Remove the limit on the number of extra directories.

Save extra directories separately to eliminate name collisions.

src/backup.c

@@ -463,8 +463,7 @@ do_backup_instance(void)
 {
 	int			i;
 	char		database_path[MAXPGPATH];
-	char		extra_path[MAXPGPATH];
+	char		extra_path[MAXPGPATH]; /* Temp value. Used as template */
-	char	   *extradirs[] = { NULL, NULL, NULL, NULL };
 	char		dst_backup_path[MAXPGPATH];
 	char		label[1024];
 	XLogRecPtr	prev_backup_start_lsn = InvalidXLogRecPtr;
@@ -478,23 +477,22 @@ do_backup_instance(void)
 	pgBackup   *prev_backup = NULL;
 	parray	   *prev_backup_filelist = NULL;
 	parray	   *backup_list = NULL;
+	parray	   *extra_dirs = NULL;
 
 	pgFile	   *pg_control = NULL;
 
 	elog(LOG, "Database backup start");
-	i = 0;
+	extra_dirs = parray_new();
+	/* TODO: Add path validation */
 	if(extradir)
 	{
 		p = strtok(extradir,":");
 		while(p!=NULL)
 		{
-			extradirs[i] = (char *)palloc(strlen(p) + 1);
+			char * dir = (char *)palloc(strlen(p) + 1);
-			strcpy(extradirs[i],p);
+			strcpy(dir,p);
-			elog(WARNING,"%s",extradirs[i]);
+			parray_append(extra_dirs, dir);
-			i++;
 			p=strtok(NULL,":");
-			if (i==3)
-				break;
 		}
 	}
 
@@ -654,11 +652,10 @@ do_backup_instance(void)
 	parse_backup_filelist_filenames(backup_files_list, pgdata);
 
 	/* Append to backup list all files dirictories from extra dirictory option */
-	for (i = 0; extradirs[i]; i++)
+	for (i = 0; i < parray_num(extra_dirs); i++)
-	{
+		/* Extra dirs numeration starts with 1. 0 value is not extra dir */
-		elog(WARNING,"%s",extradirs[i]);
+		dir_list_file(backup_files_list, (char *) parray_get(extra_dirs, i),
-		dir_list_file(backup_files_list, extradirs[i], true, true, true, true);
+					  true, true, true, i+1);
-	}
 
 	if (current.backup_mode != BACKUP_MODE_FULL)
 	{
@@ -714,8 +711,12 @@ do_backup_instance(void)
 
 			elog(VERBOSE, "Create directory \"%s\" NAME %s", dir_name, file->name);
 
-			if (file->is_extra)
+			if (file->extra_dir_num)
-				join_path_components(dirpath, extra_path, dir_name);
+			{
+				char		temp[MAXPGPATH];
+				sprintf(temp, "%s%d", extra_path, file->extra_dir_num);
+				join_path_components(dirpath, temp, dir_name);
+			}
 			else
 				join_path_components(dirpath, database_path, dir_name);
 			dir_create_dir(dirpath, DIR_PERMISSION);
@@ -783,6 +784,12 @@ do_backup_instance(void)
 		parray_walk(prev_backup_filelist, pgFileFree);
 		parray_free(prev_backup_filelist);
 	}
+	/* clean extra directories list */
+	if (extra_dirs)
+	{
+		parray_walk(extra_dirs, pfree);
+		parray_free(extra_dirs);
+	}
 
