fs/gfs2/ops_super.c - kernel/msm-4.19 - 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/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/lm_interface.h>
 #include <linux/time.h>

 #include "gfs2.h"
 #include "incore.h"
 #include "glock.h"
 #include "inode.h"
 #include "log.h"
 #include "mount.h"
 #include "quota.h"
 #include "recovery.h"
 #include "rgrp.h"
 #include "super.h"
 #include "sys.h"
 #include "util.h"
 #include "trans.h"
 #include "dir.h"
 #include "eattr.h"
 #include "bmap.h"
 #include "meta_io.h"

 /**
  * gfs2_write_inode - Make sure the inode is stable on the disk
  * @inode: The inode
  * @sync: synchronous write flag
  *
  * Returns: errno
  */

 static int gfs2_write_inode(struct inode *inode, int sync)
 {
 	struct gfs2_inode *ip = GFS2_I(inode);
 	struct gfs2_sbd *sdp = GFS2_SB(inode);
 	struct gfs2_holder gh;
 	struct buffer_head *bh;
 	struct timespec atime;
 	struct gfs2_dinode *di;
 	int ret = 0;

 	/* Check this is a "normal" inode, etc */
 	if (!test_bit(GIF_USER, &ip->i_flags) ||
 	    (current->flags & PF_MEMALLOC))
 		return 0;
 	ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 	if (ret)
 		goto do_flush;
 	ret = gfs2_trans_begin(sdp, RES_DINODE, 0);
 	if (ret)
 		goto do_unlock;
 	ret = gfs2_meta_inode_buffer(ip, &bh);
 	if (ret == 0) {
 		di = (struct gfs2_dinode *)bh->b_data;
 		atime.tv_sec = be64_to_cpu(di->di_atime);
 		atime.tv_nsec = be32_to_cpu(di->di_atime_nsec);
 		if (timespec_compare(&inode->i_atime, &atime) > 0) {
 			gfs2_trans_add_bh(ip->i_gl, bh, 1);
 			gfs2_dinode_out(ip, bh->b_data);
 		}
 		brelse(bh);
 	}
 	gfs2_trans_end(sdp);
 do_unlock:
 	gfs2_glock_dq_uninit(&gh);
 do_flush:
 	if (sync != 0)
 		gfs2_log_flush(GFS2_SB(inode), ip->i_gl);
 	return ret;
 }

 /**
  * 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;

 	gfs2_quota_sync(sdp);
 	gfs2_statfs_sync(sdp);

 	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;
 }

 /**
  * 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;

 	/*  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);

 	kthread_stop(sdp->sd_quotad_process);
 	kthread_stop(sdp->sd_logd_process);
 	kthread_stop(sdp->sd_recoverd_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_inum_inode);
 	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_ir_gh);
 		gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
 		gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
 		iput(sdp->sd_ir_inode);
 		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);
 	kfree(sdp);
 }

 /**
  * gfs2_write_super
  * @sb: the superblock
  *
  */

 static void gfs2_write_super(struct super_block *sb)
 {
 	sb->s_dirt = 0;
 }

 /**
  * 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)
 {
 	sb->s_dirt = 0;
 	if (wait && sb->s_fs_info)
 		gfs2_log_flush(sb->s_fs_info, NULL);
 	return 0;
 }

 /**
  * gfs2_write_super_lockfs - prevent further writes to the filesystem
  * @sb: the VFS structure for the filesystem
  *
  */

 static void gfs2_write_super_lockfs(struct super_block *sb)
 {
 	struct gfs2_sbd *sdp = sb->s_fs_info;
 	int error;

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

 	for (;;) {
 		error = gfs2_freeze_fs(sdp);
 		if (!error)
 			break;

 		switch (error) {
 		case -EBUSY:
 			fs_err(sdp, "waiting for recovery before freeze\n");
 			break;

 		default:
 			fs_err(sdp, "error freezing FS: %d\n", error);
 			break;
 		}

 		fs_err(sdp, "retrying...\n");
 		msleep(1000);
 	}
 }

 /**
  * gfs2_unlockfs - reallow writes to the filesystem
  * @sb: the VFS structure for the filesystem
  *
  */

 static void gfs2_unlockfs(struct super_block *sb)
 {
 	gfs2_unfreeze_fs(sb->s_fs_info);
 }

