1 // SPDX-License-Identifier: GPL-2.0
4 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
6 * This code builds two trees of free clusters extents.
7 * Trees are sorted by start of extent and by length of extent.
8 * NTFS_MAX_WND_EXTENTS defines the maximum number of elements in trees.
9 * In extreme case code reads on-disk bitmap to find free clusters.
13 #include <linux/buffer_head.h>
15 #include <linux/kernel.h>
21 * Maximum number of extents in tree.
23 #define NTFS_MAX_WND_EXTENTS (32u * 1024u)
31 struct rb_node_key start; /* Tree sorted by start. */
32 struct rb_node_key count; /* Tree sorted by len. */
35 static int wnd_rescan(struct wnd_bitmap *wnd);
36 static struct buffer_head *wnd_map(struct wnd_bitmap *wnd, size_t iw);
37 static bool wnd_is_free_hlp(struct wnd_bitmap *wnd, size_t bit, size_t bits);
39 static struct kmem_cache *ntfs_enode_cachep;
41 int __init ntfs3_init_bitmap(void)
44 kmem_cache_create("ntfs3_enode_cache", sizeof(struct e_node), 0,
45 SLAB_RECLAIM_ACCOUNT, NULL);
46 return ntfs_enode_cachep ? 0 : -ENOMEM;
49 void ntfs3_exit_bitmap(void)
51 kmem_cache_destroy(ntfs_enode_cachep);
57 * b_pos + b_len - biggest fragment.
58 * Scan range [wpos wbits) window @buf.
60 * Return: -1 if not found.
62 static size_t wnd_scan(const ulong *buf, size_t wbit, u32 wpos, u32 wend,
63 size_t to_alloc, size_t *prev_tail, size_t *b_pos,
69 u32 used = find_next_zero_bit(buf, wend, wpos);
72 if (*b_len < *prev_tail) {
73 *b_pos = wbit - *prev_tail;
83 if (*b_len < *prev_tail) {
84 *b_pos = wbit - *prev_tail;
92 * Now we have a fragment [wpos, wend) staring with 0.
94 end = wpos + to_alloc - *prev_tail;
95 free_bits = find_next_bit(buf, min(end, wend), wpos);
97 free_len = *prev_tail + free_bits - wpos;
99 if (*b_len < free_len) {
100 *b_pos = wbit + wpos - *prev_tail;
104 if (free_len >= to_alloc)
105 return wbit + wpos - *prev_tail;
107 if (free_bits >= wend) {
108 *prev_tail += free_bits - wpos;
112 wpos = free_bits + 1;
121 * wnd_close - Frees all resources.
123 void wnd_close(struct wnd_bitmap *wnd)
125 struct rb_node *node, *next;
127 kfree(wnd->free_bits);
128 run_close(&wnd->run);
130 node = rb_first(&wnd->start_tree);
133 next = rb_next(node);
134 rb_erase(node, &wnd->start_tree);
135 kmem_cache_free(ntfs_enode_cachep,
136 rb_entry(node, struct e_node, start.node));
141 static struct rb_node *rb_lookup(struct rb_root *root, size_t v)
143 struct rb_node **p = &root->rb_node;
144 struct rb_node *r = NULL;
147 struct rb_node_key *k;
149 k = rb_entry(*p, struct rb_node_key, node);
152 } else if (v > k->key) {
164 * rb_insert_count - Helper function to insert special kind of 'count' tree.
166 static inline bool rb_insert_count(struct rb_root *root, struct e_node *e)
168 struct rb_node **p = &root->rb_node;
169 struct rb_node *parent = NULL;
170 size_t e_ckey = e->count.key;
171 size_t e_skey = e->start.key;
175 rb_entry(parent = *p, struct e_node, count.node);
177 if (e_ckey > k->count.key) {
179 } else if (e_ckey < k->count.key) {
181 } else if (e_skey < k->start.key) {
183 } else if (e_skey > k->start.key) {
191 rb_link_node(&e->count.node, parent, p);
192 rb_insert_color(&e->count.node, root);
197 * rb_insert_start - Helper function to insert special kind of 'count' tree.
