[net-next-2.6.git] / fs / gfs2 / meta_io.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 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/writeback.h>
#include <linux/swap.h>
#include <linux/delay.h>
#include <linux/bio.h>
#include <linux/gfs2_ondisk.h>
#include <linux/lm_interface.h>

#include "gfs2.h"
#include "incore.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "log.h"
#include "lops.h"
#include "meta_io.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"
#include "ops_address.h"

static int aspace_get_block(struct inode *inode, sector_t lblock,
			    struct buffer_head *bh_result, int create)
{
	gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
	return -EOPNOTSUPP;
}

static int gfs2_aspace_writepage(struct page *page,
				 struct writeback_control *wbc)
{
	return block_write_full_page(page, aspace_get_block, wbc);
}

static const struct address_space_operations aspace_aops = {
	.writepage = gfs2_aspace_writepage,
	.releasepage = gfs2_releasepage,
	.sync_page = block_sync_page,
};

/**
 * gfs2_aspace_get - Create and initialize a struct inode structure
 * @sdp: the filesystem the aspace is in
 *
 * Right now a struct inode is just a struct inode.  Maybe Linux
 * will supply a more lightweight address space construct (that works)
 * in the future.
 *
 * Make sure pages/buffers in this aspace aren't in high memory.
 *
 * Returns: the aspace
 */

struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp)
{
	struct inode *aspace;

	aspace = new_inode(sdp->sd_vfs);
	if (aspace) {
		mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS);
		aspace->i_mapping->a_ops = &aspace_aops;
		aspace->i_size = ~0ULL;
		aspace->i_private = NULL;
		insert_inode_hash(aspace);
	}
	return aspace;
}

void gfs2_aspace_put(struct inode *aspace)
{
	remove_inode_hash(aspace);
	iput(aspace);
}

/**
 * gfs2_meta_inval - Invalidate all buffers associated with a glock
 * @gl: the glock
 *
 */

void gfs2_meta_inval(struct gfs2_glock *gl)
{
	struct gfs2_sbd *sdp = gl->gl_sbd;
	struct inode *aspace = gl->gl_aspace;
	struct address_space *mapping = gl->gl_aspace->i_mapping;

	gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));

	atomic_inc(&aspace->i_writecount);
	truncate_inode_pages(mapping, 0);
	atomic_dec(&aspace->i_writecount);

	gfs2_assert_withdraw(sdp, !mapping->nrpages);
}

/**
 * gfs2_meta_sync - Sync all buffers associated with a glock
 * @gl: The glock
 *
 */

void gfs2_meta_sync(struct gfs2_glock *gl)
{
	struct address_space *mapping = gl->gl_aspace->i_mapping;
	int error;

	filemap_fdatawrite(mapping);
	error = filemap_fdatawait(mapping);

	if (error)
		gfs2_io_error(gl->gl_sbd);
}

/**
 * getbuf - Get a buffer with a given address space
 * @gl: the glock
 * @blkno: the block number (filesystem scope)
 * @create: 1 if the buffer should be created
 *
 * Returns: the buffer
 */

static struct buffer_head *getbuf(struct gfs2_glock *gl, u64 blkno, int create)
{
	struct address_space *mapping = gl->gl_aspace->i_mapping;
	struct gfs2_sbd *sdp = gl->gl_sbd;
	struct page *page;
	struct buffer_head *bh;
	unsigned int shift;
	unsigned long index;
	unsigned int bufnum;

	shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
	index = blkno >> shift;             /* convert block to page */
	bufnum = blkno - (index << shift);  /* block buf index within page */

	if (create) {
		for (;;) {
			page = grab_cache_page(mapping, index);
			if (page)
				break;
			yield();
		}
	} else {
		page = find_lock_page(mapping, index);
		if (!page)
			return NULL;
	}

	if (!page_has_buffers(page))
		create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);

