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1 | /* |
2 | * Block Translation Table | |
3 | * Copyright (c) 2014-2015, Intel Corporation. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms and conditions of the GNU General Public License, | |
7 | * version 2, as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
12 | * more details. | |
13 | */ | |
14 | #include <linux/highmem.h> | |
15 | #include <linux/debugfs.h> | |
16 | #include <linux/blkdev.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/device.h> | |
19 | #include <linux/mutex.h> | |
20 | #include <linux/hdreg.h> | |
21 | #include <linux/genhd.h> | |
22 | #include <linux/sizes.h> | |
23 | #include <linux/ndctl.h> | |
24 | #include <linux/fs.h> | |
25 | #include <linux/nd.h> | |
26 | #include "btt.h" | |
27 | #include "nd.h" | |
28 | ||
29 | enum log_ent_request { | |
30 | LOG_NEW_ENT = 0, | |
31 | LOG_OLD_ENT | |
32 | }; | |
33 | ||
34 | static int btt_major; | |
35 | ||
36 | static int arena_read_bytes(struct arena_info *arena, resource_size_t offset, | |
37 | void *buf, size_t n) | |
38 | { | |
39 | struct nd_btt *nd_btt = arena->nd_btt; | |
40 | struct nd_namespace_common *ndns = nd_btt->ndns; | |
41 | ||
42 | /* arena offsets are 4K from the base of the device */ | |
43 | offset += SZ_4K; | |
44 | return nvdimm_read_bytes(ndns, offset, buf, n); | |
45 | } | |
46 | ||
47 | static int arena_write_bytes(struct arena_info *arena, resource_size_t offset, | |
48 | void *buf, size_t n) | |
49 | { | |
50 | struct nd_btt *nd_btt = arena->nd_btt; | |
51 | struct nd_namespace_common *ndns = nd_btt->ndns; | |
52 | ||
53 | /* arena offsets are 4K from the base of the device */ | |
54 | offset += SZ_4K; | |
55 | return nvdimm_write_bytes(ndns, offset, buf, n); | |
56 | } | |
57 | ||
58 | static int btt_info_write(struct arena_info *arena, struct btt_sb *super) | |
59 | { | |
60 | int ret; | |
61 | ||
62 | ret = arena_write_bytes(arena, arena->info2off, super, | |
63 | sizeof(struct btt_sb)); | |
64 | if (ret) | |
65 | return ret; | |
66 | ||
67 | return arena_write_bytes(arena, arena->infooff, super, | |
68 | sizeof(struct btt_sb)); | |
69 | } | |
70 | ||
71 | static int btt_info_read(struct arena_info *arena, struct btt_sb *super) | |
72 | { | |
73 | WARN_ON(!super); | |
74 | return arena_read_bytes(arena, arena->infooff, super, | |
75 | sizeof(struct btt_sb)); | |
76 | } | |
77 | ||
78 | /* | |
79 | * 'raw' version of btt_map write | |
80 | * Assumptions: | |
81 | * mapping is in little-endian | |
82 | * mapping contains 'E' and 'Z' flags as desired | |
83 | */ | |
84 | static int __btt_map_write(struct arena_info *arena, u32 lba, __le32 mapping) | |
85 | { | |
86 | u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE); | |
87 | ||
88 | WARN_ON(lba >= arena->external_nlba); | |
89 | return arena_write_bytes(arena, ns_off, &mapping, MAP_ENT_SIZE); | |
90 | } | |
91 | ||
92 | static int btt_map_write(struct arena_info *arena, u32 lba, u32 mapping, | |
93 | u32 z_flag, u32 e_flag) | |
94 | { | |
95 | u32 ze; | |
96 | __le32 mapping_le; | |
97 | ||
98 | /* | |
99 | * This 'mapping' is supposed to be just the LBA mapping, without | |
100 | * any flags set, so strip the flag bits. | |
101 | */ | |
102 | mapping &= MAP_LBA_MASK; | |
103 | ||
104 | ze = (z_flag << 1) + e_flag; | |
105 | switch (ze) { | |
106 | case 0: | |
107 | /* | |
108 | * We want to set neither of the Z or E flags, and | |
109 | * in the actual layout, this means setting the bit | |
110 | * positions of both to '1' to indicate a 'normal' | |
111 | * map entry | |
112 | */ | |
113 | mapping |= MAP_ENT_NORMAL; | |
114 | break; | |
115 | case 1: | |
116 | mapping |= (1 << MAP_ERR_SHIFT); | |
117 | break; | |
118 | case 2: | |
119 | mapping |= (1 << MAP_TRIM_SHIFT); | |
120 | break; | |
121 | default: | |
122 | /* | |
123 | * The case where Z and E are both sent in as '1' could be | |
124 | * construed as a valid 'normal' case, but we decide not to, | |
125 | * to avoid confusion | |
126 | */ | |
127 | WARN_ONCE(1, "Invalid use of Z and E flags\n"); | |
128 | return -EIO; | |
129 | } | |
130 | ||
131 | mapping_le = cpu_to_le32(mapping); | |
132 | return __btt_map_write(arena, lba, mapping_le); | |
133 | } | |
134 | ||
135 | static int btt_map_read(struct arena_info *arena, u32 lba, u32 *mapping, | |
136 | int *trim, int *error) | |
137 | { | |
138 | int ret; | |
139 | __le32 in; | |
140 | u32 raw_mapping, postmap, ze, z_flag, e_flag; | |
141 | u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE); | |
142 | ||
143 | WARN_ON(lba >= arena->external_nlba); | |
144 | ||
145 | ret = arena_read_bytes(arena, ns_off, &in, MAP_ENT_SIZE); | |
146 | if (ret) | |
147 | return ret; | |
148 | ||
149 | raw_mapping = le32_to_cpu(in); | |
150 | ||
151 | z_flag = (raw_mapping & MAP_TRIM_MASK) >> MAP_TRIM_SHIFT; | |
152 | e_flag = (raw_mapping & MAP_ERR_MASK) >> MAP_ERR_SHIFT; | |
153 | ze = (z_flag << 1) + e_flag; | |
154 | postmap = raw_mapping & MAP_LBA_MASK; | |
155 | ||
156 | /* Reuse the {z,e}_flag variables for *trim and *error */ | |
157 | z_flag = 0; | |
158 | e_flag = 0; | |
159 | ||
160 | switch (ze) { | |
161 | case 0: | |
162 | /* Initial state. Return postmap = premap */ | |
163 | *mapping = lba; | |
164 | break; | |
165 | case 1: | |
166 | *mapping = postmap; | |
167 | e_flag = 1; | |
168 | break; | |
169 | case 2: | |
170 | *mapping = postmap; | |
171 | z_flag = 1; | |
172 | break; | |
173 | case 3: | |
174 | *mapping = postmap; | |
175 | break; | |
176 | default: | |
177 | return -EIO; | |
178 | } | |
179 | ||
180 | if (trim) | |
181 | *trim = z_flag; | |
182 | if (error) | |
183 | *error = e_flag; | |
184 | ||
185 | return ret; | |
186 | } | |
187 | ||
188 | static int btt_log_read_pair(struct arena_info *arena, u32 lane, | |
189 | struct log_entry *ent) | |
190 | { | |
191 | WARN_ON(!ent); | |
192 | return arena_read_bytes(arena, | |
193 | arena->logoff + (2 * lane * LOG_ENT_SIZE), ent, | |
194 | 2 * LOG_ENT_SIZE); | |
195 | } | |
196 | ||
197 | static struct dentry *debugfs_root; | |
198 | ||
199 | static void arena_debugfs_init(struct arena_info *a, struct dentry *parent, | |
