/* * Block Translation Table * Copyright (c) 2014-2015, Intel Corporation. * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "btt.h" #include "nd.h" enum log_ent_request { LOG_NEW_ENT = 0, LOG_OLD_ENT }; static int btt_major; static int arena_read_bytes(struct arena_info *arena, resource_size_t offset, void *buf, size_t n) { struct nd_btt *nd_btt = arena->nd_btt; struct nd_namespace_common *ndns = nd_btt->ndns; /* arena offsets are 4K from the base of the device */ offset += SZ_4K; return nvdimm_read_bytes(ndns, offset, buf, n); } static int arena_write_bytes(struct arena_info *arena, resource_size_t offset, void *buf, size_t n) { struct nd_btt *nd_btt = arena->nd_btt; struct nd_namespace_common *ndns = nd_btt->ndns; /* arena offsets are 4K from the base of the device */ offset += SZ_4K; return nvdimm_write_bytes(ndns, offset, buf, n); } static int btt_info_write(struct arena_info *arena, struct btt_sb *super) { int ret; ret = arena_write_bytes(arena, arena->info2off, super, sizeof(struct btt_sb)); if (ret) return ret; return arena_write_bytes(arena, arena->infooff, super, sizeof(struct btt_sb)); } static int btt_info_read(struct arena_info *arena, struct btt_sb *super) { WARN_ON(!super); return arena_read_bytes(arena, arena->infooff, super, sizeof(struct btt_sb)); } /* * 'raw' version of btt_map write * Assumptions: * mapping is in little-endian * mapping contains 'E' and 'Z' flags as desired */ static int __btt_map_write(struct arena_info *arena, u32 lba, __le32 mapping) { u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE); WARN_ON(lba >= arena->external_nlba); return arena_write_bytes(arena, ns_off, &mapping, MAP_ENT_SIZE); } static int btt_map_write(struct arena_info *arena, u32 lba, u32 mapping, u32 z_flag, u32 e_flag) { u32 ze; __le32 mapping_le; /* * This 'mapping' is supposed to be just the LBA mapping, without * any flags set, so strip the flag bits. */ mapping &= MAP_LBA_MASK; ze = (z_flag << 1) + e_flag; switch (ze) { case 0: /* * We want to set neither of the Z or E flags, and * in the actual layout, this means setting the bit * positions of both to '1' to indicate a 'normal' * map entry */ mapping |= MAP_ENT_NORMAL; break; case 1: mapping |= (1 << MAP_ERR_SHIFT); break; case 2: mapping |= (1 << MAP_TRIM_SHIFT); break; default: /* * The case where Z and E are both sent in as '1' could be * construed as a valid 'normal' case, but we decide not to, * to avoid confusion */ WARN_ONCE(1, "Invalid use of Z and E flags\n"); return -EIO; } mapping_le = cpu_to_le32(mapping); return __btt_map_write(arena, lba, mapping_le); } static int btt_map_read(struct arena_info *arena, u32 lba, u32 *mapping, int *trim, int *error) { int ret; __le32 in; u32 raw_mapping, postmap, ze, z_flag, e_flag; u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE); WARN_ON(lba >= arena->external_nlba); ret = arena_read_bytes(arena, ns_off, &in, MAP_ENT_SIZE); if (ret) return ret; raw_mapping = le32_to_cpu(in); z_flag = (raw_mapping & MAP_TRIM_MASK) >> MAP_TRIM_SHIFT; e_flag = (raw_mapping & MAP_ERR_MASK) >> MAP_ERR_SHIFT; ze = (z_flag << 1) + e_flag; postmap = raw_mapping & MAP_LBA_MASK; /* Reuse the {z,e}_flag variables for *trim and *error */ z_flag = 0; e_flag = 0; switch (ze) { case 0: /* Initial state. Return postmap = premap */ *mapping = lba; break; case 1: *mapping = postmap; e_flag = 1; break; case 2: *mapping = postmap; z_flag = 1; break; case 3: *mapping = postmap; break; default: return -EIO; } if (trim) *trim = z_flag; if (error) *error = e_flag; return ret; } static int btt_log_read_pair(struct arena_info *arena, u32 lane, struct log_entry *ent) { WARN_ON(!ent); return arena_read_bytes(arena, arena->logoff + (2 * lane * LOG_ENT_SIZE), ent, 2 * LOG_ENT_SIZE); } static struct dentry *debugfs_root; static void arena_debugfs_init(struct arena_info *a, struct dentry *parent, int idx) { char dirname[32]; struct dentry *d; /* If for some reason, parent bttN was not created, exit */ if (!parent) return; snprintf(dirname, 32, "arena%d", idx); d = debugfs_create_dir(dirname, parent); if (IS_ERR_OR_NULL(d)) return; a->debugfs_dir = d; debugfs_create_x64("size", S_IRUGO, d, &a->size); debugfs_create_x64("external_lba_start", S_IRUGO, d, &a->external_lba_start); debugfs_create_x32("internal_nlba", S_IRUGO, d, &a->internal_nlba); debugfs_create_u32("internal_lbasize", S_IRUGO, d, &a->internal_lbasize); debugfs_create_x32("external_nlba", S_IRUGO, d, &a->external_nlba); debugfs_create_u32("external_lbasize", S_IRUGO, d, &a->external_lbasize); debugfs_create_u32("nfree", S_IRUGO, d, &a->nfree); debugfs_create_u16("version_major", S_IRUGO, d, &a->version_major); debugfs_create_u16("version_minor", S_IRUGO, d, &a->version_minor); debugfs_create_x64("nextoff", S_IRUGO, d, &a->nextoff); debugfs_create_x64("infooff", S_IRUGO, d, &a->infooff); debugfs_create_x64("dataoff", S_IRUGO, d, &a->dataoff); debugfs_create_x64("mapoff", S_IRUGO, d, &a->mapoff); debugfs_create_x64("logoff", S_IRUGO, d, &a->logoff); debugfs_create_x64("info2off", S_IRUGO, d, &a->info2off); debugfs_create_x32("flags", S_IRUGO, d, &a->flags); } static void btt_debugfs_init(struct btt *btt) { int i = 0; struct arena_info *arena; btt->debugfs_dir = debugfs_create_dir(dev_name(&btt->nd_btt->dev), debugfs_root); if (IS_ERR_OR_NULL(btt->debugfs_dir)) return; list_for_each_entry(arena, &btt->arena_list, list) { arena_debugfs_init(arena, btt->debugfs_dir, i); i++; } } /* * This function accepts two log entries, and uses the * sequence number to find the 'older' entry. * It also updates the sequence number in this old entry to * make it the 'new' one if the mark_flag is set. * Finally, it returns which of the entries was the older one. * * TODO The logic feels a bit kludge-y. make it better.. */ static int btt_log_get_old(struct log_entry *ent) { int old; /* * the first ever time this is seen, the entry goes into [0] * the next time, the following logic works out to put this * (next) entry into [1] */ if (ent[0].seq == 0) { ent[0].seq = cpu_to_le32(1); return 0; } if (ent[0].seq == ent[1].seq) return -EINVAL; if (le32_to_cpu(ent[0].seq) + le32_to_cpu(ent[1].seq) > 5) return -EINVAL; if (le32_to_cpu(ent[0].seq) < le32_to_cpu(ent[1].seq)) { if (le32_to_cpu(ent[1].seq) - le32_to_cpu(ent[0].seq) == 1) old = 0; else old = 1; } else { if (le32_to_cpu(ent[0].seq) - le32_to_cpu(ent[1].seq) == 1) old = 1; else old = 0; } return old; } static struct device *to_dev(struct arena_info *arena) { return &arena->nd_btt->dev; } /* * This function copies the desired (old/new) log entry into ent if * it is not NULL. It returns the sub-slot number (0 or 1) * where the desired log entry was found. Negative return values * indicate errors. */ static int btt_log_read(struct arena_info *arena, u32 lane, struct log_entry *ent, int old_flag) { int ret; int old_ent, ret_ent; struct log_entry log[2]; ret = btt_log_read_pair(arena, lane, log); if (ret) return -EIO; old_ent = btt_log_get_old(log); if (old_ent < 0 || old_ent > 1) { dev_info(to_dev(arena), "log corruption (%d): lane %d seq [%d, %d]\n", old_ent, lane, log[0].seq, log[1].seq); /* TODO set error state? */ return -EIO; } ret_ent = (old_flag ? old_ent : (1 - old_ent)); if (ent != NULL) memcpy(ent, &log[ret_ent], LOG_ENT_SIZE); return ret_ent; } /* * This function commits a log entry to media * It does _not_ prepare the freelist entry for the next write * btt_flog_write is the wrapper for updating the freelist elements */ static int __btt_log_write(struct arena_info *arena, u32 lane, u32 sub, struct log_entry *ent) { int ret; /* * Ignore the padding in log_entry for calculating log_half. * The entry is 'committed' when we write the sequence number, * and we want to ensure that that is the last thing written. * We don't bother writing the padding as that would be extra * media wear and write amplification */ unsigned int log_half = (LOG_ENT_SIZE - 2 * sizeof(u64)) / 2; u64 ns_off = arena->logoff + (((2 * lane) + sub) * LOG_ENT_SIZE); void *src = ent; /* split the 16B write into atomic, durable halves */ ret = arena_write_bytes(arena, ns_off, src, log_half); if (ret) return ret; ns_off += log_half; src += log_half; return arena_write_bytes(arena, ns_off, src, log_half); } static