Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/block/t10-pi.c

  1 /*
  2  * t10_pi.c - Functions for generating and verifying T10 Protection
  3  *            Information.
  4  *
  5  * Copyright (C) 2007, 2008, 2014 Oracle Corporation
  6  * Written by: Martin K. Petersen <martin.petersen@oracle.com>
  7  *
  8  * This program is free software; you can redistribute it and/or
  9  * modify it under the terms of the GNU General Public License version
 10  * 2 as published by the Free Software Foundation.
 11  *
 12  * This program is distributed in the hope that it will be useful, but
 13  * WITHOUT ANY WARRANTY; without even the implied warranty of
 14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 15  * General Public License for more details.
 16  *
 17  * You should have received a copy of the GNU General Public License
 18  * along with this program; see the file COPYING.  If not, write to
 19  * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
 20  * USA.
 21  *
 22  */
 23 
 24 #include <linux/t10-pi.h>
 25 #include <linux/blkdev.h>
 26 #include <linux/crc-t10dif.h>
 27 #include <net/checksum.h>
 28 
 29 typedef __be16 (csum_fn) (void *, unsigned int);
 30 
 31 static const __be16 APP_ESCAPE = (__force __be16) 0xffff;
 32 static const __be32 REF_ESCAPE = (__force __be32) 0xffffffff;
 33 
 34 static __be16 t10_pi_crc_fn(void *data, unsigned int len)
 35 {
 36         return cpu_to_be16(crc_t10dif(data, len));
 37 }
 38 
 39 static __be16 t10_pi_ip_fn(void *data, unsigned int len)
 40 {
 41         return (__force __be16)ip_compute_csum(data, len);
 42 }
 43 
 44 /*
 45  * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
 46  * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref
 47  * tag.
 48  */
 49 static int t10_pi_generate(struct blk_integrity_iter *iter, csum_fn *fn,
 50                            unsigned int type)
 51 {
 52         unsigned int i;
 53 
 54         for (i = 0 ; i < iter->data_size ; i += iter->interval) {
 55                 struct t10_pi_tuple *pi = iter->prot_buf;
 56 
 57                 pi->guard_tag = fn(iter->data_buf, iter->interval);
 58                 pi->app_tag = 0;
 59 
 60                 if (type == 1)
 61                         pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed));
 62                 else
 63                         pi->ref_tag = 0;
 64 
 65                 iter->data_buf += iter->interval;
 66                 iter->prot_buf += sizeof(struct t10_pi_tuple);
 67                 iter->seed++;
 68         }
 69 
 70         return 0;
 71 }
 72 
 73 static int t10_pi_verify(struct blk_integrity_iter *iter, csum_fn *fn,
 74                                 unsigned int type)
 75 {
 76         unsigned int i;
 77 
 78         for (i = 0 ; i < iter->data_size ; i += iter->interval) {
 79                 struct t10_pi_tuple *pi = iter->prot_buf;
 80                 __be16 csum;
 81 
 82                 switch (type) {
 83                 case 1:
 84                 case 2:
 85                         if (pi->app_tag == APP_ESCAPE)
 86                                 goto next;
 87 
 88                         if (be32_to_cpu(pi->ref_tag) !=
 89                             lower_32_bits(iter->seed)) {
 90                                 pr_err("%s: ref tag error at location %llu " \
 91                                        "(rcvd %u)\n", iter->disk_name,
 92                                        (unsigned long long)
 93                                        iter->seed, be32_to_cpu(pi->ref_tag));
 94                                 return -EILSEQ;
 95                         }
 96                         break;
 97                 case 3:
 98                         if (pi->app_tag == APP_ESCAPE &&
 99                             pi->ref_tag == REF_ESCAPE)
100                                 goto next;
101                         break;
102                 }
103 
104                 csum = fn(iter->data_buf, iter->interval);
105 
106                 if (pi->guard_tag != csum) {
107                         pr_err("%s: guard tag error at sector %llu " \
108                                "(rcvd %04x, want %04x)\n", iter->disk_name,
109                                (unsigned long long)iter->seed,
110                                be16_to_cpu(pi->guard_tag), be16_to_cpu(csum));
111                         return -EILSEQ;
112                 }
113 
114 next:
115                 iter->data_buf += iter->interval;
116                 iter->prot_buf += sizeof(struct t10_pi_tuple);
117                 iter->seed++;
118         }
119 
120         return 0;
121 }
122 
123 static int t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)
124 {
125         return t10_pi_generate(iter, t10_pi_crc_fn, 1);
126 }
127 
128 static int t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)
129 {
130         return t10_pi_generate(iter, t10_pi_ip_fn, 1);
131 }
132 
133 static int t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)
134 {
135         return t10_pi_verify(iter, t10_pi_crc_fn, 1);
136 }
137 
138 static int t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)
139 {
140         return t10_pi_verify(iter, t10_pi_ip_fn, 1);
141 }
142 
143 static int t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
144 {
145         return t10_pi_generate(iter, t10_pi_crc_fn, 3);
146 }
147 
148 static int t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
149 {
150         return t10_pi_generate(iter, t10_pi_ip_fn, 3);
151 }
152 
153 static int t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
154 {
155         return t10_pi_verify(iter, t10_pi_crc_fn, 3);
156 }
157 
158 static int t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
159 {
160         return t10_pi_verify(iter, t10_pi_ip_fn, 3);
161 }
162 
163 struct blk_integrity_profile t10_pi_type1_crc = {
164         .name                   = "T10-DIF-TYPE1-CRC",
165         .generate_fn            = t10_pi_type1_generate_crc,
166         .verify_fn              = t10_pi_type1_verify_crc,
167 };
168 EXPORT_SYMBOL(t10_pi_type1_crc);
169 
170 struct blk_integrity_profile t10_pi_type1_ip = {
171         .name                   = "T10-DIF-TYPE1-IP",
172         .generate_fn            = t10_pi_type1_generate_ip,
173         .verify_fn              = t10_pi_type1_verify_ip,
174 };
175 EXPORT_SYMBOL(t10_pi_type1_ip);
176 
177 struct blk_integrity_profile t10_pi_type3_crc = {
178         .name                   = "T10-DIF-TYPE3-CRC",
179         .generate_fn            = t10_pi_type3_generate_crc,
180         .verify_fn              = t10_pi_type3_verify_crc,
181 };
182 EXPORT_SYMBOL(t10_pi_type3_crc);
183 
184 struct blk_integrity_profile t10_pi_type3_ip = {
185         .name                   = "T10-DIF-TYPE3-IP",
186         .generate_fn            = t10_pi_type3_generate_ip,
187         .verify_fn              = t10_pi_type3_verify_ip,
188 };
189 EXPORT_SYMBOL(t10_pi_type3_ip);
190 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us