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	Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
		
			
				
	
	
		
			1016 lines
		
	
	
	
		
			24 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			1016 lines
		
	
	
	
		
			24 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-only
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/*
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 * Copyright (C) 2012 Red Hat, Inc.
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 *
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 * This file is released under the GPL.
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 */
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#include "dm-array.h"
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#include "dm-space-map.h"
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#include "dm-transaction-manager.h"
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#include <linux/export.h>
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#include <linux/device-mapper.h>
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#define DM_MSG_PREFIX "array"
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/*----------------------------------------------------------------*/
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/*
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 * The array is implemented as a fully populated btree, which points to
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 * blocks that contain the packed values.  This is more space efficient
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 * than just using a btree since we don't store 1 key per value.
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 */
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struct array_block {
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	__le32 csum;
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	__le32 max_entries;
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	__le32 nr_entries;
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	__le32 value_size;
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	__le64 blocknr; /* Block this node is supposed to live in. */
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} __packed;
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/*----------------------------------------------------------------*/
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/*
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 * Validator methods.  As usual we calculate a checksum, and also write the
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 * block location into the header (paranoia about ssds remapping areas by
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 * mistake).
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 */
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#define CSUM_XOR 595846735
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static void array_block_prepare_for_write(struct dm_block_validator *v,
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					  struct dm_block *b,
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					  size_t size_of_block)
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{
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	struct array_block *bh_le = dm_block_data(b);
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	bh_le->blocknr = cpu_to_le64(dm_block_location(b));
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	bh_le->csum = cpu_to_le32(dm_bm_checksum(&bh_le->max_entries,
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						 size_of_block - sizeof(__le32),
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						 CSUM_XOR));
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}
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static int array_block_check(struct dm_block_validator *v,
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			     struct dm_block *b,
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			     size_t size_of_block)
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{
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	struct array_block *bh_le = dm_block_data(b);
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	__le32 csum_disk;
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	if (dm_block_location(b) != le64_to_cpu(bh_le->blocknr)) {
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		DMERR_LIMIT("%s failed: blocknr %llu != wanted %llu", __func__,
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			    (unsigned long long) le64_to_cpu(bh_le->blocknr),
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			    (unsigned long long) dm_block_location(b));
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		return -ENOTBLK;
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	}
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	csum_disk = cpu_to_le32(dm_bm_checksum(&bh_le->max_entries,
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					       size_of_block - sizeof(__le32),
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					       CSUM_XOR));
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	if (csum_disk != bh_le->csum) {
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		DMERR_LIMIT("%s failed: csum %u != wanted %u", __func__,
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			    (unsigned int) le32_to_cpu(csum_disk),
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			    (unsigned int) le32_to_cpu(bh_le->csum));
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		return -EILSEQ;
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	}
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	return 0;
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}
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static struct dm_block_validator array_validator = {
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	.name = "array",
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	.prepare_for_write = array_block_prepare_for_write,
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	.check = array_block_check
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};
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/*----------------------------------------------------------------*/
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/*
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 * Functions for manipulating the array blocks.
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 */
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/*
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 * Returns a pointer to a value within an array block.
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 *
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 * index - The index into _this_ specific block.
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 */
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static void *element_at(struct dm_array_info *info, struct array_block *ab,
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			unsigned int index)
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{
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	unsigned char *entry = (unsigned char *) (ab + 1);
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	entry += index * info->value_type.size;
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	return entry;
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}
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/*
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 * Utility function that calls one of the value_type methods on every value
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 * in an array block.
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 */
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static void on_entries(struct dm_array_info *info, struct array_block *ab,
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		       void (*fn)(void *, const void *, unsigned int))
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{
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	unsigned int nr_entries = le32_to_cpu(ab->nr_entries);
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	fn(info->value_type.context, element_at(info, ab, 0), nr_entries);
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}
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/*
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 * Increment every value in an array block.
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 */
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static void inc_ablock_entries(struct dm_array_info *info, struct array_block *ab)
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{
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	struct dm_btree_value_type *vt = &info->value_type;
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	if (vt->inc)
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		on_entries(info, ab, vt->inc);
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}
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/*
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 * Decrement every value in an array block.
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 */
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static void dec_ablock_entries(struct dm_array_info *info, struct array_block *ab)
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{
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	struct dm_btree_value_type *vt = &info->value_type;
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	if (vt->dec)
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		on_entries(info, ab, vt->dec);
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}
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/*
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 * Each array block can hold this many values.
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 */
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static uint32_t calc_max_entries(size_t value_size, size_t size_of_block)
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{
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	return (size_of_block - sizeof(struct array_block)) / value_size;
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}
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/*
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 * Allocate a new array block.  The caller will need to unlock block.
