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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 | ||
b1f5b81e RJ |
18 | #ifdef CONFIG_ZRAM_DEBUG |
19 | #define DEBUG | |
20 | #endif | |
21 | ||
306b0c95 NG |
22 | #include <linux/module.h> |
23 | #include <linux/kernel.h> | |
8946a086 | 24 | #include <linux/bio.h> |
306b0c95 NG |
25 | #include <linux/bitops.h> |
26 | #include <linux/blkdev.h> | |
27 | #include <linux/buffer_head.h> | |
28 | #include <linux/device.h> | |
29 | #include <linux/genhd.h> | |
30 | #include <linux/highmem.h> | |
5a0e3ad6 | 31 | #include <linux/slab.h> |
306b0c95 | 32 | #include <linux/string.h> |
306b0c95 | 33 | #include <linux/vmalloc.h> |
fcfa8d95 | 34 | #include <linux/err.h> |
306b0c95 | 35 | |
16a4bfb9 | 36 | #include "zram_drv.h" |
306b0c95 NG |
37 | |
38 | /* Globals */ | |
f1e3cfff | 39 | static int zram_major; |
0f0e3ba3 | 40 | static struct zram *zram_devices; |
b7ca232e | 41 | static const char *default_compressor = "lzo"; |
306b0c95 | 42 | |
306b0c95 | 43 | /* Module params (documentation at end) */ |
ca3d70bd | 44 | static unsigned int num_devices = 1; |
33863c21 | 45 | |
8f7d282c SS |
46 | static inline void deprecated_attr_warn(const char *name) |
47 | { | |
48 | pr_warn_once("%d (%s) Attribute %s (and others) will be removed. %s\n", | |
49 | task_pid_nr(current), | |
50 | current->comm, | |
51 | name, | |
52 | "See zram documentation."); | |
53 | } | |
54 | ||
a68eb3b6 | 55 | #define ZRAM_ATTR_RO(name) \ |
083914ea | 56 | static ssize_t name##_show(struct device *d, \ |
a68eb3b6 SS |
57 | struct device_attribute *attr, char *b) \ |
58 | { \ | |
59 | struct zram *zram = dev_to_zram(d); \ | |
8f7d282c SS |
60 | \ |
61 | deprecated_attr_warn(__stringify(name)); \ | |
56b4e8cb | 62 | return scnprintf(b, PAGE_SIZE, "%llu\n", \ |
a68eb3b6 SS |
63 | (u64)atomic64_read(&zram->stats.name)); \ |
64 | } \ | |
083914ea | 65 | static DEVICE_ATTR_RO(name); |
a68eb3b6 | 66 | |
08eee69f | 67 | static inline bool init_done(struct zram *zram) |
be2d1d56 | 68 | { |
08eee69f | 69 | return zram->disksize; |
be2d1d56 SS |
70 | } |
71 | ||
9b3bb7ab SS |
72 | static inline struct zram *dev_to_zram(struct device *dev) |
73 | { | |
74 | return (struct zram *)dev_to_disk(dev)->private_data; | |
75 | } | |
76 | ||
77 | static ssize_t disksize_show(struct device *dev, | |
78 | struct device_attribute *attr, char *buf) | |
79 | { | |
80 | struct zram *zram = dev_to_zram(dev); | |
81 | ||
56b4e8cb | 82 | return scnprintf(buf, PAGE_SIZE, "%llu\n", zram->disksize); |
9b3bb7ab SS |
83 | } |
84 | ||
85 | static ssize_t initstate_show(struct device *dev, | |
86 | struct device_attribute *attr, char *buf) | |
87 | { | |
a68eb3b6 | 88 | u32 val; |
9b3bb7ab SS |
89 | struct zram *zram = dev_to_zram(dev); |
90 | ||
a68eb3b6 SS |
91 | down_read(&zram->init_lock); |
92 | val = init_done(zram); | |
93 | up_read(&zram->init_lock); | |
9b3bb7ab | 94 | |
56b4e8cb | 95 | return scnprintf(buf, PAGE_SIZE, "%u\n", val); |
9b3bb7ab SS |
96 | } |
97 | ||
98 | static ssize_t orig_data_size_show(struct device *dev, | |
99 | struct device_attribute *attr, char *buf) | |
100 | { | |
101 | struct zram *zram = dev_to_zram(dev); | |
102 | ||
8f7d282c | 103 | deprecated_attr_warn("orig_data_size"); |
56b4e8cb | 104 | return scnprintf(buf, PAGE_SIZE, "%llu\n", |
90a7806e | 105 | (u64)(atomic64_read(&zram->stats.pages_stored)) << PAGE_SHIFT); |
9b3bb7ab SS |
106 | } |
107 | ||
9b3bb7ab SS |
108 | static ssize_t mem_used_total_show(struct device *dev, |
109 | struct device_attribute *attr, char *buf) | |
110 | { | |
111 | u64 val = 0; | |
112 | struct zram *zram = dev_to_zram(dev); | |
9b3bb7ab | 113 | |
8f7d282c | 114 | deprecated_attr_warn("mem_used_total"); |
9b3bb7ab | 115 | down_read(&zram->init_lock); |
5a99e95b WY |
116 | if (init_done(zram)) { |
117 | struct zram_meta *meta = zram->meta; | |
722cdc17 | 118 | val = zs_get_total_pages(meta->mem_pool); |
5a99e95b | 119 | } |
9b3bb7ab SS |
120 | up_read(&zram->init_lock); |
121 | ||
722cdc17 | 122 | return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT); |
9b3bb7ab SS |
123 | } |
124 | ||
beca3ec7 SS |
125 | static ssize_t max_comp_streams_show(struct device *dev, |
126 | struct device_attribute *attr, char *buf) | |
127 | { | |
128 | int val; | |
129 | struct zram *zram = dev_to_zram(dev); | |
130 | ||
131 | down_read(&zram->init_lock); | |
132 | val = zram->max_comp_streams; | |
133 | up_read(&zram->init_lock); | |
134 | ||
56b4e8cb | 135 | return scnprintf(buf, PAGE_SIZE, "%d\n", val); |
beca3ec7 SS |
136 | } |
137 | ||
9ada9da9 MK |
138 | static ssize_t mem_limit_show(struct device *dev, |
139 | struct device_attribute *attr, char *buf) | |
140 | { | |
141 | u64 val; | |
142 | struct zram *zram = dev_to_zram(dev); | |
143 | ||
8f7d282c | 144 | deprecated_attr_warn("mem_limit"); |
9ada9da9 MK |
145 | down_read(&zram->init_lock); |
146 | val = zram->limit_pages; | |
147 | up_read(&zram->init_lock); | |
148 | ||
149 | return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT); | |
150 | } | |
151 | ||
152 | static ssize_t mem_limit_store(struct device *dev, | |
153 | struct device_attribute *attr, const char *buf, size_t len) | |
154 | { | |
155 | u64 limit; | |
156 | char *tmp; | |
157 | struct zram *zram = dev_to_zram(dev); | |
158 | ||
159 | limit = memparse(buf, &tmp); | |
160 | if (buf == tmp) /* no chars parsed, invalid input */ | |
161 | return -EINVAL; | |
162 | ||
163 | down_write(&zram->init_lock); | |
164 | zram->limit_pages = PAGE_ALIGN(limit) >> PAGE_SHIFT; | |
165 | up_write(&zram->init_lock); | |
166 | ||
167 | return len; | |
168 | } | |
169 | ||
461a8eee MK |
170 | static ssize_t mem_used_max_show(struct device *dev, |
171 | struct device_attribute *attr, char *buf) | |
172 | { | |
173 | u64 val = 0; | |
174 | struct zram *zram = dev_to_zram(dev); | |
175 | ||
8f7d282c | 176 | deprecated_attr_warn("mem_used_max"); |
461a8eee MK |
177 | down_read(&zram->init_lock); |
178 | if (init_done(zram)) | |
179 | val = atomic_long_read(&zram->stats.max_used_pages); | |
