On Linux 2.6 systems, mke2fs and badblocks will check to see whether

the filesystem appears to be busy; if so, the programs will print an
error message and abort.   (Addresses Debian Bug #308594).

6 files changed, 86 insertions, 31 deletions

diff --git a/lib/ext2fs/ChangeLog b/lib/ext2fs/ChangeLog
index 1b175758..4e83f4c1 100644
--- a/lib/ext2fs/ChangeLog
+++ b/lib/ext2fs/ChangeLog
@@ -1,3 +1,10 @@
+2005-05-29  Theodore Ts'o  <tytso@mit.edu>
+
+	* ismounted.c (ext2fs_check_mount_point): Add test to see if the
+		device appears to be busy; this only works on Linux 2.6+
+		systems, but provides some additional bullet-proofing in
+		those cases.
+
 2005-05-08  Theodore Ts'o  <tytso@mit.edu>
 
 	* test_io.c (safe_getenv): Fix bug so it would fetch the right
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 0832bc28..33ccf677 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -346,6 +346,7 @@ typedef struct ext2_struct_inode_scan *ext2_inode_scan;
 #define EXT2_MF_ISROOT		2
 #define EXT2_MF_READONLY	4
 #define EXT2_MF_SWAP		8
+#define EXT2_MF_BUSY		16
 
 /*
  * Ext2/linux mode flags.  We define them here so that we don't need
diff --git a/lib/ext2fs/ismounted.c b/lib/ext2fs/ismounted.c
index 3f2241d2..5d32de0d 100644
--- a/lib/ext2fs/ismounted.c
+++ b/lib/ext2fs/ismounted.c
@@ -278,10 +278,12 @@ static int is_swap_device(const char *file)
 
 
 /*
- * ext2fs_check_mount_point() returns 1 if the device is mounted, 0
- * otherwise.  If mtpt is non-NULL, the directory where the device is
- * mounted is copied to where mtpt is pointing, up to mtlen
- * characters.
+ * ext2fs_check_mount_point() fills determines if the device is
+ * mounted or otherwise busy, and fills in mount_flags with one or
+ * more of the following flags: EXT2_MF_MOUNTED, EXT2_MF_ISROOT,
+ * EXT2_MF_READONLY, EXT2_MF_SWAP, and EXT2_MF_BUSY.  If mtpt is
+ * non-NULL, the directory where the device is mounted is copied to
+ * where mtpt is pointing, up to mtlen characters.
  */
 #ifdef __TURBOC__
  #pragma argsused
@@ -289,24 +291,43 @@ static int is_swap_device(const char *file)
 errcode_t ext2fs_check_mount_point(const char *device, int *mount_flags,
 				  char *mtpt, int mtlen)
 {
+	struct stat	st_buf;
+	errcode_t	retval = 0;
+	int		fd;
+
 	if (is_swap_device(device)) {
 		*mount_flags = EXT2_MF_MOUNTED | EXT2_MF_SWAP;
 		strncpy(mtpt, "<swap>", mtlen);
-		return 0;
-	}
+	} else {
 #ifdef HAVE_MNTENT_H
-	return check_mntent(device, mount_flags, mtpt, mtlen);
+		retval = check_mntent(device, mount_flags, mtpt, mtlen);
 #else 
 #ifdef HAVE_GETMNTINFO
-	return check_getmntinfo(device, mount_flags, mtpt, mtlen);
+		retval = check_getmntinfo(device, mount_flags, mtpt, mtlen);
 #else
 #ifdef __GNUC__
  #warning "Can't use getmntent or getmntinfo to check for mounted filesystems!"
 #endif
-	*mount_flags = 0;
-	return 0;
+		*mount_flags = 0;
 #endif /* HAVE_GETMNTINFO */
 #endif /* HAVE_MNTENT_H */
+	}
+	if (retval)
+		return retval;
+
+#ifdef __linux__ /* This only works on Linux 2.6+ systems */
+	if ((stat(device, &st_buf) != 0) ||
+	    !S_ISBLK(st_buf.st_mode))
+		return 0;
+	fd = open(device, O_RDONLY | O_EXCL);
+	if (fd < 0) {
+		if (errno == EBUSY)
+			*mount_flags |= EXT2_MF_BUSY;
+	} else
+		close(fd);
+
+	return 0;
+#endif
 }
 
