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.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2011, 2017, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
33 * Author: Nikita Danilov <nikita.danilov@sun.com>
34 * Author: Jinshan Xiong <jinshan.xiong@intel.com>
37 #define DEBUG_SUBSYSTEM S_CLASS
39 #include <linux/list.h>
40 #include <libcfs/libcfs.h>
41 #include <obd_class.h>
42 #include <obd_support.h>
44 #include <cl_object.h>
45 #include "cl_internal.h"
47 static void cl_page_delete0(const struct lu_env *env, struct cl_page *pg);
48 static DEFINE_MUTEX(cl_page_kmem_mutex);
51 # define PASSERT(env, page, expr) \
53 if (unlikely(!(expr))) { \
54 CL_PAGE_DEBUG(D_ERROR, (env), (page), #expr "\n"); \
58 #else /* !LIBCFS_DEBUG */
59 # define PASSERT(env, page, exp) \
60 ((void)sizeof(env), (void)sizeof(page), (void)sizeof !!(exp))
61 #endif /* !LIBCFS_DEBUG */
63 #ifdef CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK
64 # define PINVRNT(env, page, expr) \
66 if (unlikely(!(expr))) { \
67 CL_PAGE_DEBUG(D_ERROR, (env), (page), #expr "\n"); \
71 #else /* !CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK */
72 # define PINVRNT(env, page, exp) \
73 ((void)sizeof(env), (void)sizeof(page), (void)sizeof !!(exp))
74 #endif /* !CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK */
76 /* Disable page statistic by default due to huge performance penalty. */
77 static void cs_page_inc(const struct cl_object *obj,
78 enum cache_stats_item item)
80 #ifdef CONFIG_DEBUG_PAGESTATE_TRACKING
81 atomic_inc(&cl_object_site(obj)->cs_pages.cs_stats[item]);
85 static void cs_page_dec(const struct cl_object *obj,
86 enum cache_stats_item item)
88 #ifdef CONFIG_DEBUG_PAGESTATE_TRACKING
89 atomic_dec(&cl_object_site(obj)->cs_pages.cs_stats[item]);
93 static void cs_pagestate_inc(const struct cl_object *obj,
94 enum cl_page_state state)
96 #ifdef CONFIG_DEBUG_PAGESTATE_TRACKING
97 atomic_inc(&cl_object_site(obj)->cs_pages_state[state]);
101 static void cs_pagestate_dec(const struct cl_object *obj,
102 enum cl_page_state state)
104 #ifdef CONFIG_DEBUG_PAGESTATE_TRACKING
105 atomic_dec(&cl_object_site(obj)->cs_pages_state[state]);
110 * Internal version of cl_page_get().
112 * This function can be used to obtain initial reference to previously
113 * unreferenced cached object. It can be called only if concurrent page
114 * reclamation is somehow prevented, e.g., by keeping a lock on a VM page,
115 * associated with \a page.
117 * Use with care! Not exported.
119 static void cl_page_get_trust(struct cl_page *page)
121 LASSERT(atomic_read(&page->cp_ref) > 0);
122 atomic_inc(&page->cp_ref);
125 static struct cl_page_slice *
126 cl_page_slice_get(const struct cl_page *cl_page, int index)
128 if (index < 0 || index >= cl_page->cp_layer_count)
131 /* To get the cp_layer_offset values fit under 256 bytes, we
132 * use the offset beyond the end of struct cl_page.
