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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2b281117 SJ |
2 | /* |
3 | * zswap.c - zswap driver file | |
4 | * | |
5 | * zswap is a backend for frontswap that takes pages that are in the process | |
6 | * of being swapped out and attempts to compress and store them in a | |
7 | * RAM-based memory pool. This can result in a significant I/O reduction on | |
8 | * the swap device and, in the case where decompressing from RAM is faster | |
9 | * than reading from the swap device, can also improve workload performance. | |
10 | * | |
11 | * Copyright (C) 2012 Seth Jennings <sjenning@linux.vnet.ibm.com> | |
2b281117 SJ |
12 | */ |
13 | ||
14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
15 | ||
16 | #include <linux/module.h> | |
17 | #include <linux/cpu.h> | |
18 | #include <linux/highmem.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/spinlock.h> | |
21 | #include <linux/types.h> | |
22 | #include <linux/atomic.h> | |
23 | #include <linux/frontswap.h> | |
24 | #include <linux/rbtree.h> | |
25 | #include <linux/swap.h> | |
26 | #include <linux/crypto.h> | |
1ec3b5fe | 27 | #include <linux/scatterlist.h> |
2b281117 | 28 | #include <linux/mempool.h> |
12d79d64 | 29 | #include <linux/zpool.h> |
1ec3b5fe | 30 | #include <crypto/acompress.h> |
2b281117 SJ |
31 | |
32 | #include <linux/mm_types.h> | |
33 | #include <linux/page-flags.h> | |
34 | #include <linux/swapops.h> | |
35 | #include <linux/writeback.h> | |
36 | #include <linux/pagemap.h> | |
45190f01 | 37 | #include <linux/workqueue.h> |
2b281117 | 38 | |
014bb1de N |
39 | #include "swap.h" |
40 | ||
2b281117 SJ |
41 | /********************************* |
42 | * statistics | |
43 | **********************************/ | |
12d79d64 | 44 | /* Total bytes used by the compressed storage */ |
f6498b77 | 45 | u64 zswap_pool_total_size; |
2b281117 | 46 | /* The number of compressed pages currently stored in zswap */ |
f6498b77 | 47 | atomic_t zswap_stored_pages = ATOMIC_INIT(0); |
a85f878b SD |
48 | /* The number of same-value filled pages currently stored in zswap */ |
49 | static atomic_t zswap_same_filled_pages = ATOMIC_INIT(0); | |
2b281117 SJ |
50 | |
51 | /* | |
52 | * The statistics below are not protected from concurrent access for | |
53 | * performance reasons so they may not be a 100% accurate. However, | |
54 | * they do provide useful information on roughly how many times a | |
55 | * certain event is occurring. | |
56 | */ | |
57 | ||
58 | /* Pool limit was hit (see zswap_max_pool_percent) */ | |
59 | static u64 zswap_pool_limit_hit; | |
60 | /* Pages written back when pool limit was reached */ | |
61 | static u64 zswap_written_back_pages; | |
62 | /* Store failed due to a reclaim failure after pool limit was reached */ | |
63 | static u64 zswap_reject_reclaim_fail; | |
64 | /* Compressed page was too big for the allocator to (optimally) store */ | |
65 | static u64 zswap_reject_compress_poor; | |
66 | /* Store failed because underlying allocator could not get memory */ | |
67 | static u64 zswap_reject_alloc_fail; | |
68 | /* Store failed because the entry metadata could not be allocated (rare) */ | |
69 | static u64 zswap_reject_kmemcache_fail; | |
70 | /* Duplicate store was encountered (rare) */ | |
71 | static u64 zswap_duplicate_entry; | |
72 | ||
45190f01 VW |
73 | /* Shrinker work queue */ |
74 | static struct workqueue_struct *shrink_wq; | |
75 | /* Pool limit was hit, we need to calm down */ | |
76 | static bool zswap_pool_reached_full; | |
77 | ||
2b281117 SJ |
78 | /********************************* |
79 | * tunables | |
80 | **********************************/ | |
c00ed16a | 81 | |
bae21db8 DS |
82 | #define ZSWAP_PARAM_UNSET "" |
83 | ||
bb8b93b5 MS |
84 | /* Enable/disable zswap */ |
85 | static bool zswap_enabled = IS_ENABLED(CONFIG_ZSWAP_DEFAULT_ON); | |
d7b028f5 DS |
86 | static int zswap_enabled_param_set(const char *, |
87 | const struct kernel_param *); | |
83aed6cd | 88 | static const struct kernel_param_ops zswap_enabled_param_ops = { |
d7b028f5 DS |
89 | .set = zswap_enabled_param_set, |
90 | .get = param_get_bool, | |
91 | }; | |
92 | module_param_cb(enabled, &zswap_enabled_param_ops, &zswap_enabled, 0644); | |
2b281117 | 93 | |
90b0fc26 | 94 | /* Crypto compressor to use */ |
bb8b93b5 | 95 | static char *zswap_compressor = CONFIG_ZSWAP_COMPRESSOR_DEFAULT; |
90b0fc26 DS |
96 | static int zswap_compressor_param_set(const char *, |
97 | const struct kernel_param *); | |
83aed6cd | 98 | static const struct kernel_param_ops zswap_compressor_param_ops = { |
90b0fc26 | 99 | .set = zswap_compressor_param_set, |
c99b42c3 DS |
100 | .get = param_get_charp, |
101 | .free = param_free_charp, | |
90b0fc26 DS |
102 | }; |
103 | module_param_cb(compressor, &zswap_compressor_param_ops, | |
c99b42c3 | 104 | &zswap_compressor, 0644); |
2b281117 | 105 | |
90b0fc26 | 106 | /* Compressed storage zpool to use */ |
bb8b93b5 | 107 | static char *zswap_zpool_type = CONFIG_ZSWAP_ZPOOL_DEFAULT; |
90b0fc26 | 108 | static int zswap_zpool_param_set(const char *, const struct kernel_param *); |
83aed6cd | 109 | static const struct kernel_param_ops zswap_zpool_param_ops = { |
c99b42c3 DS |
110 | .set = zswap_zpool_param_set, |
111 | .get = param_get_charp, | |
112 | .free = param_free_charp, | |
90b0fc26 | 113 | }; |
c99b42c3 | 114 | module_param_cb(zpool, &zswap_zpool_param_ops, &zswap_zpool_type, 0644); |
12d79d64 | 115 | |
90b0fc26 DS |
116 | /* The maximum percentage of memory that the compressed pool can occupy */ |
117 | static unsigned int zswap_max_pool_percent = 20; | |
118 | module_param_named(max_pool_percent, zswap_max_pool_percent, uint, 0644); | |
60105e12 | 119 | |
45190f01 VW |
120 | /* The threshold for accepting new pages after the max_pool_percent was hit */ |
121 | static unsigned int zswap_accept_thr_percent = 90; /* of max pool size */ | |
122 | module_param_named(accept_threshold_percent, zswap_accept_thr_percent, | |
123 | uint, 0644); | |
124 | ||
cb325ddd MS |
125 | /* |
126 | * Enable/disable handling same-value filled pages (enabled by default). | |
127 | * If disabled every page is considered non-same-value filled. | |
128 | */ | |
a85f878b SD |
129 | static bool zswap_same_filled_pages_enabled = true; |
130 | module_param_named(same_filled_pages_enabled, zswap_same_filled_pages_enabled, | |
131 | bool, 0644); | |
132 | ||
cb325ddd MS |
133 | /* Enable/disable handling non-same-value filled pages (enabled by default) */ |
134 | static bool zswap_non_same_filled_pages_enabled = true; | |
135 | module_param_named(non_same_filled_pages_enabled, zswap_non_same_filled_pages_enabled, | |
136 | bool, 0644); | |
137 | ||
2b281117 | 138 | /********************************* |
f1c54846 | 139 | * data structures |
2b281117 | 140 | **********************************/ |
2b281117 | 141 | |
1ec3b5fe BS |
142 | struct crypto_acomp_ctx { |
143 | struct crypto_acomp *acomp; | |
144 | struct acomp_req *req; | |
145 | struct crypto_wait wait; | |
146 | u8 *dstmem; | |
147 | struct mutex *mutex; | |
148 | }; | |
149 | ||
f1c54846 DS |
150 | struct zswap_pool { |
151 | struct zpool *zpool; | |
1ec3b5fe | 152 | struct crypto_acomp_ctx __percpu *acomp_ctx; |
f1c54846 DS |
153 | struct kref kref; |
154 | struct list_head list; | |
45190f01 VW |
155 | struct work_struct release_work; |
