Commit | Line | Data |
---|---|---|
306b0c95 | 1 | /* |
f1e3cfff | 2 | * Compressed RAM block device |
306b0c95 | 3 | * |
1130ebba | 4 | * Copyright (C) 2008, 2009, 2010 Nitin Gupta |
7bfb3de8 | 5 | * 2012, 2013 Minchan Kim |
306b0c95 NG |
6 | * |
7 | * This code is released using a dual license strategy: BSD/GPL | |
8 | * You can choose the licence that better fits your requirements. | |
9 | * | |
10 | * Released under the terms of 3-clause BSD License | |
11 | * Released under the terms of GNU General Public License Version 2.0 | |
12 | * | |
306b0c95 NG |
13 | */ |
14 | ||
f1e3cfff | 15 | #define KMSG_COMPONENT "zram" |
306b0c95 NG |
16 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
17 | ||
18 | #include <linux/module.h> | |
19 | #include <linux/kernel.h> | |
8946a086 | 20 | #include <linux/bio.h> |
306b0c95 NG |
21 | #include <linux/bitops.h> |
22 | #include <linux/blkdev.h> | |
23 | #include <linux/buffer_head.h> | |
24 | #include <linux/device.h> | |
25 | #include <linux/genhd.h> | |
26 | #include <linux/highmem.h> | |
5a0e3ad6 | 27 | #include <linux/slab.h> |
306b0c95 | 28 | #include <linux/string.h> |
306b0c95 | 29 | #include <linux/vmalloc.h> |
fcfa8d95 | 30 | #include <linux/err.h> |
85508ec6 | 31 | #include <linux/idr.h> |
306b0c95 | 32 | |
16a4bfb9 | 33 | #include "zram_drv.h" |
306b0c95 | 34 | |
85508ec6 | 35 | static DEFINE_IDR(zram_index_idr); |
f1e3cfff | 36 | static int zram_major; |
b7ca232e | 37 | static const char *default_compressor = "lzo"; |
306b0c95 | 38 | |
306b0c95 | 39 | /* Module params (documentation at end) */ |
ca3d70bd | 40 | static unsigned int num_devices = 1; |
33863c21 | 41 | |
8f7d282c SS |
42 | static inline void deprecated_attr_warn(const char *name) |
43 | { | |
44 | pr_warn_once("%d (%s) Attribute %s (and others) will be removed. %s\n", | |
45 | task_pid_nr(current), | |
46 | current->comm, | |
47 | name, | |
48 | "See zram documentation."); | |
49 | } | |
50 | ||
a68eb3b6 | 51 | #define ZRAM_ATTR_RO(name) \ |
3bca3ef7 | 52 | static ssize_t name##_show(struct device *d, \ |
a68eb3b6 SS |
53 | struct device_attribute *attr, char *b) \ |
54 | { \ | |
55 | struct zram *zram = dev_to_zram(d); \ | |
8f7d282c SS |
56 | \ |
57 | deprecated_attr_warn(__stringify(name)); \ | |
56b4e8cb | 58 | return scnprintf(b, PAGE_SIZE, "%llu\n", \ |
a68eb3b6 SS |
59 | (u64)atomic64_read(&zram->stats.name)); \ |
60 | } \ | |
083914ea | 61 | static DEVICE_ATTR_RO(name); |
a68eb3b6 | 62 | |
08eee69f | 63 | static inline bool init_done(struct zram *zram) |
be2d1d56 | 64 | { |
08eee69f | 65 | return zram->disksize; |
be2d1d56 SS |
66 | } |
67 | ||
9b3bb7ab SS |
68 | static inline struct zram *dev_to_zram(struct device *dev) |
69 | { | |
70 | return (struct zram *)dev_to_disk(dev)->private_data; | |
71 | } | |
72 | ||
b31177f2 | 73 | /* flag operations require table entry bit_spin_lock() being held */ |
522698d7 SS |
74 | static int zram_test_flag(struct zram_meta *meta, u32 index, |
75 | enum zram_pageflags flag) | |
99ebbd30 | 76 | { |
522698d7 SS |
77 | return meta->table[index].value & BIT(flag); |
78 | } | |
99ebbd30 | 79 | |
522698d7 SS |
80 | static void zram_set_flag(struct zram_meta *meta, u32 index, |
81 | enum zram_pageflags flag) | |
82 | { | |
83 | meta->table[index].value |= BIT(flag); | |
84 | } | |
99ebbd30 | 85 | |
522698d7 SS |
86 | static void zram_clear_flag(struct zram_meta *meta, u32 index, |
87 | enum zram_pageflags flag) | |
88 | { | |
89 | meta->table[index].value &= ~BIT(flag); | |
90 | } | |
99ebbd30 | 91 | |
522698d7 SS |
92 | static size_t zram_get_obj_size(struct zram_meta *meta, u32 index) |
93 | { | |
94 | return meta->table[index].value & (BIT(ZRAM_FLAG_SHIFT) - 1); | |
99ebbd30 AM |
95 | } |
96 | ||
522698d7 SS |
97 | static void zram_set_obj_size(struct zram_meta *meta, |
98 | u32 index, size_t size) | |
9b3bb7ab | 99 | { |
522698d7 | 100 | unsigned long flags = meta->table[index].value >> ZRAM_FLAG_SHIFT; |
9b3bb7ab | 101 | |
522698d7 SS |
102 | meta->table[index].value = (flags << ZRAM_FLAG_SHIFT) | size; |
103 | } | |
104 | ||
105 | static inline int is_partial_io(struct bio_vec *bvec) | |
106 | { | |
107 | return bvec->bv_len != PAGE_SIZE; | |
108 | } | |
109 | ||
110 | /* | |
111 | * Check if request is within bounds and aligned on zram logical blocks. | |
112 | */ | |
113 | static inline int valid_io_request(struct zram *zram, | |
114 | sector_t start, unsigned int size) | |
115 | { | |
116 | u64 end, bound; | |
117 | ||
118 | /* unaligned request */ | |
119 | if (unlikely(start & (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1))) | |
120 | return 0; | |
121 | if (unlikely(size & (ZRAM_LOGICAL_BLOCK_SIZE - 1))) | |
122 | return 0; | |
123 | ||
124 | end = start + (size >> SECTOR_SHIFT); | |
125 | bound = zram->disksize >> SECTOR_SHIFT; | |
126 | /* out of range range */ | |
127 | if (unlikely(start >= bound || end > bound || start > end)) | |
128 | return 0; | |
129 | ||
130 | /* I/O request is valid */ | |
131 | return 1; | |
132 | } | |
133 | ||
134 | static void update_position(u32 *index, int *offset, struct bio_vec *bvec) | |
135 | { | |
136 | if (*offset + bvec->bv_len >= PAGE_SIZE) | |
137 | (*index)++; | |
138 | *offset = (*offset + bvec->bv_len) % PAGE_SIZE; | |
139 | } | |
140 | ||
141 | static inline void update_used_max(struct zram *zram, | |
142 | const unsigned long pages) | |
143 | { | |
144 | unsigned long old_max, cur_max; | |
145 | ||
146 | old_max = atomic_long_read(&zram->stats.max_used_pages); | |
147 | ||
148 | do { | |
149 | cur_max = old_max; | |
150 | if (pages > cur_max) | |
151 | old_max = atomic_long_cmpxchg( | |
152 | &zram->stats.max_used_pages, cur_max, pages); | |
153 | } while (old_max != cur_max); | |
154 | } | |
155 | ||
156 | static int page_zero_filled(void *ptr) | |
157 | { | |
158 | unsigned int pos; | |
159 | unsigned long *page; | |
160 | ||
161 | page = (unsigned long *)ptr; | |
162 | ||
163 | for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) { | |
164 | if (page[pos]) | |
165 | return 0; | |
166 | } | |
167 | ||
168 | return 1; | |
169 | } | |
170 | ||
171 | static void handle_zero_page(struct bio_vec *bvec) | |
172 | { | |
173 | struct page *page = bvec->bv_page; | |
