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 crazy\n");
94 printf("extent: %llu -> %llu (%u)\n", ext->start,
95 ext->start + ext->count, ext->count);
99 printf("Tree Error: start is crazy\n");
100 printf("extent: %llu -> %llu (%u)\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 (%u)\n",
109 old->start, old->start + old->count,
111 printf("extent next: %llu -> %llu (%u)\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 (%u)\n",
119 old->start, old->start + old->count,
121 printf("extent next: %llu -> %llu (%u)\n",
122 ext->start, ext->start + ext->count,
137 #define check_tree(root, msg) do {} while (0)
138 #define print_tree(root, msg) 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;
573 bp = (struct ext2fs_rb_private *) bitmap->private;
574 arg -= bitmap->start;
576 return rb_insert_extent(arg, 1, bp);
579 static int rb_unmark_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
581 struct ext2fs_rb_private *bp;
584 bp = (struct ext2fs_rb_private *) bitmap->private;
585 arg -= bitmap->start;
587 retval = rb_remove_extent(arg, 1, bp);
588 check_tree(&bp->root, __func__);
594 static int rb_test_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
596 struct ext2fs_rb_private *bp;
598 bp = (struct ext2fs_rb_private *) bitmap->private;
599 arg -= bitmap->start;
601 return rb_test_bit(bp, arg);
604 static void rb_mark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg,
607 struct ext2fs_rb_private *bp;
609 bp = (struct ext2fs_rb_private *) bitmap->private;
610 arg -= bitmap->start;
612 rb_insert_extent(arg, num, bp);
615 static void rb_unmark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg,
618 struct ext2fs_rb_private *bp;
620 bp = (struct ext2fs_rb_private *) bitmap->private;
621 arg -= bitmap->start;
623 rb_remove_extent(arg, num, bp);
624 check_tree(&bp->root, __func__);
627 static int rb_test_clear_bmap_extent(ext2fs_generic_bitmap bitmap,
628 __u64 start, unsigned int len)
630 struct rb_node *parent = NULL, **n;
631 struct rb_node *node, *next;
632 struct ext2fs_rb_private *bp;
633 struct bmap_rb_extent *ext;
636 bp = (struct ext2fs_rb_private *) bitmap->private;
637 n = &bp->root.rb_node;
638 start -= bitmap->start;
640 if ((len == 0) || EXT2FS_RB_EMPTY_ROOT(&bp->root))
644 * If we find nothing, we should examine whole extent, but
645 * when we find match, the extent is not clean, thus be return
650 ext = node_to_extent(parent);
651 if (start < ext->start) {
653 } else if (start >= (ext->start + ext->count)) {
657 * We found extent int the tree -> extent is not
666 next = ext2fs_rb_next(node);
667 ext = node_to_extent(node);
670 if ((ext->start + ext->count) <= start)
673 /* No more merging */
674 if ((start + len) <= ext->start)
683 static errcode_t rb_set_bmap_range(ext2fs_generic_bitmap bitmap,
684 __u64 start, size_t num, void *in)
686 struct ext2fs_rb_private *bp;
687 unsigned char *cp = in;
691 bp = (struct ext2fs_rb_private *) bitmap->private;
693 for (i = 0; i < num; i++) {
695 unsigned char c = cp[i/8];
702 if ((c == 0x00) && (first_set == -1)) {
707 if (ext2fs_test_bit(i, in)) {
715 rb_insert_extent(start + first_set - bitmap->start,
720 rb_insert_extent(start + first_set - bitmap->start,
721 num - first_set, bp);
726 static errcode_t rb_get_bmap_range(ext2fs_generic_bitmap bitmap,
727 __u64 start, size_t num, void *out)
730 struct rb_node *parent = NULL, *next, **n;
