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

   * Copyright (C) 2004-2006 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/namei.h>

  #include <linux/mm.h>
  #include <linux/xattr.h>
  #include <linux/posix_acl.h>

  #include <linux/gfs2_ondisk.h>

  #include <linux/crc32.h>

  #include <linux/fiemap.h>

  #include <asm/uaccess.h>
  
  #include "gfs2.h"

  #include "incore.h"

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

  #include "xattr.h"

  #include "glock.h"
  #include "inode.h"
  #include "meta_io.h"

  #include "quota.h"
  #include "rgrp.h"
  #include "trans.h"

  #include "util.h"

  #include "super.h"

  
  /**
   * gfs2_create - Create a file
   * @dir: The directory in which to create the file
   * @dentry: The dentry of the new file
   * @mode: The mode of the new file
   *
   * Returns: errno
   */
  
  static int gfs2_create(struct inode *dir, struct dentry *dentry,
  		       int mode, struct nameidata *nd)
  {

  	struct gfs2_inode *dip = GFS2_I(dir);
  	struct gfs2_sbd *sdp = GFS2_SB(dir);

  	struct gfs2_holder ghs[2];
  	struct inode *inode;

  	gfs2_holder_init(dip->i_gl, 0, 0, ghs);
  
  	for (;;) {

  		inode = gfs2_createi(ghs, &dentry->d_name, S_IFREG | mode, 0);

  		if (!IS_ERR(inode)) {

  			gfs2_trans_end(sdp);

  			if (dip->i_alloc->al_rgd)

  				gfs2_inplace_release(dip);
  			gfs2_quota_unlock(dip);
  			gfs2_alloc_put(dip);
  			gfs2_glock_dq_uninit_m(2, ghs);

  			mark_inode_dirty(inode);

  			break;

  		} else if (PTR_ERR(inode) != -EEXIST ||

  			   (nd && nd->flags & LOOKUP_EXCL)) {

  			gfs2_holder_uninit(ghs);

  			return PTR_ERR(inode);

  		}

  		inode = gfs2_lookupi(dir, &dentry->d_name, 0);

  		if (inode) {
  			if (!IS_ERR(inode)) {

  				gfs2_holder_uninit(ghs);
  				break;
  			} else {
  				gfs2_holder_uninit(ghs);
  				return PTR_ERR(inode);
  			}

  		}
  	}

  	d_instantiate(dentry, inode);

  
  	return 0;
  }
  
  /**
   * gfs2_lookup - Look up a filename in a directory and return its inode
   * @dir: The directory inode
   * @dentry: The dentry of the new inode
   * @nd: passed from Linux VFS, ignored by us
   *
   * Called by the VFS layer. Lock dir and call gfs2_lookupi()
   *
   * Returns: errno
   */
  
  static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry,
  				  struct nameidata *nd)
  {

  	struct inode *inode = NULL;

  	dentry->d_op = &gfs2_dops;

  	inode = gfs2_lookupi(dir, &dentry->d_name, 0);

  	if (inode && IS_ERR(inode))

  		return ERR_CAST(inode);

  	if (inode) {
  		struct gfs2_glock *gl = GFS2_I(inode)->i_gl;
  		struct gfs2_holder gh;
  		int error;
  		error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
  		if (error) {
  			iput(inode);
  			return ERR_PTR(error);
  		}
  		gfs2_glock_dq_uninit(&gh);

  		return d_splice_alias(inode, dentry);

  	}

  	d_add(dentry, inode);
  
  	return NULL;
  }
  
  /**
   * gfs2_link - Link to a file
   * @old_dentry: The inode to link
   * @dir: Add link to this directory
   * @dentry: The name of the link
   *
   * Link the inode in "old_dentry" into the directory "dir" with the
   * name in "dentry".
   *
   * Returns: errno
   */
  
  static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
  		     struct dentry *dentry)
  {

  	struct gfs2_inode *dip = GFS2_I(dir);
  	struct gfs2_sbd *sdp = GFS2_SB(dir);

  	struct inode *inode = old_dentry->d_inode;

  	struct gfs2_inode *ip = GFS2_I(inode);

  	struct gfs2_holder ghs[2];
  	int alloc_required;
  	int error;

  	if (S_ISDIR(inode->i_mode))

  		return -EPERM;
  
  	gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
  	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);

  	error = gfs2_glock_nq(ghs); /* parent */
  	if (error)
  		goto out_parent;
  
  	error = gfs2_glock_nq(ghs + 1); /* child */

  	if (error)

  		goto out_child;

  	error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC);

  	if (error)
  		goto out_gunlock;

  	error = gfs2_dir_check(dir, &dentry->d_name, NULL);

  	switch (error) {
  	case -ENOENT:
  		break;
  	case 0:
  		error = -EEXIST;
  	default:
  		goto out_gunlock;
  	}
  
  	error = -EINVAL;

  	if (!dip->i_inode.i_nlink)

  		goto out_gunlock;
  	error = -EFBIG;

  	if (dip->i_entries == (u32)-1)

  		goto out_gunlock;
  	error = -EPERM;
  	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
  		goto out_gunlock;
  	error = -EINVAL;

  	if (!ip->i_inode.i_nlink)

  		goto out_gunlock;
  	error = -EMLINK;

  	if (ip->i_inode.i_nlink == (u32)-1)

