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 struct bmap_rb_extent *rcursor_next;
50 inline static struct bmap_rb_extent *node_to_extent(struct rb_node *node)
53 * This depends on the fact the struct rb_node is at the
54 * beginning of the bmap_rb_extent structure. We use this
55 * instead of the ext2fs_rb_entry macro because it causes gcc
56 * -Wall to generate a huge amount of noise.
58 return (struct bmap_rb_extent *) node;
61 static int rb_insert_extent(__u64 start, __u64 count,
62 struct ext2fs_rb_private *);
63 static void rb_get_new_extent(struct bmap_rb_extent **, __u64, __u64);
65 /* #define DEBUG_RB */
68 static void print_tree(struct rb_root *root)
70 struct rb_node *node = NULL;
71 struct bmap_rb_extent *ext;
73 printf("\t\t\t=================================\n");
74 node = ext2fs_rb_first(root);
75 for (node = ext2fs_rb_first(root); node != NULL;
76 node = ext2fs_rb_next(node)) {
77 ext = node_to_extent(node);
78 printf("\t\t\t--> (%llu -> %llu)\n",
79 ext->start, ext->start + ext->count);
81 printf("\t\t\t=================================\n");
84 static void check_tree(struct rb_root *root, const char *msg)
86 struct rb_node *new_node, *node, *next;
87 struct bmap_rb_extent *ext, *old = NULL;
89 for (node = ext2fs_rb_first(root); node;
90 node = ext2fs_rb_next(node)) {
91 ext = node_to_extent(node);
92 if (ext->count == 0) {
93 printf("Tree Error: count is zero\n");
94 printf("extent: %llu -> %llu (%llu)\n", ext->start,
95 ext->start + ext->count, ext->count);
98 if (ext->start + ext->count < ext->start) {
99 printf("Tree Error: start or count is crazy\n");
100 printf("extent: %llu -> %llu (%llu)\n", ext->start,
101 ext->start + ext->count, ext->count);
106 if (old->start > ext->start) {
107 printf("Tree Error: start is crazy\n");
108 printf("extent: %llu -> %llu (%llu)\n",
109 old->start, old->start + old->count,
111 printf("extent next: %llu -> %llu (%llu)\n",
112 ext->start, ext->start + ext->count,
116 if ((old->start + old->count) >= ext->start) {
117 printf("Tree Error: extent is crazy\n");
118 printf("extent: %llu -> %llu (%llu)\n",
119 old->start, old->start + old->count,
121 printf("extent next: %llu -> %llu (%llu)\n",
122 ext->start, ext->start + ext->count,
137 #define check_tree(root, msg) do {} while (0)
138 #define print_tree(root) do {} while (0)
141 static void rb_get_new_extent(struct bmap_rb_extent **ext, __u64 start,
144 struct bmap_rb_extent *new_ext;
147 retval = ext2fs_get_mem(sizeof (struct bmap_rb_extent),
150 perror("ext2fs_get_mem");
154 new_ext->start = start;
155 new_ext->count = count;
160 static void rb_free_extent(struct ext2fs_rb_private *bp,
161 struct bmap_rb_extent *ext)
163 if (bp->wcursor == ext)
165 if (bp->rcursor == ext)
167 if (bp->rcursor_next == ext)
168 bp->rcursor_next = NULL;
169 ext2fs_free_mem(&ext);
172 static errcode_t rb_alloc_private_data (ext2fs_generic_bitmap bitmap)
174 struct ext2fs_rb_private *bp;
177 retval = ext2fs_get_mem(sizeof (struct ext2fs_rb_private), &bp);
183 bp->rcursor_next = NULL;
186 #ifdef BMAP_STATS_OPS
191 bitmap->private = (void *) bp;
195 static errcode_t rb_new_bmap(ext2_filsys fs EXT2FS_ATTR((unused)),
196 ext2fs_generic_bitmap bitmap)
200 retval = rb_alloc_private_data (bitmap);
207 static void rb_free_tree(struct rb_root *root)
209 struct bmap_rb_extent *ext;
210 struct rb_node *node, *next;
212 for (node = ext2fs_rb_first(root); node; node = next) {
213 next = ext2fs_rb_next(node);
214 ext = node_to_extent(node);
215 ext2fs_rb_erase(node, root);
