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95d402f0 MP |
1 | /* |
2 | * Copyright (C) 2009-2011 Red Hat, Inc. | |
3 | * | |
4 | * Author: Mikulas Patocka <mpatocka@redhat.com> | |
5 | * | |
6 | * This file is released under the GPL. | |
7 | */ | |
8 | ||
afa53df8 | 9 | #include <linux/dm-bufio.h> |
95d402f0 MP |
10 | |
11 | #include <linux/device-mapper.h> | |
12 | #include <linux/dm-io.h> | |
13 | #include <linux/slab.h> | |
5b3cc15a | 14 | #include <linux/sched/mm.h> |
f495339c | 15 | #include <linux/jiffies.h> |
95d402f0 | 16 | #include <linux/vmalloc.h> |
95d402f0 | 17 | #include <linux/shrinker.h> |
6f66263f | 18 | #include <linux/module.h> |
4e420c45 | 19 | #include <linux/rbtree.h> |
86bad0c7 | 20 | #include <linux/stacktrace.h> |
95d402f0 MP |
21 | |
22 | #define DM_MSG_PREFIX "bufio" | |
23 | ||
24 | /* | |
25 | * Memory management policy: | |
26 | * Limit the number of buffers to DM_BUFIO_MEMORY_PERCENT of main memory | |
27 | * or DM_BUFIO_VMALLOC_PERCENT of vmalloc memory (whichever is lower). | |
28 | * Always allocate at least DM_BUFIO_MIN_BUFFERS buffers. | |
29 | * Start background writeback when there are DM_BUFIO_WRITEBACK_PERCENT | |
30 | * dirty buffers. | |
31 | */ | |
32 | #define DM_BUFIO_MIN_BUFFERS 8 | |
33 | ||
34 | #define DM_BUFIO_MEMORY_PERCENT 2 | |
35 | #define DM_BUFIO_VMALLOC_PERCENT 25 | |
b132ff33 | 36 | #define DM_BUFIO_WRITEBACK_RATIO 3 |
6e913b28 | 37 | #define DM_BUFIO_LOW_WATERMARK_RATIO 16 |
95d402f0 MP |
38 | |
39 | /* | |
40 | * Check buffer ages in this interval (seconds) | |
41 | */ | |
33096a78 | 42 | #define DM_BUFIO_WORK_TIMER_SECS 30 |
95d402f0 MP |
43 | |
44 | /* | |
45 | * Free buffers when they are older than this (seconds) | |
46 | */ | |
33096a78 | 47 | #define DM_BUFIO_DEFAULT_AGE_SECS 300 |
95d402f0 MP |
48 | |
49 | /* | |
33096a78 | 50 | * The nr of bytes of cached data to keep around. |
95d402f0 | 51 | */ |
33096a78 | 52 | #define DM_BUFIO_DEFAULT_RETAIN_BYTES (256 * 1024) |
95d402f0 | 53 | |
1e3b21c6 MP |
54 | /* |
55 | * Align buffer writes to this boundary. | |
56 | * Tests show that SSDs have the highest IOPS when using 4k writes. | |
57 | */ | |
58 | #define DM_BUFIO_WRITE_ALIGN 4096 | |
59 | ||
95d402f0 MP |
60 | /* |
61 | * dm_buffer->list_mode | |
62 | */ | |
63 | #define LIST_CLEAN 0 | |
64 | #define LIST_DIRTY 1 | |
65 | #define LIST_SIZE 2 | |
66 | ||
67 | /* | |
68 | * Linking of buffers: | |
ef992373 | 69 | * All buffers are linked to buffer_tree with their node field. |
95d402f0 MP |
70 | * |
71 | * Clean buffers that are not being written (B_WRITING not set) | |
72 | * are linked to lru[LIST_CLEAN] with their lru_list field. | |
73 | * | |
74 | * Dirty and clean buffers that are being written are linked to | |
75 | * lru[LIST_DIRTY] with their lru_list field. When the write | |
76 | * finishes, the buffer cannot be relinked immediately (because we | |
77 | * are in an interrupt context and relinking requires process | |
78 | * context), so some clean-not-writing buffers can be held on | |
79 | * dirty_lru too. They are later added to lru in the process | |
80 | * context. | |
81 | */ | |
82 | struct dm_bufio_client { | |
83 | struct mutex lock; | |
84 | ||
85 | struct list_head lru[LIST_SIZE]; | |
86 | unsigned long n_buffers[LIST_SIZE]; | |
87 | ||
88 | struct block_device *bdev; | |
89 | unsigned block_size; | |
f51f2e0a | 90 | s8 sectors_per_block_bits; |
95d402f0 MP |
91 | void (*alloc_callback)(struct dm_buffer *); |
92 | void (*write_callback)(struct dm_buffer *); | |
93 | ||
359dbf19 | 94 | struct kmem_cache *slab_buffer; |
21bb1327 | 95 | struct kmem_cache *slab_cache; |
95d402f0 MP |
96 | struct dm_io_client *dm_io; |
97 | ||
98 | struct list_head reserved_buffers; | |
99 | unsigned need_reserved_buffers; | |
100 | ||
55b082e6 MP |
101 | unsigned minimum_buffers; |
102 | ||
4e420c45 | 103 | struct rb_root buffer_tree; |
95d402f0 MP |
104 | wait_queue_head_t free_buffer_wait; |
105 | ||
400a0bef MP |
106 | sector_t start; |
107 | ||
95d402f0 MP |
108 | int async_write_error; |
109 | ||
110 | struct list_head client_list; | |
70704c33 | 111 | |
95d402f0 | 112 | struct shrinker shrinker; |
70704c33 MP |
113 | struct work_struct shrink_work; |
114 | atomic_long_t need_shrink; | |
95d402f0 MP |
115 | }; |
116 | ||
117 | /* | |
118 | * Buffer state bits. | |
119 | */ | |
120 | #define B_READING 0 | |
121 | #define B_WRITING 1 | |
122 | #define B_DIRTY 2 | |
123 | ||
124 | /* | |
125 | * Describes how the block was allocated: | |
126 | * kmem_cache_alloc(), __get_free_pages() or vmalloc(). | |
127 | * See the comment at alloc_buffer_data. | |
128 | */ | |
129 | enum data_mode { | |
130 | DATA_MODE_SLAB = 0, | |
131 | DATA_MODE_GET_FREE_PAGES = 1, | |
132 | DATA_MODE_VMALLOC = 2, | |
133 | DATA_MODE_LIMIT = 3 | |
134 | }; | |
135 | ||
136 | struct dm_buffer { | |
4e420c45 | 137 | struct rb_node node; |
95d402f0 | 138 | struct list_head lru_list; |
af53badc | 139 | struct list_head global_list; |
95d402f0 MP |
140 | sector_t block; |
141 | void *data; | |
03b02939 | 142 | unsigned char data_mode; /* DATA_MODE_* */ |
95d402f0 | 143 | unsigned char list_mode; /* LIST_* */ |
4e4cbee9 CH |
144 | blk_status_t read_error; |
145 | blk_status_t write_error; | |
6e913b28 | 146 | unsigned accessed; |
03b02939 | 147 | unsigned hold_count; |
95d402f0 MP |
148 | unsigned long state; |
149 | unsigned long last_accessed; | |
1e3b21c6 MP |
150 | unsigned dirty_start; |
151 | unsigned dirty_end; | |
152 | unsigned write_start; | |
153 | unsigned write_end; | |
95d402f0 | 154 | struct dm_bufio_client *c; |
2480945c | 155 | struct list_head write_list; |
45354f1e | 156 | void (*end_io)(struct dm_buffer *, blk_status_t); |
86bad0c7 MP |
157 | #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING |
158 | #define MAX_STACK 10 | |
741b58f3 | 159 | unsigned int stack_len; |
86bad0c7 MP |
160 | unsigned long stack_entries[MAX_STACK]; |
161 | #endif | |
95d402f0 MP |
162 | }; |
163 | ||
164 | /*----------------------------------------------------------------*/ | |
165 | ||
95d402f0 MP |
166 | #define dm_bufio_in_request() (!!current->bio_list) |
167 | ||
168 | static void dm_bufio_lock(struct dm_bufio_client *c) | |
169 | { | |
170 | mutex_lock_nested(&c->lock, dm_bufio_in_request()); | |
171 | } | |
172 | ||
173 | static int dm_bufio_trylock(struct dm_bufio_client *c) | |
174 | { | |
175 | return mutex_trylock(&c->lock); | |
176 | } | |
177 | ||
178 | static void dm_bufio_unlock(struct dm_bufio_client *c) | |
179 | { | |
180 | mutex_unlock(&c->lock); | |
181 | } | |
182 | ||
95d402f0 MP |
183 | /*----------------------------------------------------------------*/ |
184 | ||
185 | /* | |
186 | * Default cache size: available memory divided by the ratio. | |
187 | */ | |
188 | static unsigned long dm_bufio_default_cache_size; | |
189 | ||
190 | /* | |
191 | * Total cache size set by the user. | |
192 | */ | |
193 | static unsigned long dm_bufio_cache_size; | |
194 | ||
195 | /* | |
196 | * A copy of dm_bufio_cache_size because dm_bufio_cache_size can change | |
197 | * at any time. If it disagrees, the user has changed cache size. | |
198 | */ | |
199 | static unsigned long dm_bufio_cache_size_latch; | |
200 | ||
af53badc MP |
201 | static DEFINE_SPINLOCK(global_spinlock); |
202 | ||
203 | static LIST_HEAD(global_queue); | |
95d402f0 | 204 | |
6e913b28 MP |
205 | static unsigned long global_num = 0; |
206 | ||
95d402f0 MP |
207 | /* |
208 | * Buffers are freed after this timeout | |
209 | */ | |
210 | static unsigned dm_bufio_max_age = DM_BUFIO_DEFAULT_AGE_SECS; | |
13840d38 | 211 | static unsigned long dm_bufio_retain_bytes = DM_BUFIO_DEFAULT_RETAIN_BYTES; |
95d402f0 MP |
212 | |
213 | static unsigned long dm_bufio_peak_allocated; | |
214 | static unsigned long dm_bufio_allocated_kmem_cache; | |
215 | static unsigned long dm_bufio_allocated_get_free_pages; | |
216 | static unsigned long dm_bufio_allocated_vmalloc; | |
217 | static unsigned long dm_bufio_current_allocated; | |
218 | ||
219 | /*----------------------------------------------------------------*/ | |
220 | ||
95d402f0 MP |
221 | /* |
222 | * The current number of clients. | |
223 | */ | |
224 | static int dm_bufio_client_count; | |
225 | ||
226 | /* | |
227 | * The list of all clients. | |
228 | */ | |
229 | static LIST_HEAD(dm_bufio_all_clients); | |
230 | ||
231 | /* | |
b132ff33 | 232 | * This mutex protects dm_bufio_cache_size_latch and dm_bufio_client_count |
95d402f0 MP |
233 | */ |
234 | static DEFINE_MUTEX(dm_bufio_clients_lock); | |
235 | ||
6e913b28 MP |
236 | static struct workqueue_struct *dm_bufio_wq; |
237 | static struct delayed_work dm_bufio_cleanup_old_work; | |
238 | static struct work_struct dm_bufio_replacement_work; | |
239 | ||
240 | ||
86bad0c7 MP |
241 | #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING |
242 | static void buffer_record_stack(struct dm_buffer *b) | |
243 | { | |
741b58f3 | 244 | b->stack_len = stack_trace_save(b->stack_entries, MAX_STACK, 2); |
86bad0c7 MP |
245 | } |
246 | #endif | |
247 | ||
4e420c45 JT |
248 | /*---------------------------------------------------------------- |
249 | * A red/black tree acts as an index for all the buffers. | |
250 | *--------------------------------------------------------------*/ | |
251 | static struct dm_buffer *__find(struct dm_bufio_client *c, sector_t block) | |
252 | { | |
253 | struct rb_node *n = c->buffer_tree.rb_node; | |
254 | struct dm_buffer *b; | |
255 | ||
256 | while (n) { | |
257 | b = container_of(n, struct dm_buffer, node); | |
258 | ||
259 | if (b->block == block) | |
260 | return b; | |
261 | ||
88f878e5 | 262 | n = block < b->block ? n->rb_left : n->rb_right; |
4e420c45 JT |
