fs/gfs2/glops.c - kernel/msm-4.9 - Gitiles

 /*
  * 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/slab.h>
 #include <linux/spinlock.h>
 #include <linux/completion.h>
 #include <linux/buffer_head.h>
 #include <linux/gfs2_ondisk.h>
 #include <linux/lm_interface.h>

 #include "gfs2.h"
 #include "incore.h"
 #include "bmap.h"
 #include "glock.h"
 #include "glops.h"
 #include "inode.h"
 #include "log.h"
 #include "meta_io.h"
 #include "recovery.h"
 #include "rgrp.h"
 #include "util.h"
 #include "trans.h"

 /**
  * ail_empty_gl - remove all buffers for a given lock from the AIL
  * @gl: the glock
  *
  * None of the buffers should be dirty, locked, or pinned.
  */

 static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
 {
 	struct gfs2_sbd *sdp = gl->gl_sbd;
 	unsigned int blocks;
 	struct list_head *head = &gl->gl_ail_list;
 	struct gfs2_bufdata *bd;
 	struct buffer_head *bh;
 	int error;

 	blocks = atomic_read(&gl->gl_ail_count);
 	if (!blocks)
 		return;

 	error = gfs2_trans_begin(sdp, 0, blocks);
 	if (gfs2_assert_withdraw(sdp, !error))
 		return;

 	gfs2_log_lock(sdp);
 	while (!list_empty(head)) {
 		bd = list_entry(head->next, struct gfs2_bufdata,
 				bd_ail_gl_list);
 		bh = bd->bd_bh;
 		gfs2_remove_from_ail(bd);
 		bd->bd_bh = NULL;
 		bh->b_private = NULL;
 		bd->bd_blkno = bh->b_blocknr;
 		gfs2_assert_withdraw(sdp, !buffer_busy(bh));
 		gfs2_trans_add_revoke(sdp, bd);
 	}
 	gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
 	gfs2_log_unlock(sdp);

 	gfs2_trans_end(sdp);
 	gfs2_log_flush(sdp, NULL);
 }

 /**
  * gfs2_pte_inval - Sync and invalidate all PTEs associated with a glock
  * @gl: the glock
  *
  */

 static void gfs2_pte_inval(struct gfs2_glock *gl)
 {
 	struct gfs2_inode *ip;
 	struct inode *inode;

 	ip = gl->gl_object;
 	inode = &ip->i_inode;
 	if (!ip || !S_ISREG(inode->i_mode))
 		return;

 	unmap_shared_mapping_range(inode->i_mapping, 0, 0);
 	if (test_bit(GIF_SW_PAGED, &ip->i_flags))
 		set_bit(GLF_DIRTY, &gl->gl_flags);

 }

 /**
  * meta_go_sync - sync out the metadata for this glock
  * @gl: the glock
  *
  * Called when demoting or unlocking an EX glock.  We must flush
  * to disk all dirty buffers/pages relating to this glock, and must not
  * not return to caller to demote/unlock the glock until I/O is complete.
  */

 static void meta_go_sync(struct gfs2_glock *gl)
 {
 	if (gl->gl_state != LM_ST_EXCLUSIVE)
 		return;

 	if (test_and_clear_bit(GLF_DIRTY, &gl->gl_flags)) {
 		gfs2_log_flush(gl->gl_sbd, gl);
 		gfs2_meta_sync(gl);
 		gfs2_ail_empty_gl(gl);
 	}
 }

 /**
  * meta_go_inval - invalidate the metadata for this glock
  * @gl: the glock
  * @flags:
  *
  */

 static void meta_go_inval(struct gfs2_glock *gl, int flags)
 {
 	if (!(flags & DIO_METADATA))
 		return;

 	gfs2_meta_inval(gl);
 	if (gl->gl_object == GFS2_I(gl->gl_sbd->sd_rindex))
 		gl->gl_sbd->sd_rindex_uptodate = 0;
 	else if (gl->gl_ops == &gfs2_rgrp_glops && gl->gl_object) {
 		struct gfs2_rgrpd *rgd = (struct gfs2_rgrpd *)gl->gl_object;

 		rgd->rd_flags &= ~GFS2_RDF_UPTODATE;
 	}
 }

 /**
  * inode_go_sync - Sync the dirty data and/or metadata for an inode glock
  * @gl: the glock protecting the inode
  *
  */

