SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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/slab.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/completion.h>
  13 #include <linux/buffer_head.h>
  14 #include <linux/mm.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/gfs2_ondisk.h>
  17 #include <linux/lm_interface.h>
  18
  19 #include "gfs2.h"
  20 #include "incore.h"
  21 #include "bmap.h"
  22 #include "glock.h"
  23 #include "inode.h"
  24 #include "ops_vm.h"
  25 #include "quota.h"
  26 #include "rgrp.h"
  27 #include "trans.h"
  28 #include "util.h"
  29
  30 static struct page *gfs2_private_fault(struct vm_area_struct *vma,
  31                                         struct fault_data *fdata)
  32 {
  33         struct gfs2_inode *ip = GFS2_I(vma->vm_file->f_mapping->host);
  34
  35         set_bit(GIF_PAGED, &ip->i_flags);
  36         return filemap_fault(vma, fdata);
  37 }
  38
  39 static int alloc_page_backing(struct gfs2_inode *ip, struct page *page)
  40 {
  41         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
  42         unsigned long index = page->index;
  43         u64 lblock = index << (PAGE_CACHE_SHIFT -
  44                                     sdp->sd_sb.sb_bsize_shift);
  45         unsigned int blocks = PAGE_CACHE_SIZE >> sdp->sd_sb.sb_bsize_shift;
  46         struct gfs2_alloc *al;
  47         unsigned int data_blocks, ind_blocks;
  48         unsigned int x;
  49         int error;
  50
  51         al = gfs2_alloc_get(ip);
  52
  53         error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
  54         if (error)
  55                 goto out;
  56
  57         error = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid);
  58         if (error)
  59                 goto out_gunlock_q;
  60
  61         gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
  62
  63         al->al_requested = data_blocks + ind_blocks;
  64
  65         error = gfs2_inplace_reserve(ip);
  66         if (error)
  67                 goto out_gunlock_q;
  68
  69         error = gfs2_trans_begin(sdp, al->al_rgd->rd_length +
  70                                  ind_blocks + RES_DINODE +
  71                                  RES_STATFS + RES_QUOTA, 0);
  72         if (error)
  73                 goto out_ipres;
  74
  75         if (gfs2_is_stuffed(ip)) {
  76                 error = gfs2_unstuff_dinode(ip, NULL);
  77                 if (error)
  78                         goto out_trans;
  79         }
  80
  81         for (x = 0; x < blocks; ) {
  82                 u64 dblock;
  83                 unsigned int extlen;
  84                 int new = 1;
  85
  86                 error = gfs2_extent_map(&ip->i_inode, lblock, &new, &dblock, &extlen);
  87                 if (error)
  88                         goto out_trans;
  89
  90                 lblock += extlen;
  91                 x += extlen;
  92         }
  93
  94         gfs2_assert_warn(sdp, al->al_alloced);
  95
  96 out_trans:
  97         gfs2_trans_end(sdp);
  98 out_ipres:
  99         gfs2_inplace_release(ip);
 100 out_gunlock_q:
 101         gfs2_quota_unlock(ip);
 102 out:
 103         gfs2_alloc_put(ip);
 104         return error;
 105 }
 106
 107 static struct page *gfs2_sharewrite_fault(struct vm_area_struct *vma,
 108                                                 struct fault_data *fdata)
 109 {
 110         struct file *file = vma->vm_file;
 111         struct gfs2_file *gf = file->private_data;
 112         struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 113         struct gfs2_holder i_gh;
 114         struct page *result = NULL;
 115         int alloc_required;
 116         int error;
 117
 118         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 119         if (error)
 120                 return NULL;
 121
 122         set_bit(GIF_PAGED, &ip->i_flags);
 123         set_bit(GIF_SW_PAGED, &ip->i_flags);
 124
 125         error = gfs2_write_alloc_required(ip,
 126                                         (u64)fdata->pgoff << PAGE_CACHE_SHIFT,
 127                                         PAGE_CACHE_SIZE, &alloc_required);
 128         if (error) {
 129                 fdata->type = VM_FAULT_OOM; /* XXX: are these right? */
 130                 goto out;
 131         }
 132
 133         set_bit(GFF_EXLOCK, &gf->f_flags);
 134         result = filemap_fault(vma, fdata);
 135         clear_bit(GFF_EXLOCK, &gf->f_flags);
 136         if (!result)
 137                 goto out;
 138
 139         if (alloc_required) {
 140                 error = alloc_page_backing(ip, result);
 141                 if (error) {
 142                         if (vma->vm_flags & VM_CAN_INVALIDATE)
 143                                 unlock_page(result);
 144                         page_cache_release(result);
 145                         fdata->type = VM_FAULT_OOM;
 146                         result = NULL;
 147                         goto out;
 148                 }
 149                 set_page_dirty(result);
 150         }
 151
 152 out:
 153         gfs2_glock_dq_uninit(&i_gh);
 154
 155         return result;
 156 }
 157
 158 struct vm_operations_struct gfs2_vm_ops_private = {
 159         .fault = gfs2_private_fault,
 160 };
 161
 162 struct vm_operations_struct gfs2_vm_ops_sharewrite = {
 163         .fault = gfs2_sharewrite_fault,
 164 };
 165