
885 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
886 __u32 csum;
887 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
888 __le32 inum = cpu_to_le32(inode->i_ino);
889 __le32 gen = cpu_to_le32(inode->i_generation);
890 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
891 sizeof(inum));
892 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
893 sizeof(gen));
894 }
895
896 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
897 ext4_set_inode_state(inode, EXT4_STATE_NEW);
898
899 ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
900
901 ret = inode;
902 dquot_initialize(inode);
903 err = dquot_alloc_inode(inode);
904 if (err)
905 goto fail_drop;
906
907 err = ext4_init_acl(handle, inode, dir);
908 if (err)
909 goto fail_free_drop;
910
911 err = ext4_init_security(handle, inode, dir, qstr);
912 if (err)
913 goto fail_free_drop;
914
915 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
916 /* set extent flag only for directory, file and normal symlink*/
917 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
918 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
919 ext4_ext_tree_init(handle, inode);
920 }
921 }
922
923 if (ext4_handle_valid(handle)) {
924 ei->i_sync_tid = handle->h_transaction->t_tid;
925 ei->i_datasync_tid = handle->h_transaction->t_tid;
926 }
927
928 err = ext4_mark_inode_dirty(handle, inode);
929 if (err) {
930 ext4_std_error(sb, err);
931 goto fail_free_drop;
932 }
933
934 ext4_debug("allocating inode %lu\n", inode->i_ino);
935 trace_ext4_allocate_inode(inode, dir, mode);
936 goto really_out;
937fail:
938 ext4_std_error(sb, err);
939out:
940 iput(inode);
941 ret = ERR_PTR(err);
942really_out:
943 brelse(inode_bitmap_bh);
944 return ret;
945
946fail_free_drop:
947 dquot_free_inode(inode);
948
949fail_drop:
950 dquot_drop(inode);
951 inode->i_flags |= S_NOQUOTA;
952 clear_nlink(inode);
953 unlock_new_inode(inode);
954 iput(inode);
955 brelse(inode_bitmap_bh);
956 return ERR_PTR(err);
957}
958
959/* Verify that we are loading a valid orphan from disk */
960struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
961{
962 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
963 ext4_group_t block_group;
964 int bit;
965 struct buffer_head *bitmap_bh;
966 struct inode *inode = NULL;
967 long err = -EIO;
968
969 /* Error cases - e2fsck has already cleaned up for us */
970 if (ino > max_ino) {
971 ext4_warning(sb, "bad orphan ino %lu! e2fsck was run?", ino);
972 goto error;
973 }
974
975 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
976 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
977 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
978 if (!bitmap_bh) {
979 ext4_warning(sb, "inode bitmap error for orphan %lu", ino);
980 goto error;
981 }
982
983 /* Having the inode bit set should be a 100% indicator that this
984 * is a valid orphan (no e2fsck run on fs). Orphans also include
985 * inodes that were being truncated, so we can't check i_nlink==0.
986 */
987 if (!ext4_test_bit(bit, bitmap_bh->b_data))
988 goto bad_orphan;
989
990 inode = ext4_iget(sb, ino);
991 if (IS_ERR(inode))
992 goto iget_failed;
993
994 /*
995 * If the orphans has i_nlinks > 0 then it should be able to be
996 * truncated, otherwise it won't be removed from the orphan list
997 * during processing and an infinite loop will result.
998 */
999 if (inode->i_nlink && !ext4_can_truncate(inode))
1000 goto bad_orphan;
1001
1002 if (NEXT_ORPHAN(inode) > max_ino)
1003 goto bad_orphan;
1004 brelse(bitmap_bh);
1005 return inode;
1006
1007iget_failed:
1008 err = PTR_ERR(inode);
1009 inode = NULL;
1010bad_orphan:
1011 ext4_warning(sb, "bad orphan inode %lu! e2fsck was run?", ino);
1012 printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1013 bit, (unsigned long long)bitmap_bh->b_blocknr,
1014 ext4_test_bit(bit, bitmap_bh->b_data));
1015 printk(KERN_NOTICE "inode=%p\n", inode);
1016 if (inode) {
1017 printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
1018 is_bad_inode(inode));
1019 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
1020 NEXT_ORPHAN(inode));
1021 printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
1022 printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink);
1023 /* Avoid freeing blocks if we got a bad deleted inode */
1024 if (inode->i_nlink == 0)
1025 inode->i_blocks = 0;
1026 iput(inode);
1027 }
1028 brelse(bitmap_bh);
1029error:
1030 return ERR_PTR(err);
1031}
1032
1033unsigned long ext4_count_free_inodes(struct super_block *sb)
1034{
1035 unsigned long desc_count;
1036 struct ext4_group_desc *gdp;
1037 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1038#ifdef EXT4FS_DEBUG
1039 struct ext4_super_block *es;
1040 unsigned long bitmap_count, x;
1041 struct buffer_head *bitmap_bh = NULL;
1042
1043 es = EXT4_SB(sb)->s_es;
1044 desc_count = 0;
1045 bitmap_count = 0;
1046 gdp = NULL;
1047 for (i = 0; i < ngroups; i++) {
1048 gdp = ext4_get_group_desc(sb, i, NULL);
1049 if (!gdp)
1050 continue;
1051 desc_count += ext4_free_inodes_count(sb, gdp);
1052 brelse(bitmap_bh);
1053 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1054 if (!bitmap_bh)
1055 continue;
1056
1057 x = ext4_count_free(bitmap_bh->b_data,
1058 EXT4_INODES_PER_GROUP(sb) / 8);
1059 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1060 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1061 bitmap_count += x;
1062 }
1063 brelse(bitmap_bh);
1064 printk(KERN_DEBUG "ext4_count_free_inodes: "
1065 "stored = %u, computed = %lu, %lu\n",
1066 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1067 return desc_count;
1068#else
1069 desc_count = 0;
1070 for (i = 0; i < ngroups; i++) {
1071 gdp = ext4_get_group_desc(sb, i, NULL);
1072 if (!gdp)
1073 continue;
1074 desc_count += ext4_free_inodes_count(sb, gdp);
1075 cond_resched();
1076 }
1077 return desc_count;
1078#endif
1079}
1080
1081/* Called at mount-time, super-block is locked */
1082unsigned long ext4_count_dirs(struct super_block * sb)
1083{
1084 unsigned long count = 0;
1085 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1086
1087 for (i = 0; i < ngroups; i++) {
1088 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1089 if (!gdp)
1090 continue;
1091 count += ext4_used_dirs_count(sb, gdp);
1092 }
1093 return count;
1094}
1095
1096/*
1097 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1098 * inode table. Must be called without any spinlock held. The only place
1099 * where it is called from on active part of filesystem is ext4lazyinit
1100 * thread, so we do not need any special locks, however we have to prevent
1101 * inode allocation from the current group, so we take alloc_sem lock, to
1102 * block ext4_new_inode() until we are finished.
