[CIFS] Only convert / when server does not support posix paths

Also add warning if posix path setting changes on reconnect
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/connect.c

@@ -1722,8 +1722,15 @@ void reset_cifs_unix_caps(int xid, struct cifsTconInfo *tcon,
 			   originally at mount time */
 			if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
 				cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
-			if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0)
+			if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
+				if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
+					cERROR(1, ("POSIXPATH support change"));
 				cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
+			} else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
+				cERROR(1, ("possible reconnect error"));
+				cERROR(1,
+					("server disabled POSIX path support"));
+			}
 		}
 
 		cap &= CIFS_UNIX_CAP_MASK;
@@ -2243,7 +2250,9 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
 			tcon->unix_ext = 0; /* server does not support them */
 
 		/* convert forward to back slashes in prepath here if needed */
-		convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
+		if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) == 0)
+			convert_delimiter(cifs_sb->prepath,
+					  CIFS_DIR_SEP(cifs_sb));
 
 		if ((tcon->unix_ext == 0) && (cifs_sb->rsize > (1024 * 127))) {
 			cifs_sb->rsize = 1024 * 127;