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15#include "ext2.h"
16#include <linux/quotaops.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/cred.h>
20#include <linux/buffer_head.h>
21#include <linux/capability.h>
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38
39#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
40
41struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
42 unsigned int block_group,
43 struct buffer_head ** bh)
44{
45 unsigned long group_desc;
46 unsigned long offset;
47 struct ext2_group_desc * desc;
48 struct ext2_sb_info *sbi = EXT2_SB(sb);
49
50 if (block_group >= sbi->s_groups_count) {
51 WARN(1, "block_group >= groups_count - "
52 "block_group = %d, groups_count = %lu",
53 block_group, sbi->s_groups_count);
54
55 return NULL;
56 }
57
58 group_desc = block_group >> EXT2_DESC_PER_BLOCK_BITS(sb);
59 offset = block_group & (EXT2_DESC_PER_BLOCK(sb) - 1);
60 if (!sbi->s_group_desc[group_desc]) {
61 WARN(1, "Group descriptor not loaded - "
62 "block_group = %d, group_desc = %lu, desc = %lu",
63 block_group, group_desc, offset);
64 return NULL;
65 }
66
67 desc = (struct ext2_group_desc *) sbi->s_group_desc[group_desc]->b_data;
68 if (bh)
69 *bh = sbi->s_group_desc[group_desc];
70 return desc + offset;
71}
72
73static int ext2_valid_block_bitmap(struct super_block *sb,
74 struct ext2_group_desc *desc,
75 unsigned int block_group,
76 struct buffer_head *bh)
77{
78 ext2_grpblk_t offset;
79 ext2_grpblk_t next_zero_bit;
80 ext2_fsblk_t bitmap_blk;
81 ext2_fsblk_t group_first_block;
82
83 group_first_block = ext2_group_first_block_no(sb, block_group);
84
85
86 bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
87 offset = bitmap_blk - group_first_block;
88 if (!ext2_test_bit(offset, bh->b_data))
89
90 goto err_out;
91
92
93 bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
94 offset = bitmap_blk - group_first_block;
95 if (!ext2_test_bit(offset, bh->b_data))
96
97 goto err_out;
98
99
100 bitmap_blk = le32_to_cpu(desc->bg_inode_table);
101 offset = bitmap_blk - group_first_block;
102 next_zero_bit = ext2_find_next_zero_bit(bh->b_data,
103 offset + EXT2_SB(sb)->s_itb_per_group,
104 offset);
105 if (next_zero_bit >= offset + EXT2_SB(sb)->s_itb_per_group)
106
107 return 1;
108
109err_out:
110 ext2_error(sb, __func__,
111 "Invalid block bitmap - "
112 "block_group = %d, block = %lu",
113 block_group, bitmap_blk);
114 return 0;
115}
116
117
118
119
120
121
122
123static struct buffer_head *
124read_block_bitmap(struct super_block *sb, unsigned int block_group)
125{
126 struct ext2_group_desc * desc;
127 struct buffer_head * bh = NULL;
128 ext2_fsblk_t bitmap_blk;
129
130 desc = ext2_get_group_desc(sb, block_group, NULL);
131 if (!desc)
132 return NULL;
133 bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
134 bh = sb_getblk(sb, bitmap_blk);
135 if (unlikely(!bh)) {
136 ext2_error(sb, __func__,
137 "Cannot read block bitmap - "
138 "block_group = %d, block_bitmap = %u",
139 block_group, le32_to_cpu(desc->bg_block_bitmap));
140 return NULL;
141 }
142 if (likely(bh_uptodate_or_lock(bh)))
143 return bh;
144
145 if (bh_submit_read(bh) < 0) {
146 brelse(bh);
147 ext2_error(sb, __func__,
148 "Cannot read block bitmap - "
149 "block_group = %d, block_bitmap = %u",
150 block_group, le32_to_cpu(desc->bg_block_bitmap));
151 return NULL;
152 }
153
154 ext2_valid_block_bitmap(sb, desc, block_group, bh);
155
156
157
158
159 return bh;
160}
161
162static void group_adjust_blocks(struct super_block *sb, int group_no,
163 struct ext2_group_desc *desc, struct buffer_head *bh, int count)
164{
165 if (count) {
166 struct ext2_sb_info *sbi = EXT2_SB(sb);
167 unsigned free_blocks;
168
169 spin_lock(sb_bgl_lock(sbi, group_no));
