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15#include <linux/blkdev.h>
16#include <linux/fs.h>
17#include <linux/genhd.h>
18#include <linux/module.h>
19#include <linux/moduleparam.h>
20#include <linux/nd.h>
21#include <linux/sizes.h>
22#include "nd.h"
23
24static u32 nsblk_meta_size(struct nd_namespace_blk *nsblk)
25{
26 return nsblk->lbasize - ((nsblk->lbasize >= 4096) ? 4096 : 512);
27}
28
29static u32 nsblk_internal_lbasize(struct nd_namespace_blk *nsblk)
30{
31 return roundup(nsblk->lbasize, INT_LBASIZE_ALIGNMENT);
32}
33
34static u32 nsblk_sector_size(struct nd_namespace_blk *nsblk)
35{
36 return nsblk->lbasize - nsblk_meta_size(nsblk);
37}
38
39static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk,
40 resource_size_t ns_offset, unsigned int len)
41{
42 int i;
43
44 for (i = 0; i < nsblk->num_resources; i++) {
45 if (ns_offset < resource_size(nsblk->res[i])) {
46 if (ns_offset + len > resource_size(nsblk->res[i])) {
47 dev_WARN_ONCE(&nsblk->common.dev, 1,
48 "illegal request\n");
49 return SIZE_MAX;
50 }
51 return nsblk->res[i]->start + ns_offset;
52 }
53 ns_offset -= resource_size(nsblk->res[i]);
54 }
55
56 dev_WARN_ONCE(&nsblk->common.dev, 1, "request out of range\n");
57 return SIZE_MAX;
58}
59
60static struct nd_blk_region *to_ndbr(struct nd_namespace_blk *nsblk)
61{
62 struct nd_region *nd_region;
63 struct device *parent;
64
65 parent = nsblk->common.dev.parent;
66 nd_region = container_of(parent, struct nd_region, dev);
67 return container_of(nd_region, struct nd_blk_region, nd_region);
68}
69
70#ifdef CONFIG_BLK_DEV_INTEGRITY
71static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
72 struct bio_integrity_payload *bip, u64 lba, int rw)
73{
74 struct nd_blk_region *ndbr = to_ndbr(nsblk);
75 unsigned int len = nsblk_meta_size(nsblk);
76 resource_size_t dev_offset, ns_offset;
77 u32 internal_lbasize, sector_size;
78 int err = 0;
79
80 internal_lbasize = nsblk_internal_lbasize(nsblk);
81 sector_size = nsblk_sector_size(nsblk);
82 ns_offset = lba * internal_lbasize + sector_size;
83 dev_offset = to_dev_offset(nsblk, ns_offset, len);
84 if (dev_offset == SIZE_MAX)
85 return -EIO;
86
87 while (len) {
88 unsigned int cur_len;
89 struct bio_vec bv;
90 void *iobuf;
91
92 bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
93
94
95
96
97
98
99 cur_len = min(len, bv.bv_len);
100 iobuf = kmap_atomic(bv.bv_page);
101 err = ndbr->do_io(ndbr, dev_offset, iobuf + bv.bv_offset,
102 cur_len, rw);
103 kunmap_atomic(iobuf);
104 if (err)
105 return err;
106
107 len -= cur_len;
108 dev_offset += cur_len;
109 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
110 }
111
112 return err;
113}
114
115#else
116static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
117 struct bio_integrity_payload *bip, u64 lba, int rw)
118{
119 return 0;
120}
121#endif
122
123static int nsblk_do_bvec(struct nd_namespace_blk *nsblk,
124 struct bio_integrity_payload *bip, struct page *page,
125 unsigned int len, unsigned int off, int rw, sector_t sector)
126{
127 struct nd_blk_region *ndbr = to_ndbr(nsblk);
128 resource_size_t dev_offset, ns_offset;
129 u32 internal_lbasize, sector_size;
130 int err = 0;
131 void *iobuf;
132 u64 lba;
133
134 internal_lbasize = nsblk_internal_lbasize(nsblk);
135 sector_size = nsblk_sector_size(nsblk);
136 while (len) {
137 unsigned int cur_len;
138
139
140
141
142
143
144
145 cur_len = bip ? min(len, sector_size) : len;
146
147 lba = div_u64(sector << SECTOR_SHIFT, sector_size);
148 ns_offset = lba * internal_lbasize;
149 dev_offset = to_dev_offset(nsblk, ns_offset, cur_len);
150 if (dev_offset == SIZE_MAX)
151 return -EIO;
152
153 iobuf = kmap_atomic(page);
154 err = ndbr->do_io(ndbr, dev_offset, iobuf + off, cur_len, rw);
155 kunmap_atomic(iobuf);
156 if (err)
157 return err;
158
159 if (bip) {
160 err = nd_blk_rw_integrity(nsblk, bip, lba, rw);
161 if (err)
162 return err;
163 }
164 len -= cur_len;
165 off += cur_len;
166 sector += sector_size >> SECTOR_SHIFT;
167 }
168
169 return err;
170}
171
172static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio)
173{
174 struct bio_integrity_payload *bip;
175 struct nd_namespace_blk *nsblk;
176 struct bvec_iter iter;
177 unsigned long start;
178 struct bio_vec bvec;
179 int err = 0, rw;
180 bool do_acct;
181
182
183
184
185
186
187
188 if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
189 bio->bi_error = -EIO;
190 goto out;
191 }
192
193 bip = bio_integrity(bio);
