[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / gfs2 / page.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/pagemap.h>
#include <linux/mm.h>
#include <linux/gfs2_ondisk.h>

#include "gfs2.h"
#include "lm_interface.h"
#include "incore.h"
#include "bmap.h"
#include "inode.h"
#include "page.h"
#include "trans.h"
#include "ops_address.h"
#include "util.h"

/**
 * gfs2_pte_inval - Sync and invalidate all PTEs associated with a glock
 * @gl: the glock
 *
 */

void gfs2_pte_inval(struct gfs2_glock *gl)
{
	struct gfs2_inode *ip;
	struct inode *inode;

	ip = gl->gl_object;
	inode = &ip->i_inode;
	if (!ip || !S_ISREG(ip->i_di.di_mode))
		return;

	if (!test_bit(GIF_PAGED, &ip->i_flags))
		return;

	unmap_shared_mapping_range(inode->i_mapping, 0, 0);

	if (test_bit(GIF_SW_PAGED, &ip->i_flags))
		set_bit(GLF_DIRTY, &gl->gl_flags);

	clear_bit(GIF_SW_PAGED, &ip->i_flags);
}

/**
 * gfs2_page_inval - Invalidate all pages associated with a glock
 * @gl: the glock
 *
 */

void gfs2_page_inval(struct gfs2_glock *gl)
{
	struct gfs2_inode *ip;
	struct inode *inode;

	ip = gl->gl_object;
	inode = &ip->i_inode;
	if (!ip || !S_ISREG(ip->i_di.di_mode))
		return;

	truncate_inode_pages(inode->i_mapping, 0);
	gfs2_assert_withdraw(GFS2_SB(&ip->i_inode), !inode->i_mapping->nrpages);
	clear_bit(GIF_PAGED, &ip->i_flags);
}

/**
 * gfs2_page_sync - Sync the data pages (not metadata) associated with a glock
 * @gl: the glock
 * @flags: DIO_START | DIO_WAIT
 *
 * Syncs data (not metadata) for a regular file.
 * No-op for all other types.
 */

void gfs2_page_sync(struct gfs2_glock *gl, int flags)
{
	struct gfs2_inode *ip;
	struct inode *inode;
	struct address_space *mapping;
	int error = 0;

	ip = gl->gl_object;
	inode = &ip->i_inode;
	if (!ip || !S_ISREG(ip->i_di.di_mode))
		return;

	mapping = inode->i_mapping;

	if (flags & DIO_START)
		filemap_fdatawrite(mapping);
	if (!error && (flags & DIO_WAIT))
		error = filemap_fdatawait(mapping);

	/* Put back any errors cleared by filemap_fdatawait()
	   so they can be caught by someone who can pass them
	   up to user space. */

	if (error == -ENOSPC)
		set_bit(AS_ENOSPC, &mapping->flags);
	else if (error)
		set_bit(AS_EIO, &mapping->flags);

}

/**
 * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page
 * @ip: the inode
 * @dibh: the dinode buffer
 * @block: the block number that was allocated
 * @private: any locked page held by the caller process
 *
 * Returns: errno
 */

int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh,
			uint64_t block, void *private)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct inode *inode = &ip->i_inode;
	struct page *page = (struct page *)private;
	struct buffer_head *bh;
	int release = 0;

	if (!page || page->index) {
		page = grab_cache_page(inode->i_mapping, 0);
		if (!page)
			return -ENOMEM;
		release = 1;
	}

	if (!PageUptodate(page)) {
		void *kaddr = kmap(page);

		memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode),
		       ip->i_di.di_size);
		memset(kaddr + ip->i_di.di_size, 0,
		       PAGE_CACHE_SIZE - ip->i_di.di_size);
		kunmap(page);