174 | void *user_mem; | |
175 | ||
176 | user_mem = kmap_atomic(page); | |
177 | if (is_partial_io(bvec)) | |
178 | memset(user_mem + bvec->bv_offset, 0, bvec->bv_len); | |
179 | else | |
180 | clear_page(user_mem); | |
181 | kunmap_atomic(user_mem); | |
182 | ||
183 | flush_dcache_page(page); | |
9b3bb7ab SS |
184 | } |
185 | ||
186 | static ssize_t initstate_show(struct device *dev, | |
187 | struct device_attribute *attr, char *buf) | |
188 | { | |
a68eb3b6 | 189 | u32 val; |
9b3bb7ab SS |
190 | struct zram *zram = dev_to_zram(dev); |
191 | ||
a68eb3b6 SS |
192 | down_read(&zram->init_lock); |
193 | val = init_done(zram); | |
194 | up_read(&zram->init_lock); | |
9b3bb7ab | 195 | |
56b4e8cb | 196 | return scnprintf(buf, PAGE_SIZE, "%u\n", val); |
9b3bb7ab SS |
197 | } |
198 | ||
522698d7 SS |
199 | static ssize_t disksize_show(struct device *dev, |
200 | struct device_attribute *attr, char *buf) | |
201 | { | |
202 | struct zram *zram = dev_to_zram(dev); | |
203 | ||
204 | return scnprintf(buf, PAGE_SIZE, "%llu\n", zram->disksize); | |
205 | } | |
206 | ||
9b3bb7ab SS |
207 | static ssize_t orig_data_size_show(struct device *dev, |
208 | struct device_attribute *attr, char *buf) | |
209 | { | |
210 | struct zram *zram = dev_to_zram(dev); | |
211 | ||
8f7d282c | 212 | deprecated_attr_warn("orig_data_size"); |
56b4e8cb | 213 | return scnprintf(buf, PAGE_SIZE, "%llu\n", |
90a7806e | 214 | (u64)(atomic64_read(&zram->stats.pages_stored)) << PAGE_SHIFT); |
9b3bb7ab SS |
215 | } |
216 | ||
9b3bb7ab SS |
217 | static ssize_t mem_used_total_show(struct device *dev, |
218 | struct device_attribute *attr, char *buf) | |
219 | { | |
220 | u64 val = 0; | |
221 | struct zram *zram = dev_to_zram(dev); | |
9b3bb7ab | 222 | |
8f7d282c | 223 | deprecated_attr_warn("mem_used_total"); |
9b3bb7ab | 224 | down_read(&zram->init_lock); |
5a99e95b WY |
225 | if (init_done(zram)) { |
226 | struct zram_meta *meta = zram->meta; | |
722cdc17 | 227 | val = zs_get_total_pages(meta->mem_pool); |
5a99e95b | 228 | } |
9b3bb7ab SS |
229 | up_read(&zram->init_lock); |
230 | ||
722cdc17 | 231 | return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT); |
9b3bb7ab SS |
232 | } |
233 | ||
9ada9da9 MK |
234 | static ssize_t mem_limit_show(struct device *dev, |
235 | struct device_attribute *attr, char *buf) | |
236 | { | |
237 | u64 val; | |
238 | struct zram *zram = dev_to_zram(dev); | |
239 | ||
8f7d282c | 240 | deprecated_attr_warn("mem_limit"); |
9ada9da9 MK |
241 | down_read(&zram->init_lock); |
242 | val = zram->limit_pages; | |
243 | up_read(&zram->init_lock); | |
244 | ||
245 | return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT); | |
246 | } | |
247 | ||
248 | static ssize_t mem_limit_store(struct device *dev, | |
249 | struct device_attribute *attr, const char *buf, size_t len) | |
250 | { | |
251 | u64 limit; | |
252 | char *tmp; | |
253 | struct zram *zram = dev_to_zram(dev); | |
254 | ||
255 | limit = memparse(buf, &tmp); | |
256 | if (buf == tmp) /* no chars parsed, invalid input */ | |
257 | return -EINVAL; | |
258 | ||
259 | down_write(&zram->init_lock); | |
260 | zram->limit_pages = PAGE_ALIGN(limit) >> PAGE_SHIFT; | |
261 | up_write(&zram->init_lock); | |
262 | ||
263 | return len; | |
264 | } | |
265 | ||
461a8eee MK |
266 | static ssize_t mem_used_max_show(struct device *dev, |
267 | struct device_attribute *attr, char *buf) | |
268 | { | |
269 | u64 val = 0; | |
270 | struct zram *zram = dev_to_zram(dev); | |
271 | ||
8f7d282c | 272 | deprecated_attr_warn("mem_used_max"); |
461a8eee MK |
273 | down_read(&zram->init_lock); |
274 | if (init_done(zram)) | |
275 | val = atomic_long_read(&zram->stats.max_used_pages); | |
276 | up_read(&zram->init_lock); | |
277 | ||
278 | return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT); | |
279 | } | |
280 | ||
281 | static ssize_t mem_used_max_store(struct device *dev, | |
282 | struct device_attribute *attr, const char *buf, size_t len) | |
283 | { | |
284 | int err; | |
285 | unsigned long val; | |
286 | struct zram *zram = dev_to_zram(dev); | |
461a8eee MK |
287 | |
288 | err = kstrtoul(buf, 10, &val); | |
289 | if (err || val != 0) | |
290 | return -EINVAL; | |
291 | ||
292 | down_read(&zram->init_lock); | |
5a99e95b WY |
293 | if (init_done(zram)) { |
294 | struct zram_meta *meta = zram->meta; | |
461a8eee MK |
295 | atomic_long_set(&zram->stats.max_used_pages, |
296 | zs_get_total_pages(meta->mem_pool)); | |
5a99e95b | 297 | } |
461a8eee MK |
298 | up_read(&zram->init_lock); |
299 | ||
300 | return len; | |
301 | } | |
302 | ||
522698d7 SS |
303 | static ssize_t max_comp_streams_show(struct device *dev, |
304 | struct device_attribute *attr, char *buf) | |
305 | { | |
306 | int val; | |
307 | struct zram *zram = dev_to_zram(dev); | |
308 | ||
309 | down_read(&zram->init_lock); | |
310 | val = zram->max_comp_streams; | |
311 | up_read(&zram->init_lock); | |
312 | ||
313 | return scnprintf(buf, PAGE_SIZE, "%d\n", val); | |
314 | } | |
315 | ||
beca3ec7 SS |
316 | static ssize_t max_comp_streams_store(struct device *dev, |
317 | struct device_attribute *attr, const char *buf, size_t len) | |
318 | { | |
319 | int num; | |
320 | struct zram *zram = dev_to_zram(dev); | |
60a726e3 | 321 | int ret; |
beca3ec7 | 322 | |
60a726e3 MK |
323 | ret = kstrtoint(buf, 0, &num); |
324 | if (ret < 0) | |
325 | return ret; | |
beca3ec7 SS |
326 | if (num < 1) |
327 | return -EINVAL; | |
60a726e3 | 328 | |
beca3ec7 SS |
329 | down_write(&zram->init_lock); |
330 | if (init_done(zram)) { | |
60a726e3 | 331 | if (!zcomp_set_max_streams(zram->comp, num)) { |
fe8eb122 | 332 | pr_info("Cannot change max compression streams\n"); |
60a726e3 MK |
333 | ret = -EINVAL; |
334 | goto out; | |
335 | } | |
beca3ec7 | 336 | } |
60a726e3 | 337 | |
beca3ec7 | 338 | zram->max_comp_streams = num; |
60a726e3 MK |
339 | ret = len; |
340 | out: | |
beca3ec7 | 341 | up_write(&zram->init_lock); |
60a726e3 | 342 | return ret; |
beca3ec7 SS |
343 | } |
344 | ||
e46b8a03 SS |
345 | static ssize_t comp_algorithm_show(struct device *dev, |
346 | struct device_attribute *attr, char *buf) | |
347 | { | |
348 | size_t sz; | |
349 | struct zram *zram = dev_to_zram(dev); | |