 /*
@@ -339,20 +360,18 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 	printf("Device %s reports flags %02x\n", argv[1], mount_flags);
+	if (mount_flags & EXT2_MF_BUSY)
+		printf("\t%s is apparently in use.\n", argv[1]);
 	if (mount_flags & EXT2_MF_MOUNTED)
 		printf("\t%s is mounted.\n", argv[1]);
-
 	if (mount_flags & EXT2_MF_SWAP)
 		printf("\t%s is a swap device.\n", argv[1]);
-
 	if (mount_flags & EXT2_MF_READONLY)
 		printf("\t%s is read-only.\n", argv[1]);
-	
 	if (mount_flags & EXT2_MF_ISROOT)
 		printf("\t%s is the root filesystem.\n", argv[1]);
 	if (mntpt[0])
 		printf("\t%s is mounted on %s.\n", argv[1], mntpt);
-	
 	exit(0);
 }
 #endif /* DEBUG */
diff --git a/misc/ChangeLog b/misc/ChangeLog
index 1b2826e5..b90715dd 100644
--- a/misc/ChangeLog
+++ b/misc/ChangeLog
@@ -1,3 +1,12 @@
+2005-05-29  Theodore Ts'o  <tytso@mit.edu>
+
+	* util.c (check_mount): Check the new EXT2_MF_BUSY flag to
+		see if the device is in use by the system.
+
+	* badblocks.c (check_mount): Check the new EXT2_MF_BUSY flag to
+		see if the device is in use by the system.  (Works only
+		for Linux 2.6 systems, addresses Debian Bug #308594).
+
 2005-05-20  Theodore Ts'o  <tytso@mit.edu>
 
 	* filefrag.c (frag_report, get_bmap): The FIBMAP and FIGETBSZ
diff --git a/misc/badblocks.c b/misc/badblocks.c
index 00016e5b..9a6acdfa 100644
--- a/misc/badblocks.c
+++ b/misc/badblocks.c
@@ -780,17 +780,27 @@ static void check_mount(char *device_name)
 			device_name);
 		return;
 	}
-	if (!(mount_flags & EXT2_MF_MOUNTED))
-		return;
+	if (mount_flags & EXT2_MF_MOUNTED) {
+		fprintf(stderr, _("%s is mounted; "), device_name);
+		if (force) {
+			fputs(_("badblocks forced anyway.  "
+				"Hope /etc/mtab is incorrect.\n"), stderr);
+			return;
+		}
+	abort_badblocks:
+		fputs(_("it's not safe to run badblocks!\n"), stderr);
+		exit(1);
+	}
 
-	fprintf(stderr, _("%s is mounted; "), device_name);
-	if (force) {
-		fputs(_("badblocks forced anyway.  "
-			"Hope /etc/mtab is incorrect.\n"), stderr);
-		return;
+	if (mount_flags & EXT2_MF_BUSY) {
+		fprintf(stderr, _("%s is apparently in use by the system; "),
+			device_name);
+		if (force)
+			fputs(_("badblocks forced anyway.\n"), stderr);
+		else
+			goto abort_badblocks;
 	}
-	fputs(_("it's not safe to run badblocks!\n"), stderr);
-	exit(1);
+
 }
 
 
diff --git a/misc/util.c b/misc/util.c
index 77359c84..a08a8dd6 100644
--- a/misc/util.c
+++ b/misc/util.c
@@ -152,17 +152,26 @@ void check_mount(const char *device, int force, const char *type)
 			device);
 		return;
 	}
-	if (!(mount_flags & EXT2_MF_MOUNTED))
-		return;
-
-	fprintf(stderr, _("%s is mounted; "), device);
-	if (force) {
-		fputs(_("mke2fs forced anyway.  Hope /etc/mtab is "
-			"incorrect.\n"), stderr);
-	} else {
+	if (mount_flags & EXT2_MF_MOUNTED) {
+		fprintf(stderr, _("%s is mounted; "), device);
+		if (force) {
+			fputs(_("mke2fs forced anyway.  Hope /etc/mtab is "
+				"incorrect.\n"), stderr);
+			return;
+		}
+	abort_mke2fs:
 		fprintf(stderr, _("will not make a %s here!\n"), type);
 		exit(1);
 	}
+	if (mount_flags & EXT2_MF_BUSY) {
+		fprintf(stderr, _("%s is apparently in use by the system; "),
+			device);
+		if (force) {
+			fputs(_("mke2fs forced anyway.\n"), stderr);
+			return;
+		}
+		goto abort_mke2fs;
+	}
 }
 
 void parse_journal_opts(const char *opts)