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;
43 #ifdef ENABLE_BMAP_STATS_OPS
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),
140 new_ext->start = start;
141 new_ext->count = count;
146 static void rb_free_extent(struct ext2fs_rb_private *bp,
147 struct bmap_rb_extent *ext)
149 if (*bp->wcursor == ext)
151 if (*bp->rcursor == ext)
153 ext2fs_free_mem(&ext);
156 static errcode_t rb_alloc_private_data (ext2fs_generic_bitmap bitmap)
158 struct ext2fs_rb_private *bp;
161 retval = ext2fs_get_mem(sizeof (struct ext2fs_rb_private), &bp);
166 retval = ext2fs_get_mem(sizeof(struct bmap_rb_extent *), &bp->rcursor);
169 retval = ext2fs_get_mem(sizeof(struct bmap_rb_extent *), &bp->wcursor);
175 #ifdef ENABLE_BMAP_STATS_OPS
180 bitmap->private = (void *) bp;
184 static errcode_t rb_new_bmap(ext2_filsys fs EXT2FS_ATTR((unused)),
185 ext2fs_generic_bitmap bitmap)
189 retval = rb_alloc_private_data (bitmap);
196 static void rb_free_tree(struct rb_root *root)
198 struct bmap_rb_extent *ext;
199 struct rb_node *node, *next;
201 for (node = ext2fs_rb_first(root); node; node = next) {
202 next = ext2fs_rb_next(node);
203 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
204 ext2fs_rb_erase(node, root);
205 ext2fs_free_mem(&ext);
209 static void rb_free_bmap(ext2fs_generic_bitmap bitmap)
211 struct ext2fs_rb_private *bp;
213 bp = (struct ext2fs_rb_private *) bitmap->private;
215 rb_free_tree(&bp->root);
216 ext2fs_free_mem(&bp->rcursor);
217 ext2fs_free_mem(&bp->wcursor);
218 ext2fs_free_mem(&bp);
222 static errcode_t rb_copy_bmap(ext2fs_generic_bitmap src,
223 ext2fs_generic_bitmap dest)
225 struct ext2fs_rb_private *src_bp, *dest_bp;
226 struct bmap_rb_extent *src_ext, *dest_ext;
227 struct rb_node *dest_node, *src_node, *dest_last, **n;
228 errcode_t retval = 0;
230 retval = rb_alloc_private_data (dest);
234 src_bp = (struct ext2fs_rb_private *) src->private;
235 dest_bp = (struct ext2fs_rb_private *) dest->private;
236 *src_bp->rcursor = NULL;
237 *dest_bp->rcursor = NULL;
239 src_node = ext2fs_rb_first(&src_bp->root);
241 src_ext = ext2fs_rb_entry(src_node, struct bmap_rb_extent, node);
242 retval = ext2fs_get_mem(sizeof (struct bmap_rb_extent),
247 memcpy(dest_ext, src_ext, sizeof(struct bmap_rb_extent));
249 dest_node = &dest_ext->node;
250 n = &dest_bp->root.rb_node;
254 dest_last = ext2fs_rb_last(&dest_bp->root);
255 n = &(dest_last)->rb_right;
258 ext2fs_rb_link_node(dest_node, dest_last, n);
259 ext2fs_rb_insert_color(dest_node, &dest_bp->root);
261 src_node = ext2fs_rb_next(src_node);
267 static void rb_truncate(__u64 new_max, struct rb_root *root)
269 struct bmap_rb_extent *ext;
270 struct rb_node *node;
272 node = ext2fs_rb_last(root);
274 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
276 if ((ext->start + ext->count - 1) <= new_max)
278 else if (ext->start > new_max) {
279 ext2fs_rb_erase(node, root);
280 ext2fs_free_mem(&ext);
281 node = ext2fs_rb_last(root);
284 ext->count = new_max - ext->start + 1;
288 static errcode_t rb_resize_bmap(ext2fs_generic_bitmap bmap,
289 __u64 new_end, __u64 new_real_end)
291 struct ext2fs_rb_private *bp;
293 if (new_real_end >= bmap->real_end) {
295 bmap->real_end = new_real_end;
299 bp = (struct ext2fs_rb_private *) bmap->private;
303 /* truncate tree to new_real_end size */
304 rb_truncate(new_real_end, &bp->root);
307 bmap->real_end = new_real_end;
