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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
24struct nd_blk_device {
25 struct request_queue *queue;
26 struct gendisk *disk;
27 struct nd_namespace_blk *nsblk;
28 struct nd_blk_region *ndbr;
29 size_t disk_size;
30 u32 sector_size;
31 u32 internal_lbasize;
32};
33
34static u32 nd_blk_meta_size(struct nd_blk_device *blk_dev)
35{
36 return blk_dev->nsblk->lbasize - blk_dev->sector_size;
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
60#ifdef CONFIG_BLK_DEV_INTEGRITY
61static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
62 struct bio_integrity_payload *bip, u64 lba,
63 int rw)
64{
65 unsigned int len = nd_blk_meta_size(blk_dev);
66 resource_size_t dev_offset, ns_offset;
67 struct nd_namespace_blk *nsblk;
68 struct nd_blk_region *ndbr;
69 int err = 0;
70
71 nsblk = blk_dev->nsblk;
72 ndbr = blk_dev->ndbr;
73 ns_offset = lba * blk_dev->internal_lbasize + blk_dev->sector_size;
74 dev_offset = to_dev_offset(nsblk, ns_offset, len);
75 if (dev_offset == SIZE_MAX)
76 return -EIO;
77
78 while (len) {
79 unsigned int cur_len;
80 struct bio_vec bv;
81 void *iobuf;
82
83 bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
84
85
86
87
88
89
90 cur_len = min(len, bv.bv_len);
91 iobuf = kmap_atomic(bv.bv_page);
92 err = ndbr->do_io(ndbr, dev_offset, iobuf + bv.bv_offset,
93 cur_len, rw);
94 kunmap_atomic(iobuf);
95 if (err)
96 return err;
97
98 len -= cur_len;
99 dev_offset += cur_len;
100 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
101 }
102
103 return err;
104}
105
106#else
107static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
108 struct bio_integrity_payload *bip, u64 lba,
109 int rw)
110{
111 return 0;
112}
113#endif
114
115static int nd_blk_do_bvec(struct nd_blk_device *blk_dev,
116 struct bio_integrity_payload *bip, struct page *page,
117 unsigned int len, unsigned int off, int rw,
118 sector_t sector)
119{
120 struct nd_blk_region *ndbr = blk_dev->ndbr;
121 resource_size_t dev_offset, ns_offset;
122 int err = 0;
123 void *iobuf;
124 u64 lba;
125
126 while (len) {
127 unsigned int cur_len;
128
129
130
131
132
133
134
135 cur_len = bip ? min(len, blk_dev->sector_size) : len;
136
137 lba = div_u64(sector << SECTOR_SHIFT, blk_dev->sector_size);
138 ns_offset = lba * blk_dev->internal_lbasize;
139 dev_offset = to_dev_offset(blk_dev->nsblk, ns_offset, cur_len);
140 if (dev_offset == SIZE_MAX)
141 return -EIO;
142
143 iobuf = kmap_atomic(page);
144 err = ndbr->do_io(ndbr, dev_offset, iobuf + off, cur_len, rw);
145 kunmap_atomic(iobuf);
146 if (err)
147 return err;
148
149 if (bip) {
150 err = nd_blk_rw_integrity(blk_dev, bip, lba, rw);
151 if (err)
152 return err;
153 }
154 len -= cur_len;
155 off += cur_len;
156 sector += blk_dev->sector_size >> SECTOR_SHIFT;
157 }
158
159 return err;
160}
161
162static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio)
163{
164 struct block_device *bdev = bio->bi_bdev;
165 struct gendisk *disk = bdev->bd_disk;
166 struct bio_integrity_payload *bip;
167 struct nd_blk_device *blk_dev;
168 struct bvec_iter iter;
169 unsigned long start;
170 struct bio_vec bvec;
171 int err = 0, rw;
172 bool do_acct;
173
174
175
176
177
178
179
180 if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
181 bio->bi_error = -EIO;
182 goto out;
183 }
184
185 bip = bio_integrity(bio);
186 blk_dev = disk->private_data;
187 rw = bio_data_dir(bio);
188 do_acct = nd_iostat_start(bio, &start);
189 bio_for_each_segment(bvec, bio, iter) {
190 unsigned int len = bvec.bv_len;
191
192 BUG_ON(len > PAGE_SIZE);
193 err = nd_blk_do_bvec(blk_dev, bip, bvec.bv_page, len,
194 bvec.bv_offset, rw, iter.bi_sector);
195 if (err) {
196 dev_info(&blk_dev->nsblk->common.dev,
197 "io error in %s sector %lld, len %d,\n",
198 (rw == READ) ? "READ" : "WRITE",
199 (unsigned long long) iter.bi_sector, len);
200 bio->bi_error = err;
201 break;
202 }
203 }
204 if (do_acct)
205 nd_iostat_end(bio, start);
206
207 out:
208 bio_endio(bio);
209 return BLK_QC_T_NONE;
210}
211
212static int nd_blk_rw_bytes(struct nd_namespace_common *ndns,
213 resource_size_t offset, void *iobuf, size_t n, int rw)
214{
215 struct nd_blk_device *blk_dev = dev_get_drvdata(ndns->claim);
