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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/lzo.h> |
306b0c95 | 33 | #include <linux/string.h> |
306b0c95 | 34 | #include <linux/vmalloc.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; |
306b0c95 | 41 | |
306b0c95 | 42 | /* Module params (documentation at end) */ |
ca3d70bd | 43 | static unsigned int num_devices = 1; |
33863c21 | 44 | |
be2d1d56 SS |
45 | static inline int init_done(struct zram *zram) |
46 | { | |
47 | return zram->meta != NULL; | |
48 | } | |
49 | ||
9b3bb7ab SS |
50 | static inline struct zram *dev_to_zram(struct device *dev) |
51 | { | |
52 | return (struct zram *)dev_to_disk(dev)->private_data; | |
53 | } | |
54 | ||
55 | static ssize_t disksize_show(struct device *dev, | |
56 | struct device_attribute *attr, char *buf) | |
57 | { | |
58 | struct zram *zram = dev_to_zram(dev); | |
59 | ||
60 | return sprintf(buf, "%llu\n", zram->disksize); | |
61 | } | |
62 | ||
63 | static ssize_t initstate_show(struct device *dev, | |
64 | struct device_attribute *attr, char *buf) | |
65 | { | |
66 | struct zram *zram = dev_to_zram(dev); | |
67 | ||
be2d1d56 | 68 | return sprintf(buf, "%u\n", init_done(zram)); |
9b3bb7ab SS |
69 | } |
70 | ||
71 | static ssize_t num_reads_show(struct device *dev, | |
72 | struct device_attribute *attr, char *buf) | |
73 | { | |
74 | struct zram *zram = dev_to_zram(dev); | |
75 | ||
76 | return sprintf(buf, "%llu\n", | |
77 | (u64)atomic64_read(&zram->stats.num_reads)); | |
78 | } | |
79 | ||
80 | static ssize_t num_writes_show(struct device *dev, | |
81 | struct device_attribute *attr, char *buf) | |
82 | { | |
83 | struct zram *zram = dev_to_zram(dev); | |
84 | ||
85 | return sprintf(buf, "%llu\n", | |
86 | (u64)atomic64_read(&zram->stats.num_writes)); | |
87 | } | |
88 | ||
89 | static ssize_t invalid_io_show(struct device *dev, | |
90 | struct device_attribute *attr, char *buf) | |
91 | { | |
92 | struct zram *zram = dev_to_zram(dev); | |
93 | ||
94 | return sprintf(buf, "%llu\n", | |
95 | (u64)atomic64_read(&zram->stats.invalid_io)); | |
96 | } | |
97 | ||
98 | static ssize_t notify_free_show(struct device *dev, | |
99 | struct device_attribute *attr, char *buf) | |
100 | { | |
101 | struct zram *zram = dev_to_zram(dev); | |
102 | ||
103 | return sprintf(buf, "%llu\n", | |
104 | (u64)atomic64_read(&zram->stats.notify_free)); | |
105 | } | |
106 | ||
107 | static ssize_t zero_pages_show(struct device *dev, | |
108 | struct device_attribute *attr, char *buf) | |
109 | { | |
110 | struct zram *zram = dev_to_zram(dev); | |
111 | ||
deb0bdeb | 112 | return sprintf(buf, "%u\n", atomic_read(&zram->stats.pages_zero)); |
9b3bb7ab SS |
113 | } |
114 | ||
115 | static ssize_t orig_data_size_show(struct device *dev, | |
116 | struct device_attribute *attr, char *buf) | |
117 | { | |
118 | struct zram *zram = dev_to_zram(dev); | |
119 | ||
120 | return sprintf(buf, "%llu\n", | |
deb0bdeb | 121 | (u64)(atomic_read(&zram->stats.pages_stored)) << PAGE_SHIFT); |
9b3bb7ab SS |
122 | } |
123 | ||
124 | static ssize_t compr_data_size_show(struct device *dev, | |
125 | struct device_attribute *attr, char *buf) | |
126 | { | |
127 | struct zram *zram = dev_to_zram(dev); | |
128 | ||
129 | return sprintf(buf, "%llu\n", | |
130 | (u64)atomic64_read(&zram->stats.compr_size)); | |
131 | } | |
132 | ||
133 | static ssize_t mem_used_total_show(struct device *dev, | |
134 | struct device_attribute *attr, char *buf) | |
135 | { | |
136 | u64 val = 0; | |
137 | struct zram *zram = dev_to_zram(dev); | |
138 | struct zram_meta *meta = zram->meta; | |
139 | ||
140 | down_read(&zram->init_lock); | |
be2d1d56 | 141 | if (init_done(zram)) |
9b3bb7ab SS |
142 | val = zs_get_total_size_bytes(meta->mem_pool); |
143 | up_read(&zram->init_lock); | |
144 | ||
145 | return sprintf(buf, "%llu\n", val); | |
146 | } | |
147 | ||
92967471 | 148 | /* flag operations needs meta->tb_lock */ |
8b3cc3ed | 149 | static int zram_test_flag(struct zram_meta *meta, u32 index, |
f1e3cfff | 150 | enum zram_pageflags flag) |
306b0c95 | 151 | { |
8b3cc3ed | 152 | return meta->table[index].flags & BIT(flag); |
306b0c95 NG |
153 | } |
154 | ||
8b3cc3ed | 155 | static void zram_set_flag(struct zram_meta *meta, u32 index, |