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 */
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static int alloc_ablock(struct dm_array_info *info, size_t size_of_block,
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			uint32_t max_entries,
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			struct dm_block **block, struct array_block **ab)
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{
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	int r;
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	r = dm_tm_new_block(info->btree_info.tm, &array_validator, block);
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	if (r)
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		return r;
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	(*ab) = dm_block_data(*block);
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	(*ab)->max_entries = cpu_to_le32(max_entries);
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	(*ab)->nr_entries = cpu_to_le32(0);
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	(*ab)->value_size = cpu_to_le32(info->value_type.size);
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	return 0;
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}
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/*
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 * Pad an array block out with a particular value.  Every instance will
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 * cause an increment of the value_type.  new_nr must always be more than
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 * the current number of entries.
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 */
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static void fill_ablock(struct dm_array_info *info, struct array_block *ab,
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			const void *value, unsigned int new_nr)
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{
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	uint32_t nr_entries, delta, i;
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	struct dm_btree_value_type *vt = &info->value_type;
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	BUG_ON(new_nr > le32_to_cpu(ab->max_entries));
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	BUG_ON(new_nr < le32_to_cpu(ab->nr_entries));
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	nr_entries = le32_to_cpu(ab->nr_entries);
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	delta = new_nr - nr_entries;
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	if (vt->inc)
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		vt->inc(vt->context, value, delta);
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	for (i = nr_entries; i < new_nr; i++)
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		memcpy(element_at(info, ab, i), value, vt->size);
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	ab->nr_entries = cpu_to_le32(new_nr);
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}
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/*
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 * Remove some entries from the back of an array block.  Every value
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 * removed will be decremented.  new_nr must be <= the current number of
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 * entries.
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 */
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static void trim_ablock(struct dm_array_info *info, struct array_block *ab,
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			unsigned int new_nr)
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{
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	uint32_t nr_entries, delta;
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	struct dm_btree_value_type *vt = &info->value_type;
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	BUG_ON(new_nr > le32_to_cpu(ab->max_entries));
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	BUG_ON(new_nr > le32_to_cpu(ab->nr_entries));
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	nr_entries = le32_to_cpu(ab->nr_entries);
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	delta = nr_entries - new_nr;
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	if (vt->dec)
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		vt->dec(vt->context, element_at(info, ab, new_nr - 1), delta);
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	ab->nr_entries = cpu_to_le32(new_nr);
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}
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/*
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 * Read locks a block, and coerces it to an array block.  The caller must
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 * unlock 'block' when finished.
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 */
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static int get_ablock(struct dm_array_info *info, dm_block_t b,
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		      struct dm_block **block, struct array_block **ab)
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{
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	int r;
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	r = dm_tm_read_lock(info->btree_info.tm, b, &array_validator, block);
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	if (r)
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		return r;
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	*ab = dm_block_data(*block);
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	return 0;
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}
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/*
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 * Unlocks an array block.
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 */
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static void unlock_ablock(struct dm_array_info *info, struct dm_block *block)
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{
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	dm_tm_unlock(info->btree_info.tm, block);
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}
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/*----------------------------------------------------------------*/
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/*
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 * Btree manipulation.
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 */
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/*
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 * Looks up an array block in the btree, and then read locks it.
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 *
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 * index is the index of the index of the array_block, (ie. the array index
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 * / max_entries).
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 */
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static int lookup_ablock(struct dm_array_info *info, dm_block_t root,
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			 unsigned int index, struct dm_block **block,
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			 struct array_block **ab)
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{
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	int r;
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	uint64_t key = index;
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	__le64 block_le;
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	r = dm_btree_lookup(&info->btree_info, root, &key, &block_le);
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	if (r)
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		return r;
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	return get_ablock(info, le64_to_cpu(block_le), block, ab);
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}
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/*
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 * Insert an array block into the btree.  The block is _not_ unlocked.
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 */
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static int insert_ablock(struct dm_array_info *info, uint64_t index,
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			 struct dm_block *block, dm_block_t *root)
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{
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	__le64 block_le = cpu_to_le64(dm_block_location(block));
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	__dm_bless_for_disk(block_le);
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	return dm_btree_insert(&info->btree_info, *root, &index, &block_le, root);
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}
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/*----------------------------------------------------------------*/
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static int __shadow_ablock(struct dm_array_info *info, dm_block_t b,
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			   struct dm_block **block, struct array_block **ab)
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{
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	int inc;
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	int r = dm_tm_shadow_block(info->btree_info.tm, b,
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				   &array_validator, block, &inc);
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	if (r)
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		return r;
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	*ab = dm_block_data(*block);
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	if (inc)
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		inc_ablock_entries(info, *ab);
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	return 0;
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}
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/*
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 * The shadow op will often be a noop.  Only insert if it really
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 * copied data.