1103 */
1104int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1105 int barrier)
1106{
1107 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1108 struct ext4_sb_info *sbi = EXT4_SB(sb);
1109 struct ext4_group_desc *gdp = NULL;
1110 struct buffer_head *group_desc_bh;
1111 handle_t *handle;
1112 ext4_fsblk_t blk;
1113 int num, ret = 0, used_blks = 0;
1114
1115 /* This should not happen, but just to be sure check this */
1116 if (sb->s_flags & MS_RDONLY) {
1117 ret = 1;
1118 goto out;
1119 }
1120
1121 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1122 if (!gdp)
1123 goto out;
1124
1125 /*
1126 * We do not need to lock this, because we are the only one
1127 * handling this flag.
1128 */
1129 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1130 goto out;
1131
1132 handle = ext4_journal_start_sb(sb, 1);
1133 if (IS_ERR(handle)) {
1134 ret = PTR_ERR(handle);
1135 goto out;
1136 }
1137
1138 down_write(&grp->alloc_sem);
1139 /*
1140 * If inode bitmap was already initialized there may be some
1141 * used inodes so we need to skip blocks with used inodes in
1142 * inode table.
1143 */
1144 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
1145 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
1146 ext4_itable_unused_count(sb, gdp)),
1147 sbi->s_inodes_per_block);
1148
1149 if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) {
1150 ext4_error(sb, "Something is wrong with group %u: "
1151 "used itable blocks: %d; "
1152 "itable unused count: %u",
1153 group, used_blks,
1154 ext4_itable_unused_count(sb, gdp));
1155 ret = 1;
1156 goto err_out;
1157 }
1158
1159 blk = ext4_inode_table(sb, gdp) + used_blks;
1160 num = sbi->s_itb_per_group - used_blks;
1161
1162 BUFFER_TRACE(group_desc_bh, "get_write_access");
1163 ret = ext4_journal_get_write_access(handle,
1164 group_desc_bh);
1165 if (ret)
1166 goto err_out;
1167
1168 /*
1169 * Skip zeroout if the inode table is full. But we set the ZEROED
1170 * flag anyway, because obviously, when it is full it does not need
1171 * further zeroing.
1172 */
1173 if (unlikely(num == 0))
1174 goto skip_zeroout;
1175
1176 ext4_debug("going to zero out inode table in group %d\n",
1177 group);
1178 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1179 if (ret < 0)
1180 goto err_out;
1181 if (barrier)
1182 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1183
1184skip_zeroout:
1185 ext4_lock_group(sb, group);
1186 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1187 ext4_group_desc_csum_set(sb, group, gdp);
1188 ext4_unlock_group(sb, group);
1189
1190 BUFFER_TRACE(group_desc_bh,
1191 "call ext4_handle_dirty_metadata");
1192 ret = ext4_handle_dirty_metadata(handle, NULL,
1193 group_desc_bh);
1194
1195err_out:
1196 up_write(&grp->alloc_sem);
1197 ext4_journal_stop(handle);
1198out:
1199 return ret;
1200}
1/*
2 * linux/fs/ext4/ialloc.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * BSD ufs-inspired inode and directory allocation by
10 * Stephen Tweedie (sct@redhat.com), 1993
11 * Big-endian to little-endian byte-swapping/bitmaps by
12 * David S. Miller (davem@caip.rutgers.edu), 1995
13 */
14
15#include <linux/time.h>
16#include <linux/fs.h>
17#include <linux/jbd2.h>
18#include <linux/stat.h>
19#include <linux/string.h>
20#include <linux/quotaops.h>
21#include <linux/buffer_head.h>
22#include <linux/random.h>
23#include <linux/bitops.h>
24#include <linux/blkdev.h>
25#include <asm/byteorder.h>
26
27#include "ext4.h"
28#include "ext4_jbd2.h"
29#include "xattr.h"
30#include "acl.h"
31
32#include <trace/events/ext4.h>
33
34/*
35 * ialloc.c contains the inodes allocation and deallocation routines
36 */
37
38/*
39 * The free inodes are managed by bitmaps. A file system contains several
40 * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
41 * block for inodes, N blocks for the inode table and data blocks.
42 *
43 * The file system contains group descriptors which are located after the
44 * super block. Each descriptor contains the number of the bitmap block and
45 * the free blocks count in the block.
46 */
47
48/*
49 * To avoid calling the atomic setbit hundreds or thousands of times, we only
50 * need to use it within a single byte (to ensure we get endianness right).
51 * We can use memset for the rest of the bitmap as there are no other users.
52 */
53void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
54{
55 int i;
56
57 if (start_bit >= end_bit)
58 return;
59
60 ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
61 for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
62 ext4_set_bit(i, bitmap);
63 if (i < end_bit)
64 memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
65}
66
67/* Initializes an uninitialized inode bitmap */
68static unsigned ext4_init_inode_bitmap(struct super_block *sb,
69 struct buffer_head *bh,
70 ext4_group_t block_group,
71 struct ext4_group_desc *gdp)
72{
73 struct ext4_group_info *grp;
74 J_ASSERT_BH(bh, buffer_locked(bh));
75
76 /* If checksum is bad mark all blocks and inodes use to prevent
77 * allocation, essentially implementing a per-group read-only flag. */
78 if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
79 ext4_error(sb, "Checksum bad for group %u", block_group);
80 grp = ext4_get_group_info(sb, block_group);
81 set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
82 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
83 return 0;
84 }
85
86 memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
87 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
88 bh->b_data);
89 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
90 EXT4_INODES_PER_GROUP(sb) / 8);
91 ext4_group_desc_csum_set(sb, block_group, gdp);
92
93 return EXT4_INODES_PER_GROUP(sb);
94}
95
96void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
97{
98 if (uptodate) {
99 set_buffer_uptodate(bh);
100 set_bitmap_uptodate(bh);
101 }
102 unlock_buffer(bh);
103 put_bh(bh);
104}
105
106/*
107 * Read the inode allocation bitmap for a given block_group, reading
108 * into the specified slot in the superblock's bitmap cache.
