From: Theodore Ts'o <tytso@mit.edu>
Date: Fri, 20 Jul 2001 00:38:53 +0000 (-0400)
Subject: fstype.c (identify_fs): New file which looks at the superblock
X-Git-Tag: E2FSPROGS-1_23-WIP-0720~7
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=da376f5a13af0648159c575cf50bf78df34056f9;p=tools%2Fe2fsprogs.git

fstype.c (identify_fs): New file which looks at the superblock
	of the filesystem to determines its type.

fsck.c (fsck_device, ignore, interpret_type): Call identify_fs
	if the type specified in /etc/fstab is "auto".
---

diff --git a/misc/ChangeLog b/misc/ChangeLog
index dd6f113..9919f38 100644
--- a/misc/ChangeLog
+++ b/misc/ChangeLog
@@ -1,3 +1,11 @@
+2001-07-19  Theodore Tso  <tytso@valinux.com>
+
+	* fstype.c (identify_fs): New file which looks at the superblock
+		of the filesystem to determines its type.
+
+	* fsck.c (fsck_device, ignore, interpret_type): Call identify_fs
+		if the type specified in /etc/fstab is "auto".
+
 2001-06-23  Theodore Tso  <tytso@valinux.com>
 
 	* Release of E2fsprogs 1.22
diff --git a/misc/Makefile.in b/misc/Makefile.in
index 971ee95..d4421fc 100644
--- a/misc/Makefile.in
+++ b/misc/Makefile.in
@@ -31,12 +31,12 @@ UUIDGEN_OBJS=	uuidgen.o
 DUMPE2FS_OBJS=	dumpe2fs.o
 BADBLOCKS_OBJS=	badblocks.o
 E2IMAGE_OBJS=	e2image.o
-FSCK_OBJS=	fsck.o get_device_by_label.o base_device.o
+FSCK_OBJS=	fsck.o get_device_by_label.o base_device.o fstype.o
 
 SRCS=	$(srcdir)/tune2fs.c $(srcdir)/mklost+found.c $(srcdir)/mke2fs.c \
 		$(srcdir)/chattr.c $(srcdir)/lsattr.c $(srcdir)/dumpe2fs.c \
 		$(srcdir)/badblocks.c $(srcdir)/fsck.c $(srcdir)/util.c \
-		$(srcdir)/uuidgen.c
+		$(srcdir)/uuidgen.c $(srcdir)/fstype.c
 
 LIBS= $(LIBEXT2FS) $(LIBCOM_ERR) 
 DEPLIBS= $(LIBEXT2FS) $(LIBCOM_ERR) 
diff --git a/misc/fsck.c b/misc/fsck.c
index 17ac42d..6eefd55 100644
--- a/misc/fsck.c
+++ b/misc/fsck.c
@@ -252,6 +252,26 @@ static char *interpret_device(char *spec)
 }
 
 /*
+ * Interpret filesystem auto type if necessary
+ */
+static void interpret_type(struct fs_info *fs)
+{
+	const char	*type;
+	
+	if (strcmp(fs->type, "auto") == 0) {
+		type = identify_fs(fs->device);
+		if (type) {
+			free(fs->type);
+			fs->type = string_copy(type);
+		} else
+			fprintf(stderr, _("Could not determine "
+					  "filesystem type for %s\n"),
+				fs->device);
+	}
+}
+
+
+/*
  * Load the filesystem database from /etc/fstab
  */
 static void load_fs_info(const char *filename)
@@ -598,6 +618,7 @@ static void fsck_device(char *device, int interactive)
 
 	if ((fsent = lookup(device))) {
 		device = fsent->device;
+		interpret_type(fsent);
 		if (!type)
 			type = fsent->type;
 	}
@@ -764,6 +785,8 @@ static int ignore(struct fs_info *fs)
 	if (fs->passno == 0)
 		return 1;
 
+	interpret_type(fs);
+
 	/*
 	 * If a specific fstype is specified, and it doesn't match,
 	 * ignore it.
diff --git a/misc/fsck.h b/misc/fsck.h
index 9d9f6ea..71eb011 100644
--- a/misc/fsck.h
+++ b/misc/fsck.h
@@ -61,3 +61,4 @@ struct fsck_instance {
 
 extern char *base_device(char *device);
 extern char *string_copy(const char *s);
+extern const char *identify_fs(const char *fs_name);
diff --git a/misc/fstype.c b/misc/fstype.c
new file mode 100644
index 0000000..31f3027
--- /dev/null
+++ b/misc/fstype.c
@@ -0,0 +1,72 @@
+/*
+ * fstype.c
+ * 
+ * Copyright (C) 2001 Theodore Ts'o.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ */
+
+#include <stdio.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <fcntl.h>
+#include <sys/types.h>
+
+struct fs_magic {
+	const char *fs_name;
+	int	offset;
+	int	len;
+	char	*magic;
+};
+
+struct fs_magic type_array[] = {
+	{ "ext2", 1024+56, 2, "\123\357" },
+	{ "minix", 1040, 2, "\177\023" },
+	{ "minix", 1040, 2, "\217\023" },
+	{ "minix", 1040, 2, "\150\044" },
+	{ "minix", 1040, 2, "\170\044" },
+	{ "xfs", 0, 4, "XFSB" },
+	{ 0, 0, 0, 0 }
+};
+
+const char *identify_fs(const char *fs_name)
+{
+	char	buf[2048];
+	struct fs_magic *p;
+	int	fd;
+
+	fd = open(fs_name, O_RDONLY);
+	if (fd < 0)
+		return NULL;
+	if (lseek(fd, 0, SEEK_SET) < 0)
+		return NULL;
+	if (read(fd, buf, sizeof(buf)) != sizeof(buf))
+		return NULL;
+	for (p = type_array; p->fs_name; p++) {
+		if (memcmp(p->magic, buf+p->offset, p->len) == 0)
+			return p->fs_name;
+	}
+	return NULL;
+}
+
+#ifdef TEST_PROGRAM
+int main(int argc, char **argv)
+{
+	const char	*type;
+	
+	if (argc != 2) {
+		fprintf(stderr, "Usage: %s device\n", argv[0]);
+		exit(1);
+	}
+	type = identify_fs(argv[1]);
+	printf("%s is a %s filesystem\n", argv[1], type);
+	return (0);
+}
+#endif
+
+	
+