180 | up_read(&zram->init_lock); | |
181 | ||
182 | return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT); | |
183 | } | |
184 | ||
185 | static ssize_t mem_used_max_store(struct device *dev, | |
186 | struct device_attribute *attr, const char *buf, size_t len) | |
187 | { | |
188 | int err; | |
189 | unsigned long val; | |
190 | struct zram *zram = dev_to_zram(dev); | |
461a8eee MK |
191 | |
192 | err = kstrtoul(buf, 10, &val); | |
193 | if (err || val != 0) | |
194 | return -EINVAL; | |
195 | ||
196 | down_read(&zram->init_lock); | |
5a99e95b WY |
197 | if (init_done(zram)) { |
198 | struct zram_meta *meta = zram->meta; | |
461a8eee MK |
199 | atomic_long_set(&zram->stats.max_used_pages, |
200 | zs_get_total_pages(meta->mem_pool)); | |
5a99e95b | 201 | } |
461a8eee MK |
202 | up_read(&zram->init_lock); |
203 | ||
204 | return len; | |
205 | } | |
206 | ||
beca3ec7 SS |
207 | static ssize_t max_comp_streams_store(struct device *dev, |
208 | struct device_attribute *attr, const char *buf, size_t len) | |
209 | { | |
210 | int num; | |
211 | struct zram *zram = dev_to_zram(dev); | |
60a726e3 | 212 | int ret; |
beca3ec7 | 213 | |
60a726e3 MK |
214 | ret = kstrtoint(buf, 0, &num); |
215 | if (ret < 0) | |
216 | return ret; | |
beca3ec7 SS |
217 | if (num < 1) |
218 | return -EINVAL; | |
60a726e3 | 219 | |
beca3ec7 SS |
220 | down_write(&zram->init_lock); |
221 | if (init_done(zram)) { | |
60a726e3 | 222 | if (!zcomp_set_max_streams(zram->comp, num)) { |
fe8eb122 | 223 | pr_info("Cannot change max compression streams\n"); |
60a726e3 MK |
224 | ret = -EINVAL; |
225 | goto out; | |
226 | } | |
beca3ec7 | 227 | } |
60a726e3 | 228 | |
beca3ec7 | 229 | zram->max_comp_streams = num; |
60a726e3 MK |
230 | ret = len; |
231 | out: | |
beca3ec7 | 232 | up_write(&zram->init_lock); |
60a726e3 | 233 | return ret; |
beca3ec7 SS |
234 | } |
235 | ||
e46b8a03 SS |
236 | static ssize_t comp_algorithm_show(struct device *dev, |
237 | struct device_attribute *attr, char *buf) | |
238 | { | |
239 | size_t sz; | |
240 | struct zram *zram = dev_to_zram(dev); | |
241 | ||
242 | down_read(&zram->init_lock); | |
243 | sz = zcomp_available_show(zram->compressor, buf); | |
244 | up_read(&zram->init_lock); | |
245 | ||
246 | return sz; | |
247 | } | |
248 | ||
249 | static ssize_t comp_algorithm_store(struct device *dev, | |
250 | struct device_attribute *attr, const char *buf, size_t len) | |
251 | { | |
252 | struct zram *zram = dev_to_zram(dev); | |
253 | down_write(&zram->init_lock); | |
254 | if (init_done(zram)) { | |
255 | up_write(&zram->init_lock); | |
256 | pr_info("Can't change algorithm for initialized device\n"); | |
257 | return -EBUSY; | |
258 | } | |
259 | strlcpy(zram->compressor, buf, sizeof(zram->compressor)); | |
260 | up_write(&zram->init_lock); | |
261 | return len; | |
262 | } | |
263 | ||
92967471 | 264 | /* flag operations needs meta->tb_lock */ |
8b3cc3ed | 265 | static int zram_test_flag(struct zram_meta *meta, u32 index, |
f1e3cfff | 266 | enum zram_pageflags flag) |
306b0c95 | 267 | { |
d2d5e762 | 268 | return meta->table[index].value & BIT(flag); |
306b0c95 NG |
269 | } |
270 | ||
8b3cc3ed | 271 | static void zram_set_flag(struct zram_meta *meta, u32 index, |
f1e3cfff | 272 | enum zram_pageflags flag) |
306b0c95 | 273 | { |
d2d5e762 | 274 | meta->table[index].value |= BIT(flag); |
306b0c95 NG |
275 | } |
276 | ||
8b3cc3ed | 277 | static void zram_clear_flag(struct zram_meta *meta, u32 index, |
f1e3cfff | 278 | enum zram_pageflags flag) |
306b0c95 | 279 | { |
d2d5e762 WY |
280 | meta->table[index].value &= ~BIT(flag); |
281 | } | |
282 | ||
283 | static size_t zram_get_obj_size(struct zram_meta *meta, u32 index) | |
284 | { | |
285 | return meta->table[index].value & (BIT(ZRAM_FLAG_SHIFT) - 1); | |
286 | } | |
287 | ||
288 | static void zram_set_obj_size(struct zram_meta *meta, | |
289 | u32 index, size_t size) | |
290 | { | |
291 | unsigned long flags = meta->table[index].value >> ZRAM_FLAG_SHIFT; | |
292 | ||
293 | meta->table[index].value = (flags << ZRAM_FLAG_SHIFT) | size; | |
306b0c95 NG |
294 | } |
295 | ||
9b3bb7ab SS |
296 | static inline int is_partial_io(struct bio_vec *bvec) |
297 | { | |
298 | return bvec->bv_len != PAGE_SIZE; | |
299 | } | |
300 | ||
301 | /* | |
302 | * Check if request is within bounds and aligned on zram logical blocks. | |
303 | */ | |
54850e73 | 304 | static inline int valid_io_request(struct zram *zram, |
305 | sector_t start, unsigned int size) | |
9b3bb7ab | 306 | { |
54850e73 | 307 | u64 end, bound; |
a539c72a | 308 | |
9b3bb7ab | 309 | /* unaligned request */ |
54850e73 | 310 | if (unlikely(start & (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1))) |
9b3bb7ab | 311 | return 0; |
54850e73 | 312 | if (unlikely(size & (ZRAM_LOGICAL_BLOCK_SIZE - 1))) |
9b3bb7ab SS |
313 | return 0; |
314 | ||
54850e73 | 315 | end = start + (size >> SECTOR_SHIFT); |
9b3bb7ab SS |
316 | bound = zram->disksize >> SECTOR_SHIFT; |
317 | /* out of range range */ | |
75c7caf5 | 318 | if (unlikely(start >= bound || end > bound || start > end)) |
9b3bb7ab SS |
319 | return 0; |
320 | ||
321 | /* I/O request is valid */ | |
322 | return 1; | |
323 | } | |
324 | ||
1fec1172 | 325 | static void zram_meta_free(struct zram_meta *meta, u64 disksize) |
9b3bb7ab | 326 | { |
1fec1172 GM |
327 | size_t num_pages = disksize >> PAGE_SHIFT; |
328 | size_t index; | |
329 | ||
330 | /* Free all pages that are still in this zram device */ | |
331 | for (index = 0; index < num_pages; index++) { | |
332 | unsigned long handle = meta->table[index].handle; | |
333 | ||
334 | if (!handle) | |
335 | continue; | |
336 | ||
337 | zs_free(meta->mem_pool, handle); | |
338 | } | |
339 | ||
9b3bb7ab | 340 | zs_destroy_pool(meta->mem_pool); |
9b3bb7ab SS |
341 | vfree(meta->table); |
342 | kfree(meta); | |
343 | } | |
344 | ||
3eba0c6a | 345 | static struct zram_meta *zram_meta_alloc(int device_id, u64 disksize) |
9b3bb7ab SS |
346 | { |
347 | size_t num_pages; | |
3eba0c6a | 348 | char pool_name[8]; |