 static void inode_go_sync(struct gfs2_glock *gl)
 {
 	struct gfs2_inode *ip = gl->gl_object;
 	struct address_space *metamapping = gl->gl_aspace->i_mapping;
 	int error;

 	if (gl->gl_state != LM_ST_UNLOCKED)
 		gfs2_pte_inval(gl);
 	if (gl->gl_state != LM_ST_EXCLUSIVE)
 		return;

 	if (ip && !S_ISREG(ip->i_inode.i_mode))
 		ip = NULL;

 	if (test_bit(GLF_DIRTY, &gl->gl_flags)) {
 		gfs2_log_flush(gl->gl_sbd, gl);
 		filemap_fdatawrite(metamapping);
 		if (ip) {
 			struct address_space *mapping = ip->i_inode.i_mapping;
 			filemap_fdatawrite(mapping);
 			error = filemap_fdatawait(mapping);
 			mapping_set_error(mapping, error);
 		}
 		error = filemap_fdatawait(metamapping);
 		mapping_set_error(metamapping, error);
 		clear_bit(GLF_DIRTY, &gl->gl_flags);
 		gfs2_ail_empty_gl(gl);
 	}
 }

 /**
  * inode_go_xmote_bh - After promoting/demoting a glock
  * @gl: the glock
  *
  */

 static void inode_go_xmote_bh(struct gfs2_glock *gl)
 {
 	struct gfs2_holder *gh = gl->gl_req_gh;
 	struct buffer_head *bh;
 	int error;

 	if (gl->gl_state != LM_ST_UNLOCKED &&
 	    (!gh || !(gh->gh_flags & GL_SKIP))) {
 		error = gfs2_meta_read(gl, gl->gl_name.ln_number, 0, &bh);
 		if (!error)
 			brelse(bh);
 	}
 }

 /**
  * inode_go_inval - prepare a inode glock to be released
  * @gl: the glock
  * @flags:
  *
  */

 static void inode_go_inval(struct gfs2_glock *gl, int flags)
 {
 	struct gfs2_inode *ip = gl->gl_object;
 	int meta = (flags & DIO_METADATA);

 	if (meta) {
 		gfs2_meta_inval(gl);
 		if (ip)
 			set_bit(GIF_INVALID, &ip->i_flags);
 	}

 	if (ip && S_ISREG(ip->i_inode.i_mode))
 		truncate_inode_pages(ip->i_inode.i_mapping, 0);
 }

 /**
  * inode_go_demote_ok - Check to see if it's ok to unlock an inode glock
  * @gl: the glock
  *
  * Returns: 1 if it's ok
  */

 static int inode_go_demote_ok(struct gfs2_glock *gl)
 {
 	struct gfs2_sbd *sdp = gl->gl_sbd;
 	int demote = 0;

 	if (!gl->gl_object && !gl->gl_aspace->i_mapping->nrpages)
 		demote = 1;
 	else if (!sdp->sd_args.ar_localcaching &&
 		 time_after_eq(jiffies, gl->gl_stamp +
 			       gfs2_tune_get(sdp, gt_demote_secs) * HZ))
 		demote = 1;

 	return demote;
 }

 /**
  * inode_go_lock - operation done after an inode lock is locked by a process
  * @gl: the glock
  * @flags:
  *
  * Returns: errno
  */

 static int inode_go_lock(struct gfs2_holder *gh)
 {
 	struct gfs2_glock *gl = gh->gh_gl;
 	struct gfs2_inode *ip = gl->gl_object;
 	int error = 0;

 	if (!ip)
 		return 0;

 	if (test_bit(GIF_INVALID, &ip->i_flags)) {
 		error = gfs2_inode_refresh(ip);
 		if (error)
 			return error;
 	}

 	if ((ip->i_di.di_flags & GFS2_DIF_TRUNC_IN_PROG) &&
 	    (gl->gl_state == LM_ST_EXCLUSIVE) &&
 	    (gh->gh_state == LM_ST_EXCLUSIVE))
 		error = gfs2_truncatei_resume(ip);

 	return error;
 }

 /**
  * rgrp_go_demote_ok - Check to see if it's ok to unlock a RG's glock
  * @gl: the glock
  *
  * Returns: 1 if it's ok
  */

 static int rgrp_go_demote_ok(struct gfs2_glock *gl)
 {
 	return !gl->gl_aspace->i_mapping->nrpages;
 }

