Merge branch '3.4-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target...
[deliverable/linux.git] / fs / ext4 / ialloc.c
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 */
53 void 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 */
68 static 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_sb_info *sbi = EXT4_SB(sb);
74
75 J_ASSERT_BH(bh, buffer_locked(bh));
76
77 /* If checksum is bad mark all blocks and inodes use to prevent
78 * allocation, essentially implementing a per-group read-only flag. */
79 if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
80 ext4_error(sb, "Checksum bad for group %u", block_group);
81 ext4_free_group_clusters_set(sb, gdp, 0);
82 ext4_free_inodes_set(sb, gdp, 0);
83 ext4_itable_unused_set(sb, gdp, 0);
84 memset(bh->b_data, 0xff, sb->s_blocksize);
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
92 return EXT4_INODES_PER_GROUP(sb);
93 }
94
95 void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
96 {
97 if (uptodate) {
98 set_buffer_uptodate(bh);
99 set_bitmap_uptodate(bh);
100 }
101 unlock_buffer(bh);
102 put_bh(bh);
103 }
104
105 /*
106 * Read the inode allocation bitmap for a given block_group, reading
107 * into the specified slot in the superblock's bitmap cache.
108 *
109 * Return buffer_head of bitmap on success or NULL.
110 */
111 static struct buffer_head *
112 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
113 {
114 struct ext4_group_desc *desc;
115 struct buffer_head *bh = NULL;
116 ext4_fsblk_t bitmap_blk;
117
118 desc = ext4_get_group_desc(sb, block_group, NULL);
119 if (!desc)
120 return NULL;
121
122 bitmap_blk = ext4_inode_bitmap(sb, desc);
123 bh = sb_getblk(sb, bitmap_blk);
124 if (unlikely(!bh)) {
125 ext4_error(sb, "Cannot read inode bitmap - "
126 "block_group = %u, inode_bitmap = %llu",
127 block_group, bitmap_blk);
128 return NULL;
129 }
130 if (bitmap_uptodate(bh))
131 return bh;
132
133 lock_buffer(bh);
134 if (bitmap_uptodate(bh)) {
135 unlock_buffer(bh);
136 return bh;
137 }
138
139 ext4_lock_group(sb, block_group);
140 if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
141 ext4_init_inode_bitmap(sb, bh, block_group, desc);
142 set_bitmap_uptodate(bh);
143 set_buffer_uptodate(bh);
144 ext4_unlock_group(sb, block_group);
145 unlock_buffer(bh);
146 return bh;
147 }
148 ext4_unlock_group(sb, block_group);
149
150 if (buffer_uptodate(bh)) {
151 /*
152 * if not uninit if bh is uptodate,
153 * bitmap is also uptodate
154 */
155 set_bitmap_uptodate(bh);
156 unlock_buffer(bh);
157 return bh;
158 }
159 /*
160 * submit the buffer_head for reading
161 */
162 trace_ext4_load_inode_bitmap(sb, block_group);
163 bh->b_end_io = ext4_end_bitmap_read;
164 get_bh(bh);
165 submit_bh(READ, bh);
166 wait_on_buffer(bh);
167 if (!buffer_uptodate(bh)) {
168 put_bh(bh);
169 ext4_error(sb, "Cannot read inode bitmap - "
170 "block_group = %u, inode_bitmap = %llu",
171 block_group, bitmap_blk);
172 return NULL;
173 }
174 return bh;
175 }
176
177 /*
178 * NOTE! When we get the inode, we're the only people
179 * that have access to it, and as such there are no
180 * race conditions we have to worry about. The inode
181 * is not on the hash-lists, and it cannot be reached
182 * through the filesystem because the directory entry
183 * has been deleted earlier.
184 *
185 * HOWEVER: we must make sure that we get no aliases,
186 * which means that we have to call "clear_inode()"
187 * _before_ we mark the inode not in use in the inode
188 * bitmaps. Otherwise a newly created file might use
189 * the same inode number (not actually the same pointer
190 * though), and then we'd have two inodes sharing the
191 * same inode number and space on the harddisk.
