4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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.
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).
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
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
27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
30 * Copyright (c) 2011, 2013, Intel Corporation.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
38 * Author: Nikita Danilov <nikita.danilov@sun.com>
39 * Author: Jinshan Xiong <jinshan.xiong@intel.com>
42 #define DEBUG_SUBSYSTEM S_CLASS
44 #include <libcfs/libcfs.h>
45 #include <obd_class.h>
46 #include <obd_support.h>
47 #include <libcfs/list.h>
49 #include <cl_object.h>
50 #include "cl_internal.h"
52 static void cl_page_delete0(const struct lu_env *env, struct cl_page *pg);
55 # define PASSERT(env, page, expr) \
57 if (unlikely(!(expr))) { \
58 CL_PAGE_DEBUG(D_ERROR, (env), (page), #expr "\n"); \
62 #else /* !LIBCFS_DEBUG */
63 # define PASSERT(env, page, exp) \
64 ((void)sizeof(env), (void)sizeof(page), (void)sizeof !!(exp))
65 #endif /* !LIBCFS_DEBUG */
67 #ifdef CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK
68 # define PINVRNT(env, page, expr) \
70 if (unlikely(!(expr))) { \
71 CL_PAGE_DEBUG(D_ERROR, (env), (page), #expr "\n"); \
75 #else /* !CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK */
76 # define PINVRNT(env, page, exp) \
77 ((void)sizeof(env), (void)sizeof(page), (void)sizeof !!(exp))
78 #endif /* !CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK */
80 /* Disable page statistic by default due to huge performance penalty. */
81 #ifdef CONFIG_DEBUG_PAGESTATE_TRACKING
82 #define CS_PAGE_INC(o, item) \
83 atomic_inc(&cl_object_site(o)->cs_pages.cs_stats[CS_##item])
84 #define CS_PAGE_DEC(o, item) \
85 atomic_dec(&cl_object_site(o)->cs_pages.cs_stats[CS_##item])
86 #define CS_PAGESTATE_INC(o, state) \
87 atomic_inc(&cl_object_site(o)->cs_pages_state[state])
88 #define CS_PAGESTATE_DEC(o, state) \
89 atomic_dec(&cl_object_site(o)->cs_pages_state[state])
91 #define CS_PAGE_INC(o, item)
92 #define CS_PAGE_DEC(o, item)
93 #define CS_PAGESTATE_INC(o, state)
94 #define CS_PAGESTATE_DEC(o, state)
98 * Internal version of cl_page_get().
100 * This function can be used to obtain initial reference to previously
101 * unreferenced cached object. It can be called only if concurrent page
102 * reclamation is somehow prevented, e.g., by keeping a lock on a VM page,
103 * associated with \a page.
105 * Use with care! Not exported.
107 static void cl_page_get_trust(struct cl_page *page)
109 LASSERT(atomic_read(&page->cp_ref) > 0);
110 atomic_inc(&page->cp_ref);
114 * Returns a slice within a page, corresponding to the given layer in the
119 static const struct cl_page_slice *
120 cl_page_at_trusted(const struct cl_page *page,
121 const struct lu_device_type *dtype)
123 const struct cl_page_slice *slice;
126 list_for_each_entry(slice, &page->cp_layers, cpl_linkage) {
127 if (slice->cpl_obj->co_lu.lo_dev->ld_type == dtype)
133 static void cl_page_free(const struct lu_env *env, struct cl_page *page)
135 struct cl_object *obj = page->cp_obj;
136 int pagesize = cl_object_header(obj)->coh_page_bufsize;
138 PASSERT(env, page, list_empty(&page->cp_batch));
139 PASSERT(env, page, page->cp_owner == NULL);
140 PASSERT(env, page, page->cp_req == NULL);
141 PASSERT(env, page, page->cp_state == CPS_FREEING);
144 while (!list_empty(&page->cp_layers)) {
145 struct cl_page_slice *slice;
147 slice = list_entry(page->cp_layers.next,
148 struct cl_page_slice, cpl_linkage);
149 list_del_init(page->cp_layers.next);
150 if (unlikely(slice->cpl_ops->cpo_fini != NULL))
151 slice->cpl_ops->cpo_fini(env, slice);
153 CS_PAGE_DEC(obj, total);
154 CS_PAGESTATE_DEC(obj, page->cp_state);
155 lu_object_ref_del_at(&obj->co_lu, &page->cp_obj_ref, "cl_page", page);
156 cl_object_put(env, obj);
157 lu_ref_fini(&page->cp_reference);
158 OBD_FREE(page, pagesize);
163 * Helper function updating page state. This is the only place in the code
164 * where cl_page::cp_state field is mutated.