 /**
  * rgrp_go_lock - operation done after an rgrp lock is locked by
  *    a first holder on this node.
  * @gl: the glock
  * @flags:
  *
  * Returns: errno
  */

 static int rgrp_go_lock(struct gfs2_holder *gh)
 {
 	return gfs2_rgrp_bh_get(gh->gh_gl->gl_object);
 }

 /**
  * rgrp_go_unlock - operation done before an rgrp lock is unlocked by
  *    a last holder on this node.
  * @gl: the glock
  * @flags:
  *
  */

 static void rgrp_go_unlock(struct gfs2_holder *gh)
 {
 	gfs2_rgrp_bh_put(gh->gh_gl->gl_object);
 }

 /**
  * trans_go_sync - promote/demote the transaction glock
  * @gl: the glock
  * @state: the requested state
  * @flags:
  *
  */

 static void trans_go_sync(struct gfs2_glock *gl)
 {
 	struct gfs2_sbd *sdp = gl->gl_sbd;

 	if (gl->gl_state != LM_ST_UNLOCKED &&
 	    test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
 		gfs2_meta_syncfs(sdp);
 		gfs2_log_shutdown(sdp);
 	}
 }

 /**
  * trans_go_xmote_bh - After promoting/demoting the transaction glock
  * @gl: the glock
  *
  */

 static void trans_go_xmote_bh(struct gfs2_glock *gl)
 {
 	struct gfs2_sbd *sdp = gl->gl_sbd;
 	struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
 	struct gfs2_glock *j_gl = ip->i_gl;
 	struct gfs2_log_header_host head;
 	int error;

 	if (gl->gl_state != LM_ST_UNLOCKED &&
 	    test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
 		j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);

 		error = gfs2_find_jhead(sdp->sd_jdesc, &head);
 		if (error)
 			gfs2_consist(sdp);
 		if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT))
 			gfs2_consist(sdp);

 		/*  Initialize some head of the log stuff  */
 		if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) {
 			sdp->sd_log_sequence = head.lh_sequence + 1;
 			gfs2_log_pointers_init(sdp, head.lh_blkno);
 		}
 	}
 }

 /**
  * quota_go_demote_ok - Check to see if it's ok to unlock a quota glock
  * @gl: the glock
  *
  * Returns: 1 if it's ok
  */

 static int quota_go_demote_ok(struct gfs2_glock *gl)
 {
 	return !atomic_read(&gl->gl_lvb_count);
 }

 const struct gfs2_glock_operations gfs2_meta_glops = {
 	.go_xmote_th = meta_go_sync,
 	.go_type = LM_TYPE_META,
 };

 const struct gfs2_glock_operations gfs2_inode_glops = {
 	.go_xmote_th = inode_go_sync,
 	.go_xmote_bh = inode_go_xmote_bh,
 	.go_inval = inode_go_inval,
 	.go_demote_ok = inode_go_demote_ok,
 	.go_lock = inode_go_lock,
 	.go_type = LM_TYPE_INODE,
 	.go_min_hold_time = HZ / 10,
 };

 const struct gfs2_glock_operations gfs2_rgrp_glops = {
 	.go_xmote_th = meta_go_sync,
 	.go_inval = meta_go_inval,
 	.go_demote_ok = rgrp_go_demote_ok,
 	.go_lock = rgrp_go_lock,
 	.go_unlock = rgrp_go_unlock,
 	.go_type = LM_TYPE_RGRP,
 	.go_min_hold_time = HZ / 10,
 };

 const struct gfs2_glock_operations gfs2_trans_glops = {
 	.go_xmote_th = trans_go_sync,
 	.go_xmote_bh = trans_go_xmote_bh,
 	.go_type = LM_TYPE_NONDISK,
 };

 const struct gfs2_glock_operations gfs2_iopen_glops = {
 	.go_type = LM_TYPE_IOPEN,
 };

 const struct gfs2_glock_operations gfs2_flock_glops = {
 	.go_type = LM_TYPE_FLOCK,
 };

 const struct gfs2_glock_operations gfs2_nondisk_glops = {
 	.go_type = LM_TYPE_NONDISK,
 };

 const struct gfs2_glock_operations gfs2_quota_glops = {
 	.go_demote_ok = quota_go_demote_ok,
 	.go_type = LM_TYPE_QUOTA,
 };

 const struct gfs2_glock_operations gfs2_journal_glops = {
 	.go_type = LM_TYPE_JOURNAL,
 };
	/*
	* 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/slab.h>
	#include <linux/spinlock.h>
	#include <linux/completion.h>
	#include <linux/buffer_head.h>
	#include <linux/gfs2_ondisk.h>
	#include <linux/lm_interface.h>

