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

   * Copyright (C) 2004-2011 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 <linux/security.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"

  #include "glops.h"
  
  struct gfs2_skip_data {
  	u64 no_addr;
  	int skipped;
  	int non_block;
  };
  
  static int iget_test(struct inode *inode, void *opaque)
  {
  	struct gfs2_inode *ip = GFS2_I(inode);
  	struct gfs2_skip_data *data = opaque;
  
  	if (ip->i_no_addr == data->no_addr) {
  		if (data->non_block &&
  		    inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
  			data->skipped = 1;
  			return 0;
  		}
  		return 1;
  	}
  	return 0;
  }
  
  static int iget_set(struct inode *inode, void *opaque)
  {
  	struct gfs2_inode *ip = GFS2_I(inode);
  	struct gfs2_skip_data *data = opaque;
  
  	if (data->skipped)
  		return -ENOENT;
  	inode->i_ino = (unsigned long)(data->no_addr);
  	ip->i_no_addr = data->no_addr;
  	return 0;
  }
  
  struct inode *gfs2_ilookup(struct super_block *sb, u64 no_addr, int non_block)
  {
  	unsigned long hash = (unsigned long)no_addr;
  	struct gfs2_skip_data data;
  
  	data.no_addr = no_addr;
  	data.skipped = 0;
  	data.non_block = non_block;
  	return ilookup5(sb, hash, iget_test, &data);
  }
  
  static struct inode *gfs2_iget(struct super_block *sb, u64 no_addr,
  			       int non_block)
  {
  	struct gfs2_skip_data data;
  	unsigned long hash = (unsigned long)no_addr;
  
  	data.no_addr = no_addr;
  	data.skipped = 0;
  	data.non_block = non_block;
  	return iget5_locked(sb, hash, iget_test, iget_set, &data);
  }
  
  /**
   * gfs2_set_iop - Sets inode operations
   * @inode: The inode with correct i_mode filled in
   *
   * GFS2 lookup code fills in vfs inode contents based on info obtained
   * from directory entry inside gfs2_inode_lookup().
   */
  
  static void gfs2_set_iop(struct inode *inode)
  {
  	struct gfs2_sbd *sdp = GFS2_SB(inode);
  	umode_t mode = inode->i_mode;
  
  	if (S_ISREG(mode)) {
  		inode->i_op = &gfs2_file_iops;
  		if (gfs2_localflocks(sdp))
  			inode->i_fop = &gfs2_file_fops_nolock;
  		else
  			inode->i_fop = &gfs2_file_fops;
  	} else if (S_ISDIR(mode)) {
  		inode->i_op = &gfs2_dir_iops;
  		if (gfs2_localflocks(sdp))
  			inode->i_fop = &gfs2_dir_fops_nolock;
  		else
  			inode->i_fop = &gfs2_dir_fops;
  	} else if (S_ISLNK(mode)) {
  		inode->i_op = &gfs2_symlink_iops;
  	} else {
  		inode->i_op = &gfs2_file_iops;
  		init_special_inode(inode, inode->i_mode, inode->i_rdev);
  	}
  }
  
  /**
   * gfs2_inode_lookup - Lookup an inode
   * @sb: The super block
   * @no_addr: The inode number
   * @type: The type of the inode
   * non_block: Can we block on inodes that are being freed?
   *
   * Returns: A VFS inode, or an error
   */
  
  struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned int type,
  				u64 no_addr, u64 no_formal_ino, int non_block)
  {
  	struct inode *inode;
  	struct gfs2_inode *ip;
  	struct gfs2_glock *io_gl = NULL;
  	int error;
  
  	inode = gfs2_iget(sb, no_addr, non_block);
  	ip = GFS2_I(inode);
  
  	if (!inode)
  		return ERR_PTR(-ENOBUFS);
  
  	if (inode->i_state & I_NEW) {
  		struct gfs2_sbd *sdp = GFS2_SB(inode);
  		ip->i_no_formal_ino = no_formal_ino;
  
  		error = gfs2_glock_get(sdp, no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);
  		if (unlikely(error))
  			goto fail;
  		ip->i_gl->gl_object = ip;
  
