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/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License version 2.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/gfs2_ondisk.h>
#include <linux/lm_interface.h>
#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "inode.h"
#include "ops_vm.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"
static void pfault_be_greedy(struct gfs2_inode *ip)
{
unsigned int time;
spin_lock(&ip->i_spin);
time = ip->i_greedy;
ip->i_last_pfault = jiffies;
spin_unlock(&ip->i_spin);
igrab(&ip->i_inode);
if (gfs2_glock_be_greedy(ip->i_gl, time))
iput(&ip->i_inode);
}
static struct page *gfs2_private_nopage(struct vm_area_struct *area,
unsigned long address, int *type)
{
struct gfs2_inode *ip = GFS2_I(area->vm_file->f_mapping->host);
struct page *result;
set_bit(GIF_PAGED, &ip->i_flags);
result = filemap_nopage(area, address, type);
if (result && result != NOPAGE_OOM)
pfault_be_greedy(ip);
return result;
}
static int alloc_page_backing(struct gfs2_inode *ip, struct page *page)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
unsigned long index = page->index;
u64 lblock = index << (PAGE_CACHE_SHIFT -
sdp->sd_sb.sb_bsize_shift);
unsigned int blocks = PAGE_CACHE_SIZE >> sdp->sd_sb.sb_bsize_shift;
struct gfs2_alloc *al;
unsigned int data_blocks, ind_blocks;
unsigned int x;
int error;
al = gfs2_alloc_get(ip);
error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
if (error)
goto out;
error = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid);
if (error)
goto out_gunlock_q;
gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
al->al_requested = data_blocks + ind_blocks;
error = gfs2_inplace_reserve(ip);
if (error)
goto out_gunlock_q;
error = gfs2_trans_begin(sdp, al->al_rgd->rd_ri.ri_length +
ind_blocks + RES_DINODE +
RES_STATFS + RES_QUOTA, 0);
if (error)
goto out_ipres;
if (gfs2_is_stuffed(ip)) {
error = gfs2_unstuff_dinode(ip, NULL);
if (error)
goto out_trans;
}
for (x = 0; x < blocks; ) {
u64 dblock;
unsigned int extlen;
int new = 1;
error = gfs2_extent_map(&ip->i_inode, lblock, &new, &dblock, &extlen);
if (error)
goto out_trans;
lblock += extlen;
x += extlen;
}
gfs2_assert_warn(sdp, al->al_alloced);
out_trans:
gfs2_trans_end(sdp);
out_ipres:
gfs2_inplace_release(ip);
out_gunlock_q:
gfs2_quota_unlock(ip);
out:
gfs2_alloc_put(ip);
return error;
}
static struct page *gfs2_sharewrite_nopage(struct vm_area_struct *area,
unsigned long address, int *type)
{
struct file *file = area->vm_file;
struct gfs2_file *gf = file->private_data;
struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
struct gfs2_holder i_gh;
struct page *result = NULL;
unsigned long index = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) +
area->vm_pgoff;
int alloc_required;
int error;
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
if (error)
return NULL;
set_bit(GIF_PAGED, &ip->i_flags);
set_bit(GIF_SW_PAGED, &ip->i_flags);
error = gfs2_write_alloc_required(ip, (u64)index << PAGE_CACHE_SHIFT,
PAGE_CACHE_SIZE, &alloc_required);
if (error)
goto out;
set_bit(GFF_EXLOCK, &gf->f_flags);
result = filemap_nopage(area, address, type);
clear_bit(GFF_EXLOCK, &gf->f_flags);
if (!result || result == NOPAGE_OOM)
goto out;
if (alloc_required) {
error = alloc_page_backing(ip, result);
if (error) {
page_cache_release(result);
result = NULL;
goto out;
}
set_page_dirty(result);
}
pfault_be_greedy(ip);
out:
gfs2_glock_dq_uninit(&i_gh);
return result;
}
struct vm_operations_struct gfs2_vm_ops_private = {
.nopage = gfs2_private_nopage,
};
struct vm_operations_struct gfs2_vm_ops_sharewrite = {
.nopage = gfs2_sharewrite_nopage,
};
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