166 static inline void cl_page_state_set_trust(struct cl_page *page,
167 enum cl_page_state state)
170 *(enum cl_page_state *)&page->cp_state = state;
173 struct cl_page *cl_page_alloc(const struct lu_env *env,
174 struct cl_object *o, pgoff_t ind, struct page *vmpage,
175 enum cl_page_type type)
177 struct cl_page *page;
178 struct lu_object_header *head;
181 OBD_ALLOC_GFP(page, cl_object_header(o)->coh_page_bufsize,
185 atomic_set(&page->cp_ref, 1);
188 lu_object_ref_add_at(&o->co_lu, &page->cp_obj_ref, "cl_page",
190 page->cp_vmpage = vmpage;
191 cl_page_state_set_trust(page, CPS_CACHED);
192 page->cp_type = type;
193 INIT_LIST_HEAD(&page->cp_layers);
194 INIT_LIST_HEAD(&page->cp_batch);
195 INIT_LIST_HEAD(&page->cp_flight);
196 lu_ref_init(&page->cp_reference);
197 head = o->co_lu.lo_header;
198 list_for_each_entry(o, &head->loh_layers,
200 if (o->co_ops->coo_page_init != NULL) {
201 result = o->co_ops->coo_page_init(env, o, page,
204 cl_page_delete0(env, page);
205 cl_page_free(env, page);
206 page = ERR_PTR(result);
212 CS_PAGE_INC(o, total);
213 CS_PAGE_INC(o, create);
214 CS_PAGESTATE_DEC(o, CPS_CACHED);
217 page = ERR_PTR(-ENOMEM);
221 EXPORT_SYMBOL(cl_page_alloc);
224 * Returns a cl_page with index \a idx at the object \a o, and associated with
225 * the VM page \a vmpage.
227 * This is the main entry point into the cl_page caching interface. First, a
228 * cache (implemented as a per-object radix tree) is consulted. If page is
229 * found there, it is returned immediately. Otherwise new page is allocated
230 * and returned. In any case, additional reference to page is acquired.
232 * \see cl_object_find(), cl_lock_find()
234 struct cl_page *cl_page_find(const struct lu_env *env,
236 pgoff_t idx, struct page *vmpage,
237 enum cl_page_type type)
239 struct cl_page *page = NULL;
240 struct cl_object_header *hdr;
242 LASSERT(type == CPT_CACHEABLE || type == CPT_TRANSIENT);
247 hdr = cl_object_header(o);
248 CS_PAGE_INC(o, lookup);
250 CDEBUG(D_PAGE, "%lu@"DFID" %p %lx %d\n",
251 idx, PFID(&hdr->coh_lu.loh_fid), vmpage, vmpage->private, type);
253 if (type == CPT_CACHEABLE) {
254 /* vmpage lock is used to protect the child/parent
256 KLASSERT(PageLocked(vmpage));
258 * cl_vmpage_page() can be called here without any locks as
260 * - "vmpage" is locked (which prevents ->private from
261 * concurrent updates), and
263 * - "o" cannot be destroyed while current thread holds a
266 page = cl_vmpage_page(vmpage, o);
273 /* allocate and initialize cl_page */
274 page = cl_page_alloc(env, o, idx, vmpage, type);
277 EXPORT_SYMBOL(cl_page_find);
279 static inline int cl_page_invariant(const struct cl_page *pg)
282 * Page invariant is protected by a VM lock.
