lustre/llite/vvp_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.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  *
  31  * Implementation of cl_page for VVP layer.
  32  *
  33  *   Author: Nikita Danilov <nikita.danilov@sun.com>
  34  *   Author: Jinshan Xiong <jinshan.xiong@whamcloud.com>
  35  */
  36
  37 #define DEBUG_SUBSYSTEM S_LLITE
  38
  39 #include <linux/atomic.h>
  40 #include <linux/bitops.h>
  41 #include <linux/mm.h>
  42 #include <linux/mutex.h>
  43 #include <linux/page-flags.h>
  44 #include <linux/pagemap.h>
  45
  46 #include <libcfs/libcfs.h>
  47 #include "llite_internal.h"
  48 #include "vvp_internal.h"
  49
  50 /*****************************************************************************
  51  *
  52  * Page operations.
  53  *
  54  */
  55 static void vvp_page_discard(const struct lu_env *env,
  56                              const struct cl_page_slice *slice,
  57                              struct cl_io *unused)
  58 {
  59         struct cl_page *cp = slice->cpl_page;
  60         struct page *vmpage = cp->cp_vmpage;
  61
  62         if (cp->cp_defer_uptodate && !cp->cp_ra_used && vmpage->mapping != NULL)
  63                 ll_ra_stats_inc(vmpage->mapping->host, RA_STAT_DISCARDED);
  64 }
  65
  66 /**
  67  * Handles page transfer errors at VM level.
  68  *
  69  * This takes inode as a separate argument, because inode on which error is to
  70  * be set can be different from \a vmpage inode in case of direct-io.
  71  */
  72 static void vvp_vmpage_error(struct inode *inode, struct page *vmpage,
  73                              int ioret)
  74 {
  75         struct vvp_object *obj = cl_inode2vvp(inode);
  76
  77         if (ioret == 0) {
  78                 ClearPageError(vmpage);
  79                 obj->vob_discard_page_warned = 0;
  80         } else {
  81                 SetPageError(vmpage);
  82                 if (ioret == -ENOSPC)
  83                         set_bit(AS_ENOSPC, &inode->i_mapping->flags);
  84                 else
  85                         set_bit(AS_EIO, &inode->i_mapping->flags);
  86
  87                 if ((ioret == -ESHUTDOWN || ioret == -EINTR ||
  88                      ioret == -EIO) && obj->vob_discard_page_warned == 0) {
  89                         obj->vob_discard_page_warned = 1;
  90                         ll_dirty_page_discard_warn(inode, ioret);
  91                 }
  92         }
  93 }
  94
  95 static void vvp_page_completion_read(const struct lu_env *env,
  96                                      const struct cl_page_slice *slice,
  97                                      int ioret)
  98 {
  99         struct cl_page *cp = slice->cpl_page;
 100         struct page *vmpage = cp->cp_vmpage;
 101         struct inode *inode = vvp_object_inode(cp->cp_obj);
 102
 103         ENTRY;
 104         LASSERT(PageLocked(vmpage));
 105         CL_PAGE_HEADER(D_PAGE, env, cp, "completing READ with %d\n", ioret);
 106
 107         if (cp->cp_defer_uptodate)
 108                 ll_ra_count_put(ll_i2sbi(inode), 1);
 109
 110         if (ioret == 0)  {
 111                 /**
 112                  * cp_defer_uptodate is used for readahead page, and the
 113                  * vmpage Uptodate bit is deferred to set in ll_readpage/
 114                  * ll_io_read_page.
 115                  */
 116                 if (!cp->cp_defer_uptodate)
 117                         SetPageUptodate(vmpage);
 118         } else if (cp->cp_defer_uptodate) {
 119                 cp->cp_defer_uptodate = 0;
 120                 if (ioret == -EAGAIN) {
 121                         /* mirror read failed, it needs to destroy the page
 122                          * because subpage would be from wrong osc when trying
 123                          * to read from a new mirror
 124                          */
 125                         generic_error_remove_page(vmpage->mapping, vmpage);
 126                 }
 127         }
 128
 129         if (cp->cp_sync_io == NULL)
 130                 unlock_page(vmpage);
 131
 132         EXIT;
 133 }
 134
 135 static void vvp_page_completion_write(const struct lu_env *env,
 136                                       const struct cl_page_slice *slice,
 137                                       int ioret)
 138 {
 139         struct cl_page *cp = slice->cpl_page;
 140         struct page *vmpage = cp->cp_vmpage;
 141
 142         ENTRY;
 143         CL_PAGE_HEADER(D_PAGE, env, cp, "completing WRITE with %d\n", ioret);
 144
 145         if (cp->cp_sync_io != NULL) {
 146                 LASSERT(PageLocked(vmpage));
 147                 LASSERT(!PageWriteback(vmpage));
 148         } else {
 149                 LASSERT(PageWriteback(vmpage));
 150                 /*
 151                  * Only mark the page error only when it's an async write
 152                  * because applications won't wait for IO to finish.
 153                  */
 154                 vvp_vmpage_error(vvp_object_inode(cp->cp_obj), vmpage, ioret);
 155
 156                 end_page_writeback(vmpage);
 157         }
 158         EXIT;
 159 }
 160
 161 static const struct cl_page_operations vvp_page_ops = {
 162         .cpo_discard       = vvp_page_discard,
 163         .io = {
 164                 [CRT_READ] = {
 165                         .cpo_completion = vvp_page_completion_read,
 166                 },
 167                 [CRT_WRITE] = {
 168                         .cpo_completion = vvp_page_completion_write,
 169                 },
 170         },
 171 };
 172
 173 static const struct cl_page_operations vvp_transient_page_ops = {
 174 };
 175
 176 int vvp_page_init(const struct lu_env *env, struct cl_object *obj,
 177                 struct cl_page *page, pgoff_t index)
 178 {
 179         struct cl_page_slice *cpl = cl_object_page_slice(obj, page);
 180         struct page *vmpage = page->cp_vmpage;
 181
 182         CLOBINVRNT(env, obj, vvp_object_invariant(obj));
 183
 184         if (page->cp_type == CPT_TRANSIENT) {
 185                 /* DIO pages are referenced by userspace, we don't need to take
 186                  * a reference on them. (contrast with get_page() call above)
 187                  */
 188                 cl_page_slice_add(page, cpl, obj,
 189                                   &vvp_transient_page_ops);
 190         } else {
 191                 get_page(vmpage);
 192                 /* in cache, decref in cl_page_delete() */
 193                 refcount_inc(&page->cp_ref);
 194                 SetPagePrivate(vmpage);
 195                 vmpage->private = (unsigned long)page;
 196                 cl_page_slice_add(page, cpl, obj, &vvp_page_ops);
 197         }
 198
 199         return 0;
 200 }