156 | struct work_struct shrink_work; | |
cab7a7e5 | 157 | struct hlist_node node; |
f1c54846 | 158 | char tfm_name[CRYPTO_MAX_ALG_NAME]; |
2b281117 SJ |
159 | }; |
160 | ||
2b281117 SJ |
161 | /* |
162 | * struct zswap_entry | |
163 | * | |
164 | * This structure contains the metadata for tracking a single compressed | |
165 | * page within zswap. | |
166 | * | |
167 | * rbnode - links the entry into red-black tree for the appropriate swap type | |
f1c54846 | 168 | * offset - the swap offset for the entry. Index into the red-black tree. |
2b281117 SJ |
169 | * refcount - the number of outstanding reference to the entry. This is needed |
170 | * to protect against premature freeing of the entry by code | |
6b452516 | 171 | * concurrent calls to load, invalidate, and writeback. The lock |
2b281117 SJ |
172 | * for the zswap_tree structure that contains the entry must |
173 | * be held while changing the refcount. Since the lock must | |
174 | * be held, there is no reason to also make refcount atomic. | |
2b281117 | 175 | * length - the length in bytes of the compressed page data. Needed during |
a85f878b | 176 | * decompression. For a same value filled page length is 0. |
f1c54846 DS |
177 | * pool - the zswap_pool the entry's data is in |
178 | * handle - zpool allocation handle that stores the compressed page data | |
a85f878b | 179 | * value - value of the same-value filled pages which have same content |
2b281117 SJ |
180 | */ |
181 | struct zswap_entry { | |
182 | struct rb_node rbnode; | |
183 | pgoff_t offset; | |
184 | int refcount; | |
185 | unsigned int length; | |
f1c54846 | 186 | struct zswap_pool *pool; |
a85f878b SD |
187 | union { |
188 | unsigned long handle; | |
189 | unsigned long value; | |
190 | }; | |
2b281117 SJ |
191 | }; |
192 | ||
193 | struct zswap_header { | |
194 | swp_entry_t swpentry; | |
195 | }; | |
196 | ||
197 | /* | |
198 | * The tree lock in the zswap_tree struct protects a few things: | |
199 | * - the rbtree | |
200 | * - the refcount field of each entry in the tree | |
201 | */ | |
202 | struct zswap_tree { | |
203 | struct rb_root rbroot; | |
204 | spinlock_t lock; | |
2b281117 SJ |
205 | }; |
206 | ||
207 | static struct zswap_tree *zswap_trees[MAX_SWAPFILES]; | |
208 | ||
f1c54846 DS |
209 | /* RCU-protected iteration */ |
210 | static LIST_HEAD(zswap_pools); | |
211 | /* protects zswap_pools list modification */ | |
212 | static DEFINE_SPINLOCK(zswap_pools_lock); | |
32a4e169 DS |
213 | /* pool counter to provide unique names to zpool */ |
214 | static atomic_t zswap_pools_count = ATOMIC_INIT(0); | |
f1c54846 | 215 | |
90b0fc26 DS |
216 | /* used by param callback function */ |
217 | static bool zswap_init_started; | |
218 | ||
d7b028f5 DS |
219 | /* fatal error during init */ |
220 | static bool zswap_init_failed; | |
221 | ||
ae3d89a7 DS |
222 | /* init completed, but couldn't create the initial pool */ |
223 | static bool zswap_has_pool; | |
224 | ||
f1c54846 DS |
225 | /********************************* |
226 | * helpers and fwd declarations | |
227 | **********************************/ | |
228 | ||
229 | #define zswap_pool_debug(msg, p) \ | |
230 | pr_debug("%s pool %s/%s\n", msg, (p)->tfm_name, \ | |
231 | zpool_get_type((p)->zpool)) | |
232 | ||
233 | static int zswap_writeback_entry(struct zpool *pool, unsigned long handle); | |
234 | static int zswap_pool_get(struct zswap_pool *pool); | |
235 | static void zswap_pool_put(struct zswap_pool *pool); | |
236 | ||
237 | static const struct zpool_ops zswap_zpool_ops = { | |
238 | .evict = zswap_writeback_entry | |
239 | }; | |
240 | ||
241 | static bool zswap_is_full(void) | |
242 | { | |
ca79b0c2 AK |
243 | return totalram_pages() * zswap_max_pool_percent / 100 < |
244 | DIV_ROUND_UP(zswap_pool_total_size, PAGE_SIZE); | |
f1c54846 DS |
245 | } |
246 | ||
45190f01 VW |
247 | static bool zswap_can_accept(void) |
248 | { | |
249 | return totalram_pages() * zswap_accept_thr_percent / 100 * | |
250 | zswap_max_pool_percent / 100 > | |
251 | DIV_ROUND_UP(zswap_pool_total_size, PAGE_SIZE); | |
252 | } | |
253 | ||
f1c54846 DS |
254 | static void zswap_update_total_size(void) |
255 | { | |
256 | struct zswap_pool *pool; | |
257 | u64 total = 0; | |
258 | ||
259 | rcu_read_lock(); | |
260 | ||
261 | list_for_each_entry_rcu(pool, &zswap_pools, list) | |
262 | total += zpool_get_total_size(pool->zpool); | |
263 | ||
264 | rcu_read_unlock(); | |
265 | ||
266 | zswap_pool_total_size = total; | |
267 | } | |
268 | ||
2b281117 SJ |
269 | /********************************* |
270 | * zswap entry functions | |
271 | **********************************/ | |
272 | static struct kmem_cache *zswap_entry_cache; | |
273 | ||
dd01d7d8 | 274 | static int __init zswap_entry_cache_create(void) |
2b281117 SJ |
275 | { |
276 | zswap_entry_cache = KMEM_CACHE(zswap_entry, 0); | |
5d2d42de | 277 | return zswap_entry_cache == NULL; |
2b281117 SJ |
278 | } |
279 | ||
c119239b | 280 | static void __init zswap_entry_cache_destroy(void) |
2b281117 SJ |
281 | { |
282 | kmem_cache_destroy(zswap_entry_cache); | |
283 | } | |
284 | ||
285 | static struct zswap_entry *zswap_entry_cache_alloc(gfp_t gfp) | |
286 | { | |
287 | struct zswap_entry *entry; | |
288 | entry = kmem_cache_alloc(zswap_entry_cache, gfp); | |
289 | if (!entry) | |
290 | return NULL; | |
291 | entry->refcount = 1; | |
0ab0abcf | 292 | RB_CLEAR_NODE(&entry->rbnode); |
2b281117 SJ |
293 | return entry; |
294 | } | |
295 | ||
296 | static void zswap_entry_cache_free(struct zswap_entry *entry) | |
297 | { | |
298 | kmem_cache_free(zswap_entry_cache, entry); | |
299 | } | |
300 | ||
2b281117 SJ |
301 | /********************************* |
302 | * rbtree functions | |
303 | **********************************/ | |
304 | static struct zswap_entry *zswap_rb_search(struct rb_root *root, pgoff_t offset) | |
305 | { | |
306 | struct rb_node *node = root->rb_node; | |
307 | struct zswap_entry *entry; | |
308 | ||
309 | while (node) { | |
310 | entry = rb_entry(node, struct zswap_entry, rbnode); | |
311 | if (entry->offset > offset) | |
312 | node = node->rb_left; | |
313 | else if (entry->offset < offset) | |
314 | node = node->rb_right; | |
315 | else | |
316 | return entry; | |
317 | } | |
318 | return NULL; | |
319 | } | |
320 | ||
321 | /* | |
322 | * In the case that a entry with the same offset is found, a pointer to | |
323 | * the existing entry is stored in dupentry and the function returns -EEXIST | |
324 | */ | |
325 | static int zswap_rb_insert(struct rb_root *root, struct zswap_entry *entry, | |
326 | struct zswap_entry **dupentry) | |
327 | { | |
328 | struct rb_node **link = &root->rb_node, *parent = NULL; | |
329 | struct zswap_entry *myentry; | |
330 | ||
331 | while (*link) { | |
332 | parent = *link; | |
333 | myentry = rb_entry(parent, struct zswap_entry, rbnode); | |
334 | if (myentry->offset > entry->offset) | |
335 | link = &(*link)->rb_left; | |
336 | else if (myentry->offset < entry->offset) | |
337 | link = &(*link)->rb_right; | |
338 | else { | |
339 | *dupentry = myentry; | |
340 | return -EEXIST; | |
341 | } | |
342 | } | |
343 | rb_link_node(&entry->rbnode, parent, link); | |
344 | rb_insert_color(&entry->rbnode, root); | |
345 | return 0; | |
346 | } | |
347 | ||
0ab0abcf WY |
348 | static void zswap_rb_erase(struct rb_root *root, struct zswap_entry *entry) |
349 | { | |