199 static inline bool rb_insert_start(struct rb_root *root, struct e_node *e)
201 struct rb_node **p = &root->rb_node;
202 struct rb_node *parent = NULL;
203 size_t e_skey = e->start.key;
210 k = rb_entry(parent, struct e_node, start.node);
211 if (e_skey < k->start.key) {
213 } else if (e_skey > k->start.key) {
221 rb_link_node(&e->start.node, parent, p);
222 rb_insert_color(&e->start.node, root);
227 * wnd_add_free_ext - Adds a new extent of free space.
228 * @build: 1 when building tree.
230 static void wnd_add_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len,
233 struct e_node *e, *e0 = NULL;
234 size_t ib, end_in = bit + len;
238 /* Use extent_min to filter too short extents. */
239 if (wnd->count >= NTFS_MAX_WND_EXTENTS &&
240 len <= wnd->extent_min) {
245 /* Try to find extent before 'bit'. */
246 n = rb_lookup(&wnd->start_tree, bit);
249 n = rb_first(&wnd->start_tree);
251 e = rb_entry(n, struct e_node, start.node);
253 if (e->start.key + e->count.key == bit) {
257 rb_erase(&e->start.node, &wnd->start_tree);
258 rb_erase(&e->count.node, &wnd->count_tree);
267 e = rb_entry(n, struct e_node, start.node);
268 next_end = e->start.key + e->count.key;
269 if (e->start.key > end_in)
274 len += next_end - end_in;
276 rb_erase(&e->start.node, &wnd->start_tree);
277 rb_erase(&e->count.node, &wnd->count_tree);
283 kmem_cache_free(ntfs_enode_cachep, e);
286 if (wnd->uptodated != 1) {
287 /* Check bits before 'bit'. */
288 ib = wnd->zone_bit == wnd->zone_end ||
293 while (bit > ib && wnd_is_free_hlp(wnd, bit - 1, 1)) {
298 /* Check bits after 'end_in'. */
299 ib = wnd->zone_bit == wnd->zone_end ||
300 end_in > wnd->zone_bit
304 while (end_in < ib && wnd_is_free_hlp(wnd, end_in, 1)) {
310 /* Insert new fragment. */
311 if (wnd->count >= NTFS_MAX_WND_EXTENTS) {
313 kmem_cache_free(ntfs_enode_cachep, e0);
317 /* Compare with smallest fragment. */
318 n = rb_last(&wnd->count_tree);
319 e = rb_entry(n, struct e_node, count.node);
320 if (len <= e->count.key)
321 goto out; /* Do not insert small fragments. */
327 e2 = rb_entry(n, struct e_node, count.node);
328 /* Smallest fragment will be 'e2->count.key'. */
329 wnd->extent_min = e2->count.key;
332 /* Replace smallest fragment by new one. */
333 rb_erase(&e->start.node, &wnd->start_tree);
334 rb_erase(&e->count.node, &wnd->count_tree);
337 e = e0 ? e0 : kmem_cache_alloc(ntfs_enode_cachep, GFP_ATOMIC);
343 if (build && len <= wnd->extent_min)
344 wnd->extent_min = len;
348 if (len > wnd->extent_max)
349 wnd->extent_max = len;
351 rb_insert_start(&wnd->start_tree, e);
352 rb_insert_count(&wnd->count_tree, e);
359 * wnd_remove_free_ext - Remove a run from the cached free space.