284 LINVRNT(cl_page_is_vmlocked(NULL, pg));
286 return cl_page_in_use_noref(pg);
289 static void cl_page_state_set0(const struct lu_env *env,
290 struct cl_page *page, enum cl_page_state state)
292 enum cl_page_state old;
295 * Matrix of allowed state transitions [old][new], for sanity
298 static const int allowed_transitions[CPS_NR][CPS_NR] = {
301 [CPS_OWNED] = 1, /* io finds existing cached page */
303 [CPS_PAGEOUT] = 1, /* write-out from the cache */
304 [CPS_FREEING] = 1, /* eviction on the memory pressure */
307 [CPS_CACHED] = 1, /* release to the cache */
309 [CPS_PAGEIN] = 1, /* start read immediately */
310 [CPS_PAGEOUT] = 1, /* start write immediately */
311 [CPS_FREEING] = 1, /* lock invalidation or truncate */
314 [CPS_CACHED] = 1, /* io completion */
321 [CPS_CACHED] = 1, /* io completion */
337 old = page->cp_state;
338 PASSERT(env, page, allowed_transitions[old][state]);
339 CL_PAGE_HEADER(D_TRACE, env, page, "%d -> %d\n", old, state);
340 PASSERT(env, page, page->cp_state == old);
341 PASSERT(env, page, equi(state == CPS_OWNED, page->cp_owner != NULL));
343 CS_PAGESTATE_DEC(page->cp_obj, page->cp_state);
344 CS_PAGESTATE_INC(page->cp_obj, state);
345 cl_page_state_set_trust(page, state);
349 static void cl_page_state_set(const struct lu_env *env,
350 struct cl_page *page, enum cl_page_state state)
352 cl_page_state_set0(env, page, state);
356 * Acquires an additional reference to a page.
358 * This can be called only by caller already possessing a reference to \a
361 * \see cl_object_get(), cl_lock_get().
363 void cl_page_get(struct cl_page *page)
366 cl_page_get_trust(page);
369 EXPORT_SYMBOL(cl_page_get);
372 * Releases a reference to a page.
374 * When last reference is released, page is returned to the cache, unless it
375 * is in cl_page_state::CPS_FREEING state, in which case it is immediately
378 * \see cl_object_put(), cl_lock_put().
380 void cl_page_put(const struct lu_env *env, struct cl_page *page)
383 CL_PAGE_HEADER(D_TRACE, env, page, "%d\n",
384 atomic_read(&page->cp_ref));
386 if (atomic_dec_and_test(&page->cp_ref)) {
387 LASSERT(page->cp_state == CPS_FREEING);
389 LASSERT(atomic_read(&page->cp_ref) == 0);
390 PASSERT(env, page, page->cp_owner == NULL);
391 PASSERT(env, page, list_empty(&page->cp_batch));
393 * Page is no longer reachable by other threads. Tear
396 cl_page_free(env, page);
401 EXPORT_SYMBOL(cl_page_put);
404 * Returns a cl_page associated with a VM page, and given cl_object.
406 struct cl_page *cl_vmpage_page(struct page *vmpage, struct cl_object *obj)
408 struct cl_page *page;
411 KLASSERT(PageLocked(vmpage));
414 * NOTE: absence of races and liveness of data are guaranteed by page
415 * lock on a "vmpage". That works because object destruction has
416 * bottom-to-top pass.
419 page = (struct cl_page *)vmpage->private;
421 cl_page_get_trust(page);
422 LASSERT(page->cp_type == CPT_CACHEABLE);
426 EXPORT_SYMBOL(cl_vmpage_page);
428 const struct cl_page_slice *cl_page_at(const struct cl_page *page,
429 const struct lu_device_type *dtype)
431 return cl_page_at_trusted(page, dtype);
433 EXPORT_SYMBOL(cl_page_at);
435 #define CL_PAGE_OP(opname) offsetof(struct cl_page_operations, opname)
437 #define CL_PAGE_INVOKE(_env, _page, _op, _proto, ...) \
439 const struct lu_env *__env = (_env); \
440 struct cl_page *__page = (_page); \
441 const struct cl_page_slice *__scan; \
443 ptrdiff_t __op = (_op); \
444 int (*__method)_proto; \
447 list_for_each_entry(__scan, &__page->cp_layers, cpl_linkage) { \
448 __method = *(void **)((char *)__scan->cpl_ops + __op); \
449 if (__method != NULL) { \
450 __result = (*__method)(__env, __scan, ## __VA_ARGS__); \
460 #define CL_PAGE_INVOKE_REVERSE(_env, _page, _op, _proto, ...) \