170 free_blocks = le16_to_cpu(desc->bg_free_blocks_count);
171 desc->bg_free_blocks_count = cpu_to_le16(free_blocks + count);
172 spin_unlock(sb_bgl_lock(sbi, group_no));
173 mark_buffer_dirty(bh);
174 }
175}
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198#if 1
199static void __rsv_window_dump(struct rb_root *root, int verbose,
200 const char *fn)
201{
202 struct rb_node *n;
203 struct ext2_reserve_window_node *rsv, *prev;
204 int bad;
205
206restart:
207 n = rb_first(root);
208 bad = 0;
209 prev = NULL;
210
211 printk("Block Allocation Reservation Windows Map (%s):\n", fn);
212 while (n) {
213 rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node);
214 if (verbose)
215 printk("reservation window 0x%p "
216 "start: %lu, end: %lu\n",
217 rsv, rsv->rsv_start, rsv->rsv_end);
218 if (rsv->rsv_start && rsv->rsv_start >= rsv->rsv_end) {
219 printk("Bad reservation %p (start >= end)\n",
220 rsv);
221 bad = 1;
222 }
223 if (prev && prev->rsv_end >= rsv->rsv_start) {
224 printk("Bad reservation %p (prev->end >= start)\n",
225 rsv);
226 bad = 1;
227 }
228 if (bad) {
229 if (!verbose) {
230 printk("Restarting reservation walk in verbose mode\n");
231 verbose = 1;
232 goto restart;
233 }
234 }
235 n = rb_next(n);
236 prev = rsv;
237 }
238 printk("Window map complete.\n");
239 BUG_ON(bad);
240}
241#define rsv_window_dump(root, verbose) \
242 __rsv_window_dump((root), (verbose), __func__)
243#else
244#define rsv_window_dump(root, verbose) do {} while (0)
245#endif
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262
263static int
264goal_in_my_reservation(struct ext2_reserve_window *rsv, ext2_grpblk_t grp_goal,
265 unsigned int group, struct super_block * sb)
266{
267 ext2_fsblk_t group_first_block, group_last_block;
268
269 group_first_block = ext2_group_first_block_no(sb, group);
270 group_last_block = ext2_group_last_block_no(sb, group);
271
272 if ((rsv->_rsv_start > group_last_block) ||
273 (rsv->_rsv_end < group_first_block))
274 return 0;
275 if ((grp_goal >= 0) && ((grp_goal + group_first_block < rsv->_rsv_start)
276 || (grp_goal + group_first_block > rsv->_rsv_end)))
277 return 0;
278 return 1;
279}
280
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289
290static struct ext2_reserve_window_node *
291search_reserve_window(struct rb_root *root, ext2_fsblk_t goal)
292{
293 struct rb_node *n = root->rb_node;
294 struct ext2_reserve_window_node *rsv;
295
296 if (!n)
297 return NULL;
298
299 do {
300 rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node);
301
302 if (goal < rsv->rsv_start)
303 n = n->rb_left;
304 else if (goal > rsv->rsv_end)
305 n = n->rb_right;
306 else
307 return rsv;
308 } while (n);
309
310
311
312
313
314
315 if (rsv->rsv_start > goal) {
316 n = rb_prev(&rsv->rsv_node);
317 rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node);
318 }
319 return rsv;
320}
321
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327
328
329void ext2_rsv_window_add(struct super_block *sb,
330 struct ext2_reserve_window_node *rsv)
331{
332 struct rb_root *root = &EXT2_SB(sb)->s_rsv_window_root;
333 struct rb_node *node = &rsv->rsv_node;
334 ext2_fsblk_t start = rsv->rsv_start;
335
336 struct rb_node ** p = &root->rb_node;
337 struct rb_node * parent = NULL;
338 struct ext2_reserve_window_node *this;
339
340 while (*p)
341 {
342 parent = *p;
343 this = rb_entry(parent, struct ext2_reserve_window_node, rsv_node);
344
345 if (start < this->rsv_start)
346 p = &(*p)->rb_left;
347 else if (start > this->rsv_end)
348 p = &(*p)->rb_right;
349 else {
350 rsv_window_dump(root, 1);
351 BUG();
352 }
353 }
354
355 rb_link_node(node, parent, p);
356 rb_insert_color(node, root);
357}
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367
368static void rsv_window_remove(struct super_block *sb,