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 */
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static int __reinsert_ablock(struct dm_array_info *info, unsigned int index,
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			     struct dm_block *block, dm_block_t b,
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			     dm_block_t *root)
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{
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	int r = 0;
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	if (dm_block_location(block) != b) {
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		/*
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		 * dm_tm_shadow_block will have already decremented the old
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		 * block, but it is still referenced by the btree.  We
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		 * increment to stop the insert decrementing it below zero
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		 * when overwriting the old value.
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		 */
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		dm_tm_inc(info->btree_info.tm, b);
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		r = insert_ablock(info, index, block, root);
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	}
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	return r;
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}
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/*
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 * Looks up an array block in the btree.  Then shadows it, and updates the
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 * btree to point to this new shadow.  'root' is an input/output parameter
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 * for both the current root block, and the new one.
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 */
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static int shadow_ablock(struct dm_array_info *info, dm_block_t *root,
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			 unsigned int index, struct dm_block **block,
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			 struct array_block **ab)
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{
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	int r;
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	uint64_t key = index;
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	dm_block_t b;
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	__le64 block_le;
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	r = dm_btree_lookup(&info->btree_info, *root, &key, &block_le);
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	if (r)
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		return r;
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	b = le64_to_cpu(block_le);
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	r = __shadow_ablock(info, b, block, ab);
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	if (r)
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		return r;
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	return __reinsert_ablock(info, index, *block, b, root);
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}
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/*
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 * Allocate an new array block, and fill it with some values.
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 */
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static int insert_new_ablock(struct dm_array_info *info, size_t size_of_block,
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			     uint32_t max_entries,
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			     unsigned int block_index, uint32_t nr,
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			     const void *value, dm_block_t *root)
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{
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	int r;
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	struct dm_block *block;
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	struct array_block *ab;
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	r = alloc_ablock(info, size_of_block, max_entries, &block, &ab);
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	if (r)
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		return r;
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	fill_ablock(info, ab, value, nr);
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	r = insert_ablock(info, block_index, block, root);
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	unlock_ablock(info, block);
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	return r;
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}
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static int insert_full_ablocks(struct dm_array_info *info, size_t size_of_block,
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			       unsigned int begin_block, unsigned int end_block,
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			       unsigned int max_entries, const void *value,
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			       dm_block_t *root)
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{
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	int r = 0;
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	for (; !r && begin_block != end_block; begin_block++)
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		r = insert_new_ablock(info, size_of_block, max_entries, begin_block, max_entries, value, root);
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	return r;
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}
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/*
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 * There are a bunch of functions involved with resizing an array.  This
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 * structure holds information that commonly needed by them.  Purely here
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 * to reduce parameter count.
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 */
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struct resize {
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	/*
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	 * Describes the array.
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	 */
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	struct dm_array_info *info;
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	/*
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	 * The current root of the array.  This gets updated.
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	 */
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	dm_block_t root;
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	/*
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	 * Metadata block size.  Used to calculate the nr entries in an
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	 * array block.
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	 */
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	size_t size_of_block;
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	/*
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	 * Maximum nr entries in an array block.
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	 */
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	unsigned int max_entries;
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	/*
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	 * nr of completely full blocks in the array.
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	 *
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	 * 'old' refers to before the resize, 'new' after.
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	 */
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	unsigned int old_nr_full_blocks, new_nr_full_blocks;
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	/*
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	 * Number of entries in the final block.  0 iff only full blocks in
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	 * the array.
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	 */
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	unsigned int old_nr_entries_in_last_block, new_nr_entries_in_last_block;
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	/*
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	 * The default value used when growing the array.
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	 */
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	const void *value;
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};
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/*
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 * Removes a consecutive set of array blocks from the btree.  The values
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 * in block are decremented as a side effect of the btree remove.
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 *
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 * begin_index - the index of the first array block to remove.
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 * end_index - the one-past-the-end value.  ie. this block is not removed.
