/*
   * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.

   * Copyright (C) 2004-2007 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/bio.h>

  #include <linux/sched.h>
  #include <linux/slab.h>
  #include <linux/spinlock.h>
  #include <linux/completion.h>
  #include <linux/buffer_head.h>

  #include <linux/statfs.h>
  #include <linux/seq_file.h>
  #include <linux/mount.h>
  #include <linux/kthread.h>
  #include <linux/delay.h>

  #include <linux/gfs2_ondisk.h>

  #include <linux/crc32.h>
  #include <linux/time.h>

  #include <linux/wait.h>

  #include <linux/writeback.h>

  #include <linux/backing-dev.h>

  
  #include "gfs2.h"

  #include "incore.h"

  #include "bmap.h"
  #include "dir.h"

  #include "glock.h"
  #include "glops.h"
  #include "inode.h"
  #include "log.h"
  #include "meta_io.h"
  #include "quota.h"
  #include "recovery.h"
  #include "rgrp.h"
  #include "super.h"
  #include "trans.h"

  #include "util.h"

  #include "sys.h"

  #include "xattr.h"

  
  #define args_neq(a1, a2, x) ((a1)->ar_##x != (a2)->ar_##x)
  
  enum {
  	Opt_lockproto,
  	Opt_locktable,
  	Opt_hostdata,
  	Opt_spectator,
  	Opt_ignore_local_fs,
  	Opt_localflocks,
  	Opt_localcaching,
  	Opt_debug,
  	Opt_nodebug,
  	Opt_upgrade,
  	Opt_acl,
  	Opt_noacl,
  	Opt_quota_off,
  	Opt_quota_account,
  	Opt_quota_on,
  	Opt_quota,
  	Opt_noquota,
  	Opt_suiddir,
  	Opt_nosuiddir,
  	Opt_data_writeback,
  	Opt_data_ordered,
  	Opt_meta,
  	Opt_discard,
  	Opt_nodiscard,
  	Opt_commit,

  	Opt_err_withdraw,
  	Opt_err_panic,

  	Opt_statfs_quantum,
  	Opt_statfs_percent,
  	Opt_quota_quantum,

  	Opt_barrier,
  	Opt_nobarrier,

  	Opt_error,
  };
  
  static const match_table_t tokens = {
  	{Opt_lockproto, "lockproto=%s"},
  	{Opt_locktable, "locktable=%s"},
  	{Opt_hostdata, "hostdata=%s"},
  	{Opt_spectator, "spectator"},

  	{Opt_spectator, "norecovery"},

  	{Opt_ignore_local_fs, "ignore_local_fs"},
  	{Opt_localflocks, "localflocks"},
  	{Opt_localcaching, "localcaching"},
  	{Opt_debug, "debug"},
  	{Opt_nodebug, "nodebug"},
  	{Opt_upgrade, "upgrade"},
  	{Opt_acl, "acl"},
  	{Opt_noacl, "noacl"},
  	{Opt_quota_off, "quota=off"},
  	{Opt_quota_account, "quota=account"},
  	{Opt_quota_on, "quota=on"},
  	{Opt_quota, "quota"},
  	{Opt_noquota, "noquota"},
  	{Opt_suiddir, "suiddir"},
  	{Opt_nosuiddir, "nosuiddir"},
  	{Opt_data_writeback, "data=writeback"},
  	{Opt_data_ordered, "data=ordered"},
  	{Opt_meta, "meta"},
  	{Opt_discard, "discard"},
  	{Opt_nodiscard, "nodiscard"},
  	{Opt_commit, "commit=%d"},

  	{Opt_err_withdraw, "errors=withdraw"},
  	{Opt_err_panic, "errors=panic"},

  	{Opt_statfs_quantum, "statfs_quantum=%d"},
  	{Opt_statfs_percent, "statfs_percent=%d"},
  	{Opt_quota_quantum, "quota_quantum=%d"},

  	{Opt_barrier, "barrier"},
  	{Opt_nobarrier, "nobarrier"},

  	{Opt_error, NULL}
  };
  
  /**
   * gfs2_mount_args - Parse mount options

   * @args: The structure into which the parsed options will be written
   * @options: The options to parse

   *
   * Return: errno
   */

  int gfs2_mount_args(struct gfs2_args *args, char *options)

  {
  	char *o;
  	int token;
  	substring_t tmp[MAX_OPT_ARGS];
  	int rv;
  
  	/* Split the options into tokens with the "," character and
  	   process them */
  
  	while (1) {
  		o = strsep(&options, ",");
  		if (o == NULL)
  			break;
  		if (*o == '\0')
  			continue;
  
  		token = match_token(o, tokens, tmp);
  		switch (token) {
  		case Opt_lockproto:
  			match_strlcpy(args->ar_lockproto, &tmp[0],
  				      GFS2_LOCKNAME_LEN);
  			break;
  		case Opt_locktable:
  			match_strlcpy(args->ar_locktable, &tmp[0],
  				      GFS2_LOCKNAME_LEN);
  			break;
  		case Opt_hostdata:
  			match_strlcpy(args->ar_hostdata, &tmp[0],
  				      GFS2_LOCKNAME_LEN);
  			break;
  		case Opt_spectator:
  			args->ar_spectator = 1;
  			break;
  		case Opt_ignore_local_fs:

  			/* Retained for backwards compat only */

  			break;
  		case Opt_localflocks:
  			args->ar_localflocks = 1;
  			break;
  		case Opt_localcaching:

  			/* Retained for backwards compat only */

  			break;
  		case Opt_debug:

  			if (args->ar_errors == GFS2_ERRORS_PANIC) {

  				printk(KERN_WARNING "GFS2: -o debug and -o errors=panic "

  				       "are mutually exclusive.
  ");
  				return -EINVAL;
  			}

  			args->ar_debug = 1;
  			break;
  		case Opt_nodebug:
  			args->ar_debug = 0;
  			break;
  		case Opt_upgrade:

  			/* Retained for backwards compat only */

  			break;
  		case Opt_acl:
  			args->ar_posix_acl = 1;
  			break;
  		case Opt_noacl:
  			args->ar_posix_acl = 0;
  			break;
  		case Opt_quota_off:
  		case Opt_noquota:
  			args->ar_quota = GFS2_QUOTA_OFF;
  			break;
  		case Opt_quota_account:
  			args->ar_quota = GFS2_QUOTA_ACCOUNT;
  			break;
  		case Opt_quota_on:
  		case Opt_quota:
  			args->ar_quota = GFS2_QUOTA_ON;
  			break;
  		case Opt_suiddir:
  			args->ar_suiddir = 1;
  			break;
  		case Opt_nosuiddir:
  			args->ar_suiddir = 0;
  			break;
  		case Opt_data_writeback:
  			args->ar_data = GFS2_DATA_WRITEBACK;
  			break;
  		case Opt_data_ordered:
  			args->ar_data = GFS2_DATA_ORDERED;
  			break;
  		case Opt_meta:
  			args->ar_meta = 1;
  			break;
  		case Opt_discard:
  			args->ar_discard = 1;
  			break;
  		case Opt_nodiscard:
  			args->ar_discard = 0;
  			break;
  		case Opt_commit:
  			rv = match_int(&tmp[0], &args->ar_commit);
  			if (rv || args->ar_commit <= 0) {

  				printk(KERN_WARNING "GFS2: commit mount option requires a positive numeric argument
  ");

  				return rv ? rv : -EINVAL;
  			}
  			break;

  		case Opt_statfs_quantum:
  			rv = match_int(&tmp[0], &args->ar_statfs_quantum);
  			if (rv || args->ar_statfs_quantum < 0) {
  				printk(KERN_WARNING "GFS2: statfs_quantum mount option requires a non-negative numeric argument
  ");
  				return rv ? rv : -EINVAL;
  			}
  			break;
  		case Opt_quota_quantum:
  			rv = match_int(&tmp[0], &args->ar_quota_quantum);
  			if (rv || args->ar_quota_quantum <= 0) {
  				printk(KERN_WARNING "GFS2: quota_quantum mount option requires a positive numeric argument
  ");
  				return rv ? rv : -EINVAL;
  			}
  			break;
  		case Opt_statfs_percent:
  			rv = match_int(&tmp[0], &args->ar_statfs_percent);
  			if (rv || args->ar_statfs_percent < 0 ||
  			    args->ar_statfs_percent > 100) {
  				printk(KERN_WARNING "statfs_percent mount option requires a numeric argument between 0 and 100
  ");
  				return rv ? rv : -EINVAL;
  			}
  			break;

  		case Opt_err_withdraw:
  			args->ar_errors = GFS2_ERRORS_WITHDRAW;
  			break;
  		case Opt_err_panic:
  			if (args->ar_debug) {

  				printk(KERN_WARNING "GFS2: -o debug and -o errors=panic "

  					"are mutually exclusive.
  ");
  				return -EINVAL;
  			}
  			args->ar_errors = GFS2_ERRORS_PANIC;
  			break;

  		case Opt_barrier:
  			args->ar_nobarrier = 0;
  			break;
  		case Opt_nobarrier:
  			args->ar_nobarrier = 1;
  			break;

  		case Opt_error:
  		default:

  			printk(KERN_WARNING "GFS2: invalid mount option: %s
  ", o);

  			return -EINVAL;
  		}
  	}
  
  	return 0;
  }

  /**
   * gfs2_jindex_free - Clear all the journal index information
   * @sdp: The GFS2 superblock
   *
   */
  
  void gfs2_jindex_free(struct gfs2_sbd *sdp)
  {
  	struct list_head list, *head;
  	struct gfs2_jdesc *jd;
  	struct gfs2_journal_extent *jext;
  
  	spin_lock(&sdp->sd_jindex_spin);
  	list_add(&list, &sdp->sd_jindex_list);
  	list_del_init(&sdp->sd_jindex_list);
  	sdp->sd_journals = 0;
  	spin_unlock(&sdp->sd_jindex_spin);
  
  	while (!list_empty(&list)) {
  		jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
  		head = &jd->extent_list;
  		while (!list_empty(head)) {
  			jext = list_entry(head->next,
  					  struct gfs2_journal_extent,
  					  extent_list);
  			list_del(&jext->extent_list);
  			kfree(jext);
  		}
  		list_del(&jd->jd_list);
  		iput(jd->jd_inode);
  		kfree(jd);
  	}
  }

  static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
  {
  	struct gfs2_jdesc *jd;
  	int found = 0;
  
  	list_for_each_entry(jd, head, jd_list) {
  		if (jd->jd_jid == jid) {
  			found = 1;
  			break;
  		}
  	}
  
  	if (!found)
  		jd = NULL;
  
  	return jd;
  }
  
  struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
  {
  	struct gfs2_jdesc *jd;
  
  	spin_lock(&sdp->sd_jindex_spin);
  	jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
  	spin_unlock(&sdp->sd_jindex_spin);
  
  	return jd;
  }

  int gfs2_jdesc_check(struct gfs2_jdesc *jd)
  {

  	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
  	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);

  	u64 size = i_size_read(jd->jd_inode);

  	if (gfs2_check_internal_file_size(jd->jd_inode, 8 << 20, 1 << 30))

  		return -EIO;

  	jd->jd_blocks = size >> sdp->sd_sb.sb_bsize_shift;
  
  	if (gfs2_write_alloc_required(ip, 0, size)) {

  		gfs2_consist_inode(ip);

  		return -EIO;

  	}

  	return 0;

  }

  /**
   * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
   * @sdp: the filesystem
   *
   * Returns: errno
   */
  
  int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
  {

  	struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);

  	struct gfs2_glock *j_gl = ip->i_gl;

  	struct gfs2_holder t_gh;

  	struct gfs2_log_header_host head;

  	int error;

  	error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &t_gh);

  	if (error)
  		return error;

  	j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);

  
  	error = gfs2_find_jhead(sdp->sd_jdesc, &head);
  	if (error)
  		goto fail;
  
  	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
  		gfs2_consist(sdp);
  		error = -EIO;
  		goto fail;
  	}
  
  	/*  Initialize some head of the log stuff  */
  	sdp->sd_log_sequence = head.lh_sequence + 1;
  	gfs2_log_pointers_init(sdp, head.lh_blkno);

  	error = gfs2_quota_init(sdp);
  	if (error)

  		goto fail;

  
  	set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
  
  	gfs2_glock_dq_uninit(&t_gh);
  
  	return 0;

  fail:

  	t_gh.gh_flags |= GL_NOCACHE;
  	gfs2_glock_dq_uninit(&t_gh);
  
  	return error;
  }

  void gfs2_statfs_change_in(struct gfs2_statfs_change_host *sc, const void *buf)