369 struct ext2_reserve_window_node *rsv)
370{
371 rsv->rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
372 rsv->rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
373 rsv->rsv_alloc_hit = 0;
374 rb_erase(&rsv->rsv_node, &EXT2_SB(sb)->s_rsv_window_root);
375}
376
377
378
379
380
381
382
383static inline int rsv_is_empty(struct ext2_reserve_window *rsv)
384{
385
386 return (rsv->_rsv_end == EXT2_RESERVE_WINDOW_NOT_ALLOCATED);
387}
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410void ext2_init_block_alloc_info(struct inode *inode)
411{
412 struct ext2_inode_info *ei = EXT2_I(inode);
413 struct ext2_block_alloc_info *block_i;
414 struct super_block *sb = inode->i_sb;
415
416 block_i = kmalloc(sizeof(*block_i), GFP_NOFS);
417 if (block_i) {
418 struct ext2_reserve_window_node *rsv = &block_i->rsv_window_node;
419
420 rsv->rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
421 rsv->rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
422
423
424
425
426
427
428 if (!test_opt(sb, RESERVATION))
429 rsv->rsv_goal_size = 0;
430 else
431 rsv->rsv_goal_size = EXT2_DEFAULT_RESERVE_BLOCKS;
432 rsv->rsv_alloc_hit = 0;
433 block_i->last_alloc_logical_block = 0;
434 block_i->last_alloc_physical_block = 0;
435 }
436 ei->i_block_alloc_info = block_i;
437}
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450
451void ext2_discard_reservation(struct inode *inode)
452{
453 struct ext2_inode_info *ei = EXT2_I(inode);
454 struct ext2_block_alloc_info *block_i = ei->i_block_alloc_info;
455 struct ext2_reserve_window_node *rsv;
456 spinlock_t *rsv_lock = &EXT2_SB(inode->i_sb)->s_rsv_window_lock;
457
458 if (!block_i)
459 return;
460
461 rsv = &block_i->rsv_window_node;
462 if (!rsv_is_empty(&rsv->rsv_window)) {
463 spin_lock(rsv_lock);
464 if (!rsv_is_empty(&rsv->rsv_window))
465 rsv_window_remove(inode->i_sb, rsv);
466 spin_unlock(rsv_lock);
467 }
468}
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473
474
475
476void ext2_free_blocks (struct inode * inode, unsigned long block,
477 unsigned long count)
478{
479 struct buffer_head *bitmap_bh = NULL;
480 struct buffer_head * bh2;
481 unsigned long block_group;
482 unsigned long bit;
483 unsigned long i;
484 unsigned long overflow;
485 struct super_block * sb = inode->i_sb;
486 struct ext2_sb_info * sbi = EXT2_SB(sb);
487 struct ext2_group_desc * desc;
488 struct ext2_super_block * es = sbi->s_es;
489 unsigned freed = 0, group_freed;
490
491 if (!ext2_data_block_valid(sbi, block, count)) {
492 ext2_error (sb, "ext2_free_blocks",
493 "Freeing blocks not in datazone - "
494 "block = %lu, count = %lu", block, count);
495 goto error_return;
496 }
497
498 ext2_debug ("freeing block(s) %lu-%lu\n", block, block + count - 1);
499
500do_more:
501 overflow = 0;
502 block_group = (block - le32_to_cpu(es->s_first_data_block)) /
503 EXT2_BLOCKS_PER_GROUP(sb);
504 bit = (block - le32_to_cpu(es->s_first_data_block)) %
505 EXT2_BLOCKS_PER_GROUP(sb);
506
507
508
509
510 if (bit + count > EXT2_BLOCKS_PER_GROUP(sb)) {
511 overflow = bit + count - EXT2_BLOCKS_PER_GROUP(sb);
512 count -= overflow;
513 }
514 brelse(bitmap_bh);
515 bitmap_bh = read_block_bitmap(sb, block_group);
516 if (!bitmap_bh)
517 goto error_return;
518
519 desc = ext2_get_group_desc (sb, block_group, &bh2);
520 if (!desc)
521 goto error_return;
522
523 if (in_range (le32_to_cpu(desc->bg_block_bitmap), block, count) ||
524 in_range (le32_to_cpu(desc->bg_inode_bitmap), block, count) ||
525 in_range (block, le32_to_cpu(desc->bg_inode_table),
526 sbi->s_itb_per_group) ||
527 in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table),
528 sbi->s_itb_per_group)) {
529 ext2_error (sb, "ext2_free_blocks",
530 "Freeing blocks in system zones - "
531 "Block = %lu, count = %lu",