9b3bb7ab | 349 | struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL); |
b8179958 | 350 | |
9b3bb7ab | 351 | if (!meta) |
b8179958 | 352 | return NULL; |
9b3bb7ab | 353 | |
9b3bb7ab SS |
354 | num_pages = disksize >> PAGE_SHIFT; |
355 | meta->table = vzalloc(num_pages * sizeof(*meta->table)); | |
356 | if (!meta->table) { | |
357 | pr_err("Error allocating zram address table\n"); | |
b8179958 | 358 | goto out_error; |
9b3bb7ab SS |
359 | } |
360 | ||
3eba0c6a GM |
361 | snprintf(pool_name, sizeof(pool_name), "zram%d", device_id); |
362 | meta->mem_pool = zs_create_pool(pool_name, GFP_NOIO | __GFP_HIGHMEM); | |
9b3bb7ab SS |
363 | if (!meta->mem_pool) { |
364 | pr_err("Error creating memory pool\n"); | |
b8179958 | 365 | goto out_error; |
9b3bb7ab SS |
366 | } |
367 | ||
368 | return meta; | |
369 | ||
b8179958 | 370 | out_error: |
9b3bb7ab | 371 | vfree(meta->table); |
9b3bb7ab | 372 | kfree(meta); |
b8179958 | 373 | return NULL; |
9b3bb7ab SS |
374 | } |
375 | ||
08eee69f MK |
376 | static inline bool zram_meta_get(struct zram *zram) |
377 | { | |
378 | if (atomic_inc_not_zero(&zram->refcount)) | |
379 | return true; | |
380 | return false; | |
381 | } | |
382 | ||
383 | static inline void zram_meta_put(struct zram *zram) | |
384 | { | |
385 | atomic_dec(&zram->refcount); | |
386 | } | |
387 | ||
9b3bb7ab SS |
388 | static void update_position(u32 *index, int *offset, struct bio_vec *bvec) |
389 | { | |
390 | if (*offset + bvec->bv_len >= PAGE_SIZE) | |
391 | (*index)++; | |
392 | *offset = (*offset + bvec->bv_len) % PAGE_SIZE; | |
393 | } | |
394 | ||
306b0c95 NG |
395 | static int page_zero_filled(void *ptr) |
396 | { | |
397 | unsigned int pos; | |
398 | unsigned long *page; | |
399 | ||
400 | page = (unsigned long *)ptr; | |
401 | ||
402 | for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) { | |
403 | if (page[pos]) | |
404 | return 0; | |
405 | } | |
406 | ||
407 | return 1; | |
408 | } | |
409 | ||
9b3bb7ab SS |
410 | static void handle_zero_page(struct bio_vec *bvec) |
411 | { | |
412 | struct page *page = bvec->bv_page; | |
413 | void *user_mem; | |
414 | ||
415 | user_mem = kmap_atomic(page); | |
416 | if (is_partial_io(bvec)) | |
417 | memset(user_mem + bvec->bv_offset, 0, bvec->bv_len); | |
418 | else | |
419 | clear_page(user_mem); | |
420 | kunmap_atomic(user_mem); | |
421 | ||
422 | flush_dcache_page(page); | |
423 | } | |
424 | ||
d2d5e762 WY |
425 | |
426 | /* | |
427 | * To protect concurrent access to the same index entry, | |
428 | * caller should hold this table index entry's bit_spinlock to | |
429 | * indicate this index entry is accessing. | |
430 | */ | |
f1e3cfff | 431 | static void zram_free_page(struct zram *zram, size_t index) |
306b0c95 | 432 | { |
8b3cc3ed MK |
433 | struct zram_meta *meta = zram->meta; |
434 | unsigned long handle = meta->table[index].handle; | |
306b0c95 | 435 | |
fd1a30de | 436 | if (unlikely(!handle)) { |
2e882281 NG |
437 | /* |
438 | * No memory is allocated for zero filled pages. | |
439 | * Simply clear zero page flag. | |
440 | */ | |
8b3cc3ed MK |
441 | if (zram_test_flag(meta, index, ZRAM_ZERO)) { |
442 | zram_clear_flag(meta, index, ZRAM_ZERO); | |
90a7806e | 443 | atomic64_dec(&zram->stats.zero_pages); |
306b0c95 NG |
444 | } |
445 | return; | |
446 | } | |
447 | ||
8b3cc3ed | 448 | zs_free(meta->mem_pool, handle); |
306b0c95 | 449 | |
d2d5e762 WY |
450 | atomic64_sub(zram_get_obj_size(meta, index), |
451 | &zram->stats.compr_data_size); | |
90a7806e | 452 | atomic64_dec(&zram->stats.pages_stored); |
306b0c95 | 453 | |
8b3cc3ed | 454 | meta->table[index].handle = 0; |
d2d5e762 | 455 | zram_set_obj_size(meta, index, 0); |
306b0c95 NG |
456 | } |
457 | ||
37b51fdd | 458 | static int zram_decompress_page(struct zram *zram, char *mem, u32 index) |
306b0c95 | 459 | { |
b7ca232e | 460 | int ret = 0; |
37b51fdd | 461 | unsigned char *cmem; |
8b3cc3ed | 462 | struct zram_meta *meta = zram->meta; |
92967471 | 463 | unsigned long handle; |
023b409f | 464 | size_t size; |
92967471 | 465 | |
d2d5e762 | 466 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
92967471 | 467 | handle = meta->table[index].handle; |
d2d5e762 | 468 | size = zram_get_obj_size(meta, index); |
306b0c95 | 469 | |
8b3cc3ed | 470 | if (!handle || zram_test_flag(meta, index, ZRAM_ZERO)) { |
d2d5e762 | 471 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
42e99bd9 | 472 | clear_page(mem); |
8c921b2b JM |
473 | return 0; |
474 | } | |
306b0c95 | 475 | |
8b3cc3ed | 476 | cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO); |
92967471 | 477 | if (size == PAGE_SIZE) |
42e99bd9 | 478 | copy_page(mem, cmem); |
37b51fdd | 479 | else |
b7ca232e | 480 | ret = zcomp_decompress(zram->comp, cmem, size, mem); |
8b3cc3ed | 481 | zs_unmap_object(meta->mem_pool, handle); |
d2d5e762 | 482 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
a1dd52af | 483 | |
8c921b2b | 484 | /* Should NEVER happen. Return bio error if it does. */ |
b7ca232e | 485 | if (unlikely(ret)) { |
8c921b2b | 486 | pr_err("Decompression failed! err=%d, page=%u\n", ret, index); |
8c921b2b | 487 | return ret; |
a1dd52af | 488 | } |
306b0c95 | 489 | |
8c921b2b | 490 | return 0; |
306b0c95 NG |
491 | } |
492 | ||
37b51fdd | 493 | static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, |
b627cff3 | 494 | u32 index, int offset) |
924bd88d JM |
495 | { |
496 | int ret; | |
37b51fdd SS |
497 | struct page *page; |
498 | unsigned char *user_mem, *uncmem = NULL; | |
8b3cc3ed | 499 | struct zram_meta *meta = zram->meta; |
37b51fdd SS |
500 | page = bvec->bv_page; |
501 | ||
d2d5e762 | 502 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
8b3cc3ed MK |
503 | if (unlikely(!meta->table[index].handle) || |
504 | zram_test_flag(meta, index, ZRAM_ZERO)) { | |
d2d5e762 | 505 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
37b51fdd | 506 | handle_zero_page(bvec); |
924bd88d JM |
507 | return 0; |
508 | } | |
d2d5e762 | 509 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
924bd88d | 510 | |
37b51fdd SS |
511 | if (is_partial_io(bvec)) |