263 | } |
264 | ||
265 | return NULL; | |
266 | } | |
267 | ||
33a18062 MP |
268 | static struct dm_buffer *__find_next(struct dm_bufio_client *c, sector_t block) |
269 | { | |
270 | struct rb_node *n = c->buffer_tree.rb_node; | |
271 | struct dm_buffer *b; | |
272 | struct dm_buffer *best = NULL; | |
273 | ||
274 | while (n) { | |
275 | b = container_of(n, struct dm_buffer, node); | |
276 | ||
277 | if (b->block == block) | |
278 | return b; | |
279 | ||
280 | if (block <= b->block) { | |
281 | n = n->rb_left; | |
282 | best = b; | |
283 | } else { | |
284 | n = n->rb_right; | |
285 | } | |
286 | } | |
287 | ||
288 | return best; | |
289 | } | |
290 | ||
4e420c45 JT |
291 | static void __insert(struct dm_bufio_client *c, struct dm_buffer *b) |
292 | { | |
293 | struct rb_node **new = &c->buffer_tree.rb_node, *parent = NULL; | |
294 | struct dm_buffer *found; | |
295 | ||
296 | while (*new) { | |
297 | found = container_of(*new, struct dm_buffer, node); | |
298 | ||
299 | if (found->block == b->block) { | |
300 | BUG_ON(found != b); | |
301 | return; | |
302 | } | |
303 | ||
304 | parent = *new; | |
88f878e5 MP |
305 | new = b->block < found->block ? |
306 | &found->node.rb_left : &found->node.rb_right; | |
4e420c45 JT |
307 | } |
308 | ||
309 | rb_link_node(&b->node, parent, new); | |
310 | rb_insert_color(&b->node, &c->buffer_tree); | |
311 | } | |
312 | ||
313 | static void __remove(struct dm_bufio_client *c, struct dm_buffer *b) | |
314 | { | |
315 | rb_erase(&b->node, &c->buffer_tree); | |
316 | } | |
317 | ||
95d402f0 MP |
318 | /*----------------------------------------------------------------*/ |
319 | ||
d0a328a3 | 320 | static void adjust_total_allocated(struct dm_buffer *b, bool unlink) |
95d402f0 | 321 | { |
d0a328a3 MP |
322 | unsigned char data_mode; |
323 | long diff; | |
324 | ||
95d402f0 MP |
325 | static unsigned long * const class_ptr[DATA_MODE_LIMIT] = { |
326 | &dm_bufio_allocated_kmem_cache, | |
327 | &dm_bufio_allocated_get_free_pages, | |
328 | &dm_bufio_allocated_vmalloc, | |
329 | }; | |
330 | ||
d0a328a3 MP |
331 | data_mode = b->data_mode; |
332 | diff = (long)b->c->block_size; | |
333 | if (unlink) | |
334 | diff = -diff; | |
335 | ||
af53badc | 336 | spin_lock(&global_spinlock); |
95d402f0 MP |
337 | |
338 | *class_ptr[data_mode] += diff; | |
339 | ||
340 | dm_bufio_current_allocated += diff; | |
341 | ||
342 | if (dm_bufio_current_allocated > dm_bufio_peak_allocated) | |
343 | dm_bufio_peak_allocated = dm_bufio_current_allocated; | |
344 | ||
6e913b28 MP |
345 | b->accessed = 1; |
346 | ||
af53badc MP |
347 | if (!unlink) { |
348 | list_add(&b->global_list, &global_queue); | |
6e913b28 MP |
349 | global_num++; |
350 | if (dm_bufio_current_allocated > dm_bufio_cache_size) | |
351 | queue_work(dm_bufio_wq, &dm_bufio_replacement_work); | |
af53badc MP |
352 | } else { |
353 | list_del(&b->global_list); | |
6e913b28 | 354 | global_num--; |
af53badc MP |
355 | } |
356 | ||
357 | spin_unlock(&global_spinlock); | |
95d402f0 MP |
358 | } |
359 | ||
360 | /* | |
361 | * Change the number of clients and recalculate per-client limit. | |
362 | */ | |
363 | static void __cache_size_refresh(void) | |
364 | { | |
365 | BUG_ON(!mutex_is_locked(&dm_bufio_clients_lock)); | |
366 | BUG_ON(dm_bufio_client_count < 0); | |
367 | ||
6aa7de05 | 368 | dm_bufio_cache_size_latch = READ_ONCE(dm_bufio_cache_size); |
95d402f0 MP |
369 | |
370 | /* | |
371 | * Use default if set to 0 and report the actual cache size used. | |
372 | */ | |
373 | if (!dm_bufio_cache_size_latch) { | |
374 | (void)cmpxchg(&dm_bufio_cache_size, 0, | |
375 | dm_bufio_default_cache_size); | |
376 | dm_bufio_cache_size_latch = dm_bufio_default_cache_size; | |
377 | } | |
95d402f0 MP |
378 | } |
379 | ||
380 | /* | |
381 | * Allocating buffer data. | |
382 | * | |
383 | * Small buffers are allocated with kmem_cache, to use space optimally. | |
384 | * | |
385 | * For large buffers, we choose between get_free_pages and vmalloc. | |
386 | * Each has advantages and disadvantages. | |
387 | * | |
388 | * __get_free_pages can randomly fail if the memory is fragmented. | |
389 | * __vmalloc won't randomly fail, but vmalloc space is limited (it may be | |
390 | * as low as 128M) so using it for caching is not appropriate. | |
391 | * | |
392 | * If the allocation may fail we use __get_free_pages. Memory fragmentation | |
393 | * won't have a fatal effect here, but it just causes flushes of some other | |
394 | * buffers and more I/O will be performed. Don't use __get_free_pages if it | |
395 | * always fails (i.e. order >= MAX_ORDER). | |
396 | * | |
397 | * If the allocation shouldn't fail we use __vmalloc. This is only for the | |
398 | * initial reserve allocation, so there's no risk of wasting all vmalloc | |
399 | * space. | |
400 | */ | |
401 | static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask, | |
03b02939 | 402 | unsigned char *data_mode) |
95d402f0 | 403 | { |
21bb1327 | 404 | if (unlikely(c->slab_cache != NULL)) { |
95d402f0 | 405 | *data_mode = DATA_MODE_SLAB; |
21bb1327 | 406 | return kmem_cache_alloc(c->slab_cache, gfp_mask); |
95d402f0 MP |
407 | } |
408 | ||
f51f2e0a | 409 | if (c->block_size <= KMALLOC_MAX_SIZE && |
95d402f0 MP |
410 | gfp_mask & __GFP_NORETRY) { |
411 | *data_mode = DATA_MODE_GET_FREE_PAGES; | |
412 | return (void *)__get_free_pages(gfp_mask, | |
f51f2e0a | 413 | c->sectors_per_block_bits - (PAGE_SHIFT - SECTOR_SHIFT)); |
95d402f0 MP |
414 | } |
415 | ||
416 | *data_mode = DATA_MODE_VMALLOC; | |
502624bd MP |
417 | |
418 | /* | |
419 | * __vmalloc allocates the data pages and auxiliary structures with | |
420 | * gfp_flags that were specified, but pagetables are always allocated | |
421 | * with GFP_KERNEL, no matter what was specified as gfp_mask. | |
422 | * | |
423 | * Consequently, we must set per-process flag PF_MEMALLOC_NOIO so that | |
424 | * all allocations done by this process (including pagetables) are done | |
425 | * as if GFP_NOIO was specified. | |
426 | */ | |
590347e4 AB |
427 | if (gfp_mask & __GFP_NORETRY) { |
428 | unsigned noio_flag = memalloc_noio_save(); | |
88dca4ca | 429 | void *ptr = __vmalloc(c->block_size, gfp_mask); |
502624bd | 430 | |
502624bd | 431 | memalloc_noio_restore(noio_flag); |
590347e4 AB |
432 | return ptr; |
433 | } | |
502624bd | 434 | |
88dca4ca | 435 | return __vmalloc(c->block_size, gfp_mask); |
95d402f0 MP |
436 | } |
437 | ||
438 | /* | |
439 | * Free buffer's data. | |
440 | */ | |
441 | static void free_buffer_data(struct dm_bufio_client *c, | |
03b02939 | 442 | void *data, unsigned char data_mode) |
95d402f0 MP |
443 | { |
444 | switch (data_mode) { | |
445 | case DATA_MODE_SLAB: | |
21bb1327 | 446 | kmem_cache_free(c->slab_cache, data); |
95d402f0 MP |
447 | break; |
448 | ||
449 | case DATA_MODE_GET_FREE_PAGES: | |
f51f2e0a MP |
450 | free_pages((unsigned long)data, |
451 | c->sectors_per_block_bits - (PAGE_SHIFT - SECTOR_SHIFT)); | |
95d402f0 MP |
452 | break; |
453 | ||
454 | case DATA_MODE_VMALLOC: | |
455 | vfree(data); | |
456 | break; | |
457 | ||
458 | default: | |
459 | DMCRIT("dm_bufio_free_buffer_data: bad data mode: %d", | |
460 | data_mode); | |
461 | BUG(); | |
462 | } | |
463 | } | |
464 | ||
465 | /* | |
466 | * Allocate buffer and its data. | |
467 | */ | |
468 | static struct dm_buffer *alloc_buffer(struct dm_bufio_client *c, gfp_t gfp_mask) | |
469 | { | |
359dbf19 | 470 | struct dm_buffer *b = kmem_cache_alloc(c->slab_buffer, gfp_mask); |
95d402f0 MP |
471 | |
472 | if (!b) | |
473 | return NULL; | |
474 | ||
475 | b->c = c; | |
476 | ||
477 | b->data = alloc_buffer_data(c, gfp_mask, &b->data_mode); | |
478 | if (!b->data) { | |
359dbf19 | 479 | kmem_cache_free(c->slab_buffer, b); |
95d402f0 MP |
480 | return NULL; |
481 | } | |
482 | ||
86bad0c7 | 483 | #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING |
741b58f3 | 484 | b->stack_len = 0; |
86bad0c7 | 485 | #endif |
95d402f0 MP |
486 | return b; |
487 | } | |
488 | ||
489 | /* | |
490 | * Free buffer and its data. | |
491 | */ | |
492 | static void free_buffer(struct dm_buffer *b) | |
493 | { | |
494 | struct dm_bufio_client *c = b->c; | |
495 | ||
95d402f0 | 496 | free_buffer_data(c, b->data, b->data_mode); |
359dbf19 | 497 | kmem_cache_free(c->slab_buffer, b); |
95d402f0 MP |
498 | } |
499 | ||
500 | /* | |
ef992373 | 501 | * Link buffer to the buffer tree and clean or dirty queue. |
95d402f0 MP |
502 | */ |
503 | static void __link_buffer(struct dm_buffer *b, sector_t block, int dirty) | |
504 | { | |
505 | struct dm_bufio_client *c = b->c; | |
506 | ||
507 | c->n_buffers[dirty]++; | |
508 | b->block = block; | |
509 | b->list_mode = dirty; | |
510 | list_add(&b->lru_list, &c->lru[dirty]); | |
4e420c45 | 511 | __insert(b->c, b); |
95d402f0 | 512 | b->last_accessed = jiffies; |
26d2ef0c | 513 | |
d0a328a3 | 514 | adjust_total_allocated(b, false); |
95d402f0 MP |
515 | } |
516 | ||
517 | /* | |
ef992373 | 518 | * Unlink buffer from the buffer tree and dirty or clean queue. |
95d402f0 MP |
519 | */ |
520 | static void __unlink_buffer(struct dm_buffer *b) | |
521 | { | |
522 | struct dm_bufio_client *c = b->c; | |
523 | ||
524 | BUG_ON(!c->n_buffers[b->list_mode]); | |
525 | ||
526 | c->n_buffers[b->list_mode]--; | |
4e420c45 | 527 | __remove(b->c, b); |
95d402f0 | 528 | list_del(&b->lru_list); |
26d2ef0c | 529 | |
d0a328a3 | 530 | adjust_total_allocated(b, true); |
95d402f0 MP |
531 | } |
532 | ||
533 | /* | |
534 | * Place the buffer to the head of dirty or clean LRU queue. | |
535 | */ | |
536 | static void __relink_lru(struct dm_buffer *b, int dirty) | |
537 | { | |
538 | struct dm_bufio_client *c = b->c; | |
539 | ||
6e913b28 MP |