313 rb_test_bit(struct ext2fs_rb_private *bp, __u64 bit)
315 struct bmap_rb_extent *rcursor;
316 struct rb_node *parent = NULL;
317 struct rb_node **n = &bp->root.rb_node;
318 struct bmap_rb_extent *ext;
320 rcursor = *bp->rcursor;
324 if (bit >= rcursor->start && bit < rcursor->start + rcursor->count) {
325 #ifdef ENABLE_BMAP_STATS_OPS
331 rcursor = *bp->wcursor;
335 if (bit >= rcursor->start && bit < rcursor->start + rcursor->count)
342 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
343 if (bit < ext->start)
345 else if (bit >= (ext->start + ext->count))
355 static int rb_insert_extent(__u64 start, __u64 count,
356 struct ext2fs_rb_private *bp)
358 struct rb_root *root = &bp->root;
359 struct rb_node *parent = NULL, **n = &root->rb_node;
360 struct rb_node *new_node, *node, *next;
361 struct bmap_rb_extent *new_ext;
362 struct bmap_rb_extent *ext;
367 if (start >= ext->start &&
368 start <= (ext->start + ext->count)) {
369 #ifdef ENABLE_BMAP_STATS_OPS
378 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
380 if (start < ext->start) {
382 } else if (start > (ext->start + ext->count)) {
386 if ((start + count) <= (ext->start + ext->count))
389 if ((ext->start + ext->count) == start)
394 count += (start - ext->start);
397 new_node = &ext->node;
403 rb_get_new_extent(&new_ext, start, count);
405 new_node = &new_ext->node;
406 ext2fs_rb_link_node(new_node, parent, n);
407 ext2fs_rb_insert_color(new_node, root);
408 *bp->wcursor = new_ext;
410 node = ext2fs_rb_prev(new_node);
412 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
413 if ((ext->start + ext->count) == start) {
416 ext2fs_rb_erase(node, root);
417 rb_free_extent(bp, ext);
422 /* See if we can merge extent to the right */
423 for (node = ext2fs_rb_next(new_node); node != NULL; node = next) {
424 next = ext2fs_rb_next(node);
425 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
427 if ((ext->start + ext->count) <= start)
430 /* No more merging */
431 if ((start + count) < ext->start)
434 /* ext is embedded in new_ext interval */
435 if ((start + count) >= (ext->start + ext->count)) {
436 ext2fs_rb_erase(node, root);
437 rb_free_extent(bp, ext);
440 /* merge ext with new_ext */
441 count += ((ext->start + ext->count) -
443 ext2fs_rb_erase(node, root);
444 rb_free_extent(bp, ext);
449 new_ext->start = start;
450 new_ext->count = count;
455 static int rb_remove_extent(__u64 start, __u64 count,
456 struct ext2fs_rb_private *bp)
458 struct rb_root *root = &bp->root;
459 struct rb_node *parent = NULL, **n = &root->rb_node;
460 struct rb_node *node;
461 struct bmap_rb_extent *ext;
462 __u64 new_start, new_count;
465 if (EXT2FS_RB_EMPTY_ROOT(root))
470 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
471 if (start < ext->start) {
474 } else if (start >= (ext->start + ext->count)) {
479 if ((start > ext->start) &&
480 (start + count) < (ext->start + ext->count)) {
481 /* We have to split extent into two */
482 new_start = start + count;
483 new_count = (ext->start + ext->count) - new_start;
485 ext->count = start - ext->start;
487 rb_insert_extent(new_start, new_count, bp);
491 if ((start + count) >= (ext->start + ext->count)) {
492 ext->count = start - ext->start;
496 if (0 == ext->count) {
497 parent = ext2fs_rb_next(&ext->node);
498 ext2fs_rb_erase(&ext->node, root);
499 rb_free_extent(bp, ext);
503 if (start == ext->start) {
