text: /*
   *   fs/cifs/link.c
   *
   *   Copyright (C) International Business Machines  Corp., 2002,2008
   *   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 "cifsfs.h"
  #include "cifspdu.h"
  #include "cifsglob.h"
  #include "cifsproto.h"
  #include "cifs_debug.h"
  #include "cifs_fs_sb.h"
  #include "cifs_unicode.h"
  #ifdef CONFIG_CIFS_SMB2
  #include "smb2proto.h"
  #endif
  
  /*
   * M-F Symlink Functions - Begin
   */
  
  #define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
  #define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
  #define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
  #define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
  #define CIFS_MF_SYMLINK_FILE_SIZE \
  	(CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
  
  #define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
  #define CIFS_MF_SYMLINK_MD5_FORMAT \
  	"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n"
  #define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \
  	md5_hash[0],  md5_hash[1],  md5_hash[2],  md5_hash[3], \
  	md5_hash[4],  md5_hash[5],  md5_hash[6],  md5_hash[7], \
  	md5_hash[8],  md5_hash[9],  md5_hash[10], md5_hash[11],\
  	md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15]
  
  static int
  symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
  {
  	int rc;
  	unsigned int size;
  	struct crypto_shash *md5;
  	struct sdesc *sdescmd5;
  
  	md5 = crypto_alloc_shash("md5", 0, 0);
  	if (IS_ERR(md5)) {
  		rc = PTR_ERR(md5);
  		cifs_dbg(VFS, "%s: Crypto md5 allocation error %d\n",
  			 __func__, rc);
  		return rc;
  	}
  	size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
  	sdescmd5 = kmalloc(size, GFP_KERNEL);
  	if (!sdescmd5) {
  		rc = -ENOMEM;
  		goto symlink_hash_err;
  	}
  	sdescmd5->shash.tfm = md5;
  	sdescmd5->shash.flags = 0x0;
  
  	rc = crypto_shash_init(&sdescmd5->shash);
  	if (rc) {
  		cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
  		goto symlink_hash_err;
  	}
  	rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
  	if (rc) {
  		cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
  		goto symlink_hash_err;
  	}
  	rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
  	if (rc)
  		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
  
  symlink_hash_err:
  	crypto_free_shash(md5);
  	kfree(sdescmd5);
  
  	return rc;
  }
  
  static int
  parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
  		 char **_link_str)
  {
  	int rc;
  	unsigned int link_len;
  	const char *md5_str1;
  	const char *link_str;
  	u8 md5_hash[16];
  	char md5_str2[34];
  
  	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
  		return -EINVAL;
  
  	md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
  	link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
  
  	rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
  	if (rc != 1)
  		return -EINVAL;
  
  	rc = symlink_hash(link_len, link_str, md5_hash);
  	if (rc) {
  		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
  		return rc;
  	}
  
  	snprintf(md5_str2, sizeof(md5_str2),
  		 CIFS_MF_SYMLINK_MD5_FORMAT,
  		 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
  
  	if (strncmp(md5_str1, md5_str2, 17) != 0)
  		return -EINVAL;
  
  	if (_link_str) {
  		*_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
  		if (!*_link_str)
  			return -ENOMEM;
  	}
  
  	*_link_len = link_len;
  	return 0;
  }
  
  static int
  format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
  {
  	int rc;
  	unsigned int link_len;
  	unsigned int ofs;
  	u8 md5_hash[16];
  
  	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
  		return -EINVAL;
  
  	link_len = strlen(link_str);
  
  	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
  		return -ENAMETOOLONG;
  
  	rc = symlink_hash(link_len, link_str, md5_hash);
  	if (rc) {
  		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
  		return rc;
  	}
  
  	snprintf(buf, buf_len,
  		 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
  		 link_len,
  		 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
  