512 | /* Use a temporary buffer to decompress the page */ | |
7e5a5104 MK |
513 | uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); |
514 | ||
515 | user_mem = kmap_atomic(page); | |
516 | if (!is_partial_io(bvec)) | |
37b51fdd SS |
517 | uncmem = user_mem; |
518 | ||
519 | if (!uncmem) { | |
520 | pr_info("Unable to allocate temp memory\n"); | |
521 | ret = -ENOMEM; | |
522 | goto out_cleanup; | |
523 | } | |
924bd88d | 524 | |
37b51fdd | 525 | ret = zram_decompress_page(zram, uncmem, index); |
924bd88d | 526 | /* Should NEVER happen. Return bio error if it does. */ |
b7ca232e | 527 | if (unlikely(ret)) |
37b51fdd | 528 | goto out_cleanup; |
924bd88d | 529 | |
37b51fdd SS |
530 | if (is_partial_io(bvec)) |
531 | memcpy(user_mem + bvec->bv_offset, uncmem + offset, | |
532 | bvec->bv_len); | |
533 | ||
534 | flush_dcache_page(page); | |
535 | ret = 0; | |
536 | out_cleanup: | |
537 | kunmap_atomic(user_mem); | |
538 | if (is_partial_io(bvec)) | |
539 | kfree(uncmem); | |
540 | return ret; | |
924bd88d JM |
541 | } |
542 | ||
461a8eee MK |
543 | static inline void update_used_max(struct zram *zram, |
544 | const unsigned long pages) | |
545 | { | |
2ea55a2c | 546 | unsigned long old_max, cur_max; |
461a8eee MK |
547 | |
548 | old_max = atomic_long_read(&zram->stats.max_used_pages); | |
549 | ||
550 | do { | |
551 | cur_max = old_max; | |
552 | if (pages > cur_max) | |
553 | old_max = atomic_long_cmpxchg( | |
554 | &zram->stats.max_used_pages, cur_max, pages); | |
555 | } while (old_max != cur_max); | |
556 | } | |
557 | ||
924bd88d JM |
558 | static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, |
559 | int offset) | |
306b0c95 | 560 | { |
397c6066 | 561 | int ret = 0; |
8c921b2b | 562 | size_t clen; |
c2344348 | 563 | unsigned long handle; |
130f315a | 564 | struct page *page; |
924bd88d | 565 | unsigned char *user_mem, *cmem, *src, *uncmem = NULL; |
8b3cc3ed | 566 | struct zram_meta *meta = zram->meta; |
b7ca232e | 567 | struct zcomp_strm *zstrm; |
e46e3315 | 568 | bool locked = false; |
461a8eee | 569 | unsigned long alloced_pages; |
306b0c95 | 570 | |
8c921b2b | 571 | page = bvec->bv_page; |
924bd88d JM |
572 | if (is_partial_io(bvec)) { |
573 | /* | |
574 | * This is a partial IO. We need to read the full page | |
575 | * before to write the changes. | |
576 | */ | |
7e5a5104 | 577 | uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); |
924bd88d | 578 | if (!uncmem) { |
924bd88d JM |
579 | ret = -ENOMEM; |
580 | goto out; | |
581 | } | |
37b51fdd | 582 | ret = zram_decompress_page(zram, uncmem, index); |
397c6066 | 583 | if (ret) |
924bd88d | 584 | goto out; |
924bd88d JM |
585 | } |
586 | ||
b7ca232e | 587 | zstrm = zcomp_strm_find(zram->comp); |
e46e3315 | 588 | locked = true; |
ba82fe2e | 589 | user_mem = kmap_atomic(page); |
924bd88d | 590 | |
397c6066 | 591 | if (is_partial_io(bvec)) { |
924bd88d JM |
592 | memcpy(uncmem + offset, user_mem + bvec->bv_offset, |
593 | bvec->bv_len); | |
397c6066 NG |
594 | kunmap_atomic(user_mem); |
595 | user_mem = NULL; | |
596 | } else { | |
924bd88d | 597 | uncmem = user_mem; |
397c6066 | 598 | } |
924bd88d JM |
599 | |
600 | if (page_zero_filled(uncmem)) { | |
c4065152 WY |
601 | if (user_mem) |
602 | kunmap_atomic(user_mem); | |
f40ac2ae | 603 | /* Free memory associated with this sector now. */ |
d2d5e762 | 604 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f40ac2ae | 605 | zram_free_page(zram, index); |
92967471 | 606 | zram_set_flag(meta, index, ZRAM_ZERO); |
d2d5e762 | 607 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
f40ac2ae | 608 | |
90a7806e | 609 | atomic64_inc(&zram->stats.zero_pages); |
924bd88d JM |
610 | ret = 0; |
611 | goto out; | |
8c921b2b | 612 | } |
306b0c95 | 613 | |
b7ca232e | 614 | ret = zcomp_compress(zram->comp, zstrm, uncmem, &clen); |
397c6066 NG |
615 | if (!is_partial_io(bvec)) { |
616 | kunmap_atomic(user_mem); | |
617 | user_mem = NULL; | |
618 | uncmem = NULL; | |
619 | } | |
306b0c95 | 620 | |
b7ca232e | 621 | if (unlikely(ret)) { |
8c921b2b | 622 | pr_err("Compression failed! err=%d\n", ret); |
924bd88d | 623 | goto out; |
8c921b2b | 624 | } |
b7ca232e | 625 | src = zstrm->buffer; |
c8f2f0db | 626 | if (unlikely(clen > max_zpage_size)) { |
c8f2f0db | 627 | clen = PAGE_SIZE; |
397c6066 NG |
628 | if (is_partial_io(bvec)) |
629 | src = uncmem; | |
c8f2f0db | 630 | } |
a1dd52af | 631 | |
8b3cc3ed | 632 | handle = zs_malloc(meta->mem_pool, clen); |
fd1a30de | 633 | if (!handle) { |
596b3dd4 MR |
634 | pr_info("Error allocating memory for compressed page: %u, size=%zu\n", |
635 | index, clen); | |
924bd88d JM |
636 | ret = -ENOMEM; |
637 | goto out; | |
8c921b2b | 638 | } |
9ada9da9 | 639 | |
461a8eee MK |
640 | alloced_pages = zs_get_total_pages(meta->mem_pool); |
641 | if (zram->limit_pages && alloced_pages > zram->limit_pages) { | |
9ada9da9 MK |
642 | zs_free(meta->mem_pool, handle); |
643 | ret = -ENOMEM; | |
644 | goto out; | |
645 | } | |
646 | ||
461a8eee MK |
647 | update_used_max(zram, alloced_pages); |
648 | ||
8b3cc3ed | 649 | cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO); |
306b0c95 | 650 | |
42e99bd9 | 651 | if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) { |
397c6066 | 652 | src = kmap_atomic(page); |
42e99bd9 | 653 | copy_page(cmem, src); |
397c6066 | 654 | kunmap_atomic(src); |
42e99bd9 JL |
655 | } else { |
656 | memcpy(cmem, src, clen); | |
657 | } | |
306b0c95 | 658 | |
b7ca232e SS |
659 | zcomp_strm_release(zram->comp, zstrm); |
660 | locked = false; | |
8b3cc3ed | 661 | zs_unmap_object(meta->mem_pool, handle); |
fd1a30de | 662 | |
f40ac2ae SS |
663 | /* |
664 | * Free memory associated with this sector | |
665 | * before overwriting unused sectors. | |
666 | */ | |
d2d5e762 | 667 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f40ac2ae SS |
668 | zram_free_page(zram, index); |
669 | ||
8b3cc3ed | 670 | meta->table[index].handle = handle; |
d2d5e762 WY |
671 | zram_set_obj_size(meta, index, clen); |
672 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); | |
306b0c95 | 673 | |
