[deliverable/linux.git] / fs / gfs2 / ops_vm.c

/*
 * 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 v.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 "gfs2.h"
#include "lm_interface.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "inode.h"
#include "ops_vm.h"
#include "page.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 gfs2_holder i_gh;
	struct page *result;
	int error;

	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
	if (error)
		return NULL;

	set_bit(GIF_PAGED, &ip->i_flags);

	result = filemap_nopage(area, address, type);

	if (result && result != NOPAGE_OOM)
		pfault_be_greedy(ip);

	gfs2_glock_dq_uninit(&i_gh);

	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;
	uint64_t 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_di.di_uid, ip->i_di.di_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, gfs2_unstuffer_page, NULL);
		if (error)
			goto out_trans;
	}

	for (x = 0; x < blocks; ) {
		uint64_t 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 gfs2_inode *ip = GFS2_I(area->vm_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,
					  (uint64_t)index << PAGE_CACHE_SHIFT,
					  PAGE_CACHE_SIZE, &alloc_required);
	if (error)
		goto out;

	result = filemap_nopage(area, address, type);
	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,
};
Commit	Line	Data
b3b94faa DT	1	/*
b3b94faa DT	2	* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3a8a9a10	3	* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
b3b94faa DT	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 v.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>
5c676f6d	17	#include <linux/gfs2_ondisk.h>
b3b94faa DT	18
b3b94faa DT	19	#include "gfs2.h"
5c676f6d SW	20	#include "lm_interface.h"
5c676f6d SW	21	#include "incore.h"
b3b94faa DT	22	#include "bmap.h"
	23	#include "glock.h"
	24	#include "inode.h"
	25	#include "ops_vm.h"
	26	#include "page.h"
	27	#include "quota.h"
	28	#include "rgrp.h"
	29	#include "trans.h"
5c676f6d	30	#include "util.h"
b3b94faa DT	31
	32	static void pfault_be_greedy(struct gfs2_inode *ip)
	33	{
	34	unsigned int time;
	35
	36	spin_lock(&ip->i_spin);
	37	time = ip->i_greedy;
	38	ip->i_last_pfault = jiffies;
	39	spin_unlock(&ip->i_spin);
	40
feaa7bba	41	igrab(&ip->i_inode);
b3b94faa	42	if (gfs2_glock_be_greedy(ip->i_gl, time))
feaa7bba	43	iput(&ip->i_inode);
b3b94faa DT	44	}
	45
	46	static struct page gfs2_private_nopage(struct vm_area_struct area,
	47	unsigned long address, int *type)
	48	{
feaa7bba	49	struct gfs2_inode *ip = GFS2_I(area->vm_file->f_mapping->host);
b3b94faa DT	50	struct gfs2_holder i_gh;
	51	struct page *result;
	52	int error;
	53
b3b94faa DT	54	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
	55	if (error)
	56	return NULL;
	57
	58	set_bit(GIF_PAGED, &ip->i_flags);
	59
	60	result = filemap_nopage(area, address, type);
	61
	62	if (result && result != NOPAGE_OOM)
	63	pfault_be_greedy(ip);
	64
	65	gfs2_glock_dq_uninit(&i_gh);
	66
	67	return result;
	68	}
	69
	70	static int alloc_page_backing(struct gfs2_inode ip, struct page page)
	71	{
feaa7bba	72	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
b3b94faa	73	unsigned long index = page->index;
568f4c96 SW	74	uint64_t lblock = index << (PAGE_CACHE_SHIFT -
568f4c96 SW	75	sdp->sd_sb.sb_bsize_shift);
b3b94faa DT	76	unsigned int blocks = PAGE_CACHE_SIZE >> sdp->sd_sb.sb_bsize_shift;
	77	struct gfs2_alloc *al;
	78	unsigned int data_blocks, ind_blocks;
	79	unsigned int x;
	80	int error;
	81
	82	al = gfs2_alloc_get(ip);
	83
	84	error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
	85	if (error)
	86	goto out;
	87
	88	error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
	89	if (error)
	90	goto out_gunlock_q;
	91
fd88de56	92	gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
b3b94faa DT	93
	94	al->al_requested = data_blocks + ind_blocks;
	95
	96	error = gfs2_inplace_reserve(ip);
	97	if (error)
	98	goto out_gunlock_q;
	99
fd88de56	100	error = gfs2_trans_begin(sdp, al->al_rgd->rd_ri.ri_length +
b3b94faa DT	101	ind_blocks + RES_DINODE +
	102	RES_STATFS + RES_QUOTA, 0);
	103	if (error)
	104	goto out_ipres;
	105
	106	if (gfs2_is_stuffed(ip)) {
	107	error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page, NULL);
	108	if (error)
	109	goto out_trans;
	110	}
	111
	112	for (x = 0; x < blocks; ) {
	113	uint64_t dblock;
	114	unsigned int extlen;
	115	int new = 1;
	116
feaa7bba	117	error = gfs2_extent_map(&ip->i_inode, lblock, &new, &dblock, &extlen);
b3b94faa DT	118	if (error)
	119	goto out_trans;
	120
	121	lblock += extlen;
	122	x += extlen;
	123	}
	124
	125	gfs2_assert_warn(sdp, al->al_alloced);
	126
	127	out_trans:
	128	gfs2_trans_end(sdp);
	129
	130	out_ipres:
	131	gfs2_inplace_release(ip);
	132
	133	out_gunlock_q:
	134	gfs2_quota_unlock(ip);
	135
	136	out:
	137	gfs2_alloc_put(ip);
	138
	139	return error;
	140	}
	141
	142	static struct page gfs2_sharewrite_nopage(struct vm_area_struct area,
	143	unsigned long address, int *type)
	144	{
feaa7bba	145	struct gfs2_inode *ip = GFS2_I(area->vm_file->f_mapping->host);
b3b94faa DT	146	struct gfs2_holder i_gh;
b3b94faa DT	147	struct page *result = NULL;
568f4c96 SW	148	unsigned long index = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) +
568f4c96 SW	149	area->vm_pgoff;
b3b94faa DT	150	int alloc_required;
	151	int error;
	152
b3b94faa DT	153	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
	154	if (error)
	155	return NULL;
	156
b3b94faa DT	157	set_bit(GIF_PAGED, &ip->i_flags);
	158	set_bit(GIF_SW_PAGED, &ip->i_flags);
	159
	160	error = gfs2_write_alloc_required(ip,
	161	(uint64_t)index << PAGE_CACHE_SHIFT,
	162	PAGE_CACHE_SIZE, &alloc_required);
	163	if (error)
	164	goto out;
	165
	166	result = filemap_nopage(area, address, type);
	167	if (!result \|\| result == NOPAGE_OOM)
	168	goto out;
	169
	170	if (alloc_required) {
	171	error = alloc_page_backing(ip, result);
	172	if (error) {
	173	page_cache_release(result);
	174	result = NULL;
	175	goto out;
	176	}
	177	set_page_dirty(result);
	178	}
	179
	180	pfault_be_greedy(ip);
	181
	182	out:
	183	gfs2_glock_dq_uninit(&i_gh);
	184
	185	return result;
	186	}
	187
	188	struct vm_operations_struct gfs2_vm_ops_private = {
	189	.nopage = gfs2_private_nopage,
	190	};
	191
	192	struct vm_operations_struct gfs2_vm_ops_sharewrite = {
	193	.nopage = gfs2_sharewrite_nopage,
	194	};
	195