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48debafe MP |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Copyright (C) 2018 Red Hat. All rights reserved. | |
4 | * | |
5 | * This file is released under the GPL. | |
6 | */ | |
7 | ||
8 | #include <linux/device-mapper.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/init.h> | |
11 | #include <linux/vmalloc.h> | |
12 | #include <linux/kthread.h> | |
13 | #include <linux/dm-io.h> | |
14 | #include <linux/dm-kcopyd.h> | |
15 | #include <linux/dax.h> | |
16 | #include <linux/pfn_t.h> | |
17 | #include <linux/libnvdimm.h> | |
18 | ||
19 | #define DM_MSG_PREFIX "writecache" | |
20 | ||
21 | #define HIGH_WATERMARK 50 | |
22 | #define LOW_WATERMARK 45 | |
23 | #define MAX_WRITEBACK_JOBS 0 | |
24 | #define ENDIO_LATENCY 16 | |
25 | #define WRITEBACK_LATENCY 64 | |
26 | #define AUTOCOMMIT_BLOCKS_SSD 65536 | |
27 | #define AUTOCOMMIT_BLOCKS_PMEM 64 | |
28 | #define AUTOCOMMIT_MSEC 1000 | |
29 | ||
30 | #define BITMAP_GRANULARITY 65536 | |
31 | #if BITMAP_GRANULARITY < PAGE_SIZE | |
32 | #undef BITMAP_GRANULARITY | |
33 | #define BITMAP_GRANULARITY PAGE_SIZE | |
34 | #endif | |
35 | ||
36 | #if IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_DAX_DRIVER) | |
37 | #define DM_WRITECACHE_HAS_PMEM | |
38 | #endif | |
39 | ||
40 | #ifdef DM_WRITECACHE_HAS_PMEM | |
41 | #define pmem_assign(dest, src) \ | |
42 | do { \ | |
43 | typeof(dest) uniq = (src); \ | |
44 | memcpy_flushcache(&(dest), &uniq, sizeof(dest)); \ | |
45 | } while (0) | |
46 | #else | |
47 | #define pmem_assign(dest, src) ((dest) = (src)) | |
48 | #endif | |
49 | ||
50 | #if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(DM_WRITECACHE_HAS_PMEM) | |
51 | #define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS | |
52 | #endif | |
53 | ||
54 | #define MEMORY_SUPERBLOCK_MAGIC 0x23489321 | |
55 | #define MEMORY_SUPERBLOCK_VERSION 1 | |
56 | ||
57 | struct wc_memory_entry { | |
58 | __le64 original_sector; | |
59 | __le64 seq_count; | |
60 | }; | |
61 | ||
62 | struct wc_memory_superblock { | |
63 | union { | |
64 | struct { | |
65 | __le32 magic; | |
66 | __le32 version; | |
67 | __le32 block_size; | |
68 | __le32 pad; | |
69 | __le64 n_blocks; | |
70 | __le64 seq_count; | |
71 | }; | |
72 | __le64 padding[8]; | |
73 | }; | |
74 | struct wc_memory_entry entries[0]; | |
75 | }; | |
76 | ||
77 | struct wc_entry { | |
78 | struct rb_node rb_node; | |
79 | struct list_head lru; | |
80 | unsigned short wc_list_contiguous; | |
81 | bool write_in_progress | |
82 | #if BITS_PER_LONG == 64 | |
83 | :1 | |
84 | #endif | |
85 | ; | |
86 | unsigned long index | |
87 | #if BITS_PER_LONG == 64 | |
88 | :47 | |
89 | #endif | |
90 | ; | |
91 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS | |
92 | uint64_t original_sector; | |
93 | uint64_t seq_count; | |
94 | #endif | |
95 | }; | |
96 | ||
97 | #ifdef DM_WRITECACHE_HAS_PMEM | |
98 | #define WC_MODE_PMEM(wc) ((wc)->pmem_mode) | |
99 | #define WC_MODE_FUA(wc) ((wc)->writeback_fua) | |
100 | #else | |
101 | #define WC_MODE_PMEM(wc) false | |
102 | #define WC_MODE_FUA(wc) false | |
103 | #endif | |
104 | #define WC_MODE_SORT_FREELIST(wc) (!WC_MODE_PMEM(wc)) | |
105 | ||
106 | struct dm_writecache { | |
107 | struct mutex lock; | |
108 | struct list_head lru; | |
109 | union { | |
110 | struct list_head freelist; | |
111 | struct { | |
112 | struct rb_root freetree; | |
113 | struct wc_entry *current_free; | |
114 | }; | |
115 | }; | |
116 | struct rb_root tree; | |
117 | ||
118 | size_t freelist_size; | |
119 | size_t writeback_size; | |
120 | size_t freelist_high_watermark; | |
121 | size_t freelist_low_watermark; | |
122 | ||
123 | unsigned uncommitted_blocks; | |
124 | unsigned autocommit_blocks; | |
125 | unsigned max_writeback_jobs; | |
126 | ||
127 | int error; | |
128 | ||
129 | unsigned long autocommit_jiffies; | |
130 | struct timer_list autocommit_timer; | |
131 | struct wait_queue_head freelist_wait; | |
132 | ||
133 | atomic_t bio_in_progress[2]; | |
134 | struct wait_queue_head bio_in_progress_wait[2]; | |
135 | ||
136 | struct dm_target *ti; | |
137 | struct dm_dev *dev; | |
138 | struct dm_dev *ssd_dev; | |
139 | void *memory_map; | |
140 | uint64_t memory_map_size; | |
141 | size_t metadata_sectors; | |
142 | size_t n_blocks; | |
143 | uint64_t seq_count; | |
144 | void *block_start; | |
145 | struct wc_entry *entries; | |
146 | unsigned block_size; | |
147 | unsigned char block_size_bits; | |
148 | ||
149 | bool pmem_mode:1; | |
150 | bool writeback_fua:1; | |
151 | ||
152 | bool overwrote_committed:1; | |
153 | bool memory_vmapped:1; | |
154 | ||
155 | bool high_wm_percent_set:1; | |
156 | bool low_wm_percent_set:1; | |
157 | bool max_writeback_jobs_set:1; | |
158 | bool autocommit_blocks_set:1; | |
159 | bool autocommit_time_set:1; | |
160 | bool writeback_fua_set:1; | |
161 | bool flush_on_suspend:1; | |
162 | ||
163 | unsigned writeback_all; | |
164 | struct workqueue_struct *writeback_wq; | |
165 | struct work_struct writeback_work; | |
166 | struct work_struct flush_work; | |
167 | ||
168 | struct dm_io_client *dm_io; | |
169 | ||
170 | raw_spinlock_t endio_list_lock; | |
171 | struct list_head endio_list; | |
172 | struct task_struct *endio_thread; | |
173 | ||
174 | struct task_struct *flush_thread; | |
175 | struct bio_list flush_list; | |
176 | ||
177 | struct dm_kcopyd_client *dm_kcopyd; | |
178 | unsigned long *dirty_bitmap; | |
179 | unsigned dirty_bitmap_size; | |
180 | ||
181 | struct bio_set bio_set; | |
182 | mempool_t copy_pool; | |
183 | }; | |
184 | ||
185 | #define WB_LIST_INLINE 16 | |
186 | ||
187 | struct writeback_struct { | |
188 | struct list_head endio_entry; | |
189 | struct dm_writecache *wc; | |
190 | struct wc_entry **wc_list; | |
191 | unsigned wc_list_n; | |
192 | unsigned page_offset; | |
193 | struct page *page; | |
194 | struct wc_entry *wc_list_inline[WB_LIST_INLINE]; | |
195 | struct bio bio; | |
196 | }; | |
197 | ||
198 | struct copy_struct { | |
199 | struct list_head endio_entry; | |
200 | struct dm_writecache *wc; | |
201 | struct wc_entry *e; | |
202 | unsigned n_entries; | |
203 | int error; | |
204 | }; | |
205 | ||
206 | DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(dm_writecache_throttle, | |
207 | "A percentage of time allocated for data copying"); | |
208 | ||
209 | static void wc_lock(struct dm_writecache *wc) | |
210 | { | |
211 | mutex_lock(&wc->lock); | |
212 | } | |
213 | ||
214 | static void wc_unlock(struct dm_writecache *wc) | |
215 | { | |
216 | mutex_unlock(&wc->lock); | |
217 | } | |
218 | ||
219 | #ifdef DM_WRITECACHE_HAS_PMEM | |
220 | static int persistent_memory_claim(struct dm_writecache *wc) | |
221 | { | |
222 | int r; | |
223 | loff_t s; | |
224 | long p, da; | |
225 | pfn_t pfn; | |
226 | int id; | |
227 | struct page **pages; | |
228 | ||
229 | wc->memory_vmapped = false; | |
230 | ||
231 | if (!wc->ssd_dev->dax_dev) { | |
232 | r = -EOPNOTSUPP; | |
233 | goto err1; | |
234 | } | |
235 | s = wc->memory_map_size; | |
236 | p = s >> PAGE_SHIFT; | |
237 | if (!p) { | |
238 | r = -EINVAL; | |
239 | goto err1; | |
240 | } | |
241 | if (p != s >> PAGE_SHIFT) { | |
242 | r = -EOVERFLOW; | |
243 | goto err1; | |
244 | } | |
245 | ||
246 | id = dax_read_lock(); | |
247 | ||
248 | da = dax_direct_access(wc->ssd_dev->dax_dev, 0, p, &wc->memory_map, &pfn); | |
249 | if (da < 0) { | |
250 | wc->memory_map = NULL; | |
251 | r = da; | |
252 | goto err2; | |
253 | } | |
254 | if (!pfn_t_has_page(pfn)) { | |
255 | wc->memory_map = NULL; | |
256 | r = -EOPNOTSUPP; | |
257 | goto err2; | |
258 | } | |
259 | if (da != p) { | |
260 | long i; | |
261 | wc->memory_map = NULL; | |
50a7d3ba | 262 | pages = kvmalloc_array(p, sizeof(struct page *), GFP_KERNEL); |
48debafe MP |
263 | if (!pages) { |
264 | r = -ENOMEM; | |
265 | goto err2; | |
266 | } | |
267 | i = 0; | |
268 | do { | |
269 | long daa; | |
270 | void *dummy_addr; | |
271 | daa = dax_direct_access(wc->ssd_dev->dax_dev, i, p - i, | |
272 | &dummy_addr, &pfn); | |
273 | if (daa <= 0) { | |
274 | r = daa ? daa : -EINVAL; | |
275 | goto err3; | |
276 | } | |
277 | if (!pfn_t_has_page(pfn)) { | |
278 | r = -EOPNOTSUPP; | |
279 | goto err3; | |
280 | } | |
281 | while (daa-- && i < p) { | |
282 | pages[i++] = pfn_t_to_page(pfn); | |
283 | pfn.val++; | |
284 | } | |
285 | } while (i < p); | |
286 | wc->memory_map = vmap(pages, p, VM_MAP, PAGE_KERNEL); | |
287 | if (!wc->memory_map) { | |
288 | r = -ENOMEM; | |
289 | goto err3; | |
290 | } | |
291 | kvfree(pages); | |
292 | wc->memory_vmapped = true; | |
293 | } | |
294 | ||
295 | dax_read_unlock(id); | |
296 | return 0; | |
297 | err3: | |
298 | kvfree(pages); | |
299 | err2: | |
300 | dax_read_unlock(id); | |
301 | err1: | |
302 | return r; | |
303 | } | |
304 | #else | |
305 | static int persistent_memory_claim(struct dm_writecache *wc) | |
306 | { | |
307 | BUG(); | |
308 | } | |
309 | #endif | |
310 | ||
311 | static void persistent_memory_release(struct dm_writecache *wc) | |
312 | { | |
313 | if (wc->memory_vmapped) | |
314 | vunmap(wc->memory_map); | |
315 | } | |
316 | ||
317 | static struct page *persistent_memory_page(void *addr) | |
318 | { | |
319 | if (is_vmalloc_addr(addr)) | |
320 | return vmalloc_to_page(addr); | |
321 | else | |
322 | return virt_to_page(addr); | |
323 | } | |
324 | ||
325 | static unsigned persistent_memory_page_offset(void *addr) | |
326 | { | |
327 | return (unsigned long)addr & (PAGE_SIZE - 1); | |
328 | } | |
329 | ||
330 | static void persistent_memory_flush_cache(void *ptr, size_t size) | |
331 | { | |
332 | if (is_vmalloc_addr(ptr)) | |
333 | flush_kernel_vmap_range(ptr, size); | |
334 | } | |
335 | ||
