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d7e09d03 PT |
1 | /* |
2 | * GPL HEADER START | |
3 | * | |
4 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 only, | |
8 | * as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License version 2 for more details (a copy is included | |
14 | * in the LICENSE file that accompanied this code). | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * version 2 along with this program; If not, see | |
18 | * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf | |
19 | * | |
20 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
21 | * CA 95054 USA or visit www.sun.com if you need additional information or | |
22 | * have any questions. | |
23 | * | |
24 | * GPL HEADER END | |
25 | */ | |
26 | /* | |
27 | * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. | |
28 | * Use is subject to license terms. | |
29 | * | |
1dc563a6 | 30 | * Copyright (c) 2011, 2015, Intel Corporation. |
d7e09d03 PT |
31 | */ |
32 | /* | |
33 | * This file is part of Lustre, http://www.lustre.org/ | |
34 | * Lustre is a trademark of Sun Microsystems, Inc. | |
35 | * | |
36 | * Client Lustre Page. | |
37 | * | |
38 | * Author: Nikita Danilov <nikita.danilov@sun.com> | |
39 | */ | |
40 | ||
41 | #define DEBUG_SUBSYSTEM S_CLASS | |
42 | ||
9fdaf8c0 | 43 | #include "../../include/linux/libcfs/libcfs.h" |
610f7377 GKH |
44 | #include "../include/obd_class.h" |
45 | #include "../include/obd_support.h" | |
d7e09d03 PT |
46 | #include <linux/list.h> |
47 | ||
610f7377 | 48 | #include "../include/cl_object.h" |
d7e09d03 PT |
49 | #include "cl_internal.h" |
50 | ||
51 | static void cl_page_delete0(const struct lu_env *env, struct cl_page *pg, | |
52 | int radix); | |
53 | ||
b16d335d PL |
54 | # define PASSERT(env, page, expr) \ |
55 | do { \ | |
56 | if (unlikely(!(expr))) { \ | |
57 | CL_PAGE_DEBUG(D_ERROR, (env), (page), #expr "\n"); \ | |
58 | LASSERT(0); \ | |
59 | } \ | |
648d6e6c | 60 | } while (0) |
d7e09d03 PT |
61 | |
62 | # define PINVRNT(env, page, exp) \ | |
63 | ((void)sizeof(env), (void)sizeof(page), (void)sizeof !!(exp)) | |
64 | ||
d7e09d03 PT |
65 | /** |
66 | * Internal version of cl_page_top, it should be called if the page is | |
67 | * known to be not freed, says with page referenced, or radix tree lock held, | |
68 | * or page owned. | |
69 | */ | |
70 | static struct cl_page *cl_page_top_trusted(struct cl_page *page) | |
71 | { | |
cce3c2da | 72 | while (page->cp_parent) |
d7e09d03 PT |
73 | page = page->cp_parent; |
74 | return page; | |
75 | } | |
76 | ||
77 | /** | |
78 | * Internal version of cl_page_get(). | |
79 | * | |
80 | * This function can be used to obtain initial reference to previously | |
81 | * unreferenced cached object. It can be called only if concurrent page | |
82 | * reclamation is somehow prevented, e.g., by locking page radix-tree | |
83 | * (cl_object_header::hdr->coh_page_guard), or by keeping a lock on a VM page, | |
84 | * associated with \a page. | |
85 | * | |
86 | * Use with care! Not exported. | |
87 | */ | |
88 | static void cl_page_get_trust(struct cl_page *page) | |
89 | { | |
90 | LASSERT(atomic_read(&page->cp_ref) > 0); | |
91 | atomic_inc(&page->cp_ref); | |
92 | } | |
93 | ||
94 | /** | |
95 | * Returns a slice within a page, corresponding to the given layer in the | |
96 | * device stack. | |
97 | * | |
98 | * \see cl_lock_at() | |
99 | */ | |
100 | static const struct cl_page_slice * | |
101 | cl_page_at_trusted(const struct cl_page *page, | |
102 | const struct lu_device_type *dtype) | |
103 | { | |
104 | const struct cl_page_slice *slice; | |
d7e09d03 PT |
105 | |
106 | page = cl_page_top_trusted((struct cl_page *)page); | |
107 | do { | |
108 | list_for_each_entry(slice, &page->cp_layers, cpl_linkage) { | |
109 | if (slice->cpl_obj->co_lu.lo_dev->ld_type == dtype) | |
0a3bdb00 | 110 | return slice; |
d7e09d03 PT |
111 | } |
112 | page = page->cp_child; | |
cce3c2da | 113 | } while (page); |
0a3bdb00 | 114 | return NULL; |
d7e09d03 PT |
115 | } |
116 | ||
117 | /** | |
118 | * Returns a page with given index in the given object, or NULL if no page is | |
119 | * found. Acquires a reference on \a page. | |
120 | * | |
121 | * Locking: called under cl_object_header::coh_page_guard spin-lock. | |
122 | */ | |
123 | struct cl_page *cl_page_lookup(struct cl_object_header *hdr, pgoff_t index) | |
124 | { | |
125 | struct cl_page *page; | |
126 | ||
5e42bc9d | 127 | assert_spin_locked(&hdr->coh_page_guard); |
d7e09d03 PT |
128 | |
129 | page = radix_tree_lookup(&hdr->coh_tree, index); | |
cce3c2da | 130 | if (page) |
d7e09d03 PT |
131 | cl_page_get_trust(page); |
132 | return page; | |
133 | } | |
134 | EXPORT_SYMBOL(cl_page_lookup); | |
135 | ||
136 | /** | |
137 | * Returns a list of pages by a given [start, end] of \a obj. | |
138 | * | |
139 | * \param resched If not NULL, then we give up before hogging CPU for too | |
140 | * long and set *resched = 1, in that case caller should implement a retry | |
141 | * logic. | |
142 | * | |
143 | * Gang tree lookup (radix_tree_gang_lookup()) optimization is absolutely | |
144 | * crucial in the face of [offset, EOF] locks. | |
145 | * | |
146 | * Return at least one page in @queue unless there is no covered page. | |
147 | */ | |
148 | int cl_page_gang_lookup(const struct lu_env *env, struct cl_object *obj, | |
149 | struct cl_io *io, pgoff_t start, pgoff_t end, | |
150 | cl_page_gang_cb_t cb, void *cbdata) | |
151 | { | |
152 | struct cl_object_header *hdr; | |
153 | struct cl_page *page; | |
154 | struct cl_page **pvec; | |
155 | const struct cl_page_slice *slice; | |
156 | const struct lu_device_type *dtype; | |
157 | pgoff_t idx; | |
158 | unsigned int nr; | |
159 | unsigned int i; | |
160 | unsigned int j; | |
161 | int res = CLP_GANG_OKAY; | |
162 | int tree_lock = 1; | |
d7e09d03 PT |
163 | |
164 | idx = start; | |
165 | hdr = cl_object_header(obj); | |
166 | pvec = cl_env_info(env)->clt_pvec; | |
167 | dtype = cl_object_top(obj)->co_lu.lo_dev->ld_type; | |
168 | spin_lock(&hdr->coh_page_guard); | |
169 | while ((nr = radix_tree_gang_lookup(&hdr->coh_tree, (void **)pvec, | |
170 | idx, CLT_PVEC_SIZE)) > 0) { | |
171 | int end_of_region = 0; | |
8de056a1 | 172 | |
d7e09d03 PT |
173 | idx = pvec[nr - 1]->cp_index + 1; |
174 | for (i = 0, j = 0; i < nr; ++i) { | |
175 | page = pvec[i]; | |
176 | pvec[i] = NULL; | |
177 | ||
178 | LASSERT(page->cp_type == CPT_CACHEABLE); | |
179 | if (page->cp_index > end) { | |
180 | end_of_region = 1; | |
181 | break; | |
182 | } | |
183 | if (page->cp_state == CPS_FREEING) | |
184 | continue; | |
185 | ||
186 | slice = cl_page_at_trusted(page, dtype); | |
187 | /* | |
188 | * Pages for lsm-less file has no underneath sub-page | |
189 | * for osc, in case of ... | |
190 | */ | |
cce3c2da | 191 | PASSERT(env, page, slice); |
d7e09d03 PT |
192 | |
193 | page = slice->cpl_page; | |
194 | /* | |
195 | * Can safely call cl_page_get_trust() under | |
196 | * radix-tree spin-lock. | |
197 | * | |
198 | * XXX not true, because @page is from object another | |
