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 */
ext4_mark_bitmap_end(int start_bit,int end_bit,char * bitmap)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 */
ext4_init_inode_bitmap(struct super_block * sb,struct buffer_head * bh,ext4_group_t block_group,struct ext4_group_desc * gdp)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
ext4_end_bitmap_read(struct buffer_head * bh,int uptodate)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 *
ext4_read_inode_bitmap(struct super_block * sb,ext4_group_t block_group)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 */
ext4_free_inode(handle_t * handle,struct inode * inode)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 __u64 free_clusters;
309 __u32 free_inodes;
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 */
get_orlov_stats(struct super_block * sb,ext4_group_t g,int flex_size,struct orlov_stats * stats)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 = atomic64_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
find_group_orlov(struct super_block * sb,struct inode * parent,ext4_group_t * group,umode_t mode,const struct qstr * qstr)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 if (desc) {
492 grp_free = ext4_free_inodes_count(sb, desc);
493 if (grp_free && grp_free >= avefreei) {
494 *group = grp;
495 return 0;
496 }
497 }
498 }
499
500 if (avefreei) {
501 /*
502 * The free-inodes counter is approximate, and for really small
503 * filesystems the above test can fail to find any blockgroups
504 */
505 avefreei = 0;
506 goto fallback_retry;
507 }
508
509 return -1;
510 }
511
find_group_other(struct super_block * sb,struct inode * parent,ext4_group_t * group,umode_t mode)512 static int find_group_other(struct super_block *sb, struct inode *parent,
513 ext4_group_t *group, umode_t mode)
514 {
515 ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
516 ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
517 struct ext4_group_desc *desc;
518 int flex_size = ext4_flex_bg_size(EXT4_SB(sb));
519
520 /*
521 * Try to place the inode is the same flex group as its
522 * parent. If we can't find space, use the Orlov algorithm to
523 * find another flex group, and store that information in the
524 * parent directory's inode information so that use that flex
525 * group for future allocations.
526 */
527 if (flex_size > 1) {
528 int retry = 0;
529
530 try_again:
531 parent_group &= ~(flex_size-1);
532 last = parent_group + flex_size;
533 if (last > ngroups)
534 last = ngroups;
535 for (i = parent_group; i < last; i++) {
536 desc = ext4_get_group_desc(sb, i, NULL);
537 if (desc && ext4_free_inodes_count(sb, desc)) {
538 *group = i;
539 return 0;
540 }
541 }
542 if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
543 retry = 1;
544 parent_group = EXT4_I(parent)->i_last_alloc_group;
545 goto try_again;
546 }
547 /*
548 * If this didn't work, use the Orlov search algorithm
549 * to find a new flex group; we pass in the mode to
550 * avoid the topdir algorithms.
551 */
552 *group = parent_group + flex_size;
553 if (*group > ngroups)
554 *group = 0;
555 return find_group_orlov(sb, parent, group, mode, NULL);
556 }
557
558 /*
559 * Try to place the inode in its parent directory
560 */
561 *group = parent_group;
562 desc = ext4_get_group_desc(sb, *group, NULL);
563 if (desc && ext4_free_inodes_count(sb, desc) &&
564 ext4_free_group_clusters(sb, desc))
565 return 0;
566
567 /*
568 * We're going to place this inode in a different blockgroup from its
569 * parent. We want to cause files in a common directory to all land in
570 * the same blockgroup. But we want files which are in a different
571 * directory which shares a blockgroup with our parent to land in a
572 * different blockgroup.
573 *
574 * So add our directory's i_ino into the starting point for the hash.
575 */
576 *group = (*group + parent->i_ino) % ngroups;
577
578 /*
579 * Use a quadratic hash to find a group with a free inode and some free
580 * blocks.
581 */
582 for (i = 1; i < ngroups; i <<= 1) {
583 *group += i;
584 if (*group >= ngroups)
585 *group -= ngroups;
586 desc = ext4_get_group_desc(sb, *group, NULL);
587 if (desc && ext4_free_inodes_count(sb, desc) &&
588 ext4_free_group_clusters(sb, desc))
589 return 0;
590 }
591
592 /*
593 * That failed: try linear search for a free inode, even if that group
594 * has no free blocks.
595 */
596 *group = parent_group;
597 for (i = 0; i < ngroups; i++) {
598 if (++*group >= ngroups)
599 *group = 0;
600 desc = ext4_get_group_desc(sb, *group, NULL);
601 if (desc && ext4_free_inodes_count(sb, desc))
602 return 0;
603 }
604
605 return -1;
606 }
607
608 /*
609 * There are two policies for allocating an inode. If the new inode is
610 * a directory, then a forward search is made for a block group with both
611 * free space and a low directory-to-inode ratio; if that fails, then of
612 * the groups with above-average free space, that group with the fewest
613 * directories already is chosen.