350 | if (!RB_EMPTY_NODE(&entry->rbnode)) { | |
351 | rb_erase(&entry->rbnode, root); | |
352 | RB_CLEAR_NODE(&entry->rbnode); | |
353 | } | |
354 | } | |
355 | ||
356 | /* | |
12d79d64 | 357 | * Carries out the common pattern of freeing and entry's zpool allocation, |
0ab0abcf WY |
358 | * freeing the entry itself, and decrementing the number of stored pages. |
359 | */ | |
60105e12 | 360 | static void zswap_free_entry(struct zswap_entry *entry) |
0ab0abcf | 361 | { |
a85f878b SD |
362 | if (!entry->length) |
363 | atomic_dec(&zswap_same_filled_pages); | |
364 | else { | |
365 | zpool_free(entry->pool->zpool, entry->handle); | |
366 | zswap_pool_put(entry->pool); | |
367 | } | |
0ab0abcf WY |
368 | zswap_entry_cache_free(entry); |
369 | atomic_dec(&zswap_stored_pages); | |
f1c54846 | 370 | zswap_update_total_size(); |
0ab0abcf WY |
371 | } |
372 | ||
373 | /* caller must hold the tree lock */ | |
374 | static void zswap_entry_get(struct zswap_entry *entry) | |
375 | { | |
376 | entry->refcount++; | |
377 | } | |
378 | ||
379 | /* caller must hold the tree lock | |
380 | * remove from the tree and free it, if nobody reference the entry | |
381 | */ | |
382 | static void zswap_entry_put(struct zswap_tree *tree, | |
383 | struct zswap_entry *entry) | |
384 | { | |
385 | int refcount = --entry->refcount; | |
386 | ||
387 | BUG_ON(refcount < 0); | |
388 | if (refcount == 0) { | |
389 | zswap_rb_erase(&tree->rbroot, entry); | |
60105e12 | 390 | zswap_free_entry(entry); |
0ab0abcf WY |
391 | } |
392 | } | |
393 | ||
394 | /* caller must hold the tree lock */ | |
395 | static struct zswap_entry *zswap_entry_find_get(struct rb_root *root, | |
396 | pgoff_t offset) | |
397 | { | |
b0c9865f | 398 | struct zswap_entry *entry; |
0ab0abcf WY |
399 | |
400 | entry = zswap_rb_search(root, offset); | |
401 | if (entry) | |
402 | zswap_entry_get(entry); | |
403 | ||
404 | return entry; | |
405 | } | |
406 | ||
2b281117 SJ |
407 | /********************************* |
408 | * per-cpu code | |
409 | **********************************/ | |
410 | static DEFINE_PER_CPU(u8 *, zswap_dstmem); | |
1ec3b5fe BS |
411 | /* |
412 | * If users dynamically change the zpool type and compressor at runtime, i.e. | |
413 | * zswap is running, zswap can have more than one zpool on one cpu, but they | |
414 | * are sharing dtsmem. So we need this mutex to be per-cpu. | |
415 | */ | |
416 | static DEFINE_PER_CPU(struct mutex *, zswap_mutex); | |
2b281117 | 417 | |
ad7ed770 | 418 | static int zswap_dstmem_prepare(unsigned int cpu) |
2b281117 | 419 | { |
1ec3b5fe | 420 | struct mutex *mutex; |
2b281117 SJ |
421 | u8 *dst; |
422 | ||
ad7ed770 | 423 | dst = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu)); |
2b2695f5 | 424 | if (!dst) |
ad7ed770 | 425 | return -ENOMEM; |
2b2695f5 | 426 | |
1ec3b5fe BS |
427 | mutex = kmalloc_node(sizeof(*mutex), GFP_KERNEL, cpu_to_node(cpu)); |
428 | if (!mutex) { | |
429 | kfree(dst); | |
430 | return -ENOMEM; | |
431 | } | |
432 | ||
433 | mutex_init(mutex); | |
ad7ed770 | 434 | per_cpu(zswap_dstmem, cpu) = dst; |
1ec3b5fe | 435 | per_cpu(zswap_mutex, cpu) = mutex; |
ad7ed770 | 436 | return 0; |
2b281117 SJ |
437 | } |
438 | ||
ad7ed770 | 439 | static int zswap_dstmem_dead(unsigned int cpu) |
2b281117 | 440 | { |
1ec3b5fe | 441 | struct mutex *mutex; |
ad7ed770 | 442 | u8 *dst; |
2b281117 | 443 | |
1ec3b5fe BS |
444 | mutex = per_cpu(zswap_mutex, cpu); |
445 | kfree(mutex); | |
446 | per_cpu(zswap_mutex, cpu) = NULL; | |
447 | ||
ad7ed770 SAS |
448 | dst = per_cpu(zswap_dstmem, cpu); |
449 | kfree(dst); | |
450 | per_cpu(zswap_dstmem, cpu) = NULL; | |
f1c54846 | 451 | |
f1c54846 | 452 | return 0; |
f1c54846 DS |
453 | } |
454 | ||
cab7a7e5 | 455 | static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node) |
f1c54846 | 456 | { |
cab7a7e5 | 457 | struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node); |
1ec3b5fe BS |
458 | struct crypto_acomp_ctx *acomp_ctx = per_cpu_ptr(pool->acomp_ctx, cpu); |
459 | struct crypto_acomp *acomp; | |
460 | struct acomp_req *req; | |
461 | ||
462 | acomp = crypto_alloc_acomp_node(pool->tfm_name, 0, 0, cpu_to_node(cpu)); | |
463 | if (IS_ERR(acomp)) { | |
464 | pr_err("could not alloc crypto acomp %s : %ld\n", | |
465 | pool->tfm_name, PTR_ERR(acomp)); | |
466 | return PTR_ERR(acomp); | |
467 | } | |
468 | acomp_ctx->acomp = acomp; | |
f1c54846 | 469 | |
1ec3b5fe BS |
470 | req = acomp_request_alloc(acomp_ctx->acomp); |
471 | if (!req) { | |
472 | pr_err("could not alloc crypto acomp_request %s\n", | |
473 | pool->tfm_name); | |
474 | crypto_free_acomp(acomp_ctx->acomp); | |
cab7a7e5 SAS |
475 | return -ENOMEM; |
476 | } | |
1ec3b5fe BS |
477 | acomp_ctx->req = req; |
478 | ||
479 | crypto_init_wait(&acomp_ctx->wait); | |
480 | /* | |
481 | * if the backend of acomp is async zip, crypto_req_done() will wakeup | |
482 | * crypto_wait_req(); if the backend of acomp is scomp, the callback | |
483 | * won't be called, crypto_wait_req() will return without blocking. | |
484 | */ | |
485 | acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, | |
486 | crypto_req_done, &acomp_ctx->wait); | |
487 | ||
488 | acomp_ctx->mutex = per_cpu(zswap_mutex, cpu); | |
489 | acomp_ctx->dstmem = per_cpu(zswap_dstmem, cpu); | |
490 | ||
2b281117 | 491 | return 0; |
2b281117 SJ |
492 | } |
493 | ||
cab7a7e5 | 494 | static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node) |
f1c54846 | 495 | { |
cab7a7e5 | 496 | struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node); |
1ec3b5fe BS |
497 | struct crypto_acomp_ctx *acomp_ctx = per_cpu_ptr(pool->acomp_ctx, cpu); |
498 | ||
499 | if (!IS_ERR_OR_NULL(acomp_ctx)) { | |
500 | if (!IS_ERR_OR_NULL(acomp_ctx->req)) | |
501 | acomp_request_free(acomp_ctx->req); | |
502 | if (!IS_ERR_OR_NULL(acomp_ctx->acomp)) | |
503 | crypto_free_acomp(acomp_ctx->acomp); | |
504 | } | |
f1c54846 | 505 | |
cab7a7e5 | 506 | return 0; |
f1c54846 DS |
507 | } |
508 | ||
2b281117 | 509 | /********************************* |
f1c54846 | 510 | * pool functions |
2b281117 | 511 | **********************************/ |
f1c54846 DS |
512 | |
513 | static struct zswap_pool *__zswap_pool_current(void) | |
2b281117 | 514 | { |
f1c54846 DS |
515 | struct zswap_pool *pool; |
516 | ||
517 | pool = list_first_or_null_rcu(&zswap_pools, typeof(*pool), list); | |
ae3d89a7 DS |
518 | WARN_ONCE(!pool && zswap_has_pool, |
519 | "%s: no page storage pool!\n", __func__); | |
f1c54846 DS |
520 | |
521 | return pool; | |
522 | } | |
523 | ||
524 | static struct zswap_pool *zswap_pool_current(void) | |
525 | { | |
526 | assert_spin_locked(&zswap_pools_lock); | |
527 | ||
528 | return __zswap_pool_current(); | |
529 | } | |
530 | ||
531 | static struct zswap_pool *zswap_pool_current_get(void) | |
532 | { | |
533 | struct zswap_pool *pool; | |
534 | ||
535 | rcu_read_lock(); | |
536 | ||
537 | pool = __zswap_pool_current(); | |
ae3d89a7 | 538 | if (!zswap_pool_get(pool)) |
f1c54846 DS |
539 | pool = NULL; |
540 | ||
541 | rcu_read_unlock(); | |
542 | ||
543 | return pool; | |
544 | } | |
545 | ||
546 | static struct zswap_pool *zswap_pool_last_get(void) | |
547 | { | |
548 | struct zswap_pool *pool, *last = NULL; | |
549 | ||
550 | rcu_read_lock(); | |
551 | ||
552 | list_for_each_entry_rcu(pool, &zswap_pools, list) | |
553 | last = pool; | |
ae3d89a7 DS |
554 | WARN_ONCE(!last && zswap_has_pool, |
