fs/gfs2/ops_vm.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2006 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 version 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 <linux/lm_interface.h>
  19
  20 #include "gfs2.h"
  21 #include "incore.h"
  22 #include "bmap.h"
  23 #include "glock.h"
  24 #include "inode.h"
  25 #include "ops_vm.h"
  26 #include "quota.h"
  27 #include "rgrp.h"
  28 #include "trans.h"
  29 #include "util.h"
  30
  31 static void pfault_be_greedy(struct gfs2_inode *ip)
  32 {
  33         unsigned int time;
  34
  35         spin_lock(&ip->i_spin);
  36         time = ip->i_greedy;
  37         ip->i_last_pfault = jiffies;
  38         spin_unlock(&ip->i_spin);
  39
  40         igrab(&ip->i_inode);
  41         if (gfs2_glock_be_greedy(ip->i_gl, time))
  42                 iput(&ip->i_inode);
  43 }
  44
  45 static struct page *gfs2_private_nopage(struct vm_area_struct *area,
  46                                         unsigned long address, int *type)
  47 {
  48         struct gfs2_inode *ip = GFS2_I(area->vm_file->f_mapping->host);
  49         struct page *result;
  50
  51         set_bit(GIF_PAGED, &ip->i_flags);
  52
  53         result = filemap_nopage(area, address, type);
  54
  55         if (result && result != NOPAGE_OOM)
  56                 pfault_be_greedy(ip);
  57
  58         return result;
  59 }
  60
  61 static int alloc_page_backing(struct gfs2_inode *ip, struct page *page)
  62 {
  63         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
  64         unsigned long index = page->index;
  65         u64 lblock = index << (PAGE_CACHE_SHIFT -
  66                                     sdp->sd_sb.sb_bsize_shift);
  67         unsigned int blocks = PAGE_CACHE_SIZE >> sdp->sd_sb.sb_bsize_shift;
  68         struct gfs2_alloc *al;
  69         unsigned int data_blocks, ind_blocks;
  70         unsigned int x;
  71         int error;
  72
  73         al = gfs2_alloc_get(ip);
  74
  75         error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
  76         if (error)
  77                 goto out;
  78
  79         error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
  80         if (error)
  81                 goto out_gunlock_q;
  82
  83         gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
  84
  85         al->al_requested = data_blocks + ind_blocks;
  86
  87         error = gfs2_inplace_reserve(ip);
  88         if (error)
  89                 goto out_gunlock_q;
  90
  91         error = gfs2_trans_begin(sdp, al->al_rgd->rd_ri.ri_length +
  92                                  ind_blocks + RES_DINODE +
  93                                  RES_STATFS + RES_QUOTA, 0);
  94         if (error)
  95                 goto out_ipres;
  96
  97         if (gfs2_is_stuffed(ip)) {
  98                 error = gfs2_unstuff_dinode(ip, NULL);
  99                 if (error)
 100                         goto out_trans;
 101         }
 102
 103         for (x = 0; x < blocks; ) {
 104                 u64 dblock;
 105                 unsigned int extlen;
 106                 int new = 1;
 107
 108                 error = gfs2_extent_map(&ip->i_inode, lblock, &new, &dblock, &extlen);
 109                 if (error)
 110                         goto out_trans;
 111
 112                 lblock += extlen;
 113                 x += extlen;
 114         }
 115
 116         gfs2_assert_warn(sdp, al->al_alloced);
 117
 118 out_trans:
 119         gfs2_trans_end(sdp);
 120 out_ipres:
 121         gfs2_inplace_release(ip);
 122 out_gunlock_q:
 123         gfs2_quota_unlock(ip);
 124 out:
 125         gfs2_alloc_put(ip);
 126         return error;
 127 }
 128
 129 static struct page *gfs2_sharewrite_nopage(struct vm_area_struct *area,
 130                                            unsigned long address, int *type)
 131 {
 132         struct file *file = area->vm_file;
 133         struct gfs2_file *gf = file->private_data;
 134         struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 135         struct gfs2_holder i_gh;
 136         struct page *result = NULL;
 137         unsigned long index = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) +
 138                               area->vm_pgoff;
 139         int alloc_required;
 140         int error;
 141
 142         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 143         if (error)
 144                 return NULL;
 145
 146         set_bit(GIF_PAGED, &ip->i_flags);
 147         set_bit(GIF_SW_PAGED, &ip->i_flags);
 148
 149         error = gfs2_write_alloc_required(ip, (u64)index << PAGE_CACHE_SHIFT,
 150                                           PAGE_CACHE_SIZE, &alloc_required);
 151         if (error)
 152                 goto out;
 153
 154         set_bit(GFF_EXLOCK, &gf->f_flags);
 155         result = filemap_nopage(area, address, type);
 156         clear_bit(GFF_EXLOCK, &gf->f_flags);
 157         if (!result || result == NOPAGE_OOM)
 158                 goto out;
 159
 160         if (alloc_required) {
 161                 error = alloc_page_backing(ip, result);
 162                 if (error) {
 163                         page_cache_release(result);
 164                         result = NULL;
 165                         goto out;
 166                 }
 167                 set_page_dirty(result);
 168         }
 169
 170         pfault_be_greedy(ip);
 171 out:
 172         gfs2_glock_dq_uninit(&i_gh);
 173
 174         return result;
 175 }
 176
 177 struct vm_operations_struct gfs2_vm_ops_private = {
 178         .nopage = gfs2_private_nopage,
 179 };
 180
 181 struct vm_operations_struct gfs2_vm_ops_sharewrite = {
 182         .nopage = gfs2_sharewrite_nopage,
 183 };
 184