2 * blkmap64_rb.c --- Simple rb-tree implementation for bitmaps
4 * (C)2010 Red Hat, Inc., Lukas Czerner <lczerner@redhat.com>
7 * This file may be redistributed under the terms of the GNU Public
23 #include <sys/types.h>
33 struct bmap_rb_extent {
39 struct ext2fs_rb_private {
41 struct bmap_rb_extent **wcursor;
42 struct bmap_rb_extent **rcursor;
49 static int rb_insert_extent(__u64 start, __u64 count,
50 struct ext2fs_rb_private *);
51 static void rb_get_new_extent(struct bmap_rb_extent **, __u64, __u64);
53 /* #define DEBUG_RB */
56 static void print_tree(struct rb_root *root)
58 struct rb_node *node = NULL;
59 struct bmap_rb_extent *ext;
61 printf("\t\t\t=================================\n");
62 node = ext2fs_rb_first(root);
63 for (node = ext2fs_rb_first(root); node != NULL;
64 node = ext2fs_rb_next(node)) {
65 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
66 printf("\t\t\t--> (%llu -> %llu)\n",
67 ext->start, ext->start + ext->count);
69 printf("\t\t\t=================================\n");
72 static int check_tree(struct rb_root *root, const char *msg)
74 struct rb_node *new_node, *node, *next;
75 struct bmap_rb_extent *ext, *old = NULL;
77 for (node = ext2fs_rb_first(root); node;
78 node = ext2fs_rb_next(node)) {
79 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
80 if (ext->count <= 0) {
81 printf("Tree Error: count is crazy\n");
82 printf("extent: %llu -> %llu (%u)\n", ext->start,
83 ext->start + ext->count, ext->count);
87 printf("Tree Error: start is crazy\n");
88 printf("extent: %llu -> %llu (%u)\n", ext->start,
89 ext->start + ext->count, ext->count);
94 if (old->start > ext->start) {
95 printf("Tree Error: start is crazy\n");
96 printf("extent: %llu -> %llu (%u)\n",
97 old->start, old->start + old->count,
99 printf("extent next: %llu -> %llu (%u)\n",
100 ext->start, ext->start + ext->count,
104 if ((old->start + old->count) >= ext->start) {
105 printf("Tree Error: extent is crazy\n");
106 printf("extent: %llu -> %llu (%u)\n",
107 old->start, old->start + old->count,
109 printf("extent next: %llu -> %llu (%u)\n",
110 ext->start, ext->start + ext->count,
125 #define check_tree(root, msg) 0
126 #define print_tree(root, msg) 0
129 static void rb_get_new_extent(struct bmap_rb_extent **ext, __u64 start,
132 struct bmap_rb_extent *new_ext;
135 retval = ext2fs_get_mem(sizeof (struct bmap_rb_extent),
138 perror("ext2fs_get_mem");
142 new_ext->start = start;
143 new_ext->count = count;
148 static void rb_free_extent(struct ext2fs_rb_private *bp,
149 struct bmap_rb_extent *ext)
151 if (*bp->wcursor == ext)
153 if (*bp->rcursor == ext)
155 ext2fs_free_mem(&ext);
158 static errcode_t rb_alloc_private_data (ext2fs_generic_bitmap bitmap)
160 struct ext2fs_rb_private *bp;
163 retval = ext2fs_get_mem(sizeof (struct ext2fs_rb_private), &bp);
168 retval = ext2fs_get_mem(sizeof(struct bmap_rb_extent *), &bp->rcursor);
171 retval = ext2fs_get_mem(sizeof(struct bmap_rb_extent *), &bp->wcursor);
177 #ifdef BMAP_STATS_OPS
182 bitmap->private = (void *) bp;
186 static errcode_t rb_new_bmap(ext2_filsys fs EXT2FS_ATTR((unused)),
187 ext2fs_generic_bitmap bitmap)
191 retval = rb_alloc_private_data (bitmap);
198 static void rb_free_tree(struct rb_root *root)
200 struct bmap_rb_extent *ext;
201 struct rb_node *node, *next;
203 for (node = ext2fs_rb_first(root); node; node = next) {
204 next = ext2fs_rb_next(node);
205 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
206 ext2fs_rb_erase(node, root);
207 ext2fs_free_mem(&ext);
211 static void rb_free_bmap(ext2fs_generic_bitmap bitmap)
213 struct ext2fs_rb_private *bp;
215 bp = (struct ext2fs_rb_private *) bitmap->private;
217 rb_free_tree(&bp->root);
218 ext2fs_free_mem(&bp->rcursor);
219 ext2fs_free_mem(&bp->wcursor);
220 ext2fs_free_mem(&bp);
224 static errcode_t rb_copy_bmap(ext2fs_generic_bitmap src,
225 ext2fs_generic_bitmap dest)
227 struct ext2fs_rb_private *src_bp, *dest_bp;
