2 * Block Translation Table
3 * Copyright (c) 2014-2015, Intel Corporation.
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 #include <linux/highmem.h>
15 #include <linux/debugfs.h>
16 #include <linux/blkdev.h>
17 #include <linux/module.h>
18 #include <linux/device.h>
19 #include <linux/mutex.h>
20 #include <linux/hdreg.h>
21 #include <linux/genhd.h>
22 #include <linux/sizes.h>
23 #include <linux/ndctl.h>
29 enum log_ent_request {
36 static int arena_read_bytes(struct arena_info *arena, resource_size_t offset,
39 struct nd_btt *nd_btt = arena->nd_btt;
40 struct nd_namespace_common *ndns = nd_btt->ndns;
42 /* arena offsets are 4K from the base of the device */
44 return nvdimm_read_bytes(ndns, offset, buf, n);
47 static int arena_write_bytes(struct arena_info *arena, resource_size_t offset,
50 struct nd_btt *nd_btt = arena->nd_btt;
51 struct nd_namespace_common *ndns = nd_btt->ndns;
53 /* arena offsets are 4K from the base of the device */
55 return nvdimm_write_bytes(ndns, offset, buf, n);
58 static int btt_info_write(struct arena_info *arena, struct btt_sb *super)
62 ret = arena_write_bytes(arena, arena->info2off, super,
63 sizeof(struct btt_sb));
67 return arena_write_bytes(arena, arena->infooff, super,
68 sizeof(struct btt_sb));
71 static int btt_info_read(struct arena_info *arena, struct btt_sb *super)
74 return arena_read_bytes(arena, arena->infooff, super,
75 sizeof(struct btt_sb));
79 * 'raw' version of btt_map write
81 * mapping is in little-endian
82 * mapping contains 'E' and 'Z' flags as desired
84 static int __btt_map_write(struct arena_info *arena, u32 lba, __le32 mapping)
86 u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE);
88 WARN_ON(lba >= arena->external_nlba);
89 return arena_write_bytes(arena, ns_off, &mapping, MAP_ENT_SIZE);
92 static int btt_map_write(struct arena_info *arena, u32 lba, u32 mapping,
93 u32 z_flag, u32 e_flag)
99 * This 'mapping' is supposed to be just the LBA mapping, without
100 * any flags set, so strip the flag bits.
102 mapping &= MAP_LBA_MASK;
104 ze = (z_flag << 1) + e_flag;
108 * We want to set neither of the Z or E flags, and
109 * in the actual layout, this means setting the bit
110 * positions of both to '1' to indicate a 'normal'
113 mapping |= MAP_ENT_NORMAL;
116 mapping |= (1 << MAP_ERR_SHIFT);
119 mapping |= (1 << MAP_TRIM_SHIFT);
123 * The case where Z and E are both sent in as '1' could be
124 * construed as a valid 'normal' case, but we decide not to,
127 WARN_ONCE(1, "Invalid use of Z and E flags\n");
131 mapping_le = cpu_to_le32(mapping);
132 return __btt_map_write(arena, lba, mapping_le);
135 static int btt_map_read(struct arena_info *arena, u32 lba, u32 *mapping,
136 int *trim, int *error)
140 u32 raw_mapping, postmap, ze, z_flag, e_flag;
141 u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE);
143 WARN_ON(lba >= arena->external_nlba);
145 ret = arena_read_bytes(arena, ns_off, &in, MAP_ENT_SIZE);
149 raw_mapping = le32_to_cpu(in);
151 z_flag = (raw_mapping & MAP_TRIM_MASK) >> MAP_TRIM_SHIFT;
152 e_flag = (raw_mapping & MAP_ERR_MASK) >> MAP_ERR_SHIFT;
153 ze = (z_flag << 1) + e_flag;
154 postmap = raw_mapping & MAP_LBA_MASK;
156 /* Reuse the {z,e}_flag variables for *trim and *error */
162 /* Initial state. Return postmap = premap */
188 static int btt_log_read_pair(struct arena_info *arena, u32 lane,
189 struct log_entry *ent)
192 return arena_read_bytes(arena,
193 arena->logoff + (2 * lane * LOG_ENT_SIZE), ent,
197 static struct dentry *debugfs_root;
199 static void arena_debugfs_init(struct arena_info *a, struct dentry *parent,
205 /* If for some reason, parent bttN was not created, exit */
209 snprintf(dirname, 32, "arena%d", idx);