216 ext2fs_free_mem(&ext);
220 static void rb_free_bmap(ext2fs_generic_bitmap bitmap)
222 struct ext2fs_rb_private *bp;
224 bp = (struct ext2fs_rb_private *) bitmap->private;
226 rb_free_tree(&bp->root);
227 ext2fs_free_mem(&bp);
231 static errcode_t rb_copy_bmap(ext2fs_generic_bitmap src,
232 ext2fs_generic_bitmap dest)
234 struct ext2fs_rb_private *src_bp, *dest_bp;
235 struct bmap_rb_extent *src_ext, *dest_ext;
236 struct rb_node *dest_node, *src_node, *dest_last, **n;
237 errcode_t retval = 0;
239 retval = rb_alloc_private_data (dest);
243 src_bp = (struct ext2fs_rb_private *) src->private;
244 dest_bp = (struct ext2fs_rb_private *) dest->private;
245 src_bp->rcursor = NULL;
246 dest_bp->rcursor = NULL;
248 src_node = ext2fs_rb_first(&src_bp->root);
250 src_ext = node_to_extent(src_node);
251 retval = ext2fs_get_mem(sizeof (struct bmap_rb_extent),
256 memcpy(dest_ext, src_ext, sizeof(struct bmap_rb_extent));
258 dest_node = &dest_ext->node;
259 n = &dest_bp->root.rb_node;
263 dest_last = ext2fs_rb_last(&dest_bp->root);
264 n = &(dest_last)->rb_right;
267 ext2fs_rb_link_node(dest_node, dest_last, n);
268 ext2fs_rb_insert_color(dest_node, &dest_bp->root);
270 src_node = ext2fs_rb_next(src_node);
276 static void rb_truncate(__u64 new_max, struct rb_root *root)
278 struct bmap_rb_extent *ext;
279 struct rb_node *node;
281 node = ext2fs_rb_last(root);
283 ext = node_to_extent(node);
285 if ((ext->start + ext->count - 1) <= new_max)
287 else if (ext->start > new_max) {
288 ext2fs_rb_erase(node, root);
289 ext2fs_free_mem(&ext);
290 node = ext2fs_rb_last(root);
293 ext->count = new_max - ext->start + 1;
297 static errcode_t rb_resize_bmap(ext2fs_generic_bitmap bmap,
298 __u64 new_end, __u64 new_real_end)
300 struct ext2fs_rb_private *bp;
302 if (new_real_end >= bmap->real_end) {
304 bmap->real_end = new_real_end;
308 bp = (struct ext2fs_rb_private *) bmap->private;
312 /* truncate tree to new_real_end size */
313 rb_truncate(new_real_end, &bp->root);
316 bmap->real_end = new_real_end;
322 rb_test_bit(struct ext2fs_rb_private *bp, __u64 bit)
324 struct bmap_rb_extent *rcursor, *next_ext = NULL;
325 struct rb_node *parent = NULL, *next;
326 struct rb_node **n = &bp->root.rb_node;
327 struct bmap_rb_extent *ext;
329 rcursor = bp->rcursor;
333 if (bit >= rcursor->start && bit < rcursor->start + rcursor->count) {
334 #ifdef BMAP_STATS_OPS
340 next_ext = bp->rcursor_next;
342 next = ext2fs_rb_next(&rcursor->node);
344 next_ext = node_to_extent(next);
345 bp->rcursor_next = next_ext;
348 if ((bit >= rcursor->start + rcursor->count) &&
349 (bit < next_ext->start)) {
350 #ifdef BMAP_STATS_OPS
357 bp->rcursor_next = NULL;
359 rcursor = bp->wcursor;
363 if (bit >= rcursor->start && bit < rcursor->start + rcursor->count)
370 ext = node_to_extent(parent);
371 if (bit < ext->start)
373 else if (bit >= (ext->start + ext->count))
377 bp->rcursor_next = NULL;
384 static int rb_insert_extent(__u64 start, __u64 count,
385 struct ext2fs_rb_private *bp)
387 struct rb_root *root = &bp->root;
388 struct rb_node *parent = NULL, **n = &root->rb_node;
389 struct rb_node *new_node, *node, *next;
390 struct bmap_rb_extent *new_ext;
391 struct bmap_rb_extent *ext;
394 bp->rcursor_next = NULL;
397 if (start >= ext->start &&
398 start <= (ext->start + ext->count)) {
399 #ifdef BMAP_STATS_OPS
408 ext = node_to_extent(parent);
410 if (start < ext->start) {
412 } else if (start > (ext->start + ext->count)) {
416 if ((start + count) <= (ext->start + ext->count))
419 if ((ext->start + ext->count) == start)