f1e3cfff | 156 | enum zram_pageflags flag) |
306b0c95 | 157 | { |
8b3cc3ed | 158 | meta->table[index].flags |= BIT(flag); |
306b0c95 NG |
159 | } |
160 | ||
8b3cc3ed | 161 | static void zram_clear_flag(struct zram_meta *meta, u32 index, |
f1e3cfff | 162 | enum zram_pageflags flag) |
306b0c95 | 163 | { |
8b3cc3ed | 164 | meta->table[index].flags &= ~BIT(flag); |
306b0c95 NG |
165 | } |
166 | ||
9b3bb7ab SS |
167 | static inline int is_partial_io(struct bio_vec *bvec) |
168 | { | |
169 | return bvec->bv_len != PAGE_SIZE; | |
170 | } | |
171 | ||
172 | /* | |
173 | * Check if request is within bounds and aligned on zram logical blocks. | |
174 | */ | |
175 | static inline int valid_io_request(struct zram *zram, struct bio *bio) | |
176 | { | |
177 | u64 start, end, bound; | |
a539c72a | 178 | |
9b3bb7ab | 179 | /* unaligned request */ |
4f024f37 KO |
180 | if (unlikely(bio->bi_iter.bi_sector & |
181 | (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1))) | |
9b3bb7ab | 182 | return 0; |
4f024f37 | 183 | if (unlikely(bio->bi_iter.bi_size & (ZRAM_LOGICAL_BLOCK_SIZE - 1))) |
9b3bb7ab SS |
184 | return 0; |
185 | ||
4f024f37 KO |
186 | start = bio->bi_iter.bi_sector; |
187 | end = start + (bio->bi_iter.bi_size >> SECTOR_SHIFT); | |
9b3bb7ab SS |
188 | bound = zram->disksize >> SECTOR_SHIFT; |
189 | /* out of range range */ | |
75c7caf5 | 190 | if (unlikely(start >= bound || end > bound || start > end)) |
9b3bb7ab SS |
191 | return 0; |
192 | ||
193 | /* I/O request is valid */ | |
194 | return 1; | |
195 | } | |
196 | ||
197 | static void zram_meta_free(struct zram_meta *meta) | |
198 | { | |
199 | zs_destroy_pool(meta->mem_pool); | |
200 | kfree(meta->compress_workmem); | |
201 | free_pages((unsigned long)meta->compress_buffer, 1); | |
202 | vfree(meta->table); | |
203 | kfree(meta); | |
204 | } | |
205 | ||
206 | static struct zram_meta *zram_meta_alloc(u64 disksize) | |
207 | { | |
208 | size_t num_pages; | |
209 | struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL); | |
210 | if (!meta) | |
211 | goto out; | |
212 | ||
213 | meta->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); | |
214 | if (!meta->compress_workmem) | |
215 | goto free_meta; | |
216 | ||
217 | meta->compress_buffer = | |
218 | (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1); | |
219 | if (!meta->compress_buffer) { | |
220 | pr_err("Error allocating compressor buffer space\n"); | |
221 | goto free_workmem; | |
222 | } | |
223 | ||
224 | num_pages = disksize >> PAGE_SHIFT; | |
225 | meta->table = vzalloc(num_pages * sizeof(*meta->table)); | |
226 | if (!meta->table) { | |
227 | pr_err("Error allocating zram address table\n"); | |
228 | goto free_buffer; | |
229 | } | |
230 | ||
231 | meta->mem_pool = zs_create_pool(GFP_NOIO | __GFP_HIGHMEM); | |
232 | if (!meta->mem_pool) { | |
233 | pr_err("Error creating memory pool\n"); | |
234 | goto free_table; | |
235 | } | |
236 | ||
92967471 | 237 | rwlock_init(&meta->tb_lock); |
e46e3315 | 238 | mutex_init(&meta->buffer_lock); |
9b3bb7ab SS |
239 | return meta; |
240 | ||
241 | free_table: | |
242 | vfree(meta->table); | |
243 | free_buffer: | |
244 | free_pages((unsigned long)meta->compress_buffer, 1); | |
245 | free_workmem: | |
246 | kfree(meta->compress_workmem); | |
247 | free_meta: | |
248 | kfree(meta); | |
249 | meta = NULL; | |
250 | out: | |
251 | return meta; | |
252 | } | |
253 | ||
254 | static void update_position(u32 *index, int *offset, struct bio_vec *bvec) | |
255 | { | |
256 | if (*offset + bvec->bv_len >= PAGE_SIZE) | |
257 | (*index)++; | |
258 | *offset = (*offset + bvec->bv_len) % PAGE_SIZE; | |
259 | } | |
260 | ||
306b0c95 NG |
261 | static int page_zero_filled(void *ptr) |
262 | { | |
263 | unsigned int pos; | |
264 | unsigned long *page; | |
265 | ||
266 | page = (unsigned long *)ptr; | |
267 | ||
268 | for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) { | |
269 | if (page[pos]) | |
270 | return 0; | |
271 | } | |
272 | ||
273 | return 1; | |
274 | } | |
275 | ||
9b3bb7ab SS |
276 | static void handle_zero_page(struct bio_vec *bvec) |
277 | { | |
278 | struct page *page = bvec->bv_page; | |
279 | void *user_mem; | |
280 | ||