109 *
110 * Return buffer_head of bitmap on success or NULL.
111 */
112static struct buffer_head *
113ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
114{
115 struct ext4_group_desc *desc;
116 struct buffer_head *bh = NULL;
117 ext4_fsblk_t bitmap_blk;
118 struct ext4_group_info *grp;
119
120 desc = ext4_get_group_desc(sb, block_group, NULL);
121 if (!desc)
122 return NULL;
123
124 bitmap_blk = ext4_inode_bitmap(sb, desc);
125 bh = sb_getblk(sb, bitmap_blk);
126 if (unlikely(!bh)) {
127 ext4_error(sb, "Cannot read inode bitmap - "
128 "block_group = %u, inode_bitmap = %llu",
129 block_group, bitmap_blk);
130 return NULL;
131 }
132 if (bitmap_uptodate(bh))
133 goto verify;
134
135 lock_buffer(bh);
136 if (bitmap_uptodate(bh)) {
137 unlock_buffer(bh);
138 goto verify;
139 }
140
141 ext4_lock_group(sb, block_group);
142 if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
143 ext4_init_inode_bitmap(sb, bh, block_group, desc);
144 set_bitmap_uptodate(bh);
145 set_buffer_uptodate(bh);
146 set_buffer_verified(bh);
147 ext4_unlock_group(sb, block_group);
148 unlock_buffer(bh);
149 return bh;
150 }
151 ext4_unlock_group(sb, block_group);
152
153 if (buffer_uptodate(bh)) {
154 /*
155 * if not uninit if bh is uptodate,
156 * bitmap is also uptodate
157 */
158 set_bitmap_uptodate(bh);
159 unlock_buffer(bh);
160 goto verify;
161 }
162 /*
163 * submit the buffer_head for reading
164 */
165 trace_ext4_load_inode_bitmap(sb, block_group);
166 bh->b_end_io = ext4_end_bitmap_read;
167 get_bh(bh);
168 submit_bh(READ | REQ_META | REQ_PRIO, bh);
169 wait_on_buffer(bh);
170 if (!buffer_uptodate(bh)) {
171 put_bh(bh);
172 ext4_error(sb, "Cannot read inode bitmap - "
173 "block_group = %u, inode_bitmap = %llu",
174 block_group, bitmap_blk);
175 return NULL;
176 }
177
178verify:
179 ext4_lock_group(sb, block_group);
180 if (!buffer_verified(bh) &&
181 !ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
182 EXT4_INODES_PER_GROUP(sb) / 8)) {
183 ext4_unlock_group(sb, block_group);
184 put_bh(bh);
185 ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
186 "inode_bitmap = %llu", block_group, bitmap_blk);
187 grp = ext4_get_group_info(sb, block_group);
188 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
189 return NULL;
190 }
191 ext4_unlock_group(sb, block_group);
192 set_buffer_verified(bh);
193 return bh;
194}
195
196/*
197 * NOTE! When we get the inode, we're the only people
198 * that have access to it, and as such there are no
199 * race conditions we have to worry about. The inode
200 * is not on the hash-lists, and it cannot be reached
201 * through the filesystem because the directory entry
202 * has been deleted earlier.
203 *
204 * HOWEVER: we must make sure that we get no aliases,
205 * which means that we have to call "clear_inode()"
206 * _before_ we mark the inode not in use in the inode
207 * bitmaps. Otherwise a newly created file might use
208 * the same inode number (not actually the same pointer
209 * though), and then we'd have two inodes sharing the
210 * same inode number and space on the harddisk.
211 */
212void ext4_free_inode(handle_t *handle, struct inode *inode)
213{
214 struct super_block *sb = inode->i_sb;
215 int is_directory;
216 unsigned long ino;
217 struct buffer_head *bitmap_bh = NULL;
218 struct buffer_head *bh2;
219 ext4_group_t block_group;
220 unsigned long bit;
221 struct ext4_group_desc *gdp;
222 struct ext4_super_block *es;
223 struct ext4_sb_info *sbi;
224 int fatal = 0, err, count, cleared;
225 struct ext4_group_info *grp;
226
227 if (!sb) {
228 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
229 "nonexistent device\n", __func__, __LINE__);
230 return;
231 }
232 if (atomic_read(&inode->i_count) > 1) {
233 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
234 __func__, __LINE__, inode->i_ino,
235 atomic_read(&inode->i_count));
236 return;
237 }
238 if (inode->i_nlink) {
239 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
240 __func__, __LINE__, inode->i_ino, inode->i_nlink);
241 return;
242 }
243 sbi = EXT4_SB(sb);
244
245 ino = inode->i_ino;
246 ext4_debug("freeing inode %lu\n", ino);
247 trace_ext4_free_inode(inode);
248
249 /*
250 * Note: we must free any quota before locking the superblock,
251 * as writing the quota to disk may need the lock as well.
252 */
253 dquot_initialize(inode);
254 ext4_xattr_delete_inode(handle, inode);
255 dquot_free_inode(inode);
256 dquot_drop(inode);
257
258 is_directory = S_ISDIR(inode->i_mode);
259
260 /* Do this BEFORE marking the inode not in use or returning an error */
261 ext4_clear_inode(inode);
262
263 es = EXT4_SB(sb)->s_es;
264 if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
265 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
266 goto error_return;
267 }
268 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
269 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
270 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
271 /* Don't bother if the inode bitmap is corrupt. */
272 grp = ext4_get_group_info(sb, block_group);
273 if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) || !bitmap_bh)
274 goto error_return;
275
276 BUFFER_TRACE(bitmap_bh, "get_write_access");
277 fatal = ext4_journal_get_write_access(handle, bitmap_bh);
278 if (fatal)
279 goto error_return;
280
281 fatal = -ESRCH;
282 gdp = ext4_get_group_desc(sb, block_group, &bh2);
283 if (gdp) {
284 BUFFER_TRACE(bh2, "get_write_access");
285 fatal = ext4_journal_get_write_access(handle, bh2);
286 }
287 ext4_lock_group(sb, block_group);
288 cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
289 if (fatal || !cleared) {
290 ext4_unlock_group(sb, block_group);
291 goto out;
292 }
293
294 count = ext4_free_inodes_count(sb, gdp) + 1;
295 ext4_free_inodes_set(sb, gdp, count);
296 if (is_directory) {
297 count = ext4_used_dirs_count(sb, gdp) - 1;
298 ext4_used_dirs_set(sb, gdp, count);
299 percpu_counter_dec(&sbi->s_dirs_counter);
300 }
301 ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
302 EXT4_INODES_PER_GROUP(sb) / 8);
303 ext4_group_desc_csum_set(sb, block_group, gdp);
304 ext4_unlock_group(sb, block_group);
305
306 percpu_counter_inc(&sbi->s_freeinodes_counter);
307 if (sbi->s_log_groups_per_flex) {
308 ext4_group_t f = ext4_flex_group(sbi, block_group);
309
310 atomic_inc(&sbi->s_flex_groups[f].free_inodes);
311 if (is_directory)
312 atomic_dec(&sbi->s_flex_groups[f].used_dirs);
313 }
314 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
315 fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
316out:
317 if (cleared) {
318 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
319 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
320 if (!fatal)
321 fatal = err;
322 } else {
323 ext4_error(sb, "bit already cleared for inode %lu", ino);
324 set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
325 }
326
327error_return:
328 brelse(bitmap_bh);
329 ext4_std_error(sb, fatal);
330}
331
332struct orlov_stats {
333 __u64 free_clusters;
334 __u32 free_inodes;
335 __u32 used_dirs;
336};
337
338/*
339 * Helper function for Orlov's allocator; returns critical information
340 * for a particular block group or flex_bg. If flex_size is 1, then g
341 * is a block group number; otherwise it is flex_bg number.