194 nsblk = q->queuedata;
195 rw = bio_data_dir(bio);
196 do_acct = nd_iostat_start(bio, &start);
197 bio_for_each_segment(bvec, bio, iter) {
198 unsigned int len = bvec.bv_len;
199
200 BUG_ON(len > PAGE_SIZE);
201 err = nsblk_do_bvec(nsblk, bip, bvec.bv_page, len,
202 bvec.bv_offset, rw, iter.bi_sector);
203 if (err) {
204 dev_dbg(&nsblk->common.dev,
205 "io error in %s sector %lld, len %d,\n",
206 (rw == READ) ? "READ" : "WRITE",
207 (unsigned long long) iter.bi_sector, len);
208 bio->bi_error = err;
209 break;
210 }
211 }
212 if (do_acct)
213 nd_iostat_end(bio, start);
214
215 out:
216 bio_endio(bio);
217 return BLK_QC_T_NONE;
218}
219
220static int nsblk_rw_bytes(struct nd_namespace_common *ndns,
221 resource_size_t offset, void *iobuf, size_t n, int rw)
222{
223 struct nd_namespace_blk *nsblk = to_nd_namespace_blk(&ndns->dev);
224 struct nd_blk_region *ndbr = to_ndbr(nsblk);
225 resource_size_t dev_offset;
226
227 dev_offset = to_dev_offset(nsblk, offset, n);
228
229 if (unlikely(offset + n > nsblk->size)) {
230 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
231 return -EFAULT;
232 }
233
234 if (dev_offset == SIZE_MAX)
235 return -EIO;
236
237 return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw);
238}
239
240static const struct block_device_operations nd_blk_fops = {
241 .owner = THIS_MODULE,
242 .revalidate_disk = nvdimm_revalidate_disk,
243};
244
245static void nd_blk_release_queue(void *q)
246{
247 blk_cleanup_queue(q);
248}
249
250static void nd_blk_release_disk(void *disk)
251{
252 del_gendisk(disk);
253 put_disk(disk);
254}
255
256static int nsblk_attach_disk(struct nd_namespace_blk *nsblk)
257{
258 struct device *dev = &nsblk->common.dev;
259 resource_size_t available_disk_size;
260 struct request_queue *q;
261 struct gendisk *disk;
262 u64 internal_nlba;
263
264 internal_nlba = div_u64(nsblk->size, nsblk_internal_lbasize(nsblk));
265 available_disk_size = internal_nlba * nsblk_sector_size(nsblk);
266
267 q = blk_alloc_queue(GFP_KERNEL);
268 if (!q)
269 return -ENOMEM;
270 if (devm_add_action_or_reset(dev, nd_blk_release_queue, q))
271 return -ENOMEM;
272
273 blk_queue_make_request(q, nd_blk_make_request);
274 blk_queue_max_hw_sectors(q, UINT_MAX);
275 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
276 blk_queue_logical_block_size(q, nsblk_sector_size(nsblk));
277 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
278 q->queuedata = nsblk;
279
280 disk = alloc_disk(0);
281 if (!disk)
282 return -ENOMEM;
283
284 disk->first_minor = 0;
285 disk->fops = &nd_blk_fops;
286 disk->queue = q;
287 disk->flags = GENHD_FL_EXT_DEVT;
288 nvdimm_namespace_disk_name(&nsblk->common, disk->disk_name);
289 set_capacity(disk, 0);
290 device_add_disk(dev, disk);
291
292 if (devm_add_action_or_reset(dev, nd_blk_release_disk, disk))
293 return -ENOMEM;
294
295 if (nsblk_meta_size(nsblk)) {
296 int rc = nd_integrity_init(disk, nsblk_meta_size(nsblk));
297
298 if (rc)
299 return rc;
300 }
301
302 set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
303 revalidate_disk(disk);
304 return 0;
305}
306
307static int nd_blk_probe(struct device *dev)
308{
309 struct nd_namespace_common *ndns;
310 struct nd_namespace_blk *nsblk;
311
312 ndns = nvdimm_namespace_common_probe(dev);
313 if (IS_ERR(ndns))
314 return PTR_ERR(ndns);
315
316 nsblk = to_nd_namespace_blk(&ndns->dev);
317 nsblk->size = nvdimm_namespace_capacity(ndns);
318 dev_set_drvdata(dev, nsblk);
319
320 ndns->rw_bytes = nsblk_rw_bytes;
321 if (is_nd_btt(dev))
322 return nvdimm_namespace_attach_btt(ndns);
323 else if (nd_btt_probe(dev, ndns) == 0) {
324
325 return -ENXIO;
326 } else
327 return nsblk_attach_disk(nsblk);
328}
329
330static int nd_blk_remove(struct device *dev)
331{
332 if (is_nd_btt(dev))
333 nvdimm_namespace_detach_btt(to_nd_btt(dev));
334 return 0;
335}
336
337static struct nd_device_driver nd_blk_driver = {
338 .probe = nd_blk_probe,
339 .remove = nd_blk_remove,
340 .drv = {
341 .name = "nd_blk",
342 },
343 .type = ND_DRIVER_NAMESPACE_BLK,
344};
345
346static int __init nd_blk_init(void)
347{
348 return nd_driver_register(&nd_blk_driver);
349}
350
351static void __exit nd_blk_exit(void)
352{
353 driver_unregister(&nd_blk_driver.drv);
354}
355
356MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
357MODULE_LICENSE("GPL v2");
358MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK);
359module_init(nd_blk_init);
360module_exit(nd_blk_exit);
361