540 | b->accessed = 1; |
541 | ||
95d402f0 MP |
542 | BUG_ON(!c->n_buffers[b->list_mode]); |
543 | ||
544 | c->n_buffers[b->list_mode]--; | |
545 | c->n_buffers[dirty]++; | |
546 | b->list_mode = dirty; | |
54499afb | 547 | list_move(&b->lru_list, &c->lru[dirty]); |
eb76faf5 | 548 | b->last_accessed = jiffies; |
95d402f0 MP |
549 | } |
550 | ||
551 | /*---------------------------------------------------------------- | |
552 | * Submit I/O on the buffer. | |
553 | * | |
554 | * Bio interface is faster but it has some problems: | |
555 | * the vector list is limited (increasing this limit increases | |
556 | * memory-consumption per buffer, so it is not viable); | |
557 | * | |
558 | * the memory must be direct-mapped, not vmalloced; | |
559 | * | |
95d402f0 MP |
560 | * If the buffer is small enough (up to DM_BUFIO_INLINE_VECS pages) and |
561 | * it is not vmalloced, try using the bio interface. | |
562 | * | |
563 | * If the buffer is big, if it is vmalloced or if the underlying device | |
564 | * rejects the bio because it is too large, use dm-io layer to do the I/O. | |
565 | * The dm-io layer splits the I/O into multiple requests, avoiding the above | |
566 | * shortcomings. | |
567 | *--------------------------------------------------------------*/ | |
568 | ||
569 | /* | |
570 | * dm-io completion routine. It just calls b->bio.bi_end_io, pretending | |
571 | * that the request was handled directly with bio interface. | |
572 | */ | |
573 | static void dmio_complete(unsigned long error, void *context) | |
574 | { | |
575 | struct dm_buffer *b = context; | |
576 | ||
45354f1e | 577 | b->end_io(b, unlikely(error != 0) ? BLK_STS_IOERR : 0); |
95d402f0 MP |
578 | } |
579 | ||
400a0bef | 580 | static void use_dmio(struct dm_buffer *b, int rw, sector_t sector, |
45354f1e | 581 | unsigned n_sectors, unsigned offset) |
95d402f0 MP |
582 | { |
583 | int r; | |
584 | struct dm_io_request io_req = { | |
e6047149 MC |
585 | .bi_op = rw, |
586 | .bi_op_flags = 0, | |
95d402f0 MP |
587 | .notify.fn = dmio_complete, |
588 | .notify.context = b, | |
589 | .client = b->c->dm_io, | |
590 | }; | |
591 | struct dm_io_region region = { | |
592 | .bdev = b->c->bdev, | |
400a0bef MP |
593 | .sector = sector, |
594 | .count = n_sectors, | |
95d402f0 MP |
595 | }; |
596 | ||
597 | if (b->data_mode != DATA_MODE_VMALLOC) { | |
598 | io_req.mem.type = DM_IO_KMEM; | |
1e3b21c6 | 599 | io_req.mem.ptr.addr = (char *)b->data + offset; |
95d402f0 MP |
600 | } else { |
601 | io_req.mem.type = DM_IO_VMA; | |
1e3b21c6 | 602 | io_req.mem.ptr.vma = (char *)b->data + offset; |
95d402f0 MP |
603 | } |
604 | ||
95d402f0 | 605 | r = dm_io(&io_req, 1, ®ion, NULL); |
45354f1e MP |
606 | if (unlikely(r)) |
607 | b->end_io(b, errno_to_blk_status(r)); | |
95d402f0 MP |
608 | } |
609 | ||
45354f1e | 610 | static void bio_complete(struct bio *bio) |
445559cd | 611 | { |
45354f1e | 612 | struct dm_buffer *b = bio->bi_private; |
4e4cbee9 | 613 | blk_status_t status = bio->bi_status; |
45354f1e MP |
614 | bio_put(bio); |
615 | b->end_io(b, status); | |
445559cd DW |
616 | } |
617 | ||
45354f1e MP |
618 | static void use_bio(struct dm_buffer *b, int rw, sector_t sector, |
619 | unsigned n_sectors, unsigned offset) | |
95d402f0 | 620 | { |
45354f1e | 621 | struct bio *bio; |
95d402f0 | 622 | char *ptr; |
45354f1e | 623 | unsigned vec_size, len; |
95d402f0 | 624 | |
45354f1e MP |
625 | vec_size = b->c->block_size >> PAGE_SHIFT; |
626 | if (unlikely(b->c->sectors_per_block_bits < PAGE_SHIFT - SECTOR_SHIFT)) | |
627 | vec_size += 2; | |
628 | ||
629 | bio = bio_kmalloc(GFP_NOWAIT | __GFP_NORETRY | __GFP_NOWARN, vec_size); | |
630 | if (!bio) { | |
631 | dmio: | |
632 | use_dmio(b, rw, sector, n_sectors, offset); | |
633 | return; | |
634 | } | |
635 | ||
636 | bio->bi_iter.bi_sector = sector; | |
637 | bio_set_dev(bio, b->c->bdev); | |
638 | bio_set_op_attrs(bio, rw, 0); | |
639 | bio->bi_end_io = bio_complete; | |
640 | bio->bi_private = b; | |
95d402f0 | 641 | |
1e3b21c6 | 642 | ptr = (char *)b->data + offset; |
400a0bef | 643 | len = n_sectors << SECTOR_SHIFT; |
95d402f0 | 644 | |
95d402f0 | 645 | do { |
1e3b21c6 | 646 | unsigned this_step = min((unsigned)(PAGE_SIZE - offset_in_page(ptr)), len); |
45354f1e | 647 | if (!bio_add_page(bio, virt_to_page(ptr), this_step, |
756d097b | 648 | offset_in_page(ptr))) { |
45354f1e MP |
649 | bio_put(bio); |
650 | goto dmio; | |
95d402f0 MP |
651 | } |
652 | ||
1e3b21c6 MP |
653 | len -= this_step; |
654 | ptr += this_step; | |
95d402f0 MP |
655 | } while (len > 0); |
656 | ||
45354f1e | 657 | submit_bio(bio); |
95d402f0 MP |
658 | } |
659 | ||
6fbeb004 MP |
660 | static inline sector_t block_to_sector(struct dm_bufio_client *c, sector_t block) |
661 | { | |
662 | sector_t sector; | |
663 | ||
664 | if (likely(c->sectors_per_block_bits >= 0)) | |
665 | sector = block << c->sectors_per_block_bits; | |
666 | else | |
667 | sector = block * (c->block_size >> SECTOR_SHIFT); | |
668 | sector += c->start; | |
669 | ||
670 | return sector; | |
671 | } | |
672 | ||
45354f1e | 673 | static void submit_io(struct dm_buffer *b, int rw, void (*end_io)(struct dm_buffer *, blk_status_t)) |
95d402f0 | 674 | { |
400a0bef MP |
675 | unsigned n_sectors; |
676 | sector_t sector; | |
1e3b21c6 | 677 | unsigned offset, end; |
95d402f0 | 678 | |
45354f1e MP |
679 | b->end_io = end_io; |
680 | ||
6fbeb004 | 681 | sector = block_to_sector(b->c, b->block); |
1e3b21c6 | 682 | |
905be0a1 | 683 | if (rw != REQ_OP_WRITE) { |
f51f2e0a | 684 | n_sectors = b->c->block_size >> SECTOR_SHIFT; |
1e3b21c6 MP |
685 | offset = 0; |
686 | } else { | |
687 | if (b->c->write_callback) | |
688 | b->c->write_callback(b); | |
689 | offset = b->write_start; | |
690 | end = b->write_end; | |
691 | offset &= -DM_BUFIO_WRITE_ALIGN; | |
692 | end += DM_BUFIO_WRITE_ALIGN - 1; | |
693 | end &= -DM_BUFIO_WRITE_ALIGN; | |
694 | if (unlikely(end > b->c->block_size)) | |
695 | end = b->c->block_size; | |
696 | ||
697 | sector += offset >> SECTOR_SHIFT; | |
698 | n_sectors = (end - offset) >> SECTOR_SHIFT; | |
699 | } | |
400a0bef | 700 | |
45354f1e MP |
701 | if (b->data_mode != DATA_MODE_VMALLOC) |
702 | use_bio(b, rw, sector, n_sectors, offset); | |
95d402f0 | 703 | else |
45354f1e | 704 | use_dmio(b, rw, sector, n_sectors, offset); |
95d402f0 MP |
705 | } |
706 | ||
707 | /*---------------------------------------------------------------- | |
708 | * Writing dirty buffers | |
709 | *--------------------------------------------------------------*/ | |
710 | ||
711 | /* | |
712 | * The endio routine for write. | |
713 | * | |
714 | * Set the error, clear B_WRITING bit and wake anyone who was waiting on | |
715 | * it. | |
716 | */ | |
45354f1e | 717 | static void write_endio(struct dm_buffer *b, blk_status_t status) |
95d402f0 | 718 | { |
45354f1e MP |
719 | b->write_error = status; |
720 | if (unlikely(status)) { | |
95d402f0 | 721 | struct dm_bufio_client *c = b->c; |
4e4cbee9 CH |
722 | |
723 | (void)cmpxchg(&c->async_write_error, 0, | |
45354f1e | 724 | blk_status_to_errno(status)); |
95d402f0 MP |
725 | } |
726 | ||
727 | BUG_ON(!test_bit(B_WRITING, &b->state)); | |
728 | ||
4e857c58 | 729 | smp_mb__before_atomic(); |
95d402f0 | 730 | clear_bit(B_WRITING, &b->state); |
4e857c58 | 731 | smp_mb__after_atomic(); |
95d402f0 MP |
732 | |
733 | wake_up_bit(&b->state, B_WRITING); | |
734 | } | |
735 | ||
95d402f0 MP |
736 | /* |
737 | * Initiate a write on a dirty buffer, but don't wait for it. | |
738 | * | |
739 | * - If the buffer is not dirty, exit. | |
740 | * - If there some previous write going on, wait for it to finish (we can't | |
741 | * have two writes on the same buffer simultaneously). | |
742 | * - Submit our write and don't wait on it. We set B_WRITING indicating | |
743 | * that there is a write in progress. | |
744 | */ | |
2480945c MP |
745 | static void __write_dirty_buffer(struct dm_buffer *b, |
746 | struct list_head *write_list) | |
95d402f0 MP |
747 | { |
748 | if (!test_bit(B_DIRTY, &b->state)) | |
749 | return; | |
750 | ||
751 | clear_bit(B_DIRTY, &b->state); | |
74316201 | 752 | wait_on_bit_lock_io(&b->state, B_WRITING, TASK_UNINTERRUPTIBLE); |
95d402f0 | 753 | |
1e3b21c6 MP |
754 | b->write_start = b->dirty_start; |
755 | b->write_end = b->dirty_end; | |
756 | ||
2480945c | 757 | if (!write_list) |
905be0a1 | 758 | submit_io(b, REQ_OP_WRITE, write_endio); |
2480945c MP |
759 | else |
760 | list_add_tail(&b->write_list, write_list); | |
761 | } | |
762 | ||
763 | static void __flush_write_list(struct list_head *write_list) | |
764 | { | |
765 | struct blk_plug plug; | |
766 | blk_start_plug(&plug); | |
767 | while (!list_empty(write_list)) { | |
768 | struct dm_buffer *b = | |
769 | list_entry(write_list->next, struct dm_buffer, write_list); | |
770 | list_del(&b->write_list); | |
905be0a1 | 771 | submit_io(b, REQ_OP_WRITE, write_endio); |
7cd32674 | 772 | cond_resched(); |
2480945c MP |
773 | } |
774 | blk_finish_plug(&plug); | |
95d402f0 MP |
775 | } |
776 | ||
777 | /* | |
778 | * Wait until any activity on the buffer finishes. Possibly write the | |
779 | * buffer if it is dirty. When this function finishes, there is no I/O | |
780 | * running on the buffer and the buffer is not dirty. | |
781 | */ | |
782 | static void __make_buffer_clean(struct dm_buffer *b) | |
783 | { | |
784 | BUG_ON(b->hold_count); | |
785 | ||
786 | if (!b->state) /* fast case */ | |
787 | return; | |
788 | ||
74316201 | 789 | wait_on_bit_io(&b->state, B_READING, TASK_UNINTERRUPTIBLE); |
2480945c | 790 | __write_dirty_buffer(b, NULL); |
74316201 | 791 | wait_on_bit_io(&b->state, B_WRITING, TASK_UNINTERRUPTIBLE); |
95d402f0 MP |
792 | } |
793 | ||
794 | /* | |
