1 | // SPDX-License-Identifier: GPL-2.0-only |
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 | #include <linux/delay.h> |
19 | #include "dm-io-tracker.h" |
20 | |
21 | #define DM_MSG_PREFIX "writecache" |
22 | |
23 | #define HIGH_WATERMARK 50 |
24 | #define LOW_WATERMARK 45 |
25 | #define MAX_WRITEBACK_JOBS min(0x10000000 / PAGE_SIZE, totalram_pages() / 16) |
26 | #define ENDIO_LATENCY 16 |
27 | #define WRITEBACK_LATENCY 64 |
28 | #define AUTOCOMMIT_BLOCKS_SSD 65536 |
29 | #define AUTOCOMMIT_BLOCKS_PMEM 64 |
30 | #define AUTOCOMMIT_MSEC 1000 |
31 | #define MAX_AGE_DIV 16 |
32 | #define MAX_AGE_UNSPECIFIED -1UL |
33 | #define PAUSE_WRITEBACK (HZ * 3) |
34 | |
35 | #define BITMAP_GRANULARITY 65536 |
36 | #if BITMAP_GRANULARITY < PAGE_SIZE |
37 | #undef BITMAP_GRANULARITY |
38 | #define BITMAP_GRANULARITY PAGE_SIZE |
39 | #endif |
40 | |
41 | #if IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_FS_DAX) |
42 | #define DM_WRITECACHE_HAS_PMEM |
43 | #endif |
44 | |
45 | #ifdef DM_WRITECACHE_HAS_PMEM |
46 | #define pmem_assign(dest, src) \ |
47 | do { \ |
48 | typeof(dest) uniq = (src); \ |
49 | memcpy_flushcache(&(dest), &uniq, sizeof(dest)); \ |
50 | } while (0) |
51 | #else |
52 | #define pmem_assign(dest, src) ((dest) = (src)) |
53 | #endif |
54 | |
55 | #if IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC) && defined(DM_WRITECACHE_HAS_PMEM) |
56 | #define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
57 | #endif |
58 | |
59 | #define MEMORY_SUPERBLOCK_MAGIC 0x23489321 |
60 | #define MEMORY_SUPERBLOCK_VERSION 1 |
61 | |
62 | struct wc_memory_entry { |
63 | __le64 original_sector; |
64 | __le64 seq_count; |
65 | }; |
66 | |
67 | struct wc_memory_superblock { |
68 | union { |
69 | struct { |
70 | __le32 magic; |
71 | __le32 version; |
72 | __le32 block_size; |
73 | __le32 pad; |
74 | __le64 n_blocks; |
75 | __le64 seq_count; |
76 | }; |
77 | __le64 padding[8]; |
78 | }; |
79 | struct wc_memory_entry entries[]; |
80 | }; |
81 | |
82 | struct wc_entry { |
83 | struct rb_node rb_node; |
84 | struct list_head lru; |
85 | unsigned short wc_list_contiguous; |
86 | #if BITS_PER_LONG == 64 |
87 | bool write_in_progress : 1; |
88 | unsigned long index : 47; |
89 | #else |
90 | bool write_in_progress; |
91 | unsigned long index; |
92 | #endif |
93 | unsigned long age; |
94 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
95 | uint64_t original_sector; |
96 | uint64_t seq_count; |
97 | #endif |
98 | }; |
99 | |
100 | #ifdef DM_WRITECACHE_HAS_PMEM |
101 | #define WC_MODE_PMEM(wc) ((wc)->pmem_mode) |
102 | #define WC_MODE_FUA(wc) ((wc)->writeback_fua) |
103 | #else |
104 | #define WC_MODE_PMEM(wc) false |
105 | #define WC_MODE_FUA(wc) false |
106 | #endif |
107 | #define WC_MODE_SORT_FREELIST(wc) (!WC_MODE_PMEM(wc)) |
108 | |
109 | struct dm_writecache { |
110 | struct mutex lock; |
111 | struct list_head lru; |
112 | union { |
113 | struct list_head freelist; |
114 | struct { |
115 | struct rb_root freetree; |
116 | struct wc_entry *current_free; |
117 | }; |
118 | }; |
119 | struct rb_root tree; |
120 | |
121 | size_t freelist_size; |
122 | size_t writeback_size; |
123 | size_t freelist_high_watermark; |
124 | size_t freelist_low_watermark; |
125 | unsigned long max_age; |
126 | unsigned long pause; |
127 | |
128 | unsigned int uncommitted_blocks; |
129 | unsigned int autocommit_blocks; |
130 | unsigned int max_writeback_jobs; |
131 | |
132 | int error; |
133 | |
134 | unsigned long autocommit_jiffies; |
135 | struct timer_list autocommit_timer; |
136 | struct wait_queue_head freelist_wait; |
137 | |
138 | struct timer_list max_age_timer; |
139 | |
140 | atomic_t bio_in_progress[2]; |
141 | struct wait_queue_head bio_in_progress_wait[2]; |
142 | |
143 | struct dm_target *ti; |
144 | struct dm_dev *dev; |
145 | struct dm_dev *ssd_dev; |
146 | sector_t start_sector; |
147 | void *memory_map; |
148 | uint64_t memory_map_size; |
149 | size_t metadata_sectors; |
150 | size_t n_blocks; |
151 | uint64_t seq_count; |
152 | sector_t data_device_sectors; |
153 | void *block_start; |
154 | struct wc_entry *entries; |
155 | unsigned int block_size; |
156 | unsigned char block_size_bits; |
157 | |
158 | bool pmem_mode:1; |
159 | bool writeback_fua:1; |
160 | |
161 | bool overwrote_committed:1; |
162 | bool memory_vmapped:1; |
163 | |
164 | bool start_sector_set:1; |
165 | bool high_wm_percent_set:1; |
166 | bool low_wm_percent_set:1; |
167 | bool max_writeback_jobs_set:1; |
168 | bool autocommit_blocks_set:1; |
169 | bool autocommit_time_set:1; |
170 | bool max_age_set:1; |
171 | bool writeback_fua_set:1; |
172 | bool flush_on_suspend:1; |
173 | bool cleaner:1; |
174 | bool cleaner_set:1; |
175 | bool metadata_only:1; |
176 | bool pause_set:1; |
177 | |
178 | unsigned int high_wm_percent_value; |
179 | unsigned int low_wm_percent_value; |
180 | unsigned int autocommit_time_value; |
181 | unsigned int max_age_value; |
182 | unsigned int pause_value; |
183 | |
184 | unsigned int writeback_all; |
185 | struct workqueue_struct *writeback_wq; |
186 | struct work_struct writeback_work; |
187 | struct work_struct flush_work; |
188 | |
189 | struct dm_io_tracker iot; |
190 | |
191 | struct dm_io_client *dm_io; |
192 | |
193 | raw_spinlock_t endio_list_lock; |
194 | struct list_head endio_list; |
195 | struct task_struct *endio_thread; |
196 | |
197 | struct task_struct *flush_thread; |
198 | struct bio_list flush_list; |
199 | |
200 | struct dm_kcopyd_client *dm_kcopyd; |
201 | unsigned long *dirty_bitmap; |
202 | unsigned int dirty_bitmap_size; |
203 | |
204 | struct bio_set bio_set; |
205 | mempool_t copy_pool; |
206 | |
207 | struct { |
208 | unsigned long long reads; |
209 | unsigned long long read_hits; |
210 | unsigned long long writes; |
211 | unsigned long long write_hits_uncommitted; |
212 | unsigned long long write_hits_committed; |
213 | unsigned long long writes_around; |
214 | unsigned long long writes_allocate; |
215 | unsigned long long writes_blocked_on_freelist; |
216 | unsigned long long flushes; |
217 | unsigned long long discards; |
218 | } stats; |
219 | }; |
220 | |
221 | #define WB_LIST_INLINE 16 |
222 | |
223 | struct writeback_struct { |
224 | struct list_head endio_entry; |
225 | struct dm_writecache *wc; |
226 | struct wc_entry **wc_list; |
227 | unsigned int wc_list_n; |
228 | struct wc_entry *wc_list_inline[WB_LIST_INLINE]; |
229 | struct bio bio; |
230 | }; |
231 | |
232 | struct copy_struct { |
233 | struct list_head endio_entry; |
234 | struct dm_writecache *wc; |
235 | struct wc_entry *e; |
236 | unsigned int n_entries; |
237 | int error; |
238 | }; |
239 | |
240 | DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(dm_writecache_throttle, |
241 | "A percentage of time allocated for data copying" ); |
242 | |
243 | static void wc_lock(struct dm_writecache *wc) |
244 | { |
245 | mutex_lock(&wc->lock); |
246 | } |
247 | |
248 | static void wc_unlock(struct dm_writecache *wc) |
249 | { |
250 | mutex_unlock(lock: &wc->lock); |
251 | } |
252 | |
253 | #ifdef DM_WRITECACHE_HAS_PMEM |
254 | static int persistent_memory_claim(struct dm_writecache *wc) |
255 | { |
256 | int r; |
257 | loff_t s; |
258 | long p, da; |
259 | pfn_t pfn; |
260 | int id; |
261 | struct page **pages; |
262 | sector_t offset; |
263 | |
264 | wc->memory_vmapped = false; |
265 | |
266 | s = wc->memory_map_size; |
267 | p = s >> PAGE_SHIFT; |
268 | if (!p) { |
269 | r = -EINVAL; |
270 | goto err1; |
271 | } |
272 | if (p != s >> PAGE_SHIFT) { |
273 | r = -EOVERFLOW; |
274 | goto err1; |
275 | } |
276 | |
277 | offset = get_start_sect(bdev: wc->ssd_dev->bdev); |
278 | if (offset & (PAGE_SIZE / 512 - 1)) { |
279 | r = -EINVAL; |
280 | goto err1; |
281 | } |
282 | offset >>= PAGE_SHIFT - 9; |
283 | |
284 | id = dax_read_lock(); |
285 | |
286 | da = dax_direct_access(dax_dev: wc->ssd_dev->dax_dev, pgoff: offset, nr_pages: p, mode: DAX_ACCESS, |
287 | kaddr: &wc->memory_map, pfn: &pfn); |
288 | if (da < 0) { |
289 | wc->memory_map = NULL; |
290 | r = da; |
291 | goto err2; |
292 | } |
293 | if (!pfn_t_has_page(pfn)) { |
294 | wc->memory_map = NULL; |
295 | r = -EOPNOTSUPP; |
296 | goto err2; |
297 | } |
298 | if (da != p) { |
299 | long i; |
300 | |
301 | wc->memory_map = NULL; |
302 | pages = kvmalloc_array(n: p, size: sizeof(struct page *), GFP_KERNEL); |
303 | if (!pages) { |
304 | r = -ENOMEM; |
305 | goto err2; |
306 | } |
307 | i = 0; |
308 | do { |
309 | long daa; |
310 | |
311 | daa = dax_direct_access(dax_dev: wc->ssd_dev->dax_dev, pgoff: offset + i, |
312 | nr_pages: p - i, mode: DAX_ACCESS, NULL, pfn: &pfn); |
313 | if (daa <= 0) { |
314 | r = daa ? daa : -EINVAL; |
315 | goto err3; |
316 | } |
317 | if (!pfn_t_has_page(pfn)) { |
318 | r = -EOPNOTSUPP; |
319 | goto err3; |
320 | } |
321 | while (daa-- && i < p) { |
322 | pages[i++] = pfn_t_to_page(pfn); |
323 | pfn.val++; |
324 | if (!(i & 15)) |
325 | cond_resched(); |
326 | } |
327 | } while (i < p); |
328 | wc->memory_map = vmap(pages, count: p, VM_MAP, PAGE_KERNEL); |
329 | if (!wc->memory_map) { |
330 | r = -ENOMEM; |
331 | goto err3; |
332 | } |
333 | kvfree(addr: pages); |
334 | wc->memory_vmapped = true; |
335 | } |
336 | |
337 | dax_read_unlock(id); |
338 | |
339 | wc->memory_map += (size_t)wc->start_sector << SECTOR_SHIFT; |
340 | wc->memory_map_size -= (size_t)wc->start_sector << SECTOR_SHIFT; |
341 | |
342 | return 0; |
343 | err3: |
344 | kvfree(addr: pages); |
345 | err2: |
346 | dax_read_unlock(id); |
347 | err1: |
348 | return r; |
349 | } |
350 | #else |
351 | static int persistent_memory_claim(struct dm_writecache *wc) |
352 | { |
353 | return -EOPNOTSUPP; |
354 | } |
355 | #endif |
356 | |
357 | static void persistent_memory_release(struct dm_writecache *wc) |
358 | { |
359 | if (wc->memory_vmapped) |
360 | vunmap(addr: wc->memory_map - ((size_t)wc->start_sector << SECTOR_SHIFT)); |
361 | } |
362 | |
363 | static struct page *persistent_memory_page(void *addr) |
364 | { |
365 | if (is_vmalloc_addr(x: addr)) |
366 | return vmalloc_to_page(addr); |
367 | else |
368 | return virt_to_page(addr); |
369 | } |
370 | |
371 | static unsigned int persistent_memory_page_offset(void *addr) |
372 | { |
373 | return (unsigned long)addr & (PAGE_SIZE - 1); |
374 | } |
375 | |
376 | static void persistent_memory_flush_cache(void *ptr, size_t size) |
377 | { |
378 | if (is_vmalloc_addr(x: ptr)) |
379 | flush_kernel_vmap_range(vaddr: ptr, size); |
380 | } |
381 | |
382 | static void persistent_memory_invalidate_cache(void *ptr, size_t size) |
383 | { |
384 | if (is_vmalloc_addr(x: ptr)) |
385 | invalidate_kernel_vmap_range(vaddr: ptr, size); |
386 | } |
387 | |
388 | static struct wc_memory_superblock *sb(struct dm_writecache *wc) |
389 | { |
390 | return wc->memory_map; |
391 | } |
392 | |
393 | static struct wc_memory_entry *memory_entry(struct dm_writecache *wc, struct wc_entry *e) |
394 | { |
395 | return &sb(wc)->entries[e->index]; |
396 | } |
397 | |
398 | static void *memory_data(struct dm_writecache *wc, struct wc_entry *e) |
399 | { |
400 | return (char *)wc->block_start + (e->index << wc->block_size_bits); |
401 | } |
402 | |
403 | static sector_t cache_sector(struct dm_writecache *wc, struct wc_entry *e) |
404 | { |
405 | return wc->start_sector + wc->metadata_sectors + |
406 | ((sector_t)e->index << (wc->block_size_bits - SECTOR_SHIFT)); |
407 | } |
408 | |
409 | static uint64_t read_original_sector(struct dm_writecache *wc, struct wc_entry *e) |
410 | { |
411 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
412 | return e->original_sector; |
