/* * blkmap64_rb.c --- Simple rb-tree implementation for bitmaps * * (C)2010 Red Hat, Inc., Lukas Czerner * * %Begin-Header% * This file may be redistributed under the terms of the GNU Public * License. * %End-Header% */ #include #include #if HAVE_UNISTD_H #include #endif #include #include #if HAVE_SYS_STAT_H #include #endif #if HAVE_SYS_TYPES_H #include #endif #include "ext2_fs.h" #include "ext2fsP.h" #include "bmap64.h" #include "rbtree.h" #include struct bmap_rb_extent { struct rb_node node; __u64 start; __u64 count; }; struct ext2fs_rb_private { struct rb_root root; struct bmap_rb_extent *wcursor; struct bmap_rb_extent *rcursor; struct bmap_rb_extent *rcursor_next; #ifdef ENABLE_BMAP_STATS_OPS __u64 mark_hit; __u64 test_hit; #endif }; inline static struct bmap_rb_extent *node_to_extent(struct rb_node *node) { /* * This depends on the fact the struct rb_node is at the * beginning of the bmap_rb_extent structure. We use this * instead of the ext2fs_rb_entry macro because it causes gcc * -Wall to generate a huge amount of noise. */ return (struct bmap_rb_extent *) node; } static int rb_insert_extent(__u64 start, __u64 count, struct ext2fs_rb_private *); static void rb_get_new_extent(struct bmap_rb_extent **, __u64, __u64); /* #define DEBUG_RB */ #ifdef DEBUG_RB static void print_tree(struct rb_root *root) { struct rb_node *node = NULL; struct bmap_rb_extent *ext; printf("\t\t\t=================================\n"); node = ext2fs_rb_first(root); for (node = ext2fs_rb_first(root); node != NULL; node = ext2fs_rb_next(node)) { ext = node_to_extent(node); printf("\t\t\t--> (%llu -> %llu)\n", ext->start, ext->start + ext->count); } printf("\t\t\t=================================\n"); } static void check_tree(struct rb_root *root, const char *msg) { struct rb_node *new_node, *node, *next; struct bmap_rb_extent *ext, *old = NULL; for (node = ext2fs_rb_first(root); node; node = ext2fs_rb_next(node)) { ext = node_to_extent(node); if (ext->count == 0) { printf("Tree Error: count is zero\n"); printf("extent: %llu -> %llu (%llu)\n", ext->start, ext->start + ext->count, ext->count); goto err_out; } if (ext->start + ext->count < ext->start) { printf("Tree Error: start or count is crazy\n"); printf("extent: %llu -> %llu (%llu)\n", ext->start, ext->start + ext->count, ext->count); goto err_out; } if (old) { if (old->start > ext->start) { printf("Tree Error: start is crazy\n"); printf("extent: %llu -> %llu (%llu)\n", old->start, old->start + old->count, old->count); printf("extent next: %llu -> %llu (%llu)\n", ext->start, ext->start + ext->count, ext->count); goto err_out; } if ((old->start + old->count) >= ext->start) { printf("Tree Error: extent is crazy\n"); printf("extent: %llu -> %llu (%llu)\n", old->start, old->start + old->count, old->count); printf("extent next: %llu -> %llu (%llu)\n", ext->start, ext->start + ext->count, ext->count); goto err_out; } } old = ext; } return; err_out: printf("%s\n", msg); print_tree(root); exit(1); } #else #define check_tree(root, msg) do {} while (0) #define print_tree(root) do {} while (0) #endif static void rb_get_new_extent(struct bmap_rb_extent **ext, __u64 start, __u64 count) { struct bmap_rb_extent *new_ext; int retval; retval = ext2fs_get_mem(sizeof (struct bmap_rb_extent), &new_ext); if (retval) abort(); new_ext->start = start; new_ext->count = count; *ext = new_ext; } inline static