361 static void wnd_remove_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len)
363 struct rb_node *n, *n3;
364 struct e_node *e, *e3;
365 size_t end_in = bit + len;
366 size_t end3, end, new_key, new_len, max_new_len;
368 /* Try to find extent before 'bit'. */
369 n = rb_lookup(&wnd->start_tree, bit);
374 e = rb_entry(n, struct e_node, start.node);
375 end = e->start.key + e->count.key;
377 new_key = new_len = 0;
380 /* Range [bit,end_in) must be inside 'e' or outside 'e' and 'n'. */
381 if (e->start.key > bit)
383 else if (end_in <= end) {
384 /* Range [bit,end_in) inside 'e'. */
386 new_len = end - end_in;
387 len = bit - e->start.key;
388 } else if (bit > end) {
394 e3 = rb_entry(n3, struct e_node, start.node);
395 if (e3->start.key >= end_in)
398 if (e3->count.key == wnd->extent_max)
401 end3 = e3->start.key + e3->count.key;
403 e3->start.key = end_in;
404 rb_erase(&e3->count.node, &wnd->count_tree);
405 e3->count.key = end3 - end_in;
406 rb_insert_count(&wnd->count_tree, e3);
411 rb_erase(&e3->start.node, &wnd->start_tree);
412 rb_erase(&e3->count.node, &wnd->count_tree);
414 kmem_cache_free(ntfs_enode_cachep, e3);
418 n3 = rb_first(&wnd->count_tree);
420 n3 ? rb_entry(n3, struct e_node, count.node)->count.key
425 if (e->count.key != wnd->extent_max) {
427 } else if (rb_prev(&e->count.node)) {
430 n3 = rb_next(&e->count.node);
431 max_new_len = max(len, new_len);
433 wnd->extent_max = max_new_len;
435 e3 = rb_entry(n3, struct e_node, count.node);
436 wnd->extent_max = max(e3->count.key, max_new_len);
442 e->start.key = new_key;
443 rb_erase(&e->count.node, &wnd->count_tree);
444 e->count.key = new_len;
445 rb_insert_count(&wnd->count_tree, e);
447 rb_erase(&e->start.node, &wnd->start_tree);
448 rb_erase(&e->count.node, &wnd->count_tree);
450 kmem_cache_free(ntfs_enode_cachep, e);
454 rb_erase(&e->count.node, &wnd->count_tree);
456 rb_insert_count(&wnd->count_tree, e);
461 if (wnd->count >= NTFS_MAX_WND_EXTENTS) {
464 /* Get minimal extent. */
465 e = rb_entry(rb_last(&wnd->count_tree), struct e_node,
467 if (e->count.key > new_len)
470 /* Replace minimum. */
471 rb_erase(&e->start.node, &wnd->start_tree);
472 rb_erase(&e->count.node, &wnd->count_tree);
475 e = kmem_cache_alloc(ntfs_enode_cachep, GFP_ATOMIC);
481 e->start.key = new_key;
482 e->count.key = new_len;
483 rb_insert_start(&wnd->start_tree, e);
484 rb_insert_count(&wnd->count_tree, e);
489 if (!wnd->count && 1 != wnd->uptodated)
494 * wnd_rescan - Scan all bitmap. Used while initialization.
496 static int wnd_rescan(struct wnd_bitmap *wnd)
499 size_t prev_tail = 0;
500 struct super_block *sb = wnd->sb;
501 struct ntfs_sb_info *sbi = sb->s_fs_info;
503 u32 blocksize = sb->s_blocksize;
504 u8 cluster_bits = sbi->cluster_bits;
505 u32 wbits = 8 * sb->s_blocksize;
508 size_t wpos, wbit, iw, vbo;
509 struct buffer_head *bh = NULL;
514 wnd->extent_min = MINUS_ONE_T;
515 wnd->total_zeroes = 0;
519 for (iw = 0; iw < wnd->nwnd; iw++) {
520 if (iw + 1 == wnd->nwnd)
521 wbits = wnd->bits_last;
524 if (!wnd->free_bits[iw]) {
527 wnd_add_free_ext(wnd,
534 if (wbits == wnd->free_bits[iw]) {
537 wnd->total_zeroes += wbits;
543 u32 off = vbo & sbi->cluster_mask;
545 if (!run_lookup_entry(&wnd->run, vbo >> cluster_bits,
546 &lcn, &clen, NULL)) {
551 lbo = ((u64)lcn << cluster_bits) + off;
552 len = ((u64)clen << cluster_bits) - off;
555 bh = ntfs_bread(sb, lbo >> sb->s_blocksize_bits);
561 buf = (ulong *)bh->b_data;
563 used = bitmap_weight(buf, wbits);
566 wnd->free_bits[iw] = frb;
567 wnd->total_zeroes += frb;
573 if (wbit + wbits > wnd->nbits)
574 wbits = wnd->nbits - wbit;
577 used = find_next_zero_bit(buf, wbits, wpos);
579 if (used > wpos && prev_tail) {
580 wnd_add_free_ext(wnd, wbit + wpos - prev_tail,
588 /* No free blocks. */
593 frb = find_next_bit(buf, wbits, wpos);
595 /* Keep last free block. */
596 prev_tail += frb - wpos;
600 wnd_add_free_ext(wnd, wbit + wpos - prev_tail,
601 frb + prev_tail - wpos, true);
603 /* Skip free block and first '1'. */
605 /* Reset previous tail. */
607 } while (wpos < wbits);
622 /* Add last block. */
624 wnd_add_free_ext(wnd, wnd->nbits - prev_tail, prev_tail, true);
627 * Before init cycle wnd->uptodated was 0.