228 struct bmap_rb_extent *src_ext, *dest_ext;
229 struct rb_node *dest_node, *src_node, *dest_last, **n;
230 errcode_t retval = 0;
232 retval = rb_alloc_private_data (dest);
236 src_bp = (struct ext2fs_rb_private *) src->private;
237 dest_bp = (struct ext2fs_rb_private *) dest->private;
238 *src_bp->rcursor = NULL;
239 *dest_bp->rcursor = NULL;
241 src_node = ext2fs_rb_first(&src_bp->root);
243 src_ext = ext2fs_rb_entry(src_node, struct bmap_rb_extent, node);
244 retval = ext2fs_get_mem(sizeof (struct bmap_rb_extent),
249 memcpy(dest_ext, src_ext, sizeof(struct bmap_rb_extent));
251 dest_node = &dest_ext->node;
252 n = &dest_bp->root.rb_node;
256 dest_last = ext2fs_rb_last(&dest_bp->root);
257 n = &(dest_last)->rb_right;
260 ext2fs_rb_link_node(dest_node, dest_last, n);
261 ext2fs_rb_insert_color(dest_node, &dest_bp->root);
263 src_node = ext2fs_rb_next(src_node);
269 static void rb_truncate(__u64 new_max, struct rb_root *root)
271 struct bmap_rb_extent *ext;
272 struct rb_node *node;
274 node = ext2fs_rb_last(root);
276 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
278 if ((ext->start + ext->count - 1) <= new_max)
280 else if (ext->start > new_max) {
281 ext2fs_rb_erase(node, root);
282 ext2fs_free_mem(&ext);
283 node = ext2fs_rb_last(root);
286 ext->count = new_max - ext->start + 1;
290 static errcode_t rb_resize_bmap(ext2fs_generic_bitmap bmap,
291 __u64 new_end, __u64 new_real_end)
293 struct ext2fs_rb_private *bp;
295 if (new_real_end >= bmap->real_end) {
297 bmap->real_end = new_real_end;
301 bp = (struct ext2fs_rb_private *) bmap->private;
305 /* truncate tree to new_real_end size */
306 rb_truncate(new_real_end, &bp->root);
309 bmap->real_end = new_real_end;
315 rb_test_bit(struct ext2fs_rb_private *bp, __u64 bit)
317 struct bmap_rb_extent *rcursor;
318 struct rb_node *parent = NULL;
319 struct rb_node **n = &bp->root.rb_node;
320 struct bmap_rb_extent *ext;
323 rcursor = *bp->rcursor;
327 if (bit >= rcursor->start && bit < rcursor->start + rcursor->count) {
328 #ifdef BMAP_STATS_OPS
334 rcursor = *bp->wcursor;
338 if (bit >= rcursor->start && bit < rcursor->start + rcursor->count)
345 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
346 if (bit < ext->start)
348 else if (bit >= (ext->start + ext->count))
358 static int rb_insert_extent(__u64 start, __u64 count,
359 struct ext2fs_rb_private *bp)
361 struct rb_root *root = &bp->root;
362 struct rb_node *parent = NULL, **n = &root->rb_node;
363 struct rb_node *new_node, *node, *next;
364 struct bmap_rb_extent *new_ext;
365 struct bmap_rb_extent *ext;
370 if (start >= ext->start &&
371 start <= (ext->start + ext->count)) {
372 #ifdef BMAP_STATS_OPS
381 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
383 if (start < ext->start) {
385 } else if (start > (ext->start + ext->count)) {
389 if ((start + count) <= (ext->start + ext->count))
392 if ((ext->start + ext->count) == start)
397 count += (start - ext->start);
400 new_node = &ext->node;
406 rb_get_new_extent(&new_ext, start, count);
408 new_node = &new_ext->node;
409 ext2fs_rb_link_node(new_node, parent, n);
410 ext2fs_rb_insert_color(new_node, root);
411 *bp->wcursor = new_ext;
413 node = ext2fs_rb_prev(new_node);
415 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
416 if ((ext->start + ext->count) == start) {
419 ext2fs_rb_erase(node, root);
420 rb_free_extent(bp, ext);
425 /* See if we can merge extent to the right */
426 for (node = ext2fs_rb_next(new_node); node != NULL; node = next) {
427 next = ext2fs_rb_next(node);
428 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
430 if ((ext->start + ext->count) <= start)
433 /* No more merging */
434 if ((start + count) < ext->start)
437 /* ext is embedded in new_ext interval */
438 if ((start + count) >= (ext->start + ext->count)) {
439 ext2fs_rb_erase(node, root);
440 rb_free_extent(bp, ext);
443 /* merge ext with new_ext */
444 count += ((ext->start + ext->count) -