413 | #else |
414 | return le64_to_cpu(memory_entry(wc, e)->original_sector); |
415 | #endif |
416 | } |
417 | |
418 | static uint64_t read_seq_count(struct dm_writecache *wc, struct wc_entry *e) |
419 | { |
420 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
421 | return e->seq_count; |
422 | #else |
423 | return le64_to_cpu(memory_entry(wc, e)->seq_count); |
424 | #endif |
425 | } |
426 | |
427 | static void clear_seq_count(struct dm_writecache *wc, struct wc_entry *e) |
428 | { |
429 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
430 | e->seq_count = -1; |
431 | #endif |
432 | pmem_assign(memory_entry(wc, e)->seq_count, cpu_to_le64(-1)); |
433 | } |
434 | |
435 | static void write_original_sector_seq_count(struct dm_writecache *wc, struct wc_entry *e, |
436 | uint64_t original_sector, uint64_t seq_count) |
437 | { |
438 | struct wc_memory_entry me; |
439 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
440 | e->original_sector = original_sector; |
441 | e->seq_count = seq_count; |
442 | #endif |
443 | me.original_sector = cpu_to_le64(original_sector); |
444 | me.seq_count = cpu_to_le64(seq_count); |
445 | pmem_assign(*memory_entry(wc, e), me); |
446 | } |
447 | |
448 | #define writecache_error(wc, err, msg, arg...) \ |
449 | do { \ |
450 | if (!cmpxchg(&(wc)->error, 0, err)) \ |
451 | DMERR(msg, ##arg); \ |
452 | wake_up(&(wc)->freelist_wait); \ |
453 | } while (0) |
454 | |
455 | #define writecache_has_error(wc) (unlikely(READ_ONCE((wc)->error))) |
456 | |
457 | static void writecache_flush_all_metadata(struct dm_writecache *wc) |
458 | { |
459 | if (!WC_MODE_PMEM(wc)) |
460 | memset(wc->dirty_bitmap, -1, wc->dirty_bitmap_size); |
461 | } |
462 | |
463 | static void writecache_flush_region(struct dm_writecache *wc, void *ptr, size_t size) |
464 | { |
465 | if (!WC_MODE_PMEM(wc)) |
466 | __set_bit(((char *)ptr - (char *)wc->memory_map) / BITMAP_GRANULARITY, |
467 | wc->dirty_bitmap); |
468 | } |
469 | |
470 | static void writecache_disk_flush(struct dm_writecache *wc, struct dm_dev *dev); |
471 | |
472 | struct io_notify { |
473 | struct dm_writecache *wc; |
474 | struct completion c; |
475 | atomic_t count; |
476 | }; |
477 | |
478 | static void writecache_notify_io(unsigned long error, void *context) |
479 | { |
480 | struct io_notify *endio = context; |
481 | |
482 | if (unlikely(error != 0)) |
483 | writecache_error(endio->wc, -EIO, "error writing metadata" ); |
484 | BUG_ON(atomic_read(&endio->count) <= 0); |
485 | if (atomic_dec_and_test(v: &endio->count)) |
486 | complete(&endio->c); |
487 | } |
488 | |
489 | static void writecache_wait_for_ios(struct dm_writecache *wc, int direction) |
490 | { |
491 | wait_event(wc->bio_in_progress_wait[direction], |
492 | !atomic_read(&wc->bio_in_progress[direction])); |
493 | } |
494 | |
495 | static void ssd_commit_flushed(struct dm_writecache *wc, bool wait_for_ios) |
496 | { |
497 | struct dm_io_region region; |
498 | struct dm_io_request req; |
499 | struct io_notify endio = { |
500 | wc, |
501 | COMPLETION_INITIALIZER_ONSTACK(endio.c), |
502 | ATOMIC_INIT(1), |
503 | }; |
504 | unsigned int bitmap_bits = wc->dirty_bitmap_size * 8; |
505 | unsigned int i = 0; |
506 | |
507 | while (1) { |
508 | unsigned int j; |
509 | |
510 | i = find_next_bit(addr: wc->dirty_bitmap, size: bitmap_bits, offset: i); |
511 | if (unlikely(i == bitmap_bits)) |
512 | break; |
513 | j = find_next_zero_bit(addr: wc->dirty_bitmap, size: bitmap_bits, offset: i); |
514 | |
515 | region.bdev = wc->ssd_dev->bdev; |
516 | region.sector = (sector_t)i * (BITMAP_GRANULARITY >> SECTOR_SHIFT); |
517 | region.count = (sector_t)(j - i) * (BITMAP_GRANULARITY >> SECTOR_SHIFT); |
518 | |
519 | if (unlikely(region.sector >= wc->metadata_sectors)) |
520 | break; |
521 | if (unlikely(region.sector + region.count > wc->metadata_sectors)) |
522 | region.count = wc->metadata_sectors - region.sector; |
523 | |
524 | region.sector += wc->start_sector; |
525 | atomic_inc(v: &endio.count); |
526 | req.bi_opf = REQ_OP_WRITE | REQ_SYNC; |
527 | req.mem.type = DM_IO_VMA; |
528 | req.mem.ptr.vma = (char *)wc->memory_map + (size_t)i * BITMAP_GRANULARITY; |
529 | req.client = wc->dm_io; |
530 | req.notify.fn = writecache_notify_io; |
531 | req.notify.context = &endio; |
532 | |
533 | /* writing via async dm-io (implied by notify.fn above) won't return an error */ |
534 | (void) dm_io(io_req: &req, num_regions: 1, region: ®ion, NULL); |
535 | i = j; |
536 | } |
537 | |
538 | writecache_notify_io(error: 0, context: &endio); |
539 | wait_for_completion_io(&endio.c); |
540 | |
541 | if (wait_for_ios) |
542 | writecache_wait_for_ios(wc, WRITE); |
543 | |
544 | writecache_disk_flush(wc, dev: wc->ssd_dev); |
545 | |
546 | memset(wc->dirty_bitmap, 0, wc->dirty_bitmap_size); |
547 | } |
548 | |
549 | static void ssd_commit_superblock(struct dm_writecache *wc) |
550 | { |
551 | int r; |
552 | struct dm_io_region region; |
553 | struct dm_io_request req; |
554 | |
555 | region.bdev = wc->ssd_dev->bdev; |
556 | region.sector = 0; |
557 | region.count = max(4096U, wc->block_size) >> SECTOR_SHIFT; |
558 | |
559 | if (unlikely(region.sector + region.count > wc->metadata_sectors)) |
560 | region.count = wc->metadata_sectors - region.sector; |
561 | |
562 | region.sector += wc->start_sector; |
563 | |
564 | req.bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_FUA; |
565 | req.mem.type = DM_IO_VMA; |
566 | req.mem.ptr.vma = (char *)wc->memory_map; |
567 | req.client = wc->dm_io; |
568 | req.notify.fn = NULL; |
569 | req.notify.context = NULL; |
570 | |
571 | r = dm_io(io_req: &req, num_regions: 1, region: ®ion, NULL); |
572 | if (unlikely(r)) |
573 | writecache_error(wc, r, "error writing superblock" ); |
574 | } |
575 | |
576 | static void writecache_commit_flushed(struct dm_writecache *wc, bool wait_for_ios) |
577 | { |
578 | if (WC_MODE_PMEM(wc)) |
579 | pmem_wmb(); |
580 | else |
581 | ssd_commit_flushed(wc, wait_for_ios); |
582 | } |
583 | |
584 | static void writecache_disk_flush(struct dm_writecache *wc, struct dm_dev *dev) |
585 | { |
586 | int r; |
587 | struct dm_io_region region; |
588 | struct dm_io_request req; |
589 | |
590 | region.bdev = dev->bdev; |
591 | region.sector = 0; |
592 | region.count = 0; |
593 | req.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; |
594 | req.mem.type = DM_IO_KMEM; |
595 | req.mem.ptr.addr = NULL; |
596 | req.client = wc->dm_io; |
597 | req.notify.fn = NULL; |
598 | |
599 | r = dm_io(io_req: &req, num_regions: 1, region: ®ion, NULL); |
600 | if (unlikely(r)) |
601 | writecache_error(wc, r, "error flushing metadata: %d" , r); |
602 | } |
603 | |
604 | #define WFE_RETURN_FOLLOWING 1 |
605 | #define WFE_LOWEST_SEQ 2 |
606 | |
607 | static struct wc_entry *writecache_find_entry(struct dm_writecache *wc, |
608 | uint64_t block, int flags) |
609 | { |
610 | struct wc_entry *e; |
611 | struct rb_node *node = wc->tree.rb_node; |
612 | |
613 | if (unlikely(!node)) |
614 | return NULL; |
615 | |
616 | while (1) { |
617 | e = container_of(node, struct wc_entry, rb_node); |
618 | if (read_original_sector(wc, e) == block) |
619 | break; |
620 | |
621 | node = (read_original_sector(wc, e) >= block ? |
622 | e->rb_node.rb_left : e->rb_node.rb_right); |
623 | if (unlikely(!node)) { |
624 | if (!(flags & WFE_RETURN_FOLLOWING)) |
625 | return NULL; |
626 | if (read_original_sector(wc, e) >= block) |
627 | return e; |
628 | |
629 | node = rb_next(&e->rb_node); |
630 | if (unlikely(!node)) |
631 | return NULL; |
632 | |
633 | e = container_of(node, struct wc_entry, rb_node); |
634 | return e; |
635 | } |
636 | } |
637 | |
638 | while (1) { |
639 | struct wc_entry *e2; |
640 | |
641 | if (flags & WFE_LOWEST_SEQ) |
642 | node = rb_prev(&e->rb_node); |
643 | else |
644 | node = rb_next(&e->rb_node); |
645 | if (unlikely(!node)) |
646 | return e; |
647 | e2 = container_of(node, struct wc_entry, rb_node); |
648 | if (read_original_sector(wc, e: e2) != block) |
649 | return e; |
650 | e = e2; |
651 | } |
652 | } |
653 | |
654 | static void writecache_insert_entry(struct dm_writecache *wc, struct wc_entry *ins) |
655 | { |
656 | struct wc_entry *e; |
657 | struct rb_node **node = &wc->tree.rb_node, *parent = NULL; |
658 | |
659 | while (*node) { |
660 | e = container_of(*node, struct wc_entry, rb_node); |
661 | parent = &e->rb_node; |
662 | if (read_original_sector(wc, e) > read_original_sector(wc, e: ins)) |
663 | node = &parent->rb_left; |
664 | else |
665 | node = &parent->rb_right; |
666 | } |
667 | rb_link_node(node: &ins->rb_node, parent, rb_link: node); |
668 | rb_insert_color(&ins->rb_node, &wc->tree); |
669 | list_add(new: &ins->lru, head: &wc->lru); |
670 | ins->age = jiffies; |
671 | } |
672 | |
673 | static void writecache_unlink(struct dm_writecache *wc, struct wc_entry *e) |
674 | { |
675 | list_del(entry: &e->lru); |
676 | rb_erase(&e->rb_node, &wc->tree); |
677 | } |
678 | |
679 | static void writecache_add_to_freelist(struct dm_writecache *wc, struct wc_entry *e) |
680 | { |
681 | if (WC_MODE_SORT_FREELIST(wc)) { |
682 | struct rb_node **node = &wc->freetree.rb_node, *parent = NULL; |
683 | |
684 | if (unlikely(!*node)) |
685 | wc->current_free = e; |
686 | while (*node) { |
687 | parent = *node; |
688 | if (&e->rb_node < *node) |
689 | node = &parent->rb_left; |
690 | else |
691 | node = &parent->rb_right; |
692 | } |
693 | rb_link_node(node: &e->rb_node, parent, rb_link: node); |
694 | rb_insert_color(&e->rb_node, &wc->freetree); |
695 | } else { |
696 | list_add_tail(new: &e->lru, head: &wc->freelist); |
697 | } |
698 | wc->freelist_size++; |
699 | } |
700 | |
701 | static inline void writecache_verify_watermark(struct dm_writecache *wc) |
702 | { |
703 | if (unlikely(wc->freelist_size + wc->writeback_size <= wc->freelist_high_watermark)) |
704 | queue_work(wq: wc->writeback_wq, work: &wc->writeback_work); |
705 | } |
706 | |
707 | static void writecache_max_age_timer(struct timer_list *t) |
708 | { |
709 | struct dm_writecache *wc = from_timer(wc, t, max_age_timer); |
710 | |
711 | if (!dm_suspended(ti: wc->ti) && !writecache_has_error(wc)) { |
712 | queue_work(wq: wc->writeback_wq, work: &wc->writeback_work); |
713 | mod_timer(timer: &wc->max_age_timer, expires: jiffies + wc->max_age / MAX_AGE_DIV); |
714 | } |
715 | } |
716 | |
717 | static struct wc_entry *writecache_pop_from_freelist(struct dm_writecache *wc, sector_t expected_sector) |
718 | { |
719 | struct wc_entry *e; |
720 | |
721 | if (WC_MODE_SORT_FREELIST(wc)) { |
722 | struct rb_node *next; |
723 | |
724 | if (unlikely(!wc->current_free)) |
725 | return NULL; |
726 | e = wc->current_free; |
727 | if (expected_sector != (sector_t)-1 && unlikely(cache_sector(wc, e) != expected_sector)) |
728 | return NULL; |
729 | next = rb_next(&e->rb_node); |
730 | rb_erase(&e->rb_node, &wc->freetree); |
731 | if (unlikely(!next)) |
732 | next = rb_first(&wc->freetree); |
733 | wc->current_free = next ? container_of(next, struct wc_entry, rb_node) : NULL; |
734 | } else { |
735 | if (unlikely(list_empty(&wc->freelist))) |
736 | return NULL; |
737 | e = container_of(wc->freelist.next, struct wc_entry, lru); |
738 | if (expected_sector != (sector_t)-1 && unlikely(cache_sector(wc, e) != expected_sector)) |
739 | return NULL; |
740 | list_del(entry: &e->lru); |
741 | } |
742 | wc->freelist_size--; |
743 | |
744 | writecache_verify_watermark(wc); |
745 | |
746 | return e; |
747 | } |
748 | |
749 | static void writecache_free_entry(struct dm_writecache *wc, struct wc_entry *e) |
750 | { |
751 | writecache_unlink(wc, e); |