795 | * Find some buffer that is not held by anybody, clean it, unlink it and | |
796 | * return it. | |
797 | */ | |
798 | static struct dm_buffer *__get_unclaimed_buffer(struct dm_bufio_client *c) | |
799 | { | |
800 | struct dm_buffer *b; | |
801 | ||
802 | list_for_each_entry_reverse(b, &c->lru[LIST_CLEAN], lru_list) { | |
803 | BUG_ON(test_bit(B_WRITING, &b->state)); | |
804 | BUG_ON(test_bit(B_DIRTY, &b->state)); | |
805 | ||
806 | if (!b->hold_count) { | |
807 | __make_buffer_clean(b); | |
808 | __unlink_buffer(b); | |
809 | return b; | |
810 | } | |
7cd32674 | 811 | cond_resched(); |
95d402f0 MP |
812 | } |
813 | ||
814 | list_for_each_entry_reverse(b, &c->lru[LIST_DIRTY], lru_list) { | |
815 | BUG_ON(test_bit(B_READING, &b->state)); | |
816 | ||
817 | if (!b->hold_count) { | |
818 | __make_buffer_clean(b); | |
819 | __unlink_buffer(b); | |
820 | return b; | |
821 | } | |
7cd32674 | 822 | cond_resched(); |
95d402f0 MP |
823 | } |
824 | ||
825 | return NULL; | |
826 | } | |
827 | ||
828 | /* | |
829 | * Wait until some other threads free some buffer or release hold count on | |
830 | * some buffer. | |
831 | * | |
832 | * This function is entered with c->lock held, drops it and regains it | |
833 | * before exiting. | |
834 | */ | |
835 | static void __wait_for_free_buffer(struct dm_bufio_client *c) | |
836 | { | |
837 | DECLARE_WAITQUEUE(wait, current); | |
838 | ||
839 | add_wait_queue(&c->free_buffer_wait, &wait); | |
642fa448 | 840 | set_current_state(TASK_UNINTERRUPTIBLE); |
95d402f0 MP |
841 | dm_bufio_unlock(c); |
842 | ||
843 | io_schedule(); | |
844 | ||
95d402f0 MP |
845 | remove_wait_queue(&c->free_buffer_wait, &wait); |
846 | ||
847 | dm_bufio_lock(c); | |
848 | } | |
849 | ||
a66cc28f MP |
850 | enum new_flag { |
851 | NF_FRESH = 0, | |
852 | NF_READ = 1, | |
853 | NF_GET = 2, | |
854 | NF_PREFETCH = 3 | |
855 | }; | |
856 | ||
95d402f0 MP |
857 | /* |
858 | * Allocate a new buffer. If the allocation is not possible, wait until | |
859 | * some other thread frees a buffer. | |
860 | * | |
861 | * May drop the lock and regain it. | |
862 | */ | |
a66cc28f | 863 | static struct dm_buffer *__alloc_buffer_wait_no_callback(struct dm_bufio_client *c, enum new_flag nf) |
95d402f0 MP |
864 | { |
865 | struct dm_buffer *b; | |
41c73a49 | 866 | bool tried_noio_alloc = false; |
95d402f0 MP |
867 | |
868 | /* | |
869 | * dm-bufio is resistant to allocation failures (it just keeps | |
870 | * one buffer reserved in cases all the allocations fail). | |
871 | * So set flags to not try too hard: | |
9ea61cac DA |
872 | * GFP_NOWAIT: don't wait; if we need to sleep we'll release our |
873 | * mutex and wait ourselves. | |
95d402f0 MP |
874 | * __GFP_NORETRY: don't retry and rather return failure |
875 | * __GFP_NOMEMALLOC: don't use emergency reserves | |
876 | * __GFP_NOWARN: don't print a warning in case of failure | |
877 | * | |
878 | * For debugging, if we set the cache size to 1, no new buffers will | |
879 | * be allocated. | |
880 | */ | |
881 | while (1) { | |
882 | if (dm_bufio_cache_size_latch != 1) { | |
9ea61cac | 883 | b = alloc_buffer(c, GFP_NOWAIT | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); |
95d402f0 MP |
884 | if (b) |
885 | return b; | |
886 | } | |
887 | ||
a66cc28f MP |
888 | if (nf == NF_PREFETCH) |
889 | return NULL; | |
890 | ||
41c73a49 MP |
891 | if (dm_bufio_cache_size_latch != 1 && !tried_noio_alloc) { |
892 | dm_bufio_unlock(c); | |
893 | b = alloc_buffer(c, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); | |
894 | dm_bufio_lock(c); | |
895 | if (b) | |
896 | return b; | |
897 | tried_noio_alloc = true; | |
898 | } | |
899 | ||
95d402f0 MP |
900 | if (!list_empty(&c->reserved_buffers)) { |
901 | b = list_entry(c->reserved_buffers.next, | |
902 | struct dm_buffer, lru_list); | |
903 | list_del(&b->lru_list); | |
904 | c->need_reserved_buffers++; | |
905 | ||
906 | return b; | |
907 | } | |
908 | ||
909 | b = __get_unclaimed_buffer(c); | |
910 | if (b) | |
911 | return b; | |
912 | ||
913 | __wait_for_free_buffer(c); | |
914 | } | |
915 | } | |
916 | ||
a66cc28f | 917 | static struct dm_buffer *__alloc_buffer_wait(struct dm_bufio_client *c, enum new_flag nf) |
95d402f0 | 918 | { |
a66cc28f MP |
919 | struct dm_buffer *b = __alloc_buffer_wait_no_callback(c, nf); |
920 | ||
921 | if (!b) | |
922 | return NULL; | |
95d402f0 MP |
923 | |
924 | if (c->alloc_callback) | |
925 | c->alloc_callback(b); | |
926 | ||
927 | return b; | |
928 | } | |
929 | ||
930 | /* | |
931 | * Free a buffer and wake other threads waiting for free buffers. | |
932 | */ | |
933 | static void __free_buffer_wake(struct dm_buffer *b) | |
934 | { | |
935 | struct dm_bufio_client *c = b->c; | |
936 | ||
937 | if (!c->need_reserved_buffers) | |
938 | free_buffer(b); | |
939 | else { | |
940 | list_add(&b->lru_list, &c->reserved_buffers); | |
941 | c->need_reserved_buffers--; | |
942 | } | |
943 | ||
944 | wake_up(&c->free_buffer_wait); | |
945 | } | |
946 | ||
2480945c MP |
947 | static void __write_dirty_buffers_async(struct dm_bufio_client *c, int no_wait, |
948 | struct list_head *write_list) | |
95d402f0 MP |
949 | { |
950 | struct dm_buffer *b, *tmp; | |
951 | ||
952 | list_for_each_entry_safe_reverse(b, tmp, &c->lru[LIST_DIRTY], lru_list) { | |
953 | BUG_ON(test_bit(B_READING, &b->state)); | |
954 | ||
955 | if (!test_bit(B_DIRTY, &b->state) && | |
956 | !test_bit(B_WRITING, &b->state)) { | |
957 | __relink_lru(b, LIST_CLEAN); | |
958 | continue; | |
959 | } | |
960 | ||
961 | if (no_wait && test_bit(B_WRITING, &b->state)) | |
962 | return; | |
963 | ||
2480945c | 964 | __write_dirty_buffer(b, write_list); |
7cd32674 | 965 | cond_resched(); |
95d402f0 MP |
966 | } |
967 | } | |
968 | ||
95d402f0 MP |
969 | /* |
970 | * Check if we're over watermark. | |
971 | * If we are over threshold_buffers, start freeing buffers. | |
972 | * If we're over "limit_buffers", block until we get under the limit. | |
973 | */ | |
2480945c MP |
974 | static void __check_watermark(struct dm_bufio_client *c, |
975 | struct list_head *write_list) | |
95d402f0 | 976 | { |
b132ff33 | 977 | if (c->n_buffers[LIST_DIRTY] > c->n_buffers[LIST_CLEAN] * DM_BUFIO_WRITEBACK_RATIO) |
2480945c | 978 | __write_dirty_buffers_async(c, 1, write_list); |
95d402f0 MP |
979 | } |
980 | ||
95d402f0 MP |
981 | /*---------------------------------------------------------------- |
982 | * Getting a buffer | |
983 | *--------------------------------------------------------------*/ | |
984 | ||
95d402f0 | 985 | static struct dm_buffer *__bufio_new(struct dm_bufio_client *c, sector_t block, |
2480945c MP |
986 | enum new_flag nf, int *need_submit, |
987 | struct list_head *write_list) | |
95d402f0 MP |
988 | { |
989 | struct dm_buffer *b, *new_b = NULL; | |
990 | ||
991 | *need_submit = 0; | |
992 | ||
993 | b = __find(c, block); | |
a66cc28f MP |
994 | if (b) |
995 | goto found_buffer; | |
95d402f0 MP |
996 | |
997 | if (nf == NF_GET) | |
998 | return NULL; | |
999 | ||
a66cc28f MP |
1000 | new_b = __alloc_buffer_wait(c, nf); |
1001 | if (!new_b) | |
1002 | return NULL; | |
95d402f0 MP |
1003 | |
1004 | /* | |
1005 | * We've had a period where the mutex was unlocked, so need to | |
ef992373 | 1006 | * recheck the buffer tree. |
95d402f0 MP |
1007 | */ |
1008 | b = __find(c, block); | |
1009 | if (b) { | |
1010 | __free_buffer_wake(new_b); | |
a66cc28f | 1011 | goto found_buffer; |
95d402f0 MP |
1012 | } |
1013 | ||
2480945c | 1014 | __check_watermark(c, write_list); |
95d402f0 MP |
1015 | |
1016 | b = new_b; | |
1017 | b->hold_count = 1; | |
1018 | b->read_error = 0; | |
1019 | b->write_error = 0; | |
1020 | __link_buffer(b, block, LIST_CLEAN); | |
1021 | ||
1022 | if (nf == NF_FRESH) { | |
1023 | b->state = 0; | |
1024 | return b; | |
1025 | } | |
1026 | ||
1027 | b->state = 1 << B_READING; | |
1028 | *need_submit = 1; | |
1029 | ||
1030 | return b; | |
a66cc28f MP |
1031 | |
1032 | found_buffer: | |
1033 | if (nf == NF_PREFETCH) | |
1034 | return NULL; | |
1035 | /* | |
1036 | * Note: it is essential that we don't wait for the buffer to be | |
1037 | * read if dm_bufio_get function is used. Both dm_bufio_get and | |
1038 | * dm_bufio_prefetch can be used in the driver request routine. | |
1039 | * If the user called both dm_bufio_prefetch and dm_bufio_get on | |
1040 | * the same buffer, it would deadlock if we waited. | |
1041 | */ | |
1042 | if (nf == NF_GET && unlikely(test_bit(B_READING, &b->state))) | |
1043 | return NULL; | |
1044 | ||
1045 | b->hold_count++; | |
1046 | __relink_lru(b, test_bit(B_DIRTY, &b->state) || | |
1047 | test_bit(B_WRITING, &b->state)); | |
1048 | return b; | |
95d402f0 MP |
1049 | } |
1050 | ||
1051 | /* | |
1052 | * The endio routine for reading: set the error, clear the bit and wake up | |
1053 | * anyone waiting on the buffer. | |
1054 | */ | |
45354f1e | 1055 | static void read_endio(struct dm_buffer *b, blk_status_t status) |
95d402f0 | 1056 | { |
45354f1e | 1057 | b->read_error = status; |
95d402f0 MP |
1058 | |
1059 | BUG_ON(!test_bit(B_READING, &b->state)); | |
1060 | ||
4e857c58 | 1061 | smp_mb__before_atomic(); |
95d402f0 | 1062 | clear_bit(B_READING, &b->state); |
4e857c58 | 1063 | smp_mb__after_atomic(); |
95d402f0 MP |
1064 | |
1065 | wake_up_bit(&b->state, B_READING); | |
1066 | } | |
1067 | ||
1068 | /* | |
1069 | * A common routine for dm_bufio_new and dm_bufio_read. Operation of these | |
1070 | * functions is similar except that dm_bufio_new doesn't read the | |
1071 | * buffer from the disk (assuming that the caller overwrites all the data | |
1072 | * and uses dm_bufio_mark_buffer_dirty to write new data back). | |
1073 | */ | |
1074 | static void *new_read(struct dm_bufio_client *c, sector_t block, | |
