[linux.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 <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;
	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_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.
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>
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;
091806ed	72	struct gfs2_inode *ip;
b3b94faa DT	73
	74	aspace = new_inode(sdp->sd_vfs);
	75	if (aspace) {
f3bba03f	76	mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS);
b3b94faa DT	77	aspace->i_mapping->a_ops = &aspace_aops;
b3b94faa DT	78	aspace->i_size = ~0ULL;
091806ed BP	79	ip = GFS2_I(aspace);
091806ed BP	80	clear_bit(GIF_USER, &ip->i_flags);
b3b94faa DT	81	insert_inode_hash(aspace);
b3b94faa DT	82	}
b3b94faa DT	83	return aspace;
	84	}
	85
	86	void gfs2_aspace_put(struct inode *aspace)
	87	{
	88	remove_inode_hash(aspace);
	89	iput(aspace);
	90	}
	91
b3b94faa DT	92	/**
	93	* gfs2_meta_inval - Invalidate all buffers associated with a glock
	94	* @gl: the glock
	95	*
	96	*/
	97
	98	void gfs2_meta_inval(struct gfs2_glock *gl)
	99	{
	100	struct gfs2_sbd *sdp = gl->gl_sbd;
	101	struct inode *aspace = gl->gl_aspace;
	102	struct address_space *mapping = gl->gl_aspace->i_mapping;
	103
	104	gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
	105
	106	atomic_inc(&aspace->i_writecount);
	107	truncate_inode_pages(mapping, 0);
	108	atomic_dec(&aspace->i_writecount);
	109
	110	gfs2_assert_withdraw(sdp, !mapping->nrpages);
	111	}
	112
	113	/**
	114	* gfs2_meta_sync - Sync all buffers associated with a glock
	115	* @gl: The glock
b3b94faa DT	116	*
	117	*/
	118
7276b3b0	119	void gfs2_meta_sync(struct gfs2_glock *gl)
b3b94faa DT	120	{
b3b94faa DT	121	struct address_space *mapping = gl->gl_aspace->i_mapping;
7276b3b0	122	int error;
b3b94faa	123
7276b3b0 SW	124	filemap_fdatawrite(mapping);
7276b3b0 SW	125	error = filemap_fdatawait(mapping);
b3b94faa DT	126
	127	if (error)
	128	gfs2_io_error(gl->gl_sbd);
	129	}
	130
	131	/**
	132	* getbuf - Get a buffer with a given address space
cb4c0313	133	* @gl: the glock
b3b94faa DT	134	* @blkno: the block number (filesystem scope)
	135	* @create: 1 if the buffer should be created
	136	*
	137	* Returns: the buffer
	138	*/
	139
cb4c0313	140	static struct buffer_head getbuf(struct gfs2_glock gl, u64 blkno, int create)
b3b94faa	141	{
cb4c0313 SW	142	struct address_space *mapping = gl->gl_aspace->i_mapping;
cb4c0313 SW	143	struct gfs2_sbd *sdp = gl->gl_sbd;
b3b94faa DT	144	struct page *page;
	145	struct buffer_head *bh;
	146	unsigned int shift;
	147	unsigned long index;
	148	unsigned int bufnum;
	149
	150	shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
	151	index = blkno >> shift; /* convert block to page */
	152	bufnum = blkno - (index << shift); /* block buf index within page */
	153
	154	if (create) {
	155	for (;;) {
cb4c0313	156	page = grab_cache_page(mapping, index);
b3b94faa DT	157	if (page)
	158	break;
	159	yield();
	160	}
	161	} else {
cb4c0313	162	page = find_lock_page(mapping, index);
b3b94faa DT	163	if (!page)
	164	return NULL;
	165	}
	166
	167	if (!page_has_buffers(page))
	168	create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
	169
	170	/* Locate header for our buffer within our page */
	171	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
	172	/* Do nothing */;
	173	get_bh(bh);
	174
	175	if (!buffer_mapped(bh))
	176	map_bh(bh, sdp->sd_vfs, blkno);
	177
	178	unlock_page(page);
	179	mark_page_accessed(page);
	180	page_cache_release(page);
	181
	182	return bh;
	183	}
	184
	185	static void meta_prep_new(struct buffer_head *bh)
	186	{
	187	struct gfs2_meta_header mh = (struct gfs2_meta_header )bh->b_data;
	188
	189	lock_buffer(bh);
	190	clear_buffer_dirty(bh);
	191	set_buffer_uptodate(bh);
	192	unlock_buffer(bh);
	193
	194	mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
	195	}
	196
	197	/**
	198	* gfs2_meta_new - Get a block