void rb_free_extent(struct ext2fs_rb_private *bp, struct bmap_rb_extent *ext) { if (bp->wcursor == ext) bp->wcursor = NULL; if (bp->rcursor == ext) bp->rcursor = NULL; if (bp->rcursor_next == ext) bp->rcursor_next = NULL; ext2fs_free_mem(&ext); } static errcode_t rb_alloc_private_data (ext2fs_generic_bitmap bitmap) { struct ext2fs_rb_private *bp; errcode_t retval; retval = ext2fs_get_mem(sizeof (struct ext2fs_rb_private), &bp); if (retval) return retval; bp->root = RB_ROOT; bp->rcursor = NULL; bp->rcursor_next = NULL; bp->wcursor = NULL; #ifdef ENABLE_BMAP_STATS_OPS bp->test_hit = 0; bp->mark_hit = 0; #endif bitmap->private = (void *) bp; return 0; } static errcode_t rb_new_bmap(ext2_filsys fs EXT2FS_ATTR((unused)), ext2fs_generic_bitmap bitmap) { errcode_t retval; retval = rb_alloc_private_data (bitmap); if (retval) return retval; return 0; } static void rb_free_tree(struct rb_root *root) { struct bmap_rb_extent *ext; struct rb_node *node, *next; for (node = ext2fs_rb_first(root); node; node = next) { next = ext2fs_rb_next(node); ext = node_to_extent(node); ext2fs_rb_erase(node, root); ext2fs_free_mem(&ext); } } static void rb_free_bmap(ext2fs_generic_bitmap bitmap) { struct ext2fs_rb_private *bp; bp = (struct ext2fs_rb_private *) bitmap->private; rb_free_tree(&bp->root); ext2fs_free_mem(&bp); bp = 0; } static errcode_t rb_copy_bmap(ext2fs_generic_bitmap src, ext2fs_generic_bitmap dest) { struct ext2fs_rb_private *src_bp, *dest_bp; struct bmap_rb_extent *src_ext, *dest_ext; struct rb_node *dest_node, *src_node, *dest_last, **n; errcode_t retval = 0; retval = rb_alloc_private_data (dest); if (retval) return retval; src_bp = (struct ext2fs_rb_private *) src->private; dest_bp = (struct ext2fs_rb_private *) dest->private; src_bp->rcursor = NULL; dest_bp->rcursor = NULL; src_node = ext2fs_rb_first(&src_bp->root); while (src_node) { src_ext = node_to_extent(src_node); retval = ext2fs_get_mem(sizeof (struct bmap_rb_extent), &dest_ext); if (retval) break; memcpy(dest_ext, src_ext, sizeof(struct bmap_rb_extent)); dest_node = &dest_ext->node; n = &dest_bp->root.rb_node; dest_last = NULL; if (*n) { dest_last = ext2fs_rb_last(&dest_bp->root); n = &(dest_last)->rb_right; } ext2fs_rb_link_node(dest_node, dest_last, n); ext2fs_rb_insert_color(dest_node, &dest_bp->root); src_node = ext2fs_rb_next(src_node); } return retval; } static void rb_truncate(__u64 new_max, struct rb_root *root) { struct bmap_rb_extent *ext; struct rb_node *node; node = ext2fs_rb_last(root); while (node) { ext = node_to_extent(node); if ((ext->start + ext->count - 1) <= new_max) break; else if (ext->start > new_max) { ext2fs_rb_erase(node, root); ext2fs_free_mem(&ext); node = ext2fs_rb_last(root); continue; } else ext->count = new_max - ext->start + 1; } } static errcode_t rb_resize_bmap(ext2fs_generic_bitmap bmap, __u64 new_end, __u64 new_real_end) { struct ext2fs_rb_private *bp; if (new_real_end >= bmap->real_end) { bmap->end = new_end; bmap->real_end = new_real_end; return 0; } bp = (struct ext2fs_rb_private *) bmap->private; bp->rcursor = NULL; bp->wcursor = NULL; /* truncate tree to new_real_end size */ rb_truncate(new_real_end, &bp->root); bmap->end = new_end; bmap->real_end = new_real_end; return 0; } inline static int rb_test_bit(struct ext2fs_rb_private *bp, __u64 bit) { struct bmap_rb_extent *rcursor, *next_ext = NULL; struct rb_node *parent = NULL, *next; struct rb_node **n = &bp->root.rb_node; struct bmap_rb_extent *ext; rcursor = bp->rcursor; if (!rcursor) goto search_tree; if (bit >= rcursor->start && bit < rcursor->start + rcursor->count) { #ifdef ENABLE_BMAP_STATS_OPS bp->test_hit++; #endif return 1; } next_ext = bp->rcursor_next; if (!next_ext) { next = ext2fs_rb_next(&rcursor->node); if (next) next_ext = node_to_extent(next); bp->rcursor_next = next_ext; } if (next_ext) { if ((bit >= rcursor->start + rcursor->count) && (bit < next_ext->start)) { #ifdef BMAP_STATS_OPS bp->test_hit++; #endif return 0; } } bp->rcursor = NULL; bp->rcursor_next = NULL; rcursor = bp->wcursor; if (!rcursor) goto search_tree; if (bit >= rcursor->start && bit < rcursor->start + rcursor->count) return 1; search_tree: while (*n) { parent = *n; ext = node_to_extent(parent); if (bit < ext->start) n = &(*n)->rb_left; else if (bit >= (ext->start + ext->count)) n = &(*n)->rb_right; else { bp->rcursor = ext; bp->rcursor_next = NULL; return 1; } } return 0; } static int rb_insert_extent(__u64 start, __u64 count, struct ext2fs_rb_private *bp) { struct rb_root *root = &bp->root; struct rb_node *parent = NULL, **n = &root->rb_node; struct rb_node *new_node, *node, *next; struct bmap_rb_extent *new_ext; struct bmap_rb_extent *ext; int retval = 0; bp->rcursor_next = NULL; ext = bp->wcursor; if (ext) { if (start >= ext->start && start <= (ext->start + ext->count)) { #ifdef ENABLE_BMAP_STATS_OPS bp->mark_hit++; #endif goto got_extent; } } while (*n) { parent = *n; ext = node_to_extent(parent); if (start < ext->start) { n = &(*n)->rb_left; } else if (start > (ext->start + ext->count)) { n = &(*n)->rb_right; } else { got_extent: if ((start + count) <= (ext->start + ext->count)) return 1; if ((ext->start + ext->count) == start) retval = 0; else retval = 1; count += (start - ext->start); start = ext->start; new_ext = ext; new_node = &ext->node; goto skip_insert; } } rb_get_new_extent(&new_ext, start, count); new_node = &new_ext->node; ext2fs_rb_link_node(new_node, parent, n); ext2fs_rb_insert_color(new_node, root); bp->wcursor = new_ext; node = ext2fs_rb_prev(new_node); if (node) { ext = node_to_extent(node); if ((ext->start + ext->count) == start) { start = ext->start; count += ext->count; ext2fs_rb_erase(node, root); rb_free_extent(bp, ext); } } skip_insert: /* See if we can merge extent to the right */ for (node = ext2fs_rb_next(new_node); node != NULL; node = next) { next = ext2fs_rb_next(node); ext = node_to_extent(node); if ((ext->start + ext->count) <= start) continue; /* No more merging */ if ((start + count) < ext->start) break; /* ext is embedded in new_ext interval */ if ((start + count) >= (ext->start + ext->count)) { ext2fs_rb_erase(node, root); rb_free_extent(bp, ext); continue; } else { /* merge ext with new_ext */ count += ((ext->start + ext->count) - (start + count)); ext2fs_rb_erase(node, root); rb_free_extent(bp, ext); break; } } new_ext->start = start; new_ext->count = count; return retval; } static int rb_remove_extent(__u64 start, __u64 count, struct ext2fs_rb_private *bp) { struct rb_root *root = &bp->root; struct rb_node *parent = NULL, **n = &root->rb_node; struct rb_node *node; struct bmap_rb_extent *ext; __u64 new_start, new_count; int retval = 0; if (EXT2FS_RB_EMPTY_ROOT(root)) return 0; while (*n) { parent = *n; ext = node_to_extent(parent); if (start < ext->start) { n = &(*n)->rb_left; continue; } else if (start >= (ext->start + ext->count)) { n = &(*n)->rb_right; continue; } if ((start > ext->start) && (start + count) < (ext->start + ext->count)) { /* We have to split extent into two */ new_start = start + count; new_count = (ext->start + ext->count) - new_start; ext->count = start - ext->start; rb_insert_extent(new_start, new_count, bp); return 1; } if ((start + count) >= (ext->start + ext->count)) { ext->count = start - ext->start; retval = 1; } if (0 == ext->count) { parent = ext2fs_rb_next(&ext->node); ext2fs_rb_erase(&ext->node, root); rb_free_extent(bp, ext); break; } if (start == ext->start) { ext->start += count; ext->count -= count; return 1; } } /* See if we should delete or truncate extent on the right */ for (; parent != NULL; parent = node) { node = ext2fs_rb_next(parent); ext = node_to_extent(parent); if ((ext->start + ext->count) <= start) continue; /* No more extents to be removed/truncated */ if ((start + count) < ext->start) break; /* The entire extent is within the region to be removed */ if ((start + count) >= (ext->start + ext->count)) { ext2fs_rb_erase(parent, root); rb_free_extent(bp, ext); retval = 1; continue; } else { /* modify the last extent in reigon to be removed */ ext->count -= ((start + count) - ext->start); ext->start = start + count; retval = 1; break; } } return retval; } static int rb_mark_bmap(ext2fs_generic_bitmap bitmap, __u64 arg) { struct ext2fs_rb_private *bp; int retval; bp = (struct ext2fs_rb_private *) bitmap->private; arg -= bitmap->start; retval = rb_insert_extent(arg, 1, bp); check_tree(&bp->root, __func__); return retval; } static int rb_unmark_bmap(ext2fs_generic_bitmap bitmap, __u64 arg) { struct ext2fs_rb_private *bp; int retval; bp = (struct ext2fs_rb_private *) bitmap->private; arg -= bitmap->start; retval = rb_remove_extent(arg, 1, bp); check_tree(&bp->root, __func__); return retval; } inline static int rb_test_bmap(ext2fs_generic_bitmap bitmap, __u64 arg) { struct ext2fs_rb_private *bp; bp = (struct ext2fs_rb_private *) bitmap->private; arg -= bitmap->start; return rb_test_bit(bp, arg); } static void rb_mark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg, unsigned int num) { struct ext2fs_rb_private *bp; bp = (struct ext2fs_rb_private *) bitmap->private; arg -= bitmap->start; rb_insert_extent(arg, num, bp); check_tree(&bp->root, __func__); } static void rb_unmark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg, unsigned int num) { struct ext2fs_rb_private *bp; bp = (struct ext2fs_rb_private *) bitmap->private; arg -= bitmap->start; rb_remove_extent(arg, num, bp); check_tree(&bp->root, __func__); } static int rb_test_clear_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 start, unsigned int len) { struct rb_node *parent = NULL, **n; struct rb_node *node, *next; struct ext2fs_rb_private *bp; struct bmap_rb_extent *ext; int retval = 1; bp = (struct ext2fs_rb_private *) bitmap->private; n = &bp->root.rb_node; start -= bitmap->start; if ((len == 0) || EXT2FS_RB_EMPTY_ROOT(&bp->root)) return 1; /* * If we find nothing, we should examine whole extent, but * when we find match, the extent is not clean, thus be return * false. */ while (*n) { parent = *n; ext = node_to_extent(parent); if (start < ext->start) { n = &(*n)->rb_left; } else if (start >= (ext->start + ext->count)) { n = &(*n)->rb_right; } else { /* * We