555 | "%s: no page storage pool!\n", __func__); | |
556 | if (!zswap_pool_get(last)) | |
f1c54846 DS |
557 | last = NULL; |
558 | ||
559 | rcu_read_unlock(); | |
560 | ||
561 | return last; | |
562 | } | |
563 | ||
8bc8b228 | 564 | /* type and compressor must be null-terminated */ |
f1c54846 DS |
565 | static struct zswap_pool *zswap_pool_find_get(char *type, char *compressor) |
566 | { | |
567 | struct zswap_pool *pool; | |
568 | ||
569 | assert_spin_locked(&zswap_pools_lock); | |
570 | ||
571 | list_for_each_entry_rcu(pool, &zswap_pools, list) { | |
8bc8b228 | 572 | if (strcmp(pool->tfm_name, compressor)) |
f1c54846 | 573 | continue; |
8bc8b228 | 574 | if (strcmp(zpool_get_type(pool->zpool), type)) |
f1c54846 DS |
575 | continue; |
576 | /* if we can't get it, it's about to be destroyed */ | |
577 | if (!zswap_pool_get(pool)) | |
578 | continue; | |
579 | return pool; | |
580 | } | |
581 | ||
582 | return NULL; | |
583 | } | |
584 | ||
45190f01 VW |
585 | static void shrink_worker(struct work_struct *w) |
586 | { | |
587 | struct zswap_pool *pool = container_of(w, typeof(*pool), | |
588 | shrink_work); | |
589 | ||
590 | if (zpool_shrink(pool->zpool, 1, NULL)) | |
591 | zswap_reject_reclaim_fail++; | |
592 | zswap_pool_put(pool); | |
593 | } | |
594 | ||
f1c54846 DS |
595 | static struct zswap_pool *zswap_pool_create(char *type, char *compressor) |
596 | { | |
597 | struct zswap_pool *pool; | |
32a4e169 | 598 | char name[38]; /* 'zswap' + 32 char (max) num + \0 */ |
d0164adc | 599 | gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM; |
cab7a7e5 | 600 | int ret; |
f1c54846 | 601 | |
bae21db8 DS |
602 | if (!zswap_has_pool) { |
603 | /* if either are unset, pool initialization failed, and we | |
604 | * need both params to be set correctly before trying to | |
605 | * create a pool. | |
606 | */ | |
607 | if (!strcmp(type, ZSWAP_PARAM_UNSET)) | |
608 | return NULL; | |
609 | if (!strcmp(compressor, ZSWAP_PARAM_UNSET)) | |
610 | return NULL; | |
611 | } | |
612 | ||
f1c54846 | 613 | pool = kzalloc(sizeof(*pool), GFP_KERNEL); |
f4ae0ce0 | 614 | if (!pool) |
f1c54846 | 615 | return NULL; |
f1c54846 | 616 | |
32a4e169 DS |
617 | /* unique name for each pool specifically required by zsmalloc */ |
618 | snprintf(name, 38, "zswap%x", atomic_inc_return(&zswap_pools_count)); | |
619 | ||
620 | pool->zpool = zpool_create_pool(type, name, gfp, &zswap_zpool_ops); | |
f1c54846 DS |
621 | if (!pool->zpool) { |
622 | pr_err("%s zpool not available\n", type); | |
623 | goto error; | |
624 | } | |
625 | pr_debug("using %s zpool\n", zpool_get_type(pool->zpool)); | |
626 | ||
79cd4202 | 627 | strscpy(pool->tfm_name, compressor, sizeof(pool->tfm_name)); |
1ec3b5fe BS |
628 | |
629 | pool->acomp_ctx = alloc_percpu(*pool->acomp_ctx); | |
630 | if (!pool->acomp_ctx) { | |
f1c54846 DS |
631 | pr_err("percpu alloc failed\n"); |
632 | goto error; | |
633 | } | |
634 | ||
cab7a7e5 SAS |
635 | ret = cpuhp_state_add_instance(CPUHP_MM_ZSWP_POOL_PREPARE, |
636 | &pool->node); | |
637 | if (ret) | |
f1c54846 DS |
638 | goto error; |
639 | pr_debug("using %s compressor\n", pool->tfm_name); | |
640 | ||
641 | /* being the current pool takes 1 ref; this func expects the | |
642 | * caller to always add the new pool as the current pool | |
643 | */ | |
644 | kref_init(&pool->kref); | |
645 | INIT_LIST_HEAD(&pool->list); | |
45190f01 | 646 | INIT_WORK(&pool->shrink_work, shrink_worker); |
f1c54846 DS |
647 | |
648 | zswap_pool_debug("created", pool); | |
649 | ||
650 | return pool; | |
651 | ||
652 | error: | |
1ec3b5fe BS |
653 | if (pool->acomp_ctx) |
654 | free_percpu(pool->acomp_ctx); | |
f1c54846 DS |
655 | if (pool->zpool) |
656 | zpool_destroy_pool(pool->zpool); | |
657 | kfree(pool); | |
658 | return NULL; | |
659 | } | |
660 | ||
c99b42c3 | 661 | static __init struct zswap_pool *__zswap_pool_create_fallback(void) |
f1c54846 | 662 | { |
bae21db8 DS |
663 | bool has_comp, has_zpool; |
664 | ||
1ec3b5fe | 665 | has_comp = crypto_has_acomp(zswap_compressor, 0, 0); |
bb8b93b5 MS |
666 | if (!has_comp && strcmp(zswap_compressor, |
667 | CONFIG_ZSWAP_COMPRESSOR_DEFAULT)) { | |
f1c54846 | 668 | pr_err("compressor %s not available, using default %s\n", |
bb8b93b5 | 669 | zswap_compressor, CONFIG_ZSWAP_COMPRESSOR_DEFAULT); |
c99b42c3 | 670 | param_free_charp(&zswap_compressor); |
bb8b93b5 | 671 | zswap_compressor = CONFIG_ZSWAP_COMPRESSOR_DEFAULT; |
1ec3b5fe | 672 | has_comp = crypto_has_acomp(zswap_compressor, 0, 0); |
f1c54846 | 673 | } |
bae21db8 DS |
674 | if (!has_comp) { |
675 | pr_err("default compressor %s not available\n", | |
676 | zswap_compressor); | |
677 | param_free_charp(&zswap_compressor); | |
678 | zswap_compressor = ZSWAP_PARAM_UNSET; | |
679 | } | |
680 | ||
681 | has_zpool = zpool_has_pool(zswap_zpool_type); | |
bb8b93b5 MS |
682 | if (!has_zpool && strcmp(zswap_zpool_type, |
683 | CONFIG_ZSWAP_ZPOOL_DEFAULT)) { | |
f1c54846 | 684 | pr_err("zpool %s not available, using default %s\n", |
bb8b93b5 | 685 | zswap_zpool_type, CONFIG_ZSWAP_ZPOOL_DEFAULT); |
c99b42c3 | 686 | param_free_charp(&zswap_zpool_type); |
bb8b93b5 | 687 | zswap_zpool_type = CONFIG_ZSWAP_ZPOOL_DEFAULT; |
bae21db8 | 688 | has_zpool = zpool_has_pool(zswap_zpool_type); |
f1c54846 | 689 | } |
bae21db8 DS |
690 | if (!has_zpool) { |
691 | pr_err("default zpool %s not available\n", | |
692 | zswap_zpool_type); | |
693 | param_free_charp(&zswap_zpool_type); | |
694 | zswap_zpool_type = ZSWAP_PARAM_UNSET; | |
695 | } | |
696 | ||
697 | if (!has_comp || !has_zpool) | |
698 | return NULL; | |
f1c54846 DS |
699 | |
700 | return zswap_pool_create(zswap_zpool_type, zswap_compressor); | |
701 | } | |
702 | ||
703 | static void zswap_pool_destroy(struct zswap_pool *pool) | |
704 | { | |
705 | zswap_pool_debug("destroying", pool); | |
706 | ||
cab7a7e5 | 707 | cpuhp_state_remove_instance(CPUHP_MM_ZSWP_POOL_PREPARE, &pool->node); |
1ec3b5fe | 708 | free_percpu(pool->acomp_ctx); |
f1c54846 DS |
709 | zpool_destroy_pool(pool->zpool); |
710 | kfree(pool); | |
711 | } | |
712 | ||
713 | static int __must_check zswap_pool_get(struct zswap_pool *pool) | |
714 | { | |
ae3d89a7 DS |
715 | if (!pool) |
716 | return 0; | |
717 | ||
f1c54846 DS |
718 | return kref_get_unless_zero(&pool->kref); |
719 | } | |
720 | ||
200867af | 721 | static void __zswap_pool_release(struct work_struct *work) |
f1c54846 | 722 | { |
45190f01 VW |
723 | struct zswap_pool *pool = container_of(work, typeof(*pool), |
724 | release_work); | |
200867af DS |
725 | |
726 | synchronize_rcu(); | |
f1c54846 DS |
727 | |
728 | /* nobody should have been able to get a kref... */ | |
729 | WARN_ON(kref_get_unless_zero(&pool->kref)); | |
730 | ||
731 | /* pool is now off zswap_pools list and has no references. */ | |
732 | zswap_pool_destroy(pool); | |
733 | } | |
734 | ||
735 | static void __zswap_pool_empty(struct kref *kref) | |
736 | { | |
737 | struct zswap_pool *pool; | |
738 | ||
739 | pool = container_of(kref, typeof(*pool), kref); | |
740 | ||
741 | spin_lock(&zswap_pools_lock); | |
742 | ||
743 | WARN_ON(pool == zswap_pool_current()); | |
744 | ||
745 | list_del_rcu(&pool->list); | |
200867af | 746 | |
45190f01 VW |
747 | INIT_WORK(&pool->release_work, __zswap_pool_release); |
748 | schedule_work(&pool->release_work); | |
f1c54846 DS |
749 | |
750 | spin_unlock(&zswap_pools_lock); | |
751 | } | |
752 | ||