1075 | enum new_flag nf, struct dm_buffer **bp) | |
1076 | { | |
1077 | int need_submit; | |
1078 | struct dm_buffer *b; | |
1079 | ||
2480945c MP |
1080 | LIST_HEAD(write_list); |
1081 | ||
95d402f0 | 1082 | dm_bufio_lock(c); |
2480945c | 1083 | b = __bufio_new(c, block, nf, &need_submit, &write_list); |
86bad0c7 MP |
1084 | #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING |
1085 | if (b && b->hold_count == 1) | |
1086 | buffer_record_stack(b); | |
1087 | #endif | |
95d402f0 MP |
1088 | dm_bufio_unlock(c); |
1089 | ||
2480945c MP |
1090 | __flush_write_list(&write_list); |
1091 | ||
a66cc28f | 1092 | if (!b) |
f98c8f79 | 1093 | return NULL; |
95d402f0 MP |
1094 | |
1095 | if (need_submit) | |
905be0a1 | 1096 | submit_io(b, REQ_OP_READ, read_endio); |
95d402f0 | 1097 | |
74316201 | 1098 | wait_on_bit_io(&b->state, B_READING, TASK_UNINTERRUPTIBLE); |
95d402f0 MP |
1099 | |
1100 | if (b->read_error) { | |
4e4cbee9 | 1101 | int error = blk_status_to_errno(b->read_error); |
95d402f0 MP |
1102 | |
1103 | dm_bufio_release(b); | |
1104 | ||
1105 | return ERR_PTR(error); | |
1106 | } | |
1107 | ||
1108 | *bp = b; | |
1109 | ||
1110 | return b->data; | |
1111 | } | |
1112 | ||
1113 | void *dm_bufio_get(struct dm_bufio_client *c, sector_t block, | |
1114 | struct dm_buffer **bp) | |
1115 | { | |
1116 | return new_read(c, block, NF_GET, bp); | |
1117 | } | |
1118 | EXPORT_SYMBOL_GPL(dm_bufio_get); | |
1119 | ||
1120 | void *dm_bufio_read(struct dm_bufio_client *c, sector_t block, | |
1121 | struct dm_buffer **bp) | |
1122 | { | |
1123 | BUG_ON(dm_bufio_in_request()); | |
1124 | ||
1125 | return new_read(c, block, NF_READ, bp); | |
1126 | } | |
1127 | EXPORT_SYMBOL_GPL(dm_bufio_read); | |
1128 | ||
1129 | void *dm_bufio_new(struct dm_bufio_client *c, sector_t block, | |
1130 | struct dm_buffer **bp) | |
1131 | { | |
1132 | BUG_ON(dm_bufio_in_request()); | |
1133 | ||
1134 | return new_read(c, block, NF_FRESH, bp); | |
1135 | } | |
1136 | EXPORT_SYMBOL_GPL(dm_bufio_new); | |
1137 | ||
a66cc28f MP |
1138 | void dm_bufio_prefetch(struct dm_bufio_client *c, |
1139 | sector_t block, unsigned n_blocks) | |
1140 | { | |
1141 | struct blk_plug plug; | |
1142 | ||
2480945c MP |
1143 | LIST_HEAD(write_list); |
1144 | ||
3b6b7813 MP |
1145 | BUG_ON(dm_bufio_in_request()); |
1146 | ||
a66cc28f MP |
1147 | blk_start_plug(&plug); |
1148 | dm_bufio_lock(c); | |
1149 | ||
1150 | for (; n_blocks--; block++) { | |
1151 | int need_submit; | |
1152 | struct dm_buffer *b; | |
2480945c MP |
1153 | b = __bufio_new(c, block, NF_PREFETCH, &need_submit, |
1154 | &write_list); | |
1155 | if (unlikely(!list_empty(&write_list))) { | |
1156 | dm_bufio_unlock(c); | |
1157 | blk_finish_plug(&plug); | |
1158 | __flush_write_list(&write_list); | |
1159 | blk_start_plug(&plug); | |
1160 | dm_bufio_lock(c); | |
1161 | } | |
a66cc28f MP |
1162 | if (unlikely(b != NULL)) { |
1163 | dm_bufio_unlock(c); | |
1164 | ||
1165 | if (need_submit) | |
905be0a1 | 1166 | submit_io(b, REQ_OP_READ, read_endio); |
a66cc28f MP |
1167 | dm_bufio_release(b); |
1168 | ||
7cd32674 | 1169 | cond_resched(); |
a66cc28f MP |
1170 | |
1171 | if (!n_blocks) | |
1172 | goto flush_plug; | |
1173 | dm_bufio_lock(c); | |
1174 | } | |
a66cc28f MP |
1175 | } |
1176 | ||
1177 | dm_bufio_unlock(c); | |
1178 | ||
1179 | flush_plug: | |
1180 | blk_finish_plug(&plug); | |
1181 | } | |
1182 | EXPORT_SYMBOL_GPL(dm_bufio_prefetch); | |
1183 | ||
95d402f0 MP |
1184 | void dm_bufio_release(struct dm_buffer *b) |
1185 | { | |
1186 | struct dm_bufio_client *c = b->c; | |
1187 | ||
1188 | dm_bufio_lock(c); | |
1189 | ||
95d402f0 MP |
1190 | BUG_ON(!b->hold_count); |
1191 | ||
1192 | b->hold_count--; | |
1193 | if (!b->hold_count) { | |
1194 | wake_up(&c->free_buffer_wait); | |
1195 | ||
1196 | /* | |
1197 | * If there were errors on the buffer, and the buffer is not | |
1198 | * to be written, free the buffer. There is no point in caching | |
1199 | * invalid buffer. | |
1200 | */ | |
1201 | if ((b->read_error || b->write_error) && | |
a66cc28f | 1202 | !test_bit(B_READING, &b->state) && |
95d402f0 MP |
1203 | !test_bit(B_WRITING, &b->state) && |
1204 | !test_bit(B_DIRTY, &b->state)) { | |
1205 | __unlink_buffer(b); | |
1206 | __free_buffer_wake(b); | |
1207 | } | |
1208 | } | |
1209 | ||
1210 | dm_bufio_unlock(c); | |
1211 | } | |
1212 | EXPORT_SYMBOL_GPL(dm_bufio_release); | |
1213 | ||
1e3b21c6 MP |
1214 | void dm_bufio_mark_partial_buffer_dirty(struct dm_buffer *b, |
1215 | unsigned start, unsigned end) | |
95d402f0 MP |
1216 | { |
1217 | struct dm_bufio_client *c = b->c; | |
1218 | ||
1e3b21c6 MP |
1219 | BUG_ON(start >= end); |
1220 | BUG_ON(end > b->c->block_size); | |
1221 | ||
95d402f0 MP |
1222 | dm_bufio_lock(c); |
1223 | ||
a66cc28f MP |
1224 | BUG_ON(test_bit(B_READING, &b->state)); |
1225 | ||
1e3b21c6 MP |
1226 | if (!test_and_set_bit(B_DIRTY, &b->state)) { |
1227 | b->dirty_start = start; | |
1228 | b->dirty_end = end; | |
95d402f0 | 1229 | __relink_lru(b, LIST_DIRTY); |
1e3b21c6 MP |
1230 | } else { |
1231 | if (start < b->dirty_start) | |
1232 | b->dirty_start = start; | |
1233 | if (end > b->dirty_end) | |
1234 | b->dirty_end = end; | |
1235 | } | |
95d402f0 MP |
1236 | |
1237 | dm_bufio_unlock(c); | |
1238 | } | |
1e3b21c6 MP |
1239 | EXPORT_SYMBOL_GPL(dm_bufio_mark_partial_buffer_dirty); |
1240 | ||
1241 | void dm_bufio_mark_buffer_dirty(struct dm_buffer *b) | |
1242 | { | |
1243 | dm_bufio_mark_partial_buffer_dirty(b, 0, b->c->block_size); | |
1244 | } | |
95d402f0 MP |
1245 | EXPORT_SYMBOL_GPL(dm_bufio_mark_buffer_dirty); |
1246 | ||
1247 | void dm_bufio_write_dirty_buffers_async(struct dm_bufio_client *c) | |
1248 | { | |
2480945c MP |
1249 | LIST_HEAD(write_list); |
1250 | ||
95d402f0 MP |
1251 | BUG_ON(dm_bufio_in_request()); |
1252 | ||
1253 | dm_bufio_lock(c); | |
2480945c | 1254 | __write_dirty_buffers_async(c, 0, &write_list); |
95d402f0 | 1255 | dm_bufio_unlock(c); |
2480945c | 1256 | __flush_write_list(&write_list); |
95d402f0 MP |
1257 | } |
1258 | EXPORT_SYMBOL_GPL(dm_bufio_write_dirty_buffers_async); | |
1259 | ||
1260 | /* | |
1261 | * For performance, it is essential that the buffers are written asynchronously | |
1262 | * and simultaneously (so that the block layer can merge the writes) and then | |
1263 | * waited upon. | |
1264 | * | |
1265 | * Finally, we flush hardware disk cache. | |
1266 | */ | |
1267 | int dm_bufio_write_dirty_buffers(struct dm_bufio_client *c) | |
1268 | { | |
edc11d49 | 1269 | int a, f; |
95d402f0 MP |
1270 | unsigned long buffers_processed = 0; |
1271 | struct dm_buffer *b, *tmp; | |
1272 | ||
2480945c MP |
1273 | LIST_HEAD(write_list); |
1274 | ||
1275 | dm_bufio_lock(c); | |
1276 | __write_dirty_buffers_async(c, 0, &write_list); | |
1277 | dm_bufio_unlock(c); | |
1278 | __flush_write_list(&write_list); | |
95d402f0 | 1279 | dm_bufio_lock(c); |
95d402f0 MP |
1280 | |
1281 | again: | |
1282 | list_for_each_entry_safe_reverse(b, tmp, &c->lru[LIST_DIRTY], lru_list) { | |
1283 | int dropped_lock = 0; | |
1284 | ||
1285 | if (buffers_processed < c->n_buffers[LIST_DIRTY]) | |
1286 | buffers_processed++; | |
1287 | ||
1288 | BUG_ON(test_bit(B_READING, &b->state)); | |
1289 | ||
1290 | if (test_bit(B_WRITING, &b->state)) { | |
1291 | if (buffers_processed < c->n_buffers[LIST_DIRTY]) { | |
1292 | dropped_lock = 1; | |
1293 | b->hold_count++; | |
1294 | dm_bufio_unlock(c); | |
74316201 N |
1295 | wait_on_bit_io(&b->state, B_WRITING, |
1296 | TASK_UNINTERRUPTIBLE); | |
95d402f0 MP |
1297 | dm_bufio_lock(c); |
1298 | b->hold_count--; | |
1299 | } else | |
74316201 N |
1300 | wait_on_bit_io(&b->state, B_WRITING, |
1301 | TASK_UNINTERRUPTIBLE); | |
95d402f0 MP |
1302 | } |
1303 | ||
1304 | if (!test_bit(B_DIRTY, &b->state) && | |
1305 | !test_bit(B_WRITING, &b->state)) | |
1306 | __relink_lru(b, LIST_CLEAN); | |
1307 | ||
7cd32674 | 1308 | cond_resched(); |
95d402f0 MP |
1309 | |
1310 | /* | |
1311 | * If we dropped the lock, the list is no longer consistent, | |
1312 | * so we must restart the search. | |
1313 | * | |
1314 | * In the most common case, the buffer just processed is | |
1315 | * relinked to the clean list, so we won't loop scanning the | |
1316 | * same buffer again and again. | |
1317 | * | |
1318 | * This may livelock if there is another thread simultaneously | |
1319 | * dirtying buffers, so we count the number of buffers walked | |
1320 | * and if it exceeds the total number of buffers, it means that | |
1321 | * someone is doing some writes simultaneously with us. In | |
1322 | * this case, stop, dropping the lock. | |
1323 | */ | |
1324 | if (dropped_lock) | |
1325 | goto again; | |
1326 | } | |
1327 | wake_up(&c->free_buffer_wait); | |
1328 | dm_bufio_unlock(c); | |
1329 | ||
1330 | a = xchg(&c->async_write_error, 0); | |
1331 | f = dm_bufio_issue_flush(c); | |
1332 | if (a) | |
1333 | return a; | |
1334 | ||
1335 | return f; | |
1336 | } | |
1337 | EXPORT_SYMBOL_GPL(dm_bufio_write_dirty_buffers); | |
1338 | ||
1339 | /* | |
ef992373 | 1340 | * Use dm-io to send an empty barrier to flush the device. |
95d402f0 MP |
1341 | */ |
1342 | int dm_bufio_issue_flush(struct dm_bufio_client *c) | |
1343 | { | |
1344 | struct dm_io_request io_req = { | |
e6047149 | 1345 | .bi_op = REQ_OP_WRITE, |
ff0361b3 | 1346 | .bi_op_flags = REQ_PREFLUSH | REQ_SYNC, |
95d402f0 MP |
1347 | .mem.type = DM_IO_KMEM, |
1348 | .mem.ptr.addr = NULL, | |
1349 | .client = c->dm_io, | |
1350 | }; | |
1351 | struct dm_io_region io_reg = { | |
1352 | .bdev = c->bdev, | |
1353 | .sector = 0, | |
1354 | .count = 0, | |
1355 | }; | |
1356 | ||
1357 | BUG_ON(dm_bufio_in_request()); | |
1358 | ||
1359 | return dm_io(&io_req, 1, &io_reg, NULL); | |