350 | ||
351 | down_read(&zram->init_lock); | |
352 | sz = zcomp_available_show(zram->compressor, buf); | |
353 | up_read(&zram->init_lock); | |
354 | ||
355 | return sz; | |
356 | } | |
357 | ||
358 | static ssize_t comp_algorithm_store(struct device *dev, | |
359 | struct device_attribute *attr, const char *buf, size_t len) | |
360 | { | |
361 | struct zram *zram = dev_to_zram(dev); | |
362 | down_write(&zram->init_lock); | |
363 | if (init_done(zram)) { | |
364 | up_write(&zram->init_lock); | |
365 | pr_info("Can't change algorithm for initialized device\n"); | |
366 | return -EBUSY; | |
367 | } | |
368 | strlcpy(zram->compressor, buf, sizeof(zram->compressor)); | |
369 | up_write(&zram->init_lock); | |
370 | return len; | |
371 | } | |
372 | ||
522698d7 SS |
373 | static ssize_t compact_store(struct device *dev, |
374 | struct device_attribute *attr, const char *buf, size_t len) | |
306b0c95 | 375 | { |
522698d7 SS |
376 | unsigned long nr_migrated; |
377 | struct zram *zram = dev_to_zram(dev); | |
378 | struct zram_meta *meta; | |
306b0c95 | 379 | |
522698d7 SS |
380 | down_read(&zram->init_lock); |
381 | if (!init_done(zram)) { | |
382 | up_read(&zram->init_lock); | |
383 | return -EINVAL; | |
384 | } | |
306b0c95 | 385 | |
522698d7 SS |
386 | meta = zram->meta; |
387 | nr_migrated = zs_compact(meta->mem_pool); | |
388 | atomic64_add(nr_migrated, &zram->stats.num_migrated); | |
389 | up_read(&zram->init_lock); | |
d2d5e762 | 390 | |
522698d7 | 391 | return len; |
d2d5e762 WY |
392 | } |
393 | ||
522698d7 SS |
394 | static ssize_t io_stat_show(struct device *dev, |
395 | struct device_attribute *attr, char *buf) | |
d2d5e762 | 396 | { |
522698d7 SS |
397 | struct zram *zram = dev_to_zram(dev); |
398 | ssize_t ret; | |
d2d5e762 | 399 | |
522698d7 SS |
400 | down_read(&zram->init_lock); |
401 | ret = scnprintf(buf, PAGE_SIZE, | |
402 | "%8llu %8llu %8llu %8llu\n", | |
403 | (u64)atomic64_read(&zram->stats.failed_reads), | |
404 | (u64)atomic64_read(&zram->stats.failed_writes), | |
405 | (u64)atomic64_read(&zram->stats.invalid_io), | |
406 | (u64)atomic64_read(&zram->stats.notify_free)); | |
407 | up_read(&zram->init_lock); | |
306b0c95 | 408 | |
522698d7 | 409 | return ret; |
9b3bb7ab SS |
410 | } |
411 | ||
522698d7 SS |
412 | static ssize_t mm_stat_show(struct device *dev, |
413 | struct device_attribute *attr, char *buf) | |
9b3bb7ab | 414 | { |
522698d7 SS |
415 | struct zram *zram = dev_to_zram(dev); |
416 | u64 orig_size, mem_used = 0; | |
417 | long max_used; | |
418 | ssize_t ret; | |
a539c72a | 419 | |
522698d7 SS |
420 | down_read(&zram->init_lock); |
421 | if (init_done(zram)) | |
422 | mem_used = zs_get_total_pages(zram->meta->mem_pool); | |
9b3bb7ab | 423 | |
522698d7 SS |
424 | orig_size = atomic64_read(&zram->stats.pages_stored); |
425 | max_used = atomic_long_read(&zram->stats.max_used_pages); | |
9b3bb7ab | 426 | |
522698d7 SS |
427 | ret = scnprintf(buf, PAGE_SIZE, |
428 | "%8llu %8llu %8llu %8lu %8ld %8llu %8llu\n", | |
429 | orig_size << PAGE_SHIFT, | |
430 | (u64)atomic64_read(&zram->stats.compr_data_size), | |
431 | mem_used << PAGE_SHIFT, | |
432 | zram->limit_pages << PAGE_SHIFT, | |
433 | max_used << PAGE_SHIFT, | |
434 | (u64)atomic64_read(&zram->stats.zero_pages), | |
435 | (u64)atomic64_read(&zram->stats.num_migrated)); | |
436 | up_read(&zram->init_lock); | |
9b3bb7ab | 437 | |
522698d7 SS |
438 | return ret; |
439 | } | |
440 | ||
441 | static DEVICE_ATTR_RO(io_stat); | |
442 | static DEVICE_ATTR_RO(mm_stat); | |
443 | ZRAM_ATTR_RO(num_reads); | |
444 | ZRAM_ATTR_RO(num_writes); | |
445 | ZRAM_ATTR_RO(failed_reads); | |
446 | ZRAM_ATTR_RO(failed_writes); | |
447 | ZRAM_ATTR_RO(invalid_io); | |
448 | ZRAM_ATTR_RO(notify_free); | |
449 | ZRAM_ATTR_RO(zero_pages); | |
450 | ZRAM_ATTR_RO(compr_data_size); | |
451 | ||
452 | static inline bool zram_meta_get(struct zram *zram) | |
453 | { | |
454 | if (atomic_inc_not_zero(&zram->refcount)) | |
455 | return true; | |
456 | return false; | |
457 | } | |
458 | ||
459 | static inline void zram_meta_put(struct zram *zram) | |
460 | { | |
461 | atomic_dec(&zram->refcount); | |
462 | } | |
463 | ||
464 | static void zram_meta_free(struct zram_meta *meta, u64 disksize) | |
465 | { | |
466 | size_t num_pages = disksize >> PAGE_SHIFT; | |
467 | size_t index; | |
1fec1172 GM |
468 | |
469 | /* Free all pages that are still in this zram device */ | |
470 | for (index = 0; index < num_pages; index++) { | |
471 | unsigned long handle = meta->table[index].handle; | |
472 | ||
473 | if (!handle) | |
474 | continue; | |
475 | ||
476 | zs_free(meta->mem_pool, handle); | |
477 | } | |
478 | ||
9b3bb7ab | 479 | zs_destroy_pool(meta->mem_pool); |
9b3bb7ab SS |
480 | vfree(meta->table); |
481 | kfree(meta); | |
482 | } | |
483 | ||
3eba0c6a | 484 | static struct zram_meta *zram_meta_alloc(int device_id, u64 disksize) |
9b3bb7ab SS |
485 | { |
486 | size_t num_pages; | |
3eba0c6a | 487 | char pool_name[8]; |
9b3bb7ab | 488 | struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL); |
b8179958 | 489 | |
9b3bb7ab | 490 | if (!meta) |
b8179958 | 491 | return NULL; |
9b3bb7ab | 492 | |
9b3bb7ab SS |
493 | num_pages = disksize >> PAGE_SHIFT; |
494 | meta->table = vzalloc(num_pages * sizeof(*meta->table)); | |
495 | if (!meta->table) { | |
496 | pr_err("Error allocating zram address table\n"); | |
b8179958 | 497 | goto out_error; |
9b3bb7ab SS |
498 | } |
499 | ||
3eba0c6a GM |
500 | snprintf(pool_name, sizeof(pool_name), "zram%d", device_id); |
501 | meta->mem_pool = zs_create_pool(pool_name, GFP_NOIO | __GFP_HIGHMEM); | |
9b3bb7ab SS |
502 | if (!meta->mem_pool) { |
503 | pr_err("Error creating memory pool\n"); | |
b8179958 | 504 | goto out_error; |
9b3bb7ab SS |
505 | } |
506 | ||
507 | return meta; | |
508 | ||
b8179958 | 509 | out_error: |
9b3bb7ab | 510 | vfree(meta->table); |
9b3bb7ab | 511 | kfree(meta); |
b8179958 | 512 | return NULL; |
9b3bb7ab SS |
513 | } |
514 | ||
d2d5e762 WY |
515 | /* |
516 | * To protect concurrent access to the same index entry, | |
517 | * caller should hold this table index entry's bit_spinlock to | |
518 | * indicate this index entry is accessing. | |
519 | */ | |