342 */
343static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
344 int flex_size, struct orlov_stats *stats)
345{
346 struct ext4_group_desc *desc;
347 struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups;
348
349 if (flex_size > 1) {
350 stats->free_inodes = atomic_read(&flex_group[g].free_inodes);
351 stats->free_clusters = atomic64_read(&flex_group[g].free_clusters);
352 stats->used_dirs = atomic_read(&flex_group[g].used_dirs);
353 return;
354 }
355
356 desc = ext4_get_group_desc(sb, g, NULL);
357 if (desc) {
358 stats->free_inodes = ext4_free_inodes_count(sb, desc);
359 stats->free_clusters = ext4_free_group_clusters(sb, desc);
360 stats->used_dirs = ext4_used_dirs_count(sb, desc);
361 } else {
362 stats->free_inodes = 0;
363 stats->free_clusters = 0;
364 stats->used_dirs = 0;
365 }
366}
367
368/*
369 * Orlov's allocator for directories.
370 *
371 * We always try to spread first-level directories.
372 *
373 * If there are blockgroups with both free inodes and free blocks counts
374 * not worse than average we return one with smallest directory count.
375 * Otherwise we simply return a random group.
376 *
377 * For the rest rules look so:
378 *
379 * It's OK to put directory into a group unless
380 * it has too many directories already (max_dirs) or
381 * it has too few free inodes left (min_inodes) or
382 * it has too few free blocks left (min_blocks) or
383 * Parent's group is preferred, if it doesn't satisfy these
384 * conditions we search cyclically through the rest. If none
385 * of the groups look good we just look for a group with more
386 * free inodes than average (starting at parent's group).
387 */
388
389static int find_group_orlov(struct super_block *sb, struct inode *parent,
390 ext4_group_t *group, umode_t mode,
391 const struct qstr *qstr)
392{
393 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
394 struct ext4_sb_info *sbi = EXT4_SB(sb);
395 ext4_group_t real_ngroups = ext4_get_groups_count(sb);
396 int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
397 unsigned int freei, avefreei, grp_free;
398 ext4_fsblk_t freeb, avefreec;
399 unsigned int ndirs;
400 int max_dirs, min_inodes;
401 ext4_grpblk_t min_clusters;
402 ext4_group_t i, grp, g, ngroups;
403 struct ext4_group_desc *desc;
404 struct orlov_stats stats;
405 int flex_size = ext4_flex_bg_size(sbi);
406 struct dx_hash_info hinfo;
407
408 ngroups = real_ngroups;
409 if (flex_size > 1) {
410 ngroups = (real_ngroups + flex_size - 1) >>
411 sbi->s_log_groups_per_flex;
412 parent_group >>= sbi->s_log_groups_per_flex;
413 }
414
415 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
416 avefreei = freei / ngroups;
417 freeb = EXT4_C2B(sbi,
418 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
419 avefreec = freeb;
420 do_div(avefreec, ngroups);
421 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
422
423 if (S_ISDIR(mode) &&
424 ((parent == sb->s_root->d_inode) ||
425 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
426 int best_ndir = inodes_per_group;
427 int ret = -1;
428
429 if (qstr) {
430 hinfo.hash_version = DX_HASH_HALF_MD4;
431 hinfo.seed = sbi->s_hash_seed;
432 ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
433 grp = hinfo.hash;
434 } else
435 grp = prandom_u32();
436 parent_group = (unsigned)grp % ngroups;
437 for (i = 0; i < ngroups; i++) {
438 g = (parent_group + i) % ngroups;
439 get_orlov_stats(sb, g, flex_size, &stats);
440 if (!stats.free_inodes)
441 continue;
442 if (stats.used_dirs >= best_ndir)
443 continue;
444 if (stats.free_inodes < avefreei)
445 continue;
446 if (stats.free_clusters < avefreec)
447 continue;
448 grp = g;
449 ret = 0;
450 best_ndir = stats.used_dirs;
451 }
452 if (ret)
453 goto fallback;
454 found_flex_bg:
455 if (flex_size == 1) {
456 *group = grp;
457 return 0;
458 }
459
460 /*
461 * We pack inodes at the beginning of the flexgroup's
462 * inode tables. Block allocation decisions will do
463 * something similar, although regular files will
464 * start at 2nd block group of the flexgroup. See
465 * ext4_ext_find_goal() and ext4_find_near().