336 | static void persistent_memory_invalidate_cache(void *ptr, size_t size) | |
337 | { | |
338 | if (is_vmalloc_addr(ptr)) | |
339 | invalidate_kernel_vmap_range(ptr, size); | |
340 | } | |
341 | ||
342 | static struct wc_memory_superblock *sb(struct dm_writecache *wc) | |
343 | { | |
344 | return wc->memory_map; | |
345 | } | |
346 | ||
347 | static struct wc_memory_entry *memory_entry(struct dm_writecache *wc, struct wc_entry *e) | |
348 | { | |
349 | if (is_power_of_2(sizeof(struct wc_entry)) && 0) | |
350 | return &sb(wc)->entries[e - wc->entries]; | |
351 | else | |
352 | return &sb(wc)->entries[e->index]; | |
353 | } | |
354 | ||
355 | static void *memory_data(struct dm_writecache *wc, struct wc_entry *e) | |
356 | { | |
357 | return (char *)wc->block_start + (e->index << wc->block_size_bits); | |
358 | } | |
359 | ||
360 | static sector_t cache_sector(struct dm_writecache *wc, struct wc_entry *e) | |
361 | { | |
362 | return wc->metadata_sectors + | |
363 | ((sector_t)e->index << (wc->block_size_bits - SECTOR_SHIFT)); | |
364 | } | |
365 | ||
366 | static uint64_t read_original_sector(struct dm_writecache *wc, struct wc_entry *e) | |
367 | { | |
368 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS | |
369 | return e->original_sector; | |
370 | #else | |
371 | return le64_to_cpu(memory_entry(wc, e)->original_sector); | |
372 | #endif | |
373 | } | |
374 | ||
375 | static uint64_t read_seq_count(struct dm_writecache *wc, struct wc_entry *e) | |
376 | { | |
377 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS | |
378 | return e->seq_count; | |
379 | #else | |
380 | return le64_to_cpu(memory_entry(wc, e)->seq_count); | |
381 | #endif | |
382 | } | |
383 | ||
384 | static void clear_seq_count(struct dm_writecache *wc, struct wc_entry *e) | |
385 | { | |
386 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS | |
387 | e->seq_count = -1; | |
388 | #endif | |
389 | pmem_assign(memory_entry(wc, e)->seq_count, cpu_to_le64(-1)); | |
390 | } | |
391 | ||
392 | static void write_original_sector_seq_count(struct dm_writecache *wc, struct wc_entry *e, | |
393 | uint64_t original_sector, uint64_t seq_count) | |
394 | { | |
395 | struct wc_memory_entry me; | |
396 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS | |
397 | e->original_sector = original_sector; | |
398 | e->seq_count = seq_count; | |
399 | #endif | |
400 | me.original_sector = cpu_to_le64(original_sector); | |
401 | me.seq_count = cpu_to_le64(seq_count); | |
402 | pmem_assign(*memory_entry(wc, e), me); | |
403 | } | |
404 | ||
405 | #define writecache_error(wc, err, msg, arg...) \ | |
406 | do { \ | |
407 | if (!cmpxchg(&(wc)->error, 0, err)) \ | |
408 | DMERR(msg, ##arg); \ | |
409 | wake_up(&(wc)->freelist_wait); \ | |
410 | } while (0) | |
411 | ||
412 | #define writecache_has_error(wc) (unlikely(READ_ONCE((wc)->error))) | |
413 | ||
414 | static void writecache_flush_all_metadata(struct dm_writecache *wc) | |
415 | { | |
416 | if (!WC_MODE_PMEM(wc)) | |
417 | memset(wc->dirty_bitmap, -1, wc->dirty_bitmap_size); | |
418 | } | |
419 | ||
420 | static void writecache_flush_region(struct dm_writecache *wc, void *ptr, size_t size) | |
421 | { | |
422 | if (!WC_MODE_PMEM(wc)) | |
423 | __set_bit(((char *)ptr - (char *)wc->memory_map) / BITMAP_GRANULARITY, | |
424 | wc->dirty_bitmap); | |
425 | } | |
426 | ||
427 | static void writecache_disk_flush(struct dm_writecache *wc, struct dm_dev *dev); | |
428 | ||
429 | struct io_notify { | |
430 | struct dm_writecache *wc; | |
431 | struct completion c; | |
432 | atomic_t count; | |
433 | }; | |
434 | ||
435 | static void writecache_notify_io(unsigned long error, void *context) | |
436 | { | |
437 | struct io_notify *endio = context; | |
438 | ||
439 | if (unlikely(error != 0)) | |
440 | writecache_error(endio->wc, -EIO, "error writing metadata"); | |
441 | BUG_ON(atomic_read(&endio->count) <= 0); | |
442 | if (atomic_dec_and_test(&endio->count)) | |
443 | complete(&endio->c); | |
444 | } | |
445 | ||
446 | static void ssd_commit_flushed(struct dm_writecache *wc) | |
447 | { | |
448 | struct dm_io_region region; | |
449 | struct dm_io_request req; | |
450 | struct io_notify endio = { | |
451 | wc, | |
452 | COMPLETION_INITIALIZER_ONSTACK(endio.c), | |
453 | ATOMIC_INIT(1), | |
454 | }; | |
455 | unsigned bitmap_bits = wc->dirty_bitmap_size * BITS_PER_LONG; | |
456 | unsigned i = 0; | |
457 | ||
458 | while (1) { | |
459 | unsigned j; | |
460 | i = find_next_bit(wc->dirty_bitmap, bitmap_bits, i); | |
461 | if (unlikely(i == bitmap_bits)) | |
462 | break; | |
463 | j = find_next_zero_bit(wc->dirty_bitmap, bitmap_bits, i); | |
464 | ||
465 | region.bdev = wc->ssd_dev->bdev; | |
466 | region.sector = (sector_t)i * (BITMAP_GRANULARITY >> SECTOR_SHIFT); | |
467 | region.count = (sector_t)(j - i) * (BITMAP_GRANULARITY >> SECTOR_SHIFT); | |
468 | ||
469 | if (unlikely(region.sector >= wc->metadata_sectors)) | |
470 | break; | |
471 | if (unlikely(region.sector + region.count > wc->metadata_sectors)) | |
472 | region.count = wc->metadata_sectors - region.sector; | |
473 | ||
474 | atomic_inc(&endio.count); | |
475 | req.bi_op = REQ_OP_WRITE; | |
476 | req.bi_op_flags = REQ_SYNC; | |
477 | req.mem.type = DM_IO_VMA; | |
478 | req.mem.ptr.vma = (char *)wc->memory_map + (size_t)i * BITMAP_GRANULARITY; | |
479 | req.client = wc->dm_io; | |
480 | req.notify.fn = writecache_notify_io; | |
481 | req.notify.context = &endio; | |
482 | ||
483 | /* writing via async dm-io (implied by notify.fn above) won't return an error */ | |
484 | (void) dm_io(&req, 1, ®ion, NULL); | |
485 | i = j; | |
486 | } | |
487 | ||
488 | writecache_notify_io(0, &endio); | |
489 | wait_for_completion_io(&endio.c); | |
490 | ||
491 | writecache_disk_flush(wc, wc->ssd_dev); | |
492 | ||
493 | memset(wc->dirty_bitmap, 0, wc->dirty_bitmap_size); | |
494 | } | |
495 | ||
496 | static void writecache_commit_flushed(struct dm_writecache *wc) | |
497 | { | |
498 | if (WC_MODE_PMEM(wc)) | |
499 | wmb(); | |
500 | else | |
501 | ssd_commit_flushed(wc); | |
502 | } | |
503 | ||
504 | static void writecache_disk_flush(struct dm_writecache *wc, struct dm_dev *dev) | |
505 | { | |
506 | int r; | |
507 | struct dm_io_region region; | |
508 | struct dm_io_request req; | |
509 | ||
510 | region.bdev = dev->bdev; | |
511 | region.sector = 0; | |
512 | region.count = 0; | |
513 | req.bi_op = REQ_OP_WRITE; | |
514 | req.bi_op_flags = REQ_PREFLUSH; | |
515 | req.mem.type = DM_IO_KMEM; | |
516 | req.mem.ptr.addr = NULL; | |
517 | req.client = wc->dm_io; | |
518 | req.notify.fn = NULL; | |
519 | ||
520 | r = dm_io(&req, 1, ®ion, NULL); | |
521 | if (unlikely(r)) | |
522 | writecache_error(wc, r, "error flushing metadata: %d", r); | |
523 | } | |
524 | ||
525 | static void writecache_wait_for_ios(struct dm_writecache *wc, int direction) | |
526 | { | |
527 | wait_event(wc->bio_in_progress_wait[direction], | |
528 | !atomic_read(&wc->bio_in_progress[direction])); | |
529 | } | |
530 | ||
531 | #define WFE_RETURN_FOLLOWING 1 | |
532 | #define WFE_LOWEST_SEQ 2 | |
533 | ||
534 | static struct wc_entry *writecache_find_entry(struct dm_writecache *wc, | |
535 | uint64_t block, int flags) | |
536 | { | |
537 | struct wc_entry *e; | |
538 | struct rb_node *node = wc->tree.rb_node; | |
539 | ||
540 | if (unlikely(!node)) | |
541 | return NULL; | |
542 | ||
543 | while (1) { | |
544 | e = container_of(node, struct wc_entry, rb_node); | |
545 | if (read_original_sector(wc, e) == block) | |
546 | break; | |
547 | node = (read_original_sector(wc, e) >= block ? | |
548 | e->rb_node.rb_left : e->rb_node.rb_right); | |
549 | if (unlikely(!node)) { | |
550 | if (!(flags & WFE_RETURN_FOLLOWING)) { | |
551 | return NULL; | |
552 | } | |
553 | if (read_original_sector(wc, e) >= block) { | |
554 | break; | |
555 | } else { | |
556 | node = rb_next(&e->rb_node); | |
557 | if (unlikely(!node)) { | |
558 | return NULL; | |
559 | } | |
560 | e = container_of(node, struct wc_entry, rb_node); | |
561 | break; | |
562 | } | |
563 | } | |
564 | } | |
565 | ||
566 | while (1) { | |
567 | struct wc_entry *e2; | |
568 | if (flags & WFE_LOWEST_SEQ) | |
569 | node = rb_prev(&e->rb_node); | |
570 | else | |
571 | node = rb_next(&e->rb_node); | |
572 | if (!node) | |
573 | return e; | |
574 | e2 = container_of(node, struct wc_entry, rb_node); | |
575 | if (read_original_sector(wc, e2) != block) | |
576 | return e; | |
577 | e = e2; | |
578 | } | |
579 | } | |
580 | ||
581 | static void writecache_insert_entry(struct dm_writecache *wc, struct wc_entry *ins) | |
582 | { | |
583 | struct wc_entry *e; | |
584 | struct rb_node **node = &wc->tree.rb_node, *parent = NULL; | |
585 | ||
586 | while (*node) { | |
587 | e = container_of(*node, struct wc_entry, rb_node); | |
588 | parent = &e->rb_node; | |
589 | if (read_original_sector(wc, e) > read_original_sector(wc, ins)) | |
590 | node = &parent->rb_left; | |
591 | else | |
592 | node = &parent->rb_right; | |
593 | } | |
594 | rb_link_node(&ins->rb_node, parent, node); | |
595 | rb_insert_color(&ins->rb_node, &wc->tree); | |
596 | list_add(&ins->lru, &wc->lru); | |
597 | } | |
598 | ||
599 | static void writecache_unlink(struct dm_writecache *wc, struct wc_entry *e) | |
600 | { | |
601 | list_del(&e->lru); | |
602 | rb_erase(&e->rb_node, &wc->tree); | |
603 | } | |
604 | ||
605 | static void writecache_add_to_freelist(struct dm_writecache *wc, struct wc_entry *e) | |
606 | { | |
607 | if (WC_MODE_SORT_FREELIST(wc)) { | |
608 | struct rb_node **node = &wc->freetree.rb_node, *parent = NULL; | |
609 | if (unlikely(!*node)) | |
610 | wc->current_free = e; | |
611 | while (*node) { | |
612 | parent = *node; | |
613 | if (&e->rb_node < *node) | |