  		goto out_gunlock;

  	alloc_required = error = gfs2_diradd_alloc_required(dir, &dentry->d_name);
  	if (error < 0)

  		goto out_gunlock;

  	error = 0;

  
  	if (alloc_required) {
  		struct gfs2_alloc *al = gfs2_alloc_get(dip);

  		if (!al) {
  			error = -ENOMEM;
  			goto out_gunlock;
  		}

  		error = gfs2_quota_lock_check(dip);

  		if (error)
  			goto out_alloc;

  		al->al_requested = sdp->sd_max_dirres;
  
  		error = gfs2_inplace_reserve(dip);
  		if (error)
  			goto out_gunlock_q;

  		error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +

  					 al->al_rgd->rd_length +

  					 2 * RES_DINODE + RES_STATFS +
  					 RES_QUOTA, 0);
  		if (error)
  			goto out_ipres;
  	} else {
  		error = gfs2_trans_begin(sdp, 2 * RES_DINODE + RES_LEAF, 0);
  		if (error)
  			goto out_ipres;
  	}

  	error = gfs2_dir_add(dir, &dentry->d_name, ip, IF2DT(inode->i_mode));

  	if (error)
  		goto out_end_trans;
  
  	error = gfs2_change_nlink(ip, +1);

  out_end_trans:

  	gfs2_trans_end(sdp);

  out_ipres:

  	if (alloc_required)
  		gfs2_inplace_release(dip);

  out_gunlock_q:

  	if (alloc_required)
  		gfs2_quota_unlock(dip);

  out_alloc:

  	if (alloc_required)
  		gfs2_alloc_put(dip);

  out_gunlock:

  	gfs2_glock_dq(ghs + 1);
  out_child:
  	gfs2_glock_dq(ghs);
  out_parent:

  	gfs2_holder_uninit(ghs);
  	gfs2_holder_uninit(ghs + 1);

  	if (!error) {

  		atomic_inc(&inode->i_count);

  		d_instantiate(dentry, inode);
  		mark_inode_dirty(inode);
  	}

  	return error;
  }

  /*
   * gfs2_unlink_ok - check to see that a inode is still in a directory
   * @dip: the directory
   * @name: the name of the file
   * @ip: the inode
   *
   * Assumes that the lock on (at least) @dip is held.
   *
   * Returns: 0 if the parent/child relationship is correct, errno if it isn't
   */
  
  static int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
  			  const struct gfs2_inode *ip)
  {
  	int error;
  
  	if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
  		return -EPERM;
  
  	if ((dip->i_inode.i_mode & S_ISVTX) &&
  	    dip->i_inode.i_uid != current_fsuid() &&
  	    ip->i_inode.i_uid != current_fsuid() && !capable(CAP_FOWNER))
  		return -EPERM;
  
  	if (IS_APPEND(&dip->i_inode))
  		return -EPERM;
  
  	error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
  	if (error)
  		return error;
  
  	error = gfs2_dir_check(&dip->i_inode, name, ip);
  	if (error)
  		return error;
  
  	return 0;
  }

  /**
   * gfs2_unlink - Unlink a file
   * @dir: The inode of the directory containing the file to unlink
   * @dentry: The file itself
   *
   * Unlink a file.  Call gfs2_unlinki()
   *
   * Returns: errno
   */
  
  static int gfs2_unlink(struct inode *dir, struct dentry *dentry)
  {

  	struct gfs2_inode *dip = GFS2_I(dir);
  	struct gfs2_sbd *sdp = GFS2_SB(dir);
  	struct gfs2_inode *ip = GFS2_I(dentry->d_inode);

  	struct gfs2_holder ghs[3];
  	struct gfs2_rgrpd *rgd;
  	struct gfs2_holder ri_gh;

  	int error;

  	error = gfs2_rindex_hold(sdp, &ri_gh);
  	if (error)
  		return error;

  	gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);

  	gfs2_holder_init(ip->i_gl,  LM_ST_EXCLUSIVE, 0, ghs + 1);

  	rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr);

  	gfs2_holder_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + 2);

  	error = gfs2_glock_nq(ghs); /* parent */

  	if (error)

  		goto out_parent;
  
  	error = gfs2_glock_nq(ghs + 1); /* child */
  	if (error)
  		goto out_child;
  
  	error = gfs2_glock_nq(ghs + 2); /* rgrp */
  	if (error)
  		goto out_rgrp;

  
  	error = gfs2_unlink_ok(dip, &dentry->d_name, ip);
  	if (error)

  		goto out_gunlock;

  	error = gfs2_trans_begin(sdp, 2*RES_DINODE + RES_LEAF + RES_RG_BIT, 0);

  	if (error)

  		goto out_gunlock;

  	error = gfs2_dir_del(dip, &dentry->d_name);
          if (error)
                  goto out_end_trans;

  	error = gfs2_change_nlink(ip, -1);

  out_end_trans:
  	gfs2_trans_end(sdp);

  out_gunlock:

  	gfs2_glock_dq(ghs + 2);
  out_rgrp:

  	gfs2_holder_uninit(ghs + 2);

  	gfs2_glock_dq(ghs + 1);
  out_child:
  	gfs2_holder_uninit(ghs + 1);
  	gfs2_glock_dq(ghs);
  out_parent:
  	gfs2_holder_uninit(ghs);

  	gfs2_glock_dq_uninit(&ri_gh);

  	return error;
  }
  
  /**
   * gfs2_symlink - Create a symlink
   * @dir: The directory to create the symlink in
   * @dentry: The dentry to put the symlink in
   * @symname: The thing which the link points to
   *
   * Returns: errno
   */
  
  static int gfs2_symlink(struct inode *dir, struct dentry *dentry,
  			const char *symname)
  {

  	struct gfs2_inode *dip = GFS2_I(dir), *ip;
  	struct gfs2_sbd *sdp = GFS2_SB(dir);

  	struct gfs2_holder ghs[2];
  	struct inode *inode;
  	struct buffer_head *dibh;
  	int size;
  	int error;