628 * If any errors or limits occurs while initialization then
629 * wnd->uptodated will be -1.
630 * If 'uptodated' is still 0 then Tree is really updated.
635 if (wnd->zone_bit != wnd->zone_end) {
636 size_t zlen = wnd->zone_end - wnd->zone_bit;
638 wnd->zone_end = wnd->zone_bit;
639 wnd_zone_set(wnd, wnd->zone_bit, zlen);
646 int wnd_init(struct wnd_bitmap *wnd, struct super_block *sb, size_t nbits)
649 u32 blocksize = sb->s_blocksize;
650 u32 wbits = blocksize * 8;
652 init_rwsem(&wnd->rw_lock);
656 wnd->total_zeroes = nbits;
657 wnd->extent_max = MINUS_ONE_T;
658 wnd->zone_bit = wnd->zone_end = 0;
659 wnd->nwnd = bytes_to_block(sb, bitmap_size(nbits));
660 wnd->bits_last = nbits & (wbits - 1);
662 wnd->bits_last = wbits;
665 kcalloc(wnd->nwnd, sizeof(u16), GFP_NOFS | __GFP_NOWARN);
669 err = wnd_rescan(wnd);
679 * wnd_map - Call sb_bread for requested window.
681 static struct buffer_head *wnd_map(struct wnd_bitmap *wnd, size_t iw)
685 struct super_block *sb = wnd->sb;
686 struct ntfs_sb_info *sbi;
687 struct buffer_head *bh;
691 vbo = (u64)iw << sb->s_blocksize_bits;
693 if (!run_lookup_entry(&wnd->run, vbo >> sbi->cluster_bits, &lcn, &clen,
695 return ERR_PTR(-ENOENT);
698 lbo = ((u64)lcn << sbi->cluster_bits) + (vbo & sbi->cluster_mask);
700 bh = ntfs_bread(wnd->sb, lbo >> sb->s_blocksize_bits);
702 return ERR_PTR(-EIO);
708 * wnd_set_free - Mark the bits range from bit to bit + bits as free.
710 int wnd_set_free(struct wnd_bitmap *wnd, size_t bit, size_t bits)
713 struct super_block *sb = wnd->sb;
715 u32 wbits = 8 * sb->s_blocksize;
716 size_t iw = bit >> (sb->s_blocksize_bits + 3);
717 u32 wbit = bit & (wbits - 1);
718 struct buffer_head *bh;
720 while (iw < wnd->nwnd && bits) {
724 if (iw + 1 == wnd->nwnd)
725 wbits = wnd->bits_last;
728 op = min_t(u32, tail, bits);
730 bh = wnd_map(wnd, iw);
736 buf = (ulong *)bh->b_data;
740 __bitmap_clear(buf, wbit, op);
742 wnd->free_bits[iw] += op;
744 set_buffer_uptodate(bh);
745 mark_buffer_dirty(bh);
749 wnd->total_zeroes += op;
755 wnd_add_free_ext(wnd, bit, bits0, false);
761 * wnd_set_used - Mark the bits range from bit to bit + bits as used.