8c921b2b | 674 | /* Update stats */ |
90a7806e SS |
675 | atomic64_add(clen, &zram->stats.compr_data_size); |
676 | atomic64_inc(&zram->stats.pages_stored); | |
924bd88d | 677 | out: |
e46e3315 | 678 | if (locked) |
b7ca232e | 679 | zcomp_strm_release(zram->comp, zstrm); |
397c6066 NG |
680 | if (is_partial_io(bvec)) |
681 | kfree(uncmem); | |
924bd88d | 682 | return ret; |
8c921b2b JM |
683 | } |
684 | ||
685 | static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, | |
b627cff3 | 686 | int offset, int rw) |
8c921b2b | 687 | { |
8811a942 | 688 | unsigned long start_time = jiffies; |
c5bde238 | 689 | int ret; |
8c921b2b | 690 | |
8811a942 SS |
691 | generic_start_io_acct(rw, bvec->bv_len >> SECTOR_SHIFT, |
692 | &zram->disk->part0); | |
693 | ||
be257c61 SS |
694 | if (rw == READ) { |
695 | atomic64_inc(&zram->stats.num_reads); | |
b627cff3 | 696 | ret = zram_bvec_read(zram, bvec, index, offset); |
be257c61 SS |
697 | } else { |
698 | atomic64_inc(&zram->stats.num_writes); | |
c5bde238 | 699 | ret = zram_bvec_write(zram, bvec, index, offset); |
be257c61 | 700 | } |
c5bde238 | 701 | |
8811a942 SS |
702 | generic_end_io_acct(rw, &zram->disk->part0, start_time); |
703 | ||
0cf1e9d6 CY |
704 | if (unlikely(ret)) { |
705 | if (rw == READ) | |
706 | atomic64_inc(&zram->stats.failed_reads); | |
707 | else | |
708 | atomic64_inc(&zram->stats.failed_writes); | |
709 | } | |
710 | ||
c5bde238 | 711 | return ret; |
924bd88d JM |
712 | } |
713 | ||
f4659d8e JK |
714 | /* |
715 | * zram_bio_discard - handler on discard request | |
716 | * @index: physical block index in PAGE_SIZE units | |
717 | * @offset: byte offset within physical block | |
718 | */ | |
719 | static void zram_bio_discard(struct zram *zram, u32 index, | |
720 | int offset, struct bio *bio) | |
721 | { | |
722 | size_t n = bio->bi_iter.bi_size; | |
d2d5e762 | 723 | struct zram_meta *meta = zram->meta; |
f4659d8e JK |
724 | |
725 | /* | |
726 | * zram manages data in physical block size units. Because logical block | |
727 | * size isn't identical with physical block size on some arch, we | |
728 | * could get a discard request pointing to a specific offset within a | |
729 | * certain physical block. Although we can handle this request by | |
730 | * reading that physiclal block and decompressing and partially zeroing | |
731 | * and re-compressing and then re-storing it, this isn't reasonable | |
732 | * because our intent with a discard request is to save memory. So | |
733 | * skipping this logical block is appropriate here. | |
734 | */ | |
735 | if (offset) { | |
38515c73 | 736 | if (n <= (PAGE_SIZE - offset)) |
f4659d8e JK |
737 | return; |
738 | ||
38515c73 | 739 | n -= (PAGE_SIZE - offset); |
f4659d8e JK |
740 | index++; |
741 | } | |
742 | ||
743 | while (n >= PAGE_SIZE) { | |
d2d5e762 | 744 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f4659d8e | 745 | zram_free_page(zram, index); |
d2d5e762 | 746 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
015254da | 747 | atomic64_inc(&zram->stats.notify_free); |
f4659d8e JK |
748 | index++; |
749 | n -= PAGE_SIZE; | |
750 | } | |
751 | } | |
752 | ||
ba6b17d6 | 753 | static void zram_reset_device(struct zram *zram) |
924bd88d | 754 | { |
08eee69f MK |
755 | struct zram_meta *meta; |
756 | struct zcomp *comp; | |
757 | u64 disksize; | |
758 | ||
644d4787 | 759 | down_write(&zram->init_lock); |
9ada9da9 MK |
760 | |
761 | zram->limit_pages = 0; | |
762 | ||
be2d1d56 | 763 | if (!init_done(zram)) { |
644d4787 | 764 | up_write(&zram->init_lock); |
9b3bb7ab | 765 | return; |
644d4787 | 766 | } |
9b3bb7ab | 767 | |
08eee69f MK |
768 | meta = zram->meta; |
769 | comp = zram->comp; | |
770 | disksize = zram->disksize; | |
771 | /* | |
772 | * Refcount will go down to 0 eventually and r/w handler | |
773 | * cannot handle further I/O so it will bail out by | |
774 | * check zram_meta_get. | |
775 | */ | |
776 | zram_meta_put(zram); | |
777 | /* | |
778 | * We want to free zram_meta in process context to avoid | |
779 | * deadlock between reclaim path and any other locks. | |
780 | */ | |
781 | wait_event(zram->io_done, atomic_read(&zram->refcount) == 0); | |
782 | ||
9b3bb7ab SS |
783 | /* Reset stats */ |
784 | memset(&zram->stats, 0, sizeof(zram->stats)); | |
9b3bb7ab | 785 | zram->disksize = 0; |
08eee69f | 786 | zram->max_comp_streams = 1; |
a096cafc SS |
787 | set_capacity(zram->disk, 0); |
788 | ||
644d4787 | 789 | up_write(&zram->init_lock); |
08eee69f MK |
790 | /* I/O operation under all of CPU are done so let's free */ |
791 | zram_meta_free(meta, disksize); | |
792 | zcomp_destroy(comp); | |
9b3bb7ab SS |
793 | } |
794 | ||
9b3bb7ab SS |
795 | static ssize_t disksize_store(struct device *dev, |
796 | struct device_attribute *attr, const char *buf, size_t len) | |
797 | { | |
798 | u64 disksize; | |
d61f98c7 | 799 | struct zcomp *comp; |
9b3bb7ab SS |
800 | struct zram_meta *meta; |
801 | struct zram *zram = dev_to_zram(dev); | |
fcfa8d95 | 802 | int err; |
9b3bb7ab SS |
803 | |
804 | disksize = memparse(buf, NULL); | |
805 | if (!disksize) | |
806 | return -EINVAL; | |
807 | ||
808 | disksize = PAGE_ALIGN(disksize); | |
3eba0c6a | 809 | meta = zram_meta_alloc(zram->disk->first_minor, disksize); |
db5d711e MK |
810 | if (!meta) |
811 | return -ENOMEM; | |
b67d1ec1 | 812 | |
d61f98c7 | 813 | comp = zcomp_create(zram->compressor, zram->max_comp_streams); |
fcfa8d95 | 814 | if (IS_ERR(comp)) { |
d61f98c7 SS |
815 | pr_info("Cannot initialise %s compressing backend\n", |
816 | zram->compressor); | |
fcfa8d95 SS |
817 | err = PTR_ERR(comp); |
818 | goto out_free_meta; | |
d61f98c7 SS |
819 | } |
820 | ||
9b3bb7ab | 821 | down_write(&zram->init_lock); |
be2d1d56 | 822 | if (init_done(zram)) { |
9b3bb7ab | 823 | pr_info("Cannot change disksize for initialized device\n"); |
b7ca232e | 824 | err = -EBUSY; |
fcfa8d95 | 825 | goto out_destroy_comp; |
9b3bb7ab SS |
826 | } |
827 | ||
08eee69f MK |
828 | init_waitqueue_head(&zram->io_done); |
829 | atomic_set(&zram->refcount, 1); | |
b67d1ec1 | 830 | zram->meta = meta; |