532 block, count);
533 goto error_return;
534 }
535
536 for (i = 0, group_freed = 0; i < count; i++) {
537 if (!ext2_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
538 bit + i, bitmap_bh->b_data)) {
539 ext2_error(sb, __func__,
540 "bit already cleared for block %lu", block + i);
541 } else {
542 group_freed++;
543 }
544 }
545
546 mark_buffer_dirty(bitmap_bh);
547 if (sb->s_flags & SB_SYNCHRONOUS)
548 sync_dirty_buffer(bitmap_bh);
549
550 group_adjust_blocks(sb, block_group, desc, bh2, group_freed);
551 freed += group_freed;
552
553 if (overflow) {
554 block += count;
555 count = overflow;
556 goto do_more;
557 }
558error_return:
559 brelse(bitmap_bh);
560 if (freed) {
561 percpu_counter_add(&sbi->s_freeblocks_counter, freed);
562 dquot_free_block_nodirty(inode, freed);
563 mark_inode_dirty(inode);
564 }
565}
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575
576static ext2_grpblk_t
577bitmap_search_next_usable_block(ext2_grpblk_t start, struct buffer_head *bh,
578 ext2_grpblk_t maxblocks)
579{
580 ext2_grpblk_t next;
581
582 next = ext2_find_next_zero_bit(bh->b_data, maxblocks, start);
583 if (next >= maxblocks)
584 return -1;
585 return next;
586}
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599
600static ext2_grpblk_t
601find_next_usable_block(int start, struct buffer_head *bh, int maxblocks)
602{
603 ext2_grpblk_t here, next;
604 char *p, *r;
605
606 if (start > 0) {
607
608
609
610
611
612
613
614
615 ext2_grpblk_t end_goal = (start + 63) & ~63;
616 if (end_goal > maxblocks)
617 end_goal = maxblocks;
618 here = ext2_find_next_zero_bit(bh->b_data, end_goal, start);
619 if (here < end_goal)
620 return here;
621 ext2_debug("Bit not found near goal\n");
622 }
623
624 here = start;
625 if (here < 0)
626 here = 0;
627
628 p = ((char *)bh->b_data) + (here >> 3);
629 r = memscan(p, 0, ((maxblocks + 7) >> 3) - (here >> 3));
630 next = (r - ((char *)bh->b_data)) << 3;
631
632 if (next < maxblocks && next >= here)
633 return next;
634
635 here = bitmap_search_next_usable_block(here, bh, maxblocks);
636 return here;
637}
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661static int
662ext2_try_to_allocate(struct super_block *sb, int group,
663 struct buffer_head *bitmap_bh, ext2_grpblk_t grp_goal,
664 unsigned long *count,
665 struct ext2_reserve_window *my_rsv)
666{
667 ext2_fsblk_t group_first_block = ext2_group_first_block_no(sb, group);
668 ext2_fsblk_t group_last_block = ext2_group_last_block_no(sb, group);
669 ext2_grpblk_t start, end;
670 unsigned long num = 0;
671
672 start = 0;
673 end = group_last_block - group_first_block + 1;
674
675 if (my_rsv) {
676 if (my_rsv->_rsv_start >= group_first_block)
677 start = my_rsv->_rsv_start - group_first_block;
678 if (my_rsv->_rsv_end < group_last_block)
679 end = my_rsv->_rsv_end - group_first_block + 1;
680 if (grp_goal < start || grp_goal >= end)
681 grp_goal = -1;
682 }
683 BUG_ON(start > EXT2_BLOCKS_PER_GROUP(sb));
684
685 if (grp_goal < 0) {
686 grp_goal = find_next_usable_block(start, bitmap_bh, end);
687 if (grp_goal < 0)
688 goto fail_access;
689 if (!my_rsv) {
690 int i;
691
692 for (i = 0; i < 7 && grp_goal > start &&
693 !ext2_test_bit(grp_goal - 1,
694 bitmap_bh->b_data);
695 i++, grp_goal--)
696 ;
697 }
698 }
699
700 for (; num < *count && grp_goal < end; grp_goal++) {
701 if (ext2_set_bit_atomic(sb_bgl_lock(EXT2_SB(sb), group),
702 grp_goal, bitmap_bh->b_data)) {
703 if (num == 0)
704 continue;
705 break;
706 }
707 num++;
708 }
709
710 if (num == 0)
711 goto fail_access;
712
713 *count = num;
714 return grp_goal - num;
715fail_access:
716 return -1;
717}
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750
751static int find_next_reservable_window(
752 struct ext2_reserve_window_node *search_head,