	199	* @gl: The glock associated with this block
	200	* @blkno: The block number
	201	*
	202	* Returns: The buffer
	203	*/
	204
cd915493	205	struct buffer_head gfs2_meta_new(struct gfs2_glock gl, u64 blkno)
b3b94faa DT	206	{
b3b94faa DT	207	struct buffer_head *bh;
cb4c0313	208	bh = getbuf(gl, blkno, CREATE);
b3b94faa DT	209	meta_prep_new(bh);
	210	return bh;
	211	}
	212
	213	/**
	214	* gfs2_meta_read - Read a block from disk
	215	* @gl: The glock covering the block
	216	* @blkno: The block number
7276b3b0	217	* @flags: flags
b3b94faa DT	218	* @bhp: the place where the buffer is returned (NULL on failure)
	219	*
	220	* Returns: errno
	221	*/
	222
cd915493	223	int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
b3b94faa DT	224	struct buffer_head **bhp)
b3b94faa DT	225	{
cb4c0313	226	*bhp = getbuf(gl, blkno, CREATE);
15c7cee7	227	if (!buffer_uptodate(*bhp)) {
2e565bb6	228	ll_rw_block(READ_META, 1, bhp);
15c7cee7 BP	229	if (flags & DIO_WAIT) {
	230	int error = gfs2_meta_wait(gl->gl_sbd, *bhp);
	231	if (error) {
	232	brelse(*bhp);
	233	return error;
	234	}
7276b3b0 SW	235	}
7276b3b0 SW	236	}
b3b94faa	237
7276b3b0	238	return 0;
b3b94faa DT	239	}
	240
	241	/**
7276b3b0	242	* gfs2_meta_wait - Reread a block from disk
b3b94faa	243	* @sdp: the filesystem
7276b3b0	244	* @bh: The block to wait for
b3b94faa DT	245	*
	246	* Returns: errno
	247	*/
	248
7276b3b0	249	int gfs2_meta_wait(struct gfs2_sbd sdp, struct buffer_head bh)
b3b94faa DT	250	{
	251	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
	252	return -EIO;
	253
7276b3b0	254	wait_on_buffer(bh);
b3b94faa	255
7276b3b0 SW	256	if (!buffer_uptodate(bh)) {
	257	struct gfs2_trans *tr = current->journal_info;
	258	if (tr && tr->tr_touched)
	259	gfs2_io_error_bh(sdp, bh);
	260	return -EIO;
b3b94faa	261	}
7276b3b0 SW	262	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
7276b3b0 SW	263	return -EIO;
b3b94faa DT	264
	265	return 0;
	266	}
	267
	268	/**
586dfdaa	269	* gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
b3b94faa DT	270	* @gl: the glock the buffer belongs to
b3b94faa DT	271	* @bh: The buffer to be attached to
586dfdaa	272	* @meta: Flag to indicate whether its metadata or not
b3b94faa DT	273	*/
b3b94faa DT	274
568f4c96 SW	275	void gfs2_attach_bufdata(struct gfs2_glock gl, struct buffer_head bh,
568f4c96 SW	276	int meta)
b3b94faa DT	277	{
	278	struct gfs2_bufdata *bd;
	279
18ec7d5c SW	280	if (meta)
18ec7d5c SW	281	lock_page(bh->b_page);
b3b94faa	282
5c676f6d	283	if (bh->b_private) {
18ec7d5c SW	284	if (meta)
18ec7d5c SW	285	unlock_page(bh->b_page);
b3b94faa DT	286	return;
	287	}
	288
3e5cd087	289	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS \| __GFP_NOFAIL);
b3b94faa DT	290	bd->bd_bh = bh;
	291	bd->bd_gl = gl;
	292
	293	INIT_LIST_HEAD(&bd->bd_list_tr);
82ffa516	294	if (meta)
586dfdaa	295	lops_init_le(&bd->bd_le, &gfs2_buf_lops);
82ffa516	296	else
586dfdaa	297	lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
5c676f6d	298	bh->b_private = bd;
b3b94faa	299
18ec7d5c SW	300	if (meta)
18ec7d5c SW	301	unlock_page(bh->b_page);
b3b94faa DT	302	}
b3b94faa DT	303
16615be1 SW	304	void gfs2_remove_from_journal(struct buffer_head bh, struct gfs2_trans tr, int meta)
	305	{
	306	struct gfs2_sbd *sdp = GFS2_SB(bh->b_page->mapping->host);
	307	struct gfs2_bufdata *bd = bh->b_private;
	308	if (test_clear_buffer_pinned(bh)) {
	309	list_del_init(&bd->bd_le.le_list);
	310	if (meta) {
	311	gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
	312	sdp->sd_log_num_buf--;
	313	tr->tr_num_buf_rm++;
	314	} else {
	315	gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
	316	sdp->sd_log_num_databuf--;
	317	tr->tr_num_databuf_rm++;
	318	}
	319	tr->tr_touched = 1;
	320	brelse(bh);
	321	}
	322	if (bd) {
	323	if (bd->bd_ail) {
f91a0d3e	324	gfs2_remove_from_ail(bd);
16615be1 SW	325	bh->b_private = NULL;
	326	bd->bd_bh = NULL;
	327	bd->bd_blkno = bh->b_blocknr;
