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, 2015, 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 <linux/list.h>
45 #include <libcfs/libcfs.h>
46 #include <obd_class.h>
47 #include <obd_support.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_state == CPS_FREEING);
143 while (!list_empty(&page->cp_layers)) {
144 struct cl_page_slice *slice;
146 slice = list_entry(page->cp_layers.next,
147 struct cl_page_slice, cpl_linkage);
148 list_del_init(page->cp_layers.next);
149 if (unlikely(slice->cpl_ops->cpo_fini != NULL))
150 slice->cpl_ops->cpo_fini(env, slice);
152 CS_PAGE_DEC(obj, total);
153 CS_PAGESTATE_DEC(obj, page->cp_state);
154 lu_object_ref_del_at(&obj->co_lu, &page->cp_obj_ref, "cl_page", page);
155 cl_object_put(env, obj);
156 lu_ref_fini(&page->cp_reference);
157 OBD_FREE(page, pagesize);
162 * Helper function updating page state. This is the only place in the code
163 * where cl_page::cp_state field is mutated.
165 static inline void cl_page_state_set_trust(struct cl_page *page,
166 enum cl_page_state state)
169 *(enum cl_page_state *)&page->cp_state = state;
172 struct cl_page *cl_page_alloc(const struct lu_env *env,
173 struct cl_object *o, pgoff_t ind, struct page *vmpage,
174 enum cl_page_type type)
176 struct cl_page *page;
177 struct lu_object_header *head;
180 OBD_ALLOC_GFP(page, cl_object_header(o)->coh_page_bufsize,
184 atomic_set(&page->cp_ref, 1);
187 lu_object_ref_add_at(&o->co_lu, &page->cp_obj_ref, "cl_page",
189 page->cp_vmpage = vmpage;
190 cl_page_state_set_trust(page, CPS_CACHED);
191 page->cp_type = type;
192 INIT_LIST_HEAD(&page->cp_layers);
193 INIT_LIST_HEAD(&page->cp_batch);
194 lu_ref_init(&page->cp_reference);
195 head = o->co_lu.lo_header;
196 list_for_each_entry(o, &head->loh_layers,
198 if (o->co_ops->coo_page_init != NULL) {
199 result = o->co_ops->coo_page_init(env, o, page,
202 cl_page_delete0(env, page);
203 cl_page_free(env, page);
204 page = ERR_PTR(result);
210 CS_PAGE_INC(o, total);
211 CS_PAGE_INC(o, create);
212 CS_PAGESTATE_DEC(o, CPS_CACHED);
215 page = ERR_PTR(-ENOMEM);
221 * Returns a cl_page with index \a idx at the object \a o, and associated with
222 * the VM page \a vmpage.
224 * This is the main entry point into the cl_page caching interface. First, a
225 * cache (implemented as a per-object radix tree) is consulted. If page is
226 * found there, it is returned immediately. Otherwise new page is allocated
227 * and returned. In any case, additional reference to page is acquired.
229 * \see cl_object_find(), cl_lock_find()
231 struct cl_page *cl_page_find(const struct lu_env *env,
233 pgoff_t idx, struct page *vmpage,
234 enum cl_page_type type)
236 struct cl_page *page = NULL;
237 struct cl_object_header *hdr;
239 LASSERT(type == CPT_CACHEABLE || type == CPT_TRANSIENT);
244 hdr = cl_object_header(o);
245 CS_PAGE_INC(o, lookup);
247 CDEBUG(D_PAGE, "%lu@"DFID" %p %lx %d\n",
248 idx, PFID(&hdr->coh_lu.loh_fid), vmpage, vmpage->private, type);
250 if (type == CPT_CACHEABLE) {
251 /* vmpage lock is used to protect the child/parent
253 KLASSERT(PageLocked(vmpage));
255 * cl_vmpage_page() can be called here without any locks as