466 */
467 grp *= flex_size;
468 for (i = 0; i < flex_size; i++) {
469 if (grp+i >= real_ngroups)
470 break;
471 desc = ext4_get_group_desc(sb, grp+i, NULL);
472 if (desc && ext4_free_inodes_count(sb, desc)) {
473 *group = grp+i;
474 return 0;
475 }
476 }
477 goto fallback;
478 }
479
480 max_dirs = ndirs / ngroups + inodes_per_group / 16;
481 min_inodes = avefreei - inodes_per_group*flex_size / 4;
482 if (min_inodes < 1)
483 min_inodes = 1;
484 min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
485
486 /*
487 * Start looking in the flex group where we last allocated an
488 * inode for this parent directory
489 */
490 if (EXT4_I(parent)->i_last_alloc_group != ~0) {
491 parent_group = EXT4_I(parent)->i_last_alloc_group;
492 if (flex_size > 1)
493 parent_group >>= sbi->s_log_groups_per_flex;
494 }
495
496 for (i = 0; i < ngroups; i++) {
497 grp = (parent_group + i) % ngroups;
498 get_orlov_stats(sb, grp, flex_size, &stats);
499 if (stats.used_dirs >= max_dirs)
500 continue;
501 if (stats.free_inodes < min_inodes)
502 continue;
503 if (stats.free_clusters < min_clusters)
504 continue;
505 goto found_flex_bg;
506 }
507
508fallback:
509 ngroups = real_ngroups;
510 avefreei = freei / ngroups;
511fallback_retry:
512 parent_group = EXT4_I(parent)->i_block_group;
513 for (i = 0; i < ngroups; i++) {
514 grp = (parent_group + i) % ngroups;
515 desc = ext4_get_group_desc(sb, grp, NULL);
516 if (desc) {
517 grp_free = ext4_free_inodes_count(sb, desc);
518 if (grp_free && grp_free >= avefreei) {
519 *group = grp;
520 return 0;
521 }
522 }
523 }
524
525 if (avefreei) {
526 /*
527 * The free-inodes counter is approximate, and for really small
528 * filesystems the above test can fail to find any blockgroups
529 */
530 avefreei = 0;
531 goto fallback_retry;
532 }
533
534 return -1;
535}
536
537static int find_group_other(struct super_block *sb, struct inode *parent,
538 ext4_group_t *group, umode_t mode)
539{
540 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
541 ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
542 struct ext4_group_desc *desc;
543 int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
544
545 /*
546 * Try to place the inode is the same flex group as its
547 * parent. If we can't find space, use the Orlov algorithm to
548 * find another flex group, and store that information in the
549 * parent directory's inode information so that use that flex
550 * group for future allocations.
551 */
552 if (flex_size > 1) {
553 int retry = 0;
554
555 try_again:
556 parent_group &= ~(flex_size-1);
557 last = parent_group + flex_size;
558 if (last > ngroups)
559 last = ngroups;
560 for (i = parent_group; i < last; i++) {
561 desc = ext4_get_group_desc(sb, i, NULL);
562 if (desc && ext4_free_inodes_count(sb, desc)) {
563 *group = i;
564 return 0;
565 }
566 }
567 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
568 retry = 1;
569 parent_group = EXT4_I(parent)->i_last_alloc_group;
570 goto try_again;
571 }
572 /*
573 * If this didn't work, use the Orlov search algorithm
574 * to find a new flex group; we pass in the mode to
575 * avoid the topdir algorithms.
576 */
577 *group = parent_group + flex_size;
578 if (*group > ngroups)
579 *group = 0;
580 return find_group_orlov(sb, parent, group, mode, NULL);
581 }
582
583 /*
584 * Try to place the inode in its parent directory
585 */
586 *group = parent_group;
587 desc = ext4_get_group_desc(sb, *group, NULL);
588 if (desc && ext4_free_inodes_count(sb, desc) &&
589 ext4_free_group_clusters(sb, desc))
590 return 0;
591
592 /*
593 * We're going to place this inode in a different blockgroup from its
594 * parent. We want to cause files in a common directory to all land in
595 * the same blockgroup. But we want files which are in a different
596 * directory which shares a blockgroup with our parent to land in a
597 * different blockgroup.
598 *
599 * So add our directory's i_ino into the starting point for the hash.
600 */
601 *group = (*group + parent->i_ino) % ngroups;
602
603 /*
604 * Use a quadratic hash to find a group with a free inode and some free
605 * blocks.
606 */
607 for (i = 1; i < ngroups; i <<= 1) {
608 *group += i;
609 if (*group >= ngroups)
610 *group -= ngroups;
611 desc = ext4_get_group_desc(sb, *group, NULL);
612 if (desc && ext4_free_inodes_count(sb, desc) &&
613 ext4_free_group_clusters(sb, desc))
614 return 0;
615 }
616
617 /*
618 * That failed: try linear search for a free inode, even if that group
619 * has no free blocks.
620 */
621 *group = parent_group;
622 for (i = 0; i < ngroups; i++) {
623 if (++*group >= ngroups)
624 *group = 0;
625 desc = ext4_get_group_desc(sb, *group, NULL);
626 if (desc && ext4_free_inodes_count(sb, desc))
627 return 0;
628 }
629
630 return -1;
631}
632
633/*
634 * In no journal mode, if an inode has recently been deleted, we want
635 * to avoid reusing it until we're reasonably sure the inode table
636 * block has been written back to disk. (Yes, these values are
637 * somewhat arbitrary...)
638 */
639#define RECENTCY_MIN 5
640#define RECENTCY_DIRTY 30
641
642static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
643{
644 struct ext4_group_desc *gdp;
645 struct ext4_inode *raw_inode;
646 struct buffer_head *bh;
647 unsigned long dtime, now;
648 int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
649 int offset, ret = 0, recentcy = RECENTCY_MIN;
650
651 gdp = ext4_get_group_desc(sb, group, NULL);
652 if (unlikely(!gdp))
653 return 0;
654
655 bh = sb_getblk(sb, ext4_inode_table(sb, gdp) +
656 (ino / inodes_per_block));
657 if (unlikely(!bh) || !buffer_uptodate(bh))
658 /*
659 * If the block is not in the buffer cache, then it
660 * must have been written out.
661 */
662 goto out;
663
664 offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
665 raw_inode = (struct ext4_inode *) (bh->b_data + offset);
666 dtime = le32_to_cpu(raw_inode->i_dtime);
667 now = get_seconds();
668 if (buffer_dirty(bh))
669 recentcy += RECENTCY_DIRTY;
670
671 if (dtime && (dtime < now) && (now < dtime + recentcy))
672 ret = 1;
673out:
674 brelse(bh);
675 return ret;
676}
677
678/*
679 * There are two policies for allocating an inode. If the new inode is
680 * a directory, then a forward search is made for a block group with both
681 * free space and a low directory-to-inode ratio; if that fails, then of
682 * the groups with above-average free space, that group with the fewest
683 * directories already is chosen.
684 *
685 * For other inodes, search forward from the parent directory's block
686 * group to find a free inode.