	/* Locate header for our buffer within our page */
	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
		/* Do nothing */;
	get_bh(bh);

	if (!buffer_mapped(bh))
		map_bh(bh, sdp->sd_vfs, blkno);

	unlock_page(page);
	mark_page_accessed(page);
	page_cache_release(page);

	return bh;
}

static void meta_prep_new(struct buffer_head *bh)
{
	struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;

	lock_buffer(bh);
	clear_buffer_dirty(bh);
	set_buffer_uptodate(bh);
	unlock_buffer(bh);

	mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
}

/**
 * gfs2_meta_new - Get a block
 * @gl: The glock associated with this block
 * @blkno: The block number
 *
 * Returns: The buffer
 */

struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
{
	struct buffer_head *bh;
	bh = getbuf(gl, blkno, CREATE);
	meta_prep_new(bh);
	return bh;
}

/**
 * gfs2_meta_read - Read a block from disk
 * @gl: The glock covering the block
 * @blkno: The block number
 * @flags: flags
 * @bhp: the place where the buffer is returned (NULL on failure)
 *
 * Returns: errno
 */

int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
		   struct buffer_head **bhp)
{
	*bhp = getbuf(gl, blkno, CREATE);
	if (!buffer_uptodate(*bhp)) {
		ll_rw_block(READ_META, 1, bhp);
		if (flags & DIO_WAIT) {
			int error = gfs2_meta_wait(gl->gl_sbd, *bhp);
			if (error) {
				brelse(*bhp);
				return error;
			}
		}
	}

	return 0;
}

/**
 * gfs2_meta_wait - Reread a block from disk
 * @sdp: the filesystem
 * @bh: The block to wait for
 *
 * Returns: errno
 */

int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
{
	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
		return -EIO;

	wait_on_buffer(bh);

	if (!buffer_uptodate(bh)) {
		struct gfs2_trans *tr = current->journal_info;
		if (tr && tr->tr_touched)
			gfs2_io_error_bh(sdp, bh);
		return -EIO;
	}
	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
		return -EIO;

	return 0;
}

/**
 * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
 * @gl: the glock the buffer belongs to
 * @bh: The buffer to be attached to
 * @meta: Flag to indicate whether its metadata or not
 */

void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
			 int meta)
{
	struct gfs2_bufdata *bd;

	if (meta)
		lock_page(bh->b_page);

	if (bh->b_private) {
		if (meta)
			unlock_page(bh->b_page);
		return;
	}

	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL),
	bd->bd_bh = bh;
	bd->bd_gl = gl;

	INIT_LIST_HEAD(&bd->bd_list_tr);
	if (meta)
		lops_init_le(&bd->bd_le, &gfs2_buf_lops);
	else
		lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
	bh->b_private = bd;

	if (meta)
		unlock_page(bh->b_page);
}

void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr, int meta)
{
	struct gfs2_sbd *sdp = GFS2_SB(bh->b_page->mapping->host);
	struct gfs2_bufdata *bd = bh->b_private;
	if (test_clear_buffer_pinned(bh)) {
		list_del_init(&bd->bd_le.le_list);
		if (meta) {
			gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
			sdp->sd_log_num_buf--;
			tr->tr_num_buf_rm++;
		} else {
			gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
			sdp->sd_log_num_databuf--;
			tr->tr_num_databuf_rm++;
		}
		tr->tr_touched = 1;
		brelse(bh);
	}
	if (bd) {
		if (bd->bd_ail) {
			gfs2_remove_from_ail(bd);
			bh->b_private = NULL;
			bd->bd_bh = NULL;
			bd->bd_blkno = bh->b_blocknr;
			gfs2_trans_add_revoke(sdp, bd);
		}
	}
	clear_buffer_dirty(bh);
	clear_buffer_uptodate(bh);
}

