/* * Copyright (C) 2011 Red Hat, Inc. * * This file is released under the GPL. */ #include "dm-space-map-common.h" #include "dm-transaction-manager.h" #include <linux/bitops.h> #include <linux/device-mapper.h> #define DM_MSG_PREFIX "space map common" /*----------------------------------------------------------------*/ /* * Index validator. */ #define INDEX_CSUM_XOR 160478 static void index_prepare_for_write(struct dm_block_validator *v, struct dm_block *b, size_t block_size) { struct disk_metadata_index *mi_le = dm_block_data(b); mi_le->blocknr = cpu_to_le64(dm_block_location(b)); mi_le->csum = cpu_to_le32(dm_bm_checksum(&mi_le->padding, block_size - sizeof(__le32), INDEX_CSUM_XOR)); } static int index_check(struct dm_block_validator *v, struct dm_block *b, size_t block_size) { struct disk_metadata_index *mi_le = dm_block_data(b); __le32 csum_disk; if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) { DMERR("index_check failed blocknr %llu wanted %llu", le64_to_cpu(mi_le->blocknr), dm_block_location(b)); return -ENOTBLK; } csum_disk = cpu_to_le32(dm_bm_checksum(&mi_le->padding, block_size - sizeof(__le32), INDEX_CSUM_XOR)); if (csum_disk != mi_le->csum) { DMERR("index_check failed csum %u wanted %u", le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum)); return -EILSEQ; } return 0; } static struct dm_block_validator index_validator = { .name = "index", .prepare_for_write = index_prepare_for_write, .check = index_check }; /*----------------------------------------------------------------*/ /* * Bitmap validator */ #define BITMAP_CSUM_XOR 240779 static void bitmap_prepare_for_write(struct dm_block_validator *v, struct dm_block *b, size_t block_size) { struct disk_bitmap_header *disk_header = dm_block_data(b); disk_header->blocknr = cpu_to_le64(dm_block_location(b)); disk_header->csum = cpu_to_le32(dm_bm_checksum(&disk_header->not_used, block_size - sizeof(__le32), BITMAP_CSUM_XOR)); } static int bitmap_check(struct dm_block_validator *v, struct dm_block *b, size_t block_size) { struct disk_bitmap_header *disk_header = dm_block_data(b); __le32 csum_disk; if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) { DMERR("bitmap check failed blocknr %llu wanted %llu", le64_to_cpu(disk_header->blocknr), dm_block_location(b)); return -ENOTBLK; } csum_disk = cpu_to_le32(dm_bm_checksum(&disk_header->not_used, block_size - sizeof(__le32), BITMAP_CSUM_XOR)); if (csum_disk != disk_header->csum) { DMERR("bitmap check failed csum %u wanted %u", le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum)); return -EILSEQ; } return 0; } static struct dm_block_validator dm_sm_bitmap_validator = { .name = "sm_bitmap", .prepare_for_write = bitmap_prepare_for_write, .check = bitmap_check }; /*----------------------------------------------------------------*/ #define ENTRIES_PER_WORD 32 #define ENTRIES_SHIFT 5 static void *dm_bitmap_data(struct dm_block *b) { return dm_block_data(b) + sizeof(struct disk_bitmap_header); } #define WORD_MASK_HIGH 0xAAAAAAAAAAAAAAAAULL static unsigned bitmap_word_used(void *addr, unsigned b) { __le64 *words_le = addr; __le64 *w_le = words_le + (b >> ENTRIES_SHIFT); uint64_t bits = le64_to_cpu(*w_le); uint64_t mask = (bits + WORD_MASK_HIGH + 1) & WORD_MASK_HIGH; return !(~bits & mask); } static unsigned sm_lookup_bitmap(void *addr, unsigned b) { __le64 *words_le = addr; __le64 *w_le = words_le + (b >> ENTRIES_SHIFT); unsigned hi, lo; b = (b & (ENTRIES_PER_WORD - 1)) << 1; hi = !!test_bit_le(b, (void *) w_le); lo = !!test_bit_le(b + 1, (void *) w_le); return (hi << 1) | lo; } static void sm_set_bitmap(void *addr, unsigned b, unsigned val) { __le64 *words_le = addr; __le64 *w_le = words_le + (b >> ENTRIES_SHIFT); b = (b & (ENTRIES_PER_WORD - 1)) << 1; if (val & 2) __set_bit_le(b, (void *) w_le); else __clear_bit_le(b, (void *) w_le); if (val & 1) __set_bit_le(b + 1, (void *) w_le); else __clear_bit_le(b + 1, (void *) w_le); } static int sm_find_free(void *addr, unsigned begin, unsigned end, unsigned *result) { while (begin < end) { if (!