  	ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
  	memcpy(buf + ofs, link_str, link_len);
  
  	ofs += link_len;
  	if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
  		buf[ofs] = '\n';
  		ofs++;
  	}
  
  	while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
  		buf[ofs] = ' ';
  		ofs++;
  	}
  
  	return 0;
  }
  
  bool
  couldbe_mf_symlink(const struct cifs_fattr *fattr)
  {
  	if (!S_ISREG(fattr->cf_mode))
  		/* it's not a symlink */
  		return false;
  
  	if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
  		/* it's not a symlink */
  		return false;
  
  	return true;
  }
  
  static int
  create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
  		  struct cifs_sb_info *cifs_sb, const char *fromName,
  		  const char *toName)
  {
  	int rc;
  	u8 *buf;
  	unsigned int bytes_written = 0;
  
  	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
  	if (!buf)
  		return -ENOMEM;
  
  	rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
  	if (rc)
  		goto out;
  
  	if (tcon->ses->server->ops->create_mf_symlink)
  		rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
  					cifs_sb, fromName, buf, &bytes_written);
  	else
  		rc = -EOPNOTSUPP;
  
  	if (rc)
  		goto out;
  
  	if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
  		rc = -EIO;
  out:
  	kfree(buf);
  	return rc;
  }
  
  static int
  query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
  		 struct cifs_sb_info *cifs_sb, const unsigned char *path,
  		 char **symlinkinfo)
  {
  	int rc;
  	u8 *buf = NULL;
  	unsigned int link_len = 0;
  	unsigned int bytes_read = 0;
  
  	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
  	if (!buf)
  		return -ENOMEM;
  
  	if (tcon->ses->server->ops->query_mf_symlink)
  		rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
  					      cifs_sb, path, buf, &bytes_read);
  	else
  		rc = -ENOSYS;
  
  	if (rc)
  		goto out;
  
  	if (bytes_read == 0) { /* not a symlink */
  		rc = -EINVAL;
  		goto out;
  	}
  
  	rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
  out:
  	kfree(buf);
  	return rc;
  }
  
  int
  check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
  		 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
  		 const unsigned char *path)
  {
  	int rc;
  	u8 *buf = NULL;
  	unsigned int link_len = 0;
  	unsigned int bytes_read = 0;
  
  	if (!couldbe_mf_symlink(fattr))
  		/* it's not a symlink */
  		return 0;
  
  	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
  	if (!buf)
  		return -ENOMEM;
  
  	if (tcon->ses->server->ops->query_mf_symlink)
  		rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
  					      cifs_sb, path, buf, &bytes_read);
  	else
  		rc = -ENOSYS;
  
  	if (rc)
  		goto out;
  
  	if (bytes_read == 0) /* not a symlink */
  		goto out;
  
  	rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
  	if (rc == -EINVAL) {
  		/* it's not a symlink */
  		rc = 0;
  		goto out;
  	}
  
  	if (rc != 0)
  		goto out;
  
  	/* it is a symlink */
  	fattr->cf_eof = link_len;
  	fattr->cf_mode &= ~S_IFMT;
  	fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
  	fattr->cf_dtype = DT_LNK;
  out:
  	kfree(buf);
  	return rc;
  }
  
  /*
   * SMB 1.0 Protocol specific functions
   */
  
  int
  cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
  		      struct cifs_sb_info *cifs_sb, const unsigned char *path,
  		      char *pbuf, unsigned int *pbytes_read)
  {
  	int rc;
  	int oplock = 0;
  	struct cifs_fid fid;
  	struct cifs_open_parms oparms;
  	struct cifs_io_parms io_parms;
  	int buf_type = CIFS_NO_BUFFER;
  	FILE_ALL_INFO file_info;
  
  	oparms.tcon = tcon;
  	oparms.cifs_sb = cifs_sb;
  	oparms.desired_access = GENERIC_READ;
  	oparms.create_options = CREATE_NOT_DIR;
  	oparms.disposition = FILE_OPEN;
  	oparms.path = path;
  	oparms.fid = &fid;
  	oparms.reconnect = false;
  