462 const struct lu_env *__env = (_env); \
463 struct cl_page *__page = (_page); \
464 const struct cl_page_slice *__scan; \
466 ptrdiff_t __op = (_op); \
467 int (*__method)_proto; \
470 list_for_each_entry_reverse(__scan, &__page->cp_layers, \
472 __method = *(void **)((char *)__scan->cpl_ops + __op); \
473 if (__method != NULL) { \
474 __result = (*__method)(__env, __scan, ## __VA_ARGS__); \
484 #define CL_PAGE_INVOID(_env, _page, _op, _proto, ...) \
486 const struct lu_env *__env = (_env); \
487 struct cl_page *__page = (_page); \
488 const struct cl_page_slice *__scan; \
489 ptrdiff_t __op = (_op); \
490 void (*__method)_proto; \
492 list_for_each_entry(__scan, &__page->cp_layers, cpl_linkage) { \
493 __method = *(void **)((char *)__scan->cpl_ops + __op); \
494 if (__method != NULL) \
495 (*__method)(__env, __scan, ## __VA_ARGS__); \
499 #define CL_PAGE_INVOID_REVERSE(_env, _page, _op, _proto, ...) \
501 const struct lu_env *__env = (_env); \
502 struct cl_page *__page = (_page); \
503 const struct cl_page_slice *__scan; \
504 ptrdiff_t __op = (_op); \
505 void (*__method)_proto; \
507 /* get to the bottom page. */ \
508 list_for_each_entry_reverse(__scan, &__page->cp_layers, \
510 __method = *(void **)((char *)__scan->cpl_ops + __op); \
511 if (__method != NULL) \
512 (*__method)(__env, __scan, ## __VA_ARGS__); \
516 static int cl_page_invoke(const struct lu_env *env,
517 struct cl_io *io, struct cl_page *page, ptrdiff_t op)
520 PINVRNT(env, page, cl_object_same(page->cp_obj, io->ci_obj));
522 RETURN(CL_PAGE_INVOKE(env, page, op,
523 (const struct lu_env *,
524 const struct cl_page_slice *, struct cl_io *),
528 static void cl_page_invoid(const struct lu_env *env,
529 struct cl_io *io, struct cl_page *page, ptrdiff_t op)
532 PINVRNT(env, page, cl_object_same(page->cp_obj, io->ci_obj));
534 CL_PAGE_INVOID(env, page, op,
535 (const struct lu_env *,
536 const struct cl_page_slice *, struct cl_io *), io);
540 static void cl_page_owner_clear(struct cl_page *page)
543 if (page->cp_owner != NULL) {
544 LASSERT(page->cp_owner->ci_owned_nr > 0);
545 page->cp_owner->ci_owned_nr--;
546 page->cp_owner = NULL;
551 static void cl_page_owner_set(struct cl_page *page)
554 LASSERT(page->cp_owner != NULL);
555 page->cp_owner->ci_owned_nr++;
559 void cl_page_disown0(const struct lu_env *env,
560 struct cl_io *io, struct cl_page *pg)
562 enum cl_page_state state;
565 state = pg->cp_state;
566 PINVRNT(env, pg, state == CPS_OWNED || state == CPS_FREEING);
567 PINVRNT(env, pg, cl_page_invariant(pg) || state == CPS_FREEING);
568 cl_page_owner_clear(pg);
570 if (state == CPS_OWNED)
571 cl_page_state_set(env, pg, CPS_CACHED);
573 * Completion call-backs are executed in the bottom-up order, so that
574 * uppermost layer (llite), responsible for VFS/VM interaction runs
575 * last and can release locks safely.
577 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_disown),
578 (const struct lu_env *,
579 const struct cl_page_slice *, struct cl_io *),
585 * returns true, iff page is owned by the given io.
587 int cl_page_is_owned(const struct cl_page *pg, const struct cl_io *io)
589 struct cl_io *top = cl_io_top((struct cl_io *)io);
590 LINVRNT(cl_object_same(pg->cp_obj, io->ci_obj));
592 RETURN(pg->cp_state == CPS_OWNED && pg->cp_owner == top);
594 EXPORT_SYMBOL(cl_page_is_owned);
597 * Try to own a page by IO.
599 * Waits until page is in cl_page_state::CPS_CACHED state, and then switch it
600 * into cl_page_state::CPS_OWNED state.
602 * \pre !cl_page_is_owned(pg, io)
603 * \post result == 0 iff cl_page_is_owned(pg, io)
607 * \retval -ve failure, e.g., page was destroyed (and landed in
608 * cl_page_state::CPS_FREEING instead of cl_page_state::CPS_CACHED).
