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> |
b09ab054 | 28 | #include <linux/backing-dev.h> |
306b0c95 | 29 | #include <linux/string.h> |
306b0c95 | 30 | #include <linux/vmalloc.h> |
fcfa8d95 | 31 | #include <linux/err.h> |
85508ec6 | 32 | #include <linux/idr.h> |
6566d1a3 | 33 | #include <linux/sysfs.h> |
1dd6c834 | 34 | #include <linux/cpuhotplug.h> |
306b0c95 | 35 | |
16a4bfb9 | 36 | #include "zram_drv.h" |
306b0c95 | 37 | |
85508ec6 | 38 | static DEFINE_IDR(zram_index_idr); |
6566d1a3 SS |
39 | /* idr index must be protected */ |
40 | static DEFINE_MUTEX(zram_index_mutex); | |
41 | ||
f1e3cfff | 42 | static int zram_major; |
b7ca232e | 43 | static const char *default_compressor = "lzo"; |
306b0c95 | 44 | |
306b0c95 | 45 | /* Module params (documentation at end) */ |
ca3d70bd | 46 | static unsigned int num_devices = 1; |
33863c21 | 47 | |
8f7d282c SS |
48 | static inline void deprecated_attr_warn(const char *name) |
49 | { | |
50 | pr_warn_once("%d (%s) Attribute %s (and others) will be removed. %s\n", | |
51 | task_pid_nr(current), | |
52 | current->comm, | |
53 | name, | |
54 | "See zram documentation."); | |
55 | } | |
56 | ||
a68eb3b6 | 57 | #define ZRAM_ATTR_RO(name) \ |
3bca3ef7 | 58 | static ssize_t name##_show(struct device *d, \ |
a68eb3b6 SS |
59 | struct device_attribute *attr, char *b) \ |
60 | { \ | |
61 | struct zram *zram = dev_to_zram(d); \ | |
8f7d282c SS |
62 | \ |
63 | deprecated_attr_warn(__stringify(name)); \ | |
56b4e8cb | 64 | return scnprintf(b, PAGE_SIZE, "%llu\n", \ |
a68eb3b6 SS |
65 | (u64)atomic64_read(&zram->stats.name)); \ |
66 | } \ | |
083914ea | 67 | static DEVICE_ATTR_RO(name); |
a68eb3b6 | 68 | |
08eee69f | 69 | static inline bool init_done(struct zram *zram) |
be2d1d56 | 70 | { |
08eee69f | 71 | return zram->disksize; |
be2d1d56 SS |
72 | } |
73 | ||
9b3bb7ab SS |
74 | static inline struct zram *dev_to_zram(struct device *dev) |
75 | { | |
76 | return (struct zram *)dev_to_disk(dev)->private_data; | |
77 | } | |
78 | ||
b31177f2 | 79 | /* flag operations require table entry bit_spin_lock() being held */ |
522698d7 SS |
80 | static int zram_test_flag(struct zram_meta *meta, u32 index, |
81 | enum zram_pageflags flag) | |
99ebbd30 | 82 | { |
522698d7 SS |
83 | return meta->table[index].value & BIT(flag); |
84 | } | |
99ebbd30 | 85 | |
522698d7 SS |
86 | static void zram_set_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 void zram_clear_flag(struct zram_meta *meta, u32 index, |
93 | enum zram_pageflags flag) | |
94 | { | |
95 | meta->table[index].value &= ~BIT(flag); | |
96 | } | |
99ebbd30 | 97 | |
522698d7 SS |
98 | static size_t zram_get_obj_size(struct zram_meta *meta, u32 index) |
99 | { | |
100 | return meta->table[index].value & (BIT(ZRAM_FLAG_SHIFT) - 1); | |
99ebbd30 AM |
101 | } |
102 | ||
522698d7 SS |
103 | static void zram_set_obj_size(struct zram_meta *meta, |
104 | u32 index, size_t size) | |
9b3bb7ab | 105 | { |
522698d7 | 106 | unsigned long flags = meta->table[index].value >> ZRAM_FLAG_SHIFT; |
9b3bb7ab | 107 | |
522698d7 SS |
108 | meta->table[index].value = (flags << ZRAM_FLAG_SHIFT) | size; |
109 | } | |
110 | ||
1c53e0d2 | 111 | static inline bool is_partial_io(struct bio_vec *bvec) |
522698d7 SS |
112 | { |
113 | return bvec->bv_len != PAGE_SIZE; | |
114 | } | |
115 | ||
b09ab054 MK |
116 | static void zram_revalidate_disk(struct zram *zram) |
117 | { | |
118 | revalidate_disk(zram->disk); | |
119 | /* revalidate_disk reset the BDI_CAP_STABLE_WRITES so set again */ | |
120 | zram->disk->queue->backing_dev_info.capabilities |= | |
121 | BDI_CAP_STABLE_WRITES; | |
122 | } | |
123 | ||
522698d7 SS |
124 | /* |
125 | * Check if request is within bounds and aligned on zram logical blocks. | |
126 | */ | |
1c53e0d2 | 127 | static inline bool valid_io_request(struct zram *zram, |
522698d7 SS |
128 | sector_t start, unsigned int size) |
129 | { | |
130 | u64 end, bound; | |
131 | ||
132 | /* unaligned request */ | |
133 | if (unlikely(start & (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1))) | |
1c53e0d2 | 134 | return false; |
522698d7 | 135 | if (unlikely(size & (ZRAM_LOGICAL_BLOCK_SIZE - 1))) |
1c53e0d2 | 136 | return false; |
522698d7 SS |
137 | |
138 | end = start + (size >> SECTOR_SHIFT); | |
139 | bound = zram->disksize >> SECTOR_SHIFT; | |
140 | /* out of range range */ | |
141 | if (unlikely(start >= bound || end > bound || start > end)) | |
1c53e0d2 | 142 | return false; |
522698d7 SS |
143 | |
144 | /* I/O request is valid */ | |
1c53e0d2 | 145 | return true; |
522698d7 SS |
146 | } |
147 | ||
148 | static void update_position(u32 *index, int *offset, struct bio_vec *bvec) | |
149 | { | |
150 | if (*offset + bvec->bv_len >= PAGE_SIZE) | |
151 | (*index)++; | |
152 | *offset = (*offset + bvec->bv_len) % PAGE_SIZE; | |
153 | } | |
154 | ||
155 | static inline void update_used_max(struct zram *zram, | |
156 | const unsigned long pages) | |
157 | { | |
158 | unsigned long old_max, cur_max; | |
159 | ||
160 | old_max = atomic_long_read(&zram->stats.max_used_pages); | |
161 | ||
162 | do { | |
163 | cur_max = old_max; | |
164 | if (pages > cur_max) | |
165 | old_max = atomic_long_cmpxchg( | |
166 | &zram->stats.max_used_pages, cur_max, pages); | |
167 | } while (old_max != cur_max); | |
168 | } | |
169 | ||
1c53e0d2 | 170 | static bool page_zero_filled(void *ptr) |
522698d7 SS |
171 | { |
172 | unsigned int pos; | |
173 | unsigned long *page; | |
174 | ||
175 | page = (unsigned long *)ptr; | |
176 | ||
177 | for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) { | |
178 | if (page[pos]) | |
1c53e0d2 | 179 | return false; |
522698d7 SS |
180 | } |
181 | ||
1c53e0d2 | 182 | return true; |
522698d7 SS |
183 | } |
184 | ||
185 | static void handle_zero_page(struct bio_vec *bvec) | |
186 | { | |
187 | struct page *page = bvec->bv_page; | |
188 | void *user_mem; | |
189 | ||
190 | user_mem = kmap_atomic(page); | |
191 | if (is_partial_io(bvec)) | |
192 | memset(user_mem + bvec->bv_offset, 0, bvec->bv_len); | |
193 | else | |
194 | clear_page(user_mem); | |
195 | kunmap_atomic(user_mem); | |
196 | ||
197 | flush_dcache_page(page); | |
9b3bb7ab SS |
198 | } |
199 | ||
200 | static ssize_t initstate_show(struct device *dev, | |
201 | struct device_attribute *attr, char *buf) | |
202 | { | |
a68eb3b6 | 203 | u32 val; |
9b3bb7ab SS |
204 | struct zram *zram = dev_to_zram(dev); |
205 | ||
a68eb3b6 SS |
206 | down_read(&zram->init_lock); |
207 | val = init_done(zram); | |
208 | up_read(&zram->init_lock); | |
9b3bb7ab | 209 | |
56b4e8cb | 210 | return scnprintf(buf, PAGE_SIZE, "%u\n", val); |
9b3bb7ab SS |
211 | } |
212 | ||
522698d7 SS |
213 | static ssize_t disksize_show(struct device *dev, |
214 | struct device_attribute *attr, char *buf) | |
215 | { | |
216 | struct zram *zram = dev_to_zram(dev); | |
217 | ||
218 | return scnprintf(buf, PAGE_SIZE, "%llu\n", zram->disksize); | |
219 | } | |
220 | ||
9b3bb7ab SS |
221 | static ssize_t orig_data_size_show(struct device *dev, |