200 | int idx) | |
201 | { | |
202 | char dirname[32]; | |
203 | struct dentry *d; | |
204 | ||
205 | /* If for some reason, parent bttN was not created, exit */ | |
206 | if (!parent) | |
207 | return; | |
208 | ||
209 | snprintf(dirname, 32, "arena%d", idx); | |
210 | d = debugfs_create_dir(dirname, parent); | |
211 | if (IS_ERR_OR_NULL(d)) | |
212 | return; | |
213 | a->debugfs_dir = d; | |
214 | ||
215 | debugfs_create_x64("size", S_IRUGO, d, &a->size); | |
216 | debugfs_create_x64("external_lba_start", S_IRUGO, d, | |
217 | &a->external_lba_start); | |
218 | debugfs_create_x32("internal_nlba", S_IRUGO, d, &a->internal_nlba); | |
219 | debugfs_create_u32("internal_lbasize", S_IRUGO, d, | |
220 | &a->internal_lbasize); | |
221 | debugfs_create_x32("external_nlba", S_IRUGO, d, &a->external_nlba); | |
222 | debugfs_create_u32("external_lbasize", S_IRUGO, d, | |
223 | &a->external_lbasize); | |
224 | debugfs_create_u32("nfree", S_IRUGO, d, &a->nfree); | |
225 | debugfs_create_u16("version_major", S_IRUGO, d, &a->version_major); | |
226 | debugfs_create_u16("version_minor", S_IRUGO, d, &a->version_minor); | |
227 | debugfs_create_x64("nextoff", S_IRUGO, d, &a->nextoff); | |
228 | debugfs_create_x64("infooff", S_IRUGO, d, &a->infooff); | |
229 | debugfs_create_x64("dataoff", S_IRUGO, d, &a->dataoff); | |
230 | debugfs_create_x64("mapoff", S_IRUGO, d, &a->mapoff); | |
231 | debugfs_create_x64("logoff", S_IRUGO, d, &a->logoff); | |
232 | debugfs_create_x64("info2off", S_IRUGO, d, &a->info2off); | |
233 | debugfs_create_x32("flags", S_IRUGO, d, &a->flags); | |
234 | } | |
235 | ||
236 | static void btt_debugfs_init(struct btt *btt) | |
237 | { | |
238 | int i = 0; | |
239 | struct arena_info *arena; | |
240 | ||
241 | btt->debugfs_dir = debugfs_create_dir(dev_name(&btt->nd_btt->dev), | |
242 | debugfs_root); | |
243 | if (IS_ERR_OR_NULL(btt->debugfs_dir)) | |
244 | return; | |
245 | ||
246 | list_for_each_entry(arena, &btt->arena_list, list) { | |
247 | arena_debugfs_init(arena, btt->debugfs_dir, i); | |
248 | i++; | |
249 | } | |
250 | } | |
251 | ||
252 | /* | |
253 | * This function accepts two log entries, and uses the | |
254 | * sequence number to find the 'older' entry. | |
255 | * It also updates the sequence number in this old entry to | |
256 | * make it the 'new' one if the mark_flag is set. | |
257 | * Finally, it returns which of the entries was the older one. | |
258 | * | |
259 | * TODO The logic feels a bit kludge-y. make it better.. | |
260 | */ | |
261 | static int btt_log_get_old(struct log_entry *ent) | |
262 | { | |
263 | int old; | |
264 | ||
265 | /* | |
266 | * the first ever time this is seen, the entry goes into [0] | |
267 | * the next time, the following logic works out to put this | |
268 | * (next) entry into [1] | |
269 | */ | |
270 | if (ent[0].seq == 0) { | |
271 | ent[0].seq = cpu_to_le32(1); | |
272 | return 0; | |
273 | } | |
274 | ||
275 | if (ent[0].seq == ent[1].seq) | |
276 | return -EINVAL; | |
277 | if (le32_to_cpu(ent[0].seq) + le32_to_cpu(ent[1].seq) > 5) | |
278 | return -EINVAL; | |
279 | ||
280 | if (le32_to_cpu(ent[0].seq) < le32_to_cpu(ent[1].seq)) { | |
281 | if (le32_to_cpu(ent[1].seq) - le32_to_cpu(ent[0].seq) == 1) | |
282 | old = 0; | |
283 | else | |
284 | old = 1; | |
285 | } else { | |
286 | if (le32_to_cpu(ent[0].seq) - le32_to_cpu(ent[1].seq) == 1) | |
287 | old = 1; | |
288 | else | |
289 | old = 0; | |
290 | } | |
291 | ||
292 | return old; | |
293 | } | |
294 | ||
295 | static struct device *to_dev(struct arena_info *arena) | |
296 | { | |
297 | return &arena->nd_btt->dev; | |
298 | } | |
299 | ||
300 | /* | |
301 | * This function copies the desired (old/new) log entry into ent if | |
302 | * it is not NULL. It returns the sub-slot number (0 or 1) | |
303 | * where the desired log entry was found. Negative return values | |
304 | * indicate errors. | |
305 | */ | |
306 | static int btt_log_read(struct arena_info *arena, u32 lane, | |
307 | struct log_entry *ent, int old_flag) | |
308 | { | |
309 | int ret; | |
310 | int old_ent, ret_ent; | |
311 | struct log_entry log[2]; | |
312 | ||
313 | ret = btt_log_read_pair(arena, lane, log); | |
314 | if (ret) | |
315 | return -EIO; | |
316 | ||
317 | old_ent = btt_log_get_old(log); | |
318 | if (old_ent < 0 || old_ent > 1) { | |
319 | dev_info(to_dev(arena), | |
320 | "log corruption (%d): lane %d seq [%d, %d]\n", | |
321 | old_ent, lane, log[0].seq, log[1].seq); | |
322 | /* TODO set error state? */ | |
323 | return -EIO; | |
324 | } | |
325 | ||
326 | ret_ent = (old_flag ? old_ent : (1 - old_ent)); | |
327 | ||
328 | if (ent != NULL) | |
329 | memcpy(ent, &log[ret_ent], LOG_ENT_SIZE); | |
330 | ||
331 | return ret_ent; | |
332 | } | |
333 | ||
334 | /* | |
335 | * This function commits a log entry to media | |
336 | * It does _not_ prepare the freelist entry for the next write | |
337 | * btt_flog_write is the wrapper for updating the freelist elements | |
338 | */ | |
339 | static int __btt_log_write(struct arena_info *arena, u32 lane, | |
340 | u32 sub, struct log_entry *ent) | |
341 | { | |
342 | int ret; | |
343 | /* | |
344 | * Ignore the padding in log_entry for calculating log_half. | |
345 | * The entry is 'committed' when we write the sequence number, | |
346 | * and we want to ensure that that is the last thing written. | |
347 | * We don't bother writing the padding as that would be extra | |
348 | * media wear and write amplification | |
349 | */ | |
350 | unsigned int log_half = (LOG_ENT_SIZE - 2 * sizeof(u64)) / 2; | |
351 | u64 ns_off = arena->logoff + (((2 * lane) + sub) * LOG_ENT_SIZE); | |
352 | void *src = ent; | |
353 | ||
354 | /* split the 16B write into atomic, durable halves */ | |
355 | ret = arena_write_bytes(arena, ns_off, src, log_half); | |
356 | if (ret) | |
357 | return ret; | |
358 | ||
359 | ns_off += log_half; | |
360 | src += log_half; | |
361 | return arena_write_bytes(arena, ns_off, src, log_half); | |
362 | } | |
363 | ||
364 | static int btt_flog_write(struct arena_info *arena, u32 lane, u32 sub, | |
365 | struct log_entry *ent) | |
366 | { | |
367 | int ret; | |
368 | ||
