spufs: switch to ->free_inode()
[muen/linux.git] / 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 __be16 t10_pi_crc_fn(void *data, unsigned int len)
32 {
33         return cpu_to_be16(crc_t10dif(data, len));
34 }
35
36 static __be16 t10_pi_ip_fn(void *data, unsigned int len)
37 {
38         return (__force __be16)ip_compute_csum(data, len);
39 }
40
41 /*
42  * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
43  * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref
44  * tag.
45  */
46 static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter,
47                 csum_fn *fn, unsigned int type)
48 {
49         unsigned int i;
50
51         for (i = 0 ; i < iter->data_size ; i += iter->interval) {
52                 struct t10_pi_tuple *pi = iter->prot_buf;
53
54                 pi->guard_tag = fn(iter->data_buf, iter->interval);
55                 pi->app_tag = 0;
56
57                 if (type == 1)
58                         pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed));
59                 else
60                         pi->ref_tag = 0;
61
62                 iter->data_buf += iter->interval;
63                 iter->prot_buf += sizeof(struct t10_pi_tuple);
64                 iter->seed++;
65         }
66
67         return BLK_STS_OK;
68 }
69
70 static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter,
71                 csum_fn *fn, unsigned int type)
72 {
73         unsigned int i;
74
75         for (i = 0 ; i < iter->data_size ; i += iter->interval) {
76                 struct t10_pi_tuple *pi = iter->prot_buf;
77                 __be16 csum;
78
79                 switch (type) {
80                 case 1:
81                 case 2:
82                         if (pi->app_tag == T10_PI_APP_ESCAPE)
83                                 goto next;
84
85                         if (be32_to_cpu(pi->ref_tag) !=
86                             lower_32_bits(iter->seed)) {
87                                 pr_err("%s: ref tag error at location %llu " \
88                                        "(rcvd %u)\n", iter->disk_name,
89                                        (unsigned long long)
90                                        iter->seed, be32_to_cpu(pi->ref_tag));
91                                 return BLK_STS_PROTECTION;
92                         }
93                         break;
94                 case 3:
95                         if (pi->app_tag == T10_PI_APP_ESCAPE &&
96                             pi->ref_tag == T10_PI_REF_ESCAPE)
97                                 goto next;
98                         break;
99                 }
100
101                 csum = fn(iter->data_buf, iter->interval);
102
103                 if (pi->guard_tag != csum) {
104                         pr_err("%s: guard tag error at sector %llu " \
105                                "(rcvd %04x, want %04x)\n", iter->disk_name,
106                                (unsigned long long)iter->seed,
107                                be16_to_cpu(pi->guard_tag), be16_to_cpu(csum));
108                         return BLK_STS_PROTECTION;
109                 }
110
111 next:
112                 iter->data_buf += iter->interval;
113                 iter->prot_buf += sizeof(struct t10_pi_tuple);
114                 iter->seed++;
115         }
116
117         return BLK_STS_OK;
118 }
119
120 static blk_status_t t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)
121 {
122         return t10_pi_generate(iter, t10_pi_crc_fn, 1);
123 }
124
125 static blk_status_t t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)
126 {
127         return t10_pi_generate(iter, t10_pi_ip_fn, 1);
128 }
129
130 static blk_status_t t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)
131 {
132         return t10_pi_verify(iter, t10_pi_crc_fn, 1);
133 }
134
135 static blk_status_t t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)
136 {
137         return t10_pi_verify(iter, t10_pi_ip_fn, 1);
138 }
139
140 static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
141 {
142         return t10_pi_generate(iter, t10_pi_crc_fn, 3);
143 }
144
145 static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
146 {
147         return t10_pi_generate(iter, t10_pi_ip_fn, 3);
148 }
149
150 static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
151 {
152         return t10_pi_verify(iter, t10_pi_crc_fn, 3);
153 }
154
155 static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
156 {
157         return t10_pi_verify(iter, t10_pi_ip_fn, 3);
158 }
159
160 const struct blk_integrity_profile t10_pi_type1_crc = {
161         .name                   = "T10-DIF-TYPE1-CRC",
162         .generate_fn            = t10_pi_type1_generate_crc,
163         .verify_fn              = t10_pi_type1_verify_crc,
164 };
165 EXPORT_SYMBOL(t10_pi_type1_crc);
166
167 const struct blk_integrity_profile t10_pi_type1_ip = {
168         .name                   = "T10-DIF-TYPE1-IP",
169         .generate_fn            = t10_pi_type1_generate_ip,
170         .verify_fn              = t10_pi_type1_verify_ip,
171 };
172 EXPORT_SYMBOL(t10_pi_type1_ip);
173
174 const struct blk_integrity_profile t10_pi_type3_crc = {
175         .name                   = "T10-DIF-TYPE3-CRC",
176         .generate_fn            = t10_pi_type3_generate_crc,
177         .verify_fn              = t10_pi_type3_verify_crc,
178 };
179 EXPORT_SYMBOL(t10_pi_type3_crc);
180
181 const struct blk_integrity_profile t10_pi_type3_ip = {
182         .name                   = "T10-DIF-TYPE3-IP",
183         .generate_fn            = t10_pi_type3_generate_ip,
184         .verify_fn              = t10_pi_type3_verify_ip,
185 };
186 EXPORT_SYMBOL(t10_pi_type3_ip);
187
188 /**
189  * t10_pi_prepare - prepare PI prior submitting request to device
190  * @rq:              request with PI that should be prepared
191  * @protection_type: PI type (Type 1/Type 2/Type 3)
192  *
193  * For Type 1/Type 2, the virtual start sector is the one that was
194  * originally submitted by the block layer for the ref_tag usage. Due to
195  * partitioning, MD/DM cloning, etc. the actual physical start sector is
196  * likely to be different. Remap protection information to match the
197  * physical LBA.