/**
 * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
 * @ip: the inode who owns the buffers
 * @bstart: the first buffer in the run
 * @blen: the number of buffers in the run
 *
 */

void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct buffer_head *bh;

	while (blen) {
		bh = getbuf(ip->i_gl, bstart, NO_CREATE);
		if (bh) {
			lock_buffer(bh);
			gfs2_log_lock(sdp);
			gfs2_remove_from_journal(bh, current->journal_info, 1);
			gfs2_log_unlock(sdp);
			unlock_buffer(bh);
			brelse(bh);
		}

		bstart++;
		blen--;
	}
}

/**
 * gfs2_meta_indirect_buffer - Get a metadata buffer
 * @ip: The GFS2 inode
 * @height: The level of this buf in the metadata (indir addr) tree (if any)
 * @num: The block number (device relative) of the buffer
 * @new: Non-zero if we may create a new buffer
 * @bhp: the buffer is returned here
 *
 * Returns: errno
 */

int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
			      int new, struct buffer_head **bhp)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_glock *gl = ip->i_gl;
	struct buffer_head *bh;
	int ret = 0;

	if (new) {
		BUG_ON(height == 0);
		bh = gfs2_meta_new(gl, num);
		gfs2_trans_add_bh(ip->i_gl, bh, 1);
		gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
		gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
	} else {
		u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
		ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
		if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
			brelse(bh);
			ret = -EIO;
		}
	}
	*bhp = bh;
	return ret;
}

/**
 * gfs2_meta_ra - start readahead on an extent of a file
 * @gl: the glock the blocks belong to
 * @dblock: the starting disk block
 * @extlen: the number of blocks in the extent
 *
 * returns: the first buffer in the extent
 */

struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
{
	struct gfs2_sbd *sdp = gl->gl_sbd;
	struct buffer_head *first_bh, *bh;
	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
			  sdp->sd_sb.sb_bsize_shift;

	BUG_ON(!extlen);

	if (max_ra < 1)
		max_ra = 1;
	if (extlen > max_ra)
		extlen = max_ra;

	first_bh = getbuf(gl, dblock, CREATE);

	if (buffer_uptodate(first_bh))
		goto out;
	if (!buffer_locked(first_bh))
		ll_rw_block(READ_META, 1, &first_bh);

	dblock++;
	extlen--;

	while (extlen) {
		bh = getbuf(gl, dblock, CREATE);

		if (!buffer_uptodate(bh) && !buffer_locked(bh))
			ll_rw_block(READA, 1, &bh);
		brelse(bh);
		dblock++;
		extlen--;
		if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
			goto out;
	}