199 | * than @hdr and protected by different tree lock. | |
200 | */ | |
201 | cl_page_get_trust(page); | |
202 | lu_ref_add_atomic(&page->cp_reference, | |
203 | "gang_lookup", current); | |
204 | pvec[j++] = page; | |
205 | } | |
206 | ||
207 | /* | |
208 | * Here a delicate locking dance is performed. Current thread | |
209 | * holds a reference to a page, but has to own it before it | |
210 | * can be placed into queue. Owning implies waiting, so | |
211 | * radix-tree lock is to be released. After a wait one has to | |
212 | * check that pages weren't truncated (cl_page_own() returns | |
213 | * error in the latter case). | |
214 | */ | |
215 | spin_unlock(&hdr->coh_page_guard); | |
216 | tree_lock = 0; | |
217 | ||
218 | for (i = 0; i < j; ++i) { | |
219 | page = pvec[i]; | |
220 | if (res == CLP_GANG_OKAY) | |
221 | res = (*cb)(env, io, page, cbdata); | |
222 | lu_ref_del(&page->cp_reference, | |
223 | "gang_lookup", current); | |
224 | cl_page_put(env, page); | |
225 | } | |
226 | if (nr < CLT_PVEC_SIZE || end_of_region) | |
227 | break; | |
228 | ||
229 | if (res == CLP_GANG_OKAY && need_resched()) | |
230 | res = CLP_GANG_RESCHED; | |
231 | if (res != CLP_GANG_OKAY) | |
232 | break; | |
233 | ||
234 | spin_lock(&hdr->coh_page_guard); | |
235 | tree_lock = 1; | |
236 | } | |
237 | if (tree_lock) | |
238 | spin_unlock(&hdr->coh_page_guard); | |
0a3bdb00 | 239 | return res; |
d7e09d03 PT |
240 | } |
241 | EXPORT_SYMBOL(cl_page_gang_lookup); | |
242 | ||
243 | static void cl_page_free(const struct lu_env *env, struct cl_page *page) | |
244 | { | |
245 | struct cl_object *obj = page->cp_obj; | |
d7e09d03 PT |
246 | |
247 | PASSERT(env, page, list_empty(&page->cp_batch)); | |
cce3c2da OD |
248 | PASSERT(env, page, !page->cp_owner); |
249 | PASSERT(env, page, !page->cp_req); | |
250 | PASSERT(env, page, !page->cp_parent); | |
d7e09d03 PT |
251 | PASSERT(env, page, page->cp_state == CPS_FREEING); |
252 | ||
d7e09d03 PT |
253 | might_sleep(); |
254 | while (!list_empty(&page->cp_layers)) { | |
255 | struct cl_page_slice *slice; | |
256 | ||
257 | slice = list_entry(page->cp_layers.next, | |
926d6fb2 | 258 | struct cl_page_slice, cpl_linkage); |
d7e09d03 PT |
259 | list_del_init(page->cp_layers.next); |
260 | slice->cpl_ops->cpo_fini(env, slice); | |
261 | } | |
631abc6e | 262 | lu_object_ref_del_at(&obj->co_lu, &page->cp_obj_ref, "cl_page", page); |
d7e09d03 PT |
263 | cl_object_put(env, obj); |
264 | lu_ref_fini(&page->cp_reference); | |
d7279044 | 265 | kfree(page); |
d7e09d03 PT |
266 | } |
267 | ||
268 | /** | |
269 | * Helper function updating page state. This is the only place in the code | |
270 | * where cl_page::cp_state field is mutated. | |
271 | */ | |
272 | static inline void cl_page_state_set_trust(struct cl_page *page, | |
273 | enum cl_page_state state) | |
274 | { | |
275 | /* bypass const. */ | |
276 | *(enum cl_page_state *)&page->cp_state = state; | |
277 | } | |
278 | ||
279 | static struct cl_page *cl_page_alloc(const struct lu_env *env, | |
926d6fb2 OD |
280 | struct cl_object *o, pgoff_t ind, |
281 | struct page *vmpage, | |
282 | enum cl_page_type type) | |
d7e09d03 PT |
283 | { |
284 | struct cl_page *page; | |
285 | struct lu_object_header *head; | |
286 | ||
d37c8781 | 287 | page = kzalloc(cl_object_header(o)->coh_page_bufsize, GFP_NOFS); |
cce3c2da | 288 | if (page) { |
d7e09d03 | 289 | int result = 0; |
8de056a1 | 290 | |
d7e09d03 PT |
291 | atomic_set(&page->cp_ref, 1); |
292 | if (type == CPT_CACHEABLE) /* for radix tree */ | |
293 | atomic_inc(&page->cp_ref); | |
294 | page->cp_obj = o; | |
295 | cl_object_get(o); | |
631abc6e JH |
296 | lu_object_ref_add_at(&o->co_lu, &page->cp_obj_ref, "cl_page", |
297 | page); | |
d7e09d03 PT |
298 | page->cp_index = ind; |
299 | cl_page_state_set_trust(page, CPS_CACHED); | |
300 | page->cp_type = type; | |
301 | INIT_LIST_HEAD(&page->cp_layers); | |
302 | INIT_LIST_HEAD(&page->cp_batch); | |
303 | INIT_LIST_HEAD(&page->cp_flight); | |
304 | mutex_init(&page->cp_mutex); | |
305 | lu_ref_init(&page->cp_reference); | |
306 | head = o->co_lu.lo_header; | |
926d6fb2 | 307 | list_for_each_entry(o, &head->loh_layers, co_lu.lo_linkage) { |
cce3c2da | 308 | if (o->co_ops->coo_page_init) { |
d7e09d03 PT |
309 | result = o->co_ops->coo_page_init(env, o, |
310 | page, vmpage); | |
311 | if (result != 0) { | |
312 | cl_page_delete0(env, page, 0); | |
313 | cl_page_free(env, page); | |
314 | page = ERR_PTR(result); | |
315 | break; | |
316 | } | |
317 | } | |
318 | } | |
d7e09d03 PT |
319 | } else { |
320 | page = ERR_PTR(-ENOMEM); | |
321 | } | |
0a3bdb00 | 322 | return page; |
d7e09d03 PT |
323 | } |
324 | ||
325 | /** | |
326 | * Returns a cl_page with index \a idx at the object \a o, and associated with | |
327 | * the VM page \a vmpage. | |
328 | * | |
329 | * This is the main entry point into the cl_page caching interface. First, a | |
330 | * cache (implemented as a per-object radix tree) is consulted. If page is | |
331 | * found there, it is returned immediately. Otherwise new page is allocated | |
332 | * and returned. In any case, additional reference to page is acquired. | |
333 | * | |
334 | * \see cl_object_find(), cl_lock_find() | |
335 | */ | |
336 | static struct cl_page *cl_page_find0(const struct lu_env *env, | |
337 | struct cl_object *o, | |
338 | pgoff_t idx, struct page *vmpage, | |
339 | enum cl_page_type type, | |
340 | struct cl_page *parent) | |
341 | { | |
342 | struct cl_page *page = NULL; | |
343 | struct cl_page *ghost = NULL; | |
344 | struct cl_object_header *hdr; | |
345 | int err; | |
346 | ||
347 | LASSERT(type == CPT_CACHEABLE || type == CPT_TRANSIENT); | |
348 | might_sleep(); | |
349 | ||
d7e09d03 | 350 | hdr = cl_object_header(o); |
d7e09d03 PT |
351 | |
352 | CDEBUG(D_PAGE, "%lu@"DFID" %p %lx %d\n", | |
353 | idx, PFID(&hdr->coh_lu.loh_fid), vmpage, vmpage->private, type); | |
354 | /* fast path. */ | |
355 | if (type == CPT_CACHEABLE) { | |
437dffeb PL |
356 | /* |
357 | * vmpage lock is used to protect the child/parent | |
358 | * relationship | |
359 | */ | |
d7e09d03 PT |
360 | KLASSERT(PageLocked(vmpage)); |
361 | /* | |
362 | * cl_vmpage_page() can be called here without any locks as | |
363 | * | |
364 | * - "vmpage" is locked (which prevents ->private from | |
365 | * concurrent updates), and | |
366 | * | |
367 | * - "o" cannot be destroyed while current thread holds a | |
368 | * reference on it. | |
369 | */ | |
370 | page = cl_vmpage_page(vmpage, o); | |
371 | PINVRNT(env, page, | |
cce3c2da | 372 | ergo(page, |
d7e09d03 PT |
373 | cl_page_vmpage(env, page) == vmpage && |
374 | (void *)radix_tree_lookup(&hdr->coh_tree, | |
375 | idx) == page)); | |
376 | } | |
377 | ||
cce3c2da | 378 | if (page) |
0a3bdb00 | 379 | return page; |
d7e09d03 PT |
380 | |
381 | /* allocate and initialize cl_page */ | |
382 | page = cl_page_alloc(env, o, idx, vmpage, type); | |
383 | if (IS_ERR(page)) | |
0a3bdb00 | 384 | return page; |
d7e09d03 PT |
385 | |
386 | if (type == CPT_TRANSIENT) { | |
