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, 2014, 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);
223 * Returns a cl_page with index \a idx at the object \a o, and associated with
224 * the VM page \a vmpage.
226 * This is the main entry point into the cl_page caching interface. First, a
227 * cache (implemented as a per-object radix tree) is consulted. If page is
228 * found there, it is returned immediately. Otherwise new page is allocated
229 * and returned. In any case, additional reference to page is acquired.
231 * \see cl_object_find(), cl_lock_find()
233 struct cl_page *cl_page_find(const struct lu_env *env,
235 pgoff_t idx, struct page *vmpage,
236 enum cl_page_type type)
238 struct cl_page *page = NULL;
239 struct cl_object_header *hdr;
241 LASSERT(type == CPT_CACHEABLE || type == CPT_TRANSIENT);
246 hdr = cl_object_header(o);
247 CS_PAGE_INC(o, lookup);
249 CDEBUG(D_PAGE, "%lu@"DFID" %p %lx %d\n",
250 idx, PFID(&hdr->coh_lu.loh_fid), vmpage, vmpage->private, type);
252 if (type == CPT_CACHEABLE) {
253 /* vmpage lock is used to protect the child/parent
255 KLASSERT(PageLocked(vmpage));
257 * cl_vmpage_page() can be called here without any locks as
259 * - "vmpage" is locked (which prevents ->private from
260 * concurrent updates), and
262 * - "o" cannot be destroyed while current thread holds a
265 page = cl_vmpage_page(vmpage, o);
272 /* allocate and initialize cl_page */
273 page = cl_page_alloc(env, o, idx, vmpage, type);
276 EXPORT_SYMBOL(cl_page_find);
278 static inline int cl_page_invariant(const struct cl_page *pg)
280 return cl_page_in_use_noref(pg);
283 static void cl_page_state_set0(const struct lu_env *env,
284 struct cl_page *page, enum cl_page_state state)
286 enum cl_page_state old;
289 * Matrix of allowed state transitions [old][new], for sanity
292 static const int allowed_transitions[CPS_NR][CPS_NR] = {
295 [CPS_OWNED] = 1, /* io finds existing cached page */
297 [CPS_PAGEOUT] = 1, /* write-out from the cache */
298 [CPS_FREEING] = 1, /* eviction on the memory pressure */
301 [CPS_CACHED] = 1, /* release to the cache */
303 [CPS_PAGEIN] = 1, /* start read immediately */
304 [CPS_PAGEOUT] = 1, /* start write immediately */
305 [CPS_FREEING] = 1, /* lock invalidation or truncate */
308 [CPS_CACHED] = 1, /* io completion */
315 [CPS_CACHED] = 1, /* io completion */
331 old = page->cp_state;
332 PASSERT(env, page, allowed_transitions[old][state]);
333 CL_PAGE_HEADER(D_TRACE, env, page, "%d -> %d\n", old, state);
334 PASSERT(env, page, page->cp_state == old);
335 PASSERT(env, page, equi(state == CPS_OWNED, page->cp_owner != NULL));
337 CS_PAGESTATE_DEC(page->cp_obj, page->cp_state);
338 CS_PAGESTATE_INC(page->cp_obj, state);
339 cl_page_state_set_trust(page, state);
343 static void cl_page_state_set(const struct lu_env *env,
344 struct cl_page *page, enum cl_page_state state)
346 cl_page_state_set0(env, page, state);
350 * Acquires an additional reference to a page.
352 * This can be called only by caller already possessing a reference to \a
355 * \see cl_object_get(), cl_lock_get().
357 void cl_page_get(struct cl_page *page)
360 cl_page_get_trust(page);
363 EXPORT_SYMBOL(cl_page_get);
366 * Releases a reference to a page.
368 * When last reference is released, page is returned to the cache, unless it
369 * is in cl_page_state::CPS_FREEING state, in which case it is immediately
372 * \see cl_object_put(), cl_lock_put().