f1e3cfff | 520 | static void zram_free_page(struct zram *zram, size_t index) |
306b0c95 | 521 | { |
8b3cc3ed MK |
522 | struct zram_meta *meta = zram->meta; |
523 | unsigned long handle = meta->table[index].handle; | |
306b0c95 | 524 | |
fd1a30de | 525 | if (unlikely(!handle)) { |
2e882281 NG |
526 | /* |
527 | * No memory is allocated for zero filled pages. | |
528 | * Simply clear zero page flag. | |
529 | */ | |
8b3cc3ed MK |
530 | if (zram_test_flag(meta, index, ZRAM_ZERO)) { |
531 | zram_clear_flag(meta, index, ZRAM_ZERO); | |
90a7806e | 532 | atomic64_dec(&zram->stats.zero_pages); |
306b0c95 NG |
533 | } |
534 | return; | |
535 | } | |
536 | ||
8b3cc3ed | 537 | zs_free(meta->mem_pool, handle); |
306b0c95 | 538 | |
d2d5e762 WY |
539 | atomic64_sub(zram_get_obj_size(meta, index), |
540 | &zram->stats.compr_data_size); | |
90a7806e | 541 | atomic64_dec(&zram->stats.pages_stored); |
306b0c95 | 542 | |
8b3cc3ed | 543 | meta->table[index].handle = 0; |
d2d5e762 | 544 | zram_set_obj_size(meta, index, 0); |
306b0c95 NG |
545 | } |
546 | ||
37b51fdd | 547 | static int zram_decompress_page(struct zram *zram, char *mem, u32 index) |
306b0c95 | 548 | { |
b7ca232e | 549 | int ret = 0; |
37b51fdd | 550 | unsigned char *cmem; |
8b3cc3ed | 551 | struct zram_meta *meta = zram->meta; |
92967471 | 552 | unsigned long handle; |
023b409f | 553 | size_t size; |
92967471 | 554 | |
d2d5e762 | 555 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
92967471 | 556 | handle = meta->table[index].handle; |
d2d5e762 | 557 | size = zram_get_obj_size(meta, index); |
306b0c95 | 558 | |
8b3cc3ed | 559 | if (!handle || zram_test_flag(meta, index, ZRAM_ZERO)) { |
d2d5e762 | 560 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
42e99bd9 | 561 | clear_page(mem); |
8c921b2b JM |
562 | return 0; |
563 | } | |
306b0c95 | 564 | |
8b3cc3ed | 565 | cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO); |
92967471 | 566 | if (size == PAGE_SIZE) |
42e99bd9 | 567 | copy_page(mem, cmem); |
37b51fdd | 568 | else |
b7ca232e | 569 | ret = zcomp_decompress(zram->comp, cmem, size, mem); |
8b3cc3ed | 570 | zs_unmap_object(meta->mem_pool, handle); |
d2d5e762 | 571 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
a1dd52af | 572 | |
8c921b2b | 573 | /* Should NEVER happen. Return bio error if it does. */ |
b7ca232e | 574 | if (unlikely(ret)) { |
8c921b2b | 575 | pr_err("Decompression failed! err=%d, page=%u\n", ret, index); |
8c921b2b | 576 | return ret; |
a1dd52af | 577 | } |
306b0c95 | 578 | |
8c921b2b | 579 | return 0; |
306b0c95 NG |
580 | } |
581 | ||
37b51fdd | 582 | static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, |
b627cff3 | 583 | u32 index, int offset) |
924bd88d JM |
584 | { |
585 | int ret; | |
37b51fdd SS |
586 | struct page *page; |
587 | unsigned char *user_mem, *uncmem = NULL; | |
8b3cc3ed | 588 | struct zram_meta *meta = zram->meta; |
37b51fdd SS |
589 | page = bvec->bv_page; |
590 | ||
d2d5e762 | 591 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
8b3cc3ed MK |
592 | if (unlikely(!meta->table[index].handle) || |
593 | zram_test_flag(meta, index, ZRAM_ZERO)) { | |
d2d5e762 | 594 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
37b51fdd | 595 | handle_zero_page(bvec); |
924bd88d JM |
596 | return 0; |
597 | } | |
d2d5e762 | 598 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
924bd88d | 599 | |
37b51fdd SS |
600 | if (is_partial_io(bvec)) |
601 | /* Use a temporary buffer to decompress the page */ | |
7e5a5104 MK |
602 | uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); |
603 | ||
604 | user_mem = kmap_atomic(page); | |
605 | if (!is_partial_io(bvec)) | |
37b51fdd SS |
606 | uncmem = user_mem; |
607 | ||
608 | if (!uncmem) { | |
609 | pr_info("Unable to allocate temp memory\n"); | |
610 | ret = -ENOMEM; | |
611 | goto out_cleanup; | |
612 | } | |
924bd88d | 613 | |
37b51fdd | 614 | ret = zram_decompress_page(zram, uncmem, index); |
924bd88d | 615 | /* Should NEVER happen. Return bio error if it does. */ |
b7ca232e | 616 | if (unlikely(ret)) |
37b51fdd | 617 | goto out_cleanup; |
924bd88d | 618 | |
37b51fdd SS |
619 | if (is_partial_io(bvec)) |
620 | memcpy(user_mem + bvec->bv_offset, uncmem + offset, | |
621 | bvec->bv_len); | |
622 | ||
623 | flush_dcache_page(page); | |
624 | ret = 0; | |
625 | out_cleanup: | |
626 | kunmap_atomic(user_mem); | |
627 | if (is_partial_io(bvec)) | |
628 | kfree(uncmem); | |
629 | return ret; | |
924bd88d JM |
630 | } |
631 | ||
632 | static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, | |
633 | int offset) | |
306b0c95 | 634 | { |
397c6066 | 635 | int ret = 0; |
8c921b2b | 636 | size_t clen; |
c2344348 | 637 | unsigned long handle; |
130f315a | 638 | struct page *page; |
924bd88d | 639 | unsigned char *user_mem, *cmem, *src, *uncmem = NULL; |
8b3cc3ed | 640 | struct zram_meta *meta = zram->meta; |
b7ca232e | 641 | struct zcomp_strm *zstrm; |
e46e3315 | 642 | bool locked = false; |
461a8eee | 643 | unsigned long alloced_pages; |
306b0c95 | 644 | |
8c921b2b | 645 | page = bvec->bv_page; |
924bd88d JM |
646 | if (is_partial_io(bvec)) { |
647 | /* | |
648 | * This is a partial IO. We need to read the full page | |
649 | * before to write the changes. | |
650 | */ | |
7e5a5104 | 651 | uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); |
924bd88d | 652 | if (!uncmem) { |
924bd88d JM |
653 | ret = -ENOMEM; |
654 | goto out; | |
655 | } | |
37b51fdd | 656 | ret = zram_decompress_page(zram, uncmem, index); |
397c6066 | 657 | if (ret) |
924bd88d | 658 | goto out; |
924bd88d JM |
659 | } |
660 | ||
b7ca232e | 661 | zstrm = zcomp_strm_find(zram->comp); |
e46e3315 | 662 | locked = true; |
ba82fe2e | 663 | user_mem = kmap_atomic(page); |
924bd88d | 664 | |
397c6066 | 665 | if (is_partial_io(bvec)) { |
924bd88d JM |
666 | memcpy(uncmem + offset, user_mem + bvec->bv_offset, |
667 | bvec->bv_len); | |
397c6066 NG |
668 | kunmap_atomic(user_mem); |
669 | user_mem = NULL; | |
670 | } else { | |
924bd88d | 671 | uncmem = user_mem; |
397c6066 | 672 | } |
924bd88d JM |
673 | |
674 | if (page_zero_filled(uncmem)) { | |
c4065152 WY |
675 | if (user_mem) |
676 | kunmap_atomic(user_mem); | |
f40ac2ae | 677 | /* Free memory associated with this sector now. */ |