614 *
615 * For other inodes, search forward from the parent directory's block
616 * group to find a free inode.
617 */
ext4_new_inode(handle_t * handle,struct inode * dir,umode_t mode,const struct qstr * qstr,__u32 goal,uid_t * owner)618 struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, umode_t mode,
619 const struct qstr *qstr, __u32 goal, uid_t *owner)
620 {
621 struct super_block *sb;
622 struct buffer_head *inode_bitmap_bh = NULL;
623 struct buffer_head *group_desc_bh;
624 ext4_group_t ngroups, group = 0;
625 unsigned long ino = 0;
626 struct inode *inode;
627 struct ext4_group_desc *gdp = NULL;
628 struct ext4_inode_info *ei;
629 struct ext4_sb_info *sbi;
630 int ret2, err = 0;
631 struct inode *ret;
632 ext4_group_t i;
633 ext4_group_t flex_group;
634
635 /* Cannot create files in a deleted directory */
636 if (!dir || !dir->i_nlink)
637 return ERR_PTR(-EPERM);
638
639 sb = dir->i_sb;
640 ngroups = ext4_get_groups_count(sb);
641 trace_ext4_request_inode(dir, mode);
642 inode = new_inode(sb);
643 if (!inode)
644 return ERR_PTR(-ENOMEM);
645 ei = EXT4_I(inode);
646 sbi = EXT4_SB(sb);
647
648 if (!goal)
649 goal = sbi->s_inode_goal;
650
651 if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {
652 group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);
653 ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);
654 ret2 = 0;
655 goto got_group;
656 }
657
658 if (S_ISDIR(mode))
659 ret2 = find_group_orlov(sb, dir, &group, mode, qstr);
660 else
661 ret2 = find_group_other(sb, dir, &group, mode);
662
663 got_group:
664 EXT4_I(dir)->i_last_alloc_group = group;
665 err = -ENOSPC;
666 if (ret2 == -1)
667 goto out;
668
669 /*
670 * Normally we will only go through one pass of this loop,
671 * unless we get unlucky and it turns out the group we selected
672 * had its last inode grabbed by someone else.
673 */
674 for (i = 0; i < ngroups; i++, ino = 0) {
675 err = -EIO;
676
677 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
678 if (!gdp)
679 goto fail;
680
681 brelse(inode_bitmap_bh);
682 inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
683 if (!inode_bitmap_bh)
684 goto fail;
685
686 repeat_in_this_group:
687 ino = ext4_find_next_zero_bit((unsigned long *)
688 inode_bitmap_bh->b_data,
689 EXT4_INODES_PER_GROUP(sb), ino);
690 if (ino >= EXT4_INODES_PER_GROUP(sb))
691 goto next_group;
692 if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) {
693 ext4_error(sb, "reserved inode found cleared - "
694 "inode=%lu", ino + 1);
695 continue;
696 }
697 BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
698 err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
699 if (err)
700 goto fail;
701 ext4_lock_group(sb, group);
702 ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
703 ext4_unlock_group(sb, group);
704 ino++; /* the inode bitmap is zero-based */
705 if (!ret2)
706 goto got; /* we grabbed the inode! */
707 if (ino < EXT4_INODES_PER_GROUP(sb))
708 goto repeat_in_this_group;
709 next_group:
710 if (++group == ngroups)
711 group = 0;
712 }
713 err = -ENOSPC;
714 goto out;
715
716 got:
717 BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
718 err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
719 if (err)
720 goto fail;
721
722 /* We may have to initialize the block bitmap if it isn't already */
723 if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
724 gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
725 struct buffer_head *block_bitmap_bh;
726
727 block_bitmap_bh = ext4_read_block_bitmap(sb, group);
728 BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
729 err = ext4_journal_get_write_access(handle, block_bitmap_bh);
730 if (err) {
731 brelse(block_bitmap_bh);
732 goto fail;
733 }
734
735 BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
736 err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);
737
738 /* recheck and clear flag under lock if we still need to */
739 ext4_lock_group(sb, group);
740 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
741 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
742 ext4_free_group_clusters_set(sb, gdp,
743 ext4_free_clusters_after_init(sb, group, gdp));
744 gdp->bg_checksum = ext4_group_desc_csum(sbi, group,
745 gdp);
746 }
747 ext4_unlock_group(sb, group);