614 | node = &parent->rb_left; | |
615 | else | |
616 | node = &parent->rb_right; | |
617 | } | |
618 | rb_link_node(&e->rb_node, parent, node); | |
619 | rb_insert_color(&e->rb_node, &wc->freetree); | |
620 | } else { | |
621 | list_add_tail(&e->lru, &wc->freelist); | |
622 | } | |
623 | wc->freelist_size++; | |
624 | } | |
625 | ||
626 | static struct wc_entry *writecache_pop_from_freelist(struct dm_writecache *wc) | |
627 | { | |
628 | struct wc_entry *e; | |
629 | ||
630 | if (WC_MODE_SORT_FREELIST(wc)) { | |
631 | struct rb_node *next; | |
632 | if (unlikely(!wc->current_free)) | |
633 | return NULL; | |
634 | e = wc->current_free; | |
635 | next = rb_next(&e->rb_node); | |
636 | rb_erase(&e->rb_node, &wc->freetree); | |
637 | if (unlikely(!next)) | |
638 | next = rb_first(&wc->freetree); | |
639 | wc->current_free = next ? container_of(next, struct wc_entry, rb_node) : NULL; | |
640 | } else { | |
641 | if (unlikely(list_empty(&wc->freelist))) | |
642 | return NULL; | |
643 | e = container_of(wc->freelist.next, struct wc_entry, lru); | |
644 | list_del(&e->lru); | |
645 | } | |
646 | wc->freelist_size--; | |
647 | if (unlikely(wc->freelist_size + wc->writeback_size <= wc->freelist_high_watermark)) | |
648 | queue_work(wc->writeback_wq, &wc->writeback_work); | |
649 | ||
650 | return e; | |
651 | } | |
652 | ||
653 | static void writecache_free_entry(struct dm_writecache *wc, struct wc_entry *e) | |
654 | { | |
655 | writecache_unlink(wc, e); | |
656 | writecache_add_to_freelist(wc, e); | |
657 | clear_seq_count(wc, e); | |
658 | writecache_flush_region(wc, memory_entry(wc, e), sizeof(struct wc_memory_entry)); | |
659 | if (unlikely(waitqueue_active(&wc->freelist_wait))) | |
660 | wake_up(&wc->freelist_wait); | |
661 | } | |
662 | ||
663 | static void writecache_wait_on_freelist(struct dm_writecache *wc) | |
664 | { | |
665 | DEFINE_WAIT(wait); | |
666 | ||
667 | prepare_to_wait(&wc->freelist_wait, &wait, TASK_UNINTERRUPTIBLE); | |
668 | wc_unlock(wc); | |
669 | io_schedule(); | |
670 | finish_wait(&wc->freelist_wait, &wait); | |
671 | wc_lock(wc); | |
672 | } | |
673 | ||
674 | static void writecache_poison_lists(struct dm_writecache *wc) | |
675 | { | |
676 | /* | |
677 | * Catch incorrect access to these values while the device is suspended. | |
678 | */ | |
679 | memset(&wc->tree, -1, sizeof wc->tree); | |
680 | wc->lru.next = LIST_POISON1; | |
681 | wc->lru.prev = LIST_POISON2; | |
682 | wc->freelist.next = LIST_POISON1; | |
683 | wc->freelist.prev = LIST_POISON2; | |
684 | } | |
685 | ||
686 | static void writecache_flush_entry(struct dm_writecache *wc, struct wc_entry *e) | |
687 | { | |
688 | writecache_flush_region(wc, memory_entry(wc, e), sizeof(struct wc_memory_entry)); | |
689 | if (WC_MODE_PMEM(wc)) | |
690 | writecache_flush_region(wc, memory_data(wc, e), wc->block_size); | |
691 | } | |
692 | ||
693 | static bool writecache_entry_is_committed(struct dm_writecache *wc, struct wc_entry *e) | |
694 | { | |
695 | return read_seq_count(wc, e) < wc->seq_count; | |
696 | } | |
697 | ||
698 | static void writecache_flush(struct dm_writecache *wc) | |
699 | { | |
700 | struct wc_entry *e, *e2; | |
701 | bool need_flush_after_free; | |
702 | ||
703 | wc->uncommitted_blocks = 0; | |
704 | del_timer(&wc->autocommit_timer); | |
705 | ||
706 | if (list_empty(&wc->lru)) | |
707 | return; | |
708 | ||
709 | e = container_of(wc->lru.next, struct wc_entry, lru); | |
710 | if (writecache_entry_is_committed(wc, e)) { | |
711 | if (wc->overwrote_committed) { | |
712 | writecache_wait_for_ios(wc, WRITE); | |
713 | writecache_disk_flush(wc, wc->ssd_dev); | |
714 | wc->overwrote_committed = false; | |
715 | } | |
716 | return; | |
717 | } | |
718 | while (1) { | |
719 | writecache_flush_entry(wc, e); | |
720 | if (unlikely(e->lru.next == &wc->lru)) | |
721 | break; | |
722 | e2 = container_of(e->lru.next, struct wc_entry, lru); | |
723 | if (writecache_entry_is_committed(wc, e2)) | |
724 | break; | |
725 | e = e2; | |
726 | cond_resched(); | |
727 | } | |
728 | writecache_commit_flushed(wc); | |
729 | ||
730 | writecache_wait_for_ios(wc, WRITE); | |
731 | ||
732 | wc->seq_count++; | |
733 | pmem_assign(sb(wc)->seq_count, cpu_to_le64(wc->seq_count)); | |
734 | writecache_flush_region(wc, &sb(wc)->seq_count, sizeof sb(wc)->seq_count); | |
735 | writecache_commit_flushed(wc); | |
736 | ||
737 | wc->overwrote_committed = false; | |
738 | ||
739 | need_flush_after_free = false; | |
740 | while (1) { | |
741 | /* Free another committed entry with lower seq-count */ | |
742 | struct rb_node *rb_node = rb_prev(&e->rb_node); | |
743 | ||
744 | if (rb_node) { | |
745 | e2 = container_of(rb_node, struct wc_entry, rb_node); | |
746 | if (read_original_sector(wc, e2) == read_original_sector(wc, e) && | |
747 | likely(!e2->write_in_progress)) { | |
748 | writecache_free_entry(wc, e2); | |
749 | need_flush_after_free = true; | |
750 | } | |
751 | } | |
752 | if (unlikely(e->lru.prev == &wc->lru)) | |
753 | break; | |
754 | e = container_of(e->lru.prev, struct wc_entry, lru); | |
755 | cond_resched(); | |
756 | } | |
757 | ||
758 | if (need_flush_after_free) | |
759 | writecache_commit_flushed(wc); | |
760 | } | |
761 | ||
762 | static void writecache_flush_work(struct work_struct *work) | |
763 | { | |
764 | struct dm_writecache *wc = container_of(work, struct dm_writecache, flush_work); | |
765 | ||
766 | wc_lock(wc); | |
767 | writecache_flush(wc); | |
768 | wc_unlock(wc); | |
769 | } | |
770 | ||
771 | static void writecache_autocommit_timer(struct timer_list *t) | |
772 | { | |
773 | struct dm_writecache *wc = from_timer(wc, t, autocommit_timer); | |
774 | if (!writecache_has_error(wc)) | |
775 | queue_work(wc->writeback_wq, &wc->flush_work); | |
776 | } | |
777 | ||
778 | static void writecache_schedule_autocommit(struct dm_writecache *wc) | |
779 | { | |
780 | if (!timer_pending(&wc->autocommit_timer)) | |
781 | mod_timer(&wc->autocommit_timer, jiffies + wc->autocommit_jiffies); | |
782 | } | |
783 | ||
784 | static void writecache_discard(struct dm_writecache *wc, sector_t start, sector_t end) | |
785 | { | |
786 | struct wc_entry *e; | |
787 | bool discarded_something = false; | |
788 | ||
789 | e = writecache_find_entry(wc, start, WFE_RETURN_FOLLOWING | WFE_LOWEST_SEQ); | |
790 | if (unlikely(!e)) | |
791 | return; | |
792 | ||
793 | while (read_original_sector(wc, e) < end) { | |
794 | struct rb_node *node = rb_next(&e->rb_node); | |
795 | ||
796 | if (likely(!e->write_in_progress)) { | |
797 | if (!discarded_something) { | |
798 | writecache_wait_for_ios(wc, READ); | |
799 | writecache_wait_for_ios(wc, WRITE); | |
800 | discarded_something = true; | |
801 | } | |
802 | writecache_free_entry(wc, e); | |
803 | } | |
804 | ||
805 | if (!node) | |
806 | break; | |
807 | ||
808 | e = container_of(node, struct wc_entry, rb_node); | |
809 | } | |
810 | ||
811 | if (discarded_something) | |
812 | writecache_commit_flushed(wc); | |
813 | } | |
814 | ||
815 | static bool writecache_wait_for_writeback(struct dm_writecache *wc) | |
816 | { | |
817 | if (wc->writeback_size) { | |
818 | writecache_wait_on_freelist(wc); | |
819 | return true; | |
820 | } | |
821 | return false; | |
822 | } | |
823 | ||
824 | static void writecache_suspend(struct dm_target *ti) | |
825 | { | |
826 | struct dm_writecache *wc = ti->private; | |
827 | bool flush_on_suspend; | |
828 | ||
829 | del_timer_sync(&wc->autocommit_timer); | |
830 | ||
831 | wc_lock(wc); | |
832 | writecache_flush(wc); | |
833 | flush_on_suspend = wc->flush_on_suspend; | |
834 | if (flush_on_suspend) { | |
835 | wc->flush_on_suspend = false; | |
836 | wc->writeback_all++; | |
837 | queue_work(wc->writeback_wq, &wc->writeback_work); | |
838 | } | |
839 | wc_unlock(wc); | |
840 | ||
841 | flush_workqueue(wc->writeback_wq); | |
842 | ||
843 | wc_lock(wc); | |
844 | if (flush_on_suspend) | |
845 | wc->writeback_all--; | |
846 | while (writecache_wait_for_writeback(wc)); | |
847 | ||
848 | if (WC_MODE_PMEM(wc)) | |
849 | persistent_memory_flush_cache(wc->memory_map, wc->memory_map_size); | |
850 | ||
851 | writecache_poison_lists(wc); | |
852 | ||
853 | wc_unlock(wc); | |
854 | } | |
855 | ||
856 | static int writecache_alloc_entries(struct dm_writecache *wc) | |
857 | { | |
858 | size_t b; | |
859 | ||
860 | if (wc->entries) | |
861 | return 0; | |
50a7d3ba | 862 | wc->entries = vmalloc(array_size(sizeof(struct wc_entry), wc->n_blocks)); |
48debafe MP |
863 | if (!wc->entries) |
864 | return -ENOMEM; | |
865 | for (b = 0; b < wc->n_blocks; b++) { | |
866 | struct wc_entry *e = &wc->entries[b]; | |
867 | e->index = b; | |
868 | e->write_in_progress = false; | |
869 | } | |
870 | ||
871 | return 0; | |
872 | } | |
873 | ||
874 | static void writecache_resume(struct dm_target *ti) | |
875 | { | |
876 | struct dm_writecache *wc = ti->private; | |
877 | size_t b; | |
878 | bool need_flush = false; | |
879 | __le64 sb_seq_count; | |
880 | int r; | |
881 | ||
882 | wc_lock(wc); | |
883 | ||
884 | if (WC_MODE_PMEM(wc)) | |
885 | persistent_memory_invalidate_cache(wc->memory_map, wc->memory_map_size); | |
886 | ||
887 | wc->tree = RB_ROOT; | |
888 | INIT_LIST_HEAD(&wc->lru); | |
889 | if (WC_MODE_SORT_FREELIST(wc)) { | |
890 | wc->freetree = RB_ROOT; | |
891 | wc->current_free = NULL; | |
892 | } else { | |
893 | INIT_LIST_HEAD(&wc->freelist); | |
894 | } | |
895 | wc->freelist_size = 0; | |
896 | ||
897 | r = memcpy_mcsafe(&sb_seq_count, &sb(wc)->seq_count, sizeof(uint64_t)); | |
898 | if (r) { | |
899 | writecache_error(wc, r, "hardware memory error when reading superblock: %d", r); | |
900 | sb_seq_count = cpu_to_le64(0); | |
901 | } | |
902 | wc->seq_count = le64_to_cpu(sb_seq_count); | |