387 | if (parent) { | |
cce3c2da | 388 | LASSERT(!page->cp_parent); |
d7e09d03 PT |
389 | page->cp_parent = parent; |
390 | parent->cp_child = page; | |
391 | } | |
0a3bdb00 | 392 | return page; |
d7e09d03 PT |
393 | } |
394 | ||
395 | /* | |
396 | * XXX optimization: use radix_tree_preload() here, and change tree | |
397 | * gfp mask to GFP_KERNEL in cl_object_header_init(). | |
398 | */ | |
399 | spin_lock(&hdr->coh_page_guard); | |
400 | err = radix_tree_insert(&hdr->coh_tree, idx, page); | |
401 | if (err != 0) { | |
402 | ghost = page; | |
403 | /* | |
404 | * Noted by Jay: a lock on \a vmpage protects cl_page_find() | |
405 | * from this race, but | |
406 | * | |
407 | * 0. it's better to have cl_page interface "locally | |
408 | * consistent" so that its correctness can be reasoned | |
409 | * about without appealing to the (obscure world of) VM | |
410 | * locking. | |
411 | * | |
412 | * 1. handling this race allows ->coh_tree to remain | |
413 | * consistent even when VM locking is somehow busted, | |
414 | * which is very useful during diagnosing and debugging. | |
415 | */ | |
416 | page = ERR_PTR(err); | |
417 | CL_PAGE_DEBUG(D_ERROR, env, ghost, | |
418 | "fail to insert into radix tree: %d\n", err); | |
419 | } else { | |
420 | if (parent) { | |
cce3c2da | 421 | LASSERT(!page->cp_parent); |
d7e09d03 PT |
422 | page->cp_parent = parent; |
423 | parent->cp_child = page; | |
424 | } | |
425 | hdr->coh_pages++; | |
426 | } | |
427 | spin_unlock(&hdr->coh_page_guard); | |
428 | ||
cce3c2da | 429 | if (unlikely(ghost)) { |
d7e09d03 PT |
430 | cl_page_delete0(env, ghost, 0); |
431 | cl_page_free(env, ghost); | |
432 | } | |
0a3bdb00 | 433 | return page; |
d7e09d03 PT |
434 | } |
435 | ||
436 | struct cl_page *cl_page_find(const struct lu_env *env, struct cl_object *o, | |
437 | pgoff_t idx, struct page *vmpage, | |
438 | enum cl_page_type type) | |
439 | { | |
440 | return cl_page_find0(env, o, idx, vmpage, type, NULL); | |
441 | } | |
442 | EXPORT_SYMBOL(cl_page_find); | |
443 | ||
d7e09d03 PT |
444 | struct cl_page *cl_page_find_sub(const struct lu_env *env, struct cl_object *o, |
445 | pgoff_t idx, struct page *vmpage, | |
446 | struct cl_page *parent) | |
447 | { | |
448 | return cl_page_find0(env, o, idx, vmpage, parent->cp_type, parent); | |
449 | } | |
450 | EXPORT_SYMBOL(cl_page_find_sub); | |
451 | ||
452 | static inline int cl_page_invariant(const struct cl_page *pg) | |
453 | { | |
454 | struct cl_object_header *header; | |
455 | struct cl_page *parent; | |
456 | struct cl_page *child; | |
457 | struct cl_io *owner; | |
458 | ||
459 | /* | |
460 | * Page invariant is protected by a VM lock. | |
461 | */ | |
462 | LINVRNT(cl_page_is_vmlocked(NULL, pg)); | |
463 | ||
464 | header = cl_object_header(pg->cp_obj); | |
465 | parent = pg->cp_parent; | |
466 | child = pg->cp_child; | |
467 | owner = pg->cp_owner; | |
468 | ||
469 | return cl_page_in_use(pg) && | |
cce3c2da OD |
470 | ergo(parent, parent->cp_child == pg) && |
471 | ergo(child, child->cp_parent == pg) && | |
472 | ergo(child, pg->cp_obj != child->cp_obj) && | |
473 | ergo(parent, pg->cp_obj != parent->cp_obj) && | |
474 | ergo(owner && parent, | |
d7e09d03 | 475 | parent->cp_owner == pg->cp_owner->ci_parent) && |
cce3c2da | 476 | ergo(owner && child, child->cp_owner->ci_parent == owner) && |
d7e09d03 PT |
477 | /* |
478 | * Either page is early in initialization (has neither child | |
479 | * nor parent yet), or it is in the object radix tree. | |
480 | */ | |
481 | ergo(pg->cp_state < CPS_FREEING && pg->cp_type == CPT_CACHEABLE, | |
482 | (void *)radix_tree_lookup(&header->coh_tree, | |
483 | pg->cp_index) == pg || | |
cce3c2da | 484 | (!child && !parent)); |
d7e09d03 PT |
485 | } |
486 | ||
487 | static void cl_page_state_set0(const struct lu_env *env, | |
488 | struct cl_page *page, enum cl_page_state state) | |
489 | { | |
490 | enum cl_page_state old; | |
491 | ||
492 | /* | |
493 | * Matrix of allowed state transitions [old][new], for sanity | |
494 | * checking. | |
495 | */ | |
496 | static const int allowed_transitions[CPS_NR][CPS_NR] = { | |
497 | [CPS_CACHED] = { | |
498 | [CPS_CACHED] = 0, | |
499 | [CPS_OWNED] = 1, /* io finds existing cached page */ | |
500 | [CPS_PAGEIN] = 0, | |
501 | [CPS_PAGEOUT] = 1, /* write-out from the cache */ | |
502 | [CPS_FREEING] = 1, /* eviction on the memory pressure */ | |
503 | }, | |
504 | [CPS_OWNED] = { | |
505 | [CPS_CACHED] = 1, /* release to the cache */ | |
506 | [CPS_OWNED] = 0, | |
507 | [CPS_PAGEIN] = 1, /* start read immediately */ | |
508 | [CPS_PAGEOUT] = 1, /* start write immediately */ | |
509 | [CPS_FREEING] = 1, /* lock invalidation or truncate */ | |
510 | }, | |
511 | [CPS_PAGEIN] = { | |
512 | [CPS_CACHED] = 1, /* io completion */ | |
513 | [CPS_OWNED] = 0, | |
514 | [CPS_PAGEIN] = 0, | |
515 | [CPS_PAGEOUT] = 0, | |
516 | [CPS_FREEING] = 0, | |
517 | }, | |
518 | [CPS_PAGEOUT] = { | |
519 | [CPS_CACHED] = 1, /* io completion */ | |
520 | [CPS_OWNED] = 0, | |
521 | [CPS_PAGEIN] = 0, | |
522 | [CPS_PAGEOUT] = 0, | |
523 | [CPS_FREEING] = 0, | |
524 | }, | |
525 | [CPS_FREEING] = { | |
526 | [CPS_CACHED] = 0, | |
527 | [CPS_OWNED] = 0, | |
528 | [CPS_PAGEIN] = 0, | |
529 | [CPS_PAGEOUT] = 0, | |
530 | [CPS_FREEING] = 0, | |
531 | } | |
532 | }; | |
533 | ||
d7e09d03 PT |
534 | old = page->cp_state; |
535 | PASSERT(env, page, allowed_transitions[old][state]); | |
536 | CL_PAGE_HEADER(D_TRACE, env, page, "%d -> %d\n", old, state); | |
cce3c2da | 537 | for (; page; page = page->cp_child) { |
d7e09d03 PT |
538 | PASSERT(env, page, page->cp_state == old); |
539 | PASSERT(env, page, | |
cce3c2da | 540 | equi(state == CPS_OWNED, page->cp_owner)); |
d7e09d03 | 541 | |
d7e09d03 PT |
542 | cl_page_state_set_trust(page, state); |
543 | } | |
d7e09d03 PT |
544 | } |
545 | ||
546 | static void cl_page_state_set(const struct lu_env *env, | |
547 | struct cl_page *page, enum cl_page_state state) | |
548 | { | |
549 | cl_page_state_set0(env, page, state); | |
550 | } | |
551 | ||
552 | /** | |
553 | * Acquires an additional reference to a page. | |
554 | * | |
555 | * This can be called only by caller already possessing a reference to \a | |
556 | * page. | |
557 | * | |
558 | * \see cl_object_get(), cl_lock_get(). | |
559 | */ | |
560 | void cl_page_get(struct cl_page *page) | |
561 | { | |
d7e09d03 | 562 | cl_page_get_trust(page); |
d7e09d03 PT |
563 | } |
564 | EXPORT_SYMBOL(cl_page_get); | |
565 | ||
566 | /** | |
567 | * Releases a reference to a page. | |
568 | * | |
569 | * When last reference is released, page is returned to the cache, unless it | |
570 | * is in cl_page_state::CPS_FREEING state, in which case it is immediately | |
571 | * destroyed. | |
572 | * | |
573 | * \see cl_object_put(), cl_lock_put(). | |
574 | */ | |
575 | void cl_page_put(const struct lu_env *env, struct cl_page *page) | |
576 | { | |
577 | PASSERT(env, page, atomic_read(&page->cp_ref) > !!page->cp_parent); | |
578 | ||
d7e09d03 PT |
579 | CL_PAGE_HEADER(D_TRACE, env, page, "%d\n", |