1360 | } | |
1361 | EXPORT_SYMBOL_GPL(dm_bufio_issue_flush); | |
1362 | ||
6fbeb004 MP |
1363 | /* |
1364 | * Use dm-io to send a discard request to flush the device. | |
1365 | */ | |
1366 | int dm_bufio_issue_discard(struct dm_bufio_client *c, sector_t block, sector_t count) | |
1367 | { | |
1368 | struct dm_io_request io_req = { | |
1369 | .bi_op = REQ_OP_DISCARD, | |
1370 | .bi_op_flags = REQ_SYNC, | |
1371 | .mem.type = DM_IO_KMEM, | |
1372 | .mem.ptr.addr = NULL, | |
1373 | .client = c->dm_io, | |
1374 | }; | |
1375 | struct dm_io_region io_reg = { | |
1376 | .bdev = c->bdev, | |
1377 | .sector = block_to_sector(c, block), | |
1378 | .count = block_to_sector(c, count), | |
1379 | }; | |
1380 | ||
1381 | BUG_ON(dm_bufio_in_request()); | |
1382 | ||
1383 | return dm_io(&io_req, 1, &io_reg, NULL); | |
1384 | } | |
1385 | EXPORT_SYMBOL_GPL(dm_bufio_issue_discard); | |
1386 | ||
95d402f0 MP |
1387 | /* |
1388 | * We first delete any other buffer that may be at that new location. | |
1389 | * | |
1390 | * Then, we write the buffer to the original location if it was dirty. | |
1391 | * | |
1392 | * Then, if we are the only one who is holding the buffer, relink the buffer | |
ef992373 | 1393 | * in the buffer tree for the new location. |
95d402f0 MP |
1394 | * |
1395 | * If there was someone else holding the buffer, we write it to the new | |
1396 | * location but not relink it, because that other user needs to have the buffer | |
1397 | * at the same place. | |
1398 | */ | |
1399 | void dm_bufio_release_move(struct dm_buffer *b, sector_t new_block) | |
1400 | { | |
1401 | struct dm_bufio_client *c = b->c; | |
1402 | struct dm_buffer *new; | |
1403 | ||
1404 | BUG_ON(dm_bufio_in_request()); | |
1405 | ||
1406 | dm_bufio_lock(c); | |
1407 | ||
1408 | retry: | |
1409 | new = __find(c, new_block); | |
1410 | if (new) { | |
1411 | if (new->hold_count) { | |
1412 | __wait_for_free_buffer(c); | |
1413 | goto retry; | |
1414 | } | |
1415 | ||
1416 | /* | |
1417 | * FIXME: Is there any point waiting for a write that's going | |
1418 | * to be overwritten in a bit? | |
1419 | */ | |
1420 | __make_buffer_clean(new); | |
1421 | __unlink_buffer(new); | |
1422 | __free_buffer_wake(new); | |
1423 | } | |
1424 | ||
1425 | BUG_ON(!b->hold_count); | |
1426 | BUG_ON(test_bit(B_READING, &b->state)); | |
1427 | ||
2480945c | 1428 | __write_dirty_buffer(b, NULL); |
95d402f0 | 1429 | if (b->hold_count == 1) { |
74316201 N |
1430 | wait_on_bit_io(&b->state, B_WRITING, |
1431 | TASK_UNINTERRUPTIBLE); | |
95d402f0 | 1432 | set_bit(B_DIRTY, &b->state); |
1e3b21c6 MP |
1433 | b->dirty_start = 0; |
1434 | b->dirty_end = c->block_size; | |
95d402f0 MP |
1435 | __unlink_buffer(b); |
1436 | __link_buffer(b, new_block, LIST_DIRTY); | |
1437 | } else { | |
1438 | sector_t old_block; | |
74316201 N |
1439 | wait_on_bit_lock_io(&b->state, B_WRITING, |
1440 | TASK_UNINTERRUPTIBLE); | |
95d402f0 MP |
1441 | /* |
1442 | * Relink buffer to "new_block" so that write_callback | |
1443 | * sees "new_block" as a block number. | |
1444 | * After the write, link the buffer back to old_block. | |
1445 | * All this must be done in bufio lock, so that block number | |
1446 | * change isn't visible to other threads. | |
1447 | */ | |
1448 | old_block = b->block; | |
1449 | __unlink_buffer(b); | |
1450 | __link_buffer(b, new_block, b->list_mode); | |
905be0a1 | 1451 | submit_io(b, REQ_OP_WRITE, write_endio); |
74316201 N |
1452 | wait_on_bit_io(&b->state, B_WRITING, |
1453 | TASK_UNINTERRUPTIBLE); | |
95d402f0 MP |
1454 | __unlink_buffer(b); |
1455 | __link_buffer(b, old_block, b->list_mode); | |
1456 | } | |
1457 | ||
1458 | dm_bufio_unlock(c); | |
1459 | dm_bufio_release(b); | |
1460 | } | |
1461 | EXPORT_SYMBOL_GPL(dm_bufio_release_move); | |
1462 | ||
33a18062 MP |
1463 | static void forget_buffer_locked(struct dm_buffer *b) |
1464 | { | |
1465 | if (likely(!b->hold_count) && likely(!b->state)) { | |
1466 | __unlink_buffer(b); | |
1467 | __free_buffer_wake(b); | |
1468 | } | |
1469 | } | |
1470 | ||
55494bf2 MP |
1471 | /* |
1472 | * Free the given buffer. | |
1473 | * | |
1474 | * This is just a hint, if the buffer is in use or dirty, this function | |
1475 | * does nothing. | |
1476 | */ | |
1477 | void dm_bufio_forget(struct dm_bufio_client *c, sector_t block) | |
1478 | { | |
1479 | struct dm_buffer *b; | |
1480 | ||
1481 | dm_bufio_lock(c); | |
1482 | ||
1483 | b = __find(c, block); | |
33a18062 MP |
1484 | if (b) |
1485 | forget_buffer_locked(b); | |
55494bf2 MP |
1486 | |
1487 | dm_bufio_unlock(c); | |
1488 | } | |
afa53df8 | 1489 | EXPORT_SYMBOL_GPL(dm_bufio_forget); |
55494bf2 | 1490 | |
33a18062 MP |
1491 | void dm_bufio_forget_buffers(struct dm_bufio_client *c, sector_t block, sector_t n_blocks) |
1492 | { | |
1493 | struct dm_buffer *b; | |
1494 | sector_t end_block = block + n_blocks; | |
1495 | ||
1496 | while (block < end_block) { | |
1497 | dm_bufio_lock(c); | |
1498 | ||
1499 | b = __find_next(c, block); | |
1500 | if (b) { | |
1501 | block = b->block + 1; | |
1502 | forget_buffer_locked(b); | |
1503 | } | |
1504 | ||
1505 | dm_bufio_unlock(c); | |
1506 | ||
1507 | if (!b) | |
1508 | break; | |
1509 | } | |
1510 | ||
1511 | } | |
1512 | EXPORT_SYMBOL_GPL(dm_bufio_forget_buffers); | |
1513 | ||
55b082e6 MP |
1514 | void dm_bufio_set_minimum_buffers(struct dm_bufio_client *c, unsigned n) |
1515 | { | |
1516 | c->minimum_buffers = n; | |
1517 | } | |
afa53df8 | 1518 | EXPORT_SYMBOL_GPL(dm_bufio_set_minimum_buffers); |
55b082e6 | 1519 | |
95d402f0 MP |
1520 | unsigned dm_bufio_get_block_size(struct dm_bufio_client *c) |
1521 | { | |
1522 | return c->block_size; | |
1523 | } | |
1524 | EXPORT_SYMBOL_GPL(dm_bufio_get_block_size); | |
1525 | ||
1526 | sector_t dm_bufio_get_device_size(struct dm_bufio_client *c) | |
1527 | { | |
f51f2e0a | 1528 | sector_t s = i_size_read(c->bdev->bd_inode) >> SECTOR_SHIFT; |
a14e5ec6 MP |
1529 | if (s >= c->start) |
1530 | s -= c->start; | |
1531 | else | |
1532 | s = 0; | |
f51f2e0a MP |
1533 | if (likely(c->sectors_per_block_bits >= 0)) |
1534 | s >>= c->sectors_per_block_bits; | |
1535 | else | |
1536 | sector_div(s, c->block_size >> SECTOR_SHIFT); | |
1537 | return s; | |
95d402f0 MP |
1538 | } |
1539 | EXPORT_SYMBOL_GPL(dm_bufio_get_device_size); | |
1540 | ||
9b594826 MP |
1541 | struct dm_io_client *dm_bufio_get_dm_io_client(struct dm_bufio_client *c) |
1542 | { | |
1543 | return c->dm_io; | |
1544 | } | |
1545 | EXPORT_SYMBOL_GPL(dm_bufio_get_dm_io_client); | |
1546 | ||
95d402f0 MP |
1547 | sector_t dm_bufio_get_block_number(struct dm_buffer *b) |
1548 | { | |
1549 | return b->block; | |
1550 | } | |
1551 | EXPORT_SYMBOL_GPL(dm_bufio_get_block_number); | |
1552 | ||
1553 | void *dm_bufio_get_block_data(struct dm_buffer *b) | |
1554 | { | |
1555 | return b->data; | |
1556 | } | |
1557 | EXPORT_SYMBOL_GPL(dm_bufio_get_block_data); | |
1558 | ||
1559 | void *dm_bufio_get_aux_data(struct dm_buffer *b) | |
1560 | { | |
1561 | return b + 1; | |
1562 | } | |
1563 | EXPORT_SYMBOL_GPL(dm_bufio_get_aux_data); | |
1564 | ||
1565 | struct dm_bufio_client *dm_bufio_get_client(struct dm_buffer *b) | |
1566 | { | |
1567 | return b->c; | |
1568 | } | |
1569 | EXPORT_SYMBOL_GPL(dm_bufio_get_client); | |
1570 | ||
1571 | static void drop_buffers(struct dm_bufio_client *c) | |
1572 | { | |
1573 | struct dm_buffer *b; | |
1574 | int i; | |
86bad0c7 | 1575 | bool warned = false; |
95d402f0 MP |
1576 | |
1577 | BUG_ON(dm_bufio_in_request()); | |
1578 | ||
1579 | /* | |
1580 | * An optimization so that the buffers are not written one-by-one. | |
1581 | */ | |
1582 | dm_bufio_write_dirty_buffers_async(c); | |
1583 | ||
1584 | dm_bufio_lock(c); | |
1585 | ||
1586 | while ((b = __get_unclaimed_buffer(c))) | |
1587 | __free_buffer_wake(b); | |
1588 | ||
1589 | for (i = 0; i < LIST_SIZE; i++) | |
86bad0c7 MP |
1590 | list_for_each_entry(b, &c->lru[i], lru_list) { |
1591 | WARN_ON(!warned); | |
1592 | warned = true; | |
95d402f0 MP |
1593 | DMERR("leaked buffer %llx, hold count %u, list %d", |
1594 | (unsigned long long)b->block, b->hold_count, i); | |
86bad0c7 | 1595 | #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING |
741b58f3 TG |
1596 | stack_trace_print(b->stack_entries, b->stack_len, 1); |
1597 | /* mark unclaimed to avoid BUG_ON below */ | |
1598 | b->hold_count = 0; | |
86bad0c7 MP |
1599 | #endif |
1600 | } | |
1601 | ||
1602 | #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING | |
1603 | while ((b = __get_unclaimed_buffer(c))) | |
1604 | __free_buffer_wake(b); | |
1605 | #endif | |
95d402f0 MP |
1606 | |
1607 | for (i = 0; i < LIST_SIZE; i++) | |
1608 | BUG_ON(!list_empty(&c->lru[i])); | |
1609 | ||
1610 | dm_bufio_unlock(c); | |
1611 | } | |
1612 | ||
1613 | /* | |
33096a78 JT |
1614 | * We may not be able to evict this buffer if IO pending or the client |
1615 | * is still using it. Caller is expected to know buffer is too old. | |
1616 | * | |
9d28eb12 MP |
1617 | * And if GFP_NOFS is used, we must not do any I/O because we hold |
1618 | * dm_bufio_clients_lock and we would risk deadlock if the I/O gets | |
1619 | * rerouted to different bufio client. | |
95d402f0 | 1620 | */ |
33096a78 | 1621 | static bool __try_evict_buffer(struct dm_buffer *b, gfp_t gfp) |
95d402f0 | 1622 | { |
9d28eb12 | 1623 | if (!(gfp & __GFP_FS)) { |
95d402f0 MP |
1624 | if (test_bit(B_READING, &b->state) || |
1625 | test_bit(B_WRITING, &b->state) || | |
1626 | test_bit(B_DIRTY, &b->state)) | |
33096a78 | 1627 | return false; |
95d402f0 MP |
1628 | } |
1629 | ||
1630 | if (b->hold_count) | |
33096a78 | 1631 | return false; |
95d402f0 MP |
1632 | |
1633 | __make_buffer_clean(b); | |
1634 | __unlink_buffer(b); | |