134 return (struct cl_page_slice *)((char *)cl_page + sizeof(*cl_page) +
135 cl_page->cp_layer_offset[index]);
138 #define cl_page_slice_for_each(cl_page, slice, i) \
139 for (i = 0, slice = cl_page_slice_get(cl_page, 0); \
140 i < (cl_page)->cp_layer_count; \
141 slice = cl_page_slice_get(cl_page, ++i))
143 #define cl_page_slice_for_each_reverse(cl_page, slice, i) \
144 for (i = (cl_page)->cp_layer_count - 1, \
145 slice = cl_page_slice_get(cl_page, i); i >= 0; \
146 slice = cl_page_slice_get(cl_page, --i))
149 * Returns a slice within a cl_page, corresponding to the given layer in the
154 static const struct cl_page_slice *
155 cl_page_at_trusted(const struct cl_page *cl_page,
156 const struct lu_device_type *dtype)
158 const struct cl_page_slice *slice;
163 cl_page_slice_for_each(cl_page, slice, i) {
164 if (slice->cpl_obj->co_lu.lo_dev->ld_type == dtype)
171 static void __cl_page_free(struct cl_page *cl_page, unsigned short bufsize)
173 int index = cl_page->cp_kmem_index;
176 LASSERT(index < ARRAY_SIZE(cl_page_kmem_array));
177 LASSERT(cl_page_kmem_size_array[index] == bufsize);
178 OBD_SLAB_FREE(cl_page, cl_page_kmem_array[index], bufsize);
180 OBD_FREE(cl_page, bufsize);
184 static void cl_page_free(const struct lu_env *env, struct cl_page *cl_page,
185 struct pagevec *pvec)
187 struct cl_object *obj = cl_page->cp_obj;
188 unsigned short bufsize = cl_object_header(obj)->coh_page_bufsize;
189 struct cl_page_slice *slice;
193 PASSERT(env, cl_page, list_empty(&cl_page->cp_batch));
194 PASSERT(env, cl_page, cl_page->cp_owner == NULL);
195 PASSERT(env, cl_page, cl_page->cp_state == CPS_FREEING);
197 cl_page_slice_for_each(cl_page, slice, i) {
198 if (unlikely(slice->cpl_ops->cpo_fini != NULL))
199 slice->cpl_ops->cpo_fini(env, slice, pvec);
201 cl_page->cp_layer_count = 0;
202 cs_page_dec(obj, CS_total);
203 cs_pagestate_dec(obj, cl_page->cp_state);
204 lu_object_ref_del_at(&obj->co_lu, &cl_page->cp_obj_ref,
206 if (cl_page->cp_type != CPT_TRANSIENT)
207 cl_object_put(env, obj);
208 lu_ref_fini(&cl_page->cp_reference);
209 __cl_page_free(cl_page, bufsize);
213 static struct cl_page *__cl_page_alloc(struct cl_object *o)
216 struct cl_page *cl_page = NULL;
217 unsigned short bufsize = cl_object_header(o)->coh_page_bufsize;
219 if (OBD_FAIL_CHECK(OBD_FAIL_LLITE_PAGE_ALLOC))
223 /* the number of entries in cl_page_kmem_array is expected to
224 * only be 2-3 entries, so the lookup overhead should be low.
226 for ( ; i < ARRAY_SIZE(cl_page_kmem_array); i++) {
227 if (smp_load_acquire(&cl_page_kmem_size_array[i])
229 OBD_SLAB_ALLOC_GFP(cl_page, cl_page_kmem_array[i],
232 cl_page->cp_kmem_index = i;
235 if (cl_page_kmem_size_array[i] == 0)
239 if (i < ARRAY_SIZE(cl_page_kmem_array)) {
242 mutex_lock(&cl_page_kmem_mutex);
243 if (cl_page_kmem_size_array[i]) {
244 mutex_unlock(&cl_page_kmem_mutex);
247 snprintf(cache_name, sizeof(cache_name),
248 "cl_page_kmem-%u", bufsize);
249 cl_page_kmem_array[i] =
250 kmem_cache_create(cache_name, bufsize,
252 if (cl_page_kmem_array[i] == NULL) {
253 mutex_unlock(&cl_page_kmem_mutex);
256 smp_store_release(&cl_page_kmem_size_array[i],
258 mutex_unlock(&cl_page_kmem_mutex);
261 OBD_ALLOC_GFP(cl_page, bufsize, GFP_NOFS);
263 cl_page->cp_kmem_index = -1;
269 struct cl_page *cl_page_alloc(const struct lu_env *env, struct cl_object *o,
270 pgoff_t ind, struct page *vmpage,
271 enum cl_page_type type)
273 struct cl_page *cl_page;
274 struct cl_object *head;
278 cl_page = __cl_page_alloc(o);
279 if (cl_page != NULL) {
283 * Please fix cl_page:cp_state/type declaration if
284 * these assertions fail in the future.
286 BUILD_BUG_ON((1 << CP_STATE_BITS) < CPS_NR); /* cp_state */
287 BUILD_BUG_ON((1 << CP_TYPE_BITS) < CPT_NR); /* cp_type */
288 atomic_set(&cl_page->cp_ref, 1);
290 if (type != CPT_TRANSIENT)
292 lu_object_ref_add_at(&o->co_lu, &cl_page->cp_obj_ref,
294 cl_page->cp_vmpage = vmpage;
295 cl_page->cp_state = CPS_CACHED;
296 cl_page->cp_type = type;
297 if (type == CPT_TRANSIENT)
298 /* ref to correct inode will be added
299 * in ll_direct_rw_pages
301 cl_page->cp_inode = NULL;
303 cl_page->cp_inode = page2inode(vmpage);
304 INIT_LIST_HEAD(&cl_page->cp_batch);
305 lu_ref_init(&cl_page->cp_reference);
307 cl_page->cp_page_index = ind;
308 cl_object_for_each(o, head) {
309 if (o->co_ops->coo_page_init != NULL) {
310 result = o->co_ops->coo_page_init(env, o,
313 cl_page_delete0(env, cl_page);
314 cl_page_free(env, cl_page, NULL);
315 cl_page = ERR_PTR(result);
321 cs_page_inc(o, CS_total);
322 cs_page_inc(o, CS_create);
323 cs_pagestate_dec(o, CPS_CACHED);
326 cl_page = ERR_PTR(-ENOMEM);
332 * Returns a cl_page with index \a idx at the object \a o, and associated with
333 * the VM page \a vmpage.