753 | static void zswap_pool_put(struct zswap_pool *pool) | |
754 | { | |
755 | kref_put(&pool->kref, __zswap_pool_empty); | |
2b281117 SJ |
756 | } |
757 | ||
90b0fc26 DS |
758 | /********************************* |
759 | * param callbacks | |
760 | **********************************/ | |
761 | ||
c99b42c3 | 762 | /* val must be a null-terminated string */ |
90b0fc26 DS |
763 | static int __zswap_param_set(const char *val, const struct kernel_param *kp, |
764 | char *type, char *compressor) | |
765 | { | |
766 | struct zswap_pool *pool, *put_pool = NULL; | |
c99b42c3 | 767 | char *s = strstrip((char *)val); |
90b0fc26 DS |
768 | int ret; |
769 | ||
d7b028f5 DS |
770 | if (zswap_init_failed) { |
771 | pr_err("can't set param, initialization failed\n"); | |
772 | return -ENODEV; | |
773 | } | |
774 | ||
c99b42c3 | 775 | /* no change required */ |
ae3d89a7 | 776 | if (!strcmp(s, *(char **)kp->arg) && zswap_has_pool) |
c99b42c3 | 777 | return 0; |
90b0fc26 DS |
778 | |
779 | /* if this is load-time (pre-init) param setting, | |
780 | * don't create a pool; that's done during init. | |
781 | */ | |
782 | if (!zswap_init_started) | |
c99b42c3 | 783 | return param_set_charp(s, kp); |
90b0fc26 DS |
784 | |
785 | if (!type) { | |
c99b42c3 DS |
786 | if (!zpool_has_pool(s)) { |
787 | pr_err("zpool %s not available\n", s); | |
90b0fc26 DS |
788 | return -ENOENT; |
789 | } | |
c99b42c3 | 790 | type = s; |
90b0fc26 | 791 | } else if (!compressor) { |
1ec3b5fe | 792 | if (!crypto_has_acomp(s, 0, 0)) { |
c99b42c3 | 793 | pr_err("compressor %s not available\n", s); |
90b0fc26 DS |
794 | return -ENOENT; |
795 | } | |
c99b42c3 DS |
796 | compressor = s; |
797 | } else { | |
798 | WARN_ON(1); | |
799 | return -EINVAL; | |
90b0fc26 DS |
800 | } |
801 | ||
802 | spin_lock(&zswap_pools_lock); | |
803 | ||
804 | pool = zswap_pool_find_get(type, compressor); | |
805 | if (pool) { | |
806 | zswap_pool_debug("using existing", pool); | |
fd5bb66c | 807 | WARN_ON(pool == zswap_pool_current()); |
90b0fc26 | 808 | list_del_rcu(&pool->list); |
90b0fc26 DS |
809 | } |
810 | ||
fd5bb66c DS |
811 | spin_unlock(&zswap_pools_lock); |
812 | ||
813 | if (!pool) | |
814 | pool = zswap_pool_create(type, compressor); | |
815 | ||
90b0fc26 | 816 | if (pool) |
c99b42c3 | 817 | ret = param_set_charp(s, kp); |
90b0fc26 DS |
818 | else |
819 | ret = -EINVAL; | |
820 | ||
fd5bb66c DS |
821 | spin_lock(&zswap_pools_lock); |
822 | ||
90b0fc26 DS |
823 | if (!ret) { |
824 | put_pool = zswap_pool_current(); | |
825 | list_add_rcu(&pool->list, &zswap_pools); | |
ae3d89a7 | 826 | zswap_has_pool = true; |
90b0fc26 DS |
827 | } else if (pool) { |
828 | /* add the possibly pre-existing pool to the end of the pools | |
829 | * list; if it's new (and empty) then it'll be removed and | |
830 | * destroyed by the put after we drop the lock | |
831 | */ | |
832 | list_add_tail_rcu(&pool->list, &zswap_pools); | |
833 | put_pool = pool; | |
fd5bb66c DS |
834 | } |
835 | ||
836 | spin_unlock(&zswap_pools_lock); | |
837 | ||
838 | if (!zswap_has_pool && !pool) { | |
ae3d89a7 DS |
839 | /* if initial pool creation failed, and this pool creation also |
840 | * failed, maybe both compressor and zpool params were bad. | |
841 | * Allow changing this param, so pool creation will succeed | |
842 | * when the other param is changed. We already verified this | |
1ec3b5fe | 843 | * param is ok in the zpool_has_pool() or crypto_has_acomp() |
ae3d89a7 DS |
844 | * checks above. |
845 | */ | |
846 | ret = param_set_charp(s, kp); | |
90b0fc26 DS |
847 | } |
848 | ||
90b0fc26 DS |
849 | /* drop the ref from either the old current pool, |
850 | * or the new pool we failed to add | |
851 | */ | |
852 | if (put_pool) | |
853 | zswap_pool_put(put_pool); | |
854 | ||
855 | return ret; | |
856 | } | |
857 | ||
858 | static int zswap_compressor_param_set(const char *val, | |
859 | const struct kernel_param *kp) | |
860 | { | |
861 | return __zswap_param_set(val, kp, zswap_zpool_type, NULL); | |
862 | } | |
863 | ||
864 | static int zswap_zpool_param_set(const char *val, | |
865 | const struct kernel_param *kp) | |
866 | { | |
867 | return __zswap_param_set(val, kp, NULL, zswap_compressor); | |
868 | } | |
869 | ||
d7b028f5 DS |
870 | static int zswap_enabled_param_set(const char *val, |
871 | const struct kernel_param *kp) | |
872 | { | |
873 | if (zswap_init_failed) { | |
874 | pr_err("can't enable, initialization failed\n"); | |
875 | return -ENODEV; | |
876 | } | |
ae3d89a7 DS |
877 | if (!zswap_has_pool && zswap_init_started) { |
878 | pr_err("can't enable, no pool configured\n"); | |
879 | return -ENODEV; | |
880 | } | |
d7b028f5 DS |
881 | |
882 | return param_set_bool(val, kp); | |
883 | } | |
884 | ||
2b281117 SJ |
885 | /********************************* |
886 | * writeback code | |
887 | **********************************/ | |
888 | /* return enum for zswap_get_swap_cache_page */ | |
889 | enum zswap_get_swap_ret { | |
890 | ZSWAP_SWAPCACHE_NEW, | |
891 | ZSWAP_SWAPCACHE_EXIST, | |
67d13fe8 | 892 | ZSWAP_SWAPCACHE_FAIL, |
2b281117 SJ |
893 | }; |
894 | ||
895 | /* | |
896 | * zswap_get_swap_cache_page | |
897 | * | |
898 | * This is an adaption of read_swap_cache_async() | |
899 | * | |
900 | * This function tries to find a page with the given swap entry | |
901 | * in the swapper_space address space (the swap cache). If the page | |
902 | * is found, it is returned in retpage. Otherwise, a page is allocated, | |
903 | * added to the swap cache, and returned in retpage. | |
904 | * | |
905 | * If success, the swap cache page is returned in retpage | |
67d13fe8 WY |
906 | * Returns ZSWAP_SWAPCACHE_EXIST if page was already in the swap cache |
907 | * Returns ZSWAP_SWAPCACHE_NEW if the new page needs to be populated, | |
908 | * the new page is added to swapcache and locked | |
909 | * Returns ZSWAP_SWAPCACHE_FAIL on error | |
2b281117 SJ |
910 | */ |
911 | static int zswap_get_swap_cache_page(swp_entry_t entry, | |
912 | struct page **retpage) | |
913 | { | |
5b999aad | 914 | bool page_was_allocated; |
2b281117 | 915 | |
5b999aad DS |
916 | *retpage = __read_swap_cache_async(entry, GFP_KERNEL, |
917 | NULL, 0, &page_was_allocated); | |
918 | if (page_was_allocated) | |
919 | return ZSWAP_SWAPCACHE_NEW; | |
920 | if (!*retpage) | |
67d13fe8 | 921 | return ZSWAP_SWAPCACHE_FAIL; |
2b281117 SJ |
922 | return ZSWAP_SWAPCACHE_EXIST; |
923 | } | |
924 | ||
925 | /* | |
926 | * Attempts to free an entry by adding a page to the swap cache, | |
927 | * decompressing the entry data into the page, and issuing a | |
928 | * bio write to write the page back to the swap device. | |
929 | * | |
930 | * This can be thought of as a "resumed writeback" of the page | |
931 | * to the swap device. We are basically resuming the same swap | |
932 | * writeback path that was intercepted with the frontswap_store() | |
933 | * in the first place. After the page has been decompressed into | |
934 | * the swap cache, the compressed version stored by zswap can be | |
935 | * freed. | |
936 | */ | |
12d79d64 | 937 | static int zswap_writeback_entry(struct zpool *pool, unsigned long handle) |
2b281117 SJ |
938 | { |
939 | struct zswap_header *zhdr; | |
940 | swp_entry_t swpentry; | |
941 | struct zswap_tree *tree; | |
942 | pgoff_t offset; | |
943 | struct zswap_entry *entry; | |
944 | struct page *page; | |
1ec3b5fe BS |