222 | struct device_attribute *attr, char *buf) | |
223 | { | |
224 | struct zram *zram = dev_to_zram(dev); | |
225 | ||
8f7d282c | 226 | deprecated_attr_warn("orig_data_size"); |
56b4e8cb | 227 | return scnprintf(buf, PAGE_SIZE, "%llu\n", |
90a7806e | 228 | (u64)(atomic64_read(&zram->stats.pages_stored)) << PAGE_SHIFT); |
9b3bb7ab SS |
229 | } |
230 | ||
9b3bb7ab SS |
231 | static ssize_t mem_used_total_show(struct device *dev, |
232 | struct device_attribute *attr, char *buf) | |
233 | { | |
234 | u64 val = 0; | |
235 | struct zram *zram = dev_to_zram(dev); | |
9b3bb7ab | 236 | |
8f7d282c | 237 | deprecated_attr_warn("mem_used_total"); |
9b3bb7ab | 238 | down_read(&zram->init_lock); |
5a99e95b WY |
239 | if (init_done(zram)) { |
240 | struct zram_meta *meta = zram->meta; | |
722cdc17 | 241 | val = zs_get_total_pages(meta->mem_pool); |
5a99e95b | 242 | } |
9b3bb7ab SS |
243 | up_read(&zram->init_lock); |
244 | ||
722cdc17 | 245 | return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT); |
9b3bb7ab SS |
246 | } |
247 | ||
9ada9da9 MK |
248 | static ssize_t mem_limit_show(struct device *dev, |
249 | struct device_attribute *attr, char *buf) | |
250 | { | |
251 | u64 val; | |
252 | struct zram *zram = dev_to_zram(dev); | |
253 | ||
8f7d282c | 254 | deprecated_attr_warn("mem_limit"); |
9ada9da9 MK |
255 | down_read(&zram->init_lock); |
256 | val = zram->limit_pages; | |
257 | up_read(&zram->init_lock); | |
258 | ||
259 | return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT); | |
260 | } | |
261 | ||
262 | static ssize_t mem_limit_store(struct device *dev, | |
263 | struct device_attribute *attr, const char *buf, size_t len) | |
264 | { | |
265 | u64 limit; | |
266 | char *tmp; | |
267 | struct zram *zram = dev_to_zram(dev); | |
268 | ||
269 | limit = memparse(buf, &tmp); | |
270 | if (buf == tmp) /* no chars parsed, invalid input */ | |
271 | return -EINVAL; | |
272 | ||
273 | down_write(&zram->init_lock); | |
274 | zram->limit_pages = PAGE_ALIGN(limit) >> PAGE_SHIFT; | |
275 | up_write(&zram->init_lock); | |
276 | ||
277 | return len; | |
278 | } | |
279 | ||
461a8eee MK |
280 | static ssize_t mem_used_max_show(struct device *dev, |
281 | struct device_attribute *attr, char *buf) | |
282 | { | |
283 | u64 val = 0; | |
284 | struct zram *zram = dev_to_zram(dev); | |
285 | ||
8f7d282c | 286 | deprecated_attr_warn("mem_used_max"); |
461a8eee MK |
287 | down_read(&zram->init_lock); |
288 | if (init_done(zram)) | |
289 | val = atomic_long_read(&zram->stats.max_used_pages); | |
290 | up_read(&zram->init_lock); | |
291 | ||
292 | return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT); | |
293 | } | |
294 | ||
295 | static ssize_t mem_used_max_store(struct device *dev, | |
296 | struct device_attribute *attr, const char *buf, size_t len) | |
297 | { | |
298 | int err; | |
299 | unsigned long val; | |
300 | struct zram *zram = dev_to_zram(dev); | |
461a8eee MK |
301 | |
302 | err = kstrtoul(buf, 10, &val); | |
303 | if (err || val != 0) | |
304 | return -EINVAL; | |
305 | ||
306 | down_read(&zram->init_lock); | |
5a99e95b WY |
307 | if (init_done(zram)) { |
308 | struct zram_meta *meta = zram->meta; | |
461a8eee MK |
309 | atomic_long_set(&zram->stats.max_used_pages, |
310 | zs_get_total_pages(meta->mem_pool)); | |
5a99e95b | 311 | } |
461a8eee MK |
312 | up_read(&zram->init_lock); |
313 | ||
314 | return len; | |
315 | } | |
316 | ||
43209ea2 SS |
317 | /* |
318 | * We switched to per-cpu streams and this attr is not needed anymore. | |
319 | * However, we will keep it around for some time, because: | |
320 | * a) we may revert per-cpu streams in the future | |
321 | * b) it's visible to user space and we need to follow our 2 years | |
322 | * retirement rule; but we already have a number of 'soon to be | |
323 | * altered' attrs, so max_comp_streams need to wait for the next | |
324 | * layoff cycle. | |
325 | */ | |
522698d7 SS |
326 | static ssize_t max_comp_streams_show(struct device *dev, |
327 | struct device_attribute *attr, char *buf) | |
328 | { | |
43209ea2 | 329 | return scnprintf(buf, PAGE_SIZE, "%d\n", num_online_cpus()); |
522698d7 SS |
330 | } |
331 | ||
beca3ec7 SS |
332 | static ssize_t max_comp_streams_store(struct device *dev, |
333 | struct device_attribute *attr, const char *buf, size_t len) | |
334 | { | |
43209ea2 | 335 | return len; |
beca3ec7 SS |
336 | } |
337 | ||
e46b8a03 SS |
338 | static ssize_t comp_algorithm_show(struct device *dev, |
339 | struct device_attribute *attr, char *buf) | |
340 | { | |
341 | size_t sz; | |
342 | struct zram *zram = dev_to_zram(dev); | |
343 | ||
344 | down_read(&zram->init_lock); | |
345 | sz = zcomp_available_show(zram->compressor, buf); | |
346 | up_read(&zram->init_lock); | |
347 | ||
348 | return sz; | |
349 | } | |
350 | ||
351 | static ssize_t comp_algorithm_store(struct device *dev, | |
352 | struct device_attribute *attr, const char *buf, size_t len) | |
353 | { | |
354 | struct zram *zram = dev_to_zram(dev); | |
415403be | 355 | char compressor[CRYPTO_MAX_ALG_NAME]; |
4bbacd51 SS |
356 | size_t sz; |
357 | ||
415403be SS |
358 | strlcpy(compressor, buf, sizeof(compressor)); |
359 | /* ignore trailing newline */ | |
360 | sz = strlen(compressor); | |
361 | if (sz > 0 && compressor[sz - 1] == '\n') | |
362 | compressor[sz - 1] = 0x00; | |
363 | ||
364 | if (!zcomp_available_algorithm(compressor)) | |
1d5b43bf LH |
365 | return -EINVAL; |
366 | ||
e46b8a03 SS |
367 | down_write(&zram->init_lock); |
368 | if (init_done(zram)) { | |
369 | up_write(&zram->init_lock); | |
370 | pr_info("Can't change algorithm for initialized device\n"); | |
371 | return -EBUSY; | |
372 | } | |
4bbacd51 | 373 | |
415403be | 374 | strlcpy(zram->compressor, compressor, sizeof(compressor)); |
e46b8a03 SS |
375 | up_write(&zram->init_lock); |
376 | return len; | |
377 | } | |
378 | ||
522698d7 SS |
379 | static ssize_t compact_store(struct device *dev, |
380 | struct device_attribute *attr, const char *buf, size_t len) | |
306b0c95 | 381 | { |
522698d7 SS |
382 | struct zram *zram = dev_to_zram(dev); |
383 | struct zram_meta *meta; | |
306b0c95 | 384 | |
522698d7 SS |
385 | down_read(&zram->init_lock); |
386 | if (!init_done(zram)) { | |
387 | up_read(&zram->init_lock); | |
388 | return -EINVAL; | |
389 | } | |
306b0c95 | 390 | |
522698d7 | 391 | meta = zram->meta; |
7d3f3938 | 392 | zs_compact(meta->mem_pool); |
522698d7 | 393 | up_read(&zram->init_lock); |
d2d5e762 | 394 | |
522698d7 | 395 | return len; |
d2d5e762 WY |
396 | } |
397 | ||
522698d7 SS |
398 | static ssize_t io_stat_show(struct device *dev, |
399 | struct device_attribute *attr, char *buf) | |
d2d5e762 | 400 | { |
522698d7 SS |
401 | struct zram *zram = dev_to_zram(dev); |
402 | ssize_t ret; | |
d2d5e762 | 403 | |
522698d7 SS |
404 | down_read(&zram->init_lock); |
405 | ret = scnprintf(buf, PAGE_SIZE, | |
406 | "%8llu %8llu %8llu %8llu\n", | |
407 | (u64)atomic64_read(&zram->stats.failed_reads), | |
408 | (u64)atomic64_read(&zram->stats.failed_writes), | |