374 void cl_page_put(const struct lu_env *env, struct cl_page *page)
377 CL_PAGE_HEADER(D_TRACE, env, page, "%d\n",
378 atomic_read(&page->cp_ref));
380 if (atomic_dec_and_test(&page->cp_ref)) {
381 LASSERT(page->cp_state == CPS_FREEING);
383 LASSERT(atomic_read(&page->cp_ref) == 0);
384 PASSERT(env, page, page->cp_owner == NULL);
385 PASSERT(env, page, list_empty(&page->cp_batch));
387 * Page is no longer reachable by other threads. Tear
390 cl_page_free(env, page);
395 EXPORT_SYMBOL(cl_page_put);
398 * Returns a cl_page associated with a VM page, and given cl_object.
400 struct cl_page *cl_vmpage_page(struct page *vmpage, struct cl_object *obj)
402 struct cl_page *page;
405 KLASSERT(PageLocked(vmpage));
408 * NOTE: absence of races and liveness of data are guaranteed by page
409 * lock on a "vmpage". That works because object destruction has
410 * bottom-to-top pass.
413 page = (struct cl_page *)vmpage->private;
415 cl_page_get_trust(page);
416 LASSERT(page->cp_type == CPT_CACHEABLE);
420 EXPORT_SYMBOL(cl_vmpage_page);
422 const struct cl_page_slice *cl_page_at(const struct cl_page *page,
423 const struct lu_device_type *dtype)
425 return cl_page_at_trusted(page, dtype);
427 EXPORT_SYMBOL(cl_page_at);
429 #define CL_PAGE_OP(opname) offsetof(struct cl_page_operations, opname)
431 #define CL_PAGE_INVOKE(_env, _page, _op, _proto, ...) \
433 const struct lu_env *__env = (_env); \
434 struct cl_page *__page = (_page); \
435 const struct cl_page_slice *__scan; \
437 ptrdiff_t __op = (_op); \
438 int (*__method)_proto; \
441 list_for_each_entry(__scan, &__page->cp_layers, cpl_linkage) { \
442 __method = *(void **)((char *)__scan->cpl_ops + __op); \
443 if (__method != NULL) { \
444 __result = (*__method)(__env, __scan, ## __VA_ARGS__); \
454 #define CL_PAGE_INVOID(_env, _page, _op, _proto, ...) \
456 const struct lu_env *__env = (_env); \
457 struct cl_page *__page = (_page); \
458 const struct cl_page_slice *__scan; \
459 ptrdiff_t __op = (_op); \
460 void (*__method)_proto; \
462 list_for_each_entry(__scan, &__page->cp_layers, cpl_linkage) { \
463 __method = *(void **)((char *)__scan->cpl_ops + __op); \
464 if (__method != NULL) \
465 (*__method)(__env, __scan, ## __VA_ARGS__); \
469 #define CL_PAGE_INVOID_REVERSE(_env, _page, _op, _proto, ...) \
471 const struct lu_env *__env = (_env); \
472 struct cl_page *__page = (_page); \
473 const struct cl_page_slice *__scan; \
474 ptrdiff_t __op = (_op); \
475 void (*__method)_proto; \
477 /* get to the bottom page. */ \
478 list_for_each_entry_reverse(__scan, &__page->cp_layers, \
480 __method = *(void **)((char *)__scan->cpl_ops + __op); \
481 if (__method != NULL) \
482 (*__method)(__env, __scan, ## __VA_ARGS__); \
486 static int cl_page_invoke(const struct lu_env *env,
487 struct cl_io *io, struct cl_page *page, ptrdiff_t op)
490 PINVRNT(env, page, cl_object_same(page->cp_obj, io->ci_obj));
492 RETURN(CL_PAGE_INVOKE(env, page, op,
493 (const struct lu_env *,
494 const struct cl_page_slice *, struct cl_io *),
498 static void cl_page_invoid(const struct lu_env *env,
499 struct cl_io *io, struct cl_page *page, ptrdiff_t op)
502 PINVRNT(env, page, cl_object_same(page->cp_obj, io->ci_obj));
504 CL_PAGE_INVOID(env, page, op,
505 (const struct lu_env *,
506 const struct cl_page_slice *, struct cl_io *), io);
510 static void cl_page_owner_clear(struct cl_page *page)
513 if (page->cp_owner != NULL) {
514 LASSERT(page->cp_owner->ci_owned_nr > 0);
515 page->cp_owner->ci_owned_nr--;
516 page->cp_owner = NULL;
521 static void cl_page_owner_set(struct cl_page *page)
524 LASSERT(page->cp_owner != NULL);
525 page->cp_owner->ci_owned_nr++;
529 void cl_page_disown0(const struct lu_env *env,
530 struct cl_io *io, struct cl_page *pg)
532 enum cl_page_state state;
535 state = pg->cp_state;
536 PINVRNT(env, pg, state == CPS_OWNED || state == CPS_FREEING);
537 PINVRNT(env, pg, cl_page_invariant(pg) || state == CPS_FREEING);
538 cl_page_owner_clear(pg);
540 if (state == CPS_OWNED)
541 cl_page_state_set(env, pg, CPS_CACHED);
543 * Completion call-backs are executed in the bottom-up order, so that
544 * uppermost layer (llite), responsible for VFS/VM interaction runs
545 * last and can release locks safely.
