lustre/lov/lov_page.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   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.
   9  *
  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).
  15  *
  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
  19  *
  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
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2013, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * Implementation of cl_page for LOV layer.
  37  *
  38  *   Author: Nikita Danilov <nikita.danilov@sun.com>
  39  *   Author: Jinshan Xiong <jinshan.xiong@intel.com>
  40  */
  41
  42 #define DEBUG_SUBSYSTEM S_LOV
  43
  44 #include "lov_cl_internal.h"
  45
  46 /** \addtogroup lov
  47  *  @{
  48  */
  49
  50 /*****************************************************************************
  51  *
  52  * Lov page operations.
  53  *
  54  */
  55
  56 static int lov_page_invariant(const struct cl_page_slice *slice)
  57 {
  58         const struct cl_page  *page = slice->cpl_page;
  59         const struct cl_page  *sub  = lov_sub_page(slice);
  60
  61         return ergo(sub != NULL,
  62                     page->cp_child == sub &&
  63                     sub->cp_parent == page &&
  64                     page->cp_state == sub->cp_state);
  65 }
  66
  67 static void lov_page_fini(const struct lu_env *env,
  68                           struct cl_page_slice *slice)
  69 {
  70         struct cl_page  *sub = lov_sub_page(slice);
  71
  72         LINVRNT(lov_page_invariant(slice));
  73         ENTRY;
  74
  75         if (sub != NULL) {
  76                 LASSERT(sub->cp_state == CPS_FREEING);
  77                 lu_ref_del(&sub->cp_reference, "lov", sub->cp_parent);
  78                 sub->cp_parent = NULL;
  79                 slice->cpl_page->cp_child = NULL;
  80                 cl_page_put(env, sub);
  81         }
  82         EXIT;
  83 }
  84
  85 static int lov_page_own(const struct lu_env *env,
  86                         const struct cl_page_slice *slice, struct cl_io *io,
  87                         int nonblock)
  88 {
  89         struct lov_io     *lio = lov_env_io(env);
  90         struct lov_io_sub *sub;
  91
  92         LINVRNT(lov_page_invariant(slice));
  93         LINVRNT(!cl2lov_page(slice)->lps_invalid);
  94         ENTRY;
  95
  96         sub = lov_page_subio(env, lio, slice);
  97         if (!IS_ERR(sub)) {
  98                 lov_sub_page(slice)->cp_owner = sub->sub_io;
  99                 lov_sub_put(sub);
 100         } else
 101                 LBUG(); /* Arrgh */
 102         RETURN(0);
 103 }
 104
 105 static void lov_page_assume(const struct lu_env *env,
 106                             const struct cl_page_slice *slice, struct cl_io *io)
 107 {
 108         lov_page_own(env, slice, io, 0);
 109 }
 110
 111 static int lov_page_cache_add(const struct lu_env *env,
 112                               const struct cl_page_slice *slice,
 113                               struct cl_io *io)
 114 {
 115         struct lov_io     *lio = lov_env_io(env);
 116         struct lov_io_sub *sub;
 117         int rc = 0;
 118
 119         LINVRNT(lov_page_invariant(slice));
 120         LINVRNT(!cl2lov_page(slice)->lps_invalid);
 121         ENTRY;
 122
 123         sub = lov_page_subio(env, lio, slice);
 124         if (!IS_ERR(sub)) {
 125                 rc = cl_page_cache_add(sub->sub_env, sub->sub_io,
 126                                        slice->cpl_page->cp_child, CRT_WRITE);
 127                 lov_sub_put(sub);
 128         } else {
 129                 rc = PTR_ERR(sub);
 130                 CL_PAGE_DEBUG(D_ERROR, env, slice->cpl_page, "rc = %d\n", rc);
 131         }
 132         RETURN(rc);
 133 }
 134
 135 static int lov_page_print(const struct lu_env *env,
 136                           const struct cl_page_slice *slice,
 137                           void *cookie, lu_printer_t printer)
 138 {
 139         struct lov_page *lp = cl2lov_page(slice);
 140
 141         return (*printer)(env, cookie, LUSTRE_LOV_NAME"-page@%p\n", lp);
 142 }
 143
 144 static const struct cl_page_operations lov_page_ops = {
 145         .cpo_fini   = lov_page_fini,
 146         .cpo_own    = lov_page_own,
 147         .cpo_assume = lov_page_assume,
 148         .io = {
 149                 [CRT_WRITE] = {
 150                         .cpo_cache_add = lov_page_cache_add
 151                 }
 152         },
 153         .cpo_print  = lov_page_print
 154 };
 155
 156 static void lov_empty_page_fini(const struct lu_env *env,
 157                                 struct cl_page_slice *slice)
 158 {
 159         LASSERT(slice->cpl_page->cp_child == NULL);
 160 }
 161
 162 int lov_page_init_raid0(const struct lu_env *env, struct cl_object *obj,
 163                         struct cl_page *page, struct page *vmpage)
 164 {
 165         struct lov_object *loo = cl2lov(obj);
 166         struct lov_layout_raid0 *r0 = lov_r0(loo);
 167         struct lov_io     *lio = lov_env_io(env);
 168         struct cl_page    *subpage;
 169         struct cl_object  *subobj;
 170         struct lov_io_sub *sub;
 171         struct lov_page   *lpg = cl_object_page_slice(obj, page);
 172         loff_t             offset;
 173         obd_off            suboff;
 174         int                stripe;
 175         int                rc;
 176         ENTRY;
 177
 178         offset = cl_offset(obj, page->cp_index);
 179         stripe = lov_stripe_number(loo->lo_lsm, offset);
 180         LASSERT(stripe < r0->lo_nr);
 181         rc = lov_stripe_offset(loo->lo_lsm, offset, stripe,
 182                                &suboff);
 183         LASSERT(rc == 0);
 184
 185         lpg->lps_invalid = 1;
 186         cl_page_slice_add(page, &lpg->lps_cl, obj, &lov_page_ops);
 187
 188         sub = lov_sub_get(env, lio, stripe);
 189         if (IS_ERR(sub))
 190                 RETURN(PTR_ERR(sub));
 191
 192         subobj = lovsub2cl(r0->lo_sub[stripe]);
 193         subpage = cl_page_alloc(sub->sub_env, subobj, cl_index(subobj, suboff),
 194                                 vmpage, page->cp_type);
 195         if (!IS_ERR(subpage)) {
 196                 subpage->cp_parent = page;
 197                 page->cp_child = subpage;
 198                 lpg->lps_invalid = 0;
 199         } else
 200                 rc = PTR_ERR(subpage);
 201         lov_sub_put(sub);
 202         RETURN(rc);
 203 }
 204
 205 static const struct cl_page_operations lov_empty_page_ops = {
 206         .cpo_fini   = lov_empty_page_fini,
 207         .cpo_print  = lov_page_print
 208 };
 209
 210 int lov_page_init_empty(const struct lu_env *env, struct cl_object *obj,
 211                         struct cl_page *page, struct page *vmpage)
 212 {
 213         struct lov_page *lpg = cl_object_page_slice(obj, page);
 214         void *addr;
 215         ENTRY;
 216
 217         cl_page_slice_add(page, &lpg->lps_cl, obj, &lov_empty_page_ops);
 218         addr = kmap(vmpage);
 219         memset(addr, 0, cl_page_size(obj));
 220         kunmap(vmpage);
 221         cl_page_export(env, page, 1);
 222         RETURN(0);
 223 }
 224
 225
 226 /** @} lov */
 227