409 | (u64)atomic64_read(&zram->stats.invalid_io), | |
410 | (u64)atomic64_read(&zram->stats.notify_free)); | |
411 | up_read(&zram->init_lock); | |
306b0c95 | 412 | |
522698d7 | 413 | return ret; |
9b3bb7ab SS |
414 | } |
415 | ||
522698d7 SS |
416 | static ssize_t mm_stat_show(struct device *dev, |
417 | struct device_attribute *attr, char *buf) | |
9b3bb7ab | 418 | { |
522698d7 | 419 | struct zram *zram = dev_to_zram(dev); |
7d3f3938 | 420 | struct zs_pool_stats pool_stats; |
522698d7 SS |
421 | u64 orig_size, mem_used = 0; |
422 | long max_used; | |
423 | ssize_t ret; | |
a539c72a | 424 | |
7d3f3938 SS |
425 | memset(&pool_stats, 0x00, sizeof(struct zs_pool_stats)); |
426 | ||
522698d7 | 427 | down_read(&zram->init_lock); |
7d3f3938 | 428 | if (init_done(zram)) { |
522698d7 | 429 | mem_used = zs_get_total_pages(zram->meta->mem_pool); |
7d3f3938 SS |
430 | zs_pool_stats(zram->meta->mem_pool, &pool_stats); |
431 | } | |
9b3bb7ab | 432 | |
522698d7 SS |
433 | orig_size = atomic64_read(&zram->stats.pages_stored); |
434 | max_used = atomic_long_read(&zram->stats.max_used_pages); | |
9b3bb7ab | 435 | |
522698d7 | 436 | ret = scnprintf(buf, PAGE_SIZE, |
7d3f3938 | 437 | "%8llu %8llu %8llu %8lu %8ld %8llu %8lu\n", |
522698d7 SS |
438 | orig_size << PAGE_SHIFT, |
439 | (u64)atomic64_read(&zram->stats.compr_data_size), | |
440 | mem_used << PAGE_SHIFT, | |
441 | zram->limit_pages << PAGE_SHIFT, | |
442 | max_used << PAGE_SHIFT, | |
443 | (u64)atomic64_read(&zram->stats.zero_pages), | |
860c707d | 444 | pool_stats.pages_compacted); |
522698d7 | 445 | up_read(&zram->init_lock); |
9b3bb7ab | 446 | |
522698d7 SS |
447 | return ret; |
448 | } | |
449 | ||
623e47fc SS |
450 | static ssize_t debug_stat_show(struct device *dev, |
451 | struct device_attribute *attr, char *buf) | |
452 | { | |
453 | int version = 1; | |
454 | struct zram *zram = dev_to_zram(dev); | |
455 | ssize_t ret; | |
456 | ||
457 | down_read(&zram->init_lock); | |
458 | ret = scnprintf(buf, PAGE_SIZE, | |
459 | "version: %d\n%8llu\n", | |
460 | version, | |
461 | (u64)atomic64_read(&zram->stats.writestall)); | |
462 | up_read(&zram->init_lock); | |
463 | ||
464 | return ret; | |
465 | } | |
466 | ||
522698d7 SS |
467 | static DEVICE_ATTR_RO(io_stat); |
468 | static DEVICE_ATTR_RO(mm_stat); | |
623e47fc | 469 | static DEVICE_ATTR_RO(debug_stat); |
522698d7 SS |
470 | ZRAM_ATTR_RO(num_reads); |
471 | ZRAM_ATTR_RO(num_writes); | |
472 | ZRAM_ATTR_RO(failed_reads); | |
473 | ZRAM_ATTR_RO(failed_writes); | |
474 | ZRAM_ATTR_RO(invalid_io); | |
475 | ZRAM_ATTR_RO(notify_free); | |
476 | ZRAM_ATTR_RO(zero_pages); | |
477 | ZRAM_ATTR_RO(compr_data_size); | |
478 | ||
479 | static inline bool zram_meta_get(struct zram *zram) | |
480 | { | |
481 | if (atomic_inc_not_zero(&zram->refcount)) | |
482 | return true; | |
483 | return false; | |
484 | } | |
485 | ||
486 | static inline void zram_meta_put(struct zram *zram) | |
487 | { | |
488 | atomic_dec(&zram->refcount); | |
489 | } | |
490 | ||
491 | static void zram_meta_free(struct zram_meta *meta, u64 disksize) | |
492 | { | |
493 | size_t num_pages = disksize >> PAGE_SHIFT; | |
494 | size_t index; | |
1fec1172 GM |
495 | |
496 | /* Free all pages that are still in this zram device */ | |
497 | for (index = 0; index < num_pages; index++) { | |
498 | unsigned long handle = meta->table[index].handle; | |
499 | ||
500 | if (!handle) | |
501 | continue; | |
502 | ||
503 | zs_free(meta->mem_pool, handle); | |
504 | } | |
505 | ||
9b3bb7ab | 506 | zs_destroy_pool(meta->mem_pool); |
9b3bb7ab SS |
507 | vfree(meta->table); |
508 | kfree(meta); | |
509 | } | |
510 | ||
4ce321f5 | 511 | static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize) |
9b3bb7ab SS |
512 | { |
513 | size_t num_pages; | |
514 | struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL); | |
b8179958 | 515 | |
9b3bb7ab | 516 | if (!meta) |
b8179958 | 517 | return NULL; |
9b3bb7ab | 518 | |
9b3bb7ab SS |
519 | num_pages = disksize >> PAGE_SHIFT; |
520 | meta->table = vzalloc(num_pages * sizeof(*meta->table)); | |
521 | if (!meta->table) { | |
522 | pr_err("Error allocating zram address table\n"); | |
b8179958 | 523 | goto out_error; |
9b3bb7ab SS |
524 | } |
525 | ||
d0d8da2d | 526 | meta->mem_pool = zs_create_pool(pool_name); |
9b3bb7ab SS |
527 | if (!meta->mem_pool) { |
528 | pr_err("Error creating memory pool\n"); | |
b8179958 | 529 | goto out_error; |
9b3bb7ab SS |
530 | } |
531 | ||
532 | return meta; | |
533 | ||
b8179958 | 534 | out_error: |
9b3bb7ab | 535 | vfree(meta->table); |
9b3bb7ab | 536 | kfree(meta); |
b8179958 | 537 | return NULL; |
9b3bb7ab SS |
538 | } |
539 | ||
d2d5e762 WY |
540 | /* |
541 | * To protect concurrent access to the same index entry, | |
542 | * caller should hold this table index entry's bit_spinlock to | |
543 | * indicate this index entry is accessing. | |
544 | */ | |
f1e3cfff | 545 | static void zram_free_page(struct zram *zram, size_t index) |
306b0c95 | 546 | { |
8b3cc3ed MK |
547 | struct zram_meta *meta = zram->meta; |
548 | unsigned long handle = meta->table[index].handle; | |
306b0c95 | 549 | |
fd1a30de | 550 | if (unlikely(!handle)) { |
2e882281 NG |
551 | /* |
552 | * No memory is allocated for zero filled pages. | |
553 | * Simply clear zero page flag. | |
554 | */ | |
8b3cc3ed MK |
555 | if (zram_test_flag(meta, index, ZRAM_ZERO)) { |
556 | zram_clear_flag(meta, index, ZRAM_ZERO); | |
90a7806e | 557 | atomic64_dec(&zram->stats.zero_pages); |
306b0c95 NG |
558 | } |
559 | return; | |
560 | } | |
561 | ||
8b3cc3ed | 562 | zs_free(meta->mem_pool, handle); |
306b0c95 | 563 | |
d2d5e762 WY |
564 | atomic64_sub(zram_get_obj_size(meta, index), |
565 | &zram->stats.compr_data_size); | |
90a7806e | 566 | atomic64_dec(&zram->stats.pages_stored); |
306b0c95 | 567 | |
8b3cc3ed | 568 | meta->table[index].handle = 0; |
d2d5e762 | 569 | zram_set_obj_size(meta, index, 0); |
306b0c95 NG |
570 | } |
571 | ||
37b51fdd | 572 | static int zram_decompress_page(struct zram *zram, char *mem, u32 index) |
306b0c95 | 573 | { |
b7ca232e | 574 | int ret = 0; |
37b51fdd | 575 | unsigned char *cmem; |
8b3cc3ed | 576 | struct zram_meta *meta = zram->meta; |
92967471 | 577 | unsigned long handle; |
ebaf9ab5 | 578 | unsigned int size; |
92967471 | 579 | |
d2d5e762 | 580 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
92967471 | 581 | handle = meta->table[index].handle; |
d2d5e762 | 582 | size = zram_get_obj_size(meta, index); |
306b0c95 | 583 | |
8b3cc3ed | 584 | if (!handle || zram_test_flag(meta, index, ZRAM_ZERO)) { |
d2d5e762 | 585 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
42e99bd9 | 586 | clear_page(mem); |
8c921b2b JM |
587 | return 0; |
588 | } | |
306b0c95 | 589 | |
8b3cc3ed | 590 | cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO); |
ebaf9ab5 | 591 | if (size == PAGE_SIZE) { |
42e99bd9 | 592 | copy_page(mem, cmem); |
ebaf9ab5 SS |
593 | } else { |
594 | struct zcomp_strm *zstrm = zcomp_stream_get(zram->comp); | |
595 | ||
596 | ret = zcomp_decompress(zstrm, cmem, size, mem); | |
