Blame view
mm/cleancache.c
9.79 KB
7a338472f treewide: Replace... |
1 |
// SPDX-License-Identifier: GPL-2.0-only |
077b1f83a mm: cleancache co... |
2 3 4 5 6 |
/* * Cleancache frontend * * This code provides the generic "frontend" layer to call a matching * "backend" driver implementation of cleancache. See |
ad56b738c docs/vm: rename d... |
7 |
* Documentation/vm/cleancache.rst for more information. |
077b1f83a mm: cleancache co... |
8 9 10 |
* * Copyright (C) 2009-2010 Oracle Corp. All rights reserved. * Author: Dan Magenheimer |
077b1f83a mm: cleancache co... |
11 12 13 14 15 16 |
*/ #include <linux/module.h> #include <linux/fs.h> #include <linux/exportfs.h> #include <linux/mm.h> |
417fc2cae mm: cleancache: r... |
17 |
#include <linux/debugfs.h> |
077b1f83a mm: cleancache co... |
18 19 20 |
#include <linux/cleancache.h> /* |
3cb29d111 cleancache: remov... |
21 |
* cleancache_ops is set by cleancache_register_ops to contain the pointers |
077b1f83a mm: cleancache co... |
22 23 |
* to the cleancache "backend" implementation functions. */ |
b3c6de492 cleancache: const... |
24 |
static const struct cleancache_ops *cleancache_ops __read_mostly; |
077b1f83a mm: cleancache co... |
25 |
|
417fc2cae mm: cleancache: r... |
26 |
/* |
8fc8f4d57 mm: fix cleancach... |
27 |
* Counters available via /sys/kernel/debug/cleancache (if debugfs is |
417fc2cae mm: cleancache: r... |
28 29 30 31 32 33 34 |
* properly configured. These are for information only so are not protected * against increment races. */ static u64 cleancache_succ_gets; static u64 cleancache_failed_gets; static u64 cleancache_puts; static u64 cleancache_invalidates; |
077b1f83a mm: cleancache co... |
35 |
|
3cb29d111 cleancache: remov... |
36 37 38 39 40 41 42 43 44 45 46 |
static void cleancache_register_ops_sb(struct super_block *sb, void *unused) { switch (sb->cleancache_poolid) { case CLEANCACHE_NO_BACKEND: __cleancache_init_fs(sb); break; case CLEANCACHE_NO_BACKEND_SHARED: __cleancache_init_shared_fs(sb); break; } } |
49a9ab815 mm: cleancache: l... |
47 48 |
/* |
53d85c985 cleancache: forbi... |
49 |
* Register operations for cleancache. Returns 0 on success. |
077b1f83a mm: cleancache co... |
50 |
*/ |
b3c6de492 cleancache: const... |
51 |
int cleancache_register_ops(const struct cleancache_ops *ops) |
077b1f83a mm: cleancache co... |
52 |
{ |
3cb29d111 cleancache: remov... |
53 |
if (cmpxchg(&cleancache_ops, NULL, ops)) |
53d85c985 cleancache: forbi... |
54 |
return -EBUSY; |
3cb29d111 cleancache: remov... |
55 |
|
833f8662a cleancache: Make ... |
56 |
/* |
3cb29d111 cleancache: remov... |
57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 |
* A cleancache backend can be built as a module and hence loaded after * a cleancache enabled filesystem has called cleancache_init_fs. To * handle such a scenario, here we call ->init_fs or ->init_shared_fs * for each active super block. To differentiate between local and * shared filesystems, we temporarily initialize sb->cleancache_poolid * to CLEANCACHE_NO_BACKEND or CLEANCACHE_NO_BACKEND_SHARED * respectively in case there is no backend registered at the time * cleancache_init_fs or cleancache_init_shared_fs is called. * * Since filesystems can be mounted concurrently with cleancache * backend registration, we have to be careful to guarantee that all * cleancache enabled filesystems that has been mounted by the time * cleancache_register_ops is called has got and all mounted later will * get cleancache_poolid. This is assured by the following statements * tied together: * * a) iterate_supers skips only those super blocks that has started * ->kill_sb * * b) if iterate_supers encounters a super block that has not finished * ->mount yet, it waits until it is finished * * c) cleancache_init_fs is called from ->mount