found extent int the tree -> extent is not * clean */ return 0; } } node = parent; while (node) { next = ext2fs_rb_next(node); ext = node_to_extent(node); node = next; if ((ext->start + ext->count) <= start) continue; /* No more merging */ if ((start + len) <= ext->start) break; retval = 0; break; } return retval; } static errcode_t rb_set_bmap_range(ext2fs_generic_bitmap bitmap, __u64 start, size_t num, void *in) { struct ext2fs_rb_private *bp; unsigned char *cp = in; size_t i; int first_set = -1; bp = (struct ext2fs_rb_private *) bitmap->private; for (i = 0; i < num; i++) { if ((i & 7) == 0) { unsigned char c = cp[i/8]; if (c == 0xFF) { if (first_set == -1) first_set = i; i += 7; continue; } if ((c == 0x00) && (first_set == -1)) { i += 7; continue; } } if (ext2fs_test_bit(i, in)) { if (first_set == -1) first_set = i; continue; } if (first_set == -1) continue; rb_insert_extent(start + first_set - bitmap->start, i - first_set, bp); check_tree(&bp->root, __func__); first_set = -1; } if (first_set != -1) { rb_insert_extent(start + first_set - bitmap->start, num - first_set, bp); check_tree(&bp->root, __func__); } return 0; } static errcode_t rb_get_bmap_range(ext2fs_generic_bitmap bitmap, __u64 start, size_t num, void *out) { struct rb_node *parent = NULL, *next, **n; struct ext2fs_rb_private *bp; struct bmap_rb_extent *ext; int count; __u64 pos; bp = (struct ext2fs_rb_private *) bitmap->private; n = &bp->root.rb_node; start -= bitmap->start; if (EXT2FS_RB_EMPTY_ROOT(&bp->root)) return 0; while (*n) { parent = *n; ext = node_to_extent(parent); if (start < ext->start) { n = &(*n)->rb_left; } else if (start >= (ext->start + ext->count)) { n = &(*n)->rb_right; } else break; } memset(out, 0, (num + 7) >> 3); for (; parent != NULL; parent = next) { next = ext2fs_rb_next(parent); ext = node_to_extent(parent); pos = ext->start; count = ext->count; if (pos >= start + num) break; if (pos < start) { count -= start - pos; if (count < 0) continue; pos = start; } if (pos + count > start + num) count = start + num - pos; while (count > 0) { if ((count >= 8) && ((pos - start) % 8) == 0) { int nbytes = count >> 3; int offset = (pos - start) >> 3; memset(((char *) out) + offset, 0xFF, nbytes); pos += nbytes << 3; count -= nbytes << 3; continue; } ext2fs_fast_set_bit64((pos - start), out); pos++; count--; } } return 0; } static void rb_clear_bmap(ext2fs_generic_bitmap bitmap) { struct ext2fs_rb_private *bp; bp = (struct ext2fs_rb_private *) bitmap->private; rb_free_tree(&bp->root); bp->rcursor = NULL; bp->rcursor_next = NULL; bp->wcursor = NULL; check_tree(&bp->root, __func__); } static errcode_t rb_find_first_zero(ext2fs_generic_bitmap bitmap, __u64 start, __u64 end, __u64 *out) { struct rb_node *parent = NULL, **n; struct ext2fs_rb_private *bp; struct bmap_rb_extent *ext; bp = (struct ext2fs_rb_private *) bitmap->private; n = &bp->root.rb_node; start -= bitmap->start; end -= bitmap->start; if (start > end) return EINVAL; if (EXT2FS_RB_EMPTY_ROOT(&bp->root)) return ENOENT; while (*n) { parent = *n; ext = node_to_extent(parent); if (start < ext->start) { n = &(*n)->rb_left; } else if (start >= (ext->start + ext->count)) { n = &(*n)->rb_right; } else if (ext->start + ext->count <= end) { *out = ext->start + ext->count + bitmap->start; return 0; } else return ENOENT; } *out = start + bitmap->start; return 0; } static errcode_t