753 struct ext2_reserve_window_node *my_rsv,
754 struct super_block * sb,
755 ext2_fsblk_t start_block,
756 ext2_fsblk_t last_block)
757{
758 struct rb_node *next;
759 struct ext2_reserve_window_node *rsv, *prev;
760 ext2_fsblk_t cur;
761 int size = my_rsv->rsv_goal_size;
762
763
764
765 cur = start_block;
766 rsv = search_head;
767 if (!rsv)
768 return -1;
769
770 while (1) {
771 if (cur <= rsv->rsv_end)
772 cur = rsv->rsv_end + 1;
773
774
775
776
777
778
779
780
781
782
783 if (cur > last_block)
784 return -1;
785
786 prev = rsv;
787 next = rb_next(&rsv->rsv_node);
788 rsv = rb_entry(next,struct ext2_reserve_window_node,rsv_node);
789
790
791
792
793
794 if (!next)
795 break;
796
797 if (cur + size <= rsv->rsv_start) {
798
799
800
801
802 break;
803 }
804 }
805
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811
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815
816 if ((prev != my_rsv) && (!rsv_is_empty(&my_rsv->rsv_window)))
817 rsv_window_remove(sb, my_rsv);
818
819
820
821
822
823
824
825
826 my_rsv->rsv_start = cur;
827 my_rsv->rsv_end = cur + size - 1;
828 my_rsv->rsv_alloc_hit = 0;
829
830 if (prev != my_rsv)
831 ext2_rsv_window_add(sb, my_rsv);
832
833 return 0;
834}
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873static int alloc_new_reservation(struct ext2_reserve_window_node *my_rsv,
874 ext2_grpblk_t grp_goal, struct super_block *sb,
875 unsigned int group, struct buffer_head *bitmap_bh)
876{
877 struct ext2_reserve_window_node *search_head;
878 ext2_fsblk_t group_first_block, group_end_block, start_block;
879 ext2_grpblk_t first_free_block;
880 struct rb_root *fs_rsv_root = &EXT2_SB(sb)->s_rsv_window_root;
881 unsigned long size;
882 int ret;
883 spinlock_t *rsv_lock = &EXT2_SB(sb)->s_rsv_window_lock;
884
885 group_first_block = ext2_group_first_block_no(sb, group);
886 group_end_block = ext2_group_last_block_no(sb, group);
887
888 if (grp_goal < 0)
889 start_block = group_first_block;
890 else
891 start_block = grp_goal + group_first_block;
892
893 size = my_rsv->rsv_goal_size;
894
895 if (!rsv_is_empty(&my_rsv->rsv_window)) {
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910 if ((my_rsv->rsv_start <= group_end_block) &&
911 (my_rsv->rsv_end > group_end_block) &&
912 (start_block >= my_rsv->rsv_start))
913 return -1;
914
915 if ((my_rsv->rsv_alloc_hit >
916 (my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) {
917
918
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921
922
923 size = size * 2;
924 if (size > EXT2_MAX_RESERVE_BLOCKS)
925 size = EXT2_MAX_RESERVE_BLOCKS;
926 my_rsv->rsv_goal_size= size;
927 }
928 }
929
930 spin_lock(rsv_lock);
931
932
933
934 search_head = search_reserve_window(fs_rsv_root, start_block);
935
936
937
938
939
940
941
942
943retry:
944 ret = find_next_reservable_window(search_head, my_rsv, sb,
945 start_block, group_end_block);
946
947 if (ret == -1) {
948 if (!rsv_is_empty(&my_rsv->rsv_window))
949 rsv_window_remove(sb, my_rsv);
950 spin_unlock(rsv_lock);
951 return -1;
952 }
953
954
955
956
957
958
959
960
961
962
963 spin_unlock(rsv_lock);
964 first_free_block = bitmap_search_next_usable_block(
965 my_rsv->rsv_start - group_first_block,
966 bitmap_bh, group_end_block - group_first_block + 1);
967
968 if (first_free_block < 0) {
969
970
971
972
973 spin_lock(rsv_lock);
974 if (!rsv_is_empty(&my_rsv->rsv_window))
975 rsv_window_remove(sb, my_rsv);
976 spin_unlock(rsv_lock);
977 return -1;
978 }
979
980 start_block = first_free_block + group_first_block;
981
982
983
984
985 if (start_block >= my_rsv->rsv_start && start_block <= my_rsv->rsv_end)
986 return 0;
987
988
989
990
991
992
993 search_head = my_rsv;
994 spin_lock(rsv_lock);
995 goto retry;
996}