763 int wnd_set_used(struct wnd_bitmap *wnd, size_t bit, size_t bits)
766 struct super_block *sb = wnd->sb;
768 size_t iw = bit >> (sb->s_blocksize_bits + 3);
769 u32 wbits = 8 * sb->s_blocksize;
770 u32 wbit = bit & (wbits - 1);
771 struct buffer_head *bh;
773 while (iw < wnd->nwnd && bits) {
777 if (unlikely(iw + 1 == wnd->nwnd))
778 wbits = wnd->bits_last;
781 op = min_t(u32, tail, bits);
783 bh = wnd_map(wnd, iw);
788 buf = (ulong *)bh->b_data;
792 __bitmap_set(buf, wbit, op);
793 wnd->free_bits[iw] -= op;
795 set_buffer_uptodate(bh);
796 mark_buffer_dirty(bh);
800 wnd->total_zeroes -= op;
806 if (!RB_EMPTY_ROOT(&wnd->start_tree))
807 wnd_remove_free_ext(wnd, bit, bits0);
815 * Return: True if all clusters [bit, bit+bits) are free (bitmap only).
817 static bool wnd_is_free_hlp(struct wnd_bitmap *wnd, size_t bit, size_t bits)
819 struct super_block *sb = wnd->sb;
820 size_t iw = bit >> (sb->s_blocksize_bits + 3);
821 u32 wbits = 8 * sb->s_blocksize;
822 u32 wbit = bit & (wbits - 1);
824 while (iw < wnd->nwnd && bits) {
827 if (unlikely(iw + 1 == wnd->nwnd))
828 wbits = wnd->bits_last;
831 op = min_t(u32, tail, bits);
833 if (wbits != wnd->free_bits[iw]) {
835 struct buffer_head *bh = wnd_map(wnd, iw);
840 ret = are_bits_clear((ulong *)bh->b_data, wbit, op);
858 * Return: True if all clusters [bit, bit+bits) are free.
860 bool wnd_is_free(struct wnd_bitmap *wnd, size_t bit, size_t bits)
867 if (RB_EMPTY_ROOT(&wnd->start_tree))
870 n = rb_lookup(&wnd->start_tree, bit);
874 e = rb_entry(n, struct e_node, start.node);
876 end = e->start.key + e->count.key;
878 if (bit < end && bit + bits <= end)
882 ret = wnd_is_free_hlp(wnd, bit, bits);
890 * Return: True if all clusters [bit, bit+bits) are used.
892 bool wnd_is_used(struct wnd_bitmap *wnd, size_t bit, size_t bits)
895 struct super_block *sb = wnd->sb;
896 size_t iw = bit >> (sb->s_blocksize_bits + 3);
897 u32 wbits = 8 * sb->s_blocksize;
898 u32 wbit = bit & (wbits - 1);
903 if (RB_EMPTY_ROOT(&wnd->start_tree))
907 n = rb_lookup(&wnd->start_tree, end - 1);
911 e = rb_entry(n, struct e_node, start.node);
912 if (e->start.key + e->count.key > bit)
916 while (iw < wnd->nwnd && bits) {
919 if (unlikely(iw + 1 == wnd->nwnd))
920 wbits = wnd->bits_last;
923 op = min_t(u32, tail, bits);
925 if (wnd->free_bits[iw]) {
927 struct buffer_head *bh = wnd_map(wnd, iw);
932 ret = are_bits_set((ulong *)bh->b_data, wbit, op);
949 * wnd_find - Look for free space.
951 * - flags - BITMAP_FIND_XXX flags
953 * Return: 0 if not found.
