/*
   *   fs/cifs/dir.c
   *
   *   vfs operations that deal with dentries
   *
   *   Copyright (C) International Business Machines  Corp., 2002,2009
   *   Author(s): Steve French (sfrench@us.ibm.com)
   *
   *   This library is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU Lesser General Public License as published
   *   by the Free Software Foundation; either version 2.1 of the License, or
   *   (at your option) any later version.
   *
   *   This library is distributed in the hope that it will be useful,
   *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
   *   the GNU Lesser General Public License for more details.
   *
   *   You should have received a copy of the GNU Lesser General Public License
   *   along with this library; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  #include <linux/fs.h>
  #include <linux/stat.h>
  #include <linux/slab.h>
  #include <linux/namei.h>
  #include <linux/mount.h>
  #include <linux/file.h>
  #include "cifsfs.h"
  #include "cifspdu.h"
  #include "cifsglob.h"
  #include "cifsproto.h"
  #include "cifs_debug.h"
  #include "cifs_fs_sb.h"
  #include "cifs_unicode.h"
  
  static void
  renew_parental_timestamps(struct dentry *direntry)
  {
  	/* BB check if there is a way to get the kernel to do this or if we
  	   really need this */
  	do {
  		direntry->d_time = jiffies;
  		direntry = direntry->d_parent;
  	} while (!IS_ROOT(direntry));
  }
  
  char *
  cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,
  			struct cifs_tcon *tcon)
  {
  	int pplen = vol->prepath ? strlen(vol->prepath) + 1 : 0;
  	int dfsplen;
  	char *full_path = NULL;
  
  	/* if no prefix path, simply set path to the root of share to "" */
  	if (pplen == 0) {
  		full_path = kzalloc(1, GFP_KERNEL);
  		return full_path;
  	}
  
  	if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
  		dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
  	else
  		dfsplen = 0;
  
  	full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
  	if (full_path == NULL)
  		return full_path;
  
  	if (dfsplen)
  		strncpy(full_path, tcon->treeName, dfsplen);
  	full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
  	strncpy(full_path + dfsplen + 1, vol->prepath, pplen);
  	convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
  	full_path[dfsplen + pplen] = 0; /* add trailing null */
  	return full_path;
  }
  
  /* Note: caller must free return buffer */
  char *
  build_path_from_dentry(struct dentry *direntry)
  {
  	struct dentry *temp;
  	int namelen;
  	int dfsplen;
  	int pplen = 0;
  	char *full_path;
  	char dirsep;
  	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
  	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
  	unsigned seq;
  
  	dirsep = CIFS_DIR_SEP(cifs_sb);
  	if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
  		dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
  	else
  		dfsplen = 0;
  
  	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
  		pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
  
  cifs_bp_rename_retry:
  	namelen = dfsplen + pplen;
  	seq = read_seqbegin(&rename_lock);
  	rcu_read_lock();
  	for (temp = direntry; !IS_ROOT(temp);) {
  		namelen += (1 + temp->d_name.len);
  		temp = temp->d_parent;
  		if (temp == NULL) {
  			cifs_dbg(VFS, "corrupt dentry
  ");
  			rcu_read_unlock();
  			return NULL;
  		}
  	}
  	rcu_read_unlock();
  
  	full_path = kmalloc(namelen+1, GFP_KERNEL);
  	if (full_path == NULL)
  		return full_path;
  	full_path[namelen] = 0;	/* trailing null */
  	rcu_read_lock();
  	for (temp = direntry; !IS_ROOT(temp);) {
  		spin_lock(&temp->d_lock);
  		namelen -= 1 + temp->d_name.len;
  		if (namelen < 0) {
  			spin_unlock(&temp->d_lock);
  			break;
  		} else {
  			full_path[namelen] = dirsep;
  			strncpy(full_path + namelen + 1, temp->d_name.name,
  				temp->d_name.len);
  			cifs_dbg(FYI, "name: %s
  ", full_path + namelen);
  		}
  		spin_unlock(&temp->d_lock);
  		temp = temp->d_parent;
  		if (temp == NULL) {
  			cifs_dbg(VFS, "corrupt dentry
  ");
  			rcu_read_unlock();
  			kfree(full_path);
  			return NULL;
  		}
  	}
  	rcu_read_unlock();
  	if (namelen != dfsplen + pplen || read_seqretry(&rename_lock, seq)) {
  		cifs_dbg(FYI, "did not end path lookup where expected. namelen=%ddfsplen=%d
  ",
  			 namelen, dfsplen);
  		/* presumably this is only possible if racing with a rename
  		of one of the parent directories  (we can not lock the dentries
  		above us to prevent this, but retrying should be harmless) */
  		kfree(full_path);
  		goto cifs_bp_rename_retry;
  	}
  	/* DIR_SEP already set for byte  0 / vs \ but not for
  	   subsequent slashes in prepath which currently must
  	   be entered the right way - not sure if there is an alternative
  	   since the '\' is a valid posix character so we can not switch
  	   those safely to '/' if any are found in the middle of the prepath */
  	/* BB test paths to Windows with '/' in the midst of prepath */
  