  	/* Must be stuffed with a null terminator for gfs2_follow_link() */
  	size = strlen(symname);
  	if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode) - 1)
  		return -ENAMETOOLONG;
  
  	gfs2_holder_init(dip->i_gl, 0, 0, ghs);

  	inode = gfs2_createi(ghs, &dentry->d_name, S_IFLNK | S_IRWXUGO, 0);

  	if (IS_ERR(inode)) {

  		gfs2_holder_uninit(ghs);

  		return PTR_ERR(inode);

  	}

  	ip = ghs[1].gh_gl->gl_object;

  	ip->i_disksize = size;

  	i_size_write(inode, size);

  
  	error = gfs2_meta_inode_buffer(ip, &dibh);
  
  	if (!gfs2_assert_withdraw(sdp, !error)) {

  		gfs2_dinode_out(ip, dibh->b_data);

  		memcpy(dibh->b_data + sizeof(struct gfs2_dinode), symname,
  		       size);
  		brelse(dibh);
  	}
  
  	gfs2_trans_end(sdp);

  	if (dip->i_alloc->al_rgd)

  		gfs2_inplace_release(dip);
  	gfs2_quota_unlock(dip);
  	gfs2_alloc_put(dip);
  
  	gfs2_glock_dq_uninit_m(2, ghs);

  	d_instantiate(dentry, inode);
  	mark_inode_dirty(inode);
  
  	return 0;
  }
  
  /**
   * gfs2_mkdir - Make a directory
   * @dir: The parent directory of the new one
   * @dentry: The dentry of the new directory
   * @mode: The mode of the new directory
   *
   * Returns: errno
   */
  
  static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, int mode)
  {

  	struct gfs2_inode *dip = GFS2_I(dir), *ip;
  	struct gfs2_sbd *sdp = GFS2_SB(dir);

  	struct gfs2_holder ghs[2];
  	struct inode *inode;
  	struct buffer_head *dibh;
  	int error;

  	gfs2_holder_init(dip->i_gl, 0, 0, ghs);

  	inode = gfs2_createi(ghs, &dentry->d_name, S_IFDIR | mode, 0);

  	if (IS_ERR(inode)) {

  		gfs2_holder_uninit(ghs);

  		return PTR_ERR(inode);

  	}

  	ip = ghs[1].gh_gl->gl_object;

  	ip->i_inode.i_nlink = 2;

  	ip->i_disksize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode);

  	ip->i_diskflags |= GFS2_DIF_JDATA;

  	ip->i_entries = 2;

  
  	error = gfs2_meta_inode_buffer(ip, &dibh);
  
  	if (!gfs2_assert_withdraw(sdp, !error)) {
  		struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data;

  		struct gfs2_dirent *dent = (struct gfs2_dirent *)(di+1);

  		struct qstr str;

  		gfs2_str2qstr(&str, ".");

  		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
  		gfs2_qstr2dirent(&str, GFS2_DIRENT_SIZE(str.len), dent);

  		dent->de_inum = di->di_num; /* already GFS2 endian */

  		dent->de_type = cpu_to_be16(DT_DIR);

  		di->di_entries = cpu_to_be32(1);

  		gfs2_str2qstr(&str, "..");

  		dent = (struct gfs2_dirent *)((char*)dent + GFS2_DIRENT_SIZE(1));
  		gfs2_qstr2dirent(&str, dibh->b_size - GFS2_DIRENT_SIZE(1) - sizeof(struct gfs2_dinode), dent);

  		gfs2_inum_out(dip, dent);

  		dent->de_type = cpu_to_be16(DT_DIR);

  		gfs2_dinode_out(ip, di);

  
  		brelse(dibh);
  	}
  
  	error = gfs2_change_nlink(dip, +1);
  	gfs2_assert_withdraw(sdp, !error); /* dip already pinned */
  
  	gfs2_trans_end(sdp);

  	if (dip->i_alloc->al_rgd)

  		gfs2_inplace_release(dip);
  	gfs2_quota_unlock(dip);
  	gfs2_alloc_put(dip);
  
  	gfs2_glock_dq_uninit_m(2, ghs);

  	d_instantiate(dentry, inode);
  	mark_inode_dirty(inode);
  
  	return 0;
  }
  
  /**

   * gfs2_rmdiri - Remove a directory
   * @dip: The parent directory of the directory to be removed
   * @name: The name of the directory to be removed
   * @ip: The GFS2 inode of the directory to be removed
   *
   * Assumes Glocks on dip and ip are held
   *
   * Returns: errno
   */
  
  static int gfs2_rmdiri(struct gfs2_inode *dip, const struct qstr *name,
  		       struct gfs2_inode *ip)
  {
  	struct qstr dotname;
  	int error;
  
  	if (ip->i_entries != 2) {
  		if (gfs2_consist_inode(ip))
  			gfs2_dinode_print(ip);
  		return -EIO;
  	}
  
  	error = gfs2_dir_del(dip, name);
  	if (error)
  		return error;
  
  	error = gfs2_change_nlink(dip, -1);
  	if (error)
  		return error;
  
  	gfs2_str2qstr(&dotname, ".");
  	error = gfs2_dir_del(ip, &dotname);
  	if (error)
  		return error;
  
  	gfs2_str2qstr(&dotname, "..");
  	error = gfs2_dir_del(ip, &dotname);
  	if (error)
  		return error;
  
