1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 only,
10 * as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License version 2 for more details (a copy is included
16 * in the LICENSE file that accompanied this code).
18 * You should have received a copy of the GNU General Public License
19 * version 2 along with this program; If not, see
20 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
29 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
30 * Use is subject to license terms.
32 * Copyright (c) 2011 Whamcloud, Inc.
36 * This file is part of Lustre, http://www.lustre.org/
37 * Lustre is a trademark of Sun Microsystems, Inc.
41 * Author: Nikita Danilov <nikita.danilov@sun.com>
44 #define DEBUG_SUBSYSTEM S_CLASS
46 # define EXPORT_SYMTAB
49 #include <libcfs/libcfs.h>
50 #include <obd_class.h>
51 #include <obd_support.h>
52 #include <libcfs/list.h>
54 #include <cl_object.h>
55 #include "cl_internal.h"
57 static void cl_page_delete0(const struct lu_env *env, struct cl_page *pg,
60 static cfs_mem_cache_t *cl_page_kmem = NULL;
62 static struct lu_kmem_descr cl_page_caches[] = {
64 .ckd_cache = &cl_page_kmem,
65 .ckd_name = "cl_page_kmem",
66 .ckd_size = sizeof (struct cl_page)
74 # define PASSERT(env, page, expr) \
76 if (unlikely(!(expr))) { \
77 CL_PAGE_DEBUG(D_ERROR, (env), (page), #expr "\n"); \
81 #else /* !LIBCFS_DEBUG */
82 # define PASSERT(env, page, exp) \
83 ((void)sizeof(env), (void)sizeof(page), (void)sizeof !!(exp))
84 #endif /* !LIBCFS_DEBUG */
86 #ifdef INVARIANT_CHECK
87 # define PINVRNT(env, page, expr) \
89 if (unlikely(!(expr))) { \
90 CL_PAGE_DEBUG(D_ERROR, (env), (page), #expr "\n"); \
94 #else /* !INVARIANT_CHECK */
95 # define PINVRNT(env, page, exp) \
96 ((void)sizeof(env), (void)sizeof(page), (void)sizeof !!(exp))
97 #endif /* !INVARIANT_CHECK */
100 * Internal version of cl_page_top, it should be called with page referenced,
101 * or coh_page_guard held.
103 static struct cl_page *cl_page_top_trusted(struct cl_page *page)
105 while (page->cp_parent != NULL)
106 page = page->cp_parent;
111 * Internal version of cl_page_get().
113 * This function can be used to obtain initial reference to previously
114 * unreferenced cached object. It can be called only if concurrent page
115 * reclamation is somehow prevented, e.g., by locking page radix-tree
116 * (cl_object_header::hdr->coh_page_guard), or by keeping a lock on a VM page,
117 * associated with \a page.
119 * Use with care! Not exported.
121 static void cl_page_get_trust(struct cl_page *page)
124 * Checkless version for trusted users.
126 if (cfs_atomic_inc_return(&page->cp_ref) == 1)
127 cfs_atomic_inc(&cl_object_site(page->cp_obj)->cs_pages.cs_busy);
131 * Returns a slice within a page, corresponding to the given layer in the
136 static const struct cl_page_slice *
137 cl_page_at_trusted(const struct cl_page *page,
138 const struct lu_device_type *dtype)
140 const struct cl_page_slice *slice;
142 #ifdef INVARIANT_CHECK
143 struct cl_object_header *ch = cl_object_header(page->cp_obj);
145 if (!cfs_atomic_read(&page->cp_ref))
146 LASSERT_SPIN_LOCKED(&ch->coh_page_guard);
150 page = cl_page_top_trusted((struct cl_page *)page);
152 cfs_list_for_each_entry(slice, &page->cp_layers, cpl_linkage) {
153 if (slice->cpl_obj->co_lu.lo_dev->ld_type == dtype)
156 page = page->cp_child;
157 } while (page != NULL);
162 * Returns a page with given index in the given object, or NULL if no page is
163 * found. Acquires a reference on \a page.
165 * Locking: called under cl_object_header::coh_page_guard spin-lock.
167 struct cl_page *cl_page_lookup(struct cl_object_header *hdr, pgoff_t index)
169 struct cl_page *page;
171 LASSERT_SPIN_LOCKED(&hdr->coh_page_guard);
173 page = radix_tree_lookup(&hdr->coh_tree, index);
175 cl_page_get_trust(page);
179 EXPORT_SYMBOL(cl_page_lookup);
182 * Returns a list of pages by a given [start, end] of \a obj.
184 * \param resched If not NULL, then we give up before hogging CPU for too
185 * long and set *resched = 1, in that case caller should implement a retry
188 * Gang tree lookup (radix_tree_gang_lookup()) optimization is absolutely
189 * crucial in the face of [offset, EOF] locks.
191 * Return at least one page in @queue unless there is no covered page.
193 int cl_page_gang_lookup(const struct lu_env *env, struct cl_object *obj,
194 struct cl_io *io, pgoff_t start, pgoff_t end,
195 cl_page_gang_cb_t cb, void *cbdata)
197 struct cl_object_header *hdr;
198 struct cl_page *page;
199 struct cl_page **pvec;
200 const struct cl_page_slice *slice;
201 const struct lu_device_type *dtype;
206 int res = CLP_GANG_OKAY;
211 hdr = cl_object_header(obj);
212 pvec = cl_env_info(env)->clt_pvec;
213 dtype = cl_object_top(obj)->co_lu.lo_dev->ld_type;
214 cfs_spin_lock(&hdr->coh_page_guard);
215 while ((nr = radix_tree_gang_lookup(&hdr->coh_tree, (void **)pvec,
216 idx, CLT_PVEC_SIZE)) > 0) {
217 int end_of_region = 0;
218 idx = pvec[nr - 1]->cp_index + 1;
219 for (i = 0, j = 0; i < nr; ++i) {
223 LASSERT(page->cp_type == CPT_CACHEABLE);
224 if (page->cp_index > end) {
228 if (page->cp_state == CPS_FREEING)
231 slice = cl_page_at_trusted(page, dtype);
233 * Pages for lsm-less file has no underneath sub-page
234 * for osc, in case of ...