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015static void try_to_extend_reservation(struct ext2_reserve_window_node *my_rsv,
1016 struct super_block *sb, int size)
1017{
1018 struct ext2_reserve_window_node *next_rsv;
1019 struct rb_node *next;
1020 spinlock_t *rsv_lock = &EXT2_SB(sb)->s_rsv_window_lock;
1021
1022 if (!spin_trylock(rsv_lock))
1023 return;
1024
1025 next = rb_next(&my_rsv->rsv_node);
1026
1027 if (!next)
1028 my_rsv->rsv_end += size;
1029 else {
1030 next_rsv = rb_entry(next, struct ext2_reserve_window_node, rsv_node);
1031
1032 if ((next_rsv->rsv_start - my_rsv->rsv_end - 1) >= size)
1033 my_rsv->rsv_end += size;
1034 else
1035 my_rsv->rsv_end = next_rsv->rsv_start - 1;
1036 }
1037 spin_unlock(rsv_lock);
1038}
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066static ext2_grpblk_t
1067ext2_try_to_allocate_with_rsv(struct super_block *sb, unsigned int group,
1068 struct buffer_head *bitmap_bh, ext2_grpblk_t grp_goal,
1069 struct ext2_reserve_window_node * my_rsv,
1070 unsigned long *count)
1071{
1072 ext2_fsblk_t group_first_block, group_last_block;
1073 ext2_grpblk_t ret = 0;
1074 unsigned long num = *count;
1075
1076
1077
1078
1079
1080
1081
1082 if (my_rsv == NULL) {
1083 return ext2_try_to_allocate(sb, group, bitmap_bh,
1084 grp_goal, count, NULL);
1085 }
1086
1087
1088
1089
1090
1091
1092 group_first_block = ext2_group_first_block_no(sb, group);
1093 group_last_block = ext2_group_last_block_no(sb, group);
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110 while (1) {
1111 if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) ||
1112 !goal_in_my_reservation(&my_rsv->rsv_window,
1113 grp_goal, group, sb)) {
1114 if (my_rsv->rsv_goal_size < *count)
1115 my_rsv->rsv_goal_size = *count;
1116 ret = alloc_new_reservation(my_rsv, grp_goal, sb,
1117 group, bitmap_bh);
1118 if (ret < 0)
1119 break;
1120
1121 if (!goal_in_my_reservation(&my_rsv->rsv_window,
1122 grp_goal, group, sb))
1123 grp_goal = -1;
1124 } else if (grp_goal >= 0) {
1125 int curr = my_rsv->rsv_end -
1126 (grp_goal + group_first_block) + 1;
1127
1128 if (curr < *count)
1129 try_to_extend_reservation(my_rsv, sb,
1130 *count - curr);
1131 }
1132
1133 if ((my_rsv->rsv_start > group_last_block) ||
1134 (my_rsv->rsv_end < group_first_block)) {
1135 rsv_window_dump(&EXT2_SB(sb)->s_rsv_window_root, 1);
1136 BUG();
1137 }
1138 ret = ext2_try_to_allocate(sb, group, bitmap_bh, grp_goal,
1139 &num, &my_rsv->rsv_window);
1140 if (ret >= 0) {
1141 my_rsv->rsv_alloc_hit += num;
1142 *count = num;
1143 break;
1144 }
1145 num = *count;
1146 }
1147 return ret;
1148}
1149
1150
1151
1152
1153
1154
1155
1156static int ext2_has_free_blocks(struct ext2_sb_info *sbi)
1157{
1158 ext2_fsblk_t free_blocks, root_blocks;
1159
1160 free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
1161 root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count);
1162 if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) &&
1163 !uid_eq(sbi->s_resuid, current_fsuid()) &&
1164 (gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) ||
1165 !in_group_p (sbi->s_resgid))) {
1166 return 0;
1167 }
1168 return 1;
1169}
1170
1171
1172
1173
1174
1175int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk,
1176 unsigned int count)
1177{
1178 if ((start_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
1179 (start_blk + count - 1 < start_blk) ||
1180 (start_blk + count - 1 >= le32_to_cpu(sbi->s_es->s_blocks_count)))
1181 return 0;
1182
1183
1184 if ((start_blk <= sbi->s_sb_block) &&
1185 (start_blk + count - 1 >= sbi->s_sb_block))
1186 return 0;
1187
1188 return 1;
1189}
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal,
1206 unsigned long *count, int *errp)
1207{
1208 struct buffer_head *bitmap_bh = NULL;
