[net-next-2.6.git] / fs / gfs2 / meta_io.c

/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2008 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 "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;
	struct gfs2_inode *ip;

	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;
		ip = GFS2_I(aspace);
		clear_bit(GIF_USER, &ip->i_flags);
		insert_inode_hash(aspace);
	}
	return aspace;
}

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

/**
 * 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);
}

/**
 * gfs2_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
 */

struct buffer_head *gfs2_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 = gfs2_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 = gfs2_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 = gfs2_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 = gfs2_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 = gfs2_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.
091806ed	3	* Copyright (C) 2004-2008 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>
b3b94faa DT	22
b3b94faa DT	23	#include "gfs2.h"
5c676f6d	24	#include "incore.h"
b3b94faa DT	25	#include "glock.h"
	26	#include "glops.h"
	27	#include "inode.h"
	28	#include "log.h"
	29	#include "lops.h"
	30	#include "meta_io.h"
	31	#include "rgrp.h"
	32	#include "trans.h"
5c676f6d	33	#include "util.h"
4340fe62	34	#include "ops_address.h"
b3b94faa	35
b3b94faa DT	36	static int aspace_get_block(struct inode *inode, sector_t lblock,
	37	struct buffer_head *bh_result, int create)
	38	{
5c676f6d	39	gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
b3b94faa DT	40	return -EOPNOTSUPP;
	41	}
	42
	43	static int gfs2_aspace_writepage(struct page *page,
	44	struct writeback_control *wbc)
	45	{
	46	return block_write_full_page(page, aspace_get_block, wbc);
	47	}
	48
66de045d	49	static const struct address_space_operations aspace_aops = {
b3b94faa	50	.writepage = gfs2_aspace_writepage,
4340fe62	51	.releasepage = gfs2_releasepage,
52d4c74b	52	.sync_page = block_sync_page,
b3b94faa DT	53	};
	54
	55	/**
	56	* gfs2_aspace_get - Create and initialize a struct inode structure
	57	* @sdp: the filesystem the aspace is in
	58	*
	59	* Right now a struct inode is just a struct inode. Maybe Linux
	60	* will supply a more lightweight address space construct (that works)
	61	* in the future.
	62	*
	63	* Make sure pages/buffers in this aspace aren't in high memory.
	64	*
	65	* Returns: the aspace
	66	*/
	67
	68	struct inode gfs2_aspace_get(struct gfs2_sbd sdp)
	69	{
	70	struct inode *aspace;
091806ed	71	struct gfs2_inode *ip;
b3b94faa DT	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;
091806ed BP	78	ip = GFS2_I(aspace);
091806ed BP	79	clear_bit(GIF_USER, &ip->i_flags);
b3b94faa DT	80	insert_inode_hash(aspace);
b3b94faa DT	81	}
b3b94faa DT	82	return aspace;
	83	}
	84
	85	void gfs2_aspace_put(struct inode *aspace)
	86	{
	87	remove_inode_hash(aspace);
	88	iput(aspace);
	89	}
	90
b3b94faa DT	91	/**
	92	* gfs2_meta_sync - Sync all buffers associated with a glock
	93	* @gl: The glock
b3b94faa DT	94	*
	95	*/
	96
7276b3b0	97	void gfs2_meta_sync(struct gfs2_glock *gl)
b3b94faa DT	98	{
b3b94faa DT	99	struct address_space *mapping = gl->gl_aspace->i_mapping;
7276b3b0	100	int error;
b3b94faa	101