580 | atomic_read(&page->cp_ref)); | |
581 | ||
582 | if (atomic_dec_and_test(&page->cp_ref)) { | |
583 | LASSERT(page->cp_state == CPS_FREEING); | |
584 | ||
585 | LASSERT(atomic_read(&page->cp_ref) == 0); | |
cce3c2da | 586 | PASSERT(env, page, !page->cp_owner); |
d7e09d03 PT |
587 | PASSERT(env, page, list_empty(&page->cp_batch)); |
588 | /* | |
589 | * Page is no longer reachable by other threads. Tear | |
590 | * it down. | |
591 | */ | |
592 | cl_page_free(env, page); | |
593 | } | |
d7e09d03 PT |
594 | } |
595 | EXPORT_SYMBOL(cl_page_put); | |
596 | ||
597 | /** | |
598 | * Returns a VM page associated with a given cl_page. | |
599 | */ | |
600 | struct page *cl_page_vmpage(const struct lu_env *env, struct cl_page *page) | |
601 | { | |
602 | const struct cl_page_slice *slice; | |
603 | ||
604 | /* | |
605 | * Find uppermost layer with ->cpo_vmpage() method, and return its | |
606 | * result. | |
607 | */ | |
608 | page = cl_page_top(page); | |
609 | do { | |
610 | list_for_each_entry(slice, &page->cp_layers, cpl_linkage) { | |
cce3c2da | 611 | if (slice->cpl_ops->cpo_vmpage) |
0a3bdb00 | 612 | return slice->cpl_ops->cpo_vmpage(env, slice); |
d7e09d03 PT |
613 | } |
614 | page = page->cp_child; | |
cce3c2da | 615 | } while (page); |
d7e09d03 PT |
616 | LBUG(); /* ->cpo_vmpage() has to be defined somewhere in the stack */ |
617 | } | |
618 | EXPORT_SYMBOL(cl_page_vmpage); | |
619 | ||
620 | /** | |
621 | * Returns a cl_page associated with a VM page, and given cl_object. | |
622 | */ | |
623 | struct cl_page *cl_vmpage_page(struct page *vmpage, struct cl_object *obj) | |
624 | { | |
625 | struct cl_page *top; | |
626 | struct cl_page *page; | |
627 | ||
d7e09d03 PT |
628 | KLASSERT(PageLocked(vmpage)); |
629 | ||
630 | /* | |
631 | * NOTE: absence of races and liveness of data are guaranteed by page | |
632 | * lock on a "vmpage". That works because object destruction has | |
633 | * bottom-to-top pass. | |
634 | */ | |
635 | ||
636 | /* | |
637 | * This loop assumes that ->private points to the top-most page. This | |
638 | * can be rectified easily. | |
639 | */ | |
640 | top = (struct cl_page *)vmpage->private; | |
cce3c2da | 641 | if (!top) |
0a3bdb00 | 642 | return NULL; |
d7e09d03 | 643 | |
cce3c2da | 644 | for (page = top; page; page = page->cp_child) { |
d7e09d03 PT |
645 | if (cl_object_same(page->cp_obj, obj)) { |
646 | cl_page_get_trust(page); | |
647 | break; | |
648 | } | |
649 | } | |
650 | LASSERT(ergo(page, page->cp_type == CPT_CACHEABLE)); | |
0a3bdb00 | 651 | return page; |
d7e09d03 PT |
652 | } |
653 | EXPORT_SYMBOL(cl_vmpage_page); | |
654 | ||
655 | /** | |
656 | * Returns the top-page for a given page. | |
657 | * | |
658 | * \see cl_object_top(), cl_io_top() | |
659 | */ | |
660 | struct cl_page *cl_page_top(struct cl_page *page) | |
661 | { | |
662 | return cl_page_top_trusted(page); | |
663 | } | |
664 | EXPORT_SYMBOL(cl_page_top); | |
665 | ||
666 | const struct cl_page_slice *cl_page_at(const struct cl_page *page, | |
667 | const struct lu_device_type *dtype) | |
668 | { | |
669 | return cl_page_at_trusted(page, dtype); | |
670 | } | |
671 | EXPORT_SYMBOL(cl_page_at); | |
672 | ||
673 | #define CL_PAGE_OP(opname) offsetof(struct cl_page_operations, opname) | |
674 | ||
675 | #define CL_PAGE_INVOKE(_env, _page, _op, _proto, ...) \ | |
676 | ({ \ | |
677 | const struct lu_env *__env = (_env); \ | |
678 | struct cl_page *__page = (_page); \ | |
679 | const struct cl_page_slice *__scan; \ | |
680 | int __result; \ | |
681 | ptrdiff_t __op = (_op); \ | |
682 | int (*__method)_proto; \ | |
683 | \ | |
684 | __result = 0; \ | |
685 | __page = cl_page_top(__page); \ | |
686 | do { \ | |
687 | list_for_each_entry(__scan, &__page->cp_layers, \ | |
688 | cpl_linkage) { \ | |
689 | __method = *(void **)((char *)__scan->cpl_ops + \ | |
690 | __op); \ | |
cce3c2da | 691 | if (__method) { \ |
d7e09d03 PT |
692 | __result = (*__method)(__env, __scan, \ |
693 | ## __VA_ARGS__); \ | |
694 | if (__result != 0) \ | |
695 | break; \ | |
696 | } \ | |
697 | } \ | |
698 | __page = __page->cp_child; \ | |
cce3c2da | 699 | } while (__page && __result == 0); \ |
d7e09d03 PT |
700 | if (__result > 0) \ |
701 | __result = 0; \ | |
702 | __result; \ | |
703 | }) | |
704 | ||
705 | #define CL_PAGE_INVOID(_env, _page, _op, _proto, ...) \ | |
706 | do { \ | |
707 | const struct lu_env *__env = (_env); \ | |
708 | struct cl_page *__page = (_page); \ | |
709 | const struct cl_page_slice *__scan; \ | |
710 | ptrdiff_t __op = (_op); \ | |
711 | void (*__method)_proto; \ | |
712 | \ | |
713 | __page = cl_page_top(__page); \ | |
714 | do { \ | |
715 | list_for_each_entry(__scan, &__page->cp_layers, \ | |
716 | cpl_linkage) { \ | |
717 | __method = *(void **)((char *)__scan->cpl_ops + \ | |
718 | __op); \ | |
cce3c2da | 719 | if (__method) \ |
d7e09d03 PT |
720 | (*__method)(__env, __scan, \ |
721 | ## __VA_ARGS__); \ | |
722 | } \ | |
723 | __page = __page->cp_child; \ | |
cce3c2da | 724 | } while (__page); \ |
d7e09d03 PT |
725 | } while (0) |
726 | ||
727 | #define CL_PAGE_INVOID_REVERSE(_env, _page, _op, _proto, ...) \ | |
728 | do { \ | |
729 | const struct lu_env *__env = (_env); \ | |
730 | struct cl_page *__page = (_page); \ | |
731 | const struct cl_page_slice *__scan; \ | |
732 | ptrdiff_t __op = (_op); \ | |
733 | void (*__method)_proto; \ | |
734 | \ | |
735 | /* get to the bottom page. */ \ | |
cce3c2da | 736 | while (__page->cp_child) \ |
d7e09d03 PT |
737 | __page = __page->cp_child; \ |
738 | do { \ | |
739 | list_for_each_entry_reverse(__scan, &__page->cp_layers, \ | |
740 | cpl_linkage) { \ | |
741 | __method = *(void **)((char *)__scan->cpl_ops + \ | |
742 | __op); \ | |
cce3c2da | 743 | if (__method) \ |
d7e09d03 PT |
744 | (*__method)(__env, __scan, \ |
745 | ## __VA_ARGS__); \ | |
746 | } \ | |
747 | __page = __page->cp_parent; \ | |
cce3c2da | 748 | } while (__page); \ |
d7e09d03 PT |
749 | } while (0) |
750 | ||
751 | static int cl_page_invoke(const struct lu_env *env, | |
752 | struct cl_io *io, struct cl_page *page, ptrdiff_t op) | |
753 | ||
754 | { | |
755 | PINVRNT(env, page, cl_object_same(page->cp_obj, io->ci_obj)); | |
0a3bdb00 | 756 | return CL_PAGE_INVOKE(env, page, op, |
d7e09d03 PT |
757 | (const struct lu_env *, |
758 | const struct cl_page_slice *, struct cl_io *), | |
0a3bdb00 | 759 | io); |
d7e09d03 PT |
760 | } |
761 | ||
762 | static void cl_page_invoid(const struct lu_env *env, | |
763 | struct cl_io *io, struct cl_page *page, ptrdiff_t op) | |
764 | ||
765 | { | |
766 | PINVRNT(env, page, cl_object_same(page->cp_obj, io->ci_obj)); | |
d7e09d03 PT |
767 | CL_PAGE_INVOID(env, page, op, |
768 | (const struct lu_env *, | |
769 | const struct cl_page_slice *, struct cl_io *), io); | |
d7e09d03 PT |
770 | } |
771 | ||
772 | static void cl_page_owner_clear(struct cl_page *page) | |
773 | { | |
cce3c2da OD |
774 | for (page = cl_page_top(page); page; page = page->cp_child) { |
775 | if (page->cp_owner) { | |
d7e09d03 PT |
776 | LASSERT(page->cp_owner->ci_owned_nr > 0); |