	wait_on_buffer(first_bh);
out:
	return first_bh;
}
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
e9fc2aa0	7	* of the GNU General Public License version 2.
b3b94faa DT	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/writeback.h>
	18	#include <linux/swap.h>
	19	#include <linux/delay.h>
2e565bb6	20	#include <linux/bio.h>
5c676f6d	21	#include <linux/gfs2_ondisk.h>
7d308590	22	#include <linux/lm_interface.h>
b3b94faa DT	23
b3b94faa DT	24	#include "gfs2.h"
5c676f6d	25	#include "incore.h"
b3b94faa DT	26	#include "glock.h"
	27	#include "glops.h"
	28	#include "inode.h"
	29	#include "log.h"
	30	#include "lops.h"
	31	#include "meta_io.h"
	32	#include "rgrp.h"
	33	#include "trans.h"
5c676f6d	34	#include "util.h"
4340fe62	35	#include "ops_address.h"
b3b94faa	36
b3b94faa DT	37	static int aspace_get_block(struct inode *inode, sector_t lblock,
	38	struct buffer_head *bh_result, int create)
	39	{
5c676f6d	40	gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
b3b94faa DT	41	return -EOPNOTSUPP;
	42	}
	43
	44	static int gfs2_aspace_writepage(struct page *page,
	45	struct writeback_control *wbc)
	46	{
	47	return block_write_full_page(page, aspace_get_block, wbc);
	48	}
	49
66de045d	50	static const struct address_space_operations aspace_aops = {
b3b94faa	51	.writepage = gfs2_aspace_writepage,
4340fe62	52	.releasepage = gfs2_releasepage,
52d4c74b	53	.sync_page = block_sync_page,
b3b94faa DT	54	};
	55
	56	/**
	57	* gfs2_aspace_get - Create and initialize a struct inode structure
	58	* @sdp: the filesystem the aspace is in
	59	*
	60	* Right now a struct inode is just a struct inode. Maybe Linux
	61	* will supply a more lightweight address space construct (that works)
	62	* in the future.
	63	*
	64	* Make sure pages/buffers in this aspace aren't in high memory.
	65	*
	66	* Returns: the aspace
	67	*/
	68
	69	struct inode gfs2_aspace_get(struct gfs2_sbd sdp)
	70	{
	71	struct inode *aspace;
	72
	73	aspace = new_inode(sdp->sd_vfs);
	74	if (aspace) {
f3bba03f	75	mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS);
b3b94faa DT	76	aspace->i_mapping->a_ops = &aspace_aops;
b3b94faa DT	77	aspace->i_size = ~0ULL;
bba9dfd8	78	aspace->i_private = NULL;
b3b94faa DT	79	insert_inode_hash(aspace);
b3b94faa DT	80	}
b3b94faa DT	81	return aspace;
	82	}
	83
	84	void gfs2_aspace_put(struct inode *aspace)
	85	{
	86	remove_inode_hash(aspace);
	87	iput(aspace);
	88	}
	89
b3b94faa DT	90	/**
	91	* gfs2_meta_inval - Invalidate all buffers associated with a glock
	92	* @gl: the glock
	93	*
	94	*/
	95
	96	void gfs2_meta_inval(struct gfs2_glock *gl)
	97	{
	98	struct gfs2_sbd *sdp = gl->gl_sbd;
	99	struct inode *aspace = gl->gl_aspace;
	100	struct address_space *mapping = gl->gl_aspace->i_mapping;
	101
	102	gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
	103
	104	atomic_inc(&aspace->i_writecount);
	105	truncate_inode_pages(mapping, 0);
	106	atomic_dec(&aspace->i_writecount);
	107
	108	gfs2_assert_withdraw(sdp, !mapping->nrpages);
	109	}
	110
	111	/**
	112	* gfs2_meta_sync - Sync all buffers associated with a glock
	113	* @gl: The glock
b3b94faa DT	114	*
	115	*/
	116
7276b3b0	117	void gfs2_meta_sync(struct gfs2_glock *gl)
b3b94faa DT	118	{
b3b94faa DT	119	struct address_space *mapping = gl->gl_aspace->i_mapping;
7276b3b0	120	int error;
b3b94faa	121