  	if (pplen) {
  		int i;
  
  		cifs_dbg(FYI, "using cifs_sb prepath <%s>
  ", cifs_sb->prepath);
  		memcpy(full_path+dfsplen+1, cifs_sb->prepath, pplen-1);
  		full_path[dfsplen] = '\\';
  		for (i = 0; i < pplen-1; i++)
  			if (full_path[dfsplen+1+i] == '/')
  				full_path[dfsplen+1+i] = CIFS_DIR_SEP(cifs_sb);
  	}
  
  	if (dfsplen) {
  		strncpy(full_path, tcon->treeName, dfsplen);
  		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
  			int i;
  			for (i = 0; i < dfsplen; i++) {
  				if (full_path[i] == '\\')
  					full_path[i] = '/';
  			}
  		}
  	}
  	return full_path;
  }
  
  /*
   * Don't allow the separator character in a path component.
   * The VFS will not allow "/", but "\" is allowed by posix.
   */
  static int
  check_name(struct dentry *direntry)
  {
  	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
  	int i;
  
  	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
  		for (i = 0; i < direntry->d_name.len; i++) {
  			if (direntry->d_name.name[i] == '\\') {
  				cifs_dbg(FYI, "Invalid file name
  ");
  				return -EINVAL;
  			}
  		}
  	}
  	return 0;
  }
  
  
  /* Inode operations in similar order to how they appear in Linux file fs.h */
  
  static int
  cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
  	       struct tcon_link *tlink, unsigned oflags, umode_t mode,
  	       __u32 *oplock, struct cifs_fid *fid)
  {
  	int rc = -ENOENT;
  	int create_options = CREATE_NOT_DIR;
  	int desired_access;
  	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
  	struct cifs_tcon *tcon = tlink_tcon(tlink);
  	char *full_path = NULL;
  	FILE_ALL_INFO *buf = NULL;
  	struct inode *newinode = NULL;
  	int disposition;
  	struct TCP_Server_Info *server = tcon->ses->server;
  	struct cifs_open_parms oparms;
  
  	*oplock = 0;
  	if (tcon->ses->server->oplocks)
  		*oplock = REQ_OPLOCK;
  
  	full_path = build_path_from_dentry(direntry);
  	if (full_path == NULL) {
  		rc = -ENOMEM;
  		goto out;
  	}
  
  	if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
  	    (CIFS_UNIX_POSIX_PATH_OPS_CAP &
  			le64_to_cpu(tcon->fsUnixInfo.Capability))) {
  		rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
  				     oflags, oplock, &fid->netfid, xid);
  		switch (rc) {
  		case 0:
  			if (newinode == NULL) {
  				/* query inode info */
  				goto cifs_create_get_file_info;
  			}
  
  			if (S_ISDIR(newinode->i_mode)) {
  				CIFSSMBClose(xid, tcon, fid->netfid);
  				iput(newinode);
  				rc = -EISDIR;
  				goto out;
  			}
  
  			if (!S_ISREG(newinode->i_mode)) {
  				/*
  				 * The server may allow us to open things like
  				 * FIFOs, but the client isn't set up to deal
  				 * with that. If it's not a regular file, just
  				 * close it and proceed as if it were a normal
  				 * lookup.
  				 */
  				CIFSSMBClose(xid, tcon, fid->netfid);
  				goto cifs_create_get_file_info;
  			}
  			/* success, no need to query */
  			goto cifs_create_set_dentry;
  