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 */
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static int drop_blocks(struct resize *resize, unsigned int begin_index,
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		       unsigned int end_index)
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{
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	int r;
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	while (begin_index != end_index) {
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		uint64_t key = begin_index++;
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		r = dm_btree_remove(&resize->info->btree_info, resize->root,
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				    &key, &resize->root);
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		if (r)
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			return r;
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	}
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	return 0;
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}
 | 
						|
 | 
						|
/*
 | 
						|
 * Calculates how many blocks are needed for the array.
 | 
						|
 */
 | 
						|
static unsigned int total_nr_blocks_needed(unsigned int nr_full_blocks,
 | 
						|
				       unsigned int nr_entries_in_last_block)
 | 
						|
{
 | 
						|
	return nr_full_blocks + (nr_entries_in_last_block ? 1 : 0);
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * Shrink an array.
 | 
						|
 */
 | 
						|
static int shrink(struct resize *resize)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
	unsigned int begin, end;
 | 
						|
	struct dm_block *block;
 | 
						|
	struct array_block *ab;
 | 
						|
 | 
						|
	/*
 | 
						|
	 * Lose some blocks from the back?
 | 
						|
	 */
 | 
						|
	if (resize->new_nr_full_blocks < resize->old_nr_full_blocks) {
 | 
						|
		begin = total_nr_blocks_needed(resize->new_nr_full_blocks,
 | 
						|
					       resize->new_nr_entries_in_last_block);
 | 
						|
		end = total_nr_blocks_needed(resize->old_nr_full_blocks,
 | 
						|
					     resize->old_nr_entries_in_last_block);
 | 
						|
 | 
						|
		r = drop_blocks(resize, begin, end);
 | 
						|
		if (r)
 | 
						|
			return r;
 | 
						|
	}
 | 
						|
 | 
						|
	/*
 | 
						|
	 * Trim the new tail block
 | 
						|
	 */
 | 
						|
	if (resize->new_nr_entries_in_last_block) {
 | 
						|
		r = shadow_ablock(resize->info, &resize->root,
 | 
						|
				  resize->new_nr_full_blocks, &block, &ab);
 | 
						|
		if (r)
 | 
						|
			return r;
 | 
						|
 | 
						|
		trim_ablock(resize->info, ab, resize->new_nr_entries_in_last_block);
 | 
						|
		unlock_ablock(resize->info, block);
 | 
						|
	}
 | 
						|
 | 
						|
	return 0;
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * Grow an array.
 | 
						|
 */
 | 
						|
static int grow_extend_tail_block(struct resize *resize, uint32_t new_nr_entries)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
	struct dm_block *block;
 | 
						|
	struct array_block *ab;
 | 
						|
 | 
						|
	r = shadow_ablock(resize->info, &resize->root,
 | 
						|
			  resize->old_nr_full_blocks, &block, &ab);
 | 
						|
	if (r)
 | 
						|
		return r;
 | 
						|
 | 
						|
	fill_ablock(resize->info, ab, resize->value, new_nr_entries);
 | 
						|
	unlock_ablock(resize->info, block);
 | 
						|
 | 
						|
	return r;
 | 
						|
}
 | 
						|
 | 
						|
static int grow_add_tail_block(struct resize *resize)
 | 
						|
{
 | 
						|
	return insert_new_ablock(resize->info, resize->size_of_block,
 | 
						|
				 resize->max_entries,
 | 
						|
				 resize->new_nr_full_blocks,
 | 
						|
				 resize->new_nr_entries_in_last_block,
 | 
						|
				 resize->value, &resize->root);
 | 
						|
}
 | 
						|
 | 
						|
static int grow_needs_more_blocks(struct resize *resize)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
	unsigned int old_nr_blocks = resize->old_nr_full_blocks;
 | 
						|
 | 
						|
	if (resize->old_nr_entries_in_last_block > 0) {
 | 
						|
		old_nr_blocks++;
 | 
						|
 | 
						|
		r = grow_extend_tail_block(resize, resize->max_entries);
 | 
						|
		if (r)
 | 
						|
			return r;
 | 
						|
	}
 | 
						|
 | 
						|
	r = insert_full_ablocks(resize->info, resize->size_of_block,
 | 
						|
				old_nr_blocks,
 | 
						|
				resize->new_nr_full_blocks,
 | 
						|
				resize->max_entries, resize->value,
 | 
						|
				&resize->root);
 | 
						|
	if (r)
 | 
						|
		return r;
 | 
						|
 | 
						|
	if (resize->new_nr_entries_in_last_block)
 | 
						|
		r = grow_add_tail_block(resize);
 | 
						|
 | 
						|
	return r;
 | 
						|
}
 | 
						|
 | 
						|
static int grow(struct resize *resize)
 | 
						|
{
 | 
						|
	if (resize->new_nr_full_blocks > resize->old_nr_full_blocks)
 | 
						|
		return grow_needs_more_blocks(resize);
 | 
						|
 | 
						|
	else if (resize->old_nr_entries_in_last_block)
 | 
						|
		return grow_extend_tail_block(resize, resize->new_nr_entries_in_last_block);
 | 
						|
 | 
						|
	else
 | 
						|
		return grow_add_tail_block(resize);
 | 
						|
}
 | 
						|
 | 
						|
/*----------------------------------------------------------------*/
 | 
						|
 | 
						|
/*
 | 
						|
 * These are the value_type functions for the btree elements, which point
 | 
						|
 * to array blocks.