210 d = debugfs_create_dir(dirname, parent);
211 if (IS_ERR_OR_NULL(d))
215 debugfs_create_x64("size", S_IRUGO, d, &a->size);
216 debugfs_create_x64("external_lba_start", S_IRUGO, d,
217 &a->external_lba_start);
218 debugfs_create_x32("internal_nlba", S_IRUGO, d, &a->internal_nlba);
219 debugfs_create_u32("internal_lbasize", S_IRUGO, d,
220 &a->internal_lbasize);
221 debugfs_create_x32("external_nlba", S_IRUGO, d, &a->external_nlba);
222 debugfs_create_u32("external_lbasize", S_IRUGO, d,
223 &a->external_lbasize);
224 debugfs_create_u32("nfree", S_IRUGO, d, &a->nfree);
225 debugfs_create_u16("version_major", S_IRUGO, d, &a->version_major);
226 debugfs_create_u16("version_minor", S_IRUGO, d, &a->version_minor);
227 debugfs_create_x64("nextoff", S_IRUGO, d, &a->nextoff);
228 debugfs_create_x64("infooff", S_IRUGO, d, &a->infooff);
229 debugfs_create_x64("dataoff", S_IRUGO, d, &a->dataoff);
230 debugfs_create_x64("mapoff", S_IRUGO, d, &a->mapoff);
231 debugfs_create_x64("logoff", S_IRUGO, d, &a->logoff);
232 debugfs_create_x64("info2off", S_IRUGO, d, &a->info2off);
233 debugfs_create_x32("flags", S_IRUGO, d, &a->flags);
236 static void btt_debugfs_init(struct btt *btt)
239 struct arena_info *arena;
241 btt->debugfs_dir = debugfs_create_dir(dev_name(&btt->nd_btt->dev),
243 if (IS_ERR_OR_NULL(btt->debugfs_dir))
246 list_for_each_entry(arena, &btt->arena_list, list) {
247 arena_debugfs_init(arena, btt->debugfs_dir, i);
253 * This function accepts two log entries, and uses the
254 * sequence number to find the 'older' entry.
255 * It also updates the sequence number in this old entry to
256 * make it the 'new' one if the mark_flag is set.
257 * Finally, it returns which of the entries was the older one.
259 * TODO The logic feels a bit kludge-y. make it better..
261 static int btt_log_get_old(struct log_entry *ent)
266 * the first ever time this is seen, the entry goes into [0]
267 * the next time, the following logic works out to put this
268 * (next) entry into [1]
270 if (ent[0].seq == 0) {
271 ent[0].seq = cpu_to_le32(1);
275 if (ent[0].seq == ent[1].seq)
277 if (le32_to_cpu(ent[0].seq) + le32_to_cpu(ent[1].seq) > 5)
280 if (le32_to_cpu(ent[0].seq) < le32_to_cpu(ent[1].seq)) {
281 if (le32_to_cpu(ent[1].seq) - le32_to_cpu(ent[0].seq) == 1)
286 if (le32_to_cpu(ent[0].seq) - le32_to_cpu(ent[1].seq) == 1)
295 static struct device *to_dev(struct arena_info *arena)
297 return &arena->nd_btt->dev;
301 * This function copies the desired (old/new) log entry into ent if
302 * it is not NULL. It returns the sub-slot number (0 or 1)
303 * where the desired log entry was found. Negative return values
306 static int btt_log_read(struct arena_info *arena, u32 lane,
307 struct log_entry *ent, int old_flag)
310 int old_ent, ret_ent;
311 struct log_entry log[2];
313 ret = btt_log_read_pair(arena, lane, log);
317 old_ent = btt_log_get_old(log);
318 if (old_ent < 0 || old_ent > 1) {
319 dev_info(to_dev(arena),
320 "log corruption (%d): lane %d seq [%d, %d]\n",
321 old_ent, lane, log[0].seq, log[1].seq);
322 /* TODO set error state? */
326 ret_ent = (old_flag ? old_ent : (1 - old_ent));
329 memcpy(ent, &log[ret_ent], LOG_ENT_SIZE);
335 * This function commits a log entry to media
336 * It does _not_ prepare the freelist entry for the next write
337 * btt_flog_write is the wrapper for updating the freelist elements
339 static int __btt_log_write(struct arena_info *arena, u32 lane,
340 u32 sub, struct log_entry *ent)
344 * Ignore the padding in log_entry for calculating log_half.
345 * The entry is 'committed' when we write the sequence number,
346 * and we want to ensure that that is the last thing written.