  		case -ENOENT:
  			goto cifs_create_get_file_info;
  
  		case -EIO:
  		case -EINVAL:
  			/*
  			 * EIO could indicate that (posix open) operation is not
  			 * supported, despite what server claimed in capability
  			 * negotiation.
  			 *
  			 * POSIX open in samba versions 3.3.1 and earlier could
  			 * incorrectly fail with invalid parameter.
  			 */
  			tcon->broken_posix_open = true;
  			break;
  
  		case -EREMOTE:
  		case -EOPNOTSUPP:
  			/*
  			 * EREMOTE indicates DFS junction, which is not handled
  			 * in posix open.  If either that or op not supported
  			 * returned, follow the normal lookup.
  			 */
  			break;
  
  		default:
  			goto out;
  		}
  		/*
  		 * fallthrough to retry, using older open call, this is case
  		 * where server does not support this SMB level, and falsely
  		 * claims capability (also get here for DFS case which should be
  		 * rare for path not covered on files)
  		 */
  	}
  
  	desired_access = 0;
  	if (OPEN_FMODE(oflags) & FMODE_READ)
  		desired_access |= GENERIC_READ; /* is this too little? */
  	if (OPEN_FMODE(oflags) & FMODE_WRITE)
  		desired_access |= GENERIC_WRITE;
  
  	disposition = FILE_OVERWRITE_IF;
  	if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
  		disposition = FILE_CREATE;
  	else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
  		disposition = FILE_OVERWRITE_IF;
  	else if ((oflags & O_CREAT) == O_CREAT)
  		disposition = FILE_OPEN_IF;
  	else
  		cifs_dbg(FYI, "Create flag not set in create function
  ");
  
  	/*
  	 * BB add processing to set equivalent of mode - e.g. via CreateX with
  	 * ACLs
  	 */
  
  	if (!server->ops->open) {
  		rc = -ENOSYS;
  		goto out;
  	}
  
  	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
  	if (buf == NULL) {
  		rc = -ENOMEM;
  		goto out;
  	}
  
  	/*
  	 * if we're not using unix extensions, see if we need to set
  	 * ATTR_READONLY on the create call
  	 */
  	if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
  		create_options |= CREATE_OPTION_READONLY;
  
  	if (backup_cred(cifs_sb))
  		create_options |= CREATE_OPEN_BACKUP_INTENT;
  
  	oparms.tcon = tcon;
  	oparms.cifs_sb = cifs_sb;
  	oparms.desired_access = desired_access;
  	oparms.create_options = create_options;
  	oparms.disposition = disposition;
  	oparms.path = full_path;
  	oparms.fid = fid;
  	oparms.reconnect = false;
  
  	rc = server->ops->open(xid, &oparms, oplock, buf);
  	if (rc) {
  		cifs_dbg(FYI, "cifs_create returned 0x%x
  ", rc);
  		goto out;
  	}
  
  	/*
  	 * If Open reported that we actually created a file then we now have to
  	 * set the mode if possible.
  	 */
  	if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
  		struct cifs_unix_set_info_args args = {
  				.mode	= mode,
  				.ctime	= NO_CHANGE_64,
  				.atime	= NO_CHANGE_64,
  				.mtime	= NO_CHANGE_64,
  				.device	= 0,
  		};
  
  		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
  			args.uid = current_fsuid();
  			if (inode->i_mode & S_ISGID)
  				args.gid = inode->i_gid;
  			else
  				args.gid = current_fsgid();
  		} else {
  			args.uid = INVALID_UID; /* no change */
  			args.gid = INVALID_GID; /* no change */
  		}
  		CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
  				       current->tgid);
  	} else {
  		/*
  		 * BB implement mode setting via Windows security
  		 * descriptors e.g.
  		 */
  		/* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
  
