[deliverable/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 "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)
{
	struct buffer_head *bh, *head;
	int nr_underway = 0;
	int write_op = REQ_META |
		(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : 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) {
			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);

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

	return 0;
}

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

/**
 * 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 | REQ_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)) {
		atomic_dec(&sdp->sd_log_pinned);
		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) {
		spin_lock(&sdp->sd_ail_lock);
		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);
		}
		spin_unlock(&sdp->sd_ail_lock);
	}
	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 | REQ_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	struct buffer_head bh, head;
4a0f9a32 SW	38	int nr_underway = 0;
7b6d91da	39	int write_op = REQ_META \|
721a9602	40	(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE);
b3b94faa	41
4a0f9a32 SW	42	BUG_ON(!PageLocked(page));
	43	BUG_ON(!page_has_buffers(page));
	44
	45	head = page_buffers(page);
	46	bh = head;
	47
	48	do {
	49	if (!buffer_mapped(bh))
	50	continue;
	51	/*
	52	* If it's a fully non-blocking write attempt and we cannot
	53	* lock the buffer then redirty the page. Note that this can
	54	* potentially cause a busy-wait loop from pdflush and kswapd
	55	* activity, but those code paths have their own higher-level
	56	* throttling.
	57	*/
1b430bee	58	if (wbc->sync_mode != WB_SYNC_NONE) {
4a0f9a32 SW	59	lock_buffer(bh);
	60	} else if (!trylock_buffer(bh)) {
	61	redirty_page_for_writepage(wbc, page);
	62	continue;
	63	}
	64	if (test_clear_buffer_dirty(bh)) {
	65	mark_buffer_async_write(bh);
	66	} else {
	67	unlock_buffer(bh);
	68	}
	69	} while ((bh = bh->b_this_page) != head);
	70
	71	/*
	72	* The page and its buffers are protected by PageWriteback(), so we can
	73	* drop the bh refcounts early.
	74	*/
	75	BUG_ON(PageWriteback(page));
	76	set_page_writeback(page);
	77
	78	do {
	79	struct buffer_head *next = bh->b_this_page;
	80	if (buffer_async_write(bh)) {
	81	submit_bh(write_op, bh);
	82	nr_underway++;
	83	}
	84	bh = next;
	85	} while (bh != head);
	86	unlock_page(page);
	87
4a0f9a32 SW	88	if (nr_underway == 0)
	89	end_page_writeback(page);
	90
eaefbf96	91	return 0;
b3b94faa DT	92	}
b3b94faa DT	93
009d8518	94	const struct address_space_operations gfs2_meta_aops = {
b3b94faa	95	.writepage = gfs2_aspace_writepage,
4340fe62	96	.releasepage = gfs2_releasepage,
b3b94faa DT	97	};
b3b94faa DT	98
b3b94faa DT	99	/**
	100	* gfs2_meta_sync - Sync all buffers associated with a glock
	101	* @gl: The glock
b3b94faa DT	102	*
	103	*/
	104
7276b3b0	105	void gfs2_meta_sync(struct gfs2_glock *gl)
b3b94faa	106	{
009d8518	107	struct address_space *mapping = gfs2_glock2aspace(gl);
7276b3b0	108	int error;
b3b94faa	109
7276b3b0 SW	110	filemap_fdatawrite(mapping);
7276b3b0 SW	111	error = filemap_fdatawait(mapping);
b3b94faa DT	112
	113	if (error)
	114	gfs2_io_error(gl->gl_sbd);
	115	}
	116
	117	/**
6802e340	118	* gfs2_getbuf - Get a buffer with a given address space
cb4c0313	119	* @gl: the glock