281 | user_mem = kmap_atomic(page); | |
282 | if (is_partial_io(bvec)) | |
283 | memset(user_mem + bvec->bv_offset, 0, bvec->bv_len); | |
284 | else | |
285 | clear_page(user_mem); | |
286 | kunmap_atomic(user_mem); | |
287 | ||
288 | flush_dcache_page(page); | |
289 | } | |
290 | ||
92967471 | 291 | /* NOTE: caller should hold meta->tb_lock with write-side */ |
f1e3cfff | 292 | static void zram_free_page(struct zram *zram, size_t index) |
306b0c95 | 293 | { |
8b3cc3ed MK |
294 | struct zram_meta *meta = zram->meta; |
295 | unsigned long handle = meta->table[index].handle; | |
296 | u16 size = meta->table[index].size; | |
306b0c95 | 297 | |
fd1a30de | 298 | if (unlikely(!handle)) { |
2e882281 NG |
299 | /* |
300 | * No memory is allocated for zero filled pages. | |
301 | * Simply clear zero page flag. | |
302 | */ | |
8b3cc3ed MK |
303 | if (zram_test_flag(meta, index, ZRAM_ZERO)) { |
304 | zram_clear_flag(meta, index, ZRAM_ZERO); | |
deb0bdeb | 305 | atomic_dec(&zram->stats.pages_zero); |
306b0c95 NG |
306 | } |
307 | return; | |
308 | } | |
309 | ||
130f315a | 310 | if (unlikely(size > max_zpage_size)) |
deb0bdeb | 311 | atomic_dec(&zram->stats.bad_compress); |
306b0c95 | 312 | |
8b3cc3ed | 313 | zs_free(meta->mem_pool, handle); |
306b0c95 | 314 | |
130f315a | 315 | if (size <= PAGE_SIZE / 2) |
deb0bdeb | 316 | atomic_dec(&zram->stats.good_compress); |
306b0c95 | 317 | |
da5cc7d3 | 318 | atomic64_sub(meta->table[index].size, &zram->stats.compr_size); |
deb0bdeb | 319 | atomic_dec(&zram->stats.pages_stored); |
306b0c95 | 320 | |
8b3cc3ed MK |
321 | meta->table[index].handle = 0; |
322 | meta->table[index].size = 0; | |
306b0c95 NG |
323 | } |
324 | ||
37b51fdd | 325 | static int zram_decompress_page(struct zram *zram, char *mem, u32 index) |
306b0c95 | 326 | { |
37b51fdd SS |
327 | int ret = LZO_E_OK; |
328 | size_t clen = PAGE_SIZE; | |
329 | unsigned char *cmem; | |
8b3cc3ed | 330 | struct zram_meta *meta = zram->meta; |
92967471 MK |
331 | unsigned long handle; |
332 | u16 size; | |
333 | ||
334 | read_lock(&meta->tb_lock); | |
335 | handle = meta->table[index].handle; | |
336 | size = meta->table[index].size; | |
306b0c95 | 337 | |
8b3cc3ed | 338 | if (!handle || zram_test_flag(meta, index, ZRAM_ZERO)) { |
92967471 | 339 | read_unlock(&meta->tb_lock); |
42e99bd9 | 340 | clear_page(mem); |
8c921b2b JM |
341 | return 0; |
342 | } | |
306b0c95 | 343 | |
8b3cc3ed | 344 | cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO); |
92967471 | 345 | if (size == PAGE_SIZE) |
42e99bd9 | 346 | copy_page(mem, cmem); |
37b51fdd | 347 | else |
92967471 | 348 | ret = lzo1x_decompress_safe(cmem, size, mem, &clen); |
8b3cc3ed | 349 | zs_unmap_object(meta->mem_pool, handle); |
92967471 | 350 | read_unlock(&meta->tb_lock); |
a1dd52af | 351 | |
8c921b2b JM |
352 | /* Should NEVER happen. Return bio error if it does. */ |
353 | if (unlikely(ret != LZO_E_OK)) { | |
354 | pr_err("Decompression failed! err=%d, page=%u\n", ret, index); | |
da5cc7d3 | 355 | atomic64_inc(&zram->stats.failed_reads); |
8c921b2b | 356 | return ret; |
a1dd52af | 357 | } |
306b0c95 | 358 | |
8c921b2b | 359 | return 0; |
306b0c95 NG |
360 | } |
361 | ||
37b51fdd SS |
362 | static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, |
363 | u32 index, int offset, struct bio *bio) | |
924bd88d JM |
364 | { |
365 | int ret; | |
37b51fdd SS |
366 | struct page *page; |
367 | unsigned char *user_mem, *uncmem = NULL; | |
8b3cc3ed | 368 | struct zram_meta *meta = zram->meta; |
37b51fdd SS |
369 | page = bvec->bv_page; |
370 | ||
92967471 | 371 | read_lock(&meta->tb_lock); |
8b3cc3ed MK |
372 | if (unlikely(!meta->table[index].handle) || |
373 | zram_test_flag(meta, index, ZRAM_ZERO)) { | |
92967471 | 374 | read_unlock(&meta->tb_lock); |
37b51fdd | 375 | handle_zero_page(bvec); |
924bd88d JM |
376 | return 0; |
377 | } | |
92967471 | 378 | read_unlock(&meta->tb_lock); |
924bd88d | 379 | |
37b51fdd SS |
380 | if (is_partial_io(bvec)) |
381 | /* Use a temporary buffer to decompress the page */ | |
7e5a5104 MK |
382 | uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); |
383 | ||
384 | user_mem = kmap_atomic(page); | |
385 | if (!is_partial_io(bvec)) | |
37b51fdd SS |
386 | uncmem = user_mem; |
387 | ||