	328	gfs2_trans_add_revoke(sdp, bd);
	329	}
	330	}
	331	clear_buffer_dirty(bh);
	332	clear_buffer_uptodate(bh);
	333	}
	334
b3b94faa DT	335	/**
	336	* gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
	337	* @ip: the inode who owns the buffers
	338	* @bstart: the first buffer in the run
	339	* @blen: the number of buffers in the run
	340	*
	341	*/
	342
cd915493	343	void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
b3b94faa	344	{
feaa7bba	345	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
b3b94faa DT	346	struct buffer_head *bh;
	347
	348	while (blen) {
cb4c0313	349	bh = getbuf(ip->i_gl, bstart, NO_CREATE);
b3b94faa	350	if (bh) {
1ad38c43 SW	351	lock_buffer(bh);
1ad38c43 SW	352	gfs2_log_lock(sdp);
16615be1	353	gfs2_remove_from_journal(bh, current->journal_info, 1);
1ad38c43	354	gfs2_log_unlock(sdp);
b3b94faa	355	unlock_buffer(bh);
b3b94faa DT	356	brelse(bh);
	357	}
	358
	359	bstart++;
	360	blen--;
	361	}
	362	}
	363
b3b94faa DT	364	/**
	365	* gfs2_meta_indirect_buffer - Get a metadata buffer
	366	* @ip: The GFS2 inode
	367	* @height: The level of this buf in the metadata (indir addr) tree (if any)
	368	* @num: The block number (device relative) of the buffer
	369	* @new: Non-zero if we may create a new buffer
	370	* @bhp: the buffer is returned here
	371	*
b3b94faa DT	372	* Returns: errno
	373	*/
	374
cd915493	375	int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
b3b94faa DT	376	int new, struct buffer_head **bhp)
b3b94faa DT	377	{
7276b3b0 SW	378	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
7276b3b0 SW	379	struct gfs2_glock *gl = ip->i_gl;
f91a0d3e SW	380	struct buffer_head *bh;
f91a0d3e SW	381	int ret = 0;
b3b94faa DT	382
b3b94faa DT	383	if (new) {
f91a0d3e SW	384	BUG_ON(height == 0);
f91a0d3e SW	385	bh = gfs2_meta_new(gl, num);
d4e9c4c3	386	gfs2_trans_add_bh(ip->i_gl, bh, 1);
b3b94faa DT	387	gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
b3b94faa DT	388	gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
7276b3b0 SW	389	} else {
7276b3b0 SW	390	u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
f91a0d3e SW	391	ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
	392	if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
	393	brelse(bh);
	394	ret = -EIO;
7276b3b0	395	}
b3b94faa	396	}
b3b94faa	397	*bhp = bh;
f91a0d3e	398	return ret;
b3b94faa DT	399	}
	400
	401	/**
	402	* gfs2_meta_ra - start readahead on an extent of a file
	403	* @gl: the glock the blocks belong to
	404	* @dblock: the starting disk block
	405	* @extlen: the number of blocks in the extent
	406	*
7276b3b0	407	* returns: the first buffer in the extent
b3b94faa DT	408	*/
b3b94faa DT	409
7276b3b0	410	struct buffer_head gfs2_meta_ra(struct gfs2_glock gl, u64 dblock, u32 extlen)
b3b94faa DT	411	{
b3b94faa DT	412	struct gfs2_sbd *sdp = gl->gl_sbd;
b3b94faa	413	struct buffer_head first_bh, bh;
cd915493	414	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
568f4c96	415	sdp->sd_sb.sb_bsize_shift;
b3b94faa	416
7276b3b0 SW	417	BUG_ON(!extlen);
	418
	419	if (max_ra < 1)
	420	max_ra = 1;
b3b94faa DT	421	if (extlen > max_ra)
	422	extlen = max_ra;
	423
cb4c0313	424	first_bh = getbuf(gl, dblock, CREATE);
b3b94faa DT	425
	426	if (buffer_uptodate(first_bh))
	427	goto out;
7276b3b0	428	if (!buffer_locked(first_bh))
2e565bb6	429	ll_rw_block(READ_META, 1, &first_bh);
b3b94faa DT	430
	431	dblock++;
	432	extlen--;
	433
	434	while (extlen) {
cb4c0313	435	bh = getbuf(gl, dblock, CREATE);
b3b94faa	436
7276b3b0 SW	437	if (!buffer_uptodate(bh) && !buffer_locked(bh))
	438	ll_rw_block(READA, 1, &bh);
	439	brelse(bh);
b3b94faa DT	440	dblock++;
b3b94faa DT	441	extlen--;
7276b3b0 SW	442	if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
7276b3b0 SW	443	goto out;
b3b94faa DT	444	}
b3b94faa DT	445
7276b3b0	446	wait_on_buffer(first_bh);
a91ea69f	447	out:
7276b3b0	448	return first_bh;
b3b94faa DT	449	}
b3b94faa DT	450