Fix to bug #622, http://bugs.skysql.com/show_bug.cgi?id=622

Ensured that soft link and physical file will have same sequence number. Prevented some unnecessary error printing and added more precise logs.

log_manager/log_manager.cc

@@ -286,7 +286,8 @@ static char* add_slash(char* str);
 
 static bool check_file_and_path(
 	char* filename,
-	bool* writable);
+	bool* writable,
+	bool  do_log);
 
 static bool  file_is_symlink(char* filename);
 static int skygw_log_disable_raw(logfile_id_t id, bool emergency); /*< no locking */
@@ -2053,7 +2054,7 @@ static bool logfile_create(
 		 * If file exists but is different type, create fails and
 		 * new, increased sequence number is added to file name.
 		 */
-		if (check_file_and_path(lf->lf_full_file_name, &writable))
+		if (check_file_and_path(lf->lf_full_file_name, &writable, true))
 		{
 			/** Found similarly named file which isn't writable */
 			if (!writable || file_is_symlink(lf->lf_full_file_name))
@@ -2077,13 +2078,12 @@ static bool logfile_create(
 		
 		if (store_shmem)
 		{
-			if (check_file_and_path(lf->lf_full_file_name, &writable))
+			if (check_file_and_path(lf->lf_full_link_name, &writable, true))
 			{
-				/** Found similarly named file which isn't writable */
+				/** Found similarly named link which isn't writable */
-				if (!writable || 
+				if (!writable)
-					file_is_symlink(lf->lf_full_file_name))
 				{
-					unlink(lf->lf_full_file_name);
+					unlink(lf->lf_full_link_name);
 					nameconflicts = true;
 				}
 			}
@@ -2214,7 +2214,6 @@ return_succp:
  *
  * @return Pointer to filename, of NULL if failed.
  *
- * 
  */
 static char* form_full_file_name(
         strpart_t* parts,
@@ -2231,9 +2230,21 @@ static char* form_full_file_name(
 		
         if (lf->lf_name_seqno != -1)
         {
-		lf->lf_name_seqno = find_last_seqno(parts, 
+		int   file_sn;
-						    lf->lf_name_seqno, 
+		int   link_sn = 0;
-						    seqnoidx);	
+		char* tmp = parts[0].sp_string;
+		
+		file_sn = find_last_seqno(parts, lf->lf_name_seqno, seqnoidx);
+		
+		if (lf->lf_linkpath != NULL)
+		{
+			tmp = parts[0].sp_string;
+			parts[0].sp_string = lf->lf_linkpath;
+			link_sn = find_last_seqno(parts, lf->lf_name_seqno, seqnoidx);
+			parts[0].sp_string = tmp;
+		}
+		lf->lf_name_seqno = MAX(file_sn, link_sn);
+		
 		seqno = lf->lf_name_seqno;		
                 s = UINTLEN(seqno);
                 seqnostr = (char *)malloc((int)s+1);
@@ -2354,7 +2365,8 @@ static char* add_slash(
  */
 static bool check_file_and_path(
 	char* filename,
-	bool* writable)
+	bool* writable,
+	bool  do_log)
 {
 	int  fd;
 	bool exists;
@@ -2381,12 +2393,24 @@ static bool check_file_and_path(
 				fd = open(filename, O_CREAT|O_RDWR, S_IRWXU|S_IRWXG);
 				
 				if (fd == -1)
+				{
+					if (do_log && file_is_symlink(filename))
+					{
+						fprintf(stderr,
+							"*\n* Error : Can't access "
+							"file pointed to by %s due "
+							"to %s.\n",
+							filename,
+							strerror(errno));
+					}
+					else if (do_log)
 					{
 						fprintf(stderr,
 							"*\n* Error : Can't access %s due "
 							"to %s.\n",
 							filename,
 							strerror(errno));
+					}
 					if (writable)
 					{
 						*writable = false;
@@ -2402,12 +2426,25 @@ static bool check_file_and_path(
 							*writable = true;
 						}
 						else
+						{
+							if (do_log && 
+								file_is_symlink(filename))
+							{
+								fprintf(stderr,
+									"*\n* Error : Can't write to "
+									"file pointed to by %s due to "
+									"%s.\n", 
+									filename,
+									strerror(errno));
+							}
+							else if (do_log)
 							{
 								fprintf(stderr,
 									"*\n* Error : Can't write to "
 									"%s due to %s.\n", 
 									filename,
 									strerror(errno));
+							}
 							*writable = false;
 						}
 					}
@@ -2416,11 +2453,22 @@ static bool check_file_and_path(
 				exists = true;
 			}
 			else
+			{
+				if (do_log && file_is_symlink(filename))
+				{
+					fprintf(stderr,
+						"*\n* Error : Can't access the file "
+						"pointed to by %s due to %s.\n",
+						filename,
+						strerror(errno));
+				}
+				else if (do_log)
 				{
 					fprintf(stderr,
 						"*\n* Error : Can't access %s due to %s.\n",
 						filename,
 						strerror(errno));
+				}					
 				exists = false;
 				
 				if (writable)
@@ -3061,7 +3109,7 @@ static int find_last_seqno(
 			}
 		}
 		
-		if (check_file_and_path(filename, NULL))
+		if (check_file_and_path(filename, NULL, false))
 		{
 			seqno++;
 		}

server/MaxScale_template.cnf

@@ -31,7 +31,7 @@ threads=4
 #	backend_write_timeout=<timeout in seconds>
 #	backend_read_timeout=<timeout in seconds>
 #
-## mysql_monitor specific options:
+## MySQL monitor-specific options:
 #
 # Enable detection of replication slaves lag via replication_heartbeat 
 # table - optional.
@@ -43,6 +43,13 @@ threads=4
 #
 # 	detect_stale_master=[1|0] (default 0)
 #
+## Galera monitor-specific options:
+#
+# If disable_master_failback is not set, recovery of previously failed master 
+# causes mastership to be switched back to it. Enabling the option prevents it.
+#
+#	disable_master_failback=[0|1] (default 0)
+#
 ## Examples:
 
 [MySQL Monitor]
@@ -65,6 +72,7 @@ servers=server1,server2,server3
 user=myuser
 passwd=mypwd
 monitor_interval=10000
+disable_master_failback=1
 
 ## Filter definition
 #