752 | writecache_add_to_freelist(wc, e); |
753 | clear_seq_count(wc, e); |
754 | writecache_flush_region(wc, ptr: memory_entry(wc, e), size: sizeof(struct wc_memory_entry)); |
755 | if (unlikely(waitqueue_active(&wc->freelist_wait))) |
756 | wake_up(&wc->freelist_wait); |
757 | } |
758 | |
759 | static void writecache_wait_on_freelist(struct dm_writecache *wc) |
760 | { |
761 | DEFINE_WAIT(wait); |
762 | |
763 | prepare_to_wait(wq_head: &wc->freelist_wait, wq_entry: &wait, TASK_UNINTERRUPTIBLE); |
764 | wc_unlock(wc); |
765 | io_schedule(); |
766 | finish_wait(wq_head: &wc->freelist_wait, wq_entry: &wait); |
767 | wc_lock(wc); |
768 | } |
769 | |
770 | static void writecache_poison_lists(struct dm_writecache *wc) |
771 | { |
772 | /* |
773 | * Catch incorrect access to these values while the device is suspended. |
774 | */ |
775 | memset(&wc->tree, -1, sizeof(wc->tree)); |
776 | wc->lru.next = LIST_POISON1; |
777 | wc->lru.prev = LIST_POISON2; |
778 | wc->freelist.next = LIST_POISON1; |
779 | wc->freelist.prev = LIST_POISON2; |
780 | } |
781 | |
782 | static void writecache_flush_entry(struct dm_writecache *wc, struct wc_entry *e) |
783 | { |
784 | writecache_flush_region(wc, ptr: memory_entry(wc, e), size: sizeof(struct wc_memory_entry)); |
785 | if (WC_MODE_PMEM(wc)) |
786 | writecache_flush_region(wc, ptr: memory_data(wc, e), size: wc->block_size); |
787 | } |
788 | |
789 | static bool writecache_entry_is_committed(struct dm_writecache *wc, struct wc_entry *e) |
790 | { |
791 | return read_seq_count(wc, e) < wc->seq_count; |
792 | } |
793 | |
794 | static void writecache_flush(struct dm_writecache *wc) |
795 | { |
796 | struct wc_entry *e, *e2; |
797 | bool need_flush_after_free; |
798 | |
799 | wc->uncommitted_blocks = 0; |
800 | del_timer(timer: &wc->autocommit_timer); |
801 | |
802 | if (list_empty(head: &wc->lru)) |
803 | return; |
804 | |
805 | e = container_of(wc->lru.next, struct wc_entry, lru); |
806 | if (writecache_entry_is_committed(wc, e)) { |
807 | if (wc->overwrote_committed) { |
808 | writecache_wait_for_ios(wc, WRITE); |
809 | writecache_disk_flush(wc, dev: wc->ssd_dev); |
810 | wc->overwrote_committed = false; |
811 | } |
812 | return; |
813 | } |
814 | while (1) { |
815 | writecache_flush_entry(wc, e); |
816 | if (unlikely(e->lru.next == &wc->lru)) |
817 | break; |
818 | e2 = container_of(e->lru.next, struct wc_entry, lru); |
819 | if (writecache_entry_is_committed(wc, e: e2)) |
820 | break; |
821 | e = e2; |
822 | cond_resched(); |
823 | } |
824 | writecache_commit_flushed(wc, wait_for_ios: true); |
825 | |
826 | wc->seq_count++; |
827 | pmem_assign(sb(wc)->seq_count, cpu_to_le64(wc->seq_count)); |
828 | if (WC_MODE_PMEM(wc)) |
829 | writecache_commit_flushed(wc, wait_for_ios: false); |
830 | else |
831 | ssd_commit_superblock(wc); |
832 | |
833 | wc->overwrote_committed = false; |
834 | |
835 | need_flush_after_free = false; |
836 | while (1) { |
837 | /* Free another committed entry with lower seq-count */ |
838 | struct rb_node *rb_node = rb_prev(&e->rb_node); |
839 | |
840 | if (rb_node) { |
841 | e2 = container_of(rb_node, struct wc_entry, rb_node); |
842 | if (read_original_sector(wc, e: e2) == read_original_sector(wc, e) && |
843 | likely(!e2->write_in_progress)) { |
844 | writecache_free_entry(wc, e: e2); |
845 | need_flush_after_free = true; |
846 | } |
847 | } |
848 | if (unlikely(e->lru.prev == &wc->lru)) |
849 | break; |
850 | e = container_of(e->lru.prev, struct wc_entry, lru); |
851 | cond_resched(); |
852 | } |
853 | |
854 | if (need_flush_after_free) |
855 | writecache_commit_flushed(wc, wait_for_ios: false); |
856 | } |
857 | |
858 | static void writecache_flush_work(struct work_struct *work) |
859 | { |
860 | struct dm_writecache *wc = container_of(work, struct dm_writecache, flush_work); |
861 | |
862 | wc_lock(wc); |
863 | writecache_flush(wc); |
864 | wc_unlock(wc); |
865 | } |
866 | |
867 | static void writecache_autocommit_timer(struct timer_list *t) |
868 | { |
869 | struct dm_writecache *wc = from_timer(wc, t, autocommit_timer); |
870 | |
871 | if (!writecache_has_error(wc)) |
872 | queue_work(wq: wc->writeback_wq, work: &wc->flush_work); |
873 | } |
874 | |
875 | static void writecache_schedule_autocommit(struct dm_writecache *wc) |
876 | { |
877 | if (!timer_pending(timer: &wc->autocommit_timer)) |
878 | mod_timer(timer: &wc->autocommit_timer, expires: jiffies + wc->autocommit_jiffies); |
879 | } |
880 | |
881 | static void writecache_discard(struct dm_writecache *wc, sector_t start, sector_t end) |
882 | { |
883 | struct wc_entry *e; |
884 | bool discarded_something = false; |
885 | |
886 | e = writecache_find_entry(wc, block: start, WFE_RETURN_FOLLOWING | WFE_LOWEST_SEQ); |
887 | if (unlikely(!e)) |
888 | return; |
889 | |
890 | while (read_original_sector(wc, e) < end) { |
891 | struct rb_node *node = rb_next(&e->rb_node); |
892 | |
893 | if (likely(!e->write_in_progress)) { |
894 | if (!discarded_something) { |
895 | if (!WC_MODE_PMEM(wc)) { |
896 | writecache_wait_for_ios(wc, READ); |
897 | writecache_wait_for_ios(wc, WRITE); |
898 | } |
899 | discarded_something = true; |
900 | } |
901 | if (!writecache_entry_is_committed(wc, e)) |
902 | wc->uncommitted_blocks--; |
903 | writecache_free_entry(wc, e); |
904 | } |
905 | |
906 | if (unlikely(!node)) |
907 | break; |
908 | |
909 | e = container_of(node, struct wc_entry, rb_node); |
910 | } |
911 | |
912 | if (discarded_something) |
913 | writecache_commit_flushed(wc, wait_for_ios: false); |
914 | } |
915 | |
916 | static bool writecache_wait_for_writeback(struct dm_writecache *wc) |
917 | { |
918 | if (wc->writeback_size) { |
919 | writecache_wait_on_freelist(wc); |
920 | return true; |
921 | } |
922 | return false; |
923 | } |
924 | |
925 | static void writecache_suspend(struct dm_target *ti) |
926 | { |
927 | struct dm_writecache *wc = ti->private; |
928 | bool flush_on_suspend; |
929 | |
930 | del_timer_sync(timer: &wc->autocommit_timer); |
931 | del_timer_sync(timer: &wc->max_age_timer); |
932 | |
933 | wc_lock(wc); |
934 | writecache_flush(wc); |
935 | flush_on_suspend = wc->flush_on_suspend; |
936 | if (flush_on_suspend) { |
937 | wc->flush_on_suspend = false; |
938 | wc->writeback_all++; |
939 | queue_work(wq: wc->writeback_wq, work: &wc->writeback_work); |
940 | } |
941 | wc_unlock(wc); |
942 | |
943 | drain_workqueue(wq: wc->writeback_wq); |
944 | |
945 | wc_lock(wc); |
946 | if (flush_on_suspend) |
947 | wc->writeback_all--; |
948 | while (writecache_wait_for_writeback(wc)) |
949 | ; |
950 | |
951 | if (WC_MODE_PMEM(wc)) |
952 | persistent_memory_flush_cache(ptr: wc->memory_map, size: wc->memory_map_size); |
953 | |
954 | writecache_poison_lists(wc); |
955 | |
956 | wc_unlock(wc); |
957 | } |
958 | |
959 | static int writecache_alloc_entries(struct dm_writecache *wc) |
960 | { |
961 | size_t b; |
962 | |
963 | if (wc->entries) |
964 | return 0; |
965 | wc->entries = vmalloc(array_size(sizeof(struct wc_entry), wc->n_blocks)); |
966 | if (!wc->entries) |
967 | return -ENOMEM; |
968 | for (b = 0; b < wc->n_blocks; b++) { |
969 | struct wc_entry *e = &wc->entries[b]; |
970 | |
971 | e->index = b; |
972 | e->write_in_progress = false; |
973 | cond_resched(); |
974 | } |
975 | |
976 | return 0; |
977 | } |
978 | |
979 | static int writecache_read_metadata(struct dm_writecache *wc, sector_t n_sectors) |
980 | { |
981 | struct dm_io_region region; |
982 | struct dm_io_request req; |
983 | |
984 | region.bdev = wc->ssd_dev->bdev; |
985 | region.sector = wc->start_sector; |
986 | region.count = n_sectors; |
987 | req.bi_opf = REQ_OP_READ | REQ_SYNC; |
988 | req.mem.type = DM_IO_VMA; |
989 | req.mem.ptr.vma = (char *)wc->memory_map; |
990 | req.client = wc->dm_io; |
991 | req.notify.fn = NULL; |
992 | |
993 | return dm_io(io_req: &req, num_regions: 1, region: ®ion, NULL); |
994 | } |
995 | |
996 | static void writecache_resume(struct dm_target *ti) |
997 | { |
998 | struct dm_writecache *wc = ti->private; |
999 | size_t b; |
1000 | bool need_flush = false; |
1001 | __le64 sb_seq_count; |
1002 | int r; |
1003 | |
1004 | wc_lock(wc); |
1005 | |
1006 | wc->data_device_sectors = bdev_nr_sectors(bdev: wc->dev->bdev); |
1007 | |
1008 | if (WC_MODE_PMEM(wc)) { |
1009 | persistent_memory_invalidate_cache(ptr: wc->memory_map, size: wc->memory_map_size); |
1010 | } else { |
1011 | r = writecache_read_metadata(wc, n_sectors: wc->metadata_sectors); |
1012 | if (r) { |
1013 | size_t sb_entries_offset; |
1014 | |
1015 | writecache_error(wc, r, "unable to read metadata: %d" , r); |
1016 | sb_entries_offset = offsetof(struct wc_memory_superblock, entries); |
1017 | memset((char *)wc->memory_map + sb_entries_offset, -1, |
1018 | (wc->metadata_sectors << SECTOR_SHIFT) - sb_entries_offset); |
1019 | } |
1020 | } |
1021 | |
1022 | wc->tree = RB_ROOT; |
1023 | INIT_LIST_HEAD(list: &wc->lru); |
1024 | if (WC_MODE_SORT_FREELIST(wc)) { |
1025 | wc->freetree = RB_ROOT; |
1026 | wc->current_free = NULL; |
1027 | } else { |
1028 | INIT_LIST_HEAD(list: &wc->freelist); |
1029 | } |
1030 | wc->freelist_size = 0; |
1031 | |
1032 | r = copy_mc_to_kernel(to: &sb_seq_count, from: &sb(wc)->seq_count, |
1033 | len: sizeof(uint64_t)); |
1034 | if (r) { |
1035 | writecache_error(wc, r, "hardware memory error when reading superblock: %d" , r); |
1036 | sb_seq_count = cpu_to_le64(0); |
1037 | } |
1038 | wc->seq_count = le64_to_cpu(sb_seq_count); |
1039 | |
1040 | #ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
1041 | for (b = 0; b < wc->n_blocks; b++) { |
1042 | struct wc_entry *e = &wc->entries[b]; |
1043 | struct wc_memory_entry wme; |
1044 | |
1045 | if (writecache_has_error(wc)) { |
1046 | e->original_sector = -1; |
1047 | e->seq_count = -1; |
1048 | continue; |
1049 | } |
1050 | r = copy_mc_to_kernel(to: &wme, from: memory_entry(wc, e), |
1051 | len: sizeof(struct wc_memory_entry)); |
1052 | if (r) { |
1053 | writecache_error(wc, r, "hardware memory error when reading metadata entry %lu: %d" , |
1054 | (unsigned long)b, r); |
1055 | e->original_sector = -1; |
1056 | e->seq_count = -1; |
1057 | } else { |
1058 | e->original_sector = le64_to_cpu(wme.original_sector); |
1059 | e->seq_count = le64_to_cpu(wme.seq_count); |
1060 | } |
1061 | cond_resched(); |
1062 | } |
1063 | #endif |
1064 | for (b = 0; b < wc->n_blocks; b++) { |
1065 | struct wc_entry *e = &wc->entries[b]; |
1066 | |
1067 | if (!writecache_entry_is_committed(wc, e)) { |
1068 | if (read_seq_count(wc, e) != -1) { |
1069 | erase_this: |
1070 | clear_seq_count(wc, e); |
1071 | need_flush = true; |
1072 | } |
1073 | writecache_add_to_freelist(wc, e); |
1074 | } else { |
1075 | struct wc_entry *old; |
1076 | |
1077 | old = writecache_find_entry(wc, block: read_original_sector(wc, e), flags: 0); |
1078 | if (!old) { |
1079 | writecache_insert_entry(wc, ins: e); |
1080 | } else { |
1081 | if (read_seq_count(wc, e: old) == read_seq_count(wc, e)) { |
1082 | writecache_error(wc, -EINVAL, |
1083 | "two identical entries, position %llu, sector %llu, sequence %llu" , |
1084 | (unsigned long long)b, (unsigned long long)read_original_sector(wc, e), |
1085 | (unsigned long long)read_seq_count(wc, e)); |
1086 | } |
1087 | if (read_seq_count(wc, e: old) > read_seq_count(wc, e)) { |
1088 | goto erase_this; |
1089 | } else { |
1090 | writecache_free_entry(wc, e: old); |
1091 | writecache_insert_entry(wc, ins: e); |
1092 | need_flush = true; |
1093 | } |
1094 | } |
1095 | } |
1096 | cond_resched(); |
1097 | } |
1098 | |
1099 | if (need_flush) { |
1100 | writecache_flush_all_metadata(wc); |