236 PASSERT(env, page, slice != NULL);
238 page = slice->cpl_page;
240 * Can safely call cl_page_get_trust() under
241 * radix-tree spin-lock.
243 * XXX not true, because @page is from object another
244 * than @hdr and protected by different tree lock.
246 cl_page_get_trust(page);
247 lu_ref_add_atomic(&page->cp_reference,
248 "gang_lookup", cfs_current());
253 * Here a delicate locking dance is performed. Current thread
254 * holds a reference to a page, but has to own it before it
255 * can be placed into queue. Owning implies waiting, so
256 * radix-tree lock is to be released. After a wait one has to
257 * check that pages weren't truncated (cl_page_own() returns
258 * error in the latter case).
260 cfs_spin_unlock(&hdr->coh_page_guard);
263 for (i = 0; i < j; ++i) {
265 if (res == CLP_GANG_OKAY)
266 res = (*cb)(env, io, page, cbdata);
267 lu_ref_del(&page->cp_reference,
268 "gang_lookup", cfs_current());
269 cl_page_put(env, page);
271 if (nr < CLT_PVEC_SIZE || end_of_region)
274 if (res == CLP_GANG_OKAY && cfs_need_resched())
275 res = CLP_GANG_RESCHED;
276 if (res != CLP_GANG_OKAY)
279 cfs_spin_lock(&hdr->coh_page_guard);
283 cfs_spin_unlock(&hdr->coh_page_guard);
286 EXPORT_SYMBOL(cl_page_gang_lookup);
288 static void cl_page_free(const struct lu_env *env, struct cl_page *page)
290 struct cl_object *obj = page->cp_obj;
291 struct cl_site *site = cl_object_site(obj);
293 PASSERT(env, page, cfs_list_empty(&page->cp_batch));
294 PASSERT(env, page, page->cp_owner == NULL);
295 PASSERT(env, page, page->cp_req == NULL);
296 PASSERT(env, page, page->cp_parent == NULL);
297 PASSERT(env, page, page->cp_state == CPS_FREEING);
301 while (!cfs_list_empty(&page->cp_layers)) {
302 struct cl_page_slice *slice;
304 slice = cfs_list_entry(page->cp_layers.next,
305 struct cl_page_slice, cpl_linkage);
306 cfs_list_del_init(page->cp_layers.next);
307 slice->cpl_ops->cpo_fini(env, slice);
309 cfs_atomic_dec(&site->cs_pages.cs_total);
311 #ifdef LUSTRE_PAGESTATE_TRACKING
312 cfs_atomic_dec(&site->cs_pages_state[page->cp_state]);
314 lu_object_ref_del_at(&obj->co_lu, page->cp_obj_ref, "cl_page", page);
315 cl_object_put(env, obj);
316 lu_ref_fini(&page->cp_reference);
317 OBD_SLAB_FREE_PTR(page, cl_page_kmem);
322 * Helper function updating page state. This is the only place in the code
323 * where cl_page::cp_state field is mutated.
325 static inline void cl_page_state_set_trust(struct cl_page *page,
326 enum cl_page_state state)
329 *(enum cl_page_state *)&page->cp_state = state;
332 static int cl_page_alloc(const struct lu_env *env, struct cl_object *o,
333 pgoff_t ind, struct page *vmpage,
334 enum cl_page_type type, struct cl_page **out)
336 struct cl_page *page;
337 struct cl_page *err = NULL;
338 struct lu_object_header *head;
339 struct cl_site *site = cl_object_site(o);
344 OBD_SLAB_ALLOC_PTR_GFP(page, cl_page_kmem, CFS_ALLOC_IO);
346 cfs_atomic_set(&page->cp_ref, 1);
349 page->cp_obj_ref = lu_object_ref_add(&o->co_lu,
351 page->cp_index = ind;
352 cl_page_state_set_trust(page, CPS_CACHED);
353 page->cp_type = type;
354 CFS_INIT_LIST_HEAD(&page->cp_layers);
355 CFS_INIT_LIST_HEAD(&page->cp_batch);
356 CFS_INIT_LIST_HEAD(&page->cp_flight);
357 cfs_mutex_init(&page->cp_mutex);
358 lu_ref_init(&page->cp_reference);
359 head = o->co_lu.lo_header;
360 cfs_list_for_each_entry(o, &head->loh_layers,
362 if (o->co_ops->coo_page_init != NULL) {
363 err = o->co_ops->coo_page_init(env, o,
366 cl_page_delete0(env, page, 0);
367 cl_page_free(env, page);
374 cfs_atomic_inc(&site->cs_pages.cs_busy);
375 cfs_atomic_inc(&site->cs_pages.cs_total);
377 #ifdef LUSTRE_PAGESTATE_TRACKING
378 cfs_atomic_inc(&site->cs_pages_state[CPS_CACHED]);
380 cfs_atomic_inc(&site->cs_pages.cs_created);
384 page = ERR_PTR(-ENOMEM);
390 * Returns a cl_page with index \a idx at the object \a o, and associated with
391 * the VM page \a vmpage.
393 * This is the main entry point into the cl_page caching interface. First, a
394 * cache (implemented as a per-object radix tree) is consulted. If page is
395 * found there, it is returned immediately. Otherwise new page is allocated
396 * and returned. In any case, additional reference to page is acquired.
398 * \see cl_object_find(), cl_lock_find()
400 static struct cl_page *cl_page_find0(const struct lu_env *env,
402 pgoff_t idx, struct page *vmpage,
403 enum cl_page_type type,
404 struct cl_page *parent)
406 struct cl_page *page = NULL;
407 struct cl_page *ghost = NULL;
408 struct cl_object_header *hdr;
409 struct cl_site *site = cl_object_site(o);
412 LASSERT(type == CPT_CACHEABLE || type == CPT_TRANSIENT);
417 hdr = cl_object_header(o);
418 cfs_atomic_inc(&site->cs_pages.cs_lookup);
420 CDEBUG(D_PAGE, "%lu@"DFID" %p %lx %d\n",
421 idx, PFID(&hdr->coh_lu.loh_fid), vmpage, vmpage->private, type);
423 if (type == CPT_CACHEABLE) {
425 * cl_vmpage_page() can be called here without any locks as
427 * - "vmpage" is locked (which prevents ->private from
428 * concurrent updates), and
430 * - "o" cannot be destroyed while current thread holds a
433 page = cl_vmpage_page(vmpage, o);
436 cl_page_vmpage(env, page) == vmpage &&
437 (void *)radix_tree_lookup(&hdr->coh_tree,
442 cfs_atomic_inc(&site->cs_pages.cs_hit);
446 /* allocate and initialize cl_page */
447 err = cl_page_alloc(env, o, idx, vmpage, type, &page);
451 if (type == CPT_TRANSIENT) {
453 LASSERT(page->cp_parent == NULL);
454 page->cp_parent = parent;
455 parent->cp_child = page;
461 * XXX optimization: use radix_tree_preload() here, and change tree
462 * gfp mask to GFP_KERNEL in cl_object_header_init().