and * cleancache_invalidate_fs is called from ->kill_sb * * d) we call iterate_supers after cleancache_ops has been set * * From a) it follows that if iterate_supers skips a super block, then * either the super block is already dead, in which case we do not need * to bother initializing cleancache for it, or it was mounted after we * initiated iterate_supers. In the latter case, it must have seen * cleancache_ops set according to d) and initialized cleancache from * ->mount by itself according to c). This proves that we call * ->init_fs at least once for each active super block. * * From b) and c) it follows that if iterate_supers encounters a super * block that has already started ->init_fs, it will wait until ->mount * and hence ->init_fs has finished, then check cleancache_poolid, see * that it has already been set and therefore do nothing. This proves * that we call ->init_fs no more than once for each super block. * * Combined together, the last two paragraphs prove the function * correctness. * * Note that various cleancache callbacks may proceed before this * function is called or even concurrently with it, but since * CLEANCACHE_NO_BACKEND is negative, they will all result in a noop * until the corresponding ->init_fs has been actually called and * cleancache_ops has been set. |
833f8662a cleancache: Make ... |
106 |
*/ |
3cb29d111 cleancache: remov... |
107 |
iterate_supers(cleancache_register_ops_sb, NULL); |
53d85c985 cleancache: forbi... |
108 |
return 0; |
077b1f83a mm: cleancache co... |
109 110 111 112 113 114 |
} EXPORT_SYMBOL(cleancache_register_ops); /* Called by a cleancache-enabled filesystem at time of mount */ void __cleancache_init_fs(struct super_block *sb) { |
3cb29d111 cleancache: remov... |
115 |
int pool_id = CLEANCACHE_NO_BACKEND; |
49a9ab815 mm: cleancache: l... |
116 |
|
3cb29d111 cleancache: remov... |
117 118 119 120 |
if (cleancache_ops) { pool_id = cleancache_ops->init_fs(PAGE_SIZE); if (pool_id < 0) pool_id = CLEANCACHE_NO_POOL; |
49a9ab815 mm: cleancache: l... |
121 |
} |
3cb29d111 cleancache: remov... |
122 |
sb->cleancache_poolid = pool_id; |
077b1f83a mm: cleancache co... |
123 124 125 126 |
} EXPORT_SYMBOL(__cleancache_init_fs); /* Called by a cleancache-enabled clustered filesystem at time of mount */ |
9de162629 cleancache: zap u... |
127 |
void __cleancache_init_shared_fs(struct super_block *sb) |
077b1f83a mm: cleancache co... |
128 |
{ |
3cb29d111 cleancache: remov... |
129 |
int pool_id = CLEANCACHE_NO_BACKEND_SHARED; |
49a9ab815 mm: cleancache: l... |
130 |
|
3cb29d111 cleancache: remov... |
131 |
if (cleancache_ops) { |
85787090a fs: switch ->s_uu... |
132 |
pool_id = cleancache_ops->init_shared_fs(&sb->s_uuid, PAGE_SIZE); |
3cb29d111 cleancache: remov... |
133 134 |
if (pool_id < 0) pool_id = CLEANCACHE_NO_POOL; |
49a9ab815 mm: cleancache: l... |
135 |
} |
3cb29d111 cleancache: remov... |
136 |
sb->cleancache_poolid = pool_id; |
077b1f83a mm: cleancache co... |
137 138 139 140 141 142 143 144 145 146 |
} EXPORT_SYMBOL(__cleancache_init_shared_fs); /* * If the filesystem uses exportable filehandles, use the filehandle as * the key, else use the inode number. */ static int cleancache_get_key(struct inode *inode, struct cleancache_filekey *key) { |
b0b0382bb ->encode_fh() API... |
147 |
int (*fhfn)(struct inode *, __u32 *fh, int *, struct inode *); |
077b1f83a mm: cleancache co... |
148 149 150 151 152 153 154 |
int len = 0, maxlen = CLEANCACHE_KEY_MAX; struct super_block *sb = inode->i_sb; key->u.ino = inode->i_ino; if (sb->s_export_op != NULL) { fhfn = sb->s_export_op->encode_fh; if (fhfn) { |
b0b0382bb ->encode_fh() API... |
155 |
len = (*fhfn)(inode, &key->u.fh[0], &maxlen, NULL); |
94e07a759 fs: encode_fh: re... |
156 |
if (len <= FILEID_ROOT || len == FILEID_INVALID) |
