lustre/lov/lov_page.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  30  * Use is subject to license terms.
  31  *
  32  * Copyright (c) 2011, Whamcloud, Inc.
  33  */
  34 /*
  35  * This file is part of Lustre, http://www.lustre.org/
  36  * Lustre is a trademark of Sun Microsystems, Inc.
  37  *
  38  * Implementation of cl_page for LOV layer.
  39  *
  40  *   Author: Nikita Danilov <nikita.danilov@sun.com>
  41  */
  42
  43 #define DEBUG_SUBSYSTEM S_LOV
  44
  45 #include "lov_cl_internal.h"
  46
  47 /** \addtogroup lov
  48  *  @{
  49  */
  50
  51 /*****************************************************************************
  52  *
  53  * Lov page operations.
  54  *
  55  */
  56
  57 static int lov_page_invariant(const struct cl_page_slice *slice)
  58 {
  59         const struct cl_page  *page = slice->cpl_page;
  60         const struct cl_page  *sub  = lov_sub_page(slice);
  61
  62         return ergo(sub != NULL,
  63                     page->cp_child == sub &&
  64                     sub->cp_parent == page &&
  65                     page->cp_state == sub->cp_state);
  66 }
  67
  68 static void lov_page_fini(const struct lu_env *env,
  69                           struct cl_page_slice *slice)
  70 {
  71         struct lov_page *lp  = cl2lov_page(slice);
  72         struct cl_page  *sub = lov_sub_page(slice);
  73
  74         LINVRNT(lov_page_invariant(slice));
  75         ENTRY;
  76
  77         if (sub != NULL) {
  78                 LASSERT(sub->cp_state == CPS_FREEING);
  79                 lu_ref_del(&sub->cp_reference, "lov", sub->cp_parent);
  80                 sub->cp_parent = NULL;
  81                 slice->cpl_page->cp_child = NULL;
  82                 cl_page_put(env, sub);
  83         }
  84         OBD_SLAB_FREE_PTR(lp, lov_page_kmem);
  85         EXIT;
  86 }
  87
  88 static int lov_page_own(const struct lu_env *env,
  89                         const struct cl_page_slice *slice, struct cl_io *io,
  90                         int nonblock)
  91 {
  92         struct lov_io     *lio = lov_env_io(env);
  93         struct lov_io_sub *sub;
  94
  95         LINVRNT(lov_page_invariant(slice));
  96         LINVRNT(!cl2lov_page(slice)->lps_invalid);
  97         ENTRY;
  98
  99         sub = lov_page_subio(env, lio, slice);
 100         if (!IS_ERR(sub)) {
 101                 lov_sub_page(slice)->cp_owner = sub->sub_io;
 102                 lov_sub_put(sub);
 103         } else
 104                 LBUG(); /* Arrgh */
 105         RETURN(0);
 106 }
 107
 108 static void lov_page_assume(const struct lu_env *env,
 109                             const struct cl_page_slice *slice, struct cl_io *io)
 110 {
 111         lov_page_own(env, slice, io, 0);
 112 }
 113
 114 static int lov_page_print(const struct lu_env *env,
 115                           const struct cl_page_slice *slice,
 116                           void *cookie, lu_printer_t printer)
 117 {
 118         struct lov_page *lp = cl2lov_page(slice);
 119
 120         return (*printer)(env, cookie, LUSTRE_LOV_NAME"-page@%p\n", lp);
 121 }
 122
 123 static const struct cl_page_operations lov_page_ops = {
 124         .cpo_fini   = lov_page_fini,
 125         .cpo_own    = lov_page_own,
 126         .cpo_assume = lov_page_assume,
 127         .cpo_print  = lov_page_print
 128 };
 129
 130 static void lov_empty_page_fini(const struct lu_env *env,
 131                                 struct cl_page_slice *slice)
 132 {
 133         struct lov_page *lp  = cl2lov_page(slice);