  	/* It looks odd, but it really should be done twice */
  	error = gfs2_change_nlink(ip, -1);
  	if (error)
  		return error;
  
  	error = gfs2_change_nlink(ip, -1);
  	if (error)
  		return error;
  
  	return error;
  }
  
  /**

   * gfs2_rmdir - Remove a directory
   * @dir: The parent directory of the directory to be removed
   * @dentry: The dentry of the directory to remove
   *
   * Remove a directory. Call gfs2_rmdiri()
   *
   * Returns: errno
   */
  
  static int gfs2_rmdir(struct inode *dir, struct dentry *dentry)
  {

  	struct gfs2_inode *dip = GFS2_I(dir);
  	struct gfs2_sbd *sdp = GFS2_SB(dir);
  	struct gfs2_inode *ip = GFS2_I(dentry->d_inode);

  	struct gfs2_holder ghs[3];
  	struct gfs2_rgrpd *rgd;
  	struct gfs2_holder ri_gh;

  	int error;

  	error = gfs2_rindex_hold(sdp, &ri_gh);
  	if (error)
  		return error;

  	gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
  	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);

  	rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr);

  	gfs2_holder_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + 2);

  	error = gfs2_glock_nq(ghs); /* parent */
  	if (error)
  		goto out_parent;
  
  	error = gfs2_glock_nq(ghs + 1); /* child */

  	if (error)

  		goto out_child;
  
  	error = gfs2_glock_nq(ghs + 2); /* rgrp */
  	if (error)
  		goto out_rgrp;

  
  	error = gfs2_unlink_ok(dip, &dentry->d_name, ip);
  	if (error)
  		goto out_gunlock;

  	if (ip->i_entries < 2) {

  		if (gfs2_consist_inode(ip))

  			gfs2_dinode_print(ip);

  		error = -EIO;
  		goto out_gunlock;
  	}

  	if (ip->i_entries > 2) {

  		error = -ENOTEMPTY;
  		goto out_gunlock;
  	}

  	error = gfs2_trans_begin(sdp, 2 * RES_DINODE + 3 * RES_LEAF + RES_RG_BIT, 0);

  	if (error)
  		goto out_gunlock;

  	error = gfs2_rmdiri(dip, &dentry->d_name, ip);

  
  	gfs2_trans_end(sdp);

  out_gunlock:

  	gfs2_glock_dq(ghs + 2);
  out_rgrp:

  	gfs2_holder_uninit(ghs + 2);

  	gfs2_glock_dq(ghs + 1);
  out_child:
  	gfs2_holder_uninit(ghs + 1);
  	gfs2_glock_dq(ghs);
  out_parent:
  	gfs2_holder_uninit(ghs);

  	gfs2_glock_dq_uninit(&ri_gh);

  	return error;
  }
  
  /**
   * gfs2_mknod - Make a special file
   * @dir: The directory in which the special file will reside
   * @dentry: The dentry of the special file
   * @mode: The mode of the special file
   * @rdev: The device specification of the special file
   *
   */
  
  static int gfs2_mknod(struct inode *dir, struct dentry *dentry, int mode,
  		      dev_t dev)
  {

  	struct gfs2_inode *dip = GFS2_I(dir);

  	struct gfs2_sbd *sdp = GFS2_SB(dir);

  	struct gfs2_holder ghs[2];
  	struct inode *inode;

  
  	gfs2_holder_init(dip->i_gl, 0, 0, ghs);

  	inode = gfs2_createi(ghs, &dentry->d_name, mode, dev);

  	if (IS_ERR(inode)) {

  		gfs2_holder_uninit(ghs);

  		return PTR_ERR(inode);

  	}

  	gfs2_trans_end(sdp);

  	if (dip->i_alloc->al_rgd)

  		gfs2_inplace_release(dip);
  	gfs2_quota_unlock(dip);
  	gfs2_alloc_put(dip);
  
  	gfs2_glock_dq_uninit_m(2, ghs);

  	d_instantiate(dentry, inode);
  	mark_inode_dirty(inode);
  
  	return 0;
  }

  /*
   * gfs2_ok_to_move - check if it's ok to move a directory to another directory
   * @this: move this
   * @to: to here
   *
   * Follow @to back to the root and make sure we don't encounter @this
   * Assumes we already hold the rename lock.
   *
   * Returns: errno
   */
  
  static int gfs2_ok_to_move(struct gfs2_inode *this, struct gfs2_inode *to)
  {
  	struct inode *dir = &to->i_inode;
  	struct super_block *sb = dir->i_sb;
  	struct inode *tmp;
  	struct qstr dotdot;
  	int error = 0;
  