077b1f83a mm: cleancache co... |
157 158 159 160 161 162 163 164 165 166 167 168 169 170 |
return -1; if (maxlen > CLEANCACHE_KEY_MAX) return -1; } } return 0; } /* * "Get" data from cleancache associated with the poolid/inode/index * that were specified when the data was put to cleanache and, if * successful, use it to fill the specified page with data and return 0. * The pageframe is unchanged and returns -1 if the get fails. * Page must be locked by caller. |
49a9ab815 mm: cleancache: l... |
171 172 173 174 |
* * The function has two checks before any action is taken - whether * a backend is registered and whether the sb->cleancache_poolid * is correct. |
077b1f83a mm: cleancache co... |
175 176 177 178 179 180 |
*/ int __cleancache_get_page(struct page *page) { int ret = -1; int pool_id; struct cleancache_filekey key = { .u.key = { 0 } }; |
833f8662a cleancache: Make ... |
181 |
if (!cleancache_ops) { |
49a9ab815 mm: cleancache: l... |
182 183 184 |
cleancache_failed_gets++; goto out; } |
309381fea mm: dump page whe... |
185 |
VM_BUG_ON_PAGE(!PageLocked(page), page); |
3cb29d111 cleancache: remov... |
186 187 |
pool_id = page->mapping->host->i_sb->cleancache_poolid; if (pool_id < 0) |
077b1f83a mm: cleancache co... |
188 189 190 191 |
goto out; if (cleancache_get_key(page->mapping->host, &key) < 0) goto out; |
3cb29d111 cleancache: remov... |
192 |
ret = cleancache_ops->get_page(pool_id, key, page->index, page); |
077b1f83a mm: cleancache co... |
193 194 195 196 197 198 199 200 201 202 203 204 205 206 |
if (ret == 0) cleancache_succ_gets++; else cleancache_failed_gets++; out: return ret; } EXPORT_SYMBOL(__cleancache_get_page); /* * "Put" data from a page to cleancache and associate it with the * (previously-obtained per-filesystem) poolid and the page's, * inode and page index. Page must be locked. Note that a put_page * always "succeeds", though a subsequent get_page may succeed or fail. |
49a9ab815 mm: cleancache: l... |
207 208 209 210 |
* * The function has two checks before any action is taken - whether * a backend is registered and whether the sb->cleancache_poolid * is correct. |
077b1f83a mm: cleancache co... |
211 212 213 214 215 |
*/ void __cleancache_put_page(struct page *page) { int pool_id; struct cleancache_filekey key = { .u.key = { 0 } }; |
833f8662a cleancache: Make ... |
216 |
if (!cleancache_ops) { |
49a9ab815 mm: cleancache: l... |
217 218 219 |
cleancache_puts++; return; } |
309381fea mm: dump page whe... |
220 |
VM_BUG_ON_PAGE(!PageLocked(page), page); |
3cb29d111 cleancache: remov... |
221 |
pool_id = page->mapping->host->i_sb->cleancache_poolid; |
077b1f83a mm: cleancache co... |
222 |
if (pool_id >= 0 && |
49a9ab815 mm: cleancache: l... |
223 |
cleancache_get_key(page->mapping->host, &key) >= 0) { |
833f8662a cleancache: Make ... |
224 |
cleancache_ops->put_page(pool_id, key, page->index, page); |
077b1f83a mm: cleancache co... |
225 226 227 228 229 230 |
cleancache_puts++; } } EXPORT_SYMBOL(__cleancache_put_page); /* |
3167760f8 mm: cleancache: s... |
231 |
* Invalidate any data from cleancache associated with the poolid and the |
077b1f83a mm: cleancache co... |
232 |
* page's inode and page index so that a subsequent "get" will fail. |
49a9ab815 mm: cleancache: l... |
233 234 235 236 |
* * The function has two checks before any action is taken - whether * a backend is registered and whether the sb->cleancache_poolid * is correct. |
077b1f83a mm: cleancache co... |
237 |
*/ |
3167760f8 mm: cleancache: s... |
238 239 |
void __cleancache_invalidate_page(struct address_space *mapping, struct page *page) |
077b1f83a mm: cleancache co... |
240 241 |
{ /* careful... page->mapping is NULL sometimes when this is called */ |
3cb29d111 cleancache: remov... |
242 |