1209 struct buffer_head *gdp_bh;
1210 int group_no;
1211 int goal_group;
1212 ext2_grpblk_t grp_target_blk;
1213 ext2_grpblk_t grp_alloc_blk;
1214 ext2_fsblk_t ret_block;
1215 int bgi;
1216 int performed_allocation = 0;
1217 ext2_grpblk_t free_blocks;
1218 struct super_block *sb;
1219 struct ext2_group_desc *gdp;
1220 struct ext2_super_block *es;
1221 struct ext2_sb_info *sbi;
1222 struct ext2_reserve_window_node *my_rsv = NULL;
1223 struct ext2_block_alloc_info *block_i;
1224 unsigned short windowsz = 0;
1225 unsigned long ngroups;
1226 unsigned long num = *count;
1227 int ret;
1228
1229 *errp = -ENOSPC;
1230 sb = inode->i_sb;
1231
1232
1233
1234
1235 ret = dquot_alloc_block(inode, num);
1236 if (ret) {
1237 *errp = ret;
1238 return 0;
1239 }
1240
1241 sbi = EXT2_SB(sb);
1242 es = EXT2_SB(sb)->s_es;
1243 ext2_debug("goal=%lu.\n", goal);
1244
1245
1246
1247
1248
1249
1250
1251
1252 block_i = EXT2_I(inode)->i_block_alloc_info;
1253 if (block_i) {
1254 windowsz = block_i->rsv_window_node.rsv_goal_size;
1255 if (windowsz > 0)
1256 my_rsv = &block_i->rsv_window_node;
1257 }
1258
1259 if (!ext2_has_free_blocks(sbi)) {
1260 *errp = -ENOSPC;
1261 goto out;
1262 }
1263
1264
1265
1266
1267 if (goal < le32_to_cpu(es->s_first_data_block) ||
1268 goal >= le32_to_cpu(es->s_blocks_count))
1269 goal = le32_to_cpu(es->s_first_data_block);
1270 group_no = (goal - le32_to_cpu(es->s_first_data_block)) /
1271 EXT2_BLOCKS_PER_GROUP(sb);
1272 goal_group = group_no;
1273retry_alloc:
1274 gdp = ext2_get_group_desc(sb, group_no, &gdp_bh);
1275 if (!gdp)
1276 goto io_error;
1277
1278 free_blocks = le16_to_cpu(gdp->bg_free_blocks_count);
1279
1280
1281
1282
1283 if (my_rsv && (free_blocks < windowsz)
1284 && (free_blocks > 0)
1285 && (rsv_is_empty(&my_rsv->rsv_window)))
1286 my_rsv = NULL;
1287
1288 if (free_blocks > 0) {
1289 grp_target_blk = ((goal - le32_to_cpu(es->s_first_data_block)) %
1290 EXT2_BLOCKS_PER_GROUP(sb));
1291
1292
1293
1294
1295
1296
1297 brelse(bitmap_bh);
1298 bitmap_bh = read_block_bitmap(sb, group_no);
1299 if (!bitmap_bh)
1300 goto io_error;
1301 grp_alloc_blk = ext2_try_to_allocate_with_rsv(sb, group_no,
1302 bitmap_bh, grp_target_blk,
1303 my_rsv, &num);
1304 if (grp_alloc_blk >= 0)
1305 goto allocated;
1306 }
1307
1308 ngroups = EXT2_SB(sb)->s_groups_count;
1309 smp_rmb();
1310
1311
1312
1313
1314
1315 for (bgi = 0; bgi < ngroups; bgi++) {
1316 group_no++;
1317 if (group_no >= ngroups)
1318 group_no = 0;
1319 gdp = ext2_get_group_desc(sb, group_no, &gdp_bh);
1320 if (!gdp)
1321 goto io_error;
1322
1323 free_blocks = le16_to_cpu(gdp->bg_free_blocks_count);
1324
1325
1326
1327
1328 if (!free_blocks)
1329 continue;
1330
1331
1332
1333
1334
1335 if (my_rsv && (free_blocks <= (windowsz/2)))
1336 continue;
1337
1338 brelse(bitmap_bh);
1339 bitmap_bh = read_block_bitmap(sb, group_no);
1340 if (!bitmap_bh)
1341 goto io_error;
1342
1343
1344
1345 grp_alloc_blk = ext2_try_to_allocate_with_rsv(sb, group_no,
1346 bitmap_bh, -1, my_rsv, &num);
1347 if (grp_alloc_blk >= 0)
1348 goto allocated;
1349 }
1350
1351
1352
1353
1354
1355
1356
1357 if (my_rsv) {
1358 my_rsv = NULL;
1359 windowsz = 0;
1360 group_no = goal_group;
1361 goto retry_alloc;
1362 }
1363
1364 *errp = -ENOSPC;
1365 goto out;
1366
1367allocated:
1368
1369 ext2_debug("using block group %d(%d)\n",
1370 group_no, gdp->bg_free_blocks_count);
1371
1372 ret_block = grp_alloc_blk + ext2_group_first_block_no(sb, group_no);
1373
1374 if (in_range(le32_to_cpu(gdp->bg_block_bitmap), ret_block, num) ||
1375 in_range(le32_to_cpu(gdp->bg_inode_bitmap), ret_block, num) ||
1376 in_range(ret_block, le32_to_cpu(gdp->bg_inode_table),
1377 EXT2_SB(sb)->s_itb_per_group) ||
1378 in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table),