369 | ret = __btt_log_write(arena, lane, sub, ent); | |
370 | if (ret) | |
371 | return ret; | |
372 | ||
373 | /* prepare the next free entry */ | |
374 | arena->freelist[lane].sub = 1 - arena->freelist[lane].sub; | |
375 | if (++(arena->freelist[lane].seq) == 4) | |
376 | arena->freelist[lane].seq = 1; | |
377 | arena->freelist[lane].block = le32_to_cpu(ent->old_map); | |
378 | ||
379 | return ret; | |
380 | } | |
381 | ||
382 | /* | |
383 | * This function initializes the BTT map to the initial state, which is | |
384 | * all-zeroes, and indicates an identity mapping | |
385 | */ | |
386 | static int btt_map_init(struct arena_info *arena) | |
387 | { | |
388 | int ret = -EINVAL; | |
389 | void *zerobuf; | |
390 | size_t offset = 0; | |
391 | size_t chunk_size = SZ_2M; | |
392 | size_t mapsize = arena->logoff - arena->mapoff; | |
393 | ||
394 | zerobuf = kzalloc(chunk_size, GFP_KERNEL); | |
395 | if (!zerobuf) | |
396 | return -ENOMEM; | |
397 | ||
398 | while (mapsize) { | |
399 | size_t size = min(mapsize, chunk_size); | |
400 | ||
401 | ret = arena_write_bytes(arena, arena->mapoff + offset, zerobuf, | |
402 | size); | |
403 | if (ret) | |
404 | goto free; | |
405 | ||
406 | offset += size; | |
407 | mapsize -= size; | |
408 | cond_resched(); | |
409 | } | |
410 | ||
411 | free: | |
412 | kfree(zerobuf); | |
413 | return ret; | |
414 | } | |
415 | ||
416 | /* | |
417 | * This function initializes the BTT log with 'fake' entries pointing | |
418 | * to the initial reserved set of blocks as being free | |
419 | */ | |
420 | static int btt_log_init(struct arena_info *arena) | |
421 | { | |
422 | int ret; | |
423 | u32 i; | |
424 | struct log_entry log, zerolog; | |
425 | ||
426 | memset(&zerolog, 0, sizeof(zerolog)); | |
427 | ||
428 | for (i = 0; i < arena->nfree; i++) { | |
429 | log.lba = cpu_to_le32(i); | |
430 | log.old_map = cpu_to_le32(arena->external_nlba + i); | |
431 | log.new_map = cpu_to_le32(arena->external_nlba + i); | |
432 | log.seq = cpu_to_le32(LOG_SEQ_INIT); | |
433 | ret = __btt_log_write(arena, i, 0, &log); | |
434 | if (ret) | |
435 | return ret; | |
436 | ret = __btt_log_write(arena, i, 1, &zerolog); | |
437 | if (ret) | |
438 | return ret; | |
439 | } | |
440 | ||
441 | return 0; | |
442 | } | |
443 | ||
444 | static int btt_freelist_init(struct arena_info *arena) | |
445 | { | |
446 | int old, new, ret; | |
447 | u32 i, map_entry; | |
448 | struct log_entry log_new, log_old; | |
449 | ||
450 | arena->freelist = kcalloc(arena->nfree, sizeof(struct free_entry), | |
451 | GFP_KERNEL); | |
452 | if (!arena->freelist) | |
453 | return -ENOMEM; | |
454 | ||
455 | for (i = 0; i < arena->nfree; i++) { | |
456 | old = btt_log_read(arena, i, &log_old, LOG_OLD_ENT); | |
457 | if (old < 0) | |
458 | return old; | |
459 | ||
460 | new = btt_log_read(arena, i, &log_new, LOG_NEW_ENT); | |
461 | if (new < 0) | |
462 | return new; | |
463 | ||
464 | /* sub points to the next one to be overwritten */ | |
465 | arena->freelist[i].sub = 1 - new; | |
466 | arena->freelist[i].seq = nd_inc_seq(le32_to_cpu(log_new.seq)); | |
467 | arena->freelist[i].block = le32_to_cpu(log_new.old_map); | |
468 | ||
469 | /* This implies a newly created or untouched flog entry */ | |
470 | if (log_new.old_map == log_new.new_map) | |
471 | continue; | |
472 | ||
473 | /* Check if map recovery is needed */ | |
474 | ret = btt_map_read(arena, le32_to_cpu(log_new.lba), &map_entry, | |
475 | NULL, NULL); | |
476 | if (ret) | |
477 | return ret; | |
478 | if ((le32_to_cpu(log_new.new_map) != map_entry) && | |
479 | (le32_to_cpu(log_new.old_map) == map_entry)) { | |
480 | /* | |
481 | * Last transaction wrote the flog, but wasn't able | |
482 | * to complete the map write. So fix up the map. | |
483 | */ | |
484 | ret = btt_map_write(arena, le32_to_cpu(log_new.lba), | |
485 | le32_to_cpu(log_new.new_map), 0, 0); | |
486 | if (ret) | |
487 | return ret; | |
488 | } | |
489 | ||
490 | } | |
491 | ||
492 | return 0; | |
493 | } | |
494 | ||
495 | static int btt_rtt_init(struct arena_info *arena) | |
496 | { | |
497 | arena->rtt = kcalloc(arena->nfree, sizeof(u32), GFP_KERNEL); | |
498 | if (arena->rtt == NULL) | |
499 | return -ENOMEM; | |
500 | ||
501 | return 0; | |
502 | } | |
503 | ||
504 | static int btt_maplocks_init(struct arena_info *arena) | |
505 | { | |
506 | u32 i; | |
507 | ||
508 | arena->map_locks = kcalloc(arena->nfree, sizeof(struct aligned_lock), | |
509 | GFP_KERNEL); | |
510 | if (!arena->map_locks) | |
511 | return -ENOMEM; | |
512 | ||
513 | for (i = 0; i < arena->nfree; i++) | |
514 | spin_lock_init(&arena->map_locks[i].lock); | |
515 | ||
516 | return 0; | |
517 | } | |
518 | ||
519 | static struct arena_info *alloc_arena(struct btt *btt, size_t size, | |
520 | size_t start, size_t arena_off) | |
521 | { | |
522 | struct arena_info *arena; | |
523 | u64 logsize, mapsize, datasize; | |
524 | u64 available = size; | |
525 | ||
526 | arena = kzalloc(sizeof(struct arena_info), GFP_KERNEL); | |
527 | if (!arena) | |
528 | return NULL; | |
529 | arena->nd_btt = btt->nd_btt; | |
530 | ||
531 | if (!size) | |
532 | return arena; | |
533 | ||
534 | arena->size = size; | |
535 | arena->external_lba_start = start; | |
536 | arena->external_lbasize = btt->lbasize; | |
537 | arena->internal_lbasize = roundup(arena->external_lbasize, | |
538 | INT_LBASIZE_ALIGNMENT); | |
539 | arena->nfree = BTT_DEFAULT_NFREE; | |
540 | arena->version_major = 1; | |
541 | arena->version_minor = 1; | |
542 | ||
543 | if (available % BTT_PG_SIZE) | |
544 | available -= (available % BTT_PG_SIZE); | |
545 | ||
546 | /* Two pages are reserved for the super block and its copy */ | |
547 | available -= 2 * BTT_PG_SIZE; | |
548 | ||
549 | /* The log takes a fixed amount of space based on nfree */ | |
550 | logsize = roundup(2 * arena->nfree * sizeof(struct log_entry), | |
551 | BTT_PG_SIZE); | |
552 | available -= logsize; | |
553 | ||
554 | /* Calculate optimal split between map and data area */ | |
555 | arena->internal_nlba = div_u64(available - BTT_PG_SIZE, | |
556 | arena->internal_lbasize + MAP_ENT_SIZE); | |
557 | arena->external_nlba = arena->internal_nlba - arena->nfree; | |