	#include "gfs2.h"
	#include "incore.h"
	#include "bmap.h"
	#include "glock.h"
	#include "glops.h"
	#include "inode.h"
	#include "log.h"
	#include "meta_io.h"
	#include "recovery.h"
	#include "rgrp.h"
	#include "util.h"
	#include "trans.h"

	/**
	* ail_empty_gl - remove all buffers for a given lock from the AIL
	* @gl: the glock
	*
	* None of the buffers should be dirty, locked, or pinned.
	*/

	static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
	{
	struct gfs2_sbd *sdp = gl->gl_sbd;
	unsigned int blocks;
	struct list_head *head = &gl->gl_ail_list;
	struct gfs2_bufdata *bd;
	struct buffer_head *bh;
	int error;

	blocks = atomic_read(&gl->gl_ail_count);
	if (!blocks)
	return;

	error = gfs2_trans_begin(sdp, 0, blocks);
	if (gfs2_assert_withdraw(sdp, !error))
	return;

	gfs2_log_lock(sdp);
	while (!list_empty(head)) {
	bd = list_entry(head->next, struct gfs2_bufdata,
	bd_ail_gl_list);
	bh = bd->bd_bh;
	gfs2_remove_from_ail(bd);
	bd->bd_bh = NULL;
	bh->b_private = NULL;
	bd->bd_blkno = bh->b_blocknr;
	gfs2_assert_withdraw(sdp, !buffer_busy(bh));
	gfs2_trans_add_revoke(sdp, bd);
	}
	gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
	gfs2_log_unlock(sdp);

	gfs2_trans_end(sdp);
	gfs2_log_flush(sdp, NULL);
	}

	/**
	* gfs2_pte_inval - Sync and invalidate all PTEs associated with a glock
	* @gl: the glock
	*
	*/

	static void gfs2_pte_inval(struct gfs2_glock *gl)
	{
	struct gfs2_inode *ip;
	struct inode *inode;

	ip = gl->gl_object;
	inode = &ip->i_inode;
	if (!ip \|\| !S_ISREG(inode->i_mode))
	return;

	unmap_shared_mapping_range(inode->i_mapping, 0, 0);
	if (test_bit(GIF_SW_PAGED, &ip->i_flags))
	set_bit(GLF_DIRTY, &gl->gl_flags);

	}

	/**
	* meta_go_sync - sync out the metadata for this glock
	* @gl: the glock
	*
	* Called when demoting or unlocking an EX glock. We must flush
	* to disk all dirty buffers/pages relating to this glock, and must not
	* not return to caller to demote/unlock the glock until I/O is complete.
	*/

	static void meta_go_sync(struct gfs2_glock *gl)
	{
	if (gl->gl_state != LM_ST_EXCLUSIVE)
	return;

	if (test_and_clear_bit(GLF_DIRTY, &gl->gl_flags)) {
	gfs2_log_flush(gl->gl_sbd, gl);
	gfs2_meta_sync(gl);
	gfs2_ail_empty_gl(gl);
	}
	}

	/**
	* meta_go_inval - invalidate the metadata for this glock
	* @gl: the glock
	* @flags:
	*
	*/

	static void meta_go_inval(struct gfs2_glock *gl, int flags)
	{
	if (!(flags & DIO_METADATA))
	return;

	gfs2_meta_inval(gl);
	if (gl->gl_object == GFS2_I(gl->gl_sbd->sd_rindex))
	gl->gl_sbd->sd_rindex_uptodate = 0;
	else if (gl->gl_ops == &gfs2_rgrp_glops && gl->gl_object) {
	struct gfs2_rgrpd rgd = (struct gfs2_rgrpd )gl->gl_object;

	rgd->rd_flags &= ~GFS2_RDF_UPTODATE;
	}
	}

	/**
	* inode_go_sync - Sync the dirty data and/or metadata for an inode glock
	* @gl: the glock protecting the inode
	*
	*/

