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7#include <linux/blkdev.h>
8#include <linux/fs.h>
9#include <linux/genhd.h>
10#include <linux/module.h>
11#include <linux/moduleparam.h>
12#include <linux/nd.h>
13#include <linux/sizes.h>
14#include "nd.h"
15
16static u32 nsblk_meta_size(struct nd_namespace_blk *nsblk)
17{
18 return nsblk->lbasize - ((nsblk->lbasize >= 4096) ? 4096 : 512);
19}
20
21static u32 nsblk_internal_lbasize(struct nd_namespace_blk *nsblk)
22{
23 return roundup(nsblk->lbasize, INT_LBASIZE_ALIGNMENT);
24}
25
26static u32 nsblk_sector_size(struct nd_namespace_blk *nsblk)
27{
28 return nsblk->lbasize - nsblk_meta_size(nsblk);
29}
30
31static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk,
32 resource_size_t ns_offset, unsigned int len)
33{
34 int i;
35
36 for (i = 0; i < nsblk->num_resources; i++) {
37 if (ns_offset < resource_size(nsblk->res[i])) {
38 if (ns_offset + len > resource_size(nsblk->res[i])) {
39 dev_WARN_ONCE(&nsblk->common.dev, 1,
40 "illegal request\n");
41 return SIZE_MAX;
42 }
43 return nsblk->res[i]->start + ns_offset;
44 }
45 ns_offset -= resource_size(nsblk->res[i]);
46 }
47
48 dev_WARN_ONCE(&nsblk->common.dev, 1, "request out of range\n");
49 return SIZE_MAX;
50}
51
52static struct nd_blk_region *to_ndbr(struct nd_namespace_blk *nsblk)
53{
54 struct nd_region *nd_region;
55 struct device *parent;
56
57 parent = nsblk->common.dev.parent;
58 nd_region = container_of(parent, struct nd_region, dev);
59 return container_of(nd_region, struct nd_blk_region, nd_region);
60}
61
62#ifdef CONFIG_BLK_DEV_INTEGRITY
63static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
64 struct bio_integrity_payload *bip, u64 lba, int rw)
65{
66 struct nd_blk_region *ndbr = to_ndbr(nsblk);
67 unsigned int len = nsblk_meta_size(nsblk);
68 resource_size_t dev_offset, ns_offset;
69 u32 internal_lbasize, sector_size;
70 int err = 0;
71
72 internal_lbasize = nsblk_internal_lbasize(nsblk);
73 sector_size = nsblk_sector_size(nsblk);
74 ns_offset = lba * internal_lbasize + sector_size;
75 dev_offset = to_dev_offset(nsblk, ns_offset, len);
76 if (dev_offset == SIZE_MAX)
77 return -EIO;
78
79 while (len) {
80 unsigned int cur_len;
81 struct bio_vec bv;
82 void *iobuf;
83
84 bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
85
86
87
88
89
90
91 cur_len = min(len, bv.bv_len);
92 iobuf = kmap_atomic(bv.bv_page);
93 err = ndbr->do_io(ndbr, dev_offset, iobuf + bv.bv_offset,
94 cur_len, rw);
95 kunmap_atomic(iobuf);
96 if (err)
97 return err;
98
99 len -= cur_len;
100 dev_offset += cur_len;
101 if (!bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len))
102 return -EIO;
103 }
104
105 return err;
106}
107
108#else
109static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
110 struct bio_integrity_payload *bip, u64 lba, int rw)
111{
112 return 0;
113}
114#endif
115
116static int nsblk_do_bvec(struct nd_namespace_blk *nsblk,
117 struct bio_integrity_payload *bip, struct page *page,
118 unsigned int len, unsigned int off, int rw, sector_t sector)
119{
120 struct nd_blk_region *ndbr = to_ndbr(nsblk);
121 resource_size_t dev_offset, ns_offset;
122 u32 internal_lbasize, sector_size;
123 int err = 0;
124 void *iobuf;
125 u64 lba;
126
127 internal_lbasize = nsblk_internal_lbasize(nsblk);
128 sector_size = nsblk_sector_size(nsblk);
129 while (len) {
130 unsigned int cur_len;
131
132
133
134
135
136
137
138 cur_len = bip ? min(len, sector_size) : len;
139
140 lba = div_u64(sector << SECTOR_SHIFT, sector_size);
141 ns_offset = lba * internal_lbasize;
142 dev_offset = to_dev_offset(nsblk, ns_offset, cur_len);
143 if (dev_offset == SIZE_MAX)
144 return -EIO;
145
146 iobuf = kmap_atomic(page);
147 err = ndbr->do_io(ndbr, dev_offset, iobuf + off, cur_len, rw);
148 kunmap_atomic(iobuf);
149 if (err)
150 return err;
151
152 if (bip) {
153 err = nd_blk_rw_integrity(nsblk, bip, lba, rw);
154 if (err)
155 return err;
156 }
157 len -= cur_len;
158 off += cur_len;
159 sector += sector_size >> SECTOR_SHIFT;
160 }
161
162 return err;
163}
164
165static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio)
166{
167 struct bio_integrity_payload *bip;
168 struct nd_namespace_blk *nsblk;
169 struct bvec_iter iter;
170 unsigned long start;
171 struct bio_vec bvec;
172 int err = 0, rw;
173 bool do_acct;
174
175 if (!bio_integrity_prep(bio))
176 return BLK_QC_T_NONE;
177
178 bip = bio_integrity(bio);
