tjh.dev
Linux kernel mirror (for testing)
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * blk-integrity.c - Block layer data integrity extensions
4 *
5 * Copyright (C) 2007, 2008 Oracle Corporation
6 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
7 */
8
9#include <linux/blk-integrity.h>
10#include <linux/backing-dev.h>
11#include <linux/mempool.h>
12#include <linux/bio.h>
13#include <linux/scatterlist.h>
14#include <linux/export.h>
15#include <linux/slab.h>
16#include <linux/t10-pi.h>
17
18#include "blk.h"
19
20/**
21 * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
22 * @q: request queue
23 * @bio: bio with integrity metadata attached
24 *
25 * Description: Returns the number of elements required in a
26 * scatterlist corresponding to the integrity metadata in a bio.
27 */
28int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
29{
30 struct bio_vec iv, ivprv = { NULL };
31 unsigned int segments = 0;
32 unsigned int seg_size = 0;
33 struct bvec_iter iter;
34 int prev = 0;
35
36 bio_for_each_integrity_vec(iv, bio, iter) {
37
38 if (prev) {
39 if (!biovec_phys_mergeable(q, &ivprv, &iv))
40 goto new_segment;
41 if (seg_size + iv.bv_len > queue_max_segment_size(q))
42 goto new_segment;
43
44 seg_size += iv.bv_len;
45 } else {
46new_segment:
47 segments++;
48 seg_size = iv.bv_len;
49 }
50
51 prev = 1;
52 ivprv = iv;
53 }
54
55 return segments;
56}
57
58int blk_get_meta_cap(struct block_device *bdev, unsigned int cmd,
59 struct logical_block_metadata_cap __user *argp)
60{
61 struct blk_integrity *bi;
62 struct logical_block_metadata_cap meta_cap = {};
63 size_t usize = _IOC_SIZE(cmd);
64
65 if (!extensible_ioctl_valid(cmd, FS_IOC_GETLBMD_CAP, LBMD_SIZE_VER0))
66 return -ENOIOCTLCMD;
67
68 bi = blk_get_integrity(bdev->bd_disk);
69 if (!bi)
70 goto out;
71
72 if (bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE)
73 meta_cap.lbmd_flags |= LBMD_PI_CAP_INTEGRITY;
74 if (bi->flags & BLK_INTEGRITY_REF_TAG)
75 meta_cap.lbmd_flags |= LBMD_PI_CAP_REFTAG;
76 meta_cap.lbmd_interval = 1 << bi->interval_exp;
77 meta_cap.lbmd_size = bi->metadata_size;
78 meta_cap.lbmd_pi_size = bi->pi_tuple_size;
79 meta_cap.lbmd_pi_offset = bi->pi_offset;
80 meta_cap.lbmd_opaque_size = bi->metadata_size - bi->pi_tuple_size;
81 if (meta_cap.lbmd_opaque_size && !bi->pi_offset)
82 meta_cap.lbmd_opaque_offset = bi->pi_tuple_size;
83
84 switch (bi->csum_type) {
85 case BLK_INTEGRITY_CSUM_NONE:
86 meta_cap.lbmd_guard_tag_type = LBMD_PI_CSUM_NONE;
87 break;
88 case BLK_INTEGRITY_CSUM_IP:
89 meta_cap.lbmd_guard_tag_type = LBMD_PI_CSUM_IP;
90 break;
91 case BLK_INTEGRITY_CSUM_CRC:
92 meta_cap.lbmd_guard_tag_type = LBMD_PI_CSUM_CRC16_T10DIF;
93 break;
94 case BLK_INTEGRITY_CSUM_CRC64:
95 meta_cap.lbmd_guard_tag_type = LBMD_PI_CSUM_CRC64_NVME;
96 break;
97 }
98
99 if (bi->csum_type != BLK_INTEGRITY_CSUM_NONE)
100 meta_cap.lbmd_app_tag_size = 2;
101
102 if (bi->flags & BLK_INTEGRITY_REF_TAG) {
103 switch (bi->csum_type) {
104 case BLK_INTEGRITY_CSUM_CRC64:
105 meta_cap.lbmd_ref_tag_size =
106 sizeof_field(struct crc64_pi_tuple, ref_tag);
107 break;
108 case BLK_INTEGRITY_CSUM_CRC:
109 case BLK_INTEGRITY_CSUM_IP:
110 meta_cap.lbmd_ref_tag_size =
111 sizeof_field(struct t10_pi_tuple, ref_tag);
112 break;
113 default:
114 break;
115 }
116 }
117
118out:
119 return copy_struct_to_user(argp, usize, &meta_cap, sizeof(meta_cap),
120 NULL);
121}
122
123int blk_rq_integrity_map_user(struct request *rq, void __user *ubuf,
124 ssize_t bytes)
125{
126 int ret;
127 struct iov_iter iter;
128
129 iov_iter_ubuf(&iter, rq_data_dir(rq), ubuf, bytes);
130 ret = bio_integrity_map_user(rq->bio, &iter);
131 if (ret)
132 return ret;
133
134 rq->nr_integrity_segments = blk_rq_count_integrity_sg(rq->q, rq->bio);
135 rq->cmd_flags |= REQ_INTEGRITY;
136 return 0;
137}
138EXPORT_SYMBOL_GPL(blk_rq_integrity_map_user);
139
140bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
141 struct request *next)
142{
143 if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
144 return true;
145
146 if (blk_integrity_rq(req) == 0 || blk_integrity_rq(next) == 0)
147 return false;
148
149 if (bio_integrity(req->bio)->bip_flags !=
150 bio_integrity(next->bio)->bip_flags)
151 return false;
152
153 if (req->nr_integrity_segments + next->nr_integrity_segments >
154 q->limits.max_integrity_segments)
155 return false;
156
157 if (integrity_req_gap_back_merge(req, next->bio))
158 return false;
159
160 return true;
161}
162
163bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
164 struct bio *bio)
165{
166 int nr_integrity_segs;
167
