Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / fs / cifs / link.c
diff --git a/kernel/fs/cifs/link.c b/kernel/fs/cifs/link.c
new file mode 100644 (file)
index 0000000..e6c707c
--- /dev/null
@@ -0,0 +1,746 @@
+/*
+ *   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;
+}
+
+void *
+cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
+{
+       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)) {
+               rc = PTR_ERR(tlink);
+               tlink = NULL;
+               goto out;
+       }
+       tcon = tlink_tcon(tlink);
+       server = tcon->ses->server;
+
+       full_path = build_path_from_dentry(direntry);
+       if (!full_path)
+               goto out;
+
+       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);
+out:
+       if (rc != 0) {
+               kfree(target_path);
+               target_path = ERR_PTR(rc);
+       }
+
+       free_xid(xid);
+       if (tlink)
+               cifs_put_tlink(tlink);
+       nd_set_link(nd, target_path);
+       return NULL;
+}
+
+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;
+}