388 | if (!uncmem) { | |
389 | pr_info("Unable to allocate temp memory\n"); | |
390 | ret = -ENOMEM; | |
391 | goto out_cleanup; | |
392 | } | |
924bd88d | 393 | |
37b51fdd | 394 | ret = zram_decompress_page(zram, uncmem, index); |
924bd88d | 395 | /* Should NEVER happen. Return bio error if it does. */ |
25eeb667 | 396 | if (unlikely(ret != LZO_E_OK)) |
37b51fdd | 397 | goto out_cleanup; |
924bd88d | 398 | |
37b51fdd SS |
399 | if (is_partial_io(bvec)) |
400 | memcpy(user_mem + bvec->bv_offset, uncmem + offset, | |
401 | bvec->bv_len); | |
402 | ||
403 | flush_dcache_page(page); | |
404 | ret = 0; | |
405 | out_cleanup: | |
406 | kunmap_atomic(user_mem); | |
407 | if (is_partial_io(bvec)) | |
408 | kfree(uncmem); | |
409 | return ret; | |
924bd88d JM |
410 | } |
411 | ||
412 | static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, | |
413 | int offset) | |
306b0c95 | 414 | { |
397c6066 | 415 | int ret = 0; |
8c921b2b | 416 | size_t clen; |
c2344348 | 417 | unsigned long handle; |
130f315a | 418 | struct page *page; |
924bd88d | 419 | unsigned char *user_mem, *cmem, *src, *uncmem = NULL; |
8b3cc3ed | 420 | struct zram_meta *meta = zram->meta; |
e46e3315 | 421 | bool locked = false; |
306b0c95 | 422 | |
8c921b2b | 423 | page = bvec->bv_page; |
8b3cc3ed | 424 | src = meta->compress_buffer; |
306b0c95 | 425 | |
924bd88d JM |
426 | if (is_partial_io(bvec)) { |
427 | /* | |
428 | * This is a partial IO. We need to read the full page | |
429 | * before to write the changes. | |
430 | */ | |
7e5a5104 | 431 | uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); |
924bd88d | 432 | if (!uncmem) { |
924bd88d JM |
433 | ret = -ENOMEM; |
434 | goto out; | |
435 | } | |
37b51fdd | 436 | ret = zram_decompress_page(zram, uncmem, index); |
397c6066 | 437 | if (ret) |
924bd88d | 438 | goto out; |
924bd88d JM |
439 | } |
440 | ||
e46e3315 MK |
441 | mutex_lock(&meta->buffer_lock); |
442 | locked = true; | |
ba82fe2e | 443 | user_mem = kmap_atomic(page); |
924bd88d | 444 | |
397c6066 | 445 | if (is_partial_io(bvec)) { |
924bd88d JM |
446 | memcpy(uncmem + offset, user_mem + bvec->bv_offset, |
447 | bvec->bv_len); | |
397c6066 NG |
448 | kunmap_atomic(user_mem); |
449 | user_mem = NULL; | |
450 | } else { | |
924bd88d | 451 | uncmem = user_mem; |
397c6066 | 452 | } |
924bd88d JM |
453 | |
454 | if (page_zero_filled(uncmem)) { | |
ba82fe2e | 455 | kunmap_atomic(user_mem); |
f40ac2ae | 456 | /* Free memory associated with this sector now. */ |
92967471 | 457 | write_lock(&zram->meta->tb_lock); |
f40ac2ae | 458 | zram_free_page(zram, index); |
92967471 MK |
459 | zram_set_flag(meta, index, ZRAM_ZERO); |
460 | write_unlock(&zram->meta->tb_lock); | |
f40ac2ae | 461 | |
deb0bdeb | 462 | atomic_inc(&zram->stats.pages_zero); |
924bd88d JM |
463 | ret = 0; |
464 | goto out; | |
8c921b2b | 465 | } |
306b0c95 | 466 | |
924bd88d | 467 | ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen, |
8b3cc3ed | 468 | meta->compress_workmem); |
397c6066 NG |
469 | if (!is_partial_io(bvec)) { |
470 | kunmap_atomic(user_mem); | |
471 | user_mem = NULL; | |
472 | uncmem = NULL; | |
473 | } | |
306b0c95 | 474 | |
8c921b2b | 475 | if (unlikely(ret != LZO_E_OK)) { |
8c921b2b | 476 | pr_err("Compression failed! err=%d\n", ret); |
924bd88d | 477 | goto out; |
8c921b2b | 478 | } |
306b0c95 | 479 | |
c8f2f0db | 480 | if (unlikely(clen > max_zpage_size)) { |
deb0bdeb | 481 | atomic_inc(&zram->stats.bad_compress); |
c8f2f0db | 482 | clen = PAGE_SIZE; |
397c6066 NG |
483 | src = NULL; |
484 | if (is_partial_io(bvec)) | |
485 | src = uncmem; | |
c8f2f0db | 486 | } |
a1dd52af | 487 | |
8b3cc3ed | 488 | handle = zs_malloc(meta->mem_pool, clen); |
fd1a30de | 489 | if (!handle) { |
596b3dd4 MR |
490 | pr_info("Error allocating memory for compressed page: %u, size=%zu\n", |
491 | index, clen); | |
924bd88d JM |
492 | ret = -ENOMEM; |
493 | goto out; | |
8c921b2b | 494 | } |
8b3cc3ed | 495 | cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO); |
306b0c95 | 496 | |
42e99bd9 | 497 | if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) { |
397c6066 | 498 | src = kmap_atomic(page); |
42e99bd9 | 499 | copy_page(cmem, src); |
397c6066 | 500 | kunmap_atomic(src); |
42e99bd9 JL |
501 | } else { |