int btt_flog_write(struct arena_info *arena, u32 lane, u32 sub, struct log_entry *ent) { int ret; ret = __btt_log_write(arena, lane, sub, ent); if (ret) return ret; /* prepare the next free entry */ arena->freelist[lane].sub = 1 - arena->freelist[lane].sub; if (++(arena->freelist[lane].seq) == 4) arena->freelist[lane].seq = 1; arena->freelist[lane].block = le32_to_cpu(ent->old_map); return ret; } /* * This function initializes the BTT map to the initial state, which is * all-zeroes, and indicates an identity mapping */ static int btt_map_init(struct arena_info *arena) { int ret = -EINVAL; void *zerobuf; size_t offset = 0; size_t chunk_size = SZ_2M; size_t mapsize = arena->logoff - arena->mapoff; zerobuf = kzalloc(chunk_size, GFP_KERNEL); if (!zerobuf) return -ENOMEM; while (mapsize) { size_t size = min(mapsize, chunk_size); ret = arena_write_bytes(arena, arena->mapoff + offset, zerobuf, size); if (ret) goto free; offset += size; mapsize -= size; cond_resched(); } free: kfree(zerobuf); return ret; } /* * This function initializes the BTT log with 'fake' entries pointing * to the initial reserved set of blocks as being free */ static int btt_log_init(struct arena_info *arena) { int ret; u32 i; struct log_entry log, zerolog; memset(&zerolog, 0, sizeof(zerolog)); for (i = 0; i < arena->nfree; i++) { log.lba = cpu_to_le32(i); log.old_map = cpu_to_le32(arena->external_nlba + i); log.new_map = cpu_to_le32(arena->external_nlba + i); log.seq = cpu_to_le32(LOG_SEQ_INIT); ret = __btt_log_write(arena, i, 0, &log); if (ret) return ret; ret = __btt_log_write(arena, i, 1, &zerolog); if (ret) return ret; } return 0; } static int btt_freelist_init(struct arena_info *arena) { int old, new, ret; u32 i, map_entry; struct log_entry log_new, log_old; arena->freelist = kcalloc(arena->nfree, sizeof(struct free_entry), GFP_KERNEL); if (!arena->freelist) return -ENOMEM; for (i = 0; i < arena->nfree; i++) { old = btt_log_read(arena, i, &log_old, LOG_OLD_ENT); if (old < 0) return old; new = btt_log_read(arena, i, &log_new, LOG_NEW_ENT); if (new < 0) return new; /* sub points to the next one to be overwritten */ arena->freelist[i].sub = 1 - new; arena->freelist[i].seq = nd_inc_seq(le32_to_cpu(log_new.seq)); arena->freelist[i].block = le32_to_cpu(log_new.old_map); /* This implies a newly created or untouched flog entry */ if (log_new.old_map == log_new.new_map) continue; /* Check if map recovery is needed */ ret = btt_map_read(arena, le32_to_cpu(log_new.lba), &map_entry, NULL, NULL); if (ret) return ret; if ((le32_to_cpu(log_new.new_map) != map_entry) && (le32_to_cpu(log_new.old_map) == map_entry)) { /* * Last transaction wrote the flog, but wasn't able * to complete the map write. So fix up the map. */ ret = btt_map_write(arena, le32_to_cpu(log_new.lba), le32_to_cpu(log_new.new_map), 0, 0); if (ret) return ret; } } return 0; } static int btt_rtt_init(struct arena_info *arena) { arena->rtt = kcalloc(arena->nfree, sizeof(u32), GFP_KERNEL); if (arena->rtt == NULL) return -ENOMEM; return 0; } static int btt_maplocks_init(struct arena_info *arena) { u32 i; arena->map_locks = kcalloc(arena->nfree, sizeof(struct aligned_lock), GFP_KERNEL); if (!arena->map_locks) return -ENOMEM; for (i = 0; i < arena->nfree; i++) spin_lock_init(&arena->map_locks[i].lock); return 0; } static struct arena_info *alloc_arena(struct btt *btt, size_t size, size_t start, size_t arena_off) { struct arena_info *arena; u64 logsize, mapsize, datasize; u64 available = size; arena = kzalloc(sizeof(struct arena_info), GFP_KERNEL); if (!arena) return NULL; arena->nd_btt = btt->nd_btt; if (!size) return arena; arena->size = size; arena->external_lba_start = start; arena->external_lbasize = btt->lbasize; arena->internal_lbasize = roundup(arena->external_lbasize, INT_LBASIZE_ALIGNMENT); arena->nfree = BTT_DEFAULT_NFREE; arena->version_major = 1; arena->version_minor = 1; if (available % BTT_PG_SIZE) available -= (available % BTT_PG_SIZE); /* Two pages are reserved for the super block and its copy */ available -= 2 * BTT_PG_SIZE; /* The log takes a fixed amount of space based on nfree */ logsize = roundup(2 * arena->nfree * sizeof(struct log_entry), BTT_PG_SIZE); available -= logsize; /* Calculate optimal split between map and data area */ arena->internal_nlba = div_u64(available - BTT_PG_SIZE, arena->internal_lbasize + MAP_ENT_SIZE); arena->external_nlba = arena->internal_nlba - arena->nfree; mapsize = roundup((arena->external_nlba * MAP_ENT_SIZE), BTT_PG_SIZE); datasize = available - mapsize; /* 'Absolute' values, relative to start of storage space */ arena->infooff = arena_off; arena->dataoff = arena->infooff + BTT_PG_SIZE; arena->mapoff = arena->dataoff + datasize; arena->logoff = arena->mapoff + mapsize; arena->info2off = arena->logoff + logsize; return arena; } static void free_arenas(struct btt *btt) { struct arena_info *arena, *next; list_for_each_entry_safe(arena, next, &btt->arena_list, list) { list_del(&arena->list); kfree(arena->rtt); kfree(arena->map_locks); kfree(arena->freelist); debugfs_remove_recursive(arena->debugfs_dir); kfree(arena); } } /* * This function checks if the metadata layout is valid and error free */ static int arena_is_valid(struct arena_info *arena, struct btt_sb *super, u8 *uuid, u32 lbasize) { u64 checksum; if (memcmp(super->uuid, uuid, 16)) return 0; checksum = le64_to_cpu(super->checksum); super->checksum = 0; if (checksum != nd_btt_sb_checksum(super)) return 0; super->checksum = cpu_to_le64(checksum); if (lbasize != le32_to_cpu(super->external_lbasize)) return 0; /* TODO: figure out action for this */ if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0) dev_info(to_dev(arena), "Found arena with an error flag\n"); return 1; } /* * This function reads an existing valid btt superblock and * populates the corresponding arena_info struct */ static void parse_arena_meta(struct arena_info *arena, struct btt_sb *super, u64 arena_off) { arena->internal_nlba = le32_to_cpu(super->internal_nlba); arena->internal_lbasize = le32_to_cpu(super->internal_lbasize); arena->external_nlba = le32_to_cpu(super->external_nlba); arena->external_lbasize = le32_to_cpu(super->external_lbasize); arena->nfree = le32_to_cpu(super->nfree); arena->version_major = le16_to_cpu(super->version_major); arena->version_minor = le16_to_cpu(super->version_minor); arena->nextoff = (super->nextoff == 0) ? 0 : (arena_off + le64_to_cpu(super->nextoff)); arena->infooff = arena_off; arena->dataoff = arena_off + le64_to_cpu(super->dataoff); arena->mapoff = arena_off + le64_to_cpu(super->mapoff); arena->logoff = arena_off + le64_to_cpu(super->logoff); arena->info2off = arena_off + le64_to_cpu(super->info2off); arena->size = (super->nextoff > 0) ? (le64_to_cpu(super->nextoff)) : (arena->info2off - arena->infooff + BTT_PG_SIZE); arena->flags = le32_to_cpu(super->flags); } static int discover_arenas(struct btt *btt) { int ret = 0; struct arena_info *arena; struct btt_sb *super; size_t remaining = btt->rawsize; u64 cur_nlba = 0; size_t cur_off = 0; int num_arenas = 0; super = kzalloc(sizeof(*super), GFP_KERNEL); if (!super) return -ENOMEM; while (remaining) { /* Alloc memory for arena */ arena = alloc_arena(btt, 0, 0, 0); if (!arena) { ret = -ENOMEM; goto out_super; } arena->infooff = cur_off; ret = btt_info_read(arena, super); if (ret) goto out; if (!arena_is_valid(arena, super, btt->nd_btt->uuid, btt->lbasize)) { if (remaining == btt->rawsize) { btt->init_state = INIT_NOTFOUND; dev_info(to_dev(arena), "No existing arenas\n"); goto out; } else { dev_info(to_dev(arena), "Found corrupted metadata!\n"); ret = -ENODEV; goto out; } } arena->external_lba_start = cur_nlba; parse_arena_meta(arena, super, cur_off); ret = btt_freelist_init(arena); if (ret) goto out; ret = btt_rtt_init(arena); if (ret) goto out; ret = btt_maplocks_init(arena); if (ret) goto out; list_add_tail(&arena->list, &btt->arena_list); remaining -= arena->size; cur_off += arena->size; cur_nlba += arena->external_nlba; num_arenas++; if (arena->nextoff == 0) break; } btt->num_arenas = num_arenas; btt->nlba = cur_nlba; btt->init_state = INIT_READY; kfree(super); return ret; out: kfree(arena); free_arenas(btt); out_super: kfree(super); return ret; } static int create_arenas(struct