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, 2012, 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  */
  40
  41 #define DEBUG_SUBSYSTEM S_LOV
  42
  43 #include "lov_cl_internal.h"
  44
  45 /** \addtogroup lov
  46  *  @{
  47  */
  48
  49 /*****************************************************************************
  50  *
  51  * Lov page operations.
  52  *
  53  */
  54
  55 static int lov_page_invariant(const struct cl_page_slice *slice)
  56 {
  57         const struct cl_page  *page = slice->cpl_page;
  58         const struct cl_page  *sub  = lov_sub_page(slice);
  59
  60         return ergo(sub != NULL,
  61                     page->cp_child == sub &&
  62                     sub->cp_parent == page &&
  63                     page->cp_state == sub->cp_state);
  64 }
  65
  66 static void lov_page_fini(const struct lu_env *env,
  67                           struct cl_page_slice *slice)
  68 {
  69         struct cl_page  *sub = lov_sub_page(slice);
  70
  71         LINVRNT(lov_page_invariant(slice));
  72         ENTRY;
  73
  74         if (sub != NULL) {
  75                 LASSERT(sub->cp_state == CPS_FREEING);
  76                 lu_ref_del(&sub->cp_reference, "lov", sub->cp_parent);
  77                 sub->cp_parent = NULL;
  78                 slice->cpl_page->cp_child = NULL;
  79                 cl_page_put(env, sub);
  80         }
  81         EXIT;
  82 }
  83
  84 static int lov_page_own(const struct lu_env *env,
  85                         const struct cl_page_slice *slice, struct cl_io *io,
  86                         int nonblock)
  87 {
  88         struct lov_io     *lio = lov_env_io(env);
  89         struct lov_io_sub *sub;
  90
  91         LINVRNT(lov_page_invariant(slice));
  92         LINVRNT(!cl2lov_page(slice)->lps_invalid);
  93         ENTRY;
  94
  95         sub = lov_page_subio(env, lio, slice);
  96         if (!IS_ERR(sub)) {
  97                 lov_sub_page(slice)->cp_owner = sub->sub_io;
  98                 lov_sub_put(sub);
  99         } else
 100                 LBUG(); /* Arrgh */
 101         RETURN(0);
 102 }
 103
 104 static void lov_page_assume(const struct lu_env *env,
 105                             const struct cl_page_slice *slice, struct cl_io *io)
 106 {
 107         lov_page_own(env, slice, io, 0);
 108 }
 109
 110 static int lov_page_cache_add(const struct lu_env *env,
 111                               const struct cl_page_slice *slice,
 112                               struct cl_io *io)
 113 {
 114         struct lov_io     *lio = lov_env_io(env);
 115         struct lov_io_sub *sub;
 116         int rc = 0;
 117
 118         LINVRNT(lov_page_invariant(slice));
 119         LINVRNT(!cl2lov_page(slice)->lps_invalid);
 120         ENTRY;
 121
 122         sub = lov_page_subio(env, lio, slice);
 123         if (!IS_ERR(sub)) {
 124                 rc = cl_page_cache_add(sub->sub_env, sub->sub_io,
 125                                        slice->cpl_page->cp_child, CRT_WRITE);
 126                 lov_sub_put(sub);
 127         } else {
 128                 rc = PTR_ERR(sub);
 129                 CL_PAGE_DEBUG(D_ERROR, env, slice->cpl_page, "rc = %d\n", rc);
 130         }
 131         RETURN(rc);
 132 }
 133
 134 static int lov_page_print(const struct lu_env *env,
 135                           const struct cl_page_slice *slice,
 136                           void *cookie, lu_printer_t printer)
 137 {
 138         struct lov_page *lp = cl2lov_page(slice);
 139
 140         return (*printer)(env, cookie, LUSTRE_LOV_NAME"-page@%p\n", lp);
 141 }
 142
 143 static const struct cl_page_operations lov_page_ops = {
 144         .cpo_fini   = lov_page_fini,
 145         .cpo_own    = lov_page_own,
 146         .cpo_assume = lov_page_assume,
 147         .io = {
 148                 [CRT_WRITE] = {
 149                         .cpo_cache_add = lov_page_cache_add
 150                 }
 151         },
 152         .cpo_print  = lov_page_print
 153 };
 154
 155 static void lov_empty_page_fini(const struct lu_env *env,
 156                                 struct cl_page_slice *slice)
 157 {
 158         LASSERT(slice->cpl_page->cp_child == NULL);
 159 }
 160
 161 int lov_page_init_raid0(const struct lu_env *env, struct cl_object *obj,
 162                         struct cl_page *page, cfs_page_t *vmpage)
 163 {
 164         struct lov_object *loo = cl2lov(obj);
 165         struct lov_layout_raid0 *r0 = lov_r0(loo);
 166         struct lov_io     *lio = lov_env_io(env);
 167         struct cl_page    *subpage;
 168         struct cl_object  *subobj;
 169         struct lov_io_sub *sub;
 170         struct lov_page   *lpg = cl_object_page_slice(obj, page);
 171         loff_t             offset;
 172         obd_off            suboff;
 173         int                stripe;
 174         int                rc;
 175         ENTRY;
 176
 177         offset = cl_offset(obj, page->cp_index);
 178         stripe = lov_stripe_number(loo->lo_lsm, offset);
 179         LASSERT(stripe < r0->lo_nr);
 180         rc = lov_stripe_offset(loo->lo_lsm, offset, stripe,
 181                                    &suboff);
 182         LASSERT(rc == 0);
 183
 184         lpg->lps_invalid = 1;
 185         cl_page_slice_add(page, &lpg->lps_cl, obj, &lov_page_ops);
 186
 187         sub = lov_sub_get(env, lio, stripe);
 188         if (IS_ERR(sub))
 189                 GOTO(out, rc = PTR_ERR(sub));
 190
 191         subobj = lovsub2cl(r0->lo_sub[stripe]);
 192         subpage = cl_page_find_sub(sub->sub_env, subobj,
 193                                    cl_index(subobj, suboff), vmpage, page);
 194         lov_sub_put(sub);
 195         if (IS_ERR(subpage))
 196                 GOTO(out, rc = PTR_ERR(subpage));
 197
 198         if (likely(subpage->cp_parent == page)) {
 199                 lu_ref_add(&subpage->cp_reference, "lov", page);
 200                 lpg->lps_invalid = 0;
 201                 rc = 0;
 202         } else {
 203                 CL_PAGE_DEBUG(D_ERROR, env, page, "parent page\n");
 204                 CL_PAGE_DEBUG(D_ERROR, env, subpage, "child page\n");
 205                 LASSERT(0);
 206         }
 207
 208         EXIT;
 209 out:
 210         return rc;
 211 }
 212
 213
 214 static const struct cl_page_operations lov_empty_page_ops = {
 215         .cpo_fini   = lov_empty_page_fini,
 216         .cpo_print  = lov_page_print
 217 };
 218
 219 int lov_page_init_empty(const struct lu_env *env, struct cl_object *obj,
 220                         struct cl_page *page, cfs_page_t *vmpage)
 221 {
 222         struct lov_page *lpg = cl_object_page_slice(obj, page);
 223         void *addr;
 224         ENTRY;
 225
 226         cl_page_slice_add(page, &lpg->lps_cl, obj, &lov_empty_page_ops);
 227         addr = cfs_kmap(vmpage);
 228         memset(addr, 0, cl_page_size(obj));
 229         cfs_kunmap(vmpage);
 230         cl_page_export(env, page, 1);
 231         RETURN(0);
 232 }
 233
 234
 235 /** @} lov */
 236