  {
  	const struct gfs2_statfs_change *str = buf;
  
  	sc->sc_total = be64_to_cpu(str->sc_total);
  	sc->sc_free = be64_to_cpu(str->sc_free);
  	sc->sc_dinodes = be64_to_cpu(str->sc_dinodes);
  }
  
  static void gfs2_statfs_change_out(const struct gfs2_statfs_change_host *sc, void *buf)
  {
  	struct gfs2_statfs_change *str = buf;
  
  	str->sc_total = cpu_to_be64(sc->sc_total);
  	str->sc_free = cpu_to_be64(sc->sc_free);
  	str->sc_dinodes = cpu_to_be64(sc->sc_dinodes);
  }

  int gfs2_statfs_init(struct gfs2_sbd *sdp)
  {

  	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);

  	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;

  	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);

  	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;

  	struct buffer_head *m_bh, *l_bh;
  	struct gfs2_holder gh;
  	int error;
  
  	error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
  				   &gh);
  	if (error)
  		return error;
  
  	error = gfs2_meta_inode_buffer(m_ip, &m_bh);
  	if (error)
  		goto out;
  
  	if (sdp->sd_args.ar_spectator) {
  		spin_lock(&sdp->sd_statfs_spin);
  		gfs2_statfs_change_in(m_sc, m_bh->b_data +
  				      sizeof(struct gfs2_dinode));
  		spin_unlock(&sdp->sd_statfs_spin);
  	} else {
  		error = gfs2_meta_inode_buffer(l_ip, &l_bh);
  		if (error)
  			goto out_m_bh;
  
  		spin_lock(&sdp->sd_statfs_spin);
  		gfs2_statfs_change_in(m_sc, m_bh->b_data +
  				      sizeof(struct gfs2_dinode));
  		gfs2_statfs_change_in(l_sc, l_bh->b_data +
  				      sizeof(struct gfs2_dinode));
  		spin_unlock(&sdp->sd_statfs_spin);
  
  		brelse(l_bh);
  	}

  out_m_bh:

  	brelse(m_bh);

  out:

  	gfs2_glock_dq_uninit(&gh);

  	return 0;
  }

  void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
  			s64 dinodes)

  {

  	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);

  	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;

  	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;

  	struct buffer_head *l_bh;

  	s64 x, y;
  	int need_sync = 0;

  	int error;
  
  	error = gfs2_meta_inode_buffer(l_ip, &l_bh);
  	if (error)
  		return;

  	gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);

  
  	spin_lock(&sdp->sd_statfs_spin);
  	l_sc->sc_total += total;
  	l_sc->sc_free += free;
  	l_sc->sc_dinodes += dinodes;

  	gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));

  	if (sdp->sd_args.ar_statfs_percent) {
  		x = 100 * l_sc->sc_free;
  		y = m_sc->sc_free * sdp->sd_args.ar_statfs_percent;
  		if (x >= y || x <= -y)
  			need_sync = 1;
  	}

  	spin_unlock(&sdp->sd_statfs_spin);
  
  	brelse(l_bh);

  	if (need_sync)

  		gfs2_wake_up_statfs(sdp);

  }

  void update_statfs(struct gfs2_sbd *sdp, struct buffer_head *m_bh,
  		   struct buffer_head *l_bh)
  {
  	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
  	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
  	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
  	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
  
  	gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
  
  	spin_lock(&sdp->sd_statfs_spin);
  	m_sc->sc_total += l_sc->sc_total;
  	m_sc->sc_free += l_sc->sc_free;
  	m_sc->sc_dinodes += l_sc->sc_dinodes;
  	memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
  	memset(l_bh->b_data + sizeof(struct gfs2_dinode),
  	       0, sizeof(struct gfs2_statfs_change));
  	spin_unlock(&sdp->sd_statfs_spin);
  
  	gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
  	gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
  }

  int gfs2_statfs_sync(struct super_block *sb, int type)

  {

  	struct gfs2_sbd *sdp = sb->s_fs_info;

  	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
  	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);

  	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
  	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;

  	struct gfs2_holder gh;
  	struct buffer_head *m_bh, *l_bh;
  	int error;
  
  	error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
  				   &gh);
  	if (error)
  		return error;
  
  	error = gfs2_meta_inode_buffer(m_ip, &m_bh);
  	if (error)
  		goto out;
  
  	spin_lock(&sdp->sd_statfs_spin);
  	gfs2_statfs_change_in(m_sc, m_bh->b_data +

  			      sizeof(struct gfs2_dinode));

  	if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
  		spin_unlock(&sdp->sd_statfs_spin);
  		goto out_bh;
  	}
  	spin_unlock(&sdp->sd_statfs_spin);
  
  	error = gfs2_meta_inode_buffer(l_ip, &l_bh);
  	if (error)
  		goto out_bh;
  
  	error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
  	if (error)
  		goto out_bh2;

  	update_statfs(sdp, m_bh, l_bh);

  	sdp->sd_statfs_force_sync = 0;

  
  	gfs2_trans_end(sdp);

  out_bh2:

  	brelse(l_bh);

  out_bh:

  	brelse(m_bh);

  out:

  	gfs2_glock_dq_uninit(&gh);

  	return error;
  }

  struct lfcc {
  	struct list_head list;
  	struct gfs2_holder gh;
  };
  
  /**
   * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
   *                            journals are clean
   * @sdp: the file system
   * @state: the state to put the transaction lock into
   * @t_gh: the hold on the transaction lock
   *
   * Returns: errno
   */

  static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp,
  				    struct gfs2_holder *t_gh)

  {

  	struct gfs2_inode *ip;

  	struct gfs2_jdesc *jd;
  	struct lfcc *lfcc;
  	LIST_HEAD(list);

  	struct gfs2_log_header_host lh;

  	int error;

  	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
  		lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
  		if (!lfcc) {
  			error = -ENOMEM;
  			goto out;
  		}

  		ip = GFS2_I(jd->jd_inode);
  		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);

  		if (error) {
  			kfree(lfcc);
  			goto out;
  		}
  		list_add(&lfcc->list, &list);
  	}
  
  	error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED,

  				   GL_NOCACHE, t_gh);