d2d5e762 | 678 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f40ac2ae | 679 | zram_free_page(zram, index); |
92967471 | 680 | zram_set_flag(meta, index, ZRAM_ZERO); |
d2d5e762 | 681 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
f40ac2ae | 682 | |
90a7806e | 683 | atomic64_inc(&zram->stats.zero_pages); |
924bd88d JM |
684 | ret = 0; |
685 | goto out; | |
8c921b2b | 686 | } |
306b0c95 | 687 | |
b7ca232e | 688 | ret = zcomp_compress(zram->comp, zstrm, uncmem, &clen); |
397c6066 NG |
689 | if (!is_partial_io(bvec)) { |
690 | kunmap_atomic(user_mem); | |
691 | user_mem = NULL; | |
692 | uncmem = NULL; | |
693 | } | |
306b0c95 | 694 | |
b7ca232e | 695 | if (unlikely(ret)) { |
8c921b2b | 696 | pr_err("Compression failed! err=%d\n", ret); |
924bd88d | 697 | goto out; |
8c921b2b | 698 | } |
b7ca232e | 699 | src = zstrm->buffer; |
c8f2f0db | 700 | if (unlikely(clen > max_zpage_size)) { |
c8f2f0db | 701 | clen = PAGE_SIZE; |
397c6066 NG |
702 | if (is_partial_io(bvec)) |
703 | src = uncmem; | |
c8f2f0db | 704 | } |
a1dd52af | 705 | |
8b3cc3ed | 706 | handle = zs_malloc(meta->mem_pool, clen); |
fd1a30de | 707 | if (!handle) { |
596b3dd4 MR |
708 | pr_info("Error allocating memory for compressed page: %u, size=%zu\n", |
709 | index, clen); | |
924bd88d JM |
710 | ret = -ENOMEM; |
711 | goto out; | |
8c921b2b | 712 | } |
9ada9da9 | 713 | |
461a8eee MK |
714 | alloced_pages = zs_get_total_pages(meta->mem_pool); |
715 | if (zram->limit_pages && alloced_pages > zram->limit_pages) { | |
9ada9da9 MK |
716 | zs_free(meta->mem_pool, handle); |
717 | ret = -ENOMEM; | |
718 | goto out; | |
719 | } | |
720 | ||
461a8eee MK |
721 | update_used_max(zram, alloced_pages); |
722 | ||
8b3cc3ed | 723 | cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO); |
306b0c95 | 724 | |
42e99bd9 | 725 | if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) { |
397c6066 | 726 | src = kmap_atomic(page); |
42e99bd9 | 727 | copy_page(cmem, src); |
397c6066 | 728 | kunmap_atomic(src); |
42e99bd9 JL |
729 | } else { |
730 | memcpy(cmem, src, clen); | |
731 | } | |
306b0c95 | 732 | |
b7ca232e SS |
733 | zcomp_strm_release(zram->comp, zstrm); |
734 | locked = false; | |
8b3cc3ed | 735 | zs_unmap_object(meta->mem_pool, handle); |
fd1a30de | 736 | |
f40ac2ae SS |
737 | /* |
738 | * Free memory associated with this sector | |
739 | * before overwriting unused sectors. | |
740 | */ | |
d2d5e762 | 741 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f40ac2ae SS |
742 | zram_free_page(zram, index); |
743 | ||
8b3cc3ed | 744 | meta->table[index].handle = handle; |
d2d5e762 WY |
745 | zram_set_obj_size(meta, index, clen); |
746 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); | |
306b0c95 | 747 | |
8c921b2b | 748 | /* Update stats */ |
90a7806e SS |
749 | atomic64_add(clen, &zram->stats.compr_data_size); |
750 | atomic64_inc(&zram->stats.pages_stored); | |
924bd88d | 751 | out: |
e46e3315 | 752 | if (locked) |
b7ca232e | 753 | zcomp_strm_release(zram->comp, zstrm); |
397c6066 NG |
754 | if (is_partial_io(bvec)) |
755 | kfree(uncmem); | |
924bd88d | 756 | return ret; |
8c921b2b JM |
757 | } |
758 | ||
f4659d8e JK |
759 | /* |
760 | * zram_bio_discard - handler on discard request | |
761 | * @index: physical block index in PAGE_SIZE units | |
762 | * @offset: byte offset within physical block | |
763 | */ | |
764 | static void zram_bio_discard(struct zram *zram, u32 index, | |
765 | int offset, struct bio *bio) | |
766 | { | |
767 | size_t n = bio->bi_iter.bi_size; | |
d2d5e762 | 768 | struct zram_meta *meta = zram->meta; |
f4659d8e JK |
769 | |
770 | /* | |
771 | * zram manages data in physical block size units. Because logical block | |
772 | * size isn't identical with physical block size on some arch, we | |
773 | * could get a discard request pointing to a specific offset within a | |
774 | * certain physical block. Although we can handle this request by | |
775 | * reading that physiclal block and decompressing and partially zeroing | |
776 | * and re-compressing and then re-storing it, this isn't reasonable | |
777 | * because our intent with a discard request is to save memory. So | |
778 | * skipping this logical block is appropriate here. | |
779 | */ | |
780 | if (offset) { | |
38515c73 | 781 | if (n <= (PAGE_SIZE - offset)) |
f4659d8e JK |
782 | return; |
783 | ||
38515c73 | 784 | n -= (PAGE_SIZE - offset); |
f4659d8e JK |
785 | index++; |
786 | } | |
787 | ||
788 | while (n >= PAGE_SIZE) { | |
d2d5e762 | 789 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f4659d8e | 790 | zram_free_page(zram, index); |
d2d5e762 | 791 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
015254da | 792 | atomic64_inc(&zram->stats.notify_free); |
f4659d8e JK |
793 | index++; |
794 | n -= PAGE_SIZE; | |
795 | } | |
796 | } | |
797 | ||
522698d7 SS |
798 | static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, |
799 | int offset, int rw) | |
9b3bb7ab | 800 | { |
522698d7 | 801 | unsigned long start_time = jiffies; |
9b3bb7ab | 802 | int ret; |
9b3bb7ab | 803 | |
522698d7 SS |
804 | generic_start_io_acct(rw, bvec->bv_len >> SECTOR_SHIFT, |
805 | &zram->disk->part0); | |
46a51c80 | 806 | |
522698d7 SS |
807 | if (rw == READ) { |
808 | atomic64_inc(&zram->stats.num_reads); | |
809 | ret = zram_bvec_read(zram, bvec, index, offset); | |
810 | } else { | |
811 | atomic64_inc(&zram->stats.num_writes); | |
812 | ret = zram_bvec_write(zram, bvec, index, offset); | |
1b672224 | 813 | } |
9b3bb7ab | 814 | |
522698d7 | 815 | generic_end_io_acct(rw, &zram->disk->part0, start_time); |
9b3bb7ab | 816 | |
522698d7 SS |
817 | if (unlikely(ret)) { |
818 | if (rw == READ) | |
819 | atomic64_inc(&zram->stats.failed_reads); | |
820 | else | |
821 | atomic64_inc(&zram->stats.failed_writes); | |
1b672224 | 822 | } |
9b3bb7ab | 823 | |
1b672224 | 824 | return ret; |
8c921b2b JM |
825 | } |
826 | ||
be257c61 | 827 | static void __zram_make_request(struct zram *zram, struct bio *bio) |
8c921b2b | 828 | { |
b627cff3 | 829 | int offset, rw; |
8c921b2b | 830 | u32 index; |
7988613b KO |
831 | struct bio_vec bvec; |
832 | struct bvec_iter iter; | |
8c921b2b | 833 | |
4f024f37 KO |
834 | index = bio->bi_iter.bi_sector >> SECTORS_PER_PAGE_SHIFT; |