198  *
199  * Type 3 does not have a reference tag so no remapping is required.
200  */
201 void t10_pi_prepare(struct request *rq, u8 protection_type)
202 {
203         const int tuple_sz = rq->q->integrity.tuple_size;
204         u32 ref_tag = t10_pi_ref_tag(rq);
205         struct bio *bio;
206
207         if (protection_type == T10_PI_TYPE3_PROTECTION)
208                 return;
209
210         __rq_for_each_bio(bio, rq) {
211                 struct bio_integrity_payload *bip = bio_integrity(bio);
212                 u32 virt = bip_get_seed(bip) & 0xffffffff;
213                 struct bio_vec iv;
214                 struct bvec_iter iter;
215
216                 /* Already remapped? */
217                 if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
218                         break;
219
220                 bip_for_each_vec(iv, bip, iter) {
221                         void *p, *pmap;
222                         unsigned int j;
223
224                         pmap = kmap_atomic(iv.bv_page);
225                         p = pmap + iv.bv_offset;
226                         for (j = 0; j < iv.bv_len; j += tuple_sz) {
227                                 struct t10_pi_tuple *pi = p;
228
229                                 if (be32_to_cpu(pi->ref_tag) == virt)
230                                         pi->ref_tag = cpu_to_be32(ref_tag);
231                                 virt++;
232                                 ref_tag++;
233                                 p += tuple_sz;
234                         }
235
236                         kunmap_atomic(pmap);
237                 }
238
239                 bip->bip_flags |= BIP_MAPPED_INTEGRITY;
240         }
241 }
242 EXPORT_SYMBOL(t10_pi_prepare);
243
244 /**
245  * t10_pi_complete - prepare PI prior returning request to the block layer
246  * @rq:              request with PI that should be prepared
247  * @protection_type: PI type (Type 1/Type 2/Type 3)
248  * @intervals:       total elements to prepare
249  *
250  * For Type 1/Type 2, the virtual start sector is the one that was
251  * originally submitted by the block layer for the ref_tag usage. Due to
252  * partitioning, MD/DM cloning, etc. the actual physical start sector is
253  * likely to be different. Since the physical start sector was submitted
254  * to the device, we should remap it back to virtual values expected by the
255  * block layer.
256  *
257  * Type 3 does not have a reference tag so no remapping is required.
258  */
259 void t10_pi_complete(struct request *rq, u8 protection_type,
260                      unsigned int intervals)
261 {
262         const int tuple_sz = rq->q->integrity.tuple_size;
263         u32 ref_tag = t10_pi_ref_tag(rq);
264         struct bio *bio;
265
266         if (protection_type == T10_PI_TYPE3_PROTECTION)
267                 return;
268
269         __rq_for_each_bio(bio, rq) {
270                 struct bio_integrity_payload *bip = bio_integrity(bio);
271                 u32 virt = bip_get_seed(bip) & 0xffffffff;
272                 struct bio_vec iv;
273                 struct bvec_iter iter;
274
275                 bip_for_each_vec(iv, bip, iter) {
276                         void *p, *pmap;
277                         unsigned int j;
278
279                         pmap = kmap_atomic(iv.bv_page);
280                         p = pmap + iv.bv_offset;
281                         for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) {
282                                 struct t10_pi_tuple *pi = p;
283
284                                 if (be32_to_cpu(pi->ref_tag) == ref_tag)
285                                         pi->ref_tag = cpu_to_be32(virt);
286                                 virt++;
287                                 ref_tag++;
288                                 intervals--;
289                                 p += tuple_sz;
290                         }
291
292                         kunmap_atomic(pmap);
293                 }
294         }
295 }
296 EXPORT_SYMBOL(t10_pi_complete);