  	gfs2_str2qstr(&dotdot, "..");
  
  	igrab(dir);
  
  	for (;;) {
  		if (dir == &this->i_inode) {
  			error = -EINVAL;
  			break;
  		}
  		if (dir == sb->s_root->d_inode) {
  			error = 0;
  			break;
  		}
  
  		tmp = gfs2_lookupi(dir, &dotdot, 1);
  		if (IS_ERR(tmp)) {
  			error = PTR_ERR(tmp);
  			break;
  		}
  
  		iput(dir);
  		dir = tmp;
  	}
  
  	iput(dir);
  
  	return error;
  }

  /**
   * gfs2_rename - Rename a file
   * @odir: Parent directory of old file name
   * @odentry: The old dentry of the file
   * @ndir: Parent directory of new file name
   * @ndentry: The new dentry of the file
   *
   * Returns: errno
   */
  
  static int gfs2_rename(struct inode *odir, struct dentry *odentry,
  		       struct inode *ndir, struct dentry *ndentry)
  {

  	struct gfs2_inode *odip = GFS2_I(odir);
  	struct gfs2_inode *ndip = GFS2_I(ndir);
  	struct gfs2_inode *ip = GFS2_I(odentry->d_inode);

  	struct gfs2_inode *nip = NULL;

  	struct gfs2_sbd *sdp = GFS2_SB(odir);

  	struct gfs2_holder ghs[5], r_gh = { .gh_gl = NULL, };

  	struct gfs2_rgrpd *nrgd;

  	unsigned int num_gh;
  	int dir_rename = 0;

  	int alloc_required = 0;

  	unsigned int x;
  	int error;

  	if (ndentry->d_inode) {

  		nip = GFS2_I(ndentry->d_inode);

  		if (ip == nip)
  			return 0;
  	}

  	if (odip != ndip) {
  		error = gfs2_glock_nq_init(sdp->sd_rename_gl, LM_ST_EXCLUSIVE,
  					   0, &r_gh);

  		if (error)
  			goto out;

  		if (S_ISDIR(ip->i_inode.i_mode)) {
  			dir_rename = 1;
  			/* don't move a dirctory into it's subdir */
  			error = gfs2_ok_to_move(ip, ndip);
  			if (error)
  				goto out_gunlock_r;
  		}

  	}

  	num_gh = 1;

  	gfs2_holder_init(odip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);

  	if (odip != ndip) {
  		gfs2_holder_init(ndip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
  		num_gh++;
  	}
  	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
  	num_gh++;

  	if (nip) {
  		gfs2_holder_init(nip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
  		num_gh++;

  		/* grab the resource lock for unlink flag twiddling 
  		 * this is the case of the target file already existing
  		 * so we unlink before doing the rename
  		 */

  		nrgd = gfs2_blk2rgrpd(sdp, nip->i_no_addr);

  		if (nrgd)
  			gfs2_holder_init(nrgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh++);

  	}

  	for (x = 0; x < num_gh; x++) {
  		error = gfs2_glock_nq(ghs + x);
  		if (error)
  			goto out_gunlock;
  	}

  
  	/* Check out the old directory */
  
  	error = gfs2_unlink_ok(odip, &odentry->d_name, ip);
  	if (error)
  		goto out_gunlock;
  
  	/* Check out the new directory */
  
  	if (nip) {
  		error = gfs2_unlink_ok(ndip, &ndentry->d_name, nip);
  		if (error)
  			goto out_gunlock;

  		if (S_ISDIR(nip->i_inode.i_mode)) {

  			if (nip->i_entries < 2) {

  				if (gfs2_consist_inode(nip))

  					gfs2_dinode_print(nip);

  				error = -EIO;
  				goto out_gunlock;
  			}

  			if (nip->i_entries > 2) {

  				error = -ENOTEMPTY;
  				goto out_gunlock;
  			}
  		}
  	} else {

  		error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC);

  		if (error)
  			goto out_gunlock;

  		error = gfs2_dir_check(ndir, &ndentry->d_name, NULL);

  		switch (error) {
  		case -ENOENT:
  			error = 0;
  			break;
  		case 0:
  			error = -EEXIST;
  		default:
  			goto out_gunlock;
  		};
  
  		if (odip != ndip) {

  			if (!ndip->i_inode.i_nlink) {

  				error = -EINVAL;
  				goto out_gunlock;
  			}

  			if (ndip->i_entries == (u32)-1) {

  				error = -EFBIG;
  				goto out_gunlock;
  			}

  			if (S_ISDIR(ip->i_inode.i_mode) &&

  			    ndip->i_inode.i_nlink == (u32)-1) {

  				error = -EMLINK;
  				goto out_gunlock;
  			}
  		}
  	}
  
  	/* Check out the dir to be renamed */
  
  	if (dir_rename) {

  		error = gfs2_permission(odentry->d_inode, MAY_WRITE);

  		if (error)
  			goto out_gunlock;
  	}

  	if (nip == NULL)
  		alloc_required = gfs2_diradd_alloc_required(ndir, &ndentry->d_name);
  	error = alloc_required;

  	if (error < 0)

  		goto out_gunlock;

  	error = 0;

  
  	if (alloc_required) {
  		struct gfs2_alloc *al = gfs2_alloc_get(ndip);

  		if (!al) {
  			error = -ENOMEM;
  			goto out_gunlock;
  		}

  		error = gfs2_quota_lock_check(ndip);

  		if (error)
  			goto out_alloc;

  		al->al_requested = sdp->sd_max_dirres;
  
  		error = gfs2_inplace_reserve(ndip);
  		if (error)
  			goto out_gunlock_q;

  		error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +

  					 al->al_rgd->rd_length +

  					 4 * RES_DINODE + 4 * RES_LEAF +

  					 RES_STATFS + RES_QUOTA + 4, 0);

  		if (error)
  			goto out_ipreserv;
  	} else {
  		error = gfs2_trans_begin(sdp, 4 * RES_DINODE +