945 | struct scatterlist input, output; |
946 | struct crypto_acomp_ctx *acomp_ctx; | |
947 | ||
fc6697a8 | 948 | u8 *src, *tmp = NULL; |
2b281117 | 949 | unsigned int dlen; |
0ab0abcf | 950 | int ret; |
2b281117 SJ |
951 | struct writeback_control wbc = { |
952 | .sync_mode = WB_SYNC_NONE, | |
953 | }; | |
954 | ||
fc6697a8 TT |
955 | if (!zpool_can_sleep_mapped(pool)) { |
956 | tmp = kmalloc(PAGE_SIZE, GFP_ATOMIC); | |
957 | if (!tmp) | |
958 | return -ENOMEM; | |
959 | } | |
960 | ||
2b281117 | 961 | /* extract swpentry from data */ |
12d79d64 | 962 | zhdr = zpool_map_handle(pool, handle, ZPOOL_MM_RO); |
2b281117 | 963 | swpentry = zhdr->swpentry; /* here */ |
2b281117 SJ |
964 | tree = zswap_trees[swp_type(swpentry)]; |
965 | offset = swp_offset(swpentry); | |
2b281117 SJ |
966 | |
967 | /* find and ref zswap entry */ | |
968 | spin_lock(&tree->lock); | |
0ab0abcf | 969 | entry = zswap_entry_find_get(&tree->rbroot, offset); |
2b281117 SJ |
970 | if (!entry) { |
971 | /* entry was invalidated */ | |
972 | spin_unlock(&tree->lock); | |
068619e3 | 973 | zpool_unmap_handle(pool, handle); |
fc6697a8 | 974 | kfree(tmp); |
2b281117 SJ |
975 | return 0; |
976 | } | |
2b281117 SJ |
977 | spin_unlock(&tree->lock); |
978 | BUG_ON(offset != entry->offset); | |
979 | ||
46b76f2e ML |
980 | src = (u8 *)zhdr + sizeof(struct zswap_header); |
981 | if (!zpool_can_sleep_mapped(pool)) { | |
982 | memcpy(tmp, src, entry->length); | |
983 | src = tmp; | |
984 | zpool_unmap_handle(pool, handle); | |
985 | } | |
986 | ||
2b281117 SJ |
987 | /* try to allocate swap cache page */ |
988 | switch (zswap_get_swap_cache_page(swpentry, &page)) { | |
67d13fe8 | 989 | case ZSWAP_SWAPCACHE_FAIL: /* no memory or invalidate happened */ |
2b281117 SJ |
990 | ret = -ENOMEM; |
991 | goto fail; | |
992 | ||
67d13fe8 | 993 | case ZSWAP_SWAPCACHE_EXIST: |
2b281117 | 994 | /* page is already in the swap cache, ignore for now */ |
09cbfeaf | 995 | put_page(page); |
2b281117 SJ |
996 | ret = -EEXIST; |
997 | goto fail; | |
998 | ||
999 | case ZSWAP_SWAPCACHE_NEW: /* page is locked */ | |
1000 | /* decompress */ | |
1ec3b5fe | 1001 | acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); |
2b281117 | 1002 | dlen = PAGE_SIZE; |
fc6697a8 | 1003 | |
1ec3b5fe BS |
1004 | mutex_lock(acomp_ctx->mutex); |
1005 | sg_init_one(&input, src, entry->length); | |
1006 | sg_init_table(&output, 1); | |
1007 | sg_set_page(&output, page, PAGE_SIZE, 0); | |
1008 | acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, dlen); | |
1009 | ret = crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait); | |
1010 | dlen = acomp_ctx->req->dlen; | |
1011 | mutex_unlock(acomp_ctx->mutex); | |
1012 | ||
2b281117 SJ |
1013 | BUG_ON(ret); |
1014 | BUG_ON(dlen != PAGE_SIZE); | |
1015 | ||
1016 | /* page is up to date */ | |
1017 | SetPageUptodate(page); | |
1018 | } | |
1019 | ||
b349acc7 WY |
1020 | /* move it to the tail of the inactive list after end_writeback */ |
1021 | SetPageReclaim(page); | |
1022 | ||
2b281117 SJ |
1023 | /* start writeback */ |
1024 | __swap_writepage(page, &wbc, end_swap_bio_write); | |
09cbfeaf | 1025 | put_page(page); |
2b281117 SJ |
1026 | zswap_written_back_pages++; |
1027 | ||
1028 | spin_lock(&tree->lock); | |
2b281117 | 1029 | /* drop local reference */ |
0ab0abcf | 1030 | zswap_entry_put(tree, entry); |
2b281117 SJ |
1031 | |
1032 | /* | |
0ab0abcf WY |
1033 | * There are two possible situations for entry here: |
1034 | * (1) refcount is 1(normal case), entry is valid and on the tree | |
1035 | * (2) refcount is 0, entry is freed and not on the tree | |
1036 | * because invalidate happened during writeback | |
1037 | * search the tree and free the entry if find entry | |
1038 | */ | |
1039 | if (entry == zswap_rb_search(&tree->rbroot, offset)) | |
1040 | zswap_entry_put(tree, entry); | |
2b281117 | 1041 | spin_unlock(&tree->lock); |
2b281117 | 1042 | |
0ab0abcf WY |
1043 | goto end; |
1044 | ||
1045 | /* | |
1046 | * if we get here due to ZSWAP_SWAPCACHE_EXIST | |
c0c641d7 RD |
1047 | * a load may be happening concurrently. |
1048 | * it is safe and okay to not free the entry. | |
0ab0abcf | 1049 | * if we free the entry in the following put |
c0c641d7 | 1050 | * it is also okay to return !0 |
0ab0abcf | 1051 | */ |
2b281117 SJ |
1052 | fail: |
1053 | spin_lock(&tree->lock); | |
0ab0abcf | 1054 | zswap_entry_put(tree, entry); |
2b281117 | 1055 | spin_unlock(&tree->lock); |
0ab0abcf WY |
1056 | |
1057 | end: | |
fc6697a8 TT |
1058 | if (zpool_can_sleep_mapped(pool)) |
1059 | zpool_unmap_handle(pool, handle); | |
1060 | else | |
1061 | kfree(tmp); | |
1062 | ||
2b281117 SJ |
1063 | return ret; |
1064 | } | |
1065 | ||
a85f878b SD |
1066 | static int zswap_is_page_same_filled(void *ptr, unsigned long *value) |
1067 | { | |
1068 | unsigned int pos; | |
1069 | unsigned long *page; | |
1070 | ||
1071 | page = (unsigned long *)ptr; | |
1072 | for (pos = 1; pos < PAGE_SIZE / sizeof(*page); pos++) { | |
1073 | if (page[pos] != page[0]) | |
1074 | return 0; | |
1075 | } | |
1076 | *value = page[0]; | |
1077 | return 1; | |
1078 | } | |
1079 | ||
1080 | static void zswap_fill_page(void *ptr, unsigned long value) | |
1081 | { | |
1082 | unsigned long *page; | |
1083 | ||
1084 | page = (unsigned long *)ptr; | |
1085 | memset_l(page, value, PAGE_SIZE / sizeof(unsigned long)); | |
1086 | } | |
1087 | ||
2b281117 SJ |
1088 | /********************************* |
1089 | * frontswap hooks | |
1090 | **********************************/ | |
1091 | /* attempts to compress and store an single page */ | |
1092 | static int zswap_frontswap_store(unsigned type, pgoff_t offset, | |
1093 | struct page *page) | |
1094 | { | |
1095 | struct zswap_tree *tree = zswap_trees[type]; | |
1096 | struct zswap_entry *entry, *dupentry; | |
1ec3b5fe BS |
1097 | struct scatterlist input, output; |
1098 | struct crypto_acomp_ctx *acomp_ctx; | |
2b281117 | 1099 | int ret; |
9c3760eb | 1100 | unsigned int hlen, dlen = PAGE_SIZE; |
a85f878b | 1101 | unsigned long handle, value; |
2b281117 SJ |
1102 | char *buf; |
1103 | u8 *src, *dst; | |
9c3760eb | 1104 | struct zswap_header zhdr = { .swpentry = swp_entry(type, offset) }; |
d2fcd82b | 1105 | gfp_t gfp; |
2b281117 | 1106 | |
7ba71669 HY |
1107 | /* THP isn't supported */ |
1108 | if (PageTransHuge(page)) { | |
1109 | ret = -EINVAL; | |
1110 | goto reject; | |
1111 | } | |
1112 | ||
c00ed16a | 1113 | if (!zswap_enabled || !tree) { |
2b281117 SJ |
1114 | ret = -ENODEV; |
1115 | goto reject; | |
1116 | } | |
1117 | ||
1118 | /* reclaim space if needed */ | |
1119 | if (zswap_is_full()) { | |
45190f01 VW |
1120 | struct zswap_pool *pool; |
1121 | ||
2b281117 | 1122 | zswap_pool_limit_hit++; |
45190f01 VW |
1123 | zswap_pool_reached_full = true; |
1124 | pool = zswap_pool_last_get(); | |
1125 | if (pool) | |
1126 | queue_work(shrink_wq, &pool->shrink_work); | |
1127 | ret = -ENOMEM; | |
1128 | goto reject; | |
1129 | } | |
16e536ef | 1130 | |
45190f01 VW |
1131 | if (zswap_pool_reached_full) { |
1132 | if (!zswap_can_accept()) { | |
16e536ef LW |
1133 | ret = -ENOMEM; |
1134 | goto reject; | |
45190f01 VW |
1135 | } else |
1136 | zswap_pool_reached_full = false; | |
2b281117 SJ |
1137 | } |
1138 | ||
1139 | /* allocate entry */ | |
1140 | entry = zswap_entry_cache_alloc(GFP_KERNEL); | |
1141 | if (!entry) { | |
1142 | zswap_reject_kmemcache_fail++; | |