748 brelse(block_bitmap_bh);
749
750 if (err)
751 goto fail;
752 }
753
754 BUFFER_TRACE(group_desc_bh, "get_write_access");
755 err = ext4_journal_get_write_access(handle, group_desc_bh);
756 if (err)
757 goto fail;
758
759 /* Update the relevant bg descriptor fields */
760 if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
761 int free;
762 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
763
764 down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
765 ext4_lock_group(sb, group); /* while we modify the bg desc */
766 free = EXT4_INODES_PER_GROUP(sb) -
767 ext4_itable_unused_count(sb, gdp);
768 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
769 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
770 free = 0;
771 }
772 /*
773 * Check the relative inode number against the last used
774 * relative inode number in this group. if it is greater
775 * we need to update the bg_itable_unused count
776 */
777 if (ino > free)
778 ext4_itable_unused_set(sb, gdp,
779 (EXT4_INODES_PER_GROUP(sb) - ino));
780 up_read(&grp->alloc_sem);
781 } else {
782 ext4_lock_group(sb, group);
783 }
784
785 ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
786 if (S_ISDIR(mode)) {
787 ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
788 if (sbi->s_log_groups_per_flex) {
789 ext4_group_t f = ext4_flex_group(sbi, group);
790
791 atomic_inc(&sbi->s_flex_groups[f].used_dirs);
792 }
793 }
794 if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
795 gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
796 }
797 ext4_unlock_group(sb, group);
798
799 BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
800 err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
801 if (err)
802 goto fail;
803
804 percpu_counter_dec(&sbi->s_freeinodes_counter);
805 if (S_ISDIR(mode))
806 percpu_counter_inc(&sbi->s_dirs_counter);
807 ext4_mark_super_dirty(sb);
808
809 if (sbi->s_log_groups_per_flex) {
810 flex_group = ext4_flex_group(sbi, group);
811 atomic_dec(&sbi->s_flex_groups[flex_group].free_inodes);
812 }
813 if (owner) {
814 inode->i_mode = mode;
815 inode->i_uid = owner[0];
816 inode->i_gid = owner[1];
817 } else if (test_opt(sb, GRPID)) {
818 inode->i_mode = mode;
819 inode->i_uid = current_fsuid();
820 inode->i_gid = dir->i_gid;
821 } else
822 inode_init_owner(inode, dir, mode);
823
824 inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);
825 /* This is the optimal IO size (for stat), not the fs block size */
826 inode->i_blocks = 0;
827 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
828 ext4_current_time(inode);
829
830 memset(ei->i_data, 0, sizeof(ei->i_data));
831 ei->i_dir_start_lookup = 0;
832 ei->i_disksize = 0;
833
834 /* Don't inherit extent flag from directory, amongst others. */
835 ei->i_flags =
836 ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
837 ei->i_file_acl = 0;
838 ei->i_dtime = 0;
839 ei->i_block_group = group;
840 ei->i_last_alloc_group = ~0;
841
842 ext4_set_inode_flags(inode);
843 if (IS_DIRSYNC(inode))
844 ext4_handle_sync(handle);
845 if (insert_inode_locked(inode) < 0) {
846 /*
847 * Likely a bitmap corruption causing inode to be allocated
848 * twice.
849 */
850 err = -EIO;
851 goto fail;
852 }
853 spin_lock(&sbi->s_next_gen_lock);
854 inode->i_generation = sbi->s_next_generation++;
855 spin_unlock(&sbi->s_next_gen_lock);
856
857 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
858 ext4_set_inode_state(inode, EXT4_STATE_NEW);
859
860 ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
861
862 ret = inode;
863 dquot_initialize(inode);
864 err = dquot_alloc_inode(inode);
865 if (err)
866 goto fail_drop;
867
868 err = ext4_init_acl(handle, inode, dir);
869 if (err)
870 goto fail_free_drop;
871
872 err = ext4_init_security(handle, inode, dir, qstr);
873 if (err)
874 goto fail_free_drop;
875
876 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
877 /* set extent flag only for directory, file and normal symlink*/
878 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
879 ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
880 ext4_ext_tree_init(handle, inode);
881 }
882 }
883
884 if (ext4_handle_valid(handle)) {
885 ei->i_sync_tid = handle->h_transaction->t_tid;
886 ei->i_datasync_tid = handle->h_transaction->t_tid;