btt *btt) { size_t remaining = btt->rawsize; size_t cur_off = 0; while (remaining) { struct arena_info *arena; size_t arena_size = min_t(u64, ARENA_MAX_SIZE, remaining); remaining -= arena_size; if (arena_size < ARENA_MIN_SIZE) break; arena = alloc_arena(btt, arena_size, btt->nlba, cur_off); if (!arena) { free_arenas(btt); return -ENOMEM; } btt->nlba += arena->external_nlba; if (remaining >= ARENA_MIN_SIZE) arena->nextoff = arena->size; else arena->nextoff = 0; cur_off += arena_size; list_add_tail(&arena->list, &btt->arena_list); } return 0; } /* * This function completes arena initialization by writing * all the metadata. * It is only called for an uninitialized arena when a write * to that arena occurs for the first time. */ static int btt_arena_write_layout(struct arena_info *arena, u8 *uuid) { int ret; struct btt_sb *super; ret = btt_map_init(arena); if (ret) return ret; ret = btt_log_init(arena); if (ret) return ret; super = kzalloc(sizeof(struct btt_sb), GFP_NOIO); if (!super) return -ENOMEM; strncpy(super->signature, BTT_SIG, BTT_SIG_LEN); memcpy(super->uuid, uuid, 16); super->flags = cpu_to_le32(arena->flags); super->version_major = cpu_to_le16(arena->version_major); super->version_minor = cpu_to_le16(arena->version_minor); super->external_lbasize = cpu_to_le32(arena->external_lbasize); super->external_nlba = cpu_to_le32(arena->external_nlba); super->internal_lbasize = cpu_to_le32(arena->internal_lbasize); super->internal_nlba = cpu_to_le32(arena->internal_nlba); super->nfree = cpu_to_le32(arena->nfree); super->infosize = cpu_to_le32(sizeof(struct btt_sb)); super->nextoff = cpu_to_le64(arena->nextoff); /* * Subtract arena->infooff (arena start) so numbers are relative * to 'this' arena */ super->dataoff = cpu_to_le64(arena->dataoff - arena->infooff); super->mapoff = cpu_to_le64(arena->mapoff - arena->infooff); super->logoff = cpu_to_le64(arena->logoff - arena->infooff); super->info2off = cpu_to_le64(arena->info2off - arena->infooff); super->flags = 0; super->checksum = cpu_to_le64(nd_btt_sb_checksum(super)); ret = btt_info_write(arena, super); kfree(super); return ret; } /* * This function completes the initialization for the BTT namespace * such that it is ready to accept IOs */ static int btt_meta_init(struct btt *btt) { int ret = 0; struct arena_info *arena; mutex_lock(&btt->init_lock); list_for_each_entry(arena, &btt->arena_list, list) { ret = btt_arena_write_layout(arena, btt->nd_btt->uuid); if (ret) goto unlock; ret = btt_freelist_init(arena); if (ret) goto unlock; ret = btt_rtt_init(arena); if (ret) goto unlock; ret = btt_maplocks_init(arena); if (ret) goto unlock; } btt->init_state = INIT_READY; unlock: mutex_unlock(&btt->init_lock); return ret; } static u32 btt_meta_size(struct btt *btt) { return btt->lbasize - btt->sector_size; } /* * This function calculates the arena in which the given LBA lies * by doing a linear walk. This is acceptable since we expect only * a few arenas. If we have backing devices that get much larger, * we can construct a balanced binary tree of arenas at init time * so that this range search becomes faster. */ static int lba_to_arena(struct btt *btt, sector_t sector, __u32 *premap, struct arena_info **arena) { struct arena_info *arena_list; __u64 lba = div_u64(sector << SECTOR_SHIFT, btt->sector_size); list_for_each_entry(arena_list, &btt->arena_list, list) { if (lba < arena_list->external_nlba) { *arena = arena_list; *premap = lba; return 0; } lba -= arena_list->external_nlba; } return -EIO; } /* * The following (lock_map, unlock_map) are mostly just to improve * readability, since they index into an array of locks */ static void lock_map(struct arena_info *arena, u32 premap) __acquires(&arena->map_locks[idx].lock) { u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree; spin_lock(&arena->map_locks[idx].lock); } static void unlock_map(struct arena_info *arena, u32 premap) __releases(&arena->map_locks[idx].lock) { u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree; spin_unlock(&arena->map_locks[idx].lock); } static u64 to_namespace_offset(struct arena_info *arena, u64 