  		/* Could set r/o dos attribute if mode & 0222 == 0 */
  	}
  
  cifs_create_get_file_info:
  	/* server might mask mode so we have to query for it */
  	if (tcon->unix_ext)
  		rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb,
  					      xid);
  	else {
  		rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,
  					 xid, fid);
  		if (newinode) {
  			if (server->ops->set_lease_key)
  				server->ops->set_lease_key(newinode, fid);
  			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
  				newinode->i_mode = mode;
  			if ((*oplock & CIFS_CREATE_ACTION) &&
  			    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) {
  				newinode->i_uid = current_fsuid();
  				if (inode->i_mode & S_ISGID)
  					newinode->i_gid = inode->i_gid;
  				else
  					newinode->i_gid = current_fsgid();
  			}
  		}
  	}
  
  cifs_create_set_dentry:
  	if (rc != 0) {
  		cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d
  ",
  			 rc);
  		goto out_err;
  	}
  
  	if (S_ISDIR(newinode->i_mode)) {
  		rc = -EISDIR;
  		goto out_err;
  	}
  
  	d_drop(direntry);
  	d_add(direntry, newinode);
  
  out:
  	kfree(buf);
  	kfree(full_path);
  	return rc;
  
  out_err:
  	if (server->ops->close)
  		server->ops->close(xid, tcon, fid);
  	if (newinode)
  		iput(newinode);
  	goto out;
  }
  
  int
  cifs_atomic_open(struct inode *inode, struct dentry *direntry,
  		 struct file *file, unsigned oflags, umode_t mode,
  		 int *opened)
  {
  	int rc;
  	unsigned int xid;
  	struct tcon_link *tlink;
  	struct cifs_tcon *tcon;
  	struct TCP_Server_Info *server;
  	struct cifs_fid fid;
  	struct cifs_pending_open open;
  	__u32 oplock;
  	struct cifsFileInfo *file_info;
  
  	/*
  	 * Posix open is only called (at lookup time) for file create now. For
  	 * opens (rather than creates), because we do not know if it is a file
  	 * or directory yet, and current Samba no longer allows us to do posix
  	 * open on dirs, we could end up wasting an open call on what turns out
  	 * to be a dir. For file opens, we wait to call posix open till
  	 * cifs_open.  It could be added to atomic_open in the future but the
  	 * performance tradeoff of the extra network request when EISDIR or
  	 * EACCES is returned would have to be weighed against the 50% reduction
  	 * in network traffic in the other paths.
  	 */
  	if (!(oflags & O_CREAT)) {
  		struct dentry *res;
  
  		/*
  		 * Check for hashed negative dentry. We have already revalidated
  		 * the dentry and it is fine. No need to perform another lookup.
  		 */
  		if (!d_unhashed(direntry))
  			return -ENOENT;
  
  		res = cifs_lookup(inode, direntry, 0);
  		if (IS_ERR(res))
  			return PTR_ERR(res);
  
  		return finish_no_open(file, res);
  	}
  
  	rc = check_name(direntry);
  	if (rc)
  		return rc;
  
  	xid = get_xid();
  
  	cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p
  ",
  		 inode, direntry, direntry);
  
  	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
  	if (IS_ERR(tlink)) {
  		rc = PTR_ERR(tlink);
  		goto out_free_xid;
  	}
  
  	tcon = tlink_tcon(tlink);
  	server = tcon->ses->server;
  
  	if (server->ops->new_lease_key)
  		server->ops->new_lease_key(&fid);
  
  	cifs_add_pending_open(&fid, tlink, &open);
  
  	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
  			    &oplock, &fid);
  
  	if (rc) {
  		cifs_del_pending_open(&open);
  		goto out;
  	}
  
  	if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
  		*opened |= FILE_CREATED;
  
  	rc = finish_open(file, direntry, generic_file_open, opened);
  	if (rc) {
  		if (server->ops->close)
  			server->ops->close(xid, tcon, &fid);
  		cifs_del_pending_open(&open);
  		goto out;
  	}
  
  	if (file->f_flags & O_DIRECT &&
  	    CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
  		if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
  			file->f_op = &cifs_file_direct_nobrl_ops;
  		else
  			file->f_op = &cifs_file_direct_ops;
  		}
  
  	file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
  	if (file_info == NULL) {
  		if (server->ops->close)
  			server->ops->close(xid, tcon, &fid);
  		cifs_del_pending_open(&open);
  		fput(file);
  		rc = -ENOMEM;
  	}
  