464 cfs_spin_lock(&hdr->coh_page_guard);
465 err = radix_tree_insert(&hdr->coh_tree, idx, page);
469 * Noted by Jay: a lock on \a vmpage protects cl_page_find()
470 * from this race, but
472 * 0. it's better to have cl_page interface "locally
473 * consistent" so that its correctness can be reasoned
474 * about without appealing to the (obscure world of) VM
477 * 1. handling this race allows ->coh_tree to remain
478 * consistent even when VM locking is somehow busted,
479 * which is very useful during diagnosing and debugging.
482 CL_PAGE_DEBUG(D_ERROR, env, ghost,
483 "fail to insert into radix tree: %d\n", err);
486 LASSERT(page->cp_parent == NULL);
487 page->cp_parent = parent;
488 parent->cp_child = page;
492 cfs_spin_unlock(&hdr->coh_page_guard);
494 if (unlikely(ghost != NULL)) {
495 cfs_atomic_dec(&site->cs_pages.cs_busy);
496 cl_page_delete0(env, ghost, 0);
497 cl_page_free(env, ghost);
502 struct cl_page *cl_page_find(const struct lu_env *env, struct cl_object *o,
503 pgoff_t idx, struct page *vmpage,
504 enum cl_page_type type)
506 return cl_page_find0(env, o, idx, vmpage, type, NULL);
508 EXPORT_SYMBOL(cl_page_find);
511 struct cl_page *cl_page_find_sub(const struct lu_env *env, struct cl_object *o,
512 pgoff_t idx, struct page *vmpage,
513 struct cl_page *parent)
515 return cl_page_find0(env, o, idx, vmpage, parent->cp_type, parent);
517 EXPORT_SYMBOL(cl_page_find_sub);
519 static inline int cl_page_invariant(const struct cl_page *pg)
521 struct cl_object_header *header;
522 struct cl_page *parent;
523 struct cl_page *child;
527 * Page invariant is protected by a VM lock.
529 LINVRNT(cl_page_is_vmlocked(NULL, pg));
531 header = cl_object_header(pg->cp_obj);
532 parent = pg->cp_parent;
533 child = pg->cp_child;
534 owner = pg->cp_owner;
536 return cfs_atomic_read(&pg->cp_ref) > 0 &&
537 ergo(parent != NULL, parent->cp_child == pg) &&
538 ergo(child != NULL, child->cp_parent == pg) &&
539 ergo(child != NULL, pg->cp_obj != child->cp_obj) &&
540 ergo(parent != NULL, pg->cp_obj != parent->cp_obj) &&
541 ergo(owner != NULL && parent != NULL,
542 parent->cp_owner == pg->cp_owner->ci_parent) &&
543 ergo(owner != NULL && child != NULL,
544 child->cp_owner->ci_parent == owner) &&
546 * Either page is early in initialization (has neither child
547 * nor parent yet), or it is in the object radix tree.
549 ergo(pg->cp_state < CPS_FREEING && pg->cp_type == CPT_CACHEABLE,
550 (void *)radix_tree_lookup(&header->coh_tree,
551 pg->cp_index) == pg ||
552 (child == NULL && parent == NULL));
555 static void cl_page_state_set0(const struct lu_env *env,
556 struct cl_page *page, enum cl_page_state state)
558 enum cl_page_state old;
559 #ifdef LUSTRE_PAGESTATE_TRACKING
560 struct cl_site *site = cl_object_site(page->cp_obj);
564 * Matrix of allowed state transitions [old][new], for sanity
567 static const int allowed_transitions[CPS_NR][CPS_NR] = {
570 [CPS_OWNED] = 1, /* io finds existing cached page */
572 [CPS_PAGEOUT] = 1, /* write-out from the cache */
573 [CPS_FREEING] = 1, /* eviction on the memory pressure */
576 [CPS_CACHED] = 1, /* release to the cache */
578 [CPS_PAGEIN] = 1, /* start read immediately */
579 [CPS_PAGEOUT] = 1, /* start write immediately */
580 [CPS_FREEING] = 1, /* lock invalidation or truncate */
583 [CPS_CACHED] = 1, /* io completion */
590 [CPS_CACHED] = 1, /* io completion */
606 old = page->cp_state;
607 PASSERT(env, page, allowed_transitions[old][state]);
608 CL_PAGE_HEADER(D_TRACE, env, page, "%d -> %d\n", old, state);
609 for (; page != NULL; page = page->cp_child) {
610 PASSERT(env, page, page->cp_state == old);
612 equi(state == CPS_OWNED, page->cp_owner != NULL));
614 #ifdef LUSTRE_PAGESTATE_TRACKING
615 cfs_atomic_dec(&site->cs_pages_state[page->cp_state]);
616 cfs_atomic_inc(&site->cs_pages_state[state]);
618 cl_page_state_set_trust(page, state);
623 static void cl_page_state_set(const struct lu_env *env,
624 struct cl_page *page, enum cl_page_state state)
626 cl_page_state_set0(env, page, state);
630 * Acquires an additional reference to a page.
632 * This can be called only by caller already possessing a reference to \a
635 * \see cl_object_get(), cl_lock_get().
637 void cl_page_get(struct cl_page *page)
640 LASSERT(page->cp_state != CPS_FREEING);
641 cl_page_get_trust(page);
644 EXPORT_SYMBOL(cl_page_get);
647 * Releases a reference to a page.
649 * When last reference is released, page is returned to the cache, unless it
650 * is in cl_page_state::CPS_FREEING state, in which case it is immediately
653 * \see cl_object_put(), cl_lock_put().