687 */
688struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
689 umode_t mode, const struct qstr *qstr,
690 __u32 goal, uid_t *owner, int handle_type,
691 unsigned int line_no, int nblocks)
692{
693 struct super_block *sb;
694 struct buffer_head *inode_bitmap_bh = NULL;
695 struct buffer_head *group_desc_bh;
696 ext4_group_t ngroups, group = 0;
697 unsigned long ino = 0;
698 struct inode *inode;
699 struct ext4_group_desc *gdp = NULL;
700 struct ext4_inode_info *ei;
701 struct ext4_sb_info *sbi;
702 int ret2, err = 0;
703 struct inode *ret;
704 ext4_group_t i;
705 ext4_group_t flex_group;
706 struct ext4_group_info *grp;
707
708 /* Cannot create files in a deleted directory */
709 if (!dir || !dir->i_nlink)
710 return ERR_PTR(-EPERM);
711
712 sb = dir->i_sb;
713 ngroups = ext4_get_groups_count(sb);
714 trace_ext4_request_inode(dir, mode);
715 inode = new_inode(sb);
716 if (!inode)
717 return ERR_PTR(-ENOMEM);
718 ei = EXT4_I(inode);
719 sbi = EXT4_SB(sb);
720
721 /*
722 * Initalize owners and quota early so that we don't have to account
723 * for quota initialization worst case in standard inode creating
724 * transaction
725 */
726 if (owner) {
727 inode->i_mode = mode;
728 i_uid_write(inode, owner[0]);
729 i_gid_write(inode, owner[1]);
730 } else if (test_opt(sb, GRPID)) {
731 inode->i_mode = mode;
732 inode->i_uid = current_fsuid();
733 inode->i_gid = dir->i_gid;
734 } else
735 inode_init_owner(inode, dir, mode);
736 dquot_initialize(inode);
737
738 if (!goal)
739 goal = sbi->s_inode_goal;
740
741 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
742 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
743 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
744 ret2 = 0;
745 goto got_group;
746 }
747
748 if (S_ISDIR(mode))
749 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
750 else
751 ret2 = find_group_other(sb, dir, &group, mode);
752
753got_group:
754 EXT4_I(dir)->i_last_alloc_group = group;
755 err = -ENOSPC;
756 if (ret2 == -1)
757 goto out;
758
759 /*
760 * Normally we will only go through one pass of this loop,
761 * unless we get unlucky and it turns out the group we selected
762 * had its last inode grabbed by someone else.
763 */
764 for (i = 0; i < ngroups; i++, ino = 0) {
765 err = -EIO;
766
767 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
768 if (!gdp)
769 goto out;
770
771 /*
772 * Check free inodes count before loading bitmap.
773 */
774 if (ext4_free_inodes_count(sb, gdp) == 0) {
775 if (++group == ngroups)
776 group = 0;
777 continue;
778 }
779
780 grp = ext4_get_group_info(sb, group);
781 /* Skip groups with already-known suspicious inode tables */
782 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
783 if (++group == ngroups)
784 group = 0;
785 continue;
786 }
787
788 brelse(inode_bitmap_bh);
789 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
790 /* Skip groups with suspicious inode tables */
791 if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) || !inode_bitmap_bh) {
792 if (++group == ngroups)
793 group = 0;
794 continue;
795 }
796
797repeat_in_this_group:
798 ino = ext4_find_next_zero_bit((unsigned long *)
799 inode_bitmap_bh->b_data,
800 EXT4_INODES_PER_GROUP(sb), ino);
801 if (ino >= EXT4_INODES_PER_GROUP(sb))
802 goto next_group;
803 if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) {
804 ext4_error(sb, "reserved inode found cleared - "
805 "inode=%lu", ino + 1);
806 continue;
807 }
808 if ((EXT4_SB(sb)->s_journal == NULL) &&
809 recently_deleted(sb, group, ino)) {
810 ino++;
811 goto next_inode;
812 }
813 if (!handle) {
814 BUG_ON(nblocks <= 0);
815 handle = __ext4_journal_start_sb(dir->i_sb, line_no,
816 handle_type, nblocks,
817 0);
818 if (IS_ERR(handle)) {
819 err = PTR_ERR(handle);
820 ext4_std_error(sb, err);
821 goto out;
822 }
823 }
824 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
825 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
826 if (err) {
827 ext4_std_error(sb, err);
828 goto out;
829 }
830 ext4_lock_group(sb, group);
831 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
832 ext4_unlock_group(sb, group);
833 ino++; /* the inode bitmap is zero-based */
834 if (!ret2)
835 goto got; /* we grabbed the inode! */
836next_inode:
837 if (ino < EXT4_INODES_PER_GROUP(sb))
838 goto repeat_in_this_group;
839next_group:
840 if (++group == ngroups)
841 group = 0;
842 }
843 err = -ENOSPC;
844 goto out;
845
846got:
847 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
848 err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
849 if (err) {
850 ext4_std_error(sb, err);
851 goto out;
852 }
853
854 /* We may have to initialize the block bitmap if it isn't already */
855 if (ext4_has_group_desc_csum(sb) &&
856 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
857 struct buffer_head *block_bitmap_bh;
858
859 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
860 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
861 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
862 if (err) {
863 brelse(block_bitmap_bh);
864 ext4_std_error(sb, err);
865 goto out;
866 }
867
868 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
869 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
870
871 /* recheck and clear flag under lock if we still need to */
872 ext4_lock_group(sb, group);
873 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
874 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
875 ext4_free_group_clusters_set(sb, gdp,
876 ext4_free_clusters_after_init(sb, group, gdp));
877 ext4_block_bitmap_csum_set(sb, group, gdp,
878 block_bitmap_bh);
879 ext4_group_desc_csum_set(sb, group, gdp);
880 }
881 ext4_unlock_group(sb, group);
882 brelse(block_bitmap_bh);
883
884 if (err) {
885 ext4_std_error(sb, err);
886 goto out;
887 }
888 }
889
890 BUFFER_TRACE(group_desc_bh, "get_write_access");
891 err = ext4_journal_get_write_access(handle, group_desc_bh);
892 if (err) {
893 ext4_std_error(sb, err);
894 goto out;
895 }
896
897 /* Update the relevant bg descriptor fields */
898 if (ext4_has_group_desc_csum(sb)) {
899 int free;
900 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
901
902 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