903 | ||
904 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS | |
905 | for (b = 0; b < wc->n_blocks; b++) { | |
906 | struct wc_entry *e = &wc->entries[b]; | |
907 | struct wc_memory_entry wme; | |
908 | if (writecache_has_error(wc)) { | |
909 | e->original_sector = -1; | |
910 | e->seq_count = -1; | |
911 | continue; | |
912 | } | |
913 | r = memcpy_mcsafe(&wme, memory_entry(wc, e), sizeof(struct wc_memory_entry)); | |
914 | if (r) { | |
915 | writecache_error(wc, r, "hardware memory error when reading metadata entry %lu: %d", | |
916 | (unsigned long)b, r); | |
917 | e->original_sector = -1; | |
918 | e->seq_count = -1; | |
919 | } else { | |
920 | e->original_sector = le64_to_cpu(wme.original_sector); | |
921 | e->seq_count = le64_to_cpu(wme.seq_count); | |
922 | } | |
923 | } | |
924 | #endif | |
925 | for (b = 0; b < wc->n_blocks; b++) { | |
926 | struct wc_entry *e = &wc->entries[b]; | |
927 | if (!writecache_entry_is_committed(wc, e)) { | |
928 | if (read_seq_count(wc, e) != -1) { | |
929 | erase_this: | |
930 | clear_seq_count(wc, e); | |
931 | need_flush = true; | |
932 | } | |
933 | writecache_add_to_freelist(wc, e); | |
934 | } else { | |
935 | struct wc_entry *old; | |
936 | ||
937 | old = writecache_find_entry(wc, read_original_sector(wc, e), 0); | |
938 | if (!old) { | |
939 | writecache_insert_entry(wc, e); | |
940 | } else { | |
941 | if (read_seq_count(wc, old) == read_seq_count(wc, e)) { | |
942 | writecache_error(wc, -EINVAL, | |
943 | "two identical entries, position %llu, sector %llu, sequence %llu", | |
944 | (unsigned long long)b, (unsigned long long)read_original_sector(wc, e), | |
945 | (unsigned long long)read_seq_count(wc, e)); | |
946 | } | |
947 | if (read_seq_count(wc, old) > read_seq_count(wc, e)) { | |
948 | goto erase_this; | |
949 | } else { | |
950 | writecache_free_entry(wc, old); | |
951 | writecache_insert_entry(wc, e); | |
952 | need_flush = true; | |
953 | } | |
954 | } | |
955 | } | |
956 | cond_resched(); | |
957 | } | |
958 | ||
959 | if (need_flush) { | |
960 | writecache_flush_all_metadata(wc); | |
961 | writecache_commit_flushed(wc); | |
962 | } | |
963 | ||
964 | wc_unlock(wc); | |
965 | } | |
966 | ||
967 | static int process_flush_mesg(unsigned argc, char **argv, struct dm_writecache *wc) | |
968 | { | |
969 | if (argc != 1) | |
970 | return -EINVAL; | |
971 | ||
972 | wc_lock(wc); | |
973 | if (dm_suspended(wc->ti)) { | |
974 | wc_unlock(wc); | |
975 | return -EBUSY; | |
976 | } | |
977 | if (writecache_has_error(wc)) { | |
978 | wc_unlock(wc); | |
979 | return -EIO; | |
980 | } | |
981 | ||
982 | writecache_flush(wc); | |
983 | wc->writeback_all++; | |
984 | queue_work(wc->writeback_wq, &wc->writeback_work); | |
985 | wc_unlock(wc); | |
986 | ||
987 | flush_workqueue(wc->writeback_wq); | |
988 | ||
989 | wc_lock(wc); | |
990 | wc->writeback_all--; | |
991 | if (writecache_has_error(wc)) { | |
992 | wc_unlock(wc); | |
993 | return -EIO; | |
994 | } | |
995 | wc_unlock(wc); | |
996 | ||
997 | return 0; | |
998 | } | |
999 | ||
1000 | static int process_flush_on_suspend_mesg(unsigned argc, char **argv, struct dm_writecache *wc) | |
1001 | { | |
1002 | if (argc != 1) | |
1003 | return -EINVAL; | |
1004 | ||
1005 | wc_lock(wc); | |
1006 | wc->flush_on_suspend = true; | |
1007 | wc_unlock(wc); | |
1008 | ||
1009 | return 0; | |
1010 | } | |
1011 | ||
1012 | static int writecache_message(struct dm_target *ti, unsigned argc, char **argv, | |
1013 | char *result, unsigned maxlen) | |
1014 | { | |
1015 | int r = -EINVAL; | |
1016 | struct dm_writecache *wc = ti->private; | |
1017 | ||
1018 | if (!strcasecmp(argv[0], "flush")) | |
1019 | r = process_flush_mesg(argc, argv, wc); | |
1020 | else if (!strcasecmp(argv[0], "flush_on_suspend")) | |
1021 | r = process_flush_on_suspend_mesg(argc, argv, wc); | |
1022 | else | |
1023 | DMERR("unrecognised message received: %s", argv[0]); | |
1024 | ||
1025 | return r; | |
1026 | } | |
1027 | ||
1028 | static void bio_copy_block(struct dm_writecache *wc, struct bio *bio, void *data) | |
1029 | { | |
1030 | void *buf; | |
1031 | unsigned long flags; | |
1032 | unsigned size; | |
1033 | int rw = bio_data_dir(bio); | |
1034 | unsigned remaining_size = wc->block_size; | |
1035 | ||
1036 | do { | |
1037 | struct bio_vec bv = bio_iter_iovec(bio, bio->bi_iter); | |
1038 | buf = bvec_kmap_irq(&bv, &flags); | |
1039 | size = bv.bv_len; | |
1040 | if (unlikely(size > remaining_size)) | |
1041 | size = remaining_size; | |
1042 | ||
1043 | if (rw == READ) { | |
1044 | int r; | |
1045 | r = memcpy_mcsafe(buf, data, size); | |
1046 | flush_dcache_page(bio_page(bio)); | |
1047 | if (unlikely(r)) { | |
1048 | writecache_error(wc, r, "hardware memory error when reading data: %d", r); | |
1049 | bio->bi_status = BLK_STS_IOERR; | |
1050 | } | |
1051 | } else { | |
1052 | flush_dcache_page(bio_page(bio)); | |
1053 | memcpy_flushcache(data, buf, size); | |
1054 | } | |
1055 | ||
1056 | bvec_kunmap_irq(buf, &flags); | |
1057 | ||
1058 | data = (char *)data + size; | |
1059 | remaining_size -= size; | |
1060 | bio_advance(bio, size); | |
1061 | } while (unlikely(remaining_size)); | |
1062 | } | |
1063 | ||
1064 | static int writecache_flush_thread(void *data) | |
1065 | { | |
1066 | struct dm_writecache *wc = data; | |
1067 | ||
1068 | while (1) { | |
1069 | struct bio *bio; | |
1070 | ||
1071 | wc_lock(wc); | |
1072 | bio = bio_list_pop(&wc->flush_list); | |
1073 | if (!bio) { | |
1074 | set_current_state(TASK_INTERRUPTIBLE); | |
1075 | wc_unlock(wc); | |
1076 | ||
1077 | if (unlikely(kthread_should_stop())) { | |
1078 | set_current_state(TASK_RUNNING); | |
1079 | break; | |
1080 | } | |
1081 | ||
1082 | schedule(); | |
1083 | continue; | |
1084 | } | |
1085 | ||
1086 | if (bio_op(bio) == REQ_OP_DISCARD) { | |
1087 | writecache_discard(wc, bio->bi_iter.bi_sector, | |
1088 | bio_end_sector(bio)); | |
1089 | wc_unlock(wc); | |
1090 | bio_set_dev(bio, wc->dev->bdev); | |
1091 | generic_make_request(bio); | |
1092 | } else { | |
1093 | writecache_flush(wc); | |
1094 | wc_unlock(wc); | |
1095 | if (writecache_has_error(wc)) | |
1096 | bio->bi_status = BLK_STS_IOERR; | |
1097 | bio_endio(bio); | |
1098 | } | |
1099 | } | |
1100 | ||
1101 | return 0; | |
1102 | } | |
1103 | ||
1104 | static void writecache_offload_bio(struct dm_writecache *wc, struct bio *bio) | |
1105 | { | |
1106 | if (bio_list_empty(&wc->flush_list)) | |
1107 | wake_up_process(wc->flush_thread); | |
1108 | bio_list_add(&wc->flush_list, bio); | |
1109 | } | |
1110 | ||
1111 | static int writecache_map(struct dm_target *ti, struct bio *bio) | |
1112 | { | |
1113 | struct wc_entry *e; | |
1114 | struct dm_writecache *wc = ti->private; | |
1115 | ||
1116 | bio->bi_private = NULL; | |
1117 | ||
1118 | wc_lock(wc); | |
1119 | ||
1120 | if (unlikely(bio->bi_opf & REQ_PREFLUSH)) { | |
1121 | if (writecache_has_error(wc)) | |
1122 | goto unlock_error; | |
1123 | if (WC_MODE_PMEM(wc)) { | |
1124 | writecache_flush(wc); | |
1125 | if (writecache_has_error(wc)) | |
1126 | goto unlock_error; | |
1127 | goto unlock_submit; | |
1128 | } else { | |
1129 | writecache_offload_bio(wc, bio); | |
1130 | goto unlock_return; | |
1131 | } | |
1132 | } | |
1133 | ||
1134 | bio->bi_iter.bi_sector = dm_target_offset(ti, bio->bi_iter.bi_sector); | |
1135 | ||
1136 | if (unlikely((((unsigned)bio->bi_iter.bi_sector | bio_sectors(bio)) & | |
1137 | (wc->block_size / 512 - 1)) != 0)) { | |
1138 | DMERR("I/O is not aligned, sector %llu, size %u, block size %u", | |
1139 | (unsigned long long)bio->bi_iter.bi_sector, | |
1140 | bio->bi_iter.bi_size, wc->block_size); | |
1141 | goto unlock_error; | |
1142 | } | |
1143 | ||
1144 | if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) { | |
1145 | if (writecache_has_error(wc)) | |
1146 | goto unlock_error; | |
1147 | if (WC_MODE_PMEM(wc)) { | |
1148 | writecache_discard(wc, bio->bi_iter.bi_sector, bio_end_sector(bio)); | |
1149 | goto unlock_remap_origin; | |
1150 | } else { | |
1151 | writecache_offload_bio(wc, bio); | |
1152 | goto unlock_return; | |
1153 | } | |
1154 | } | |
1155 | ||
1156 | if (bio_data_dir(bio) == READ) { | |
1157 | read_next_block: | |
1158 | e = writecache_find_entry(wc, bio->bi_iter.bi_sector, WFE_RETURN_FOLLOWING); | |
1159 | if (e && read_original_sector(wc, e) == bio->bi_iter.bi_sector) { | |
1160 | if (WC_MODE_PMEM(wc)) { | |
1161 | bio_copy_block(wc, bio, memory_data(wc, e)); | |
1162 | if (bio->bi_iter.bi_size) | |
1163 | goto read_next_block; | |
1164 | goto unlock_submit; | |
1165 | } else { | |
1166 | dm_accept_partial_bio(bio, wc->block_size >> SECTOR_SHIFT); | |
1167 | bio_set_dev(bio, wc->ssd_dev->bdev); | |
1168 | bio->bi_iter.bi_sector = cache_sector(wc, e); | |
1169 | if (!writecache_entry_is_committed(wc, e)) | |
1170 | writecache_wait_for_ios(wc, WRITE); | |
1171 | goto unlock_remap; | |
1172 | } | |
1173 | } else { | |
1174 | if (e) { | |
1175 | sector_t next_boundary = | |
1176 | read_original_sector(wc, e) - bio->bi_iter.bi_sector; | |
1177 | if (next_boundary < bio->bi_iter.bi_size >> SECTOR_SHIFT) { | |
1178 | dm_accept_partial_bio(bio, next_boundary); | |
1179 | } | |
1180 | } | |
1181 | goto unlock_remap_origin; | |
1182 | } | |
1183 | } else { | |
1184 | do { | |
1185 | if (writecache_has_error(wc)) | |
1186 | goto unlock_error; | |
1187 | e = writecache_find_entry(wc, bio->bi_iter.bi_sector, 0); | |
1188 | if (e) { | |
1189 | if (!writecache_entry_is_committed(wc, e)) | |
1190 | goto bio_copy; | |
1191 | if (!WC_MODE_PMEM(wc) && !e->write_in_progress) { | |
1192 | wc->overwrote_committed = true; | |
1193 | goto bio_copy; | |
1194 | } | |
1195 | } | |
1196 | e = writecache_pop_from_freelist(wc); | |