1635 | __free_buffer_wake(b); | |
1636 | ||
33096a78 | 1637 | return true; |
95d402f0 MP |
1638 | } |
1639 | ||
13840d38 | 1640 | static unsigned long get_retain_buffers(struct dm_bufio_client *c) |
33096a78 | 1641 | { |
f51f2e0a MP |
1642 | unsigned long retain_bytes = READ_ONCE(dm_bufio_retain_bytes); |
1643 | if (likely(c->sectors_per_block_bits >= 0)) | |
1644 | retain_bytes >>= c->sectors_per_block_bits + SECTOR_SHIFT; | |
1645 | else | |
1646 | retain_bytes /= c->block_size; | |
1647 | return retain_bytes; | |
33096a78 JT |
1648 | } |
1649 | ||
70704c33 | 1650 | static void __scan(struct dm_bufio_client *c) |
95d402f0 MP |
1651 | { |
1652 | int l; | |
1653 | struct dm_buffer *b, *tmp; | |
33096a78 | 1654 | unsigned long freed = 0; |
fbc7c07e SB |
1655 | unsigned long count = c->n_buffers[LIST_CLEAN] + |
1656 | c->n_buffers[LIST_DIRTY]; | |
13840d38 | 1657 | unsigned long retain_target = get_retain_buffers(c); |
95d402f0 MP |
1658 | |
1659 | for (l = 0; l < LIST_SIZE; l++) { | |
7dc19d5a | 1660 | list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list) { |
70704c33 MP |
1661 | if (count - freed <= retain_target) |
1662 | atomic_long_set(&c->need_shrink, 0); | |
1663 | if (!atomic_long_read(&c->need_shrink)) | |
1664 | return; | |
1665 | if (__try_evict_buffer(b, GFP_KERNEL)) { | |
1666 | atomic_long_dec(&c->need_shrink); | |
33096a78 | 1667 | freed++; |
70704c33 | 1668 | } |
7cd32674 | 1669 | cond_resched(); |
7dc19d5a | 1670 | } |
95d402f0 MP |
1671 | } |
1672 | } | |
1673 | ||
70704c33 MP |
1674 | static void shrink_work(struct work_struct *w) |
1675 | { | |
1676 | struct dm_bufio_client *c = container_of(w, struct dm_bufio_client, shrink_work); | |
1677 | ||
1678 | dm_bufio_lock(c); | |
1679 | __scan(c); | |
1680 | dm_bufio_unlock(c); | |
1681 | } | |
1682 | ||
1683 | static unsigned long dm_bufio_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) | |
95d402f0 | 1684 | { |
7dc19d5a | 1685 | struct dm_bufio_client *c; |
95d402f0 | 1686 | |
7dc19d5a | 1687 | c = container_of(shrink, struct dm_bufio_client, shrinker); |
70704c33 MP |
1688 | atomic_long_add(sc->nr_to_scan, &c->need_shrink); |
1689 | queue_work(dm_bufio_wq, &c->shrink_work); | |
95d402f0 | 1690 | |
70704c33 | 1691 | return sc->nr_to_scan; |
7dc19d5a | 1692 | } |
95d402f0 | 1693 | |
70704c33 | 1694 | static unsigned long dm_bufio_shrink_count(struct shrinker *shrink, struct shrink_control *sc) |
7dc19d5a | 1695 | { |
d12067f4 | 1696 | struct dm_bufio_client *c = container_of(shrink, struct dm_bufio_client, shrinker); |
fbc7c07e SB |
1697 | unsigned long count = READ_ONCE(c->n_buffers[LIST_CLEAN]) + |
1698 | READ_ONCE(c->n_buffers[LIST_DIRTY]); | |
1699 | unsigned long retain_target = get_retain_buffers(c); | |
70704c33 MP |
1700 | unsigned long queued_for_cleanup = atomic_long_read(&c->need_shrink); |
1701 | ||
1702 | if (unlikely(count < retain_target)) | |
1703 | count = 0; | |
1704 | else | |
1705 | count -= retain_target; | |
95d402f0 | 1706 | |
70704c33 MP |
1707 | if (unlikely(count < queued_for_cleanup)) |
1708 | count = 0; | |
1709 | else | |
1710 | count -= queued_for_cleanup; | |
1711 | ||
1712 | return count; | |
95d402f0 MP |
1713 | } |
1714 | ||
1715 | /* | |
1716 | * Create the buffering interface | |
1717 | */ | |
1718 | struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsigned block_size, | |
1719 | unsigned reserved_buffers, unsigned aux_size, | |
1720 | void (*alloc_callback)(struct dm_buffer *), | |
1721 | void (*write_callback)(struct dm_buffer *)) | |
1722 | { | |
1723 | int r; | |
1724 | struct dm_bufio_client *c; | |
1725 | unsigned i; | |
359dbf19 | 1726 | char slab_name[27]; |
95d402f0 | 1727 | |
f51f2e0a MP |
1728 | if (!block_size || block_size & ((1 << SECTOR_SHIFT) - 1)) { |
1729 | DMERR("%s: block size not specified or is not multiple of 512b", __func__); | |
1730 | r = -EINVAL; | |
1731 | goto bad_client; | |
1732 | } | |
95d402f0 | 1733 | |
d8c712ea | 1734 | c = kzalloc(sizeof(*c), GFP_KERNEL); |
95d402f0 MP |
1735 | if (!c) { |
1736 | r = -ENOMEM; | |
1737 | goto bad_client; | |
1738 | } | |
4e420c45 | 1739 | c->buffer_tree = RB_ROOT; |
95d402f0 MP |
1740 | |
1741 | c->bdev = bdev; | |
1742 | c->block_size = block_size; | |
f51f2e0a MP |
1743 | if (is_power_of_2(block_size)) |
1744 | c->sectors_per_block_bits = __ffs(block_size) - SECTOR_SHIFT; | |
1745 | else | |
1746 | c->sectors_per_block_bits = -1; | |
95d402f0 | 1747 | |
95d402f0 MP |
1748 | c->alloc_callback = alloc_callback; |
1749 | c->write_callback = write_callback; | |
1750 | ||
1751 | for (i = 0; i < LIST_SIZE; i++) { | |
1752 | INIT_LIST_HEAD(&c->lru[i]); | |
1753 | c->n_buffers[i] = 0; | |
1754 | } | |
1755 | ||
95d402f0 MP |
1756 | mutex_init(&c->lock); |
1757 | INIT_LIST_HEAD(&c->reserved_buffers); | |
1758 | c->need_reserved_buffers = reserved_buffers; | |
1759 | ||
afa53df8 | 1760 | dm_bufio_set_minimum_buffers(c, DM_BUFIO_MIN_BUFFERS); |
55b082e6 | 1761 | |
95d402f0 MP |
1762 | init_waitqueue_head(&c->free_buffer_wait); |
1763 | c->async_write_error = 0; | |
1764 | ||
1765 | c->dm_io = dm_io_client_create(); | |
1766 | if (IS_ERR(c->dm_io)) { | |
1767 | r = PTR_ERR(c->dm_io); | |
1768 | goto bad_dm_io; | |
1769 | } | |
1770 | ||
f51f2e0a MP |
1771 | if (block_size <= KMALLOC_MAX_SIZE && |
1772 | (block_size < PAGE_SIZE || !is_power_of_2(block_size))) { | |
f7879b4c MP |
1773 | unsigned align = min(1U << __ffs(block_size), (unsigned)PAGE_SIZE); |
1774 | snprintf(slab_name, sizeof slab_name, "dm_bufio_cache-%u", block_size); | |
1775 | c->slab_cache = kmem_cache_create(slab_name, block_size, align, | |
6b5e718c | 1776 | SLAB_RECLAIM_ACCOUNT, NULL); |
21bb1327 MP |
1777 | if (!c->slab_cache) { |
1778 | r = -ENOMEM; | |
1779 | goto bad; | |
95d402f0 MP |
1780 | } |
1781 | } | |
359dbf19 MP |
1782 | if (aux_size) |
1783 | snprintf(slab_name, sizeof slab_name, "dm_bufio_buffer-%u", aux_size); | |
1784 | else | |
1785 | snprintf(slab_name, sizeof slab_name, "dm_bufio_buffer"); | |
1786 | c->slab_buffer = kmem_cache_create(slab_name, sizeof(struct dm_buffer) + aux_size, | |
1787 | 0, SLAB_RECLAIM_ACCOUNT, NULL); | |
1788 | if (!c->slab_buffer) { | |
1789 | r = -ENOMEM; | |
1790 | goto bad; | |
1791 | } | |
95d402f0 MP |
1792 | |
1793 | while (c->need_reserved_buffers) { | |
1794 | struct dm_buffer *b = alloc_buffer(c, GFP_KERNEL); | |
1795 | ||
1796 | if (!b) { | |
1797 | r = -ENOMEM; | |
0e696d38 | 1798 | goto bad; |
95d402f0 MP |
1799 | } |
1800 | __free_buffer_wake(b); | |
1801 | } | |
1802 | ||
70704c33 MP |
1803 | INIT_WORK(&c->shrink_work, shrink_work); |
1804 | atomic_long_set(&c->need_shrink, 0); | |
1805 | ||
46898e9a AK |
1806 | c->shrinker.count_objects = dm_bufio_shrink_count; |
1807 | c->shrinker.scan_objects = dm_bufio_shrink_scan; | |
1808 | c->shrinker.seeks = 1; | |
1809 | c->shrinker.batch = 0; | |
1810 | r = register_shrinker(&c->shrinker); | |
1811 | if (r) | |
0e696d38 | 1812 | goto bad; |
46898e9a | 1813 | |
95d402f0 MP |
1814 | mutex_lock(&dm_bufio_clients_lock); |
1815 | dm_bufio_client_count++; | |
1816 | list_add(&c->client_list, &dm_bufio_all_clients); | |
1817 | __cache_size_refresh(); | |
1818 | mutex_unlock(&dm_bufio_clients_lock); | |
1819 | ||
95d402f0 MP |
1820 | return c; |
1821 | ||
0e696d38 | 1822 | bad: |
95d402f0 MP |
1823 | while (!list_empty(&c->reserved_buffers)) { |
1824 | struct dm_buffer *b = list_entry(c->reserved_buffers.next, | |
1825 | struct dm_buffer, lru_list); | |
1826 | list_del(&b->lru_list); | |
1827 | free_buffer(b); | |
1828 | } | |
21bb1327 | 1829 | kmem_cache_destroy(c->slab_cache); |
359dbf19 | 1830 | kmem_cache_destroy(c->slab_buffer); |
95d402f0 MP |
1831 | dm_io_client_destroy(c->dm_io); |
1832 | bad_dm_io: | |
bde14184 | 1833 | mutex_destroy(&c->lock); |
95d402f0 MP |
1834 | kfree(c); |
1835 | bad_client: | |
1836 | return ERR_PTR(r); | |
1837 | } | |
1838 | EXPORT_SYMBOL_GPL(dm_bufio_client_create); | |
1839 | ||
1840 | /* | |
1841 | * Free the buffering interface. | |
1842 | * It is required that there are no references on any buffers. | |
1843 | */ | |
1844 | void dm_bufio_client_destroy(struct dm_bufio_client *c) | |
1845 | { | |
1846 | unsigned i; | |
1847 | ||
1848 | drop_buffers(c); | |
1849 | ||
1850 | unregister_shrinker(&c->shrinker); | |
70704c33 | 1851 | flush_work(&c->shrink_work); |
95d402f0 MP |
1852 | |
1853 | mutex_lock(&dm_bufio_clients_lock); | |
1854 | ||
1855 | list_del(&c->client_list); | |
1856 | dm_bufio_client_count--; | |
1857 | __cache_size_refresh(); | |
1858 | ||
1859 | mutex_unlock(&dm_bufio_clients_lock); | |
1860 | ||
4e420c45 | 1861 | BUG_ON(!RB_EMPTY_ROOT(&c->buffer_tree)); |
95d402f0 MP |
1862 | BUG_ON(c->need_reserved_buffers); |
1863 | ||
1864 | while (!list_empty(&c->reserved_buffers)) { | |
1865 | struct dm_buffer *b = list_entry(c->reserved_buffers.next, | |
1866 | struct dm_buffer, lru_list); | |
1867 | list_del(&b->lru_list); | |
1868 | free_buffer(b); | |
1869 | } | |
1870 | ||
1871 | for (i = 0; i < LIST_SIZE; i++) | |
1872 | if (c->n_buffers[i]) | |
1873 | DMERR("leaked buffer count %d: %ld", i, c->n_buffers[i]); | |
1874 | ||
1875 | for (i = 0; i < LIST_SIZE; i++) | |
1876 | BUG_ON(c->n_buffers[i]); | |
1877 | ||
21bb1327 | 1878 | kmem_cache_destroy(c->slab_cache); |
359dbf19 | 1879 | kmem_cache_destroy(c->slab_buffer); |
95d402f0 | 1880 | dm_io_client_destroy(c->dm_io); |
bde14184 | 1881 | mutex_destroy(&c->lock); |
95d402f0 MP |
1882 | kfree(c); |
1883 | } | |
1884 | EXPORT_SYMBOL_GPL(dm_bufio_client_destroy); | |
1885 | ||
400a0bef MP |
1886 | void dm_bufio_set_sector_offset(struct dm_bufio_client *c, sector_t start) |
1887 | { | |
1888 | c->start = start; | |
1889 | } | |