168 if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
169 return true;
170
171 if (blk_integrity_rq(req) == 0 || bio_integrity(bio) == NULL)
172 return false;
173
174 if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
175 return false;
176
177 nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
178 if (req->nr_integrity_segments + nr_integrity_segs >
179 q->limits.max_integrity_segments)
180 return false;
181
182 return true;
183}
184
185static inline struct blk_integrity *dev_to_bi(struct device *dev)
186{
187 return &dev_to_disk(dev)->queue->limits.integrity;
188}
189
190const char *blk_integrity_profile_name(struct blk_integrity *bi)
191{
192 switch (bi->csum_type) {
193 case BLK_INTEGRITY_CSUM_IP:
194 if (bi->flags & BLK_INTEGRITY_REF_TAG)
195 return "T10-DIF-TYPE1-IP";
196 return "T10-DIF-TYPE3-IP";
197 case BLK_INTEGRITY_CSUM_CRC:
198 if (bi->flags & BLK_INTEGRITY_REF_TAG)
199 return "T10-DIF-TYPE1-CRC";
200 return "T10-DIF-TYPE3-CRC";
201 case BLK_INTEGRITY_CSUM_CRC64:
202 if (bi->flags & BLK_INTEGRITY_REF_TAG)
203 return "EXT-DIF-TYPE1-CRC64";
204 return "EXT-DIF-TYPE3-CRC64";
205 case BLK_INTEGRITY_CSUM_NONE:
206 break;
207 }
208
209 return "nop";
210}
211EXPORT_SYMBOL_GPL(blk_integrity_profile_name);
212
213static ssize_t flag_store(struct device *dev, const char *page, size_t count,
214 unsigned char flag)
215{
216 struct request_queue *q = dev_to_disk(dev)->queue;
217 struct queue_limits lim;
218 unsigned long val;
219 int err;
220
221 err = kstrtoul(page, 10, &val);
222 if (err)
223 return err;
224
225 /* note that the flags are inverted vs the values in the sysfs files */
226 lim = queue_limits_start_update(q);
227 if (val)
228 lim.integrity.flags &= ~flag;
229 else
230 lim.integrity.flags |= flag;
231
232 err = queue_limits_commit_update_frozen(q, &lim);
233 if (err)
234 return err;
235 return count;
236}
237
238static ssize_t flag_show(struct device *dev, char *page, unsigned char flag)
239{
240 struct blk_integrity *bi = dev_to_bi(dev);
241
242 return sysfs_emit(page, "%d\n", !(bi->flags & flag));
243}
244
245static ssize_t format_show(struct device *dev, struct device_attribute *attr,
246 char *page)
247{
248 struct blk_integrity *bi = dev_to_bi(dev);
249
250 if (!bi->metadata_size)
251 return sysfs_emit(page, "none\n");
252 return sysfs_emit(page, "%s\n", blk_integrity_profile_name(bi));
253}
254
255static ssize_t tag_size_show(struct device *dev, struct device_attribute *attr,
256 char *page)
257{
258 struct blk_integrity *bi = dev_to_bi(dev);
259
260 return sysfs_emit(page, "%u\n", bi->tag_size);
261}
262
263static ssize_t protection_interval_bytes_show(struct device *dev,
264 struct device_attribute *attr,
265 char *page)
266{
267 struct blk_integrity *bi = dev_to_bi(dev);
268
269 return sysfs_emit(page, "%u\n",
270 bi->interval_exp ? 1 << bi->interval_exp : 0);
271}
272
273static ssize_t read_verify_store(struct device *dev,
274 struct device_attribute *attr,
275 const char *page, size_t count)
276{
277 return flag_store(dev, page, count, BLK_INTEGRITY_NOVERIFY);
278}
279
280static ssize_t read_verify_show(struct device *dev,
281 struct device_attribute *attr, char *page)
282{
283 return flag_show(dev, page, BLK_INTEGRITY_NOVERIFY);
284}
285
286static ssize_t write_generate_store(struct device *dev,
287 struct device_attribute *attr,
288 const char *page, size_t count)
289{
290 return flag_store(dev, page, count, BLK_INTEGRITY_NOGENERATE);
291}
292
293static ssize_t write_generate_show(struct device *dev,
294 struct device_attribute *attr, char *page)
295{
296 return flag_show(dev, page, BLK_INTEGRITY_NOGENERATE);
297}
298
299static ssize_t device_is_integrity_capable_show(struct device *dev,
300 struct device_attribute *attr,
301 char *page)
302{
303 struct blk_integrity *bi = dev_to_bi(dev);
304
305 return sysfs_emit(page, "%u\n",
306 !!(bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE));
307}
308
309static DEVICE_ATTR_RO(format);
310static DEVICE_ATTR_RO(tag_size);
311static DEVICE_ATTR_RO(protection_interval_bytes);
312static DEVICE_ATTR_RW(read_verify);
313static DEVICE_ATTR_RW(write_generate);
314static DEVICE_ATTR_RO(device_is_integrity_capable);
315
316static struct attribute *integrity_attrs[] = {
317 &dev_attr_format.attr,
318 &dev_attr_tag_size.attr,
319 &dev_attr_protection_interval_bytes.attr,
320 &dev_attr_read_verify.attr,
321 &dev_attr_write_generate.attr,
322 &dev_attr_device_is_integrity_capable.attr,
323 NULL
324};
325
326const struct attribute_group blk_integrity_attr_group = {
327 .name = "integrity",
328 .attrs = integrity_attrs,
329};