int pool_id = mapping->host->i_sb->cleancache_poolid; |
077b1f83a mm: cleancache co... |
243 |
struct cleancache_filekey key = { .u.key = { 0 } }; |
833f8662a cleancache: Make ... |
244 |
if (!cleancache_ops) |
49a9ab815 mm: cleancache: l... |
245 |
return; |
3cb29d111 cleancache: remov... |
246 |
if (pool_id >= 0) { |
309381fea mm: dump page whe... |
247 |
VM_BUG_ON_PAGE(!PageLocked(page), page); |
077b1f83a mm: cleancache co... |
248 |
if (cleancache_get_key(mapping->host, &key) >= 0) { |
833f8662a cleancache: Make ... |
249 |
cleancache_ops->invalidate_page(pool_id, |
49a9ab815 mm: cleancache: l... |
250 |
key, page->index); |
417fc2cae mm: cleancache: r... |
251 |
cleancache_invalidates++; |
077b1f83a mm: cleancache co... |
252 253 254 |
} } } |
3167760f8 mm: cleancache: s... |
255 |
EXPORT_SYMBOL(__cleancache_invalidate_page); |
077b1f83a mm: cleancache co... |
256 257 |
/* |
3167760f8 mm: cleancache: s... |
258 |
* Invalidate all data from cleancache associated with the poolid and the |
077b1f83a mm: cleancache co... |
259 260 |
* mappings's inode so that all subsequent gets to this poolid/inode * will fail. |
49a9ab815 mm: cleancache: l... |
261 262 263 264 |
* * The function has two checks before any action is taken - whether * a backend is registered and whether the sb->cleancache_poolid * is correct. |
077b1f83a mm: cleancache co... |
265 |
*/ |
3167760f8 mm: cleancache: s... |
266 |
void __cleancache_invalidate_inode(struct address_space *mapping) |
077b1f83a mm: cleancache co... |
267 |
{ |
3cb29d111 cleancache: remov... |
268 |
int pool_id = mapping->host->i_sb->cleancache_poolid; |
077b1f83a mm: cleancache co... |
269 |
struct cleancache_filekey key = { .u.key = { 0 } }; |
833f8662a cleancache: Make ... |
270 |
if (!cleancache_ops) |
49a9ab815 mm: cleancache: l... |
271 |
return; |
077b1f83a mm: cleancache co... |
272 |
if (pool_id >= 0 && cleancache_get_key(mapping->host, &key) >= 0) |
833f8662a cleancache: Make ... |
273 |
cleancache_ops->invalidate_inode(pool_id, key); |
077b1f83a mm: cleancache co... |
274 |
} |
3167760f8 mm: cleancache: s... |
275 |
EXPORT_SYMBOL(__cleancache_invalidate_inode); |
077b1f83a mm: cleancache co... |
276 277 278 |
/* * Called by any cleancache-enabled filesystem at time of unmount; |
49a9ab815 mm: cleancache: l... |
279 280 |
* note that pool_id is surrendered and may be returned by a subsequent * cleancache_init_fs or cleancache_init_shared_fs. |
077b1f83a mm: cleancache co... |
281 |
*/ |
3167760f8 mm: cleancache: s... |
282 |
void __cleancache_invalidate_fs(struct super_block *sb) |
077b1f83a mm: cleancache co... |
283 |
{ |
3cb29d111 cleancache: remov... |
284 |
int pool_id; |
49a9ab815 mm: cleancache: l... |
285 |
|
3cb29d111 cleancache: remov... |
286 287 288 289 290 |
pool_id = sb->cleancache_poolid; sb->cleancache_poolid = CLEANCACHE_NO_POOL; if (cleancache_ops && pool_id >= 0) cleancache_ops->invalidate_fs(pool_id); |
077b1f83a mm: cleancache co... |
291 |
} |
3167760f8 mm: cleancache: s... |
292 |
EXPORT_SYMBOL(__cleancache_invalidate_fs); |
077b1f83a mm: cleancache co... |
293 |
|
077b1f83a mm: cleancache co... |
294 295 |
static int __init init_cleancache(void) { |
417fc2cae mm: cleancache: r... |
296 297 |
#ifdef CONFIG_DEBUG_FS struct dentry *root = debugfs_create_dir("cleancache", NULL); |
c4e41349a mm: cleancache: n... |
298 |
|
0825a6f98 mm: use octal not... |
299 300 301 302 |
debugfs_create_u64("succ_gets", 0444, root, &cleancache_succ_gets); debugfs_create_u64("failed_gets", 0444, root, &cleancache_failed_gets); debugfs_create_u64("puts", 0444, root, &cleancache_puts); debugfs_create_u64("invalidates", 0444, root, &cleancache_invalidates); |
417fc2cae mm: cleancache: r... |
303 |
#endif |
077b1f83a mm: cleancache co... |
304 305 306 |
return 0; } module_init(init_cleancache) |