  		error = gfs2_glock_get(sdp, no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
  		if (unlikely(error))
  			goto fail_put;
  
  		set_bit(GIF_INVALID, &ip->i_flags);
  		error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
  		if (unlikely(error))
  			goto fail_iopen;
  
  		ip->i_iopen_gh.gh_gl->gl_object = ip;
  		gfs2_glock_put(io_gl);
  		io_gl = NULL;
  
  		if (type == DT_UNKNOWN) {
  			/* Inode glock must be locked already */
  			error = gfs2_inode_refresh(GFS2_I(inode));
  			if (error)
  				goto fail_refresh;
  		} else {
  			inode->i_mode = DT2IF(type);
  		}
  
  		gfs2_set_iop(inode);
  		unlock_new_inode(inode);
  	}
  
  	return inode;
  
  fail_refresh:
  	ip->i_iopen_gh.gh_gl->gl_object = NULL;
  	gfs2_glock_dq_uninit(&ip->i_iopen_gh);
  fail_iopen:
  	if (io_gl)
  		gfs2_glock_put(io_gl);
  fail_put:
  	ip->i_gl->gl_object = NULL;
  	gfs2_glock_put(ip->i_gl);
  fail:
  	iget_failed(inode);
  	return ERR_PTR(error);
  }
  
  struct inode *gfs2_lookup_by_inum(struct gfs2_sbd *sdp, u64 no_addr,
  				  u64 *no_formal_ino, unsigned int blktype)
  {
  	struct super_block *sb = sdp->sd_vfs;
  	struct gfs2_holder i_gh;
  	struct inode *inode = NULL;
  	int error;
  
  	/* Must not read in block until block type is verified */
  	error = gfs2_glock_nq_num(sdp, no_addr, &gfs2_inode_glops,
  				  LM_ST_EXCLUSIVE, GL_SKIP, &i_gh);
  	if (error)
  		return ERR_PTR(error);
  
  	error = gfs2_check_blk_type(sdp, no_addr, blktype);
  	if (error)
  		goto fail;
  
  	inode = gfs2_inode_lookup(sb, DT_UNKNOWN, no_addr, 0, 1);
  	if (IS_ERR(inode))
  		goto fail;
  
  	/* Two extra checks for NFS only */
  	if (no_formal_ino) {
  		error = -ESTALE;
  		if (GFS2_I(inode)->i_no_formal_ino != *no_formal_ino)
  			goto fail_iput;
  
  		error = -EIO;
  		if (GFS2_I(inode)->i_diskflags & GFS2_DIF_SYSTEM)
  			goto fail_iput;
  
  		error = 0;
  	}
  
  fail:
  	gfs2_glock_dq_uninit(&i_gh);
  	return error ? ERR_PTR(error) : inode;
  fail_iput:
  	iput(inode);
  	goto fail;
  }
  
  
  struct inode *gfs2_lookup_simple(struct inode *dip, const char *name)
  {
  	struct qstr qstr;
  	struct inode *inode;
  	gfs2_str2qstr(&qstr, name);
  	inode = gfs2_lookupi(dip, &qstr, 1);
  	/* gfs2_lookupi has inconsistent callers: vfs
  	 * related routines expect NULL for no entry found,
  	 * gfs2_lookup_simple callers expect ENOENT
  	 * and do not check for NULL.
  	 */
  	if (inode == NULL)
  		return ERR_PTR(-ENOENT);
  	else
  		return inode;
  }
  
  
  /**
   * gfs2_lookupi - Look up a filename in a directory and return its inode
   * @d_gh: An initialized holder for the directory glock
   * @name: The name of the inode to look for
   * @is_root: If 1, ignore the caller's permissions
   * @i_gh: An uninitialized holder for the new inode glock
   *
   * This can be called via the VFS filldir function when NFS is doing
   * a readdirplus and the inode which its intending to stat isn't
   * already in cache. In this case we must not take the directory glock
   * again, since the readdir call will have already taken that lock.
   *
   * Returns: errno
   */
  
  struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
  			   int is_root)
  {
  	struct super_block *sb = dir->i_sb;
  	struct gfs2_inode *dip = GFS2_I(dir);
  	struct gfs2_holder d_gh;
  	int error = 0;
  	struct inode *inode = NULL;
  	int unlock = 0;
  
