// SPDX-License-Identifier: GPL-2.0-only/* * 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 "dm-btree-internal.h"#include "dm-persistent-data-internal.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(const 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(const 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_LIMIT("%s failed: blocknr %llu != wanted %llu", __func__,			    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_LIMIT("%s failed: csum %u != wanted %u", __func__,			    le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));		return -EILSEQ;	} 	return 0;} static const 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 dm_bitmap_prepare_for_write(const 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 dm_bitmap_check(const 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_LIMIT("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_LIMIT("bitmap check failed: csum %u != wanted %u",			    le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));		return -EILSEQ;	} 	return 0;} static const struct dm_block_validator dm_sm_bitmap_validator = {	.name = "sm_bitmap",	.prepare_for_write = dm_bitmap_prepare_for_write,	.check = dm_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 int dm_bitmap_word_used(void *addr, unsigned int 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 int sm_lookup_bitmap(void *addr, unsigned int b){	__le64 *words_le = addr;	__le64 *w_le = words_le + (b >> ENTRIES_SHIFT);	unsigned int 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 int b, unsigned int 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 int begin, unsigned int end,			unsigned int *result){	while (begin < end) {		if (!(begin & (ENTRIES_PER_WORD - 1)) &&		    dm_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){	memset(ll, 0, sizeof(struct ll_disk)); 	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;	ll->bitmap_index_changed = false; 	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 int 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;	} 	/*	 * We need to set this before the dm_tm_new_block() call below.	 */	ll->nr_blocks = nr_blocks;	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)); 		dm_tm_unlock(ll->tm, b); 		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;	} 	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; 	if (b >= ll->nr_blocks) {		DMERR_LIMIT("metadata block out of bounds");		return -EINVAL;	} 	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); 	dm_tm_unlock(ll->tm, blk); 	return 0;} static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,				      uint32_t *result){	__le32 le_rc;	int 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_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result){	int r = sm_ll_lookup_bitmap(ll, b, result); 	if (r)		return r; 	if (*result != 3)		return r; 	return sm_ll_lookup_big_ref_count(ll, b, result);} 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);	if (end == 0)		end = ll->entries_per_block; 	for (i = index_begin; i < index_end; i++, begin = 0) {		struct dm_block *blk;		unsigned int 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 int, 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;		} 		dm_tm_unlock(ll->tm, blk); 		*result = i * ll->entries_per_block + (dm_block_t) position;		return 0;	} 	return -ENOSPC;} int sm_ll_find_common_free_block(struct ll_disk *old_ll, struct ll_disk *new_ll,				 dm_block_t begin, dm_block_t end, dm_block_t *b){	int r;	uint32_t count; 	do {		r = sm_ll_find_free_block(new_ll, begin, new_ll->nr_blocks, b);		if (r)			break; 		/* double check this block wasn't used in the old transaction */		if (*b >= old_ll->nr_blocks)			count = 0;		else {			r = sm_ll_lookup(old_ll, *b, &count);			if (r)				break; 			if (count)				begin = *b + 1;		}	} while (count); 	return r;} /*----------------------------------------------------------------*/ int sm_ll_insert(struct ll_disk *ll, dm_block_t b,		 uint32_t ref_count, int32_t *nr_allocations){	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 (old > 2) {		r = sm_ll_lookup_big_ref_count(ll, b, &old);		if (r < 0) {			dm_tm_unlock(ll->tm, nb);			return r;		}	} 	if (r) {		dm_tm_unlock(ll->tm, nb);		return r;	} 	if (ref_count <= 2) {		sm_set_bitmap(bm_le, bit, ref_count);		dm_tm_unlock(ll->tm, nb); 		if (old > 2) {			r = dm_btree_remove(&ll->ref_count_info,					    ll->ref_count_root,					    &b, &ll->ref_count_root);			if (r)				return r;		} 	} else {		__le32 le_rc = cpu_to_le32(ref_count); 		sm_set_bitmap(bm_le, bit, 3);		dm_tm_unlock(ll->tm, nb); 		__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) {		*nr_allocations = 1;		ll->nr_allocated++;		le32_add_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) {		*nr_allocations = -1;		ll->nr_allocated--;		le32_add_cpu(&ie_disk.nr_free, 1);		ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));	} else

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