  					 5 * RES_LEAF + 4, 0);

  		if (error)
  			goto out_gunlock;
  	}
  
  	/* Remove the target file, if it exists */
  
  	if (nip) {

  		if (S_ISDIR(nip->i_inode.i_mode))

  			error = gfs2_rmdiri(ndip, &ndentry->d_name, nip);
  		else {
  			error = gfs2_dir_del(ndip, &ndentry->d_name);
  			if (error)
  				goto out_end_trans;

  			error = gfs2_change_nlink(nip, -1);

  		}

  		if (error)
  			goto out_end_trans;
  	}
  
  	if (dir_rename) {
  		struct qstr name;

  		gfs2_str2qstr(&name, "..");

  
  		error = gfs2_change_nlink(ndip, +1);
  		if (error)
  			goto out_end_trans;
  		error = gfs2_change_nlink(odip, -1);
  		if (error)
  			goto out_end_trans;

  		error = gfs2_dir_mvino(ip, &name, ndip, DT_DIR);

  		if (error)
  			goto out_end_trans;
  	} else {
  		struct buffer_head *dibh;
  		error = gfs2_meta_inode_buffer(ip, &dibh);
  		if (error)
  			goto out_end_trans;

  		ip->i_inode.i_ctime = CURRENT_TIME;

  		gfs2_trans_add_bh(ip->i_gl, dibh, 1);

  		gfs2_dinode_out(ip, dibh->b_data);

  		brelse(dibh);
  	}
  
  	error = gfs2_dir_del(odip, &odentry->d_name);
  	if (error)
  		goto out_end_trans;

  	error = gfs2_dir_add(ndir, &ndentry->d_name, ip, IF2DT(ip->i_inode.i_mode));

  	if (error)
  		goto out_end_trans;

  out_end_trans:

  	gfs2_trans_end(sdp);

  out_ipreserv:

  	if (alloc_required)
  		gfs2_inplace_release(ndip);

  out_gunlock_q:

  	if (alloc_required)
  		gfs2_quota_unlock(ndip);

  out_alloc:

  	if (alloc_required)
  		gfs2_alloc_put(ndip);

  out_gunlock:

  	while (x--) {
  		gfs2_glock_dq(ghs + x);

  		gfs2_holder_uninit(ghs + x);

  	}

  out_gunlock_r:

  	if (r_gh.gh_gl)

  		gfs2_glock_dq_uninit(&r_gh);

  out:

  	return error;
  }
  
  /**

   * gfs2_follow_link - Follow a symbolic link
   * @dentry: The dentry of the link
   * @nd: Data that we pass to vfs_follow_link()

   *

   * This can handle symlinks of any size.

   *

   * Returns: 0 on success or error code

   */

  static void *gfs2_follow_link(struct dentry *dentry, struct nameidata *nd)

  {

  	struct gfs2_inode *ip = GFS2_I(dentry->d_inode);

  	struct gfs2_holder i_gh;
  	struct buffer_head *dibh;
  	unsigned int x;

  	char *buf;

  	int error;
  
  	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
  	error = gfs2_glock_nq(&i_gh);
  	if (error) {
  		gfs2_holder_uninit(&i_gh);

  		nd_set_link(nd, ERR_PTR(error));
  		return NULL;

  	}
  
  	if (!ip->i_disksize) {
  		gfs2_consist_inode(ip);

  		buf = ERR_PTR(-EIO);

  		goto out;
  	}
  
  	error = gfs2_meta_inode_buffer(ip, &dibh);

  	if (error) {
  		buf = ERR_PTR(error);

  		goto out;

  	}

  	x = ip->i_disksize + 1;
  	buf = kmalloc(x, GFP_NOFS);
  	if (!buf)
  		buf = ERR_PTR(-ENOMEM);
  	else
  		memcpy(buf, dibh->b_data + sizeof(struct gfs2_dinode), x);

  	brelse(dibh);
  out:
  	gfs2_glock_dq_uninit(&i_gh);

  	nd_set_link(nd, buf);
  	return NULL;

  }

  static void gfs2_put_link(struct dentry *dentry, struct nameidata *nd, void *p)

  {

  	char *s = nd_get_link(nd);
  	if (!IS_ERR(s))
  		kfree(s);

  }
  
  /**
   * gfs2_permission -
   * @inode:
   * @mask:
   * @nd: passed from Linux VFS, ignored by us
   *

   * This may be called from the VFS directly, or from within GFS2 with the
   * inode locked, so we look to see if the glock is already locked and only
   * lock the glock if its not already been done.
   *

   * Returns: errno
   */

  int gfs2_permission(struct inode *inode, int mask)

  {

  	struct gfs2_inode *ip = GFS2_I(inode);

  	struct gfs2_holder i_gh;
  	int error;

  	int unlock = 0;

  	if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) {

  		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
  		if (error)
  			return error;
  		unlock = 1;
  	}

  	if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode))
  		error = -EACCES;
  	else
  		error = generic_permission(inode, mask, gfs2_check_acl);

  	if (unlock)

  		gfs2_glock_dq_uninit(&i_gh);

  
  	return error;
  }

  /*

   * XXX(truncate): the truncate_setsize calls should be moved to the end.