	static void inode_go_sync(struct gfs2_glock *gl)
	{
	struct gfs2_inode *ip = gl->gl_object;
	struct address_space *metamapping = gl->gl_aspace->i_mapping;
	int error;

	if (gl->gl_state != LM_ST_UNLOCKED)
	gfs2_pte_inval(gl);
	if (gl->gl_state != LM_ST_EXCLUSIVE)
	return;

	if (ip && !S_ISREG(ip->i_inode.i_mode))
	ip = NULL;

	if (test_bit(GLF_DIRTY, &gl->gl_flags)) {
	gfs2_log_flush(gl->gl_sbd, gl);
	filemap_fdatawrite(metamapping);
	if (ip) {
	struct address_space *mapping = ip->i_inode.i_mapping;
	filemap_fdatawrite(mapping);
	error = filemap_fdatawait(mapping);
	mapping_set_error(mapping, error);
	}
	error = filemap_fdatawait(metamapping);
	mapping_set_error(metamapping, error);
	clear_bit(GLF_DIRTY, &gl->gl_flags);
	gfs2_ail_empty_gl(gl);
	}
	}

	/**
	* inode_go_xmote_bh - After promoting/demoting a glock
	* @gl: the glock
	*
	*/

	static void inode_go_xmote_bh(struct gfs2_glock *gl)
	{
	struct gfs2_holder *gh = gl->gl_req_gh;
	struct buffer_head *bh;
	int error;

	if (gl->gl_state != LM_ST_UNLOCKED &&
	(!gh \|\| !(gh->gh_flags & GL_SKIP))) {
	error = gfs2_meta_read(gl, gl->gl_name.ln_number, 0, &bh);
	if (!error)
	brelse(bh);
	}
	}

	/**
	* inode_go_inval - prepare a inode glock to be released
	* @gl: the glock
	* @flags:
	*
	*/

	static void inode_go_inval(struct gfs2_glock *gl, int flags)
	{
	struct gfs2_inode *ip = gl->gl_object;
	int meta = (flags & DIO_METADATA);

	if (meta) {
	gfs2_meta_inval(gl);
	if (ip)
	set_bit(GIF_INVALID, &ip->i_flags);
	}

	if (ip && S_ISREG(ip->i_inode.i_mode))
	truncate_inode_pages(ip->i_inode.i_mapping, 0);
	}

	/**
	* inode_go_demote_ok - Check to see if it's ok to unlock an inode glock
	* @gl: the glock
	*
	* Returns: 1 if it's ok
	*/

	static int inode_go_demote_ok(struct gfs2_glock *gl)
	{
	struct gfs2_sbd *sdp = gl->gl_sbd;
	int demote = 0;

	if (!gl->gl_object && !gl->gl_aspace->i_mapping->nrpages)
	demote = 1;
	else if (!sdp->sd_args.ar_localcaching &&
	time_after_eq(jiffies, gl->gl_stamp +
	gfs2_tune_get(sdp, gt_demote_secs) * HZ))
	demote = 1;

	return demote;
	}

	/**
	* inode_go_lock - operation done after an inode lock is locked by a process
	* @gl: the glock
	* @flags:
	*
	* Returns: errno
	*/

	static int inode_go_lock(struct gfs2_holder *gh)
	{
	struct gfs2_glock *gl = gh->gh_gl;
	struct gfs2_inode *ip = gl->gl_object;
	int error = 0;

	if (!ip)
	return 0;

	if (test_bit(GIF_INVALID, &ip->i_flags)) {
	error = gfs2_inode_refresh(ip);
	if (error)
	return error;
	}

	if ((ip->i_di.di_flags & GFS2_DIF_TRUNC_IN_PROG) &&
	(gl->gl_state == LM_ST_EXCLUSIVE) &&
	(gh->gh_state == LM_ST_EXCLUSIVE))
	error = gfs2_truncatei_resume(ip);

	return error;
	}

	/**
	* rgrp_go_demote_ok - Check to see if it's ok to unlock a RG's glock
	* @gl: the glock
	*
	* Returns: 1 if it's ok
	*/

	static int rgrp_go_demote_ok(struct gfs2_glock *gl)
	{
	return !gl->gl_aspace->i_mapping->nrpages;
	}