655 void cl_page_put(const struct lu_env *env, struct cl_page *page)
657 struct cl_object_header *hdr;
658 struct cl_site *site = cl_object_site(page->cp_obj);
660 PASSERT(env, page, cfs_atomic_read(&page->cp_ref) > !!page->cp_parent);
663 CL_PAGE_HEADER(D_TRACE, env, page, "%d\n",
664 cfs_atomic_read(&page->cp_ref));
666 hdr = cl_object_header(cl_object_top(page->cp_obj));
667 if (cfs_atomic_dec_and_lock(&page->cp_ref, &hdr->coh_page_guard)) {
668 cfs_atomic_dec(&site->cs_pages.cs_busy);
669 /* We're going to access the page w/o a reference, but it's
670 * ok because we have grabbed the lock coh_page_guard, which
671 * means nobody is able to free this page behind us.
673 if (page->cp_state == CPS_FREEING) {
674 /* We drop the page reference and check the page state
675 * inside the coh_page_guard. So that if it gets here,
676 * it is the REALLY last reference to this page.
678 cfs_spin_unlock(&hdr->coh_page_guard);
680 LASSERT(cfs_atomic_read(&page->cp_ref) == 0);
681 PASSERT(env, page, page->cp_owner == NULL);
682 PASSERT(env, page, cfs_list_empty(&page->cp_batch));
684 * Page is no longer reachable by other threads. Tear
687 cl_page_free(env, page);
692 cfs_spin_unlock(&hdr->coh_page_guard);
697 EXPORT_SYMBOL(cl_page_put);
700 * Returns a VM page associated with a given cl_page.
702 cfs_page_t *cl_page_vmpage(const struct lu_env *env, struct cl_page *page)
704 const struct cl_page_slice *slice;
707 * Find uppermost layer with ->cpo_vmpage() method, and return its
710 page = cl_page_top(page);
712 cfs_list_for_each_entry(slice, &page->cp_layers, cpl_linkage) {
713 if (slice->cpl_ops->cpo_vmpage != NULL)
714 RETURN(slice->cpl_ops->cpo_vmpage(env, slice));
716 page = page->cp_child;
717 } while (page != NULL);
718 LBUG(); /* ->cpo_vmpage() has to be defined somewhere in the stack */
720 EXPORT_SYMBOL(cl_page_vmpage);
723 * Returns a cl_page associated with a VM page, and given cl_object.
725 struct cl_page *cl_vmpage_page(cfs_page_t *vmpage, struct cl_object *obj)
727 struct cl_page *page;
728 struct cl_object_header *hdr;
731 KLASSERT(PageLocked(vmpage));
734 * NOTE: absence of races and liveness of data are guaranteed by page
735 * lock on a "vmpage". That works because object destruction has
736 * bottom-to-top pass.
740 * This loop assumes that ->private points to the top-most page. This
741 * can be rectified easily.
743 hdr = cl_object_header(cl_object_top(obj));
744 cfs_spin_lock(&hdr->coh_page_guard);
745 for (page = (void *)vmpage->private;
746 page != NULL; page = page->cp_child) {
747 if (cl_object_same(page->cp_obj, obj)) {
748 cl_page_get_trust(page);
752 cfs_spin_unlock(&hdr->coh_page_guard);
753 LASSERT(ergo(page, page->cp_type == CPT_CACHEABLE));
756 EXPORT_SYMBOL(cl_vmpage_page);
759 * Returns the top-page for a given page.
761 * \see cl_object_top(), cl_io_top()
763 struct cl_page *cl_page_top(struct cl_page *page)
765 return cl_page_top_trusted(page);
767 EXPORT_SYMBOL(cl_page_top);
769 const struct cl_page_slice *cl_page_at(const struct cl_page *page,
770 const struct lu_device_type *dtype)
772 return cl_page_at_trusted(page, dtype);
774 EXPORT_SYMBOL(cl_page_at);
776 #define CL_PAGE_OP(opname) offsetof(struct cl_page_operations, opname)
778 #define CL_PAGE_INVOKE(_env, _page, _op, _proto, ...) \
780 const struct lu_env *__env = (_env); \
781 struct cl_page *__page = (_page); \
782 const struct cl_page_slice *__scan; \
784 ptrdiff_t __op = (_op); \
785 int (*__method)_proto; \
788 __page = cl_page_top(__page); \
790 cfs_list_for_each_entry(__scan, &__page->cp_layers, \
792 __method = *(void **)((char *)__scan->cpl_ops + \
794 if (__method != NULL) { \
795 __result = (*__method)(__env, __scan, \
801 __page = __page->cp_child; \
802 } while (__page != NULL && __result == 0); \
808 #define CL_PAGE_INVOID(_env, _page, _op, _proto, ...) \
810 const struct lu_env *__env = (_env); \
811 struct cl_page *__page = (_page); \
812 const struct cl_page_slice *__scan; \
813 ptrdiff_t __op = (_op); \
814 void (*__method)_proto; \
816 __page = cl_page_top(__page); \
818 cfs_list_for_each_entry(__scan, &__page->cp_layers, \
820 __method = *(void **)((char *)__scan->cpl_ops + \
822 if (__method != NULL) \
823 (*__method)(__env, __scan, \
826 __page = __page->cp_child; \
827 } while (__page != NULL); \
830 #define CL_PAGE_INVOID_REVERSE(_env, _page, _op, _proto, ...) \
832 const struct lu_env *__env = (_env); \
833 struct cl_page *__page = (_page); \
834 const struct cl_page_slice *__scan; \
835 ptrdiff_t __op = (_op); \
836 void (*__method)_proto; \
838 /* get to the bottom page. */ \
839 while (__page->cp_child != NULL) \
840 __page = __page->cp_child; \
842 cfs_list_for_each_entry_reverse(__scan, &__page->cp_layers, \
844 __method = *(void **)((char *)__scan->cpl_ops + \
846 if (__method != NULL) \
847 (*__method)(__env, __scan, \
850 __page = __page->cp_parent; \
851 } while (__page != NULL); \
854 static int cl_page_invoke(const struct lu_env *env,
855 struct cl_io *io, struct cl_page *page, ptrdiff_t op)
858 PINVRNT(env, page, cl_object_same(page->cp_obj, io->ci_obj));
