[linux-2.6-block.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"

static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc)
{
	int err;
	struct buffer_head *bh, *head;
	int nr_underway = 0;
	int write_op = (1 << BIO_RW_META) | ((wbc->sync_mode == WB_SYNC_ALL ?
			WRITE_SYNC_PLUG : WRITE));

	BUG_ON(!PageLocked(page));
	BUG_ON(!page_has_buffers(page));

	head = page_buffers(page);
	bh = head;

	do {
		if (!buffer_mapped(bh))
			continue;
		/*
		 * If it's a fully non-blocking write attempt and we cannot
		 * lock the buffer then redirty the page.  Note that this can
		 * potentially cause a busy-wait loop from pdflush and kswapd
		 * activity, but those code paths have their own higher-level
		 * throttling.
		 */
		if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
			lock_buffer(bh);
		} else if (!trylock_buffer(bh)) {
			redirty_page_for_writepage(wbc, page);
			continue;
		}
		if (test_clear_buffer_dirty(bh)) {
			mark_buffer_async_write(bh);
		} else {
			unlock_buffer(bh);
		}
	} while ((bh = bh->b_this_page) != head);

	/*
	 * The page and its buffers are protected by PageWriteback(), so we can
	 * drop the bh refcounts early.
	 */
	BUG_ON(PageWriteback(page));
	set_page_writeback(page);

	do {
		struct buffer_head *next = bh->b_this_page;
		if (buffer_async_write(bh)) {
			submit_bh(write_op, bh);
			nr_underway++;
		}
		bh = next;
	} while (bh != head);
	unlock_page(page);

	err = 0;
	if (nr_underway == 0)
		end_page_writeback(page);

	return err;
}

const struct address_space_operations gfs2_meta_aops = {
	.writepage = gfs2_aspace_writepage,
	.releasepage = gfs2_releasepage,
	.sync_page = block_sync_page,
};

/**
 * 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 = gfs2_glock2aspace(gl);
	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 = gfs2_glock2aspace(gl);
	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)
{
	struct gfs2_sbd *sdp = gl->gl_sbd;
	struct buffer_head *bh;

	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
		return -EIO;

	*bhp = bh = gfs2_getbuf(gl, blkno, CREATE);

	lock_buffer(bh);
	if (buffer_uptodate(bh)) {
		unlock_buffer(bh);
		return 0;
	}
	bh->b_end_io = end_buffer_read_sync;
	get_bh(bh);
	submit_bh(READ_SYNC | (1 << BIO_RW_META), bh);
	if (!(flags & DIO_WAIT))
		return 0;