b3b94faa DT	120	* @blkno: the block number (filesystem scope)
	121	* @create: 1 if the buffer should be created
	122	*
	123	* Returns: the buffer
	124	*/
	125
6802e340	126	struct buffer_head gfs2_getbuf(struct gfs2_glock gl, u64 blkno, int create)
b3b94faa	127	{
009d8518	128	struct address_space *mapping = gfs2_glock2aspace(gl);
cb4c0313	129	struct gfs2_sbd *sdp = gl->gl_sbd;
b3b94faa DT	130	struct page *page;
	131	struct buffer_head *bh;
	132	unsigned int shift;
	133	unsigned long index;
	134	unsigned int bufnum;
	135
	136	shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
	137	index = blkno >> shift; /* convert block to page */
	138	bufnum = blkno - (index << shift); /* block buf index within page */
	139
	140	if (create) {
	141	for (;;) {
cb4c0313	142	page = grab_cache_page(mapping, index);
b3b94faa DT	143	if (page)
	144	break;
	145	yield();
	146	}
	147	} else {
cb4c0313	148	page = find_lock_page(mapping, index);
b3b94faa DT	149	if (!page)
	150	return NULL;
	151	}
	152
	153	if (!page_has_buffers(page))
	154	create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
	155
	156	/* Locate header for our buffer within our page */
	157	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
	158	/* Do nothing */;
	159	get_bh(bh);
	160
	161	if (!buffer_mapped(bh))
	162	map_bh(bh, sdp->sd_vfs, blkno);
	163
	164	unlock_page(page);
	165	mark_page_accessed(page);
	166	page_cache_release(page);
	167
	168	return bh;
	169	}
	170
	171	static void meta_prep_new(struct buffer_head *bh)
	172	{
	173	struct gfs2_meta_header mh = (struct gfs2_meta_header )bh->b_data;
	174
	175	lock_buffer(bh);
	176	clear_buffer_dirty(bh);
	177	set_buffer_uptodate(bh);
	178	unlock_buffer(bh);
	179
	180	mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
	181	}
	182
	183	/**
	184	* gfs2_meta_new - Get a block
	185	* @gl: The glock associated with this block
	186	* @blkno: The block number
	187	*
	188	* Returns: The buffer
	189	*/
	190
cd915493	191	struct buffer_head gfs2_meta_new(struct gfs2_glock gl, u64 blkno)
b3b94faa DT	192	{
b3b94faa DT	193	struct buffer_head *bh;
6802e340	194	bh = gfs2_getbuf(gl, blkno, CREATE);
b3b94faa DT	195	meta_prep_new(bh);
	196	return bh;
	197	}
	198
	199	/**
	200	* gfs2_meta_read - Read a block from disk
	201	* @gl: The glock covering the block
	202	* @blkno: The block number
7276b3b0	203	* @flags: flags
b3b94faa DT	204	* @bhp: the place where the buffer is returned (NULL on failure)
	205	*
	206	* Returns: errno
	207	*/
	208
cd915493	209	int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
b3b94faa DT	210	struct buffer_head **bhp)
b3b94faa DT	211	{
c969f58c SW	212	struct gfs2_sbd *sdp = gl->gl_sbd;
	213	struct buffer_head *bh;
	214
	215	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
	216	return -EIO;
	217
	218	*bhp = bh = gfs2_getbuf(gl, blkno, CREATE);
	219
	220	lock_buffer(bh);
	221	if (buffer_uptodate(bh)) {
	222	unlock_buffer(bh);
	223	return 0;
	224	}
	225	bh->b_end_io = end_buffer_read_sync;
	226	get_bh(bh);
7b6d91da	227	submit_bh(READ_SYNC \| REQ_META, bh);
c969f58c SW	228	if (!(flags & DIO_WAIT))
	229	return 0;
	230
	231	wait_on_buffer(bh);
	232	if (unlikely(!buffer_uptodate(bh))) {
	233	struct gfs2_trans *tr = current->journal_info;
	234	if (tr && tr->tr_touched)
	235	gfs2_io_error_bh(sdp, bh);