609 * or, page was owned by another thread, or in IO.
611 * \see cl_page_disown()
612 * \see cl_page_operations::cpo_own()
613 * \see cl_page_own_try()
616 static int cl_page_own0(const struct lu_env *env, struct cl_io *io,
617 struct cl_page *pg, int nonblock)
621 PINVRNT(env, pg, !cl_page_is_owned(pg, io));
626 if (pg->cp_state == CPS_FREEING) {
629 result = CL_PAGE_INVOKE(env, pg, CL_PAGE_OP(cpo_own),
630 (const struct lu_env *,
631 const struct cl_page_slice *,
632 struct cl_io *, int),
635 PASSERT(env, pg, pg->cp_owner == NULL);
636 PASSERT(env, pg, pg->cp_req == NULL);
637 pg->cp_owner = cl_io_top(io);;
638 cl_page_owner_set(pg);
639 if (pg->cp_state != CPS_FREEING) {
640 cl_page_state_set(env, pg, CPS_OWNED);
642 cl_page_disown0(env, io, pg);
647 PINVRNT(env, pg, ergo(result == 0, cl_page_invariant(pg)));
652 * Own a page, might be blocked.
654 * \see cl_page_own0()
656 int cl_page_own(const struct lu_env *env, struct cl_io *io, struct cl_page *pg)
658 return cl_page_own0(env, io, pg, 0);
660 EXPORT_SYMBOL(cl_page_own);
663 * Nonblock version of cl_page_own().
665 * \see cl_page_own0()
667 int cl_page_own_try(const struct lu_env *env, struct cl_io *io,
670 return cl_page_own0(env, io, pg, 1);
672 EXPORT_SYMBOL(cl_page_own_try);
676 * Assume page ownership.
678 * Called when page is already locked by the hosting VM.
680 * \pre !cl_page_is_owned(pg, io)
681 * \post cl_page_is_owned(pg, io)
683 * \see cl_page_operations::cpo_assume()
685 void cl_page_assume(const struct lu_env *env,
686 struct cl_io *io, struct cl_page *pg)
688 PINVRNT(env, pg, cl_object_same(pg->cp_obj, io->ci_obj));
693 cl_page_invoid(env, io, pg, CL_PAGE_OP(cpo_assume));
694 PASSERT(env, pg, pg->cp_owner == NULL);
695 pg->cp_owner = cl_io_top(io);
696 cl_page_owner_set(pg);
697 cl_page_state_set(env, pg, CPS_OWNED);
700 EXPORT_SYMBOL(cl_page_assume);
703 * Releases page ownership without unlocking the page.
705 * Moves page into cl_page_state::CPS_CACHED without releasing a lock on the
706 * underlying VM page (as VM is supposed to do this itself).
708 * \pre cl_page_is_owned(pg, io)
709 * \post !cl_page_is_owned(pg, io)
711 * \see cl_page_assume()
713 void cl_page_unassume(const struct lu_env *env,
714 struct cl_io *io, struct cl_page *pg)
716 PINVRNT(env, pg, cl_page_is_owned(pg, io));
717 PINVRNT(env, pg, cl_page_invariant(pg));
721 cl_page_owner_clear(pg);
722 cl_page_state_set(env, pg, CPS_CACHED);
723 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_unassume),
724 (const struct lu_env *,
725 const struct cl_page_slice *, struct cl_io *),
729 EXPORT_SYMBOL(cl_page_unassume);
732 * Releases page ownership.
734 * Moves page into cl_page_state::CPS_CACHED.
736 * \pre cl_page_is_owned(pg, io)
737 * \post !cl_page_is_owned(pg, io)
740 * \see cl_page_operations::cpo_disown()
742 void cl_page_disown(const struct lu_env *env,
743 struct cl_io *io, struct cl_page *pg)
745 PINVRNT(env, pg, cl_page_is_owned(pg, io) ||
746 pg->cp_state == CPS_FREEING);
750 cl_page_disown0(env, io, pg);
753 EXPORT_SYMBOL(cl_page_disown);
756 * Called when page is to be removed from the object, e.g., as a result of
759 * Calls cl_page_operations::cpo_discard() top-to-bottom.