  	rc = CIFS_open(xid, &oparms, &oplock, &file_info);
  	if (rc)
  		return rc;
  
  	if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
  		rc = -ENOENT;
  		/* it's not a symlink */
  		goto out;
  	}
  
  	io_parms.netfid = fid.netfid;
  	io_parms.pid = current->tgid;
  	io_parms.tcon = tcon;
  	io_parms.offset = 0;
  	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
  
  	rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
  out:
  	CIFSSMBClose(xid, tcon, fid.netfid);
  	return rc;
  }
  
  int
  cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
  		       struct cifs_sb_info *cifs_sb, const unsigned char *path,
  		       char *pbuf, unsigned int *pbytes_written)
  {
  	int rc;
  	int oplock = 0;
  	struct cifs_fid fid;
  	struct cifs_open_parms oparms;
  	struct cifs_io_parms io_parms;
  	int create_options = CREATE_NOT_DIR;
  
  	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 = path;
  	oparms.fid = &fid;
  	oparms.reconnect = false;
  
  	rc = CIFS_open(xid, &oparms, &oplock, NULL);
  	if (rc)
  		return rc;
  
  	io_parms.netfid = fid.netfid;
  	io_parms.pid = current->tgid;
  	io_parms.tcon = tcon;
  	io_parms.offset = 0;
  	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
  
  	rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf, NULL, 0);
  	CIFSSMBClose(xid, tcon, fid.netfid);
  	return rc;
  }
  
  /*
   * SMB 2.1/SMB3 Protocol specific functions
   */
  #ifdef CONFIG_CIFS_SMB2
  int
  smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
  		      struct cifs_sb_info *cifs_sb, const unsigned char *path,
  		      char *pbuf, unsigned int *pbytes_read)
  {
  	int rc;
  	struct cifs_fid fid;
  	struct cifs_open_parms oparms;
  	struct cifs_io_parms io_parms;
  	int buf_type = CIFS_NO_BUFFER;
  	__le16 *utf16_path;
  	__u8 oplock = SMB2_OPLOCK_LEVEL_II;
  	struct smb2_file_all_info *pfile_info = NULL;
  
  	oparms.tcon = tcon;
  	oparms.cifs_sb = cifs_sb;
  	oparms.desired_access = GENERIC_READ;
  	oparms.create_options = CREATE_NOT_DIR;
  	if (backup_cred(cifs_sb))
  		oparms.create_options |= CREATE_OPEN_BACKUP_INTENT;
  	oparms.disposition = FILE_OPEN;
  	oparms.fid = &fid;
  	oparms.reconnect = false;
  
  	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
  	if (utf16_path == NULL)
  		return -ENOMEM;
  
  	pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
  			     GFP_KERNEL);
  
  	if (pfile_info == NULL) {
  		kfree(utf16_path);
  		return  -ENOMEM;
  	}
  
  	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL);
  	if (rc)
  		goto qmf_out_open_fail;
  
  	if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
  		/* it's not a symlink */
  		rc = -ENOENT; /* Is there a better rc to return? */
  		goto qmf_out;
  	}
  
  	io_parms.netfid = fid.netfid;
  	io_parms.pid = current->tgid;
  	io_parms.tcon = tcon;
  	io_parms.offset = 0;
  	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
  	io_parms.persistent_fid = fid.persistent_fid;
  	io_parms.volatile_fid = fid.volatile_fid;
  	rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
  qmf_out:
  	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
  qmf_out_open_fail:
  	kfree(utf16_path);
  	kfree(pfile_info);
  	return rc;
  }
  
  int
  smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
  		       struct cifs_sb_info *cifs_sb, const unsigned char *path,
  		       char *pbuf, unsigned int *pbytes_written)
  {
  	int rc;
  	struct cifs_fid fid;
  	struct cifs_open_parms oparms;
  	struct cifs_io_parms io_parms;
  	int create_options = CREATE_NOT_DIR;
  	__le16 *utf16_path;
  	__u8 oplock = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
  	struct kvec iov[2];
  
  	if (backup_cred(cifs_sb))
  		create_options |= CREATE_OPEN_BACKUP_INTENT;
  
  	cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
  
  	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
  	if (!utf16_path)
  		return -ENOMEM;
  
  	oparms.tcon = tcon;
  	oparms.cifs_sb = cifs_sb;
  	oparms.desired_access = GENERIC_WRITE;
  	oparms.create_options = create_options;
  	oparms.disposition = FILE_CREATE;
  	oparms.fid = &fid;
  	oparms.reconnect = false;
  