7276b3b0 SW	122	filemap_fdatawrite(mapping);
7276b3b0 SW	123	error = filemap_fdatawait(mapping);
b3b94faa DT	124
	125	if (error)
	126	gfs2_io_error(gl->gl_sbd);
	127	}
	128
	129	/**
	130	* getbuf - Get a buffer with a given address space
cb4c0313	131	* @gl: the glock
b3b94faa DT	132	* @blkno: the block number (filesystem scope)
	133	* @create: 1 if the buffer should be created
	134	*
	135	* Returns: the buffer
	136	*/
	137
cb4c0313	138	static struct buffer_head getbuf(struct gfs2_glock gl, u64 blkno, int create)
b3b94faa	139	{
cb4c0313 SW	140	struct address_space *mapping = gl->gl_aspace->i_mapping;
cb4c0313 SW	141	struct gfs2_sbd *sdp = gl->gl_sbd;
b3b94faa DT	142	struct page *page;
	143	struct buffer_head *bh;
	144	unsigned int shift;
	145	unsigned long index;
	146	unsigned int bufnum;
	147
	148	shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
	149	index = blkno >> shift; /* convert block to page */
	150	bufnum = blkno - (index << shift); /* block buf index within page */
	151
	152	if (create) {
	153	for (;;) {
cb4c0313	154	page = grab_cache_page(mapping, index);
b3b94faa DT	155	if (page)
	156	break;
	157	yield();
	158	}
	159	} else {
cb4c0313	160	page = find_lock_page(mapping, index);
b3b94faa DT	161	if (!page)
	162	return NULL;
	163	}
	164
	165	if (!page_has_buffers(page))
	166	create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
	167
	168	/* Locate header for our buffer within our page */
	169	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
	170	/* Do nothing */;
	171	get_bh(bh);
	172
	173	if (!buffer_mapped(bh))
	174	map_bh(bh, sdp->sd_vfs, blkno);
	175
	176	unlock_page(page);
	177	mark_page_accessed(page);
	178	page_cache_release(page);
	179
	180	return bh;
	181	}
	182
	183	static void meta_prep_new(struct buffer_head *bh)
	184	{
	185	struct gfs2_meta_header mh = (struct gfs2_meta_header )bh->b_data;
	186
	187	lock_buffer(bh);
	188	clear_buffer_dirty(bh);
	189	set_buffer_uptodate(bh);
	190	unlock_buffer(bh);
	191
	192	mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
	193	}
	194
	195	/**
	196	* gfs2_meta_new - Get a block
	197	* @gl: The glock associated with this block
	198	* @blkno: The block number
	199	*
	200	* Returns: The buffer
	201	*/
	202
cd915493	203	struct buffer_head gfs2_meta_new(struct gfs2_glock gl, u64 blkno)
b3b94faa DT	204	{
b3b94faa DT	205	struct buffer_head *bh;
cb4c0313	206	bh = getbuf(gl, blkno, CREATE);
b3b94faa DT	207	meta_prep_new(bh);
	208	return bh;
	209	}
	210
	211	/**
	212	* gfs2_meta_read - Read a block from disk
	213	* @gl: The glock covering the block
	214	* @blkno: The block number
7276b3b0	215	* @flags: flags
b3b94faa DT	216	* @bhp: the place where the buffer is returned (NULL on failure)
	217	*
	218	* Returns: errno
	219	*/
	220
cd915493	221	int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
b3b94faa DT	222	struct buffer_head **bhp)
b3b94faa DT	223	{
cb4c0313	224	*bhp = getbuf(gl, blkno, CREATE);
15c7cee7	225	if (!buffer_uptodate(*bhp)) {
2e565bb6	226	ll_rw_block(READ_META, 1, bhp);
15c7cee7 BP	227	if (flags & DIO_WAIT) {
	228	int error = gfs2_meta_wait(gl->gl_sbd, *bhp);
	229	if (error) {
	230	brelse(*bhp);
	231	return error;
	232	}
7276b3b0 SW	233	}
7276b3b0 SW	234	}
b3b94faa	235
7276b3b0	236	return 0;
b3b94faa DT	237	}
	238
	239	/**
