Increase size of bgw_library_name.

This commit increases the size of the bgw_library_name member of
the BackgroundWorker struct from BGW_MAXLEN (96) bytes to MAXPGPATH
(default of 1024) bytes so that it can store longer file names
(e.g., absolute paths).

Author: Yurii Rashkovskii
Reviewed-by: Daniel Gustafsson, Aleksander Alekseev
Discussion: https://postgr.es/m/CA%2BRLCQyjFV5Y8tG5QgUb6gjteL4S3p%2B1gcyqWTqigyM93WZ9Pg%40mail.gmail.com

Author: nathan-bossart

doc/src/sgml/bgworker.sgml

@@ -59,7 +59,7 @@ typedef struct BackgroundWorker
     int         bgw_flags;
     BgWorkerStartTime bgw_start_time;
     int         bgw_restart_time;       /* in seconds, or BGW_NEVER_RESTART */
-    char        bgw_library_name[BGW_MAXLEN];
+    char        bgw_library_name[MAXPGPATH];
     char        bgw_function_name[BGW_MAXLEN];
     Datum       bgw_main_arg;
     char        bgw_extra[BGW_EXTRALEN];

src/backend/postmaster/bgworker.c

@@ -362,7 +362,7 @@ BackgroundWorkerStateChange(bool allow_new_workers)
 		ascii_safe_strlcpy(rw->rw_worker.bgw_type,
 						   slot->worker.bgw_type, BGW_MAXLEN);
 		ascii_safe_strlcpy(rw->rw_worker.bgw_library_name,
-						   slot->worker.bgw_library_name, BGW_MAXLEN);
+						   slot->worker.bgw_library_name, MAXPGPATH);
 		ascii_safe_strlcpy(rw->rw_worker.bgw_function_name,
 						   slot->worker.bgw_function_name, BGW_MAXLEN);
 

src/backend/replication/logical/launcher.c

@@ -456,7 +456,7 @@ logicalrep_worker_launch(Oid dbid, Oid subid, const char *subname, Oid userid,
 	bgw.bgw_flags = BGWORKER_SHMEM_ACCESS |
 		BGWORKER_BACKEND_DATABASE_CONNECTION;
 	bgw.bgw_start_time = BgWorkerStart_RecoveryFinished;
-	snprintf(bgw.bgw_library_name, BGW_MAXLEN, "postgres");
+	snprintf(bgw.bgw_library_name, MAXPGPATH, "postgres");
 
 	if (is_parallel_apply_worker)
 		snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ParallelApplyWorkerMain");
@@ -910,7 +910,7 @@ ApplyLauncherRegister(void)
 	bgw.bgw_flags = BGWORKER_SHMEM_ACCESS |
 		BGWORKER_BACKEND_DATABASE_CONNECTION;
 	bgw.bgw_start_time = BgWorkerStart_RecoveryFinished;
-	snprintf(bgw.bgw_library_name, BGW_MAXLEN, "postgres");
+	snprintf(bgw.bgw_library_name, MAXPGPATH, "postgres");
 	snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ApplyLauncherMain");
 	snprintf(bgw.bgw_name, BGW_MAXLEN,
 			 "logical replication launcher");

src/include/postmaster/bgworker.h

@@ -93,7 +93,7 @@ typedef struct BackgroundWorker
 	int			bgw_flags;
 	BgWorkerStartTime bgw_start_time;
 	int			bgw_restart_time;	/* in seconds, or BGW_NEVER_RESTART */
-	char		bgw_library_name[BGW_MAXLEN];
+	char		bgw_library_name[MAXPGPATH];
 	char		bgw_function_name[BGW_MAXLEN];
 	Datum		bgw_main_arg;
 	char		bgw_extra[BGW_EXTRALEN];