335 * This is the main entry point into the cl_page caching interface. First, a
336 * cache (implemented as a per-object radix tree) is consulted. If page is
337 * found there, it is returned immediately. Otherwise new page is allocated
338 * and returned. In any case, additional reference to page is acquired.
340 * \see cl_object_find(), cl_lock_find()
342 struct cl_page *cl_page_find(const struct lu_env *env,
344 pgoff_t idx, struct page *vmpage,
345 enum cl_page_type type)
347 struct cl_page *page = NULL;
348 struct cl_object_header *hdr;
350 LASSERT(type == CPT_CACHEABLE || type == CPT_TRANSIENT);
355 hdr = cl_object_header(o);
356 cs_page_inc(o, CS_lookup);
358 CDEBUG(D_PAGE, "%lu@"DFID" %p %lx %d\n",
359 idx, PFID(&hdr->coh_lu.loh_fid), vmpage, vmpage->private, type);
361 if (type == CPT_CACHEABLE) {
362 /* vmpage lock is used to protect the child/parent
364 LASSERT(PageLocked(vmpage));
366 * cl_vmpage_page() can be called here without any locks as
368 * - "vmpage" is locked (which prevents ->private from
369 * concurrent updates), and
371 * - "o" cannot be destroyed while current thread holds a
374 page = cl_vmpage_page(vmpage, o);
376 cs_page_inc(o, CS_hit);
381 /* allocate and initialize cl_page */
382 page = cl_page_alloc(env, o, idx, vmpage, type);
385 EXPORT_SYMBOL(cl_page_find);
387 static inline int cl_page_invariant(const struct cl_page *pg)
389 return cl_page_in_use_noref(pg);
392 static void cl_page_state_set0(const struct lu_env *env,
393 struct cl_page *cl_page,
394 enum cl_page_state state)
396 enum cl_page_state old;
399 * Matrix of allowed state transitions [old][new], for sanity
402 static const int allowed_transitions[CPS_NR][CPS_NR] = {
405 [CPS_OWNED] = 1, /* io finds existing cached page */
407 [CPS_PAGEOUT] = 1, /* write-out from the cache */
408 [CPS_FREEING] = 1, /* eviction on the memory pressure */
411 [CPS_CACHED] = 1, /* release to the cache */
413 [CPS_PAGEIN] = 1, /* start read immediately */
414 [CPS_PAGEOUT] = 1, /* start write immediately */
415 [CPS_FREEING] = 1, /* lock invalidation or truncate */
418 [CPS_CACHED] = 1, /* io completion */
425 [CPS_CACHED] = 1, /* io completion */
441 old = cl_page->cp_state;
442 PASSERT(env, cl_page, allowed_transitions[old][state]);
443 CL_PAGE_HEADER(D_TRACE, env, cl_page, "%d -> %d\n", old, state);
444 PASSERT(env, cl_page, cl_page->cp_state == old);
445 PASSERT(env, cl_page, equi(state == CPS_OWNED,
446 cl_page->cp_owner != NULL));
448 cs_pagestate_dec(cl_page->cp_obj, cl_page->cp_state);
449 cs_pagestate_inc(cl_page->cp_obj, state);
450 cl_page->cp_state = state;
454 static void cl_page_state_set(const struct lu_env *env,
455 struct cl_page *page, enum cl_page_state state)
457 cl_page_state_set0(env, page, state);
461 * Acquires an additional reference to a page.
463 * This can be called only by caller already possessing a reference to \a
466 * \see cl_object_get(), cl_lock_get().
468 void cl_page_get(struct cl_page *page)
471 cl_page_get_trust(page);
474 EXPORT_SYMBOL(cl_page_get);
477 * Releases a reference to a page, use the pagevec to release the pages
478 * in batch if provided.
480 * Users need to do a final pagevec_release() to release any trailing pages.