597 | zcomp_stream_put(zram->comp); | |
598 | } | |
8b3cc3ed | 599 | zs_unmap_object(meta->mem_pool, handle); |
d2d5e762 | 600 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
a1dd52af | 601 | |
8c921b2b | 602 | /* Should NEVER happen. Return bio error if it does. */ |
b7ca232e | 603 | if (unlikely(ret)) { |
8c921b2b | 604 | pr_err("Decompression failed! err=%d, page=%u\n", ret, index); |
8c921b2b | 605 | return ret; |
a1dd52af | 606 | } |
306b0c95 | 607 | |
8c921b2b | 608 | return 0; |
306b0c95 NG |
609 | } |
610 | ||
37b51fdd | 611 | static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, |
b627cff3 | 612 | u32 index, int offset) |
924bd88d JM |
613 | { |
614 | int ret; | |
37b51fdd SS |
615 | struct page *page; |
616 | unsigned char *user_mem, *uncmem = NULL; | |
8b3cc3ed | 617 | struct zram_meta *meta = zram->meta; |
37b51fdd SS |
618 | page = bvec->bv_page; |
619 | ||
d2d5e762 | 620 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
8b3cc3ed MK |
621 | if (unlikely(!meta->table[index].handle) || |
622 | zram_test_flag(meta, index, ZRAM_ZERO)) { | |
d2d5e762 | 623 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
37b51fdd | 624 | handle_zero_page(bvec); |
924bd88d JM |
625 | return 0; |
626 | } | |
d2d5e762 | 627 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
924bd88d | 628 | |
37b51fdd SS |
629 | if (is_partial_io(bvec)) |
630 | /* Use a temporary buffer to decompress the page */ | |
7e5a5104 MK |
631 | uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); |
632 | ||
633 | user_mem = kmap_atomic(page); | |
634 | if (!is_partial_io(bvec)) | |
37b51fdd SS |
635 | uncmem = user_mem; |
636 | ||
637 | if (!uncmem) { | |
70864969 | 638 | pr_err("Unable to allocate temp memory\n"); |
37b51fdd SS |
639 | ret = -ENOMEM; |
640 | goto out_cleanup; | |
641 | } | |
924bd88d | 642 | |
37b51fdd | 643 | ret = zram_decompress_page(zram, uncmem, index); |
924bd88d | 644 | /* Should NEVER happen. Return bio error if it does. */ |
b7ca232e | 645 | if (unlikely(ret)) |
37b51fdd | 646 | goto out_cleanup; |
924bd88d | 647 | |
37b51fdd SS |
648 | if (is_partial_io(bvec)) |
649 | memcpy(user_mem + bvec->bv_offset, uncmem + offset, | |
650 | bvec->bv_len); | |
651 | ||
652 | flush_dcache_page(page); | |
653 | ret = 0; | |
654 | out_cleanup: | |
655 | kunmap_atomic(user_mem); | |
656 | if (is_partial_io(bvec)) | |
657 | kfree(uncmem); | |
658 | return ret; | |
924bd88d JM |
659 | } |
660 | ||
661 | static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, | |
662 | int offset) | |
306b0c95 | 663 | { |
397c6066 | 664 | int ret = 0; |
ebaf9ab5 | 665 | unsigned int clen; |
da9556a2 | 666 | unsigned long handle = 0; |
130f315a | 667 | struct page *page; |
924bd88d | 668 | unsigned char *user_mem, *cmem, *src, *uncmem = NULL; |
8b3cc3ed | 669 | struct zram_meta *meta = zram->meta; |
17162f41 | 670 | struct zcomp_strm *zstrm = NULL; |
461a8eee | 671 | unsigned long alloced_pages; |
306b0c95 | 672 | |
8c921b2b | 673 | page = bvec->bv_page; |
924bd88d JM |
674 | if (is_partial_io(bvec)) { |
675 | /* | |
676 | * This is a partial IO. We need to read the full page | |
677 | * before to write the changes. | |
678 | */ | |
7e5a5104 | 679 | uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); |
924bd88d | 680 | if (!uncmem) { |
924bd88d JM |
681 | ret = -ENOMEM; |
682 | goto out; | |
683 | } | |
37b51fdd | 684 | ret = zram_decompress_page(zram, uncmem, index); |
397c6066 | 685 | if (ret) |
924bd88d | 686 | goto out; |
924bd88d JM |
687 | } |
688 | ||
da9556a2 | 689 | compress_again: |
ba82fe2e | 690 | user_mem = kmap_atomic(page); |
397c6066 | 691 | if (is_partial_io(bvec)) { |
924bd88d JM |
692 | memcpy(uncmem + offset, user_mem + bvec->bv_offset, |
693 | bvec->bv_len); | |
397c6066 NG |
694 | kunmap_atomic(user_mem); |
695 | user_mem = NULL; | |
696 | } else { | |
924bd88d | 697 | uncmem = user_mem; |
397c6066 | 698 | } |
924bd88d JM |
699 | |
700 | if (page_zero_filled(uncmem)) { | |
c4065152 WY |
701 | if (user_mem) |
702 | kunmap_atomic(user_mem); | |
f40ac2ae | 703 | /* Free memory associated with this sector now. */ |
d2d5e762 | 704 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f40ac2ae | 705 | zram_free_page(zram, index); |
92967471 | 706 | zram_set_flag(meta, index, ZRAM_ZERO); |
d2d5e762 | 707 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
f40ac2ae | 708 | |
90a7806e | 709 | atomic64_inc(&zram->stats.zero_pages); |
924bd88d JM |
710 | ret = 0; |
711 | goto out; | |
8c921b2b | 712 | } |
306b0c95 | 713 | |
2aea8493 | 714 | zstrm = zcomp_stream_get(zram->comp); |
ebaf9ab5 | 715 | ret = zcomp_compress(zstrm, uncmem, &clen); |
397c6066 NG |
716 | if (!is_partial_io(bvec)) { |
717 | kunmap_atomic(user_mem); | |
718 | user_mem = NULL; | |
719 | uncmem = NULL; | |
720 | } | |
306b0c95 | 721 | |
b7ca232e | 722 | if (unlikely(ret)) { |
8c921b2b | 723 | pr_err("Compression failed! err=%d\n", ret); |
924bd88d | 724 | goto out; |
8c921b2b | 725 | } |
da9556a2 | 726 | |
b7ca232e | 727 | src = zstrm->buffer; |
c8f2f0db | 728 | if (unlikely(clen > max_zpage_size)) { |
c8f2f0db | 729 | clen = PAGE_SIZE; |
397c6066 NG |
730 | if (is_partial_io(bvec)) |
731 | src = uncmem; | |
c8f2f0db | 732 | } |
a1dd52af | 733 | |
da9556a2 SS |
734 | /* |
735 | * handle allocation has 2 paths: | |
736 | * a) fast path is executed with preemption disabled (for | |
737 | * per-cpu streams) and has __GFP_DIRECT_RECLAIM bit clear, | |
738 | * since we can't sleep; | |
739 | * b) slow path enables preemption and attempts to allocate | |
740 | * the page with __GFP_DIRECT_RECLAIM bit set. we have to | |
741 | * put per-cpu compression stream and, thus, to re-do | |
742 | * the compression once handle is allocated. | |
743 | * | |
744 | * if we have a 'non-null' handle here then we are coming | |
745 | * from the slow path and handle has already been allocated. | |
746 | */ | |
747 | if (!handle) | |
748 | handle = zs_malloc(meta->mem_pool, clen, | |
749 | __GFP_KSWAPD_RECLAIM | | |
750 | __GFP_NOWARN | | |
9bc482d3 MK |
751 | __GFP_HIGHMEM | |
752 | __GFP_MOVABLE); | |
fd1a30de | 753 | if (!handle) { |
2aea8493 | 754 | zcomp_stream_put(zram->comp); |
da9556a2 SS |
755 | zstrm = NULL; |
756 | ||
623e47fc SS |
757 | atomic64_inc(&zram->stats.writestall); |
758 | ||
da9556a2 | 759 | handle = zs_malloc(meta->mem_pool, clen, |
9bc482d3 MK |
760 | GFP_NOIO | __GFP_HIGHMEM | |
761 | __GFP_MOVABLE); | |
da9556a2 SS |
762 | if (handle) |
763 | goto compress_again; | |
764 | ||
ebaf9ab5 | 765 | pr_err("Error allocating memory for compressed page: %u, size=%u\n", |
596b3dd4 | 766 | index, clen); |
924bd88d JM |
767 | ret = -ENOMEM; |
768 | goto out; | |
8c921b2b | 769 | } |
9ada9da9 | 770 | |
461a8eee | 771 | alloced_pages = zs_get_total_pages(meta->mem_pool); |
12372755 SS |
772 | update_used_max(zram, alloced_pages); |
773 | ||
461a8eee | 774 | if (zram->limit_pages && alloced_pages > zram->limit_pages) { |
9ada9da9 MK |
775 | zs_free(meta->mem_pool, handle); |
776 | ret = -ENOMEM; | |
777 | goto out; | |