558 | ||
559 | mapsize = roundup((arena->external_nlba * MAP_ENT_SIZE), BTT_PG_SIZE); | |
560 | datasize = available - mapsize; | |
561 | ||
562 | /* 'Absolute' values, relative to start of storage space */ | |
563 | arena->infooff = arena_off; | |
564 | arena->dataoff = arena->infooff + BTT_PG_SIZE; | |
565 | arena->mapoff = arena->dataoff + datasize; | |
566 | arena->logoff = arena->mapoff + mapsize; | |
567 | arena->info2off = arena->logoff + logsize; | |
568 | return arena; | |
569 | } | |
570 | ||
571 | static void free_arenas(struct btt *btt) | |
572 | { | |
573 | struct arena_info *arena, *next; | |
574 | ||
575 | list_for_each_entry_safe(arena, next, &btt->arena_list, list) { | |
576 | list_del(&arena->list); | |
577 | kfree(arena->rtt); | |
578 | kfree(arena->map_locks); | |
579 | kfree(arena->freelist); | |
580 | debugfs_remove_recursive(arena->debugfs_dir); | |
581 | kfree(arena); | |
582 | } | |
583 | } | |
584 | ||
585 | /* | |
586 | * This function checks if the metadata layout is valid and error free | |
587 | */ | |
588 | static int arena_is_valid(struct arena_info *arena, struct btt_sb *super, | |
589 | u8 *uuid, u32 lbasize) | |
590 | { | |
591 | u64 checksum; | |
592 | ||
593 | if (memcmp(super->uuid, uuid, 16)) | |
594 | return 0; | |
595 | ||
596 | checksum = le64_to_cpu(super->checksum); | |
597 | super->checksum = 0; | |
598 | if (checksum != nd_btt_sb_checksum(super)) | |
599 | return 0; | |
600 | super->checksum = cpu_to_le64(checksum); | |
601 | ||
602 | if (lbasize != le32_to_cpu(super->external_lbasize)) | |
603 | return 0; | |
604 | ||
605 | /* TODO: figure out action for this */ | |
606 | if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0) | |
607 | dev_info(to_dev(arena), "Found arena with an error flag\n"); | |
608 | ||
609 | return 1; | |
610 | } | |
611 | ||
612 | /* | |
613 | * This function reads an existing valid btt superblock and | |
614 | * populates the corresponding arena_info struct | |
615 | */ | |
616 | static void parse_arena_meta(struct arena_info *arena, struct btt_sb *super, | |
617 | u64 arena_off) | |
618 | { | |
619 | arena->internal_nlba = le32_to_cpu(super->internal_nlba); | |
620 | arena->internal_lbasize = le32_to_cpu(super->internal_lbasize); | |
621 | arena->external_nlba = le32_to_cpu(super->external_nlba); | |
622 | arena->external_lbasize = le32_to_cpu(super->external_lbasize); | |
623 | arena->nfree = le32_to_cpu(super->nfree); | |
624 | arena->version_major = le16_to_cpu(super->version_major); | |
625 | arena->version_minor = le16_to_cpu(super->version_minor); | |
626 | ||
627 | arena->nextoff = (super->nextoff == 0) ? 0 : (arena_off + | |
628 | le64_to_cpu(super->nextoff)); | |
629 | arena->infooff = arena_off; | |
630 | arena->dataoff = arena_off + le64_to_cpu(super->dataoff); | |
631 | arena->mapoff = arena_off + le64_to_cpu(super->mapoff); | |
632 | arena->logoff = arena_off + le64_to_cpu(super->logoff); | |
633 | arena->info2off = arena_off + le64_to_cpu(super->info2off); | |
634 | ||
635 | arena->size = (super->nextoff > 0) ? (le64_to_cpu(super->nextoff)) : | |
636 | (arena->info2off - arena->infooff + BTT_PG_SIZE); | |
637 | ||
638 | arena->flags = le32_to_cpu(super->flags); | |
639 | } | |
640 | ||
641 | static int discover_arenas(struct btt *btt) | |
642 | { | |
643 | int ret = 0; | |
644 | struct arena_info *arena; | |
645 | struct btt_sb *super; | |
646 | size_t remaining = btt->rawsize; | |
647 | u64 cur_nlba = 0; | |
648 | size_t cur_off = 0; | |
649 | int num_arenas = 0; | |
650 | ||
651 | super = kzalloc(sizeof(*super), GFP_KERNEL); | |
652 | if (!super) | |
653 | return -ENOMEM; | |
654 | ||
655 | while (remaining) { | |
656 | /* Alloc memory for arena */ | |
657 | arena = alloc_arena(btt, 0, 0, 0); | |
658 | if (!arena) { | |
659 | ret = -ENOMEM; | |
660 | goto out_super; | |
661 | } | |
662 | ||
663 | arena->infooff = cur_off; | |
664 | ret = btt_info_read(arena, super); | |
665 | if (ret) | |
666 | goto out; | |
667 | ||
668 | if (!arena_is_valid(arena, super, btt->nd_btt->uuid, | |
669 | btt->lbasize)) { | |
670 | if (remaining == btt->rawsize) { | |
671 | btt->init_state = INIT_NOTFOUND; | |
672 | dev_info(to_dev(arena), "No existing arenas\n"); | |
673 | goto out; | |
674 | } else { | |
675 | dev_info(to_dev(arena), | |
676 | "Found corrupted metadata!\n"); | |
677 | ret = -ENODEV; | |
678 | goto out; | |
679 | } | |
680 | } | |
681 | ||
682 | arena->external_lba_start = cur_nlba; | |
683 | parse_arena_meta(arena, super, cur_off); | |
684 | ||
685 | ret = btt_freelist_init(arena); | |
686 | if (ret) | |
687 | goto out; | |
688 | ||
689 | ret = btt_rtt_init(arena); | |
690 | if (ret) | |
691 | goto out; | |
692 | ||
693 | ret = btt_maplocks_init(arena); | |
694 | if (ret) | |
695 | goto out; | |
696 | ||
697 | list_add_tail(&arena->list, &btt->arena_list); | |
698 | ||
699 | remaining -= arena->size; | |
700 | cur_off += arena->size; | |
701 | cur_nlba += arena->external_nlba; | |
702 | num_arenas++; | |
703 | ||
704 | if (arena->nextoff == 0) | |
705 | break; | |
706 | } | |
707 | btt->num_arenas = num_arenas; | |
708 | btt->nlba = cur_nlba; | |
709 | btt->init_state = INIT_READY; | |
710 | ||
711 | kfree(super); | |
712 | return ret; | |
713 | ||
714 | out: | |
715 | kfree(arena); | |
716 | free_arenas(btt); | |
717 | out_super: | |
718 | kfree(super); | |
719 | return ret; | |
720 | } | |
721 | ||
722 | static int create_arenas(struct btt *btt) | |
723 | { | |
724 | size_t remaining = btt->rawsize; | |
725 | size_t cur_off = 0; | |
726 | ||
727 | while (remaining) { | |
728 | struct arena_info *arena; | |
729 | size_t arena_size = min_t(u64, ARENA_MAX_SIZE, remaining); | |
730 | ||
731 | remaining -= arena_size; | |
732 | if (arena_size < ARENA_MIN_SIZE) | |
733 | break; | |
734 | ||
735 | arena = alloc_arena(btt, arena_size, btt->nlba, cur_off); | |
736 | if (!arena) { | |
737 | free_arenas(btt); | |
738 | return -ENOMEM; | |
739 | } | |
740 | btt->nlba += arena->external_nlba; | |
741 | if (remaining >= ARENA_MIN_SIZE) | |
742 | arena->nextoff = arena->size; | |
743 | else | |
744 | arena->nextoff = 0; | |