  out:
  	cifs_put_tlink(tlink);
  out_free_xid:
  	free_xid(xid);
  	return rc;
  }
  
  int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
  		bool excl)
  {
  	int rc;
  	unsigned int xid = get_xid();
  	/*
  	 * BB below access is probably too much for mknod to request
  	 *    but we have to do query and setpathinfo so requesting
  	 *    less could fail (unless we want to request getatr and setatr
  	 *    permissions (only).  At least for POSIX we do not have to
  	 *    request so much.
  	 */
  	unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
  	struct tcon_link *tlink;
  	struct cifs_tcon *tcon;
  	struct TCP_Server_Info *server;
  	struct cifs_fid fid;
  	__u32 oplock;
  
  	cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p
  ",
  		 inode, direntry, direntry);
  
  	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
  	rc = PTR_ERR(tlink);
  	if (IS_ERR(tlink))
  		goto out_free_xid;
  
  	tcon = tlink_tcon(tlink);
  	server = tcon->ses->server;
  
  	if (server->ops->new_lease_key)
  		server->ops->new_lease_key(&fid);
  
  	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
  			    &oplock, &fid);
  	if (!rc && server->ops->close)
  		server->ops->close(xid, tcon, &fid);
  
  	cifs_put_tlink(tlink);
  out_free_xid:
  	free_xid(xid);
  	return rc;
  }
  
  int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
  		dev_t device_number)
  {
  	int rc = -EPERM;
  	unsigned int xid;
  	int create_options = CREATE_NOT_DIR | CREATE_OPTION_SPECIAL;
  	struct cifs_sb_info *cifs_sb;
  	struct tcon_link *tlink;
  	struct cifs_tcon *tcon;
  	struct cifs_io_parms io_parms;
  	char *full_path = NULL;
  	struct inode *newinode = NULL;
  	__u32 oplock = 0;
  	struct cifs_fid fid;
  	struct cifs_open_parms oparms;
  	FILE_ALL_INFO *buf = NULL;
  	unsigned int bytes_written;
  	struct win_dev *pdev;
  	struct kvec iov[2];
  
  	if (!old_valid_dev(device_number))
  		return -EINVAL;
  
  	cifs_sb = CIFS_SB(inode->i_sb);
  	tlink = cifs_sb_tlink(cifs_sb);
  	if (IS_ERR(tlink))
  		return PTR_ERR(tlink);
  
  	tcon = tlink_tcon(tlink);
  
  	xid = get_xid();
  
  	full_path = build_path_from_dentry(direntry);
  	if (full_path == NULL) {
  		rc = -ENOMEM;
  		goto mknod_out;
  	}
  
  	if (tcon->unix_ext) {
  		struct cifs_unix_set_info_args args = {
  			.mode	= mode & ~current_umask(),
  			.ctime	= NO_CHANGE_64,
  			.atime	= NO_CHANGE_64,
  			.mtime	= NO_CHANGE_64,
  			.device	= device_number,
  		};
  		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
  			args.uid = current_fsuid();
  			args.gid = current_fsgid();
  		} else {
  			args.uid = INVALID_UID; /* no change */
  			args.gid = INVALID_GID; /* no change */
  		}
  		rc = CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
  					    cifs_sb->local_nls,
  					    cifs_remap(cifs_sb));
  		if (rc)
  			goto mknod_out;
  
  		rc = cifs_get_inode_info_unix(&newinode, full_path,
  						inode->i_sb, xid);
  
  		if (rc == 0)
  			d_instantiate(direntry, newinode);
  		goto mknod_out;
  	}
  
  	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL))
  		goto mknod_out;
  
  
  	cifs_dbg(FYI, "sfu compat create special file
  ");
  
  	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
  	if (buf == NULL) {
  		kfree(full_path);
  		rc = -ENOMEM;
  		free_xid(xid);
  		return rc;
  	}
  
  	if (backup_cred(cifs_sb))
  		create_options |= CREATE_OPEN_BACKUP_INTENT;
  
  	oparms.tcon = tcon;
  	oparms.cifs_sb = cifs_sb;
  	oparms.desired_access = GENERIC_WRITE;
  	oparms.create_options = create_options;
  	oparms.disposition = FILE_CREATE;
  	oparms.path = full_path;
  	oparms.fid = &fid;
  	oparms.reconnect = false;
  
  	if (tcon->ses->server->oplocks)
  		oplock = REQ_OPLOCK;
  	else
  		oplock = 0;
  	rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, buf);
  	if (rc)
  		goto mknod_out;
  