1197 | if (unlikely(!e)) { | |
1198 | writecache_wait_on_freelist(wc); | |
1199 | continue; | |
1200 | } | |
1201 | write_original_sector_seq_count(wc, e, bio->bi_iter.bi_sector, wc->seq_count); | |
1202 | writecache_insert_entry(wc, e); | |
1203 | wc->uncommitted_blocks++; | |
1204 | bio_copy: | |
1205 | if (WC_MODE_PMEM(wc)) { | |
1206 | bio_copy_block(wc, bio, memory_data(wc, e)); | |
1207 | } else { | |
1208 | dm_accept_partial_bio(bio, wc->block_size >> SECTOR_SHIFT); | |
1209 | bio_set_dev(bio, wc->ssd_dev->bdev); | |
1210 | bio->bi_iter.bi_sector = cache_sector(wc, e); | |
1211 | if (unlikely(wc->uncommitted_blocks >= wc->autocommit_blocks)) { | |
1212 | wc->uncommitted_blocks = 0; | |
1213 | queue_work(wc->writeback_wq, &wc->flush_work); | |
1214 | } else { | |
1215 | writecache_schedule_autocommit(wc); | |
1216 | } | |
1217 | goto unlock_remap; | |
1218 | } | |
1219 | } while (bio->bi_iter.bi_size); | |
1220 | ||
1221 | if (unlikely(wc->uncommitted_blocks >= wc->autocommit_blocks)) | |
1222 | writecache_flush(wc); | |
1223 | else | |
1224 | writecache_schedule_autocommit(wc); | |
1225 | goto unlock_submit; | |
1226 | } | |
1227 | ||
1228 | unlock_remap_origin: | |
1229 | bio_set_dev(bio, wc->dev->bdev); | |
1230 | wc_unlock(wc); | |
1231 | return DM_MAPIO_REMAPPED; | |
1232 | ||
1233 | unlock_remap: | |
1234 | /* make sure that writecache_end_io decrements bio_in_progress: */ | |
1235 | bio->bi_private = (void *)1; | |
1236 | atomic_inc(&wc->bio_in_progress[bio_data_dir(bio)]); | |
1237 | wc_unlock(wc); | |
1238 | return DM_MAPIO_REMAPPED; | |
1239 | ||
1240 | unlock_submit: | |
1241 | wc_unlock(wc); | |
1242 | bio_endio(bio); | |
1243 | return DM_MAPIO_SUBMITTED; | |
1244 | ||
1245 | unlock_return: | |
1246 | wc_unlock(wc); | |
1247 | return DM_MAPIO_SUBMITTED; | |
1248 | ||
1249 | unlock_error: | |
1250 | wc_unlock(wc); | |
1251 | bio_io_error(bio); | |
1252 | return DM_MAPIO_SUBMITTED; | |
1253 | } | |
1254 | ||
1255 | static int writecache_end_io(struct dm_target *ti, struct bio *bio, blk_status_t *status) | |
1256 | { | |
1257 | struct dm_writecache *wc = ti->private; | |
1258 | ||
1259 | if (bio->bi_private != NULL) { | |
1260 | int dir = bio_data_dir(bio); | |
1261 | if (atomic_dec_and_test(&wc->bio_in_progress[dir])) | |
1262 | if (unlikely(waitqueue_active(&wc->bio_in_progress_wait[dir]))) | |
1263 | wake_up(&wc->bio_in_progress_wait[dir]); | |
1264 | } | |
1265 | return 0; | |
1266 | } | |
1267 | ||
1268 | static int writecache_iterate_devices(struct dm_target *ti, | |
1269 | iterate_devices_callout_fn fn, void *data) | |
1270 | { | |
1271 | struct dm_writecache *wc = ti->private; | |
1272 | ||
1273 | return fn(ti, wc->dev, 0, ti->len, data); | |
1274 | } | |
1275 | ||
1276 | static void writecache_io_hints(struct dm_target *ti, struct queue_limits *limits) | |
1277 | { | |
1278 | struct dm_writecache *wc = ti->private; | |
1279 | ||
1280 | if (limits->logical_block_size < wc->block_size) | |
1281 | limits->logical_block_size = wc->block_size; | |
1282 | ||
1283 | if (limits->physical_block_size < wc->block_size) | |
1284 | limits->physical_block_size = wc->block_size; | |
1285 | ||
1286 | if (limits->io_min < wc->block_size) | |
1287 | limits->io_min = wc->block_size; | |
1288 | } | |
1289 | ||
1290 | ||
1291 | static void writecache_writeback_endio(struct bio *bio) | |
1292 | { | |
1293 | struct writeback_struct *wb = container_of(bio, struct writeback_struct, bio); | |
1294 | struct dm_writecache *wc = wb->wc; | |
1295 | unsigned long flags; | |
1296 | ||
1297 | raw_spin_lock_irqsave(&wc->endio_list_lock, flags); | |
1298 | if (unlikely(list_empty(&wc->endio_list))) | |
1299 | wake_up_process(wc->endio_thread); | |
1300 | list_add_tail(&wb->endio_entry, &wc->endio_list); | |
1301 | raw_spin_unlock_irqrestore(&wc->endio_list_lock, flags); | |
1302 | } | |
1303 | ||
1304 | static void writecache_copy_endio(int read_err, unsigned long write_err, void *ptr) | |
1305 | { | |
1306 | struct copy_struct *c = ptr; | |
1307 | struct dm_writecache *wc = c->wc; | |
1308 | ||
1309 | c->error = likely(!(read_err | write_err)) ? 0 : -EIO; | |
1310 | ||
1311 | raw_spin_lock_irq(&wc->endio_list_lock); | |
1312 | if (unlikely(list_empty(&wc->endio_list))) | |
1313 | wake_up_process(wc->endio_thread); | |
1314 | list_add_tail(&c->endio_entry, &wc->endio_list); | |
1315 | raw_spin_unlock_irq(&wc->endio_list_lock); | |
1316 | } | |
1317 | ||
1318 | static void __writecache_endio_pmem(struct dm_writecache *wc, struct list_head *list) | |
1319 | { | |
1320 | unsigned i; | |
1321 | struct writeback_struct *wb; | |
1322 | struct wc_entry *e; | |
1323 | unsigned long n_walked = 0; | |
1324 | ||
1325 | do { | |
1326 | wb = list_entry(list->next, struct writeback_struct, endio_entry); | |
1327 | list_del(&wb->endio_entry); | |
1328 | ||
1329 | if (unlikely(wb->bio.bi_status != BLK_STS_OK)) | |
1330 | writecache_error(wc, blk_status_to_errno(wb->bio.bi_status), | |
1331 | "write error %d", wb->bio.bi_status); | |
1332 | i = 0; | |
1333 | do { | |
1334 | e = wb->wc_list[i]; | |
1335 | BUG_ON(!e->write_in_progress); | |
1336 | e->write_in_progress = false; | |
1337 | INIT_LIST_HEAD(&e->lru); | |
1338 | if (!writecache_has_error(wc)) | |
1339 | writecache_free_entry(wc, e); | |
1340 | BUG_ON(!wc->writeback_size); | |
1341 | wc->writeback_size--; | |
1342 | n_walked++; | |
1343 | if (unlikely(n_walked >= ENDIO_LATENCY)) { | |
1344 | writecache_commit_flushed(wc); | |
1345 | wc_unlock(wc); | |
1346 | wc_lock(wc); | |
1347 | n_walked = 0; | |
1348 | } | |
1349 | } while (++i < wb->wc_list_n); | |
1350 | ||
1351 | if (wb->wc_list != wb->wc_list_inline) | |
1352 | kfree(wb->wc_list); | |
1353 | bio_put(&wb->bio); | |
1354 | } while (!list_empty(list)); | |
1355 | } | |
1356 | ||
1357 | static void __writecache_endio_ssd(struct dm_writecache *wc, struct list_head *list) | |
1358 | { | |
1359 | struct copy_struct *c; | |
1360 | struct wc_entry *e; | |
1361 | ||
1362 | do { | |
1363 | c = list_entry(list->next, struct copy_struct, endio_entry); | |
1364 | list_del(&c->endio_entry); | |
1365 | ||
1366 | if (unlikely(c->error)) | |
1367 | writecache_error(wc, c->error, "copy error"); | |
1368 | ||
1369 | e = c->e; | |
1370 | do { | |
1371 | BUG_ON(!e->write_in_progress); | |
1372 | e->write_in_progress = false; | |
1373 | INIT_LIST_HEAD(&e->lru); | |
1374 | if (!writecache_has_error(wc)) | |
1375 | writecache_free_entry(wc, e); | |
1376 | ||
1377 | BUG_ON(!wc->writeback_size); | |
1378 | wc->writeback_size--; | |
1379 | e++; | |
1380 | } while (--c->n_entries); | |
1381 | mempool_free(c, &wc->copy_pool); | |
1382 | } while (!list_empty(list)); | |
1383 | } | |
1384 | ||
1385 | static int writecache_endio_thread(void *data) | |
1386 | { | |
1387 | struct dm_writecache *wc = data; | |
1388 | ||
1389 | while (1) { | |
1390 | struct list_head list; | |
1391 | ||
1392 | raw_spin_lock_irq(&wc->endio_list_lock); | |
1393 | if (!list_empty(&wc->endio_list)) | |
1394 | goto pop_from_list; | |
1395 | set_current_state(TASK_INTERRUPTIBLE); | |
1396 | raw_spin_unlock_irq(&wc->endio_list_lock); | |
1397 | ||
1398 | if (unlikely(kthread_should_stop())) { | |
1399 | set_current_state(TASK_RUNNING); | |
1400 | break; | |
1401 | } | |
1402 | ||
1403 | schedule(); | |
1404 | ||
1405 | continue; | |
1406 | ||
1407 | pop_from_list: | |
1408 | list = wc->endio_list; | |
1409 | list.next->prev = list.prev->next = &list; | |
1410 | INIT_LIST_HEAD(&wc->endio_list); | |
1411 | raw_spin_unlock_irq(&wc->endio_list_lock); | |
1412 | ||
1413 | if (!WC_MODE_FUA(wc)) | |
1414 | writecache_disk_flush(wc, wc->dev); | |
1415 | ||
1416 | wc_lock(wc); | |
1417 | ||
1418 | if (WC_MODE_PMEM(wc)) { | |
1419 | __writecache_endio_pmem(wc, &list); | |
1420 | } else { | |
1421 | __writecache_endio_ssd(wc, &list); | |
1422 | writecache_wait_for_ios(wc, READ); | |
1423 | } | |
1424 | ||
1425 | writecache_commit_flushed(wc); | |
1426 | ||
1427 | wc_unlock(wc); | |
1428 | } | |
1429 | ||
1430 | return 0; | |
1431 | } | |
1432 | ||
1433 | static bool wc_add_block(struct writeback_struct *wb, struct wc_entry *e, gfp_t gfp) | |
1434 | { | |
1435 | struct dm_writecache *wc = wb->wc; | |
1436 | unsigned block_size = wc->block_size; | |
1437 | void *address = memory_data(wc, e); | |
1438 | ||
1439 | persistent_memory_flush_cache(address, block_size); | |
1440 | return bio_add_page(&wb->bio, persistent_memory_page(address), | |
1441 | block_size, persistent_memory_page_offset(address)) != 0; | |
1442 | } | |
1443 | ||
1444 | struct writeback_list { | |
1445 | struct list_head list; | |
1446 | size_t size; | |
1447 | }; | |
1448 | ||
1449 | static void __writeback_throttle(struct dm_writecache *wc, struct writeback_list *wbl) | |
1450 | { | |
1451 | if (unlikely(wc->max_writeback_jobs)) { | |
1452 | if (READ_ONCE(wc->writeback_size) - wbl->size >= wc->max_writeback_jobs) { | |
1453 | wc_lock(wc); | |
1454 | while (wc->writeback_size - wbl->size >= wc->max_writeback_jobs) | |
1455 | writecache_wait_on_freelist(wc); | |
1456 | wc_unlock(wc); | |
1457 | } | |
1458 | } | |
1459 | cond_resched(); | |
1460 | } | |
1461 | ||
1462 | static void __writecache_writeback_pmem(struct dm_writecache *wc, struct writeback_list *wbl) | |
1463 | { | |
1464 | struct wc_entry *e, *f; | |
1465 | struct bio *bio; | |
1466 | struct writeback_struct *wb; | |
1467 | unsigned max_pages; | |
1468 | ||
1469 | while (wbl->size) { | |
1470 | wbl->size--; | |
1471 | e = container_of(wbl->list.prev, struct wc_entry, lru); | |
1472 | list_del(&e->lru); | |
1473 | ||
1474 | max_pages = e->wc_list_contiguous; | |
1475 | ||
1476 | bio = bio_alloc_bioset(GFP_NOIO, max_pages, &wc->bio_set); | |