  
  	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
  		error = gfs2_jdesc_check(jd);
  		if (error)
  			break;
  		error = gfs2_find_jhead(jd, &lh);
  		if (error)
  			break;
  		if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
  			error = -EBUSY;
  			break;
  		}
  	}
  
  	if (error)
  		gfs2_glock_dq_uninit(t_gh);

  out:

  	while (!list_empty(&list)) {
  		lfcc = list_entry(list.next, struct lfcc, list);
  		list_del(&lfcc->list);
  		gfs2_glock_dq_uninit(&lfcc->gh);
  		kfree(lfcc);
  	}

  	return error;
  }
  
  /**
   * gfs2_freeze_fs - freezes the file system
   * @sdp: the file system
   *
   * This function flushes data and meta data for all machines by

   * acquiring the transaction log exclusively.  All journals are

   * ensured to be in a clean state as well.
   *
   * Returns: errno
   */
  
  int gfs2_freeze_fs(struct gfs2_sbd *sdp)
  {
  	int error = 0;

  	mutex_lock(&sdp->sd_freeze_lock);

  
  	if (!sdp->sd_freeze_count++) {
  		error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
  		if (error)
  			sdp->sd_freeze_count--;
  	}

  	mutex_unlock(&sdp->sd_freeze_lock);

  
  	return error;
  }
  
  /**
   * gfs2_unfreeze_fs - unfreezes the file system
   * @sdp: the file system
   *
   * This function allows the file system to proceed by unlocking
   * the exclusively held transaction lock.  Other GFS2 nodes are
   * now free to acquire the lock shared and go on with their lives.
   *
   */
  
  void gfs2_unfreeze_fs(struct gfs2_sbd *sdp)
  {

  	mutex_lock(&sdp->sd_freeze_lock);

  
  	if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
  		gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);

  	mutex_unlock(&sdp->sd_freeze_lock);

  }

  void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
  {
  	struct gfs2_dinode *str = buf;
  
  	str->di_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
  	str->di_header.mh_type = cpu_to_be32(GFS2_METATYPE_DI);
  	str->di_header.mh_format = cpu_to_be32(GFS2_FORMAT_DI);
  	str->di_num.no_addr = cpu_to_be64(ip->i_no_addr);
  	str->di_num.no_formal_ino = cpu_to_be64(ip->i_no_formal_ino);
  	str->di_mode = cpu_to_be32(ip->i_inode.i_mode);
  	str->di_uid = cpu_to_be32(ip->i_inode.i_uid);
  	str->di_gid = cpu_to_be32(ip->i_inode.i_gid);
  	str->di_nlink = cpu_to_be32(ip->i_inode.i_nlink);
  	str->di_size = cpu_to_be64(i_size_read(&ip->i_inode));
  	str->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode));
  	str->di_atime = cpu_to_be64(ip->i_inode.i_atime.tv_sec);
  	str->di_mtime = cpu_to_be64(ip->i_inode.i_mtime.tv_sec);
  	str->di_ctime = cpu_to_be64(ip->i_inode.i_ctime.tv_sec);
  
  	str->di_goal_meta = cpu_to_be64(ip->i_goal);
  	str->di_goal_data = cpu_to_be64(ip->i_goal);
  	str->di_generation = cpu_to_be64(ip->i_generation);
  
  	str->di_flags = cpu_to_be32(ip->i_diskflags);
  	str->di_height = cpu_to_be16(ip->i_height);
  	str->di_payload_format = cpu_to_be32(S_ISDIR(ip->i_inode.i_mode) &&
  					     !(ip->i_diskflags & GFS2_DIF_EXHASH) ?
  					     GFS2_FORMAT_DE : 0);
  	str->di_depth = cpu_to_be16(ip->i_depth);
  	str->di_entries = cpu_to_be32(ip->i_entries);
  
  	str->di_eattr = cpu_to_be64(ip->i_eattr);
  	str->di_atime_nsec = cpu_to_be32(ip->i_inode.i_atime.tv_nsec);
  	str->di_mtime_nsec = cpu_to_be32(ip->i_inode.i_mtime.tv_nsec);
  	str->di_ctime_nsec = cpu_to_be32(ip->i_inode.i_ctime.tv_nsec);
  }

  
  /**
   * gfs2_write_inode - Make sure the inode is stable on the disk
   * @inode: The inode

   * @wbc: The writeback control structure

   *
   * Returns: errno
   */

  static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc)

  {
  	struct gfs2_inode *ip = GFS2_I(inode);
  	struct gfs2_sbd *sdp = GFS2_SB(inode);

  	struct address_space *metamapping = gfs2_glock2aspace(ip->i_gl);

  	struct backing_dev_info *bdi = metamapping->backing_dev_info;

  	int ret = 0;

  	if (wbc->sync_mode == WB_SYNC_ALL)

  		gfs2_log_flush(GFS2_SB(inode), ip->i_gl);

  	if (bdi->dirty_exceeded)
  		gfs2_ail1_flush(sdp, wbc);

  	else
  		filemap_fdatawrite(metamapping);

  	if (wbc->sync_mode == WB_SYNC_ALL)

  		ret = filemap_fdatawait(metamapping);
  	if (ret)
  		mark_inode_dirty_sync(inode);

  	return ret;
  }
  
  /**

   * gfs2_dirty_inode - check for atime updates
   * @inode: The inode in question
   * @flags: The type of dirty
   *
   * Unfortunately it can be called under any combination of inode
   * glock and transaction lock, so we have to check carefully.
   *
   * At the moment this deals only with atime - it should be possible
   * to expand that role in future, once a review of the locking has
   * been carried out.
   */
  
  static void gfs2_dirty_inode(struct inode *inode, int flags)
  {
  	struct gfs2_inode *ip = GFS2_I(inode);
  	struct gfs2_sbd *sdp = GFS2_SB(inode);
  	struct buffer_head *bh;
  	struct gfs2_holder gh;
  	int need_unlock = 0;
  	int need_endtrans = 0;
  	int ret;
  
  	if (!(flags & (I_DIRTY_DATASYNC|I_DIRTY_SYNC)))
  		return;
  