1101 | writecache_commit_flushed(wc, wait_for_ios: false); |
1102 | } |
1103 | |
1104 | writecache_verify_watermark(wc); |
1105 | |
1106 | if (wc->max_age != MAX_AGE_UNSPECIFIED) |
1107 | mod_timer(timer: &wc->max_age_timer, expires: jiffies + wc->max_age / MAX_AGE_DIV); |
1108 | |
1109 | wc_unlock(wc); |
1110 | } |
1111 | |
1112 | static int process_flush_mesg(unsigned int argc, char **argv, struct dm_writecache *wc) |
1113 | { |
1114 | if (argc != 1) |
1115 | return -EINVAL; |
1116 | |
1117 | wc_lock(wc); |
1118 | if (dm_suspended(ti: wc->ti)) { |
1119 | wc_unlock(wc); |
1120 | return -EBUSY; |
1121 | } |
1122 | if (writecache_has_error(wc)) { |
1123 | wc_unlock(wc); |
1124 | return -EIO; |
1125 | } |
1126 | |
1127 | writecache_flush(wc); |
1128 | wc->writeback_all++; |
1129 | queue_work(wq: wc->writeback_wq, work: &wc->writeback_work); |
1130 | wc_unlock(wc); |
1131 | |
1132 | flush_workqueue(wc->writeback_wq); |
1133 | |
1134 | wc_lock(wc); |
1135 | wc->writeback_all--; |
1136 | if (writecache_has_error(wc)) { |
1137 | wc_unlock(wc); |
1138 | return -EIO; |
1139 | } |
1140 | wc_unlock(wc); |
1141 | |
1142 | return 0; |
1143 | } |
1144 | |
1145 | static int process_flush_on_suspend_mesg(unsigned int argc, char **argv, struct dm_writecache *wc) |
1146 | { |
1147 | if (argc != 1) |
1148 | return -EINVAL; |
1149 | |
1150 | wc_lock(wc); |
1151 | wc->flush_on_suspend = true; |
1152 | wc_unlock(wc); |
1153 | |
1154 | return 0; |
1155 | } |
1156 | |
1157 | static void activate_cleaner(struct dm_writecache *wc) |
1158 | { |
1159 | wc->flush_on_suspend = true; |
1160 | wc->cleaner = true; |
1161 | wc->freelist_high_watermark = wc->n_blocks; |
1162 | wc->freelist_low_watermark = wc->n_blocks; |
1163 | } |
1164 | |
1165 | static int process_cleaner_mesg(unsigned int argc, char **argv, struct dm_writecache *wc) |
1166 | { |
1167 | if (argc != 1) |
1168 | return -EINVAL; |
1169 | |
1170 | wc_lock(wc); |
1171 | activate_cleaner(wc); |
1172 | if (!dm_suspended(ti: wc->ti)) |
1173 | writecache_verify_watermark(wc); |
1174 | wc_unlock(wc); |
1175 | |
1176 | return 0; |
1177 | } |
1178 | |
1179 | static int process_clear_stats_mesg(unsigned int argc, char **argv, struct dm_writecache *wc) |
1180 | { |
1181 | if (argc != 1) |
1182 | return -EINVAL; |
1183 | |
1184 | wc_lock(wc); |
1185 | memset(&wc->stats, 0, sizeof(wc->stats)); |
1186 | wc_unlock(wc); |
1187 | |
1188 | return 0; |
1189 | } |
1190 | |
1191 | static int writecache_message(struct dm_target *ti, unsigned int argc, char **argv, |
1192 | char *result, unsigned int maxlen) |
1193 | { |
1194 | int r = -EINVAL; |
1195 | struct dm_writecache *wc = ti->private; |
1196 | |
1197 | if (!strcasecmp(s1: argv[0], s2: "flush" )) |
1198 | r = process_flush_mesg(argc, argv, wc); |
1199 | else if (!strcasecmp(s1: argv[0], s2: "flush_on_suspend" )) |
1200 | r = process_flush_on_suspend_mesg(argc, argv, wc); |
1201 | else if (!strcasecmp(s1: argv[0], s2: "cleaner" )) |
1202 | r = process_cleaner_mesg(argc, argv, wc); |
1203 | else if (!strcasecmp(s1: argv[0], s2: "clear_stats" )) |
1204 | r = process_clear_stats_mesg(argc, argv, wc); |
1205 | else |
1206 | DMERR("unrecognised message received: %s" , argv[0]); |
1207 | |
1208 | return r; |
1209 | } |
1210 | |
1211 | static void memcpy_flushcache_optimized(void *dest, void *source, size_t size) |
1212 | { |
1213 | /* |
1214 | * clflushopt performs better with block size 1024, 2048, 4096 |
1215 | * non-temporal stores perform better with block size 512 |
1216 | * |
1217 | * block size 512 1024 2048 4096 |
1218 | * movnti 496 MB/s 642 MB/s 725 MB/s 744 MB/s |
1219 | * clflushopt 373 MB/s 688 MB/s 1.1 GB/s 1.2 GB/s |
1220 | * |
1221 | * We see that movnti performs better for 512-byte blocks, and |
1222 | * clflushopt performs better for 1024-byte and larger blocks. So, we |
1223 | * prefer clflushopt for sizes >= 768. |
1224 | * |
1225 | * NOTE: this happens to be the case now (with dm-writecache's single |
1226 | * threaded model) but re-evaluate this once memcpy_flushcache() is |
1227 | * enabled to use movdir64b which might invalidate this performance |
1228 | * advantage seen with cache-allocating-writes plus flushing. |
1229 | */ |
1230 | #ifdef CONFIG_X86 |
1231 | if (static_cpu_has(X86_FEATURE_CLFLUSHOPT) && |
1232 | likely(boot_cpu_data.x86_clflush_size == 64) && |
1233 | likely(size >= 768)) { |
1234 | do { |
1235 | memcpy((void *)dest, (void *)source, 64); |
1236 | clflushopt(p: (void *)dest); |
1237 | dest += 64; |
1238 | source += 64; |
1239 | size -= 64; |
1240 | } while (size >= 64); |
1241 | return; |
1242 | } |
1243 | #endif |
1244 | memcpy_flushcache(dst: dest, src: source, cnt: size); |
1245 | } |
1246 | |
1247 | static void bio_copy_block(struct dm_writecache *wc, struct bio *bio, void *data) |
1248 | { |
1249 | void *buf; |
1250 | unsigned int size; |
1251 | int rw = bio_data_dir(bio); |
1252 | unsigned int remaining_size = wc->block_size; |
1253 | |
1254 | do { |
1255 | struct bio_vec bv = bio_iter_iovec(bio, bio->bi_iter); |
1256 | |
1257 | buf = bvec_kmap_local(bvec: &bv); |
1258 | size = bv.bv_len; |
1259 | if (unlikely(size > remaining_size)) |
1260 | size = remaining_size; |
1261 | |
1262 | if (rw == READ) { |
1263 | int r; |
1264 | |
1265 | r = copy_mc_to_kernel(to: buf, from: data, len: size); |
1266 | flush_dcache_page(bio_page(bio)); |
1267 | if (unlikely(r)) { |
1268 | writecache_error(wc, r, "hardware memory error when reading data: %d" , r); |
1269 | bio->bi_status = BLK_STS_IOERR; |
1270 | } |
1271 | } else { |
1272 | flush_dcache_page(bio_page(bio)); |
1273 | memcpy_flushcache_optimized(dest: data, source: buf, size); |
1274 | } |
1275 | |
1276 | kunmap_local(buf); |
1277 | |
1278 | data = (char *)data + size; |
1279 | remaining_size -= size; |
1280 | bio_advance(bio, nbytes: size); |
1281 | } while (unlikely(remaining_size)); |
1282 | } |
1283 | |
1284 | static int writecache_flush_thread(void *data) |
1285 | { |
1286 | struct dm_writecache *wc = data; |
1287 | |
1288 | while (1) { |
1289 | struct bio *bio; |
1290 | |
1291 | wc_lock(wc); |
1292 | bio = bio_list_pop(bl: &wc->flush_list); |
1293 | if (!bio) { |
1294 | set_current_state(TASK_INTERRUPTIBLE); |
1295 | wc_unlock(wc); |
1296 | |
1297 | if (unlikely(kthread_should_stop())) { |
1298 | set_current_state(TASK_RUNNING); |
1299 | break; |
1300 | } |
1301 | |
1302 | schedule(); |
1303 | continue; |
1304 | } |
1305 | |
1306 | if (bio_op(bio) == REQ_OP_DISCARD) { |
1307 | writecache_discard(wc, start: bio->bi_iter.bi_sector, |
1308 | bio_end_sector(bio)); |
1309 | wc_unlock(wc); |
1310 | bio_set_dev(bio, bdev: wc->dev->bdev); |
1311 | submit_bio_noacct(bio); |
1312 | } else { |
1313 | writecache_flush(wc); |
1314 | wc_unlock(wc); |
1315 | if (writecache_has_error(wc)) |
1316 | bio->bi_status = BLK_STS_IOERR; |
1317 | bio_endio(bio); |
1318 | } |
1319 | } |
1320 | |
1321 | return 0; |
1322 | } |
1323 | |
1324 | static void writecache_offload_bio(struct dm_writecache *wc, struct bio *bio) |
1325 | { |
1326 | if (bio_list_empty(bl: &wc->flush_list)) |
1327 | wake_up_process(tsk: wc->flush_thread); |
1328 | bio_list_add(bl: &wc->flush_list, bio); |
1329 | } |
1330 | |
1331 | enum wc_map_op { |
1332 | WC_MAP_SUBMIT, |
1333 | WC_MAP_REMAP, |
1334 | WC_MAP_REMAP_ORIGIN, |
1335 | WC_MAP_RETURN, |
1336 | WC_MAP_ERROR, |
1337 | }; |
1338 | |
1339 | static void writecache_map_remap_origin(struct dm_writecache *wc, struct bio *bio, |
1340 | struct wc_entry *e) |
1341 | { |
1342 | if (e) { |
1343 | sector_t next_boundary = |
1344 | read_original_sector(wc, e) - bio->bi_iter.bi_sector; |
1345 | if (next_boundary < bio->bi_iter.bi_size >> SECTOR_SHIFT) |
1346 | dm_accept_partial_bio(bio, n_sectors: next_boundary); |
1347 | } |
1348 | } |
1349 | |
1350 | static enum wc_map_op writecache_map_read(struct dm_writecache *wc, struct bio *bio) |
1351 | { |
1352 | enum wc_map_op map_op; |
1353 | struct wc_entry *e; |
1354 | |
1355 | read_next_block: |
1356 | wc->stats.reads++; |
1357 | e = writecache_find_entry(wc, block: bio->bi_iter.bi_sector, WFE_RETURN_FOLLOWING); |
1358 | if (e && read_original_sector(wc, e) == bio->bi_iter.bi_sector) { |
1359 | wc->stats.read_hits++; |
1360 | if (WC_MODE_PMEM(wc)) { |
1361 | bio_copy_block(wc, bio, data: memory_data(wc, e)); |
1362 | if (bio->bi_iter.bi_size) |
1363 | goto read_next_block; |
1364 | map_op = WC_MAP_SUBMIT; |
1365 | } else { |
1366 | dm_accept_partial_bio(bio, n_sectors: wc->block_size >> SECTOR_SHIFT); |
1367 | bio_set_dev(bio, bdev: wc->ssd_dev->bdev); |
1368 | bio->bi_iter.bi_sector = cache_sector(wc, e); |
1369 | if (!writecache_entry_is_committed(wc, e)) |
1370 | writecache_wait_for_ios(wc, WRITE); |
1371 | map_op = WC_MAP_REMAP; |
1372 | } |
1373 | } else { |
1374 | writecache_map_remap_origin(wc, bio, e); |
1375 | wc->stats.reads += (bio->bi_iter.bi_size - wc->block_size) >> wc->block_size_bits; |
1376 | map_op = WC_MAP_REMAP_ORIGIN; |
1377 | } |
1378 | |
1379 | return map_op; |
1380 | } |
1381 | |
1382 | static void writecache_bio_copy_ssd(struct dm_writecache *wc, struct bio *bio, |
1383 | struct wc_entry *e, bool search_used) |
1384 | { |
1385 | unsigned int bio_size = wc->block_size; |
1386 | sector_t start_cache_sec = cache_sector(wc, e); |
1387 | sector_t current_cache_sec = start_cache_sec + (bio_size >> SECTOR_SHIFT); |
1388 | |
1389 | while (bio_size < bio->bi_iter.bi_size) { |
1390 | if (!search_used) { |
1391 | struct wc_entry *f = writecache_pop_from_freelist(wc, expected_sector: current_cache_sec); |
1392 | |
1393 | if (!f) |
1394 | break; |
1395 | write_original_sector_seq_count(wc, e: f, original_sector: bio->bi_iter.bi_sector + |
1396 | (bio_size >> SECTOR_SHIFT), seq_count: wc->seq_count); |
1397 | writecache_insert_entry(wc, ins: f); |
1398 | wc->uncommitted_blocks++; |
1399 | } else { |
1400 | struct wc_entry *f; |
1401 | struct rb_node *next = rb_next(&e->rb_node); |
1402 | |
1403 | if (!next) |
1404 | break; |
1405 | f = container_of(next, struct wc_entry, rb_node); |
1406 | if (f != e + 1) |
1407 | break; |
1408 | if (read_original_sector(wc, e: f) != |
1409 | read_original_sector(wc, e) + (wc->block_size >> SECTOR_SHIFT)) |
1410 | break; |
1411 | if (unlikely(f->write_in_progress)) |
1412 | break; |
1413 | if (writecache_entry_is_committed(wc, e: f)) |
1414 | wc->overwrote_committed = true; |
1415 | e = f; |
1416 | } |
1417 | bio_size += wc->block_size; |
1418 | current_cache_sec += wc->block_size >> SECTOR_SHIFT; |
1419 | } |
1420 | |
1421 | bio_set_dev(bio, bdev: wc->ssd_dev->bdev); |
1422 | bio->bi_iter.bi_sector = start_cache_sec; |
1423 | dm_accept_partial_bio(bio, n_sectors: bio_size >> SECTOR_SHIFT); |
1424 | |
1425 | wc->stats.writes += bio->bi_iter.bi_size >> wc->block_size_bits; |
1426 | wc->stats.writes_allocate += (bio->bi_iter.bi_size - wc->block_size) >> wc->block_size_bits; |
1427 | |
1428 | if (unlikely(wc->uncommitted_blocks >= wc->autocommit_blocks)) { |
1429 | wc->uncommitted_blocks = 0; |
1430 | queue_work(wq: wc->writeback_wq, work: &wc->flush_work); |
1431 | } else { |
1432 | writecache_schedule_autocommit(wc); |
1433 | } |
1434 | } |
1435 | |
1436 | static enum wc_map_op writecache_map_write(struct dm_writecache *wc, struct bio *bio) |
1437 | { |
1438 | struct wc_entry *e; |
1439 | |
1440 | do { |
1441 | bool found_entry = false; |
1442 | bool search_used = false; |
1443 | |
1444 | if (writecache_has_error(wc)) { |
1445 | wc->stats.writes += bio->bi_iter.bi_size >> wc->block_size_bits; |
1446 | return WC_MAP_ERROR; |
1447 | } |