1477 | wb = container_of(bio, struct writeback_struct, bio); | |
1478 | wb->wc = wc; | |
1479 | wb->bio.bi_end_io = writecache_writeback_endio; | |
1480 | bio_set_dev(&wb->bio, wc->dev->bdev); | |
1481 | wb->bio.bi_iter.bi_sector = read_original_sector(wc, e); | |
1482 | wb->page_offset = PAGE_SIZE; | |
1483 | if (max_pages <= WB_LIST_INLINE || | |
50a7d3ba KC |
1484 | unlikely(!(wb->wc_list = kmalloc_array(max_pages, sizeof(struct wc_entry *), |
1485 | GFP_NOIO | __GFP_NORETRY | | |
1486 | __GFP_NOMEMALLOC | __GFP_NOWARN)))) { | |
48debafe MP |
1487 | wb->wc_list = wb->wc_list_inline; |
1488 | max_pages = WB_LIST_INLINE; | |
1489 | } | |
1490 | ||
1491 | BUG_ON(!wc_add_block(wb, e, GFP_NOIO)); | |
1492 | ||
1493 | wb->wc_list[0] = e; | |
1494 | wb->wc_list_n = 1; | |
1495 | ||
1496 | while (wbl->size && wb->wc_list_n < max_pages) { | |
1497 | f = container_of(wbl->list.prev, struct wc_entry, lru); | |
1498 | if (read_original_sector(wc, f) != | |
1499 | read_original_sector(wc, e) + (wc->block_size >> SECTOR_SHIFT)) | |
1500 | break; | |
1501 | if (!wc_add_block(wb, f, GFP_NOWAIT | __GFP_NOWARN)) | |
1502 | break; | |
1503 | wbl->size--; | |
1504 | list_del(&f->lru); | |
1505 | wb->wc_list[wb->wc_list_n++] = f; | |
1506 | e = f; | |
1507 | } | |
1508 | bio_set_op_attrs(&wb->bio, REQ_OP_WRITE, WC_MODE_FUA(wc) * REQ_FUA); | |
1509 | if (writecache_has_error(wc)) { | |
1510 | bio->bi_status = BLK_STS_IOERR; | |
1511 | bio_endio(&wb->bio); | |
1512 | } else { | |
1513 | submit_bio(&wb->bio); | |
1514 | } | |
1515 | ||
1516 | __writeback_throttle(wc, wbl); | |
1517 | } | |
1518 | } | |
1519 | ||
1520 | static void __writecache_writeback_ssd(struct dm_writecache *wc, struct writeback_list *wbl) | |
1521 | { | |
1522 | struct wc_entry *e, *f; | |
1523 | struct dm_io_region from, to; | |
1524 | struct copy_struct *c; | |
1525 | ||
1526 | while (wbl->size) { | |
1527 | unsigned n_sectors; | |
1528 | ||
1529 | wbl->size--; | |
1530 | e = container_of(wbl->list.prev, struct wc_entry, lru); | |
1531 | list_del(&e->lru); | |
1532 | ||
1533 | n_sectors = e->wc_list_contiguous << (wc->block_size_bits - SECTOR_SHIFT); | |
1534 | ||
1535 | from.bdev = wc->ssd_dev->bdev; | |
1536 | from.sector = cache_sector(wc, e); | |
1537 | from.count = n_sectors; | |
1538 | to.bdev = wc->dev->bdev; | |
1539 | to.sector = read_original_sector(wc, e); | |
1540 | to.count = n_sectors; | |
1541 | ||
1542 | c = mempool_alloc(&wc->copy_pool, GFP_NOIO); | |
1543 | c->wc = wc; | |
1544 | c->e = e; | |
1545 | c->n_entries = e->wc_list_contiguous; | |
1546 | ||
1547 | while ((n_sectors -= wc->block_size >> SECTOR_SHIFT)) { | |
1548 | wbl->size--; | |
1549 | f = container_of(wbl->list.prev, struct wc_entry, lru); | |
1550 | BUG_ON(f != e + 1); | |
1551 | list_del(&f->lru); | |
1552 | e = f; | |
1553 | } | |
1554 | ||
1555 | dm_kcopyd_copy(wc->dm_kcopyd, &from, 1, &to, 0, writecache_copy_endio, c); | |
1556 | ||
1557 | __writeback_throttle(wc, wbl); | |
1558 | } | |
1559 | } | |
1560 | ||
1561 | static void writecache_writeback(struct work_struct *work) | |
1562 | { | |
1563 | struct dm_writecache *wc = container_of(work, struct dm_writecache, writeback_work); | |
1564 | struct blk_plug plug; | |
1565 | struct wc_entry *e, *f, *g; | |
1566 | struct rb_node *node, *next_node; | |
1567 | struct list_head skipped; | |
1568 | struct writeback_list wbl; | |
1569 | unsigned long n_walked; | |
1570 | ||
1571 | wc_lock(wc); | |
1572 | restart: | |
1573 | if (writecache_has_error(wc)) { | |
1574 | wc_unlock(wc); | |
1575 | return; | |
1576 | } | |
1577 | ||
1578 | if (unlikely(wc->writeback_all)) { | |
1579 | if (writecache_wait_for_writeback(wc)) | |
1580 | goto restart; | |
1581 | } | |
1582 | ||
1583 | if (wc->overwrote_committed) { | |
1584 | writecache_wait_for_ios(wc, WRITE); | |
1585 | } | |
1586 | ||
1587 | n_walked = 0; | |
1588 | INIT_LIST_HEAD(&skipped); | |
1589 | INIT_LIST_HEAD(&wbl.list); | |
1590 | wbl.size = 0; | |
1591 | while (!list_empty(&wc->lru) && | |
1592 | (wc->writeback_all || | |
1593 | wc->freelist_size + wc->writeback_size <= wc->freelist_low_watermark)) { | |
1594 | ||
1595 | n_walked++; | |
1596 | if (unlikely(n_walked > WRITEBACK_LATENCY) && | |
1597 | likely(!wc->writeback_all) && likely(!dm_suspended(wc->ti))) { | |
1598 | queue_work(wc->writeback_wq, &wc->writeback_work); | |
1599 | break; | |
1600 | } | |
1601 | ||
1602 | e = container_of(wc->lru.prev, struct wc_entry, lru); | |
1603 | BUG_ON(e->write_in_progress); | |
1604 | if (unlikely(!writecache_entry_is_committed(wc, e))) { | |
1605 | writecache_flush(wc); | |
1606 | } | |
1607 | node = rb_prev(&e->rb_node); | |
1608 | if (node) { | |
1609 | f = container_of(node, struct wc_entry, rb_node); | |
1610 | if (unlikely(read_original_sector(wc, f) == | |
1611 | read_original_sector(wc, e))) { | |
1612 | BUG_ON(!f->write_in_progress); | |
1613 | list_del(&e->lru); | |
1614 | list_add(&e->lru, &skipped); | |
1615 | cond_resched(); | |
1616 | continue; | |
1617 | } | |
1618 | } | |
1619 | wc->writeback_size++; | |
1620 | list_del(&e->lru); | |
1621 | list_add(&e->lru, &wbl.list); | |
1622 | wbl.size++; | |
1623 | e->write_in_progress = true; | |
1624 | e->wc_list_contiguous = 1; | |
1625 | ||
1626 | f = e; | |
1627 | ||
1628 | while (1) { | |
1629 | next_node = rb_next(&f->rb_node); | |
1630 | if (unlikely(!next_node)) | |
1631 | break; | |
1632 | g = container_of(next_node, struct wc_entry, rb_node); | |
1633 | if (read_original_sector(wc, g) == | |
1634 | read_original_sector(wc, f)) { | |
1635 | f = g; | |
1636 | continue; | |
1637 | } | |
1638 | if (read_original_sector(wc, g) != | |
1639 | read_original_sector(wc, f) + (wc->block_size >> SECTOR_SHIFT)) | |
1640 | break; | |
1641 | if (unlikely(g->write_in_progress)) | |
1642 | break; | |
1643 | if (unlikely(!writecache_entry_is_committed(wc, g))) | |
1644 | break; | |
1645 | ||
1646 | if (!WC_MODE_PMEM(wc)) { | |
1647 | if (g != f + 1) | |
1648 | break; | |
1649 | } | |
1650 | ||
1651 | n_walked++; | |
1652 | //if (unlikely(n_walked > WRITEBACK_LATENCY) && likely(!wc->writeback_all)) | |
1653 | // break; | |
1654 | ||
1655 | wc->writeback_size++; | |
1656 | list_del(&g->lru); | |
1657 | list_add(&g->lru, &wbl.list); | |
1658 | wbl.size++; | |
1659 | g->write_in_progress = true; | |
1660 | g->wc_list_contiguous = BIO_MAX_PAGES; | |
1661 | f = g; | |
1662 | e->wc_list_contiguous++; | |
1663 | if (unlikely(e->wc_list_contiguous == BIO_MAX_PAGES)) | |
1664 | break; | |
1665 | } | |
1666 | cond_resched(); | |
1667 | } | |
1668 | ||
1669 | if (!list_empty(&skipped)) { | |
1670 | list_splice_tail(&skipped, &wc->lru); | |
1671 | /* | |
1672 | * If we didn't do any progress, we must wait until some | |
1673 | * writeback finishes to avoid burning CPU in a loop | |
1674 | */ | |
1675 | if (unlikely(!wbl.size)) | |
1676 | writecache_wait_for_writeback(wc); | |
1677 | } | |
1678 | ||
1679 | wc_unlock(wc); | |
1680 | ||
1681 | blk_start_plug(&plug); | |
1682 | ||
1683 | if (WC_MODE_PMEM(wc)) | |
1684 | __writecache_writeback_pmem(wc, &wbl); | |
1685 | else | |
1686 | __writecache_writeback_ssd(wc, &wbl); | |
1687 | ||
1688 | blk_finish_plug(&plug); | |
1689 | ||
1690 | if (unlikely(wc->writeback_all)) { | |
1691 | wc_lock(wc); | |
1692 | while (writecache_wait_for_writeback(wc)); | |
1693 | wc_unlock(wc); | |
1694 | } | |
1695 | } | |
1696 | ||
1697 | static int calculate_memory_size(uint64_t device_size, unsigned block_size, | |
1698 | size_t *n_blocks_p, size_t *n_metadata_blocks_p) | |
1699 | { | |
1700 | uint64_t n_blocks, offset; | |
1701 | struct wc_entry e; | |
1702 | ||
1703 | n_blocks = device_size; | |
1704 | do_div(n_blocks, block_size + sizeof(struct wc_memory_entry)); | |
1705 | ||
1706 | while (1) { | |
1707 | if (!n_blocks) | |
1708 | return -ENOSPC; | |
1709 | /* Verify the following entries[n_blocks] won't overflow */ | |
1710 | if (n_blocks >= ((size_t)-sizeof(struct wc_memory_superblock) / | |
1711 | sizeof(struct wc_memory_entry))) | |
1712 | return -EFBIG; | |
1713 | offset = offsetof(struct wc_memory_superblock, entries[n_blocks]); | |
1714 | offset = (offset + block_size - 1) & ~(uint64_t)(block_size - 1); | |
1715 | if (offset + n_blocks * block_size <= device_size) | |
1716 | break; | |
1717 | n_blocks--; | |
1718 | } | |
1719 | ||
1720 | /* check if the bit field overflows */ | |
1721 | e.index = n_blocks; | |
1722 | if (e.index != n_blocks) | |
1723 | return -EFBIG; | |
1724 | ||
1725 | if (n_blocks_p) | |
1726 | *n_blocks_p = n_blocks; | |
1727 | if (n_metadata_blocks_p) | |
1728 | *n_metadata_blocks_p = offset >> __ffs(block_size); | |
1729 | return 0; | |
1730 | } | |
1731 | ||
1732 | static int init_memory(struct dm_writecache *wc) | |
1733 | { | |
1734 | size_t b; | |
1735 | int r; | |
1736 | ||
1737 | r = calculate_memory_size(wc->memory_map_size, wc->block_size, &wc->n_blocks, NULL); | |
1738 | if (r) | |
1739 | return r; | |
1740 | ||
1741 | r = writecache_alloc_entries(wc); | |
1742 | if (r) | |
1743 | return r; | |
1744 | ||
1745 | for (b = 0; b < ARRAY_SIZE(sb(wc)->padding); b++) | |
1746 | pmem_assign(sb(wc)->padding[b], cpu_to_le64(0)); | |
1747 | pmem_assign(sb(wc)->version, cpu_to_le32(MEMORY_SUPERBLOCK_VERSION)); | |
1748 | pmem_assign(sb(wc)->block_size, cpu_to_le32(wc->block_size)); | |
1749 | pmem_assign(sb(wc)->n_blocks, cpu_to_le64(wc->n_blocks)); | |
1750 | pmem_assign(sb(wc)->seq_count, cpu_to_le64(0)); | |
1751 | ||
1752 | for (b = 0; b < wc->n_blocks; b++) | |
1753 | write_original_sector_seq_count(wc, &wc->entries[b], -1, -1); | |
1754 | ||
1755 | writecache_flush_all_metadata(wc); | |
1756 | writecache_commit_flushed(wc); | |
1757 | pmem_assign(sb(wc)->magic, cpu_to_le32(MEMORY_SUPERBLOCK_MAGIC)); | |
