ismounted.c (is_swap_device): New function used by

ext2fs_check_if_mounted and ext2fs_check_mount_point which
	determines whether or not the specified device is a swap
	device by using /proc/swaps.  More bulletproofing for
	idiotic/careless system administrators!

TODO

@@ -190,11 +190,6 @@ TODO list.
 
 							- Ted
 
-----------------------------------------------------------------
-
-check_if_mounted() should check to see if the file is in /proc/swaps,
-to avoid mkfs's or checking a active swap partition.
-
 -----------------------------------------------------------------
 
 Debugfs's link command should set the file type information

lib/ext2fs/ChangeLog

@@ -1,5 +1,11 @@
 2001-12-24  Theodore Tso  <tytso@valinux.com>
 
+	* ismounted.c (is_swap_device): New function used by
+		ext2fs_check_if_mounted and ext2fs_check_mount_point which
+		determines whether or not the specified device is a swap
+		device by using /proc/swaps.  More bulletproofing for
+		idiotic/careless system administrators!
+
 	* ext2fs.h, openfs.c (ext2fs_open), initialize.c
 		(ext2fs_initialize), mkdir.c (ext2fs_mkdir): Add a new
 		field to struct_ext2_filsys, umask.  This field is

lib/ext2fs/ext2fs.h

@@ -325,6 +325,7 @@ typedef struct ext2_struct_inode_scan *ext2_inode_scan;
 #define EXT2_MF_MOUNTED		1
 #define EXT2_MF_ISROOT		2
 #define EXT2_MF_READONLY	4
+#define EXT2_MF_SWAP		8
 
 /*
  * Ext2/linux mode flags.  We define them here so that we don't need

lib/ext2fs/ismounted.c

@@ -146,6 +146,45 @@ exit:
 	return retval;
 }
 
+/*
+ * Check to see if we're dealing with the swap device.
+ */
+static int is_swap_device(const char *file)
+{
+	FILE		*f;
+	char		buf[1024], *cp;
+	dev_t		file_dev;
+	struct stat	st_buf;
+
+	file_dev = 0;
+#ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */
+	if (stat(file, &st_buf) == 0)
+		file_dev = st_buf.st_rdev;
+#endif	
+
+	f = fopen("/proc/swaps", "r");
+	if (!f)
+		return;
+	/* Skip the first line */
+	fgets(buf, sizeof(buf), f);
+	while (!feof(f)) {
+		if (!fgets(buf, sizeof(buf), f))
+			break;
+		if ((cp = strchr(buf, ' ')) != NULL)
+			*cp = 0;
+		if ((cp = strchr(buf, '\t')) != NULL)
+			*cp = 0;
+		if (strcmp(buf, file) == 0)
+			return 1;
+#ifndef __GNU__
+		if (file_dev && (stat(buf, &st_buf) == 0) &&
+		    file_dev == st_buf.st_rdev)
+			return 1;
+#endif
+	}
+	return 0;
+}
+
 static errcode_t check_mntent(const char *file, int *mount_flags,
 			      char *mtpt, int mtlen)
 {
@@ -217,6 +256,11 @@ static errcode_t check_getmntinfo(const char *file, int *mount_flags,
 errcode_t ext2fs_check_mount_point(const char *device, int *mount_flags,
 				  char *mtpt, int mtlen)
 {
+	if (is_swap_device(device)) {
+		*mount_flags = EXT2_MF_MOUNTED | EXT2_MF_SWAP;
+		strncpy(mtpt, "<swap>", mtlen);
+		return 0;
+	}
 #ifdef HAVE_MNTENT_H
 	return check_mntent(device, mount_flags, mtpt, mtlen);
 #else 
@@ -262,7 +306,10 @@ int main(int argc, char **argv)
 	printf("Device %s reports flags %02x\n", argv[1], mount_flags);
 	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]);