1890 | EXPORT_SYMBOL_GPL(dm_bufio_set_sector_offset); | |
1891 | ||
33096a78 | 1892 | static unsigned get_max_age_hz(void) |
95d402f0 | 1893 | { |
6aa7de05 | 1894 | unsigned max_age = READ_ONCE(dm_bufio_max_age); |
95d402f0 | 1895 | |
33096a78 JT |
1896 | if (max_age > UINT_MAX / HZ) |
1897 | max_age = UINT_MAX / HZ; | |
95d402f0 | 1898 | |
33096a78 JT |
1899 | return max_age * HZ; |
1900 | } | |
95d402f0 | 1901 | |
33096a78 JT |
1902 | static bool older_than(struct dm_buffer *b, unsigned long age_hz) |
1903 | { | |
f495339c | 1904 | return time_after_eq(jiffies, b->last_accessed + age_hz); |
33096a78 JT |
1905 | } |
1906 | ||
1907 | static void __evict_old_buffers(struct dm_bufio_client *c, unsigned long age_hz) | |
1908 | { | |
1909 | struct dm_buffer *b, *tmp; | |
13840d38 MP |
1910 | unsigned long retain_target = get_retain_buffers(c); |
1911 | unsigned long count; | |
390020ad | 1912 | LIST_HEAD(write_list); |
33096a78 JT |
1913 | |
1914 | dm_bufio_lock(c); | |
1915 | ||
390020ad MP |
1916 | __check_watermark(c, &write_list); |
1917 | if (unlikely(!list_empty(&write_list))) { | |
1918 | dm_bufio_unlock(c); | |
1919 | __flush_write_list(&write_list); | |
1920 | dm_bufio_lock(c); | |
1921 | } | |
1922 | ||
33096a78 JT |
1923 | count = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY]; |
1924 | list_for_each_entry_safe_reverse(b, tmp, &c->lru[LIST_CLEAN], lru_list) { | |
1925 | if (count <= retain_target) | |
1926 | break; | |
1927 | ||
1928 | if (!older_than(b, age_hz)) | |
1929 | break; | |
1930 | ||
1931 | if (__try_evict_buffer(b, 0)) | |
1932 | count--; | |
95d402f0 | 1933 | |
7cd32674 | 1934 | cond_resched(); |
95d402f0 | 1935 | } |
33096a78 JT |
1936 | |
1937 | dm_bufio_unlock(c); | |
1938 | } | |
1939 | ||
6e913b28 MP |
1940 | static void do_global_cleanup(struct work_struct *w) |
1941 | { | |
1942 | struct dm_bufio_client *locked_client = NULL; | |
1943 | struct dm_bufio_client *current_client; | |
1944 | struct dm_buffer *b; | |
1945 | unsigned spinlock_hold_count; | |
1946 | unsigned long threshold = dm_bufio_cache_size - | |
1947 | dm_bufio_cache_size / DM_BUFIO_LOW_WATERMARK_RATIO; | |
1948 | unsigned long loops = global_num * 2; | |
1949 | ||
1950 | mutex_lock(&dm_bufio_clients_lock); | |
1951 | ||
1952 | while (1) { | |
1953 | cond_resched(); | |
1954 | ||
1955 | spin_lock(&global_spinlock); | |
1956 | if (unlikely(dm_bufio_current_allocated <= threshold)) | |
1957 | break; | |
1958 | ||
1959 | spinlock_hold_count = 0; | |
1960 | get_next: | |
1961 | if (!loops--) | |
1962 | break; | |
1963 | if (unlikely(list_empty(&global_queue))) | |
1964 | break; | |
1965 | b = list_entry(global_queue.prev, struct dm_buffer, global_list); | |
1966 | ||
1967 | if (b->accessed) { | |
1968 | b->accessed = 0; | |
1969 | list_move(&b->global_list, &global_queue); | |
1970 | if (likely(++spinlock_hold_count < 16)) | |
1971 | goto get_next; | |
1972 | spin_unlock(&global_spinlock); | |
1973 | continue; | |
1974 | } | |
1975 | ||
1976 | current_client = b->c; | |
1977 | if (unlikely(current_client != locked_client)) { | |
1978 | if (locked_client) | |
1979 | dm_bufio_unlock(locked_client); | |
1980 | ||
1981 | if (!dm_bufio_trylock(current_client)) { | |
1982 | spin_unlock(&global_spinlock); | |
1983 | dm_bufio_lock(current_client); | |
1984 | locked_client = current_client; | |
1985 | continue; | |
1986 | } | |
1987 | ||
1988 | locked_client = current_client; | |
1989 | } | |
1990 | ||
1991 | spin_unlock(&global_spinlock); | |
1992 | ||
1993 | if (unlikely(!__try_evict_buffer(b, GFP_KERNEL))) { | |
1994 | spin_lock(&global_spinlock); | |
1995 | list_move(&b->global_list, &global_queue); | |
1996 | spin_unlock(&global_spinlock); | |
1997 | } | |
1998 | } | |
1999 | ||
2000 | spin_unlock(&global_spinlock); | |
2001 | ||
2002 | if (locked_client) | |
2003 | dm_bufio_unlock(locked_client); | |
2004 | ||
2005 | mutex_unlock(&dm_bufio_clients_lock); | |
2006 | } | |
2007 | ||
33096a78 JT |
2008 | static void cleanup_old_buffers(void) |
2009 | { | |
2010 | unsigned long max_age_hz = get_max_age_hz(); | |
2011 | struct dm_bufio_client *c; | |
2012 | ||
2013 | mutex_lock(&dm_bufio_clients_lock); | |
2014 | ||
390020ad MP |
2015 | __cache_size_refresh(); |
2016 | ||
33096a78 JT |
2017 | list_for_each_entry(c, &dm_bufio_all_clients, client_list) |
2018 | __evict_old_buffers(c, max_age_hz); | |
2019 | ||
95d402f0 MP |
2020 | mutex_unlock(&dm_bufio_clients_lock); |
2021 | } | |
2022 | ||
95d402f0 MP |
2023 | static void work_fn(struct work_struct *w) |
2024 | { | |
2025 | cleanup_old_buffers(); | |
2026 | ||
6e913b28 | 2027 | queue_delayed_work(dm_bufio_wq, &dm_bufio_cleanup_old_work, |
95d402f0 MP |
2028 | DM_BUFIO_WORK_TIMER_SECS * HZ); |
2029 | } | |
2030 | ||
2031 | /*---------------------------------------------------------------- | |
2032 | * Module setup | |
2033 | *--------------------------------------------------------------*/ | |
2034 | ||
2035 | /* | |
2036 | * This is called only once for the whole dm_bufio module. | |
2037 | * It initializes memory limit. | |
2038 | */ | |
2039 | static int __init dm_bufio_init(void) | |
2040 | { | |
2041 | __u64 mem; | |
2042 | ||
4cb57ab4 MP |
2043 | dm_bufio_allocated_kmem_cache = 0; |
2044 | dm_bufio_allocated_get_free_pages = 0; | |
2045 | dm_bufio_allocated_vmalloc = 0; | |
2046 | dm_bufio_current_allocated = 0; | |
2047 | ||
ca79b0c2 | 2048 | mem = (__u64)mult_frac(totalram_pages() - totalhigh_pages(), |
74d4108d | 2049 | DM_BUFIO_MEMORY_PERCENT, 100) << PAGE_SHIFT; |
95d402f0 MP |
2050 | |
2051 | if (mem > ULONG_MAX) | |
2052 | mem = ULONG_MAX; | |
2053 | ||
2054 | #ifdef CONFIG_MMU | |
74d4108d EB |
2055 | if (mem > mult_frac(VMALLOC_TOTAL, DM_BUFIO_VMALLOC_PERCENT, 100)) |
2056 | mem = mult_frac(VMALLOC_TOTAL, DM_BUFIO_VMALLOC_PERCENT, 100); | |
95d402f0 MP |
2057 | #endif |
2058 | ||
2059 | dm_bufio_default_cache_size = mem; | |
2060 | ||
2061 | mutex_lock(&dm_bufio_clients_lock); | |
2062 | __cache_size_refresh(); | |
2063 | mutex_unlock(&dm_bufio_clients_lock); | |
2064 | ||
edd1ea2a | 2065 | dm_bufio_wq = alloc_workqueue("dm_bufio_cache", WQ_MEM_RECLAIM, 0); |
95d402f0 MP |
2066 | if (!dm_bufio_wq) |
2067 | return -ENOMEM; | |
2068 | ||
6e913b28 MP |
2069 | INIT_DELAYED_WORK(&dm_bufio_cleanup_old_work, work_fn); |
2070 | INIT_WORK(&dm_bufio_replacement_work, do_global_cleanup); | |
2071 | queue_delayed_work(dm_bufio_wq, &dm_bufio_cleanup_old_work, | |
95d402f0 MP |
2072 | DM_BUFIO_WORK_TIMER_SECS * HZ); |
2073 | ||
2074 | return 0; | |
2075 | } | |
2076 | ||
2077 | /* | |
2078 | * This is called once when unloading the dm_bufio module. | |
2079 | */ | |
2080 | static void __exit dm_bufio_exit(void) | |
2081 | { | |
2082 | int bug = 0; | |
95d402f0 | 2083 | |
6e913b28 MP |
2084 | cancel_delayed_work_sync(&dm_bufio_cleanup_old_work); |
2085 | flush_workqueue(dm_bufio_wq); | |
95d402f0 MP |
2086 | destroy_workqueue(dm_bufio_wq); |
2087 | ||
95d402f0 MP |
2088 | if (dm_bufio_client_count) { |
2089 | DMCRIT("%s: dm_bufio_client_count leaked: %d", | |
2090 | __func__, dm_bufio_client_count); | |
2091 | bug = 1; | |
2092 | } | |
2093 | ||
2094 | if (dm_bufio_current_allocated) { | |
2095 | DMCRIT("%s: dm_bufio_current_allocated leaked: %lu", | |
2096 | __func__, dm_bufio_current_allocated); | |
2097 | bug = 1; | |
2098 | } | |
2099 | ||
2100 | if (dm_bufio_allocated_get_free_pages) { | |
2101 | DMCRIT("%s: dm_bufio_allocated_get_free_pages leaked: %lu", | |
2102 | __func__, dm_bufio_allocated_get_free_pages); | |
2103 | bug = 1; | |
2104 | } | |
2105 | ||
2106 | if (dm_bufio_allocated_vmalloc) { | |
2107 | DMCRIT("%s: dm_bufio_vmalloc leaked: %lu", | |
2108 | __func__, dm_bufio_allocated_vmalloc); | |
2109 | bug = 1; | |
2110 | } | |
2111 | ||
86a49e2d | 2112 | BUG_ON(bug); |
95d402f0 MP |
2113 | } |
2114 | ||
2115 | module_init(dm_bufio_init) | |
2116 | module_exit(dm_bufio_exit) | |
2117 | ||
2118 | module_param_named(max_cache_size_bytes, dm_bufio_cache_size, ulong, S_IRUGO | S_IWUSR); | |
2119 | MODULE_PARM_DESC(max_cache_size_bytes, "Size of metadata cache"); | |
2120 | ||
2121 | module_param_named(max_age_seconds, dm_bufio_max_age, uint, S_IRUGO | S_IWUSR); | |
2122 | MODULE_PARM_DESC(max_age_seconds, "Max age of a buffer in seconds"); | |
33096a78 | 2123 | |
13840d38 | 2124 | module_param_named(retain_bytes, dm_bufio_retain_bytes, ulong, S_IRUGO | S_IWUSR); |
33096a78 | 2125 | MODULE_PARM_DESC(retain_bytes, "Try to keep at least this many bytes cached in memory"); |
95d402f0 MP |
2126 | |
2127 | module_param_named(peak_allocated_bytes, dm_bufio_peak_allocated, ulong, S_IRUGO | S_IWUSR); | |
2128 | MODULE_PARM_DESC(peak_allocated_bytes, "Tracks the maximum allocated memory"); | |
2129 | ||
2130 | module_param_named(allocated_kmem_cache_bytes, dm_bufio_allocated_kmem_cache, ulong, S_IRUGO); | |
2131 | MODULE_PARM_DESC(allocated_kmem_cache_bytes, "Memory allocated with kmem_cache_alloc"); | |
2132 | ||
2133 | module_param_named(allocated_get_free_pages_bytes, dm_bufio_allocated_get_free_pages, ulong, S_IRUGO); | |
2134 | MODULE_PARM_DESC(allocated_get_free_pages_bytes, "Memory allocated with get_free_pages"); | |
2135 | ||
2136 | module_param_named(allocated_vmalloc_bytes, dm_bufio_allocated_vmalloc, ulong, S_IRUGO); | |
2137 | MODULE_PARM_DESC(allocated_vmalloc_bytes, "Memory allocated with vmalloc"); | |
2138 | ||
2139 | module_param_named(current_allocated_bytes, dm_bufio_current_allocated, ulong, S_IRUGO); | |
2140 | MODULE_PARM_DESC(current_allocated_bytes, "Memory currently used by the cache"); | |
2141 | ||
2142 | MODULE_AUTHOR("Mikulas Patocka <dm-devel@redhat.com>"); | |
2143 | MODULE_DESCRIPTION(DM_NAME " buffered I/O library"); | |
2144 | MODULE_LICENSE("GPL"); |