diff --git a/e2fsck/unix.c b/e2fsck/unix.c
index 63487775..48db71ab 100644
--- a/e2fsck/unix.c
+++ b/e2fsck/unix.c
@@ -1173,7 +1173,7 @@ int main (int argc, char *argv[])
 	int old_bitmaps;
 	__u32 features[3];
 	char *cp;
-	int qtype;  /* quota type */
+	int qtype = -99;  /* quota type */
 
 	clear_problem_context(&pctx);
 	sigcatcher_setup();
diff --git a/e2fsck/util.c b/e2fsck/util.c
index 7c4caab0..f3ba6453 100644
--- a/e2fsck/util.c
+++ b/e2fsck/util.c
@@ -795,7 +795,6 @@ void e2fsck_set_bitmap_type(ext2_filsys fs, unsigned int default_type,
 			    const char *profile_name, unsigned int *old_type)
 {
 	unsigned type;
-	errcode_t	retval;
 
 	if (old_type)
 		*old_type = fs->default_bitmap_type;
diff --git a/lib/ext2fs/blkmap64_rb.c b/lib/ext2fs/blkmap64_rb.c
index 7196e906..6007238c 100644
--- a/lib/ext2fs/blkmap64_rb.c
+++ b/lib/ext2fs/blkmap64_rb.c
@@ -70,7 +70,7 @@ static void print_tree(struct rb_root *root)
 	printf("\t\t\t=================================\n");
 }
 
-static int check_tree(struct rb_root *root, const char *msg)
+static void check_tree(struct rb_root *root, const char *msg)
 {
 	struct rb_node *new_node, *node, *next;
 	struct bmap_rb_extent *ext, *old = NULL;
@@ -115,7 +115,7 @@ static int check_tree(struct rb_root *root, const char *msg)
 		}
 		old = ext;
 	}
-	return 0;
+	return;
 
 err_out:
 	printf("%s\n", msg);
@@ -123,8 +123,8 @@ err_out:
 	exit(1);
 }
 #else
-#define check_tree(root, msg) 0
-#define print_tree(root, msg) 0
+#define check_tree(root, msg) do {} while (0)
+#define print_tree(root, msg) do {} while (0)
 #endif
 
 static void rb_get_new_extent(struct bmap_rb_extent **ext, __u64 start,
diff --git a/lib/ext2fs/bmap.c b/lib/ext2fs/bmap.c
index 16d51e0b..aadd22ed 100644
--- a/lib/ext2fs/bmap.c
+++ b/lib/ext2fs/bmap.c
@@ -95,7 +95,7 @@ static _BMAP_INLINE_ errcode_t block_dind_bmap(ext2_filsys fs, int flags,
 					       int *blocks_alloc,
 					       blk_t nr, blk_t *ret_blk)
 {
-	blk_t		b;
+	blk_t		b = 0;
 	errcode_t	retval;
 	blk_t		addr_per_block;
 
@@ -115,7 +115,7 @@ static _BMAP_INLINE_ errcode_t block_tind_bmap(ext2_filsys fs, int flags,
 					       int *blocks_alloc,
 					       blk_t nr, blk_t *ret_blk)
 {
-	blk_t		b;
+	blk_t		b = 0;
 	errcode_t	retval;
 	blk_t		addr_per_block;
 
diff --git a/lib/ext2fs/ismounted.c b/lib/ext2fs/ismounted.c
index bf532ae0..6a223df5 100644
--- a/lib/ext2fs/ismounted.c
+++ b/lib/ext2fs/ismounted.c
@@ -302,9 +302,7 @@ leave:
 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;
@@ -327,15 +325,18 @@ errcode_t ext2fs_check_mount_point(const char *device, int *mount_flags,
 		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);
+	{
+		struct stat st_buf;
+
+		if (stat(device, &st_buf) == 0 && S_ISBLK(st_buf.st_mode)) {
+			int fd = open(device, O_RDONLY | O_EXCL);
+
+			if (fd >= 0)
+				close(fd);
+			else if (errno == EBUSY)
+				*mount_flags |= EXT2_MF_BUSY;
+		}
+	}
 #endif
 
 	return 0;
diff --git a/lib/ext2fs/mkjournal.c b/lib/ext2fs/mkjournal.c
index 30ccdd20..c154d916 100644
--- a/lib/ext2fs/mkjournal.c
+++ b/lib/ext2fs/mkjournal.c
@@ -496,7 +496,7 @@ errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t num_blocks, int flags)
 	ext2_ino_t		journal_ino;
 	struct stat		st;
 	char			jfile[1024];
-	int			mount_flags, f;
+	int			mount_flags;
 	int			fd = -1;
 
 	if (flags & EXT2_MKJOURNAL_NO_MNT_CHECK)
@@ -507,6 +507,9 @@ errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t num_blocks, int flags)
 		return retval;
 
 	if (mount_flags & EXT2_MF_MOUNTED) {
+#if HAVE_EXT2_IOCTLS
+		int f = 0;
+#endif
 		strcat(jfile, "/.journal");
 