347 * We don't bother writing the padding as that would be extra
348 * media wear and write amplification
350 unsigned int log_half = (LOG_ENT_SIZE - 2 * sizeof(u64)) / 2;
351 u64 ns_off = arena->logoff + (((2 * lane) + sub) * LOG_ENT_SIZE);
354 /* split the 16B write into atomic, durable halves */
355 ret = arena_write_bytes(arena, ns_off, src, log_half);
361 return arena_write_bytes(arena, ns_off, src, log_half);
364 static int btt_flog_write(struct arena_info *arena, u32 lane, u32 sub,
365 struct log_entry *ent)
369 ret = __btt_log_write(arena, lane, sub, ent);
373 /* prepare the next free entry */
374 arena->freelist[lane].sub = 1 - arena->freelist[lane].sub;
375 if (++(arena->freelist[lane].seq) == 4)
376 arena->freelist[lane].seq = 1;
377 arena->freelist[lane].block = le32_to_cpu(ent->old_map);
383 * This function initializes the BTT map to the initial state, which is
384 * all-zeroes, and indicates an identity mapping
386 static int btt_map_init(struct arena_info *arena)
391 size_t chunk_size = SZ_2M;
392 size_t mapsize = arena->logoff - arena->mapoff;
394 zerobuf = kzalloc(chunk_size, GFP_KERNEL);
399 size_t size = min(mapsize, chunk_size);
401 ret = arena_write_bytes(arena, arena->mapoff + offset, zerobuf,
417 * This function initializes the BTT log with 'fake' entries pointing
418 * to the initial reserved set of blocks as being free
420 static int btt_log_init(struct arena_info *arena)
424 struct log_entry log, zerolog;
426 memset(&zerolog, 0, sizeof(zerolog));
428 for (i = 0; i < arena->nfree; i++) {
429 log.lba = cpu_to_le32(i);
430 log.old_map = cpu_to_le32(arena->external_nlba + i);
431 log.new_map = cpu_to_le32(arena->external_nlba + i);
432 log.seq = cpu_to_le32(LOG_SEQ_INIT);
433 ret = __btt_log_write(arena, i, 0, &log);
436 ret = __btt_log_write(arena, i, 1, &zerolog);
444 static int btt_freelist_init(struct arena_info *arena)
448 struct log_entry log_new;
450 arena->freelist = kcalloc(arena->nfree, sizeof(struct free_entry),
452 if (!arena->freelist)
455 for (i = 0; i < arena->nfree; i++) {
456 new = btt_log_read(arena, i, &log_new, LOG_NEW_ENT);
460 /* sub points to the next one to be overwritten */
461 arena->freelist[i].sub = 1 - new;
462 arena->freelist[i].seq = nd_inc_seq(le32_to_cpu(log_new.seq));
463 arena->freelist[i].block = le32_to_cpu(log_new.old_map);
465 /* This implies a newly created or untouched flog entry */
466 if (log_new.old_map == log_new.new_map)
469 /* Check if map recovery is needed */
470 ret = btt_map_read(arena, le32_to_cpu(log_new.lba), &map_entry,
474 if ((le32_to_cpu(log_new.new_map) != map_entry) &&
475 (le32_to_cpu(log_new.old_map) == map_entry)) {
477 * Last transaction wrote the flog, but wasn't able
478 * to complete the map write. So fix up the map.
480 ret = btt_map_write(arena, le32_to_cpu(log_new.lba),
481 le32_to_cpu(log_new.new_map), 0, 0);
491 static int btt_rtt_init(struct arena_info *arena)
493 arena->rtt = kcalloc(arena->nfree, sizeof(u32), GFP_KERNEL);
494 if (arena->rtt == NULL)
500 static int btt_maplocks_init(struct arena_info *arena)
504 arena->map_locks = kcalloc(arena->nfree, sizeof(struct aligned_lock),
506 if (!arena->map_locks)
509 for (i = 0; i < arena->nfree; i++)
510 spin_lock_init(&arena->map_locks[i].lock);
515 static struct arena_info *alloc_arena(struct btt *btt, size_t size,
516 size_t start, size_t arena_off)
518 struct arena_info *arena;
519 u64 logsize, mapsize, datasize;
520 u64 available = size;
522 arena = kzalloc(sizeof(struct arena_info), GFP_KERNEL);
525 arena->nd_btt = btt->nd_btt;
531 arena->external_lba_start = start;
532 arena->external_lbasize = btt->lbasize;
533 arena->internal_lbasize = roundup(arena->external_lbasize,
534 INT_LBASIZE_ALIGNMENT);
535 arena->nfree = BTT_DEFAULT_NFREE;
536 arena->version_major = 1;
537 arena->version_minor = 1;
539 if (available % BTT_PG_SIZE)
540 available -= (available % BTT_PG_SIZE);
542 /* Two pages are reserved for the super block and its copy */
543 available -= 2 * BTT_PG_SIZE;