745 | cur_off += arena_size; | |
746 | list_add_tail(&arena->list, &btt->arena_list); | |
747 | } | |
748 | ||
749 | return 0; | |
750 | } | |
751 | ||
752 | /* | |
753 | * This function completes arena initialization by writing | |
754 | * all the metadata. | |
755 | * It is only called for an uninitialized arena when a write | |
756 | * to that arena occurs for the first time. | |
757 | */ | |
758 | static int btt_arena_write_layout(struct arena_info *arena, u8 *uuid) | |
759 | { | |
760 | int ret; | |
761 | struct btt_sb *super; | |
762 | ||
763 | ret = btt_map_init(arena); | |
764 | if (ret) | |
765 | return ret; | |
766 | ||
767 | ret = btt_log_init(arena); | |
768 | if (ret) | |
769 | return ret; | |
770 | ||
771 | super = kzalloc(sizeof(struct btt_sb), GFP_NOIO); | |
772 | if (!super) | |
773 | return -ENOMEM; | |
774 | ||
775 | strncpy(super->signature, BTT_SIG, BTT_SIG_LEN); | |
776 | memcpy(super->uuid, uuid, 16); | |
777 | super->flags = cpu_to_le32(arena->flags); | |
778 | super->version_major = cpu_to_le16(arena->version_major); | |
779 | super->version_minor = cpu_to_le16(arena->version_minor); | |
780 | super->external_lbasize = cpu_to_le32(arena->external_lbasize); | |
781 | super->external_nlba = cpu_to_le32(arena->external_nlba); | |
782 | super->internal_lbasize = cpu_to_le32(arena->internal_lbasize); | |
783 | super->internal_nlba = cpu_to_le32(arena->internal_nlba); | |
784 | super->nfree = cpu_to_le32(arena->nfree); | |
785 | super->infosize = cpu_to_le32(sizeof(struct btt_sb)); | |
786 | super->nextoff = cpu_to_le64(arena->nextoff); | |
787 | /* | |
788 | * Subtract arena->infooff (arena start) so numbers are relative | |
789 | * to 'this' arena | |
790 | */ | |
791 | super->dataoff = cpu_to_le64(arena->dataoff - arena->infooff); | |
792 | super->mapoff = cpu_to_le64(arena->mapoff - arena->infooff); | |
793 | super->logoff = cpu_to_le64(arena->logoff - arena->infooff); | |
794 | super->info2off = cpu_to_le64(arena->info2off - arena->infooff); | |
795 | ||
796 | super->flags = 0; | |
797 | super->checksum = cpu_to_le64(nd_btt_sb_checksum(super)); | |
798 | ||
799 | ret = btt_info_write(arena, super); | |
800 | ||
801 | kfree(super); | |
802 | return ret; | |
803 | } | |
804 | ||
805 | /* | |
806 | * This function completes the initialization for the BTT namespace | |
807 | * such that it is ready to accept IOs | |
808 | */ | |
809 | static int btt_meta_init(struct btt *btt) | |
810 | { | |
811 | int ret = 0; | |
812 | struct arena_info *arena; | |
813 | ||
814 | mutex_lock(&btt->init_lock); | |
815 | list_for_each_entry(arena, &btt->arena_list, list) { | |
816 | ret = btt_arena_write_layout(arena, btt->nd_btt->uuid); | |
817 | if (ret) | |
818 | goto unlock; | |
819 | ||
820 | ret = btt_freelist_init(arena); | |
821 | if (ret) | |
822 | goto unlock; | |
823 | ||
824 | ret = btt_rtt_init(arena); | |
825 | if (ret) | |
826 | goto unlock; | |
827 | ||
828 | ret = btt_maplocks_init(arena); | |
829 | if (ret) | |
830 | goto unlock; | |
831 | } | |
832 | ||
833 | btt->init_state = INIT_READY; | |
834 | ||
835 | unlock: | |
836 | mutex_unlock(&btt->init_lock); | |
837 | return ret; | |
838 | } | |
839 | ||
41cd8b70 VV |
840 | static u32 btt_meta_size(struct btt *btt) |
841 | { | |
842 | return btt->lbasize - btt->sector_size; | |
843 | } | |
844 | ||
5212e11f VV |
845 | /* |
846 | * This function calculates the arena in which the given LBA lies | |
847 | * by doing a linear walk. This is acceptable since we expect only | |
848 | * a few arenas. If we have backing devices that get much larger, | |
849 | * we can construct a balanced binary tree of arenas at init time | |
850 | * so that this range search becomes faster. | |
851 | */ | |
852 | static int lba_to_arena(struct btt *btt, sector_t sector, __u32 *premap, | |
853 | struct arena_info **arena) | |
854 | { | |
855 | struct arena_info *arena_list; | |
856 | __u64 lba = div_u64(sector << SECTOR_SHIFT, btt->sector_size); | |
857 | ||
858 | list_for_each_entry(arena_list, &btt->arena_list, list) { | |
859 | if (lba < arena_list->external_nlba) { | |
860 | *arena = arena_list; | |
861 | *premap = lba; | |
862 | return 0; | |
863 | } | |
864 | lba -= arena_list->external_nlba; | |
865 | } | |
866 | ||
867 | return -EIO; | |
868 | } | |
869 | ||
870 | /* | |
871 | * The following (lock_map, unlock_map) are mostly just to improve | |
872 | * readability, since they index into an array of locks | |
873 | */ | |
874 | static void lock_map(struct arena_info *arena, u32 premap) | |
875 | __acquires(&arena->map_locks[idx].lock) | |
876 | { | |
877 | u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree; | |
878 | ||
879 | spin_lock(&arena->map_locks[idx].lock); | |
880 | } | |
881 | ||
882 | static void unlock_map(struct arena_info *arena, u32 premap) | |
883 | __releases(&arena->map_locks[idx].lock) | |
884 | { | |
885 | u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree; | |
886 | ||
887 | spin_unlock(&arena->map_locks[idx].lock); | |
888 | } | |
889 | ||
890 | static u64 to_namespace_offset(struct arena_info *arena, u64 lba) | |
891 | { | |
892 | return arena->dataoff + ((u64)lba * arena->internal_lbasize); | |
893 | } | |
894 | ||
895 | static int btt_data_read(struct arena_info *arena, struct page *page, | |
896 | unsigned int off, u32 lba, u32 len) | |
897 | { | |
898 | int ret; | |
899 | u64 nsoff = to_namespace_offset(arena, lba); | |
900 | void *mem = kmap_atomic(page); | |
901 | ||
902 | ret = arena_read_bytes(arena, nsoff, mem + off, len); | |
903 | kunmap_atomic(mem); | |
904 | ||
905 | return ret; | |
906 | } | |
907 | ||
908 | static int btt_data_write(struct arena_info *arena, u32 lba, | |
909 | struct page *page, unsigned int off, u32 len) | |
910 | { | |
911 | int ret; | |
912 | u64 nsoff = to_namespace_offset(arena, lba); | |
913 | void *mem = kmap_atomic(page); | |
914 | ||
915 | ret = arena_write_bytes(arena, nsoff, mem + off, len); | |
916 | kunmap_atomic(mem); | |
917 | ||
918 | return ret; | |
919 | } | |
920 | ||
921 | static void zero_fill_data(struct page *page, unsigned int off, u32 len) | |
922 | { | |
923 | void *mem = kmap_atomic(page); | |
