cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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dm-btree-spine.c (5728B)


      1/*
      2 * Copyright (C) 2011 Red Hat, Inc.
      3 *
      4 * This file is released under the GPL.
      5 */
      6
      7#include "dm-btree-internal.h"
      8#include "dm-transaction-manager.h"
      9
     10#include <linux/device-mapper.h>
     11
     12#define DM_MSG_PREFIX "btree spine"
     13
     14/*----------------------------------------------------------------*/
     15
     16#define BTREE_CSUM_XOR 121107
     17
     18static void node_prepare_for_write(struct dm_block_validator *v,
     19				   struct dm_block *b,
     20				   size_t block_size)
     21{
     22	struct btree_node *n = dm_block_data(b);
     23	struct node_header *h = &n->header;
     24
     25	h->blocknr = cpu_to_le64(dm_block_location(b));
     26	h->csum = cpu_to_le32(dm_bm_checksum(&h->flags,
     27					     block_size - sizeof(__le32),
     28					     BTREE_CSUM_XOR));
     29}
     30
     31static int node_check(struct dm_block_validator *v,
     32		      struct dm_block *b,
     33		      size_t block_size)
     34{
     35	struct btree_node *n = dm_block_data(b);
     36	struct node_header *h = &n->header;
     37	size_t value_size;
     38	__le32 csum_disk;
     39	uint32_t flags, nr_entries, max_entries;
     40
     41	if (dm_block_location(b) != le64_to_cpu(h->blocknr)) {
     42		DMERR_LIMIT("node_check failed: blocknr %llu != wanted %llu",
     43			    le64_to_cpu(h->blocknr), dm_block_location(b));
     44		return -ENOTBLK;
     45	}
     46
     47	csum_disk = cpu_to_le32(dm_bm_checksum(&h->flags,
     48					       block_size - sizeof(__le32),
     49					       BTREE_CSUM_XOR));
     50	if (csum_disk != h->csum) {
     51		DMERR_LIMIT("node_check failed: csum %u != wanted %u",
     52			    le32_to_cpu(csum_disk), le32_to_cpu(h->csum));
     53		return -EILSEQ;
     54	}
     55
     56	nr_entries = le32_to_cpu(h->nr_entries);
     57	max_entries = le32_to_cpu(h->max_entries);
     58	value_size = le32_to_cpu(h->value_size);
     59
     60	if (sizeof(struct node_header) +
     61	    (sizeof(__le64) + value_size) * max_entries > block_size) {
     62		DMERR_LIMIT("node_check failed: max_entries too large");
     63		return -EILSEQ;
     64	}
     65
     66	if (nr_entries > max_entries) {
     67		DMERR_LIMIT("node_check failed: too many entries");
     68		return -EILSEQ;
     69	}
     70
     71	/*
     72	 * The node must be either INTERNAL or LEAF.
     73	 */
     74	flags = le32_to_cpu(h->flags);
     75	if (!(flags & INTERNAL_NODE) && !(flags & LEAF_NODE)) {
     76		DMERR_LIMIT("node_check failed: node is neither INTERNAL or LEAF");
     77		return -EILSEQ;
     78	}
     79
     80	return 0;
     81}
     82
     83struct dm_block_validator btree_node_validator = {
     84	.name = "btree_node",
     85	.prepare_for_write = node_prepare_for_write,
     86	.check = node_check
     87};
     88
     89/*----------------------------------------------------------------*/
     90
     91int bn_read_lock(struct dm_btree_info *info, dm_block_t b,
     92		 struct dm_block **result)
     93{
     94	return dm_tm_read_lock(info->tm, b, &btree_node_validator, result);
     95}
     96
     97static int bn_shadow(struct dm_btree_info *info, dm_block_t orig,
     98	      struct dm_btree_value_type *vt,
     99	      struct dm_block **result)
    100{
    101	int r, inc;
    102
    103	r = dm_tm_shadow_block(info->tm, orig, &btree_node_validator,
    104			       result, &inc);
    105	if (!r && inc)
    106		inc_children(info->tm, dm_block_data(*result), vt);
    107
    108	return r;
    109}
    110
    111int new_block(struct dm_btree_info *info, struct dm_block **result)
    112{
    113	return dm_tm_new_block(info->tm, &btree_node_validator, result);