482 void cl_pagevec_put(const struct lu_env *env, struct cl_page *page,
483 struct pagevec *pvec)
486 CL_PAGE_HEADER(D_TRACE, env, page, "%d\n",
487 atomic_read(&page->cp_ref));
489 if (atomic_dec_and_test(&page->cp_ref)) {
490 LASSERT(page->cp_state == CPS_FREEING);
492 LASSERT(atomic_read(&page->cp_ref) == 0);
493 PASSERT(env, page, page->cp_owner == NULL);
494 PASSERT(env, page, list_empty(&page->cp_batch));
496 * Page is no longer reachable by other threads. Tear
499 cl_page_free(env, page, pvec);
504 EXPORT_SYMBOL(cl_pagevec_put);
507 * Releases a reference to a page, wrapper to cl_pagevec_put
509 * When last reference is released, page is returned to the cache, unless it
510 * is in cl_page_state::CPS_FREEING state, in which case it is immediately
513 * \see cl_object_put(), cl_lock_put().
515 void cl_page_put(const struct lu_env *env, struct cl_page *page)
517 cl_pagevec_put(env, page, NULL);
519 EXPORT_SYMBOL(cl_page_put);
522 * Returns a cl_page associated with a VM page, and given cl_object.
524 struct cl_page *cl_vmpage_page(struct page *vmpage, struct cl_object *obj)
526 struct cl_page *page;
529 LASSERT(PageLocked(vmpage));
532 * NOTE: absence of races and liveness of data are guaranteed by page
533 * lock on a "vmpage". That works because object destruction has
534 * bottom-to-top pass.
537 page = (struct cl_page *)vmpage->private;
539 cl_page_get_trust(page);
540 LASSERT(page->cp_type == CPT_CACHEABLE);
544 EXPORT_SYMBOL(cl_vmpage_page);
546 const struct cl_page_slice *cl_page_at(const struct cl_page *page,
547 const struct lu_device_type *dtype)
549 return cl_page_at_trusted(page, dtype);
551 EXPORT_SYMBOL(cl_page_at);
553 static void cl_page_owner_clear(struct cl_page *page)
556 if (page->cp_owner != NULL) {
557 LASSERT(page->cp_owner->ci_owned_nr > 0);
558 page->cp_owner->ci_owned_nr--;
559 page->cp_owner = NULL;
564 static void cl_page_owner_set(struct cl_page *page)
567 LASSERT(page->cp_owner != NULL);
568 page->cp_owner->ci_owned_nr++;
572 void cl_page_disown0(const struct lu_env *env, struct cl_page *cp)
575 enum cl_page_state state;
578 state = cp->cp_state;
579 PINVRNT(env, cp, state == CPS_OWNED || state == CPS_FREEING);
580 PINVRNT(env, cp, cl_page_invariant(cp) || state == CPS_FREEING);
581 cl_page_owner_clear(cp);
583 if (state == CPS_OWNED)
584 cl_page_state_set(env, cp, CPS_CACHED);
586 if (cp->cp_type == CPT_CACHEABLE) {
587 vmpage = cp->cp_vmpage;
588 LASSERT(vmpage != NULL);
589 LASSERT(PageLocked(vmpage));
597 * returns true, iff page is owned by the given io.
599 int cl_page_is_owned(const struct cl_page *pg, const struct cl_io *io)
601 struct cl_io *top = cl_io_top((struct cl_io *)io);
602 LINVRNT(cl_object_same(pg->cp_obj, io->ci_obj));
604 RETURN(pg->cp_state == CPS_OWNED && pg->cp_owner == top);
606 EXPORT_SYMBOL(cl_page_is_owned);
609 * Try to own a page by IO.
611 * Waits until page is in cl_page_state::CPS_CACHED state, and then switch it
612 * into cl_page_state::CPS_OWNED state.
614 * \pre !cl_page_is_owned(cl_page, io)
615 * \post result == 0 iff cl_page_is_owned(cl_page, io)
619 * \retval -ve failure, e.g., cl_page was destroyed (and landed in
620 * cl_page_state::CPS_FREEING instead of cl_page_state::CPS_CACHED).
621 * or, page was owned by another thread, or in IO.