rb_find_first_set(ext2fs_generic_bitmap bitmap, __u64 start, __u64 end, __u64 *out) { struct rb_node *parent = NULL, **n; struct rb_node *node; struct ext2fs_rb_private *bp; struct bmap_rb_extent *ext; bp = (struct ext2fs_rb_private *) bitmap->private; n = &bp->root.rb_node; start -= bitmap->start; end -= bitmap->start; if (start > end) return EINVAL; if (EXT2FS_RB_EMPTY_ROOT(&bp->root)) return ENOENT; while (*n) { parent = *n; ext = node_to_extent(parent); if (start < ext->start) { n = &(*n)->rb_left; } else if (start >= (ext->start + ext->count)) { n = &(*n)->rb_right; } else { /* The start bit is set */ *out = start + bitmap->start; return 0; } } node = parent; ext = node_to_extent(node); if (ext->start < start) { node = ext2fs_rb_next(node); if (node == NULL) return ENOENT; ext = node_to_extent(node); } if (ext->start <= end) { *out = ext->start + bitmap->start; return 0; } return ENOENT; } #ifdef ENABLE_BMAP_STATS static void rb_print_stats(ext2fs_generic_bitmap bitmap) { struct ext2fs_rb_private *bp; struct rb_node *node = NULL; struct bmap_rb_extent *ext; __u64 count = 0; __u64 max_size = 0; __u64 min_size = ULONG_MAX; __u64 size = 0, avg_size = 0; double eff; #ifdef ENABLE_BMAP_STATS_OPS __u64 mark_all, test_all; double m_hit = 0.0, t_hit = 0.0; #endif bp = (struct ext2fs_rb_private *) bitmap->private; for (node = ext2fs_rb_first(&bp->root); node != NULL; node = ext2fs_rb_next(node)) { ext = node_to_extent(node); count++; if (ext->count > max_size) max_size = ext->count; if (ext->count < min_size) min_size = ext->count; size += ext->count; } if (count) avg_size = size / count; if (min_size == ULONG_MAX) min_size = 0; eff = (double)((count * sizeof(struct bmap_rb_extent)) << 3) / (bitmap->real_end - bitmap->start); #ifdef ENABLE_BMAP_STATS_OPS mark_all = bitmap->stats.mark_count + bitmap->stats.mark_ext_count; test_all = bitmap->stats.test_count + bitmap->stats.test_ext_count; if (mark_all) m_hit = ((double)bp->mark_hit / mark_all) * 100; if (test_all) t_hit = ((double)bp->test_hit / test_all) * 100; fprintf(stderr, "%16llu cache hits on test (%.2f%%)\n" "%16llu cache hits on mark (%.2f%%)\n", bp->test_hit, t_hit, bp->mark_hit, m_hit); #endif fprintf(stderr, "%16llu extents (%llu bytes)\n", count, ((count * sizeof(struct bmap_rb_extent)) + sizeof(struct ext2fs_rb_private))); fprintf(stderr, "%16llu bits minimum size\n", min_size); fprintf(stderr, "%16llu bits maximum size\n" "%16llu bits average size\n", max_size, avg_size); fprintf(stderr, "%16llu bits set in bitmap (out of %llu)\n", size, bitmap->real_end - bitmap->start); fprintf(stderr, "%16.4lf memory / bitmap bit memory ratio (bitarray = 1)\n", eff); } #else static void rb_print_stats(ext2fs_generic_bitmap bitmap EXT2FS_ATTR((unused))) { } #endif struct ext2_bitmap_ops ext2fs_blkmap64_rbtree = { .type = EXT2FS_BMAP64_RBTREE, .new_bmap = rb_new_bmap, .free_bmap = rb_free_bmap, .copy_bmap = rb_copy_bmap, .resize_bmap = rb_resize_bmap, .mark_bmap = rb_mark_bmap, .unmark_bmap = rb_unmark_bmap, .test_bmap = rb_test_bmap, .test_clear_bmap_extent = rb_test_clear_bmap_extent, .mark_bmap_extent = rb_mark_bmap_extent, .unmark_bmap_extent = rb_unmark_bmap_extent, .set_bmap_range = rb_set_bmap_range, .get_bmap_range = rb_get_bmap_range, .clear_bmap = rb_clear_bmap, .print_stats = rb_print_stats, .find_first_zero = rb_find_first_zero, .find_first_set = rb_find_first_set, };