  	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
  		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
  		if (ret) {
  			fs_err(sdp, "dirty_inode: glock %d
  ", ret);
  			return;
  		}
  		need_unlock = 1;
  	}
  
  	if (current->journal_info == NULL) {
  		ret = gfs2_trans_begin(sdp, RES_DINODE, 0);
  		if (ret) {
  			fs_err(sdp, "dirty_inode: gfs2_trans_begin %d
  ", ret);
  			goto out;
  		}
  		need_endtrans = 1;
  	}
  
  	ret = gfs2_meta_inode_buffer(ip, &bh);
  	if (ret == 0) {
  		gfs2_trans_add_bh(ip->i_gl, bh, 1);
  		gfs2_dinode_out(ip, bh->b_data);
  		brelse(bh);
  	}
  
  	if (need_endtrans)
  		gfs2_trans_end(sdp);
  out:
  	if (need_unlock)
  		gfs2_glock_dq_uninit(&gh);
  }
  
  /**

   * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
   * @sdp: the filesystem
   *
   * Returns: errno
   */
  
  static int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
  {
  	struct gfs2_holder t_gh;
  	int error;

  	flush_workqueue(gfs2_delete_workqueue);

  	gfs2_quota_sync(sdp->sd_vfs, 0, 1);

  	gfs2_statfs_sync(sdp->sd_vfs, 0);

  
  	error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, GL_NOCACHE,
  				   &t_gh);
  	if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
  		return error;
  
  	gfs2_meta_syncfs(sdp);
  	gfs2_log_shutdown(sdp);
  
  	clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
  
  	if (t_gh.gh_gl)
  		gfs2_glock_dq_uninit(&t_gh);
  
  	gfs2_quota_cleanup(sdp);
  
  	return error;
  }
  
  static int gfs2_umount_recovery_wait(void *word)
  {
  	schedule();
  	return 0;
  }
  
  /**
   * gfs2_put_super - Unmount the filesystem
   * @sb: The VFS superblock
   *
   */
  
  static void gfs2_put_super(struct super_block *sb)
  {
  	struct gfs2_sbd *sdp = sb->s_fs_info;
  	int error;
  	struct gfs2_jdesc *jd;
  
  	/*  Unfreeze the filesystem, if we need to  */
  
  	mutex_lock(&sdp->sd_freeze_lock);
  	if (sdp->sd_freeze_count)
  		gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
  	mutex_unlock(&sdp->sd_freeze_lock);
  
  	/* No more recovery requests */
  	set_bit(SDF_NORECOVERY, &sdp->sd_flags);
  	smp_mb();
  
  	/* Wait on outstanding recovery */
  restart:
  	spin_lock(&sdp->sd_jindex_spin);
  	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
  		if (!test_bit(JDF_RECOVERY, &jd->jd_flags))
  			continue;
  		spin_unlock(&sdp->sd_jindex_spin);
  		wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
  			    gfs2_umount_recovery_wait, TASK_UNINTERRUPTIBLE);
  		goto restart;
  	}
  	spin_unlock(&sdp->sd_jindex_spin);
  
  	kthread_stop(sdp->sd_quotad_process);
  	kthread_stop(sdp->sd_logd_process);
  
  	if (!(sb->s_flags & MS_RDONLY)) {
  		error = gfs2_make_fs_ro(sdp);
  		if (error)
  			gfs2_io_error(sdp);
  	}
  	/*  At this point, we're through modifying the disk  */
  
  	/*  Release stuff  */
  
  	iput(sdp->sd_jindex);

  	iput(sdp->sd_statfs_inode);
  	iput(sdp->sd_rindex);
  	iput(sdp->sd_quota_inode);
  
  	gfs2_glock_put(sdp->sd_rename_gl);
  	gfs2_glock_put(sdp->sd_trans_gl);
  
  	if (!sdp->sd_args.ar_spectator) {
  		gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
  		gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);

  		gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
  		gfs2_glock_dq_uninit(&sdp->sd_qc_gh);

  		iput(sdp->sd_sc_inode);
  		iput(sdp->sd_qc_inode);
  	}
  
  	gfs2_glock_dq_uninit(&sdp->sd_live_gh);
  	gfs2_clear_rgrpd(sdp);
  	gfs2_jindex_free(sdp);
  	/*  Take apart glock structures and buffer lists  */
  	gfs2_gl_hash_clear(sdp);
  	/*  Unmount the locking protocol  */
  	gfs2_lm_unmount(sdp);
  
  	/*  At this point, we're through participating in the lockspace  */
  	gfs2_sys_fs_del(sdp);
  }
  
  /**

   * gfs2_sync_fs - sync the filesystem
   * @sb: the superblock
   *
   * Flushes the log to disk.
   */
  
  static int gfs2_sync_fs(struct super_block *sb, int wait)
  {

  	struct gfs2_sbd *sdp = sb->s_fs_info;
  	if (wait && sdp)
  		gfs2_log_flush(sdp, NULL);

  	return 0;
  }
  
  /**
   * gfs2_freeze - prevent further writes to the filesystem
   * @sb: the VFS structure for the filesystem
   *
   */
  
  static int gfs2_freeze(struct super_block *sb)
  {
  	struct gfs2_sbd *sdp = sb->s_fs_info;
  	int error;
  
  	if (test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
  		return -EINVAL;
  
  	for (;;) {
  		error = gfs2_freeze_fs(sdp);
  		if (!error)
  			break;
  
  		switch (error) {
  		case -EBUSY:
  			fs_err(sdp, "waiting for recovery before freeze
  ");
  			break;
  
  		default:
  			fs_err(sdp, "error freezing FS: %d
  ", error);
  			break;
  		}
  
  		fs_err(sdp, "retrying...
  ");
  		msleep(1000);
  	}
  	return 0;
  }
  
  /**
   * gfs2_unfreeze - reallow writes to the filesystem
   * @sb: the VFS structure for the filesystem
   *
   */
  
  static int gfs2_unfreeze(struct super_block *sb)
  {
  	gfs2_unfreeze_fs(sb->s_fs_info);
  	return 0;
  }
  
  /**
   * statfs_fill - fill in the sg for a given RG
   * @rgd: the RG
   * @sc: the sc structure
   *
   * Returns: 0 on success, -ESTALE if the LVB is invalid
   */
  
  static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
  			    struct gfs2_statfs_change_host *sc)
  {
  	gfs2_rgrp_verify(rgd);
  	sc->sc_total += rgd->rd_data;
  	sc->sc_free += rgd->rd_free;
  	sc->sc_dinodes += rgd->rd_dinodes;
  	return 0;
  }
  