623 * \see cl_page_disown()
624 * \see cl_page_own_try()
627 static int cl_page_own0(const struct lu_env *env, struct cl_io *io,
628 struct cl_page *cl_page, int nonblock)
630 struct page *vmpage = cl_page->cp_vmpage;
634 PINVRNT(env, cl_page, !cl_page_is_owned(cl_page, io));
636 if (cl_page->cp_state == CPS_FREEING) {
641 LASSERT(vmpage != NULL);
643 if (cl_page->cp_type == CPT_TRANSIENT) {
645 } else if (nonblock) {
646 if (!trylock_page(vmpage)) {
651 if (unlikely(PageWriteback(vmpage))) {
658 wait_on_page_writeback(vmpage);
661 PASSERT(env, cl_page, cl_page->cp_owner == NULL);
662 cl_page->cp_owner = cl_io_top(io);
663 cl_page_owner_set(cl_page);
665 if (cl_page->cp_state == CPS_FREEING) {
666 cl_page_disown0(env, cl_page);
671 cl_page_state_set(env, cl_page, CPS_OWNED);
674 PINVRNT(env, cl_page, ergo(result == 0,
675 cl_page_invariant(cl_page)));
680 * Own a page, might be blocked.
682 * \see cl_page_own0()
684 int cl_page_own(const struct lu_env *env, struct cl_io *io, struct cl_page *pg)
686 return cl_page_own0(env, io, pg, 0);
688 EXPORT_SYMBOL(cl_page_own);
691 * Nonblock version of cl_page_own().
693 * \see cl_page_own0()
695 int cl_page_own_try(const struct lu_env *env, struct cl_io *io,
698 return cl_page_own0(env, io, pg, 1);
700 EXPORT_SYMBOL(cl_page_own_try);
704 * Assume page ownership.
706 * Called when page is already locked by the hosting VM.
708 * \pre !cl_page_is_owned(cl_page, io)
709 * \post cl_page_is_owned(cl_page, io)
711 * \see cl_page_operations::cpo_assume()
713 void cl_page_assume(const struct lu_env *env,
714 struct cl_io *io, struct cl_page *cl_page)
716 const struct cl_page_slice *slice;
721 PINVRNT(env, cl_page,
722 cl_object_same(cl_page->cp_obj, io->ci_obj));
725 cl_page_slice_for_each(cl_page, slice, i) {
726 if (slice->cpl_ops->cpo_assume != NULL)
727 (*slice->cpl_ops->cpo_assume)(env, slice, io);
730 PASSERT(env, cl_page, cl_page->cp_owner == NULL);
731 cl_page->cp_owner = cl_io_top(io);
732 cl_page_owner_set(cl_page);
733 cl_page_state_set(env, cl_page, CPS_OWNED);
736 EXPORT_SYMBOL(cl_page_assume);
739 * Releases page ownership without unlocking the page.
741 * Moves cl_page into cl_page_state::CPS_CACHED without releasing a lock
742 * on the underlying VM page (as VM is supposed to do this itself).
744 * \pre cl_page_is_owned(cl_page, io)
745 * \post !cl_page_is_owned(cl_page, io)
747 * \see cl_page_assume()
749 void cl_page_unassume(const struct lu_env *env,
750 struct cl_io *io, struct cl_page *cl_page)
752 const struct cl_page_slice *slice;
756 PINVRNT(env, cl_page, cl_page_is_owned(cl_page, io));
757 PINVRNT(env, cl_page, cl_page_invariant(cl_page));
760 cl_page_owner_clear(cl_page);
761 cl_page_state_set(env, cl_page, CPS_CACHED);
763 cl_page_slice_for_each_reverse(cl_page, slice, i) {
764 if (slice->cpl_ops->cpo_unassume != NULL)
765 (*slice->cpl_ops->cpo_unassume)(env, slice, io);
770 EXPORT_SYMBOL(cl_page_unassume);
773 * Releases page ownership.
775 * Moves page into cl_page_state::CPS_CACHED.
777 * \pre cl_page_is_owned(pg, io)
778 * \post !cl_page_is_owned(pg, io)
782 void cl_page_disown(const struct lu_env *env,
783 struct cl_io *io, struct cl_page *pg)
785 PINVRNT(env, pg, cl_page_is_owned(pg, io) ||
786 pg->cp_state == CPS_FREEING);
788 cl_page_disown0(env, pg);
790 EXPORT_SYMBOL(cl_page_disown);
793 * Called when cl_page is to be removed from the object, e.g.,
794 * as a result of truncate.
796 * Calls cl_page_operations::cpo_discard() top-to-bottom.