257 * - "vmpage" is locked (which prevents ->private from
258 * concurrent updates), and
260 * - "o" cannot be destroyed while current thread holds a
263 page = cl_vmpage_page(vmpage, o);
270 /* allocate and initialize cl_page */
271 page = cl_page_alloc(env, o, idx, vmpage, type);
274 EXPORT_SYMBOL(cl_page_find);
276 static inline int cl_page_invariant(const struct cl_page *pg)
278 return cl_page_in_use_noref(pg);
281 static void cl_page_state_set0(const struct lu_env *env,
282 struct cl_page *page, enum cl_page_state state)
284 enum cl_page_state old;
287 * Matrix of allowed state transitions [old][new], for sanity
290 static const int allowed_transitions[CPS_NR][CPS_NR] = {
293 [CPS_OWNED] = 1, /* io finds existing cached page */
295 [CPS_PAGEOUT] = 1, /* write-out from the cache */
296 [CPS_FREEING] = 1, /* eviction on the memory pressure */
299 [CPS_CACHED] = 1, /* release to the cache */
301 [CPS_PAGEIN] = 1, /* start read immediately */
302 [CPS_PAGEOUT] = 1, /* start write immediately */
303 [CPS_FREEING] = 1, /* lock invalidation or truncate */
306 [CPS_CACHED] = 1, /* io completion */
313 [CPS_CACHED] = 1, /* io completion */
329 old = page->cp_state;
330 PASSERT(env, page, allowed_transitions[old][state]);
331 CL_PAGE_HEADER(D_TRACE, env, page, "%d -> %d\n", old, state);
332 PASSERT(env, page, page->cp_state == old);
333 PASSERT(env, page, equi(state == CPS_OWNED, page->cp_owner != NULL));
335 CS_PAGESTATE_DEC(page->cp_obj, page->cp_state);
336 CS_PAGESTATE_INC(page->cp_obj, state);
337 cl_page_state_set_trust(page, state);
341 static void cl_page_state_set(const struct lu_env *env,
342 struct cl_page *page, enum cl_page_state state)
344 cl_page_state_set0(env, page, state);
348 * Acquires an additional reference to a page.
350 * This can be called only by caller already possessing a reference to \a
353 * \see cl_object_get(), cl_lock_get().
355 void cl_page_get(struct cl_page *page)
358 cl_page_get_trust(page);
361 EXPORT_SYMBOL(cl_page_get);
364 * Releases a reference to a page.
366 * When last reference is released, page is returned to the cache, unless it
367 * is in cl_page_state::CPS_FREEING state, in which case it is immediately
370 * \see cl_object_put(), cl_lock_put().
372 void cl_page_put(const struct lu_env *env, struct cl_page *page)
375 CL_PAGE_HEADER(D_TRACE, env, page, "%d\n",
376 atomic_read(&page->cp_ref));
378 if (atomic_dec_and_test(&page->cp_ref)) {
379 LASSERT(page->cp_state == CPS_FREEING);
381 LASSERT(atomic_read(&page->cp_ref) == 0);
382 PASSERT(env, page, page->cp_owner == NULL);
383 PASSERT(env, page, list_empty(&page->cp_batch));
385 * Page is no longer reachable by other threads. Tear
388 cl_page_free(env, page);
393 EXPORT_SYMBOL(cl_page_put);
396 * Returns a cl_page associated with a VM page, and given cl_object.
398 struct cl_page *cl_vmpage_page(struct page *vmpage, struct cl_object *obj)
400 struct cl_page *page;
403 KLASSERT(PageLocked(vmpage));
406 * NOTE: absence of races and liveness of data are guaranteed by page
407 * lock on a "vmpage". That works because object destruction has
408 * bottom-to-top pass.