d61f98c7 | 831 | zram->comp = comp; |
9b3bb7ab SS |
832 | zram->disksize = disksize; |
833 | set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); | |
9b3bb7ab | 834 | up_write(&zram->init_lock); |
b4c5c609 MK |
835 | |
836 | /* | |
837 | * Revalidate disk out of the init_lock to avoid lockdep splat. | |
838 | * It's okay because disk's capacity is protected by init_lock | |
839 | * so that revalidate_disk always sees up-to-date capacity. | |
840 | */ | |
841 | revalidate_disk(zram->disk); | |
842 | ||
9b3bb7ab | 843 | return len; |
b7ca232e | 844 | |
fcfa8d95 SS |
845 | out_destroy_comp: |
846 | up_write(&zram->init_lock); | |
847 | zcomp_destroy(comp); | |
848 | out_free_meta: | |
1fec1172 | 849 | zram_meta_free(meta, disksize); |
b7ca232e | 850 | return err; |
9b3bb7ab SS |
851 | } |
852 | ||
853 | static ssize_t reset_store(struct device *dev, | |
854 | struct device_attribute *attr, const char *buf, size_t len) | |
855 | { | |
856 | int ret; | |
857 | unsigned short do_reset; | |
858 | struct zram *zram; | |
859 | struct block_device *bdev; | |
860 | ||
861 | zram = dev_to_zram(dev); | |
862 | bdev = bdget_disk(zram->disk, 0); | |
863 | ||
46a51c80 RK |
864 | if (!bdev) |
865 | return -ENOMEM; | |
866 | ||
ba6b17d6 | 867 | mutex_lock(&bdev->bd_mutex); |
9b3bb7ab | 868 | /* Do not reset an active device! */ |
2b269ce6 | 869 | if (bdev->bd_openers) { |
1b672224 RK |
870 | ret = -EBUSY; |
871 | goto out; | |
872 | } | |
9b3bb7ab SS |
873 | |
874 | ret = kstrtou16(buf, 10, &do_reset); | |
875 | if (ret) | |
1b672224 | 876 | goto out; |
9b3bb7ab | 877 | |
1b672224 RK |
878 | if (!do_reset) { |
879 | ret = -EINVAL; | |
880 | goto out; | |
881 | } | |
9b3bb7ab SS |
882 | |
883 | /* Make sure all pending I/O is finished */ | |
46a51c80 | 884 | fsync_bdev(bdev); |
ba6b17d6 | 885 | zram_reset_device(zram); |
ba6b17d6 SS |
886 | |
887 | mutex_unlock(&bdev->bd_mutex); | |
888 | revalidate_disk(zram->disk); | |
1b672224 | 889 | bdput(bdev); |
9b3bb7ab | 890 | |
9b3bb7ab | 891 | return len; |
1b672224 RK |
892 | |
893 | out: | |
ba6b17d6 | 894 | mutex_unlock(&bdev->bd_mutex); |
1b672224 RK |
895 | bdput(bdev); |
896 | return ret; | |
8c921b2b JM |
897 | } |
898 | ||
be257c61 | 899 | static void __zram_make_request(struct zram *zram, struct bio *bio) |
8c921b2b | 900 | { |
b627cff3 | 901 | int offset, rw; |
8c921b2b | 902 | u32 index; |
7988613b KO |
903 | struct bio_vec bvec; |
904 | struct bvec_iter iter; | |
8c921b2b | 905 | |
4f024f37 KO |
906 | index = bio->bi_iter.bi_sector >> SECTORS_PER_PAGE_SHIFT; |
907 | offset = (bio->bi_iter.bi_sector & | |
908 | (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; | |
8c921b2b | 909 | |
f4659d8e JK |
910 | if (unlikely(bio->bi_rw & REQ_DISCARD)) { |
911 | zram_bio_discard(zram, index, offset, bio); | |
912 | bio_endio(bio, 0); | |
913 | return; | |
914 | } | |
915 | ||
b627cff3 | 916 | rw = bio_data_dir(bio); |
7988613b | 917 | bio_for_each_segment(bvec, bio, iter) { |
924bd88d JM |
918 | int max_transfer_size = PAGE_SIZE - offset; |
919 | ||
7988613b | 920 | if (bvec.bv_len > max_transfer_size) { |
924bd88d JM |
921 | /* |
922 | * zram_bvec_rw() can only make operation on a single | |
923 | * zram page. Split the bio vector. | |
924 | */ | |
925 | struct bio_vec bv; | |
926 | ||
7988613b | 927 | bv.bv_page = bvec.bv_page; |
924bd88d | 928 | bv.bv_len = max_transfer_size; |
7988613b | 929 | bv.bv_offset = bvec.bv_offset; |
924bd88d | 930 | |
b627cff3 | 931 | if (zram_bvec_rw(zram, &bv, index, offset, rw) < 0) |
924bd88d JM |
932 | goto out; |
933 | ||
7988613b | 934 | bv.bv_len = bvec.bv_len - max_transfer_size; |
924bd88d | 935 | bv.bv_offset += max_transfer_size; |
b627cff3 | 936 | if (zram_bvec_rw(zram, &bv, index + 1, 0, rw) < 0) |
924bd88d JM |
937 | goto out; |
938 | } else | |
b627cff3 | 939 | if (zram_bvec_rw(zram, &bvec, index, offset, rw) < 0) |
924bd88d JM |
940 | goto out; |
941 | ||
7988613b | 942 | update_position(&index, &offset, &bvec); |
a1dd52af | 943 | } |
306b0c95 NG |
944 | |
945 | set_bit(BIO_UPTODATE, &bio->bi_flags); | |
946 | bio_endio(bio, 0); | |
7d7854b4 | 947 | return; |
306b0c95 NG |
948 | |
949 | out: | |
306b0c95 | 950 | bio_io_error(bio); |
306b0c95 NG |
951 | } |
952 | ||
306b0c95 | 953 | /* |
f1e3cfff | 954 | * Handler function for all zram I/O requests. |
306b0c95 | 955 | */ |
5a7bbad2 | 956 | static void zram_make_request(struct request_queue *queue, struct bio *bio) |
306b0c95 | 957 | { |
f1e3cfff | 958 | struct zram *zram = queue->queuedata; |
306b0c95 | 959 | |
08eee69f | 960 | if (unlikely(!zram_meta_get(zram))) |
3de738cd | 961 | goto error; |
0900beae | 962 | |
54850e73 | 963 | if (!valid_io_request(zram, bio->bi_iter.bi_sector, |
964 | bio->bi_iter.bi_size)) { | |
da5cc7d3 | 965 | atomic64_inc(&zram->stats.invalid_io); |
08eee69f | 966 | goto put_zram; |
6642a67c JM |
967 | } |
968 | ||
be257c61 | 969 | __zram_make_request(zram, bio); |
08eee69f | 970 | zram_meta_put(zram); |
b4fdcb02 | 971 | return; |
08eee69f MK |
972 | put_zram: |
973 | zram_meta_put(zram); | |
0900beae JM |
974 | error: |
975 | bio_io_error(bio); | |
306b0c95 NG |
976 | } |
977 | ||
2ccbec05 NG |
978 | static void zram_slot_free_notify(struct block_device *bdev, |
979 | unsigned long index) | |
107c161b | 980 | { |
f1e3cfff | 981 | struct zram *zram; |
f614a9f4 | 982 | struct zram_meta *meta; |
107c161b | 983 | |
f1e3cfff | 984 | zram = bdev->bd_disk->private_data; |
f614a9f4 | 985 | meta = zram->meta; |
a0c516cb | 986 | |
d2d5e762 | 987 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f614a9f4 | 988 | zram_free_page(zram, index); |
d2d5e762 | 989 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
f614a9f4 | 990 | atomic64_inc(&zram->stats.notify_free); |
107c161b NG |
991 | } |
992 | ||
8c7f0102 | 993 | static int zram_rw_page(struct block_device *bdev, sector_t sector, |
994 | struct page *page, int rw) | |
995 | { | |
08eee69f | 996 | int offset, err = -EIO; |
8c7f0102 | 997 | u32 index; |
998 | struct zram *zram; | |
999 | struct bio_vec bv; | |