192 */
193 void ext4_free_inode(handle_t *handle, struct inode *inode)
194 {
195 struct super_block *sb = inode->i_sb;
196 int is_directory;
197 unsigned long ino;
198 struct buffer_head *bitmap_bh = NULL;
199 struct buffer_head *bh2;
200 ext4_group_t block_group;
201 unsigned long bit;
202 struct ext4_group_desc *gdp;
203 struct ext4_super_block *es;
204 struct ext4_sb_info *sbi;
205 int fatal = 0, err, count, cleared;
206
207 if (!sb) {
208 printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
209 "nonexistent device\n", __func__, __LINE__);
210 return;
211 }
212 if (atomic_read(&inode->i_count) > 1) {
213 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
214 __func__, __LINE__, inode->i_ino,
215 atomic_read(&inode->i_count));
216 return;
217 }
218 if (inode->i_nlink) {
219 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
220 __func__, __LINE__, inode->i_ino, inode->i_nlink);
221 return;
222 }
223 sbi = EXT4_SB(sb);
224
225 ino = inode->i_ino;
226 ext4_debug("freeing inode %lu\n", ino);
227 trace_ext4_free_inode(inode);
228
229 /*
230 * Note: we must free any quota before locking the superblock,
231 * as writing the quota to disk may need the lock as well.
232 */
233 dquot_initialize(inode);
234 ext4_xattr_delete_inode(handle, inode);
235 dquot_free_inode(inode);
236 dquot_drop(inode);
237
238 is_directory = S_ISDIR(inode->i_mode);
239
240 /* Do this BEFORE marking the inode not in use or returning an error */
241 ext4_clear_inode(inode);
242
243 es = EXT4_SB(sb)->s_es;
244 if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
245 ext4_error(sb, "reserved or nonexistent inode %lu", ino);
246 goto error_return;
247 }
248 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
249 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
250 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
251 if (!bitmap_bh)
252 goto error_return;
253
254 BUFFER_TRACE(bitmap_bh, "get_write_access");
255 fatal = ext4_journal_get_write_access(handle, bitmap_bh);
256 if (fatal)
257 goto error_return;
258
259 fatal = -ESRCH;
260 gdp = ext4_get_group_desc(sb, block_group, &bh2);
261 if (gdp) {
262 BUFFER_TRACE(bh2, "get_write_access");
263 fatal = ext4_journal_get_write_access(handle, bh2);
264 }
265 ext4_lock_group(sb, block_group);
266 cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
267 if (fatal || !cleared) {
268 ext4_unlock_group(sb, block_group);
269 goto out;
270 }
271
272 count = ext4_free_inodes_count(sb, gdp) + 1;
273 ext4_free_inodes_set(sb, gdp, count);
274 if (is_directory) {
275 count = ext4_used_dirs_count(sb, gdp) - 1;
276 ext4_used_dirs_set(sb, gdp, count);
277 percpu_counter_dec(&sbi->s_dirs_counter);
278 }
279 gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
280 ext4_unlock_group(sb, block_group);
281
282 percpu_counter_inc(&sbi->s_freeinodes_counter);
283 if (sbi->s_log_groups_per_flex) {
284 ext4_group_t f = ext4_flex_group(sbi, block_group);
285
286 atomic_inc(&sbi->s_flex_groups[f].free_inodes);
287 if (is_directory)
288 atomic_dec(&sbi->s_flex_groups[f].used_dirs);
289 }
290 BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
291 fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
292 out:
293 if (cleared) {
294 BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
295 err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
296 if (!fatal)
297 fatal = err;
298 ext4_mark_super_dirty(sb);
299 } else
300 ext4_error(sb, "bit already cleared for inode %lu", ino);
301
302 error_return:
303 brelse(bitmap_bh);
304 ext4_std_error(sb, fatal);
305 }
306
307 struct orlov_stats {
308 __u32 free_inodes;
309 __u32 free_clusters;
310 __u32 used_dirs;
311 };
312
313 /*
314 * Helper function for Orlov's allocator; returns critical information
315 * for a particular block group or flex_bg. If flex_size is 1, then g
316 * is a block group number; otherwise it is flex_bg number.
317 */
318 static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
319 int flex_size, struct orlov_stats *stats)
320 {
321 struct ext4_group_desc *desc;
322 struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups;
323
324 if (flex_size > 1) {
325 stats->free_inodes = atomic_read(&flex_group[g].free_inodes);
326 stats->free_clusters = atomic_read(&flex_group[g].free_clusters);
327 stats->used_dirs = atomic_read(&flex_group[g].used_dirs);
328 return;
329 }
330
331 desc = ext4_get_group_desc(sb, g, NULL);
332 if (desc) {
333 stats->free_inodes = ext4_free_inodes_count(sb, desc);
334 stats->free_clusters = ext4_free_group_clusters(sb, desc);
335 stats->used_dirs = ext4_used_dirs_count(sb, desc);
336 } else {
337 stats->free_inodes = 0;
338 stats->free_clusters = 0;
339 stats->used_dirs = 0;
340 }
341 }
342
343 /*
344 * Orlov's allocator for directories.
