Properly check for readdir/closedir() failures

Clear errno before calling readdir() and handle old MinGW errno bug
while adding full test coverage for readdir/closedir failures.

Backpatch through 8.4.

contrib/pg_standby/pg_standby.c

@@ -256,7 +256,7 @@ CustomizableCleanupPriorWALFiles(void)
 		 */
 		if ((xldir = opendir(archiveLocation)) != NULL)
 		{
-			while ((xlde = readdir(xldir)) != NULL)
+			while (errno = 0, (xlde = readdir(xldir)) != NULL)
 			{
 				/*
 				 * We ignore the timeline part of the XLOG segment identifiers
@@ -294,13 +294,26 @@ CustomizableCleanupPriorWALFiles(void)
 					}
 				}
 			}
+
+#ifdef WIN32
+			/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
+			if (GetLastError() == ERROR_NO_MORE_FILES)
+				errno = 0;
+#endif
+
+			if (errno)
+				fprintf(stderr, "%s: could not read archive location \"%s\": %s\n",
+						progname, archiveLocation, strerror(errno));
 			if (debug)
 				fprintf(stderr, "\n");
 		}
 		else
 			fprintf(stderr, "%s: archiveLocation \"%s\" open error\n", progname, archiveLocation);
 
-		closedir(xldir);
+		if (closedir(xldir))
+			fprintf(stderr, "%s: could not close archive location \"%s\": %s\n",
+					progname, archiveLocation, strerror(errno));
+
 		fflush(stderr);
 	}
 }

src/backend/storage/file/fd.c

@@ -1582,11 +1582,7 @@ ReadDir(DIR *dir, const char *dirname)
 		return dent;
 
 #ifdef WIN32
-
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
-	/*
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
-	 * released version
-	 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif

src/bin/initdb/initdb.c

@@ -861,7 +861,7 @@ check_data_dir(char *dir)
 	if (!chkdir)
 		return (errno == ENOENT) ? 0 : -1;
 
-	while ((file = readdir(chkdir)) != NULL)
+	while (errno = 0, (file = readdir(chkdir)) != NULL)
 	{
 		if (strcmp(".", file->d_name) == 0 ||
 			strcmp("..", file->d_name) == 0)
@@ -877,18 +877,12 @@ check_data_dir(char *dir)
 	}
 
 #ifdef WIN32
-
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
-	/*
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
-	 * released version
-	 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif
 
-	closedir(chkdir);
+	if (errno || closedir(chkdir))
-
-	if (errno != 0)
 		result = -1;			/* some kind of I/O error? */
 
 	return result;

src/bin/pg_resetxlog/pg_resetxlog.c

@@ -700,8 +700,7 @@ FindEndOfXLOG(void)
 		exit(1);
 	}
 
-	errno = 0;
+	while (errno = 0, (xlde = readdir(xldir)) != NULL)
-	while ((xlde = readdir(xldir)) != NULL)
 	{
 		if (strlen(xlde->d_name) == 24 &&
 			strspn(xlde->d_name, "0123456789ABCDEF") == 24)
@@ -725,25 +724,27 @@ FindEndOfXLOG(void)
 				newXlogSeg = seg;
 			}
 		}
-		errno = 0;
 	}
-#ifdef WIN32
 
-	/*
+#ifdef WIN32
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
-	 * released version
-	 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif
 
 	if (errno)
 	{
-		fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
+		fprintf(stderr, _("%s: could not read directory \"%s\": %s\n"),
+				progname, XLOGDIR, strerror(errno));
+		exit(1);
+	}
+
+	if (closedir(xldir))
+	{
+		fprintf(stderr, _("%s: could not close directory \"%s\": %s\n"),
 				progname, XLOGDIR, strerror(errno));
 		exit(1);
 	}
-	closedir(xldir);
 
 	/*
 	 * Finally, convert to new xlog seg size, and advance by one to ensure we
@@ -775,8 +776,7 @@ KillExistingXLOG(void)
 		exit(1);
 	}
 