		SetPageUptodate(page);
	}

	if (!page_has_buffers(page))
		create_empty_buffers(page, 1 << inode->i_blkbits,
				     (1 << BH_Uptodate));

	bh = page_buffers(page);

	if (!buffer_mapped(bh))
		map_bh(bh, inode->i_sb, block);

	set_buffer_uptodate(bh);
	if ((sdp->sd_args.ar_data == GFS2_DATA_ORDERED) || gfs2_is_jdata(ip))
		gfs2_trans_add_bh(ip->i_gl, bh, 0);
	mark_buffer_dirty(bh);

	if (release) {
		unlock_page(page);
		page_cache_release(page);
	}

	return 0;
}

/**
 * gfs2_block_truncate_page - Deal with zeroing out data for truncate
 *
 * This is partly borrowed from ext3.
 */
int gfs2_block_truncate_page(struct address_space *mapping)
{
	struct inode *inode = mapping->host;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	loff_t from = inode->i_size;
	unsigned long index = from >> PAGE_CACHE_SHIFT;
	unsigned offset = from & (PAGE_CACHE_SIZE-1);
	unsigned blocksize, iblock, length, pos;
	struct buffer_head *bh;
	struct page *page;
	void *kaddr;
	int err;

	page = grab_cache_page(mapping, index);
	if (!page)
		return 0;

	blocksize = inode->i_sb->s_blocksize;
	length = blocksize - (offset & (blocksize - 1));
	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);

	if (!page_has_buffers(page))
		create_empty_buffers(page, blocksize, 0);

	/* Find the buffer that contains "offset" */
	bh = page_buffers(page);
	pos = blocksize;
	while (offset >= pos) {
		bh = bh->b_this_page;
		iblock++;
		pos += blocksize;
	}

	err = 0;

	if (!buffer_mapped(bh)) {
		gfs2_get_block(inode, iblock, bh, 0);
		/* unmapped? It's a hole - nothing to do */
		if (!buffer_mapped(bh))
			goto unlock;
	}

	/* Ok, it's mapped. Make sure it's up-to-date */
	if (PageUptodate(page))
		set_buffer_uptodate(bh);

	if (!buffer_uptodate(bh)) {
		err = -EIO;
		ll_rw_block(READ, 1, &bh);
		wait_on_buffer(bh);
		/* Uhhuh. Read error. Complain and punt. */
		if (!buffer_uptodate(bh))
			goto unlock;
	}

	if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip))
		gfs2_trans_add_bh(ip->i_gl, bh, 0);

	kaddr = kmap_atomic(page, KM_USER0);
	memset(kaddr + offset, 0, length);
	flush_dcache_page(page);
	kunmap_atomic(kaddr, KM_USER0);

unlock:
	unlock_page(page);
	page_cache_release(page);
	return err;
}

void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
			    unsigned int from, unsigned int to)
{
	struct buffer_head *head = page_buffers(page);
	unsigned int bsize = head->b_size;
	struct buffer_head *bh;
	unsigned int start, end;