345 *
346 * We always try to spread first-level directories.
347 *
348 * If there are blockgroups with both free inodes and free blocks counts
349 * not worse than average we return one with smallest directory count.
350 * Otherwise we simply return a random group.
351 *
352 * For the rest rules look so:
353 *
354 * It's OK to put directory into a group unless
355 * it has too many directories already (max_dirs) or
356 * it has too few free inodes left (min_inodes) or
357 * it has too few free blocks left (min_blocks) or
358 * Parent's group is preferred, if it doesn't satisfy these
359 * conditions we search cyclically through the rest. If none
360 * of the groups look good we just look for a group with more
361 * free inodes than average (starting at parent's group).
362 */
363
364 static int find_group_orlov(struct super_block *sb, struct inode *parent,
365 ext4_group_t *group, umode_t mode,
366 const struct qstr *qstr)
367 {
368 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
369 struct ext4_sb_info *sbi = EXT4_SB(sb);
370 ext4_group_t real_ngroups = ext4_get_groups_count(sb);
371 int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
372 unsigned int freei, avefreei, grp_free;
373 ext4_fsblk_t freeb, avefreec;
374 unsigned int ndirs;
375 int max_dirs, min_inodes;
376 ext4_grpblk_t min_clusters;
377 ext4_group_t i, grp, g, ngroups;
378 struct ext4_group_desc *desc;
379 struct orlov_stats stats;
380 int flex_size = ext4_flex_bg_size(sbi);
381 struct dx_hash_info hinfo;
382
383 ngroups = real_ngroups;
384 if (flex_size > 1) {
385 ngroups = (real_ngroups + flex_size - 1) >>
386 sbi->s_log_groups_per_flex;
387 parent_group >>= sbi->s_log_groups_per_flex;
388 }
389
390 freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
391 avefreei = freei / ngroups;
392 freeb = EXT4_C2B(sbi,
393 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
394 avefreec = freeb;
395 do_div(avefreec, ngroups);
396 ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
397
398 if (S_ISDIR(mode) &&
399 ((parent == sb->s_root->d_inode) ||
400 (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
401 int best_ndir = inodes_per_group;
402 int ret = -1;
403
404 if (qstr) {
405 hinfo.hash_version = DX_HASH_HALF_MD4;
406 hinfo.seed = sbi->s_hash_seed;
407 ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
408 grp = hinfo.hash;
409 } else
410 get_random_bytes(&grp, sizeof(grp));
411 parent_group = (unsigned)grp % ngroups;
412 for (i = 0; i < ngroups; i++) {
413 g = (parent_group + i) % ngroups;
414 get_orlov_stats(sb, g, flex_size, &stats);
415 if (!stats.free_inodes)
416 continue;
417 if (stats.used_dirs >= best_ndir)
418 continue;
419 if (stats.free_inodes < avefreei)
420 continue;
421 if (stats.free_clusters < avefreec)
422 continue;
423 grp = g;
424 ret = 0;
425 best_ndir = stats.used_dirs;
426 }
427 if (ret)
428 goto fallback;
429 found_flex_bg:
430 if (flex_size == 1) {
431 *group = grp;
432 return 0;
433 }
434
435 /*
436 * We pack inodes at the beginning of the flexgroup's
437 * inode tables. Block allocation decisions will do
438 * something similar, although regular files will
439 * start at 2nd block group of the flexgroup. See
440 * ext4_ext_find_goal() and ext4_find_near().