   */

  static int setattr_size(struct inode *inode, struct iattr *attr)
  {

  	struct gfs2_inode *ip = GFS2_I(inode);

  	struct gfs2_sbd *sdp = GFS2_SB(inode);

  	int error;

  	if (attr->ia_size != ip->i_disksize) {

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

  		if (error)
  			return error;

  		truncate_setsize(inode, attr->ia_size);

  		gfs2_trans_end(sdp);

  	}

  	error = gfs2_truncatei(ip, attr->ia_size);

  	if (error && (inode->i_size != ip->i_disksize))
  		i_size_write(inode, ip->i_disksize);

  
  	return error;
  }
  
  static int setattr_chown(struct inode *inode, struct iattr *attr)
  {

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

  	struct buffer_head *dibh;

  	u32 ouid, ogid, nuid, ngid;

  	int error;

  	ouid = inode->i_uid;
  	ogid = inode->i_gid;

  	nuid = attr->ia_uid;
  	ngid = attr->ia_gid;
  
  	if (!(attr->ia_valid & ATTR_UID) || ouid == nuid)
  		ouid = nuid = NO_QUOTA_CHANGE;
  	if (!(attr->ia_valid & ATTR_GID) || ogid == ngid)
  		ogid = ngid = NO_QUOTA_CHANGE;

  	if (!gfs2_alloc_get(ip))
  		return -ENOMEM;

  
  	error = gfs2_quota_lock(ip, nuid, ngid);
  	if (error)
  		goto out_alloc;
  
  	if (ouid != NO_QUOTA_CHANGE || ogid != NO_QUOTA_CHANGE) {
  		error = gfs2_quota_check(ip, nuid, ngid);
  		if (error)
  			goto out_gunlock_q;
  	}
  
  	error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_QUOTA, 0);
  	if (error)
  		goto out_gunlock_q;
  
  	error = gfs2_meta_inode_buffer(ip, &dibh);
  	if (error)
  		goto out_end_trans;

  	if ((attr->ia_valid & ATTR_SIZE) &&
  	    attr->ia_size != i_size_read(inode)) {
  		int error;
  
  		error = vmtruncate(inode, attr->ia_size);
  		gfs2_assert_warn(sdp, !error);
  	}
  
  	setattr_copy(inode, attr);
  	mark_inode_dirty(inode);

  	gfs2_trans_add_bh(ip->i_gl, dibh, 1);

  	gfs2_dinode_out(ip, dibh->b_data);

  	brelse(dibh);
  
  	if (ouid != NO_QUOTA_CHANGE || ogid != NO_QUOTA_CHANGE) {

  		u64 blocks = gfs2_get_inode_blocks(&ip->i_inode);
  		gfs2_quota_change(ip, -blocks, ouid, ogid);
  		gfs2_quota_change(ip, blocks, nuid, ngid);

  	}

  out_end_trans:

  	gfs2_trans_end(sdp);

  out_gunlock_q:

  	gfs2_quota_unlock(ip);

  out_alloc:

  	gfs2_alloc_put(ip);

  	return error;
  }
  
  /**
   * gfs2_setattr - Change attributes on an inode
   * @dentry: The dentry which is changing
   * @attr: The structure describing the change
   *
   * The VFS layer wants to change one or more of an inodes attributes.  Write
   * that change out to disk.
   *
   * Returns: errno
   */
  
  static int gfs2_setattr(struct dentry *dentry, struct iattr *attr)
  {
  	struct inode *inode = dentry->d_inode;

  	struct gfs2_inode *ip = GFS2_I(inode);

  	struct gfs2_holder i_gh;
  	int error;

  	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
  	if (error)
  		return error;
  
  	error = -EPERM;
  	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
  		goto out;
  
  	error = inode_change_ok(inode, attr);
  	if (error)
  		goto out;
  
  	if (attr->ia_valid & ATTR_SIZE)
  		error = setattr_size(inode, attr);
  	else if (attr->ia_valid & (ATTR_UID | ATTR_GID))
  		error = setattr_chown(inode, attr);
  	else if ((attr->ia_valid & ATTR_MODE) && IS_POSIXACL(inode))
  		error = gfs2_acl_chmod(ip, attr);
  	else
  		error = gfs2_setattr_simple(ip, attr);

  out:

  	gfs2_glock_dq_uninit(&i_gh);

  	if (!error)
  		mark_inode_dirty(inode);

  	return error;
  }
  
  /**
   * gfs2_getattr - Read out an inode's attributes

   * @mnt: The vfsmount the inode is being accessed from

   * @dentry: The dentry to stat
   * @stat: The inode's stats
   *

   * This may be called from the VFS directly, or from within GFS2 with the
   * inode locked, so we look to see if the glock is already locked and only
   * lock the glock if its not already been done. Note that its the NFS
   * readdirplus operation which causes this to be called (from filldir)
   * with the glock already held.
   *