 		/*
@@ -519,7 +522,6 @@ errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t num_blocks, int flags)
 #if HAVE_EXT2_IOCTLS
 		fd = open(jfile, O_RDONLY);
 		if (fd >= 0) {
-			f = 0;
 			ioctl(fd, EXT2_IOC_SETFLAGS, &f);
 			close(fd);
 		}
diff --git a/lib/ext2fs/rw_bitmaps.c b/lib/ext2fs/rw_bitmaps.c
index 53f6ec48..3f3ed651 100644
--- a/lib/ext2fs/rw_bitmaps.c
+++ b/lib/ext2fs/rw_bitmaps.c
@@ -154,7 +154,6 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
 	int block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
 	int inode_nbytes = EXT2_INODES_PER_GROUP(fs->super) / 8;
 	int csum_flag = 0;
-	int do_image = fs->flags & EXT2_FLAG_IMAGE_FILE;
 	unsigned int	cnt;
 	blk64_t	blk;
 	blk64_t	blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
diff --git a/lib/ext2fs/unix_io.c b/lib/ext2fs/unix_io.c
index 73716546..19be6308 100644
--- a/lib/ext2fs/unix_io.c
+++ b/lib/ext2fs/unix_io.c
@@ -472,7 +472,7 @@ static errcode_t unix_open(const char *name, int flags, io_channel *channel)
 	io_channel	io = NULL;
 	struct unix_private_data *data = NULL;
 	errcode_t	retval;
-	int		open_flags, zeroes = 0;
+	int		open_flags;
 	int		f_nocache = 0;
 	ext2fs_struct_stat st;
 #ifdef __linux__
@@ -550,9 +550,12 @@ static errcode_t unix_open(const char *name, int flags, io_channel *channel)
 	}
 
 #ifdef BLKDISCARDZEROES
-	ioctl(data->dev, BLKDISCARDZEROES, &zeroes);
-	if (zeroes)
-		io->flags |= CHANNEL_FLAGS_DISCARD_ZEROES;
+	{
+		int zeroes = 0;
+		if (ioctl(data->dev, BLKDISCARDZEROES, &zeroes) == 0 &&
+		    zeroes)
+			io->flags |= CHANNEL_FLAGS_DISCARD_ZEROES;
+	}
 #endif
 
 #if defined(__CYGWIN__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
@@ -920,7 +923,6 @@ static errcode_t unix_discard(io_channel channel, unsigned long long block,
 			      unsigned long long count)
 {
 	struct unix_private_data *data;
-	__uint64_t	range[2];
 	int		ret;
 
 	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
@@ -929,6 +931,8 @@ static errcode_t unix_discard(io_channel channel, unsigned long long block,
 
 	if (channel->flags & CHANNEL_FLAGS_BLOCK_DEVICE) {
 #ifdef BLKDISCARD
+		__uint64_t range[2];
+
 		range[0] = (__uint64_t)(block) * channel->block_size;
 		range[1] = (__uint64_t)(count) * channel->block_size;
 
diff --git a/lib/quota/quotaio.c b/lib/quota/quotaio.c
index 7cdd6530..ac34a80d 100644
--- a/lib/quota/quotaio.c
+++ b/lib/quota/quotaio.c
@@ -117,7 +117,6 @@ static int compute_num_blocks_proc(ext2_filsys fs, blk64_t *blocknr,
 			       int ref_offset EXT2FS_ATTR((unused)),
 			       void *private)
 {
-	blk64_t	block;
 	blk64_t *num_blocks = private;
 
 	*num_blocks += 1;
@@ -128,7 +127,6 @@ errcode_t quota_inode_truncate(ext2_filsys fs, ext2_ino_t ino)
 {
 	struct ext2_inode inode;
 	errcode_t err;
-	int i;
 
 	if ((err = ext2fs_read_inode(fs, ino, &inode)))
 		return err;
diff --git a/lib/uuid/gen_uuid.c b/lib/uuid/gen_uuid.c
index 42d7563d..efa4e3d3 100644
--- a/lib/uuid/gen_uuid.c
+++ b/lib/uuid/gen_uuid.c
@@ -176,8 +176,7 @@ static void get_random_bytes(void *buf, int nbytes)
 {
 	int i, n = nbytes, fd = get_random_fd();
 	int lose_counter = 0;
-	unsigned char *cp = (unsigned char *) buf;
-	unsigned short tmp_seed[3];
+	unsigned char *cp = buf;
 