441 */
442 grp *= flex_size;
443 for (i = 0; i < flex_size; i++) {
444 if (grp+i >= real_ngroups)
445 break;
446 desc = ext4_get_group_desc(sb, grp+i, NULL);
447 if (desc && ext4_free_inodes_count(sb, desc)) {
448 *group = grp+i;
449 return 0;
450 }
451 }
452 goto fallback;
453 }
454
455 max_dirs = ndirs / ngroups + inodes_per_group / 16;
456 min_inodes = avefreei - inodes_per_group*flex_size / 4;
457 if (min_inodes < 1)
458 min_inodes = 1;
459 min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;
460
461 /*
462 * Start looking in the flex group where we last allocated an
463 * inode for this parent directory
464 */
465 if (EXT4_I(parent)->i_last_alloc_group != ~0) {
466 parent_group = EXT4_I(parent)->i_last_alloc_group;
467 if (flex_size > 1)
468 parent_group >>= sbi->s_log_groups_per_flex;
469 }
470
471 for (i = 0; i < ngroups; i++) {
472 grp = (parent_group + i) % ngroups;
473 get_orlov_stats(sb, grp, flex_size, &stats);
474 if (stats.used_dirs >= max_dirs)
475 continue;
476 if (stats.free_inodes < min_inodes)
477 continue;
478 if (stats.free_clusters < min_clusters)
479 continue;
480 goto found_flex_bg;
481 }
482
483 fallback:
484 ngroups = real_ngroups;
485 avefreei = freei / ngroups;
486 fallback_retry:
487 parent_group = EXT4_I(parent)->i_block_group;
488 for (i = 0; i < ngroups; i++) {
489 grp = (parent_group + i) % ngroups;
490 desc = ext4_get_group_desc(sb, grp, NULL);
491 grp_free = ext4_free_inodes_count(sb, desc);
492 if (desc && grp_free && grp_free >= avefreei) {
493 *group = grp;
494 return 0;
495 }
496 }
497
498 if (avefreei) {
499 /*
500 * The free-inodes counter is approximate, and for really small
501 * filesystems the above test can fail to find any blockgroups
502 */
503 avefreei = 0;
504 goto fallback_retry;
505 }
506
507 return -1;
508 }
509
510 static int find_group_other(struct super_block *sb, struct inode *parent,
511 ext4_group_t *group, umode_t mode)
512 {
513 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
514 ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
515 struct ext4_group_desc *desc;
516 int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
517
518 /*
519 * Try to place the inode is the same flex group as its
520 * parent. If we can't find space, use the Orlov algorithm to
521 * find another flex group, and store that information in the
522 * parent directory's inode information so that use that flex
523 * group for future allocations.
524 */
525 if (flex_size > 1) {
526 int retry = 0;
527
528 try_again:
529 parent_group &= ~(flex_size-1);
530 last = parent_group + flex_size;
531 if (last > ngroups)
532 last = ngroups;
533 for (i = parent_group; i < last; i++) {
534 desc = ext4_get_group_desc(sb, i, NULL);
535 if (desc && ext4_free_inodes_count(sb, desc)) {
536 *group = i;
537 return 0;
538 }
539 }
540 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
541 retry = 1;
542 parent_group = EXT4_I(parent)->i_last_alloc_group;
543 goto try_again;
544 }
545 /*
546 * If this didn't work, use the Orlov search algorithm
547 * to find a new flex group; we pass in the mode to
548 * avoid the topdir algorithms.
549 */
550 *group = parent_group + flex_size;
551 if (*group > ngroups)
552 *group = 0;
553 return find_group_orlov(sb, parent, group, mode, NULL);
554 }
555
556 /*
557 * Try to place the inode in its parent directory
558 */
559 *group = parent_group;
560 desc = ext4_get_group_desc(sb, *group, NULL);
561 if (desc && ext4_free_inodes_count(sb, desc) &&
562 ext4_free_group_clusters(sb, desc))
563 return 0;
564
565 /*
566 * We're going to place this inode in a different blockgroup from its
567 * parent. We want to cause files in a common directory to all land in
568 * the same blockgroup. But we want files which are in a different
569 * directory which shares a blockgroup with our parent to land in a
570 * different blockgroup.
571 *
572 * So add our directory's i_ino into the starting point for the hash.
573 */
574 *group = (*group + parent->i_ino) % ngroups;
575
576 /*
577 * Use a quadratic hash to find a group with a free inode and some free
578 * blocks.
579 */
580 for (i = 1; i < ngroups; i <<= 1) {
581 *group += i;
582 if (*group >= ngroups)
583 *group -= ngroups;
584 desc = ext4_get_group_desc(sb, *group, NULL);
585 if (desc && ext4_free_inodes_count(sb, desc) &&
586 ext4_free_group_clusters(sb, desc))
587 return 0;
588 }
589
590 /*
591 * That failed: try linear search for a free inode, even if that group
592 * has no free blocks.