778 | } | |
779 | ||
8b3cc3ed | 780 | cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO); |
306b0c95 | 781 | |
42e99bd9 | 782 | if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) { |
397c6066 | 783 | src = kmap_atomic(page); |
42e99bd9 | 784 | copy_page(cmem, src); |
397c6066 | 785 | kunmap_atomic(src); |
42e99bd9 JL |
786 | } else { |
787 | memcpy(cmem, src, clen); | |
788 | } | |
306b0c95 | 789 | |
2aea8493 | 790 | zcomp_stream_put(zram->comp); |
17162f41 | 791 | zstrm = NULL; |
8b3cc3ed | 792 | zs_unmap_object(meta->mem_pool, handle); |
fd1a30de | 793 | |
f40ac2ae SS |
794 | /* |
795 | * Free memory associated with this sector | |
796 | * before overwriting unused sectors. | |
797 | */ | |
d2d5e762 | 798 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f40ac2ae SS |
799 | zram_free_page(zram, index); |
800 | ||
8b3cc3ed | 801 | meta->table[index].handle = handle; |
d2d5e762 WY |
802 | zram_set_obj_size(meta, index, clen); |
803 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); | |
306b0c95 | 804 | |
8c921b2b | 805 | /* Update stats */ |
90a7806e SS |
806 | atomic64_add(clen, &zram->stats.compr_data_size); |
807 | atomic64_inc(&zram->stats.pages_stored); | |
924bd88d | 808 | out: |
17162f41 | 809 | if (zstrm) |
2aea8493 | 810 | zcomp_stream_put(zram->comp); |
397c6066 NG |
811 | if (is_partial_io(bvec)) |
812 | kfree(uncmem); | |
924bd88d | 813 | return ret; |
8c921b2b JM |
814 | } |
815 | ||
f4659d8e JK |
816 | /* |
817 | * zram_bio_discard - handler on discard request | |
818 | * @index: physical block index in PAGE_SIZE units | |
819 | * @offset: byte offset within physical block | |
820 | */ | |
821 | static void zram_bio_discard(struct zram *zram, u32 index, | |
822 | int offset, struct bio *bio) | |
823 | { | |
824 | size_t n = bio->bi_iter.bi_size; | |
d2d5e762 | 825 | struct zram_meta *meta = zram->meta; |
f4659d8e JK |
826 | |
827 | /* | |
828 | * zram manages data in physical block size units. Because logical block | |
829 | * size isn't identical with physical block size on some arch, we | |
830 | * could get a discard request pointing to a specific offset within a | |
831 | * certain physical block. Although we can handle this request by | |
832 | * reading that physiclal block and decompressing and partially zeroing | |
833 | * and re-compressing and then re-storing it, this isn't reasonable | |
834 | * because our intent with a discard request is to save memory. So | |
835 | * skipping this logical block is appropriate here. | |
836 | */ | |
837 | if (offset) { | |
38515c73 | 838 | if (n <= (PAGE_SIZE - offset)) |
f4659d8e JK |
839 | return; |
840 | ||
38515c73 | 841 | n -= (PAGE_SIZE - offset); |
f4659d8e JK |
842 | index++; |
843 | } | |
844 | ||
845 | while (n >= PAGE_SIZE) { | |
d2d5e762 | 846 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f4659d8e | 847 | zram_free_page(zram, index); |
d2d5e762 | 848 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
015254da | 849 | atomic64_inc(&zram->stats.notify_free); |
f4659d8e JK |
850 | index++; |
851 | n -= PAGE_SIZE; | |
852 | } | |
853 | } | |
854 | ||
522698d7 | 855 | static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, |
c11f0c0b | 856 | int offset, bool is_write) |
9b3bb7ab | 857 | { |
522698d7 | 858 | unsigned long start_time = jiffies; |
c11f0c0b | 859 | int rw_acct = is_write ? REQ_OP_WRITE : REQ_OP_READ; |
9b3bb7ab | 860 | int ret; |
9b3bb7ab | 861 | |
c11f0c0b | 862 | generic_start_io_acct(rw_acct, bvec->bv_len >> SECTOR_SHIFT, |
522698d7 | 863 | &zram->disk->part0); |
46a51c80 | 864 | |
c11f0c0b | 865 | if (!is_write) { |
522698d7 SS |
866 | atomic64_inc(&zram->stats.num_reads); |
867 | ret = zram_bvec_read(zram, bvec, index, offset); | |
868 | } else { | |
869 | atomic64_inc(&zram->stats.num_writes); | |
870 | ret = zram_bvec_write(zram, bvec, index, offset); | |
1b672224 | 871 | } |
9b3bb7ab | 872 | |
c11f0c0b | 873 | generic_end_io_acct(rw_acct, &zram->disk->part0, start_time); |
9b3bb7ab | 874 | |
522698d7 | 875 | if (unlikely(ret)) { |
c11f0c0b | 876 | if (!is_write) |
522698d7 SS |
877 | atomic64_inc(&zram->stats.failed_reads); |
878 | else | |
879 | atomic64_inc(&zram->stats.failed_writes); | |
1b672224 | 880 | } |
9b3bb7ab | 881 | |
1b672224 | 882 | return ret; |
8c921b2b JM |
883 | } |
884 | ||
be257c61 | 885 | static void __zram_make_request(struct zram *zram, struct bio *bio) |
8c921b2b | 886 | { |
abf54548 | 887 | int offset; |
8c921b2b | 888 | u32 index; |
7988613b KO |
889 | struct bio_vec bvec; |
890 | struct bvec_iter iter; | |
8c921b2b | 891 | |
4f024f37 KO |
892 | index = bio->bi_iter.bi_sector >> SECTORS_PER_PAGE_SHIFT; |
893 | offset = (bio->bi_iter.bi_sector & | |
894 | (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; | |
8c921b2b | 895 | |
95fe6c1a | 896 | if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) { |
f4659d8e | 897 | zram_bio_discard(zram, index, offset, bio); |
4246a0b6 | 898 | bio_endio(bio); |
f4659d8e JK |
899 | return; |
900 | } | |
901 | ||
7988613b | 902 | bio_for_each_segment(bvec, bio, iter) { |
924bd88d JM |
903 | int max_transfer_size = PAGE_SIZE - offset; |
904 | ||
7988613b | 905 | if (bvec.bv_len > max_transfer_size) { |
924bd88d JM |
906 | /* |
907 | * zram_bvec_rw() can only make operation on a single | |
908 | * zram page. Split the bio vector. | |
909 | */ | |
910 | struct bio_vec bv; | |
911 | ||
7988613b | 912 | bv.bv_page = bvec.bv_page; |
924bd88d | 913 | bv.bv_len = max_transfer_size; |
7988613b | 914 | bv.bv_offset = bvec.bv_offset; |
924bd88d | 915 | |
abf54548 | 916 | if (zram_bvec_rw(zram, &bv, index, offset, |
c11f0c0b | 917 | op_is_write(bio_op(bio))) < 0) |
924bd88d JM |
918 | goto out; |
919 | ||
7988613b | 920 | bv.bv_len = bvec.bv_len - max_transfer_size; |
924bd88d | 921 | bv.bv_offset += max_transfer_size; |
abf54548 | 922 | if (zram_bvec_rw(zram, &bv, index + 1, 0, |
c11f0c0b | 923 | op_is_write(bio_op(bio))) < 0) |
924bd88d JM |
924 | goto out; |
925 | } else | |
abf54548 | 926 | if (zram_bvec_rw(zram, &bvec, index, offset, |
c11f0c0b | 927 | op_is_write(bio_op(bio))) < 0) |
924bd88d JM |
928 | goto out; |
929 | ||
7988613b | 930 | update_position(&index, &offset, &bvec); |
a1dd52af | 931 | } |
306b0c95 | 932 | |
4246a0b6 | 933 | bio_endio(bio); |
7d7854b4 | 934 | return; |
306b0c95 NG |
935 | |
936 | out: | |
306b0c95 | 937 | bio_io_error(bio); |
306b0c95 NG |
938 | } |
939 | ||
306b0c95 | 940 | /* |
f1e3cfff | 941 | * Handler function for all zram I/O requests. |
306b0c95 | 942 | */ |
dece1635 | 943 | static blk_qc_t zram_make_request(struct request_queue *queue, struct bio *bio) |
306b0c95 | 944 | { |
f1e3cfff | 945 | struct zram *zram = queue->queuedata; |
306b0c95 | 946 | |
08eee69f | 947 | if (unlikely(!zram_meta_get(zram))) |
3de738cd | 948 | goto error; |
0900beae | 949 | |
54efd50b KO |
950 | blk_queue_split(queue, &bio, queue->bio_split); |
951 | ||
54850e73 | 952 | if (!valid_io_request(zram, bio->bi_iter.bi_sector, |
953 | bio->bi_iter.bi_size)) { | |
