Adds a new -C, --gen-conf option to generate the configuration file from the content file.

HISTORY

@@ -5,6 +5,10 @@ SnapRAID HISTORY
 ==========
  * If the underline filesystem doesn't support the FIEMAP command,
    fallback to use the inode number for sorting files.
+   This happens with reiserfs in Linux.
+ * Added a new -C, --gen-conf option to generate a dummy configuration
+   file from the info in the content file.
+   Just in case that you lose everything, except the content file.
 
 4.0 2013/9
 ==========

snapraid.1

@@ -43,7 +43,7 @@ snapraid [\(hyc, \(hy\(hyconf CONFIG]
 .PP
 .PD
 .PP
-snapraid [\(hyV, \(hy\(hyversion] [\(hyh, \(hy\(hyhelp]
+snapraid [\(hyV, \(hy\(hyversion] [\(hyh, \(hy\(hyhelp] [\(hyC, \(hy\(hygen\(hyconf CONTENT]
 .PD 0
 .PP
 .PD
@@ -689,6 +689,15 @@ It\(cqs present mainly for advanced manual recovering.
 Processes only the specified number of blocks.
 It\(cqs present mainly for advanced manual recovering.
 .TP
+.B \(hyC, \(hy\(hygen\(hyconf CONTENT_FILE
+Generates a dummy configuration file from an existing
+content file.
+The configuration file is written in the standard output,
+and it doesn\(cqt overwrite an existing one.
+This configuration file also contains the information
+needed to reconstruct the disk mount points, in case you
+lose the entire system.
+.TP
 .B \(hyv, \(hy\(hyverbose
 Prints more information in the processing.
 .TP

snapraid.c

@@ -119,6 +119,7 @@ struct option long_options[] = {
 	{ "find-by-name", 0, 0, 'N' }, /* deprecated in SnapRAID 4.0 */
 	{ "audit-only", 0, 0, 'a' },
 	{ "speed-test", 0, 0, 'T' },
+	{ "gen-conf", 1, 0, 'C' },
 	{ "verbose", 0, 0, 'v' },
 	{ "gui", 0, 0, 'G' }, /* undocumented GUI interface command */
 	{ "help", 0, 0, 'h' },
@@ -181,7 +182,7 @@ struct option long_options[] = {
 };
 #endif
 
-#define OPTIONS "c:f:d:mep:o:s:t:i:l:ZEUDNaTvhVG"
+#define OPTIONS "c:f:d:mep:o:s:t:i:l:ZEUDNaTC:vhVG"
 
 volatile int global_interrupt = 0;
 
@@ -228,8 +229,11 @@ int main(int argc, char* argv[])
 	const char* import;
 	const char* log;
 	int lock;
+	const char* gen_conf;
 
 	os_init();
+	raid_init();
+	crc32c_init();
 
 	/* defaults */
 	conf = CONF;
@@ -246,6 +250,7 @@ int main(int argc, char* argv[])
 	import = 0;
 	log = 0;
 	lock = 0;
+	gen_conf = 0;
 
 	opterr = 0;
 	while ((c =
@@ -356,6 +361,9 @@ int main(int argc, char* argv[])
 		case 'T' :
 			speed();
 			exit(EXIT_SUCCESS);
+		case 'C' :
+			gen_conf = optarg;
+			break;
 		case OPT_TEST_KILL_AFTER_SYNC :
 			opt.kill_after_sync = 1;
 			break;
@@ -419,6 +427,12 @@ int main(int argc, char* argv[])
 		}
 	}
 
+	if (gen_conf != 0) {
+		generate_configuration(gen_conf);
+		os_done();
+		exit(EXIT_SUCCESS);
+	}
+
 	if (optind + 1 != argc) {
 		usage();
 		exit(EXIT_FAILURE);
@@ -505,9 +519,6 @@ int main(int argc, char* argv[])
 		}
 	}
 
-	raid_init();
-	crc32c_init();
-
 	/* open the log file */
 	if (log == 0)
 		log = "2";

snapraid.d

@@ -13,7 +13,7 @@ Synopsis
 	:	[-s, --start BLKSTART] [-t, --count BLKCOUNT]
 	:	sync|status|scrub|diff|dup|pool|check|fix|rehash
 
-	:snapraid [-V, --version] [-h, --help]
+	:snapraid [-V, --version] [-h, --help] [-C, --gen-conf CONTENT]
 
 Description
 	SnapRAID is a backup program for disk arrays. It stores redundancy
@@ -513,6 +513,15 @@ Options
 		Processes only the specified number of blocks.
 		It's present mainly for advanced manual recovering.
 