  	if (!name->len || name->len > GFS2_FNAMESIZE)
  		return ERR_PTR(-ENAMETOOLONG);
  
  	if ((name->len == 1 && memcmp(name->name, ".", 1) == 0) ||
  	    (name->len == 2 && memcmp(name->name, "..", 2) == 0 &&
  	     dir == sb->s_root->d_inode)) {
  		igrab(dir);
  		return dir;
  	}
  
  	if (gfs2_glock_is_locked_by_me(dip->i_gl) == NULL) {
  		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
  		if (error)
  			return ERR_PTR(error);
  		unlock = 1;
  	}
  
  	if (!is_root) {

  		error = gfs2_permission(dir, MAY_EXEC);

  		if (error)
  			goto out;
  	}
  
  	inode = gfs2_dir_search(dir, name);
  	if (IS_ERR(inode))
  		error = PTR_ERR(inode);
  out:
  	if (unlock)
  		gfs2_glock_dq_uninit(&d_gh);
  	if (error == -ENOENT)
  		return NULL;
  	return inode ? inode : ERR_PTR(error);
  }
  
  /**
   * create_ok - OK to create a new on-disk inode here?
   * @dip:  Directory in which dinode is to be created
   * @name:  Name of new dinode
   * @mode:
   *
   * Returns: errno
   */
  
  static int create_ok(struct gfs2_inode *dip, const struct qstr *name,

  		     umode_t mode)

  {
  	int error;

  	error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);

  	if (error)
  		return error;
  
  	/*  Don't create entries in an unlinked directory  */
  	if (!dip->i_inode.i_nlink)
  		return -ENOENT;
  
  	error = gfs2_dir_check(&dip->i_inode, name, NULL);
  	switch (error) {
  	case -ENOENT:
  		error = 0;
  		break;
  	case 0:
  		return -EEXIST;
  	default:
  		return error;
  	}
  
  	if (dip->i_entries == (u32)-1)
  		return -EFBIG;
  	if (S_ISDIR(mode) && dip->i_inode.i_nlink == (u32)-1)
  		return -EMLINK;
  
  	return 0;
  }

  static void munge_mode_uid_gid(struct gfs2_inode *dip, umode_t *mode,

  			       unsigned int *uid, unsigned int *gid)
  {
  	if (GFS2_SB(&dip->i_inode)->sd_args.ar_suiddir &&
  	    (dip->i_inode.i_mode & S_ISUID) && dip->i_inode.i_uid) {
  		if (S_ISDIR(*mode))
  			*mode |= S_ISUID;
  		else if (dip->i_inode.i_uid != current_fsuid())
  			*mode &= ~07111;
  		*uid = dip->i_inode.i_uid;
  	} else
  		*uid = current_fsuid();
  
  	if (dip->i_inode.i_mode & S_ISGID) {
  		if (S_ISDIR(*mode))
  			*mode |= S_ISGID;
  		*gid = dip->i_inode.i_gid;
  	} else
  		*gid = current_fsgid();
  }
  
  static int alloc_dinode(struct gfs2_inode *dip, u64 *no_addr, u64 *generation)
  {
  	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
  	int error;

  	int dblocks = 1;

  	error = gfs2_rindex_update(sdp);
  	if (error)
  		fs_warn(sdp, "rindex update returns %d
  ", error);

  	error = gfs2_inplace_reserve(dip, RES_DINODE);

  	if (error)
  		goto out;
  
  	error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS, 0);
  	if (error)
  		goto out_ipreserv;

  	error = gfs2_alloc_blocks(dip, no_addr, &dblocks, 1, generation);

  
  	gfs2_trans_end(sdp);
  
  out_ipreserv:
  	gfs2_inplace_release(dip);
  out:

  	return error;
  }

  static void gfs2_init_dir(struct buffer_head *dibh,
  			  const struct gfs2_inode *parent)