860 RETURN(CL_PAGE_INVOKE(env, page, op,
861 (const struct lu_env *,
862 const struct cl_page_slice *, struct cl_io *),
866 static void cl_page_invoid(const struct lu_env *env,
867 struct cl_io *io, struct cl_page *page, ptrdiff_t op)
870 PINVRNT(env, page, cl_object_same(page->cp_obj, io->ci_obj));
872 CL_PAGE_INVOID(env, page, op,
873 (const struct lu_env *,
874 const struct cl_page_slice *, struct cl_io *), io);
878 static void cl_page_owner_clear(struct cl_page *page)
881 for (page = cl_page_top(page); page != NULL; page = page->cp_child) {
882 if (page->cp_owner != NULL) {
883 LASSERT(page->cp_owner->ci_owned_nr > 0);
884 page->cp_owner->ci_owned_nr--;
885 page->cp_owner = NULL;
886 page->cp_task = NULL;
892 static void cl_page_owner_set(struct cl_page *page)
895 for (page = cl_page_top(page); page != NULL; page = page->cp_child) {
896 LASSERT(page->cp_owner != NULL);
897 page->cp_owner->ci_owned_nr++;
902 void cl_page_disown0(const struct lu_env *env,
903 struct cl_io *io, struct cl_page *pg)
905 enum cl_page_state state;
908 state = pg->cp_state;
909 PINVRNT(env, pg, state == CPS_OWNED || state == CPS_FREEING);
910 PINVRNT(env, pg, cl_page_invariant(pg));
911 cl_page_owner_clear(pg);
913 if (state == CPS_OWNED)
914 cl_page_state_set(env, pg, CPS_CACHED);
916 * Completion call-backs are executed in the bottom-up order, so that
917 * uppermost layer (llite), responsible for VFS/VM interaction runs
918 * last and can release locks safely.
920 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_disown),
921 (const struct lu_env *,
922 const struct cl_page_slice *, struct cl_io *),
928 * returns true, iff page is owned by the given io.
930 int cl_page_is_owned(const struct cl_page *pg, const struct cl_io *io)
932 LINVRNT(cl_object_same(pg->cp_obj, io->ci_obj));
934 RETURN(pg->cp_state == CPS_OWNED && pg->cp_owner == io);
936 EXPORT_SYMBOL(cl_page_is_owned);
939 * Try to own a page by IO.
941 * Waits until page is in cl_page_state::CPS_CACHED state, and then switch it
942 * into cl_page_state::CPS_OWNED state.
944 * \pre !cl_page_is_owned(pg, io)
945 * \post result == 0 iff cl_page_is_owned(pg, io)
949 * \retval -ve failure, e.g., page was destroyed (and landed in
950 * cl_page_state::CPS_FREEING instead of cl_page_state::CPS_CACHED).
951 * or, page was owned by another thread, or in IO.
953 * \see cl_page_disown()
954 * \see cl_page_operations::cpo_own()
955 * \see cl_page_own_try()
958 static int cl_page_own0(const struct lu_env *env, struct cl_io *io,
959 struct cl_page *pg, int nonblock)
963 PINVRNT(env, pg, !cl_page_is_owned(pg, io));
966 pg = cl_page_top(pg);
969 if (pg->cp_state == CPS_FREEING) {
972 result = CL_PAGE_INVOKE(env, pg, CL_PAGE_OP(cpo_own),
973 (const struct lu_env *,
974 const struct cl_page_slice *,
975 struct cl_io *, int),
978 PASSERT(env, pg, pg->cp_owner == NULL);
979 PASSERT(env, pg, pg->cp_req == NULL);
981 pg->cp_task = current;
982 cl_page_owner_set(pg);
983 if (pg->cp_state != CPS_FREEING) {
984 cl_page_state_set(env, pg, CPS_OWNED);
986 cl_page_disown0(env, io, pg);
991 PINVRNT(env, pg, ergo(result == 0, cl_page_invariant(pg)));
996 * Own a page, might be blocked.
998 * \see cl_page_own0()
1000 int cl_page_own(const struct lu_env *env, struct cl_io *io, struct cl_page *pg)
1002 return cl_page_own0(env, io, pg, 0);
1004 EXPORT_SYMBOL(cl_page_own);
1007 * Nonblock version of cl_page_own().
1009 * \see cl_page_own0()
1011 int cl_page_own_try(const struct lu_env *env, struct cl_io *io,
1014 return cl_page_own0(env, io, pg, 1);
1016 EXPORT_SYMBOL(cl_page_own_try);
1020 * Assume page ownership.
1022 * Called when page is already locked by the hosting VM.
1024 * \pre !cl_page_is_owned(pg, io)
1025 * \post cl_page_is_owned(pg, io)
1027 * \see cl_page_operations::cpo_assume()
1029 void cl_page_assume(const struct lu_env *env,
1030 struct cl_io *io, struct cl_page *pg)
1032 PASSERT(env, pg, pg->cp_owner == NULL);
1033 PINVRNT(env, pg, cl_object_same(pg->cp_obj, io->ci_obj));
1034 PINVRNT(env, pg, cl_page_invariant(pg));
1037 pg = cl_page_top(pg);
1040 cl_page_invoid(env, io, pg, CL_PAGE_OP(cpo_assume));
1042 pg->cp_task = current;
1043 cl_page_owner_set(pg);
1044 cl_page_state_set(env, pg, CPS_OWNED);
1047 EXPORT_SYMBOL(cl_page_assume);
1050 * Releases page ownership without unlocking the page.
1052 * Moves page into cl_page_state::CPS_CACHED without releasing a lock on the
1053 * underlying VM page (as VM is supposed to do this itself).
1055 * \pre cl_page_is_owned(pg, io)
1056 * \post !cl_page_is_owned(pg, io)
1058 * \see cl_page_assume()
1060 void cl_page_unassume(const struct lu_env *env,
1061 struct cl_io *io, struct cl_page *pg)
1063 PINVRNT(env, pg, cl_page_is_owned(pg, io));
1064 PINVRNT(env, pg, cl_page_invariant(pg));
1067 pg = cl_page_top(pg);
1069 cl_page_owner_clear(pg);
1070 cl_page_state_set(env, pg, CPS_CACHED);
1071 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_unassume),
1072 (const struct lu_env *,
1073 const struct cl_page_slice *, struct cl_io *),
1077 EXPORT_SYMBOL(cl_page_unassume);
1080 * Releases page ownership.