593 */
594 *group = parent_group;
595 for (i = 0; i < ngroups; i++) {
596 if (++*group >= ngroups)
597 *group = 0;
598 desc = ext4_get_group_desc(sb, *group, NULL);
599 if (desc && ext4_free_inodes_count(sb, desc))
600 return 0;
601 }
602
603 return -1;
604 }
605
606 /*
607 * There are two policies for allocating an inode. If the new inode is
608 * a directory, then a forward search is made for a block group with both
609 * free space and a low directory-to-inode ratio; if that fails, then of
610 * the groups with above-average free space, that group with the fewest
611 * directories already is chosen.
612 *
613 * For other inodes, search forward from the parent directory's block
614 * group to find a free inode.
615 */
616 struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, umode_t mode,
617 const struct qstr *qstr, __u32 goal, uid_t *owner)
618 {
619 struct super_block *sb;
620 struct buffer_head *inode_bitmap_bh = NULL;
621 struct buffer_head *group_desc_bh;
622 ext4_group_t ngroups, group = 0;
623 unsigned long ino = 0;
624 struct inode *inode;
625 struct ext4_group_desc *gdp = NULL;
626 struct ext4_inode_info *ei;
627 struct ext4_sb_info *sbi;
628 int ret2, err = 0;
629 struct inode *ret;
630 ext4_group_t i;
631 ext4_group_t flex_group;
632
633 /* Cannot create files in a deleted directory */
634 if (!dir || !dir->i_nlink)
635 return ERR_PTR(-EPERM);
636
637 sb = dir->i_sb;
638 ngroups = ext4_get_groups_count(sb);
639 trace_ext4_request_inode(dir, mode);
640 inode = new_inode(sb);
641 if (!inode)
642 return ERR_PTR(-ENOMEM);
643 ei = EXT4_I(inode);
644 sbi = EXT4_SB(sb);
645
646 if (!goal)
647 goal = sbi->s_inode_goal;
648
649 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
650 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
651 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
652 ret2 = 0;
653 goto got_group;
654 }
655
656 if (S_ISDIR(mode))
657 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
658 else
659 ret2 = find_group_other(sb, dir, &group, mode);
660
661 got_group:
662 EXT4_I(dir)->i_last_alloc_group = group;
663 err = -ENOSPC;
664 if (ret2 == -1)
665 goto out;
666
667 /*
668 * Normally we will only go through one pass of this loop,
669 * unless we get unlucky and it turns out the group we selected
670 * had its last inode grabbed by someone else.
671 */
672 for (i = 0; i < ngroups; i++, ino = 0) {
673 err = -EIO;
674
675 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
676 if (!gdp)
677 goto fail;
678
679 brelse(inode_bitmap_bh);
680 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
681 if (!inode_bitmap_bh)
682 goto fail;
683
684 repeat_in_this_group:
685 ino = ext4_find_next_zero_bit((unsigned long *)
686 inode_bitmap_bh->b_data,
687 EXT4_INODES_PER_GROUP(sb), ino);
688 if (ino >= EXT4_INODES_PER_GROUP(sb)) {
689 if (++group == ngroups)
690 group = 0;
691 continue;
692 }
693 if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) {
694 ext4_error(sb, "reserved inode found cleared - "
695 "inode=%lu", ino + 1);
696 continue;
697 }
698 ext4_lock_group(sb, group);
699 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
700 ext4_unlock_group(sb, group);
701 ino++; /* the inode bitmap is zero-based */
702 if (!ret2)
703 goto got; /* we grabbed the inode! */
704 if (ino < EXT4_INODES_PER_GROUP(sb))
705 goto repeat_in_this_group;
706 }
707 err = -ENOSPC;
708 goto out;
709
710 got:
711 /* We may have to initialize the block bitmap if it isn't already */
712 if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
713 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
714 struct buffer_head *block_bitmap_bh;
715
716 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
717 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
718 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
719 if (err) {
720 brelse(block_bitmap_bh);
721 goto fail;
722 }
723