835 | offset = (bio->bi_iter.bi_sector & | |
836 | (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; | |
8c921b2b | 837 | |
f4659d8e JK |
838 | if (unlikely(bio->bi_rw & REQ_DISCARD)) { |
839 | zram_bio_discard(zram, index, offset, bio); | |
840 | bio_endio(bio, 0); | |
841 | return; | |
842 | } | |
843 | ||
b627cff3 | 844 | rw = bio_data_dir(bio); |
7988613b | 845 | bio_for_each_segment(bvec, bio, iter) { |
924bd88d JM |
846 | int max_transfer_size = PAGE_SIZE - offset; |
847 | ||
7988613b | 848 | if (bvec.bv_len > max_transfer_size) { |
924bd88d JM |
849 | /* |
850 | * zram_bvec_rw() can only make operation on a single | |
851 | * zram page. Split the bio vector. | |
852 | */ | |
853 | struct bio_vec bv; | |
854 | ||
7988613b | 855 | bv.bv_page = bvec.bv_page; |
924bd88d | 856 | bv.bv_len = max_transfer_size; |
7988613b | 857 | bv.bv_offset = bvec.bv_offset; |
924bd88d | 858 | |
b627cff3 | 859 | if (zram_bvec_rw(zram, &bv, index, offset, rw) < 0) |
924bd88d JM |
860 | goto out; |
861 | ||
7988613b | 862 | bv.bv_len = bvec.bv_len - max_transfer_size; |
924bd88d | 863 | bv.bv_offset += max_transfer_size; |
b627cff3 | 864 | if (zram_bvec_rw(zram, &bv, index + 1, 0, rw) < 0) |
924bd88d JM |
865 | goto out; |
866 | } else | |
b627cff3 | 867 | if (zram_bvec_rw(zram, &bvec, index, offset, rw) < 0) |
924bd88d JM |
868 | goto out; |
869 | ||
7988613b | 870 | update_position(&index, &offset, &bvec); |
a1dd52af | 871 | } |
306b0c95 NG |
872 | |
873 | set_bit(BIO_UPTODATE, &bio->bi_flags); | |
874 | bio_endio(bio, 0); | |
7d7854b4 | 875 | return; |
306b0c95 NG |
876 | |
877 | out: | |
306b0c95 | 878 | bio_io_error(bio); |
306b0c95 NG |
879 | } |
880 | ||
306b0c95 | 881 | /* |
f1e3cfff | 882 | * Handler function for all zram I/O requests. |
306b0c95 | 883 | */ |
5a7bbad2 | 884 | static void zram_make_request(struct request_queue *queue, struct bio *bio) |
306b0c95 | 885 | { |
f1e3cfff | 886 | struct zram *zram = queue->queuedata; |
306b0c95 | 887 | |
08eee69f | 888 | if (unlikely(!zram_meta_get(zram))) |
3de738cd | 889 | goto error; |
0900beae | 890 | |
54850e73 | 891 | if (!valid_io_request(zram, bio->bi_iter.bi_sector, |
892 | bio->bi_iter.bi_size)) { | |
da5cc7d3 | 893 | atomic64_inc(&zram->stats.invalid_io); |
08eee69f | 894 | goto put_zram; |
6642a67c JM |
895 | } |
896 | ||
be257c61 | 897 | __zram_make_request(zram, bio); |
08eee69f | 898 | zram_meta_put(zram); |
b4fdcb02 | 899 | return; |
08eee69f MK |
900 | put_zram: |
901 | zram_meta_put(zram); | |
0900beae JM |
902 | error: |
903 | bio_io_error(bio); | |
306b0c95 NG |
904 | } |
905 | ||
2ccbec05 NG |
906 | static void zram_slot_free_notify(struct block_device *bdev, |
907 | unsigned long index) | |
107c161b | 908 | { |
f1e3cfff | 909 | struct zram *zram; |
f614a9f4 | 910 | struct zram_meta *meta; |
107c161b | 911 | |
f1e3cfff | 912 | zram = bdev->bd_disk->private_data; |
f614a9f4 | 913 | meta = zram->meta; |
a0c516cb | 914 | |
d2d5e762 | 915 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f614a9f4 | 916 | zram_free_page(zram, index); |
d2d5e762 | 917 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
f614a9f4 | 918 | atomic64_inc(&zram->stats.notify_free); |
107c161b NG |
919 | } |
920 | ||
8c7f0102 | 921 | static int zram_rw_page(struct block_device *bdev, sector_t sector, |
922 | struct page *page, int rw) | |
923 | { | |
08eee69f | 924 | int offset, err = -EIO; |
8c7f0102 | 925 | u32 index; |
926 | struct zram *zram; | |
927 | struct bio_vec bv; | |
928 | ||
929 | zram = bdev->bd_disk->private_data; | |
08eee69f MK |
930 | if (unlikely(!zram_meta_get(zram))) |
931 | goto out; | |
932 | ||
8c7f0102 | 933 | if (!valid_io_request(zram, sector, PAGE_SIZE)) { |
934 | atomic64_inc(&zram->stats.invalid_io); | |
08eee69f MK |
935 | err = -EINVAL; |
936 | goto put_zram; | |
8c7f0102 | 937 | } |
938 | ||
939 | index = sector >> SECTORS_PER_PAGE_SHIFT; | |
940 | offset = sector & (SECTORS_PER_PAGE - 1) << SECTOR_SHIFT; | |
941 | ||
942 | bv.bv_page = page; | |
943 | bv.bv_len = PAGE_SIZE; | |
944 | bv.bv_offset = 0; | |
945 | ||
946 | err = zram_bvec_rw(zram, &bv, index, offset, rw); | |
08eee69f MK |
947 | put_zram: |
948 | zram_meta_put(zram); | |
949 | out: | |
8c7f0102 | 950 | /* |
951 | * If I/O fails, just return error(ie, non-zero) without | |
952 | * calling page_endio. | |
953 | * It causes resubmit the I/O with bio request by upper functions | |
954 | * of rw_page(e.g., swap_readpage, __swap_writepage) and | |
955 | * bio->bi_end_io does things to handle the error | |
956 | * (e.g., SetPageError, set_page_dirty and extra works). | |
957 | */ | |
958 | if (err == 0) | |
959 | page_endio(page, rw, 0); | |
960 | return err; | |
961 | } | |
962 | ||
522698d7 SS |
963 | static void zram_reset_device(struct zram *zram) |
964 | { | |
965 | struct zram_meta *meta; | |
966 | struct zcomp *comp; | |
967 | u64 disksize; | |
306b0c95 | 968 | |
522698d7 | 969 | down_write(&zram->init_lock); |
9b3bb7ab | 970 | |
522698d7 SS |
971 | zram->limit_pages = 0; |
972 | ||
973 | if (!init_done(zram)) { | |
974 | up_write(&zram->init_lock); | |
975 | return; | |
976 | } | |
977 | ||
978 | meta = zram->meta; | |
979 | comp = zram->comp; | |
980 | disksize = zram->disksize; | |
981 | /* | |
982 | * Refcount will go down to 0 eventually and r/w handler | |
983 | * cannot handle further I/O so it will bail out by | |
984 | * check zram_meta_get. | |
985 | */ | |
986 | zram_meta_put(zram); | |
987 | /* | |
988 | * We want to free zram_meta in process context to avoid | |
989 | * deadlock between reclaim path and any other locks. | |
990 | */ | |
991 | wait_event(zram->io_done, atomic_read(&zram->refcount) == 0); | |
992 | ||
993 | /* Reset stats */ | |
994 | memset(&zram->stats, 0, sizeof(zram->stats)); | |
995 | zram->disksize = 0; | |
996 | zram->max_comp_streams = 1; | |
997 | ||
998 | set_capacity(zram->disk, 0); | |
999 | part_stat_set_all(&zram->disk->part0, 0); | |
1000 | ||
1001 | up_write(&zram->init_lock); | |
1002 | /* I/O operation under all of CPU are done so let's free */ | |
1003 | zram_meta_free(meta, disksize); | |
1004 | zcomp_destroy(comp); | |
1005 | } | |
1006 | ||
1007 | static ssize_t disksize_store(struct device *dev, | |