1448 | e = writecache_find_entry(wc, block: bio->bi_iter.bi_sector, flags: 0); |
1449 | if (e) { |
1450 | if (!writecache_entry_is_committed(wc, e)) { |
1451 | wc->stats.write_hits_uncommitted++; |
1452 | search_used = true; |
1453 | goto bio_copy; |
1454 | } |
1455 | wc->stats.write_hits_committed++; |
1456 | if (!WC_MODE_PMEM(wc) && !e->write_in_progress) { |
1457 | wc->overwrote_committed = true; |
1458 | search_used = true; |
1459 | goto bio_copy; |
1460 | } |
1461 | found_entry = true; |
1462 | } else { |
1463 | if (unlikely(wc->cleaner) || |
1464 | (wc->metadata_only && !(bio->bi_opf & REQ_META))) |
1465 | goto direct_write; |
1466 | } |
1467 | e = writecache_pop_from_freelist(wc, expected_sector: (sector_t)-1); |
1468 | if (unlikely(!e)) { |
1469 | if (!WC_MODE_PMEM(wc) && !found_entry) { |
1470 | direct_write: |
1471 | e = writecache_find_entry(wc, block: bio->bi_iter.bi_sector, WFE_RETURN_FOLLOWING); |
1472 | writecache_map_remap_origin(wc, bio, e); |
1473 | wc->stats.writes_around += bio->bi_iter.bi_size >> wc->block_size_bits; |
1474 | wc->stats.writes += bio->bi_iter.bi_size >> wc->block_size_bits; |
1475 | return WC_MAP_REMAP_ORIGIN; |
1476 | } |
1477 | wc->stats.writes_blocked_on_freelist++; |
1478 | writecache_wait_on_freelist(wc); |
1479 | continue; |
1480 | } |
1481 | write_original_sector_seq_count(wc, e, original_sector: bio->bi_iter.bi_sector, seq_count: wc->seq_count); |
1482 | writecache_insert_entry(wc, ins: e); |
1483 | wc->uncommitted_blocks++; |
1484 | wc->stats.writes_allocate++; |
1485 | bio_copy: |
1486 | if (WC_MODE_PMEM(wc)) { |
1487 | bio_copy_block(wc, bio, data: memory_data(wc, e)); |
1488 | wc->stats.writes++; |
1489 | } else { |
1490 | writecache_bio_copy_ssd(wc, bio, e, search_used); |
1491 | return WC_MAP_REMAP; |
1492 | } |
1493 | } while (bio->bi_iter.bi_size); |
1494 | |
1495 | if (unlikely(bio->bi_opf & REQ_FUA || wc->uncommitted_blocks >= wc->autocommit_blocks)) |
1496 | writecache_flush(wc); |
1497 | else |
1498 | writecache_schedule_autocommit(wc); |
1499 | |
1500 | return WC_MAP_SUBMIT; |
1501 | } |
1502 | |
1503 | static enum wc_map_op writecache_map_flush(struct dm_writecache *wc, struct bio *bio) |
1504 | { |
1505 | if (writecache_has_error(wc)) |
1506 | return WC_MAP_ERROR; |
1507 | |
1508 | if (WC_MODE_PMEM(wc)) { |
1509 | wc->stats.flushes++; |
1510 | writecache_flush(wc); |
1511 | if (writecache_has_error(wc)) |
1512 | return WC_MAP_ERROR; |
1513 | else if (unlikely(wc->cleaner) || unlikely(wc->metadata_only)) |
1514 | return WC_MAP_REMAP_ORIGIN; |
1515 | return WC_MAP_SUBMIT; |
1516 | } |
1517 | /* SSD: */ |
1518 | if (dm_bio_get_target_bio_nr(bio)) |
1519 | return WC_MAP_REMAP_ORIGIN; |
1520 | wc->stats.flushes++; |
1521 | writecache_offload_bio(wc, bio); |
1522 | return WC_MAP_RETURN; |
1523 | } |
1524 | |
1525 | static enum wc_map_op writecache_map_discard(struct dm_writecache *wc, struct bio *bio) |
1526 | { |
1527 | wc->stats.discards += bio->bi_iter.bi_size >> wc->block_size_bits; |
1528 | |
1529 | if (writecache_has_error(wc)) |
1530 | return WC_MAP_ERROR; |
1531 | |
1532 | if (WC_MODE_PMEM(wc)) { |
1533 | writecache_discard(wc, start: bio->bi_iter.bi_sector, bio_end_sector(bio)); |
1534 | return WC_MAP_REMAP_ORIGIN; |
1535 | } |
1536 | /* SSD: */ |
1537 | writecache_offload_bio(wc, bio); |
1538 | return WC_MAP_RETURN; |
1539 | } |
1540 | |
1541 | static int writecache_map(struct dm_target *ti, struct bio *bio) |
1542 | { |
1543 | struct dm_writecache *wc = ti->private; |
1544 | enum wc_map_op map_op; |
1545 | |
1546 | bio->bi_private = NULL; |
1547 | |
1548 | wc_lock(wc); |
1549 | |
1550 | if (unlikely(bio->bi_opf & REQ_PREFLUSH)) { |
1551 | map_op = writecache_map_flush(wc, bio); |
1552 | goto done; |
1553 | } |
1554 | |
1555 | bio->bi_iter.bi_sector = dm_target_offset(ti, bio->bi_iter.bi_sector); |
1556 | |
1557 | if (unlikely((((unsigned int)bio->bi_iter.bi_sector | bio_sectors(bio)) & |
1558 | (wc->block_size / 512 - 1)) != 0)) { |
1559 | DMERR("I/O is not aligned, sector %llu, size %u, block size %u" , |
1560 | (unsigned long long)bio->bi_iter.bi_sector, |
1561 | bio->bi_iter.bi_size, wc->block_size); |
1562 | map_op = WC_MAP_ERROR; |
1563 | goto done; |
1564 | } |
1565 | |
1566 | if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) { |
1567 | map_op = writecache_map_discard(wc, bio); |
1568 | goto done; |
1569 | } |
1570 | |
1571 | if (bio_data_dir(bio) == READ) |
1572 | map_op = writecache_map_read(wc, bio); |
1573 | else |
1574 | map_op = writecache_map_write(wc, bio); |
1575 | done: |
1576 | switch (map_op) { |
1577 | case WC_MAP_REMAP_ORIGIN: |
1578 | if (likely(wc->pause != 0)) { |
1579 | if (bio_op(bio) == REQ_OP_WRITE) { |
1580 | dm_iot_io_begin(iot: &wc->iot, len: 1); |
1581 | bio->bi_private = (void *)2; |
1582 | } |
1583 | } |
1584 | bio_set_dev(bio, bdev: wc->dev->bdev); |
1585 | wc_unlock(wc); |
1586 | return DM_MAPIO_REMAPPED; |
1587 | |
1588 | case WC_MAP_REMAP: |
1589 | /* make sure that writecache_end_io decrements bio_in_progress: */ |
1590 | bio->bi_private = (void *)1; |
1591 | atomic_inc(v: &wc->bio_in_progress[bio_data_dir(bio)]); |
1592 | wc_unlock(wc); |
1593 | return DM_MAPIO_REMAPPED; |
1594 | |
1595 | case WC_MAP_SUBMIT: |
1596 | wc_unlock(wc); |
1597 | bio_endio(bio); |
1598 | return DM_MAPIO_SUBMITTED; |
1599 | |
1600 | case WC_MAP_RETURN: |
1601 | wc_unlock(wc); |
1602 | return DM_MAPIO_SUBMITTED; |
1603 | |
1604 | case WC_MAP_ERROR: |
1605 | wc_unlock(wc); |
1606 | bio_io_error(bio); |
1607 | return DM_MAPIO_SUBMITTED; |
1608 | |
1609 | default: |
1610 | BUG(); |
1611 | wc_unlock(wc); |
1612 | return DM_MAPIO_KILL; |
1613 | } |
1614 | } |
1615 | |
1616 | static int writecache_end_io(struct dm_target *ti, struct bio *bio, blk_status_t *status) |
1617 | { |
1618 | struct dm_writecache *wc = ti->private; |
1619 | |
1620 | if (bio->bi_private == (void *)1) { |
1621 | int dir = bio_data_dir(bio); |
1622 | |
1623 | if (atomic_dec_and_test(v: &wc->bio_in_progress[dir])) |
1624 | if (unlikely(waitqueue_active(&wc->bio_in_progress_wait[dir]))) |
1625 | wake_up(&wc->bio_in_progress_wait[dir]); |
1626 | } else if (bio->bi_private == (void *)2) { |
1627 | dm_iot_io_end(iot: &wc->iot, len: 1); |
1628 | } |
1629 | return 0; |
1630 | } |
1631 | |
1632 | static int writecache_iterate_devices(struct dm_target *ti, |
1633 | iterate_devices_callout_fn fn, void *data) |
1634 | { |
1635 | struct dm_writecache *wc = ti->private; |
1636 | |
1637 | return fn(ti, wc->dev, 0, ti->len, data); |
1638 | } |
1639 | |
1640 | static void writecache_io_hints(struct dm_target *ti, struct queue_limits *limits) |
1641 | { |
1642 | struct dm_writecache *wc = ti->private; |
1643 | |
1644 | if (limits->logical_block_size < wc->block_size) |
1645 | limits->logical_block_size = wc->block_size; |
1646 | |
1647 | if (limits->physical_block_size < wc->block_size) |
1648 | limits->physical_block_size = wc->block_size; |
1649 | |
1650 | if (limits->io_min < wc->block_size) |
1651 | limits->io_min = wc->block_size; |
1652 | } |
1653 | |
1654 | |
1655 | static void writecache_writeback_endio(struct bio *bio) |
1656 | { |
1657 | struct writeback_struct *wb = container_of(bio, struct writeback_struct, bio); |
1658 | struct dm_writecache *wc = wb->wc; |
1659 | unsigned long flags; |
1660 | |
1661 | raw_spin_lock_irqsave(&wc->endio_list_lock, flags); |
1662 | if (unlikely(list_empty(&wc->endio_list))) |
1663 | wake_up_process(tsk: wc->endio_thread); |
1664 | list_add_tail(new: &wb->endio_entry, head: &wc->endio_list); |
1665 | raw_spin_unlock_irqrestore(&wc->endio_list_lock, flags); |
1666 | } |
1667 | |
1668 | static void writecache_copy_endio(int read_err, unsigned long write_err, void *ptr) |
1669 | { |
1670 | struct copy_struct *c = ptr; |
1671 | struct dm_writecache *wc = c->wc; |
1672 | |
1673 | c->error = likely(!(read_err | write_err)) ? 0 : -EIO; |
1674 | |
1675 | raw_spin_lock_irq(&wc->endio_list_lock); |
1676 | if (unlikely(list_empty(&wc->endio_list))) |
1677 | wake_up_process(tsk: wc->endio_thread); |
1678 | list_add_tail(new: &c->endio_entry, head: &wc->endio_list); |
1679 | raw_spin_unlock_irq(&wc->endio_list_lock); |
1680 | } |
1681 | |
1682 | static void __writecache_endio_pmem(struct dm_writecache *wc, struct list_head *list) |
1683 | { |
1684 | unsigned int i; |
1685 | struct writeback_struct *wb; |
1686 | struct wc_entry *e; |
1687 | unsigned long n_walked = 0; |
1688 | |
1689 | do { |
1690 | wb = list_entry(list->next, struct writeback_struct, endio_entry); |
1691 | list_del(entry: &wb->endio_entry); |
1692 | |
1693 | if (unlikely(wb->bio.bi_status != BLK_STS_OK)) |
1694 | writecache_error(wc, blk_status_to_errno(wb->bio.bi_status), |
1695 | "write error %d" , wb->bio.bi_status); |
1696 | i = 0; |
1697 | do { |
1698 | e = wb->wc_list[i]; |
1699 | BUG_ON(!e->write_in_progress); |
1700 | e->write_in_progress = false; |
1701 | INIT_LIST_HEAD(list: &e->lru); |
1702 | if (!writecache_has_error(wc)) |
1703 | writecache_free_entry(wc, e); |
1704 | BUG_ON(!wc->writeback_size); |
1705 | wc->writeback_size--; |
1706 | n_walked++; |
1707 | if (unlikely(n_walked >= ENDIO_LATENCY)) { |
1708 | writecache_commit_flushed(wc, wait_for_ios: false); |
1709 | wc_unlock(wc); |
1710 | wc_lock(wc); |
1711 | n_walked = 0; |
1712 | } |
1713 | } while (++i < wb->wc_list_n); |
1714 | |
1715 | if (wb->wc_list != wb->wc_list_inline) |
1716 | kfree(objp: wb->wc_list); |
1717 | bio_put(&wb->bio); |
1718 | } while (!list_empty(head: list)); |
1719 | } |
1720 | |
1721 | static void __writecache_endio_ssd(struct dm_writecache *wc, struct list_head *list) |
1722 | { |
1723 | struct copy_struct *c; |
1724 | struct wc_entry *e; |
1725 | |
1726 | do { |
1727 | c = list_entry(list->next, struct copy_struct, endio_entry); |
1728 | list_del(entry: &c->endio_entry); |
1729 | |
1730 | if (unlikely(c->error)) |
1731 | writecache_error(wc, c->error, "copy error" ); |
1732 | |
1733 | e = c->e; |
1734 | do { |
1735 | BUG_ON(!e->write_in_progress); |
1736 | e->write_in_progress = false; |
1737 | INIT_LIST_HEAD(list: &e->lru); |
1738 | if (!writecache_has_error(wc)) |
1739 | writecache_free_entry(wc, e); |
1740 | |
1741 | BUG_ON(!wc->writeback_size); |
1742 | wc->writeback_size--; |
1743 | e++; |
1744 | } while (--c->n_entries); |
1745 | mempool_free(element: c, pool: &wc->copy_pool); |
1746 | } while (!list_empty(head: list)); |
1747 | } |
1748 | |
1749 | static int writecache_endio_thread(void *data) |
1750 | { |
1751 | struct dm_writecache *wc = data; |
1752 | |
1753 | while (1) { |
1754 | struct list_head list; |
1755 | |
1756 | raw_spin_lock_irq(&wc->endio_list_lock); |
1757 | if (!list_empty(head: &wc->endio_list)) |
1758 | goto pop_from_list; |
1759 | set_current_state(TASK_INTERRUPTIBLE); |
1760 | raw_spin_unlock_irq(&wc->endio_list_lock); |
1761 | |
1762 | if (unlikely(kthread_should_stop())) { |
1763 | set_current_state(TASK_RUNNING); |
1764 | break; |
1765 | } |
1766 | |
1767 | schedule(); |
1768 | |
1769 | continue; |
1770 | |
1771 | pop_from_list: |
1772 | list = wc->endio_list; |
1773 | list.next->prev = list.prev->next = &list; |
1774 | INIT_LIST_HEAD(list: &wc->endio_list); |
1775 | raw_spin_unlock_irq(&wc->endio_list_lock); |
1776 | |
1777 | if (!WC_MODE_FUA(wc)) |
1778 | writecache_disk_flush(wc, dev: wc->dev); |
1779 | |
1780 | wc_lock(wc); |
1781 | |
1782 | if (WC_MODE_PMEM(wc)) { |
1783 | __writecache_endio_pmem(wc, list: &list); |
1784 | } else { |
1785 | __writecache_endio_ssd(wc, list: &list); |
1786 | writecache_wait_for_ios(wc, READ); |
1787 | } |
1788 | |