(begin & (ENTRIES_PER_WORD - 1)) && bitmap_word_used(addr, begin)) { begin += ENTRIES_PER_WORD; continue; } if (!sm_lookup_bitmap(addr, begin)) { *result = begin; return 0; } begin++; } return -ENOSPC; } /*----------------------------------------------------------------*/ static int sm_ll_init(struct ll_disk *ll, struct dm_transaction_manager *tm) { ll->tm = tm; ll->bitmap_info.tm = tm; ll->bitmap_info.levels = 1; /* * Because the new bitmap blocks are created via a shadow * operation, the old entry has already had its reference count * decremented and we don't need the btree to do any bookkeeping. */ ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry); ll->bitmap_info.value_type.inc = NULL; ll->bitmap_info.value_type.dec = NULL; ll->bitmap_info.value_type.equal = NULL; ll->ref_count_info.tm = tm; ll->ref_count_info.levels = 1; ll->ref_count_info.value_type.size = sizeof(uint32_t); ll->ref_count_info.value_type.inc = NULL; ll->ref_count_info.value_type.dec = NULL; ll->ref_count_info.value_type.equal = NULL; ll->block_size = dm_bm_block_size(dm_tm_get_bm(tm)); if (ll->block_size > (1 << 30)) { DMERR("block size too big to hold bitmaps"); return -EINVAL; } ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) * ENTRIES_PER_BYTE; ll->nr_blocks = 0; ll->bitmap_root = 0; ll->ref_count_root = 0; return 0; } int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks) { int r; dm_block_t i, nr_blocks, nr_indexes; unsigned old_blocks, blocks; nr_blocks = ll->nr_blocks + extra_blocks; old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block); blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block); nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block); if (nr_indexes > ll->max_entries(ll)) { DMERR("space map too large"); return -EINVAL; } for (i = old_blocks; i < blocks; i++) { struct dm_block *b; struct disk_index_entry idx; r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b); if (r < 0) return r; idx.blocknr = cpu_to_le64(dm_block_location(b)); r = dm_tm_unlock(ll->tm, b); if (r < 0) return r; idx.nr_free = cpu_to_le32(ll->entries_per_block); idx.none_free_before = 0; r = ll->save_ie(ll, i, &idx); if (r < 0) return r; } ll->nr_blocks = nr_blocks; return 0; } int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result) { int r; dm_block_t index = b; struct disk_index_entry ie_disk; struct dm_block *blk; b = do_div(index, ll->entries_per_block); r = ll->load_ie(ll, index, &ie_disk); if (r < 0) return r; r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr), &dm_sm_bitmap_validator, &blk); if (r < 0) return r; *result = sm_lookup_bitmap(dm_bitmap_data(blk), b); return dm_tm_unlock(ll->tm, blk); } int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result) { __le32 le_rc; int r = sm_ll_lookup_bitmap(ll, b, result); if (r) return r; if (*result != 3) return r; r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc); if (r < 0) return r; *result = le32_to_cpu(le_rc); return r; } int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin, dm_block_t end, dm_block_t *result) { int r; struct disk_index_entry ie_disk; dm_block_t i, index_begin = begin; dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block); /* * FIXME: Use shifts */ begin = do_div(index_begin, ll->entries_per_block); end = do_div(end, ll->entries_per_block); for (i = index_begin; i < index_end; i++, begin = 0) { struct dm_block *blk; unsigned position; uint32_t bit_end; r = ll->load_ie(ll, i, &ie_disk); if (r < 0) return r; if (le32_to_cpu(ie_disk.nr_free) == 0) continue; r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr), &dm_sm_bitmap_validator, &blk); if (r < 0) return r; bit_end = (i == index_end - 1) ? end : ll->entries_per_block; r = sm_find_free(dm_bitmap_data(blk), max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)), bit_end, &position); if (r == -ENOSPC) { /* * This might happen because we started searching * part way through the bitmap. */ dm_tm_unlock(ll->tm, blk); continue; } else if (r < 0) { dm_tm_unlock(ll->tm, blk); return r; } r = dm_tm_unlock(ll->tm, blk); if (r < 0) return r; *result = i * ll->entries_per_block + (dm_block_t) position; return 0; } return -ENOSPC; } int sm_ll_insert(struct ll_disk *ll, dm_block_t b, uint32_t ref_count, enum allocation_event *ev) { int r; uint32_t bit, old; struct dm_block *nb; dm_block_t index = b; struct disk_index_entry ie_disk; void *bm_le; int inc; bit = do_div(index, ll->entries_per_block); r = ll->load_ie(ll, index, &ie_disk); if (r < 0) return r; r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr), &dm_sm_bitmap_validator, &nb, &inc); if (r < 0) { DMERR("dm_tm_shadow_block() failed"); return r; } ie_disk.blocknr = cpu_to_le64(dm_block_location(nb)); bm_le = dm_bitmap_data(nb); old = sm_lookup_bitmap(bm_le, bit); if (ref_count <= 2) { sm_set_bitmap(bm_le, bit, ref_count); r = dm_tm_unlock(ll->tm, nb); if (r < 0) return r; #if 0 /* FIXME: dm_btree_remove doesn't handle this yet */ if (old > 2) { r = dm_btree_remove(&ll->ref_count_info, ll->ref_count_root, &b, &ll->ref_count_root); if (r) return r; } #endif } else { __le32 le_rc = cpu_to_le32(ref_count); sm_set_bitmap(bm_le, bit, 3); r = dm_tm_unlock(ll->tm, nb); if (r < 0) return r; __dm_bless_for_disk(&le_rc); r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc, &ll->ref_count_root); if (r < 0) { DMERR("ref count insert failed"); return r; } } if (ref_count && !old) { *ev = SM_ALLOC; ll->nr_allocated++; ie_disk.nr_free = cpu_to_le32(le32_to_cpu(ie_disk.nr_free) - 1); if (le32_to_cpu(ie_disk.none_free_before) == bit) ie_disk.none_free_before = cpu_to_le32(bit + 1); } else if (old && !ref_count) { *ev = SM_FREE; ll->nr_allocated--; ie_disk.nr_free = cpu_to_le32(le32_to_cpu(ie_disk.nr_free) + 1); ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit)); } return ll->save_ie(ll, index, &ie_disk); } int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev) { int r; uint32_t rc; r = sm_ll_lookup(ll, b, &rc); if (r) return r; return sm_ll_insert(ll, b, rc + 1, ev); } int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev) { int r; uint32_t rc; r = sm_ll_lookup(ll, b, &rc); if (r) return r; if (!rc) return -EINVAL; return sm_ll_insert(ll, b, rc - 1, ev); } int sm_ll_commit(struct ll_disk *ll) { return ll->commit(ll); } /*----------------------------------------------------------------*/ static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *ie) { memcpy(ie, ll->mi_le.index + index, sizeof(*ie)); return 0; } static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *ie) { memcpy(ll->mi_le.index + index, ie, sizeof(*ie)); return 0; } static int metadata_ll_init_index(struct ll_disk *ll) { int r; struct dm_block *b; r = dm_tm_new_block(ll->tm, &index_validator, &b); if (r < 0) return r; memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le)); ll->bitmap_root = dm_block_location(b); return dm_tm_unlock(ll->tm, b); } static int metadata_ll_open(struct ll_disk *ll) { int r; struct dm_block *block; r = dm_tm_read_lock(ll->tm, ll->bitmap_root, &index_validator, &block); if (r) return r; memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le)); return