	for (bh = head, start = 0; bh != head || !start;
	     bh = bh->b_this_page, start = end) {
		end = start + bsize;
		if (end <= from || start >= to)
			continue;
		gfs2_trans_add_bh(ip->i_gl, bh, 0);
	}
}
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/pagemap.h>
	16	#include <linux/mm.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 "inode.h"
	24	#include "page.h"
	25	#include "trans.h"
257f9b4e	26	#include "ops_address.h"
5c676f6d	27	#include "util.h"
b3b94faa DT	28
	29	/**
	30	* gfs2_pte_inval - Sync and invalidate all PTEs associated with a glock
	31	* @gl: the glock
	32	*
	33	*/
	34
	35	void gfs2_pte_inval(struct gfs2_glock *gl)
	36	{
	37	struct gfs2_inode *ip;
	38	struct inode *inode;
	39
5c676f6d	40	ip = gl->gl_object;
feaa7bba	41	inode = &ip->i_inode;
b3b94faa DT	42	if (!ip \|\| !S_ISREG(ip->i_di.di_mode))
	43	return;
	44
	45	if (!test_bit(GIF_PAGED, &ip->i_flags))
	46	return;
	47
feaa7bba	48	unmap_shared_mapping_range(inode->i_mapping, 0, 0);
b3b94faa	49
feaa7bba SW	50	if (test_bit(GIF_SW_PAGED, &ip->i_flags))
feaa7bba SW	51	set_bit(GLF_DIRTY, &gl->gl_flags);
b3b94faa DT	52
	53	clear_bit(GIF_SW_PAGED, &ip->i_flags);
	54	}
	55
	56	/**
	57	* gfs2_page_inval - Invalidate all pages associated with a glock
	58	* @gl: the glock
	59	*
	60	*/
	61
	62	void gfs2_page_inval(struct gfs2_glock *gl)
	63	{
	64	struct gfs2_inode *ip;
	65	struct inode *inode;
	66
5c676f6d	67	ip = gl->gl_object;
feaa7bba	68	inode = &ip->i_inode;
b3b94faa DT	69	if (!ip \|\| !S_ISREG(ip->i_di.di_mode))
	70	return;
	71
feaa7bba SW	72	truncate_inode_pages(inode->i_mapping, 0);
feaa7bba SW	73	gfs2_assert_withdraw(GFS2_SB(&ip->i_inode), !inode->i_mapping->nrpages);
b3b94faa DT	74	clear_bit(GIF_PAGED, &ip->i_flags);
	75	}
	76
	77	/**
	78	* gfs2_page_sync - Sync the data pages (not metadata) associated with a glock
	79	* @gl: the glock
	80	* @flags: DIO_START \| DIO_WAIT
	81	*
	82	* Syncs data (not metadata) for a regular file.
	83	* No-op for all other types.
	84	*/
	85
	86	void gfs2_page_sync(struct gfs2_glock *gl, int flags)
	87	{
	88	struct gfs2_inode *ip;
	89	struct inode *inode;
feaa7bba SW	90	struct address_space *mapping;
feaa7bba SW	91	int error = 0;
b3b94faa	92
5c676f6d	93	ip = gl->gl_object;
feaa7bba	94	inode = &ip->i_inode;
b3b94faa DT	95	if (!ip \|\| !S_ISREG(ip->i_di.di_mode))
	96	return;
	97
feaa7bba	98	mapping = inode->i_mapping;
b3b94faa	99
feaa7bba SW	100	if (flags & DIO_START)
	101	filemap_fdatawrite(mapping);
	102	if (!error && (flags & DIO_WAIT))
	103	error = filemap_fdatawait(mapping);
b3b94faa	104
feaa7bba SW	105	/* Put back any errors cleared by filemap_fdatawait()
	106	so they can be caught by someone who can pass them
	107	up to user space. */
b3b94faa	108
feaa7bba SW	109	if (error == -ENOSPC)
	110	set_bit(AS_ENOSPC, &mapping->flags);
	111	else if (error)
	112	set_bit(AS_EIO, &mapping->flags);
b3b94faa	113
b3b94faa DT	114	}
	115
	116	/**
	117	* gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page
	118	* @ip: the inode
	119	* @dibh: the dinode buffer
	120	* @block: the block number that was allocated
	121	* @private: any locked page held by the caller process
	122	*
	123	* Returns: errno
	124	*/
	125
	126	int gfs2_unstuffer_page(struct gfs2_inode ip, struct buffer_head dibh,
	127	uint64_t block, void *private)
	128	{
feaa7bba SW	129	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
feaa7bba SW	130	struct inode *inode = &ip->i_inode;
b3b94faa DT	131	struct page page = (struct page )private;
	132	struct buffer_head *bh;
	133	int release = 0;
	134
	135	if (!page \|\| page->index) {
	136	page = grab_cache_page(inode->i_mapping, 0);
	137	if (!page)
	138	return -ENOMEM;
	139	release = 1;
	140	}
	141
	142	if (!PageUptodate(page)) {
	143	void *kaddr = kmap(page);
	144