 /**
  * 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;

 	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;
 	int error;

 	error = gfs2_mount_args(sdp, data, 1);
 	if (error)
 		return error;

 	if (sdp->sd_args.ar_spectator)
 		*flags |= MS_RDONLY;
 	else {
 		if (*flags & MS_RDONLY) {
 			if (!(sb->s_flags & MS_RDONLY))
 				error = gfs2_make_fs_ro(sdp);
 		} else if (!(*flags & MS_RDONLY) &&
 			   (sb->s_flags & MS_RDONLY)) {
 			error = gfs2_make_fs_rw(sdp);
 		}
 	}

 	return error;
 }

 /**
  * 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 void gfs2_drop_inode(struct inode *inode)
 {
 	struct gfs2_inode *ip = GFS2_I(inode);

 	if (test_bit(GIF_USER, &ip->i_flags) && 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);
 	}
 	generic_drop_inode(inode);
 }

 /**
  * gfs2_clear_inode - Deallocate an inode when VFS is done with it
  * @inode: The VFS inode
  *
  */

 static void gfs2_clear_inode(struct inode *inode)
 {
 	struct gfs2_inode *ip = GFS2_I(inode);

 	/* This tells us its a "real" inode and not one which only
 	 * serves to contain an address space (see rgrp.c, meta_io.c)
 	 * which therefore doesn't have its own glocks.
 	 */
 	if (test_bit(GIF_USER, &ip->i_flags)) {
 		ip->i_gl->gl_object = NULL;
 		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 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
  * @mnt: vfsmount
  *
  * Returns: 0 on success or error code
  */

 static int gfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
 {
 	struct gfs2_sbd *sdp = mnt->mnt_sb->s_fs_info;
 	struct gfs2_args *args = &sdp->sd_args;

 	if (is_ancestor(mnt->mnt_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_ignore_local_fs)
 		seq_printf(s, ",ignore_local_fs");
 	if (args->ar_localflocks)
 		seq_printf(s, ",localflocks");
 	if (args->ar_localcaching)
 		seq_printf(s, ",localcaching");
 	if (args->ar_debug)
 		seq_printf(s, ",debug");
 	if (args->ar_upgrade)
 		seq_printf(s, ",upgrade");
 	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);
 	}

 	return 0;
 }

 /*
  * 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_delete_inode(struct inode *inode)
 {
 	struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
 	struct gfs2_inode *ip = GFS2_I(inode);
 	struct gfs2_holder gh;
 	int error;

 	if (!test_bit(GIF_USER, &ip->i_flags))
 		goto out;

 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 	if (unlikely(error)) {
 		gfs2_glock_dq_uninit(&ip->i_iopen_gh);
 		goto out;
 	}

 	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;

 	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);
 	if (error)
 		goto out_unlock;

 out_truncate:
 	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:
 	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)
 		fs_warn(sdp, "gfs2_delete_inode: %d\n", error);
 out:
 	truncate_inode_pages(&inode->i_data, 0);
 	clear_inode(inode);
 }

 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;
 	}
 	return &ip->i_inode;
 }

 static void gfs2_destroy_inode(struct inode *inode)
 {
 	kmem_cache_free(gfs2_inode_cachep, inode);
 }

 const struct super_operations gfs2_super_ops = {
 	.alloc_inode		= gfs2_alloc_inode,
 	.destroy_inode		= gfs2_destroy_inode,
 	.write_inode		= gfs2_write_inode,
 	.delete_inode		= gfs2_delete_inode,
 	.put_super		= gfs2_put_super,
 	.write_super		= gfs2_write_super,
 	.sync_fs		= gfs2_sync_fs,
 	.write_super_lockfs 	= gfs2_write_super_lockfs,
 	.unlockfs		= gfs2_unlockfs,
 	.statfs			= gfs2_statfs,
 	.remount_fs		= gfs2_remount_fs,
 	.clear_inode		= gfs2_clear_inode,
 	.drop_inode		= gfs2_drop_inode,
 	.show_options		= gfs2_show_options,
 };
	/*
	* 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/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/lm_interface.h>
	#include <linux/time.h>