dm_tm_unlock(ll->tm, block); } static dm_block_t metadata_ll_max_entries(struct ll_disk *ll) { return MAX_METADATA_BITMAPS; } static int metadata_ll_commit(struct ll_disk *ll) { int r, inc; struct dm_block *b; r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc); if (r) return r; memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le)); ll->bitmap_root = dm_block_location(b); return dm_tm_unlock(ll->tm, b); } int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm) { int r; r = sm_ll_init(ll, tm); if (r < 0) return r; ll->load_ie = metadata_ll_load_ie; ll->save_ie = metadata_ll_save_ie; ll->init_index = metadata_ll_init_index; ll->open_index = metadata_ll_open; ll->max_entries = metadata_ll_max_entries; ll->commit = metadata_ll_commit; ll->nr_blocks = 0; ll->nr_allocated = 0; r = ll->init_index(ll); if (r < 0) return r; r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root); if (r < 0) return r; return 0; } int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm, void *root_le, size_t len) { int r; struct disk_sm_root *smr = root_le; if (len < sizeof(struct disk_sm_root)) { DMERR("sm_metadata root too small"); return -ENOMEM; } r = sm_ll_init(ll, tm); if (r < 0) return r; ll->load_ie = metadata_ll_load_ie; ll->save_ie = metadata_ll_save_ie; ll->init_index = metadata_ll_init_index; ll->open_index = metadata_ll_open; ll->max_entries = metadata_ll_max_entries; ll->commit = metadata_ll_commit; ll->nr_blocks = le64_to_cpu(smr->nr_blocks); ll->nr_allocated = le64_to_cpu(smr->nr_allocated); ll->bitmap_root = le64_to_cpu(smr->bitmap_root); ll->ref_count_root = le64_to_cpu(smr->ref_count_root); return ll->open_index(ll); } /*----------------------------------------------------------------*/ static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *ie) { return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie); } static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index, struct disk_index_entry *ie) { __dm_bless_for_disk(ie); return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root, &index, ie, &ll->bitmap_root); } static int disk_ll_init_index(struct ll_disk *ll) { return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root); } static int disk_ll_open(struct ll_disk *ll) { /* nothing to do */ return 0; } static dm_block_t disk_ll_max_entries(struct ll_disk *ll) { return -1ULL; } static int disk_ll_commit(struct ll_disk *ll) { return 0; } int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm) { int r; r = sm_ll_init(ll, tm); if (r < 0) return r; ll->load_ie = disk_ll_load_ie; ll->save_ie = disk_ll_save_ie; ll->init_index = disk_ll_init_index; ll->open_index = disk_ll_open; ll->max_entries = disk_ll_max_entries; ll->commit = disk_ll_commit; ll->nr_blocks = 0; ll->nr_allocated = 0; r = ll->init_index(ll); if (r < 0) return r; r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root); if (r < 0) return r; return 0; } int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm, void *root_le, size_t len) { int r; struct disk_sm_root *smr = root_le; if (len < sizeof(struct disk_sm_root)) { DMERR("sm_metadata root too small"); return -ENOMEM; } r = sm_ll_init(ll, tm); if (r < 0) return r; ll->load_ie = disk_ll_load_ie; ll->save_ie = disk_ll_save_ie; ll->init_index = disk_ll_init_index; ll->open_index = disk_ll_open; ll->max_entries = disk_ll_max_entries; ll->commit = disk_ll_commit; ll->nr_blocks = le64_to_cpu(smr->nr_blocks); ll->nr_allocated = le64_to_cpu(smr->nr_allocated); ll->bitmap_root = le64_to_cpu(smr->bitmap_root); ll->ref_count_root = le64_to_cpu(smr->ref_count_root); return ll->open_index(ll); } /*----------------------------------------------------------------*/