761 * \pre cl_page_is_owned(pg, io)
763 * \see cl_page_operations::cpo_discard()
765 void cl_page_discard(const struct lu_env *env,
766 struct cl_io *io, struct cl_page *pg)
768 PINVRNT(env, pg, cl_page_is_owned(pg, io));
769 PINVRNT(env, pg, cl_page_invariant(pg));
771 cl_page_invoid(env, io, pg, CL_PAGE_OP(cpo_discard));
773 EXPORT_SYMBOL(cl_page_discard);
776 * Version of cl_page_delete() that can be called for not fully constructed
777 * pages, e.g,. in a error handling cl_page_find()->cl_page_delete0()
778 * path. Doesn't check page invariant.
780 static void cl_page_delete0(const struct lu_env *env, struct cl_page *pg)
784 PASSERT(env, pg, pg->cp_state != CPS_FREEING);
787 * Severe all ways to obtain new pointers to @pg.
789 cl_page_owner_clear(pg);
791 cl_page_state_set0(env, pg, CPS_FREEING);
793 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_delete),
794 (const struct lu_env *, const struct cl_page_slice *));
800 * Called when a decision is made to throw page out of memory.
802 * Notifies all layers about page destruction by calling
803 * cl_page_operations::cpo_delete() method top-to-bottom.
805 * Moves page into cl_page_state::CPS_FREEING state (this is the only place
806 * where transition to this state happens).
808 * Eliminates all venues through which new references to the page can be
811 * - removes page from the radix trees,
813 * - breaks linkage from VM page to cl_page.
815 * Once page reaches cl_page_state::CPS_FREEING, all remaining references will
816 * drain after some time, at which point page will be recycled.
818 * \pre VM page is locked
819 * \post pg->cp_state == CPS_FREEING
821 * \see cl_page_operations::cpo_delete()
823 void cl_page_delete(const struct lu_env *env, struct cl_page *pg)
825 PINVRNT(env, pg, cl_page_invariant(pg));
827 cl_page_delete0(env, pg);
830 EXPORT_SYMBOL(cl_page_delete);
833 * Marks page up-to-date.
835 * Call cl_page_operations::cpo_export() through all layers top-to-bottom. The
836 * layer responsible for VM interaction has to mark/clear page as up-to-date
837 * by the \a uptodate argument.
839 * \see cl_page_operations::cpo_export()
841 void cl_page_export(const struct lu_env *env, struct cl_page *pg, int uptodate)
843 PINVRNT(env, pg, cl_page_invariant(pg));
844 CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_export),
845 (const struct lu_env *,
846 const struct cl_page_slice *, int), uptodate);
848 EXPORT_SYMBOL(cl_page_export);
851 * Returns true, iff \a pg is VM locked in a suitable sense by the calling
854 int cl_page_is_vmlocked(const struct lu_env *env, const struct cl_page *pg)
857 const struct cl_page_slice *slice;
860 slice = container_of(pg->cp_layers.next,
861 const struct cl_page_slice, cpl_linkage);
862 PASSERT(env, pg, slice->cpl_ops->cpo_is_vmlocked != NULL);
864 * Call ->cpo_is_vmlocked() directly instead of going through
865 * CL_PAGE_INVOKE(), because cl_page_is_vmlocked() is used by
866 * cl_page_invariant().
868 result = slice->cpl_ops->cpo_is_vmlocked(env, slice);
869 PASSERT(env, pg, result == -EBUSY || result == -ENODATA);
870 RETURN(result == -EBUSY);
872 EXPORT_SYMBOL(cl_page_is_vmlocked);
874 static enum cl_page_state cl_req_type_state(enum cl_req_type crt)
877 RETURN(crt == CRT_WRITE ? CPS_PAGEOUT : CPS_PAGEIN);
880 static void cl_page_io_start(const struct lu_env *env,
881 struct cl_page *pg, enum cl_req_type crt)
884 * Page is queued for IO, change its state.