903 ext4_lock_group(sb, group); /* while we modify the bg desc */
904 free = EXT4_INODES_PER_GROUP(sb) -
905 ext4_itable_unused_count(sb, gdp);
906 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
907 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
908 free = 0;
909 }
910 /*
911 * Check the relative inode number against the last used
912 * relative inode number in this group. if it is greater
913 * we need to update the bg_itable_unused count
914 */
915 if (ino > free)
916 ext4_itable_unused_set(sb, gdp,
917 (EXT4_INODES_PER_GROUP(sb) - ino));
918 up_read(&grp->alloc_sem);
919 } else {
920 ext4_lock_group(sb, group);
921 }
922
923 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
924 if (S_ISDIR(mode)) {
925 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
926 if (sbi->s_log_groups_per_flex) {
927 ext4_group_t f = ext4_flex_group(sbi, group);
928
929 atomic_inc(&sbi->s_flex_groups[f].used_dirs);
930 }
931 }
932 if (ext4_has_group_desc_csum(sb)) {
933 ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
934 EXT4_INODES_PER_GROUP(sb) / 8);
935 ext4_group_desc_csum_set(sb, group, gdp);
936 }
937 ext4_unlock_group(sb, group);
938
939 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
940 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
941 if (err) {
942 ext4_std_error(sb, err);
943 goto out;
944 }
945
946 percpu_counter_dec(&sbi->s_freeinodes_counter);
947 if (S_ISDIR(mode))
948 percpu_counter_inc(&sbi->s_dirs_counter);
949
950 if (sbi->s_log_groups_per_flex) {
951 flex_group = ext4_flex_group(sbi, group);
952 atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes);
953 }
954
955 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
956 /* This is the optimal IO size (for stat), not the fs block size */
957 inode->i_blocks = 0;
958 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
959 ext4_current_time(inode);
960
961 memset(ei->i_data, 0, sizeof(ei->i_data));
962 ei->i_dir_start_lookup = 0;
963 ei->i_disksize = 0;
964
965 /* Don't inherit extent flag from directory, amongst others. */
966 ei->i_flags =
967 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
968 ei->i_file_acl = 0;
969 ei->i_dtime = 0;
970 ei->i_block_group = group;
971 ei->i_last_alloc_group = ~0;
972
973 ext4_set_inode_flags(inode);
974 if (IS_DIRSYNC(inode))
975 ext4_handle_sync(handle);
976 if (insert_inode_locked(inode) < 0) {
977 /*
978 * Likely a bitmap corruption causing inode to be allocated
979 * twice.
980 */
981 err = -EIO;
982 ext4_error(sb, "failed to insert inode %lu: doubly allocated?",
983 inode->i_ino);
984 goto out;
985 }
986 spin_lock(&sbi->s_next_gen_lock);
987 inode->i_generation = sbi->s_next_generation++;
988 spin_unlock(&sbi->s_next_gen_lock);
989
990 /* Precompute checksum seed for inode metadata */
991 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
992 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
993 __u32 csum;
994 __le32 inum = cpu_to_le32(inode->i_ino);
995 __le32 gen = cpu_to_le32(inode->i_generation);
996 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
997 sizeof(inum));
998 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
999 sizeof(gen));
1000 }
1001
1002 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
1003 ext4_set_inode_state(inode, EXT4_STATE_NEW);
1004
1005 ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
1006
1007 ei->i_inline_off = 0;
1008 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_INLINE_DATA))
1009 ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
1010
1011 ret = inode;
1012 err = dquot_alloc_inode(inode);
1013 if (err)
1014 goto fail_drop;
1015
1016 err = ext4_init_acl(handle, inode, dir);
1017 if (err)
1018 goto fail_free_drop;
1019
1020 err = ext4_init_security(handle, inode, dir, qstr);
1021 if (err)
1022 goto fail_free_drop;
1023
1024 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
1025 /* set extent flag only for directory, file and normal symlink*/
1026 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
1027 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
1028 ext4_ext_tree_init(handle, inode);
1029 }
1030 }
1031
1032 if (ext4_handle_valid(handle)) {
1033 ei->i_sync_tid = handle->h_transaction->t_tid;
1034 ei->i_datasync_tid = handle->h_transaction->t_tid;
1035 }
1036
1037 err = ext4_mark_inode_dirty(handle, inode);
1038 if (err) {
1039 ext4_std_error(sb, err);
1040 goto fail_free_drop;
1041 }
1042
1043 ext4_debug("allocating inode %lu\n", inode->i_ino);
1044 trace_ext4_allocate_inode(inode, dir, mode);
1045 brelse(inode_bitmap_bh);
1046 return ret;
1047
1048fail_free_drop:
1049 dquot_free_inode(inode);
1050fail_drop:
1051 clear_nlink(inode);
1052 unlock_new_inode(inode);
1053out:
1054 dquot_drop(inode);
1055 inode->i_flags |= S_NOQUOTA;
1056 iput(inode);
1057 brelse(inode_bitmap_bh);
1058 return ERR_PTR(err);
1059}
1060
1061/* Verify that we are loading a valid orphan from disk */
1062struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
1063{
1064 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
1065 ext4_group_t block_group;
1066 int bit;
1067 struct buffer_head *bitmap_bh;
1068 struct inode *inode = NULL;
1069 long err = -EIO;
1070
1071 /* Error cases - e2fsck has already cleaned up for us */
1072 if (ino > max_ino) {
1073 ext4_warning(sb, "bad orphan ino %lu! e2fsck was run?", ino);
1074 goto error;
1075 }
1076
1077 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
1078 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
1079 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
1080 if (!bitmap_bh) {
1081 ext4_warning(sb, "inode bitmap error for orphan %lu", ino);
1082 goto error;
1083 }
1084
1085 /* Having the inode bit set should be a 100% indicator that this
1086 * is a valid orphan (no e2fsck run on fs). Orphans also include
1087 * inodes that were being truncated, so we can't check i_nlink==0.
1088 */
1089 if (!ext4_test_bit(bit, bitmap_bh->b_data))
1090 goto bad_orphan;
1091
1092 inode = ext4_iget(sb, ino);
1093 if (IS_ERR(inode))
1094 goto iget_failed;
1095
1096 /*
1097 * If the orphans has i_nlinks > 0 then it should be able to be
1098 * truncated, otherwise it won't be removed from the orphan list
1099 * during processing and an infinite loop will result.