1008 | struct device_attribute *attr, const char *buf, size_t len) | |
2f6a3bed | 1009 | { |
522698d7 SS |
1010 | u64 disksize; |
1011 | struct zcomp *comp; | |
1012 | struct zram_meta *meta; | |
2f6a3bed | 1013 | struct zram *zram = dev_to_zram(dev); |
522698d7 | 1014 | int err; |
2f6a3bed | 1015 | |
522698d7 SS |
1016 | disksize = memparse(buf, NULL); |
1017 | if (!disksize) | |
1018 | return -EINVAL; | |
2f6a3bed | 1019 | |
522698d7 SS |
1020 | disksize = PAGE_ALIGN(disksize); |
1021 | meta = zram_meta_alloc(zram->disk->first_minor, disksize); | |
1022 | if (!meta) | |
1023 | return -ENOMEM; | |
1024 | ||
1025 | comp = zcomp_create(zram->compressor, zram->max_comp_streams); | |
1026 | if (IS_ERR(comp)) { | |
1027 | pr_info("Cannot initialise %s compressing backend\n", | |
1028 | zram->compressor); | |
1029 | err = PTR_ERR(comp); | |
1030 | goto out_free_meta; | |
1031 | } | |
1032 | ||
1033 | down_write(&zram->init_lock); | |
1034 | if (init_done(zram)) { | |
1035 | pr_info("Cannot change disksize for initialized device\n"); | |
1036 | err = -EBUSY; | |
1037 | goto out_destroy_comp; | |
1038 | } | |
1039 | ||
1040 | init_waitqueue_head(&zram->io_done); | |
1041 | atomic_set(&zram->refcount, 1); | |
1042 | zram->meta = meta; | |
1043 | zram->comp = comp; | |
1044 | zram->disksize = disksize; | |
1045 | set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); | |
1046 | up_write(&zram->init_lock); | |
1047 | ||
1048 | /* | |
1049 | * Revalidate disk out of the init_lock to avoid lockdep splat. | |
1050 | * It's okay because disk's capacity is protected by init_lock | |
1051 | * so that revalidate_disk always sees up-to-date capacity. | |
1052 | */ | |
1053 | revalidate_disk(zram->disk); | |
1054 | ||
1055 | return len; | |
1056 | ||
1057 | out_destroy_comp: | |
1058 | up_write(&zram->init_lock); | |
1059 | zcomp_destroy(comp); | |
1060 | out_free_meta: | |
1061 | zram_meta_free(meta, disksize); | |
1062 | return err; | |
2f6a3bed SS |
1063 | } |
1064 | ||
522698d7 SS |
1065 | static ssize_t reset_store(struct device *dev, |
1066 | struct device_attribute *attr, const char *buf, size_t len) | |
4f2109f6 | 1067 | { |
522698d7 SS |
1068 | int ret; |
1069 | unsigned short do_reset; | |
1070 | struct zram *zram; | |
1071 | struct block_device *bdev; | |
4f2109f6 | 1072 | |
522698d7 SS |
1073 | zram = dev_to_zram(dev); |
1074 | bdev = bdget_disk(zram->disk, 0); | |
4f2109f6 | 1075 | |
522698d7 SS |
1076 | if (!bdev) |
1077 | return -ENOMEM; | |
4f2109f6 | 1078 | |
522698d7 SS |
1079 | mutex_lock(&bdev->bd_mutex); |
1080 | /* Do not reset an active device! */ | |
1081 | if (bdev->bd_openers) { | |
1082 | ret = -EBUSY; | |
1083 | goto out; | |
1084 | } | |
1085 | ||
1086 | ret = kstrtou16(buf, 10, &do_reset); | |
1087 | if (ret) | |
1088 | goto out; | |
1089 | ||
1090 | if (!do_reset) { | |
1091 | ret = -EINVAL; | |
1092 | goto out; | |
1093 | } | |
1094 | ||
1095 | /* Make sure all pending I/O is finished */ | |
1096 | fsync_bdev(bdev); | |
1097 | zram_reset_device(zram); | |
1098 | ||
1099 | mutex_unlock(&bdev->bd_mutex); | |
1100 | revalidate_disk(zram->disk); | |
1101 | bdput(bdev); | |
1102 | ||
1103 | return len; | |
4f2109f6 | 1104 | |
522698d7 SS |
1105 | out: |
1106 | mutex_unlock(&bdev->bd_mutex); | |
1107 | bdput(bdev); | |
4f2109f6 SS |
1108 | return ret; |
1109 | } | |
1110 | ||
522698d7 SS |
1111 | static const struct block_device_operations zram_devops = { |
1112 | .swap_slot_free_notify = zram_slot_free_notify, | |
1113 | .rw_page = zram_rw_page, | |
1114 | .owner = THIS_MODULE | |
1115 | }; | |
1116 | ||
1117 | static DEVICE_ATTR_WO(compact); | |
1118 | static DEVICE_ATTR_RW(disksize); | |
1119 | static DEVICE_ATTR_RO(initstate); | |
1120 | static DEVICE_ATTR_WO(reset); | |
1121 | static DEVICE_ATTR_RO(orig_data_size); | |
1122 | static DEVICE_ATTR_RO(mem_used_total); | |
1123 | static DEVICE_ATTR_RW(mem_limit); | |
1124 | static DEVICE_ATTR_RW(mem_used_max); | |
1125 | static DEVICE_ATTR_RW(max_comp_streams); | |
1126 | static DEVICE_ATTR_RW(comp_algorithm); | |
a68eb3b6 | 1127 | |
9b3bb7ab SS |
1128 | static struct attribute *zram_disk_attrs[] = { |
1129 | &dev_attr_disksize.attr, | |
1130 | &dev_attr_initstate.attr, | |
1131 | &dev_attr_reset.attr, | |
1132 | &dev_attr_num_reads.attr, | |
1133 | &dev_attr_num_writes.attr, | |
64447249 SS |
1134 | &dev_attr_failed_reads.attr, |
1135 | &dev_attr_failed_writes.attr, | |
99ebbd30 | 1136 | &dev_attr_compact.attr, |
9b3bb7ab SS |
1137 | &dev_attr_invalid_io.attr, |
1138 | &dev_attr_notify_free.attr, | |
1139 | &dev_attr_zero_pages.attr, | |
1140 | &dev_attr_orig_data_size.attr, | |
1141 | &dev_attr_compr_data_size.attr, | |
1142 | &dev_attr_mem_used_total.attr, | |
9ada9da9 | 1143 | &dev_attr_mem_limit.attr, |
461a8eee | 1144 | &dev_attr_mem_used_max.attr, |
beca3ec7 | 1145 | &dev_attr_max_comp_streams.attr, |
e46b8a03 | 1146 | &dev_attr_comp_algorithm.attr, |
2f6a3bed | 1147 | &dev_attr_io_stat.attr, |
4f2109f6 | 1148 | &dev_attr_mm_stat.attr, |
9b3bb7ab SS |
1149 | NULL, |
1150 | }; | |
1151 | ||
1152 | static struct attribute_group zram_disk_attr_group = { | |
1153 | .attrs = zram_disk_attrs, | |
1154 | }; | |
1155 | ||
92ff1528 SS |
1156 | /* |
1157 | * Allocate and initialize new zram device. the function returns | |
1158 | * '>= 0' device_id upon success, and negative value otherwise. | |
1159 | */ | |
1160 | static int zram_add(void) | |
306b0c95 | 1161 | { |
85508ec6 | 1162 | struct zram *zram; |
ee980160 | 1163 | struct request_queue *queue; |
92ff1528 | 1164 | int ret, device_id; |
85508ec6 SS |
1165 | |
1166 | zram = kzalloc(sizeof(struct zram), GFP_KERNEL); | |
1167 | if (!zram) | |
1168 | return -ENOMEM; | |
1169 | ||
92ff1528 | 1170 | ret = idr_alloc(&zram_index_idr, zram, 0, 0, GFP_KERNEL); |
85508ec6 SS |
1171 | if (ret < 0) |
1172 | goto out_free_dev; | |
92ff1528 | 1173 | device_id = ret; |
de1a21a0 | 1174 | |
0900beae | 1175 | init_rwsem(&zram->init_lock); |
306b0c95 | 1176 | |
ee980160 SS |
1177 | queue = blk_alloc_queue(GFP_KERNEL); |
1178 | if (!queue) { | |
306b0c95 NG |
1179 | pr_err("Error allocating disk queue for device %d\n", |
1180 | device_id); | |
85508ec6 SS |