  {
  	struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data;
  	struct gfs2_dirent *dent = (struct gfs2_dirent *)(di+1);
  
  	gfs2_qstr2dirent(&gfs2_qdot, GFS2_DIRENT_SIZE(gfs2_qdot.len), dent);
  	dent->de_inum = di->di_num; /* already GFS2 endian */
  	dent->de_type = cpu_to_be16(DT_DIR);
  
  	dent = (struct gfs2_dirent *)((char*)dent + GFS2_DIRENT_SIZE(1));
  	gfs2_qstr2dirent(&gfs2_qdotdot, dibh->b_size - GFS2_DIRENT_SIZE(1) - sizeof(struct gfs2_dinode), dent);
  	gfs2_inum_out(parent, dent);
  	dent->de_type = cpu_to_be16(DT_DIR);
  	
  }

  /**
   * init_dinode - Fill in a new dinode structure

   * @dip: The directory this inode is being created in

   * @gl: The glock covering the new inode

   * @inum: The inode number
   * @mode: The file permissions
   * @uid: The uid of the new inode
   * @gid: The gid of the new inode
   * @generation: The generation number of the new inode
   * @dev: The device number (if a device node)
   * @symname: The symlink destination (if a symlink)
   * @size: The inode size (ignored for directories)
   * @bhp: The buffer head (returned to caller)

   *
   */
  
  static void init_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,

  			const struct gfs2_inum_host *inum, umode_t mode,

  			unsigned int uid, unsigned int gid,

  			const u64 *generation, dev_t dev, const char *symname,
  			unsigned size, struct buffer_head **bhp)

  {
  	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
  	struct gfs2_dinode *di;
  	struct buffer_head *dibh;
  	struct timespec tv = CURRENT_TIME;
  
  	dibh = gfs2_meta_new(gl, inum->no_addr);
  	gfs2_trans_add_bh(gl, dibh, 1);
  	gfs2_metatype_set(dibh, GFS2_METATYPE_DI, GFS2_FORMAT_DI);
  	gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
  	di = (struct gfs2_dinode *)dibh->b_data;
  
  	di->di_num.no_formal_ino = cpu_to_be64(inum->no_formal_ino);
  	di->di_num.no_addr = cpu_to_be64(inum->no_addr);
  	di->di_mode = cpu_to_be32(mode);
  	di->di_uid = cpu_to_be32(uid);
  	di->di_gid = cpu_to_be32(gid);
  	di->di_nlink = 0;

  	di->di_size = cpu_to_be64(size);

  	di->di_blocks = cpu_to_be64(1);
  	di->di_atime = di->di_mtime = di->di_ctime = cpu_to_be64(tv.tv_sec);
  	di->di_major = cpu_to_be32(MAJOR(dev));
  	di->di_minor = cpu_to_be32(MINOR(dev));
  	di->di_goal_meta = di->di_goal_data = cpu_to_be64(inum->no_addr);
  	di->di_generation = cpu_to_be64(*generation);
  	di->di_flags = 0;

  	di->__pad1 = 0;
  	di->di_payload_format = cpu_to_be32(S_ISDIR(mode) ? GFS2_FORMAT_DE : 0);
  	di->di_height = 0;
  	di->__pad2 = 0;
  	di->__pad3 = 0;
  	di->di_depth = 0;
  	di->di_entries = 0;
  	memset(&di->__pad4, 0, sizeof(di->__pad4));
  	di->di_eattr = 0;
  	di->di_atime_nsec = cpu_to_be32(tv.tv_nsec);
  	di->di_mtime_nsec = cpu_to_be32(tv.tv_nsec);
  	di->di_ctime_nsec = cpu_to_be32(tv.tv_nsec);
  	memset(&di->di_reserved, 0, sizeof(di->di_reserved));

  
  	switch(mode & S_IFMT) {	
  	case S_IFREG:

  		if ((dip->i_diskflags & GFS2_DIF_INHERIT_JDATA) ||
  		    gfs2_tune_get(sdp, gt_new_files_jdata))
  			di->di_flags |= cpu_to_be32(GFS2_DIF_JDATA);

  		break;
  	case S_IFDIR:

  		di->di_flags |= cpu_to_be32(dip->i_diskflags &
  					    GFS2_DIF_INHERIT_JDATA);
  		di->di_flags |= cpu_to_be32(GFS2_DIF_JDATA);
  		di->di_size = cpu_to_be64(sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode));
  		di->di_entries = cpu_to_be32(2);
  		gfs2_init_dir(dibh, dip);

  		break;
  	case S_IFLNK:
  		memcpy(dibh->b_data + sizeof(struct gfs2_dinode), symname, size);
  		break;