777 | page->cp_owner->ci_owned_nr--; | |
778 | page->cp_owner = NULL; | |
779 | page->cp_task = NULL; | |
780 | } | |
781 | } | |
d7e09d03 PT |
782 | } |
783 | ||
784 | static void cl_page_owner_set(struct cl_page *page) | |
785 | { | |
cce3c2da | 786 | for (page = cl_page_top(page); page; page = page->cp_child) |
d7e09d03 | 787 | page->cp_owner->ci_owned_nr++; |
d7e09d03 PT |
788 | } |
789 | ||
790 | void cl_page_disown0(const struct lu_env *env, | |
791 | struct cl_io *io, struct cl_page *pg) | |
792 | { | |
793 | enum cl_page_state state; | |
794 | ||
d7e09d03 PT |
795 | state = pg->cp_state; |
796 | PINVRNT(env, pg, state == CPS_OWNED || state == CPS_FREEING); | |
797 | PINVRNT(env, pg, cl_page_invariant(pg)); | |
798 | cl_page_owner_clear(pg); | |
799 | ||
800 | if (state == CPS_OWNED) | |
801 | cl_page_state_set(env, pg, CPS_CACHED); | |
802 | /* | |
803 | * Completion call-backs are executed in the bottom-up order, so that | |
804 | * uppermost layer (llite), responsible for VFS/VM interaction runs | |
805 | * last and can release locks safely. | |
806 | */ | |
807 | CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_disown), | |
808 | (const struct lu_env *, | |
809 | const struct cl_page_slice *, struct cl_io *), | |
810 | io); | |
d7e09d03 PT |
811 | } |
812 | ||
813 | /** | |
814 | * returns true, iff page is owned by the given io. | |
815 | */ | |
816 | int cl_page_is_owned(const struct cl_page *pg, const struct cl_io *io) | |
817 | { | |
818 | LINVRNT(cl_object_same(pg->cp_obj, io->ci_obj)); | |
0a3bdb00 | 819 | return pg->cp_state == CPS_OWNED && pg->cp_owner == io; |
d7e09d03 PT |
820 | } |
821 | EXPORT_SYMBOL(cl_page_is_owned); | |
822 | ||
823 | /** | |
824 | * Try to own a page by IO. | |
825 | * | |
826 | * Waits until page is in cl_page_state::CPS_CACHED state, and then switch it | |
827 | * into cl_page_state::CPS_OWNED state. | |
828 | * | |
829 | * \pre !cl_page_is_owned(pg, io) | |
830 | * \post result == 0 iff cl_page_is_owned(pg, io) | |
831 | * | |
832 | * \retval 0 success | |
833 | * | |
834 | * \retval -ve failure, e.g., page was destroyed (and landed in | |
835 | * cl_page_state::CPS_FREEING instead of cl_page_state::CPS_CACHED). | |
836 | * or, page was owned by another thread, or in IO. | |
837 | * | |
838 | * \see cl_page_disown() | |
839 | * \see cl_page_operations::cpo_own() | |
840 | * \see cl_page_own_try() | |
841 | * \see cl_page_own | |
842 | */ | |
843 | static int cl_page_own0(const struct lu_env *env, struct cl_io *io, | |
844 | struct cl_page *pg, int nonblock) | |
845 | { | |
846 | int result; | |
847 | ||
848 | PINVRNT(env, pg, !cl_page_is_owned(pg, io)); | |
849 | ||
d7e09d03 PT |
850 | pg = cl_page_top(pg); |
851 | io = cl_io_top(io); | |
852 | ||
853 | if (pg->cp_state == CPS_FREEING) { | |
854 | result = -ENOENT; | |
855 | } else { | |
856 | result = CL_PAGE_INVOKE(env, pg, CL_PAGE_OP(cpo_own), | |
857 | (const struct lu_env *, | |
858 | const struct cl_page_slice *, | |
859 | struct cl_io *, int), | |
860 | io, nonblock); | |
861 | if (result == 0) { | |
cce3c2da OD |
862 | PASSERT(env, pg, !pg->cp_owner); |
863 | PASSERT(env, pg, !pg->cp_req); | |
d7e09d03 PT |
864 | pg->cp_owner = io; |
865 | pg->cp_task = current; | |
866 | cl_page_owner_set(pg); | |
867 | if (pg->cp_state != CPS_FREEING) { | |
868 | cl_page_state_set(env, pg, CPS_OWNED); | |
869 | } else { | |
870 | cl_page_disown0(env, io, pg); | |
871 | result = -ENOENT; | |
872 | } | |
873 | } | |
874 | } | |
875 | PINVRNT(env, pg, ergo(result == 0, cl_page_invariant(pg))); | |
0a3bdb00 | 876 | return result; |
d7e09d03 PT |
877 | } |
878 | ||
879 | /** | |
880 | * Own a page, might be blocked. | |
881 | * | |
882 | * \see cl_page_own0() | |
883 | */ | |
884 | int cl_page_own(const struct lu_env *env, struct cl_io *io, struct cl_page *pg) | |
885 | { | |
886 | return cl_page_own0(env, io, pg, 0); | |
887 | } | |
888 | EXPORT_SYMBOL(cl_page_own); | |
889 | ||
890 | /** | |
891 | * Nonblock version of cl_page_own(). | |
892 | * | |
893 | * \see cl_page_own0() | |
894 | */ | |
895 | int cl_page_own_try(const struct lu_env *env, struct cl_io *io, | |
896 | struct cl_page *pg) | |
897 | { | |
898 | return cl_page_own0(env, io, pg, 1); | |
899 | } | |
900 | EXPORT_SYMBOL(cl_page_own_try); | |
901 | ||
d7e09d03 PT |
902 | /** |
903 | * Assume page ownership. | |
904 | * | |
905 | * Called when page is already locked by the hosting VM. | |
906 | * | |
907 | * \pre !cl_page_is_owned(pg, io) | |
908 | * \post cl_page_is_owned(pg, io) | |
909 | * | |
910 | * \see cl_page_operations::cpo_assume() | |
911 | */ | |
912 | void cl_page_assume(const struct lu_env *env, | |
913 | struct cl_io *io, struct cl_page *pg) | |
914 | { | |
915 | PINVRNT(env, pg, cl_object_same(pg->cp_obj, io->ci_obj)); | |
916 | ||
d7e09d03 PT |
917 | pg = cl_page_top(pg); |
918 | io = cl_io_top(io); | |
919 | ||
920 | cl_page_invoid(env, io, pg, CL_PAGE_OP(cpo_assume)); | |
cce3c2da | 921 | PASSERT(env, pg, !pg->cp_owner); |
d7e09d03 PT |
922 | pg->cp_owner = io; |
923 | pg->cp_task = current; | |
924 | cl_page_owner_set(pg); | |
925 | cl_page_state_set(env, pg, CPS_OWNED); | |
d7e09d03 PT |
926 | } |
927 | EXPORT_SYMBOL(cl_page_assume); | |
928 | ||
929 | /** | |
930 | * Releases page ownership without unlocking the page. | |
931 | * | |
932 | * Moves page into cl_page_state::CPS_CACHED without releasing a lock on the | |
933 | * underlying VM page (as VM is supposed to do this itself). | |
934 | * | |
935 | * \pre cl_page_is_owned(pg, io) | |
936 | * \post !cl_page_is_owned(pg, io) | |
937 | * | |
938 | * \see cl_page_assume() | |
939 | */ | |
940 | void cl_page_unassume(const struct lu_env *env, | |
941 | struct cl_io *io, struct cl_page *pg) | |
942 | { | |
943 | PINVRNT(env, pg, cl_page_is_owned(pg, io)); | |
944 | PINVRNT(env, pg, cl_page_invariant(pg)); | |
945 | ||
d7e09d03 PT |
946 | pg = cl_page_top(pg); |
947 | io = cl_io_top(io); | |
948 | cl_page_owner_clear(pg); | |
949 | cl_page_state_set(env, pg, CPS_CACHED); | |
950 | CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_unassume), | |
951 | (const struct lu_env *, | |
952 | const struct cl_page_slice *, struct cl_io *), | |
953 | io); | |
d7e09d03 PT |
954 | } |
955 | EXPORT_SYMBOL(cl_page_unassume); | |
956 | ||
957 | /** | |
958 | * Releases page ownership. | |
959 | * | |
960 | * Moves page into cl_page_state::CPS_CACHED. | |
961 | * | |
962 | * \pre cl_page_is_owned(pg, io) | |
963 | * \post !cl_page_is_owned(pg, io) | |
964 | * | |
965 | * \see cl_page_own() | |
966 | * \see cl_page_operations::cpo_disown() | |
967 | */ | |
968 | void cl_page_disown(const struct lu_env *env, | |
969 | struct cl_io *io, struct cl_page *pg) | |
970 | { | |
971 | PINVRNT(env, pg, cl_page_is_owned(pg, io)); | |
972 | ||
d7e09d03 PT |
973 | pg = cl_page_top(pg); |
974 | io = cl_io_top(io); | |
975 | cl_page_disown0(env, io, pg); | |
d7e09d03 PT |
976 | } |
977 | EXPORT_SYMBOL(cl_page_disown); | |
978 | ||
979 | /** | |
