Add support for searching /proc/evms/volumes when interpreting

LABEL=xxx or UUID=xxx.  

Add new utility program /sbin/findfs, which interprets LABEL=xxx or
UUID=xxx, and returns the device name.  (Part of tune2fs).

misc/ChangeLog

@@ -1,5 +1,17 @@
 2002-08-17  Theodore Ts'o  <tytso@mit.edu>
 
+	* findfs.8.in: New man page.
+
+	* tune2fs.c (do_findfs): If tune2fs is executed with argv[0] set
+		to findfs, then it will interpret argv[1] as one of
+		LABEL=xxx or UUID=xxx and translate it to a device name.
+
+	* get_device_by_label.c (uuidcache_init): Moved code which
+		interpreted /proc/partitions into read_partitions(), and
+		then added support for interpreting /proc/evms/volumes in
+		read_evms().  uuidcache_init() calls both read_evms() and
+		read_partitions().
+
 	* mke2fs.8.in: Add a common usage of the -n option.  (Addresses
 		Debian Bug #146437)
 

misc/Makefile.in

@@ -17,7 +17,7 @@ INSTALL = @INSTALL@
 SPROGS=		mke2fs badblocks tune2fs dumpe2fs $(E2IMAGE_PROG) @FSCK_PROG@
 USPROGS=	mklost+found
 SMANPAGES=	tune2fs.8 mklost+found.8 mke2fs.8 dumpe2fs.8 badblocks.8 \
-			e2label.8 $(E2IMAGE_MAN) @FSCK_MAN@
+			e2label.8 findfs.8 $(E2IMAGE_MAN) @FSCK_MAN@
 
 UPROGS=		chattr lsattr uuidgen
 UMANPAGES=	chattr.1 lsattr.1 uuidgen.1
@@ -116,6 +116,9 @@ mke2fs.8: $(DEP_SUBSTITUTE) $(srcdir)/mke2fs.8.in
 e2label.8: $(DEP_SUBSTITUTE) $(srcdir)/e2label.8.in
 	$(SUBSTITUTE) $(srcdir)/e2label.8.in e2label.8
 
+findfs.8: $(DEP_SUBSTITUTE) $(srcdir)/findfs.8.in
+	$(SUBSTITUTE) $(srcdir)/findfs.8.in findfs.8
+
 e2image.8: $(DEP_SUBSTITUTE) $(srcdir)/e2image.8.in
 	$(SUBSTITUTE) $(srcdir)/e2image.8.in e2image.8
 
@@ -157,6 +160,8 @@ install: all $(SMANPAGES) $(UMANPAGES) installdirs
 		$(DESTDIR)$(root_sbindir)/mkfs.ext3
 	$(LN) -f $(DESTDIR)$(root_sbindir)/tune2fs \
 		$(DESTDIR)$(root_sbindir)/e2label
+	$(LN) -f $(DESTDIR)$(root_sbindir)/tune2fs \
+		$(DESTDIR)$(root_sbindir)/findfs
 	for i in $(UPROGS); do \
 		$(INSTALL_PROGRAM) $$i $(DESTDIR)$(bindir)/$$i; \
 		$(STRIP) $(DESTDIR)$(bindir)/$$i; \

misc/get_device_by_label.c

@@ -37,6 +37,7 @@
 extern char *ext2fs_find_block_device(dev_t device);
 
 #define PROC_PARTITIONS "/proc/partitions"
+#define PROC_EVMS_VOLUMES "/proc/evms/volumes"
 #define DEVLABELDIR	"/dev"
 #define VG_DIR          "/proc/lvm/VGs"
 
@@ -197,7 +198,8 @@ static void init_lvm(void)
 #endif
 
 static void
-uuidcache_init(void) {
+read_partitions(void)
+{
 	char line[100];
 	char *s;
 	int ma, mi, sz;
@@ -210,13 +212,6 @@ uuidcache_init(void) {
 	int firstPass;
 	int handleOnFirst;
 