+	-C, --gen-conf CONTENT_FILE
+		Generates a dummy configuration file from an existing
+		content file.
+		The configuration file is written in the standard output,
+		and it doesn't overwrite an existing one.
+		This configuration file also contains the information
+		needed to reconstruct the disk mount points, in case you
+		lose the entire system.
+
 	-v, --verbose
 		Prints more information in the processing.
 

snapraid.txt

@@ -17,7 +17,7 @@ snapraid [-c, --conf CONFIG]
 	[-s, --start BLKSTART] [-t, --count BLKCOUNT]
 	sync|status|scrub|diff|dup|pool|check|fix|rehash
 
-snapraid [-V, --version] [-h, --help]
+snapraid [-V, --version] [-h, --help] [-C, --gen-conf CONTENT]
 
 
 2 DESCRIPTION
@@ -556,6 +556,15 @@ SnapRAID provides the following options:
         Processes only the specified number of blocks.
         It's present mainly for advanced manual recovering.
 
+    -C, --gen-conf CONTENT_FILE
+        Generates a dummy configuration file from an existing
+        content file.
+        The configuration file is written in the standard output,
+        and it doesn't overwrite an existing one.
+        This configuration file also contains the information
+        needed to reconstruct the disk mount points, in case you
+        lose the entire system.
+
     -v, --verbose
         Prints more information in the processing.
 

state.c

@@ -39,6 +39,7 @@ void state_init(struct snapraid_state* state)
 	state->lockfile[0] = 0;
 	state->level = 1; /* default is the lowest protection */
 	state->loaded_blockmax = 0;
+	state->no_conf = 0;
 
 	tommy_list_init(&state->disklist);
 	tommy_list_init(&state->maplist);
@@ -873,6 +874,17 @@ static struct snapraid_disk* find_disk(struct snapraid_state* state, const char*
 			return disk;
 	}
 
+	if (state->no_conf) {
+		/* without a configuration file, add disks automatically */
+		struct snapraid_disk* disk;
+
+		disk = disk_alloc(name, "DUMMY/", -1);
+
+		tommy_list_insert_tail(&state->disklist, &disk->node, disk);
+
+		return disk;
+	}
+
 	return 0;
 }
 
@@ -3477,3 +3489,57 @@ int state_progress(struct snapraid_state* state, block_off_t blockpos, block_off
 	return 0;
 }
 
+void generate_configuration(const char* path)
+{
+	struct snapraid_state state;
+	struct snapraid_content* content;
+	tommy_node* j;
+
+	state_init(&state);
+
+	/* mark that we are without a configuration file */
+	state.no_conf = 1;
+
+	/* create the dummy content entry */
+	content = content_alloc(path, -1);
+
+	/* adds the content entry */
+	tommy_list_insert_tail(&state.contentlist, &content->node, content);
+
+	/* read the content file */
+	state_read(&state);
+
+	/* output a dummy configuration file */
+	printf("# Configuration file generated from %s\n", path);
+	printf("\n");
+	printf("# Use this blocksize\n");
+	printf("block_size %u\n", state.block_size / 1024);
+	printf("\n");
+	printf("# Set the correct path for the Parity file\n");
+	printf("parity ENTER_HERE_THE_PARITY_FILE\n");
+	printf("\n");
+	printf("# Set the correct path for the Q-Parity file (if used)\n");
+	printf("q-parity ENTER_HERE_THE_PARITY_FILE\n");
+	printf("\n");
+	printf("# Add any other content file\n");
+	printf("content %s\n", path);
+	printf("\n");
+	for(j=state.maplist;j;j=j->next) {
+		struct snapraid_map* map = j->data;
+		struct snapraid_disk* disk;
+		printf("# Set the correct dir for disk '%s'\n", map->name);
+		printf("# Disk '%s' is the one with system id '%s'\n", map->name, map->uuid);
+		disk = find_disk(&state, map->name);
+		if (disk && disk->filelist) {
+			struct snapraid_file* file = disk->filelist->data;
+			if (file) {
+				printf("# and containing: %s\n", file->sub);
+			}
+		}
+		printf("disk %s ENTER_HERE_THE_DIR\n", map->name);
+		printf("\n");
+	}
+
+	state_done(&state);
+}
+

state.h

@@ -93,6 +93,7 @@ struct snapraid_state {
 	time_t progress_last; /**< Last update of progress visualization. */
 	time_t progress_interruption; /**< Start of the measure interruption. */
 	time_t progress_subtract; /**< Time to subtract for the interruptions. */
+	int no_conf; /**< Automatically add missing info. Used to load content without a configuration file. */
 };
 
 /**
@@ -198,5 +199,13 @@ void state_progress_stop(struct snapraid_state* state);
  */
 void state_progress_restart(struct snapraid_state* state);
 
+/****************************************************************************/
+/* misc */
+
+/**
+ * Generate a dummy configuration file from a content file.
+ */
+void generate_configuration(const char* content);
+
 #endif