 | 
						|
 */
 | 
						|
static void block_inc(void *context, const void *value, unsigned int count)
 | 
						|
{
 | 
						|
	const __le64 *block_le = value;
 | 
						|
	struct dm_array_info *info = context;
 | 
						|
	unsigned int i;
 | 
						|
 | 
						|
	for (i = 0; i < count; i++, block_le++)
 | 
						|
		dm_tm_inc(info->btree_info.tm, le64_to_cpu(*block_le));
 | 
						|
}
 | 
						|
 | 
						|
static void __block_dec(void *context, const void *value)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
	uint64_t b;
 | 
						|
	__le64 block_le;
 | 
						|
	uint32_t ref_count;
 | 
						|
	struct dm_block *block;
 | 
						|
	struct array_block *ab;
 | 
						|
	struct dm_array_info *info = context;
 | 
						|
 | 
						|
	memcpy(&block_le, value, sizeof(block_le));
 | 
						|
	b = le64_to_cpu(block_le);
 | 
						|
 | 
						|
	r = dm_tm_ref(info->btree_info.tm, b, &ref_count);
 | 
						|
	if (r) {
 | 
						|
		DMERR_LIMIT("couldn't get reference count for block %llu",
 | 
						|
			    (unsigned long long) b);
 | 
						|
		return;
 | 
						|
	}
 | 
						|
 | 
						|
	if (ref_count == 1) {
 | 
						|
		/*
 | 
						|
		 * We're about to drop the last reference to this ablock.
 | 
						|
		 * So we need to decrement the ref count of the contents.
 | 
						|
		 */
 | 
						|
		r = get_ablock(info, b, &block, &ab);
 | 
						|
		if (r) {
 | 
						|
			DMERR_LIMIT("couldn't get array block %llu",
 | 
						|
				    (unsigned long long) b);
 | 
						|
			return;
 | 
						|
		}
 | 
						|
 | 
						|
		dec_ablock_entries(info, ab);
 | 
						|
		unlock_ablock(info, block);
 | 
						|
	}
 | 
						|
 | 
						|
	dm_tm_dec(info->btree_info.tm, b);
 | 
						|
}
 | 
						|
 | 
						|
static void block_dec(void *context, const void *value, unsigned int count)
 | 
						|
{
 | 
						|
	unsigned int i;
 | 
						|
 | 
						|
	for (i = 0; i < count; i++, value += sizeof(__le64))
 | 
						|
		__block_dec(context, value);
 | 
						|
}
 | 
						|
 | 
						|
static int block_equal(void *context, const void *value1, const void *value2)
 | 
						|
{
 | 
						|
	return !memcmp(value1, value2, sizeof(__le64));
 | 
						|
}
 | 
						|
 | 
						|
/*----------------------------------------------------------------*/
 | 
						|
 | 
						|
void dm_array_info_init(struct dm_array_info *info,
 | 
						|
			struct dm_transaction_manager *tm,
 | 
						|
			struct dm_btree_value_type *vt)
 | 
						|
{
 | 
						|
	struct dm_btree_value_type *bvt = &info->btree_info.value_type;
 | 
						|
 | 
						|
	memcpy(&info->value_type, vt, sizeof(info->value_type));
 | 
						|
	info->btree_info.tm = tm;
 | 
						|
	info->btree_info.levels = 1;
 | 
						|
 | 
						|
	bvt->context = info;
 | 
						|
	bvt->size = sizeof(__le64);
 | 
						|
	bvt->inc = block_inc;
 | 
						|
	bvt->dec = block_dec;
 | 
						|
	bvt->equal = block_equal;
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_info_init);
 | 
						|
 | 
						|
int dm_array_empty(struct dm_array_info *info, dm_block_t *root)
 | 
						|
{
 | 
						|
	return dm_btree_empty(&info->btree_info, root);
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_empty);
 | 
						|
 | 
						|
static int array_resize(struct dm_array_info *info, dm_block_t root,
 | 
						|
			uint32_t old_size, uint32_t new_size,
 | 
						|
			const void *value, dm_block_t *new_root)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
	struct resize resize;
 | 
						|
 | 
						|
	if (old_size == new_size) {
 | 
						|
		*new_root = root;
 | 
						|
		return 0;
 | 
						|
	}
 | 
						|
 | 
						|
	resize.info = info;
 | 
						|
	resize.root = root;
 | 
						|
	resize.size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
 | 
						|
	resize.max_entries = calc_max_entries(info->value_type.size,
 | 
						|
					      resize.size_of_block);
 | 
