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
  19 #include "gfs2.h"
  20 #include "lm_interface.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         uint64_t 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                 uint64_t 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
 121  out_ipres:
 122         gfs2_inplace_release(ip);
 123
 124  out_gunlock_q:
 125         gfs2_quota_unlock(ip);
 126
 127  out:
 128         gfs2_alloc_put(ip);
 129
 130         return error;
 131 }
 132
 133 static struct page *gfs2_sharewrite_nopage(struct vm_area_struct *area,
 134                                            unsigned long address, int *type)
 135 {
 136         struct file *file = area->vm_file;
 137         struct gfs2_file *gf = file->private_data;
 138         struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 139         struct gfs2_holder i_gh;
 140         struct page *result = NULL;
 141         unsigned long index = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) +
 142                               area->vm_pgoff;
 143         int alloc_required;
 144         int error;
 145
 146         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 147         if (error)
 148                 return NULL;
 149
 150         set_bit(GIF_PAGED, &ip->i_flags);
 151         set_bit(GIF_SW_PAGED, &ip->i_flags);
 152
 153         error = gfs2_write_alloc_required(ip, (u64)index << PAGE_CACHE_SHIFT,
 154                                           PAGE_CACHE_SIZE, &alloc_required);
 155         if (error)
 156                 goto out;
 157
 158         set_bit(GFF_EXLOCK, &gf->f_flags);
 159         result = filemap_nopage(area, address, type);
 160         clear_bit(GFF_EXLOCK, &gf->f_flags);
 161         if (!result || result == NOPAGE_OOM)
 162                 goto out;
 163
 164         if (alloc_required) {
 165                 error = alloc_page_backing(ip, result);
 166                 if (error) {
 167                         page_cache_release(result);
 168                         result = NULL;
 169                         goto out;
 170                 }
 171                 set_page_dirty(result);
 172         }
 173
 174         pfault_be_greedy(ip);
 175 out:
 176         gfs2_glock_dq_uninit(&i_gh);
 177
 178         return result;
 179 }
 180
 181 struct vm_operations_struct gfs2_vm_ops_private = {
 182         .nopage = gfs2_private_nopage,
 183 };
 184
 185 struct vm_operations_struct gfs2_vm_ops_sharewrite = {
 186         .nopage = gfs2_sharewrite_nopage,
 187 };
 188