  /**
   * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
   * @sdp: the filesystem
   * @sc: the sc info that will be returned
   *
   * Any error (other than a signal) will cause this routine to fall back
   * to the synchronous version.
   *
   * FIXME: This really shouldn't busy wait like this.
   *
   * Returns: errno
   */
  
  static int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
  {

  	struct gfs2_rgrpd *rgd_next;
  	struct gfs2_holder *gha, *gh;
  	unsigned int slots = 64;
  	unsigned int x;
  	int done;
  	int error = 0, err;
  
  	memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
  	gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
  	if (!gha)
  		return -ENOMEM;

  	rgd_next = gfs2_rgrpd_get_first(sdp);
  
  	for (;;) {
  		done = 1;
  
  		for (x = 0; x < slots; x++) {
  			gh = gha + x;
  
  			if (gh->gh_gl && gfs2_glock_poll(gh)) {
  				err = gfs2_glock_wait(gh);
  				if (err) {
  					gfs2_holder_uninit(gh);
  					error = err;
  				} else {
  					if (!error)
  						error = statfs_slow_fill(
  							gh->gh_gl->gl_object, sc);
  					gfs2_glock_dq_uninit(gh);
  				}
  			}
  
  			if (gh->gh_gl)
  				done = 0;
  			else if (rgd_next && !error) {
  				error = gfs2_glock_nq_init(rgd_next->rd_gl,
  							   LM_ST_SHARED,
  							   GL_ASYNC,
  							   gh);
  				rgd_next = gfs2_rgrpd_get_next(rgd_next);
  				done = 0;
  			}
  
  			if (signal_pending(current))
  				error = -ERESTARTSYS;
  		}
  
  		if (done)
  			break;
  
  		yield();
  	}

  	kfree(gha);
  	return error;
  }
  
  /**
   * gfs2_statfs_i - Do a statfs
   * @sdp: the filesystem
   * @sg: the sg structure
   *
   * Returns: errno
   */
  
  static int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
  {
  	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
  	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
  
  	spin_lock(&sdp->sd_statfs_spin);
  
  	*sc = *m_sc;
  	sc->sc_total += l_sc->sc_total;
  	sc->sc_free += l_sc->sc_free;
  	sc->sc_dinodes += l_sc->sc_dinodes;
  
  	spin_unlock(&sdp->sd_statfs_spin);
  
  	if (sc->sc_free < 0)
  		sc->sc_free = 0;
  	if (sc->sc_free > sc->sc_total)
  		sc->sc_free = sc->sc_total;
  	if (sc->sc_dinodes < 0)
  		sc->sc_dinodes = 0;
  
  	return 0;
  }
  
  /**
   * gfs2_statfs - Gather and return stats about the filesystem
   * @sb: The superblock
   * @statfsbuf: The buffer
   *
   * Returns: 0 on success or error code
   */
  
  static int gfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
  {
  	struct super_block *sb = dentry->d_inode->i_sb;
  	struct gfs2_sbd *sdp = sb->s_fs_info;
  	struct gfs2_statfs_change_host sc;
  	int error;

  	error = gfs2_rindex_update(sdp);
  	if (error)
  		return error;

  	if (gfs2_tune_get(sdp, gt_statfs_slow))
  		error = gfs2_statfs_slow(sdp, &sc);
  	else
  		error = gfs2_statfs_i(sdp, &sc);
  
  	if (error)
  		return error;
  
  	buf->f_type = GFS2_MAGIC;
  	buf->f_bsize = sdp->sd_sb.sb_bsize;
  	buf->f_blocks = sc.sc_total;
  	buf->f_bfree = sc.sc_free;
  	buf->f_bavail = sc.sc_free;
  	buf->f_files = sc.sc_dinodes + sc.sc_free;
  	buf->f_ffree = sc.sc_free;
  	buf->f_namelen = GFS2_FNAMESIZE;
  
  	return 0;
  }
  
  /**
   * gfs2_remount_fs - called when the FS is remounted
   * @sb:  the filesystem
   * @flags:  the remount flags
   * @data:  extra data passed in (not used right now)
   *
   * Returns: errno
   */
  
  static int gfs2_remount_fs(struct super_block *sb, int *flags, char *data)
  {
  	struct gfs2_sbd *sdp = sb->s_fs_info;
  	struct gfs2_args args = sdp->sd_args; /* Default to current settings */
  	struct gfs2_tune *gt = &sdp->sd_tune;
  	int error;
  
  	spin_lock(&gt->gt_spin);

  	args.ar_commit = gt->gt_logd_secs;

  	args.ar_quota_quantum = gt->gt_quota_quantum;
  	if (gt->gt_statfs_slow)
  		args.ar_statfs_quantum = 0;
  	else
  		args.ar_statfs_quantum = gt->gt_statfs_quantum;

  	spin_unlock(&gt->gt_spin);

  	error = gfs2_mount_args(&args, data);

  	if (error)
  		return error;
  
  	/* Not allowed to change locking details */
  	if (strcmp(args.ar_lockproto, sdp->sd_args.ar_lockproto) ||
  	    strcmp(args.ar_locktable, sdp->sd_args.ar_locktable) ||
  	    strcmp(args.ar_hostdata, sdp->sd_args.ar_hostdata))
  		return -EINVAL;
  
  	/* Some flags must not be changed */
  	if (args_neq(&args, &sdp->sd_args, spectator) ||

  	    args_neq(&args, &sdp->sd_args, localflocks) ||

  	    args_neq(&args, &sdp->sd_args, meta))
  		return -EINVAL;
  
  	if (sdp->sd_args.ar_spectator)
  		*flags |= MS_RDONLY;
  
  	if ((sb->s_flags ^ *flags) & MS_RDONLY) {
  		if (*flags & MS_RDONLY)
  			error = gfs2_make_fs_ro(sdp);
  		else
  			error = gfs2_make_fs_rw(sdp);
  		if (error)
  			return error;
  	}
  
  	sdp->sd_args = args;
  	if (sdp->sd_args.ar_posix_acl)
  		sb->s_flags |= MS_POSIXACL;
  	else
  		sb->s_flags &= ~MS_POSIXACL;

  	if (sdp->sd_args.ar_nobarrier)
  		set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
  	else
  		clear_bit(SDF_NOBARRIERS, &sdp->sd_flags);

  	spin_lock(&gt->gt_spin);

  	gt->gt_logd_secs = args.ar_commit;