 134
 135         LASSERT(slice->cpl_page->cp_child == NULL);
 136         ENTRY;
 137         OBD_SLAB_FREE_PTR(lp, lov_page_kmem);
 138         EXIT;
 139 }
 140
 141 struct cl_page *lov_page_init_raid0(const struct lu_env *env,
 142                                     struct cl_object *obj, struct cl_page *page,
 143                                     cfs_page_t *vmpage)
 144 {
 145         struct lov_object *loo = cl2lov(obj);
 146         struct lov_layout_raid0 *r0 = lov_r0(loo);
 147         struct lov_io     *lio = lov_env_io(env);
 148         struct cl_page    *subpage;
 149         struct cl_object  *subobj;
 150         struct lov_io_sub *sub;
 151         struct lov_page   *lpg;
 152         struct cl_page    *result;
 153         loff_t             offset;
 154         obd_off            suboff;
 155         int                stripe;
 156         int                rc;
 157         ENTRY;
 158
 159         offset = cl_offset(obj, page->cp_index);
 160         stripe = lov_stripe_number(r0->lo_lsm, offset);
 161         LASSERT(stripe < r0->lo_nr);
 162         rc = lov_stripe_offset(r0->lo_lsm, offset, stripe,
 163                                    &suboff);
 164         LASSERT(rc == 0);
 165
 166         OBD_SLAB_ALLOC_PTR_GFP(lpg, lov_page_kmem, CFS_ALLOC_IO);
 167         if (lpg == NULL)
 168                 GOTO(out, result = ERR_PTR(-ENOMEM));
 169
 170         lpg->lps_invalid = 1;
 171         cl_page_slice_add(page, &lpg->lps_cl, obj, &lov_page_ops);
 172
 173         sub = lov_sub_get(env, lio, stripe);
 174         if (IS_ERR(sub))
 175                 GOTO(out, result = (struct cl_page *)sub);
 176
 177         subobj = lovsub2cl(r0->lo_sub[stripe]);
 178         subpage = cl_page_find_sub(sub->sub_env, subobj,
 179                                    cl_index(subobj, suboff), vmpage, page);
 180         lov_sub_put(sub);
 181         if (IS_ERR(subpage))
 182                 GOTO(out, result = subpage);
 183
 184         if (likely(subpage->cp_parent == page)) {
 185                 lu_ref_add(&subpage->cp_reference, "lov", page);
 186                 lpg->lps_invalid = 0;
 187                 result = NULL;
 188         } else {
 189                 CL_PAGE_DEBUG(D_ERROR, env, page, "parent page\n");
 190                 CL_PAGE_DEBUG(D_ERROR, env, subpage, "child page\n");
 191                 LASSERT(0);
 192         }
 193
 194         EXIT;
 195 out:
 196         return(result);
 197 }
 198
 199
 200 static const struct cl_page_operations lov_empty_page_ops = {
 201         .cpo_fini   = lov_empty_page_fini,
 202         .cpo_print  = lov_page_print
 203 };
 204
 205 struct cl_page *lov_page_init_empty(const struct lu_env *env,
 206                                     struct cl_object *obj, struct cl_page *page,
 207                                     cfs_page_t *vmpage)
 208 {
 209         struct lov_page   *lpg;
 210         int result = -ENOMEM;
 211         ENTRY;
 212
 213         OBD_SLAB_ALLOC_PTR_GFP(lpg, lov_page_kmem, CFS_ALLOC_IO);
 214         if (lpg != NULL) {
 215                 void *addr;
 216                 cl_page_slice_add(page, &lpg->lps_cl,
 217                                   obj, &lov_empty_page_ops);
 218                 addr = cfs_kmap(vmpage);
 219                 memset(addr, 0, cl_page_size(obj));
 220                 cfs_kunmap(vmpage);
 221                 cl_page_export(env, page, 1);
 222                 result = 0;
 223         }
 224         RETURN(ERR_PTR(result));
 225 }
 226
 227
 228 /** @} lov */
 229