411 page = (struct cl_page *)vmpage->private;
413 cl_page_get_trust(page);
414 LASSERT(page->cp_type == CPT_CACHEABLE);
418 EXPORT_SYMBOL(cl_vmpage_page);
420 const struct cl_page_slice *cl_page_at(const struct cl_page *page,
421 const struct lu_device_type *dtype)
423 return cl_page_at_trusted(page, dtype);
425 EXPORT_SYMBOL(cl_page_at);
427 #define CL_PAGE_OP(opname) offsetof(struct cl_page_operations, opname)
429 #define CL_PAGE_INVOKE(_env, _page, _op, _proto, ...) \
431 const struct lu_env *__env = (_env); \
432 struct cl_page *__page = (_page); \
433 const struct cl_page_slice *__scan; \
435 ptrdiff_t __op = (_op); \
436 int (*__method)_proto; \
439 list_for_each_entry(__scan, &__page->cp_layers, cpl_linkage) { \
440 __method = *(void **)((char *)__scan->cpl_ops + __op); \
441 if (__method != NULL) { \
442 __result = (*__method)(__env, __scan, ## __VA_ARGS__); \
452 #define CL_PAGE_INVOID(_env, _page, _op, _proto, ...) \
454 const struct lu_env *__env = (_env); \
455 struct cl_page *__page = (_page); \
456 const struct cl_page_slice *__scan; \
457 ptrdiff_t __op = (_op); \
458 void (*__method)_proto; \
460 list_for_each_entry(__scan, &__page->cp_layers, cpl_linkage) { \
461 __method = *(void **)((char *)__scan->cpl_ops + __op); \
462 if (__method != NULL) \
463 (*__method)(__env, __scan, ## __VA_ARGS__); \
467 #define CL_PAGE_INVOID_REVERSE(_env, _page, _op, _proto, ...) \
469 const struct lu_env *__env = (_env); \
470 struct cl_page *__page = (_page); \
471 const struct cl_page_slice *__scan; \
472 ptrdiff_t __op = (_op); \
473 void (*__method)_proto; \
475 /* get to the bottom page. */ \
476 list_for_each_entry_reverse(__scan, &__page->cp_layers, \
478 __method = *(void **)((char *)__scan->cpl_ops + __op); \
479 if (__method != NULL) \
480 (*__method)(__env, __scan, ## __VA_ARGS__); \
484 static int cl_page_invoke(const struct lu_env *env,
485 struct cl_io *io, struct cl_page *page, ptrdiff_t op)
488 PINVRNT(env, page, cl_object_same(page->cp_obj, io->ci_obj));
490 RETURN(CL_PAGE_INVOKE(env, page, op,
491 (const struct lu_env *,
492 const struct cl_page_slice *, struct cl_io *),
496 static void cl_page_invoid(const struct lu_env *env,
497 struct cl_io *io, struct cl_page *page, ptrdiff_t op)
500 PINVRNT(env, page, cl_object_same(page->cp_obj, io->ci_obj));
502 CL_PAGE_INVOID(env, page, op,
503 (const struct lu_env *,
504 const struct cl_page_slice *, struct cl_io *), io);
508 static void cl_page_owner_clear(struct cl_page *page)
511 if (page->cp_owner != NULL) {
512 LASSERT(page->cp_owner->ci_owned_nr > 0);
513 page->cp_owner->ci_owned_nr--;
514 page->cp_owner = NULL;
519 static void cl_page_owner_set(struct cl_page *page)
522 LASSERT(page->cp_owner != NULL);
523 page->cp_owner->ci_owned_nr++;
527 void cl_page_disown0(const struct lu_env *env,
528 struct cl_io *io, struct cl_page *pg)
530 enum cl_page_state state;
533 state = pg->cp_state;
534 PINVRNT(env, pg, state == CPS_OWNED || state == CPS_FREEING);
535 PINVRNT(env, pg, cl_page_invariant(pg) || state == CPS_FREEING);
536 cl_page_owner_clear(pg);
538 if (state == CPS_OWNED)
539 cl_page_state_set(env, pg, CPS_CACHED);
541 * Completion call-backs are executed in the bottom-up order, so that
542 * uppermost layer (llite), responsible for VFS/VM interaction runs
543 * last and can release locks safely.
545 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_disown),
546 (const struct lu_env *,
547 const struct cl_page_slice *, struct cl_io *),
553 * returns true, iff page is owned by the given io.
555 int cl_page_is_owned(const struct cl_page *pg, const struct cl_io *io)
557 struct cl_io *top = cl_io_top((struct cl_io *)io);
558 LINVRNT(cl_object_same(pg->cp_obj, io->ci_obj));
560 RETURN(pg->cp_state == CPS_OWNED && pg->cp_owner == top);
562 EXPORT_SYMBOL(cl_page_is_owned);
565 * Try to own a page by IO.
567 * Waits until page is in cl_page_state::CPS_CACHED state, and then switch it
568 * into cl_page_state::CPS_OWNED state.
570 * \pre !cl_page_is_owned(pg, io)
571 * \post result == 0 iff cl_page_is_owned(pg, io)
575 * \retval -ve failure, e.g., page was destroyed (and landed in
576 * cl_page_state::CPS_FREEING instead of cl_page_state::CPS_CACHED).
577 * or, page was owned by another thread, or in IO.