1789 | writecache_commit_flushed(wc, wait_for_ios: false); |
1790 | |
1791 | wc_unlock(wc); |
1792 | } |
1793 | |
1794 | return 0; |
1795 | } |
1796 | |
1797 | static bool wc_add_block(struct writeback_struct *wb, struct wc_entry *e) |
1798 | { |
1799 | struct dm_writecache *wc = wb->wc; |
1800 | unsigned int block_size = wc->block_size; |
1801 | void *address = memory_data(wc, e); |
1802 | |
1803 | persistent_memory_flush_cache(ptr: address, size: block_size); |
1804 | |
1805 | if (unlikely(bio_end_sector(&wb->bio) >= wc->data_device_sectors)) |
1806 | return true; |
1807 | |
1808 | return bio_add_page(bio: &wb->bio, page: persistent_memory_page(addr: address), |
1809 | len: block_size, off: persistent_memory_page_offset(addr: address)) != 0; |
1810 | } |
1811 | |
1812 | struct writeback_list { |
1813 | struct list_head list; |
1814 | size_t size; |
1815 | }; |
1816 | |
1817 | static void __writeback_throttle(struct dm_writecache *wc, struct writeback_list *wbl) |
1818 | { |
1819 | if (unlikely(wc->max_writeback_jobs)) { |
1820 | if (READ_ONCE(wc->writeback_size) - wbl->size >= wc->max_writeback_jobs) { |
1821 | wc_lock(wc); |
1822 | while (wc->writeback_size - wbl->size >= wc->max_writeback_jobs) |
1823 | writecache_wait_on_freelist(wc); |
1824 | wc_unlock(wc); |
1825 | } |
1826 | } |
1827 | cond_resched(); |
1828 | } |
1829 | |
1830 | static void __writecache_writeback_pmem(struct dm_writecache *wc, struct writeback_list *wbl) |
1831 | { |
1832 | struct wc_entry *e, *f; |
1833 | struct bio *bio; |
1834 | struct writeback_struct *wb; |
1835 | unsigned int max_pages; |
1836 | |
1837 | while (wbl->size) { |
1838 | wbl->size--; |
1839 | e = container_of(wbl->list.prev, struct wc_entry, lru); |
1840 | list_del(entry: &e->lru); |
1841 | |
1842 | max_pages = e->wc_list_contiguous; |
1843 | |
1844 | bio = bio_alloc_bioset(bdev: wc->dev->bdev, nr_vecs: max_pages, opf: REQ_OP_WRITE, |
1845 | GFP_NOIO, bs: &wc->bio_set); |
1846 | wb = container_of(bio, struct writeback_struct, bio); |
1847 | wb->wc = wc; |
1848 | bio->bi_end_io = writecache_writeback_endio; |
1849 | bio->bi_iter.bi_sector = read_original_sector(wc, e); |
1850 | |
1851 | if (unlikely(max_pages > WB_LIST_INLINE)) |
1852 | wb->wc_list = kmalloc_array(n: max_pages, size: sizeof(struct wc_entry *), |
1853 | GFP_NOIO | __GFP_NORETRY | |
1854 | __GFP_NOMEMALLOC | __GFP_NOWARN); |
1855 | |
1856 | if (likely(max_pages <= WB_LIST_INLINE) || unlikely(!wb->wc_list)) { |
1857 | wb->wc_list = wb->wc_list_inline; |
1858 | max_pages = WB_LIST_INLINE; |
1859 | } |
1860 | |
1861 | BUG_ON(!wc_add_block(wb, e)); |
1862 | |
1863 | wb->wc_list[0] = e; |
1864 | wb->wc_list_n = 1; |
1865 | |
1866 | while (wbl->size && wb->wc_list_n < max_pages) { |
1867 | f = container_of(wbl->list.prev, struct wc_entry, lru); |
1868 | if (read_original_sector(wc, e: f) != |
1869 | read_original_sector(wc, e) + (wc->block_size >> SECTOR_SHIFT)) |
1870 | break; |
1871 | if (!wc_add_block(wb, e: f)) |
1872 | break; |
1873 | wbl->size--; |
1874 | list_del(entry: &f->lru); |
1875 | wb->wc_list[wb->wc_list_n++] = f; |
1876 | e = f; |
1877 | } |
1878 | if (WC_MODE_FUA(wc)) |
1879 | bio->bi_opf |= REQ_FUA; |
1880 | if (writecache_has_error(wc)) { |
1881 | bio->bi_status = BLK_STS_IOERR; |
1882 | bio_endio(bio); |
1883 | } else if (unlikely(!bio_sectors(bio))) { |
1884 | bio->bi_status = BLK_STS_OK; |
1885 | bio_endio(bio); |
1886 | } else { |
1887 | submit_bio(bio); |
1888 | } |
1889 | |
1890 | __writeback_throttle(wc, wbl); |
1891 | } |
1892 | } |
1893 | |
1894 | static void __writecache_writeback_ssd(struct dm_writecache *wc, struct writeback_list *wbl) |
1895 | { |
1896 | struct wc_entry *e, *f; |
1897 | struct dm_io_region from, to; |
1898 | struct copy_struct *c; |
1899 | |
1900 | while (wbl->size) { |
1901 | unsigned int n_sectors; |
1902 | |
1903 | wbl->size--; |
1904 | e = container_of(wbl->list.prev, struct wc_entry, lru); |
1905 | list_del(entry: &e->lru); |
1906 | |
1907 | n_sectors = e->wc_list_contiguous << (wc->block_size_bits - SECTOR_SHIFT); |
1908 | |
1909 | from.bdev = wc->ssd_dev->bdev; |
1910 | from.sector = cache_sector(wc, e); |
1911 | from.count = n_sectors; |
1912 | to.bdev = wc->dev->bdev; |
1913 | to.sector = read_original_sector(wc, e); |
1914 | to.count = n_sectors; |
1915 | |
1916 | c = mempool_alloc(pool: &wc->copy_pool, GFP_NOIO); |
1917 | c->wc = wc; |
1918 | c->e = e; |
1919 | c->n_entries = e->wc_list_contiguous; |
1920 | |
1921 | while ((n_sectors -= wc->block_size >> SECTOR_SHIFT)) { |
1922 | wbl->size--; |
1923 | f = container_of(wbl->list.prev, struct wc_entry, lru); |
1924 | BUG_ON(f != e + 1); |
1925 | list_del(entry: &f->lru); |
1926 | e = f; |
1927 | } |
1928 | |
1929 | if (unlikely(to.sector + to.count > wc->data_device_sectors)) { |
1930 | if (to.sector >= wc->data_device_sectors) { |
1931 | writecache_copy_endio(read_err: 0, write_err: 0, ptr: c); |
1932 | continue; |
1933 | } |
1934 | from.count = to.count = wc->data_device_sectors - to.sector; |
1935 | } |
1936 | |
1937 | dm_kcopyd_copy(kc: wc->dm_kcopyd, from: &from, num_dests: 1, dests: &to, flags: 0, fn: writecache_copy_endio, context: c); |
1938 | |
1939 | __writeback_throttle(wc, wbl); |
1940 | } |
1941 | } |
1942 | |
1943 | static void writecache_writeback(struct work_struct *work) |
1944 | { |
1945 | struct dm_writecache *wc = container_of(work, struct dm_writecache, writeback_work); |
1946 | struct blk_plug plug; |
1947 | struct wc_entry *f, *g, *e = NULL; |
1948 | struct rb_node *node, *next_node; |
1949 | struct list_head skipped; |
1950 | struct writeback_list wbl; |
1951 | unsigned long n_walked; |
1952 | |
1953 | if (!WC_MODE_PMEM(wc)) { |
1954 | /* Wait for any active kcopyd work on behalf of ssd writeback */ |
1955 | dm_kcopyd_client_flush(kc: wc->dm_kcopyd); |
1956 | } |
1957 | |
1958 | if (likely(wc->pause != 0)) { |
1959 | while (1) { |
1960 | unsigned long idle; |
1961 | |
1962 | if (unlikely(wc->cleaner) || unlikely(wc->writeback_all) || |
1963 | unlikely(dm_suspended(wc->ti))) |
1964 | break; |
1965 | idle = dm_iot_idle_time(iot: &wc->iot); |
1966 | if (idle >= wc->pause) |
1967 | break; |
1968 | idle = wc->pause - idle; |
1969 | if (idle > HZ) |
1970 | idle = HZ; |
1971 | schedule_timeout_idle(timeout: idle); |
1972 | } |
1973 | } |
1974 | |
1975 | wc_lock(wc); |
1976 | restart: |
1977 | if (writecache_has_error(wc)) { |
1978 | wc_unlock(wc); |
1979 | return; |
1980 | } |
1981 | |
1982 | if (unlikely(wc->writeback_all)) { |
1983 | if (writecache_wait_for_writeback(wc)) |
1984 | goto restart; |
1985 | } |
1986 | |
1987 | if (wc->overwrote_committed) |
1988 | writecache_wait_for_ios(wc, WRITE); |
1989 | |
1990 | n_walked = 0; |
1991 | INIT_LIST_HEAD(list: &skipped); |
1992 | INIT_LIST_HEAD(list: &wbl.list); |
1993 | wbl.size = 0; |
1994 | while (!list_empty(head: &wc->lru) && |
1995 | (wc->writeback_all || |
1996 | wc->freelist_size + wc->writeback_size <= wc->freelist_low_watermark || |
1997 | (jiffies - container_of(wc->lru.prev, struct wc_entry, lru)->age >= |
1998 | wc->max_age - wc->max_age / MAX_AGE_DIV))) { |
1999 | |
2000 | n_walked++; |
2001 | if (unlikely(n_walked > WRITEBACK_LATENCY) && |
2002 | likely(!wc->writeback_all)) { |
2003 | if (likely(!dm_suspended(wc->ti))) |
2004 | queue_work(wq: wc->writeback_wq, work: &wc->writeback_work); |
2005 | break; |
2006 | } |
2007 | |
2008 | if (unlikely(wc->writeback_all)) { |
2009 | if (unlikely(!e)) { |
2010 | writecache_flush(wc); |
2011 | e = container_of(rb_first(&wc->tree), struct wc_entry, rb_node); |
2012 | } else |
2013 | e = g; |
2014 | } else |
2015 | e = container_of(wc->lru.prev, struct wc_entry, lru); |
2016 | BUG_ON(e->write_in_progress); |
2017 | if (unlikely(!writecache_entry_is_committed(wc, e))) |
2018 | writecache_flush(wc); |
2019 | |
2020 | node = rb_prev(&e->rb_node); |
2021 | if (node) { |
2022 | f = container_of(node, struct wc_entry, rb_node); |
2023 | if (unlikely(read_original_sector(wc, f) == |
2024 | read_original_sector(wc, e))) { |
2025 | BUG_ON(!f->write_in_progress); |
2026 | list_move(list: &e->lru, head: &skipped); |
2027 | cond_resched(); |
2028 | continue; |
2029 | } |
2030 | } |
2031 | wc->writeback_size++; |
2032 | list_move(list: &e->lru, head: &wbl.list); |
2033 | wbl.size++; |
2034 | e->write_in_progress = true; |
2035 | e->wc_list_contiguous = 1; |
2036 | |
2037 | f = e; |
2038 | |
2039 | while (1) { |
2040 | next_node = rb_next(&f->rb_node); |
2041 | if (unlikely(!next_node)) |
2042 | break; |
2043 | g = container_of(next_node, struct wc_entry, rb_node); |
2044 | if (unlikely(read_original_sector(wc, g) == |
2045 | read_original_sector(wc, f))) { |
2046 | f = g; |
2047 | continue; |
2048 | } |
2049 | if (read_original_sector(wc, e: g) != |
2050 | read_original_sector(wc, e: f) + (wc->block_size >> SECTOR_SHIFT)) |
2051 | break; |
2052 | if (unlikely(g->write_in_progress)) |
2053 | break; |
2054 | if (unlikely(!writecache_entry_is_committed(wc, g))) |
2055 | break; |
2056 | |
2057 | if (!WC_MODE_PMEM(wc)) { |
2058 | if (g != f + 1) |
2059 | break; |
2060 | } |
2061 | |
2062 | n_walked++; |
2063 | //if (unlikely(n_walked > WRITEBACK_LATENCY) && likely(!wc->writeback_all)) |
2064 | // break; |
2065 | |
2066 | wc->writeback_size++; |
2067 | list_move(list: &g->lru, head: &wbl.list); |
2068 | wbl.size++; |
2069 | g->write_in_progress = true; |
2070 | g->wc_list_contiguous = BIO_MAX_VECS; |
2071 | f = g; |
2072 | e->wc_list_contiguous++; |
2073 | if (unlikely(e->wc_list_contiguous == BIO_MAX_VECS)) { |
2074 | if (unlikely(wc->writeback_all)) { |
2075 | next_node = rb_next(&f->rb_node); |
2076 | if (likely(next_node)) |
2077 | g = container_of(next_node, struct wc_entry, rb_node); |
2078 | } |
2079 | break; |
2080 | } |
2081 | } |
2082 | cond_resched(); |
2083 | } |
2084 | |
2085 | if (!list_empty(head: &skipped)) { |
2086 | list_splice_tail(list: &skipped, head: &wc->lru); |
2087 | /* |
2088 | * If we didn't do any progress, we must wait until some |
2089 | * writeback finishes to avoid burning CPU in a loop |
2090 | */ |
2091 | if (unlikely(!wbl.size)) |
2092 | writecache_wait_for_writeback(wc); |
2093 | } |
2094 | |
2095 | wc_unlock(wc); |
2096 | |
2097 | blk_start_plug(&plug); |
2098 | |
2099 | if (WC_MODE_PMEM(wc)) |
2100 | __writecache_writeback_pmem(wc, wbl: &wbl); |
2101 | else |
2102 | __writecache_writeback_ssd(wc, wbl: &wbl); |
2103 | |
2104 | blk_finish_plug(&plug); |
2105 | |
2106 | if (unlikely(wc->writeback_all)) { |
2107 | wc_lock(wc); |
2108 | while (writecache_wait_for_writeback(wc)) |
2109 | ; |
2110 | wc_unlock(wc); |
2111 | } |
2112 | } |
2113 | |
2114 | static int calculate_memory_size(uint64_t device_size, unsigned int block_size, |
2115 | size_t *n_blocks_p, size_t *n_metadata_blocks_p) |
2116 | { |
2117 | uint64_t n_blocks, offset; |
2118 | struct wc_entry e; |
2119 | |
2120 | n_blocks = device_size; |
2121 | do_div(n_blocks, block_size + sizeof(struct wc_memory_entry)); |
2122 | |
2123 | while (1) { |
2124 | if (!n_blocks) |
2125 | return -ENOSPC; |
2126 | /* Verify the following entries[n_blocks] won't overflow */ |
2127 | if (n_blocks >= ((size_t)-sizeof(struct wc_memory_superblock) / |
2128 | sizeof(struct wc_memory_entry))) |
2129 | return -EFBIG; |
2130 | offset = offsetof(struct wc_memory_superblock, entries[n_blocks]); |
2131 | offset = (offset + block_size - 1) & ~(uint64_t)(block_size - 1); |
2132 | if (offset + n_blocks * block_size <= device_size) |
2133 | break; |
2134 | n_blocks--; |
2135 | } |
2136 | |
2137 | /* check if the bit field overflows */ |
2138 | e.index = n_blocks; |