216 struct nd_namespace_blk *nsblk = blk_dev->nsblk;
217 struct nd_blk_region *ndbr = blk_dev->ndbr;
218 resource_size_t dev_offset;
219
220 dev_offset = to_dev_offset(nsblk, offset, n);
221
222 if (unlikely(offset + n > blk_dev->disk_size)) {
223 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
224 return -EFAULT;
225 }
226
227 if (dev_offset == SIZE_MAX)
228 return -EIO;
229
230 return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw);
231}
232
233static const struct block_device_operations nd_blk_fops = {
234 .owner = THIS_MODULE,
235 .revalidate_disk = nvdimm_revalidate_disk,
236};
237
238static int nd_blk_attach_disk(struct nd_namespace_common *ndns,
239 struct nd_blk_device *blk_dev)
240{
241 resource_size_t available_disk_size;
242 struct gendisk *disk;
243 u64 internal_nlba;
244
245 internal_nlba = div_u64(blk_dev->disk_size, blk_dev->internal_lbasize);
246 available_disk_size = internal_nlba * blk_dev->sector_size;
247
248 blk_dev->queue = blk_alloc_queue(GFP_KERNEL);
249 if (!blk_dev->queue)
250 return -ENOMEM;
251
252 blk_queue_make_request(blk_dev->queue, nd_blk_make_request);
253 blk_queue_max_hw_sectors(blk_dev->queue, UINT_MAX);
254 blk_queue_bounce_limit(blk_dev->queue, BLK_BOUNCE_ANY);
255 blk_queue_logical_block_size(blk_dev->queue, blk_dev->sector_size);
256 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, blk_dev->queue);
257
258 disk = blk_dev->disk = alloc_disk(0);
259 if (!disk) {
260 blk_cleanup_queue(blk_dev->queue);
261 return -ENOMEM;
262 }
263
264 disk->driverfs_dev = &ndns->dev;
265 disk->first_minor = 0;
266 disk->fops = &nd_blk_fops;
267 disk->private_data = blk_dev;
268 disk->queue = blk_dev->queue;
269 disk->flags = GENHD_FL_EXT_DEVT;
270 nvdimm_namespace_disk_name(ndns, disk->disk_name);
271 set_capacity(disk, 0);
272 add_disk(disk);
273
274 if (nd_blk_meta_size(blk_dev)) {
275 int rc = nd_integrity_init(disk, nd_blk_meta_size(blk_dev));
276
277 if (rc) {
278 del_gendisk(disk);
279 put_disk(disk);
280 blk_cleanup_queue(blk_dev->queue);
281 return rc;
282 }
283 }
284
285 set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
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 struct nd_blk_device *blk_dev;
295 int rc;
296
297 ndns = nvdimm_namespace_common_probe(dev);
298 if (IS_ERR(ndns))
299 return PTR_ERR(ndns);
300
301 blk_dev = kzalloc(sizeof(*blk_dev), GFP_KERNEL);
302 if (!blk_dev)
303 return -ENOMEM;
304
305 nsblk = to_nd_namespace_blk(&ndns->dev);
306 blk_dev->disk_size = nvdimm_namespace_capacity(ndns);
307 blk_dev->ndbr = to_nd_blk_region(dev->parent);
308 blk_dev->nsblk = to_nd_namespace_blk(&ndns->dev);
309 blk_dev->internal_lbasize = roundup(nsblk->lbasize,
310 INT_LBASIZE_ALIGNMENT);
311 blk_dev->sector_size = ((nsblk->lbasize >= 4096) ? 4096 : 512);
312 dev_set_drvdata(dev, blk_dev);
313
314 ndns->rw_bytes = nd_blk_rw_bytes;
315 if (is_nd_btt(dev))
316 rc = nvdimm_namespace_attach_btt(ndns);
317 else if (nd_btt_probe(ndns, blk_dev) == 0) {
318
319 rc = -ENXIO;
320 } else
321 rc = nd_blk_attach_disk(ndns, blk_dev);
322 if (rc)
323 kfree(blk_dev);
324 return rc;
325}
326
327static void nd_blk_detach_disk(struct nd_blk_device *blk_dev)
328{
329 del_gendisk(blk_dev->disk);
330 put_disk(blk_dev->disk);
331 blk_cleanup_queue(blk_dev->queue);
332}
333
334static int nd_blk_remove(struct device *dev)
335{
336 struct nd_blk_device *blk_dev = dev_get_drvdata(dev);
337
338 if (is_nd_btt(dev))
339 nvdimm_namespace_detach_btt(to_nd_btt(dev)->ndns);
340 else
341 nd_blk_detach_disk(blk_dev);
342 kfree(blk_dev);
343
344 return 0;
345}
346
347static struct nd_device_driver nd_blk_driver = {
348 .probe = nd_blk_probe,
349 .remove = nd_blk_remove,
350 .drv = {
351 .name = "nd_blk",
352 },
353 .type = ND_DRIVER_NAMESPACE_BLK,
354};
355
356static int __init nd_blk_init(void)
357{
358 return nd_driver_register(&nd_blk_driver);
359}
360
361static void __exit nd_blk_exit(void)
362{
363 driver_unregister(&nd_blk_driver.drv);
364}
365
366MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
367MODULE_LICENSE("GPL v2");
368MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK);
369module_init(nd_blk_init);
370module_exit(nd_blk_exit);
371