510 /* See if we should delete or truncate extent on the right */
511 for (; parent != NULL; parent = node) {
512 node = ext2fs_rb_next(parent);
513 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
514 if ((ext->start + ext->count) <= start)
517 /* No more extents to be removed/truncated */
518 if ((start + count) < ext->start)
521 /* The entire extent is within the region to be removed */
522 if ((start + count) >= (ext->start + ext->count)) {
523 ext2fs_rb_erase(parent, root);
524 rb_free_extent(bp, ext);
528 /* modify the last extent in reigon to be removed */
529 ext->count -= ((start + count) - ext->start);
530 ext->start = start + count;
539 static int rb_mark_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
541 struct ext2fs_rb_private *bp;
543 bp = (struct ext2fs_rb_private *) bitmap->private;
544 arg -= bitmap->start;
546 return rb_insert_extent(arg, 1, bp);
549 static int rb_unmark_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
551 struct ext2fs_rb_private *bp;
554 bp = (struct ext2fs_rb_private *) bitmap->private;
555 arg -= bitmap->start;
557 retval = rb_remove_extent(arg, 1, bp);
558 check_tree(&bp->root, __func__);
564 static int rb_test_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
566 struct ext2fs_rb_private *bp;
568 bp = (struct ext2fs_rb_private *) bitmap->private;
569 arg -= bitmap->start;
571 return rb_test_bit(bp, arg);
574 static void rb_mark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg,
577 struct ext2fs_rb_private *bp;
579 bp = (struct ext2fs_rb_private *) bitmap->private;
580 arg -= bitmap->start;
582 rb_insert_extent(arg, num, bp);
585 static void rb_unmark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg,
588 struct ext2fs_rb_private *bp;
590 bp = (struct ext2fs_rb_private *) bitmap->private;
591 arg -= bitmap->start;
593 rb_remove_extent(arg, num, bp);
594 check_tree(&bp->root, __func__);
597 static int rb_test_clear_bmap_extent(ext2fs_generic_bitmap bitmap,
598 __u64 start, unsigned int len)
600 struct rb_node *parent = NULL, **n;
601 struct rb_node *node, *next;
602 struct ext2fs_rb_private *bp;
603 struct bmap_rb_extent *ext;
606 bp = (struct ext2fs_rb_private *) bitmap->private;
607 n = &bp->root.rb_node;
608 start -= bitmap->start;
610 if ((len == 0) || EXT2FS_RB_EMPTY_ROOT(&bp->root))
614 * If we find nothing, we should examine whole extent, but
615 * when we find match, the extent is not clean, thus be return
620 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
621 if (start < ext->start) {
623 } else if (start >= (ext->start + ext->count)) {
627 * We found extent int the tree -> extent is not
636 next = ext2fs_rb_next(node);
637 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
640 if ((ext->start + ext->count) <= start)
643 /* No more merging */
644 if ((start + len) <= ext->start)
653 static errcode_t rb_set_bmap_range(ext2fs_generic_bitmap bitmap,
654 __u64 start, size_t num, void *in)
656 struct ext2fs_rb_private *bp;
660 bp = (struct ext2fs_rb_private *) bitmap->private;
662 for (i = 0; i < num; i++) {
663 ret = ext2fs_test_bit(i, in);
665 rb_insert_extent(start + i - bitmap->start, 1, bp);
671 static errcode_t rb_get_bmap_range(ext2fs_generic_bitmap bitmap,
672 __u64 start, size_t num, void *out)
675 struct rb_node *parent = NULL, *next, **n;
676 struct ext2fs_rb_private *bp;
677 struct bmap_rb_extent *ext;
680 bp = (struct ext2fs_rb_private *) bitmap->private;