2139 | if (e.index != n_blocks) |
2140 | return -EFBIG; |
2141 | |
2142 | if (n_blocks_p) |
2143 | *n_blocks_p = n_blocks; |
2144 | if (n_metadata_blocks_p) |
2145 | *n_metadata_blocks_p = offset >> __ffs(block_size); |
2146 | return 0; |
2147 | } |
2148 | |
2149 | static int init_memory(struct dm_writecache *wc) |
2150 | { |
2151 | size_t b; |
2152 | int r; |
2153 | |
2154 | r = calculate_memory_size(device_size: wc->memory_map_size, block_size: wc->block_size, n_blocks_p: &wc->n_blocks, NULL); |
2155 | if (r) |
2156 | return r; |
2157 | |
2158 | r = writecache_alloc_entries(wc); |
2159 | if (r) |
2160 | return r; |
2161 | |
2162 | for (b = 0; b < ARRAY_SIZE(sb(wc)->padding); b++) |
2163 | pmem_assign(sb(wc)->padding[b], cpu_to_le64(0)); |
2164 | pmem_assign(sb(wc)->version, cpu_to_le32(MEMORY_SUPERBLOCK_VERSION)); |
2165 | pmem_assign(sb(wc)->block_size, cpu_to_le32(wc->block_size)); |
2166 | pmem_assign(sb(wc)->n_blocks, cpu_to_le64(wc->n_blocks)); |
2167 | pmem_assign(sb(wc)->seq_count, cpu_to_le64(0)); |
2168 | |
2169 | for (b = 0; b < wc->n_blocks; b++) { |
2170 | write_original_sector_seq_count(wc, e: &wc->entries[b], original_sector: -1, seq_count: -1); |
2171 | cond_resched(); |
2172 | } |
2173 | |
2174 | writecache_flush_all_metadata(wc); |
2175 | writecache_commit_flushed(wc, wait_for_ios: false); |
2176 | pmem_assign(sb(wc)->magic, cpu_to_le32(MEMORY_SUPERBLOCK_MAGIC)); |
2177 | writecache_flush_region(wc, ptr: &sb(wc)->magic, size: sizeof(sb(wc)->magic)); |
2178 | writecache_commit_flushed(wc, wait_for_ios: false); |
2179 | |
2180 | return 0; |
2181 | } |
2182 | |
2183 | static void writecache_dtr(struct dm_target *ti) |
2184 | { |
2185 | struct dm_writecache *wc = ti->private; |
2186 | |
2187 | if (!wc) |
2188 | return; |
2189 | |
2190 | if (wc->endio_thread) |
2191 | kthread_stop(k: wc->endio_thread); |
2192 | |
2193 | if (wc->flush_thread) |
2194 | kthread_stop(k: wc->flush_thread); |
2195 | |
2196 | bioset_exit(&wc->bio_set); |
2197 | |
2198 | mempool_exit(pool: &wc->copy_pool); |
2199 | |
2200 | if (wc->writeback_wq) |
2201 | destroy_workqueue(wq: wc->writeback_wq); |
2202 | |
2203 | if (wc->dev) |
2204 | dm_put_device(ti, d: wc->dev); |
2205 | |
2206 | if (wc->ssd_dev) |
2207 | dm_put_device(ti, d: wc->ssd_dev); |
2208 | |
2209 | vfree(addr: wc->entries); |
2210 | |
2211 | if (wc->memory_map) { |
2212 | if (WC_MODE_PMEM(wc)) |
2213 | persistent_memory_release(wc); |
2214 | else |
2215 | vfree(addr: wc->memory_map); |
2216 | } |
2217 | |
2218 | if (wc->dm_kcopyd) |
2219 | dm_kcopyd_client_destroy(kc: wc->dm_kcopyd); |
2220 | |
2221 | if (wc->dm_io) |
2222 | dm_io_client_destroy(client: wc->dm_io); |
2223 | |
2224 | vfree(addr: wc->dirty_bitmap); |
2225 | |
2226 | kfree(objp: wc); |
2227 | } |
2228 | |
2229 | static int writecache_ctr(struct dm_target *ti, unsigned int argc, char **argv) |
2230 | { |
2231 | struct dm_writecache *wc; |
2232 | struct dm_arg_set as; |
2233 | const char *string; |
2234 | unsigned int opt_params; |
2235 | size_t offset, data_size; |
2236 | int i, r; |
2237 | char dummy; |
2238 | int high_wm_percent = HIGH_WATERMARK; |
2239 | int low_wm_percent = LOW_WATERMARK; |
2240 | uint64_t x; |
2241 | struct wc_memory_superblock s; |
2242 | |
2243 | static struct dm_arg _args[] = { |
2244 | {0, 18, "Invalid number of feature args" }, |
2245 | }; |
2246 | |
2247 | as.argc = argc; |
2248 | as.argv = argv; |
2249 | |
2250 | wc = kzalloc(size: sizeof(struct dm_writecache), GFP_KERNEL); |
2251 | if (!wc) { |
2252 | ti->error = "Cannot allocate writecache structure" ; |
2253 | r = -ENOMEM; |
2254 | goto bad; |
2255 | } |
2256 | ti->private = wc; |
2257 | wc->ti = ti; |
2258 | |
2259 | mutex_init(&wc->lock); |
2260 | wc->max_age = MAX_AGE_UNSPECIFIED; |
2261 | writecache_poison_lists(wc); |
2262 | init_waitqueue_head(&wc->freelist_wait); |
2263 | timer_setup(&wc->autocommit_timer, writecache_autocommit_timer, 0); |
2264 | timer_setup(&wc->max_age_timer, writecache_max_age_timer, 0); |
2265 | |
2266 | for (i = 0; i < 2; i++) { |
2267 | atomic_set(v: &wc->bio_in_progress[i], i: 0); |
2268 | init_waitqueue_head(&wc->bio_in_progress_wait[i]); |
2269 | } |
2270 | |
2271 | wc->dm_io = dm_io_client_create(); |
2272 | if (IS_ERR(ptr: wc->dm_io)) { |
2273 | r = PTR_ERR(ptr: wc->dm_io); |
2274 | ti->error = "Unable to allocate dm-io client" ; |
2275 | wc->dm_io = NULL; |
2276 | goto bad; |
2277 | } |
2278 | |
2279 | wc->writeback_wq = alloc_workqueue(fmt: "writecache-writeback" , flags: WQ_MEM_RECLAIM, max_active: 1); |
2280 | if (!wc->writeback_wq) { |
2281 | r = -ENOMEM; |
2282 | ti->error = "Could not allocate writeback workqueue" ; |
2283 | goto bad; |
2284 | } |
2285 | INIT_WORK(&wc->writeback_work, writecache_writeback); |
2286 | INIT_WORK(&wc->flush_work, writecache_flush_work); |
2287 | |
2288 | dm_iot_init(iot: &wc->iot); |
2289 | |
2290 | raw_spin_lock_init(&wc->endio_list_lock); |
2291 | INIT_LIST_HEAD(list: &wc->endio_list); |
2292 | wc->endio_thread = kthread_run(writecache_endio_thread, wc, "writecache_endio" ); |
2293 | if (IS_ERR(ptr: wc->endio_thread)) { |
2294 | r = PTR_ERR(ptr: wc->endio_thread); |
2295 | wc->endio_thread = NULL; |
2296 | ti->error = "Couldn't spawn endio thread" ; |
2297 | goto bad; |
2298 | } |
2299 | |
2300 | /* |
2301 | * Parse the mode (pmem or ssd) |
2302 | */ |
2303 | string = dm_shift_arg(as: &as); |
2304 | if (!string) |
2305 | goto bad_arguments; |
2306 | |
2307 | if (!strcasecmp(s1: string, s2: "s" )) { |
2308 | wc->pmem_mode = false; |
2309 | } else if (!strcasecmp(s1: string, s2: "p" )) { |
2310 | #ifdef DM_WRITECACHE_HAS_PMEM |
2311 | wc->pmem_mode = true; |
2312 | wc->writeback_fua = true; |
2313 | #else |
2314 | /* |
2315 | * If the architecture doesn't support persistent memory or |
2316 | * the kernel doesn't support any DAX drivers, this driver can |
2317 | * only be used in SSD-only mode. |
2318 | */ |
2319 | r = -EOPNOTSUPP; |
2320 | ti->error = "Persistent memory or DAX not supported on this system" ; |
2321 | goto bad; |
2322 | #endif |
2323 | } else { |
2324 | goto bad_arguments; |
2325 | } |
2326 | |
2327 | if (WC_MODE_PMEM(wc)) { |
2328 | r = bioset_init(&wc->bio_set, BIO_POOL_SIZE, |
2329 | offsetof(struct writeback_struct, bio), |
2330 | flags: BIOSET_NEED_BVECS); |
2331 | if (r) { |
2332 | ti->error = "Could not allocate bio set" ; |
2333 | goto bad; |
2334 | } |
2335 | } else { |
2336 | wc->pause = PAUSE_WRITEBACK; |
2337 | r = mempool_init_kmalloc_pool(pool: &wc->copy_pool, min_nr: 1, size: sizeof(struct copy_struct)); |
2338 | if (r) { |
2339 | ti->error = "Could not allocate mempool" ; |
2340 | goto bad; |
2341 | } |
2342 | } |
2343 | |
2344 | /* |
2345 | * Parse the origin data device |
2346 | */ |
2347 | string = dm_shift_arg(as: &as); |
2348 | if (!string) |
2349 | goto bad_arguments; |
2350 | r = dm_get_device(ti, path: string, mode: dm_table_get_mode(t: ti->table), result: &wc->dev); |
2351 | if (r) { |
2352 | ti->error = "Origin data device lookup failed" ; |
2353 | goto bad; |
2354 | } |
2355 | |
2356 | /* |
2357 | * Parse cache data device (be it pmem or ssd) |
2358 | */ |
2359 | string = dm_shift_arg(as: &as); |
2360 | if (!string) |
2361 | goto bad_arguments; |
2362 | |
2363 | r = dm_get_device(ti, path: string, mode: dm_table_get_mode(t: ti->table), result: &wc->ssd_dev); |
2364 | if (r) { |
2365 | ti->error = "Cache data device lookup failed" ; |
2366 | goto bad; |
2367 | } |
2368 | wc->memory_map_size = bdev_nr_bytes(bdev: wc->ssd_dev->bdev); |
2369 | |
2370 | /* |
2371 | * Parse the cache block size |
2372 | */ |
2373 | string = dm_shift_arg(as: &as); |
2374 | if (!string) |
2375 | goto bad_arguments; |
2376 | if (sscanf(string, "%u%c" , &wc->block_size, &dummy) != 1 || |
2377 | wc->block_size < 512 || wc->block_size > PAGE_SIZE || |
2378 | (wc->block_size & (wc->block_size - 1))) { |
2379 | r = -EINVAL; |
2380 | ti->error = "Invalid block size" ; |
2381 | goto bad; |
2382 | } |
2383 | if (wc->block_size < bdev_logical_block_size(bdev: wc->dev->bdev) || |
2384 | wc->block_size < bdev_logical_block_size(bdev: wc->ssd_dev->bdev)) { |
2385 | r = -EINVAL; |
2386 | ti->error = "Block size is smaller than device logical block size" ; |
2387 | goto bad; |
2388 | } |
2389 | wc->block_size_bits = __ffs(wc->block_size); |
2390 | |
2391 | wc->max_writeback_jobs = MAX_WRITEBACK_JOBS; |
2392 | wc->autocommit_blocks = !WC_MODE_PMEM(wc) ? AUTOCOMMIT_BLOCKS_SSD : AUTOCOMMIT_BLOCKS_PMEM; |
2393 | wc->autocommit_jiffies = msecs_to_jiffies(AUTOCOMMIT_MSEC); |
2394 | |
2395 | /* |
2396 | * Parse optional arguments |
2397 | */ |
2398 | r = dm_read_arg_group(arg: _args, arg_set: &as, num_args: &opt_params, error: &ti->error); |
2399 | if (r) |
2400 | goto bad; |
2401 | |
2402 | while (opt_params) { |
2403 | string = dm_shift_arg(as: &as), opt_params--; |
2404 | if (!strcasecmp(s1: string, s2: "start_sector" ) && opt_params >= 1) { |
2405 | unsigned long long start_sector; |
2406 | |
2407 | string = dm_shift_arg(as: &as), opt_params--; |
2408 | if (sscanf(string, "%llu%c" , &start_sector, &dummy) != 1) |
2409 | goto invalid_optional; |
2410 | wc->start_sector = start_sector; |
2411 | wc->start_sector_set = true; |
2412 | if (wc->start_sector != start_sector || |
2413 | wc->start_sector >= wc->memory_map_size >> SECTOR_SHIFT) |
2414 | goto invalid_optional; |
2415 | } else if (!strcasecmp(s1: string, s2: "high_watermark" ) && opt_params >= 1) { |
2416 | string = dm_shift_arg(as: &as), opt_params--; |
2417 | if (sscanf(string, "%d%c" , &high_wm_percent, &dummy) != 1) |
2418 | goto invalid_optional; |
2419 | if (high_wm_percent < 0 || high_wm_percent > 100) |
2420 | goto invalid_optional; |
2421 | wc->high_wm_percent_value = high_wm_percent; |
2422 | wc->high_wm_percent_set = true; |
2423 | } else if (!strcasecmp(s1: string, s2: "low_watermark" ) && opt_params >= 1) { |
2424 | string = dm_shift_arg(as: &as), opt_params--; |
2425 | if (sscanf(string, "%d%c" , &low_wm_percent, &dummy) != 1) |
2426 | goto invalid_optional; |
2427 | if (low_wm_percent < 0 || low_wm_percent > 100) |
2428 | goto invalid_optional; |
2429 | wc->low_wm_percent_value = low_wm_percent; |
2430 | wc->low_wm_percent_set = true; |
2431 | } else if (!strcasecmp(s1: string, s2: "writeback_jobs" ) && opt_params >= 1) { |
2432 | string = dm_shift_arg(as: &as), opt_params--; |
2433 | if (sscanf(string, "%u%c" , &wc->max_writeback_jobs, &dummy) != 1) |
2434 | goto invalid_optional; |
2435 | wc->max_writeback_jobs_set = true; |
2436 | } else if (!strcasecmp(s1: string, s2: "autocommit_blocks" ) && opt_params >= 1) { |
2437 | string = dm_shift_arg(as: &as), opt_params--; |
2438 | if (sscanf(string, "%u%c" , &wc->autocommit_blocks, &dummy) != 1) |
2439 | goto invalid_optional; |
2440 | wc->autocommit_blocks_set = true; |
2441 | } else if (!strcasecmp(s1: string, s2: "autocommit_time" ) && opt_params >= 1) { |
2442 | unsigned int autocommit_msecs; |
2443 | |
2444 | string = dm_shift_arg(as: &as), opt_params--; |
2445 | if (sscanf(string, "%u%c" , &autocommit_msecs, &dummy) != 1) |
2446 | goto invalid_optional; |
2447 | if (autocommit_msecs > 3600000) |
2448 | goto invalid_optional; |
2449 | wc->autocommit_jiffies = msecs_to_jiffies(m: autocommit_msecs); |
2450 | wc->autocommit_time_value = autocommit_msecs; |
2451 | wc->autocommit_time_set = true; |
2452 | } else if (!strcasecmp(s1: string, s2: "max_age" ) && opt_params >= 1) { |
2453 | unsigned int max_age_msecs; |
2454 | |
2455 | string = dm_shift_arg(as: &as), opt_params--; |
2456 | if (sscanf(string, "%u%c" , &max_age_msecs, &dummy) != 1) |