-	errno = 0;
+	while (errno = 0, (xlde = readdir(xldir)) != NULL)
-	while ((xlde = readdir(xldir)) != NULL)
 	{
 		if (strlen(xlde->d_name) == 24 &&
 			strspn(xlde->d_name, "0123456789ABCDEF") == 24)
@@ -789,25 +789,27 @@ KillExistingXLOG(void)
 				exit(1);
 			}
 		}
-		errno = 0;
 	}
-#ifdef WIN32
 
-	/*
+#ifdef WIN32
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
-	 * released version
-	 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif
 
 	if (errno)
 	{
-		fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
+		fprintf(stderr, _("%s: could not read directory \"%s\": %s\n"),
+				progname, XLOGDIR, strerror(errno));
+		exit(1);
+	}
+
+	if (closedir(xldir))
+	{
+		fprintf(stderr, _("%s: could not close directory \"%s\": %s\n"),
 				progname, XLOGDIR, strerror(errno));
 		exit(1);
 	}
-	closedir(xldir);
 }
 
 
@@ -831,8 +833,7 @@ KillExistingArchiveStatus(void)
 		exit(1);
 	}
 
-	errno = 0;
+	while (errno = 0, (xlde = readdir(xldir)) != NULL)
-	while ((xlde = readdir(xldir)) != NULL)
 	{
 		if (strspn(xlde->d_name, "0123456789ABCDEF") == 24 &&
 			(strcmp(xlde->d_name + 24, ".ready") == 0 ||
@@ -846,25 +847,27 @@ KillExistingArchiveStatus(void)
 				exit(1);
 			}
 		}
-		errno = 0;
 	}
-#ifdef WIN32
 
-	/*
+#ifdef WIN32
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
-	 * released version
-	 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif
 
 	if (errno)
 	{
-		fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
+		fprintf(stderr, _("%s: could not read directory \"%s\": %s\n"),
+				progname, ARCHSTATDIR, strerror(errno));
+		exit(1);
+	}
+
+	if (closedir(xldir))
+	{
+		fprintf(stderr, _("%s: could not close directory \"%s\": %s\n"),
 				progname, ARCHSTATDIR, strerror(errno));
 		exit(1);
 	}
-	closedir(xldir);
 }
 
 

src/port/dirent.c

@@ -100,15 +100,19 @@ readdir(DIR *d)
 	strcpy(d->ret.d_name, fd.cFileName);		/* Both strings are MAX_PATH
 												 * long */
 	d->ret.d_namlen = strlen(d->ret.d_name);
+
 	return &d->ret;
 }
 
 int
 closedir(DIR *d)
 {
+	int ret = 0;
+
 	if (d->handle != INVALID_HANDLE_VALUE)
-		FindClose(d->handle);
+		ret = !FindClose(d->handle);
 	free(d->dirname);
 	free(d);
-	return 0;
+
+	return ret;
 }

src/port/dirmod.c

@@ -330,8 +330,7 @@ pgfnames(const char *path)
 
 	filenames = (char **) palloc(fnsize * sizeof(char *));
 
-	errno = 0;
+	while (errno = 0, (file = readdir(dir)) != NULL)
-	while ((file = readdir(dir)) != NULL)
 	{
 		if (strcmp(file->d_name, ".") != 0 && strcmp(file->d_name, "..") != 0)
 		{
@@ -343,17 +342,14 @@ pgfnames(const char *path)
 			}
 			filenames[numnames++] = pstrdup(file->d_name);
 		}
-		errno = 0;
 	}
-#ifdef WIN32
 
-	/*
+#ifdef WIN32
-	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
+	/* Bug in old Mingw dirent.c;  fixed in mingw-runtime-3.2, 2003-10-10 */
-	 * released version
-	 */
 	if (GetLastError() == ERROR_NO_MORE_FILES)
 		errno = 0;
 #endif
+
 	if (errno)
 	{
 #ifndef FRONTEND
@@ -366,7 +362,15 @@ pgfnames(const char *path)
 
 	filenames[numnames] = NULL;
 
-	closedir(dir);
+	if (closedir(dir))
+	{
+#ifndef FRONTEND
+		elog(WARNING, "could not close directory \"%s\": %m", path);
+#else
+		fprintf(stderr, _("could not close directory \"%s\": %s\n"),
+				path, strerror(errno));
+#endif
+	}
 
 	return filenames;
 }