  	}

  	set_buffer_uptodate(dibh);
  
  	*bhp = dibh;
  }
  
  static int make_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,

  		       umode_t mode, const struct gfs2_inum_host *inum,

  		       const u64 *generation, dev_t dev, const char *symname,
  		       unsigned int size, struct buffer_head **bhp)

  {
  	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
  	unsigned int uid, gid;
  	int error;
  
  	munge_mode_uid_gid(dip, &mode, &uid, &gid);

  	if (!gfs2_qadata_get(dip))

  		return -ENOMEM;
  
  	error = gfs2_quota_lock(dip, uid, gid);
  	if (error)
  		goto out;
  
  	error = gfs2_quota_check(dip, uid, gid);
  	if (error)
  		goto out_quota;
  
  	error = gfs2_trans_begin(sdp, RES_DINODE + RES_QUOTA, 0);
  	if (error)
  		goto out_quota;

  	init_dinode(dip, gl, inum, mode, uid, gid, generation, dev, symname, size, bhp);

  	gfs2_quota_change(dip, +1, uid, gid);
  	gfs2_trans_end(sdp);
  
  out_quota:
  	gfs2_quota_unlock(dip);
  out:

  	gfs2_qadata_put(dip);

  	return error;
  }
  
  static int link_dinode(struct gfs2_inode *dip, const struct qstr *name,
  		       struct gfs2_inode *ip)
  {
  	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);

  	struct gfs2_qadata *qa;

  	int alloc_required;
  	struct buffer_head *dibh;
  	int error;

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

  		return -ENOMEM;
  
  	error = gfs2_quota_lock(dip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
  	if (error)
  		goto fail;
  
  	error = alloc_required = gfs2_diradd_alloc_required(&dip->i_inode, name);
  	if (alloc_required < 0)
  		goto fail_quota_locks;
  	if (alloc_required) {
  		error = gfs2_quota_check(dip, dip->i_inode.i_uid, dip->i_inode.i_gid);
  		if (error)
  			goto fail_quota_locks;

  		error = gfs2_inplace_reserve(dip, sdp->sd_max_dirres);

  		if (error)
  			goto fail_quota_locks;
  
  		error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +

  					 dip->i_rgd->rd_length +

  					 2 * RES_DINODE +
  					 RES_STATFS + RES_QUOTA, 0);
  		if (error)
  			goto fail_ipreserv;
  	} else {
  		error = gfs2_trans_begin(sdp, RES_LEAF + 2 * RES_DINODE, 0);
  		if (error)
  			goto fail_quota_locks;
  	}
  
  	error = gfs2_dir_add(&dip->i_inode, name, ip);
  	if (error)
  		goto fail_end_trans;
  
  	error = gfs2_meta_inode_buffer(ip, &dibh);
  	if (error)
  		goto fail_end_trans;

  	set_nlink(&ip->i_inode, S_ISDIR(ip->i_inode.i_mode) ? 2 : 1);

  	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
  	gfs2_dinode_out(ip, dibh->b_data);
  	brelse(dibh);
  	return 0;
  
  fail_end_trans:
  	gfs2_trans_end(sdp);
  
  fail_ipreserv:

  	gfs2_inplace_release(dip);

  
  fail_quota_locks:
  	gfs2_quota_unlock(dip);
  
  fail:

  	gfs2_qadata_put(dip);

  	return error;
  }

  static int gfs2_initxattrs(struct inode *inode, const struct xattr *xattr_array,

  		    void *fs_info)

  {

  	const struct xattr *xattr;
  	int err = 0;
  
  	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
  		err = __gfs2_xattr_set(inode, xattr->name, xattr->value,
  				       xattr->value_len, 0,
  				       GFS2_EATYPE_SECURITY);
  		if (err < 0)
  			break;