1b50259b	145	memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode),
b3b94faa	146	ip->i_di.di_size);
1b50259b	147	memset(kaddr + ip->i_di.di_size, 0,
b3b94faa DT	148	PAGE_CACHE_SIZE - ip->i_di.di_size);
	149	kunmap(page);
	150
	151	SetPageUptodate(page);
	152	}
	153
	154	if (!page_has_buffers(page))
	155	create_empty_buffers(page, 1 << inode->i_blkbits,
	156	(1 << BH_Uptodate));
	157
	158	bh = page_buffers(page);
	159
	160	if (!buffer_mapped(bh))
	161	map_bh(bh, inode->i_sb, block);
	162
	163	set_buffer_uptodate(bh);
18ec7d5c SW	164	if ((sdp->sd_args.ar_data == GFS2_DATA_ORDERED) \|\| gfs2_is_jdata(ip))
18ec7d5c SW	165	gfs2_trans_add_bh(ip->i_gl, bh, 0);
b3b94faa DT	166	mark_buffer_dirty(bh);
	167
	168	if (release) {
	169	unlock_page(page);
	170	page_cache_release(page);
	171	}
	172
	173	return 0;
	174	}
	175
	176	/**
257f9b4e	177	* gfs2_block_truncate_page - Deal with zeroing out data for truncate
b3b94faa	178	*
257f9b4e	179	* This is partly borrowed from ext3.
b3b94faa	180	*/
257f9b4e	181	int gfs2_block_truncate_page(struct address_space *mapping)
b3b94faa	182	{
257f9b4e	183	struct inode *inode = mapping->host;
feaa7bba SW	184	struct gfs2_inode *ip = GFS2_I(inode);
feaa7bba SW	185	struct gfs2_sbd *sdp = GFS2_SB(inode);
257f9b4e SW	186	loff_t from = inode->i_size;
	187	unsigned long index = from >> PAGE_CACHE_SHIFT;
	188	unsigned offset = from & (PAGE_CACHE_SIZE-1);
	189	unsigned blocksize, iblock, length, pos;
b3b94faa	190	struct buffer_head *bh;
257f9b4e	191	struct page *page;
b3b94faa	192	void *kaddr;
257f9b4e SW	193	int err;
	194
	195	page = grab_cache_page(mapping, index);
	196	if (!page)
	197	return 0;
b3b94faa	198
257f9b4e SW	199	blocksize = inode->i_sb->s_blocksize;
	200	length = blocksize - (offset & (blocksize - 1));
	201	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
b3b94faa DT	202
b3b94faa DT	203	if (!page_has_buffers(page))
257f9b4e	204	create_empty_buffers(page, blocksize, 0);
b3b94faa	205
257f9b4e SW	206	/* Find the buffer that contains "offset" */
	207	bh = page_buffers(page);
	208	pos = blocksize;
	209	while (offset >= pos) {
	210	bh = bh->b_this_page;
	211	iblock++;
	212	pos += blocksize;
	213	}
b3b94faa	214
257f9b4e	215	err = 0;
b3b94faa	216
257f9b4e SW	217	if (!buffer_mapped(bh)) {
	218	gfs2_get_block(inode, iblock, bh, 0);
	219	/* unmapped? It's a hole - nothing to do */
	220	if (!buffer_mapped(bh))
	221	goto unlock;
	222	}
	223
	224	/* Ok, it's mapped. Make sure it's up-to-date */
	225	if (PageUptodate(page))
	226	set_buffer_uptodate(bh);
	227
	228	if (!buffer_uptodate(bh)) {
	229	err = -EIO;
	230	ll_rw_block(READ, 1, &bh);
	231	wait_on_buffer(bh);
	232	/* Uhhuh. Read error. Complain and punt. */
	233	if (!buffer_uptodate(bh))
	234	goto unlock;
	235	}
	236
18ec7d5c SW	237	if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED \|\| gfs2_is_jdata(ip))
18ec7d5c SW	238	gfs2_trans_add_bh(ip->i_gl, bh, 0);
b3b94faa	239
257f9b4e SW	240	kaddr = kmap_atomic(page, KM_USER0);
	241	memset(kaddr + offset, 0, length);
	242	flush_dcache_page(page);
	243	kunmap_atomic(kaddr, KM_USER0);
	244
	245	unlock:
b3b94faa DT	246	unlock_page(page);
b3b94faa DT	247	page_cache_release(page);
257f9b4e	248	return err;
b3b94faa DT	249	}
b3b94faa DT	250
257f9b4e	251	void gfs2_page_add_databufs(struct gfs2_inode ip, struct page page,
b3b94faa DT	252	unsigned int from, unsigned int to)
	253	{
	254	struct buffer_head *head = page_buffers(page);
	255	unsigned int bsize = head->b_size;
	256	struct buffer_head *bh;
	257	unsigned int start, end;
	258
29937ac6	259	for (bh = head, start = 0; bh != head \|\| !start;
b3b94faa DT	260	bh = bh->b_this_page, start = end) {
	261	end = start + bsize;
	262	if (end <= from \|\| start >= to)
	263	continue;
18ec7d5c	264	gfs2_trans_add_bh(ip->i_gl, bh, 0);
b3b94faa DT	265	}
	266	}
	267