	236	brelse(bh);
	237	return -EIO;
7276b3b0	238	}
b3b94faa	239
7276b3b0	240	return 0;
b3b94faa DT	241	}
	242
	243	/**
7276b3b0	244	* gfs2_meta_wait - Reread a block from disk
b3b94faa	245	* @sdp: the filesystem
7276b3b0	246	* @bh: The block to wait for
b3b94faa DT	247	*
	248	* Returns: errno
	249	*/
	250
7276b3b0	251	int gfs2_meta_wait(struct gfs2_sbd sdp, struct buffer_head bh)
b3b94faa DT	252	{
	253	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
	254	return -EIO;
	255
7276b3b0	256	wait_on_buffer(bh);
b3b94faa	257
7276b3b0 SW	258	if (!buffer_uptodate(bh)) {
	259	struct gfs2_trans *tr = current->journal_info;
	260	if (tr && tr->tr_touched)
	261	gfs2_io_error_bh(sdp, bh);
	262	return -EIO;
b3b94faa	263	}
7276b3b0 SW	264	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
7276b3b0 SW	265	return -EIO;
b3b94faa DT	266
	267	return 0;
	268	}
	269
	270	/**
586dfdaa	271	* gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
b3b94faa DT	272	* @gl: the glock the buffer belongs to
b3b94faa DT	273	* @bh: The buffer to be attached to
586dfdaa	274	* @meta: Flag to indicate whether its metadata or not
b3b94faa DT	275	*/
b3b94faa DT	276
568f4c96 SW	277	void gfs2_attach_bufdata(struct gfs2_glock gl, struct buffer_head bh,
568f4c96 SW	278	int meta)
b3b94faa DT	279	{
	280	struct gfs2_bufdata *bd;
	281
18ec7d5c SW	282	if (meta)
18ec7d5c SW	283	lock_page(bh->b_page);
b3b94faa	284
5c676f6d	285	if (bh->b_private) {
18ec7d5c SW	286	if (meta)
18ec7d5c SW	287	unlock_page(bh->b_page);
b3b94faa DT	288	return;
	289	}
	290
3e5cd087	291	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS \| __GFP_NOFAIL);
b3b94faa DT	292	bd->bd_bh = bh;
	293	bd->bd_gl = gl;
	294
	295	INIT_LIST_HEAD(&bd->bd_list_tr);
82ffa516	296	if (meta)
586dfdaa	297	lops_init_le(&bd->bd_le, &gfs2_buf_lops);
82ffa516	298	else
586dfdaa	299	lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
5c676f6d	300	bh->b_private = bd;
b3b94faa	301
18ec7d5c SW	302	if (meta)
18ec7d5c SW	303	unlock_page(bh->b_page);
b3b94faa DT	304	}
b3b94faa DT	305
16615be1 SW	306	void gfs2_remove_from_journal(struct buffer_head bh, struct gfs2_trans tr, int meta)
16615be1 SW	307	{
009d8518 SW	308	struct address_space *mapping = bh->b_page->mapping;
009d8518 SW	309	struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
16615be1	310	struct gfs2_bufdata *bd = bh->b_private;
009d8518	311
16615be1	312	if (test_clear_buffer_pinned(bh)) {
5e687eac	313	atomic_dec(&sdp->sd_log_pinned);
16615be1 SW	314	list_del_init(&bd->bd_le.le_list);
	315	if (meta) {
	316	gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
	317	sdp->sd_log_num_buf--;
	318	tr->tr_num_buf_rm++;
	319	} else {
	320	gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
	321	sdp->sd_log_num_databuf--;
	322	tr->tr_num_databuf_rm++;
	323	}
	324	tr->tr_touched = 1;
	325	brelse(bh);
	326	}
	327	if (bd) {
c618e87a	328	spin_lock(&sdp->sd_ail_lock);
16615be1	329	if (bd->bd_ail) {
f91a0d3e	330	gfs2_remove_from_ail(bd);
16615be1 SW	331	bh->b_private = NULL;
	332	bd->bd_bh = NULL;
	333	bd->bd_blkno = bh->b_blocknr;
	334	gfs2_trans_add_revoke(sdp, bd);
	335	}
c618e87a	336	spin_unlock(&sdp->sd_ail_lock);
16615be1 SW	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))
7b6d91da	436	ll_rw_block(READ_SYNC \| REQ_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