7276b3b0	240	* gfs2_meta_wait - Reread a block from disk
b3b94faa	241	* @sdp: the filesystem
7276b3b0	242	* @bh: The block to wait for
b3b94faa DT	243	*
	244	* Returns: errno
	245	*/
	246
7276b3b0	247	int gfs2_meta_wait(struct gfs2_sbd sdp, struct buffer_head bh)
b3b94faa DT	248	{
	249	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
	250	return -EIO;
	251
7276b3b0	252	wait_on_buffer(bh);
b3b94faa	253
7276b3b0 SW	254	if (!buffer_uptodate(bh)) {
	255	struct gfs2_trans *tr = current->journal_info;
	256	if (tr && tr->tr_touched)
	257	gfs2_io_error_bh(sdp, bh);
	258	return -EIO;
b3b94faa	259	}
7276b3b0 SW	260	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
7276b3b0 SW	261	return -EIO;
b3b94faa DT	262
	263	return 0;
	264	}
	265
	266	/**
586dfdaa	267	* gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
b3b94faa DT	268	* @gl: the glock the buffer belongs to
b3b94faa DT	269	* @bh: The buffer to be attached to
586dfdaa	270	* @meta: Flag to indicate whether its metadata or not
b3b94faa DT	271	*/
b3b94faa DT	272
568f4c96 SW	273	void gfs2_attach_bufdata(struct gfs2_glock gl, struct buffer_head bh,
568f4c96 SW	274	int meta)
b3b94faa DT	275	{
	276	struct gfs2_bufdata *bd;
	277
18ec7d5c SW	278	if (meta)
18ec7d5c SW	279	lock_page(bh->b_page);
b3b94faa	280
5c676f6d	281	if (bh->b_private) {
18ec7d5c SW	282	if (meta)
18ec7d5c SW	283	unlock_page(bh->b_page);
b3b94faa DT	284	return;
	285	}
	286
c3762229	287	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS \| __GFP_NOFAIL),
b3b94faa DT	288	bd->bd_bh = bh;
	289	bd->bd_gl = gl;
	290
	291	INIT_LIST_HEAD(&bd->bd_list_tr);
82ffa516	292	if (meta)
586dfdaa	293	lops_init_le(&bd->bd_le, &gfs2_buf_lops);
82ffa516	294	else
586dfdaa	295	lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
5c676f6d	296	bh->b_private = bd;
b3b94faa	297
18ec7d5c SW	298	if (meta)
18ec7d5c SW	299	unlock_page(bh->b_page);
b3b94faa DT	300	}
b3b94faa DT	301
16615be1 SW	302	void gfs2_remove_from_journal(struct buffer_head bh, struct gfs2_trans tr, int meta)
	303	{
	304	struct gfs2_sbd *sdp = GFS2_SB(bh->b_page->mapping->host);
	305	struct gfs2_bufdata *bd = bh->b_private;
	306	if (test_clear_buffer_pinned(bh)) {
	307	list_del_init(&bd->bd_le.le_list);
	308	if (meta) {
	309	gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
	310	sdp->sd_log_num_buf--;
	311	tr->tr_num_buf_rm++;
	312	} else {
	313	gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
	314	sdp->sd_log_num_databuf--;
	315	tr->tr_num_databuf_rm++;
	316	}
	317	tr->tr_touched = 1;
	318	brelse(bh);
	319	}
	320	if (bd) {
	321	if (bd->bd_ail) {
f91a0d3e	322	gfs2_remove_from_ail(bd);
16615be1 SW	323	bh->b_private = NULL;
	324	bd->bd_bh = NULL;
	325	bd->bd_blkno = bh->b_blocknr;
	326	gfs2_trans_add_revoke(sdp, bd);
	327	}
	328	}
	329	clear_buffer_dirty(bh);
	330	clear_buffer_uptodate(bh);
	331	}
	332
b3b94faa DT	333	/**
	334	* gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
	335	* @ip: the inode who owns the buffers
	336	* @bstart: the first buffer in the run
	337	* @blen: the number of buffers in the run
	338	*
	339	*/
	340
cd915493	341	void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
b3b94faa	342	{
feaa7bba	343	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
b3b94faa DT	344	struct buffer_head *bh;
	345
	346	while (blen) {