 	/* In case of backup from replica >= 9.6 we must fix minRecPoint,
 	 * First we must find pg_control in backup_files_list.
@@ -2237,10 +2244,12 @@ backup_files(void *arg)
 					continue;
 				}
 			}
-			else if (file->is_extra)
+			else if (file->extra_dir_num)
 			{
+				char temp[MAXPGPATH];
+				sprintf(temp, "%s%d", arguments->extra, file->extra_dir_num);
 				if (!copy_file(file->extradir,
-							   arguments->extra,
+							   temp,
 							   file))
 				{
 					file->write_size = BYTES_INVALID;

src/catalog.c

@@ -406,7 +406,7 @@ pgBackupCreateDir(pgBackup *backup)
 {
 	int		i;
 	char	path[MAXPGPATH];
-	char   *subdirs[] = { DATABASE_DIR, EXTRA_DIR, NULL };
+	char   *subdirs[] = { DATABASE_DIR, NULL };
 
 	pgBackupGetPath(backup, path, lengthof(path), NULL);
 

src/dir.c

@@ -120,7 +120,8 @@ static int BlackListCompare(const void *str1, const void *str2);
 static bool dir_check_file(const char *root, pgFile *file);
 static void dir_list_file_internal(parray *files, const char *root,
 								   pgFile *parent, bool exclude,
-								   bool omit_symlink, parray *black_list, bool is_extra);
+								   bool omit_symlink, parray *black_list, 
+								   int extra_dir_num);
 
 static void list_data_directories(parray *files, const char *path, bool is_root,
 								  bool exclude);
@@ -156,7 +157,7 @@ dir_create_dir(const char *dir, mode_t mode)
 }
 
 pgFile *
-pgFileNew(const char *path, bool omit_symlink, bool is_extra)
+pgFileNew(const char *path, bool omit_symlink, int extra_dir_num)
 {
 	struct stat		st;
 	pgFile		   *file;
@@ -174,7 +175,8 @@ pgFileNew(const char *path, bool omit_symlink, bool is_extra)
 	file = pgFileInit(path);
 	file->size = st.st_size;
 	file->mode = st.st_mode;
-	file->is_extra = is_extra;
+	file->is_extra = extra_dir_num > 0;
+	file->extra_dir_num = extra_dir_num;
 	file->extradir = NULL;
 
 	return file;
@@ -374,7 +376,7 @@ BlackListCompare(const void *str1, const void *str2)
  */
 void
 dir_list_file(parray *files, const char *root, bool exclude, bool omit_symlink,
-			  bool add_root, bool is_extra)
+			  bool add_root, int extra_dir_num)
 {
 	pgFile	   *file;
 	parray	   *black_list = NULL;
@@ -411,7 +413,7 @@ dir_list_file(parray *files, const char *root, bool exclude, bool omit_symlink,
 		parray_qsort(black_list, BlackListCompare);
 	}
 
-	file = pgFileNew(root, false, is_extra);
+	file = pgFileNew(root, false, extra_dir_num);
 	if (file == NULL)
 		return;
 
@@ -427,7 +429,8 @@ dir_list_file(parray *files, const char *root, bool exclude, bool omit_symlink,
 		parray_append(files, file);
 	}
 
-	dir_list_file_internal(files, root, file, exclude, omit_symlink, black_list, is_extra);
+	dir_list_file_internal(files, root, file, exclude, omit_symlink, black_list,
+						   extra_dir_num);
 }
 
 /*
@@ -615,7 +618,7 @@ dir_check_file(const char *root, pgFile *file)
  */
 static void
 dir_list_file_internal(parray *files, const char *root, pgFile *parent,
-		bool exclude, bool omit_symlink, parray *black_list, bool is_extra)
+		bool exclude, bool omit_symlink, parray *black_list, int extra_dir_num)
 {
 	DIR		    *dir;
 	struct dirent *dent;
@@ -644,7 +647,7 @@ dir_list_file_internal(parray *files, const char *root, pgFile *parent,
 
 		join_path_components(child, parent->path, dent->d_name);
 
-		file = pgFileNew(child, omit_symlink, is_extra);
+		file = pgFileNew(child, omit_symlink, extra_dir_num);
 		if (file == NULL)
 			continue;
 
@@ -677,7 +680,7 @@ dir_list_file_internal(parray *files, const char *root, pgFile *parent,
 		}
 