924 | ||
925 | memset(mem + off, 0, len); | |
926 | kunmap_atomic(mem); | |
927 | } | |
928 | ||
41cd8b70 VV |
929 | #ifdef CONFIG_BLK_DEV_INTEGRITY |
930 | static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip, | |
931 | struct arena_info *arena, u32 postmap, int rw) | |
932 | { | |
933 | unsigned int len = btt_meta_size(btt); | |
934 | u64 meta_nsoff; | |
935 | int ret = 0; | |
936 | ||
937 | if (bip == NULL) | |
938 | return 0; | |
939 | ||
940 | meta_nsoff = to_namespace_offset(arena, postmap) + btt->sector_size; | |
941 | ||
942 | while (len) { | |
943 | unsigned int cur_len; | |
944 | struct bio_vec bv; | |
945 | void *mem; | |
946 | ||
947 | bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter); | |
948 | /* | |
949 | * The 'bv' obtained from bvec_iter_bvec has its .bv_len and | |
950 | * .bv_offset already adjusted for iter->bi_bvec_done, and we | |
951 | * can use those directly | |
952 | */ | |
953 | ||
954 | cur_len = min(len, bv.bv_len); | |
955 | mem = kmap_atomic(bv.bv_page); | |
956 | if (rw) | |
957 | ret = arena_write_bytes(arena, meta_nsoff, | |
958 | mem + bv.bv_offset, cur_len); | |
959 | else | |
960 | ret = arena_read_bytes(arena, meta_nsoff, | |
961 | mem + bv.bv_offset, cur_len); | |
962 | ||
963 | kunmap_atomic(mem); | |
964 | if (ret) | |
965 | return ret; | |
966 | ||
967 | len -= cur_len; | |
968 | meta_nsoff += cur_len; | |
969 | bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len); | |
970 | } | |
971 | ||
972 | return ret; | |
973 | } | |
974 | ||
975 | #else /* CONFIG_BLK_DEV_INTEGRITY */ | |
976 | static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip, | |
977 | struct arena_info *arena, u32 postmap, int rw) | |
978 | { | |
979 | return 0; | |
980 | } | |
981 | #endif | |
982 | ||
983 | static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip, | |
984 | struct page *page, unsigned int off, sector_t sector, | |
985 | unsigned int len) | |
5212e11f VV |
986 | { |
987 | int ret = 0; | |
988 | int t_flag, e_flag; | |
989 | struct arena_info *arena = NULL; | |
990 | u32 lane = 0, premap, postmap; | |
991 | ||
992 | while (len) { | |
993 | u32 cur_len; | |
994 | ||
995 | lane = nd_region_acquire_lane(btt->nd_region); | |
996 | ||
997 | ret = lba_to_arena(btt, sector, &premap, &arena); | |
998 | if (ret) | |
999 | goto out_lane; | |
1000 | ||
1001 | cur_len = min(btt->sector_size, len); | |
1002 | ||
1003 | ret = btt_map_read(arena, premap, &postmap, &t_flag, &e_flag); | |
1004 | if (ret) | |
1005 | goto out_lane; | |
1006 | ||
1007 | /* | |
1008 | * We loop to make sure that the post map LBA didn't change | |
1009 | * from under us between writing the RTT and doing the actual | |
1010 | * read. | |
1011 | */ | |
1012 | while (1) { | |
1013 | u32 new_map; | |
1014 | ||
1015 | if (t_flag) { | |
1016 | zero_fill_data(page, off, cur_len); | |
1017 | goto out_lane; | |
1018 | } | |
1019 | ||
1020 | if (e_flag) { | |
1021 | ret = -EIO; | |
1022 | goto out_lane; | |
1023 | } | |
1024 | ||
1025 | arena->rtt[lane] = RTT_VALID | postmap; | |
1026 | /* | |
1027 | * Barrier to make sure this write is not reordered | |
1028 | * to do the verification map_read before the RTT store | |
1029 | */ | |
1030 | barrier(); | |
1031 | ||
1032 | ret = btt_map_read(arena, premap, &new_map, &t_flag, | |
1033 | &e_flag); | |
1034 | if (ret) | |
1035 | goto out_rtt; | |
1036 | ||
1037 | if (postmap == new_map) | |
1038 | break; | |
1039 | ||
1040 | postmap = new_map; | |
1041 | } | |
1042 | ||
1043 | ret = btt_data_read(arena, page, off, postmap, cur_len); | |
1044 | if (ret) | |
1045 | goto out_rtt; | |
1046 | ||
41cd8b70 VV |
1047 | if (bip) { |
1048 | ret = btt_rw_integrity(btt, bip, arena, postmap, READ); | |
1049 | if (ret) | |
1050 | goto out_rtt; | |
1051 | } | |
1052 | ||
5212e11f VV |
1053 | arena->rtt[lane] = RTT_INVALID; |
1054 | nd_region_release_lane(btt->nd_region, lane); | |
1055 | ||
1056 | len -= cur_len; | |
1057 | off += cur_len; | |
1058 | sector += btt->sector_size >> SECTOR_SHIFT; | |
1059 | } | |
1060 | ||
1061 | return 0; | |
1062 | ||
1063 | out_rtt: | |
1064 | arena->rtt[lane] = RTT_INVALID; | |
1065 | out_lane: | |
1066 | nd_region_release_lane(btt->nd_region, lane); | |
1067 | return ret; | |
1068 | } | |
1069 | ||
41cd8b70 VV |
1070 | static int btt_write_pg(struct btt *btt, struct bio_integrity_payload *bip, |
1071 | sector_t sector, struct page *page, unsigned int off, | |
1072 | unsigned int len) | |
5212e11f VV |
1073 | { |
1074 | int ret = 0; | |
1075 | struct arena_info *arena = NULL; | |
1076 | u32 premap = 0, old_postmap, new_postmap, lane = 0, i; | |
1077 | struct log_entry log; | |
1078 | int sub; | |
1079 | ||
1080 | while (len) { | |
1081 | u32 cur_len; | |
1082 | ||
1083 | lane = nd_region_acquire_lane(btt->nd_region); | |
1084 | ||
1085 | ret = lba_to_arena(btt, sector, &premap, &arena); | |
1086 | if (ret) | |
1087 | goto out_lane; | |
1088 | cur_len = min(btt->sector_size, len); | |
1089 | ||
1090 | if ((arena->flags & IB_FLAG_ERROR_MASK) != 0) { | |
1091 | ret = -EIO; | |
1092 | goto out_lane; | |
1093 | } | |
1094 | ||
1095 | new_postmap = arena->freelist[lane].block; | |
1096 | ||
1097 | /* Wait if the new block is being read from */ | |
1098 | for (i = 0; i < arena->nfree; i++) | |
1099 | while (arena->rtt[i] == (RTT_VALID | new_postmap)) | |
1100 | cpu_relax(); | |
1101 | ||
1102 | ||
1103 | if (new_postmap >= arena->internal_nlba) { | |
1104 | ret = -EIO; | |
1105 | goto out_lane; | |
41cd8b70 VV |
1106 | } |
1107 | ||
1108 | ret = btt_data_write(arena, new_postmap, page, off, cur_len); | |
5212e11f VV |
1109 | if (ret) |
1110 | goto out_lane; | |
1111 | ||
41cd8b70 VV |
1112 | if (bip) { |
1113 | ret = btt_rw_integrity(btt, bip, arena, new_postmap, | |
1114 | WRITE); | |
1115 | if (ret) | |
1116 | goto out_lane; | |
1117 | } | |
1118 | ||
5212e11f VV |
1119 | lock_map(arena, premap); |
1120 | ret = btt_map_read(arena, premap, &old_postmap, NULL, NULL); | |
1121 | if (ret) | |
1122 | goto out_map; | |
1123 | if (old_postmap >= arena->internal_nlba) { | |
1124 | ret = -EIO; | |
1125 | goto out_map; | |
1126 | } | |
1127 | ||