545 /* The log takes a fixed amount of space based on nfree */
546 logsize = roundup(2 * arena->nfree * sizeof(struct log_entry),
548 available -= logsize;
550 /* Calculate optimal split between map and data area */
551 arena->internal_nlba = div_u64(available - BTT_PG_SIZE,
552 arena->internal_lbasize + MAP_ENT_SIZE);
553 arena->external_nlba = arena->internal_nlba - arena->nfree;
555 mapsize = roundup((arena->external_nlba * MAP_ENT_SIZE), BTT_PG_SIZE);
556 datasize = available - mapsize;
558 /* 'Absolute' values, relative to start of storage space */
559 arena->infooff = arena_off;
560 arena->dataoff = arena->infooff + BTT_PG_SIZE;
561 arena->mapoff = arena->dataoff + datasize;
562 arena->logoff = arena->mapoff + mapsize;
563 arena->info2off = arena->logoff + logsize;
567 static void free_arenas(struct btt *btt)
569 struct arena_info *arena, *next;
571 list_for_each_entry_safe(arena, next, &btt->arena_list, list) {
572 list_del(&arena->list);
574 kfree(arena->map_locks);
575 kfree(arena->freelist);
576 debugfs_remove_recursive(arena->debugfs_dir);
582 * This function reads an existing valid btt superblock and
583 * populates the corresponding arena_info struct
585 static void parse_arena_meta(struct arena_info *arena, struct btt_sb *super,
588 arena->internal_nlba = le32_to_cpu(super->internal_nlba);
589 arena->internal_lbasize = le32_to_cpu(super->internal_lbasize);
590 arena->external_nlba = le32_to_cpu(super->external_nlba);
591 arena->external_lbasize = le32_to_cpu(super->external_lbasize);
592 arena->nfree = le32_to_cpu(super->nfree);
593 arena->version_major = le16_to_cpu(super->version_major);
594 arena->version_minor = le16_to_cpu(super->version_minor);
596 arena->nextoff = (super->nextoff == 0) ? 0 : (arena_off +
597 le64_to_cpu(super->nextoff));
598 arena->infooff = arena_off;
599 arena->dataoff = arena_off + le64_to_cpu(super->dataoff);
600 arena->mapoff = arena_off + le64_to_cpu(super->mapoff);
601 arena->logoff = arena_off + le64_to_cpu(super->logoff);
602 arena->info2off = arena_off + le64_to_cpu(super->info2off);
604 arena->size = (le64_to_cpu(super->nextoff) > 0)
605 ? (le64_to_cpu(super->nextoff))
606 : (arena->info2off - arena->infooff + BTT_PG_SIZE);
608 arena->flags = le32_to_cpu(super->flags);
611 static int discover_arenas(struct btt *btt)
614 struct arena_info *arena;
615 struct btt_sb *super;
616 size_t remaining = btt->rawsize;
621 super = kzalloc(sizeof(*super), GFP_KERNEL);
626 /* Alloc memory for arena */
627 arena = alloc_arena(btt, 0, 0, 0);
633 arena->infooff = cur_off;
634 ret = btt_info_read(arena, super);
638 if (!nd_btt_arena_is_valid(btt->nd_btt, super)) {
639 if (remaining == btt->rawsize) {
640 btt->init_state = INIT_NOTFOUND;
641 dev_info(to_dev(arena), "No existing arenas\n");
644 dev_info(to_dev(arena),
645 "Found corrupted metadata!\n");
651 arena->external_lba_start = cur_nlba;
652 parse_arena_meta(arena, super, cur_off);
654 ret = btt_freelist_init(arena);
658 ret = btt_rtt_init(arena);
662 ret = btt_maplocks_init(arena);
666 list_add_tail(&arena->list, &btt->arena_list);
668 remaining -= arena->size;
669 cur_off += arena->size;
670 cur_nlba += arena->external_nlba;
673 if (arena->nextoff == 0)
676 btt->num_arenas = num_arenas;
677 btt->nlba = cur_nlba;
678 btt->init_state = INIT_READY;
691 static int create_arenas(struct btt *btt)
693 size_t remaining = btt->rawsize;
697 struct arena_info *arena;
698 size_t arena_size = min_t(u64, ARENA_MAX_SIZE, remaining);
700 remaining -= arena_size;
701 if (arena_size < ARENA_MIN_SIZE)
704 arena = alloc_arena(btt, arena_size, btt->nlba, cur_off);
709 btt->nlba += arena->external_nlba;
710 if (remaining >= ARENA_MIN_SIZE)
711 arena->nextoff = arena->size;
714 cur_off += arena_size;
715 list_add_tail(&arena->list, &btt->arena_list);
722 * This function completes arena initialization by writing
724 * It is only called for an uninitialized arena when a write
725 * to that arena occurs for the first time.