502 | memcpy(cmem, src, clen); | |
503 | } | |
306b0c95 | 504 | |
8b3cc3ed | 505 | zs_unmap_object(meta->mem_pool, handle); |
fd1a30de | 506 | |
f40ac2ae SS |
507 | /* |
508 | * Free memory associated with this sector | |
509 | * before overwriting unused sectors. | |
510 | */ | |
92967471 | 511 | write_lock(&zram->meta->tb_lock); |
f40ac2ae SS |
512 | zram_free_page(zram, index); |
513 | ||
8b3cc3ed MK |
514 | meta->table[index].handle = handle; |
515 | meta->table[index].size = clen; | |
92967471 | 516 | write_unlock(&zram->meta->tb_lock); |
306b0c95 | 517 | |
8c921b2b | 518 | /* Update stats */ |
da5cc7d3 | 519 | atomic64_add(clen, &zram->stats.compr_size); |
deb0bdeb | 520 | atomic_inc(&zram->stats.pages_stored); |
8c921b2b | 521 | if (clen <= PAGE_SIZE / 2) |
deb0bdeb | 522 | atomic_inc(&zram->stats.good_compress); |
306b0c95 | 523 | |
924bd88d | 524 | out: |
e46e3315 MK |
525 | if (locked) |
526 | mutex_unlock(&meta->buffer_lock); | |
397c6066 NG |
527 | if (is_partial_io(bvec)) |
528 | kfree(uncmem); | |
529 | ||
924bd88d | 530 | if (ret) |
da5cc7d3 | 531 | atomic64_inc(&zram->stats.failed_writes); |
924bd88d | 532 | return ret; |
8c921b2b JM |
533 | } |
534 | ||
535 | static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, | |
924bd88d | 536 | int offset, struct bio *bio, int rw) |
8c921b2b | 537 | { |
c5bde238 | 538 | int ret; |
8c921b2b | 539 | |
e46e3315 | 540 | if (rw == READ) |
c5bde238 | 541 | ret = zram_bvec_read(zram, bvec, index, offset, bio); |
e46e3315 | 542 | else |
c5bde238 | 543 | ret = zram_bvec_write(zram, bvec, index, offset); |
c5bde238 JM |
544 | |
545 | return ret; | |
924bd88d JM |
546 | } |
547 | ||
2b86ab9c | 548 | static void zram_reset_device(struct zram *zram, bool reset_capacity) |
924bd88d | 549 | { |
9b3bb7ab SS |
550 | size_t index; |
551 | struct zram_meta *meta; | |
552 | ||
644d4787 | 553 | down_write(&zram->init_lock); |
be2d1d56 | 554 | if (!init_done(zram)) { |
644d4787 | 555 | up_write(&zram->init_lock); |
9b3bb7ab | 556 | return; |
644d4787 | 557 | } |
9b3bb7ab SS |
558 | |
559 | meta = zram->meta; | |
9b3bb7ab SS |
560 | /* Free all pages that are still in this zram device */ |
561 | for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) { | |
562 | unsigned long handle = meta->table[index].handle; | |
563 | if (!handle) | |
564 | continue; | |
565 | ||
566 | zs_free(meta->mem_pool, handle); | |
567 | } | |
568 | ||
569 | zram_meta_free(zram->meta); | |
570 | zram->meta = NULL; | |
571 | /* Reset stats */ | |
572 | memset(&zram->stats, 0, sizeof(zram->stats)); | |
573 | ||
574 | zram->disksize = 0; | |
2b86ab9c MK |
575 | if (reset_capacity) |
576 | set_capacity(zram->disk, 0); | |
644d4787 | 577 | up_write(&zram->init_lock); |
9b3bb7ab SS |
578 | } |
579 | ||
580 | static void zram_init_device(struct zram *zram, struct zram_meta *meta) | |
581 | { | |
582 | if (zram->disksize > 2 * (totalram_pages << PAGE_SHIFT)) { | |
583 | pr_info( | |
584 | "There is little point creating a zram of greater than " | |
585 | "twice the size of memory since we expect a 2:1 compression " | |
586 | "ratio. Note that zram uses about 0.1%% of the size of " | |
587 | "the disk when not in use so a huge zram is " | |
588 | "wasteful.\n" | |
589 | "\tMemory Size: %lu kB\n" | |
590 | "\tSize you selected: %llu kB\n" | |
591 | "Continuing anyway ...\n", | |
592 | (totalram_pages << PAGE_SHIFT) >> 10, zram->disksize >> 10 | |
593 | ); | |
594 | } | |
595 | ||
596 | /* zram devices sort of resembles non-rotational disks */ | |
597 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); | |
598 | ||
599 | zram->meta = meta; | |
9b3bb7ab SS |
600 | pr_debug("Initialization done!\n"); |
601 | } | |
602 | ||
603 | static ssize_t disksize_store(struct device *dev, | |
604 | struct device_attribute *attr, const char *buf, size_t len) | |
605 | { | |
606 | u64 disksize; | |
607 | struct zram_meta *meta; | |
608 | struct zram *zram = dev_to_zram(dev); | |
609 | ||
610 | disksize = memparse(buf, NULL); | |
611 | if (!disksize) | |
612 | return -EINVAL; | |
613 | ||
614 | disksize = PAGE_ALIGN(disksize); | |
615 | meta = zram_meta_alloc(disksize); | |
db5d711e MK |
616 | if (!meta) |
617 | return -ENOMEM; | |