724 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
725 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
726 brelse(block_bitmap_bh);
727
728 /* recheck and clear flag under lock if we still need to */
729 ext4_lock_group(sb, group);
730 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
731 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
732 ext4_free_group_clusters_set(sb, gdp,
733 ext4_free_clusters_after_init(sb, group, gdp));
734 gdp->bg_checksum = ext4_group_desc_csum(sbi, group,
735 gdp);
736 }
737 ext4_unlock_group(sb, group);
738
739 if (err)
740 goto fail;
741 }
742
743 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
744 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
745 if (err)
746 goto fail;
747
748 BUFFER_TRACE(group_desc_bh, "get_write_access");
749 err = ext4_journal_get_write_access(handle, group_desc_bh);
750 if (err)
751 goto fail;
752
753 /* Update the relevant bg descriptor fields */
754 if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
755 int free;
756 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
757
758 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
759 ext4_lock_group(sb, group); /* while we modify the bg desc */
760 free = EXT4_INODES_PER_GROUP(sb) -
761 ext4_itable_unused_count(sb, gdp);
762 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
763 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
764 free = 0;
765 }
766 /*
767 * Check the relative inode number against the last used
768 * relative inode number in this group. if it is greater
769 * we need to update the bg_itable_unused count
770 */
771 if (ino > free)
772 ext4_itable_unused_set(sb, gdp,
773 (EXT4_INODES_PER_GROUP(sb) - ino));
774 up_read(&grp->alloc_sem);
775 }
776 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
777 if (S_ISDIR(mode)) {
778 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
779 if (sbi->s_log_groups_per_flex) {
780 ext4_group_t f = ext4_flex_group(sbi, group);
781
782 atomic_inc(&sbi->s_flex_groups[f].used_dirs);
783 }
784 }
785 if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
786 gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
787 ext4_unlock_group(sb, group);
788 }
789
790 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
791 err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
792 if (err)
793 goto fail;
794
795 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
796 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
797 if (err)
798 goto fail;
799
800 percpu_counter_dec(&sbi->s_freeinodes_counter);
801 if (S_ISDIR(mode))
802 percpu_counter_inc(&sbi->s_dirs_counter);
803 ext4_mark_super_dirty(sb);
804
805 if (sbi->s_log_groups_per_flex) {
806 flex_group = ext4_flex_group(sbi, group);
807 atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes);
808 }
809 if (owner) {
810 inode->i_mode = mode;
811 inode->i_uid = owner[0];
812 inode->i_gid = owner[1];
813 } else if (test_opt(sb, GRPID)) {
814 inode->i_mode = mode;
815 inode->i_uid = current_fsuid();
816 inode->i_gid = dir->i_gid;
817 } else
818 inode_init_owner(inode, dir, mode);
819
820 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
821 /* This is the optimal IO size (for stat), not the fs block size */
822 inode->i_blocks = 0;
823 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
824 ext4_current_time(inode);
825
826 memset(ei->i_data, 0, sizeof(ei->i_data));
827 ei->i_dir_start_lookup = 0;
828 ei->i_disksize = 0;
829
830 /* Don't inherit extent flag from directory, amongst others. */
831 ei->i_flags =
832 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
833 ei->i_file_acl = 0;
834 ei->i_dtime = 0;
835 ei->i_block_group = group;
836 ei->i_last_alloc_group = ~0;
837
838 ext4_set_inode_flags(inode);
839 if (IS_DIRSYNC(inode))
840 ext4_handle_sync(handle);
841 if (insert_inode_locked(inode) < 0) {
842 /*
843 * Likely a bitmap corruption causing inode to be allocated
844 * twice.