727 static int btt_arena_write_layout(struct arena_info *arena)
731 struct btt_sb *super;
732 struct nd_btt *nd_btt = arena->nd_btt;
733 const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
735 ret = btt_map_init(arena);
739 ret = btt_log_init(arena);
743 super = kzalloc(sizeof(struct btt_sb), GFP_NOIO);
747 strncpy(super->signature, BTT_SIG, BTT_SIG_LEN);
748 memcpy(super->uuid, nd_btt->uuid, 16);
749 memcpy(super->parent_uuid, parent_uuid, 16);
750 super->flags = cpu_to_le32(arena->flags);
751 super->version_major = cpu_to_le16(arena->version_major);
752 super->version_minor = cpu_to_le16(arena->version_minor);
753 super->external_lbasize = cpu_to_le32(arena->external_lbasize);
754 super->external_nlba = cpu_to_le32(arena->external_nlba);
755 super->internal_lbasize = cpu_to_le32(arena->internal_lbasize);
756 super->internal_nlba = cpu_to_le32(arena->internal_nlba);
757 super->nfree = cpu_to_le32(arena->nfree);
758 super->infosize = cpu_to_le32(sizeof(struct btt_sb));
759 super->nextoff = cpu_to_le64(arena->nextoff);
761 * Subtract arena->infooff (arena start) so numbers are relative
764 super->dataoff = cpu_to_le64(arena->dataoff - arena->infooff);
765 super->mapoff = cpu_to_le64(arena->mapoff - arena->infooff);
766 super->logoff = cpu_to_le64(arena->logoff - arena->infooff);
767 super->info2off = cpu_to_le64(arena->info2off - arena->infooff);
770 sum = nd_sb_checksum((struct nd_gen_sb *) super);
771 super->checksum = cpu_to_le64(sum);
773 ret = btt_info_write(arena, super);
780 * This function completes the initialization for the BTT namespace
781 * such that it is ready to accept IOs
783 static int btt_meta_init(struct btt *btt)
786 struct arena_info *arena;
788 mutex_lock(&btt->init_lock);
789 list_for_each_entry(arena, &btt->arena_list, list) {
790 ret = btt_arena_write_layout(arena);
794 ret = btt_freelist_init(arena);
798 ret = btt_rtt_init(arena);
802 ret = btt_maplocks_init(arena);
807 btt->init_state = INIT_READY;
810 mutex_unlock(&btt->init_lock);
814 static u32 btt_meta_size(struct btt *btt)
816 return btt->lbasize - btt->sector_size;
820 * This function calculates the arena in which the given LBA lies
821 * by doing a linear walk. This is acceptable since we expect only
822 * a few arenas. If we have backing devices that get much larger,
823 * we can construct a balanced binary tree of arenas at init time
824 * so that this range search becomes faster.
826 static int lba_to_arena(struct btt *btt, sector_t sector, __u32 *premap,
827 struct arena_info **arena)
829 struct arena_info *arena_list;
830 __u64 lba = div_u64(sector << SECTOR_SHIFT, btt->sector_size);
832 list_for_each_entry(arena_list, &btt->arena_list, list) {
833 if (lba < arena_list->external_nlba) {
838 lba -= arena_list->external_nlba;
845 * The following (lock_map, unlock_map) are mostly just to improve
846 * readability, since they index into an array of locks
848 static void lock_map(struct arena_info *arena, u32 premap)
849 __acquires(&arena->map_locks[idx].lock)
851 u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree;
853 spin_lock(&arena->map_locks[idx].lock);
856 static void unlock_map(struct arena_info *arena, u32 premap)
857 __releases(&arena->map_locks[idx].lock)
859 u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree;
861 spin_unlock(&arena->map_locks[idx].lock);
864 static u64 to_namespace_offset(struct arena_info *arena, u64 lba)
866 return arena->dataoff + ((u64)lba * arena->internal_lbasize);
869 static int btt_data_read(struct arena_info *arena, struct page *page,
870 unsigned int off, u32 lba, u32 len)
873 u64 nsoff = to_namespace_offset(arena, lba);
874 void *mem = kmap_atomic(page);
876 ret = arena_read_bytes(arena, nsoff, mem + off, len);
882 static int btt_data_write(struct arena_info *arena, u32 lba,
883 struct page *page, unsigned int off, u32 len)
886 u64 nsoff = to_namespace_offset(arena, lba);
887 void *mem = kmap_atomic(page);
889 ret = arena_write_bytes(arena, nsoff, mem + off, len);
895 static void zero_fill_data(struct page *page, unsigned int off, u32 len)
897 void *mem = kmap_atomic(page);
899 memset(mem + off, 0, len);
903 #ifdef CONFIG_BLK_DEV_INTEGRITY
904 static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
905 struct arena_info *arena, u32 postmap, int rw)
907 unsigned int len = btt_meta_size(btt);