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

	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 address_space *mapping = bh->b_page->mapping;
	struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
	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_SYNC | (1 << BIO_RW_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"
b3b94faa	34
4a0f9a32	35	static int gfs2_aspace_writepage(struct page page, struct writeback_control wbc)
b3b94faa	36	{
4a0f9a32 SW	37	int err;
	38	struct buffer_head bh, head;
	39	int nr_underway = 0;
	40	int write_op = (1 << BIO_RW_META) \| ((wbc->sync_mode == WB_SYNC_ALL ?
	41	WRITE_SYNC_PLUG : WRITE));
b3b94faa	42
4a0f9a32 SW	43	BUG_ON(!PageLocked(page));
	44	BUG_ON(!page_has_buffers(page));
	45
	46	head = page_buffers(page);
	47	bh = head;
	48
	49	do {
	50	if (!buffer_mapped(bh))
	51	continue;
	52	/*
	53	* If it's a fully non-blocking write attempt and we cannot
	54	* lock the buffer then redirty the page. Note that this can
	55	* potentially cause a busy-wait loop from pdflush and kswapd
	56	* activity, but those code paths have their own higher-level
	57	* throttling.
	58	*/
	59	if (wbc->sync_mode != WB_SYNC_NONE \|\| !wbc->nonblocking) {
	60	lock_buffer(bh);
	61	} else if (!trylock_buffer(bh)) {
	62	redirty_page_for_writepage(wbc, page);
	63	continue;
	64	}
	65	if (test_clear_buffer_dirty(bh)) {
	66	mark_buffer_async_write(bh);
	67	} else {
	68	unlock_buffer(bh);
	69	}
	70	} while ((bh = bh->b_this_page) != head);
	71
	72	/*
	73	* The page and its buffers are protected by PageWriteback(), so we can
	74	* drop the bh refcounts early.
	75	*/
	76	BUG_ON(PageWriteback(page));
	77	set_page_writeback(page);
	78
	79	do {
	80	struct buffer_head *next = bh->b_this_page;
	81	if (buffer_async_write(bh)) {
	82	submit_bh(write_op, bh);
	83	nr_underway++;
	84	}
	85	bh = next;
	86	} while (bh != head);
	87	unlock_page(page);
	88
	89	err = 0;
	90	if (nr_underway == 0)
	91	end_page_writeback(page);
	92
	93	return err;
b3b94faa DT	94	}
b3b94faa DT	95
009d8518	96	const struct address_space_operations gfs2_meta_aops = {
b3b94faa	97	.writepage = gfs2_aspace_writepage,
4340fe62	98	.releasepage = gfs2_releasepage,
52d4c74b	99	.sync_page = block_sync_page,
b3b94faa DT	100	};
b3b94faa DT	101
b3b94faa DT	102	/**
	103	* gfs2_meta_sync - Sync all buffers associated with a glock
	104	* @gl: The glock
b3b94faa DT	105	*
	106	*/
	107
7276b3b0	108	void gfs2_meta_sync(struct gfs2_glock *gl)
b3b94faa	109	{
009d8518	110	struct address_space *mapping = gfs2_glock2aspace(gl);
7276b3b0	111	int error;
b3b94faa	112
7276b3b0 SW	113	filemap_fdatawrite(mapping);
7276b3b0 SW	114	error = filemap_fdatawait(mapping);
b3b94faa DT	115
	116	if (error)
	117	gfs2_io_error(gl->gl_sbd);
	118	}
	119
	120	/**
6802e340	121	* gfs2_getbuf - Get a buffer with a given address space
cb4c0313	122	* @gl: the glock
b3b94faa DT	123	* @blkno: the block number (filesystem scope)
	124	* @create: 1 if the buffer should be created
	125	*
	126	* Returns: the buffer
	127	*/
	128
6802e340	129	struct buffer_head gfs2_getbuf(struct gfs2_glock gl, u64 blkno, int create)
b3b94faa	130	{
009d8518	131	struct address_space *mapping = gfs2_glock2aspace(gl);
cb4c0313	132	struct gfs2_sbd *sdp = gl->gl_sbd;
b3b94faa DT	133	struct page *page;
	134	struct buffer_head *bh;
	135	unsigned int shift;
	136	unsigned long index;
	137	unsigned int bufnum;
	138
	139	shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
	140	index = blkno >> shift; /* convert block to page */
	141	bufnum = blkno - (index << shift); /* block buf index within page */
	142
	143	if (create) {
	144	for (;;) {
cb4c0313	145	page = grab_cache_page(mapping, index);
b3b94faa DT	146	if (page)
	147	break;
	148	yield();
	149	}
	150	} else {
cb4c0313	151	page = find_lock_page(mapping, index);
b3b94faa DT	152	if (!page)
	153	return NULL;
	154	}
	155
	156	if (!page_has_buffers(page))
	157	create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
	158
	159	/* Locate header for our buffer within our page */
	160	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
	161	/* Do nothing */;
	162	get_bh(bh);
	163
	164	if (!buffer_mapped(bh))
	165	map_bh(bh, sdp->sd_vfs, blkno);
	166
	167	unlock_page(page);
	168	mark_page_accessed(page);
	169	page_cache_release(page);
	170
	171	return bh;
	172	}
	173
	174	static void meta_prep_new(struct buffer_head *bh)