 	if (fd >= 0) {
 		while (n > 0) {
@@ -200,12 +199,16 @@ static void get_random_bytes(void *buf, int nbytes)
 	for (cp = buf, i = 0; i < nbytes; i++)
 		*cp++ ^= (rand() >> 7) & 0xFF;
 #ifdef DO_JRAND_MIX
-	memcpy(tmp_seed, jrand_seed, sizeof(tmp_seed));
-	jrand_seed[2] = jrand_seed[2] ^ syscall(__NR_gettid);
-	for (cp = buf, i = 0; i < nbytes; i++)
-		*cp++ ^= (jrand48(tmp_seed) >> 7) & 0xFF;
-	memcpy(jrand_seed, tmp_seed,
-	       sizeof(jrand_seed)-sizeof(unsigned short));
+	{
+		unsigned short tmp_seed[3];
+
+		memcpy(tmp_seed, jrand_seed, sizeof(tmp_seed));
+		jrand_seed[2] = jrand_seed[2] ^ syscall(__NR_gettid);
+		for (cp = buf, i = 0; i < nbytes; i++)
+			*cp++ ^= (jrand48(tmp_seed) >> 7) & 0xFF;
+		memcpy(jrand_seed, tmp_seed,
+		       sizeof(jrand_seed) - sizeof(unsigned short));
+	}
 #endif
 
 	return;
diff --git a/misc/badblocks.c b/misc/badblocks.c
index 890d5107..f37cf269 100644
--- a/misc/badblocks.c
+++ b/misc/badblocks.c
@@ -68,19 +68,18 @@ extern int optind;
 const char * program_name = "badblocks";
 const char * done_string = N_("done                                                 \n");
 
-static int v_flag = 0;			/* verbose */
-static int w_flag = 0;			/* do r/w test: 0=no, 1=yes,
+static int v_flag;			/* verbose */
+static int w_flag;			/* do r/w test: 0=no, 1=yes,
 					 * 2=non-destructive */
-static int s_flag = 0;			/* show progress of test */
-static int force = 0;			/* force check of mounted device */
-static int t_flag = 0;			/* number of test patterns */
-static int t_max = 0;			/* allocated test patterns */
-static unsigned int *t_patts = NULL;	/* test patterns */
-static int current_O_DIRECT = 0;	/* Current status of O_DIRECT flag */
-static int use_buffered_io = 0;
-static int exclusive_ok = 0;
-static unsigned int max_bb = 0;		/* Abort test if more than this number of bad blocks has been encountered */
-static unsigned int d_flag = 0;		/* delay factor between reads */
+static int s_flag;			/* show progress of test */
+static int force;			/* force check of mounted device */
+static int t_flag;			/* number of test patterns */
+static int t_max;			/* allocated test patterns */
+static unsigned int *t_patts;		/* test patterns */
+static int use_buffered_io;
+static int exclusive_ok;
+static unsigned int max_bb;		/* Abort test if more than this number of bad blocks has been encountered */
+static unsigned int d_flag;		/* delay factor between reads */
 static struct timeval time_start;
 
 #define T_INC 32
@@ -286,6 +285,7 @@ static void set_o_direct(int dev, unsigned char *buffer, size_t size,
 			 ext2_loff_t offset)
 {
 #ifdef O_DIRECT
+	static int current_O_DIRECT;	/* Current status of O_DIRECT flag */
 	int new_flag = O_DIRECT;
 	int flag;
 
diff --git a/misc/ismounted.c b/misc/ismounted.c
index 4671af8e..6aa0e04d 100644
--- a/misc/ismounted.c
+++ b/misc/ismounted.c
@@ -40,6 +40,7 @@
 
 #include "et/com_err.h"
 
+#ifdef HAVE_SETMNTENT
 static char *skip_over_blank(char *cp)
 {
 	while (*cp && isspace(*cp))
@@ -69,6 +70,7 @@ static char *parse_word(char **buf)
 	*buf = next;
 	return word;
 }
+#endif
 
 /*
  * Helper function which checks a file in /etc/mtab format to see if a
diff --git a/misc/mke2fs.c b/misc/mke2fs.c
index 0f9a299f..df9c1c14 100644
--- a/misc/mke2fs.c
+++ b/misc/mke2fs.c
@@ -146,6 +146,7 @@ static int int_log10(unsigned long long arg)
 	return l;
 }
 
+#ifdef __linux__
 static int parse_version_number(const char *s)
 {
 	int	major, minor, rev;
@@ -167,6 +168,7 @@ static int parse_version_number(const char *s)
 		return 0;
 	return ((((major * 256) + minor) * 256) + rev);
 }
+#endif
 
 /*
  * Helper function for read_bb_file and test_disk