914 meta_nsoff = to_namespace_offset(arena, postmap) + btt->sector_size;
917 unsigned int cur_len;
921 bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
923 * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
924 * .bv_offset already adjusted for iter->bi_bvec_done, and we
925 * can use those directly
928 cur_len = min(len, bv.bv_len);
929 mem = kmap_atomic(bv.bv_page);
931 ret = arena_write_bytes(arena, meta_nsoff,
932 mem + bv.bv_offset, cur_len);
934 ret = arena_read_bytes(arena, meta_nsoff,
935 mem + bv.bv_offset, cur_len);
942 meta_nsoff += cur_len;
943 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
949 #else /* CONFIG_BLK_DEV_INTEGRITY */
950 static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
951 struct arena_info *arena, u32 postmap, int rw)
957 static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip,
958 struct page *page, unsigned int off, sector_t sector,
963 struct arena_info *arena = NULL;
964 u32 lane = 0, premap, postmap;
969 lane = nd_region_acquire_lane(btt->nd_region);
971 ret = lba_to_arena(btt, sector, &premap, &arena);
975 cur_len = min(btt->sector_size, len);
977 ret = btt_map_read(arena, premap, &postmap, &t_flag, &e_flag);
982 * We loop to make sure that the post map LBA didn't change
983 * from under us between writing the RTT and doing the actual
990 zero_fill_data(page, off, cur_len);
999 arena->rtt[lane] = RTT_VALID | postmap;
1001 * Barrier to make sure this write is not reordered
1002 * to do the verification map_read before the RTT store
1006 ret = btt_map_read(arena, premap, &new_map, &t_flag,
1011 if (postmap == new_map)
1017 ret = btt_data_read(arena, page, off, postmap, cur_len);
1022 ret = btt_rw_integrity(btt, bip, arena, postmap, READ);
1027 arena->rtt[lane] = RTT_INVALID;
1028 nd_region_release_lane(btt->nd_region, lane);
1032 sector += btt->sector_size >> SECTOR_SHIFT;
1038 arena->rtt[lane] = RTT_INVALID;
1040 nd_region_release_lane(btt->nd_region, lane);
1044 static int btt_write_pg(struct btt *btt, struct bio_integrity_payload *bip,
1045 sector_t sector, struct page *page, unsigned int off,
1049 struct arena_info *arena = NULL;
1050 u32 premap = 0, old_postmap, new_postmap, lane = 0, i;
1051 struct log_entry log;
1057 lane = nd_region_acquire_lane(btt->nd_region);
1059 ret = lba_to_arena(btt, sector, &premap, &arena);
1062 cur_len = min(btt->sector_size, len);
1064 if ((arena->flags & IB_FLAG_ERROR_MASK) != 0) {
1069 new_postmap = arena->freelist[lane].block;
1071 /* Wait if the new block is being read from */
1072 for (i = 0; i < arena->nfree; i++)
1073 while (arena->rtt[i] == (RTT_VALID | new_postmap))
1077 if (new_postmap >= arena->internal_nlba) {
1082 ret = btt_data_write(arena, new_postmap, page, off, cur_len);
1087 ret = btt_rw_integrity(btt, bip, arena, new_postmap,
1093 lock_map(arena, premap);
1094 ret = btt_map_read(arena, premap, &old_postmap, NULL, NULL);
1097 if (old_postmap >= arena->internal_nlba) {
1102 log.lba = cpu_to_le32(premap);
1103 log.old_map = cpu_to_le32(old_postmap);
1104 log.new_map = cpu_to_le32(new_postmap);
1105 log.seq = cpu_to_le32(arena->freelist[lane].seq);
1106 sub = arena->freelist[lane].sub;
1107 ret = btt_flog_write(arena, lane, sub, &log);
1111 ret = btt_map_write(arena, premap, new_postmap, 0, 0);
1115 unlock_map(arena, premap);
1116 nd_region_release_lane(btt->nd_region, lane);
1120 sector += btt->sector_size >> SECTOR_SHIFT;
1126 unlock_map(arena, premap);
1128 nd_region_release_lane(btt->nd_region, lane);
1132 static int btt_do_bvec(struct btt *btt, struct bio_integrity_payload *bip,
1133 struct page *page, unsigned int len, unsigned int off,
1134 int rw, sector_t sector)
1139 ret = btt_read_pg(btt, bip, page, off, sector, len);
1140 flush_dcache_page(page);
1142 flush_dcache_page(page);
1143 ret = btt_write_pg(btt, bip, sector, page, off, len);
1149 static blk_qc_t btt_make_request(struct request_queue *q, struct bio *bio)
1151 struct bio_integrity_payload *bip = bio_integrity(bio);
1152 struct btt *btt = q->queuedata;
1153 struct bvec_iter iter;
1154 unsigned long start;
1155 struct bio_vec bvec;
1160 * bio_integrity_enabled also checks if the bio already has an
1161 * integrity payload attached. If it does, we *don't* do a
1162 * bio_integrity_prep here - the payload has been generated by
1163 * another kernel subsystem, and we just pass it through.