	/**
	* rgrp_go_lock - operation done after an rgrp lock is locked by
	* a first holder on this node.
	* @gl: the glock
	* @flags:
	*
	* Returns: errno
	*/

	static int rgrp_go_lock(struct gfs2_holder *gh)
	{
	return gfs2_rgrp_bh_get(gh->gh_gl->gl_object);
	}

	/**
	* rgrp_go_unlock - operation done before an rgrp lock is unlocked by
	* a last holder on this node.
	* @gl: the glock
	* @flags:
	*
	*/

	static void rgrp_go_unlock(struct gfs2_holder *gh)
	{
	gfs2_rgrp_bh_put(gh->gh_gl->gl_object);
	}

	/**
	* trans_go_sync - promote/demote the transaction glock
	* @gl: the glock
	* @state: the requested state
	* @flags:
	*
	*/

	static void trans_go_sync(struct gfs2_glock *gl)
	{
	struct gfs2_sbd *sdp = gl->gl_sbd;

	if (gl->gl_state != LM_ST_UNLOCKED &&
	test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
	gfs2_meta_syncfs(sdp);
	gfs2_log_shutdown(sdp);
	}
	}

	/**
	* trans_go_xmote_bh - After promoting/demoting the transaction glock
	* @gl: the glock
	*
	*/

	static void trans_go_xmote_bh(struct gfs2_glock *gl)
	{
	struct gfs2_sbd *sdp = gl->gl_sbd;
	struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
	struct gfs2_glock *j_gl = ip->i_gl;
	struct gfs2_log_header_host head;
	int error;

	if (gl->gl_state != LM_ST_UNLOCKED &&
	test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
	j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);

	error = gfs2_find_jhead(sdp->sd_jdesc, &head);
	if (error)
	gfs2_consist(sdp);
	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT))
	gfs2_consist(sdp);

	/* Initialize some head of the log stuff */
	if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) {
	sdp->sd_log_sequence = head.lh_sequence + 1;
	gfs2_log_pointers_init(sdp, head.lh_blkno);
	}
	}
	}

	/**
	* quota_go_demote_ok - Check to see if it's ok to unlock a quota glock
	* @gl: the glock
	*
	* Returns: 1 if it's ok
	*/

	static int quota_go_demote_ok(struct gfs2_glock *gl)
	{
	return !atomic_read(&gl->gl_lvb_count);
	}

	const struct gfs2_glock_operations gfs2_meta_glops = {
	.go_xmote_th = meta_go_sync,
	.go_type = LM_TYPE_META,
	};

	const struct gfs2_glock_operations gfs2_inode_glops = {
	.go_xmote_th = inode_go_sync,
	.go_xmote_bh = inode_go_xmote_bh,
	.go_inval = inode_go_inval,
	.go_demote_ok = inode_go_demote_ok,
	.go_lock = inode_go_lock,
	.go_type = LM_TYPE_INODE,
	.go_min_hold_time = HZ / 10,
	};

	const struct gfs2_glock_operations gfs2_rgrp_glops = {
	.go_xmote_th = meta_go_sync,
	.go_inval = meta_go_inval,
	.go_demote_ok = rgrp_go_demote_ok,
	.go_lock = rgrp_go_lock,
	.go_unlock = rgrp_go_unlock,
	.go_type = LM_TYPE_RGRP,
	.go_min_hold_time = HZ / 10,
	};

	const struct gfs2_glock_operations gfs2_trans_glops = {
	.go_xmote_th = trans_go_sync,
	.go_xmote_bh = trans_go_xmote_bh,
	.go_type = LM_TYPE_NONDISK,
	};

	const struct gfs2_glock_operations gfs2_iopen_glops = {
	.go_type = LM_TYPE_IOPEN,
	};

	const struct gfs2_glock_operations gfs2_flock_glops = {
	.go_type = LM_TYPE_FLOCK,
	};

	const struct gfs2_glock_operations gfs2_nondisk_glops = {
	.go_type = LM_TYPE_NONDISK,
	};

	const struct gfs2_glock_operations gfs2_quota_glops = {
	.go_demote_ok = quota_go_demote_ok,
	.go_type = LM_TYPE_QUOTA,
	};

	const struct gfs2_glock_operations gfs2_journal_glops = {
	.go_type = LM_TYPE_JOURNAL,
	};