  	}

  	return err;
  }

  static int gfs2_security_init(struct gfs2_inode *dip, struct gfs2_inode *ip,
  			      const struct qstr *qstr)
  {
  	return security_inode_init_security(&ip->i_inode, &dip->i_inode, qstr,
  					    &gfs2_initxattrs, NULL);
  }

  /**

   * gfs2_create_inode - Create a new inode
   * @dir: The parent directory
   * @dentry: The new dentry
   * @mode: The permissions on the new inode
   * @dev: For device nodes, this is the device number
   * @symname: For symlinks, this is the link destination
   * @size: The initial size of the inode (ignored for directories)

   *

   * Returns: 0 on success, or error code

   */

  static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,

  			     umode_t mode, dev_t dev, const char *symname,

  			     unsigned int size, int excl)

  {

  	const struct qstr *name = &dentry->d_name;
  	struct gfs2_holder ghs[2];

  	struct inode *inode = NULL;

  	struct gfs2_inode *dip = GFS2_I(dir);

  	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
  	struct gfs2_inum_host inum = { .no_addr = 0, .no_formal_ino = 0 };
  	int error;
  	u64 generation;
  	struct buffer_head *bh = NULL;
  
  	if (!name->len || name->len > GFS2_FNAMESIZE)

  		return -ENAMETOOLONG;

  	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);

  	if (error)
  		goto fail;
  
  	error = create_ok(dip, name, mode);

  	if ((error == -EEXIST) && S_ISREG(mode) && !excl) {
  		inode = gfs2_lookupi(dir, &dentry->d_name, 0);
  		gfs2_glock_dq_uninit(ghs);
  		d_instantiate(dentry, inode);
  		return IS_ERR(inode) ? PTR_ERR(inode) : 0;
  	}

  	if (error)
  		goto fail_gunlock;
  
  	error = alloc_dinode(dip, &inum.no_addr, &generation);
  	if (error)
  		goto fail_gunlock;
  	inum.no_formal_ino = generation;
  
  	error = gfs2_glock_nq_num(sdp, inum.no_addr, &gfs2_inode_glops,
  				  LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
  	if (error)
  		goto fail_gunlock;

  	error = make_dinode(dip, ghs[1].gh_gl, mode, &inum, &generation, dev, symname, size, &bh);

  	if (error)
  		goto fail_gunlock2;
  
  	inode = gfs2_inode_lookup(dir->i_sb, IF2DT(mode), inum.no_addr,
  				  inum.no_formal_ino, 0);
  	if (IS_ERR(inode))
  		goto fail_gunlock2;
  
  	error = gfs2_inode_refresh(GFS2_I(inode));
  	if (error)
  		goto fail_gunlock2;
  
  	error = gfs2_acl_create(dip, inode);
  	if (error)
  		goto fail_gunlock2;
  
  	error = gfs2_security_init(dip, GFS2_I(inode), name);
  	if (error)
  		goto fail_gunlock2;
  
  	error = link_dinode(dip, name, GFS2_I(inode));
  	if (error)
  		goto fail_gunlock2;
  
  	if (bh)
  		brelse(bh);

  
  	gfs2_trans_end(sdp);

  	/* Check if we reserved space in the rgrp. Function link_dinode may
  	   not, depending on whether alloc is required. */
  	if (dip->i_res)
  		gfs2_inplace_release(dip);

  	gfs2_quota_unlock(dip);

  	gfs2_qadata_put(dip);

  	mark_inode_dirty(inode);

  	gfs2_glock_dq_uninit_m(2, ghs);

  	d_instantiate(dentry, inode);
  	return 0;

  
  fail_gunlock2:
  	gfs2_glock_dq_uninit(ghs + 1);

  fail_gunlock:

  	gfs2_glock_dq_uninit(ghs);

  	if (inode && !IS_ERR(inode)) {
  		set_bit(GIF_ALLOC_FAILED, &GFS2_I(inode)->i_flags);
  		iput(inode);
  	}

  fail:
  	if (bh)
  		brelse(bh);

  	return error;

  }

  /**

   * 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,

  		       umode_t mode, struct nameidata *nd)

  {

  	int excl = 0;
  	if (nd && (nd->flags & LOOKUP_EXCL))
  		excl = 1;
  	return gfs2_create_inode(dir, dentry, S_IFREG | mode, 0, NULL, 0, excl);