887 }
888
889 err = ext4_mark_inode_dirty(handle, inode);
890 if (err) {
891 ext4_std_error(sb, err);
892 goto fail_free_drop;
893 }
894
895 ext4_debug("allocating inode %lu\n", inode->i_ino);
896 trace_ext4_allocate_inode(inode, dir, mode);
897 goto really_out;
898 fail:
899 ext4_std_error(sb, err);
900 out:
901 iput(inode);
902 ret = ERR_PTR(err);
903 really_out:
904 brelse(inode_bitmap_bh);
905 return ret;
906
907 fail_free_drop:
908 dquot_free_inode(inode);
909
910 fail_drop:
911 dquot_drop(inode);
912 inode->i_flags |= S_NOQUOTA;
913 clear_nlink(inode);
914 unlock_new_inode(inode);
915 iput(inode);
916 brelse(inode_bitmap_bh);
917 return ERR_PTR(err);
918 }
919
920 /* Verify that we are loading a valid orphan from disk */
ext4_orphan_get(struct super_block * sb,unsigned long ino)921 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
922 {
923 unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
924 ext4_group_t block_group;
925 int bit;
926 struct buffer_head *bitmap_bh;
927 struct inode *inode = NULL;
928 long err = -EIO;
929
930 /* Error cases - e2fsck has already cleaned up for us */
931 if (ino > max_ino) {
932 ext4_warning(sb, "bad orphan ino %lu! e2fsck was run?", ino);
933 goto error;
934 }
935
936 block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
937 bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
938 bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
939 if (!bitmap_bh) {
940 ext4_warning(sb, "inode bitmap error for orphan %lu", ino);
941 goto error;
942 }
943
944 /* Having the inode bit set should be a 100% indicator that this
945 * is a valid orphan (no e2fsck run on fs). Orphans also include
946 * inodes that were being truncated, so we can't check i_nlink==0.
947 */
948 if (!ext4_test_bit(bit, bitmap_bh->b_data))
949 goto bad_orphan;
950
951 inode = ext4_iget(sb, ino);
952 if (IS_ERR(inode))
953 goto iget_failed;
954
955 /*
956 * If the orphans has i_nlinks > 0 then it should be able to be
957 * truncated, otherwise it won't be removed from the orphan list
958 * during processing and an infinite loop will result.
959 */
960 if (inode->i_nlink && !ext4_can_truncate(inode))
961 goto bad_orphan;
962
963 if (NEXT_ORPHAN(inode) > max_ino)
964 goto bad_orphan;
965 brelse(bitmap_bh);
966 return inode;
967
968 iget_failed:
969 err = PTR_ERR(inode);
970 inode = NULL;
971 bad_orphan:
972 ext4_warning(sb, "bad orphan inode %lu! e2fsck was run?", ino);
973 printk(KERN_NOTICE "ext4_test_bit(bit=%d, block=%llu) = %d\n",
974 bit, (unsigned long long)bitmap_bh->b_blocknr,
975 ext4_test_bit(bit, bitmap_bh->b_data));
976 printk(KERN_NOTICE "inode=%p\n", inode);
977 if (inode) {
978 printk(KERN_NOTICE "is_bad_inode(inode)=%d\n",
979 is_bad_inode(inode));
980 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
981 NEXT_ORPHAN(inode));
982 printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
983 printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink);
984 /* Avoid freeing blocks if we got a bad deleted inode */
985 if (inode->i_nlink == 0)
986 inode->i_blocks = 0;
987 iput(inode);
988 }
989 brelse(bitmap_bh);
990 error:
991 return ERR_PTR(err);
992 }
993
ext4_count_free_inodes(struct super_block * sb)994 unsigned long ext4_count_free_inodes(struct super_block *sb)
995 {
996 unsigned long desc_count;
997 struct ext4_group_desc *gdp;
998 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
999 #ifdef EXT4FS_DEBUG
1000 struct ext4_super_block *es;
1001 unsigned long bitmap_count, x;
1002 struct buffer_head *bitmap_bh = NULL;
1003
1004 es = EXT4_SB(sb)->s_es;
1005 desc_count = 0;
1006 bitmap_count = 0;
1007 gdp = NULL;
1008 for (i = 0; i < ngroups; i++) {
1009 gdp = ext4_get_group_desc(sb, i, NULL);
1010 if (!gdp)
1011 continue;
1012 desc_count += ext4_free_inodes_count(sb, gdp);
1013 brelse(bitmap_bh);
1014 bitmap_bh = ext4_read_inode_bitmap(sb, i);
1015 if (!bitmap_bh)
1016 continue;
1017
1018 x = ext4_count_free(bitmap_bh->b_data,
1019 EXT4_INODES_PER_GROUP(sb) / 8);
1020 printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
1021 (unsigned long) i, ext4_free_inodes_count(sb, gdp), x);
1022 bitmap_count += x;
1023 }
1024 brelse(bitmap_bh);
1025 printk(KERN_DEBUG "ext4_count_free_inodes: "