cb4c0313	347	bh = getbuf(ip->i_gl, bstart, NO_CREATE);
b3b94faa	348	if (bh) {
1ad38c43 SW	349	lock_buffer(bh);
1ad38c43 SW	350	gfs2_log_lock(sdp);
16615be1	351	gfs2_remove_from_journal(bh, current->journal_info, 1);
1ad38c43	352	gfs2_log_unlock(sdp);
b3b94faa	353	unlock_buffer(bh);
b3b94faa DT	354	brelse(bh);
	355	}
	356
	357	bstart++;
	358	blen--;
	359	}
	360	}
	361
b3b94faa DT	362	/**
	363	* gfs2_meta_indirect_buffer - Get a metadata buffer
	364	* @ip: The GFS2 inode
	365	* @height: The level of this buf in the metadata (indir addr) tree (if any)
	366	* @num: The block number (device relative) of the buffer
	367	* @new: Non-zero if we may create a new buffer
	368	* @bhp: the buffer is returned here
	369	*
b3b94faa DT	370	* Returns: errno
	371	*/
	372
cd915493	373	int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
b3b94faa DT	374	int new, struct buffer_head **bhp)
b3b94faa DT	375	{
7276b3b0 SW	376	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
7276b3b0 SW	377	struct gfs2_glock *gl = ip->i_gl;
f91a0d3e SW	378	struct buffer_head *bh;
f91a0d3e SW	379	int ret = 0;
b3b94faa DT	380
b3b94faa DT	381	if (new) {
f91a0d3e SW	382	BUG_ON(height == 0);
f91a0d3e SW	383	bh = gfs2_meta_new(gl, num);
d4e9c4c3	384	gfs2_trans_add_bh(ip->i_gl, bh, 1);
b3b94faa DT	385	gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
b3b94faa DT	386	gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
7276b3b0 SW	387	} else {
7276b3b0 SW	388	u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
f91a0d3e SW	389	ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
	390	if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
	391	brelse(bh);
	392	ret = -EIO;
7276b3b0	393	}
b3b94faa	394	}
b3b94faa	395	*bhp = bh;
f91a0d3e	396	return ret;
b3b94faa DT	397	}
	398
	399	/**
	400	* gfs2_meta_ra - start readahead on an extent of a file
	401	* @gl: the glock the blocks belong to
	402	* @dblock: the starting disk block
	403	* @extlen: the number of blocks in the extent
	404	*
7276b3b0	405	* returns: the first buffer in the extent
b3b94faa DT	406	*/
b3b94faa DT	407
7276b3b0	408	struct buffer_head gfs2_meta_ra(struct gfs2_glock gl, u64 dblock, u32 extlen)
b3b94faa DT	409	{
b3b94faa DT	410	struct gfs2_sbd *sdp = gl->gl_sbd;
b3b94faa	411	struct buffer_head first_bh, bh;
cd915493	412	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
568f4c96	413	sdp->sd_sb.sb_bsize_shift;
b3b94faa	414
7276b3b0 SW	415	BUG_ON(!extlen);
	416
	417	if (max_ra < 1)
	418	max_ra = 1;
b3b94faa DT	419	if (extlen > max_ra)
	420	extlen = max_ra;
	421
cb4c0313	422	first_bh = getbuf(gl, dblock, CREATE);
b3b94faa DT	423
	424	if (buffer_uptodate(first_bh))
	425	goto out;
7276b3b0	426	if (!buffer_locked(first_bh))
2e565bb6	427	ll_rw_block(READ_META, 1, &first_bh);
b3b94faa DT	428
	429	dblock++;
	430	extlen--;
	431
	432	while (extlen) {
cb4c0313	433	bh = getbuf(gl, dblock, CREATE);
b3b94faa	434
7276b3b0 SW	435	if (!buffer_uptodate(bh) && !buffer_locked(bh))
	436	ll_rw_block(READA, 1, &bh);
	437	brelse(bh);
b3b94faa DT	438	dblock++;
b3b94faa DT	439	extlen--;
7276b3b0 SW	440	if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
7276b3b0 SW	441	goto out;
b3b94faa DT	442	}
b3b94faa DT	443
7276b3b0	444	wait_on_buffer(first_bh);
a91ea69f	445	out:
7276b3b0	446	return first_bh;
b3b94faa DT	447	}
b3b94faa DT	448