579 * \see cl_page_disown()
580 * \see cl_page_operations::cpo_own()
581 * \see cl_page_own_try()
584 static int cl_page_own0(const struct lu_env *env, struct cl_io *io,
585 struct cl_page *pg, int nonblock)
589 PINVRNT(env, pg, !cl_page_is_owned(pg, io));
594 if (pg->cp_state == CPS_FREEING) {
597 result = CL_PAGE_INVOKE(env, pg, CL_PAGE_OP(cpo_own),
598 (const struct lu_env *,
599 const struct cl_page_slice *,
600 struct cl_io *, int),
603 PASSERT(env, pg, pg->cp_owner == NULL);
604 pg->cp_owner = cl_io_top(io);;
605 cl_page_owner_set(pg);
606 if (pg->cp_state != CPS_FREEING) {
607 cl_page_state_set(env, pg, CPS_OWNED);
609 cl_page_disown0(env, io, pg);
614 PINVRNT(env, pg, ergo(result == 0, cl_page_invariant(pg)));
619 * Own a page, might be blocked.
621 * \see cl_page_own0()
623 int cl_page_own(const struct lu_env *env, struct cl_io *io, struct cl_page *pg)
625 return cl_page_own0(env, io, pg, 0);
627 EXPORT_SYMBOL(cl_page_own);
630 * Nonblock version of cl_page_own().
632 * \see cl_page_own0()
634 int cl_page_own_try(const struct lu_env *env, struct cl_io *io,
637 return cl_page_own0(env, io, pg, 1);
639 EXPORT_SYMBOL(cl_page_own_try);
643 * Assume page ownership.
645 * Called when page is already locked by the hosting VM.
647 * \pre !cl_page_is_owned(pg, io)
648 * \post cl_page_is_owned(pg, io)
650 * \see cl_page_operations::cpo_assume()
652 void cl_page_assume(const struct lu_env *env,
653 struct cl_io *io, struct cl_page *pg)
655 PINVRNT(env, pg, cl_object_same(pg->cp_obj, io->ci_obj));
660 cl_page_invoid(env, io, pg, CL_PAGE_OP(cpo_assume));
661 PASSERT(env, pg, pg->cp_owner == NULL);
662 pg->cp_owner = cl_io_top(io);
663 cl_page_owner_set(pg);
664 cl_page_state_set(env, pg, CPS_OWNED);
667 EXPORT_SYMBOL(cl_page_assume);
670 * Releases page ownership without unlocking the page.
672 * Moves page into cl_page_state::CPS_CACHED without releasing a lock on the
673 * underlying VM page (as VM is supposed to do this itself).
675 * \pre cl_page_is_owned(pg, io)
676 * \post !cl_page_is_owned(pg, io)
678 * \see cl_page_assume()
680 void cl_page_unassume(const struct lu_env *env,
681 struct cl_io *io, struct cl_page *pg)
683 PINVRNT(env, pg, cl_page_is_owned(pg, io));
684 PINVRNT(env, pg, cl_page_invariant(pg));
688 cl_page_owner_clear(pg);
689 cl_page_state_set(env, pg, CPS_CACHED);
690 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_unassume),
691 (const struct lu_env *,
692 const struct cl_page_slice *, struct cl_io *),
696 EXPORT_SYMBOL(cl_page_unassume);
699 * Releases page ownership.
701 * Moves page into cl_page_state::CPS_CACHED.
703 * \pre cl_page_is_owned(pg, io)
704 * \post !cl_page_is_owned(pg, io)
707 * \see cl_page_operations::cpo_disown()
709 void cl_page_disown(const struct lu_env *env,
710 struct cl_io *io, struct cl_page *pg)
712 PINVRNT(env, pg, cl_page_is_owned(pg, io) ||
713 pg->cp_state == CPS_FREEING);
717 cl_page_disown0(env, io, pg);
720 EXPORT_SYMBOL(cl_page_disown);
723 * Called when page is to be removed from the object, e.g., as a result of
726 * Calls cl_page_operations::cpo_discard() top-to-bottom.
728 * \pre cl_page_is_owned(pg, io)
730 * \see cl_page_operations::cpo_discard()
732 void cl_page_discard(const struct lu_env *env,
733 struct cl_io *io, struct cl_page *pg)
735 PINVRNT(env, pg, cl_page_is_owned(pg, io));
736 PINVRNT(env, pg, cl_page_invariant(pg));
738 cl_page_invoid(env, io, pg, CL_PAGE_OP(cpo_discard));
740 EXPORT_SYMBOL(cl_page_discard);
743 * Version of cl_page_delete() that can be called for not fully constructed
744 * pages, e.g. in an error handling cl_page_find()->cl_page_delete0()
745 * path. Doesn't check page invariant.