547 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_disown),
548 (const struct lu_env *,
549 const struct cl_page_slice *, struct cl_io *),
555 * returns true, iff page is owned by the given io.
557 int cl_page_is_owned(const struct cl_page *pg, const struct cl_io *io)
559 struct cl_io *top = cl_io_top((struct cl_io *)io);
560 LINVRNT(cl_object_same(pg->cp_obj, io->ci_obj));
562 RETURN(pg->cp_state == CPS_OWNED && pg->cp_owner == top);
564 EXPORT_SYMBOL(cl_page_is_owned);
567 * Try to own a page by IO.
569 * Waits until page is in cl_page_state::CPS_CACHED state, and then switch it
570 * into cl_page_state::CPS_OWNED state.
572 * \pre !cl_page_is_owned(pg, io)
573 * \post result == 0 iff cl_page_is_owned(pg, io)
577 * \retval -ve failure, e.g., page was destroyed (and landed in
578 * cl_page_state::CPS_FREEING instead of cl_page_state::CPS_CACHED).
579 * or, page was owned by another thread, or in IO.
581 * \see cl_page_disown()
582 * \see cl_page_operations::cpo_own()
583 * \see cl_page_own_try()
586 static int cl_page_own0(const struct lu_env *env, struct cl_io *io,
587 struct cl_page *pg, int nonblock)
591 PINVRNT(env, pg, !cl_page_is_owned(pg, io));
596 if (pg->cp_state == CPS_FREEING) {
599 result = CL_PAGE_INVOKE(env, pg, CL_PAGE_OP(cpo_own),
600 (const struct lu_env *,
601 const struct cl_page_slice *,
602 struct cl_io *, int),
605 PASSERT(env, pg, pg->cp_owner == NULL);
606 PASSERT(env, pg, pg->cp_req == NULL);
607 pg->cp_owner = cl_io_top(io);;
608 cl_page_owner_set(pg);
609 if (pg->cp_state != CPS_FREEING) {
610 cl_page_state_set(env, pg, CPS_OWNED);
612 cl_page_disown0(env, io, pg);
617 PINVRNT(env, pg, ergo(result == 0, cl_page_invariant(pg)));
622 * Own a page, might be blocked.
624 * \see cl_page_own0()
626 int cl_page_own(const struct lu_env *env, struct cl_io *io, struct cl_page *pg)
628 return cl_page_own0(env, io, pg, 0);
630 EXPORT_SYMBOL(cl_page_own);
633 * Nonblock version of cl_page_own().
635 * \see cl_page_own0()
637 int cl_page_own_try(const struct lu_env *env, struct cl_io *io,
640 return cl_page_own0(env, io, pg, 1);
642 EXPORT_SYMBOL(cl_page_own_try);
646 * Assume page ownership.
648 * Called when page is already locked by the hosting VM.
