/* * Copyright (C) 2011 Red Hat, Inc. * * This file is released under the GPL. */ #include "dm-space-map-common.h"#include "dm-space-map-disk.h"#include "dm-space-map.h"#include "dm-transaction-manager.h" #include <linux/list.h>#include <linux/slab.h>#include <linux/export.h>#include <linux/device-mapper.h> #define DM_MSG_PREFIX "space map disk" /*----------------------------------------------------------------*/ /* * Space map interface. */struct sm_disk {	struct dm_space_map sm; 	struct ll_disk ll;	struct ll_disk old_ll; 	dm_block_t begin;	dm_block_t nr_allocated_this_transaction;}; static void sm_disk_destroy(struct dm_space_map *sm){	struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 	kfree(smd);} static int sm_disk_extend(struct dm_space_map *sm, dm_block_t extra_blocks){	struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 	return sm_ll_extend(&smd->ll, extra_blocks);} static int sm_disk_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count){	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);	*count = smd->old_ll.nr_blocks; 	return 0;} static int sm_disk_get_nr_free(struct dm_space_map *sm, dm_block_t *count){	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);	*count = (smd->old_ll.nr_blocks - smd->old_ll.nr_allocated) - smd->nr_allocated_this_transaction; 	return 0;} static int sm_disk_get_count(struct dm_space_map *sm, dm_block_t b,			     uint32_t *result){	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);	return sm_ll_lookup(&smd->ll, b, result);} static int sm_disk_count_is_more_than_one(struct dm_space_map *sm, dm_block_t b,					  int *result){	int r;	uint32_t count; 	r = sm_disk_get_count(sm, b, &count);	if (r)		return r; 	return count > 1;} static int sm_disk_set_count(struct dm_space_map *sm, dm_block_t b,			     uint32_t count){	int r;	uint32_t old_count;	enum allocation_event ev;	struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 	r = sm_ll_insert(&smd->ll, b, count, &ev);	if (!r) {		switch (ev) {		case SM_NONE:			break; 		case SM_ALLOC:			/*			 * This _must_ be free in the prior transaction			 * otherwise we've lost atomicity.			 */			smd->nr_allocated_this_transaction++;			break; 		case SM_FREE:			/*			 * It's only free if it's also free in the last			 * transaction.			 */			r = sm_ll_lookup(&smd->old_ll, b, &old_count);			if (r)				return r; 			if (!old_count)				smd->nr_allocated_this_transaction--;			break;		}	} 	return r;} static int sm_disk_inc_block(struct dm_space_map *sm, dm_block_t b){	int r;	enum allocation_event ev;	struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 	r = sm_ll_inc(&smd->ll, b, &ev);	if (!r && (ev == SM_ALLOC))		/*		 * This _must_ be free in the prior transaction		 * otherwise we've lost atomicity.		 */		smd->nr_allocated_this_transaction++; 	return r;} static int sm_disk_dec_block(struct dm_space_map *sm, dm_block_t b){	enum allocation_event ev;	struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 	return sm_ll_dec(&smd->ll, b, &ev);} static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b){	int r;	enum allocation_event ev;	struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 	/* FIXME: we should loop round a couple of times */	r = sm_ll_find_free_block(&smd->old_ll, smd->begin, smd->old_ll.nr_blocks, b);	if (r)		return r; 	smd->begin = *b + 1;	r = sm_ll_inc(&smd->ll, *b, &ev);	if (!r) {		BUG_ON(ev != SM_ALLOC);		smd->nr_allocated_this_transaction++;	} 	return r;} static int sm_disk_commit(struct dm_space_map *sm){	int r;	dm_block_t nr_free;	struct sm_disk *smd = container_of(sm, struct sm_disk, sm); 	r = sm_disk_get_nr_free(sm, &nr_free);	if (r)		return r; 	r = sm_ll_commit(&smd->ll);	if (r)		return r; 	memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll));	smd->begin = 0;	smd->nr_allocated_this_transaction = 0; 	r = sm_disk_get_nr_free(sm, &nr_free);	if (r)		return r; 	return 0;} static int sm_disk_root_size(struct dm_space_map *sm, size_t *result){	*result = sizeof(struct disk_sm_root); 	return 0;} static int sm_disk_copy_root(struct dm_space_map *sm, void *where_le, size_t max){	struct sm_disk *smd = container_of(sm, struct sm_disk, sm);	struct disk_sm_root root_le; 	root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks);	root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated);	root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root);	root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root); 	if (max < sizeof(root_le))		return -ENOSPC; 	memcpy(where_le, &root_le, sizeof(root_le)); 	return 0;} /*----------------------------------------------------------------*/ static struct dm_space_map ops = {	.destroy = sm_disk_destroy,	.extend = sm_disk_extend,	.get_nr_blocks = sm_disk_get_nr_blocks,	.get_nr_free = sm_disk_get_nr_free,	.get_count = sm_disk_get_count,	.count_is_more_than_one = sm_disk_count_is_more_than_one,	.set_count = sm_disk_set_count,	.inc_block = sm_disk_inc_block,	.dec_block = sm_disk_dec_block,	.new_block = sm_disk_new_block,	.commit = sm_disk_commit,	.root_size = sm_disk_root_size,	.copy_root = sm_disk_copy_root,	.register_threshold_callback = NULL}; struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm,				       dm_block_t nr_blocks){	int r;	struct sm_disk *smd; 	smd = kmalloc(sizeof(*smd), GFP_KERNEL);	if (!smd)		return ERR_PTR(-ENOMEM); 	smd->begin = 0;	smd->nr_allocated_this_transaction = 0;	memcpy(&smd->sm, &ops, sizeof(smd->sm)); 	r = sm_ll_new_disk(&smd->ll, tm);	if (r)		goto bad; 	r = sm_ll_extend(&smd->ll, nr_blocks);	if (r)		goto bad; 	r = sm_disk_commit(&smd->sm);	if (r)		goto bad; 	return &smd->sm; bad:	kfree(smd);	return ERR_PTR(r);}EXPORT_SYMBOL_GPL(dm_sm_disk_create); struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm,				     void *root_le, size_t len){	int r;	struct sm_disk *smd; 	smd = kmalloc(sizeof(*smd), GFP_KERNEL);	if (!smd)		return ERR_PTR(-ENOMEM); 	smd->begin = 0;	smd->nr_allocated_this_transaction = 0;	memcpy(&smd->sm, &ops, sizeof(smd->sm)); 	r = sm_ll_open_disk(&smd->ll, tm, root_le, len);	if (r)		goto bad; 	r = sm_disk_commit(&smd->sm);	if (r)		goto bad; 	return &smd->sm; bad:	kfree(smd);	return ERR_PTR(r);}EXPORT_SYMBOL_GPL(dm_sm_disk_open); /*----------------------------------------------------------------*/