	175	{
	176	struct gfs2_meta_header mh = (struct gfs2_meta_header )bh->b_data;
	177
	178	lock_buffer(bh);
	179	clear_buffer_dirty(bh);
	180	set_buffer_uptodate(bh);
	181	unlock_buffer(bh);
	182
	183	mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
	184	}
	185
	186	/**
	187	* gfs2_meta_new - Get a block
	188	* @gl: The glock associated with this block
	189	* @blkno: The block number
	190	*
	191	* Returns: The buffer
	192	*/
	193
cd915493	194	struct buffer_head gfs2_meta_new(struct gfs2_glock gl, u64 blkno)
b3b94faa DT	195	{
b3b94faa DT	196	struct buffer_head *bh;
6802e340	197	bh = gfs2_getbuf(gl, blkno, CREATE);
b3b94faa DT	198	meta_prep_new(bh);
	199	return bh;
	200	}
	201
	202	/**
	203	* gfs2_meta_read - Read a block from disk
	204	* @gl: The glock covering the block
	205	* @blkno: The block number
7276b3b0	206	* @flags: flags
b3b94faa DT	207	* @bhp: the place where the buffer is returned (NULL on failure)
	208	*
	209	* Returns: errno
	210	*/
	211
cd915493	212	int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
b3b94faa DT	213	struct buffer_head **bhp)
b3b94faa DT	214	{
c969f58c SW	215	struct gfs2_sbd *sdp = gl->gl_sbd;
	216	struct buffer_head *bh;
	217
	218	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
	219	return -EIO;
	220
	221	*bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
	222
	223	lock_buffer(bh);
	224	if (buffer_uptodate(bh)) {
	225	unlock_buffer(bh);
	226	return 0;
	227	}
	228	bh->b_end_io = end_buffer_read_sync;
	229	get_bh(bh);
	230	submit_bh(READ_SYNC \| (1 << BIO_RW_META), bh);
	231	if (!(flags & DIO_WAIT))
	232	return 0;
	233
	234	wait_on_buffer(bh);
	235	if (unlikely(!buffer_uptodate(bh))) {
	236	struct gfs2_trans *tr = current->journal_info;
	237	if (tr && tr->tr_touched)
	238	gfs2_io_error_bh(sdp, bh);
	239	brelse(bh);
	240	return -EIO;
7276b3b0	241	}
b3b94faa	242
7276b3b0	243	return 0;
b3b94faa DT	244	}
	245
	246	/**
7276b3b0	247	* gfs2_meta_wait - Reread a block from disk
b3b94faa	248	* @sdp: the filesystem
7276b3b0	249	* @bh: The block to wait for
b3b94faa DT	250	*
	251	* Returns: errno
	252	*/
	253
7276b3b0	254	int gfs2_meta_wait(struct gfs2_sbd sdp, struct buffer_head bh)
b3b94faa DT	255	{
	256	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
	257	return -EIO;
	258
7276b3b0	259	wait_on_buffer(bh);
b3b94faa	260
7276b3b0 SW	261	if (!buffer_uptodate(bh)) {
	262	struct gfs2_trans *tr = current->journal_info;
	263	if (tr && tr->tr_touched)
	264	gfs2_io_error_bh(sdp, bh);
	265	return -EIO;
b3b94faa	266	}
7276b3b0 SW	267	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
7276b3b0 SW	268	return -EIO;
b3b94faa DT	269
	270	return 0;
	271	}
	272
	273	/**
586dfdaa	274	* gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
b3b94faa DT	275	* @gl: the glock the buffer belongs to
b3b94faa DT	276	* @bh: The buffer to be attached to
586dfdaa	277	* @meta: Flag to indicate whether its metadata or not
b3b94faa DT	278	*/
b3b94faa DT	279
568f4c96 SW	280	void gfs2_attach_bufdata(struct gfs2_glock gl, struct buffer_head bh,
568f4c96 SW	281	int meta)
b3b94faa DT	282	{
	283	struct gfs2_bufdata *bd;
	284
18ec7d5c SW	285	if (meta)
18ec7d5c SW	286	lock_page(bh->b_page);
b3b94faa	287
5c676f6d	288	if (bh->b_private) {
18ec7d5c SW	289	if (meta)
18ec7d5c SW	290	unlock_page(bh->b_page);
b3b94faa DT	291	return;
	292	}
	293
3e5cd087	294	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS \| __GFP_NOFAIL);
b3b94faa DT	295	bd->bd_bh = bh;
	296	bd->bd_gl = gl;
	297
	298	INIT_LIST_HEAD(&bd->bd_list_tr);
82ffa516	299	if (meta)
586dfdaa	300	lops_init_le(&bd->bd_le, &gfs2_buf_lops);
82ffa516	301	else
586dfdaa	302	lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
5c676f6d	303	bh->b_private = bd;
b3b94faa	304
18ec7d5c SW	305	if (meta)
18ec7d5c SW	306	unlock_page(bh->b_page);
b3b94faa DT	307	}
b3b94faa DT	308
16615be1 SW	309	void gfs2_remove_from_journal(struct buffer_head bh, struct gfs2_trans tr, int meta)
16615be1 SW	310	{
009d8518 SW	311	struct address_space *mapping = bh->b_page->mapping;
009d8518 SW	312	struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
16615be1	313	struct gfs2_bufdata *bd = bh->b_private;
009d8518	314
16615be1 SW	315	if (test_clear_buffer_pinned(bh)) {
	316	list_del_init(&bd->bd_le.le_list);
	317	if (meta) {
	318	gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
	319	sdp->sd_log_num_buf--;