650 * \pre !cl_page_is_owned(pg, io)
651 * \post cl_page_is_owned(pg, io)
653 * \see cl_page_operations::cpo_assume()
655 void cl_page_assume(const struct lu_env *env,
656 struct cl_io *io, struct cl_page *pg)
658 PINVRNT(env, pg, cl_object_same(pg->cp_obj, io->ci_obj));
663 cl_page_invoid(env, io, pg, CL_PAGE_OP(cpo_assume));
664 PASSERT(env, pg, pg->cp_owner == NULL);
665 pg->cp_owner = cl_io_top(io);
666 cl_page_owner_set(pg);
667 cl_page_state_set(env, pg, CPS_OWNED);
670 EXPORT_SYMBOL(cl_page_assume);
673 * Releases page ownership without unlocking the page.
675 * Moves page into cl_page_state::CPS_CACHED without releasing a lock on the
676 * underlying VM page (as VM is supposed to do this itself).
678 * \pre cl_page_is_owned(pg, io)
679 * \post !cl_page_is_owned(pg, io)
681 * \see cl_page_assume()
683 void cl_page_unassume(const struct lu_env *env,
684 struct cl_io *io, struct cl_page *pg)
686 PINVRNT(env, pg, cl_page_is_owned(pg, io));
687 PINVRNT(env, pg, cl_page_invariant(pg));
691 cl_page_owner_clear(pg);
692 cl_page_state_set(env, pg, CPS_CACHED);
693 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_unassume),
694 (const struct lu_env *,
695 const struct cl_page_slice *, struct cl_io *),
699 EXPORT_SYMBOL(cl_page_unassume);
702 * Releases page ownership.
704 * Moves page into cl_page_state::CPS_CACHED.
706 * \pre cl_page_is_owned(pg, io)
707 * \post !cl_page_is_owned(pg, io)
710 * \see cl_page_operations::cpo_disown()
712 void cl_page_disown(const struct lu_env *env,
713 struct cl_io *io, struct cl_page *pg)
715 PINVRNT(env, pg, cl_page_is_owned(pg, io) ||
716 pg->cp_state == CPS_FREEING);
720 cl_page_disown0(env, io, pg);
723 EXPORT_SYMBOL(cl_page_disown);
726 * Called when page is to be removed from the object, e.g., as a result of
729 * Calls cl_page_operations::cpo_discard() top-to-bottom.
731 * \pre cl_page_is_owned(pg, io)
733 * \see cl_page_operations::cpo_discard()
735 void cl_page_discard(const struct lu_env *env,
736 struct cl_io *io, struct cl_page *pg)
738 PINVRNT(env, pg, cl_page_is_owned(pg, io));
739 PINVRNT(env, pg, cl_page_invariant(pg));
741 cl_page_invoid(env, io, pg, CL_PAGE_OP(cpo_discard));
743 EXPORT_SYMBOL(cl_page_discard);
746 * Version of cl_page_delete() that can be called for not fully constructed
747 * pages, e.g. in an error handling cl_page_find()->cl_page_delete0()
748 * path. Doesn't check page invariant.
750 static void cl_page_delete0(const struct lu_env *env, struct cl_page *pg)
754 PASSERT(env, pg, pg->cp_state != CPS_FREEING);
757 * Severe all ways to obtain new pointers to @pg.
759 cl_page_owner_clear(pg);
761 cl_page_state_set0(env, pg, CPS_FREEING);
763 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_delete),
764 (const struct lu_env *, const struct cl_page_slice *));
770 * Called when a decision is made to throw page out of memory.
772 * Notifies all layers about page destruction by calling
773 * cl_page_operations::cpo_delete() method top-to-bottom.
775 * Moves page into cl_page_state::CPS_FREEING state (this is the only place
776 * where transition to this state happens).
778 * Eliminates all venues through which new references to the page can be
781 * - removes page from the radix trees,
783 * - breaks linkage from VM page to cl_page.
785 * Once page reaches cl_page_state::CPS_FREEING, all remaining references will
786 * drain after some time, at which point page will be recycled.