    114}
    115
    116void unlock_block(struct dm_btree_info *info, struct dm_block *b)
    117{
    118	dm_tm_unlock(info->tm, b);
    119}
    120
    121/*----------------------------------------------------------------*/
    122
    123void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info)
    124{
    125	s->info = info;
    126	s->count = 0;
    127	s->nodes[0] = NULL;
    128	s->nodes[1] = NULL;
    129}
    130
    131void exit_ro_spine(struct ro_spine *s)
    132{
    133	int i;
    134
    135	for (i = 0; i < s->count; i++) {
    136		unlock_block(s->info, s->nodes[i]);
    137	}
    138}
    139
    140int ro_step(struct ro_spine *s, dm_block_t new_child)
    141{
    142	int r;
    143
    144	if (s->count == 2) {
    145		unlock_block(s->info, s->nodes[0]);
    146		s->nodes[0] = s->nodes[1];
    147		s->count--;
    148	}
    149
    150	r = bn_read_lock(s->info, new_child, s->nodes + s->count);
    151	if (!r)
    152		s->count++;
    153
    154	return r;
    155}
    156
    157void ro_pop(struct ro_spine *s)
    158{
    159	BUG_ON(!s->count);
    160	--s->count;
    161	unlock_block(s->info, s->nodes[s->count]);
    162}
    163
    164struct btree_node *ro_node(struct ro_spine *s)
    165{
    166	struct dm_block *block;
    167
    168	BUG_ON(!s->count);
    169	block = s->nodes[s->count - 1];
    170
    171	return dm_block_data(block);
    172}
    173
    174/*----------------------------------------------------------------*/
    175
    176void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info)
    177{
    178	s->info = info;
    179	s->count = 0;
    180}
    181
    182void exit_shadow_spine(struct shadow_spine *s)
    183{
    184	int i;
    185
    186	for (i = 0; i < s->count; i++) {
    187		unlock_block(s->info, s->nodes[i]);
    188	}
    189}
    190
    191int shadow_step(struct shadow_spine *s, dm_block_t b,
    192		struct dm_btree_value_type *vt)
    193{
    194	int r;
    195
    196	if (s->count == 2) {
    197		unlock_block(s->info, s->nodes[0]);
    198		s->nodes[0] = s->nodes[1];
    199		s->count--;
    200	}
    201
    202	r = bn_shadow(s->info, b, vt, s->nodes + s->count);
    203	if (!r) {
    204		if (!s->count)
    205			s->root = dm_block_location(s->nodes[0]);
    206
    207		s->count++;
    208	}
    209
    210	return r;
    211}
    212
    213struct dm_block *shadow_current(struct shadow_spine *s)
    214{
    215	BUG_ON(!s->count);
    216
    217	return s->nodes[s->count - 1];
    218}
    219
    220struct dm_block *shadow_parent(struct shadow_spine *s)
    221{
    222	BUG_ON(s->count != 2);
    223
    224	return s->count == 2 ? s->nodes[0] : NULL;
    225}
    226
    227int shadow_has_parent(struct shadow_spine *s)
    228{
    229	return s->count >= 2;
    230}
    231
    232dm_block_t shadow_root(struct shadow_spine *s)
    233{
    234	return s->root;
    235}
    236
    237static void le64_inc(void *context, const void *value_le, unsigned count)
    238{
    239	dm_tm_with_runs(context, value_le, count, dm_tm_inc_range);
    240}
    241
    242static void le64_dec(void *context, const void *value_le, unsigned count)
    243{
    244	dm_tm_with_runs(context, value_le, count, dm_tm_dec_range);
    245}
    246
    247static int le64_equal(void *context, const void *value1_le, const void *value2_le)
    248{
    249	__le64 v1_le, v2_le;
    250
    251	memcpy(&v1_le, value1_le, sizeof(v1_le));
    252	memcpy(&v2_le, value2_le, sizeof(v2_le));
    253	return v1_le == v2_le;
    254}
    255
    256void init_le64_type(struct dm_transaction_manager *tm,
    257		    struct dm_btree_value_type *vt)
    258{
    259	vt->context = tm;
    260	vt->size = sizeof(__le64);
    261	vt->inc = le64_inc;
    262	vt->dec = le64_dec;
    263	vt->equal = le64_equal;
    264}