955 size_t wnd_find(struct wnd_bitmap *wnd, size_t to_alloc, size_t hint,
956 size_t flags, size_t *allocated)
958 struct super_block *sb;
959 u32 wbits, wpos, wzbit, wzend;
960 size_t fnd, max_alloc, b_len, b_pos;
961 size_t iw, prev_tail, nwnd, wbit, ebit, zbit, zend;
962 size_t to_alloc0 = to_alloc;
964 const struct e_node *e;
965 const struct rb_node *pr, *cr;
968 struct buffer_head *bh;
970 /* Fast checking for available free space. */
971 if (flags & BITMAP_FIND_FULL) {
972 size_t zeroes = wnd_zeroes(wnd);
974 zeroes -= wnd->zone_end - wnd->zone_bit;
975 if (zeroes < to_alloc0)
978 if (to_alloc0 > wnd->extent_max)
981 if (to_alloc > wnd->extent_max)
982 to_alloc = wnd->extent_max;
985 if (wnd->zone_bit <= hint && hint < wnd->zone_end)
986 hint = wnd->zone_end;
988 max_alloc = wnd->nbits;
991 if (hint >= max_alloc)
994 if (RB_EMPTY_ROOT(&wnd->start_tree)) {
995 if (wnd->uptodated == 1) {
996 /* Extents tree is updated -> No free space. */
1004 goto allocate_biggest;
1006 /* Use hint: Enumerate extents by start >= hint. */
1008 cr = wnd->start_tree.rb_node;
1011 e = rb_entry(cr, struct e_node, start.node);
1013 if (e->start.key == hint)
1016 if (e->start.key < hint) {
1026 e = pr ? rb_entry(pr, struct e_node, start.node) : NULL;
1032 goto allocate_biggest;
1034 if (e->start.key + e->count.key > hint) {
1035 /* We have found extension with 'hint' inside. */
1036 size_t len = e->start.key + e->count.key - hint;
1038 if (len >= to_alloc && hint + to_alloc <= max_alloc) {
1043 if (!(flags & BITMAP_FIND_FULL)) {
1047 if (hint + len <= max_alloc) {
1056 /* Allocate from biggest free extent. */
1057 e = rb_entry(rb_first(&wnd->count_tree), struct e_node, count.node);
1058 if (e->count.key != wnd->extent_max)
1059 wnd->extent_max = e->count.key;
1061 if (e->count.key < max_alloc) {
1062 if (e->count.key >= to_alloc) {
1064 } else if (flags & BITMAP_FIND_FULL) {
1065 if (e->count.key < to_alloc0) {
1066 /* Biggest free block is less then requested. */
1069 to_alloc = e->count.key;
1070 } else if (-1 != wnd->uptodated) {
1071 to_alloc = e->count.key;
1073 /* Check if we can use more bits. */
1074 size_t op, max_check;
1075 struct rb_root start_tree;
1077 memcpy(&start_tree, &wnd->start_tree,
1078 sizeof(struct rb_root));
1079 memset(&wnd->start_tree, 0, sizeof(struct rb_root));
1081 max_check = e->start.key + to_alloc;
1082 if (max_check > max_alloc)
1083 max_check = max_alloc;
1084 for (op = e->start.key + e->count.key; op < max_check;
1086 if (!wnd_is_free(wnd, op, 1))
1089 memcpy(&wnd->start_tree, &start_tree,
1090 sizeof(struct rb_root));
1091 to_alloc = op - e->start.key;
1094 /* Prepare to return. */
1096 if (e->start.key + to_alloc > max_alloc)
1097 to_alloc = max_alloc - e->start.key;
1101 if (wnd->uptodated == 1) {
1102 /* Extents tree is updated -> no free space. */
1106 b_len = e->count.key;
