Fix pg_resetxlog to use correct path to postmaster.pid.

tglsfdc · tglsfdc · commit 614ba4844d3f · 2012-11-22T11:25:09.000-05:00
Since we've already chdir'd into the data directory, the file should be referenced as just "postmaster.pid", without prefixing the directory path. This is harmless in the normal case where an absolute PGDATA path is used, but quite dangerous if a relative path is specified, since the program might then fail to notice an active postmaster. Reported by Hari Babu. This got broken in my commit eb5949d, so patch all active versions.
diff --git a/src/bin/pg_resetxlog/pg_resetxlog.c b/src/bin/pg_resetxlog/pg_resetxlog.c
@@ -95,7 +95,6 @@ main(int argc, char *argv[])
 	char	   *endptr3;
 	char	   *DataDir;
 	int			fd;
-	char		path[MAXPGPATH];
 
 	set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_resetxlog"));
 
@@ -270,21 +269,20 @@ main(int argc, char *argv[])
 	 * Check for a postmaster lock file --- if there is one, refuse to
 	 * proceed, on grounds we might be interfering with a live installation.
 	 */
-	snprintf(path, MAXPGPATH, "%s/postmaster.pid", DataDir);
-
-	if ((fd = open(path, O_RDONLY, 0)) < 0)
+	if ((fd = open("postmaster.pid", O_RDONLY, 0)) < 0)
 	{
 		if (errno != ENOENT)
 		{
-			fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"), progname, path, strerror(errno));
+			fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
+					progname, "postmaster.pid", strerror(errno));
 			exit(1);
 		}
 	}
 	else
 	{
 		fprintf(stderr, _("%s: lock file \"%s\" exists\n"
 						  "Is a server running?  If not, delete the lock file and try again.\n"),
-				progname, path);
+				progname, "postmaster.pid");
 		exit(1);
 	}
 

Original file line number	Diff line number	Diff line change
`@@ -95,7 +95,6 @@ main(int argc, char *argv[])`
`95`	`95`	`char *endptr3;`
`96`	`96`	`char *DataDir;`
`97`	`97`	`int fd;`
`98`		`- char path[MAXPGPATH];`
`99`	`98`
`100`	`99`	`set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_resetxlog"));`
`101`	`100`
`@@ -270,21 +269,20 @@ main(int argc, char *argv[])`
`270`	`269`	`* Check for a postmaster lock file --- if there is one, refuse to`
`271`	`270`	`* proceed, on grounds we might be interfering with a live installation.`
`272`	`271`	`*/`
`273`		`- snprintf(path, MAXPGPATH, "%s/postmaster.pid", DataDir);`
`274`		`-`
`275`		`- if ((fd = open(path, O_RDONLY, 0)) < 0)`
	`272`	`+ if ((fd = open("postmaster.pid", O_RDONLY, 0)) < 0)`
`276`	`273`	`{`
`277`	`274`	`if (errno != ENOENT)`
`278`	`275`	`{`
`279`		`- fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"), progname, path, strerror(errno));`
	`276`	`+ fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),`
	`277`	`+ progname, "postmaster.pid", strerror(errno));`
`280`	`278`	`exit(1);`
`281`	`279`	`}`
`282`	`280`	`}`
`283`	`281`	`else`
`284`	`282`	`{`
`285`	`283`	`fprintf(stderr, _("%s: lock file \"%s\" exists\n"`
`286`	`284`	`"Is a server running? If not, delete the lock file and try again.\n"),`
`287`		`- progname, path);`
	`285`	`+ progname, "postmaster.pid");`
`288`	`286`	`exit(1);`
`289`	`287`	`}`
`290`	`288`