798 * \pre cl_page_is_owned(cl_page, io)
800 * \see cl_page_operations::cpo_discard()
802 void cl_page_discard(const struct lu_env *env,
803 struct cl_io *io, struct cl_page *cp)
806 const struct cl_page_slice *slice;
809 PINVRNT(env, cp, cl_page_is_owned(cp, io));
810 PINVRNT(env, cp, cl_page_invariant(cp));
812 cl_page_slice_for_each(cp, slice, i) {
813 if (slice->cpl_ops->cpo_discard != NULL)
814 (*slice->cpl_ops->cpo_discard)(env, slice, io);
817 if (cp->cp_type == CPT_CACHEABLE) {
818 vmpage = cp->cp_vmpage;
819 LASSERT(vmpage != NULL);
820 LASSERT(PageLocked(vmpage));
821 generic_error_remove_page(vmpage->mapping, vmpage);
823 cl_page_delete(env, cp);
826 EXPORT_SYMBOL(cl_page_discard);
829 * Version of cl_page_delete() that can be called for not fully constructed
830 * cl_pages, e.g. in an error handling cl_page_find()->cl_page_delete0()
831 * path. Doesn't check cl_page invariant.
833 static void cl_page_delete0(const struct lu_env *env,
834 struct cl_page *cl_page)
836 const struct cl_page_slice *slice;
841 PASSERT(env, cl_page, cl_page->cp_state != CPS_FREEING);
844 * Severe all ways to obtain new pointers to @pg.
846 cl_page_owner_clear(cl_page);
847 cl_page_state_set0(env, cl_page, CPS_FREEING);
849 cl_page_slice_for_each_reverse(cl_page, slice, i) {
850 if (slice->cpl_ops->cpo_delete != NULL)
851 (*slice->cpl_ops->cpo_delete)(env, slice);
858 * Called when a decision is made to throw page out of memory.
860 * Notifies all layers about page destruction by calling
861 * cl_page_operations::cpo_delete() method top-to-bottom.
863 * Moves page into cl_page_state::CPS_FREEING state (this is the only place
864 * where transition to this state happens).
866 * Eliminates all venues through which new references to the page can be
869 * - removes page from the radix trees,
871 * - breaks linkage from VM page to cl_page.
873 * Once page reaches cl_page_state::CPS_FREEING, all remaining references will
874 * drain after some time, at which point page will be recycled.
876 * \pre VM page is locked
877 * \post pg->cp_state == CPS_FREEING
879 * \see cl_page_operations::cpo_delete()
881 void cl_page_delete(const struct lu_env *env, struct cl_page *pg)
883 PINVRNT(env, pg, cl_page_invariant(pg));
885 cl_page_delete0(env, pg);
888 EXPORT_SYMBOL(cl_page_delete);
890 void cl_page_touch(const struct lu_env *env,
891 const struct cl_page *cl_page, size_t to)
893 const struct cl_page_slice *slice;
898 cl_page_slice_for_each(cl_page, slice, i) {
899 if (slice->cpl_ops->cpo_page_touch != NULL)
900 (*slice->cpl_ops->cpo_page_touch)(env, slice, to);
905 EXPORT_SYMBOL(cl_page_touch);
907 static enum cl_page_state cl_req_type_state(enum cl_req_type crt)
910 RETURN(crt == CRT_WRITE ? CPS_PAGEOUT : CPS_PAGEIN);
913 static void cl_page_io_start(const struct lu_env *env,
914 struct cl_page *pg, enum cl_req_type crt)
917 * Page is queued for IO, change its state.
920 cl_page_owner_clear(pg);
921 cl_page_state_set(env, pg, cl_req_type_state(crt));
926 * Prepares page for immediate transfer. cl_page_operations::cpo_prep() is
927 * called top-to-bottom. Every layer either agrees to submit this page (by
928 * returning 0), or requests to omit this page (by returning -EALREADY). Layer
929 * handling interactions with the VM also has to inform VM that page is under
932 int cl_page_prep(const struct lu_env *env, struct cl_io *io,
933 struct cl_page *cl_page, enum cl_req_type crt)
935 const struct cl_page_slice *slice;
939 PINVRNT(env, cl_page, cl_page_is_owned(cl_page, io));
940 PINVRNT(env, cl_page, cl_page_invariant(cl_page));
941 PINVRNT(env, cl_page, crt < CRT_NR);
944 * this has to be called bottom-to-top, so that llite can set up
945 * PG_writeback without risking other layers deciding to skip this
951 if (cl_page->cp_type != CPT_TRANSIENT) {
952 cl_page_slice_for_each(cl_page, slice, i) {
953 if (slice->cpl_ops->io[crt].cpo_prep)
955 (*slice->cpl_ops->io[crt].cpo_prep)(env,
965 cl_page_io_start(env, cl_page, crt);
968 CL_PAGE_HEADER(D_TRACE, env, cl_page, "%d %d\n", crt, result);
971 EXPORT_SYMBOL(cl_page_prep);
974 * Notify layers about transfer completion.