1107 b_pos = e->start.key;
1111 log2_bits = sb->s_blocksize_bits + 3;
1113 /* At most two ranges [hint, max_alloc) + [0, hint). */
1116 /* TODO: Optimize request for case nbits > wbits. */
1117 iw = hint >> log2_bits;
1118 wbits = sb->s_blocksize * 8;
1119 wpos = hint & (wbits - 1);
1123 if (max_alloc == wnd->nbits) {
1126 size_t t = max_alloc + wbits - 1;
1128 nwnd = likely(t > max_alloc) ? (t >> log2_bits) : wnd->nwnd;
1131 /* Enumerate all windows. */
1132 for (; iw < nwnd; iw++) {
1133 wbit = iw << log2_bits;
1135 if (!wnd->free_bits[iw]) {
1136 if (prev_tail > b_len) {
1137 b_pos = wbit - prev_tail;
1141 /* Skip full used window. */
1147 if (unlikely(iw + 1 == nwnd)) {
1148 if (max_alloc == wnd->nbits) {
1149 wbits = wnd->bits_last;
1151 size_t t = max_alloc & (wbits - 1);
1155 fbits_valid = false;
1160 if (wnd->zone_end > wnd->zone_bit) {
1161 ebit = wbit + wbits;
1162 zbit = max(wnd->zone_bit, wbit);
1163 zend = min(wnd->zone_end, ebit);
1165 /* Here we have a window [wbit, ebit) and zone [zbit, zend). */
1167 /* Zone does not overlap window. */
1169 wzbit = zbit - wbit;
1170 wzend = zend - wbit;
1172 /* Zone overlaps window. */
1173 if (wnd->free_bits[iw] == wzend - wzbit) {
1179 /* Scan two ranges window: [wbit, zbit) and [zend, ebit). */
1180 bh = wnd_map(wnd, iw);
1189 buf = (ulong *)bh->b_data;
1191 /* Scan range [wbit, zbit). */
1193 /* Scan range [wpos, zbit). */
1194 fnd = wnd_scan(buf, wbit, wpos, wzbit,
1195 to_alloc, &prev_tail,
1197 if (fnd != MINUS_ONE_T) {
1205 /* Scan range [zend, ebit). */
1206 if (wzend < wbits) {
1207 fnd = wnd_scan(buf, wbit,
1208 max(wzend, wpos), wbits,
1209 to_alloc, &prev_tail,
1211 if (fnd != MINUS_ONE_T) {
1223 /* Current window does not overlap zone. */
1224 if (!wpos && fbits_valid && wnd->free_bits[iw] == wbits) {
1225 /* Window is empty. */
1226 if (prev_tail + wbits >= to_alloc) {
1227 fnd = wbit + wpos - prev_tail;
1231 /* Increase 'prev_tail' and process next window. */
1238 bh = wnd_map(wnd, iw);
1246 buf = (ulong *)bh->b_data;
1248 /* Scan range [wpos, eBits). */
1249 fnd = wnd_scan(buf, wbit, wpos, wbits, to_alloc, &prev_tail,
1252 if (fnd != MINUS_ONE_T)
1256 if (b_len < prev_tail) {
1257 /* The last fragment. */
1259 b_pos = max_alloc - prev_tail;
1264 * We have scanned range [hint max_alloc).
1265 * Prepare to scan range [0 hint + to_alloc).
1267 size_t nextmax = hint + to_alloc;
1269 if (likely(nextmax >= hint) && nextmax < max_alloc)
1270 max_alloc = nextmax;
1278 wnd->extent_max = b_len;
1280 if (flags & BITMAP_FIND_FULL)
1287 if (flags & BITMAP_FIND_MARK_AS_USED) {
1288 /* TODO: Optimize remove extent (pass 'e'?). */
1289 if (wnd_set_used(wnd, fnd, to_alloc))
1291 } else if (wnd->extent_max != MINUS_ONE_T &&
1292 to_alloc > wnd->extent_max) {
1293 wnd->extent_max = to_alloc;
1304 * wnd_extend - Extend bitmap ($MFT bitmap).