-	if (uuidCache)
-		return;
-
-#ifdef VG_DIR
-	init_lvm();
-#endif
-	
 	procpt = fopen(PROC_PARTITIONS, "r");
 	if (!procpt)
 		return;
@@ -259,6 +254,10 @@ uuidcache_init(void) {
 				devname = string_copy(device);
 			if (!devname)
 				continue;
+#ifdef DEBUG
+			printf("Checking partition %s (%d, %d)\n",
+			       devname, ma, mi);
+#endif
 			if (!get_label_uuid(devname, &label, uuid))
 				uuidcache_addentry(devname, label, uuid);
 			else
@@ -270,6 +269,64 @@ uuidcache_init(void) {
 	fclose(procpt);
 }
 
+static void
+read_evms(void)
+{
+	char line[100];
+	char *s;
+	int ma, mi, sz;
+	FILE *procpt;
+	char uuid[16], *label, *devname;
+	char device[110];
+	dev_t	dev;
+	struct stat statbuf;
+
+	procpt = fopen(PROC_EVMS_VOLUMES, "r");
+	if (!procpt)
+		return;
+	while (fgets(line, sizeof(line), procpt)) {
+		if (sscanf (line, " %d %d %d %*s %*s %[^\n ]",
+			    &ma, &mi, &sz, device) != 4)
+			continue;
+
+		/*
+		 * We first look for the device in the named location,
+		 * but if we don't find it, or if the stat information
+		 * doesn't check out, we use ext2fs_find_block_device
+		 * to find it.
+		 */
+		dev = makedev(ma, mi);
+		if ((stat(device, &statbuf) < 0) || (statbuf.st_rdev != dev)) {
+			devname = ext2fs_find_block_device(dev);
+		} else
+			devname = string_copy(device);
+		if (!devname)
+			continue;
+#ifdef DEBUG
+		printf("Checking partition %s (%d, %d)\n",
+		       devname, ma, mi);
+#endif
+		if (!get_label_uuid(devname, &label, uuid))
+			uuidcache_addentry(devname, label, uuid);
+		else
+			free(devname);
+	}
+	fclose(procpt);
+}
+
+static void
+uuidcache_init(void)
+{
+	if (uuidCache)
+		return;
+
+#ifdef VG_DIR
+	init_lvm();
+#endif
+	read_evms();
+	read_partitions();
+}
+
 #define UUID   1
 #define VOL    2
 
@@ -328,7 +385,7 @@ get_spec_by_uuid(const char *s)
 	return get_spec_by_x(UUID, uuid);
 
  bad_uuid:
-	fprintf(stderr, _("WARNING: %s: bad UUID"), s);
+	fprintf(stderr, _("WARNING: %s: bad UUID\n"), s);
 	return NULL;
 }
 
@@ -371,3 +428,10 @@ char *interpret_spec(char *spec)
 		dev = string_copy(spec);
 	return dev;
 }
+
+#ifdef DEBUG
+main(int argc, char **argv)
+{
+	uuidcache_init();
+}
+#endif

misc/tune2fs.c

@@ -627,8 +627,26 @@ static void parse_tune2fs_options(int argc, char **argv)
 	if (!open_flag && !l_flag)
 		usage();
 	device_name = argv[optind];
-}	
+}
 
+do_findfs(int argc, char **argv)
+{
+	char	*dev;
+
+	if ((argc != 2) ||
+	    (strncmp(argv[1], "LABEL=", 6) && strncmp(argv[1], "UUID=", 5))) {
+		fprintf(stderr, "Usage: findfs LABEL=<label>|UUID=<uuid>\n");
+		exit(2);
+	}
+	dev = interpret_spec(argv[1]);
+	if (!dev) {
+		fprintf(stderr, "Filesystem matching %s not found\n", 
+			argv[1]);
+		exit(1);
+	}
+	puts(dev);
+	exit(0);
+}
 
 
 int main (int argc, char ** argv)
@@ -647,6 +665,8 @@ int main (int argc, char ** argv)
 		program_name = *argv;
 	initialize_ext2_error_table();
 
+	if (strcmp(get_progname(argv[0]), "findfs") == 0)
+		do_findfs(argc, argv);
 	if (strcmp(get_progname(argv[0]), "e2label") == 0)
 		parse_e2label_options(argc, argv);
 	else