  }
  
  /**
   * 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 = gfs2_lookupi(dir, &dentry->d_name, 0);
  	if (inode && !IS_ERR(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);

  }
  
  /**
   * 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];

  	struct buffer_head *dibh;

  	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 = -ENOENT;
  	if (inode->i_nlink == 0)
  		goto out_gunlock;

  	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_qadata *qa = gfs2_qadata_get(dip);
  
  		if (!qa) {

  			error = -ENOMEM;
  			goto out_gunlock;
  		}

  		error = gfs2_quota_lock_check(dip);

  		if (error)
  			goto out_alloc;

  		error = gfs2_inplace_reserve(dip, sdp->sd_max_dirres);

  		if (error)
  			goto out_gunlock_q;

  		error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +

  					 gfs2_rg_blocks(dip) +

  					 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_meta_inode_buffer(ip, &dibh);

  	if (error)
  		goto out_end_trans;

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

  	if (error)
  		goto out_brelse;
  
  	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
  	inc_nlink(&ip->i_inode);
  	ip->i_inode.i_ctime = CURRENT_TIME;

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

  out_brelse:
  	brelse(dibh);

  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_qadata_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);

  	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_inode - Removes an inode from its parent dir and unlinks it
   * @dip: The parent directory
   * @name: The name of the entry in the parent directory
   * @bh: The inode buffer for the inode to be removed
   * @inode: The inode to be removed
   *
   * Called with all the locks and in a transaction. This will only be
   * called for a directory after it has been checked to ensure it is empty.
   *
   * Returns: 0 on success, or an error
   */
  
  static int gfs2_unlink_inode(struct gfs2_inode *dip,
  			     const struct dentry *dentry,
  			     struct buffer_head *bh)
  {
  	struct inode *inode = dentry->d_inode;
  	struct gfs2_inode *ip = GFS2_I(inode);
  	int error;
  
  	error = gfs2_dir_del(dip, dentry);
  	if (error)
  		return error;
  
  	ip->i_entries = 0;
  	inode->i_ctime = CURRENT_TIME;
  	if (S_ISDIR(inode->i_mode))
  		clear_nlink(inode);
  	else
  		drop_nlink(inode);

  	mark_inode_dirty(inode);
  	if (inode->i_nlink == 0)
  		gfs2_unlink_di(inode);
  	return 0;
  }
  
  
  /**
   * gfs2_unlink - Unlink an inode (this does rmdir as well)
   * @dir: The inode of the directory containing the inode to unlink

   * @dentry: The file itself
   *

   * This routine uses the type of the inode as a flag to figure out
   * whether this is an unlink or an rmdir.

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

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

  	int error = -EROFS;

  	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);

  	if (!rgd)
  		goto out_inodes;

  	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 = -ENOENT;

  	if (inode->i_nlink == 0)

  		goto out_rgrp;

  	if (S_ISDIR(inode->i_mode)) {
  		error = -ENOTEMPTY;
  		if (ip->i_entries > 2 || inode->i_nlink > 2)
  			goto out_rgrp;
  	}

  	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 + 3*RES_LEAF + RES_RG_BIT, 0);

  	if (error)

  		goto out_gunlock;

  	error = gfs2_meta_inode_buffer(ip, &bh);
  	if (error)
  		goto out_end_trans;

  	error = gfs2_unlink_inode(dip, dentry, bh);
  	brelse(bh);

  out_end_trans:
  	gfs2_trans_end(sdp);

  out_gunlock:

  	gfs2_glock_dq(ghs + 2);
  out_rgrp:

  	gfs2_glock_dq(ghs + 1);
  out_child:

  	gfs2_glock_dq(ghs);
  out_parent:

  	gfs2_holder_uninit(ghs + 2);
  out_inodes:
  	gfs2_holder_uninit(ghs + 1);

  	gfs2_holder_uninit(ghs);

  	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_sbd *sdp = GFS2_SB(dir);

  	unsigned int size;

  	size = strlen(symname);
  	if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode) - 1)
  		return -ENAMETOOLONG;

  	return gfs2_create_inode(dir, dentry, S_IFLNK | S_IRWXUGO, 0, symname, size, 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, umode_t mode)