1181 | ret = -ENOMEM; |
1182 | goto out_free_idr; | |
306b0c95 NG |
1183 | } |
1184 | ||
ee980160 | 1185 | blk_queue_make_request(queue, zram_make_request); |
306b0c95 | 1186 | |
85508ec6 | 1187 | /* gendisk structure */ |
f1e3cfff NG |
1188 | zram->disk = alloc_disk(1); |
1189 | if (!zram->disk) { | |
94b8435f | 1190 | pr_warn("Error allocating disk structure for device %d\n", |
306b0c95 | 1191 | device_id); |
201c7b72 | 1192 | ret = -ENOMEM; |
39a9b8ac | 1193 | goto out_free_queue; |
306b0c95 NG |
1194 | } |
1195 | ||
f1e3cfff NG |
1196 | zram->disk->major = zram_major; |
1197 | zram->disk->first_minor = device_id; | |
1198 | zram->disk->fops = &zram_devops; | |
ee980160 SS |
1199 | zram->disk->queue = queue; |
1200 | zram->disk->queue->queuedata = zram; | |
f1e3cfff NG |
1201 | zram->disk->private_data = zram; |
1202 | snprintf(zram->disk->disk_name, 16, "zram%d", device_id); | |
306b0c95 | 1203 | |
33863c21 | 1204 | /* Actual capacity set using syfs (/sys/block/zram<id>/disksize */ |
f1e3cfff | 1205 | set_capacity(zram->disk, 0); |
b67d1ec1 SS |
1206 | /* zram devices sort of resembles non-rotational disks */ |
1207 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); | |
b277da0a | 1208 | queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, zram->disk->queue); |
a1dd52af NG |
1209 | /* |
1210 | * To ensure that we always get PAGE_SIZE aligned | |
1211 | * and n*PAGE_SIZED sized I/O requests. | |
1212 | */ | |
f1e3cfff | 1213 | blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE); |
7b19b8d4 RJ |
1214 | blk_queue_logical_block_size(zram->disk->queue, |
1215 | ZRAM_LOGICAL_BLOCK_SIZE); | |
f1e3cfff NG |
1216 | blk_queue_io_min(zram->disk->queue, PAGE_SIZE); |
1217 | blk_queue_io_opt(zram->disk->queue, PAGE_SIZE); | |
f4659d8e JK |
1218 | zram->disk->queue->limits.discard_granularity = PAGE_SIZE; |
1219 | zram->disk->queue->limits.max_discard_sectors = UINT_MAX; | |
1220 | /* | |
1221 | * zram_bio_discard() will clear all logical blocks if logical block | |
1222 | * size is identical with physical block size(PAGE_SIZE). But if it is | |
1223 | * different, we will skip discarding some parts of logical blocks in | |
1224 | * the part of the request range which isn't aligned to physical block | |
1225 | * size. So we can't ensure that all discarded logical blocks are | |
1226 | * zeroed. | |
1227 | */ | |
1228 | if (ZRAM_LOGICAL_BLOCK_SIZE == PAGE_SIZE) | |
1229 | zram->disk->queue->limits.discard_zeroes_data = 1; | |
1230 | else | |
1231 | zram->disk->queue->limits.discard_zeroes_data = 0; | |
1232 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, zram->disk->queue); | |
5d83d5a0 | 1233 | |
f1e3cfff | 1234 | add_disk(zram->disk); |
306b0c95 | 1235 | |
33863c21 NG |
1236 | ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj, |
1237 | &zram_disk_attr_group); | |
1238 | if (ret < 0) { | |
94b8435f | 1239 | pr_warn("Error creating sysfs group"); |
39a9b8ac | 1240 | goto out_free_disk; |
33863c21 | 1241 | } |
e46b8a03 | 1242 | strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor)); |
be2d1d56 | 1243 | zram->meta = NULL; |
beca3ec7 | 1244 | zram->max_comp_streams = 1; |
d12b63c9 SS |
1245 | |
1246 | pr_info("Added device: %s\n", zram->disk->disk_name); | |
92ff1528 | 1247 | return device_id; |
de1a21a0 | 1248 | |
39a9b8ac JL |
1249 | out_free_disk: |
1250 | del_gendisk(zram->disk); | |
1251 | put_disk(zram->disk); | |
1252 | out_free_queue: | |
ee980160 | 1253 | blk_cleanup_queue(queue); |
85508ec6 SS |
1254 | out_free_idr: |
1255 | idr_remove(&zram_index_idr, device_id); | |
1256 | out_free_dev: | |
1257 | kfree(zram); | |
de1a21a0 | 1258 | return ret; |
306b0c95 NG |
1259 | } |
1260 | ||
85508ec6 | 1261 | static void zram_remove(struct zram *zram) |
306b0c95 | 1262 | { |
d12b63c9 | 1263 | pr_info("Removed device: %s\n", zram->disk->disk_name); |
85508ec6 SS |
1264 | /* |
1265 | * Remove sysfs first, so no one will perform a disksize | |
1266 | * store while we destroy the devices | |
1267 | */ | |
1268 | sysfs_remove_group(&disk_to_dev(zram->disk)->kobj, | |
1269 | &zram_disk_attr_group); | |
306b0c95 | 1270 | |
85508ec6 SS |
1271 | zram_reset_device(zram); |
1272 | idr_remove(&zram_index_idr, zram->disk->first_minor); | |
1273 | blk_cleanup_queue(zram->disk->queue); | |
1274 | del_gendisk(zram->disk); | |
1275 | put_disk(zram->disk); | |
1276 | kfree(zram); | |
1277 | } | |
a096cafc | 1278 | |
85508ec6 SS |
1279 | static int zram_remove_cb(int id, void *ptr, void *data) |
1280 | { | |
1281 | zram_remove(ptr); | |
1282 | return 0; | |
1283 | } | |
a096cafc | 1284 | |
85508ec6 SS |
1285 | static void destroy_devices(void) |
1286 | { | |
1287 | idr_for_each(&zram_index_idr, &zram_remove_cb, NULL); | |
1288 | idr_destroy(&zram_index_idr); | |
a096cafc | 1289 | unregister_blkdev(zram_major, "zram"); |
306b0c95 NG |
1290 | } |
1291 | ||
f1e3cfff | 1292 | static int __init zram_init(void) |
306b0c95 | 1293 | { |
92ff1528 | 1294 | int ret; |
306b0c95 | 1295 | |
f1e3cfff NG |
1296 | zram_major = register_blkdev(0, "zram"); |
1297 | if (zram_major <= 0) { | |
94b8435f | 1298 | pr_warn("Unable to get major number\n"); |
a096cafc | 1299 | return -EBUSY; |
306b0c95 NG |
1300 | } |
1301 | ||
92ff1528 SS |
1302 | while (num_devices != 0) { |
1303 | ret = zram_add(); | |
1304 | if (ret < 0) | |
a096cafc | 1305 | goto out_error; |
92ff1528 | 1306 | num_devices--; |
de1a21a0 NG |
1307 | } |
1308 | ||
306b0c95 | 1309 | return 0; |
de1a21a0 | 1310 | |
a096cafc | 1311 | out_error: |
85508ec6 | 1312 | destroy_devices(); |
306b0c95 NG |
1313 | return ret; |
1314 | } | |
1315 | ||
f1e3cfff | 1316 | static void __exit zram_exit(void) |
306b0c95 | 1317 | { |
85508ec6 | 1318 | destroy_devices(); |
306b0c95 NG |
1319 | } |
1320 | ||
f1e3cfff NG |
1321 | module_init(zram_init); |
1322 | module_exit(zram_exit); | |
306b0c95 | 1323 | |
9b3bb7ab | 1324 | module_param(num_devices, uint, 0); |
c3cdb40e | 1325 | MODULE_PARM_DESC(num_devices, "Number of pre-created zram devices"); |
9b3bb7ab | 1326 | |
306b0c95 NG |
1327 | MODULE_LICENSE("Dual BSD/GPL"); |
1328 | MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); | |
f1e3cfff | 1329 | MODULE_DESCRIPTION("Compressed RAM Block Device"); |