1758 | writecache_flush_region(wc, &sb(wc)->magic, sizeof sb(wc)->magic); | |
1759 | writecache_commit_flushed(wc); | |
1760 | ||
1761 | return 0; | |
1762 | } | |
1763 | ||
1764 | static void writecache_dtr(struct dm_target *ti) | |
1765 | { | |
1766 | struct dm_writecache *wc = ti->private; | |
1767 | ||
1768 | if (!wc) | |
1769 | return; | |
1770 | ||
1771 | if (wc->endio_thread) | |
1772 | kthread_stop(wc->endio_thread); | |
1773 | ||
1774 | if (wc->flush_thread) | |
1775 | kthread_stop(wc->flush_thread); | |
1776 | ||
1777 | bioset_exit(&wc->bio_set); | |
1778 | ||
1779 | mempool_exit(&wc->copy_pool); | |
1780 | ||
1781 | if (wc->writeback_wq) | |
1782 | destroy_workqueue(wc->writeback_wq); | |
1783 | ||
1784 | if (wc->dev) | |
1785 | dm_put_device(ti, wc->dev); | |
1786 | ||
1787 | if (wc->ssd_dev) | |
1788 | dm_put_device(ti, wc->ssd_dev); | |
1789 | ||
1790 | if (wc->entries) | |
1791 | vfree(wc->entries); | |
1792 | ||
1793 | if (wc->memory_map) { | |
1794 | if (WC_MODE_PMEM(wc)) | |
1795 | persistent_memory_release(wc); | |
1796 | else | |
1797 | vfree(wc->memory_map); | |
1798 | } | |
1799 | ||
1800 | if (wc->dm_kcopyd) | |
1801 | dm_kcopyd_client_destroy(wc->dm_kcopyd); | |
1802 | ||
1803 | if (wc->dm_io) | |
1804 | dm_io_client_destroy(wc->dm_io); | |
1805 | ||
1806 | if (wc->dirty_bitmap) | |
1807 | vfree(wc->dirty_bitmap); | |
1808 | ||
1809 | kfree(wc); | |
1810 | } | |
1811 | ||
1812 | static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv) | |
1813 | { | |
1814 | struct dm_writecache *wc; | |
1815 | struct dm_arg_set as; | |
1816 | const char *string; | |
1817 | unsigned opt_params; | |
1818 | size_t offset, data_size; | |
1819 | int i, r; | |
1820 | char dummy; | |
1821 | int high_wm_percent = HIGH_WATERMARK; | |
1822 | int low_wm_percent = LOW_WATERMARK; | |
1823 | uint64_t x; | |
1824 | struct wc_memory_superblock s; | |
1825 | ||
1826 | static struct dm_arg _args[] = { | |
1827 | {0, 10, "Invalid number of feature args"}, | |
1828 | }; | |
1829 | ||
1830 | as.argc = argc; | |
1831 | as.argv = argv; | |
1832 | ||
1833 | wc = kzalloc(sizeof(struct dm_writecache), GFP_KERNEL); | |
1834 | if (!wc) { | |
1835 | ti->error = "Cannot allocate writecache structure"; | |
1836 | r = -ENOMEM; | |
1837 | goto bad; | |
1838 | } | |
1839 | ti->private = wc; | |
1840 | wc->ti = ti; | |
1841 | ||
1842 | mutex_init(&wc->lock); | |
1843 | writecache_poison_lists(wc); | |
1844 | init_waitqueue_head(&wc->freelist_wait); | |
1845 | timer_setup(&wc->autocommit_timer, writecache_autocommit_timer, 0); | |
1846 | ||
1847 | for (i = 0; i < 2; i++) { | |
1848 | atomic_set(&wc->bio_in_progress[i], 0); | |
1849 | init_waitqueue_head(&wc->bio_in_progress_wait[i]); | |
1850 | } | |
1851 | ||
1852 | wc->dm_io = dm_io_client_create(); | |
1853 | if (IS_ERR(wc->dm_io)) { | |
1854 | r = PTR_ERR(wc->dm_io); | |
1855 | ti->error = "Unable to allocate dm-io client"; | |
1856 | wc->dm_io = NULL; | |
1857 | goto bad; | |
1858 | } | |
1859 | ||
1860 | wc->writeback_wq = alloc_workqueue("writecache-writeabck", WQ_MEM_RECLAIM, 1); | |
1861 | if (!wc->writeback_wq) { | |
1862 | r = -ENOMEM; | |
1863 | ti->error = "Could not allocate writeback workqueue"; | |
1864 | goto bad; | |
1865 | } | |
1866 | INIT_WORK(&wc->writeback_work, writecache_writeback); | |
1867 | INIT_WORK(&wc->flush_work, writecache_flush_work); | |
1868 | ||
1869 | raw_spin_lock_init(&wc->endio_list_lock); | |
1870 | INIT_LIST_HEAD(&wc->endio_list); | |
1871 | wc->endio_thread = kthread_create(writecache_endio_thread, wc, "writecache_endio"); | |
1872 | if (IS_ERR(wc->endio_thread)) { | |
1873 | r = PTR_ERR(wc->endio_thread); | |
1874 | wc->endio_thread = NULL; | |
1875 | ti->error = "Couldn't spawn endio thread"; | |
1876 | goto bad; | |
1877 | } | |
1878 | wake_up_process(wc->endio_thread); | |
1879 | ||
1880 | /* | |
1881 | * Parse the mode (pmem or ssd) | |
1882 | */ | |
1883 | string = dm_shift_arg(&as); | |
1884 | if (!string) | |
1885 | goto bad_arguments; | |
1886 | ||
1887 | if (!strcasecmp(string, "s")) { | |
1888 | wc->pmem_mode = false; | |
1889 | } else if (!strcasecmp(string, "p")) { | |
1890 | #ifdef DM_WRITECACHE_HAS_PMEM | |
1891 | wc->pmem_mode = true; | |
1892 | wc->writeback_fua = true; | |
1893 | #else | |
1894 | /* | |
1895 | * If the architecture doesn't support persistent memory or | |
1896 | * the kernel doesn't support any DAX drivers, this driver can | |
1897 | * only be used in SSD-only mode. | |
1898 | */ | |
1899 | r = -EOPNOTSUPP; | |
1900 | ti->error = "Persistent memory or DAX not supported on this system"; | |
1901 | goto bad; | |
1902 | #endif | |
1903 | } else { | |
1904 | goto bad_arguments; | |
1905 | } | |
1906 | ||
1907 | if (WC_MODE_PMEM(wc)) { | |
1908 | r = bioset_init(&wc->bio_set, BIO_POOL_SIZE, | |
1909 | offsetof(struct writeback_struct, bio), | |
1910 | BIOSET_NEED_BVECS); | |
1911 | if (r) { | |
1912 | ti->error = "Could not allocate bio set"; | |
1913 | goto bad; | |
1914 | } | |
1915 | } else { | |
1916 | r = mempool_init_kmalloc_pool(&wc->copy_pool, 1, sizeof(struct copy_struct)); | |
1917 | if (r) { | |
1918 | ti->error = "Could not allocate mempool"; | |
1919 | goto bad; | |
1920 | } | |
1921 | } | |
1922 | ||
1923 | /* | |
1924 | * Parse the origin data device | |
1925 | */ | |
1926 | string = dm_shift_arg(&as); | |
1927 | if (!string) | |
1928 | goto bad_arguments; | |
1929 | r = dm_get_device(ti, string, dm_table_get_mode(ti->table), &wc->dev); | |
1930 | if (r) { | |
1931 | ti->error = "Origin data device lookup failed"; | |
1932 | goto bad; | |
1933 | } | |
1934 | ||
1935 | /* | |
1936 | * Parse cache data device (be it pmem or ssd) | |
1937 | */ | |
1938 | string = dm_shift_arg(&as); | |
1939 | if (!string) | |
1940 | goto bad_arguments; | |
1941 | ||
1942 | r = dm_get_device(ti, string, dm_table_get_mode(ti->table), &wc->ssd_dev); | |
1943 | if (r) { | |
1944 | ti->error = "Cache data device lookup failed"; | |
1945 | goto bad; | |
1946 | } | |
1947 | wc->memory_map_size = i_size_read(wc->ssd_dev->bdev->bd_inode); | |
1948 | ||
1949 | if (WC_MODE_PMEM(wc)) { | |
1950 | r = persistent_memory_claim(wc); | |
1951 | if (r) { | |
1952 | ti->error = "Unable to map persistent memory for cache"; | |
1953 | goto bad; | |
1954 | } | |
1955 | } | |
1956 | ||
1957 | /* | |
1958 | * Parse the cache block size | |
1959 | */ | |
1960 | string = dm_shift_arg(&as); | |
1961 | if (!string) | |
1962 | goto bad_arguments; | |
1963 | if (sscanf(string, "%u%c", &wc->block_size, &dummy) != 1 || | |
1964 | wc->block_size < 512 || wc->block_size > PAGE_SIZE || | |
1965 | (wc->block_size & (wc->block_size - 1))) { | |
1966 | r = -EINVAL; | |
1967 | ti->error = "Invalid block size"; | |
1968 | goto bad; | |
1969 | } | |
1970 | wc->block_size_bits = __ffs(wc->block_size); | |
1971 | ||
1972 | wc->max_writeback_jobs = MAX_WRITEBACK_JOBS; | |
1973 | wc->autocommit_blocks = !WC_MODE_PMEM(wc) ? AUTOCOMMIT_BLOCKS_SSD : AUTOCOMMIT_BLOCKS_PMEM; | |
1974 | wc->autocommit_jiffies = msecs_to_jiffies(AUTOCOMMIT_MSEC); | |
1975 | ||
1976 | /* | |
1977 | * Parse optional arguments | |
1978 | */ | |
1979 | r = dm_read_arg_group(_args, &as, &opt_params, &ti->error); | |
1980 | if (r) | |
1981 | goto bad; | |
1982 | ||
1983 | while (opt_params) { | |
1984 | string = dm_shift_arg(&as), opt_params--; | |
1985 | if (!strcasecmp(string, "high_watermark") && opt_params >= 1) { | |
1986 | string = dm_shift_arg(&as), opt_params--; | |
1987 | if (sscanf(string, "%d%c", &high_wm_percent, &dummy) != 1) | |
1988 | goto invalid_optional; | |
1989 | if (high_wm_percent < 0 || high_wm_percent > 100) | |
1990 | goto invalid_optional; | |
1991 | wc->high_wm_percent_set = true; | |
1992 | } else if (!strcasecmp(string, "low_watermark") && opt_params >= 1) { | |
1993 | string = dm_shift_arg(&as), opt_params--; | |
1994 | if (sscanf(string, "%d%c", &low_wm_percent, &dummy) != 1) | |
1995 | goto invalid_optional; | |
1996 | if (low_wm_percent < 0 || low_wm_percent > 100) | |
1997 | goto invalid_optional; | |
1998 | wc->low_wm_percent_set = true; | |
1999 | } else if (!strcasecmp(string, "writeback_jobs") && opt_params >= 1) { | |
2000 | string = dm_shift_arg(&as), opt_params--; | |
2001 | if (sscanf(string, "%u%c", &wc->max_writeback_jobs, &dummy) != 1) | |
2002 | goto invalid_optional; | |
2003 | wc->max_writeback_jobs_set = true; | |
2004 | } else if (!strcasecmp(string, "autocommit_blocks") && opt_params >= 1) { | |
2005 | string = dm_shift_arg(&as), opt_params--; | |
2006 | if (sscanf(string, "%u%c", &wc->autocommit_blocks, &dummy) != 1) | |
2007 | goto invalid_optional; | |
2008 | wc->autocommit_blocks_set = true; | |
2009 | } else if (!strcasecmp(string, "autocommit_time") && opt_params >= 1) { | |
2010 | unsigned autocommit_msecs; | |
2011 | string = dm_shift_arg(&as), opt_params--; | |
2012 | if (sscanf(string, "%u%c", &autocommit_msecs, &dummy) != 1) | |
2013 | goto invalid_optional; | |
2014 | if (autocommit_msecs > 3600000) | |
2015 | goto invalid_optional; | |
2016 | wc->autocommit_jiffies = msecs_to_jiffies(autocommit_msecs); | |
2017 | wc->autocommit_time_set = true; | |
2018 | } else if (!strcasecmp(string, "fua")) { | |
2019 | if (WC_MODE_PMEM(wc)) { | |
2020 | wc->writeback_fua = true; | |
2021 | wc->writeback_fua_set = true; | |
2022 | } else goto invalid_optional; | |
2023 | } else if (!strcasecmp(string, "nofua")) { | |
2024 | if (WC_MODE_PMEM(wc)) { | |
2025 | wc->writeback_fua = false; | |
2026 | wc->writeback_fua_set = true; | |
2027 | } else goto invalid_optional; | |
2028 | } else { | |
2029 | invalid_optional: | |
2030 | r = -EINVAL; | |
2031 | ti->error = "Invalid optional argument"; | |
2032 | goto bad; | |
2033 | } | |