747 static void cl_page_delete0(const struct lu_env *env, struct cl_page *pg)
751 PASSERT(env, pg, pg->cp_state != CPS_FREEING);
754 * Severe all ways to obtain new pointers to @pg.
756 cl_page_owner_clear(pg);
758 cl_page_state_set0(env, pg, CPS_FREEING);
760 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(cpo_delete),
761 (const struct lu_env *, const struct cl_page_slice *));
767 * Called when a decision is made to throw page out of memory.
769 * Notifies all layers about page destruction by calling
770 * cl_page_operations::cpo_delete() method top-to-bottom.
772 * Moves page into cl_page_state::CPS_FREEING state (this is the only place
773 * where transition to this state happens).
775 * Eliminates all venues through which new references to the page can be
778 * - removes page from the radix trees,
780 * - breaks linkage from VM page to cl_page.
782 * Once page reaches cl_page_state::CPS_FREEING, all remaining references will
783 * drain after some time, at which point page will be recycled.
785 * \pre VM page is locked
786 * \post pg->cp_state == CPS_FREEING
788 * \see cl_page_operations::cpo_delete()
790 void cl_page_delete(const struct lu_env *env, struct cl_page *pg)
792 PINVRNT(env, pg, cl_page_invariant(pg));
794 cl_page_delete0(env, pg);
797 EXPORT_SYMBOL(cl_page_delete);
800 * Marks page up-to-date.
802 * Call cl_page_operations::cpo_export() through all layers top-to-bottom. The
803 * layer responsible for VM interaction has to mark/clear page as up-to-date
804 * by the \a uptodate argument.
806 * \see cl_page_operations::cpo_export()
808 void cl_page_export(const struct lu_env *env, struct cl_page *pg, int uptodate)
810 PINVRNT(env, pg, cl_page_invariant(pg));
811 CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_export),
812 (const struct lu_env *,
813 const struct cl_page_slice *, int), uptodate);
815 EXPORT_SYMBOL(cl_page_export);
818 * Returns true, iff \a pg is VM locked in a suitable sense by the calling
821 int cl_page_is_vmlocked(const struct lu_env *env, const struct cl_page *pg)
824 const struct cl_page_slice *slice;
827 slice = container_of(pg->cp_layers.next,
828 const struct cl_page_slice, cpl_linkage);
829 PASSERT(env, pg, slice->cpl_ops->cpo_is_vmlocked != NULL);
831 * Call ->cpo_is_vmlocked() directly instead of going through
832 * CL_PAGE_INVOKE(), because cl_page_is_vmlocked() is used by
833 * cl_page_invariant().
835 result = slice->cpl_ops->cpo_is_vmlocked(env, slice);
836 PASSERT(env, pg, result == -EBUSY || result == -ENODATA);
837 RETURN(result == -EBUSY);
839 EXPORT_SYMBOL(cl_page_is_vmlocked);
841 static enum cl_page_state cl_req_type_state(enum cl_req_type crt)
844 RETURN(crt == CRT_WRITE ? CPS_PAGEOUT : CPS_PAGEIN);
847 static void cl_page_io_start(const struct lu_env *env,
848 struct cl_page *pg, enum cl_req_type crt)
851 * Page is queued for IO, change its state.
854 cl_page_owner_clear(pg);
855 cl_page_state_set(env, pg, cl_req_type_state(crt));
860 * Prepares page for immediate transfer. cl_page_operations::cpo_prep() is
861 * called top-to-bottom. Every layer either agrees to submit this page (by
862 * returning 0), or requests to omit this page (by returning -EALREADY). Layer
863 * handling interactions with the VM also has to inform VM that page is under
866 int cl_page_prep(const struct lu_env *env, struct cl_io *io,
867 struct cl_page *pg, enum cl_req_type crt)
871 PINVRNT(env, pg, cl_page_is_owned(pg, io));
872 PINVRNT(env, pg, cl_page_invariant(pg));
873 PINVRNT(env, pg, crt < CRT_NR);
876 * XXX this has to be called bottom-to-top, so that llite can set up
877 * PG_writeback without risking other layers deciding to skip this
882 result = cl_page_invoke(env, io, pg, CL_PAGE_OP(io[crt].cpo_prep));
884 cl_page_io_start(env, pg, crt);
886 KLASSERT(ergo(crt == CRT_WRITE && pg->cp_type == CPT_CACHEABLE,
888 PageWriteback(cl_page_vmpage(pg)))));
889 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result);
892 EXPORT_SYMBOL(cl_page_prep);
895 * Notify layers about transfer completion.