9b3bb7ab | 618 | down_write(&zram->init_lock); |
be2d1d56 | 619 | if (init_done(zram)) { |
9b3bb7ab SS |
620 | up_write(&zram->init_lock); |
621 | zram_meta_free(meta); | |
622 | pr_info("Cannot change disksize for initialized device\n"); | |
623 | return -EBUSY; | |
624 | } | |
625 | ||
626 | zram->disksize = disksize; | |
627 | set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); | |
628 | zram_init_device(zram, meta); | |
629 | up_write(&zram->init_lock); | |
630 | ||
631 | return len; | |
632 | } | |
633 | ||
634 | static ssize_t reset_store(struct device *dev, | |
635 | struct device_attribute *attr, const char *buf, size_t len) | |
636 | { | |
637 | int ret; | |
638 | unsigned short do_reset; | |
639 | struct zram *zram; | |
640 | struct block_device *bdev; | |
641 | ||
642 | zram = dev_to_zram(dev); | |
643 | bdev = bdget_disk(zram->disk, 0); | |
644 | ||
46a51c80 RK |
645 | if (!bdev) |
646 | return -ENOMEM; | |
647 | ||
9b3bb7ab | 648 | /* Do not reset an active device! */ |
1b672224 RK |
649 | if (bdev->bd_holders) { |
650 | ret = -EBUSY; | |
651 | goto out; | |
652 | } | |
9b3bb7ab SS |
653 | |
654 | ret = kstrtou16(buf, 10, &do_reset); | |
655 | if (ret) | |
1b672224 | 656 | goto out; |
9b3bb7ab | 657 | |
1b672224 RK |
658 | if (!do_reset) { |
659 | ret = -EINVAL; | |
660 | goto out; | |
661 | } | |
9b3bb7ab SS |
662 | |
663 | /* Make sure all pending I/O is finished */ | |
46a51c80 | 664 | fsync_bdev(bdev); |
1b672224 | 665 | bdput(bdev); |
9b3bb7ab | 666 | |
2b86ab9c | 667 | zram_reset_device(zram, true); |
9b3bb7ab | 668 | return len; |
1b672224 RK |
669 | |
670 | out: | |
671 | bdput(bdev); | |
672 | return ret; | |
8c921b2b JM |
673 | } |
674 | ||
675 | static void __zram_make_request(struct zram *zram, struct bio *bio, int rw) | |
676 | { | |
7988613b | 677 | int offset; |
8c921b2b | 678 | u32 index; |
7988613b KO |
679 | struct bio_vec bvec; |
680 | struct bvec_iter iter; | |
8c921b2b JM |
681 | |
682 | switch (rw) { | |
683 | case READ: | |
da5cc7d3 | 684 | atomic64_inc(&zram->stats.num_reads); |
8c921b2b JM |
685 | break; |
686 | case WRITE: | |
da5cc7d3 | 687 | atomic64_inc(&zram->stats.num_writes); |
8c921b2b JM |
688 | break; |
689 | } | |
690 | ||
4f024f37 KO |
691 | index = bio->bi_iter.bi_sector >> SECTORS_PER_PAGE_SHIFT; |
692 | offset = (bio->bi_iter.bi_sector & | |
693 | (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; | |
8c921b2b | 694 | |
7988613b | 695 | bio_for_each_segment(bvec, bio, iter) { |
924bd88d JM |
696 | int max_transfer_size = PAGE_SIZE - offset; |
697 | ||
7988613b | 698 | if (bvec.bv_len > max_transfer_size) { |
924bd88d JM |
699 | /* |
700 | * zram_bvec_rw() can only make operation on a single | |
701 | * zram page. Split the bio vector. | |
702 | */ | |
703 | struct bio_vec bv; | |
704 | ||
7988613b | 705 | bv.bv_page = bvec.bv_page; |
924bd88d | 706 | bv.bv_len = max_transfer_size; |
7988613b | 707 | bv.bv_offset = bvec.bv_offset; |
924bd88d JM |
708 | |
709 | if (zram_bvec_rw(zram, &bv, index, offset, bio, rw) < 0) | |
710 | goto out; | |
711 | ||
7988613b | 712 | bv.bv_len = bvec.bv_len - max_transfer_size; |
924bd88d JM |
713 | bv.bv_offset += max_transfer_size; |
714 | if (zram_bvec_rw(zram, &bv, index+1, 0, bio, rw) < 0) | |
715 | goto out; | |
716 | } else | |
7988613b | 717 | if (zram_bvec_rw(zram, &bvec, index, offset, bio, rw) |
924bd88d JM |
718 | < 0) |
719 | goto out; | |
720 | ||
7988613b | 721 | update_position(&index, &offset, &bvec); |
a1dd52af | 722 | } |
306b0c95 NG |
723 | |
724 | set_bit(BIO_UPTODATE, &bio->bi_flags); | |
725 | bio_endio(bio, 0); | |
7d7854b4 | 726 | return; |
306b0c95 NG |
727 | |
728 | out: | |
306b0c95 | 729 | bio_io_error(bio); |
306b0c95 NG |
730 | } |
731 | ||
306b0c95 | 732 | /* |
f1e3cfff | 733 | * Handler function for all zram I/O requests. |
306b0c95 | 734 | */ |
5a7bbad2 | 735 | static void zram_make_request(struct request_queue *queue, struct bio *bio) |
306b0c95 | 736 | { |
f1e3cfff | 737 | struct zram *zram = queue->queuedata; |
306b0c95 | 738 | |
0900beae | 739 | down_read(&zram->init_lock); |
be2d1d56 | 740 | if (unlikely(!init_done(zram))) |
3de738cd | 741 | goto error; |
0900beae | 742 | |
f1e3cfff | 743 | if (!valid_io_request(zram, bio)) { |