1306 int wnd_extend(struct wnd_bitmap *wnd, size_t new_bits)
1309 struct super_block *sb = wnd->sb;
1310 struct ntfs_sb_info *sbi = sb->s_fs_info;
1311 u32 blocksize = sb->s_blocksize;
1312 u32 wbits = blocksize * 8;
1314 size_t bits, iw, new_wnd;
1315 size_t old_bits = wnd->nbits;
1318 if (new_bits <= old_bits)
1321 /* Align to 8 byte boundary. */
1322 new_wnd = bytes_to_block(sb, bitmap_size(new_bits));
1323 new_last = new_bits & (wbits - 1);
1327 if (new_wnd != wnd->nwnd) {
1328 new_free = kmalloc(new_wnd * sizeof(u16), GFP_NOFS);
1332 memcpy(new_free, wnd->free_bits, wnd->nwnd * sizeof(short));
1333 memset(new_free + wnd->nwnd, 0,
1334 (new_wnd - wnd->nwnd) * sizeof(short));
1335 kfree(wnd->free_bits);
1336 wnd->free_bits = new_free;
1339 /* Zero bits [old_bits,new_bits). */
1340 bits = new_bits - old_bits;
1341 b0 = old_bits & (wbits - 1);
1343 for (iw = old_bits >> (sb->s_blocksize_bits + 3); bits; iw += 1) {
1346 u64 vbo, lbo, bytes;
1347 struct buffer_head *bh;
1350 if (iw + 1 == new_wnd)
1353 op = b0 + bits > wbits ? wbits - b0 : bits;
1354 vbo = (u64)iw * blocksize;
1356 err = ntfs_vbo_to_lbo(sbi, &wnd->run, vbo, &lbo, &bytes);
1360 bh = ntfs_bread(sb, lbo >> sb->s_blocksize_bits);
1365 buf = (ulong *)bh->b_data;
1367 __bitmap_clear(buf, b0, blocksize * 8 - b0);
1368 frb = wbits - bitmap_weight(buf, wbits);
1369 wnd->total_zeroes += frb - wnd->free_bits[iw];
1370 wnd->free_bits[iw] = frb;
1372 set_buffer_uptodate(bh);
1373 mark_buffer_dirty(bh);
1375 /* err = sync_dirty_buffer(bh); */
1381 wnd->nbits = new_bits;
1382 wnd->nwnd = new_wnd;
1383 wnd->bits_last = new_last;
1385 wnd_add_free_ext(wnd, old_bits, new_bits - old_bits, false);
1390 void wnd_zone_set(struct wnd_bitmap *wnd, size_t lcn, size_t len)
1392 size_t zlen = wnd->zone_end - wnd->zone_bit;
1395 wnd_add_free_ext(wnd, wnd->zone_bit, zlen, false);
1397 if (!RB_EMPTY_ROOT(&wnd->start_tree) && len)
1398 wnd_remove_free_ext(wnd, lcn, len);
1400 wnd->zone_bit = lcn;
1401 wnd->zone_end = lcn + len;
1404 int ntfs_trim_fs(struct ntfs_sb_info *sbi, struct fstrim_range *range)
1407 struct super_block *sb = sbi->sb;
1408 struct wnd_bitmap *wnd = &sbi->used.bitmap;
1409 u32 wbits = 8 * sb->s_blocksize;
1410 CLST len = 0, lcn = 0, done = 0;
1411 CLST minlen = bytes_to_cluster(sbi, range->minlen);
1412 CLST lcn_from = bytes_to_cluster(sbi, range->start);
1413 size_t iw = lcn_from >> (sb->s_blocksize_bits + 3);
1414 u32 wbit = lcn_from & (wbits - 1);
1421 if (range->len == (u64)-1)
1422 lcn_to = wnd->nbits;
1424 lcn_to = bytes_to_cluster(sbi, range->start + range->len);
1426 down_read_nested(&wnd->rw_lock, BITMAP_MUTEX_CLUSTERS);
1428 for (; iw < wnd->nwnd; iw++, wbit = 0) {
1429 CLST lcn_wnd = iw * wbits;
1430 struct buffer_head *bh;
1432 if (lcn_wnd > lcn_to)
1435 if (!wnd->free_bits[iw])
1438 if (iw + 1 == wnd->nwnd)
1439 wbits = wnd->bits_last;
1441 if (lcn_wnd + wbits > lcn_to)
1442 wbits = lcn_to - lcn_wnd;
1444 bh = wnd_map(wnd, iw);
1450 buf = (ulong *)bh->b_data;
1452 for (; wbit < wbits; wbit++) {
1453 if (!test_bit(wbit, buf)) {
1455 lcn = lcn_wnd + wbit;
1459 if (len >= minlen) {
1460 err = ntfs_discard(sbi, lcn, len);
1470 /* Process the last fragment. */
1471 if (len >= minlen) {
1472 err = ntfs_discard(sbi, lcn, len);
1479 range->len = (u64)done << sbi->cluster_bits;
1481 up_read(&wnd->rw_lock);