424 count += (start - ext->start);
427 new_node = &ext->node;
433 rb_get_new_extent(&new_ext, start, count);
435 new_node = &new_ext->node;
436 ext2fs_rb_link_node(new_node, parent, n);
437 ext2fs_rb_insert_color(new_node, root);
438 bp->wcursor = new_ext;
440 node = ext2fs_rb_prev(new_node);
442 ext = node_to_extent(node);
443 if ((ext->start + ext->count) == start) {
446 ext2fs_rb_erase(node, root);
447 rb_free_extent(bp, ext);
452 /* See if we can merge extent to the right */
453 for (node = ext2fs_rb_next(new_node); node != NULL; node = next) {
454 next = ext2fs_rb_next(node);
455 ext = node_to_extent(node);
457 if ((ext->start + ext->count) <= start)
460 /* No more merging */
461 if ((start + count) < ext->start)
464 /* ext is embedded in new_ext interval */
465 if ((start + count) >= (ext->start + ext->count)) {
466 ext2fs_rb_erase(node, root);
467 rb_free_extent(bp, ext);
470 /* merge ext with new_ext */
471 count += ((ext->start + ext->count) -
473 ext2fs_rb_erase(node, root);
474 rb_free_extent(bp, ext);
479 new_ext->start = start;
480 new_ext->count = count;
485 static int rb_remove_extent(__u64 start, __u64 count,
486 struct ext2fs_rb_private *bp)
488 struct rb_root *root = &bp->root;
489 struct rb_node *parent = NULL, **n = &root->rb_node;
490 struct rb_node *node;
491 struct bmap_rb_extent *ext;
492 __u64 new_start, new_count;
495 if (EXT2FS_RB_EMPTY_ROOT(root))
500 ext = node_to_extent(parent);
501 if (start < ext->start) {
504 } else if (start >= (ext->start + ext->count)) {
509 if ((start > ext->start) &&
510 (start + count) < (ext->start + ext->count)) {
511 /* We have to split extent into two */
512 new_start = start + count;
513 new_count = (ext->start + ext->count) - new_start;
515 ext->count = start - ext->start;
517 rb_insert_extent(new_start, new_count, bp);
521 if ((start + count) >= (ext->start + ext->count)) {
522 ext->count = start - ext->start;
526 if (0 == ext->count) {
527 parent = ext2fs_rb_next(&ext->node);
528 ext2fs_rb_erase(&ext->node, root);
529 rb_free_extent(bp, ext);
533 if (start == ext->start) {
540 /* See if we should delete or truncate extent on the right */
541 for (; parent != NULL; parent = node) {
542 node = ext2fs_rb_next(parent);
543 ext = node_to_extent(parent);
544 if ((ext->start + ext->count) <= start)
547 /* No more extents to be removed/truncated */
548 if ((start + count) < ext->start)
551 /* The entire extent is within the region to be removed */
552 if ((start + count) >= (ext->start + ext->count)) {
553 ext2fs_rb_erase(parent, root);
554 rb_free_extent(bp, ext);
558 /* modify the last extent in reigon to be removed */
559 ext->count -= ((start + count) - ext->start);
560 ext->start = start + count;
569 static int rb_mark_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
571 struct ext2fs_rb_private *bp;
574 bp = (struct ext2fs_rb_private *) bitmap->private;
575 arg -= bitmap->start;
577 retval = rb_insert_extent(arg, 1, bp);
578 check_tree(&bp->root, __func__);
582 static int rb_unmark_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
584 struct ext2fs_rb_private *bp;
587 bp = (struct ext2fs_rb_private *) bitmap->private;
588 arg -= bitmap->start;
590 retval = rb_remove_extent(arg, 1, bp);
591 check_tree(&bp->root, __func__);
597 static int rb_test_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
599 struct ext2fs_rb_private *bp;
601 bp = (struct ext2fs_rb_private *) bitmap->private;
602 arg -= bitmap->start;
604 return rb_test_bit(bp, arg);
607 static void rb_mark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg,