1000 | ||
1001 | zram = bdev->bd_disk->private_data; | |
08eee69f MK |
1002 | if (unlikely(!zram_meta_get(zram))) |
1003 | goto out; | |
1004 | ||
8c7f0102 | 1005 | if (!valid_io_request(zram, sector, PAGE_SIZE)) { |
1006 | atomic64_inc(&zram->stats.invalid_io); | |
08eee69f MK |
1007 | err = -EINVAL; |
1008 | goto put_zram; | |
8c7f0102 | 1009 | } |
1010 | ||
1011 | index = sector >> SECTORS_PER_PAGE_SHIFT; | |
1012 | offset = sector & (SECTORS_PER_PAGE - 1) << SECTOR_SHIFT; | |
1013 | ||
1014 | bv.bv_page = page; | |
1015 | bv.bv_len = PAGE_SIZE; | |
1016 | bv.bv_offset = 0; | |
1017 | ||
1018 | err = zram_bvec_rw(zram, &bv, index, offset, rw); | |
08eee69f MK |
1019 | put_zram: |
1020 | zram_meta_put(zram); | |
1021 | out: | |
8c7f0102 | 1022 | /* |
1023 | * If I/O fails, just return error(ie, non-zero) without | |
1024 | * calling page_endio. | |
1025 | * It causes resubmit the I/O with bio request by upper functions | |
1026 | * of rw_page(e.g., swap_readpage, __swap_writepage) and | |
1027 | * bio->bi_end_io does things to handle the error | |
1028 | * (e.g., SetPageError, set_page_dirty and extra works). | |
1029 | */ | |
1030 | if (err == 0) | |
1031 | page_endio(page, rw, 0); | |
1032 | return err; | |
1033 | } | |
1034 | ||
f1e3cfff | 1035 | static const struct block_device_operations zram_devops = { |
f1e3cfff | 1036 | .swap_slot_free_notify = zram_slot_free_notify, |
8c7f0102 | 1037 | .rw_page = zram_rw_page, |
107c161b | 1038 | .owner = THIS_MODULE |
306b0c95 NG |
1039 | }; |
1040 | ||
083914ea GM |
1041 | static DEVICE_ATTR_RW(disksize); |
1042 | static DEVICE_ATTR_RO(initstate); | |
1043 | static DEVICE_ATTR_WO(reset); | |
1044 | static DEVICE_ATTR_RO(orig_data_size); | |
1045 | static DEVICE_ATTR_RO(mem_used_total); | |
1046 | static DEVICE_ATTR_RW(mem_limit); | |
1047 | static DEVICE_ATTR_RW(mem_used_max); | |
1048 | static DEVICE_ATTR_RW(max_comp_streams); | |
1049 | static DEVICE_ATTR_RW(comp_algorithm); | |
9b3bb7ab | 1050 | |
2f6a3bed SS |
1051 | static ssize_t io_stat_show(struct device *dev, |
1052 | struct device_attribute *attr, char *buf) | |
1053 | { | |
1054 | struct zram *zram = dev_to_zram(dev); | |
1055 | ssize_t ret; | |
1056 | ||
1057 | down_read(&zram->init_lock); | |
1058 | ret = scnprintf(buf, PAGE_SIZE, | |
1059 | "%8llu %8llu %8llu %8llu\n", | |
1060 | (u64)atomic64_read(&zram->stats.failed_reads), | |
1061 | (u64)atomic64_read(&zram->stats.failed_writes), | |
1062 | (u64)atomic64_read(&zram->stats.invalid_io), | |
1063 | (u64)atomic64_read(&zram->stats.notify_free)); | |
1064 | up_read(&zram->init_lock); | |
1065 | ||
1066 | return ret; | |
1067 | } | |
1068 | ||
4f2109f6 SS |
1069 | static ssize_t mm_stat_show(struct device *dev, |
1070 | struct device_attribute *attr, char *buf) | |
1071 | { | |
1072 | struct zram *zram = dev_to_zram(dev); | |
1073 | u64 orig_size, mem_used = 0; | |
1074 | long max_used; | |
1075 | ssize_t ret; | |
1076 | ||
1077 | down_read(&zram->init_lock); | |
1078 | if (init_done(zram)) | |
1079 | mem_used = zs_get_total_pages(zram->meta->mem_pool); | |
1080 | ||
1081 | orig_size = atomic64_read(&zram->stats.pages_stored); | |
1082 | max_used = atomic_long_read(&zram->stats.max_used_pages); | |
1083 | ||
1084 | ret = scnprintf(buf, PAGE_SIZE, | |
1085 | "%8llu %8llu %8llu %8lu %8ld %8llu %8llu\n", | |
1086 | orig_size << PAGE_SHIFT, | |
1087 | (u64)atomic64_read(&zram->stats.compr_data_size), | |
1088 | mem_used << PAGE_SHIFT, | |
1089 | zram->limit_pages << PAGE_SHIFT, | |
1090 | max_used << PAGE_SHIFT, | |
1091 | (u64)atomic64_read(&zram->stats.zero_pages), | |
1092 | (u64)atomic64_read(&zram->stats.num_migrated)); | |
1093 | up_read(&zram->init_lock); | |
1094 | ||
1095 | return ret; | |
1096 | } | |
1097 | ||
2f6a3bed | 1098 | static DEVICE_ATTR_RO(io_stat); |
4f2109f6 | 1099 | static DEVICE_ATTR_RO(mm_stat); |
a68eb3b6 SS |
1100 | ZRAM_ATTR_RO(num_reads); |
1101 | ZRAM_ATTR_RO(num_writes); | |
64447249 SS |
1102 | ZRAM_ATTR_RO(failed_reads); |
1103 | ZRAM_ATTR_RO(failed_writes); | |
a68eb3b6 SS |
1104 | ZRAM_ATTR_RO(invalid_io); |
1105 | ZRAM_ATTR_RO(notify_free); | |
1106 | ZRAM_ATTR_RO(zero_pages); | |
1107 | ZRAM_ATTR_RO(compr_data_size); | |
1108 | ||
9b3bb7ab SS |
1109 | static struct attribute *zram_disk_attrs[] = { |
1110 | &dev_attr_disksize.attr, | |
1111 | &dev_attr_initstate.attr, | |
1112 | &dev_attr_reset.attr, | |
1113 | &dev_attr_num_reads.attr, | |
1114 | &dev_attr_num_writes.attr, | |
64447249 SS |
1115 | &dev_attr_failed_reads.attr, |
1116 | &dev_attr_failed_writes.attr, | |
9b3bb7ab SS |
1117 | &dev_attr_invalid_io.attr, |
1118 | &dev_attr_notify_free.attr, | |
1119 | &dev_attr_zero_pages.attr, | |
1120 | &dev_attr_orig_data_size.attr, | |
1121 | &dev_attr_compr_data_size.attr, | |
1122 | &dev_attr_mem_used_total.attr, | |
9ada9da9 | 1123 | &dev_attr_mem_limit.attr, |
461a8eee | 1124 | &dev_attr_mem_used_max.attr, |
beca3ec7 | 1125 | &dev_attr_max_comp_streams.attr, |
e46b8a03 | 1126 | &dev_attr_comp_algorithm.attr, |
2f6a3bed | 1127 | &dev_attr_io_stat.attr, |
4f2109f6 | 1128 | &dev_attr_mm_stat.attr, |
9b3bb7ab SS |
1129 | NULL, |
1130 | }; | |
1131 | ||
1132 | static struct attribute_group zram_disk_attr_group = { | |
1133 | .attrs = zram_disk_attrs, | |
1134 | }; | |
1135 | ||
f1e3cfff | 1136 | static int create_device(struct zram *zram, int device_id) |
306b0c95 | 1137 | { |
ee980160 | 1138 | struct request_queue *queue; |
39a9b8ac | 1139 | int ret = -ENOMEM; |
de1a21a0 | 1140 | |
0900beae | 1141 | init_rwsem(&zram->init_lock); |
306b0c95 | 1142 | |
ee980160 SS |
1143 | queue = blk_alloc_queue(GFP_KERNEL); |
1144 | if (!queue) { | |
306b0c95 NG |
1145 | pr_err("Error allocating disk queue for device %d\n", |
1146 | device_id); | |
de1a21a0 | 1147 | goto out; |
306b0c95 NG |
1148 | } |
1149 | ||
ee980160 | 1150 | blk_queue_make_request(queue, zram_make_request); |
306b0c95 NG |
1151 | |
1152 | /* gendisk structure */ | |
f1e3cfff NG |
1153 | zram->disk = alloc_disk(1); |
1154 | if (!zram->disk) { | |