						|
 | 
						|
	resize.old_nr_full_blocks = old_size / resize.max_entries;
 | 
						|
	resize.old_nr_entries_in_last_block = old_size % resize.max_entries;
 | 
						|
	resize.new_nr_full_blocks = new_size / resize.max_entries;
 | 
						|
	resize.new_nr_entries_in_last_block = new_size % resize.max_entries;
 | 
						|
	resize.value = value;
 | 
						|
 | 
						|
	r = ((new_size > old_size) ? grow : shrink)(&resize);
 | 
						|
	if (r)
 | 
						|
		return r;
 | 
						|
 | 
						|
	*new_root = resize.root;
 | 
						|
	return 0;
 | 
						|
}
 | 
						|
 | 
						|
int dm_array_resize(struct dm_array_info *info, dm_block_t root,
 | 
						|
		    uint32_t old_size, uint32_t new_size,
 | 
						|
		    const void *value, dm_block_t *new_root)
 | 
						|
	__dm_written_to_disk(value)
 | 
						|
{
 | 
						|
	int r = array_resize(info, root, old_size, new_size, value, new_root);
 | 
						|
 | 
						|
	__dm_unbless_for_disk(value);
 | 
						|
	return r;
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_resize);
 | 
						|
 | 
						|
static int populate_ablock_with_values(struct dm_array_info *info, struct array_block *ab,
 | 
						|
				       value_fn fn, void *context,
 | 
						|
				       unsigned int base, unsigned int new_nr)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
	unsigned int i;
 | 
						|
	struct dm_btree_value_type *vt = &info->value_type;
 | 
						|
 | 
						|
	BUG_ON(le32_to_cpu(ab->nr_entries));
 | 
						|
	BUG_ON(new_nr > le32_to_cpu(ab->max_entries));
 | 
						|
 | 
						|
	for (i = 0; i < new_nr; i++) {
 | 
						|
		r = fn(base + i, element_at(info, ab, i), context);
 | 
						|
		if (r)
 | 
						|
			return r;
 | 
						|
 | 
						|
		if (vt->inc)
 | 
						|
			vt->inc(vt->context, element_at(info, ab, i), 1);
 | 
						|
	}
 | 
						|
 | 
						|
	ab->nr_entries = cpu_to_le32(new_nr);
 | 
						|
	return 0;
 | 
						|
}
 | 
						|
 | 
						|
int dm_array_new(struct dm_array_info *info, dm_block_t *root,
 | 
						|
		 uint32_t size, value_fn fn, void *context)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
	struct dm_block *block;
 | 
						|
	struct array_block *ab;
 | 
						|
	unsigned int block_index, end_block, size_of_block, max_entries;
 | 
						|
 | 
						|
	r = dm_array_empty(info, root);
 | 
						|
	if (r)
 | 
						|
		return r;
 | 
						|
 | 
						|
	size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
 | 
						|
	max_entries = calc_max_entries(info->value_type.size, size_of_block);
 | 
						|
	end_block = dm_div_up(size, max_entries);
 | 
						|
 | 
						|
	for (block_index = 0; block_index != end_block; block_index++) {
 | 
						|
		r = alloc_ablock(info, size_of_block, max_entries, &block, &ab);
 | 
						|
		if (r)
 | 
						|
			break;
 | 
						|
 | 
						|
		r = populate_ablock_with_values(info, ab, fn, context,
 | 
						|
						block_index * max_entries,
 | 
						|
						min(max_entries, size));
 | 
						|
		if (r) {
 | 
						|
			unlock_ablock(info, block);
 | 
						|
			break;
 | 
						|
		}
 | 
						|
 | 
						|
		r = insert_ablock(info, block_index, block, root);
 | 
						|
		unlock_ablock(info, block);
 | 
						|
		if (r)
 | 
						|
			break;
 | 
						|
 | 
						|
		size -= max_entries;
 | 
						|
	}
 | 
						|
 | 
						|
	return r;
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_new);
 | 
						|
 | 
						|
int dm_array_del(struct dm_array_info *info, dm_block_t root)
 | 
						|
{
 | 
						|
	return dm_btree_del(&info->btree_info, root);
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_del);
 | 
						|
 | 
						|
int dm_array_get_value(struct dm_array_info *info, dm_block_t root,
 | 
						|
		       uint32_t index, void *value_le)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
	struct dm_block *block;
 | 
						|
	struct array_block *ab;
 | 
						|