  	/*
  	 * BB Do not bother to decode buf since no local inode yet to put
  	 * timestamps in, but we can reuse it safely.
  	 */
  
  	pdev = (struct win_dev *)buf;
  	io_parms.pid = current->tgid;
  	io_parms.tcon = tcon;
  	io_parms.offset = 0;
  	io_parms.length = sizeof(struct win_dev);
  	iov[1].iov_base = buf;
  	iov[1].iov_len = sizeof(struct win_dev);
  	if (S_ISCHR(mode)) {
  		memcpy(pdev->type, "IntxCHR", 8);
  		pdev->major = cpu_to_le64(MAJOR(device_number));
  		pdev->minor = cpu_to_le64(MINOR(device_number));
  		rc = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
  							&bytes_written, iov, 1);
  	} else if (S_ISBLK(mode)) {
  		memcpy(pdev->type, "IntxBLK", 8);
  		pdev->major = cpu_to_le64(MAJOR(device_number));
  		pdev->minor = cpu_to_le64(MINOR(device_number));
  		rc = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
  							&bytes_written, iov, 1);
  	} /* else if (S_ISFIFO) */
  	tcon->ses->server->ops->close(xid, tcon, &fid);
  	d_drop(direntry);
  
  	/* FIXME: add code here to set EAs */
  
  mknod_out:
  	kfree(full_path);
  	kfree(buf);
  	free_xid(xid);
  	cifs_put_tlink(tlink);
  	return rc;
  }
  
  struct dentry *
  cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
  	    unsigned int flags)
  {
  	unsigned int xid;
  	int rc = 0; /* to get around spurious gcc warning, set to zero here */
  	struct cifs_sb_info *cifs_sb;
  	struct tcon_link *tlink;
  	struct cifs_tcon *pTcon;
  	struct inode *newInode = NULL;
  	char *full_path = NULL;
  
  	xid = get_xid();
  
  	cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p
  ",
  		 parent_dir_inode, direntry, direntry);
  
  	/* check whether path exists */
  
  	cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
  	tlink = cifs_sb_tlink(cifs_sb);
  	if (IS_ERR(tlink)) {
  		free_xid(xid);
  		return (struct dentry *)tlink;
  	}
  	pTcon = tlink_tcon(tlink);
  
  	rc = check_name(direntry);
  	if (rc)
  		goto lookup_out;
  
  	/* can not grab the rename sem here since it would
  	deadlock in the cases (beginning of sys_rename itself)
  	in which we already have the sb rename sem */
  	full_path = build_path_from_dentry(direntry);
  	if (full_path == NULL) {
  		rc = -ENOMEM;
  		goto lookup_out;
  	}
  
  	if (d_really_is_positive(direntry)) {
  		cifs_dbg(FYI, "non-NULL inode in lookup
  ");
  	} else {
  		cifs_dbg(FYI, "NULL inode in lookup
  ");
  	}
  	cifs_dbg(FYI, "Full path: %s inode = 0x%p
  ",
  		 full_path, d_inode(direntry));
  
  	if (pTcon->unix_ext) {
  		rc = cifs_get_inode_info_unix(&newInode, full_path,
  					      parent_dir_inode->i_sb, xid);
  	} else {
  		rc = cifs_get_inode_info(&newInode, full_path, NULL,
  				parent_dir_inode->i_sb, xid, NULL);
  	}
  
  	if ((rc == 0) && (newInode != NULL)) {
  		d_add(direntry, newInode);
  		/* since paths are not looked up by component - the parent
  		   directories are presumed to be good here */
  		renew_parental_timestamps(direntry);
  
