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 struct page *gfs2_private_nopage(struct vm_area_struct *area,
  32                                         unsigned long address, int *type)
  33 {
  34         struct gfs2_inode *ip = GFS2_I(area->vm_file->f_mapping->host);
  35
  36         set_bit(GIF_PAGED, &ip->i_flags);
  37         return filemap_nopage(area, address, type);
  38 }
  39
  40 static int alloc_page_backing(struct gfs2_inode *ip, struct page *page)
  41 {
  42         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
  43         unsigned long index = page->index;
  44         u64 lblock = index << (PAGE_CACHE_SHIFT -
  45                                     sdp->sd_sb.sb_bsize_shift);
  46         unsigned int blocks = PAGE_CACHE_SIZE >> sdp->sd_sb.sb_bsize_shift;
  47         struct gfs2_alloc *al;
  48         unsigned int data_blocks, ind_blocks;
  49         unsigned int x;
  50         int error;
  51
  52         al = gfs2_alloc_get(ip);
  53
  54         error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
  55         if (error)
  56                 goto out;
  57
  58         error = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid);
  59         if (error)
  60                 goto out_gunlock_q;
  61
  62         gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
  63
  64         al->al_requested = data_blocks + ind_blocks;
  65
  66         error = gfs2_inplace_reserve(ip);
  67         if (error)
  68                 goto out_gunlock_q;
  69
  70         error = gfs2_trans_begin(sdp, al->al_rgd->rd_ri.ri_length +
  71                                  ind_blocks + RES_DINODE +
  72                                  RES_STATFS + RES_QUOTA, 0);
  73         if (error)
  74                 goto out_ipres;
  75
  76         if (gfs2_is_stuffed(ip)) {
  77                 error = gfs2_unstuff_dinode(ip, NULL);
  78                 if (error)
  79                         goto out_trans;
  80         }
  81
  82         for (x = 0; x < blocks; ) {
  83                 u64 dblock;
  84                 unsigned int extlen;
  85                 int new = 1;
  86
  87                 error = gfs2_extent_map(&ip->i_inode, lblock, &new, &dblock, &extlen);
  88                 if (error)
  89                         goto out_trans;
  90
  91                 lblock += extlen;
  92                 x += extlen;
  93         }
  94
  95         gfs2_assert_warn(sdp, al->al_alloced);
  96
  97 out_trans:
  98         gfs2_trans_end(sdp);
  99 out_ipres:
 100         gfs2_inplace_release(ip);
 101 out_gunlock_q:
 102         gfs2_quota_unlock(ip);
 103 out:
 104         gfs2_alloc_put(ip);
 105         return error;
 106 }
 107
 108 static struct page *gfs2_sharewrite_nopage(struct vm_area_struct *area,
 109                                            unsigned long address, int *type)
 110 {
 111         struct file *file = area->vm_file;
 112         struct gfs2_file *gf = file->private_data;
 113         struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 114         struct gfs2_holder i_gh;
 115         struct page *result = NULL;
 116         unsigned long index = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) +
 117                               area->vm_pgoff;
 118         int alloc_required;
 119         int error;
 120
 121         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 122         if (error)
 123                 return NULL;
 124
 125         set_bit(GIF_PAGED, &ip->i_flags);
 126         set_bit(GIF_SW_PAGED, &ip->i_flags);
 127
 128         error = gfs2_write_alloc_required(ip, (u64)index << PAGE_CACHE_SHIFT,
 129                                           PAGE_CACHE_SIZE, &alloc_required);
 130         if (error)
 131                 goto out;
 132
 133         set_bit(GFF_EXLOCK, &gf->f_flags);
 134         result = filemap_nopage(area, address, type);
 135         clear_bit(GFF_EXLOCK, &gf->f_flags);
 136         if (!result || result == NOPAGE_OOM)
 137                 goto out;
 138
 139         if (alloc_required) {
 140                 error = alloc_page_backing(ip, result);
 141                 if (error) {
 142                         page_cache_release(result);
 143                         result = NULL;
 144                         goto out;
 145                 }
 146                 set_page_dirty(result);
 147         }
 148
 149 out:
 150         gfs2_glock_dq_uninit(&i_gh);
 151
 152         return result;
 153 }
 154
 155 struct vm_operations_struct gfs2_vm_ops_private = {
 156         .nopage = gfs2_private_nopage,
 157 };
 158
 159 struct vm_operations_struct gfs2_vm_ops_sharewrite = {
 160         .nopage = gfs2_sharewrite_nopage,
 161 };
 162