2457 | goto invalid_optional; |
2458 | if (max_age_msecs > 86400000) |
2459 | goto invalid_optional; |
2460 | wc->max_age = msecs_to_jiffies(m: max_age_msecs); |
2461 | wc->max_age_set = true; |
2462 | wc->max_age_value = max_age_msecs; |
2463 | } else if (!strcasecmp(s1: string, s2: "cleaner" )) { |
2464 | wc->cleaner_set = true; |
2465 | wc->cleaner = true; |
2466 | } else if (!strcasecmp(s1: string, s2: "fua" )) { |
2467 | if (WC_MODE_PMEM(wc)) { |
2468 | wc->writeback_fua = true; |
2469 | wc->writeback_fua_set = true; |
2470 | } else |
2471 | goto invalid_optional; |
2472 | } else if (!strcasecmp(s1: string, s2: "nofua" )) { |
2473 | if (WC_MODE_PMEM(wc)) { |
2474 | wc->writeback_fua = false; |
2475 | wc->writeback_fua_set = true; |
2476 | } else |
2477 | goto invalid_optional; |
2478 | } else if (!strcasecmp(s1: string, s2: "metadata_only" )) { |
2479 | wc->metadata_only = true; |
2480 | } else if (!strcasecmp(s1: string, s2: "pause_writeback" ) && opt_params >= 1) { |
2481 | unsigned int pause_msecs; |
2482 | |
2483 | if (WC_MODE_PMEM(wc)) |
2484 | goto invalid_optional; |
2485 | string = dm_shift_arg(as: &as), opt_params--; |
2486 | if (sscanf(string, "%u%c" , &pause_msecs, &dummy) != 1) |
2487 | goto invalid_optional; |
2488 | if (pause_msecs > 60000) |
2489 | goto invalid_optional; |
2490 | wc->pause = msecs_to_jiffies(m: pause_msecs); |
2491 | wc->pause_set = true; |
2492 | wc->pause_value = pause_msecs; |
2493 | } else { |
2494 | invalid_optional: |
2495 | r = -EINVAL; |
2496 | ti->error = "Invalid optional argument" ; |
2497 | goto bad; |
2498 | } |
2499 | } |
2500 | |
2501 | if (high_wm_percent < low_wm_percent) { |
2502 | r = -EINVAL; |
2503 | ti->error = "High watermark must be greater than or equal to low watermark" ; |
2504 | goto bad; |
2505 | } |
2506 | |
2507 | if (WC_MODE_PMEM(wc)) { |
2508 | if (!dax_synchronous(dax_dev: wc->ssd_dev->dax_dev)) { |
2509 | r = -EOPNOTSUPP; |
2510 | ti->error = "Asynchronous persistent memory not supported as pmem cache" ; |
2511 | goto bad; |
2512 | } |
2513 | |
2514 | r = persistent_memory_claim(wc); |
2515 | if (r) { |
2516 | ti->error = "Unable to map persistent memory for cache" ; |
2517 | goto bad; |
2518 | } |
2519 | } else { |
2520 | size_t n_blocks, n_metadata_blocks; |
2521 | uint64_t n_bitmap_bits; |
2522 | |
2523 | wc->memory_map_size -= (uint64_t)wc->start_sector << SECTOR_SHIFT; |
2524 | |
2525 | bio_list_init(bl: &wc->flush_list); |
2526 | wc->flush_thread = kthread_run(writecache_flush_thread, wc, "dm_writecache_flush" ); |
2527 | if (IS_ERR(ptr: wc->flush_thread)) { |
2528 | r = PTR_ERR(ptr: wc->flush_thread); |
2529 | wc->flush_thread = NULL; |
2530 | ti->error = "Couldn't spawn flush thread" ; |
2531 | goto bad; |
2532 | } |
2533 | |
2534 | r = calculate_memory_size(device_size: wc->memory_map_size, block_size: wc->block_size, |
2535 | n_blocks_p: &n_blocks, n_metadata_blocks_p: &n_metadata_blocks); |
2536 | if (r) { |
2537 | ti->error = "Invalid device size" ; |
2538 | goto bad; |
2539 | } |
2540 | |
2541 | n_bitmap_bits = (((uint64_t)n_metadata_blocks << wc->block_size_bits) + |
2542 | BITMAP_GRANULARITY - 1) / BITMAP_GRANULARITY; |
2543 | /* this is limitation of test_bit functions */ |
2544 | if (n_bitmap_bits > 1U << 31) { |
2545 | r = -EFBIG; |
2546 | ti->error = "Invalid device size" ; |
2547 | goto bad; |
2548 | } |
2549 | |
2550 | wc->memory_map = vmalloc(size: n_metadata_blocks << wc->block_size_bits); |
2551 | if (!wc->memory_map) { |
2552 | r = -ENOMEM; |
2553 | ti->error = "Unable to allocate memory for metadata" ; |
2554 | goto bad; |
2555 | } |
2556 | |
2557 | wc->dm_kcopyd = dm_kcopyd_client_create(throttle: &dm_kcopyd_throttle); |
2558 | if (IS_ERR(ptr: wc->dm_kcopyd)) { |
2559 | r = PTR_ERR(ptr: wc->dm_kcopyd); |
2560 | ti->error = "Unable to allocate dm-kcopyd client" ; |
2561 | wc->dm_kcopyd = NULL; |
2562 | goto bad; |
2563 | } |
2564 | |
2565 | wc->metadata_sectors = n_metadata_blocks << (wc->block_size_bits - SECTOR_SHIFT); |
2566 | wc->dirty_bitmap_size = (n_bitmap_bits + BITS_PER_LONG - 1) / |
2567 | BITS_PER_LONG * sizeof(unsigned long); |
2568 | wc->dirty_bitmap = vzalloc(size: wc->dirty_bitmap_size); |
2569 | if (!wc->dirty_bitmap) { |
2570 | r = -ENOMEM; |
2571 | ti->error = "Unable to allocate dirty bitmap" ; |
2572 | goto bad; |
2573 | } |
2574 | |
2575 | r = writecache_read_metadata(wc, n_sectors: wc->block_size >> SECTOR_SHIFT); |
2576 | if (r) { |
2577 | ti->error = "Unable to read first block of metadata" ; |
2578 | goto bad; |
2579 | } |
2580 | } |
2581 | |
2582 | r = copy_mc_to_kernel(to: &s, from: sb(wc), len: sizeof(struct wc_memory_superblock)); |
2583 | if (r) { |
2584 | ti->error = "Hardware memory error when reading superblock" ; |
2585 | goto bad; |
2586 | } |
2587 | if (!le32_to_cpu(s.magic) && !le32_to_cpu(s.version)) { |
2588 | r = init_memory(wc); |
2589 | if (r) { |
2590 | ti->error = "Unable to initialize device" ; |
2591 | goto bad; |
2592 | } |
2593 | r = copy_mc_to_kernel(to: &s, from: sb(wc), |
2594 | len: sizeof(struct wc_memory_superblock)); |
2595 | if (r) { |
2596 | ti->error = "Hardware memory error when reading superblock" ; |
2597 | goto bad; |
2598 | } |
2599 | } |
2600 | |
2601 | if (le32_to_cpu(s.magic) != MEMORY_SUPERBLOCK_MAGIC) { |
2602 | ti->error = "Invalid magic in the superblock" ; |
2603 | r = -EINVAL; |
2604 | goto bad; |
2605 | } |
2606 | |
2607 | if (le32_to_cpu(s.version) != MEMORY_SUPERBLOCK_VERSION) { |
2608 | ti->error = "Invalid version in the superblock" ; |
2609 | r = -EINVAL; |
2610 | goto bad; |
2611 | } |
2612 | |
2613 | if (le32_to_cpu(s.block_size) != wc->block_size) { |
2614 | ti->error = "Block size does not match superblock" ; |
2615 | r = -EINVAL; |
2616 | goto bad; |
2617 | } |
2618 | |
2619 | wc->n_blocks = le64_to_cpu(s.n_blocks); |
2620 | |
2621 | offset = wc->n_blocks * sizeof(struct wc_memory_entry); |
2622 | if (offset / sizeof(struct wc_memory_entry) != le64_to_cpu(sb(wc)->n_blocks)) { |
2623 | overflow: |
2624 | ti->error = "Overflow in size calculation" ; |
2625 | r = -EINVAL; |
2626 | goto bad; |
2627 | } |
2628 | offset += sizeof(struct wc_memory_superblock); |
2629 | if (offset < sizeof(struct wc_memory_superblock)) |
2630 | goto overflow; |
2631 | offset = (offset + wc->block_size - 1) & ~(size_t)(wc->block_size - 1); |
2632 | data_size = wc->n_blocks * (size_t)wc->block_size; |
2633 | if (!offset || (data_size / wc->block_size != wc->n_blocks) || |
2634 | (offset + data_size < offset)) |
2635 | goto overflow; |
2636 | if (offset + data_size > wc->memory_map_size) { |
2637 | ti->error = "Memory area is too small" ; |
2638 | r = -EINVAL; |
2639 | goto bad; |
2640 | } |
2641 | |
2642 | wc->metadata_sectors = offset >> SECTOR_SHIFT; |
2643 | wc->block_start = (char *)sb(wc) + offset; |
2644 | |
2645 | x = (uint64_t)wc->n_blocks * (100 - high_wm_percent); |
2646 | x += 50; |
2647 | do_div(x, 100); |
2648 | wc->freelist_high_watermark = x; |
2649 | x = (uint64_t)wc->n_blocks * (100 - low_wm_percent); |
2650 | x += 50; |
2651 | do_div(x, 100); |
2652 | wc->freelist_low_watermark = x; |
2653 | |
2654 | if (wc->cleaner) |
2655 | activate_cleaner(wc); |
2656 | |
2657 | r = writecache_alloc_entries(wc); |
2658 | if (r) { |
2659 | ti->error = "Cannot allocate memory" ; |
2660 | goto bad; |
2661 | } |
2662 | |
2663 | ti->num_flush_bios = WC_MODE_PMEM(wc) ? 1 : 2; |
2664 | ti->flush_supported = true; |
2665 | ti->num_discard_bios = 1; |
2666 | |
2667 | if (WC_MODE_PMEM(wc)) |
2668 | persistent_memory_flush_cache(ptr: wc->memory_map, size: wc->memory_map_size); |
2669 | |
2670 | return 0; |
2671 | |
2672 | bad_arguments: |
2673 | r = -EINVAL; |
2674 | ti->error = "Bad arguments" ; |
2675 | bad: |
2676 | writecache_dtr(ti); |
2677 | return r; |
2678 | } |
2679 | |
2680 | static void writecache_status(struct dm_target *ti, status_type_t type, |
2681 | unsigned int status_flags, char *result, unsigned int maxlen) |
2682 | { |
2683 | struct dm_writecache *wc = ti->private; |
2684 | unsigned int ; |
2685 | unsigned int sz = 0; |
2686 | |
2687 | switch (type) { |
2688 | case STATUSTYPE_INFO: |
2689 | DMEMIT("%ld %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu" , |
2690 | writecache_has_error(wc), |
2691 | (unsigned long long)wc->n_blocks, (unsigned long long)wc->freelist_size, |
2692 | (unsigned long long)wc->writeback_size, |
2693 | wc->stats.reads, |
2694 | wc->stats.read_hits, |
2695 | wc->stats.writes, |
2696 | wc->stats.write_hits_uncommitted, |
2697 | wc->stats.write_hits_committed, |
2698 | wc->stats.writes_around, |
2699 | wc->stats.writes_allocate, |
2700 | wc->stats.writes_blocked_on_freelist, |
2701 | wc->stats.flushes, |
2702 | wc->stats.discards); |
2703 | break; |
2704 | case STATUSTYPE_TABLE: |
2705 | DMEMIT("%c %s %s %u " , WC_MODE_PMEM(wc) ? 'p' : 's', |
2706 | wc->dev->name, wc->ssd_dev->name, wc->block_size); |
2707 | extra_args = 0; |
2708 | if (wc->start_sector_set) |
2709 | extra_args += 2; |
2710 | if (wc->high_wm_percent_set) |
2711 | extra_args += 2; |
2712 | if (wc->low_wm_percent_set) |
2713 | extra_args += 2; |
2714 | if (wc->max_writeback_jobs_set) |
2715 | extra_args += 2; |
2716 | if (wc->autocommit_blocks_set) |
2717 | extra_args += 2; |
2718 | if (wc->autocommit_time_set) |
2719 | extra_args += 2; |
2720 | if (wc->max_age_set) |
2721 | extra_args += 2; |
2722 | if (wc->cleaner_set) |
2723 | extra_args++; |
2724 | if (wc->writeback_fua_set) |
2725 | extra_args++; |
2726 | if (wc->metadata_only) |
2727 | extra_args++; |
2728 | if (wc->pause_set) |
2729 | extra_args += 2; |
2730 | |
2731 | DMEMIT("%u" , extra_args); |
2732 | if (wc->start_sector_set) |
2733 | DMEMIT(" start_sector %llu" , (unsigned long long)wc->start_sector); |
2734 | if (wc->high_wm_percent_set) |
2735 | DMEMIT(" high_watermark %u" , wc->high_wm_percent_value); |
2736 | if (wc->low_wm_percent_set) |
2737 | DMEMIT(" low_watermark %u" , wc->low_wm_percent_value); |
2738 | if (wc->max_writeback_jobs_set) |
2739 | DMEMIT(" writeback_jobs %u" , wc->max_writeback_jobs); |
2740 | if (wc->autocommit_blocks_set) |
2741 | DMEMIT(" autocommit_blocks %u" , wc->autocommit_blocks); |
2742 | if (wc->autocommit_time_set) |
2743 | DMEMIT(" autocommit_time %u" , wc->autocommit_time_value); |
2744 | if (wc->max_age_set) |
2745 | DMEMIT(" max_age %u" , wc->max_age_value); |
2746 | if (wc->cleaner_set) |
2747 | DMEMIT(" cleaner" ); |
2748 | if (wc->writeback_fua_set) |
2749 | DMEMIT(" %sfua" , wc->writeback_fua ? "" : "no" ); |
2750 | if (wc->metadata_only) |
2751 | DMEMIT(" metadata_only" ); |
2752 | if (wc->pause_set) |
2753 | DMEMIT(" pause_writeback %u" , wc->pause_value); |
2754 | break; |
2755 | case STATUSTYPE_IMA: |
2756 | *result = '\0'; |
2757 | break; |
2758 | } |
2759 | } |
2760 | |
2761 | static struct target_type writecache_target = { |
2762 | .name = "writecache" , |
2763 | .version = {1, 6, 0}, |
2764 | .module = THIS_MODULE, |
2765 | .ctr = writecache_ctr, |
2766 | .dtr = writecache_dtr, |
2767 | .status = writecache_status, |
2768 | .postsuspend = writecache_suspend, |
2769 | .resume = writecache_resume, |
2770 | .message = writecache_message, |
2771 | .map = writecache_map, |
2772 | .end_io = writecache_end_io, |
2773 | .iterate_devices = writecache_iterate_devices, |
2774 | .io_hints = writecache_io_hints, |
2775 | }; |
2776 | module_dm(writecache); |
2777 | |
2778 | MODULE_DESCRIPTION(DM_NAME " writecache target" ); |
2779 | MODULE_AUTHOR("Mikulas Patocka <dm-devel@redhat.com>" ); |
2780 | MODULE_LICENSE("GPL" ); |
2781 | |