446 ext2fs_rb_erase(node, root);
447 rb_free_extent(bp, ext);
452 new_ext->start = start;
453 new_ext->count = count;
458 static int rb_remove_extent(__u64 start, __u64 count,
459 struct ext2fs_rb_private *bp)
461 struct rb_root *root = &bp->root;
462 struct rb_node *parent = NULL, **n = &root->rb_node;
463 struct rb_node *node;
464 struct bmap_rb_extent *ext;
465 __u64 new_start, new_count;
468 if (EXT2FS_RB_EMPTY_ROOT(root))
473 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
474 if (start < ext->start) {
477 } else if (start >= (ext->start + ext->count)) {
482 if ((start > ext->start) &&
483 (start + count) < (ext->start + ext->count)) {
484 /* We have to split extent into two */
485 new_start = start + count;
486 new_count = (ext->start + ext->count) - new_start;
488 ext->count = start - ext->start;
490 rb_insert_extent(new_start, new_count, bp);
494 if ((start + count) >= (ext->start + ext->count)) {
495 ext->count = start - ext->start;
499 if (0 == ext->count) {
500 parent = ext2fs_rb_next(&ext->node);
501 ext2fs_rb_erase(&ext->node, root);
502 rb_free_extent(bp, ext);
506 if (start == ext->start) {
513 /* See if we should delete or truncate extent on the right */
514 for (; parent != NULL; parent = node) {
515 node = ext2fs_rb_next(parent);
516 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
517 if ((ext->start + ext->count) <= start)
520 /* No more extents to be removed/truncated */
521 if ((start + count) < ext->start)
524 /* The entire extent is within the region to be removed */
525 if ((start + count) >= (ext->start + ext->count)) {
526 ext2fs_rb_erase(parent, root);
527 rb_free_extent(bp, ext);
531 /* modify the last extent in reigon to be removed */
532 ext->count -= ((start + count) - ext->start);
533 ext->start = start + count;
542 static int rb_mark_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
544 struct ext2fs_rb_private *bp;
548 bp = (struct ext2fs_rb_private *) bitmap->private;
549 arg -= bitmap->start;
551 return rb_insert_extent(arg, 1, bp);
554 static int rb_unmark_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
556 struct ext2fs_rb_private *bp;
559 bp = (struct ext2fs_rb_private *) bitmap->private;
560 arg -= bitmap->start;
562 retval = rb_remove_extent(arg, 1, bp);
563 check_tree(&bp->root, __func__);
569 static int rb_test_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
571 struct ext2fs_rb_private *bp;
573 bp = (struct ext2fs_rb_private *) bitmap->private;
574 arg -= bitmap->start;
576 return rb_test_bit(bp, arg);
579 static void rb_mark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg,
582 struct ext2fs_rb_private *bp;
583 struct bmap_rb_extent *new_ext;
585 bp = (struct ext2fs_rb_private *) bitmap->private;
586 arg -= bitmap->start;
588 rb_insert_extent(arg, num, bp);
591 static void rb_unmark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg,
594 struct ext2fs_rb_private *bp;
597 bp = (struct ext2fs_rb_private *) bitmap->private;
598 arg -= bitmap->start;
600 rb_remove_extent(arg, num, bp);
601 check_tree(&bp->root, __func__);
604 static int rb_test_clear_bmap_extent(ext2fs_generic_bitmap bitmap,
605 __u64 start, unsigned int len)
607 struct rb_node *parent = NULL, **n;
608 struct rb_node *node, *next;
609 struct ext2fs_rb_private *bp;
610 struct bmap_rb_extent *ext;
613 bp = (struct ext2fs_rb_private *) bitmap->private;
614 n = &bp->root.rb_node;
615 start -= bitmap->start;
617 if ((len == 0) || EXT2FS_RB_EMPTY_ROOT(&bp->root))
621 * If we find nothing, we should examine whole extent, but
622 * when we find match, the extent is not clean, thus be return
627 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
628 if (start < ext->start) {
630 } else if (start >= (ext->start + ext->count)) {
634 * We found extent int the tree -> extent is not
643 next = ext2fs_rb_next(node);
644 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
647 if ((ext->start + ext->count) <= start)
650 /* No more merging */