  	gt->gt_quota_quantum = args.ar_quota_quantum;
  	if (args.ar_statfs_quantum) {
  		gt->gt_statfs_slow = 0;
  		gt->gt_statfs_quantum = args.ar_statfs_quantum;
  	}
  	else {
  		gt->gt_statfs_slow = 1;
  		gt->gt_statfs_quantum = 30;
  	}

  	spin_unlock(&gt->gt_spin);

  	gfs2_online_uevent(sdp);

  	return 0;
  }
  
  /**
   * gfs2_drop_inode - Drop an inode (test for remote unlink)
   * @inode: The inode to drop
   *
   * If we've received a callback on an iopen lock then its because a
   * remote node tried to deallocate the inode but failed due to this node
   * still having the inode open. Here we mark the link count zero
   * since we know that it must have reached zero if the GLF_DEMOTE flag
   * is set on the iopen glock. If we didn't do a disk read since the
   * remote node removed the final link then we might otherwise miss
   * this event. This check ensures that this node will deallocate the
   * inode's blocks, or alternatively pass the baton on to another
   * node for later deallocation.
   */

  static int gfs2_drop_inode(struct inode *inode)

  {
  	struct gfs2_inode *ip = GFS2_I(inode);

  	if (inode->i_nlink) {

  		struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
  		if (gl && test_bit(GLF_DEMOTE, &gl->gl_flags))
  			clear_nlink(inode);
  	}

  	return generic_drop_inode(inode);

  }
  
  static int is_ancestor(const struct dentry *d1, const struct dentry *d2)
  {
  	do {
  		if (d1 == d2)
  			return 1;
  		d1 = d1->d_parent;
  	} while (!IS_ROOT(d1));
  	return 0;
  }
  
  /**
   * gfs2_show_options - Show mount options for /proc/mounts
   * @s: seq_file structure

   * @root: root of this (sub)tree

   *
   * Returns: 0 on success or error code
   */

  static int gfs2_show_options(struct seq_file *s, struct dentry *root)

  {

  	struct gfs2_sbd *sdp = root->d_sb->s_fs_info;

  	struct gfs2_args *args = &sdp->sd_args;

  	int val;

  	if (is_ancestor(root, sdp->sd_master_dir))

  		seq_printf(s, ",meta");
  	if (args->ar_lockproto[0])
  		seq_printf(s, ",lockproto=%s", args->ar_lockproto);
  	if (args->ar_locktable[0])
  		seq_printf(s, ",locktable=%s", args->ar_locktable);
  	if (args->ar_hostdata[0])
  		seq_printf(s, ",hostdata=%s", args->ar_hostdata);
  	if (args->ar_spectator)
  		seq_printf(s, ",spectator");

  	if (args->ar_localflocks)
  		seq_printf(s, ",localflocks");

  	if (args->ar_debug)
  		seq_printf(s, ",debug");

  	if (args->ar_posix_acl)
  		seq_printf(s, ",acl");
  	if (args->ar_quota != GFS2_QUOTA_DEFAULT) {
  		char *state;
  		switch (args->ar_quota) {
  		case GFS2_QUOTA_OFF:
  			state = "off";
  			break;
  		case GFS2_QUOTA_ACCOUNT:
  			state = "account";
  			break;
  		case GFS2_QUOTA_ON:
  			state = "on";
  			break;
  		default:
  			state = "unknown";
  			break;
  		}
  		seq_printf(s, ",quota=%s", state);
  	}
  	if (args->ar_suiddir)
  		seq_printf(s, ",suiddir");
  	if (args->ar_data != GFS2_DATA_DEFAULT) {
  		char *state;
  		switch (args->ar_data) {
  		case GFS2_DATA_WRITEBACK:
  			state = "writeback";
  			break;
  		case GFS2_DATA_ORDERED:
  			state = "ordered";
  			break;
  		default:
  			state = "unknown";
  			break;
  		}
  		seq_printf(s, ",data=%s", state);
  	}
  	if (args->ar_discard)
  		seq_printf(s, ",discard");

  	val = sdp->sd_tune.gt_logd_secs;
  	if (val != 30)

  		seq_printf(s, ",commit=%d", val);
  	val = sdp->sd_tune.gt_statfs_quantum;
  	if (val != 30)
  		seq_printf(s, ",statfs_quantum=%d", val);
  	val = sdp->sd_tune.gt_quota_quantum;
  	if (val != 60)
  		seq_printf(s, ",quota_quantum=%d", val);
  	if (args->ar_statfs_percent)
  		seq_printf(s, ",statfs_percent=%d", args->ar_statfs_percent);

  	if (args->ar_errors != GFS2_ERRORS_DEFAULT) {
  		const char *state;
  
  		switch (args->ar_errors) {
  		case GFS2_ERRORS_WITHDRAW:
  			state = "withdraw";
  			break;
  		case GFS2_ERRORS_PANIC:
  			state = "panic";
  			break;
  		default:
  			state = "unknown";
  			break;
  		}
  		seq_printf(s, ",errors=%s", state);
  	}

  	if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
  		seq_printf(s, ",nobarrier");

  	if (test_bit(SDF_DEMOTE, &sdp->sd_flags))
  		seq_printf(s, ",demote_interface_used");

  	return 0;
  }

  static void gfs2_final_release_pages(struct gfs2_inode *ip)
  {
  	struct inode *inode = &ip->i_inode;
  	struct gfs2_glock *gl = ip->i_gl;
  
  	truncate_inode_pages(gfs2_glock2aspace(ip->i_gl), 0);
  	truncate_inode_pages(&inode->i_data, 0);
  
  	if (atomic_read(&gl->gl_revokes) == 0) {
  		clear_bit(GLF_LFLUSH, &gl->gl_flags);
  		clear_bit(GLF_DIRTY, &gl->gl_flags);
  	}
  }
  
  static int gfs2_dinode_dealloc(struct gfs2_inode *ip)
  {
  	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);

  	struct gfs2_qadata *qa;

  	struct gfs2_rgrpd *rgd;

  	struct gfs2_holder gh;

  	int error;
  
  	if (gfs2_get_inode_blocks(&ip->i_inode) != 1) {

  		gfs2_consist_inode(ip);

  		return -EIO;
  	}

  	qa = gfs2_qadata_get(ip);
  	if (!qa)

  		return -ENOMEM;
  
  	error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
  	if (error)
  		goto out;

  	rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr);
  	if (!rgd) {
  		gfs2_consist_inode(ip);
  		error = -EIO;

  		goto out_qs;