610 struct ext2fs_rb_private *bp;
612 bp = (struct ext2fs_rb_private *) bitmap->private;
613 arg -= bitmap->start;
615 rb_insert_extent(arg, num, bp);
616 check_tree(&bp->root, __func__);
619 static void rb_unmark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg,
622 struct ext2fs_rb_private *bp;
624 bp = (struct ext2fs_rb_private *) bitmap->private;
625 arg -= bitmap->start;
627 rb_remove_extent(arg, num, bp);
628 check_tree(&bp->root, __func__);
631 static int rb_test_clear_bmap_extent(ext2fs_generic_bitmap bitmap,
632 __u64 start, unsigned int len)
634 struct rb_node *parent = NULL, **n;
635 struct rb_node *node, *next;
636 struct ext2fs_rb_private *bp;
637 struct bmap_rb_extent *ext;
640 bp = (struct ext2fs_rb_private *) bitmap->private;
641 n = &bp->root.rb_node;
642 start -= bitmap->start;
644 if ((len == 0) || EXT2FS_RB_EMPTY_ROOT(&bp->root))
648 * If we find nothing, we should examine whole extent, but
649 * when we find match, the extent is not clean, thus be return
654 ext = node_to_extent(parent);
655 if (start < ext->start) {
657 } else if (start >= (ext->start + ext->count)) {
661 * We found extent int the tree -> extent is not
670 next = ext2fs_rb_next(node);
671 ext = node_to_extent(node);
674 if ((ext->start + ext->count) <= start)
677 /* No more merging */
678 if ((start + len) <= ext->start)
687 static errcode_t rb_set_bmap_range(ext2fs_generic_bitmap bitmap,
688 __u64 start, size_t num, void *in)
690 struct ext2fs_rb_private *bp;
691 unsigned char *cp = in;
695 bp = (struct ext2fs_rb_private *) bitmap->private;
697 for (i = 0; i < num; i++) {
699 unsigned char c = cp[i/8];
706 if ((c == 0x00) && (first_set == -1)) {
711 if (ext2fs_test_bit(i, in)) {
719 rb_insert_extent(start + first_set - bitmap->start,
721 check_tree(&bp->root, __func__);
724 if (first_set != -1) {
725 rb_insert_extent(start + first_set - bitmap->start,
726 num - first_set, bp);
727 check_tree(&bp->root, __func__);
733 static errcode_t rb_get_bmap_range(ext2fs_generic_bitmap bitmap,
734 __u64 start, size_t num, void *out)
737 struct rb_node *parent = NULL, *next, **n;
738 struct ext2fs_rb_private *bp;
739 struct bmap_rb_extent *ext;
743 bp = (struct ext2fs_rb_private *) bitmap->private;
744 n = &bp->root.rb_node;
745 start -= bitmap->start;
747 if (EXT2FS_RB_EMPTY_ROOT(&bp->root))
752 ext = node_to_extent(parent);
753 if (start < ext->start) {
755 } else if (start >= (ext->start + ext->count)) {
761 memset(out, 0, (num + 7) >> 3);
763 for (; parent != NULL; parent = next) {
764 next = ext2fs_rb_next(parent);
765 ext = node_to_extent(parent);
769 if (pos >= start + num)
772 count -= start - pos;
777 if (pos + count > start + num)
778 count = start + num - pos;
782 ((pos - start) % 8) == 0) {
783 int nbytes = count >> 3;
784 int offset = (pos - start) >> 3;
786 memset(((char *) out) + offset, 0xFF, nbytes);
788 count -= nbytes << 3;
791 ext2fs_fast_set_bit64((pos - start), out);
799 static void rb_clear_bmap(ext2fs_generic_bitmap bitmap)
801 struct ext2fs_rb_private *bp;
803 bp = (struct ext2fs_rb_private *) bitmap->private;
805 rb_free_tree(&bp->root);
807 bp->rcursor_next = NULL;
809 check_tree(&bp->root, __func__);
812 static errcode_t rb_find_first_zero(ext2fs_generic_bitmap bitmap,
813 __u64 start, __u64 end, __u64 *out)
815 struct rb_node *parent = NULL, **n;
816 struct ext2fs_rb_private *bp;
817 struct bmap_rb_extent *ext;
819 bp = (struct ext2fs_rb_private *) bitmap->private;
820 n = &bp->root.rb_node;
821 start -= bitmap->start;