1143 | ret = -ENOMEM; | |
1144 | goto reject; | |
1145 | } | |
1146 | ||
a85f878b SD |
1147 | if (zswap_same_filled_pages_enabled) { |
1148 | src = kmap_atomic(page); | |
1149 | if (zswap_is_page_same_filled(src, &value)) { | |
1150 | kunmap_atomic(src); | |
1151 | entry->offset = offset; | |
1152 | entry->length = 0; | |
1153 | entry->value = value; | |
1154 | atomic_inc(&zswap_same_filled_pages); | |
1155 | goto insert_entry; | |
1156 | } | |
1157 | kunmap_atomic(src); | |
1158 | } | |
1159 | ||
cb325ddd MS |
1160 | if (!zswap_non_same_filled_pages_enabled) { |
1161 | ret = -EINVAL; | |
1162 | goto freepage; | |
1163 | } | |
1164 | ||
f1c54846 DS |
1165 | /* if entry is successfully added, it keeps the reference */ |
1166 | entry->pool = zswap_pool_current_get(); | |
1167 | if (!entry->pool) { | |
1168 | ret = -EINVAL; | |
1169 | goto freepage; | |
1170 | } | |
1171 | ||
2b281117 | 1172 | /* compress */ |
1ec3b5fe BS |
1173 | acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); |
1174 | ||
1175 | mutex_lock(acomp_ctx->mutex); | |
1176 | ||
1177 | dst = acomp_ctx->dstmem; | |
1178 | sg_init_table(&input, 1); | |
1179 | sg_set_page(&input, page, PAGE_SIZE, 0); | |
1180 | ||
1181 | /* zswap_dstmem is of size (PAGE_SIZE * 2). Reflect same in sg_list */ | |
1182 | sg_init_one(&output, dst, PAGE_SIZE * 2); | |
1183 | acomp_request_set_params(acomp_ctx->req, &input, &output, PAGE_SIZE, dlen); | |
1184 | /* | |
1185 | * it maybe looks a little bit silly that we send an asynchronous request, | |
1186 | * then wait for its completion synchronously. This makes the process look | |
1187 | * synchronous in fact. | |
1188 | * Theoretically, acomp supports users send multiple acomp requests in one | |
1189 | * acomp instance, then get those requests done simultaneously. but in this | |
1190 | * case, frontswap actually does store and load page by page, there is no | |
1191 | * existing method to send the second page before the first page is done | |
1192 | * in one thread doing frontswap. | |
1193 | * but in different threads running on different cpu, we have different | |
1194 | * acomp instance, so multiple threads can do (de)compression in parallel. | |
1195 | */ | |
1196 | ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx->wait); | |
1197 | dlen = acomp_ctx->req->dlen; | |
1198 | ||
2b281117 SJ |
1199 | if (ret) { |
1200 | ret = -EINVAL; | |
f1c54846 | 1201 | goto put_dstmem; |
2b281117 SJ |
1202 | } |
1203 | ||
1204 | /* store */ | |
9c3760eb | 1205 | hlen = zpool_evictable(entry->pool->zpool) ? sizeof(zhdr) : 0; |
d2fcd82b HZ |
1206 | gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM; |
1207 | if (zpool_malloc_support_movable(entry->pool->zpool)) | |
1208 | gfp |= __GFP_HIGHMEM | __GFP_MOVABLE; | |
1209 | ret = zpool_malloc(entry->pool->zpool, hlen + dlen, gfp, &handle); | |
2b281117 SJ |
1210 | if (ret == -ENOSPC) { |
1211 | zswap_reject_compress_poor++; | |
f1c54846 | 1212 | goto put_dstmem; |
2b281117 SJ |
1213 | } |
1214 | if (ret) { | |
1215 | zswap_reject_alloc_fail++; | |
f1c54846 | 1216 | goto put_dstmem; |
2b281117 | 1217 | } |
ae34af1f | 1218 | buf = zpool_map_handle(entry->pool->zpool, handle, ZPOOL_MM_WO); |
9c3760eb YZ |
1219 | memcpy(buf, &zhdr, hlen); |
1220 | memcpy(buf + hlen, dst, dlen); | |
f1c54846 | 1221 | zpool_unmap_handle(entry->pool->zpool, handle); |
1ec3b5fe | 1222 | mutex_unlock(acomp_ctx->mutex); |
2b281117 SJ |
1223 | |
1224 | /* populate entry */ | |
1225 | entry->offset = offset; | |
1226 | entry->handle = handle; | |
1227 | entry->length = dlen; | |
1228 | ||
a85f878b | 1229 | insert_entry: |
2b281117 SJ |
1230 | /* map */ |
1231 | spin_lock(&tree->lock); | |
1232 | do { | |
1233 | ret = zswap_rb_insert(&tree->rbroot, entry, &dupentry); | |
1234 | if (ret == -EEXIST) { | |
1235 | zswap_duplicate_entry++; | |
1236 | /* remove from rbtree */ | |
0ab0abcf WY |
1237 | zswap_rb_erase(&tree->rbroot, dupentry); |
1238 | zswap_entry_put(tree, dupentry); | |
2b281117 SJ |
1239 | } |
1240 | } while (ret == -EEXIST); | |
1241 | spin_unlock(&tree->lock); | |
1242 | ||
1243 | /* update stats */ | |
1244 | atomic_inc(&zswap_stored_pages); | |
f1c54846 | 1245 | zswap_update_total_size(); |
f6498b77 | 1246 | count_vm_event(ZSWPOUT); |
2b281117 SJ |
1247 | |
1248 | return 0; | |
1249 | ||
f1c54846 | 1250 | put_dstmem: |
1ec3b5fe | 1251 | mutex_unlock(acomp_ctx->mutex); |
f1c54846 DS |
1252 | zswap_pool_put(entry->pool); |
1253 | freepage: | |
2b281117 SJ |
1254 | zswap_entry_cache_free(entry); |
1255 | reject: | |
1256 | return ret; | |
1257 | } | |
1258 | ||
1259 | /* | |
1260 | * returns 0 if the page was successfully decompressed | |
1261 | * return -1 on entry not found or error | |
1262 | */ | |
1263 | static int zswap_frontswap_load(unsigned type, pgoff_t offset, | |
1264 | struct page *page) | |
1265 | { | |
1266 | struct zswap_tree *tree = zswap_trees[type]; | |
1267 | struct zswap_entry *entry; | |
1ec3b5fe BS |
1268 | struct scatterlist input, output; |
1269 | struct crypto_acomp_ctx *acomp_ctx; | |
fc6697a8 | 1270 | u8 *src, *dst, *tmp; |
2b281117 | 1271 | unsigned int dlen; |
0ab0abcf | 1272 | int ret; |
2b281117 SJ |
1273 | |
1274 | /* find */ | |
1275 | spin_lock(&tree->lock); | |
0ab0abcf | 1276 | entry = zswap_entry_find_get(&tree->rbroot, offset); |
2b281117 SJ |
1277 | if (!entry) { |
1278 | /* entry was written back */ | |
1279 | spin_unlock(&tree->lock); | |
1280 | return -1; | |
1281 | } | |
2b281117 SJ |
1282 | spin_unlock(&tree->lock); |
1283 | ||
a85f878b SD |
1284 | if (!entry->length) { |
1285 | dst = kmap_atomic(page); | |
1286 | zswap_fill_page(dst, entry->value); | |
1287 | kunmap_atomic(dst); | |
fc6697a8 | 1288 | ret = 0; |
f6498b77 | 1289 | goto stats; |
a85f878b SD |
1290 | } |
1291 | ||
fc6697a8 | 1292 | if (!zpool_can_sleep_mapped(entry->pool->zpool)) { |
fc6697a8 TT |
1293 | tmp = kmalloc(entry->length, GFP_ATOMIC); |
1294 | if (!tmp) { | |
1295 | ret = -ENOMEM; | |
1296 | goto freeentry; | |
1297 | } | |
1298 | } | |
1299 | ||
2b281117 SJ |
1300 | /* decompress */ |
1301 | dlen = PAGE_SIZE; | |
9c3760eb YZ |
1302 | src = zpool_map_handle(entry->pool->zpool, entry->handle, ZPOOL_MM_RO); |
1303 | if (zpool_evictable(entry->pool->zpool)) | |
1304 | src += sizeof(struct zswap_header); | |
1ec3b5fe | 1305 | |
fc6697a8 | 1306 | if (!zpool_can_sleep_mapped(entry->pool->zpool)) { |
fc6697a8 TT |
1307 | memcpy(tmp, src, entry->length); |
1308 | src = tmp; | |
fc6697a8 TT |
1309 | zpool_unmap_handle(entry->pool->zpool, entry->handle); |
1310 | } | |
1311 | ||
1ec3b5fe BS |
1312 | acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); |
1313 | mutex_lock(acomp_ctx->mutex); | |
1314 | sg_init_one(&input, src, entry->length); | |
1315 | sg_init_table(&output, 1); | |
1316 | sg_set_page(&output, page, PAGE_SIZE, 0); | |
1317 | acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, dlen); | |
1318 | ret = crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait); | |
1319 | mutex_unlock(acomp_ctx->mutex); | |
1320 | ||
fc6697a8 TT |
1321 | if (zpool_can_sleep_mapped(entry->pool->zpool)) |
1322 | zpool_unmap_handle(entry->pool->zpool, entry->handle); | |
1323 | else | |
1324 | kfree(tmp); | |
1325 | ||
2b281117 | 1326 | BUG_ON(ret); |
f6498b77 JW |
1327 | stats: |
1328 | count_vm_event(ZSWPIN); | |
a85f878b | 1329 | freeentry: |
2b281117 | 1330 | spin_lock(&tree->lock); |