  	}

  	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, &gh);

  	if (error)

  		goto out_qs;

  	error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA,
  				 sdp->sd_jdesc->jd_blocks);

  	if (error)
  		goto out_rg_gunlock;
  
  	gfs2_free_di(rgd, ip);
  
  	gfs2_final_release_pages(ip);
  
  	gfs2_trans_end(sdp);
  
  out_rg_gunlock:

  	gfs2_glock_dq_uninit(&gh);

  out_qs:
  	gfs2_quota_unhold(ip);
  out:

  	gfs2_qadata_put(ip);

  	return error;
  }

  /**
   * gfs2_evict_inode - Remove an inode from cache
   * @inode: The inode to evict
   *
   * There are three cases to consider:
   * 1. i_nlink == 0, we are final opener (and must deallocate)
   * 2. i_nlink == 0, we are not the final opener (and cannot deallocate)
   * 3. i_nlink > 0
   *
   * If the fs is read only, then we have to treat all cases as per #3
   * since we are unable to do any deallocation. The inode will be
   * deallocated by the next read/write node to attempt an allocation
   * in the same resource group
   *

   * We have to (at the moment) hold the inodes main lock to cover
   * the gap between unlocking the shared lock on the iopen lock and
   * taking the exclusive lock. I'd rather do a shared -> exclusive
   * conversion on the iopen lock, but we can change that later. This
   * is safe, just less efficient.
   */

  static void gfs2_evict_inode(struct inode *inode)

  {

  	struct super_block *sb = inode->i_sb;
  	struct gfs2_sbd *sdp = sb->s_fs_info;

  	struct gfs2_inode *ip = GFS2_I(inode);
  	struct gfs2_holder gh;
  	int error;

  	if (inode->i_nlink || (sb->s_flags & MS_RDONLY))

  		goto out;

  	/* Must not read inode block until block type has been verified */
  	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, &gh);

  	if (unlikely(error)) {
  		gfs2_glock_dq_uninit(&ip->i_iopen_gh);
  		goto out;
  	}

  	if (!test_bit(GIF_ALLOC_FAILED, &ip->i_flags)) {
  		error = gfs2_check_blk_type(sdp, ip->i_no_addr, GFS2_BLKST_UNLINKED);
  		if (error)
  			goto out_truncate;
  	}

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

  	ip->i_iopen_gh.gh_flags |= GL_NOCACHE;

  	gfs2_glock_dq_wait(&ip->i_iopen_gh);
  	gfs2_holder_reinit(LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB | GL_NOCACHE, &ip->i_iopen_gh);
  	error = gfs2_glock_nq(&ip->i_iopen_gh);
  	if (error)
  		goto out_truncate;

  	/* Case 1 starts here */

  	if (S_ISDIR(inode->i_mode) &&
  	    (ip->i_diskflags & GFS2_DIF_EXHASH)) {
  		error = gfs2_dir_exhash_dealloc(ip);
  		if (error)
  			goto out_unlock;
  	}
  
  	if (ip->i_eattr) {
  		error = gfs2_ea_dealloc(ip);
  		if (error)
  			goto out_unlock;
  	}
  
  	if (!gfs2_is_stuffed(ip)) {
  		error = gfs2_file_dealloc(ip);
  		if (error)
  			goto out_unlock;
  	}
  
  	error = gfs2_dinode_dealloc(ip);

  	goto out_unlock;

  
  out_truncate:

  	gfs2_log_flush(sdp, ip->i_gl);
  	write_inode_now(inode, 1);

  	gfs2_ail_flush(ip->i_gl, 0);

  	/* Case 2 starts here */

  	error = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
  	if (error)
  		goto out_unlock;

  	/* Needs to be done before glock release & also in a transaction */
  	truncate_inode_pages(&inode->i_data, 0);

  	gfs2_trans_end(sdp);
  
  out_unlock:

  	/* Error path for case 1 */

  	if (test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags))
  		gfs2_glock_dq(&ip->i_iopen_gh);
  	gfs2_holder_uninit(&ip->i_iopen_gh);
  	gfs2_glock_dq_uninit(&gh);
  	if (error && error != GLR_TRYFAILED && error != -EROFS)

  		fs_warn(sdp, "gfs2_evict_inode: %d
  ", error);

  out:

  	/* Case 3 starts here */

  	truncate_inode_pages(&inode->i_data, 0);

  	end_writeback(inode);

  	gfs2_dir_hash_inval(ip);

  	ip->i_gl->gl_object = NULL;

  	gfs2_glock_add_to_lru(ip->i_gl);

  	gfs2_glock_put(ip->i_gl);
  	ip->i_gl = NULL;
  	if (ip->i_iopen_gh.gh_gl) {
  		ip->i_iopen_gh.gh_gl->gl_object = NULL;
  		gfs2_glock_dq_uninit(&ip->i_iopen_gh);
  	}

  }
  
  static struct inode *gfs2_alloc_inode(struct super_block *sb)
  {
  	struct gfs2_inode *ip;
  
  	ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
  	if (ip) {
  		ip->i_flags = 0;
  		ip->i_gl = NULL;

  		ip->i_rgd = NULL;

  	}
  	return &ip->i_inode;
  }

  static void gfs2_i_callback(struct rcu_head *head)

  {

  	struct inode *inode = container_of(head, struct inode, i_rcu);

  	kmem_cache_free(gfs2_inode_cachep, inode);
  }

  static void gfs2_destroy_inode(struct inode *inode)
  {
  	call_rcu(&inode->i_rcu, gfs2_i_callback);
  }

  const struct super_operations gfs2_super_ops = {
  	.alloc_inode		= gfs2_alloc_inode,
  	.destroy_inode		= gfs2_destroy_inode,
  	.write_inode		= gfs2_write_inode,

  	.dirty_inode		= gfs2_dirty_inode,

  	.evict_inode		= gfs2_evict_inode,

  	.put_super		= gfs2_put_super,

  	.sync_fs		= gfs2_sync_fs,
  	.freeze_fs 		= gfs2_freeze,
  	.unfreeze_fs		= gfs2_unfreeze,
  	.statfs			= gfs2_statfs,
  	.remount_fs		= gfs2_remount_fs,

  	.drop_inode		= gfs2_drop_inode,
  	.show_options		= gfs2_show_options,
  };