da5cc7d3 | 954 | atomic64_inc(&zram->stats.invalid_io); |
08eee69f | 955 | goto put_zram; |
6642a67c JM |
956 | } |
957 | ||
be257c61 | 958 | __zram_make_request(zram, bio); |
08eee69f | 959 | zram_meta_put(zram); |
dece1635 | 960 | return BLK_QC_T_NONE; |
08eee69f MK |
961 | put_zram: |
962 | zram_meta_put(zram); | |
0900beae JM |
963 | error: |
964 | bio_io_error(bio); | |
dece1635 | 965 | return BLK_QC_T_NONE; |
306b0c95 NG |
966 | } |
967 | ||
2ccbec05 NG |
968 | static void zram_slot_free_notify(struct block_device *bdev, |
969 | unsigned long index) | |
107c161b | 970 | { |
f1e3cfff | 971 | struct zram *zram; |
f614a9f4 | 972 | struct zram_meta *meta; |
107c161b | 973 | |
f1e3cfff | 974 | zram = bdev->bd_disk->private_data; |
f614a9f4 | 975 | meta = zram->meta; |
a0c516cb | 976 | |
d2d5e762 | 977 | bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); |
f614a9f4 | 978 | zram_free_page(zram, index); |
d2d5e762 | 979 | bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); |
f614a9f4 | 980 | atomic64_inc(&zram->stats.notify_free); |
107c161b NG |
981 | } |
982 | ||
8c7f0102 | 983 | static int zram_rw_page(struct block_device *bdev, sector_t sector, |
c11f0c0b | 984 | struct page *page, bool is_write) |
8c7f0102 | 985 | { |
08eee69f | 986 | int offset, err = -EIO; |
8c7f0102 | 987 | u32 index; |
988 | struct zram *zram; | |
989 | struct bio_vec bv; | |
990 | ||
991 | zram = bdev->bd_disk->private_data; | |
08eee69f MK |
992 | if (unlikely(!zram_meta_get(zram))) |
993 | goto out; | |
994 | ||
8c7f0102 | 995 | if (!valid_io_request(zram, sector, PAGE_SIZE)) { |
996 | atomic64_inc(&zram->stats.invalid_io); | |
08eee69f MK |
997 | err = -EINVAL; |
998 | goto put_zram; | |
8c7f0102 | 999 | } |
1000 | ||
1001 | index = sector >> SECTORS_PER_PAGE_SHIFT; | |
1002 | offset = sector & (SECTORS_PER_PAGE - 1) << SECTOR_SHIFT; | |
1003 | ||
1004 | bv.bv_page = page; | |
1005 | bv.bv_len = PAGE_SIZE; | |
1006 | bv.bv_offset = 0; | |
1007 | ||
c11f0c0b | 1008 | err = zram_bvec_rw(zram, &bv, index, offset, is_write); |
08eee69f MK |
1009 | put_zram: |
1010 | zram_meta_put(zram); | |
1011 | out: | |
8c7f0102 | 1012 | /* |
1013 | * If I/O fails, just return error(ie, non-zero) without | |
1014 | * calling page_endio. | |
1015 | * It causes resubmit the I/O with bio request by upper functions | |
1016 | * of rw_page(e.g., swap_readpage, __swap_writepage) and | |
1017 | * bio->bi_end_io does things to handle the error | |
1018 | * (e.g., SetPageError, set_page_dirty and extra works). | |
1019 | */ | |
1020 | if (err == 0) | |
c11f0c0b | 1021 | page_endio(page, is_write, 0); |
8c7f0102 | 1022 | return err; |
1023 | } | |
1024 | ||
522698d7 SS |
1025 | static void zram_reset_device(struct zram *zram) |
1026 | { | |
1027 | struct zram_meta *meta; | |
1028 | struct zcomp *comp; | |
1029 | u64 disksize; | |
306b0c95 | 1030 | |
522698d7 | 1031 | down_write(&zram->init_lock); |
9b3bb7ab | 1032 | |
522698d7 SS |
1033 | zram->limit_pages = 0; |
1034 | ||
1035 | if (!init_done(zram)) { | |
1036 | up_write(&zram->init_lock); | |
1037 | return; | |
1038 | } | |
1039 | ||
1040 | meta = zram->meta; | |
1041 | comp = zram->comp; | |
1042 | disksize = zram->disksize; | |
1043 | /* | |
1044 | * Refcount will go down to 0 eventually and r/w handler | |
1045 | * cannot handle further I/O so it will bail out by | |
1046 | * check zram_meta_get. | |
1047 | */ | |
1048 | zram_meta_put(zram); | |
1049 | /* | |
1050 | * We want to free zram_meta in process context to avoid | |
1051 | * deadlock between reclaim path and any other locks. | |
1052 | */ | |
1053 | wait_event(zram->io_done, atomic_read(&zram->refcount) == 0); | |
1054 | ||
1055 | /* Reset stats */ | |
1056 | memset(&zram->stats, 0, sizeof(zram->stats)); | |
1057 | zram->disksize = 0; | |
522698d7 SS |
1058 | |
1059 | set_capacity(zram->disk, 0); | |
1060 | part_stat_set_all(&zram->disk->part0, 0); | |
1061 | ||
1062 | up_write(&zram->init_lock); | |
1063 | /* I/O operation under all of CPU are done so let's free */ | |
1064 | zram_meta_free(meta, disksize); | |
1065 | zcomp_destroy(comp); | |
1066 | } | |
1067 | ||
1068 | static ssize_t disksize_store(struct device *dev, | |
1069 | struct device_attribute *attr, const char *buf, size_t len) | |
2f6a3bed | 1070 | { |
522698d7 SS |
1071 | u64 disksize; |
1072 | struct zcomp *comp; | |
1073 | struct zram_meta *meta; | |
2f6a3bed | 1074 | struct zram *zram = dev_to_zram(dev); |
522698d7 | 1075 | int err; |
2f6a3bed | 1076 | |
522698d7 SS |
1077 | disksize = memparse(buf, NULL); |
1078 | if (!disksize) | |
1079 | return -EINVAL; | |
2f6a3bed | 1080 | |
522698d7 | 1081 | disksize = PAGE_ALIGN(disksize); |
4ce321f5 | 1082 | meta = zram_meta_alloc(zram->disk->disk_name, disksize); |
522698d7 SS |
1083 | if (!meta) |
1084 | return -ENOMEM; | |
1085 | ||
da9556a2 | 1086 | comp = zcomp_create(zram->compressor); |
522698d7 | 1087 | if (IS_ERR(comp)) { |
70864969 | 1088 | pr_err("Cannot initialise %s compressing backend\n", |
522698d7 SS |
1089 | zram->compressor); |
1090 | err = PTR_ERR(comp); | |
1091 | goto out_free_meta; | |
1092 | } | |
1093 | ||
1094 | down_write(&zram->init_lock); | |
1095 | if (init_done(zram)) { | |
1096 | pr_info("Cannot change disksize for initialized device\n"); | |
1097 | err = -EBUSY; | |
1098 | goto out_destroy_comp; | |
1099 | } | |
1100 | ||
1101 | init_waitqueue_head(&zram->io_done); | |
1102 | atomic_set(&zram->refcount, 1); | |
1103 | zram->meta = meta; | |
1104 | zram->comp = comp; | |
1105 | zram->disksize = disksize; | |
1106 | set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); | |
b09ab054 | 1107 | zram_revalidate_disk(zram); |
e7ccfc4c | 1108 | up_write(&zram->init_lock); |
522698d7 SS |
1109 | |
1110 | return len; | |
1111 | ||
1112 | out_destroy_comp: | |
1113 | up_write(&zram->init_lock); | |
1114 | zcomp_destroy(comp); | |
1115 | out_free_meta: | |
1116 | zram_meta_free(meta, disksize); | |
1117 | return err; | |
2f6a3bed SS |
1118 | } |
1119 | ||
522698d7 SS |
1120 | static ssize_t reset_store(struct device *dev, |
1121 | struct device_attribute *attr, const char *buf, size_t len) | |
4f2109f6 | 1122 | { |
522698d7 SS |
1123 | int ret; |
1124 | unsigned short do_reset; | |
1125 | struct zram *zram; | |
1126 | struct block_device *bdev; | |
4f2109f6 | 1127 | |
f405c445 SS |
1128 | ret = kstrtou16(buf, 10, &do_reset); |
1129 | if (ret) | |
1130 | return ret; | |
1131 | ||
1132 | if (!do_reset) | |
1133 | return -EINVAL; | |
1134 | ||
522698d7 SS |
1135 | zram = dev_to_zram(dev); |
1136 | bdev = bdget_disk(zram->disk, 0); | |
522698d7 SS |
1137 | if (!bdev) |
1138 | return -ENOMEM; | |
4f2109f6 | 1139 | |
522698d7 | 1140 | mutex_lock(&bdev->bd_mutex); |
f405c445 SS |
1141 | /* Do not reset an active device or claimed device */ |
1142 | if (bdev->bd_openers || zram->claim) { | |
1143 | mutex_unlock(&bdev->bd_mutex); | |
1144 | bdput(bdev); | |
1145 | return -EBUSY; | |
522698d7 SS |
1146 | } |
1147 | ||
f405c445 SS |
1148 | /* From now on, anyone can't open /dev/zram[0-9] */ |