da5cc7d3 | 744 | atomic64_inc(&zram->stats.invalid_io); |
3de738cd | 745 | goto error; |
6642a67c JM |
746 | } |
747 | ||
8c921b2b | 748 | __zram_make_request(zram, bio, bio_data_dir(bio)); |
0900beae | 749 | up_read(&zram->init_lock); |
306b0c95 | 750 | |
b4fdcb02 | 751 | return; |
0900beae | 752 | |
0900beae | 753 | error: |
3de738cd | 754 | up_read(&zram->init_lock); |
0900beae | 755 | bio_io_error(bio); |
306b0c95 NG |
756 | } |
757 | ||
2ccbec05 NG |
758 | static void zram_slot_free_notify(struct block_device *bdev, |
759 | unsigned long index) | |
107c161b | 760 | { |
f1e3cfff | 761 | struct zram *zram; |
f614a9f4 | 762 | struct zram_meta *meta; |
107c161b | 763 | |
f1e3cfff | 764 | zram = bdev->bd_disk->private_data; |
f614a9f4 | 765 | meta = zram->meta; |
a0c516cb | 766 | |
f614a9f4 MK |
767 | write_lock(&meta->tb_lock); |
768 | zram_free_page(zram, index); | |
769 | write_unlock(&meta->tb_lock); | |
770 | atomic64_inc(&zram->stats.notify_free); | |
107c161b NG |
771 | } |
772 | ||
f1e3cfff | 773 | static const struct block_device_operations zram_devops = { |
f1e3cfff | 774 | .swap_slot_free_notify = zram_slot_free_notify, |
107c161b | 775 | .owner = THIS_MODULE |
306b0c95 NG |
776 | }; |
777 | ||
9b3bb7ab SS |
778 | static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR, |
779 | disksize_show, disksize_store); | |
780 | static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL); | |
781 | static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store); | |
782 | static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL); | |
783 | static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL); | |
784 | static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL); | |
785 | static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL); | |
786 | static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL); | |
787 | static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL); | |
788 | static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL); | |
789 | static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL); | |
790 | ||
791 | static struct attribute *zram_disk_attrs[] = { | |
792 | &dev_attr_disksize.attr, | |
793 | &dev_attr_initstate.attr, | |
794 | &dev_attr_reset.attr, | |
795 | &dev_attr_num_reads.attr, | |
796 | &dev_attr_num_writes.attr, | |
797 | &dev_attr_invalid_io.attr, | |
798 | &dev_attr_notify_free.attr, | |
799 | &dev_attr_zero_pages.attr, | |
800 | &dev_attr_orig_data_size.attr, | |
801 | &dev_attr_compr_data_size.attr, | |
802 | &dev_attr_mem_used_total.attr, | |
803 | NULL, | |
804 | }; | |
805 | ||
806 | static struct attribute_group zram_disk_attr_group = { | |
807 | .attrs = zram_disk_attrs, | |
808 | }; | |
809 | ||
f1e3cfff | 810 | static int create_device(struct zram *zram, int device_id) |
306b0c95 | 811 | { |
39a9b8ac | 812 | int ret = -ENOMEM; |
de1a21a0 | 813 | |
0900beae | 814 | init_rwsem(&zram->init_lock); |
306b0c95 | 815 | |
f1e3cfff NG |
816 | zram->queue = blk_alloc_queue(GFP_KERNEL); |
817 | if (!zram->queue) { | |
306b0c95 NG |
818 | pr_err("Error allocating disk queue for device %d\n", |
819 | device_id); | |
de1a21a0 | 820 | goto out; |
306b0c95 NG |
821 | } |
822 | ||
f1e3cfff NG |
823 | blk_queue_make_request(zram->queue, zram_make_request); |
824 | zram->queue->queuedata = zram; | |
306b0c95 NG |
825 | |
826 | /* gendisk structure */ | |
f1e3cfff NG |
827 | zram->disk = alloc_disk(1); |
828 | if (!zram->disk) { | |
94b8435f | 829 | pr_warn("Error allocating disk structure for device %d\n", |
306b0c95 | 830 | device_id); |
39a9b8ac | 831 | goto out_free_queue; |
306b0c95 NG |
832 | } |
833 | ||
f1e3cfff NG |
834 | zram->disk->major = zram_major; |
835 | zram->disk->first_minor = device_id; | |
836 | zram->disk->fops = &zram_devops; | |
837 | zram->disk->queue = zram->queue; | |
838 | zram->disk->private_data = zram; | |
839 | snprintf(zram->disk->disk_name, 16, "zram%d", device_id); | |
306b0c95 | 840 | |
33863c21 | 841 | /* Actual capacity set using syfs (/sys/block/zram<id>/disksize */ |
f1e3cfff | 842 | set_capacity(zram->disk, 0); |
5d83d5a0 | 843 | |
a1dd52af NG |
844 | /* |
845 | * To ensure that we always get PAGE_SIZE aligned | |