  	} else if (rc == -ENOENT) {
  		rc = 0;
  		direntry->d_time = jiffies;
  		d_add(direntry, NULL);
  	/*	if it was once a directory (but how can we tell?) we could do
  		shrink_dcache_parent(direntry); */
  	} else if (rc != -EACCES) {
  		cifs_dbg(FYI, "Unexpected lookup error %d
  ", rc);
  		/* We special case check for Access Denied - since that
  		is a common return code */
  	}
  
  lookup_out:
  	kfree(full_path);
  	cifs_put_tlink(tlink);
  	free_xid(xid);
  	return ERR_PTR(rc);
  }
  
  static int
  cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
  {
  	if (flags & LOOKUP_RCU)
  		return -ECHILD;
  
  	if (d_really_is_positive(direntry)) {
  		if (cifs_revalidate_dentry(direntry))
  			return 0;
  		else {
  			/*
  			 * If the inode wasn't known to be a dfs entry when
  			 * the dentry was instantiated, such as when created
  			 * via ->readdir(), it needs to be set now since the
  			 * attributes will have been updated by
  			 * cifs_revalidate_dentry().
  			 */
  			if (IS_AUTOMOUNT(d_inode(direntry)) &&
  			   !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
  				spin_lock(&direntry->d_lock);
  				direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
  				spin_unlock(&direntry->d_lock);
  			}
  
  			return 1;
  		}
  	}
  
  	/*
  	 * This may be nfsd (or something), anyway, we can't see the
  	 * intent of this. So, since this can be for creation, drop it.
  	 */
  	if (!flags)
  		return 0;
  
  	/*
  	 * Drop the negative dentry, in order to make sure to use the
  	 * case sensitive name which is specified by user if this is
  	 * for creation.
  	 */
  	if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
  		return 0;
  
  	if (time_after(jiffies, direntry->d_time + HZ) || !lookupCacheEnabled)
  		return 0;
  
  	return 1;
  }
  
  /* static int cifs_d_delete(struct dentry *direntry)
  {
  	int rc = 0;
  
  	cifs_dbg(FYI, "In cifs d_delete, name = %pd
  ", direntry);
  
  	return rc;
  }     */
  
  const struct dentry_operations cifs_dentry_ops = {
  	.d_revalidate = cifs_d_revalidate,
  	.d_automount = cifs_dfs_d_automount,
  /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
  };
  
  static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
  {
  	struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
  	unsigned long hash;
  	wchar_t c;
  	int i, charlen;
  
  	hash = init_name_hash();
  	for (i = 0; i < q->len; i += charlen) {
  		charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
  		/* error out if we can't convert the character */
  		if (unlikely(charlen < 0))
  			return charlen;
  		hash = partial_name_hash(cifs_toupper(c), hash);
  	}
  	q->hash = end_name_hash(hash);
  
  	return 0;
  }
  
  static int cifs_ci_compare(const struct dentry *parent, const struct dentry *dentry,
  		unsigned int len, const char *str, const struct qstr *name)
  {
  	struct nls_table *codepage = CIFS_SB(parent->d_sb)->local_nls;
  	wchar_t c1, c2;
  	int i, l1, l2;
  
  	/*
  	 * We make the assumption here that uppercase characters in the local
  	 * codepage are always the same length as their lowercase counterparts.
  	 *
  	 * If that's ever not the case, then this will fail to match it.
  	 */
  	if (name->len != len)
  		return 1;
  
  	for (i = 0; i < len; i += l1) {
  		/* Convert characters in both strings to UTF-16. */
  		l1 = codepage->char2uni(&str[i], len - i, &c1);
  		l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
  
  		/*
  		 * If we can't convert either character, just declare it to
  		 * be 1 byte long and compare the original byte.
  		 */
  		if (unlikely(l1 < 0 && l2 < 0)) {
  			if (str[i] != name->name[i])
  				return 1;
  			l1 = 1;
  			continue;
  		}
  
  		/*
  		 * Here, we again ass|u|me that upper/lowercase versions of
  		 * a character are the same length in the local NLS.
  		 */
  		if (l1 != l2)
  			return 1;
  
  		/* Now compare uppercase versions of these characters */
  		if (cifs_toupper(c1) != cifs_toupper(c2))
  			return 1;
  	}
  
  	return 0;
  }
  
  const struct dentry_operations cifs_ci_dentry_ops = {
  	.d_revalidate = cifs_d_revalidate,
  	.d_hash = cifs_ci_hash,
  	.d_compare = cifs_ci_compare,
  	.d_automount = cifs_dfs_d_automount,
  };