1165 if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
1166 bio->bi_error = -EIO;
1170 do_acct = nd_iostat_start(bio, &start);
1171 rw = bio_data_dir(bio);
1172 bio_for_each_segment(bvec, bio, iter) {
1173 unsigned int len = bvec.bv_len;
1175 BUG_ON(len > PAGE_SIZE);
1176 /* Make sure len is in multiples of sector size. */
1177 /* XXX is this right? */
1178 BUG_ON(len < btt->sector_size);
1179 BUG_ON(len % btt->sector_size);
1181 err = btt_do_bvec(btt, bip, bvec.bv_page, len, bvec.bv_offset,
1182 rw, iter.bi_sector);
1184 dev_info(&btt->nd_btt->dev,
1185 "io error in %s sector %lld, len %d,\n",
1186 (rw == READ) ? "READ" : "WRITE",
1187 (unsigned long long) iter.bi_sector, len);
1188 bio->bi_error = err;
1193 nd_iostat_end(bio, start);
1197 return BLK_QC_T_NONE;
1200 static int btt_rw_page(struct block_device *bdev, sector_t sector,
1201 struct page *page, int rw)
1203 struct btt *btt = bdev->bd_disk->private_data;
1206 rc = btt_do_bvec(btt, NULL, page, PAGE_CACHE_SIZE, 0, rw, sector);
1208 page_endio(page, rw & WRITE, 0);
1214 static int btt_getgeo(struct block_device *bd, struct hd_geometry *geo)
1216 /* some standard values */
1217 geo->heads = 1 << 6;
1218 geo->sectors = 1 << 5;
1219 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
1223 static const struct block_device_operations btt_fops = {
1224 .owner = THIS_MODULE,
1225 .rw_page = btt_rw_page,
1226 .getgeo = btt_getgeo,
1227 .revalidate_disk = nvdimm_revalidate_disk,
1230 static int btt_blk_init(struct btt *btt)
1232 struct nd_btt *nd_btt = btt->nd_btt;
1233 struct nd_namespace_common *ndns = nd_btt->ndns;
1235 /* create a new disk and request queue for btt */
1236 btt->btt_queue = blk_alloc_queue(GFP_KERNEL);
1237 if (!btt->btt_queue)
1240 btt->btt_disk = alloc_disk(0);
1241 if (!btt->btt_disk) {
1242 blk_cleanup_queue(btt->btt_queue);
1246 nvdimm_namespace_disk_name(ndns, btt->btt_disk->disk_name);
1247 btt->btt_disk->driverfs_dev = &btt->nd_btt->dev;
1248 btt->btt_disk->major = btt_major;
1249 btt->btt_disk->first_minor = 0;
1250 btt->btt_disk->fops = &btt_fops;
1251 btt->btt_disk->private_data = btt;
1252 btt->btt_disk->queue = btt->btt_queue;
1253 btt->btt_disk->flags = GENHD_FL_EXT_DEVT;
1255 blk_queue_make_request(btt->btt_queue, btt_make_request);
1256 blk_queue_logical_block_size(btt->btt_queue, btt->sector_size);
1257 blk_queue_max_hw_sectors(btt->btt_queue, UINT_MAX);
1258 blk_queue_bounce_limit(btt->btt_queue, BLK_BOUNCE_ANY);
1259 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, btt->btt_queue);
1260 btt->btt_queue->queuedata = btt;
1262 set_capacity(btt->btt_disk, 0);
1263 add_disk(btt->btt_disk);
1264 if (btt_meta_size(btt)) {
1265 int rc = nd_integrity_init(btt->btt_disk, btt_meta_size(btt));
1268 del_gendisk(btt->btt_disk);
1269 put_disk(btt->btt_disk);
1270 blk_cleanup_queue(btt->btt_queue);
1274 set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9);
1275 revalidate_disk(btt->btt_disk);
1280 static void btt_blk_cleanup(struct btt *btt)
1282 del_gendisk(btt->btt_disk);
1283 put_disk(btt->btt_disk);
1284 blk_cleanup_queue(btt->btt_queue);
1288 * btt_init - initialize a block translation table for the given device
1289 * @nd_btt: device with BTT geometry and backing device info
1290 * @rawsize: raw size in bytes of the backing device
1291 * @lbasize: lba size of the backing device
1292 * @uuid: A uuid for the backing device - this is stored on media
1293 * @maxlane: maximum number of parallel requests the device can handle
1295 * Initialize a Block Translation Table on a backing device to provide
1296 * single sector power fail atomicity.
