fs/cifs/link.c - LeafOS-Devices/android_kernel_samsung_universal7904 - Gitiles

 /*
  *   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_NONE;
 	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_NONE;
 	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_follow_link(struct dentry *direntry, void **cookie)
 {
 	struct inode *inode = d_inode(direntry);
 	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;

 	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);
 	}
 	return *cookie = 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;
 }
	/*
	* 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_NONE;
	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_NONE;
	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_follow_link(struct dentry direntry, void *cookie)
	{
	struct inode *inode = d_inode(direntry);
	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;

	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);
	}
	return *cookie = 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;
	}