1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/*
* sd_dif.c - SCSI Data Integrity Field
*
* Copyright (C) 2007, 2008 Oracle Corporation
* Written by: Martin K. Petersen <martin.petersen@oracle.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
* USA.
*
*/
#include <linux/blkdev.h>
#include <linux/t10-pi.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsicam.h>
#include "sd.h"
/*
* Configure exchange of protection information between OS and HBA.
*/
void sd_dif_config_host(struct scsi_disk *sdkp)
{
struct scsi_device *sdp = sdkp->device;
struct gendisk *disk = sdkp->disk;
u8 type = sdkp->protection_type;
struct blk_integrity bi;
int dif, dix;
dif = scsi_host_dif_capable(sdp->host, type);
dix = scsi_host_dix_capable(sdp->host, type);
if (!dix && scsi_host_dix_capable(sdp->host, 0)) {
dif = 0; dix = 1;
}
if (!dix)
return;
memset(&bi, 0, sizeof(bi));
/* Enable DMA of protection information */
if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP) {
if (type == T10_PI_TYPE3_PROTECTION)
bi.profile = &t10_pi_type3_ip;
else
bi.profile = &t10_pi_type1_ip;
bi.flags |= BLK_INTEGRITY_IP_CHECKSUM;
} else
if (type == T10_PI_TYPE3_PROTECTION)
bi.profile = &t10_pi_type3_crc;
else
bi.profile = &t10_pi_type1_crc;
bi.tuple_size = sizeof(struct t10_pi_tuple);
sd_printk(KERN_NOTICE, sdkp,
"Enabling DIX %s protection\n", bi.profile->name);
if (dif && type) {
bi.flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
if (!sdkp->ATO)
goto out;
if (type == T10_PI_TYPE3_PROTECTION)
bi.tag_size = sizeof(u16) + sizeof(u32);
else
bi.tag_size = sizeof(u16);
sd_printk(KERN_NOTICE, sdkp, "DIF application tag size %u\n",
bi.tag_size);
}
out:
blk_integrity_register(disk, &bi);
}
/*
* The virtual start sector is the one that was originally submitted
* by the block layer. Due to partitioning, MD/DM cloning, etc. the
* actual physical start sector is likely to be different. Remap
* protection information to match the physical LBA.
*
* From a protocol perspective there's a slight difference between
* Type 1 and 2. The latter uses 32-byte CDBs exclusively, and the
* reference tag is seeded in the CDB. This gives us the potential to
* avoid virt->phys remapping during write. However, at read time we
* don't know whether the virt sector is the same as when we wrote it
* (we could be reading from real disk as opposed to MD/DM device. So
* we always remap Type 2 making it identical to Type 1.
*
* Type 3 does not have a reference tag so no remapping is required.
*/
void sd_dif_prepare(struct scsi_cmnd *scmd)
{
const int tuple_sz = sizeof(struct t10_pi_tuple);
struct bio *bio;
struct scsi_disk *sdkp;
struct t10_pi_tuple *pi;
u32 phys, virt;
sdkp = scsi_disk(scmd->request->rq_disk);
if (sdkp->protection_type == T10_PI_TYPE3_PROTECTION)
return;
phys = scsi_prot_ref_tag(scmd);
__rq_for_each_bio(bio, scmd->request) {
struct bio_integrity_payload *bip = bio_integrity(bio);
struct bio_vec iv;
struct bvec_iter iter;
unsigned int j;
/* Already remapped? */
if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
break;
virt = bip_get_seed(bip) & 0xffffffff;
bip_for_each_vec(iv, bip, iter) {
pi = kmap_atomic(iv.bv_page) + iv.bv_offset;
for (j = 0; j < iv.bv_len; j += tuple_sz, pi++) {
if (be32_to_cpu(pi->ref_tag) == virt)
pi->ref_tag = cpu_to_be32(phys);
virt++;
phys++;
}
kunmap_atomic(pi);
}
bip->bip_flags |= BIP_MAPPED_INTEGRITY;
}
}
/*
* Remap physical sector values in the reference tag to the virtual
* values expected by the block layer.
*/
void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
{
const int tuple_sz = sizeof(struct t10_pi_tuple);
struct scsi_disk *sdkp;
struct bio *bio;
struct t10_pi_tuple *pi;
unsigned int j, intervals;
u32 phys, virt;
sdkp = scsi_disk(scmd->request->rq_disk);
if (sdkp->protection_type == T10_PI_TYPE3_PROTECTION || good_bytes == 0)
return;
intervals = good_bytes / scsi_prot_interval(scmd);
phys = scsi_prot_ref_tag(scmd);
__rq_for_each_bio(bio, scmd->request) {
struct bio_integrity_payload *bip = bio_integrity(bio);
struct bio_vec iv;
struct bvec_iter iter;
virt = bip_get_seed(bip) & 0xffffffff;
bip_for_each_vec(iv, bip, iter) {
pi = kmap_atomic(iv.bv_page) + iv.bv_offset;
for (j = 0; j < iv.bv_len; j += tuple_sz, pi++) {
if (intervals == 0) {
kunmap_atomic(pi);
return;
}
if (be32_to_cpu(pi->ref_tag) == phys)
pi->ref_tag = cpu_to_be32(virt);
virt++;
phys++;
intervals--;
}
kunmap_atomic(pi);
}
}
}
|