1302 * Pointer to a new struct btt on success, NULL on failure.
1304 static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
1305 u32 lbasize, u8 *uuid, struct nd_region *nd_region)
1309 struct device *dev = &nd_btt->dev;
1311 btt = kzalloc(sizeof(struct btt), GFP_KERNEL);
1315 btt->nd_btt = nd_btt;
1316 btt->rawsize = rawsize;
1317 btt->lbasize = lbasize;
1318 btt->sector_size = ((lbasize >= 4096) ? 4096 : 512);
1319 INIT_LIST_HEAD(&btt->arena_list);
1320 mutex_init(&btt->init_lock);
1321 btt->nd_region = nd_region;
1323 ret = discover_arenas(btt);
1325 dev_err(dev, "init: error in arena_discover: %d\n", ret);
1329 if (btt->init_state != INIT_READY && nd_region->ro) {
1330 dev_info(dev, "%s is read-only, unable to init btt metadata\n",
1331 dev_name(&nd_region->dev));
1333 } else if (btt->init_state != INIT_READY) {
1334 btt->num_arenas = (rawsize / ARENA_MAX_SIZE) +
1335 ((rawsize % ARENA_MAX_SIZE) ? 1 : 0);
1336 dev_dbg(dev, "init: %d arenas for %llu rawsize\n",
1337 btt->num_arenas, rawsize);
1339 ret = create_arenas(btt);
1341 dev_info(dev, "init: create_arenas: %d\n", ret);
1345 ret = btt_meta_init(btt);
1347 dev_err(dev, "init: error in meta_init: %d\n", ret);
1352 ret = btt_blk_init(btt);
1354 dev_err(dev, "init: error in blk_init: %d\n", ret);
1358 btt_debugfs_init(btt);
1368 * btt_fini - de-initialize a BTT
1369 * @btt: the BTT handle that was generated by btt_init
1371 * De-initialize a Block Translation Table on device removal
1376 static void btt_fini(struct btt *btt)
1379 btt_blk_cleanup(btt);
1381 debugfs_remove_recursive(btt->debugfs_dir);
1386 int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns)
1388 struct nd_btt *nd_btt = to_nd_btt(ndns->claim);
1389 struct nd_region *nd_region;
1393 if (!nd_btt->uuid || !nd_btt->ndns || !nd_btt->lbasize)
1396 rawsize = nvdimm_namespace_capacity(ndns) - SZ_4K;
1397 if (rawsize < ARENA_MIN_SIZE) {
1400 nd_region = to_nd_region(nd_btt->dev.parent);
1401 btt = btt_init(nd_btt, rawsize, nd_btt->lbasize, nd_btt->uuid,
1409 EXPORT_SYMBOL(nvdimm_namespace_attach_btt);
1411 int nvdimm_namespace_detach_btt(struct nd_namespace_common *ndns)
1413 struct nd_btt *nd_btt = to_nd_btt(ndns->claim);
1414 struct btt *btt = nd_btt->btt;
1421 EXPORT_SYMBOL(nvdimm_namespace_detach_btt);
1423 static int __init nd_btt_init(void)
1427 btt_major = register_blkdev(0, "btt");
1431 debugfs_root = debugfs_create_dir("btt", NULL);
1432 if (IS_ERR_OR_NULL(debugfs_root)) {
1440 unregister_blkdev(btt_major, "btt");
1445 static void __exit nd_btt_exit(void)
1447 debugfs_remove_recursive(debugfs_root);
1448 unregister_blkdev(btt_major, "btt");
1451 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_BTT);
1452 MODULE_AUTHOR("Vishal Verma <vishal.l.verma@linux.intel.com>");
1453 MODULE_LICENSE("GPL v2");
1454 module_init(nd_btt_init);
1455 module_exit(nd_btt_exit);