897 * Invoked by transfer sub-system (which is a part of osc) to notify layers
898 * that a transfer, of which this page is a part of has completed.
900 * Completion call-backs are executed in the bottom-up order, so that
901 * uppermost layer (llite), responsible for the VFS/VM interaction runs last
902 * and can release locks safely.
904 * \pre pg->cp_state == CPS_PAGEIN || pg->cp_state == CPS_PAGEOUT
905 * \post pg->cp_state == CPS_CACHED
907 * \see cl_page_operations::cpo_completion()
909 void cl_page_completion(const struct lu_env *env,
910 struct cl_page *pg, enum cl_req_type crt, int ioret)
912 struct cl_sync_io *anchor = pg->cp_sync_io;
914 PASSERT(env, pg, crt < CRT_NR);
915 PASSERT(env, pg, pg->cp_state == cl_req_type_state(crt));
918 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, ioret);
919 cl_page_state_set(env, pg, CPS_CACHED);
922 CL_PAGE_INVOID_REVERSE(env, pg, CL_PAGE_OP(io[crt].cpo_completion),
923 (const struct lu_env *,
924 const struct cl_page_slice *, int), ioret);
925 if (anchor != NULL) {
926 LASSERT(pg->cp_sync_io == anchor);
927 pg->cp_sync_io = NULL;
928 cl_sync_io_note(env, anchor, ioret);
932 EXPORT_SYMBOL(cl_page_completion);
935 * Notify layers that transfer formation engine decided to yank this page from
936 * the cache and to make it a part of a transfer.
938 * \pre pg->cp_state == CPS_CACHED
939 * \post pg->cp_state == CPS_PAGEIN || pg->cp_state == CPS_PAGEOUT
941 * \see cl_page_operations::cpo_make_ready()
943 int cl_page_make_ready(const struct lu_env *env, struct cl_page *pg,
944 enum cl_req_type crt)
948 PINVRNT(env, pg, crt < CRT_NR);
953 result = CL_PAGE_INVOKE(env, pg, CL_PAGE_OP(io[crt].cpo_make_ready),
954 (const struct lu_env *,
955 const struct cl_page_slice *));
957 PASSERT(env, pg, pg->cp_state == CPS_CACHED);
958 cl_page_io_start(env, pg, crt);
960 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", crt, result);
963 EXPORT_SYMBOL(cl_page_make_ready);
966 * Called if a pge is being written back by kernel's intention.
968 * \pre cl_page_is_owned(pg, io)
969 * \post ergo(result == 0, pg->cp_state == CPS_PAGEOUT)
971 * \see cl_page_operations::cpo_flush()
973 int cl_page_flush(const struct lu_env *env, struct cl_io *io,
978 PINVRNT(env, pg, cl_page_is_owned(pg, io));
979 PINVRNT(env, pg, cl_page_invariant(pg));
983 result = cl_page_invoke(env, io, pg, CL_PAGE_OP(cpo_flush));
985 CL_PAGE_HEADER(D_TRACE, env, pg, "%d\n", result);
988 EXPORT_SYMBOL(cl_page_flush);
991 * Tells transfer engine that only part of a page is to be transmitted.
993 * \see cl_page_operations::cpo_clip()
995 void cl_page_clip(const struct lu_env *env, struct cl_page *pg,
998 PINVRNT(env, pg, cl_page_invariant(pg));
1000 CL_PAGE_HEADER(D_TRACE, env, pg, "%d %d\n", from, to);
1001 CL_PAGE_INVOID(env, pg, CL_PAGE_OP(cpo_clip),
1002 (const struct lu_env *,
1003 const struct cl_page_slice *,int, int),
1006 EXPORT_SYMBOL(cl_page_clip);
1009 * Prints human readable representation of \a pg to the \a f.