788 * \pre VM page is locked
789 * \post pg->cp_state == CPS_FREEING
791 * \see cl_page_operations::cpo_delete()
793 void cl_page_delete(const struct lu_env *env, struct cl_page *pg)
795 PINVRNT(env, pg, cl_page_invariant(pg));
797 cl_page_delete0(env, pg);
800 EXPORT_SYMBOL(cl_page_delete);
803 * Marks page up-to-date.
805 * Call cl_page_operations::cpo_export() through all layers top-to-bottom. The
806 * layer responsible for VM interaction has to mark/clear page as up-to-date
807 * by the \a uptodate argument.
809 * \see cl_page_operations::cpo_export()
811 void cl_page_export(const struct lu_env *env, struct cl_page *pg, int uptodate)
813 PINVRNT(env, pg, cl_page_invariant(pg));
814 CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_export),
815 (const struct lu_env *,
816 const struct cl_page_slice *, int), uptodate);
818 EXPORT_SYMBOL(cl_page_export);
821 * Returns true, iff \a pg is VM locked in a suitable sense by the calling
824 int cl_page_is_vmlocked(const struct lu_env *env, const struct cl_page *pg)
827 const struct cl_page_slice *slice;
830 slice = container_of(pg->cp_layers.next,
831 const struct cl_page_slice, cpl_linkage);
832 PASSERT(env, pg, slice->cpl_ops->cpo_is_vmlocked != NULL);
834 * Call ->cpo_is_vmlocked() directly instead of going through
835 * CL_PAGE_INVOKE(), because cl_page_is_vmlocked() is used by
836 * cl_page_invariant().
838 result = slice->cpl_ops->cpo_is_vmlocked(env, slice);
839 PASSERT(env, pg, result == -EBUSY || result == -ENODATA);
840 RETURN(result == -EBUSY);
842 EXPORT_SYMBOL(cl_page_is_vmlocked);
844 static enum cl_page_state cl_req_type_state(enum cl_req_type crt)
847 RETURN(crt == CRT_WRITE ? CPS_PAGEOUT : CPS_PAGEIN);
850 static void cl_page_io_start(const struct lu_env *env,
851 struct cl_page *pg, enum cl_req_type crt)
854 * Page is queued for IO, change its state.
857 cl_page_owner_clear(pg);
858 cl_page_state_set(env, pg, cl_req_type_state(crt));
863 * Prepares page for immediate transfer. cl_page_operations::cpo_prep() is
864 * called top-to-bottom. Every layer either agrees to submit this page (by
865 * returning 0), or requests to omit this page (by returning -EALREADY). Layer
866 * handling interactions with the VM also has to inform VM that page is under
869 int cl_page_prep(const struct lu_env *env, struct cl_io *io,
870 struct cl_page *pg, enum cl_req_type crt)
874 PINVRNT(env, pg, cl_page_is_owned(pg, io));
875 PINVRNT(env, pg, cl_page_invariant(pg));
876 PINVRNT(env, pg, crt < CRT_NR);
879 * XXX this has to be called bottom-to-top, so that llite can set up
880 * PG_writeback without risking other layers deciding to skip this
885 result = cl_page_invoke(env, io, pg, CL_PAGE_OP(io[crt].cpo_prep));
887 cl_page_io_start(env, pg, crt);
889 KLASSERT(ergo(crt == CRT_WRITE && pg->cp_type == CPT_CACHEABLE,
891 PageWriteback(cl_page_vmpage(pg)))));
892 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result);
895 EXPORT_SYMBOL(cl_page_prep);
898 * Notify layers about transfer completion.
900 * Invoked by transfer sub-system (which is a part of osc) to notify layers
901 * that a transfer, of which this page is a part of has completed.
903 * Completion call-backs are executed in the bottom-up order, so that
904 * uppermost layer (llite), responsible for the VFS/VM interaction runs last
905 * and can release locks safely.