	320	tr->tr_num_buf_rm++;
	321	} else {
	322	gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
	323	sdp->sd_log_num_databuf--;
	324	tr->tr_num_databuf_rm++;
	325	}
	326	tr->tr_touched = 1;
	327	brelse(bh);
	328	}
	329	if (bd) {
	330	if (bd->bd_ail) {
f91a0d3e	331	gfs2_remove_from_ail(bd);
16615be1 SW	332	bh->b_private = NULL;
	333	bd->bd_bh = NULL;
	334	bd->bd_blkno = bh->b_blocknr;
	335	gfs2_trans_add_revoke(sdp, bd);
	336	}
	337	}
	338	clear_buffer_dirty(bh);
	339	clear_buffer_uptodate(bh);
	340	}
	341
b3b94faa DT	342	/**
	343	* gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
	344	* @ip: the inode who owns the buffers
	345	* @bstart: the first buffer in the run
	346	* @blen: the number of buffers in the run
	347	*
	348	*/
	349
cd915493	350	void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
b3b94faa	351	{
feaa7bba	352	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
b3b94faa DT	353	struct buffer_head *bh;
	354
	355	while (blen) {
6802e340	356	bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE);
b3b94faa	357	if (bh) {
1ad38c43 SW	358	lock_buffer(bh);
1ad38c43 SW	359	gfs2_log_lock(sdp);
16615be1	360	gfs2_remove_from_journal(bh, current->journal_info, 1);
1ad38c43	361	gfs2_log_unlock(sdp);
b3b94faa	362	unlock_buffer(bh);
b3b94faa DT	363	brelse(bh);
	364	}
	365
	366	bstart++;
	367	blen--;
	368	}
	369	}
	370
b3b94faa DT	371	/**
	372	* gfs2_meta_indirect_buffer - Get a metadata buffer
	373	* @ip: The GFS2 inode
	374	* @height: The level of this buf in the metadata (indir addr) tree (if any)
	375	* @num: The block number (device relative) of the buffer
	376	* @new: Non-zero if we may create a new buffer
	377	* @bhp: the buffer is returned here
	378	*
b3b94faa DT	379	* Returns: errno
	380	*/
	381
cd915493	382	int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
b3b94faa DT	383	int new, struct buffer_head **bhp)
b3b94faa DT	384	{
7276b3b0 SW	385	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
7276b3b0 SW	386	struct gfs2_glock *gl = ip->i_gl;
f91a0d3e SW	387	struct buffer_head *bh;
f91a0d3e SW	388	int ret = 0;
b3b94faa DT	389
b3b94faa DT	390	if (new) {
f91a0d3e SW	391	BUG_ON(height == 0);
f91a0d3e SW	392	bh = gfs2_meta_new(gl, num);
d4e9c4c3	393	gfs2_trans_add_bh(ip->i_gl, bh, 1);
b3b94faa DT	394	gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
b3b94faa DT	395	gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
7276b3b0 SW	396	} else {
7276b3b0 SW	397	u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
f91a0d3e SW	398	ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
	399	if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
	400	brelse(bh);
	401	ret = -EIO;
7276b3b0	402	}
b3b94faa	403	}
b3b94faa	404	*bhp = bh;
f91a0d3e	405	return ret;
b3b94faa DT	406	}
	407
	408	/**
	409	* gfs2_meta_ra - start readahead on an extent of a file
	410	* @gl: the glock the blocks belong to
	411	* @dblock: the starting disk block
	412	* @extlen: the number of blocks in the extent
	413	*
7276b3b0	414	* returns: the first buffer in the extent
b3b94faa DT	415	*/
b3b94faa DT	416
7276b3b0	417	struct buffer_head gfs2_meta_ra(struct gfs2_glock gl, u64 dblock, u32 extlen)
b3b94faa DT	418	{
b3b94faa DT	419	struct gfs2_sbd *sdp = gl->gl_sbd;
b3b94faa	420	struct buffer_head first_bh, bh;
cd915493	421	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
568f4c96	422	sdp->sd_sb.sb_bsize_shift;
b3b94faa	423
7276b3b0 SW	424	BUG_ON(!extlen);
	425
	426	if (max_ra < 1)
	427	max_ra = 1;
b3b94faa DT	428	if (extlen > max_ra)
	429	extlen = max_ra;
	430
6802e340	431	first_bh = gfs2_getbuf(gl, dblock, CREATE);
b3b94faa DT	432
	433	if (buffer_uptodate(first_bh))
	434	goto out;
7276b3b0	435	if (!buffer_locked(first_bh))
c969f58c	436	ll_rw_block(READ_SYNC \| (1 << BIO_RW_META), 1, &first_bh);
b3b94faa DT	437
	438	dblock++;
	439	extlen--;
	440
	441	while (extlen) {
6802e340	442	bh = gfs2_getbuf(gl, dblock, CREATE);
b3b94faa	443
7276b3b0 SW	444	if (!buffer_uptodate(bh) && !buffer_locked(bh))
	445	ll_rw_block(READA, 1, &bh);
	446	brelse(bh);
b3b94faa DT	447	dblock++;
b3b94faa DT	448	extlen--;
7276b3b0 SW	449	if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
7276b3b0 SW	450	goto out;
b3b94faa DT	451	}
b3b94faa DT	452
7276b3b0	453	wait_on_buffer(first_bh);
a91ea69f	454	out:
7276b3b0	455	return first_bh;
b3b94faa DT	456	}
b3b94faa DT	457