1026 "stored = %u, computed = %lu, %lu\n",
1027 le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
1028 return desc_count;
1029 #else
1030 desc_count = 0;
1031 for (i = 0; i < ngroups; i++) {
1032 gdp = ext4_get_group_desc(sb, i, NULL);
1033 if (!gdp)
1034 continue;
1035 desc_count += ext4_free_inodes_count(sb, gdp);
1036 cond_resched();
1037 }
1038 return desc_count;
1039 #endif
1040 }
1041
1042 /* Called at mount-time, super-block is locked */
ext4_count_dirs(struct super_block * sb)1043 unsigned long ext4_count_dirs(struct super_block * sb)
1044 {
1045 unsigned long count = 0;
1046 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
1047
1048 for (i = 0; i < ngroups; i++) {
1049 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1050 if (!gdp)
1051 continue;
1052 count += ext4_used_dirs_count(sb, gdp);
1053 }
1054 return count;
1055 }
1056
1057 /*
1058 * Zeroes not yet zeroed inode table - just write zeroes through the whole
1059 * inode table. Must be called without any spinlock held. The only place
1060 * where it is called from on active part of filesystem is ext4lazyinit
1061 * thread, so we do not need any special locks, however we have to prevent
1062 * inode allocation from the current group, so we take alloc_sem lock, to
1063 * block ext4_new_inode() until we are finished.
1064 */
ext4_init_inode_table(struct super_block * sb,ext4_group_t group,int barrier)1065 int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
1066 int barrier)
1067 {
1068 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1069 struct ext4_sb_info *sbi = EXT4_SB(sb);
1070 struct ext4_group_desc *gdp = NULL;
1071 struct buffer_head *group_desc_bh;
1072 handle_t *handle;
1073 ext4_fsblk_t blk;
1074 int num, ret = 0, used_blks = 0;
1075
1076 /* This should not happen, but just to be sure check this */
1077 if (sb->s_flags & MS_RDONLY) {
1078 ret = 1;
1079 goto out;
1080 }
1081
1082 gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
1083 if (!gdp)
1084 goto out;
1085
1086 /*
1087 * We do not need to lock this, because we are the only one
1088 * handling this flag.
1089 */
1090 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
1091 goto out;
1092
1093 handle = ext4_journal_start_sb(sb, 1);
1094 if (IS_ERR(handle)) {
1095 ret = PTR_ERR(handle);
1096 goto out;
1097 }
1098
1099 down_write(&grp->alloc_sem);
1100 /*
1101 * If inode bitmap was already initialized there may be some
1102 * used inodes so we need to skip blocks with used inodes in
1103 * inode table.
1104 */
1105 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)))
1106 used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) -
1107 ext4_itable_unused_count(sb, gdp)),
1108 sbi->s_inodes_per_block);
1109
1110 if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) {
1111 ext4_error(sb, "Something is wrong with group %u: "
1112 "used itable blocks: %d; "
1113 "itable unused count: %u",
1114 group, used_blks,
1115 ext4_itable_unused_count(sb, gdp));
1116 ret = 1;
1117 goto err_out;
1118 }
1119
1120 blk = ext4_inode_table(sb, gdp) + used_blks;
1121 num = sbi->s_itb_per_group - used_blks;
1122
1123 BUFFER_TRACE(group_desc_bh, "get_write_access");
1124 ret = ext4_journal_get_write_access(handle,
1125 group_desc_bh);
1126 if (ret)
1127 goto err_out;
1128
1129 /*
1130 * Skip zeroout if the inode table is full. But we set the ZEROED
1131 * flag anyway, because obviously, when it is full it does not need
1132 * further zeroing.
1133 */
1134 if (unlikely(num == 0))
1135 goto skip_zeroout;
1136
1137 ext4_debug("going to zero out inode table in group %d\n",
1138 group);
1139 ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);
1140 if (ret < 0)
1141 goto err_out;
1142 if (barrier)
1143 blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
1144
1145 skip_zeroout:
1146 ext4_lock_group(sb, group);
1147 gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
1148 gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
1149 ext4_unlock_group(sb, group);
1150
1151 BUFFER_TRACE(group_desc_bh,
1152 "call ext4_handle_dirty_metadata");
1153 ret = ext4_handle_dirty_metadata(handle, NULL,
1154 group_desc_bh);
1155
1156 err_out:
1157 up_write(&grp->alloc_sem);
1158 ext4_journal_stop(handle);
1159 out:
1160 return ret;
1161 }
1162