7276b3b0 SW	102	filemap_fdatawrite(mapping);
7276b3b0 SW	103	error = filemap_fdatawait(mapping);
b3b94faa DT	104
	105	if (error)
	106	gfs2_io_error(gl->gl_sbd);
	107	}
	108
	109	/**
6802e340	110	* gfs2_getbuf - Get a buffer with a given address space
cb4c0313	111	* @gl: the glock
b3b94faa DT	112	* @blkno: the block number (filesystem scope)
	113	* @create: 1 if the buffer should be created
	114	*
	115	* Returns: the buffer
	116	*/
	117
6802e340	118	struct buffer_head gfs2_getbuf(struct gfs2_glock gl, u64 blkno, int create)
b3b94faa	119	{
cb4c0313 SW	120	struct address_space *mapping = gl->gl_aspace->i_mapping;
cb4c0313 SW	121	struct gfs2_sbd *sdp = gl->gl_sbd;
b3b94faa DT	122	struct page *page;
	123	struct buffer_head *bh;
	124	unsigned int shift;
	125	unsigned long index;
	126	unsigned int bufnum;
	127
	128	shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
	129	index = blkno >> shift; /* convert block to page */
	130	bufnum = blkno - (index << shift); /* block buf index within page */
	131
	132	if (create) {
	133	for (;;) {
cb4c0313	134	page = grab_cache_page(mapping, index);
b3b94faa DT	135	if (page)
	136	break;
	137	yield();
	138	}
	139	} else {
cb4c0313	140	page = find_lock_page(mapping, index);
b3b94faa DT	141	if (!page)
	142	return NULL;
	143	}
	144
	145	if (!page_has_buffers(page))
	146	create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
	147
	148	/* Locate header for our buffer within our page */
	149	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
	150	/* Do nothing */;
	151	get_bh(bh);
	152
	153	if (!buffer_mapped(bh))
	154	map_bh(bh, sdp->sd_vfs, blkno);
	155
	156	unlock_page(page);
	157	mark_page_accessed(page);
	158	page_cache_release(page);
	159
	160	return bh;
	161	}
	162
	163	static void meta_prep_new(struct buffer_head *bh)
	164	{
	165	struct gfs2_meta_header mh = (struct gfs2_meta_header )bh->b_data;
	166
	167	lock_buffer(bh);
	168	clear_buffer_dirty(bh);
	169	set_buffer_uptodate(bh);
	170	unlock_buffer(bh);
	171
	172	mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
	173	}
	174
	175	/**
	176	* gfs2_meta_new - Get a block
	177	* @gl: The glock associated with this block
	178	* @blkno: The block number
	179	*
	180	* Returns: The buffer
	181	*/
	182
cd915493	183	struct buffer_head gfs2_meta_new(struct gfs2_glock gl, u64 blkno)
b3b94faa DT	184	{
b3b94faa DT	185	struct buffer_head *bh;
6802e340	186	bh = gfs2_getbuf(gl, blkno, CREATE);
b3b94faa DT	187	meta_prep_new(bh);
	188	return bh;
	189	}
	190
	191	/**
	192	* gfs2_meta_read - Read a block from disk
	193	* @gl: The glock covering the block
	194	* @blkno: The block number
7276b3b0	195	* @flags: flags
b3b94faa DT	196	* @bhp: the place where the buffer is returned (NULL on failure)
	197	*
	198	* Returns: errno
	199	*/
	200
cd915493	201	int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
b3b94faa DT	202	struct buffer_head **bhp)
b3b94faa DT	203	{
6802e340	204	*bhp = gfs2_getbuf(gl, blkno, CREATE);
15c7cee7	205	if (!buffer_uptodate(*bhp)) {
2e565bb6	206	ll_rw_block(READ_META, 1, bhp);
15c7cee7 BP	207	if (flags & DIO_WAIT) {
	208	int error = gfs2_meta_wait(gl->gl_sbd, *bhp);
	209	if (error) {
	210	brelse(*bhp);
	211	return error;
	212	}
7276b3b0 SW	213	}
7276b3b0 SW	214	}
b3b94faa	215
7276b3b0	216	return 0;
b3b94faa DT	217	}
	218
	219	/**