1149 | zram->claim = true; | |
1150 | mutex_unlock(&bdev->bd_mutex); | |
522698d7 | 1151 | |
f405c445 | 1152 | /* Make sure all the pending I/O are finished */ |
522698d7 SS |
1153 | fsync_bdev(bdev); |
1154 | zram_reset_device(zram); | |
b09ab054 | 1155 | zram_revalidate_disk(zram); |
522698d7 SS |
1156 | bdput(bdev); |
1157 | ||
f405c445 SS |
1158 | mutex_lock(&bdev->bd_mutex); |
1159 | zram->claim = false; | |
1160 | mutex_unlock(&bdev->bd_mutex); | |
1161 | ||
522698d7 | 1162 | return len; |
f405c445 SS |
1163 | } |
1164 | ||
1165 | static int zram_open(struct block_device *bdev, fmode_t mode) | |
1166 | { | |
1167 | int ret = 0; | |
1168 | struct zram *zram; | |
1169 | ||
1170 | WARN_ON(!mutex_is_locked(&bdev->bd_mutex)); | |
1171 | ||
1172 | zram = bdev->bd_disk->private_data; | |
1173 | /* zram was claimed to reset so open request fails */ | |
1174 | if (zram->claim) | |
1175 | ret = -EBUSY; | |
4f2109f6 SS |
1176 | |
1177 | return ret; | |
1178 | } | |
1179 | ||
522698d7 | 1180 | static const struct block_device_operations zram_devops = { |
f405c445 | 1181 | .open = zram_open, |
522698d7 SS |
1182 | .swap_slot_free_notify = zram_slot_free_notify, |
1183 | .rw_page = zram_rw_page, | |
1184 | .owner = THIS_MODULE | |
1185 | }; | |
1186 | ||
1187 | static DEVICE_ATTR_WO(compact); | |
1188 | static DEVICE_ATTR_RW(disksize); | |
1189 | static DEVICE_ATTR_RO(initstate); | |
1190 | static DEVICE_ATTR_WO(reset); | |
1191 | static DEVICE_ATTR_RO(orig_data_size); | |
1192 | static DEVICE_ATTR_RO(mem_used_total); | |
1193 | static DEVICE_ATTR_RW(mem_limit); | |
1194 | static DEVICE_ATTR_RW(mem_used_max); | |
1195 | static DEVICE_ATTR_RW(max_comp_streams); | |
1196 | static DEVICE_ATTR_RW(comp_algorithm); | |
a68eb3b6 | 1197 | |
9b3bb7ab SS |
1198 | static struct attribute *zram_disk_attrs[] = { |
1199 | &dev_attr_disksize.attr, | |
1200 | &dev_attr_initstate.attr, | |
1201 | &dev_attr_reset.attr, | |
1202 | &dev_attr_num_reads.attr, | |
1203 | &dev_attr_num_writes.attr, | |
64447249 SS |
1204 | &dev_attr_failed_reads.attr, |
1205 | &dev_attr_failed_writes.attr, | |
99ebbd30 | 1206 | &dev_attr_compact.attr, |
9b3bb7ab SS |
1207 | &dev_attr_invalid_io.attr, |
1208 | &dev_attr_notify_free.attr, | |
1209 | &dev_attr_zero_pages.attr, | |
1210 | &dev_attr_orig_data_size.attr, | |
1211 | &dev_attr_compr_data_size.attr, | |
1212 | &dev_attr_mem_used_total.attr, | |
9ada9da9 | 1213 | &dev_attr_mem_limit.attr, |
461a8eee | 1214 | &dev_attr_mem_used_max.attr, |
beca3ec7 | 1215 | &dev_attr_max_comp_streams.attr, |
e46b8a03 | 1216 | &dev_attr_comp_algorithm.attr, |
2f6a3bed | 1217 | &dev_attr_io_stat.attr, |
4f2109f6 | 1218 | &dev_attr_mm_stat.attr, |
623e47fc | 1219 | &dev_attr_debug_stat.attr, |
9b3bb7ab SS |
1220 | NULL, |
1221 | }; | |
1222 | ||
1223 | static struct attribute_group zram_disk_attr_group = { | |
1224 | .attrs = zram_disk_attrs, | |
1225 | }; | |
1226 | ||
92ff1528 SS |
1227 | /* |
1228 | * Allocate and initialize new zram device. the function returns | |
1229 | * '>= 0' device_id upon success, and negative value otherwise. | |
1230 | */ | |
1231 | static int zram_add(void) | |
306b0c95 | 1232 | { |
85508ec6 | 1233 | struct zram *zram; |
ee980160 | 1234 | struct request_queue *queue; |
92ff1528 | 1235 | int ret, device_id; |
85508ec6 SS |
1236 | |
1237 | zram = kzalloc(sizeof(struct zram), GFP_KERNEL); | |
1238 | if (!zram) | |
1239 | return -ENOMEM; | |
1240 | ||
92ff1528 | 1241 | ret = idr_alloc(&zram_index_idr, zram, 0, 0, GFP_KERNEL); |
85508ec6 SS |
1242 | if (ret < 0) |
1243 | goto out_free_dev; | |
92ff1528 | 1244 | device_id = ret; |
de1a21a0 | 1245 | |
0900beae | 1246 | init_rwsem(&zram->init_lock); |
306b0c95 | 1247 | |
ee980160 SS |
1248 | queue = blk_alloc_queue(GFP_KERNEL); |
1249 | if (!queue) { | |
306b0c95 NG |
1250 | pr_err("Error allocating disk queue for device %d\n", |
1251 | device_id); | |
85508ec6 SS |
1252 | ret = -ENOMEM; |
1253 | goto out_free_idr; | |
306b0c95 NG |
1254 | } |
1255 | ||
ee980160 | 1256 | blk_queue_make_request(queue, zram_make_request); |
306b0c95 | 1257 | |
85508ec6 | 1258 | /* gendisk structure */ |
f1e3cfff NG |
1259 | zram->disk = alloc_disk(1); |
1260 | if (!zram->disk) { | |
70864969 | 1261 | pr_err("Error allocating disk structure for device %d\n", |
306b0c95 | 1262 | device_id); |
201c7b72 | 1263 | ret = -ENOMEM; |
39a9b8ac | 1264 | goto out_free_queue; |
306b0c95 NG |
1265 | } |
1266 | ||
f1e3cfff NG |
1267 | zram->disk->major = zram_major; |
1268 | zram->disk->first_minor = device_id; | |
1269 | zram->disk->fops = &zram_devops; | |
ee980160 SS |
1270 | zram->disk->queue = queue; |
1271 | zram->disk->queue->queuedata = zram; | |
f1e3cfff NG |
1272 | zram->disk->private_data = zram; |
1273 | snprintf(zram->disk->disk_name, 16, "zram%d", device_id); | |
306b0c95 | 1274 | |
33863c21 | 1275 | /* Actual capacity set using syfs (/sys/block/zram<id>/disksize */ |
f1e3cfff | 1276 | set_capacity(zram->disk, 0); |
b67d1ec1 SS |
1277 | /* zram devices sort of resembles non-rotational disks */ |
1278 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); | |
b277da0a | 1279 | queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, zram->disk->queue); |
a1dd52af NG |
1280 | /* |
1281 | * To ensure that we always get PAGE_SIZE aligned | |
1282 | * and n*PAGE_SIZED sized I/O requests. | |
1283 | */ | |
f1e3cfff | 1284 | blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE); |
7b19b8d4 RJ |
1285 | blk_queue_logical_block_size(zram->disk->queue, |
1286 | ZRAM_LOGICAL_BLOCK_SIZE); | |
f1e3cfff NG |
1287 | blk_queue_io_min(zram->disk->queue, PAGE_SIZE); |
1288 | blk_queue_io_opt(zram->disk->queue, PAGE_SIZE); | |
f4659d8e | 1289 | zram->disk->queue->limits.discard_granularity = PAGE_SIZE; |
2bb4cd5c | 1290 | blk_queue_max_discard_sectors(zram->disk->queue, UINT_MAX); |
f4659d8e JK |
1291 | /* |
1292 | * zram_bio_discard() will clear all logical blocks if logical block | |
1293 | * size is identical with physical block size(PAGE_SIZE). But if it is | |
1294 | * different, we will skip discarding some parts of logical blocks in | |
1295 | * the part of the request range which isn't aligned to physical block | |
1296 | * size. So we can't ensure that all discarded logical blocks are | |
1297 | * zeroed. | |
1298 | */ | |
1299 | if (ZRAM_LOGICAL_BLOCK_SIZE == PAGE_SIZE) | |
1300 | zram->disk->queue->limits.discard_zeroes_data = 1; | |
1301 | else | |
1302 | zram->disk->queue->limits.discard_zeroes_data = 0; | |
1303 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, zram->disk->queue); | |
5d83d5a0 | 1304 | |
f1e3cfff | 1305 | add_disk(zram->disk); |
306b0c95 | 1306 | |
33863c21 NG |
1307 | ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj, |
1308 | &zram_disk_attr_group); | |
1309 | if (ret < 0) { | |
70864969 SS |
1310 | pr_err("Error creating sysfs group for device %d\n", |
1311 | device_id); | |
39a9b8ac | 1312 | goto out_free_disk; |
33863c21 | 1313 | } |
e46b8a03 | 1314 | strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor)); |