980 | * Called when page is to be removed from the object, e.g., as a result of | |
981 | * truncate. | |
982 | * | |
983 | * Calls cl_page_operations::cpo_discard() top-to-bottom. | |
984 | * | |
985 | * \pre cl_page_is_owned(pg, io) | |
986 | * | |
987 | * \see cl_page_operations::cpo_discard() | |
988 | */ | |
989 | void cl_page_discard(const struct lu_env *env, | |
990 | struct cl_io *io, struct cl_page *pg) | |
991 | { | |
992 | PINVRNT(env, pg, cl_page_is_owned(pg, io)); | |
993 | PINVRNT(env, pg, cl_page_invariant(pg)); | |
994 | ||
995 | cl_page_invoid(env, io, pg, CL_PAGE_OP(cpo_discard)); | |
996 | } | |
997 | EXPORT_SYMBOL(cl_page_discard); | |
998 | ||
999 | /** | |
1000 | * Version of cl_page_delete() that can be called for not fully constructed | |
1001 | * pages, e.g,. in a error handling cl_page_find()->cl_page_delete0() | |
1002 | * path. Doesn't check page invariant. | |
1003 | */ | |
1004 | static void cl_page_delete0(const struct lu_env *env, struct cl_page *pg, | |
1005 | int radix) | |
1006 | { | |
1007 | struct cl_page *tmp = pg; | |
d7e09d03 PT |
1008 | |
1009 | PASSERT(env, pg, pg == cl_page_top(pg)); | |
1010 | PASSERT(env, pg, pg->cp_state != CPS_FREEING); | |
1011 | ||
1012 | /* | |
1013 | * Severe all ways to obtain new pointers to @pg. | |
1014 | */ | |
1015 | cl_page_owner_clear(pg); | |
1016 | ||
1017 | /* | |
1018 | * unexport the page firstly before freeing it so that | |
1019 | * the page content is considered to be invalid. | |
1020 | * We have to do this because a CPS_FREEING cl_page may | |
1021 | * be NOT under the protection of a cl_lock. | |
1022 | * Afterwards, if this page is found by other threads, then this | |
1023 | * page will be forced to reread. | |
1024 | */ | |
1025 | cl_page_export(env, pg, 0); | |
1026 | cl_page_state_set0(env, pg, CPS_FREEING); | |
1027 | ||
1028 | CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_delete), | |
1029 | (const struct lu_env *, const struct cl_page_slice *)); | |
1030 | ||
1031 | if (tmp->cp_type == CPT_CACHEABLE) { | |
1032 | if (!radix) | |
1033 | /* !radix means that @pg is not yet in the radix tree, | |
1034 | * skip removing it. | |
1035 | */ | |
1036 | tmp = pg->cp_child; | |
cce3c2da | 1037 | for (; tmp; tmp = tmp->cp_child) { |
d7e09d03 PT |
1038 | void *value; |
1039 | struct cl_object_header *hdr; | |
1040 | ||
1041 | hdr = cl_object_header(tmp->cp_obj); | |
1042 | spin_lock(&hdr->coh_page_guard); | |
1043 | value = radix_tree_delete(&hdr->coh_tree, | |
1044 | tmp->cp_index); | |
1045 | PASSERT(env, tmp, value == tmp); | |
1046 | PASSERT(env, tmp, hdr->coh_pages > 0); | |
1047 | hdr->coh_pages--; | |
1048 | spin_unlock(&hdr->coh_page_guard); | |
1049 | cl_page_put(env, tmp); | |
1050 | } | |
1051 | } | |
d7e09d03 PT |
1052 | } |
1053 | ||
1054 | /** | |
1055 | * Called when a decision is made to throw page out of memory. | |
1056 | * | |
1057 | * Notifies all layers about page destruction by calling | |
1058 | * cl_page_operations::cpo_delete() method top-to-bottom. | |
1059 | * | |
1060 | * Moves page into cl_page_state::CPS_FREEING state (this is the only place | |
1061 | * where transition to this state happens). | |
1062 | * | |
1063 | * Eliminates all venues through which new references to the page can be | |
1064 | * obtained: | |
1065 | * | |
1066 | * - removes page from the radix trees, | |
1067 | * | |
1068 | * - breaks linkage from VM page to cl_page. | |
1069 | * | |
1070 | * Once page reaches cl_page_state::CPS_FREEING, all remaining references will | |
1071 | * drain after some time, at which point page will be recycled. | |
1072 | * | |
1073 | * \pre pg == cl_page_top(pg) | |
1074 | * \pre VM page is locked | |
1075 | * \post pg->cp_state == CPS_FREEING | |
1076 | * | |
1077 | * \see cl_page_operations::cpo_delete() | |
1078 | */ | |
1079 | void cl_page_delete(const struct lu_env *env, struct cl_page *pg) | |
1080 | { | |
1081 | PINVRNT(env, pg, cl_page_invariant(pg)); | |
d7e09d03 | 1082 | cl_page_delete0(env, pg, 1); |
d7e09d03 PT |
1083 | } |
1084 | EXPORT_SYMBOL(cl_page_delete); | |
1085 | ||
1086 | /** | |
1087 | * Unmaps page from user virtual memory. | |
1088 | * | |
1089 | * Calls cl_page_operations::cpo_unmap() through all layers top-to-bottom. The | |
1090 | * layer responsible for VM interaction has to unmap page from user space | |
1091 | * virtual memory. | |
1092 | * | |
1093 | * \see cl_page_operations::cpo_unmap() | |
1094 | */ | |
1095 | int cl_page_unmap(const struct lu_env *env, | |
1096 | struct cl_io *io, struct cl_page *pg) | |
1097 | { | |
1098 | PINVRNT(env, pg, cl_page_is_owned(pg, io)); | |
1099 | PINVRNT(env, pg, cl_page_invariant(pg)); | |
1100 | ||
1101 | return cl_page_invoke(env, io, pg, CL_PAGE_OP(cpo_unmap)); | |
1102 | } | |
1103 | EXPORT_SYMBOL(cl_page_unmap); | |
1104 | ||
1105 | /** | |
1106 | * Marks page up-to-date. | |
1107 | * | |
1108 | * Call cl_page_operations::cpo_export() through all layers top-to-bottom. The | |
1109 | * layer responsible for VM interaction has to mark/clear page as up-to-date | |
1110 | * by the \a uptodate argument. | |
1111 | * | |
1112 | * \see cl_page_operations::cpo_export() | |
1113 | */ | |
1114 | void cl_page_export(const struct lu_env *env, struct cl_page *pg, int uptodate) | |
1115 | { | |
1116 | PINVRNT(env, pg, cl_page_invariant(pg)); | |
1117 | CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_export), | |
1118 | (const struct lu_env *, | |
1119 | const struct cl_page_slice *, int), uptodate); | |
1120 | } | |
1121 | EXPORT_SYMBOL(cl_page_export); | |
1122 | ||
1123 | /** | |
1124 | * Returns true, iff \a pg is VM locked in a suitable sense by the calling | |
1125 | * thread. | |
1126 | */ | |
1127 | int cl_page_is_vmlocked(const struct lu_env *env, const struct cl_page *pg) | |
1128 | { | |
1129 | int result; | |
1130 | const struct cl_page_slice *slice; | |
1131 | ||
d7e09d03 PT |
1132 | pg = cl_page_top_trusted((struct cl_page *)pg); |
1133 | slice = container_of(pg->cp_layers.next, | |
1134 | const struct cl_page_slice, cpl_linkage); | |
cce3c2da | 1135 | PASSERT(env, pg, slice->cpl_ops->cpo_is_vmlocked); |
d7e09d03 PT |
1136 | /* |
1137 | * Call ->cpo_is_vmlocked() directly instead of going through | |
1138 | * CL_PAGE_INVOKE(), because cl_page_is_vmlocked() is used by | |
1139 | * cl_page_invariant(). | |
1140 | */ | |
1141 | result = slice->cpl_ops->cpo_is_vmlocked(env, slice); | |
1142 | PASSERT(env, pg, result == -EBUSY || result == -ENODATA); | |
0a3bdb00 | 1143 | return result == -EBUSY; |
d7e09d03 PT |
1144 | } |
1145 | EXPORT_SYMBOL(cl_page_is_vmlocked); | |
1146 | ||
1147 | static enum cl_page_state cl_req_type_state(enum cl_req_type crt) | |
1148 | { | |
0a3bdb00 | 1149 | return crt == CRT_WRITE ? CPS_PAGEOUT : CPS_PAGEIN; |
d7e09d03 PT |
1150 | } |
1151 | ||
1152 | static void cl_page_io_start(const struct lu_env *env, | |
1153 | struct cl_page *pg, enum cl_req_type crt) | |
1154 | { | |
1155 | /* | |
1156 | * Page is queued for IO, change its state. | |
1157 | */ | |
d7e09d03 PT |
1158 | cl_page_owner_clear(pg); |