976 * Invoked by transfer sub-system (which is a part of osc) to notify layers
977 * that a transfer, of which this page is a part of has completed.
979 * Completion call-backs are executed in the bottom-up order, so that
980 * uppermost layer (llite), responsible for the VFS/VM interaction runs last
981 * and can release locks safely.
983 * \pre cl_page->cp_state == CPS_PAGEIN || cl_page->cp_state == CPS_PAGEOUT
984 * \post cl_page->cl_page_state == CPS_CACHED
986 * \see cl_page_operations::cpo_completion()
988 void cl_page_completion(const struct lu_env *env,
989 struct cl_page *cl_page, enum cl_req_type crt,
992 const struct cl_page_slice *slice;
993 struct cl_sync_io *anchor = cl_page->cp_sync_io;
997 PASSERT(env, cl_page, crt < CRT_NR);
998 PASSERT(env, cl_page, cl_page->cp_state == cl_req_type_state(crt));
1000 CL_PAGE_HEADER(D_TRACE, env, cl_page, "%d %d\n", crt, ioret);
1001 cl_page_state_set(env, cl_page, CPS_CACHED);
1005 cl_page_slice_for_each_reverse(cl_page, slice, i) {
1006 if (slice->cpl_ops->io[crt].cpo_completion != NULL)
1007 (*slice->cpl_ops->io[crt].cpo_completion)(env, slice,
1011 if (anchor != NULL) {
1012 LASSERT(cl_page->cp_sync_io == anchor);
1013 cl_page->cp_sync_io = NULL;
1014 cl_sync_io_note(env, anchor, ioret);
1018 EXPORT_SYMBOL(cl_page_completion);
1021 * Notify layers that transfer formation engine decided to yank this page from
1022 * the cache and to make it a part of a transfer.
1024 * \pre cl_page->cp_state == CPS_CACHED
1025 * \post cl_page->cp_state == CPS_PAGEIN || cl_page->cp_state == CPS_PAGEOUT
1027 * \see cl_page_operations::cpo_make_ready()
1029 int cl_page_make_ready(const struct lu_env *env, struct cl_page *cl_page,
1030 enum cl_req_type crt)
1032 const struct cl_page_slice *slice;
1037 PINVRNT(env, cl_page, crt < CRT_NR);
1041 cl_page_slice_for_each(cl_page, slice, i) {
1042 if (slice->cpl_ops->io[crt].cpo_make_ready != NULL)
1043 result = (*slice->cpl_ops->io[crt].cpo_make_ready)(env, slice);
1050 PASSERT(env, cl_page, cl_page->cp_state == CPS_CACHED);
1051 cl_page_io_start(env, cl_page, crt);
1053 CL_PAGE_HEADER(D_TRACE, env, cl_page, "%d %d\n", crt, result);
1057 EXPORT_SYMBOL(cl_page_make_ready);
1060 * Called if a page is being written back by kernel's intention.
1062 * \pre cl_page_is_owned(cl_page, io)
1063 * \post ergo(result == 0, cl_page->cp_state == CPS_PAGEOUT)
1065 * \see cl_page_operations::cpo_flush()
1067 int cl_page_flush(const struct lu_env *env, struct cl_io *io,
1068 struct cl_page *cl_page)
1070 const struct cl_page_slice *slice;
1075 PINVRNT(env, cl_page, cl_page_is_owned(cl_page, io));
1076 PINVRNT(env, cl_page, cl_page_invariant(cl_page));
1078 cl_page_slice_for_each(cl_page, slice, i) {
1079 if (slice->cpl_ops->cpo_flush != NULL)
1080 result = (*slice->cpl_ops->cpo_flush)(env, slice, io);
1087 CL_PAGE_HEADER(D_TRACE, env, cl_page, "%d\n", result);
1090 EXPORT_SYMBOL(cl_page_flush);
1093 * Tells transfer engine that only part of a page is to be transmitted.
1095 * \see cl_page_operations::cpo_clip()
1097 void cl_page_clip(const struct lu_env *env, struct cl_page *cl_page,
1100 const struct cl_page_slice *slice;
1103 PINVRNT(env, cl_page, cl_page_invariant(cl_page));
1105 CL_PAGE_HEADER(D_TRACE, env, cl_page, "%d %d\n", from, to);
1106 cl_page_slice_for_each(cl_page, slice, i) {
1107 if (slice->cpl_ops->cpo_clip != NULL)
1108 (*slice->cpl_ops->cpo_clip)(env, slice, from, to);
1111 EXPORT_SYMBOL(cl_page_clip);
1114 * Prints human readable representation of \a pg to the \a f.