179 nsblk = q->queuedata;
180 rw = bio_data_dir(bio);
181 do_acct = nd_iostat_start(bio, &start);
182 bio_for_each_segment(bvec, bio, iter) {
183 unsigned int len = bvec.bv_len;
184
185 BUG_ON(len > PAGE_SIZE);
186 err = nsblk_do_bvec(nsblk, bip, bvec.bv_page, len,
187 bvec.bv_offset, rw, iter.bi_sector);
188 if (err) {
189 dev_dbg(&nsblk->common.dev,
190 "io error in %s sector %lld, len %d,\n",
191 (rw == READ) ? "READ" : "WRITE",
192 (unsigned long long) iter.bi_sector, len);
193 bio->bi_status = errno_to_blk_status(err);
194 break;
195 }
196 }
197 if (do_acct)
198 nd_iostat_end(bio, start);
199
200 bio_endio(bio);
201 return BLK_QC_T_NONE;
202}
203
204static int nsblk_rw_bytes(struct nd_namespace_common *ndns,
205 resource_size_t offset, void *iobuf, size_t n, int rw,
206 unsigned long flags)
207{
208 struct nd_namespace_blk *nsblk = to_nd_namespace_blk(&ndns->dev);
209 struct nd_blk_region *ndbr = to_ndbr(nsblk);
210 resource_size_t dev_offset;
211
212 dev_offset = to_dev_offset(nsblk, offset, n);
213
214 if (unlikely(offset + n > nsblk->size)) {
215 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
216 return -EFAULT;
217 }
218
219 if (dev_offset == SIZE_MAX)
220 return -EIO;
221
222 return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw);
223}
224
225static const struct block_device_operations nd_blk_fops = {
226 .owner = THIS_MODULE,
227 .revalidate_disk = nvdimm_revalidate_disk,
228};
229
230static void nd_blk_release_queue(void *q)
231{
232 blk_cleanup_queue(q);
233}
234
235static void nd_blk_release_disk(void *disk)
236{
237 del_gendisk(disk);
238 put_disk(disk);
239}
240
241static int nsblk_attach_disk(struct nd_namespace_blk *nsblk)
242{
243 struct device *dev = &nsblk->common.dev;
244 resource_size_t available_disk_size;
245 struct request_queue *q;
246 struct gendisk *disk;
247 u64 internal_nlba;
248
249 internal_nlba = div_u64(nsblk->size, nsblk_internal_lbasize(nsblk));
250 available_disk_size = internal_nlba * nsblk_sector_size(nsblk);
251
252 q = blk_alloc_queue(GFP_KERNEL);
253 if (!q)
254 return -ENOMEM;
255 if (devm_add_action_or_reset(dev, nd_blk_release_queue, q))
256 return -ENOMEM;
257
258 blk_queue_make_request(q, nd_blk_make_request);
259 blk_queue_max_hw_sectors(q, UINT_MAX);
260 blk_queue_logical_block_size(q, nsblk_sector_size(nsblk));
261 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
262 q->queuedata = nsblk;
263
264 disk = alloc_disk(0);
265 if (!disk)
266 return -ENOMEM;
267
268 disk->first_minor = 0;
269 disk->fops = &nd_blk_fops;
270 disk->queue = q;
271 disk->flags = GENHD_FL_EXT_DEVT;
272 nvdimm_namespace_disk_name(&nsblk->common, disk->disk_name);
273
274 if (devm_add_action_or_reset(dev, nd_blk_release_disk, disk))
275 return -ENOMEM;
276
277 if (nsblk_meta_size(nsblk)) {
278 int rc = nd_integrity_init(disk, nsblk_meta_size(nsblk));
279
280 if (rc)
281 return rc;
282 }
283
284 set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
285 device_add_disk(dev, disk, NULL);
286 revalidate_disk(disk);
287 return 0;
288}
289
290static int nd_blk_probe(struct device *dev)
291{
292 struct nd_namespace_common *ndns;
293 struct nd_namespace_blk *nsblk;
294
295 ndns = nvdimm_namespace_common_probe(dev);
296 if (IS_ERR(ndns))
297 return PTR_ERR(ndns);
298
299 nsblk = to_nd_namespace_blk(&ndns->dev);
300 nsblk->size = nvdimm_namespace_capacity(ndns);
301 dev_set_drvdata(dev, nsblk);
302
303 ndns->rw_bytes = nsblk_rw_bytes;
304 if (is_nd_btt(dev))
305 return nvdimm_namespace_attach_btt(ndns);
306 else if (nd_btt_probe(dev, ndns) == 0) {
307
308 return -ENXIO;
309 } else
310 return nsblk_attach_disk(nsblk);
311}
312
313static int nd_blk_remove(struct device *dev)
314{
315 if (is_nd_btt(dev))
316 nvdimm_namespace_detach_btt(to_nd_btt(dev));
317 return 0;
318}
319
320static struct nd_device_driver nd_blk_driver = {
321 .probe = nd_blk_probe,
322 .remove = nd_blk_remove,
323 .drv = {
324 .name = "nd_blk",
325 },
326 .type = ND_DRIVER_NAMESPACE_BLK,
327};
328
329static int __init nd_blk_init(void)
330{
331 return nd_driver_register(&nd_blk_driver);
332}
333
334static void __exit nd_blk_exit(void)
335{
336 driver_unregister(&nd_blk_driver.drv);
337}
338
339MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
340MODULE_LICENSE("GPL v2");
341MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK);
342module_init(nd_blk_init);
343module_exit(nd_blk_exit);
344