1082 * Moves page into cl_page_state::CPS_CACHED.
1084 * \pre cl_page_is_owned(pg, io)
1085 * \post !cl_page_is_owned(pg, io)
1087 * \see cl_page_own()
1088 * \see cl_page_operations::cpo_disown()
1090 void cl_page_disown(const struct lu_env *env,
1091 struct cl_io *io, struct cl_page *pg)
1093 PINVRNT(env, pg, cl_page_is_owned(pg, io));
1096 pg = cl_page_top(pg);
1098 cl_page_disown0(env, io, pg);
1101 EXPORT_SYMBOL(cl_page_disown);
1104 * Called when page is to be removed from the object, e.g., as a result of
1107 * Calls cl_page_operations::cpo_discard() top-to-bottom.
1109 * \pre cl_page_is_owned(pg, io)
1111 * \see cl_page_operations::cpo_discard()
1113 void cl_page_discard(const struct lu_env *env,
1114 struct cl_io *io, struct cl_page *pg)
1116 PINVRNT(env, pg, cl_page_is_owned(pg, io));
1117 PINVRNT(env, pg, cl_page_invariant(pg));
1119 cl_page_invoid(env, io, pg, CL_PAGE_OP(cpo_discard));
1121 EXPORT_SYMBOL(cl_page_discard);
1124 * Version of cl_page_delete() that can be called for not fully constructed
1125 * pages, e.g,. in a error handling cl_page_find()->cl_page_delete0()
1126 * path. Doesn't check page invariant.
1128 static void cl_page_delete0(const struct lu_env *env, struct cl_page *pg,
1131 struct cl_page *tmp = pg;
1134 PASSERT(env, pg, pg == cl_page_top(pg));
1135 PASSERT(env, pg, pg->cp_state != CPS_FREEING);
1138 * Severe all ways to obtain new pointers to @pg.
1140 cl_page_owner_clear(pg);
1143 * unexport the page firstly before freeing it so that
1144 * the page content is considered to be invalid.
1145 * We have to do this because a CPS_FREEING cl_page may
1146 * be NOT under the protection of a cl_lock.
1147 * Afterwards, if this page is found by other threads, then this
1148 * page will be forced to reread.
1150 cl_page_export(env, pg, 0);
1151 cl_page_state_set0(env, pg, CPS_FREEING);
1153 if (tmp->cp_type == CPT_CACHEABLE) {
1155 /* !radix means that @pg is not yet in the radix tree,
1159 for (; tmp != NULL; tmp = tmp->cp_child) {
1161 struct cl_object_header *hdr;
1163 hdr = cl_object_header(tmp->cp_obj);
1164 cfs_spin_lock(&hdr->coh_page_guard);
1165 value = radix_tree_delete(&hdr->coh_tree,
1167 PASSERT(env, tmp, value == tmp);
1168 PASSERT(env, tmp, hdr->coh_pages > 0);
1170 cfs_spin_unlock(&hdr->coh_page_guard);
1174 CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_delete),
1175 (const struct lu_env *, const struct cl_page_slice *));
1180 * Called when a decision is made to throw page out of memory.
1182 * Notifies all layers about page destruction by calling
1183 * cl_page_operations::cpo_delete() method top-to-bottom.
1185 * Moves page into cl_page_state::CPS_FREEING state (this is the only place
1186 * where transition to this state happens).
1188 * Eliminates all venues through which new references to the page can be
1191 * - removes page from the radix trees,
1193 * - breaks linkage from VM page to cl_page.
1195 * Once page reaches cl_page_state::CPS_FREEING, all remaining references will
1196 * drain after some time, at which point page will be recycled.
1198 * \pre pg == cl_page_top(pg)
1199 * \pre VM page is locked
1200 * \post pg->cp_state == CPS_FREEING
1202 * \see cl_page_operations::cpo_delete()
1204 void cl_page_delete(const struct lu_env *env, struct cl_page *pg)
1206 PINVRNT(env, pg, cl_page_invariant(pg));
1208 cl_page_delete0(env, pg, 1);
1211 EXPORT_SYMBOL(cl_page_delete);
1214 * Unmaps page from user virtual memory.
1216 * Calls cl_page_operations::cpo_unmap() through all layers top-to-bottom. The
1217 * layer responsible for VM interaction has to unmap page from user space
1220 * \see cl_page_operations::cpo_unmap()
1222 int cl_page_unmap(const struct lu_env *env,
1223 struct cl_io *io, struct cl_page *pg)
1225 PINVRNT(env, pg, cl_page_is_owned(pg, io));
1226 PINVRNT(env, pg, cl_page_invariant(pg));
1228 return cl_page_invoke(env, io, pg, CL_PAGE_OP(cpo_unmap));
1230 EXPORT_SYMBOL(cl_page_unmap);
1233 * Marks page up-to-date.
1235 * Call cl_page_operations::cpo_export() through all layers top-to-bottom. The
1236 * layer responsible for VM interaction has to mark/clear page as up-to-date
1237 * by the \a uptodate argument.
1239 * \see cl_page_operations::cpo_export()
1241 void cl_page_export(const struct lu_env *env, struct cl_page *pg, int uptodate)
1243 PINVRNT(env, pg, cl_page_invariant(pg));
1244 CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_export),
1245 (const struct lu_env *,
1246 const struct cl_page_slice *, int), uptodate);
1248 EXPORT_SYMBOL(cl_page_export);
1251 * Returns true, iff \a pg is VM locked in a suitable sense by the calling
1254 int cl_page_is_vmlocked(const struct lu_env *env, const struct cl_page *pg)
1257 const struct cl_page_slice *slice;
1260 pg = cl_page_top_trusted((struct cl_page *)pg);
1261 slice = container_of(pg->cp_layers.next,
1262 const struct cl_page_slice, cpl_linkage);
1263 PASSERT(env, pg, slice->cpl_ops->cpo_is_vmlocked != NULL);
1265 * Call ->cpo_is_vmlocked() directly instead of going through
1266 * CL_PAGE_INVOKE(), because cl_page_is_vmlocked() is used by
1267 * cl_page_invariant().