  {

  	return gfs2_create_inode(dir, dentry, S_IFDIR | mode, 0, NULL, 0, 0);

  }
  
  /**

   * 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

   * @dev: The device specification of the special file

   *
   */

  static int gfs2_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,

  		      dev_t dev)
  {

  	return gfs2_create_inode(dir, dentry, mode, dev, NULL, 0, 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;

  	int error = 0;

  	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, &gfs2_qdotdot, 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;
  	}

  	error = -ENOENT;
  	if (ip->i_inode.i_nlink == 0)
  		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 (nip->i_inode.i_nlink == 0) {
  			error = -EAGAIN;
  			goto out_gunlock;
  		}

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

  			if (nip->i_entries < 2) {

  				gfs2_consist_inode(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 = -ENOENT;

  				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_qadata *qa = gfs2_qadata_get(ndip);
  
  		if (!qa) {

  			error = -ENOMEM;
  			goto out_gunlock;
  		}

  		error = gfs2_quota_lock_check(ndip);

  		if (error)
  			goto out_alloc;

  		error = gfs2_inplace_reserve(ndip, sdp->sd_max_dirres);

  		if (error)
  			goto out_gunlock_q;

  		error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +

  					 gfs2_rg_blocks(ndip) +

  					 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) {

  		struct buffer_head *bh;
  		error = gfs2_meta_inode_buffer(nip, &bh);

  		if (error)
  			goto out_end_trans;

  		error = gfs2_unlink_inode(ndip, ndentry, bh);
  		brelse(bh);

  	}
  
  	if (dir_rename) {

  		error = gfs2_dir_mvino(ip, &gfs2_qdotdot, 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);

  	if (error)
  		goto out_end_trans;

  	error = gfs2_dir_add(ndir, &ndentry->d_name, ip);

  	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_qadata_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 size;

  	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;

  	}

  	size = (unsigned int)i_size_read(&ip->i_inode);
  	if (size == 0) {

  		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;

  	}

  	buf = kzalloc(size + 1, GFP_NOFS);

  	if (!buf)
  		buf = ERR_PTR(-ENOMEM);
  	else

  		memcpy(buf, dibh->b_data + sizeof(struct gfs2_dinode), size);

  	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: The inode
   * @mask: The mask to be tested
   * @flags: Indicates whether this is an RCU path walk or not

   *

   * 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;

  	struct gfs2_holder i_gh;
  	int error;

  	int unlock = 0;

  
  	ip = GFS2_I(inode);

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

  		if (mask & MAY_NOT_BLOCK)

  			return -ECHILD;

  		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);

  	if (unlock)

  		gfs2_glock_dq_uninit(&i_gh);

  
  	return error;
  }

  static int __gfs2_setattr_simple(struct inode *inode, struct iattr *attr)

  {

  	setattr_copy(inode, attr);
  	mark_inode_dirty(inode);

  	return 0;
  }
  
  /**
   * gfs2_setattr_simple -
   * @ip:
   * @attr:
   *
   * Returns: errno
   */

  int gfs2_setattr_simple(struct inode *inode, struct iattr *attr)

  {
  	int error;
  
  	if (current->journal_info)

  		return __gfs2_setattr_simple(inode, attr);

  	error = gfs2_trans_begin(GFS2_SB(inode), RES_DINODE, 0);

  	if (error)
  		return error;

  	error = __gfs2_setattr_simple(inode, attr);
  	gfs2_trans_end(GFS2_SB(inode));

  	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);

  	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_qadata_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_setattr_simple(inode, attr);

  	if (error)
  		goto out_end_trans;

  	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_qadata_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 = gfs2_setattr_size(inode, attr->ia_size);

  	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(inode, attr);

  out:

  	if (!error)
  		mark_inode_dirty(inode);

  	gfs2_glock_dq_uninit(&i_gh);

  	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,

  	.get_acl = gfs2_get_acl,

  };

  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_unlink,

  	.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,

  	.get_acl = gfs2_get_acl,

  };

  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,

  	.get_acl = gfs2_get_acl,

  };