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 <asm/semaphore.h>
  18
  19 #include "gfs2.h"
  20 #include "bmap.h"
  21 #include "glock.h"
  22 #include "inode.h"
  23 #include "ops_vm.h"
  24 #include "page.h"
  25 #include "quota.h"
  26 #include "rgrp.h"
  27 #include "trans.h"
  28
  29 static void pfault_be_greedy(struct gfs2_inode *ip)
  30 {
  31         unsigned int time;
  32
  33         spin_lock(&ip->i_spin);
  34         time = ip->i_greedy;
  35         ip->i_last_pfault = jiffies;
  36         spin_unlock(&ip->i_spin);
  37
  38         gfs2_inode_hold(ip);
  39         if (gfs2_glock_be_greedy(ip->i_gl, time))
  40                 gfs2_inode_put(ip);
  41 }
  42
  43 static struct page *gfs2_private_nopage(struct vm_area_struct *area,
  44                                         unsigned long address, int *type)
  45 {
  46         struct gfs2_inode *ip = get_v2ip(area->vm_file->f_mapping->host);
  47         struct gfs2_holder i_gh;
  48         struct page *result;
  49         int error;
  50
  51         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
  52         if (error)
  53                 return NULL;
  54
  55         set_bit(GIF_PAGED, &ip->i_flags);
  56
  57         result = filemap_nopage(area, address, type);
  58
  59         if (result && result != NOPAGE_OOM)
  60                 pfault_be_greedy(ip);
  61
  62         gfs2_glock_dq_uninit(&i_gh);
  63
  64         return result;
  65 }
  66
  67 static int alloc_page_backing(struct gfs2_inode *ip, struct page *page)
  68 {
  69         struct gfs2_sbd *sdp = ip->i_sbd;
  70         unsigned long index = page->index;
  71         uint64_t lblock = index << (PAGE_CACHE_SHIFT -
  72                                     sdp->sd_sb.sb_bsize_shift);
  73         unsigned int blocks = PAGE_CACHE_SIZE >> sdp->sd_sb.sb_bsize_shift;
  74         struct gfs2_alloc *al;
  75         unsigned int data_blocks, ind_blocks;
  76         unsigned int x;
  77         int error;
  78
  79         al = gfs2_alloc_get(ip);
  80
  81         error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
  82         if (error)
  83                 goto out;
  84
  85         error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
  86         if (error)
  87                 goto out_gunlock_q;
  88
  89         gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE,
  90                               &data_blocks, &ind_blocks);
  91
  92         al->al_requested = data_blocks + ind_blocks;
  93
  94         error = gfs2_inplace_reserve(ip);
  95         if (error)
  96                 goto out_gunlock_q;
  97
  98         error = gfs2_trans_begin(sdp,
  99                                  al->al_rgd->rd_ri.ri_length +
 100                                  ind_blocks + RES_DINODE +
 101                                  RES_STATFS + RES_QUOTA, 0);
 102         if (error)
 103                 goto out_ipres;
 104
 105         if (gfs2_is_stuffed(ip)) {
 106                 error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page, NULL);
 107                 if (error)
 108                         goto out_trans;
 109         }
 110
 111         for (x = 0; x < blocks; ) {
 112                 uint64_t dblock;
 113                 unsigned int extlen;
 114                 int new = 1;
 115
 116                 error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
 117                 if (error)
 118                         goto out_trans;
 119
 120                 lblock += extlen;
 121                 x += extlen;
 122         }
 123
 124         gfs2_assert_warn(sdp, al->al_alloced);
 125
 126  out_trans:
 127         gfs2_trans_end(sdp);
 128
 129  out_ipres:
 130         gfs2_inplace_release(ip);
 131
 132  out_gunlock_q:
 133         gfs2_quota_unlock(ip);
 134
 135  out:
 136         gfs2_alloc_put(ip);
 137
 138         return error;
 139 }
 140
 141 static struct page *gfs2_sharewrite_nopage(struct vm_area_struct *area,
 142                                            unsigned long address, int *type)
 143 {
 144         struct gfs2_inode *ip = get_v2ip(area->vm_file->f_mapping->host);
 145         struct gfs2_holder i_gh;
 146         struct page *result = NULL;
 147         unsigned long index = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) +
 148                               area->vm_pgoff;
 149         int alloc_required;
 150         int error;
 151
 152         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 153         if (error)
 154                 return NULL;
 155
 156         set_bit(GIF_PAGED, &ip->i_flags);
 157         set_bit(GIF_SW_PAGED, &ip->i_flags);
 158
 159         error = gfs2_write_alloc_required(ip,
 160                                           (uint64_t)index << PAGE_CACHE_SHIFT,
 161                                           PAGE_CACHE_SIZE, &alloc_required);
 162         if (error)
 163                 goto out;
 164
 165         result = filemap_nopage(area, address, type);
 166         if (!result || result == NOPAGE_OOM)
 167                 goto out;
 168
 169         if (alloc_required) {
 170                 error = alloc_page_backing(ip, result);
 171                 if (error) {
 172                         page_cache_release(result);
 173                         result = NULL;
 174                         goto out;
 175                 }
 176                 set_page_dirty(result);
 177         }
 178
 179         pfault_be_greedy(ip);
 180
 181  out:
 182         gfs2_glock_dq_uninit(&i_gh);
 183
 184         return result;
 185 }
 186
 187 struct vm_operations_struct gfs2_vm_ops_private = {
 188         .nopage = gfs2_private_nopage,
 189 };
 190
 191 struct vm_operations_struct gfs2_vm_ops_sharewrite = {
 192         .nopage = gfs2_sharewrite_nopage,
 193 };
 194