1011 void cl_page_header_print(const struct lu_env *env, void *cookie,
1012 lu_printer_t printer, const struct cl_page *pg)
1014 (*printer)(env, cookie,
1015 "page@%p[%d %p %d %d %p]\n",
1016 pg, atomic_read(&pg->cp_ref), pg->cp_obj,
1017 pg->cp_state, pg->cp_type,
1020 EXPORT_SYMBOL(cl_page_header_print);
1023 * Prints human readable representation of \a pg to the \a f.
1025 void cl_page_print(const struct lu_env *env, void *cookie,
1026 lu_printer_t printer, const struct cl_page *pg)
1028 cl_page_header_print(env, cookie, printer, pg);
1029 CL_PAGE_INVOKE(env, (struct cl_page *)pg, CL_PAGE_OP(cpo_print),
1030 (const struct lu_env *env,
1031 const struct cl_page_slice *slice,
1032 void *cookie, lu_printer_t p), cookie, printer);
1033 (*printer)(env, cookie, "end page@%p\n", pg);
1035 EXPORT_SYMBOL(cl_page_print);
1038 * Cancel a page which is still in a transfer.
1040 int cl_page_cancel(const struct lu_env *env, struct cl_page *page)
1042 return CL_PAGE_INVOKE(env, page, CL_PAGE_OP(cpo_cancel),
1043 (const struct lu_env *,
1044 const struct cl_page_slice *));
1048 * Converts a byte offset within object \a obj into a page index.
1050 loff_t cl_offset(const struct cl_object *obj, pgoff_t idx)
1052 return (loff_t)idx << PAGE_SHIFT;
1054 EXPORT_SYMBOL(cl_offset);
1057 * Converts a page index into a byte offset within object \a obj.
1059 pgoff_t cl_index(const struct cl_object *obj, loff_t offset)
1061 return offset >> PAGE_SHIFT;
1063 EXPORT_SYMBOL(cl_index);
1065 size_t cl_page_size(const struct cl_object *obj)
1067 return 1UL << PAGE_SHIFT;
1069 EXPORT_SYMBOL(cl_page_size);
1072 * Adds page slice to the compound page.
1074 * This is called by cl_object_operations::coo_page_init() methods to add a
1075 * per-layer state to the page. New state is added at the end of
1076 * cl_page::cp_layers list, that is, it is at the bottom of the stack.
1078 * \see cl_lock_slice_add(), cl_req_slice_add(), cl_io_slice_add()
1080 void cl_page_slice_add(struct cl_page *page, struct cl_page_slice *slice,
1081 struct cl_object *obj, pgoff_t index,
1082 const struct cl_page_operations *ops)
1085 list_add_tail(&slice->cpl_linkage, &page->cp_layers);
1086 slice->cpl_obj = obj;
1087 slice->cpl_index = index;
1088 slice->cpl_ops = ops;
1089 slice->cpl_page = page;
1092 EXPORT_SYMBOL(cl_page_slice_add);
1095 * Allocate and initialize cl_cache, called by ll_init_sbi().
1097 struct cl_client_cache *cl_cache_init(unsigned long lru_page_max)
1099 struct cl_client_cache *cache = NULL;
1102 OBD_ALLOC(cache, sizeof(*cache));
1106 /* Initialize cache data */
1107 atomic_set(&cache->ccc_users, 1);
1108 cache->ccc_lru_max = lru_page_max;
1109 atomic_long_set(&cache->ccc_lru_left, lru_page_max);
1110 spin_lock_init(&cache->ccc_lru_lock);
1111 INIT_LIST_HEAD(&cache->ccc_lru);
1113 /* turn unstable check off by default as it impacts performance */
1114 cache->ccc_unstable_check = 0;
1115 atomic_long_set(&cache->ccc_unstable_nr, 0);
1116 init_waitqueue_head(&cache->ccc_unstable_waitq);
1120 EXPORT_SYMBOL(cl_cache_init);
1123 * Increase cl_cache refcount
1125 void cl_cache_incref(struct cl_client_cache *cache)
1127 atomic_inc(&cache->ccc_users);
1129 EXPORT_SYMBOL(cl_cache_incref);
1132 * Decrease cl_cache refcount and free the cache if refcount=0.
1133 * Since llite, lov and osc all hold cl_cache refcount,
1134 * the free will not cause race. (LU-6173)
1136 void cl_cache_decref(struct cl_client_cache *cache)
1138 if (atomic_dec_and_test(&cache->ccc_users))
1139 OBD_FREE(cache, sizeof(*cache));
1141 EXPORT_SYMBOL(cl_cache_decref);