fs/gfs2/ops_vm.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License v.2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/mm.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/gfs2_ondisk.h>
  18 #include <asm/semaphore.h>
  19
  20 #include "gfs2.h"
  21 #include "lm_interface.h"
  22 #include "incore.h"
  23 #include "bmap.h"
  24 #include "glock.h"
  25 #include "inode.h"
  26 #include "ops_vm.h"
  27 #include "page.h"
  28 #include "quota.h"
  29 #include "rgrp.h"
  30 #include "trans.h"
  31 #include "util.h"
  32
  33 static void pfault_be_greedy(struct gfs2_inode *ip)
  34 {
  35         unsigned int time;
  36
  37         spin_lock(&ip->i_spin);
  38         time = ip->i_greedy;
  39         ip->i_last_pfault = jiffies;
  40         spin_unlock(&ip->i_spin);
  41
  42         gfs2_inode_hold(ip);
  43         if (gfs2_glock_be_greedy(ip->i_gl, time))
  44                 gfs2_inode_put(ip);
  45 }
  46
  47 static struct page *gfs2_private_nopage(struct vm_area_struct *area,
  48                                         unsigned long address, int *type)
  49 {
  50         struct gfs2_inode *ip = area->vm_file->f_mapping->host->u.generic_ip;
  51         struct gfs2_holder i_gh;
  52         struct page *result;
  53         int error;
  54
  55         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
  56         if (error)
  57                 return NULL;
  58
  59         set_bit(GIF_PAGED, &ip->i_flags);
  60
  61         result = filemap_nopage(area, address, type);
  62
  63         if (result && result != NOPAGE_OOM)
  64                 pfault_be_greedy(ip);
  65
  66         gfs2_glock_dq_uninit(&i_gh);
  67
  68         return result;
  69 }
  70
  71 static int alloc_page_backing(struct gfs2_inode *ip, struct page *page)
  72 {
  73         struct gfs2_sbd *sdp = ip->i_sbd;
  74         unsigned long index = page->index;
  75         uint64_t lblock = index << (PAGE_CACHE_SHIFT -
  76                                     sdp->sd_sb.sb_bsize_shift);
  77         unsigned int blocks = PAGE_CACHE_SIZE >> sdp->sd_sb.sb_bsize_shift;
  78         struct gfs2_alloc *al;
  79         unsigned int data_blocks, ind_blocks;
  80         unsigned int x;
  81         int error;
  82
  83         al = gfs2_alloc_get(ip);
  84
  85         error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
  86         if (error)
  87                 goto out;
  88
  89         error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
  90         if (error)
  91                 goto out_gunlock_q;
  92
  93         gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE,
  94                               &data_blocks, &ind_blocks);
  95
  96         al->al_requested = data_blocks + ind_blocks;
  97
  98         error = gfs2_inplace_reserve(ip);
  99         if (error)
 100                 goto out_gunlock_q;
 101
 102         error = gfs2_trans_begin(sdp,
 103                                  al->al_rgd->rd_ri.ri_length +
 104                                  ind_blocks + RES_DINODE +
 105                                  RES_STATFS + RES_QUOTA, 0);
 106         if (error)
 107                 goto out_ipres;
 108
 109         if (gfs2_is_stuffed(ip)) {
 110                 error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page, NULL);
 111                 if (error)
 112                         goto out_trans;
 113         }
 114
 115         for (x = 0; x < blocks; ) {
 116                 uint64_t dblock;
 117                 unsigned int extlen;
 118                 int new = 1;
 119
 120                 error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
 121                 if (error)
 122                         goto out_trans;
 123
 124                 lblock += extlen;
 125                 x += extlen;
 126         }
 127
 128         gfs2_assert_warn(sdp, al->al_alloced);
 129
 130  out_trans:
 131         gfs2_trans_end(sdp);
 132
 133  out_ipres:
 134         gfs2_inplace_release(ip);
 135
 136  out_gunlock_q:
 137         gfs2_quota_unlock(ip);
 138
 139  out:
 140         gfs2_alloc_put(ip);
 141
 142         return error;
 143 }
 144
 145 static struct page *gfs2_sharewrite_nopage(struct vm_area_struct *area,
 146                                            unsigned long address, int *type)
 147 {
 148         struct gfs2_inode *ip = area->vm_file->f_mapping->host->u.generic_ip;
 149         struct gfs2_holder i_gh;
 150         struct page *result = NULL;
 151         unsigned long index = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) +
 152                               area->vm_pgoff;
 153         int alloc_required;
 154         int error;
 155
 156         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 157         if (error)
 158                 return NULL;
 159
 160         set_bit(GIF_PAGED, &ip->i_flags);
 161         set_bit(GIF_SW_PAGED, &ip->i_flags);
 162
 163         error = gfs2_write_alloc_required(ip,
 164                                           (uint64_t)index << PAGE_CACHE_SHIFT,
 165                                           PAGE_CACHE_SIZE, &alloc_required);
 166         if (error)
 167                 goto out;
 168
 169         result = filemap_nopage(area, address, type);
 170         if (!result || result == NOPAGE_OOM)
 171                 goto out;
 172
 173         if (alloc_required) {
 174                 error = alloc_page_backing(ip, result);
 175                 if (error) {
 176                         page_cache_release(result);
 177                         result = NULL;
 178                         goto out;
 179                 }
 180                 set_page_dirty(result);
 181         }
 182
 183         pfault_be_greedy(ip);
 184
 185  out:
 186         gfs2_glock_dq_uninit(&i_gh);
 187
 188         return result;
 189 }
 190
 191 struct vm_operations_struct gfs2_vm_ops_private = {
 192         .nopage = gfs2_private_nopage,
 193 };
 194
 195 struct vm_operations_struct gfs2_vm_ops_sharewrite = {
 196         .nopage = gfs2_sharewrite_nopage,
 197 };
 198