be2d1d56 | 1315 | zram->meta = NULL; |
d12b63c9 SS |
1316 | |
1317 | pr_info("Added device: %s\n", zram->disk->disk_name); | |
92ff1528 | 1318 | return device_id; |
de1a21a0 | 1319 | |
39a9b8ac JL |
1320 | out_free_disk: |
1321 | del_gendisk(zram->disk); | |
1322 | put_disk(zram->disk); | |
1323 | out_free_queue: | |
ee980160 | 1324 | blk_cleanup_queue(queue); |
85508ec6 SS |
1325 | out_free_idr: |
1326 | idr_remove(&zram_index_idr, device_id); | |
1327 | out_free_dev: | |
1328 | kfree(zram); | |
de1a21a0 | 1329 | return ret; |
306b0c95 NG |
1330 | } |
1331 | ||
6566d1a3 | 1332 | static int zram_remove(struct zram *zram) |
306b0c95 | 1333 | { |
6566d1a3 SS |
1334 | struct block_device *bdev; |
1335 | ||
1336 | bdev = bdget_disk(zram->disk, 0); | |
1337 | if (!bdev) | |
1338 | return -ENOMEM; | |
1339 | ||
1340 | mutex_lock(&bdev->bd_mutex); | |
1341 | if (bdev->bd_openers || zram->claim) { | |
1342 | mutex_unlock(&bdev->bd_mutex); | |
1343 | bdput(bdev); | |
1344 | return -EBUSY; | |
1345 | } | |
1346 | ||
1347 | zram->claim = true; | |
1348 | mutex_unlock(&bdev->bd_mutex); | |
1349 | ||
85508ec6 SS |
1350 | /* |
1351 | * Remove sysfs first, so no one will perform a disksize | |
6566d1a3 SS |
1352 | * store while we destroy the devices. This also helps during |
1353 | * hot_remove -- zram_reset_device() is the last holder of | |
1354 | * ->init_lock, no later/concurrent disksize_store() or any | |
1355 | * other sysfs handlers are possible. | |
85508ec6 SS |
1356 | */ |
1357 | sysfs_remove_group(&disk_to_dev(zram->disk)->kobj, | |
1358 | &zram_disk_attr_group); | |
306b0c95 | 1359 | |
6566d1a3 SS |
1360 | /* Make sure all the pending I/O are finished */ |
1361 | fsync_bdev(bdev); | |
85508ec6 | 1362 | zram_reset_device(zram); |
6566d1a3 SS |
1363 | bdput(bdev); |
1364 | ||
1365 | pr_info("Removed device: %s\n", zram->disk->disk_name); | |
1366 | ||
85508ec6 SS |
1367 | blk_cleanup_queue(zram->disk->queue); |
1368 | del_gendisk(zram->disk); | |
1369 | put_disk(zram->disk); | |
1370 | kfree(zram); | |
6566d1a3 SS |
1371 | return 0; |
1372 | } | |
1373 | ||
1374 | /* zram-control sysfs attributes */ | |
1375 | static ssize_t hot_add_show(struct class *class, | |
1376 | struct class_attribute *attr, | |
1377 | char *buf) | |
1378 | { | |
1379 | int ret; | |
1380 | ||
1381 | mutex_lock(&zram_index_mutex); | |
1382 | ret = zram_add(); | |
1383 | mutex_unlock(&zram_index_mutex); | |
1384 | ||
1385 | if (ret < 0) | |
1386 | return ret; | |
1387 | return scnprintf(buf, PAGE_SIZE, "%d\n", ret); | |
1388 | } | |
1389 | ||
1390 | static ssize_t hot_remove_store(struct class *class, | |
1391 | struct class_attribute *attr, | |
1392 | const char *buf, | |
1393 | size_t count) | |
1394 | { | |
1395 | struct zram *zram; | |
1396 | int ret, dev_id; | |
1397 | ||
1398 | /* dev_id is gendisk->first_minor, which is `int' */ | |
1399 | ret = kstrtoint(buf, 10, &dev_id); | |
1400 | if (ret) | |
1401 | return ret; | |
1402 | if (dev_id < 0) | |
1403 | return -EINVAL; | |
1404 | ||
1405 | mutex_lock(&zram_index_mutex); | |
1406 | ||
1407 | zram = idr_find(&zram_index_idr, dev_id); | |
17ec4cd9 | 1408 | if (zram) { |
6566d1a3 | 1409 | ret = zram_remove(zram); |
529e71e1 TI |
1410 | if (!ret) |
1411 | idr_remove(&zram_index_idr, dev_id); | |
17ec4cd9 | 1412 | } else { |
6566d1a3 | 1413 | ret = -ENODEV; |
17ec4cd9 | 1414 | } |
6566d1a3 SS |
1415 | |
1416 | mutex_unlock(&zram_index_mutex); | |
1417 | return ret ? ret : count; | |
85508ec6 | 1418 | } |
a096cafc | 1419 | |
5c7e9ccd SS |
1420 | /* |
1421 | * NOTE: hot_add attribute is not the usual read-only sysfs attribute. In a | |
1422 | * sense that reading from this file does alter the state of your system -- it | |
1423 | * creates a new un-initialized zram device and returns back this device's | |
1424 | * device_id (or an error code if it fails to create a new device). | |
1425 | */ | |
6566d1a3 | 1426 | static struct class_attribute zram_control_class_attrs[] = { |
5c7e9ccd | 1427 | __ATTR(hot_add, 0400, hot_add_show, NULL), |
6566d1a3 SS |
1428 | __ATTR_WO(hot_remove), |
1429 | __ATTR_NULL, | |
1430 | }; | |
1431 | ||
1432 | static struct class zram_control_class = { | |
1433 | .name = "zram-control", | |
1434 | .owner = THIS_MODULE, | |
1435 | .class_attrs = zram_control_class_attrs, | |
1436 | }; | |
1437 | ||
85508ec6 SS |
1438 | static int zram_remove_cb(int id, void *ptr, void *data) |
1439 | { | |
1440 | zram_remove(ptr); | |
1441 | return 0; | |
1442 | } | |
a096cafc | 1443 | |
85508ec6 SS |
1444 | static void destroy_devices(void) |
1445 | { | |
6566d1a3 | 1446 | class_unregister(&zram_control_class); |
85508ec6 SS |
1447 | idr_for_each(&zram_index_idr, &zram_remove_cb, NULL); |
1448 | idr_destroy(&zram_index_idr); | |
a096cafc | 1449 | unregister_blkdev(zram_major, "zram"); |
1dd6c834 | 1450 | cpuhp_remove_multi_state(CPUHP_ZCOMP_PREPARE); |
306b0c95 NG |
1451 | } |
1452 | ||
f1e3cfff | 1453 | static int __init zram_init(void) |
306b0c95 | 1454 | { |
92ff1528 | 1455 | int ret; |
306b0c95 | 1456 | |
1dd6c834 AMG |
1457 | ret = cpuhp_setup_state_multi(CPUHP_ZCOMP_PREPARE, "block/zram:prepare", |
1458 | zcomp_cpu_up_prepare, zcomp_cpu_dead); | |
1459 | if (ret < 0) | |
1460 | return ret; | |
1461 | ||
6566d1a3 SS |
1462 | ret = class_register(&zram_control_class); |
1463 | if (ret) { | |
70864969 | 1464 | pr_err("Unable to register zram-control class\n"); |
1dd6c834 | 1465 | cpuhp_remove_multi_state(CPUHP_ZCOMP_PREPARE); |
6566d1a3 SS |
1466 | return ret; |
1467 | } | |
1468 | ||
f1e3cfff NG |
1469 | zram_major = register_blkdev(0, "zram"); |
1470 | if (zram_major <= 0) { | |
70864969 | 1471 | pr_err("Unable to get major number\n"); |
6566d1a3 | 1472 | class_unregister(&zram_control_class); |
1dd6c834 | 1473 | cpuhp_remove_multi_state(CPUHP_ZCOMP_PREPARE); |
a096cafc | 1474 | return -EBUSY; |
306b0c95 NG |
1475 | } |
1476 | ||
92ff1528 | 1477 | while (num_devices != 0) { |
6566d1a3 | 1478 | mutex_lock(&zram_index_mutex); |
92ff1528 | 1479 | ret = zram_add(); |
6566d1a3 | 1480 | mutex_unlock(&zram_index_mutex); |
92ff1528 | 1481 | if (ret < 0) |
a096cafc | 1482 | goto out_error; |
92ff1528 | 1483 | num_devices--; |
de1a21a0 NG |
1484 | } |
1485 | ||
306b0c95 | 1486 | return 0; |
de1a21a0 | 1487 | |
a096cafc | 1488 | out_error: |
85508ec6 | 1489 | destroy_devices(); |
306b0c95 NG |
1490 | return ret; |
1491 | } | |
1492 | ||
f1e3cfff | 1493 | static void __exit zram_exit(void) |
306b0c95 | 1494 | { |
85508ec6 | 1495 | destroy_devices(); |
306b0c95 NG |
1496 | } |
1497 | ||
f1e3cfff NG |
1498 | module_init(zram_init); |
1499 | module_exit(zram_exit); | |
306b0c95 | 1500 | |
9b3bb7ab | 1501 | module_param(num_devices, uint, 0); |
c3cdb40e | 1502 | MODULE_PARM_DESC(num_devices, "Number of pre-created zram devices"); |
9b3bb7ab | 1503 | |
306b0c95 NG |
1504 | MODULE_LICENSE("Dual BSD/GPL"); |
1505 | MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); | |
f1e3cfff | 1506 | MODULE_DESCRIPTION("Compressed RAM Block Device"); |