2034 | } | |
2035 | ||
2036 | if (high_wm_percent < low_wm_percent) { | |
2037 | r = -EINVAL; | |
2038 | ti->error = "High watermark must be greater than or equal to low watermark"; | |
2039 | goto bad; | |
2040 | } | |
2041 | ||
2042 | if (!WC_MODE_PMEM(wc)) { | |
2043 | struct dm_io_region region; | |
2044 | struct dm_io_request req; | |
2045 | size_t n_blocks, n_metadata_blocks; | |
2046 | uint64_t n_bitmap_bits; | |
2047 | ||
2048 | bio_list_init(&wc->flush_list); | |
2049 | wc->flush_thread = kthread_create(writecache_flush_thread, wc, "dm_writecache_flush"); | |
2050 | if (IS_ERR(wc->flush_thread)) { | |
2051 | r = PTR_ERR(wc->flush_thread); | |
2052 | wc->flush_thread = NULL; | |
2053 | ti->error = "Couldn't spawn endio thread"; | |
2054 | goto bad; | |
2055 | } | |
2056 | wake_up_process(wc->flush_thread); | |
2057 | ||
2058 | r = calculate_memory_size(wc->memory_map_size, wc->block_size, | |
2059 | &n_blocks, &n_metadata_blocks); | |
2060 | if (r) { | |
2061 | ti->error = "Invalid device size"; | |
2062 | goto bad; | |
2063 | } | |
2064 | ||
2065 | n_bitmap_bits = (((uint64_t)n_metadata_blocks << wc->block_size_bits) + | |
2066 | BITMAP_GRANULARITY - 1) / BITMAP_GRANULARITY; | |
2067 | /* this is limitation of test_bit functions */ | |
2068 | if (n_bitmap_bits > 1U << 31) { | |
2069 | r = -EFBIG; | |
2070 | ti->error = "Invalid device size"; | |
2071 | goto bad; | |
2072 | } | |
2073 | ||
2074 | wc->memory_map = vmalloc(n_metadata_blocks << wc->block_size_bits); | |
2075 | if (!wc->memory_map) { | |
2076 | r = -ENOMEM; | |
2077 | ti->error = "Unable to allocate memory for metadata"; | |
2078 | goto bad; | |
2079 | } | |
2080 | ||
2081 | wc->dm_kcopyd = dm_kcopyd_client_create(&dm_kcopyd_throttle); | |
2082 | if (IS_ERR(wc->dm_kcopyd)) { | |
2083 | r = PTR_ERR(wc->dm_kcopyd); | |
2084 | ti->error = "Unable to allocate dm-kcopyd client"; | |
2085 | wc->dm_kcopyd = NULL; | |
2086 | goto bad; | |
2087 | } | |
2088 | ||
2089 | wc->metadata_sectors = n_metadata_blocks << (wc->block_size_bits - SECTOR_SHIFT); | |
2090 | wc->dirty_bitmap_size = (n_bitmap_bits + BITS_PER_LONG - 1) / | |
2091 | BITS_PER_LONG * sizeof(unsigned long); | |
2092 | wc->dirty_bitmap = vzalloc(wc->dirty_bitmap_size); | |
2093 | if (!wc->dirty_bitmap) { | |
2094 | r = -ENOMEM; | |
2095 | ti->error = "Unable to allocate dirty bitmap"; | |
2096 | goto bad; | |
2097 | } | |
2098 | ||
2099 | region.bdev = wc->ssd_dev->bdev; | |
2100 | region.sector = 0; | |
2101 | region.count = wc->metadata_sectors; | |
2102 | req.bi_op = REQ_OP_READ; | |
2103 | req.bi_op_flags = REQ_SYNC; | |
2104 | req.mem.type = DM_IO_VMA; | |
2105 | req.mem.ptr.vma = (char *)wc->memory_map; | |
2106 | req.client = wc->dm_io; | |
2107 | req.notify.fn = NULL; | |
2108 | ||
2109 | r = dm_io(&req, 1, ®ion, NULL); | |
2110 | if (r) { | |
2111 | ti->error = "Unable to read metadata"; | |
2112 | goto bad; | |
2113 | } | |
2114 | } | |
2115 | ||
2116 | r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock)); | |
2117 | if (r) { | |
2118 | ti->error = "Hardware memory error when reading superblock"; | |
2119 | goto bad; | |
2120 | } | |
2121 | if (!le32_to_cpu(s.magic) && !le32_to_cpu(s.version)) { | |
2122 | r = init_memory(wc); | |
2123 | if (r) { | |
2124 | ti->error = "Unable to initialize device"; | |
2125 | goto bad; | |
2126 | } | |
2127 | r = memcpy_mcsafe(&s, sb(wc), sizeof(struct wc_memory_superblock)); | |
2128 | if (r) { | |
2129 | ti->error = "Hardware memory error when reading superblock"; | |
2130 | goto bad; | |
2131 | } | |
2132 | } | |
2133 | ||
2134 | if (le32_to_cpu(s.magic) != MEMORY_SUPERBLOCK_MAGIC) { | |
2135 | ti->error = "Invalid magic in the superblock"; | |
2136 | r = -EINVAL; | |
2137 | goto bad; | |
2138 | } | |
2139 | ||
2140 | if (le32_to_cpu(s.version) != MEMORY_SUPERBLOCK_VERSION) { | |
2141 | ti->error = "Invalid version in the superblock"; | |
2142 | r = -EINVAL; | |
2143 | goto bad; | |
2144 | } | |
2145 | ||
2146 | if (le32_to_cpu(s.block_size) != wc->block_size) { | |
2147 | ti->error = "Block size does not match superblock"; | |
2148 | r = -EINVAL; | |
2149 | goto bad; | |
2150 | } | |
2151 | ||
2152 | wc->n_blocks = le64_to_cpu(s.n_blocks); | |
2153 | ||
2154 | offset = wc->n_blocks * sizeof(struct wc_memory_entry); | |
2155 | if (offset / sizeof(struct wc_memory_entry) != le64_to_cpu(sb(wc)->n_blocks)) { | |
2156 | overflow: | |
2157 | ti->error = "Overflow in size calculation"; | |
2158 | r = -EINVAL; | |
2159 | goto bad; | |
2160 | } | |
2161 | offset += sizeof(struct wc_memory_superblock); | |
2162 | if (offset < sizeof(struct wc_memory_superblock)) | |
2163 | goto overflow; | |
2164 | offset = (offset + wc->block_size - 1) & ~(size_t)(wc->block_size - 1); | |
2165 | data_size = wc->n_blocks * (size_t)wc->block_size; | |
2166 | if (!offset || (data_size / wc->block_size != wc->n_blocks) || | |
2167 | (offset + data_size < offset)) | |
2168 | goto overflow; | |
2169 | if (offset + data_size > wc->memory_map_size) { | |
2170 | ti->error = "Memory area is too small"; | |
2171 | r = -EINVAL; | |
2172 | goto bad; | |
2173 | } | |
2174 | ||
2175 | wc->metadata_sectors = offset >> SECTOR_SHIFT; | |
2176 | wc->block_start = (char *)sb(wc) + offset; | |
2177 | ||
2178 | x = (uint64_t)wc->n_blocks * (100 - high_wm_percent); | |
2179 | x += 50; | |
2180 | do_div(x, 100); | |
2181 | wc->freelist_high_watermark = x; | |
2182 | x = (uint64_t)wc->n_blocks * (100 - low_wm_percent); | |
2183 | x += 50; | |
2184 | do_div(x, 100); | |
2185 | wc->freelist_low_watermark = x; | |
2186 | ||
2187 | r = writecache_alloc_entries(wc); | |
2188 | if (r) { | |
2189 | ti->error = "Cannot allocate memory"; | |
2190 | goto bad; | |
2191 | } | |
2192 | ||
2193 | ti->num_flush_bios = 1; | |
2194 | ti->flush_supported = true; | |
2195 | ti->num_discard_bios = 1; | |
2196 | ||
2197 | if (WC_MODE_PMEM(wc)) | |
2198 | persistent_memory_flush_cache(wc->memory_map, wc->memory_map_size); | |
2199 | ||
2200 | return 0; | |
2201 | ||
2202 | bad_arguments: | |
2203 | r = -EINVAL; | |
2204 | ti->error = "Bad arguments"; | |
2205 | bad: | |
2206 | writecache_dtr(ti); | |
2207 | return r; | |
2208 | } | |
2209 | ||
2210 | static void writecache_status(struct dm_target *ti, status_type_t type, | |
2211 | unsigned status_flags, char *result, unsigned maxlen) | |
2212 | { | |
2213 | struct dm_writecache *wc = ti->private; | |
2214 | unsigned extra_args; | |
2215 | unsigned sz = 0; | |
2216 | uint64_t x; | |
2217 | ||
2218 | switch (type) { | |
2219 | case STATUSTYPE_INFO: | |
2220 | DMEMIT("%ld %llu %llu %llu", writecache_has_error(wc), | |
2221 | (unsigned long long)wc->n_blocks, (unsigned long long)wc->freelist_size, | |
2222 | (unsigned long long)wc->writeback_size); | |
2223 | break; | |
2224 | case STATUSTYPE_TABLE: | |
2225 | DMEMIT("%c %s %s %u ", WC_MODE_PMEM(wc) ? 'p' : 's', | |
2226 | wc->dev->name, wc->ssd_dev->name, wc->block_size); | |
2227 | extra_args = 0; | |
2228 | if (wc->high_wm_percent_set) | |
2229 | extra_args += 2; | |
2230 | if (wc->low_wm_percent_set) | |
2231 | extra_args += 2; | |
2232 | if (wc->max_writeback_jobs_set) | |
2233 | extra_args += 2; | |
2234 | if (wc->autocommit_blocks_set) | |
2235 | extra_args += 2; | |
2236 | if (wc->autocommit_time_set) | |
2237 | extra_args += 2; | |
2238 | if (wc->writeback_fua_set) | |
2239 | extra_args++; | |
2240 | ||
2241 | DMEMIT("%u", extra_args); | |
2242 | if (wc->high_wm_percent_set) { | |
2243 | x = (uint64_t)wc->freelist_high_watermark * 100; | |
2244 | x += wc->n_blocks / 2; | |
2245 | do_div(x, (size_t)wc->n_blocks); | |
2246 | DMEMIT(" high_watermark %u", 100 - (unsigned)x); | |
2247 | } | |
2248 | if (wc->low_wm_percent_set) { | |
2249 | x = (uint64_t)wc->freelist_low_watermark * 100; | |
2250 | x += wc->n_blocks / 2; | |
2251 | do_div(x, (size_t)wc->n_blocks); | |
2252 | DMEMIT(" low_watermark %u", 100 - (unsigned)x); | |
2253 | } | |
2254 | if (wc->max_writeback_jobs_set) | |
2255 | DMEMIT(" writeback_jobs %u", wc->max_writeback_jobs); | |
2256 | if (wc->autocommit_blocks_set) | |
2257 | DMEMIT(" autocommit_blocks %u", wc->autocommit_blocks); | |
2258 | if (wc->autocommit_time_set) | |
2259 | DMEMIT(" autocommit_time %u", jiffies_to_msecs(wc->autocommit_jiffies)); | |
2260 | if (wc->writeback_fua_set) | |
2261 | DMEMIT(" %sfua", wc->writeback_fua ? "" : "no"); | |
2262 | break; | |
2263 | } | |
2264 | } | |
2265 | ||
2266 | static struct target_type writecache_target = { | |
2267 | .name = "writecache", | |
2268 | .version = {1, 0, 0}, | |
2269 | .module = THIS_MODULE, | |
2270 | .ctr = writecache_ctr, | |
2271 | .dtr = writecache_dtr, | |
2272 | .status = writecache_status, | |
2273 | .postsuspend = writecache_suspend, | |
2274 | .resume = writecache_resume, | |
2275 | .message = writecache_message, | |
2276 | .map = writecache_map, | |
2277 | .end_io = writecache_end_io, | |
2278 | .iterate_devices = writecache_iterate_devices, | |
2279 | .io_hints = writecache_io_hints, | |
2280 | }; | |
2281 | ||
2282 | static int __init dm_writecache_init(void) | |
2283 | { | |
2284 | int r; | |
2285 | ||
2286 | r = dm_register_target(&writecache_target); | |
2287 | if (r < 0) { | |
2288 | DMERR("register failed %d", r); | |
2289 | return r; | |
2290 | } | |
2291 | ||
2292 | return 0; | |
2293 | } | |
2294 | ||
2295 | static void __exit dm_writecache_exit(void) | |
2296 | { | |
2297 | dm_unregister_target(&writecache_target); | |
2298 | } | |
2299 | ||
2300 | module_init(dm_writecache_init); | |
2301 | module_exit(dm_writecache_exit); | |
2302 | ||
2303 | MODULE_DESCRIPTION(DM_NAME " writecache target"); | |
2304 | MODULE_AUTHOR("Mikulas Patocka <dm-devel@redhat.com>"); | |
2305 | MODULE_LICENSE("GPL"); |