907 * \pre pg->cp_state == CPS_PAGEIN || pg->cp_state == CPS_PAGEOUT
908 * \post pg->cp_state == CPS_CACHED
910 * \see cl_page_operations::cpo_completion()
912 void cl_page_completion(const struct lu_env *env,
913 struct cl_page *pg, enum cl_req_type crt, int ioret)
915 struct cl_sync_io *anchor = pg->cp_sync_io;
917 PASSERT(env, pg, crt < CRT_NR);
918 /* cl_page::cp_req already cleared by the caller (osc_completion()) */
919 PASSERT(env, pg, pg->cp_req == NULL);
920 PASSERT(env, pg, pg->cp_state == cl_req_type_state(crt));
923 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, ioret);
924 cl_page_state_set(env, pg, CPS_CACHED);
927 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(io[crt].cpo_completion),
928 (const struct lu_env *,
929 const struct cl_page_slice *, int), ioret);
931 LASSERT(pg->cp_sync_io == anchor);
932 pg->cp_sync_io = NULL;
935 * As page->cp_obj is pinned by a reference from page->cp_req, it is
936 * safe to call cl_page_put() without risking object destruction in a
937 * non-blocking context.
939 cl_page_put(env, pg);
942 cl_sync_io_note(env, anchor, ioret);
946 EXPORT_SYMBOL(cl_page_completion);
949 * Notify layers that transfer formation engine decided to yank this page from
950 * the cache and to make it a part of a transfer.
952 * \pre pg->cp_state == CPS_CACHED
953 * \post pg->cp_state == CPS_PAGEIN || pg->cp_state == CPS_PAGEOUT
955 * \see cl_page_operations::cpo_make_ready()
957 int cl_page_make_ready(const struct lu_env *env, struct cl_page *pg,
958 enum cl_req_type crt)
962 PINVRNT(env, pg, crt < CRT_NR);
967 result = CL_PAGE_INVOKE(env, pg, CL_PAGE_OP(io[crt].cpo_make_ready),
968 (const struct lu_env *,
969 const struct cl_page_slice *));
971 PASSERT(env, pg, pg->cp_state == CPS_CACHED);
972 cl_page_io_start(env, pg, crt);
974 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result);
977 EXPORT_SYMBOL(cl_page_make_ready);
980 * Called if a pge is being written back by kernel's intention.
982 * \pre cl_page_is_owned(pg, io)
983 * \post ergo(result == 0, pg->cp_state == CPS_PAGEOUT)
985 * \see cl_page_operations::cpo_flush()
987 int cl_page_flush(const struct lu_env *env, struct cl_io *io,
992 PINVRNT(env, pg, cl_page_is_owned(pg, io));
993 PINVRNT(env, pg, cl_page_invariant(pg));
997 result = cl_page_invoke(env, io, pg, CL_PAGE_OP(cpo_flush));
999 CL_PAGE_HEADER(D_TRACE, env, pg, "%d\n", result);
1002 EXPORT_SYMBOL(cl_page_flush);
1005 * Tells transfer engine that only part of a page is to be transmitted.
1007 * \see cl_page_operations::cpo_clip()
1009 void cl_page_clip(const struct lu_env *env, struct cl_page *pg,
1012 PINVRNT(env, pg, cl_page_invariant(pg));
1014 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", from, to);
1015 CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_clip),
1016 (const struct lu_env *,
1017 const struct cl_page_slice *,int, int),
1020 EXPORT_SYMBOL(cl_page_clip);
1023 * Prints human readable representation of \a pg to the \a f.
1025 void cl_page_header_print(const struct lu_env *env, void *cookie,
1026 lu_printer_t printer, const struct cl_page *pg)
1028 (*printer)(env, cookie,
1029 "page@%p[%d %p %d %d %d %p %p]\n",
1030 pg, atomic_read(&pg->cp_ref), pg->cp_obj,
1031 pg->cp_state, pg->cp_error, pg->cp_type,
1032 pg->cp_owner, pg->cp_req);
1034 EXPORT_SYMBOL(cl_page_header_print);
1037 * Prints human readable representation of \a pg to the \a f.