1269 result = slice->cpl_ops->cpo_is_vmlocked(env, slice);
1270 PASSERT(env, pg, result == -EBUSY || result == -ENODATA);
1271 RETURN(result == -EBUSY);
1273 EXPORT_SYMBOL(cl_page_is_vmlocked);
1275 static enum cl_page_state cl_req_type_state(enum cl_req_type crt)
1278 RETURN(crt == CRT_WRITE ? CPS_PAGEOUT : CPS_PAGEIN);
1281 static void cl_page_io_start(const struct lu_env *env,
1282 struct cl_page *pg, enum cl_req_type crt)
1285 * Page is queued for IO, change its state.
1288 cl_page_owner_clear(pg);
1289 cl_page_state_set(env, pg, cl_req_type_state(crt));
1294 * Prepares page for immediate transfer. cl_page_operations::cpo_prep() is
1295 * called top-to-bottom. Every layer either agrees to submit this page (by
1296 * returning 0), or requests to omit this page (by returning -EALREADY). Layer
1297 * handling interactions with the VM also has to inform VM that page is under
1300 int cl_page_prep(const struct lu_env *env, struct cl_io *io,
1301 struct cl_page *pg, enum cl_req_type crt)
1305 PINVRNT(env, pg, cl_page_is_owned(pg, io));
1306 PINVRNT(env, pg, cl_page_invariant(pg));
1307 PINVRNT(env, pg, crt < CRT_NR);
1310 * XXX this has to be called bottom-to-top, so that llite can set up
1311 * PG_writeback without risking other layers deciding to skip this
1314 result = cl_page_invoke(env, io, pg, CL_PAGE_OP(io[crt].cpo_prep));
1316 cl_page_io_start(env, pg, crt);
1318 KLASSERT(ergo(crt == CRT_WRITE && pg->cp_type == CPT_CACHEABLE,
1320 PageWriteback(cl_page_vmpage(env, pg)))));
1321 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result);
1324 EXPORT_SYMBOL(cl_page_prep);
1327 * Notify layers about transfer completion.
1329 * Invoked by transfer sub-system (which is a part of osc) to notify layers
1330 * that a transfer, of which this page is a part of has completed.
1332 * Completion call-backs are executed in the bottom-up order, so that
1333 * uppermost layer (llite), responsible for the VFS/VM interaction runs last
1334 * and can release locks safely.
1336 * \pre pg->cp_state == CPS_PAGEIN || pg->cp_state == CPS_PAGEOUT
1337 * \post pg->cp_state == CPS_CACHED
1339 * \see cl_page_operations::cpo_completion()
1341 void cl_page_completion(const struct lu_env *env,
1342 struct cl_page *pg, enum cl_req_type crt, int ioret)
1344 struct cl_sync_io *anchor = pg->cp_sync_io;
1346 PASSERT(env, pg, crt < CRT_NR);
1347 /* cl_page::cp_req already cleared by the caller (osc_completion()) */
1348 PASSERT(env, pg, pg->cp_req == NULL);
1349 PASSERT(env, pg, pg->cp_state == cl_req_type_state(crt));
1352 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, ioret);
1353 if (crt == CRT_READ && ioret == 0) {
1354 PASSERT(env, pg, !(pg->cp_flags & CPF_READ_COMPLETED));
1355 pg->cp_flags |= CPF_READ_COMPLETED;
1358 cl_page_state_set(env, pg, CPS_CACHED);
1359 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(io[crt].cpo_completion),
1360 (const struct lu_env *,
1361 const struct cl_page_slice *, int), ioret);
1363 LASSERT(cl_page_is_vmlocked(env, pg));
1364 LASSERT(pg->cp_sync_io == anchor);
1365 pg->cp_sync_io = NULL;
1366 cl_sync_io_note(anchor, ioret);
1369 /* Don't assert the page writeback bit here because the lustre file
1370 * may be as a backend of swap space. in this case, the page writeback
1371 * is set by VM, and obvious we shouldn't clear it at all. Fortunately
1372 * this type of pages are all TRANSIENT pages. */
1373 KLASSERT(ergo(pg->cp_type == CPT_CACHEABLE,
1374 !PageWriteback(cl_page_vmpage(env, pg))));
1377 EXPORT_SYMBOL(cl_page_completion);
1380 * Notify layers that transfer formation engine decided to yank this page from
1381 * the cache and to make it a part of a transfer.
1383 * \pre pg->cp_state == CPS_CACHED
1384 * \post pg->cp_state == CPS_PAGEIN || pg->cp_state == CPS_PAGEOUT
1386 * \see cl_page_operations::cpo_make_ready()
1388 int cl_page_make_ready(const struct lu_env *env, struct cl_page *pg,
1389 enum cl_req_type crt)
1393 PINVRNT(env, pg, crt < CRT_NR);
1396 result = CL_PAGE_INVOKE(env, pg, CL_PAGE_OP(io[crt].cpo_make_ready),
1397 (const struct lu_env *,
1398 const struct cl_page_slice *));
1400 PASSERT(env, pg, pg->cp_state == CPS_CACHED);
1401 cl_page_io_start(env, pg, crt);
1403 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result);
1406 EXPORT_SYMBOL(cl_page_make_ready);
1409 * Notify layers that high level io decided to place this page into a cache
1410 * for future transfer.
1412 * The layer implementing transfer engine (osc) has to register this page in
1415 * \pre cl_page_is_owned(pg, io)
1416 * \post ergo(result == 0,
1417 * pg->cp_state == CPS_PAGEIN || pg->cp_state == CPS_PAGEOUT)
1419 * \see cl_page_operations::cpo_cache_add()
1421 int cl_page_cache_add(const struct lu_env *env, struct cl_io *io,
1422 struct cl_page *pg, enum cl_req_type crt)
1426 PINVRNT(env, pg, crt < CRT_NR);
1427 PINVRNT(env, pg, cl_page_is_owned(pg, io));
1428 PINVRNT(env, pg, cl_page_invariant(pg));
1431 result = cl_page_invoke(env, io, pg, CL_PAGE_OP(io[crt].cpo_cache_add));
1433 cl_page_owner_clear(pg);
1434 cl_page_state_set(env, pg, CPS_CACHED);
1436 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result);
1439 EXPORT_SYMBOL(cl_page_cache_add);
1442 * Checks whether page is protected by any extent lock is at least required
1445 * \return the same as in cl_page_operations::cpo_is_under_lock() method.