	size_t size_of_block;
 | 
						|
	unsigned int entry, max_entries;
 | 
						|
 | 
						|
	size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
 | 
						|
	max_entries = calc_max_entries(info->value_type.size, size_of_block);
 | 
						|
 | 
						|
	r = lookup_ablock(info, root, index / max_entries, &block, &ab);
 | 
						|
	if (r)
 | 
						|
		return r;
 | 
						|
 | 
						|
	entry = index % max_entries;
 | 
						|
	if (entry >= le32_to_cpu(ab->nr_entries))
 | 
						|
		r = -ENODATA;
 | 
						|
	else
 | 
						|
		memcpy(value_le, element_at(info, ab, entry),
 | 
						|
		       info->value_type.size);
 | 
						|
 | 
						|
	unlock_ablock(info, block);
 | 
						|
	return r;
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_get_value);
 | 
						|
 | 
						|
static int array_set_value(struct dm_array_info *info, dm_block_t root,
 | 
						|
			   uint32_t index, const void *value, dm_block_t *new_root)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
	struct dm_block *block;
 | 
						|
	struct array_block *ab;
 | 
						|
	size_t size_of_block;
 | 
						|
	unsigned int max_entries;
 | 
						|
	unsigned int entry;
 | 
						|
	void *old_value;
 | 
						|
	struct dm_btree_value_type *vt = &info->value_type;
 | 
						|
 | 
						|
	size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
 | 
						|
	max_entries = calc_max_entries(info->value_type.size, size_of_block);
 | 
						|
 | 
						|
	r = shadow_ablock(info, &root, index / max_entries, &block, &ab);
 | 
						|
	if (r)
 | 
						|
		return r;
 | 
						|
	*new_root = root;
 | 
						|
 | 
						|
	entry = index % max_entries;
 | 
						|
	if (entry >= le32_to_cpu(ab->nr_entries)) {
 | 
						|
		r = -ENODATA;
 | 
						|
		goto out;
 | 
						|
	}
 | 
						|
 | 
						|
	old_value = element_at(info, ab, entry);
 | 
						|
	if (vt->dec &&
 | 
						|
	    (!vt->equal || !vt->equal(vt->context, old_value, value))) {
 | 
						|
		vt->dec(vt->context, old_value, 1);
 | 
						|
		if (vt->inc)
 | 
						|
			vt->inc(vt->context, value, 1);
 | 
						|
	}
 | 
						|
 | 
						|
	memcpy(old_value, value, info->value_type.size);
 | 
						|
 | 
						|
out:
 | 
						|
	unlock_ablock(info, block);
 | 
						|
	return r;
 | 
						|
}
 | 
						|
 | 
						|
int dm_array_set_value(struct dm_array_info *info, dm_block_t root,
 | 
						|
		 uint32_t index, const void *value, dm_block_t *new_root)
 | 
						|
	__dm_written_to_disk(value)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
 | 
						|
	r = array_set_value(info, root, index, value, new_root);
 | 
						|
	__dm_unbless_for_disk(value);
 | 
						|
	return r;
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_set_value);
 | 
						|
 | 
						|
struct walk_info {
 | 
						|
	struct dm_array_info *info;
 | 
						|
	int (*fn)(void *context, uint64_t key, void *leaf);
 | 
						|
	void *context;
 | 
						|
};
 | 
						|
 | 
						|
static int walk_ablock(void *context, uint64_t *keys, void *leaf)
 | 
						|
{
 | 
						|
	struct walk_info *wi = context;
 | 
						|
 | 
						|
	int r;
 | 
						|
	unsigned int i;
 | 
						|
	__le64 block_le;
 | 
						|
	unsigned int nr_entries, max_entries;
 | 
						|
	struct dm_block *block;
 | 
						|
	struct array_block *ab;
 | 
						|
 | 
						|
	memcpy(&block_le, leaf, sizeof(block_le));
 | 
						|
	r = get_ablock(wi->info, le64_to_cpu(block_le), &block, &ab);
 | 
						|
	if (r)
 | 
						|
		return r;
 | 
						|
 | 
						|
	max_entries = le32_to_cpu(ab->max_entries);
 | 
						|
	nr_entries = le32_to_cpu(ab->nr_entries);
 | 
						|
	for (i = 0; i < nr_entries; i++) {
 | 
						|
		r = wi->fn(wi->context, keys[0] * max_entries + i,
 | 
						|
			   element_at(wi->info, ab, i));
 | 
						|
 | 
						|
		if (r)
 | 
						|
			break;
 | 
						|
	}
 | 
						|
 | 
						|
	unlock_ablock(wi->info, block);
 | 
						|