731 struct ext2fs_rb_private *bp;
732 struct bmap_rb_extent *ext;
736 bp = (struct ext2fs_rb_private *) bitmap->private;
737 n = &bp->root.rb_node;
738 start -= bitmap->start;
740 if (EXT2FS_RB_EMPTY_ROOT(&bp->root))
745 ext = node_to_extent(parent);
746 if (start < ext->start) {
748 } else if (start >= (ext->start + ext->count)) {
754 memset(out, 0, (num + 7) >> 3);
756 for (; parent != NULL; parent = next) {
757 next = ext2fs_rb_next(parent);
758 ext = node_to_extent(parent);
762 if (pos >= start + num)
765 count -= start - pos;
770 if (pos + count > start + num)
771 count = start + num - pos;
775 ((pos - start) % 8) == 0) {
776 int nbytes = count >> 3;
777 int offset = (pos - start) >> 3;
779 memset(((char *) out) + offset, 0xFF, nbytes);
781 count -= nbytes << 3;
784 ext2fs_fast_set_bit64((pos - start), out);
792 static void rb_clear_bmap(ext2fs_generic_bitmap bitmap)
794 struct ext2fs_rb_private *bp;
796 bp = (struct ext2fs_rb_private *) bitmap->private;
798 rb_free_tree(&bp->root);
800 bp->rcursor_next = NULL;
805 static void rb_print_stats(ext2fs_generic_bitmap bitmap)
807 struct ext2fs_rb_private *bp;
808 struct rb_node *node = NULL;
809 struct bmap_rb_extent *ext;
812 __u64 min_size = ULONG_MAX;
813 __u64 size = 0, avg_size = 0;
815 #ifdef BMAP_STATS_OPS
816 __u64 mark_all, test_all;
817 double m_hit = 0.0, t_hit = 0.0;
820 bp = (struct ext2fs_rb_private *) bitmap->private;
822 node = ext2fs_rb_first(&bp->root);
823 for (node = ext2fs_rb_first(&bp->root); node != NULL;
824 node = ext2fs_rb_next(node)) {
825 ext = node_to_extent(node);
827 if (ext->count > max_size)
828 max_size = ext->count;
829 if (ext->count < min_size)
830 min_size = ext->count;
835 avg_size = size / count;
836 if (min_size == ULONG_MAX)
838 eff = (double)((count * sizeof(struct bmap_rb_extent)) << 3) /
839 (bitmap->real_end - bitmap->start);
840 #ifdef BMAP_STATS_OPS
841 mark_all = bitmap->stats.mark_count + bitmap->stats.mark_ext_count;
842 test_all = bitmap->stats.test_count + bitmap->stats.test_ext_count;
844 m_hit = ((double)bp->mark_hit / mark_all) * 100;
846 t_hit = ((double)bp->test_hit / test_all) * 100;
848 fprintf(stderr, "%16llu cache hits on test (%.2f%%)\n"
849 "%16llu cache hits on mark (%.2f%%)\n",
850 bp->test_hit, t_hit, bp->mark_hit, m_hit);
852 fprintf(stderr, "%16llu extents (%llu bytes)\n",
853 count, ((count * sizeof(struct bmap_rb_extent)) +
854 sizeof(struct ext2fs_rb_private)));
855 fprintf(stderr, "%16llu bits minimum size\n",
857 fprintf(stderr, "%16llu bits maximum size\n"
858 "%16llu bits average size\n",
860 fprintf(stderr, "%16llu bits set in bitmap (out of %llu)\n", size,
861 bitmap->real_end - bitmap->start);
863 "%16.4lf memory / bitmap bit memory ratio (bitarray = 1)\n",
867 static void rb_print_stats(ext2fs_generic_bitmap bitmap){}
870 struct ext2_bitmap_ops ext2fs_blkmap64_rbtree = {
871 .type = EXT2FS_BMAP64_RBTREE,
872 .new_bmap = rb_new_bmap,
873 .free_bmap = rb_free_bmap,
874 .copy_bmap = rb_copy_bmap,
875 .resize_bmap = rb_resize_bmap,
876 .mark_bmap = rb_mark_bmap,
877 .unmark_bmap = rb_unmark_bmap,
878 .test_bmap = rb_test_bmap,
879 .test_clear_bmap_extent = rb_test_clear_bmap_extent,
880 .mark_bmap_extent = rb_mark_bmap_extent,
881 .unmark_bmap_extent = rb_unmark_bmap_extent,
882 .set_bmap_range = rb_set_bmap_range,
883 .get_bmap_range = rb_get_bmap_range,
884 .clear_bmap = rb_clear_bmap,
885 .print_stats = rb_print_stats,