887 cl_page_owner_clear(pg);
888 cl_page_state_set(env, pg, cl_req_type_state(crt));
893 * Prepares page for immediate transfer. cl_page_operations::cpo_prep() is
894 * called top-to-bottom. Every layer either agrees to submit this page (by
895 * returning 0), or requests to omit this page (by returning -EALREADY). Layer
896 * handling interactions with the VM also has to inform VM that page is under
899 int cl_page_prep(const struct lu_env *env, struct cl_io *io,
900 struct cl_page *pg, enum cl_req_type crt)
904 PINVRNT(env, pg, cl_page_is_owned(pg, io));
905 PINVRNT(env, pg, cl_page_invariant(pg));
906 PINVRNT(env, pg, crt < CRT_NR);
909 * XXX this has to be called bottom-to-top, so that llite can set up
910 * PG_writeback without risking other layers deciding to skip this
915 result = cl_page_invoke(env, io, pg, CL_PAGE_OP(io[crt].cpo_prep));
917 cl_page_io_start(env, pg, crt);
919 KLASSERT(ergo(crt == CRT_WRITE && pg->cp_type == CPT_CACHEABLE,
921 PageWriteback(cl_page_vmpage(pg)))));
922 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result);
925 EXPORT_SYMBOL(cl_page_prep);
928 * Notify layers about transfer completion.
930 * Invoked by transfer sub-system (which is a part of osc) to notify layers
931 * that a transfer, of which this page is a part of has completed.
933 * Completion call-backs are executed in the bottom-up order, so that
934 * uppermost layer (llite), responsible for the VFS/VM interaction runs last
935 * and can release locks safely.
937 * \pre pg->cp_state == CPS_PAGEIN || pg->cp_state == CPS_PAGEOUT
938 * \post pg->cp_state == CPS_CACHED
940 * \see cl_page_operations::cpo_completion()
942 void cl_page_completion(const struct lu_env *env,
943 struct cl_page *pg, enum cl_req_type crt, int ioret)
945 struct cl_sync_io *anchor = pg->cp_sync_io;
947 PASSERT(env, pg, crt < CRT_NR);
948 /* cl_page::cp_req already cleared by the caller (osc_completion()) */
949 PASSERT(env, pg, pg->cp_req == NULL);
950 PASSERT(env, pg, pg->cp_state == cl_req_type_state(crt));
953 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, ioret);
954 cl_page_state_set(env, pg, CPS_CACHED);
957 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(io[crt].cpo_completion),
958 (const struct lu_env *,
959 const struct cl_page_slice *, int), ioret);
961 LASSERT(cl_page_is_vmlocked(env, pg));
962 LASSERT(pg->cp_sync_io == anchor);
963 pg->cp_sync_io = NULL;
966 * As page->cp_obj is pinned by a reference from page->cp_req, it is
967 * safe to call cl_page_put() without risking object destruction in a
968 * non-blocking context.
970 cl_page_put(env, pg);
973 cl_sync_io_note(anchor, ioret);
977 EXPORT_SYMBOL(cl_page_completion);
980 * Notify layers that transfer formation engine decided to yank this page from
981 * the cache and to make it a part of a transfer.
983 * \pre pg->cp_state == CPS_CACHED
984 * \post pg->cp_state == CPS_PAGEIN || pg->cp_state == CPS_PAGEOUT
986 * \see cl_page_operations::cpo_make_ready()
988 int cl_page_make_ready(const struct lu_env *env, struct cl_page *pg,
989 enum cl_req_type crt)
993 PINVRNT(env, pg, crt < CRT_NR);
998 result = CL_PAGE_INVOKE(env, pg, CL_PAGE_OP(io[crt].cpo_make_ready),
999 (const struct lu_env *,
1000 const struct cl_page_slice *));
1002 PASSERT(env, pg, pg->cp_state == CPS_CACHED);
1003 cl_page_io_start(env, pg, crt);
1005 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result);
1008 EXPORT_SYMBOL(cl_page_make_ready);
1011 * Called if a pge is being written back by kernel's intention.
1013 * \pre cl_page_is_owned(pg, io)
1014 * \post ergo(result == 0, pg->cp_state == CPS_PAGEOUT)
1016 * \see cl_page_operations::cpo_flush()
1018 int cl_page_flush(const struct lu_env *env, struct cl_io *io,
1023 PINVRNT(env, pg, cl_page_is_owned(pg, io));
1024 PINVRNT(env, pg, cl_page_invariant(pg));
1028 result = cl_page_invoke(env, io, pg, CL_PAGE_OP(cpo_flush));
1030 CL_PAGE_HEADER(D_TRACE, env, pg, "%d\n", result);
1033 EXPORT_SYMBOL(cl_page_flush);
1036 * Checks whether page is protected by any extent lock is at least required
1039 * \return the same as in cl_page_operations::cpo_is_under_lock() method.