845 */
846 err = -EIO;
847 goto fail;
848 }
849 spin_lock(&sbi->s_next_gen_lock);
850 inode->i_generation = sbi->s_next_generation++;
851 spin_unlock(&sbi->s_next_gen_lock);
852
853 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
854 ext4_set_inode_state(inode, EXT4_STATE_NEW);
855
856 ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
857
858 ret = inode;
859 dquot_initialize(inode);
860 err = dquot_alloc_inode(inode);
861 if (err)
862 goto fail_drop;
863
864 err = ext4_init_acl(handle, inode, dir);
865 if (err)
866 goto fail_free_drop;
867
868 err = ext4_init_security(handle, inode, dir, qstr);
869 if (err)
870 goto fail_free_drop;
871
872 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
873 /* set extent flag only for directory, file and normal symlink*/
874 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
875 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
876 ext4_ext_tree_init(handle, inode);
877 }
878 }
879
880 if (ext4_handle_valid(handle)) {
881 ei->i_sync_tid = handle->h_transaction->t_tid;
882 ei->i_datasync_tid = handle->h_transaction->t_tid;
883 }
884
885 err = ext4_mark_inode_dirty(handle, inode);
886 if (err) {
887 ext4_std_error(sb, err);
888 goto fail_free_drop;
889 }
890
891 ext4_debug("allocating inode %lu\n", inode->i_ino);
892 trace_ext4_allocate_inode(inode, dir, mode);
893 goto really_out;
894 fail:
895 ext4_std_error(sb, err);
896 out:
897 iput(inode);
898 ret = ERR_PTR(err);
899 really_out:
900 brelse(inode_bitmap_bh);
901 return ret;
902
903 fail_free_drop:
904 dquot_free_inode(inode);
905
906 fail_drop:
907 dquot_drop(inode);
908 inode->i_flags |= S_NOQUOTA;
909 clear_nlink(inode);
910 unlock_new_inode(inode);
911 iput(inode);
912 brelse(inode_bitmap_bh);
913 return ERR_PTR(err);
914 }
915
916 /* Verify that we are loading a valid orphan from disk */
917 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
918 {
919 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
920 ext4_group_t block_group;
921 int bit;
922 struct buffer_head *bitmap_bh;
923 struct inode *inode = NULL;
924 long err = -EIO;
925
926 /* Error cases - e2fsck has already cleaned up for us */
927 if (ino > max_ino) {
928 ext4_warning(sb, "bad orphan ino %lu! e2fsck was run?", ino);
929 goto error;
930 }
931
932 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
933 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
934 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
935 if (!bitmap_bh) {
936 ext4_warning(sb, "inode bitmap error for orphan %lu", ino);
937 goto error;
938 }
939
940 /* Having the inode bit set should be a 100% indicator that this
941 * is a valid orphan (no e2fsck run on fs). Orphans also include
942 * inodes that were being truncated, so we can't check i_nlink==0.
943 */
944 if (!ext4_test_bit(bit, bitmap_bh->b_data))
945 goto bad_orphan;
946
947 inode = ext4_iget(sb, ino);
948 if (IS_ERR(inode))
949 goto iget_failed;
950
951 /*
952 * If the orphans has i_nlinks > 0 then it should be able to be
953 * truncated, otherwise it won't be removed from the orphan list
954 * during processing and an infinite loop will result.
955 */
956 if (inode->i_nlink && !ext4_can_truncate(inode))
957 goto bad_orphan;
958
959 if (NEXT_ORPHAN(inode) > max_ino)
960 goto bad_orphan;
961 brelse(bitmap_bh);
962 return inode;
963
964 iget_failed:
965 err = PTR_ERR(inode);
966 inode = NULL;
967 bad_orphan:
968 ext4_warning(sb, "bad orphan inode %lu! e2fsck was run?", ino);
969 printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n",
970 bit, (unsigned long long)bitmap_bh->b_blocknr,
971 ext4_test_bit(bit, bitmap_bh->b_data));
972 printk(KERN_NOTICE "inode=%p\n", inode);
973 if (inode) {
974 printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
975 is_bad_inode(inode));
976 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
977 NEXT_ORPHAN(inode));
978 printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
979 printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink);
980 /* Avoid freeing blocks if we got a bad deleted inode */
981 if (inode->i_nlink == 0)
982 inode->i_blocks = 0;
983 iput(inode);
984 }
985 brelse(bitmap_bh);
986 error:
987 return ERR_PTR(err);
988 }
989
990 unsigned long ext4_count_free_inodes(struct super_block *sb)
991 {
992 unsigned long desc_count;
993 struct ext4_group_desc *gdp;
994 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
995 #ifdef EXT4FS_DEBUG
996 struct ext4_super_block *es;
997 unsigned long bitmap_count, x;
998 struct buffer_head *bitmap_bh = NULL;
999
1000 es = EXT4_SB(sb)->s_es;
1001 desc_count = 0;
1002 bitmap_count = 0;
1003 gdp = NULL;
1004 for (i = 0; i < ngroups; i++) {