846 | * and n*PAGE_SIZED sized I/O requests. | |
847 | */ | |
f1e3cfff | 848 | blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE); |
7b19b8d4 RJ |
849 | blk_queue_logical_block_size(zram->disk->queue, |
850 | ZRAM_LOGICAL_BLOCK_SIZE); | |
f1e3cfff NG |
851 | blk_queue_io_min(zram->disk->queue, PAGE_SIZE); |
852 | blk_queue_io_opt(zram->disk->queue, PAGE_SIZE); | |
5d83d5a0 | 853 | |
f1e3cfff | 854 | add_disk(zram->disk); |
306b0c95 | 855 | |
33863c21 NG |
856 | ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj, |
857 | &zram_disk_attr_group); | |
858 | if (ret < 0) { | |
94b8435f | 859 | pr_warn("Error creating sysfs group"); |
39a9b8ac | 860 | goto out_free_disk; |
33863c21 | 861 | } |
33863c21 | 862 | |
be2d1d56 | 863 | zram->meta = NULL; |
39a9b8ac | 864 | return 0; |
de1a21a0 | 865 | |
39a9b8ac JL |
866 | out_free_disk: |
867 | del_gendisk(zram->disk); | |
868 | put_disk(zram->disk); | |
869 | out_free_queue: | |
870 | blk_cleanup_queue(zram->queue); | |
de1a21a0 NG |
871 | out: |
872 | return ret; | |
306b0c95 NG |
873 | } |
874 | ||
f1e3cfff | 875 | static void destroy_device(struct zram *zram) |
306b0c95 | 876 | { |
33863c21 NG |
877 | sysfs_remove_group(&disk_to_dev(zram->disk)->kobj, |
878 | &zram_disk_attr_group); | |
33863c21 | 879 | |
59d3fe54 RK |
880 | del_gendisk(zram->disk); |
881 | put_disk(zram->disk); | |
306b0c95 | 882 | |
59d3fe54 | 883 | blk_cleanup_queue(zram->queue); |
306b0c95 NG |
884 | } |
885 | ||
f1e3cfff | 886 | static int __init zram_init(void) |
306b0c95 | 887 | { |
de1a21a0 | 888 | int ret, dev_id; |
306b0c95 | 889 | |
5fa5a901 | 890 | if (num_devices > max_num_devices) { |
94b8435f | 891 | pr_warn("Invalid value for num_devices: %u\n", |
5fa5a901 | 892 | num_devices); |
de1a21a0 NG |
893 | ret = -EINVAL; |
894 | goto out; | |
306b0c95 NG |
895 | } |
896 | ||
f1e3cfff NG |
897 | zram_major = register_blkdev(0, "zram"); |
898 | if (zram_major <= 0) { | |
94b8435f | 899 | pr_warn("Unable to get major number\n"); |
de1a21a0 NG |
900 | ret = -EBUSY; |
901 | goto out; | |
306b0c95 NG |
902 | } |
903 | ||
306b0c95 | 904 | /* Allocate the device array and initialize each one */ |
5fa5a901 | 905 | zram_devices = kzalloc(num_devices * sizeof(struct zram), GFP_KERNEL); |
43801f6e | 906 | if (!zram_devices) { |
de1a21a0 NG |
907 | ret = -ENOMEM; |
908 | goto unregister; | |
909 | } | |
306b0c95 | 910 | |
5fa5a901 | 911 | for (dev_id = 0; dev_id < num_devices; dev_id++) { |
43801f6e | 912 | ret = create_device(&zram_devices[dev_id], dev_id); |
de1a21a0 | 913 | if (ret) |
3bf040c7 | 914 | goto free_devices; |
de1a21a0 NG |
915 | } |
916 | ||
ca3d70bd DB |
917 | pr_info("Created %u device(s) ...\n", num_devices); |
918 | ||
306b0c95 | 919 | return 0; |
de1a21a0 | 920 | |
3bf040c7 | 921 | free_devices: |
de1a21a0 | 922 | while (dev_id) |
43801f6e NW |
923 | destroy_device(&zram_devices[--dev_id]); |
924 | kfree(zram_devices); | |
de1a21a0 | 925 | unregister: |
f1e3cfff | 926 | unregister_blkdev(zram_major, "zram"); |
de1a21a0 | 927 | out: |
306b0c95 NG |
928 | return ret; |
929 | } | |
930 | ||
f1e3cfff | 931 | static void __exit zram_exit(void) |
306b0c95 NG |
932 | { |
933 | int i; | |
f1e3cfff | 934 | struct zram *zram; |
306b0c95 | 935 | |
5fa5a901 | 936 | for (i = 0; i < num_devices; i++) { |
43801f6e | 937 | zram = &zram_devices[i]; |
306b0c95 | 938 | |
f1e3cfff | 939 | destroy_device(zram); |
2b86ab9c MK |
940 | /* |
941 | * Shouldn't access zram->disk after destroy_device | |
942 | * because destroy_device already released zram->disk. | |
943 | */ | |
944 | zram_reset_device(zram, false); | |
306b0c95 NG |
945 | } |
946 | ||
f1e3cfff | 947 | unregister_blkdev(zram_major, "zram"); |
306b0c95 | 948 | |
43801f6e | 949 | kfree(zram_devices); |
306b0c95 NG |
950 | pr_debug("Cleanup done!\n"); |
951 | } | |
952 | ||
f1e3cfff NG |
953 | module_init(zram_init); |
954 | module_exit(zram_exit); | |
306b0c95 | 955 | |
9b3bb7ab SS |
956 | module_param(num_devices, uint, 0); |
957 | MODULE_PARM_DESC(num_devices, "Number of zram devices"); | |
958 | ||
306b0c95 NG |
959 | MODULE_LICENSE("Dual BSD/GPL"); |
960 | MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); | |
f1e3cfff | 961 | MODULE_DESCRIPTION("Compressed RAM Block Device"); |