1116 void cl_page_header_print(const struct lu_env *env, void *cookie,
1117 lu_printer_t printer, const struct cl_page *pg)
1119 (*printer)(env, cookie,
1120 "page@%p[%d %p %d %d %p]\n",
1121 pg, atomic_read(&pg->cp_ref), pg->cp_obj,
1122 pg->cp_state, pg->cp_type,
1125 EXPORT_SYMBOL(cl_page_header_print);
1128 * Prints human readable representation of \a cl_page to the \a f.
1130 void cl_page_print(const struct lu_env *env, void *cookie,
1131 lu_printer_t printer, const struct cl_page *cl_page)
1133 const struct cl_page_slice *slice;
1137 cl_page_header_print(env, cookie, printer, cl_page);
1138 cl_page_slice_for_each(cl_page, slice, i) {
1139 if (slice->cpl_ops->cpo_print != NULL)
1140 result = (*slice->cpl_ops->cpo_print)(env, slice,
1145 (*printer)(env, cookie, "end page@%p\n", cl_page);
1147 EXPORT_SYMBOL(cl_page_print);
1150 * Converts a byte offset within object \a obj into a page index.
1152 loff_t cl_offset(const struct cl_object *obj, pgoff_t idx)
1154 return (loff_t)idx << PAGE_SHIFT;
1156 EXPORT_SYMBOL(cl_offset);
1159 * Converts a page index into a byte offset within object \a obj.
1161 pgoff_t cl_index(const struct cl_object *obj, loff_t offset)
1163 return offset >> PAGE_SHIFT;
1165 EXPORT_SYMBOL(cl_index);
1167 size_t cl_page_size(const struct cl_object *obj)
1169 return 1UL << PAGE_SHIFT;
1171 EXPORT_SYMBOL(cl_page_size);
1174 * Adds page slice to the compound page.
1176 * This is called by cl_object_operations::coo_page_init() methods to add a
1177 * per-layer state to the page. New state is added at the end of
1178 * cl_page::cp_layers list, that is, it is at the bottom of the stack.
1180 * \see cl_lock_slice_add(), cl_req_slice_add(), cl_io_slice_add()
1182 void cl_page_slice_add(struct cl_page *cl_page, struct cl_page_slice *slice,
1183 struct cl_object *obj,
1184 const struct cl_page_operations *ops)
1186 unsigned int offset = (char *)slice -
1187 ((char *)cl_page + sizeof(*cl_page));
1190 LASSERT(cl_page->cp_layer_count < CP_MAX_LAYER);
1191 LASSERT(offset < (1 << sizeof(cl_page->cp_layer_offset[0]) * 8));
1192 cl_page->cp_layer_offset[cl_page->cp_layer_count++] = offset;
1193 slice->cpl_obj = obj;
1194 slice->cpl_ops = ops;
1195 slice->cpl_page = cl_page;
1199 EXPORT_SYMBOL(cl_page_slice_add);
1202 * Allocate and initialize cl_cache, called by ll_init_sbi().
1204 struct cl_client_cache *cl_cache_init(unsigned long lru_page_max)
1206 struct cl_client_cache *cache = NULL;
1209 OBD_ALLOC(cache, sizeof(*cache));
1213 /* Initialize cache data */
1214 atomic_set(&cache->ccc_users, 1);
1215 cache->ccc_lru_max = lru_page_max;
1216 atomic_long_set(&cache->ccc_lru_left, lru_page_max);
1217 spin_lock_init(&cache->ccc_lru_lock);
1218 INIT_LIST_HEAD(&cache->ccc_lru);
1220 /* turn unstable check off by default as it impacts performance */
1221 cache->ccc_unstable_check = 0;
1222 atomic_long_set(&cache->ccc_unstable_nr, 0);
1223 init_waitqueue_head(&cache->ccc_unstable_waitq);
1224 mutex_init(&cache->ccc_max_cache_mb_lock);
1228 EXPORT_SYMBOL(cl_cache_init);
1231 * Increase cl_cache refcount
1233 void cl_cache_incref(struct cl_client_cache *cache)
1235 atomic_inc(&cache->ccc_users);
1237 EXPORT_SYMBOL(cl_cache_incref);
1240 * Decrease cl_cache refcount and free the cache if refcount=0.
1241 * Since llite, lov and osc all hold cl_cache refcount,
1242 * the free will not cause race. (LU-6173)
1244 void cl_cache_decref(struct cl_client_cache *cache)
1246 if (atomic_dec_and_test(&cache->ccc_users))
1247 OBD_FREE(cache, sizeof(*cache));
1249 EXPORT_SYMBOL(cl_cache_decref);