  	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL);
  	if (rc) {
  		kfree(utf16_path);
  		return rc;
  	}
  
  	io_parms.netfid = fid.netfid;
  	io_parms.pid = current->tgid;
  	io_parms.tcon = tcon;
  	io_parms.offset = 0;
  	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
  	io_parms.persistent_fid = fid.persistent_fid;
  	io_parms.volatile_fid = fid.volatile_fid;
  
  	/* iov[0] is reserved for smb header */
  	iov[1].iov_base = pbuf;
  	iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
  
  	rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
  
  	/* Make sure we wrote all of the symlink data */
  	if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
  		rc = -EIO;
  
  	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
  
  	kfree(utf16_path);
  	return rc;
  }
  #endif /* CONFIG_CIFS_SMB2 */
  
  /*
   * M-F Symlink Functions - End
   */
  
  int
  cifs_hardlink(struct dentry *old_file, struct inode *inode,
  	      struct dentry *direntry)
  {
  	int rc = -EACCES;
  	unsigned int xid;
  	char *from_name = NULL;
  	char *to_name = NULL;
  	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
  	struct tcon_link *tlink;
  	struct cifs_tcon *tcon;
  	struct TCP_Server_Info *server;
  	struct cifsInodeInfo *cifsInode;
  
  	tlink = cifs_sb_tlink(cifs_sb);
  	if (IS_ERR(tlink))
  		return PTR_ERR(tlink);
  	tcon = tlink_tcon(tlink);
  
  	xid = get_xid();
  
  	from_name = build_path_from_dentry(old_file);
  	to_name = build_path_from_dentry(direntry);
  	if ((from_name == NULL) || (to_name == NULL)) {
  		rc = -ENOMEM;
  		goto cifs_hl_exit;
  	}
  
  	if (tcon->unix_ext)
  		rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
  					    cifs_sb->local_nls,
  					    cifs_remap(cifs_sb));
  	else {
  		server = tcon->ses->server;
  		if (!server->ops->create_hardlink) {
  			rc = -ENOSYS;
  			goto cifs_hl_exit;
  		}
  		rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
  						  cifs_sb);
  		if ((rc == -EIO) || (rc == -EINVAL))
  			rc = -EOPNOTSUPP;
  	}
  
  	d_drop(direntry);	/* force new lookup from server of target */
  
  	/*
  	 * if source file is cached (oplocked) revalidate will not go to server
  	 * until the file is closed or oplock broken so update nlinks locally
  	 */
  	if (d_really_is_positive(old_file)) {
  		cifsInode = CIFS_I(d_inode(old_file));
  		if (rc == 0) {
  			spin_lock(&d_inode(old_file)->i_lock);
  			inc_nlink(d_inode(old_file));
  			spin_unlock(&d_inode(old_file)->i_lock);
  
  			/*
  			 * parent dir timestamps will update from srv within a
  			 * second, would it really be worth it to set the parent
  			 * dir cifs inode time to zero to force revalidate
  			 * (faster) for it too?
  			 */
  		}
  		/*
  		 * if not oplocked will force revalidate to get info on source
  		 * file from srv.  Note Samba server prior to 4.2 has bug -
  		 * not updating src file ctime on hardlinks but Windows servers
  		 * handle it properly
  		 */
  		cifsInode->time = 0;
  