681 n = &bp->root.rb_node;
682 start -= bitmap->start;
684 if (EXT2FS_RB_EMPTY_ROOT(&bp->root))
689 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
690 if (start < ext->start) {
692 } else if (start >= (ext->start + ext->count)) {
699 for (; parent != NULL; parent = next) {
700 next = ext2fs_rb_next(parent);
701 ext = ext2fs_rb_entry(parent, struct bmap_rb_extent, node);
703 while (((pos - start) < num) &&
704 (pos < ext->start)) {
705 ext2fs_fast_clear_bit64((pos - start), out);
709 if ((pos - start) >= num)
712 while (((pos - start) < num) &&
713 (pos < (ext->start + ext->count))) {
714 ext2fs_fast_set_bit64((pos - start), out);
719 while ((pos - start) < num) {
720 ext2fs_fast_clear_bit64((pos - start), out);
727 static void rb_clear_bmap(ext2fs_generic_bitmap bitmap)
729 struct ext2fs_rb_private *bp;
731 bp = (struct ext2fs_rb_private *) bitmap->private;
733 rb_free_tree(&bp->root);
738 #ifdef ENABLE_BMAP_STATS
739 static void rb_print_stats(ext2fs_generic_bitmap bitmap)
741 struct ext2fs_rb_private *bp;
742 struct rb_node *node = NULL;
743 struct bmap_rb_extent *ext;
746 __u64 min_size = ULONG_MAX;
747 __u64 size = 0, avg_size = 0;
749 #ifdef ENABLE_BMAP_STATS_OPS
750 __u64 mark_all, test_all;
751 double m_hit = 0.0, t_hit = 0.0;
754 bp = (struct ext2fs_rb_private *) bitmap->private;
756 node = ext2fs_rb_first(&bp->root);
757 for (node = ext2fs_rb_first(&bp->root); node != NULL;
758 node = ext2fs_rb_next(node)) {
759 ext = ext2fs_rb_entry(node, struct bmap_rb_extent, node);
761 if (ext->count > max_size)
762 max_size = ext->count;
763 if (ext->count < min_size)
764 min_size = ext->count;
769 avg_size = size / count;
770 if (min_size == ULONG_MAX)
772 eff = (double)((count * sizeof(struct bmap_rb_extent)) << 3) /
773 (bitmap->real_end - bitmap->start);
774 #ifdef ENABLE_BMAP_STATS_OPS
775 mark_all = bitmap->stats.mark_count + bitmap->stats.mark_ext_count;
776 test_all = bitmap->stats.test_count + bitmap->stats.test_ext_count;
778 m_hit = ((double)bp->mark_hit / mark_all) * 100;
780 t_hit = ((double)bp->test_hit / test_all) * 100;
782 fprintf(stderr, "%16llu cache hits on test (%.2f%%)\n"
783 "%16llu cache hits on mark (%.2f%%)\n",
784 bp->test_hit, t_hit, bp->mark_hit, m_hit);
786 fprintf(stderr, "%16llu extents (%llu bytes)\n",
787 count, ((count * sizeof(struct bmap_rb_extent)) +
788 sizeof(struct ext2fs_rb_private)));
789 fprintf(stderr, "%16llu bits minimum size\n",
791 fprintf(stderr, "%16llu bits maximum size\n"
792 "%16llu bits average size\n",
794 fprintf(stderr, "%16llu bits set in bitmap (out of %llu)\n", size,
795 bitmap->real_end - bitmap->start);
797 "%16.4lf memory / bitmap bit memory ratio (bitarray = 1)\n",
801 static void rb_print_stats(ext2fs_generic_bitmap bitmap){}
804 struct ext2_bitmap_ops ext2fs_blkmap64_rbtree = {
805 .type = EXT2FS_BMAP64_RBTREE,
806 .new_bmap = rb_new_bmap,
807 .free_bmap = rb_free_bmap,
808 .copy_bmap = rb_copy_bmap,
809 .resize_bmap = rb_resize_bmap,
810 .mark_bmap = rb_mark_bmap,
811 .unmark_bmap = rb_unmark_bmap,
812 .test_bmap = rb_test_bmap,
813 .test_clear_bmap_extent = rb_test_clear_bmap_extent,
814 .mark_bmap_extent = rb_mark_bmap_extent,
815 .unmark_bmap_extent = rb_unmark_bmap_extent,
816 .set_bmap_range = rb_set_bmap_range,
817 .get_bmap_range = rb_get_bmap_range,
818 .clear_bmap = rb_clear_bmap,
819 .print_stats = rb_print_stats,