 		/* If it is extra dir, remember it */
-		if (is_extra)
+		if (extra_dir_num)
 		{
 			file->extradir = pgut_strdup(root);
 			dirname(file->extradir);
@@ -705,7 +708,7 @@ dir_list_file_internal(parray *files, const char *root, pgFile *parent,
 		 */
 		if (S_ISDIR(file->mode))
 			dir_list_file_internal(files, root, file, exclude, omit_symlink,
-								   black_list, is_extra);
+								   black_list, extra_dir_num);
 	}
 
 	if (errno && errno != ENOENT)
@@ -1201,11 +1204,12 @@ print_file_list(FILE *out, const parray *files, const char *root)
 		fprintf(out, "{\"path\":\"%s\", \"size\":\"" INT64_FORMAT "\", "
 					 "\"mode\":\"%u\", \"is_datafile\":\"%u\", "
 					 "\"is_cfs\":\"%u\", \"crc\":\"%u\", "
-					 "\"compress_alg\":\"%s\", \"is_extra\":\"%u\"",
+					 "\"compress_alg\":\"%s\", \"is_extra\":\"%u\""
+					 ", \"extra_dir_num\":\"%u\"",
 				path, file->write_size, file->mode,
 				file->is_datafile ? 1 : 0, file->is_cfs ? 1 : 0, file->crc,
 				deparse_compress_alg(file->compress_alg),
-				file->is_extra ? 1 : 0);
+				file->is_extra ? 1 : 0, file->extra_dir_num);
 
 		if (file->extradir)
 			fprintf(out, ",\"extradir\":\"%s\"", file->extradir);
@@ -1399,6 +1403,7 @@ dir_read_file_list(const char *root, const char *extra_path, const char *file_tx
 					is_datafile,
 					is_cfs,
 					is_extra,
+					extra_dir_num,
 					crc,
 					segno,
 					n_blocks;
@@ -1412,10 +1417,15 @@ dir_read_file_list(const char *root, const char *extra_path, const char *file_tx
 		get_control_value(buf, "crc", NULL, &crc, true);
 		get_control_value(buf, "compress_alg", compress_alg_string, NULL, false);
 		get_control_value(buf, "is_extra", NULL, &is_extra, false);
+		get_control_value(buf, "extra_dir_num", NULL, &extra_dir_num, false);
 
 		if (root)
-			if (is_extra)
+			if (extra_dir_num)
-				join_path_components(filepath, extra_path, path);
+			{
+				char temp[MAXPGPATH];
+				sprintf(temp, "%s%ld", extra_path, extra_dir_num);
+				join_path_components(filepath, temp, path);
+			}
 			else
 				join_path_components(filepath, root, path);
 		else

src/pg_probackup.h

@@ -117,6 +117,7 @@ typedef struct pgFile
 	bool	is_cfs;			/* Flag to distinguish files compressed by CFS*/
 	bool	is_database;
 	bool	is_extra;
+	bool	extra_dir_num;	/* Number of extra directory. 0 if not extra */
 	char	*extradir;		/* File from extra directory */
 	bool	exists_in_prev;	/* Mark files, both data and regular, that exists in previous backup */
 	CompressAlg compress_alg; /* compression algorithm applied to the file */
@@ -516,7 +517,7 @@ extern const char* deparse_compress_alg(int alg);
 
 /* in dir.c */
 extern void dir_list_file(parray *files, const char *root, bool exclude,
-						  bool omit_symlink, bool add_root, bool is_extra);
+						  bool omit_symlink, bool add_root, int extra_dir_num);
 extern void create_data_directories(const char *data_dir,
 									const char *backup_dir,
 									bool extract_tablespaces);
@@ -534,7 +535,7 @@ extern bool dir_is_empty(const char *path);
 extern bool fileExists(const char *path);
 extern size_t pgFileSize(const char *path);
 
-extern pgFile *pgFileNew(const char *path, bool omit_symlink, bool is_extra);
+extern pgFile *pgFileNew(const char *path, bool omit_symlink, int extra_dir_num);
 extern pgFile *pgFileInit(const char *path);
 extern void pgFileDelete(pgFile *file);
 extern void pgFileFree(void *file);