1040 * \see cl_page_operations::cpo_is_under_lock()
1042 int cl_page_is_under_lock(const struct lu_env *env, struct cl_io *io,
1043 struct cl_page *page, pgoff_t *max_index)
1047 PINVRNT(env, page, cl_page_invariant(page));
1050 rc = CL_PAGE_INVOKE_REVERSE(env, page, CL_PAGE_OP(cpo_is_under_lock),
1051 (const struct lu_env *,
1052 const struct cl_page_slice *,
1053 struct cl_io *, pgoff_t *),
1057 EXPORT_SYMBOL(cl_page_is_under_lock);
1060 * Tells transfer engine that only part of a page is to be transmitted.
1062 * \see cl_page_operations::cpo_clip()
1064 void cl_page_clip(const struct lu_env *env, struct cl_page *pg,
1067 PINVRNT(env, pg, cl_page_invariant(pg));
1069 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", from, to);
1070 CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_clip),
1071 (const struct lu_env *,
1072 const struct cl_page_slice *,int, int),
1075 EXPORT_SYMBOL(cl_page_clip);
1078 * Prints human readable representation of \a pg to the \a f.
1080 void cl_page_header_print(const struct lu_env *env, void *cookie,
1081 lu_printer_t printer, const struct cl_page *pg)
1083 (*printer)(env, cookie,
1084 "page@%p[%d %p %d %d %d %p %p]\n",
1085 pg, atomic_read(&pg->cp_ref), pg->cp_obj,
1086 pg->cp_state, pg->cp_error, pg->cp_type,
1087 pg->cp_owner, pg->cp_req);
1089 EXPORT_SYMBOL(cl_page_header_print);
1092 * Prints human readable representation of \a pg to the \a f.
1094 void cl_page_print(const struct lu_env *env, void *cookie,
1095 lu_printer_t printer, const struct cl_page *pg)
1097 cl_page_header_print(env, cookie, printer, pg);
1098 CL_PAGE_INVOKE(env, (struct cl_page *)pg, CL_PAGE_OP(cpo_print),
1099 (const struct lu_env *env,
1100 const struct cl_page_slice *slice,
1101 void *cookie, lu_printer_t p), cookie, printer);
1102 (*printer)(env, cookie, "end page@%p\n", pg);
1104 EXPORT_SYMBOL(cl_page_print);
1107 * Cancel a page which is still in a transfer.
1109 int cl_page_cancel(const struct lu_env *env, struct cl_page *page)
1111 return CL_PAGE_INVOKE(env, page, CL_PAGE_OP(cpo_cancel),
1112 (const struct lu_env *,
1113 const struct cl_page_slice *));
1115 EXPORT_SYMBOL(cl_page_cancel);
1118 * Converts a byte offset within object \a obj into a page index.
1120 loff_t cl_offset(const struct cl_object *obj, pgoff_t idx)
1122 return (loff_t)idx << PAGE_CACHE_SHIFT;
1124 EXPORT_SYMBOL(cl_offset);
1127 * Converts a page index into a byte offset within object \a obj.
1129 pgoff_t cl_index(const struct cl_object *obj, loff_t offset)
1131 return offset >> PAGE_CACHE_SHIFT;
1133 EXPORT_SYMBOL(cl_index);
1135 int cl_page_size(const struct cl_object *obj)
1137 return 1 << PAGE_CACHE_SHIFT;
1139 EXPORT_SYMBOL(cl_page_size);
1142 * Adds page slice to the compound page.
1144 * This is called by cl_object_operations::coo_page_init() methods to add a
1145 * per-layer state to the page. New state is added at the end of
1146 * cl_page::cp_layers list, that is, it is at the bottom of the stack.
1148 * \see cl_lock_slice_add(), cl_req_slice_add(), cl_io_slice_add()
1150 void cl_page_slice_add(struct cl_page *page, struct cl_page_slice *slice,
1151 struct cl_object *obj, pgoff_t index,
1152 const struct cl_page_operations *ops)
1155 list_add_tail(&slice->cpl_linkage, &page->cp_layers);
1156 slice->cpl_obj = obj;
1157 slice->cpl_index = index;
1158 slice->cpl_ops = ops;
1159 slice->cpl_page = page;
1162 EXPORT_SYMBOL(cl_page_slice_add);
1164 int cl_page_init(void)
1169 void cl_page_fini(void)