822 end -= bitmap->start;
827 if (EXT2FS_RB_EMPTY_ROOT(&bp->root))
832 ext = node_to_extent(parent);
833 if (start < ext->start) {
835 } else if (start >= (ext->start + ext->count)) {
837 } else if (ext->start + ext->count <= end) {
838 *out = ext->start + ext->count + bitmap->start;
844 *out = start + bitmap->start;
848 static errcode_t rb_find_first_set(ext2fs_generic_bitmap bitmap,
849 __u64 start, __u64 end, __u64 *out)
851 struct rb_node *parent = NULL, **n;
852 struct rb_node *node;
853 struct ext2fs_rb_private *bp;
854 struct bmap_rb_extent *ext;
856 bp = (struct ext2fs_rb_private *) bitmap->private;
857 n = &bp->root.rb_node;
858 start -= bitmap->start;
859 end -= bitmap->start;
864 if (EXT2FS_RB_EMPTY_ROOT(&bp->root))
869 ext = node_to_extent(parent);
870 if (start < ext->start) {
872 } else if (start >= (ext->start + ext->count)) {
875 /* The start bit is set */
876 *out = start + bitmap->start;
882 ext = node_to_extent(node);
883 if (ext->start < start) {
884 node = ext2fs_rb_next(node);
887 ext = node_to_extent(node);
889 if (ext->start <= end) {
890 *out = ext->start + bitmap->start;
897 static void rb_print_stats(ext2fs_generic_bitmap bitmap)
899 struct ext2fs_rb_private *bp;
900 struct rb_node *node = NULL;
901 struct bmap_rb_extent *ext;
904 __u64 min_size = ULONG_MAX;
905 __u64 size = 0, avg_size = 0;
907 #ifdef BMAP_STATS_OPS
908 __u64 mark_all, test_all;
909 double m_hit = 0.0, t_hit = 0.0;
912 bp = (struct ext2fs_rb_private *) bitmap->private;
914 for (node = ext2fs_rb_first(&bp->root); node != NULL;
915 node = ext2fs_rb_next(node)) {
916 ext = node_to_extent(node);
918 if (ext->count > max_size)
919 max_size = ext->count;
920 if (ext->count < min_size)
921 min_size = ext->count;
926 avg_size = size / count;
927 if (min_size == ULONG_MAX)
929 eff = (double)((count * sizeof(struct bmap_rb_extent)) << 3) /
930 (bitmap->real_end - bitmap->start);
931 #ifdef BMAP_STATS_OPS
932 mark_all = bitmap->stats.mark_count + bitmap->stats.mark_ext_count;
933 test_all = bitmap->stats.test_count + bitmap->stats.test_ext_count;
935 m_hit = ((double)bp->mark_hit / mark_all) * 100;
937 t_hit = ((double)bp->test_hit / test_all) * 100;
939 fprintf(stderr, "%16llu cache hits on test (%.2f%%)\n"
940 "%16llu cache hits on mark (%.2f%%)\n",
941 bp->test_hit, t_hit, bp->mark_hit, m_hit);
943 fprintf(stderr, "%16llu extents (%llu bytes)\n",
944 count, ((count * sizeof(struct bmap_rb_extent)) +
945 sizeof(struct ext2fs_rb_private)));
946 fprintf(stderr, "%16llu bits minimum size\n",
948 fprintf(stderr, "%16llu bits maximum size\n"
949 "%16llu bits average size\n",
951 fprintf(stderr, "%16llu bits set in bitmap (out of %llu)\n", size,
952 bitmap->real_end - bitmap->start);
954 "%16.4lf memory / bitmap bit memory ratio (bitarray = 1)\n",
958 static void rb_print_stats(ext2fs_generic_bitmap bitmap){}
961 struct ext2_bitmap_ops ext2fs_blkmap64_rbtree = {
962 .type = EXT2FS_BMAP64_RBTREE,
963 .new_bmap = rb_new_bmap,
964 .free_bmap = rb_free_bmap,
965 .copy_bmap = rb_copy_bmap,
966 .resize_bmap = rb_resize_bmap,
967 .mark_bmap = rb_mark_bmap,
968 .unmark_bmap = rb_unmark_bmap,
969 .test_bmap = rb_test_bmap,
970 .test_clear_bmap_extent = rb_test_clear_bmap_extent,
971 .mark_bmap_extent = rb_mark_bmap_extent,
972 .unmark_bmap_extent = rb_unmark_bmap_extent,
973 .set_bmap_range = rb_set_bmap_range,
974 .get_bmap_range = rb_get_bmap_range,
975 .clear_bmap = rb_clear_bmap,
976 .print_stats = rb_print_stats,
977 .find_first_zero = rb_find_first_zero,
978 .find_first_set = rb_find_first_set,