cifs: Add create MFSymlinks to protocol ops struct

Add a new protocol ops function create_mf_symlink and have
create_mf_symlink() use it.

This patchset moves the MFSymlink operations completely to the
ops structure so that we only use the right protocol versions when
querying or creating MFSymlinks.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

fs/cifs/cifsglob.h

@@ -373,6 +373,9 @@ struct smb_version_operations {
 	int (*query_mf_symlink)(unsigned int, struct cifs_tcon *,
 				struct cifs_sb_info *, const unsigned char *,
 				char *, unsigned int *);
+	int (*create_mf_symlink)(unsigned int, struct cifs_tcon *,
+				 struct cifs_sb_info *, const unsigned char *,
+				 char *, unsigned int *);
 	/* if we can do cache read operations */
 	bool (*is_read_op)(__u32);
 	/* set oplock level for the inode */

fs/cifs/cifsproto.h

@@ -500,4 +500,8 @@ 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 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);
 #endif			/* _CIFSPROTO_H */

fs/cifs/link.c

@@ -180,59 +180,31 @@ format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
 
 static int
 create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
-		    const char *fromName, const char *toName,
-		    struct cifs_sb_info *cifs_sb)
+		  struct cifs_sb_info *cifs_sb, const char *fromName,
+		  const char *toName)
 {
 	int rc;
-	int oplock = 0;
-	int remap;
-	int create_options = CREATE_NOT_DIR;
-	__u16 netfid = 0;
 	u8 *buf;
 	unsigned int bytes_written = 0;
-	struct cifs_io_parms io_parms;
-	struct nls_table *nls_codepage;
-
-	nls_codepage = cifs_sb->local_nls;
-	remap = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR;
 
 	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 != 0) {
-		kfree(buf);
-		return rc;
-	}
-
-	if (backup_cred(cifs_sb))
-		create_options |= CREATE_OPEN_BACKUP_INTENT;
-
-	rc = CIFSSMBOpen(xid, tcon, fromName, FILE_CREATE, GENERIC_WRITE,
-			 create_options, &netfid, &oplock, NULL,
-			 nls_codepage, remap);
-	if (rc != 0) {
-		kfree(buf);
-		return rc;
-	}
-
-	io_parms.netfid = netfid;
-	io_parms.pid = current->tgid;
-	io_parms.tcon = tcon;
-	io_parms.offset = 0;
-	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
+	if (rc)
+		goto out;
 
-	rc = CIFSSMBWrite(xid, &io_parms, &bytes_written, buf, NULL, 0);
-	CIFSSMBClose(xid, tcon, netfid);
-	kfree(buf);
-	if (rc != 0)
-		return rc;
+	rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon, cifs_sb,
+					fromName, buf, &bytes_written);
+	if (rc)
+		goto out;
 
 	if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
-		return -EIO;
-
-	return 0;
+		rc = -EIO;
+out:
+	kfree(buf);
+	return rc;
 }
 
 static int
@@ -319,6 +291,39 @@ out:
 	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;
+	__u16 netfid = 0;
+	struct cifs_io_parms io_parms;
+	int create_options = CREATE_NOT_DIR;
+
+	if (backup_cred(cifs_sb))
+		create_options |= CREATE_OPEN_BACKUP_INTENT;
+
+	rc = CIFSSMBOpen(xid, tcon, path, FILE_CREATE, GENERIC_WRITE,
+			 create_options, &netfid, &oplock, NULL,
+			 cifs_sb->local_nls,
+			 cifs_sb->mnt_cifs_flags &
+				CIFS_MOUNT_MAP_SPECIAL_CHR);
+	if (rc)
+		return rc;
+
+	io_parms.netfid = 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, netfid);
+	return rc;
+}
+
 int
 check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 		 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
@@ -553,8 +558,7 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *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, full_path, symname,
-					cifs_sb);
+		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);

fs/cifs/smb1ops.c

@@ -1010,6 +1010,7 @@ struct smb_version_operations smb1_operations = {
 	.mand_unlock_range = cifs_unlock_range,
 	.push_mand_locks = cifs_push_mandatory_locks,
 	.query_mf_symlink = cifs_query_mf_symlink,
+	.create_mf_symlink = cifs_create_mf_symlink,
 	.is_read_op = cifs_is_read_op,
 };