1039 void cl_page_print(const struct lu_env *env, void *cookie,
1040 lu_printer_t printer, const struct cl_page *pg)
1042 cl_page_header_print(env, cookie, printer, pg);
1043 CL_PAGE_INVOKE(env, (struct cl_page *)pg, CL_PAGE_OP(cpo_print),
1044 (const struct lu_env *env,
1045 const struct cl_page_slice *slice,
1046 void *cookie, lu_printer_t p), cookie, printer);
1047 (*printer)(env, cookie, "end page@%p\n", pg);
1049 EXPORT_SYMBOL(cl_page_print);
1052 * Cancel a page which is still in a transfer.
1054 int cl_page_cancel(const struct lu_env *env, struct cl_page *page)
1056 return CL_PAGE_INVOKE(env, page, CL_PAGE_OP(cpo_cancel),
1057 (const struct lu_env *,
1058 const struct cl_page_slice *));
1062 * Converts a byte offset within object \a obj into a page index.
1064 loff_t cl_offset(const struct cl_object *obj, pgoff_t idx)
1066 return (loff_t)idx << PAGE_CACHE_SHIFT;
1068 EXPORT_SYMBOL(cl_offset);
1071 * Converts a page index into a byte offset within object \a obj.
1073 pgoff_t cl_index(const struct cl_object *obj, loff_t offset)
1075 return offset >> PAGE_CACHE_SHIFT;
1077 EXPORT_SYMBOL(cl_index);
1079 size_t cl_page_size(const struct cl_object *obj)
1081 return 1UL << PAGE_CACHE_SHIFT;
1083 EXPORT_SYMBOL(cl_page_size);
1086 * Adds page slice to the compound page.
1088 * This is called by cl_object_operations::coo_page_init() methods to add a
1089 * per-layer state to the page. New state is added at the end of
1090 * cl_page::cp_layers list, that is, it is at the bottom of the stack.
1092 * \see cl_lock_slice_add(), cl_req_slice_add(), cl_io_slice_add()
1094 void cl_page_slice_add(struct cl_page *page, struct cl_page_slice *slice,
1095 struct cl_object *obj, pgoff_t index,
1096 const struct cl_page_operations *ops)
1099 list_add_tail(&slice->cpl_linkage, &page->cp_layers);
1100 slice->cpl_obj = obj;
1101 slice->cpl_index = index;
1102 slice->cpl_ops = ops;
1103 slice->cpl_page = page;
1106 EXPORT_SYMBOL(cl_page_slice_add);
1109 * Allocate and initialize cl_cache, called by ll_init_sbi().
1111 struct cl_client_cache *cl_cache_init(unsigned long lru_page_max)
1113 struct cl_client_cache *cache = NULL;
1116 OBD_ALLOC(cache, sizeof(*cache));
1120 /* Initialize cache data */
1121 atomic_set(&cache->ccc_users, 1);
1122 cache->ccc_lru_max = lru_page_max;
1123 atomic_long_set(&cache->ccc_lru_left, lru_page_max);
1124 spin_lock_init(&cache->ccc_lru_lock);
1125 INIT_LIST_HEAD(&cache->ccc_lru);
1127 /* turn unstable check off by default as it impacts performance */
1128 cache->ccc_unstable_check = 0;
1129 atomic_long_set(&cache->ccc_unstable_nr, 0);
1130 init_waitqueue_head(&cache->ccc_unstable_waitq);
1134 EXPORT_SYMBOL(cl_cache_init);
1137 * Increase cl_cache refcount
1139 void cl_cache_incref(struct cl_client_cache *cache)
1141 atomic_inc(&cache->ccc_users);
1143 EXPORT_SYMBOL(cl_cache_incref);
1146 * Decrease cl_cache refcount and free the cache if refcount=0.
1147 * Since llite, lov and osc all hold cl_cache refcount,
1148 * the free will not cause race. (LU-6173)
1150 void cl_cache_decref(struct cl_client_cache *cache)
1152 if (atomic_dec_and_test(&cache->ccc_users))
1153 OBD_FREE(cache, sizeof(*cache));
1155 EXPORT_SYMBOL(cl_cache_decref);