7276b3b0	220	* gfs2_meta_wait - Reread a block from disk
b3b94faa	221	* @sdp: the filesystem
7276b3b0	222	* @bh: The block to wait for
b3b94faa DT	223	*
	224	* Returns: errno
	225	*/
	226
7276b3b0	227	int gfs2_meta_wait(struct gfs2_sbd sdp, struct buffer_head bh)
b3b94faa DT	228	{
	229	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
	230	return -EIO;
	231
7276b3b0	232	wait_on_buffer(bh);
b3b94faa	233
7276b3b0 SW	234	if (!buffer_uptodate(bh)) {
	235	struct gfs2_trans *tr = current->journal_info;
	236	if (tr && tr->tr_touched)
	237	gfs2_io_error_bh(sdp, bh);
	238	return -EIO;
b3b94faa	239	}
7276b3b0 SW	240	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
7276b3b0 SW	241	return -EIO;
b3b94faa DT	242
	243	return 0;
	244	}
	245
	246	/**
586dfdaa	247	* gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
b3b94faa DT	248	* @gl: the glock the buffer belongs to
b3b94faa DT	249	* @bh: The buffer to be attached to
586dfdaa	250	* @meta: Flag to indicate whether its metadata or not
b3b94faa DT	251	*/
b3b94faa DT	252
568f4c96 SW	253	void gfs2_attach_bufdata(struct gfs2_glock gl, struct buffer_head bh,
568f4c96 SW	254	int meta)
b3b94faa DT	255	{
	256	struct gfs2_bufdata *bd;
	257
18ec7d5c SW	258	if (meta)
18ec7d5c SW	259	lock_page(bh->b_page);
b3b94faa	260
5c676f6d	261	if (bh->b_private) {
18ec7d5c SW	262	if (meta)
18ec7d5c SW	263	unlock_page(bh->b_page);
b3b94faa DT	264	return;
	265	}
	266
3e5cd087	267	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS \| __GFP_NOFAIL);
b3b94faa DT	268	bd->bd_bh = bh;
	269	bd->bd_gl = gl;
	270
	271	INIT_LIST_HEAD(&bd->bd_list_tr);
82ffa516	272	if (meta)
586dfdaa	273	lops_init_le(&bd->bd_le, &gfs2_buf_lops);
82ffa516	274	else
586dfdaa	275	lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
5c676f6d	276	bh->b_private = bd;
b3b94faa	277
18ec7d5c SW	278	if (meta)
18ec7d5c SW	279	unlock_page(bh->b_page);
b3b94faa DT	280	}
b3b94faa DT	281
16615be1 SW	282	void gfs2_remove_from_journal(struct buffer_head bh, struct gfs2_trans tr, int meta)
	283	{
	284	struct gfs2_sbd *sdp = GFS2_SB(bh->b_page->mapping->host);
	285	struct gfs2_bufdata *bd = bh->b_private;
	286	if (test_clear_buffer_pinned(bh)) {
	287	list_del_init(&bd->bd_le.le_list);
	288	if (meta) {
	289	gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
	290	sdp->sd_log_num_buf--;
	291	tr->tr_num_buf_rm++;
	292	} else {
	293	gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
	294	sdp->sd_log_num_databuf--;
	295	tr->tr_num_databuf_rm++;
	296	}
	297	tr->tr_touched = 1;
	298	brelse(bh);
	299	}
	300	if (bd) {
	301	if (bd->bd_ail) {
f91a0d3e	302	gfs2_remove_from_ail(bd);
16615be1 SW	303	bh->b_private = NULL;
	304	bd->bd_bh = NULL;
	305	bd->bd_blkno = bh->b_blocknr;
	306	gfs2_trans_add_revoke(sdp, bd);
	307	}
	308	}
	309	clear_buffer_dirty(bh);
	310	clear_buffer_uptodate(bh);
	311	}
	312
b3b94faa DT	313	/**
	314	* gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
	315	* @ip: the inode who owns the buffers
	316	* @bstart: the first buffer in the run
	317	* @blen: the number of buffers in the run
	318	*
	319	*/
	320
cd915493	321	void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
b3b94faa	322	{
feaa7bba	323	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
b3b94faa DT	324	struct buffer_head *bh;
	325
	326	while (blen) {