	#include "gfs2.h"
	#include "incore.h"
	#include "glock.h"
	#include "inode.h"
	#include "log.h"
	#include "mount.h"
	#include "quota.h"
	#include "recovery.h"
	#include "rgrp.h"
	#include "super.h"
	#include "sys.h"
	#include "util.h"
	#include "trans.h"
	#include "dir.h"
	#include "eattr.h"
	#include "bmap.h"
	#include "meta_io.h"

	/**
	* gfs2_write_inode - Make sure the inode is stable on the disk
	* @inode: The inode
	* @sync: synchronous write flag
	*
	* Returns: errno
	*/

	static int gfs2_write_inode(struct inode *inode, int sync)
	{
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	struct gfs2_holder gh;
	struct buffer_head *bh;
	struct timespec atime;
	struct gfs2_dinode *di;
	int ret = 0;

	/* Check this is a "normal" inode, etc */
	if (!test_bit(GIF_USER, &ip->i_flags) \|\|
	(current->flags & PF_MEMALLOC))
	return 0;
	ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
	if (ret)
	goto do_flush;
	ret = gfs2_trans_begin(sdp, RES_DINODE, 0);
	if (ret)
	goto do_unlock;
	ret = gfs2_meta_inode_buffer(ip, &bh);
	if (ret == 0) {
	di = (struct gfs2_dinode *)bh->b_data;
	atime.tv_sec = be64_to_cpu(di->di_atime);
	atime.tv_nsec = be32_to_cpu(di->di_atime_nsec);
	if (timespec_compare(&inode->i_atime, &atime) > 0) {
	gfs2_trans_add_bh(ip->i_gl, bh, 1);
	gfs2_dinode_out(ip, bh->b_data);
	}
	brelse(bh);
	}
	gfs2_trans_end(sdp);
	do_unlock:
	gfs2_glock_dq_uninit(&gh);
	do_flush:
	if (sync != 0)
	gfs2_log_flush(GFS2_SB(inode), ip->i_gl);
	return ret;
	}

	/**
	* 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;

	gfs2_quota_sync(sdp);
	gfs2_statfs_sync(sdp);

	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;
	}

	/**
	* 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;

	/* 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);

	kthread_stop(sdp->sd_quotad_process);
	kthread_stop(sdp->sd_logd_process);
	kthread_stop(sdp->sd_recoverd_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_inum_inode);
	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_ir_gh);
	gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
	gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
	iput(sdp->sd_ir_inode);
	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);
	kfree(sdp);
	}

	/**
	* gfs2_write_super
	* @sb: the superblock
	*
	*/

	static void gfs2_write_super(struct super_block *sb)
	{
	sb->s_dirt = 0;
	}

	/**
	* 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)
	{
	sb->s_dirt = 0;
	if (wait && sb->s_fs_info)
	gfs2_log_flush(sb->s_fs_info, NULL);
	return 0;
	}

	/**
	* gfs2_write_super_lockfs - prevent further writes to the filesystem
	* @sb: the VFS structure for the filesystem
	*
	*/

	static void gfs2_write_super_lockfs(struct super_block *sb)
	{
	struct gfs2_sbd *sdp = sb->s_fs_info;
	int error;

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

	for (;;) {
	error = gfs2_freeze_fs(sdp);
	if (!error)
	break;

	switch (error) {
	case -EBUSY:
	fs_err(sdp, "waiting for recovery before freeze\n");
	break;

	default:
	fs_err(sdp, "error freezing FS: %d\n", error);
	break;
	}

	fs_err(sdp, "retrying...\n");
	msleep(1000);
	}
	}

	/**
	* gfs2_unlockfs - reallow writes to the filesystem
	* @sb: the VFS structure for the filesystem
	*
	*/

	static void gfs2_unlockfs(struct super_block *sb)
	{
	gfs2_unfreeze_fs(sb->s_fs_info);
	}