651 if ((start + len) <= ext->start)
660 static errcode_t rb_set_bmap_range(ext2fs_generic_bitmap bitmap,
661 __u64 start, size_t num, void *in)
663 struct ext2fs_rb_private *bp;
667 bp = (struct ext2fs_rb_private *) bitmap->private;
669 for (i = 0; i < num; i++) {
670 ret = ext2fs_test_bit(i, in);
672 rb_insert_extent(start + i - bitmap->start, 1, bp);
678 static errcode_t rb_get_bmap_range(ext2fs_generic_bitmap bitmap,
679 __u64 start, size_t num, void *out)
682 struct rb_node *parent = NULL, *next, **n;
683 struct ext2fs_rb_private *bp;
684 struct bmap_rb_extent *ext;
687 bp = (struct ext2fs_rb_private *) bitmap->private;
688 n = &bp->root.rb_node;
689 start -= bitmap->start;
691 if (EXT2FS_RB_EMPTY_ROOT(&bp->root))
696 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
697 if (start < ext->start) {
699 } else if (start >= (ext->start + ext->count)) {
706 for (; parent != NULL; parent = next) {
707 next = ext2fs_rb_next(parent);
708 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
710 while (((pos - start) < num) &&
711 (pos < ext->start)) {
712 ext2fs_fast_clear_bit64((pos - start), out);
716 if ((pos - start) >= num)
719 while (((pos - start) < num) &&
720 (pos < (ext->start + ext->count))) {
721 ext2fs_fast_set_bit64((pos - start), out);
726 while ((pos - start) < num) {
727 ext2fs_fast_clear_bit64((pos - start), out);
734 static void rb_clear_bmap(ext2fs_generic_bitmap bitmap)
736 struct ext2fs_rb_private *bp;
738 bp = (struct ext2fs_rb_private *) bitmap->private;
740 rb_free_tree(&bp->root);
746 static void rb_print_stats(ext2fs_generic_bitmap bitmap)
748 struct ext2fs_rb_private *bp;
749 struct rb_node *node = NULL;
750 struct bmap_rb_extent *ext;
753 __u64 min_size = ULONG_MAX;
754 __u64 size = 0, avg_size = 0;
755 __u64 mark_all, test_all;
756 double eff, m_hit = 0.0, t_hit = 0.0;
758 bp = (struct ext2fs_rb_private *) bitmap->private;
760 node = ext2fs_rb_first(&bp->root);
761 for (node = ext2fs_rb_first(&bp->root); node != NULL;
762 node = ext2fs_rb_next(node)) {
763 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
765 if (ext->count > max_size)
766 max_size = ext->count;
767 if (ext->count < min_size)
768 min_size = ext->count;
773 avg_size = size / count;
774 if (min_size == ULONG_MAX)
776 eff = (double)((count * sizeof(struct bmap_rb_extent)) << 3) /
777 (bitmap->real_end - bitmap->start);
778 #ifdef BMAP_STATS_OPS
779 mark_all = bitmap->stats.mark_count + bitmap->stats.mark_ext_count;
780 test_all = bitmap->stats.test_count + bitmap->stats.test_ext_count;
782 m_hit = ((double)bp->mark_hit / mark_all) * 100;
784 t_hit = ((double)bp->test_hit / test_all) * 100;
786 fprintf(stderr, "%16llu cache hits on test (%.2f%%)\n"
787 "%16llu cache hits on mark (%.2f%%)\n",
788 bp->test_hit, t_hit, bp->mark_hit, m_hit);
790 fprintf(stderr, "%16llu extents (%llu bytes)\n",
791 count, ((count * sizeof(struct bmap_rb_extent)) +
792 sizeof(struct ext2fs_rb_private)));
793 fprintf(stderr, "%16llu bits minimum size\n",
795 fprintf(stderr, "%16llu bits maximum size\n"
796 "%16llu bits average size\n",
798 fprintf(stderr, "%16llu bits set in bitmap (out of %llu)\n", size,
799 bitmap->real_end - bitmap->start);
801 "%16.4lf memory / bitmap bit memory ratio (bitarray = 1)\n",
805 static void rb_print_stats(ext2fs_generic_bitmap bitmap){}
808 struct ext2_bitmap_ops ext2fs_blkmap64_rbtree = {
809 .type = EXT2FS_BMAP64_RBTREE,
810 .new_bmap = rb_new_bmap,
811 .free_bmap = rb_free_bmap,
812 .copy_bmap = rb_copy_bmap,
813 .resize_bmap = rb_resize_bmap,
814 .mark_bmap = rb_mark_bmap,
815 .unmark_bmap = rb_unmark_bmap,
816 .test_bmap = rb_test_bmap,
817 .test_clear_bmap_extent = rb_test_clear_bmap_extent,
818 .mark_bmap_extent = rb_mark_bmap_extent,
819 .unmark_bmap_extent = rb_unmark_bmap_extent,
820 .set_bmap_range = rb_set_bmap_range,
821 .get_bmap_range = rb_get_bmap_range,
822 .clear_bmap = rb_clear_bmap,
823 .print_stats = rb_print_stats,