1005 gdp = ext4_get_group_desc(sb, i, NULL);
1006 if (!gdp)
1007 continue;
1008 desc_count += ext4_free_inodes_count(sb, gdp);
1009 brelse(bitmap_bh);
1010 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1011 if (!bitmap_bh)
1012 continue;
1013
1014 x = ext4_count_free(bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8);
1015 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1016 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1017 bitmap_count += x;
1018 }
1019 brelse(bitmap_bh);
1020 printk(KERN_DEBUG "ext4_count_free_inodes: "
1021 "stored = %u, computed = %lu, %lu\n",
1022 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1023 return desc_count;
1024 #else
1025 desc_count = 0;
1026 for (i = 0; i < ngroups; i++) {
1027 gdp = ext4_get_group_desc(sb, i, NULL);
1028 if (!gdp)
1029 continue;
1030 desc_count += ext4_free_inodes_count(sb, gdp);
1031 cond_resched();
1032 }
1033 return desc_count;
1034 #endif
1035 }
1036
1037 /* Called at mount-time, super-block is locked */
1038 unsigned long ext4_count_dirs(struct super_block * sb)
1039 {
1040 unsigned long count = 0;
1041 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1042
1043 for (i = 0; i < ngroups; i++) {
1044 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1045 if (!gdp)
1046 continue;
1047 count += ext4_used_dirs_count(sb, gdp);
1048 }
1049 return count;
1050 }
1051
1052 /*
1053 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1054 * inode table. Must be called without any spinlock held. The only place
1055 * where it is called from on active part of filesystem is ext4lazyinit
1056 * thread, so we do not need any special locks, however we have to prevent
1057 * inode allocation from the current group, so we take alloc_sem lock, to
1058 * block ext4_new_inode() until we are finished.
1059 */
1060 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1061 int barrier)
1062 {
1063 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1064 struct ext4_sb_info *sbi = EXT4_SB(sb);
1065 struct ext4_group_desc *gdp = NULL;
1066 struct buffer_head *group_desc_bh;
1067 handle_t *handle;
1068 ext4_fsblk_t blk;
1069 int num, ret = 0, used_blks = 0;
1070
1071 /* This should not happen, but just to be sure check this */
1072 if (sb->s_flags & MS_RDONLY) {
1073 ret = 1;
1074 goto out;
1075 }
1076
1077 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1078 if (!gdp)
1079 goto out;
1080
1081 /*
1082 * We do not need to lock this, because we are the only one
1083 * handling this flag.
1084 */
1085 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1086 goto out;
1087
1088 handle = ext4_journal_start_sb(sb, 1);
1089 if (IS_ERR(handle)) {
1090 ret = PTR_ERR(handle);
1091 goto out;
1092 }
1093
1094 down_write(&grp->alloc_sem);
1095 /*
1096 * If inode bitmap was already initialized there may be some
1097 * used inodes so we need to skip blocks with used inodes in
1098 * inode table.
1099 */
1100 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
1101 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
1102 ext4_itable_unused_count(sb, gdp)),
1103 sbi->s_inodes_per_block);
1104
1105 if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) {
1106 ext4_error(sb, "Something is wrong with group %u: "
1107 "used itable blocks: %d; "
1108 "itable unused count: %u",
1109 group, used_blks,
1110 ext4_itable_unused_count(sb, gdp));
1111 ret = 1;
1112 goto err_out;
1113 }
1114
1115 blk = ext4_inode_table(sb, gdp) + used_blks;
1116 num = sbi->s_itb_per_group - used_blks;
1117
1118 BUFFER_TRACE(group_desc_bh, "get_write_access");
1119 ret = ext4_journal_get_write_access(handle,
1120 group_desc_bh);
1121 if (ret)
1122 goto err_out;
1123
1124 /*
1125 * Skip zeroout if the inode table is full. But we set the ZEROED
1126 * flag anyway, because obviously, when it is full it does not need
1127 * further zeroing.
1128 */
1129 if (unlikely(num == 0))
1130 goto skip_zeroout;
1131
1132 ext4_debug("going to zero out inode table in group %d\n",
1133 group);
1134 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1135 if (ret < 0)
1136 goto err_out;
1137 if (barrier)
1138 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1139
1140 skip_zeroout:
1141 ext4_lock_group(sb, group);
1142 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1143 gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
1144 ext4_unlock_group(sb, group);
1145
1146 BUFFER_TRACE(group_desc_bh,
1147 "call ext4_handle_dirty_metadata");
1148 ret = ext4_handle_dirty_metadata(handle, NULL,
1149 group_desc_bh);
1150
1151 err_out:
1152 up_write(&grp->alloc_sem);
1153 ext4_journal_stop(handle);
1154 out:
1155 return ret;
1156 }
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