1159 | cl_page_state_set(env, pg, cl_req_type_state(crt)); | |
d7e09d03 PT |
1160 | } |
1161 | ||
1162 | /** | |
1163 | * Prepares page for immediate transfer. cl_page_operations::cpo_prep() is | |
1164 | * called top-to-bottom. Every layer either agrees to submit this page (by | |
1165 | * returning 0), or requests to omit this page (by returning -EALREADY). Layer | |
1166 | * handling interactions with the VM also has to inform VM that page is under | |
1167 | * transfer now. | |
1168 | */ | |
1169 | int cl_page_prep(const struct lu_env *env, struct cl_io *io, | |
1170 | struct cl_page *pg, enum cl_req_type crt) | |
1171 | { | |
1172 | int result; | |
1173 | ||
1174 | PINVRNT(env, pg, cl_page_is_owned(pg, io)); | |
1175 | PINVRNT(env, pg, cl_page_invariant(pg)); | |
1176 | PINVRNT(env, pg, crt < CRT_NR); | |
1177 | ||
1178 | /* | |
1179 | * XXX this has to be called bottom-to-top, so that llite can set up | |
1180 | * PG_writeback without risking other layers deciding to skip this | |
1181 | * page. | |
1182 | */ | |
1183 | if (crt >= CRT_NR) | |
1184 | return -EINVAL; | |
1185 | result = cl_page_invoke(env, io, pg, CL_PAGE_OP(io[crt].cpo_prep)); | |
1186 | if (result == 0) | |
1187 | cl_page_io_start(env, pg, crt); | |
1188 | ||
d7e09d03 PT |
1189 | CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result); |
1190 | return result; | |
1191 | } | |
1192 | EXPORT_SYMBOL(cl_page_prep); | |
1193 | ||
1194 | /** | |
1195 | * Notify layers about transfer completion. | |
1196 | * | |
1197 | * Invoked by transfer sub-system (which is a part of osc) to notify layers | |
1198 | * that a transfer, of which this page is a part of has completed. | |
1199 | * | |
1200 | * Completion call-backs are executed in the bottom-up order, so that | |
1201 | * uppermost layer (llite), responsible for the VFS/VM interaction runs last | |
1202 | * and can release locks safely. | |
1203 | * | |
1204 | * \pre pg->cp_state == CPS_PAGEIN || pg->cp_state == CPS_PAGEOUT | |
1205 | * \post pg->cp_state == CPS_CACHED | |
1206 | * | |
1207 | * \see cl_page_operations::cpo_completion() | |
1208 | */ | |
1209 | void cl_page_completion(const struct lu_env *env, | |
1210 | struct cl_page *pg, enum cl_req_type crt, int ioret) | |
1211 | { | |
1212 | struct cl_sync_io *anchor = pg->cp_sync_io; | |
1213 | ||
1214 | PASSERT(env, pg, crt < CRT_NR); | |
1215 | /* cl_page::cp_req already cleared by the caller (osc_completion()) */ | |
cce3c2da | 1216 | PASSERT(env, pg, !pg->cp_req); |
d7e09d03 PT |
1217 | PASSERT(env, pg, pg->cp_state == cl_req_type_state(crt)); |
1218 | ||
d7e09d03 PT |
1219 | CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, ioret); |
1220 | if (crt == CRT_READ && ioret == 0) { | |
1221 | PASSERT(env, pg, !(pg->cp_flags & CPF_READ_COMPLETED)); | |
1222 | pg->cp_flags |= CPF_READ_COMPLETED; | |
1223 | } | |
1224 | ||
1225 | cl_page_state_set(env, pg, CPS_CACHED); | |
1226 | if (crt >= CRT_NR) | |
1227 | return; | |
1228 | CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(io[crt].cpo_completion), | |
1229 | (const struct lu_env *, | |
1230 | const struct cl_page_slice *, int), ioret); | |
1231 | if (anchor) { | |
1232 | LASSERT(cl_page_is_vmlocked(env, pg)); | |
1233 | LASSERT(pg->cp_sync_io == anchor); | |
1234 | pg->cp_sync_io = NULL; | |
1235 | } | |
1236 | /* | |
1237 | * As page->cp_obj is pinned by a reference from page->cp_req, it is | |
1238 | * safe to call cl_page_put() without risking object destruction in a | |
1239 | * non-blocking context. | |
1240 | */ | |
1241 | cl_page_put(env, pg); | |
1242 | ||
1243 | if (anchor) | |
1244 | cl_sync_io_note(anchor, ioret); | |
d7e09d03 PT |
1245 | } |
1246 | EXPORT_SYMBOL(cl_page_completion); | |
1247 | ||
1248 | /** | |
1249 | * Notify layers that transfer formation engine decided to yank this page from | |
1250 | * the cache and to make it a part of a transfer. | |
1251 | * | |
1252 | * \pre pg->cp_state == CPS_CACHED | |
1253 | * \post pg->cp_state == CPS_PAGEIN || pg->cp_state == CPS_PAGEOUT | |
1254 | * | |
1255 | * \see cl_page_operations::cpo_make_ready() | |
1256 | */ | |
1257 | int cl_page_make_ready(const struct lu_env *env, struct cl_page *pg, | |
1258 | enum cl_req_type crt) | |
1259 | { | |
1260 | int result; | |
1261 | ||
1262 | PINVRNT(env, pg, crt < CRT_NR); | |
1263 | ||
d7e09d03 | 1264 | if (crt >= CRT_NR) |
0a3bdb00 | 1265 | return -EINVAL; |
d7e09d03 PT |
1266 | result = CL_PAGE_INVOKE(env, pg, CL_PAGE_OP(io[crt].cpo_make_ready), |
1267 | (const struct lu_env *, | |
1268 | const struct cl_page_slice *)); | |
1269 | if (result == 0) { | |
1270 | PASSERT(env, pg, pg->cp_state == CPS_CACHED); | |
1271 | cl_page_io_start(env, pg, crt); | |
1272 | } | |
1273 | CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result); | |
0a3bdb00 | 1274 | return result; |
d7e09d03 PT |
1275 | } |
1276 | EXPORT_SYMBOL(cl_page_make_ready); | |
1277 | ||
1278 | /** | |
1279 | * Notify layers that high level io decided to place this page into a cache | |
1280 | * for future transfer. | |
1281 | * | |
1282 | * The layer implementing transfer engine (osc) has to register this page in | |
1283 | * its queues. | |
1284 | * | |
1285 | * \pre cl_page_is_owned(pg, io) | |
1286 | * \post cl_page_is_owned(pg, io) | |
1287 | * | |
1288 | * \see cl_page_operations::cpo_cache_add() | |
1289 | */ | |
1290 | int cl_page_cache_add(const struct lu_env *env, struct cl_io *io, | |
1291 | struct cl_page *pg, enum cl_req_type crt) | |
1292 | { | |
1293 | const struct cl_page_slice *scan; | |
1294 | int result = 0; | |
1295 | ||
1296 | PINVRNT(env, pg, crt < CRT_NR); | |
1297 | PINVRNT(env, pg, cl_page_is_owned(pg, io)); | |
1298 | PINVRNT(env, pg, cl_page_invariant(pg)); | |
1299 | ||
d7e09d03 | 1300 | if (crt >= CRT_NR) |
0a3bdb00 | 1301 | return -EINVAL; |
d7e09d03 PT |
1302 | |
1303 | list_for_each_entry(scan, &pg->cp_layers, cpl_linkage) { | |
cce3c2da | 1304 | if (!scan->cpl_ops->io[crt].cpo_cache_add) |
d7e09d03 PT |
1305 | continue; |
1306 | ||
1307 | result = scan->cpl_ops->io[crt].cpo_cache_add(env, scan, io); | |
1308 | if (result != 0) | |
1309 | break; | |
1310 | } | |
1311 | CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result); | |
0a3bdb00 | 1312 | return result; |
d7e09d03 PT |
1313 | } |
1314 | EXPORT_SYMBOL(cl_page_cache_add); | |
1315 | ||
1316 | /** | |
1317 | * Called if a pge is being written back by kernel's intention. | |
1318 | * | |
1319 | * \pre cl_page_is_owned(pg, io) | |
1320 | * \post ergo(result == 0, pg->cp_state == CPS_PAGEOUT) | |
1321 | * | |
1322 | * \see cl_page_operations::cpo_flush() | |
1323 | */ | |
1324 | int cl_page_flush(const struct lu_env *env, struct cl_io *io, | |
1325 | struct cl_page *pg) | |
1326 | { | |
1327 | int result; | |
1328 | ||
1329 | PINVRNT(env, pg, cl_page_is_owned(pg, io)); | |
1330 | PINVRNT(env, pg, cl_page_invariant(pg)); | |
1331 | ||
d7e09d03 PT |
1332 | result = cl_page_invoke(env, io, pg, CL_PAGE_OP(cpo_flush)); |
1333 | ||
1334 | CL_PAGE_HEADER(D_TRACE, env, pg, "%d\n", result); | |
0a3bdb00 | 1335 | return result; |