1128 | log.lba = cpu_to_le32(premap); | |
1129 | log.old_map = cpu_to_le32(old_postmap); | |
1130 | log.new_map = cpu_to_le32(new_postmap); | |
1131 | log.seq = cpu_to_le32(arena->freelist[lane].seq); | |
1132 | sub = arena->freelist[lane].sub; | |
1133 | ret = btt_flog_write(arena, lane, sub, &log); | |
1134 | if (ret) | |
1135 | goto out_map; | |
1136 | ||
1137 | ret = btt_map_write(arena, premap, new_postmap, 0, 0); | |
1138 | if (ret) | |
1139 | goto out_map; | |
1140 | ||
1141 | unlock_map(arena, premap); | |
1142 | nd_region_release_lane(btt->nd_region, lane); | |
1143 | ||
1144 | len -= cur_len; | |
1145 | off += cur_len; | |
1146 | sector += btt->sector_size >> SECTOR_SHIFT; | |
1147 | } | |
1148 | ||
1149 | return 0; | |
1150 | ||
1151 | out_map: | |
1152 | unlock_map(arena, premap); | |
1153 | out_lane: | |
1154 | nd_region_release_lane(btt->nd_region, lane); | |
1155 | return ret; | |
1156 | } | |
1157 | ||
41cd8b70 VV |
1158 | static int btt_do_bvec(struct btt *btt, struct bio_integrity_payload *bip, |
1159 | struct page *page, unsigned int len, unsigned int off, | |
1160 | int rw, sector_t sector) | |
5212e11f VV |
1161 | { |
1162 | int ret; | |
1163 | ||
1164 | if (rw == READ) { | |
41cd8b70 | 1165 | ret = btt_read_pg(btt, bip, page, off, sector, len); |
5212e11f VV |
1166 | flush_dcache_page(page); |
1167 | } else { | |
1168 | flush_dcache_page(page); | |
41cd8b70 | 1169 | ret = btt_write_pg(btt, bip, sector, page, off, len); |
5212e11f VV |
1170 | } |
1171 | ||
1172 | return ret; | |
1173 | } | |
1174 | ||
1175 | static void btt_make_request(struct request_queue *q, struct bio *bio) | |
1176 | { | |
41cd8b70 | 1177 | struct bio_integrity_payload *bip = bio_integrity(bio); |
5212e11f VV |
1178 | struct btt *btt = q->queuedata; |
1179 | struct bvec_iter iter; | |
f0dc089c | 1180 | unsigned long start; |
5212e11f VV |
1181 | struct bio_vec bvec; |
1182 | int err = 0, rw; | |
f0dc089c | 1183 | bool do_acct; |
5212e11f | 1184 | |
41cd8b70 VV |
1185 | /* |
1186 | * bio_integrity_enabled also checks if the bio already has an | |
1187 | * integrity payload attached. If it does, we *don't* do a | |
1188 | * bio_integrity_prep here - the payload has been generated by | |
1189 | * another kernel subsystem, and we just pass it through. | |
1190 | */ | |
1191 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
1192 | err = -EIO; | |
1193 | goto out; | |
1194 | } | |
1195 | ||
f0dc089c | 1196 | do_acct = nd_iostat_start(bio, &start); |
5212e11f VV |
1197 | rw = bio_data_dir(bio); |
1198 | bio_for_each_segment(bvec, bio, iter) { | |
1199 | unsigned int len = bvec.bv_len; | |
1200 | ||
1201 | BUG_ON(len > PAGE_SIZE); | |
1202 | /* Make sure len is in multiples of sector size. */ | |
1203 | /* XXX is this right? */ | |
1204 | BUG_ON(len < btt->sector_size); | |
1205 | BUG_ON(len % btt->sector_size); | |
1206 | ||
41cd8b70 | 1207 | err = btt_do_bvec(btt, bip, bvec.bv_page, len, bvec.bv_offset, |
5212e11f VV |
1208 | rw, iter.bi_sector); |
1209 | if (err) { | |
1210 | dev_info(&btt->nd_btt->dev, | |
1211 | "io error in %s sector %lld, len %d,\n", | |
1212 | (rw == READ) ? "READ" : "WRITE", | |
1213 | (unsigned long long) iter.bi_sector, len); | |
f0dc089c | 1214 | break; |
5212e11f VV |
1215 | } |
1216 | } | |
f0dc089c DW |
1217 | if (do_acct) |
1218 | nd_iostat_end(bio, start); | |
5212e11f VV |
1219 | |
1220 | out: | |
1221 | bio_endio(bio, err); | |
1222 | } | |
1223 | ||
1224 | static int btt_rw_page(struct block_device *bdev, sector_t sector, | |
1225 | struct page *page, int rw) | |
1226 | { | |
1227 | struct btt *btt = bdev->bd_disk->private_data; | |
1228 | ||
41cd8b70 | 1229 | btt_do_bvec(btt, NULL, page, PAGE_CACHE_SIZE, 0, rw, sector); |
5212e11f VV |
1230 | page_endio(page, rw & WRITE, 0); |
1231 | return 0; | |
1232 | } | |
1233 | ||
1234 | ||
1235 | static int btt_getgeo(struct block_device *bd, struct hd_geometry *geo) | |
1236 | { | |
1237 | /* some standard values */ | |
1238 | geo->heads = 1 << 6; | |
1239 | geo->sectors = 1 << 5; | |
1240 | geo->cylinders = get_capacity(bd->bd_disk) >> 11; | |
1241 | return 0; | |
1242 | } | |
1243 | ||
1244 | static const struct block_device_operations btt_fops = { | |
1245 | .owner = THIS_MODULE, | |
1246 | .rw_page = btt_rw_page, | |
1247 | .getgeo = btt_getgeo, | |
58138820 | 1248 | .revalidate_disk = nvdimm_revalidate_disk, |
5212e11f VV |
1249 | }; |
1250 | ||
1251 | static int btt_blk_init(struct btt *btt) | |
1252 | { | |
1253 | struct nd_btt *nd_btt = btt->nd_btt; | |
1254 | struct nd_namespace_common *ndns = nd_btt->ndns; | |
1255 | ||
1256 | /* create a new disk and request queue for btt */ | |
1257 | btt->btt_queue = blk_alloc_queue(GFP_KERNEL); | |
1258 | if (!btt->btt_queue) | |
1259 | return -ENOMEM; | |
1260 | ||
1261 | btt->btt_disk = alloc_disk(0); | |
1262 | if (!btt->btt_disk) { | |
1263 | blk_cleanup_queue(btt->btt_queue); | |
1264 | return -ENOMEM; | |
1265 | } | |
1266 | ||
1267 | nvdimm_namespace_disk_name(ndns, btt->btt_disk->disk_name); | |
1268 | btt->btt_disk->driverfs_dev = &btt->nd_btt->dev; | |
1269 | btt->btt_disk->major = btt_major; | |
1270 | btt->btt_disk->first_minor = 0; | |
1271 | btt->btt_disk->fops = &btt_fops; | |
1272 | btt->btt_disk->private_data = btt; | |
1273 | btt->btt_disk->queue = btt->btt_queue; | |
1274 | btt->btt_disk->flags = GENHD_FL_EXT_DEVT; | |
1275 | ||
1276 | blk_queue_make_request(btt->btt_queue, btt_make_request); | |
1277 | blk_queue_logical_block_size(btt->btt_queue, btt->sector_size); | |
1278 | blk_queue_max_hw_sectors(btt->btt_queue, UINT_MAX); | |
1279 | blk_queue_bounce_limit(btt->btt_queue, BLK_BOUNCE_ANY); | |
1280 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, btt->btt_queue); | |
1281 | btt->btt_queue->queuedata = btt; | |
1282 | ||
41cd8b70 | 1283 | set_capacity(btt->btt_disk, 0); |
5212e11f | 1284 | add_disk(btt->btt_disk); |
41cd8b70 VV |
1285 | if (btt_meta_size(btt)) { |
1286 | int rc = nd_integrity_init(btt->btt_disk, btt_meta_size(btt)); | |
1287 | ||
1288 | if (rc) { | |
1289 | del_gendisk(btt->btt_disk); | |
1290 | put_disk(btt->btt_disk); | |
1291 | blk_cleanup_queue(btt->btt_queue); | |