94b8435f | 1155 | pr_warn("Error allocating disk structure for device %d\n", |
306b0c95 | 1156 | device_id); |
39a9b8ac | 1157 | goto out_free_queue; |
306b0c95 NG |
1158 | } |
1159 | ||
f1e3cfff NG |
1160 | zram->disk->major = zram_major; |
1161 | zram->disk->first_minor = device_id; | |
1162 | zram->disk->fops = &zram_devops; | |
ee980160 SS |
1163 | zram->disk->queue = queue; |
1164 | zram->disk->queue->queuedata = zram; | |
f1e3cfff NG |
1165 | zram->disk->private_data = zram; |
1166 | snprintf(zram->disk->disk_name, 16, "zram%d", device_id); | |
306b0c95 | 1167 | |
33863c21 | 1168 | /* Actual capacity set using syfs (/sys/block/zram<id>/disksize */ |
f1e3cfff | 1169 | set_capacity(zram->disk, 0); |
b67d1ec1 SS |
1170 | /* zram devices sort of resembles non-rotational disks */ |
1171 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); | |
b277da0a | 1172 | queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, zram->disk->queue); |
a1dd52af NG |
1173 | /* |
1174 | * To ensure that we always get PAGE_SIZE aligned | |
1175 | * and n*PAGE_SIZED sized I/O requests. | |
1176 | */ | |
f1e3cfff | 1177 | blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE); |
7b19b8d4 RJ |
1178 | blk_queue_logical_block_size(zram->disk->queue, |
1179 | ZRAM_LOGICAL_BLOCK_SIZE); | |
f1e3cfff NG |
1180 | blk_queue_io_min(zram->disk->queue, PAGE_SIZE); |
1181 | blk_queue_io_opt(zram->disk->queue, PAGE_SIZE); | |
f4659d8e JK |
1182 | zram->disk->queue->limits.discard_granularity = PAGE_SIZE; |
1183 | zram->disk->queue->limits.max_discard_sectors = UINT_MAX; | |
1184 | /* | |
1185 | * zram_bio_discard() will clear all logical blocks if logical block | |
1186 | * size is identical with physical block size(PAGE_SIZE). But if it is | |
1187 | * different, we will skip discarding some parts of logical blocks in | |
1188 | * the part of the request range which isn't aligned to physical block | |
1189 | * size. So we can't ensure that all discarded logical blocks are | |
1190 | * zeroed. | |
1191 | */ | |
1192 | if (ZRAM_LOGICAL_BLOCK_SIZE == PAGE_SIZE) | |
1193 | zram->disk->queue->limits.discard_zeroes_data = 1; | |
1194 | else | |
1195 | zram->disk->queue->limits.discard_zeroes_data = 0; | |
1196 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, zram->disk->queue); | |
5d83d5a0 | 1197 | |
f1e3cfff | 1198 | add_disk(zram->disk); |
306b0c95 | 1199 | |
33863c21 NG |
1200 | ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj, |
1201 | &zram_disk_attr_group); | |
1202 | if (ret < 0) { | |
94b8435f | 1203 | pr_warn("Error creating sysfs group"); |
39a9b8ac | 1204 | goto out_free_disk; |
33863c21 | 1205 | } |
e46b8a03 | 1206 | strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor)); |
be2d1d56 | 1207 | zram->meta = NULL; |
beca3ec7 | 1208 | zram->max_comp_streams = 1; |
39a9b8ac | 1209 | return 0; |
de1a21a0 | 1210 | |
39a9b8ac JL |
1211 | out_free_disk: |
1212 | del_gendisk(zram->disk); | |
1213 | put_disk(zram->disk); | |
1214 | out_free_queue: | |
ee980160 | 1215 | blk_cleanup_queue(queue); |
de1a21a0 NG |
1216 | out: |
1217 | return ret; | |
306b0c95 NG |
1218 | } |
1219 | ||
a096cafc | 1220 | static void destroy_devices(unsigned int nr) |
306b0c95 | 1221 | { |
a096cafc SS |
1222 | struct zram *zram; |
1223 | unsigned int i; | |
33863c21 | 1224 | |
a096cafc SS |
1225 | for (i = 0; i < nr; i++) { |
1226 | zram = &zram_devices[i]; | |
1227 | /* | |
1228 | * Remove sysfs first, so no one will perform a disksize | |
1229 | * store while we destroy the devices | |
1230 | */ | |
1231 | sysfs_remove_group(&disk_to_dev(zram->disk)->kobj, | |
1232 | &zram_disk_attr_group); | |
306b0c95 | 1233 | |
a096cafc SS |
1234 | zram_reset_device(zram); |
1235 | ||
ee980160 | 1236 | blk_cleanup_queue(zram->disk->queue); |
a096cafc SS |
1237 | del_gendisk(zram->disk); |
1238 | put_disk(zram->disk); | |
a096cafc SS |
1239 | } |
1240 | ||
1241 | kfree(zram_devices); | |
1242 | unregister_blkdev(zram_major, "zram"); | |
1243 | pr_info("Destroyed %u device(s)\n", nr); | |
306b0c95 NG |
1244 | } |
1245 | ||
f1e3cfff | 1246 | static int __init zram_init(void) |
306b0c95 | 1247 | { |
de1a21a0 | 1248 | int ret, dev_id; |
306b0c95 | 1249 | |
5fa5a901 | 1250 | if (num_devices > max_num_devices) { |
94b8435f | 1251 | pr_warn("Invalid value for num_devices: %u\n", |
5fa5a901 | 1252 | num_devices); |
a096cafc | 1253 | return -EINVAL; |
306b0c95 NG |
1254 | } |
1255 | ||
f1e3cfff NG |
1256 | zram_major = register_blkdev(0, "zram"); |
1257 | if (zram_major <= 0) { | |
94b8435f | 1258 | pr_warn("Unable to get major number\n"); |
a096cafc | 1259 | return -EBUSY; |
306b0c95 NG |
1260 | } |
1261 | ||
306b0c95 | 1262 | /* Allocate the device array and initialize each one */ |
5fa5a901 | 1263 | zram_devices = kzalloc(num_devices * sizeof(struct zram), GFP_KERNEL); |
43801f6e | 1264 | if (!zram_devices) { |
a096cafc SS |
1265 | unregister_blkdev(zram_major, "zram"); |
1266 | return -ENOMEM; | |
de1a21a0 | 1267 | } |
306b0c95 | 1268 | |
5fa5a901 | 1269 | for (dev_id = 0; dev_id < num_devices; dev_id++) { |
43801f6e | 1270 | ret = create_device(&zram_devices[dev_id], dev_id); |
de1a21a0 | 1271 | if (ret) |
a096cafc | 1272 | goto out_error; |
de1a21a0 NG |
1273 | } |
1274 | ||
a096cafc | 1275 | pr_info("Created %u device(s)\n", num_devices); |
306b0c95 | 1276 | return 0; |
de1a21a0 | 1277 | |
a096cafc SS |
1278 | out_error: |
1279 | destroy_devices(dev_id); | |
306b0c95 NG |
1280 | return ret; |
1281 | } | |
1282 | ||
f1e3cfff | 1283 | static void __exit zram_exit(void) |
306b0c95 | 1284 | { |
a096cafc | 1285 | destroy_devices(num_devices); |
306b0c95 NG |
1286 | } |
1287 | ||
f1e3cfff NG |
1288 | module_init(zram_init); |
1289 | module_exit(zram_exit); | |
306b0c95 | 1290 | |
9b3bb7ab SS |
1291 | module_param(num_devices, uint, 0); |
1292 | MODULE_PARM_DESC(num_devices, "Number of zram devices"); | |
1293 | ||
306b0c95 NG |
1294 | MODULE_LICENSE("Dual BSD/GPL"); |
1295 | MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); | |
f1e3cfff | 1296 | MODULE_DESCRIPTION("Compressed RAM Block Device"); |