0ab0abcf | 1331 | zswap_entry_put(tree, entry); |
2b281117 SJ |
1332 | spin_unlock(&tree->lock); |
1333 | ||
fc6697a8 | 1334 | return ret; |
2b281117 SJ |
1335 | } |
1336 | ||
1337 | /* frees an entry in zswap */ | |
1338 | static void zswap_frontswap_invalidate_page(unsigned type, pgoff_t offset) | |
1339 | { | |
1340 | struct zswap_tree *tree = zswap_trees[type]; | |
1341 | struct zswap_entry *entry; | |
2b281117 SJ |
1342 | |
1343 | /* find */ | |
1344 | spin_lock(&tree->lock); | |
1345 | entry = zswap_rb_search(&tree->rbroot, offset); | |
1346 | if (!entry) { | |
1347 | /* entry was written back */ | |
1348 | spin_unlock(&tree->lock); | |
1349 | return; | |
1350 | } | |
1351 | ||
1352 | /* remove from rbtree */ | |
0ab0abcf | 1353 | zswap_rb_erase(&tree->rbroot, entry); |
2b281117 SJ |
1354 | |
1355 | /* drop the initial reference from entry creation */ | |
0ab0abcf | 1356 | zswap_entry_put(tree, entry); |
2b281117 SJ |
1357 | |
1358 | spin_unlock(&tree->lock); | |
2b281117 SJ |
1359 | } |
1360 | ||
1361 | /* frees all zswap entries for the given swap type */ | |
1362 | static void zswap_frontswap_invalidate_area(unsigned type) | |
1363 | { | |
1364 | struct zswap_tree *tree = zswap_trees[type]; | |
0bd42136 | 1365 | struct zswap_entry *entry, *n; |
2b281117 SJ |
1366 | |
1367 | if (!tree) | |
1368 | return; | |
1369 | ||
1370 | /* walk the tree and free everything */ | |
1371 | spin_lock(&tree->lock); | |
0ab0abcf | 1372 | rbtree_postorder_for_each_entry_safe(entry, n, &tree->rbroot, rbnode) |
60105e12 | 1373 | zswap_free_entry(entry); |
2b281117 SJ |
1374 | tree->rbroot = RB_ROOT; |
1375 | spin_unlock(&tree->lock); | |
aa9bca05 WY |
1376 | kfree(tree); |
1377 | zswap_trees[type] = NULL; | |
2b281117 SJ |
1378 | } |
1379 | ||
2b281117 SJ |
1380 | static void zswap_frontswap_init(unsigned type) |
1381 | { | |
1382 | struct zswap_tree *tree; | |
1383 | ||
9cd1f701 | 1384 | tree = kzalloc(sizeof(*tree), GFP_KERNEL); |
60105e12 MK |
1385 | if (!tree) { |
1386 | pr_err("alloc failed, zswap disabled for swap type %d\n", type); | |
1387 | return; | |
1388 | } | |
1389 | ||
2b281117 SJ |
1390 | tree->rbroot = RB_ROOT; |
1391 | spin_lock_init(&tree->lock); | |
1392 | zswap_trees[type] = tree; | |
2b281117 SJ |
1393 | } |
1394 | ||
1da0d94a | 1395 | static const struct frontswap_ops zswap_frontswap_ops = { |
2b281117 SJ |
1396 | .store = zswap_frontswap_store, |
1397 | .load = zswap_frontswap_load, | |
1398 | .invalidate_page = zswap_frontswap_invalidate_page, | |
1399 | .invalidate_area = zswap_frontswap_invalidate_area, | |
1400 | .init = zswap_frontswap_init | |
1401 | }; | |
1402 | ||
1403 | /********************************* | |
1404 | * debugfs functions | |
1405 | **********************************/ | |
1406 | #ifdef CONFIG_DEBUG_FS | |
1407 | #include <linux/debugfs.h> | |
1408 | ||
1409 | static struct dentry *zswap_debugfs_root; | |
1410 | ||
1411 | static int __init zswap_debugfs_init(void) | |
1412 | { | |
1413 | if (!debugfs_initialized()) | |
1414 | return -ENODEV; | |
1415 | ||
1416 | zswap_debugfs_root = debugfs_create_dir("zswap", NULL); | |
2b281117 | 1417 | |
0825a6f9 JP |
1418 | debugfs_create_u64("pool_limit_hit", 0444, |
1419 | zswap_debugfs_root, &zswap_pool_limit_hit); | |
1420 | debugfs_create_u64("reject_reclaim_fail", 0444, | |
1421 | zswap_debugfs_root, &zswap_reject_reclaim_fail); | |
1422 | debugfs_create_u64("reject_alloc_fail", 0444, | |
1423 | zswap_debugfs_root, &zswap_reject_alloc_fail); | |
1424 | debugfs_create_u64("reject_kmemcache_fail", 0444, | |
1425 | zswap_debugfs_root, &zswap_reject_kmemcache_fail); | |
1426 | debugfs_create_u64("reject_compress_poor", 0444, | |
1427 | zswap_debugfs_root, &zswap_reject_compress_poor); | |
1428 | debugfs_create_u64("written_back_pages", 0444, | |
1429 | zswap_debugfs_root, &zswap_written_back_pages); | |
1430 | debugfs_create_u64("duplicate_entry", 0444, | |
1431 | zswap_debugfs_root, &zswap_duplicate_entry); | |
1432 | debugfs_create_u64("pool_total_size", 0444, | |
1433 | zswap_debugfs_root, &zswap_pool_total_size); | |
1434 | debugfs_create_atomic_t("stored_pages", 0444, | |
1435 | zswap_debugfs_root, &zswap_stored_pages); | |
a85f878b | 1436 | debugfs_create_atomic_t("same_filled_pages", 0444, |
0825a6f9 | 1437 | zswap_debugfs_root, &zswap_same_filled_pages); |
2b281117 SJ |
1438 | |
1439 | return 0; | |
1440 | } | |
2b281117 SJ |
1441 | #else |
1442 | static int __init zswap_debugfs_init(void) | |
1443 | { | |
1444 | return 0; | |
1445 | } | |
2b281117 SJ |
1446 | #endif |
1447 | ||
1448 | /********************************* | |
1449 | * module init and exit | |
1450 | **********************************/ | |
1451 | static int __init init_zswap(void) | |
1452 | { | |
f1c54846 | 1453 | struct zswap_pool *pool; |
ad7ed770 | 1454 | int ret; |
60105e12 | 1455 | |
90b0fc26 DS |
1456 | zswap_init_started = true; |
1457 | ||
2b281117 SJ |
1458 | if (zswap_entry_cache_create()) { |
1459 | pr_err("entry cache creation failed\n"); | |
f1c54846 | 1460 | goto cache_fail; |
2b281117 | 1461 | } |
f1c54846 | 1462 | |
ad7ed770 SAS |
1463 | ret = cpuhp_setup_state(CPUHP_MM_ZSWP_MEM_PREPARE, "mm/zswap:prepare", |
1464 | zswap_dstmem_prepare, zswap_dstmem_dead); | |
1465 | if (ret) { | |
f1c54846 DS |
1466 | pr_err("dstmem alloc failed\n"); |
1467 | goto dstmem_fail; | |
2b281117 | 1468 | } |
f1c54846 | 1469 | |
cab7a7e5 SAS |
1470 | ret = cpuhp_setup_state_multi(CPUHP_MM_ZSWP_POOL_PREPARE, |
1471 | "mm/zswap_pool:prepare", | |
1472 | zswap_cpu_comp_prepare, | |
1473 | zswap_cpu_comp_dead); | |
1474 | if (ret) | |
1475 | goto hp_fail; | |
1476 | ||
f1c54846 | 1477 | pool = __zswap_pool_create_fallback(); |
ae3d89a7 DS |
1478 | if (pool) { |
1479 | pr_info("loaded using pool %s/%s\n", pool->tfm_name, | |
1480 | zpool_get_type(pool->zpool)); | |
1481 | list_add(&pool->list, &zswap_pools); | |
1482 | zswap_has_pool = true; | |
1483 | } else { | |
f1c54846 | 1484 | pr_err("pool creation failed\n"); |
ae3d89a7 | 1485 | zswap_enabled = false; |
2b281117 | 1486 | } |
60105e12 | 1487 | |
45190f01 VW |
1488 | shrink_wq = create_workqueue("zswap-shrink"); |
1489 | if (!shrink_wq) | |
1490 | goto fallback_fail; | |
1491 | ||
1da0d94a CH |
1492 | ret = frontswap_register_ops(&zswap_frontswap_ops); |
1493 | if (ret) | |
1494 | goto destroy_wq; | |
2b281117 SJ |
1495 | if (zswap_debugfs_init()) |
1496 | pr_warn("debugfs initialization failed\n"); | |
1497 | return 0; | |
f1c54846 | 1498 | |
1da0d94a CH |
1499 | destroy_wq: |
1500 | destroy_workqueue(shrink_wq); | |
45190f01 | 1501 | fallback_fail: |
38aeb071 DC |
1502 | if (pool) |
1503 | zswap_pool_destroy(pool); | |
cab7a7e5 | 1504 | hp_fail: |
ad7ed770 | 1505 | cpuhp_remove_state(CPUHP_MM_ZSWP_MEM_PREPARE); |
f1c54846 | 1506 | dstmem_fail: |
c119239b | 1507 | zswap_entry_cache_destroy(); |
f1c54846 | 1508 | cache_fail: |
d7b028f5 DS |
1509 | /* if built-in, we aren't unloaded on failure; don't allow use */ |
1510 | zswap_init_failed = true; | |
1511 | zswap_enabled = false; | |
2b281117 SJ |
1512 | return -ENOMEM; |
1513 | } | |
1514 | /* must be late so crypto has time to come up */ | |
1515 | late_initcall(init_zswap); | |
1516 | ||
1517 | MODULE_LICENSE("GPL"); | |
68386da8 | 1518 | MODULE_AUTHOR("Seth Jennings <sjennings@variantweb.net>"); |
2b281117 | 1519 | MODULE_DESCRIPTION("Compressed cache for swap pages"); |