1292 | return rc; | |
1293 | } | |
1294 | } | |
1295 | set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9); | |
58138820 | 1296 | revalidate_disk(btt->btt_disk); |
5212e11f VV |
1297 | |
1298 | return 0; | |
1299 | } | |
1300 | ||
1301 | static void btt_blk_cleanup(struct btt *btt) | |
1302 | { | |
41cd8b70 | 1303 | blk_integrity_unregister(btt->btt_disk); |
5212e11f VV |
1304 | del_gendisk(btt->btt_disk); |
1305 | put_disk(btt->btt_disk); | |
1306 | blk_cleanup_queue(btt->btt_queue); | |
1307 | } | |
1308 | ||
1309 | /** | |
1310 | * btt_init - initialize a block translation table for the given device | |
1311 | * @nd_btt: device with BTT geometry and backing device info | |
1312 | * @rawsize: raw size in bytes of the backing device | |
1313 | * @lbasize: lba size of the backing device | |
1314 | * @uuid: A uuid for the backing device - this is stored on media | |
1315 | * @maxlane: maximum number of parallel requests the device can handle | |
1316 | * | |
1317 | * Initialize a Block Translation Table on a backing device to provide | |
1318 | * single sector power fail atomicity. | |
1319 | * | |
1320 | * Context: | |
1321 | * Might sleep. | |
1322 | * | |
1323 | * Returns: | |
1324 | * Pointer to a new struct btt on success, NULL on failure. | |
1325 | */ | |
1326 | static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize, | |
1327 | u32 lbasize, u8 *uuid, struct nd_region *nd_region) | |
1328 | { | |
1329 | int ret; | |
1330 | struct btt *btt; | |
1331 | struct device *dev = &nd_btt->dev; | |
1332 | ||
1333 | btt = kzalloc(sizeof(struct btt), GFP_KERNEL); | |
1334 | if (!btt) | |
1335 | return NULL; | |
1336 | ||
1337 | btt->nd_btt = nd_btt; | |
1338 | btt->rawsize = rawsize; | |
1339 | btt->lbasize = lbasize; | |
1340 | btt->sector_size = ((lbasize >= 4096) ? 4096 : 512); | |
1341 | INIT_LIST_HEAD(&btt->arena_list); | |
1342 | mutex_init(&btt->init_lock); | |
1343 | btt->nd_region = nd_region; | |
1344 | ||
1345 | ret = discover_arenas(btt); | |
1346 | if (ret) { | |
1347 | dev_err(dev, "init: error in arena_discover: %d\n", ret); | |
1348 | goto out_free; | |
1349 | } | |
1350 | ||
58138820 DW |
1351 | if (btt->init_state != INIT_READY && nd_region->ro) { |
1352 | dev_info(dev, "%s is read-only, unable to init btt metadata\n", | |
1353 | dev_name(&nd_region->dev)); | |
1354 | goto out_free; | |
1355 | } else if (btt->init_state != INIT_READY) { | |
5212e11f VV |
1356 | btt->num_arenas = (rawsize / ARENA_MAX_SIZE) + |
1357 | ((rawsize % ARENA_MAX_SIZE) ? 1 : 0); | |
1358 | dev_dbg(dev, "init: %d arenas for %llu rawsize\n", | |
1359 | btt->num_arenas, rawsize); | |
1360 | ||
1361 | ret = create_arenas(btt); | |
1362 | if (ret) { | |
1363 | dev_info(dev, "init: create_arenas: %d\n", ret); | |
1364 | goto out_free; | |
1365 | } | |
1366 | ||
1367 | ret = btt_meta_init(btt); | |
1368 | if (ret) { | |
1369 | dev_err(dev, "init: error in meta_init: %d\n", ret); | |
58138820 | 1370 | goto out_free; |
5212e11f VV |
1371 | } |
1372 | } | |
1373 | ||
1374 | ret = btt_blk_init(btt); | |
1375 | if (ret) { | |
1376 | dev_err(dev, "init: error in blk_init: %d\n", ret); | |
1377 | goto out_free; | |
1378 | } | |
1379 | ||
1380 | btt_debugfs_init(btt); | |
1381 | ||
1382 | return btt; | |
1383 | ||
1384 | out_free: | |
1385 | kfree(btt); | |
1386 | return NULL; | |
1387 | } | |
1388 | ||
1389 | /** | |
1390 | * btt_fini - de-initialize a BTT | |
1391 | * @btt: the BTT handle that was generated by btt_init | |
1392 | * | |
1393 | * De-initialize a Block Translation Table on device removal | |
1394 | * | |
1395 | * Context: | |
1396 | * Might sleep. | |
1397 | */ | |
1398 | static void btt_fini(struct btt *btt) | |
1399 | { | |
1400 | if (btt) { | |
1401 | btt_blk_cleanup(btt); | |
1402 | free_arenas(btt); | |
1403 | debugfs_remove_recursive(btt->debugfs_dir); | |
1404 | kfree(btt); | |
1405 | } | |
1406 | } | |
1407 | ||
1408 | int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns) | |
1409 | { | |
1410 | struct nd_btt *nd_btt = to_nd_btt(ndns->claim); | |
1411 | struct nd_region *nd_region; | |
1412 | struct btt *btt; | |
1413 | size_t rawsize; | |
1414 | ||
1415 | if (!nd_btt->uuid || !nd_btt->ndns || !nd_btt->lbasize) | |
1416 | return -ENODEV; | |
1417 | ||
1418 | rawsize = nvdimm_namespace_capacity(ndns) - SZ_4K; | |
1419 | if (rawsize < ARENA_MIN_SIZE) { | |
1420 | return -ENXIO; | |
1421 | } | |
1422 | nd_region = to_nd_region(nd_btt->dev.parent); | |
1423 | btt = btt_init(nd_btt, rawsize, nd_btt->lbasize, nd_btt->uuid, | |
1424 | nd_region); | |
1425 | if (!btt) | |
1426 | return -ENOMEM; | |
1427 | nd_btt->btt = btt; | |
1428 | ||
1429 | return 0; | |
1430 | } | |
1431 | EXPORT_SYMBOL(nvdimm_namespace_attach_btt); | |
1432 | ||
1433 | int nvdimm_namespace_detach_btt(struct nd_namespace_common *ndns) | |
1434 | { | |
1435 | struct nd_btt *nd_btt = to_nd_btt(ndns->claim); | |
1436 | struct btt *btt = nd_btt->btt; | |
1437 | ||
1438 | btt_fini(btt); | |
1439 | nd_btt->btt = NULL; | |
1440 | ||
1441 | return 0; | |
1442 | } | |
1443 | EXPORT_SYMBOL(nvdimm_namespace_detach_btt); | |
1444 | ||
1445 | static int __init nd_btt_init(void) | |
1446 | { | |
1447 | int rc; | |
1448 | ||
1449 | BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K); | |
1450 | ||
1451 | btt_major = register_blkdev(0, "btt"); | |
1452 | if (btt_major < 0) | |
1453 | return btt_major; | |
1454 | ||
1455 | debugfs_root = debugfs_create_dir("btt", NULL); | |
1456 | if (IS_ERR_OR_NULL(debugfs_root)) { | |
1457 | rc = -ENXIO; | |
1458 | goto err_debugfs; | |
1459 | } | |
1460 | ||
1461 | return 0; | |
1462 | ||
1463 | err_debugfs: | |
1464 | unregister_blkdev(btt_major, "btt"); | |
1465 | ||
1466 | return rc; | |
1467 | } | |
1468 | ||
1469 | static void __exit nd_btt_exit(void) | |
1470 | { | |
1471 | debugfs_remove_recursive(debugfs_root); | |
1472 | unregister_blkdev(btt_major, "btt"); | |
1473 | } | |
1474 | ||
1475 | MODULE_ALIAS_ND_DEVICE(ND_DEVICE_BTT); | |
1476 | MODULE_AUTHOR("Vishal Verma <vishal.l.verma@linux.intel.com>"); | |
1477 | MODULE_LICENSE("GPL v2"); | |
1478 | module_init(nd_btt_init); | |
1479 | module_exit(nd_btt_exit); |