d7e09d03 PT |
1336 | } |
1337 | EXPORT_SYMBOL(cl_page_flush); | |
1338 | ||
1339 | /** | |
1340 | * Checks whether page is protected by any extent lock is at least required | |
1341 | * mode. | |
1342 | * | |
1343 | * \return the same as in cl_page_operations::cpo_is_under_lock() method. | |
1344 | * \see cl_page_operations::cpo_is_under_lock() | |
1345 | */ | |
1346 | int cl_page_is_under_lock(const struct lu_env *env, struct cl_io *io, | |
1347 | struct cl_page *page) | |
1348 | { | |
1349 | int rc; | |
1350 | ||
1351 | PINVRNT(env, page, cl_page_invariant(page)); | |
1352 | ||
d7e09d03 PT |
1353 | rc = CL_PAGE_INVOKE(env, page, CL_PAGE_OP(cpo_is_under_lock), |
1354 | (const struct lu_env *, | |
1355 | const struct cl_page_slice *, struct cl_io *), | |
1356 | io); | |
1357 | PASSERT(env, page, rc != 0); | |
0a3bdb00 | 1358 | return rc; |
d7e09d03 PT |
1359 | } |
1360 | EXPORT_SYMBOL(cl_page_is_under_lock); | |
1361 | ||
1362 | static int page_prune_cb(const struct lu_env *env, struct cl_io *io, | |
1363 | struct cl_page *page, void *cbdata) | |
1364 | { | |
1365 | cl_page_own(env, io, page); | |
1366 | cl_page_unmap(env, io, page); | |
1367 | cl_page_discard(env, io, page); | |
1368 | cl_page_disown(env, io, page); | |
1369 | return CLP_GANG_OKAY; | |
1370 | } | |
1371 | ||
1372 | /** | |
1373 | * Purges all cached pages belonging to the object \a obj. | |
1374 | */ | |
1375 | int cl_pages_prune(const struct lu_env *env, struct cl_object *clobj) | |
1376 | { | |
1377 | struct cl_thread_info *info; | |
1378 | struct cl_object *obj = cl_object_top(clobj); | |
1379 | struct cl_io *io; | |
1380 | int result; | |
1381 | ||
d7e09d03 PT |
1382 | info = cl_env_info(env); |
1383 | io = &info->clt_io; | |
1384 | ||
1385 | /* | |
1386 | * initialize the io. This is ugly since we never do IO in this | |
1387 | * function, we just make cl_page_list functions happy. -jay | |
1388 | */ | |
1389 | io->ci_obj = obj; | |
1390 | io->ci_ignore_layout = 1; | |
1391 | result = cl_io_init(env, io, CIT_MISC, obj); | |
1392 | if (result != 0) { | |
1393 | cl_io_fini(env, io); | |
0a3bdb00 | 1394 | return io->ci_result; |
d7e09d03 PT |
1395 | } |
1396 | ||
1397 | do { | |
1398 | result = cl_page_gang_lookup(env, obj, io, 0, CL_PAGE_EOF, | |
1399 | page_prune_cb, NULL); | |
1400 | if (result == CLP_GANG_RESCHED) | |
1401 | cond_resched(); | |
1402 | } while (result != CLP_GANG_OKAY); | |
1403 | ||
1404 | cl_io_fini(env, io); | |
0a3bdb00 | 1405 | return result; |
d7e09d03 PT |
1406 | } |
1407 | EXPORT_SYMBOL(cl_pages_prune); | |
1408 | ||
1409 | /** | |
1410 | * Tells transfer engine that only part of a page is to be transmitted. | |
1411 | * | |
1412 | * \see cl_page_operations::cpo_clip() | |
1413 | */ | |
1414 | void cl_page_clip(const struct lu_env *env, struct cl_page *pg, | |
1415 | int from, int to) | |
1416 | { | |
1417 | PINVRNT(env, pg, cl_page_invariant(pg)); | |
1418 | ||
1419 | CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", from, to); | |
1420 | CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_clip), | |
1421 | (const struct lu_env *, | |
574150f0 | 1422 | const struct cl_page_slice *, int, int), |
d7e09d03 PT |
1423 | from, to); |
1424 | } | |
1425 | EXPORT_SYMBOL(cl_page_clip); | |
1426 | ||
1427 | /** | |
1428 | * Prints human readable representation of \a pg to the \a f. | |
1429 | */ | |
1430 | void cl_page_header_print(const struct lu_env *env, void *cookie, | |
1431 | lu_printer_t printer, const struct cl_page *pg) | |
1432 | { | |
1433 | (*printer)(env, cookie, | |
1434 | "page@%p[%d %p:%lu ^%p_%p %d %d %d %p %p %#x]\n", | |
1435 | pg, atomic_read(&pg->cp_ref), pg->cp_obj, | |
1436 | pg->cp_index, pg->cp_parent, pg->cp_child, | |
1437 | pg->cp_state, pg->cp_error, pg->cp_type, | |
1438 | pg->cp_owner, pg->cp_req, pg->cp_flags); | |
1439 | } | |
1440 | EXPORT_SYMBOL(cl_page_header_print); | |
1441 | ||
1442 | /** | |
1443 | * Prints human readable representation of \a pg to the \a f. | |
1444 | */ | |
1445 | void cl_page_print(const struct lu_env *env, void *cookie, | |
1446 | lu_printer_t printer, const struct cl_page *pg) | |
1447 | { | |
1448 | struct cl_page *scan; | |
1449 | ||
cce3c2da OD |
1450 | for (scan = cl_page_top((struct cl_page *)pg); scan; |
1451 | scan = scan->cp_child) | |
d7e09d03 PT |
1452 | cl_page_header_print(env, cookie, printer, scan); |
1453 | CL_PAGE_INVOKE(env, (struct cl_page *)pg, CL_PAGE_OP(cpo_print), | |
1454 | (const struct lu_env *env, | |
1455 | const struct cl_page_slice *slice, | |
1456 | void *cookie, lu_printer_t p), cookie, printer); | |
1457 | (*printer)(env, cookie, "end page@%p\n", pg); | |
1458 | } | |
1459 | EXPORT_SYMBOL(cl_page_print); | |
1460 | ||
1461 | /** | |
1462 | * Cancel a page which is still in a transfer. | |
1463 | */ | |
1464 | int cl_page_cancel(const struct lu_env *env, struct cl_page *page) | |
1465 | { | |
1466 | return CL_PAGE_INVOKE(env, page, CL_PAGE_OP(cpo_cancel), | |
1467 | (const struct lu_env *, | |
1468 | const struct cl_page_slice *)); | |
1469 | } | |
1470 | EXPORT_SYMBOL(cl_page_cancel); | |
1471 | ||
1472 | /** | |
1473 | * Converts a byte offset within object \a obj into a page index. | |
1474 | */ | |
1475 | loff_t cl_offset(const struct cl_object *obj, pgoff_t idx) | |
1476 | { | |
1477 | /* | |
1478 | * XXX for now. | |
1479 | */ | |
09cbfeaf | 1480 | return (loff_t)idx << PAGE_SHIFT; |
d7e09d03 PT |
1481 | } |
1482 | EXPORT_SYMBOL(cl_offset); | |
1483 | ||
1484 | /** | |
1485 | * Converts a page index into a byte offset within object \a obj. | |
1486 | */ | |
1487 | pgoff_t cl_index(const struct cl_object *obj, loff_t offset) | |
1488 | { | |
1489 | /* | |
1490 | * XXX for now. | |
1491 | */ | |
09cbfeaf | 1492 | return offset >> PAGE_SHIFT; |
d7e09d03 PT |
1493 | } |
1494 | EXPORT_SYMBOL(cl_index); | |
1495 | ||
1496 | int cl_page_size(const struct cl_object *obj) | |
1497 | { | |
09cbfeaf | 1498 | return 1 << PAGE_SHIFT; |
d7e09d03 PT |
1499 | } |
1500 | EXPORT_SYMBOL(cl_page_size); | |
1501 | ||
1502 | /** | |
1503 | * Adds page slice to the compound page. | |
1504 | * | |
1505 | * This is called by cl_object_operations::coo_page_init() methods to add a | |
1506 | * per-layer state to the page. New state is added at the end of | |
1507 | * cl_page::cp_layers list, that is, it is at the bottom of the stack. | |
1508 | * | |
1509 | * \see cl_lock_slice_add(), cl_req_slice_add(), cl_io_slice_add() | |
1510 | */ | |
1511 | void cl_page_slice_add(struct cl_page *page, struct cl_page_slice *slice, | |
1512 | struct cl_object *obj, | |
1513 | const struct cl_page_operations *ops) | |
1514 | { | |
d7e09d03 PT |
1515 | list_add_tail(&slice->cpl_linkage, &page->cp_layers); |
1516 | slice->cpl_obj = obj; | |
1517 | slice->cpl_ops = ops; | |
1518 | slice->cpl_page = page; | |
d7e09d03 PT |
1519 | } |
1520 | EXPORT_SYMBOL(cl_page_slice_add); | |
1521 | ||
1522 | int cl_page_init(void) | |
1523 | { | |
1524 | return 0; | |
1525 | } | |
1526 | ||
1527 | void cl_page_fini(void) | |
1528 | { | |
1529 | } |