	/**
	* 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;

	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;
	int error;

	error = gfs2_mount_args(sdp, data, 1);
	if (error)
	return error;

	if (sdp->sd_args.ar_spectator)
	*flags \|= MS_RDONLY;
	else {
	if (*flags & MS_RDONLY) {
	if (!(sb->s_flags & MS_RDONLY))
	error = gfs2_make_fs_ro(sdp);
	} else if (!(*flags & MS_RDONLY) &&
	(sb->s_flags & MS_RDONLY)) {
	error = gfs2_make_fs_rw(sdp);
	}
	}

	return error;
	}

	/**
	* 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 void gfs2_drop_inode(struct inode *inode)
	{
	struct gfs2_inode *ip = GFS2_I(inode);

	if (test_bit(GIF_USER, &ip->i_flags) && 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);
	}
	generic_drop_inode(inode);
	}

	/**
	* gfs2_clear_inode - Deallocate an inode when VFS is done with it
	* @inode: The VFS inode
	*
	*/

	static void gfs2_clear_inode(struct inode *inode)
	{
	struct gfs2_inode *ip = GFS2_I(inode);

	/* This tells us its a "real" inode and not one which only
	* serves to contain an address space (see rgrp.c, meta_io.c)
	* which therefore doesn't have its own glocks.
	*/
	if (test_bit(GIF_USER, &ip->i_flags)) {
	ip->i_gl->gl_object = NULL;
	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 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
	* @mnt: vfsmount
	*
	* Returns: 0 on success or error code
	*/

	static int gfs2_show_options(struct seq_file s, struct vfsmount mnt)
	{
	struct gfs2_sbd *sdp = mnt->mnt_sb->s_fs_info;
	struct gfs2_args *args = &sdp->sd_args;

	if (is_ancestor(mnt->mnt_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_ignore_local_fs)
	seq_printf(s, ",ignore_local_fs");
	if (args->ar_localflocks)
	seq_printf(s, ",localflocks");
	if (args->ar_localcaching)
	seq_printf(s, ",localcaching");
	if (args->ar_debug)
	seq_printf(s, ",debug");
	if (args->ar_upgrade)
	seq_printf(s, ",upgrade");
	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);
	}

	return 0;
	}

	/*
	* 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_delete_inode(struct inode *inode)
	{
	struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder gh;
	int error;

	if (!test_bit(GIF_USER, &ip->i_flags))
	goto out;

	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
	if (unlikely(error)) {
	gfs2_glock_dq_uninit(&ip->i_iopen_gh);
	goto out;
	}

	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;

	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);
	if (error)
	goto out_unlock;

	out_truncate:
	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:
	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)
	fs_warn(sdp, "gfs2_delete_inode: %d\n", error);
	out:
	truncate_inode_pages(&inode->i_data, 0);
	clear_inode(inode);
	}

	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;
	}
	return &ip->i_inode;
	}

	static void gfs2_destroy_inode(struct inode *inode)
	{
	kmem_cache_free(gfs2_inode_cachep, inode);
	}

	const struct super_operations gfs2_super_ops = {
	.alloc_inode = gfs2_alloc_inode,
	.destroy_inode = gfs2_destroy_inode,
	.write_inode = gfs2_write_inode,
	.delete_inode = gfs2_delete_inode,
	.put_super = gfs2_put_super,
	.write_super = gfs2_write_super,
	.sync_fs = gfs2_sync_fs,
	.write_super_lockfs = gfs2_write_super_lockfs,
	.unlockfs = gfs2_unlockfs,
	.statfs = gfs2_statfs,
	.remount_fs = gfs2_remount_fs,
	.clear_inode = gfs2_clear_inode,
	.drop_inode = gfs2_drop_inode,
	.show_options = gfs2_show_options,
	};