	return r;
 | 
						|
}
 | 
						|
 | 
						|
int dm_array_walk(struct dm_array_info *info, dm_block_t root,
 | 
						|
		  int (*fn)(void *, uint64_t key, void *leaf),
 | 
						|
		  void *context)
 | 
						|
{
 | 
						|
	struct walk_info wi;
 | 
						|
 | 
						|
	wi.info = info;
 | 
						|
	wi.fn = fn;
 | 
						|
	wi.context = context;
 | 
						|
 | 
						|
	return dm_btree_walk(&info->btree_info, root, walk_ablock, &wi);
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_walk);
 | 
						|
 | 
						|
/*----------------------------------------------------------------*/
 | 
						|
 | 
						|
static int load_ablock(struct dm_array_cursor *c)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
	__le64 value_le;
 | 
						|
	uint64_t key;
 | 
						|
 | 
						|
	if (c->block)
 | 
						|
		unlock_ablock(c->info, c->block);
 | 
						|
 | 
						|
	c->block = NULL;
 | 
						|
	c->ab = NULL;
 | 
						|
	c->index = 0;
 | 
						|
 | 
						|
	r = dm_btree_cursor_get_value(&c->cursor, &key, &value_le);
 | 
						|
	if (r) {
 | 
						|
		DMERR("dm_btree_cursor_get_value failed");
 | 
						|
		dm_btree_cursor_end(&c->cursor);
 | 
						|
 | 
						|
	} else {
 | 
						|
		r = get_ablock(c->info, le64_to_cpu(value_le), &c->block, &c->ab);
 | 
						|
		if (r) {
 | 
						|
			DMERR("get_ablock failed");
 | 
						|
			dm_btree_cursor_end(&c->cursor);
 | 
						|
		}
 | 
						|
	}
 | 
						|
 | 
						|
	return r;
 | 
						|
}
 | 
						|
 | 
						|
int dm_array_cursor_begin(struct dm_array_info *info, dm_block_t root,
 | 
						|
			  struct dm_array_cursor *c)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
 | 
						|
	memset(c, 0, sizeof(*c));
 | 
						|
	c->info = info;
 | 
						|
	r = dm_btree_cursor_begin(&info->btree_info, root, true, &c->cursor);
 | 
						|
	if (r) {
 | 
						|
		DMERR("couldn't create btree cursor");
 | 
						|
		return r;
 | 
						|
	}
 | 
						|
 | 
						|
	return load_ablock(c);
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_cursor_begin);
 | 
						|
 | 
						|
void dm_array_cursor_end(struct dm_array_cursor *c)
 | 
						|
{
 | 
						|
	if (c->block) {
 | 
						|
		unlock_ablock(c->info, c->block);
 | 
						|
		dm_btree_cursor_end(&c->cursor);
 | 
						|
	}
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_cursor_end);
 | 
						|
 | 
						|
int dm_array_cursor_next(struct dm_array_cursor *c)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
 | 
						|
	if (!c->block)
 | 
						|
		return -ENODATA;
 | 
						|
 | 
						|
	c->index++;
 | 
						|
 | 
						|
	if (c->index >= le32_to_cpu(c->ab->nr_entries)) {
 | 
						|
		r = dm_btree_cursor_next(&c->cursor);
 | 
						|
		if (r)
 | 
						|
			return r;
 | 
						|
 | 
						|
		r = load_ablock(c);
 | 
						|
		if (r)
 | 
						|
			return r;
 | 
						|
	}
 | 
						|
 | 
						|
	return 0;
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_cursor_next);
 | 
						|
 | 
						|
int dm_array_cursor_skip(struct dm_array_cursor *c, uint32_t count)
 | 
						|
{
 | 
						|
	int r;
 | 
						|
 | 
						|
	do {
 | 
						|
		uint32_t remaining = le32_to_cpu(c->ab->nr_entries) - c->index;
 | 
						|
 | 
						|
		if (count < remaining) {
 | 
						|
			c->index += count;
 | 
						|
			return 0;
 | 
						|
		}
 | 
						|
 | 
						|
		count -= remaining;
 | 
						|
		r = dm_array_cursor_next(c);
 | 
						|
 | 
						|
	} while (!r);
 | 
						|
 | 
						|
	return r;
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_cursor_skip);
 | 
						|
 | 
						|
void dm_array_cursor_get_value(struct dm_array_cursor *c, void **value_le)
 | 
						|
{
 | 
						|
	*value_le = element_at(c->info, c->ab, c->index);
 | 
						|
}
 | 
						|
EXPORT_SYMBOL_GPL(dm_array_cursor_get_value);
 | 
						|
 | 
						|
/*----------------------------------------------------------------*/
 |