1100 */
1101 if (inode->i_nlink && !ext4_can_truncate(inode))
1102 goto bad_orphan;
1103
1104 if (NEXT_ORPHAN(inode) > max_ino)
1105 goto bad_orphan;
1106 brelse(bitmap_bh);
1107 return inode;
1108
1109iget_failed:
1110 err = PTR_ERR(inode);
1111 inode = NULL;
1112bad_orphan:
1113 ext4_warning(sb, "bad orphan inode %lu! e2fsck was run?", ino);
1114 printk(KERN_WARNING "ext4_test_bit(bit=%d, block=%llu) = %d\n",
1115 bit, (unsigned long long)bitmap_bh->b_blocknr,
1116 ext4_test_bit(bit, bitmap_bh->b_data));
1117 printk(KERN_WARNING "inode=%p\n", inode);
1118 if (inode) {
1119 printk(KERN_WARNING "is_bad_inode(inode)=%d\n",
1120 is_bad_inode(inode));
1121 printk(KERN_WARNING "NEXT_ORPHAN(inode)=%u\n",
1122 NEXT_ORPHAN(inode));
1123 printk(KERN_WARNING "max_ino=%lu\n", max_ino);
1124 printk(KERN_WARNING "i_nlink=%u\n", inode->i_nlink);
1125 /* Avoid freeing blocks if we got a bad deleted inode */
1126 if (inode->i_nlink == 0)
1127 inode->i_blocks = 0;
1128 iput(inode);
1129 }
1130 brelse(bitmap_bh);
1131error:
1132 return ERR_PTR(err);
1133}
1134
1135unsigned long ext4_count_free_inodes(struct super_block *sb)
1136{
1137 unsigned long desc_count;
1138 struct ext4_group_desc *gdp;
1139 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1140#ifdef EXT4FS_DEBUG
1141 struct ext4_super_block *es;
1142 unsigned long bitmap_count, x;
1143 struct buffer_head *bitmap_bh = NULL;
1144
1145 es = EXT4_SB(sb)->s_es;
1146 desc_count = 0;
1147 bitmap_count = 0;
1148 gdp = NULL;
1149 for (i = 0; i < ngroups; i++) {
1150 gdp = ext4_get_group_desc(sb, i, NULL);
1151 if (!gdp)
1152 continue;
1153 desc_count += ext4_free_inodes_count(sb, gdp);
1154 brelse(bitmap_bh);
1155 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1156 if (!bitmap_bh)
1157 continue;
1158
1159 x = ext4_count_free(bitmap_bh->b_data,
1160 EXT4_INODES_PER_GROUP(sb) / 8);
1161 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1162 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1163 bitmap_count += x;
1164 }
1165 brelse(bitmap_bh);
1166 printk(KERN_DEBUG "ext4_count_free_inodes: "
1167 "stored = %u, computed = %lu, %lu\n",
1168 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1169 return desc_count;
1170#else
1171 desc_count = 0;
1172 for (i = 0; i < ngroups; i++) {
1173 gdp = ext4_get_group_desc(sb, i, NULL);
1174 if (!gdp)
1175 continue;
1176 desc_count += ext4_free_inodes_count(sb, gdp);
1177 cond_resched();
1178 }
1179 return desc_count;
1180#endif
1181}
1182
1183/* Called at mount-time, super-block is locked */
1184unsigned long ext4_count_dirs(struct super_block * sb)
1185{
1186 unsigned long count = 0;
1187 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1188
1189 for (i = 0; i < ngroups; i++) {
1190 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1191 if (!gdp)
1192 continue;
1193 count += ext4_used_dirs_count(sb, gdp);
1194 }
1195 return count;
1196}
1197
1198/*
1199 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1200 * inode table. Must be called without any spinlock held. The only place
1201 * where it is called from on active part of filesystem is ext4lazyinit
1202 * thread, so we do not need any special locks, however we have to prevent
1203 * inode allocation from the current group, so we take alloc_sem lock, to
1204 * block ext4_new_inode() until we are finished.
1205 */
1206int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1207 int barrier)
1208{
1209 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1210 struct ext4_sb_info *sbi = EXT4_SB(sb);
1211 struct ext4_group_desc *gdp = NULL;
1212 struct buffer_head *group_desc_bh;
1213 handle_t *handle;
1214 ext4_fsblk_t blk;
1215 int num, ret = 0, used_blks = 0;
1216
1217 /* This should not happen, but just to be sure check this */
1218 if (sb->s_flags & MS_RDONLY) {
1219 ret = 1;
1220 goto out;
1221 }
1222
1223 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1224 if (!gdp)
1225 goto out;
1226
1227 /*
1228 * We do not need to lock this, because we are the only one
1229 * handling this flag.
1230 */
1231 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1232 goto out;
1233
1234 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
1235 if (IS_ERR(handle)) {
1236 ret = PTR_ERR(handle);
1237 goto out;
1238 }
1239
1240 down_write(&grp->alloc_sem);
1241 /*
1242 * If inode bitmap was already initialized there may be some
1243 * used inodes so we need to skip blocks with used inodes in
1244 * inode table.
1245 */
1246 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
1247 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
1248 ext4_itable_unused_count(sb, gdp)),
1249 sbi->s_inodes_per_block);
1250
1251 if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) {
1252 ext4_error(sb, "Something is wrong with group %u: "
1253 "used itable blocks: %d; "
1254 "itable unused count: %u",
1255 group, used_blks,
1256 ext4_itable_unused_count(sb, gdp));
1257 ret = 1;
1258 goto err_out;
1259 }
1260
1261 blk = ext4_inode_table(sb, gdp) + used_blks;
1262 num = sbi->s_itb_per_group - used_blks;
1263
1264 BUFFER_TRACE(group_desc_bh, "get_write_access");
1265 ret = ext4_journal_get_write_access(handle,
1266 group_desc_bh);
1267 if (ret)
1268 goto err_out;
1269
1270 /*
1271 * Skip zeroout if the inode table is full. But we set the ZEROED
1272 * flag anyway, because obviously, when it is full it does not need
1273 * further zeroing.
1274 */
1275 if (unlikely(num == 0))
1276 goto skip_zeroout;
1277
1278 ext4_debug("going to zero out inode table in group %d\n",
1279 group);
1280 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1281 if (ret < 0)
1282 goto err_out;
1283 if (barrier)
1284 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1285
1286skip_zeroout:
1287 ext4_lock_group(sb, group);
1288 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1289 ext4_group_desc_csum_set(sb, group, gdp);
1290 ext4_unlock_group(sb, group);
1291
1292 BUFFER_TRACE(group_desc_bh,
1293 "call ext4_handle_dirty_metadata");
1294 ret = ext4_handle_dirty_metadata(handle, NULL,
1295 group_desc_bh);
1296
1297err_out:
1298 up_write(&grp->alloc_sem);
1299 ext4_journal_stop(handle);
1300out:
1301 return ret;
1302}