1446 * \see cl_page_operations::cpo_is_under_lock()
1448 int cl_page_is_under_lock(const struct lu_env *env, struct cl_io *io,
1449 struct cl_page *page)
1453 PINVRNT(env, page, cl_page_invariant(page));
1456 rc = CL_PAGE_INVOKE(env, page, CL_PAGE_OP(cpo_is_under_lock),
1457 (const struct lu_env *,
1458 const struct cl_page_slice *, struct cl_io *),
1460 PASSERT(env, page, rc != 0);
1463 EXPORT_SYMBOL(cl_page_is_under_lock);
1465 static int page_prune_cb(const struct lu_env *env, struct cl_io *io,
1466 struct cl_page *page, void *cbdata)
1468 cl_page_own(env, io, page);
1469 cl_page_unmap(env, io, page);
1470 cl_page_discard(env, io, page);
1471 cl_page_disown(env, io, page);
1472 return CLP_GANG_OKAY;
1476 * Purges all cached pages belonging to the object \a obj.
1478 int cl_pages_prune(const struct lu_env *env, struct cl_object *clobj)
1480 struct cl_thread_info *info;
1481 struct cl_object *obj = cl_object_top(clobj);
1486 info = cl_env_info(env);
1490 * initialize the io. This is ugly since we never do IO in this
1491 * function, we just make cl_page_list functions happy. -jay
1494 result = cl_io_init(env, io, CIT_MISC, obj);
1496 cl_io_fini(env, io);
1497 RETURN(io->ci_result);
1501 result = cl_page_gang_lookup(env, obj, io, 0, CL_PAGE_EOF,
1502 page_prune_cb, NULL);
1503 if (result == CLP_GANG_RESCHED)
1505 } while (result != CLP_GANG_OKAY);
1507 cl_io_fini(env, io);
1510 EXPORT_SYMBOL(cl_pages_prune);
1513 * Tells transfer engine that only part of a page is to be transmitted.
1515 * \see cl_page_operations::cpo_clip()
1517 void cl_page_clip(const struct lu_env *env, struct cl_page *pg,
1520 PINVRNT(env, pg, cl_page_invariant(pg));
1522 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", from, to);
1523 CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_clip),
1524 (const struct lu_env *,
1525 const struct cl_page_slice *,int, int),
1528 EXPORT_SYMBOL(cl_page_clip);
1531 * Prints human readable representation of \a pg to the \a f.
1533 void cl_page_header_print(const struct lu_env *env, void *cookie,
1534 lu_printer_t printer, const struct cl_page *pg)
1536 (*printer)(env, cookie,
1537 "page@%p[%d %p:%lu ^%p_%p %d %d %d %p %p %#x]\n",
1538 pg, cfs_atomic_read(&pg->cp_ref), pg->cp_obj,
1539 pg->cp_index, pg->cp_parent, pg->cp_child,
1540 pg->cp_state, pg->cp_error, pg->cp_type,
1541 pg->cp_owner, pg->cp_req, pg->cp_flags);
1543 EXPORT_SYMBOL(cl_page_header_print);
1546 * Prints human readable representation of \a pg to the \a f.
1548 void cl_page_print(const struct lu_env *env, void *cookie,
1549 lu_printer_t printer, const struct cl_page *pg)
1551 struct cl_page *scan;
1553 for (scan = cl_page_top((struct cl_page *)pg);
1554 scan != NULL; scan = scan->cp_child)
1555 cl_page_header_print(env, cookie, printer, scan);
1556 CL_PAGE_INVOKE(env, (struct cl_page *)pg, CL_PAGE_OP(cpo_print),
1557 (const struct lu_env *env,
1558 const struct cl_page_slice *slice,
1559 void *cookie, lu_printer_t p), cookie, printer);
1560 (*printer)(env, cookie, "end page@%p\n", pg);
1562 EXPORT_SYMBOL(cl_page_print);
1565 * Cancel a page which is still in a transfer.
1567 int cl_page_cancel(const struct lu_env *env, struct cl_page *page)
1569 return CL_PAGE_INVOKE(env, page, CL_PAGE_OP(cpo_cancel),
1570 (const struct lu_env *,
1571 const struct cl_page_slice *));
1573 EXPORT_SYMBOL(cl_page_cancel);
1576 * Converts a byte offset within object \a obj into a page index.
1578 loff_t cl_offset(const struct cl_object *obj, pgoff_t idx)
1583 return (loff_t)idx << CFS_PAGE_SHIFT;
1585 EXPORT_SYMBOL(cl_offset);
1588 * Converts a page index into a byte offset within object \a obj.
1590 pgoff_t cl_index(const struct cl_object *obj, loff_t offset)
1595 return offset >> CFS_PAGE_SHIFT;
1597 EXPORT_SYMBOL(cl_index);
1599 int cl_page_size(const struct cl_object *obj)
1601 return 1 << CFS_PAGE_SHIFT;
1603 EXPORT_SYMBOL(cl_page_size);
1606 * Adds page slice to the compound page.
1608 * This is called by cl_object_operations::coo_page_init() methods to add a
1609 * per-layer state to the page. New state is added at the end of
1610 * cl_page::cp_layers list, that is, it is at the bottom of the stack.
1612 * \see cl_lock_slice_add(), cl_req_slice_add(), cl_io_slice_add()
1614 void cl_page_slice_add(struct cl_page *page, struct cl_page_slice *slice,
1615 struct cl_object *obj,
1616 const struct cl_page_operations *ops)
1619 cfs_list_add_tail(&slice->cpl_linkage, &page->cp_layers);
1620 slice->cpl_obj = obj;
1621 slice->cpl_ops = ops;
1622 slice->cpl_page = page;
1625 EXPORT_SYMBOL(cl_page_slice_add);
1627 int cl_page_init(void)
1629 return lu_kmem_init(cl_page_caches);
1632 void cl_page_fini(void)
1634 lu_kmem_fini(cl_page_caches);