   * Returns: errno
   */
  
  static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
  			struct kstat *stat)
  {
  	struct inode *inode = dentry->d_inode;

  	struct gfs2_inode *ip = GFS2_I(inode);

  	struct gfs2_holder gh;
  	int error;

  	int unlock = 0;

  	if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) {

  		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
  		if (error)
  			return error;
  		unlock = 1;

  	}

  	generic_fillattr(inode, stat);

  	if (unlock)

  		gfs2_glock_dq_uninit(&gh);
  
  	return 0;

  }
  
  static int gfs2_setxattr(struct dentry *dentry, const char *name,
  			 const void *data, size_t size, int flags)
  {

  	struct inode *inode = dentry->d_inode;

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

  	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
  	ret = gfs2_glock_nq(&gh);
  	if (ret == 0) {
  		ret = generic_setxattr(dentry, name, data, size, flags);
  		gfs2_glock_dq(&gh);
  	}
  	gfs2_holder_uninit(&gh);
  	return ret;

  }
  
  static ssize_t gfs2_getxattr(struct dentry *dentry, const char *name,
  			     void *data, size_t size)
  {

  	struct inode *inode = dentry->d_inode;
  	struct gfs2_inode *ip = GFS2_I(inode);
  	struct gfs2_holder gh;
  	int ret;

  	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
  	ret = gfs2_glock_nq(&gh);
  	if (ret == 0) {
  		ret = generic_getxattr(dentry, name, data, size);
  		gfs2_glock_dq(&gh);
  	}
  	gfs2_holder_uninit(&gh);
  	return ret;

  }
  
  static int gfs2_removexattr(struct dentry *dentry, const char *name)
  {

  	struct inode *inode = dentry->d_inode;
  	struct gfs2_inode *ip = GFS2_I(inode);
  	struct gfs2_holder gh;
  	int ret;

  	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
  	ret = gfs2_glock_nq(&gh);
  	if (ret == 0) {
  		ret = generic_removexattr(dentry, name);
  		gfs2_glock_dq(&gh);
  	}
  	gfs2_holder_uninit(&gh);
  	return ret;

  }

  static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
  		       u64 start, u64 len)
  {
  	struct gfs2_inode *ip = GFS2_I(inode);
  	struct gfs2_holder gh;
  	int ret;
  
  	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
  	if (ret)
  		return ret;
  
  	mutex_lock(&inode->i_mutex);
  
  	ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
  	if (ret)
  		goto out;
  
  	if (gfs2_is_stuffed(ip)) {
  		u64 phys = ip->i_no_addr << inode->i_blkbits;
  		u64 size = i_size_read(inode);
  		u32 flags = FIEMAP_EXTENT_LAST|FIEMAP_EXTENT_NOT_ALIGNED|
  			    FIEMAP_EXTENT_DATA_INLINE;
  		phys += sizeof(struct gfs2_dinode);
  		phys += start;
  		if (start + len > size)
  			len = size - start;
  		if (start < size)
  			ret = fiemap_fill_next_extent(fieinfo, start, phys,
  						      len, flags);
  		if (ret == 1)
  			ret = 0;
  	} else {
  		ret = __generic_block_fiemap(inode, fieinfo, start, len,
  					     gfs2_block_map);
  	}
  
  	gfs2_glock_dq_uninit(&gh);
  out:
  	mutex_unlock(&inode->i_mutex);
  	return ret;
  }

  const struct inode_operations gfs2_file_iops = {

  	.permission = gfs2_permission,

  	.setattr = gfs2_setattr,
  	.getattr = gfs2_getattr,
  	.setxattr = gfs2_setxattr,
  	.getxattr = gfs2_getxattr,
  	.listxattr = gfs2_listxattr,
  	.removexattr = gfs2_removexattr,

  	.fiemap = gfs2_fiemap,

  };

  const struct inode_operations gfs2_dir_iops = {

  	.create = gfs2_create,
  	.lookup = gfs2_lookup,
  	.link = gfs2_link,
  	.unlink = gfs2_unlink,
  	.symlink = gfs2_symlink,
  	.mkdir = gfs2_mkdir,
  	.rmdir = gfs2_rmdir,
  	.mknod = gfs2_mknod,
  	.rename = gfs2_rename,

  	.permission = gfs2_permission,

  	.setattr = gfs2_setattr,
  	.getattr = gfs2_getattr,
  	.setxattr = gfs2_setxattr,
  	.getxattr = gfs2_getxattr,
  	.listxattr = gfs2_listxattr,
  	.removexattr = gfs2_removexattr,

  	.fiemap = gfs2_fiemap,

  };

  const struct inode_operations gfs2_symlink_iops = {

  	.readlink = generic_readlink,

  	.follow_link = gfs2_follow_link,

  	.put_link = gfs2_put_link,

  	.permission = gfs2_permission,

  	.setattr = gfs2_setattr,
  	.getattr = gfs2_getattr,
  	.setxattr = gfs2_setxattr,
  	.getxattr = gfs2_getxattr,
  	.listxattr = gfs2_listxattr,
  	.removexattr = gfs2_removexattr,

  	.fiemap = gfs2_fiemap,

  };