  		/*
  		 * Will update parent dir timestamps from srv within a second.
  		 * Would it really be worth it to set the parent dir (cifs
  		 * inode) time field to zero to force revalidate on parent
  		 * directory faster ie
  		 *
  		 * CIFS_I(inode)->time = 0;
  		 */
  	}
  
  cifs_hl_exit:
  	kfree(from_name);
  	kfree(to_name);
  	free_xid(xid);
  	cifs_put_tlink(tlink);
  	return rc;
  }
  
  const char *
  cifs_get_link(struct dentry *direntry, struct inode *inode,
  	      struct delayed_call *done)
  {
  	int rc = -ENOMEM;
  	unsigned int xid;
  	char *full_path = NULL;
  	char *target_path = NULL;
  	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
  	struct tcon_link *tlink = NULL;
  	struct cifs_tcon *tcon;
  	struct TCP_Server_Info *server;
  
  	if (!direntry)
  		return ERR_PTR(-ECHILD);
  
  	xid = get_xid();
  
  	tlink = cifs_sb_tlink(cifs_sb);
  	if (IS_ERR(tlink)) {
  		free_xid(xid);
  		return ERR_CAST(tlink);
  	}
  	tcon = tlink_tcon(tlink);
  	server = tcon->ses->server;
  
  	full_path = build_path_from_dentry(direntry);
  	if (!full_path) {
  		free_xid(xid);
  		cifs_put_tlink(tlink);
  		return ERR_PTR(-ENOMEM);
  	}
  
  	cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
  
  	rc = -EACCES;
  	/*
  	 * First try Minshall+French Symlinks, if configured
  	 * and fallback to UNIX Extensions Symlinks.
  	 */
  	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
  		rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
  				      &target_path);
  
  	if (rc != 0 && server->ops->query_symlink)
  		rc = server->ops->query_symlink(xid, tcon, full_path,
  						&target_path, cifs_sb);
  
  	kfree(full_path);
  	free_xid(xid);
  	cifs_put_tlink(tlink);
  	if (rc != 0) {
  		kfree(target_path);
  		return ERR_PTR(rc);
  	}
  	set_delayed_call(done, kfree_link, target_path);
  	return target_path;
  }
  
  int
  cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
  {
  	int rc = -EOPNOTSUPP;
  	unsigned int xid;
  	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
  	struct tcon_link *tlink;
  	struct cifs_tcon *pTcon;
  	char *full_path = NULL;
  	struct inode *newinode = NULL;
  
  	xid = get_xid();
  
  	tlink = cifs_sb_tlink(cifs_sb);
  	if (IS_ERR(tlink)) {
  		rc = PTR_ERR(tlink);
  		goto symlink_exit;
  	}
  	pTcon = tlink_tcon(tlink);
  
  	full_path = build_path_from_dentry(direntry);
  	if (full_path == NULL) {
  		rc = -ENOMEM;
  		goto symlink_exit;
  	}
  
  	cifs_dbg(FYI, "Full path: %s\n", full_path);
  	cifs_dbg(FYI, "symname is %s\n", symname);
  
  	/* BB what if DFS and this volume is on different share? BB */
  	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
  		rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
  	else if (pTcon->unix_ext)
  		rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
  					   cifs_sb->local_nls,
  					   cifs_remap(cifs_sb));
  	/* else
  	   rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
  					cifs_sb_target->local_nls); */
  
  	if (rc == 0) {
  		if (pTcon->unix_ext)
  			rc = cifs_get_inode_info_unix(&newinode, full_path,
  						      inode->i_sb, xid);
  		else
  			rc = cifs_get_inode_info(&newinode, full_path, NULL,
  						 inode->i_sb, xid, NULL);
  
  		if (rc != 0) {
  			cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
  				 rc);
  		} else {
  			d_instantiate(direntry, newinode);
  		}
  	}
  symlink_exit:
  	kfree(full_path);
  	cifs_put_tlink(tlink);
  	free_xid(xid);
  	return rc;
  }
  