lba) { return arena->dataoff + ((u64)lba * arena->internal_lbasize); } static int btt_data_read(struct arena_info *arena, struct page *page, unsigned int off, u32 lba, u32 len) { int ret; u64 nsoff = to_namespace_offset(arena, lba); void *mem = kmap_atomic(page); ret = arena_read_bytes(arena, nsoff, mem + off, len); kunmap_atomic(mem); return ret; } static int btt_data_write(struct arena_info *arena, u32 lba, struct page *page, unsigned int off, u32 len) { int ret; u64 nsoff = to_namespace_offset(arena, lba); void *mem = kmap_atomic(page); ret = arena_write_bytes(arena, nsoff, mem + off, len); kunmap_atomic(mem); return ret; } static void zero_fill_data(struct page *page, unsigned int off, u32 len) { void *mem = kmap_atomic(page); memset(mem + off, 0, len); kunmap_atomic(mem); } #ifdef CONFIG_BLK_DEV_INTEGRITY static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip, struct arena_info *arena, u32 postmap, int rw) { unsigned int len = btt_meta_size(btt); u64 meta_nsoff; int ret = 0; if (bip == NULL) return 0; meta_nsoff = to_namespace_offset(arena, postmap) + btt->sector_size; while (len) { unsigned int cur_len; struct bio_vec bv; void *mem; bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter); /* * The 'bv' obtained from bvec_iter_bvec has its .bv_len and * .bv_offset already adjusted for iter->bi_bvec_done, and we * can use those directly */ cur_len = min(len, bv.bv_len); mem = kmap_atomic(bv.bv_page); if (rw) ret = arena_write_bytes(arena, meta_nsoff, mem + bv.bv_offset, cur_len); else ret = arena_read_bytes(arena, meta_nsoff, mem + bv.bv_offset, cur_len); kunmap_atomic(mem); if (ret) return ret; len -= cur_len; meta_nsoff += cur_len; bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len); } return ret; } #else /* CONFIG_BLK_DEV_INTEGRITY */ static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip, struct arena_info *arena, u32 postmap, int rw) { return 0; } #endif static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip, struct page *page, unsigned int off, sector_t sector, unsigned int len) { int ret = 0; int t_flag, e_flag; struct arena_info *arena = NULL; u32 lane = 0, premap, postmap; while (len) { u32 cur_len; lane = nd_region_acquire_lane(btt->nd_region); ret = lba_to_arena(btt, sector, &premap, &arena); if (ret) goto out_lane; cur_len = min(btt->sector_size, len); ret = btt_map_read(arena, premap, &postmap, &t_flag, &e_flag); if (ret) goto out_lane; /* * We loop to make sure that the post map LBA didn't change * from under us between writing the RTT and doing the actual * read. */ while (1) { u32 new_map; if (t_flag) { zero_fill_data(page, off, cur_len); goto out_lane; } if (e_flag) { ret = -EIO; goto out_lane; } arena->rtt[lane] = RTT_VALID | postmap; /* * Barrier to make sure this write is not reordered * to do the verification map_read before the RTT store */ barrier(); ret = btt_map_read(arena, premap, &new_map, &t_flag, &e_flag); if (ret) goto out_rtt; if (postmap == new_map) break; postmap = new_map; } ret = btt_data_read(arena, page, off, postmap, cur_len); if (ret) goto out_rtt; if (bip) { ret = btt_rw_integrity(btt, bip, arena, postmap, READ); if (ret) goto out_rtt; } arena->rtt[lane] = RTT_INVALID; nd_region_release_lane(btt->nd_region, lane); len -= cur_len; off += cur_len; sector += btt->sector_size >> SECTOR_SHIFT; } return 0; out_rtt: arena->rtt[lane] = RTT_INVALID; out_lane: nd_region_release_lane(btt->nd_region, lane); return ret; } static int btt_write_pg(struct btt *btt, struct bio_integrity_payload *bip, sector_t sector, struct page *page, unsigned int off, unsigned int len) { int ret = 0; struct arena_info *arena = NULL; u32 premap = 0, old_postmap, new_postmap, lane = 0, i; struct log_entry log; int sub; while (len) { u32 cur_len; lane = nd_region_acquire_lane(btt->nd_region); ret = lba_to_arena(btt, sector, &premap, &arena); if (ret) goto out_lane; cur_len = min(btt->sector_size, len); if ((arena->flags & IB_FLAG_ERROR_MASK) != 0) { ret = -EIO; goto out_lane; } new_postmap = arena->freelist[lane].block; /* Wait if the new block is being read from */ for (i = 0; i < arena->nfree; i++) while (arena->rtt[i] == (RTT_VALID | new_postmap)) cpu_relax(); if (new_postmap >= arena->internal_nlba) { ret = -EIO; goto out_lane; } ret = btt_data_write(arena, new_postmap, page, off, cur_len); if (ret) goto out_lane; if (bip) { ret = btt_rw_integrity(btt, bip, arena, new_postmap, WRITE); if (ret) goto out_lane; } lock_map(arena, premap); ret = btt_map_read(arena, premap, &old_postmap, NULL, NULL); if (ret) goto out_map; if (old_postmap >= arena->internal_nlba) { ret = -EIO; goto out_map; } log.lba = cpu_to_le32(premap); log.old_map = cpu_to_le32(old_postmap); log.new_map = cpu_to_le32(new_postmap); log.seq = cpu_to_le32(arena->freelist[lane].seq); sub = arena->freelist[lane].sub; ret = btt_flog_write(arena, lane, sub, &log); if (ret) goto out_map; ret = btt_map_write(arena, premap, new_postmap, 0, 0); if (ret) goto out_map; unlock_map(arena, premap); nd_region_release_lane(btt->nd_region, lane); len -= cur_len; off += cur_len; sector += btt->sector_size >> SECTOR_SHIFT; } return 0; out_map: unlock_map(arena, premap); out_lane: nd_region_release_lane(btt->nd_region, lane); return ret; } static int btt_do_bvec(struct btt *btt, struct bio_integrity_payload *bip, struct page *page, unsigned int len, unsigned int off, int rw, sector_t sector) { int ret; if (rw == READ) { ret = btt_read_pg(btt, bip, page, off, sector, len); flush_dcache_page(page); } else { flush_dcache_page(page); ret = btt_write_pg(btt, bip, sector, page, off, len); } return ret; } static void btt_make_request(struct request_queue *q, struct bio *bio) { struct bio_integrity_payload *bip = bio_integrity(bio); struct btt *btt = q->queuedata; struct bvec_iter iter; struct bio_vec bvec; int err = 0, rw; /* * bio_integrity_enabled also checks if the bio already has an * integrity payload attached. If it does, we *don't* do a * bio_integrity_prep here - the payload has been generated by * another kernel subsystem, and we just pass it through. */ if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { err = -EIO; goto out; } rw = bio_data_dir(bio); bio_for_each_segment(bvec, bio, iter) { unsigned int len = bvec.bv_len; BUG_ON(len > PAGE_SIZE); /* Make sure len is in multiples of sector size. */ /* XXX is this right? */ BUG_ON(len < btt->sector_size); BUG_ON(len % btt->sector_size); err = btt_do_bvec(btt, bip, bvec.bv_page, len, bvec.bv_offset, rw, iter.bi_sector); if (err) { dev_info(&btt->nd_btt->dev, "io error in %s sector %lld, len %d,\n", (rw == READ) ? "READ" : "WRITE", (unsigned long long) iter.bi_sector, len); goto out; } } out: bio_endio(bio, err); } static int btt_rw_page(struct block_device *bdev, sector_t sector, struct page *page, int rw) { struct btt *btt = bdev->bd_disk->private_data; btt_do_bvec(btt, NULL, page, PAGE_CACHE_SIZE, 0, rw, sector); page_endio(page, rw & WRITE, 0); return 0; } static int btt_getgeo(struct block_device *bd, struct hd_geometry *geo) { /* some standard values */ geo->heads = 1 << 6; geo->sectors = 1 << 5; geo->cylinders = get_capacity(bd->bd_disk) >> 11; return 0; } static const struct block_device_operations btt_fops = { .owner = THIS_MODULE, .rw_page = btt_rw_page, .getgeo = btt_getgeo, }; static int btt_blk_init(struct btt *btt) { struct nd_btt *nd_btt = btt->nd_btt; struct nd_namespace_common *ndns = nd_btt->ndns; /* create a new disk and request queue for btt */ btt->btt_queue = blk_alloc_queue(GFP_KERNEL); if (!btt->btt_queue) return -ENOMEM; btt->btt_disk = alloc_disk(0); if (!btt->btt_disk) { blk_cleanup_queue(btt->btt_queue); return -ENOMEM; } nvdimm_namespace_disk_name(ndns, btt->btt_disk->disk_name); btt->btt_disk->driverfs_dev = &btt->nd_btt->dev; btt->btt_disk->major = btt_major; btt->btt_disk->first_minor = 0; btt->btt_disk->fops = &btt_fops; btt->btt_disk->private_data = btt; btt->btt_disk->queue = btt->btt_queue; btt->btt_disk->flags = GENHD_FL_EXT_DEVT; blk_queue_make_request(btt->btt_queue, btt_make_request); blk_queue_logical_block_size(btt->btt_queue, btt->sector_size); blk_queue_max_hw_sectors(btt->btt_queue, UINT_MAX); blk_queue_bounce_limit(btt->btt_queue, BLK_BOUNCE_ANY); queue_flag_set_unlocked(QUEUE_FLAG_NONROT, btt->btt_queue); btt->btt_queue->queuedata = btt; set_capacity(btt->btt_disk, 0); add_disk(btt->btt_disk); if (btt_meta_size(btt)) { int rc = nd_integrity_init(btt->btt_disk, btt_meta_size(btt)); if (rc) { del_gendisk(btt->btt_disk); put_disk(btt->btt_disk); blk_cleanup_queue(btt->btt_queue); return rc; } } set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9); return 0; } static void btt_blk_cleanup(struct btt *btt) { blk_integrity_unregister(btt->btt_disk); del_gendisk(btt->btt_disk); put_disk(btt->btt_disk); blk_cleanup_queue(btt->btt_queue); } /** * btt_init - initialize a block translation table for the given device * @nd_btt: device with BTT geometry and backing device info * @rawsize: raw size in bytes of the backing device * @lbasize: lba size of the backing device * @uuid: A uuid for the backing device - this is stored on media * @maxlane: maximum number of parallel requests the device can handle * * Initialize a Block Translation Table on a backing device to provide * single sector power fail atomicity. * * Context: * Might sleep. * * Returns: * Pointer to a new struct btt on success, NULL on failure. */ static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize, u32 lbasize, u8 *uuid, struct nd_region *nd_region) { int ret; struct btt *btt; struct device *dev = &nd_btt->dev; btt = kzalloc(sizeof(struct btt), GFP_KERNEL); if (!btt) return NULL; btt->nd_btt = nd_btt; btt->rawsize = rawsize; btt->lbasize = lbasize; btt->sector_size = ((lbasize >= 4096) ? 4096 : 512); INIT_LIST_HEAD(&btt->arena_list); mutex_init(&btt->init_lock); btt->nd_region = nd_region; ret = discover_arenas(btt); if (ret) { dev_err(dev, "init: error in arena_discover: %d\n", ret); goto out_free; } if (btt->init_state != INIT_READY) { btt->num_arenas = (rawsize / ARENA_MAX_SIZE) + ((rawsize % ARENA_MAX_SIZE) ? 1 : 0); dev_dbg(dev, "init: %d arenas for %llu rawsize\n", btt->num_arenas, rawsize); ret = create_arenas(btt); if (ret) { dev_info(dev, "init: create_arenas: %d\n", ret); goto out_free; } ret = btt_meta_init(btt); if (ret) { dev_err(dev, "init: error in meta_init: %d\n", ret); return NULL; } } ret = btt_blk_init(btt); if (ret) { dev_err(dev, "init: error in blk_init: %d\n", ret); goto out_free; } btt_debugfs_init(btt); return btt; out_free: kfree(btt); return NULL; } /** * btt_fini - de-initialize a BTT * @btt: the BTT handle that was generated by btt_init * * De-initialize a Block Translation Table on device removal * * Context: * Might sleep. */ static void btt_fini(struct btt *btt) { if (btt) { btt_blk_cleanup(btt); free_arenas(btt); debugfs_remove_recursive(btt->debugfs_dir); kfree(btt); } } int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns) { struct nd_btt *nd_btt = to_nd_btt(ndns->claim); struct nd_region *nd_region; struct btt *btt; size_t rawsize; if (!nd_btt->uuid || !nd_btt->ndns || !nd_btt->lbasize) return -ENODEV; rawsize = nvdimm_namespace_capacity(ndns) - SZ_4K; if (rawsize < ARENA_MIN_SIZE) { return -ENXIO; } nd_region = to_nd_region(nd_btt->dev.parent); btt = btt_init(nd_btt, rawsize, nd_btt->lbasize, nd_btt->uuid, nd_region); if (!btt) return -ENOMEM; nd_btt->btt = btt; return 0; } EXPORT_SYMBOL(nvdimm_namespace_attach_btt); int nvdimm_namespace_detach_btt(struct nd_namespace_common *ndns) { struct nd_btt *nd_btt = to_nd_btt(ndns->claim); struct btt *btt = nd_btt->btt; btt_fini(btt); nd_btt->btt = NULL; return 0; } EXPORT_SYMBOL(nvdimm_namespace_detach_btt); static int __init nd_btt_init(void) { int rc; BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K); btt_major = register_blkdev(0, "btt"); if (btt_major < 0) return btt_major; debugfs_root = debugfs_create_dir("btt", NULL); if (IS_ERR_OR_NULL(debugfs_root)) { rc = -ENXIO; goto err_debugfs; } return 0; err_debugfs: unregister_blkdev(btt_major, "btt"); return rc; } static void __exit nd_btt_exit(void) { debugfs_remove_recursive(debugfs_root); unregister_blkdev(btt_major, "btt"); } MODULE_ALIAS_ND_DEVICE(ND_DEVICE_BTT); MODULE_AUTHOR("Vishal Verma "); MODULE_LICENSE("GPL v2"); module_init(nd_btt_init); module_exit(nd_btt_exit);