1379 EXT2_SB(sb)->s_itb_per_group)) {
1380 ext2_error(sb, "ext2_new_blocks",
1381 "Allocating block in system zone - "
1382 "blocks from "E2FSBLK", length %lu",
1383 ret_block, num);
1384
1385
1386
1387
1388
1389 num = *count;
1390 goto retry_alloc;
1391 }
1392
1393 performed_allocation = 1;
1394
1395 if (ret_block + num - 1 >= le32_to_cpu(es->s_blocks_count)) {
1396 ext2_error(sb, "ext2_new_blocks",
1397 "block("E2FSBLK") >= blocks count(%d) - "
1398 "block_group = %d, es == %p ", ret_block,
1399 le32_to_cpu(es->s_blocks_count), group_no, es);
1400 goto out;
1401 }
1402
1403 group_adjust_blocks(sb, group_no, gdp, gdp_bh, -num);
1404 percpu_counter_sub(&sbi->s_freeblocks_counter, num);
1405
1406 mark_buffer_dirty(bitmap_bh);
1407 if (sb->s_flags & SB_SYNCHRONOUS)
1408 sync_dirty_buffer(bitmap_bh);
1409
1410 *errp = 0;
1411 brelse(bitmap_bh);
1412 if (num < *count) {
1413 dquot_free_block_nodirty(inode, *count-num);
1414 mark_inode_dirty(inode);
1415 *count = num;
1416 }
1417 return ret_block;
1418
1419io_error:
1420 *errp = -EIO;
1421out:
1422
1423
1424
1425 if (!performed_allocation) {
1426 dquot_free_block_nodirty(inode, *count);
1427 mark_inode_dirty(inode);
1428 }
1429 brelse(bitmap_bh);
1430 return 0;
1431}
1432
1433ext2_fsblk_t ext2_new_block(struct inode *inode, unsigned long goal, int *errp)
1434{
1435 unsigned long count = 1;
1436
1437 return ext2_new_blocks(inode, goal, &count, errp);
1438}
1439
1440#ifdef EXT2FS_DEBUG
1441
1442unsigned long ext2_count_free(struct buffer_head *map, unsigned int numchars)
1443{
1444 return numchars * BITS_PER_BYTE - memweight(map->b_data, numchars);
1445}
1446
1447#endif
1448
1449unsigned long ext2_count_free_blocks (struct super_block * sb)
1450{
1451 struct ext2_group_desc * desc;
1452 unsigned long desc_count = 0;
1453 int i;
1454#ifdef EXT2FS_DEBUG
1455 unsigned long bitmap_count, x;
1456 struct ext2_super_block *es;
1457
1458 es = EXT2_SB(sb)->s_es;
1459 desc_count = 0;
1460 bitmap_count = 0;
1461 desc = NULL;
1462 for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
1463 struct buffer_head *bitmap_bh;
1464 desc = ext2_get_group_desc (sb, i, NULL);
1465 if (!desc)
1466 continue;
1467 desc_count += le16_to_cpu(desc->bg_free_blocks_count);
1468 bitmap_bh = read_block_bitmap(sb, i);
1469 if (!bitmap_bh)
1470 continue;
1471
1472 x = ext2_count_free(bitmap_bh, sb->s_blocksize);
1473 printk ("group %d: stored = %d, counted = %lu\n",
1474 i, le16_to_cpu(desc->bg_free_blocks_count), x);
1475 bitmap_count += x;
1476 brelse(bitmap_bh);
1477 }
1478 printk("ext2_count_free_blocks: stored = %lu, computed = %lu, %lu\n",
1479 (long)le32_to_cpu(es->s_free_blocks_count),
1480 desc_count, bitmap_count);
1481 return bitmap_count;
1482#else
1483 for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
1484 desc = ext2_get_group_desc (sb, i, NULL);
1485 if (!desc)
1486 continue;
1487 desc_count += le16_to_cpu(desc->bg_free_blocks_count);
1488 }
1489 return desc_count;
1490#endif
1491}
1492
1493static inline int test_root(int a, int b)
1494{
1495 int num = b;
1496
1497 while (a > num)
1498 num *= b;
1499 return num == a;
1500}
1501
1502static int ext2_group_sparse(int group)
1503{
1504 if (group <= 1)
1505 return 1;
1506 return (test_root(group, 3) || test_root(group, 5) ||
1507 test_root(group, 7));
1508}
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518int ext2_bg_has_super(struct super_block *sb, int group)
1519{
1520 if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
1521 !ext2_group_sparse(group))
1522 return 0;
1523 return 1;
1524}
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535unsigned long ext2_bg_num_gdb(struct super_block *sb, int group)
1536{
1537 return ext2_bg_has_super(sb, group) ? EXT2_SB(sb)->s_gdb_count : 0;
1538}
1539
1540