6802e340	327	bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
b3b94faa	328	if (bh) {
1ad38c43 SW	329	lock_buffer(bh);
1ad38c43 SW	330	gfs2_log_lock(sdp);
16615be1	331	gfs2_remove_from_journal(bh, current->journal_info, 1);
1ad38c43	332	gfs2_log_unlock(sdp);
b3b94faa	333	unlock_buffer(bh);
b3b94faa DT	334	brelse(bh);
	335	}
	336
	337	bstart++;
	338	blen--;
	339	}
	340	}
	341
b3b94faa DT	342	/**
	343	* gfs2_meta_indirect_buffer - Get a metadata buffer
	344	* @ip: The GFS2 inode
	345	* @height: The level of this buf in the metadata (indir addr) tree (if any)
	346	* @num: The block number (device relative) of the buffer
	347	* @new: Non-zero if we may create a new buffer
	348	* @bhp: the buffer is returned here
	349	*
b3b94faa DT	350	* Returns: errno
	351	*/
	352
cd915493	353	int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
b3b94faa DT	354	int new, struct buffer_head **bhp)
b3b94faa DT	355	{
7276b3b0 SW	356	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
7276b3b0 SW	357	struct gfs2_glock *gl = ip->i_gl;
f91a0d3e SW	358	struct buffer_head *bh;
f91a0d3e SW	359	int ret = 0;
b3b94faa DT	360
b3b94faa DT	361	if (new) {
f91a0d3e SW	362	BUG_ON(height == 0);
f91a0d3e SW	363	bh = gfs2_meta_new(gl, num);
d4e9c4c3	364	gfs2_trans_add_bh(ip->i_gl, bh, 1);
b3b94faa DT	365	gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
b3b94faa DT	366	gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
7276b3b0 SW	367	} else {
7276b3b0 SW	368	u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
f91a0d3e SW	369	ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
	370	if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
	371	brelse(bh);
	372	ret = -EIO;
7276b3b0	373	}
b3b94faa	374	}
b3b94faa	375	*bhp = bh;
f91a0d3e	376	return ret;
b3b94faa DT	377	}
	378
	379	/**
	380	* gfs2_meta_ra - start readahead on an extent of a file
	381	* @gl: the glock the blocks belong to
	382	* @dblock: the starting disk block
	383	* @extlen: the number of blocks in the extent
	384	*
7276b3b0	385	* returns: the first buffer in the extent
b3b94faa DT	386	*/
b3b94faa DT	387
7276b3b0	388	struct buffer_head gfs2_meta_ra(struct gfs2_glock gl, u64 dblock, u32 extlen)
b3b94faa DT	389	{
b3b94faa DT	390	struct gfs2_sbd *sdp = gl->gl_sbd;
b3b94faa	391	struct buffer_head first_bh, bh;
cd915493	392	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
568f4c96	393	sdp->sd_sb.sb_bsize_shift;
b3b94faa	394
7276b3b0 SW	395	BUG_ON(!extlen);
	396
	397	if (max_ra < 1)
	398	max_ra = 1;
b3b94faa DT	399	if (extlen > max_ra)
	400	extlen = max_ra;
	401
6802e340	402	first_bh = gfs2_getbuf(gl, dblock, CREATE);
b3b94faa DT	403
	404	if (buffer_uptodate(first_bh))
	405	goto out;
7276b3b0	406	if (!buffer_locked(first_bh))
2e565bb6	407	ll_rw_block(READ_META, 1, &first_bh);
b3b94faa DT	408
	409	dblock++;
	410	extlen--;
	411
	412	while (extlen) {
6802e340	413	bh = gfs2_getbuf(gl, dblock, CREATE);
b3b94faa	414
7276b3b0 SW	415	if (!buffer_uptodate(bh) && !buffer_locked(bh))
	416	ll_rw_block(READA, 1, &bh);
	417	brelse(bh);
b3b94faa DT	418	dblock++;
b3b94faa DT	419	extlen--;
7276b3b0 SW	420	if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
7276b3b0 SW	421	goto out;
b3b94faa DT	422	}
b3b94faa DT	423
7276b3b0	424	wait_on_buffer(first_bh);
a91ea69f	425	out:
7276b3b0	426	return first_bh;
b3b94faa DT	427	}
b3b94faa DT	428