diff --git a/kpartx/dasd.c b/kpartx/dasd.c
index 14b9d3a..f039864 100644
--- a/kpartx/dasd.c
+++ b/kpartx/dasd.c
@@ -22,6 +22,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -117,13 +118,13 @@ read_dasd_pt(int fd, __attribute__((unused)) struct slice all,
 
 		sprintf(pathname, "/dev/.kpartx-node-%u-%u",
 			(unsigned int)major(dev), (unsigned int)minor(dev));
-		if ((fd_dasd = open(pathname, O_RDONLY)) == -1) {
+		if ((fd_dasd = open(pathname, O_RDONLY | O_DIRECT)) == -1) {
 			/* Devicenode does not exist. Try to create one */
 			if (mknod(pathname, 0600 | S_IFBLK, dev) == -1) {
 				/* Couldn't create a device node */
 				return -1;
 			}
-			fd_dasd = open(pathname, O_RDONLY);
+			fd_dasd = open(pathname, O_RDONLY | O_DIRECT);
 			/*
 			 * The file will vanish when the last process (we)
 			 * has ceased to access it.
@@ -175,7 +176,7 @@ read_dasd_pt(int fd, __attribute__((unused)) struct slice all,
 	 * Get volume label, extract name and type.
 	 */
 
-	if (!(data = (unsigned char *)malloc(blocksize)))
+	if (aligned_malloc((void **)&data, blocksize, NULL))
 		goto out;
 
 
diff --git a/kpartx/gpt.c b/kpartx/gpt.c
index 785b34e..f7fefb7 100644
--- a/kpartx/gpt.c
+++ b/kpartx/gpt.c
@@ -243,8 +243,7 @@ alloc_read_gpt_entries(int fd, gpt_header * gpt)
 
 	if (!count) return NULL;
 
-	pte = (gpt_entry *)malloc(count);
-	if (!pte)
+	if (aligned_malloc((void **)&pte, get_sector_size(fd), &count))
 		return NULL;
 	memset(pte, 0, count);
 
@@ -269,12 +268,11 @@ static gpt_header *
 alloc_read_gpt_header(int fd, uint64_t lba)
 {
 	gpt_header *gpt;
-	gpt = (gpt_header *)
-	    malloc(sizeof (gpt_header));
-	if (!gpt)
+	size_t size = sizeof (gpt_header);
+	if (aligned_malloc((void **)&gpt, get_sector_size(fd), &size))
 		return NULL;
-	memset(gpt, 0, sizeof (*gpt));
-	if (!read_lba(fd, lba, gpt, sizeof (gpt_header))) {
+	memset(gpt, 0, size);
+	if (!read_lba(fd, lba, gpt, size)) {
 		free(gpt);
 		return NULL;
 	}
@@ -498,6 +496,7 @@ find_valid_gpt(int fd, gpt_header ** gpt, gpt_entry ** ptes)
 	gpt_header *pgpt = NULL, *agpt = NULL;
 	gpt_entry *pptes = NULL, *aptes = NULL;
 	legacy_mbr *legacymbr = NULL;
+	size_t size = sizeof(legacy_mbr);
 	uint64_t lastlba;
 	if (!gpt || !ptes)
 		return 0;
@@ -526,11 +525,10 @@ find_valid_gpt(int fd, gpt_header ** gpt, gpt_entry ** ptes)
 	}
 
 	/* This will be added to the EFI Spec. per Intel after v1.02. */
-	legacymbr = malloc(sizeof (*legacymbr));
-	if (legacymbr) {
-		memset(legacymbr, 0, sizeof (*legacymbr));
-		read_lba(fd, 0, (uint8_t *) legacymbr,
-			 sizeof (*legacymbr));
+	if (aligned_malloc((void **)&legacymbr, get_sector_size(fd),
+			   &size) == 0) {
+		memset(legacymbr, 0, size);
+		read_lba(fd, 0, (uint8_t *) legacymbr, size);
 		good_pmbr = is_pmbr_valid(legacymbr);
 		free(legacymbr);
 		legacymbr=NULL;
diff --git a/kpartx/kpartx.c b/kpartx/kpartx.c
index d3620c5..c24ad6d 100644
--- a/kpartx/kpartx.c
+++ b/kpartx/kpartx.c
@@ -19,6 +19,7 @@
  * cva, 2002-10-26
  */
 
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <fcntl.h>
 #include <errno.h>
@@ -41,7 +42,6 @@
 
 #define SIZE(a) (sizeof(a)/sizeof((a)[0]))
 
-#define READ_SIZE	1024
 #define MAXTYPES	64
 #define MAXSLICES	256
 #define DM_TARGET	"linear"
@@ -388,7 +388,7 @@ main(int argc, char **argv){
 		set_delimiter(mapname, delim);
 	}
 
-	fd = open(device, O_RDONLY);
+	fd = open(device, O_RDONLY | O_DIRECT);
 
 	if (fd == -1) {
 		perror(device);
@@ -690,9 +690,9 @@ xmalloc (size_t size) {
  */
 
 static int
-sseek(int fd, unsigned int secnr) {
+sseek(int fd, unsigned int secnr, int secsz) {
 	off64_t in, out;
-	in = ((off64_t) secnr << 9);
+	in = ((off64_t) secnr * secsz);
 	out = 1;
 
 	if ((out = lseek64(fd, in, SEEK_SET)) != in)
@@ -703,6 +703,31 @@ sseek(int fd, unsigned int secnr) {
 	return 0;
 }
 
+int
+aligned_malloc(void **mem_p, size_t align, size_t *size_p)
+{
+	static size_t pgsize = 0;
+	size_t size;
+	int err;
+
+	if (!mem_p || !align || (size_p && !*size_p))
+		return EINVAL;
+
+	if (!pgsize)
+		pgsize = getpagesize();
+
+	if (size_p)
+		size = ((*size_p + align - 1) / align) * align;
+	else
+		size = pgsize;
+
+	err = posix_memalign(mem_p, pgsize, size);
+	if (!err && size_p)
+		*size_p = size;
+	return err;
+}
+
+/* always in sector size blocks */
 static
 struct block {
 	unsigned int secnr;
@@ -710,30 +735,39 @@ struct block {
 	struct block *next;
 } *blockhead;
 
+/* blknr is always in 512 byte blocks */
 char *
-getblock (int fd, unsigned int secnr) {
+getblock (int fd, unsigned int blknr) {
+	unsigned int secsz = get_sector_size(fd);
+	unsigned int blks_per_sec = secsz / 512;
+	unsigned int secnr = blknr / blks_per_sec;
+	unsigned int blk_off = (blknr % blks_per_sec) * 512;
 	struct block *bp;
 
 	for (bp = blockhead; bp; bp = bp->next)
 
 		if (bp->secnr == secnr)
-			return bp->block;
+			return bp->block + blk_off;
 
-	if (sseek(fd, secnr))
+	if (sseek(fd, secnr, secsz))
 		return NULL;
 
 	bp = xmalloc(sizeof(struct block));
 	bp->secnr = secnr;
 	bp->next = blockhead;
 	blockhead = bp;
-	bp->block = (char *) xmalloc(READ_SIZE);
+	if (aligned_malloc((void **)&bp->block, secsz, NULL)) {
+		fprintf(stderr, "aligned_malloc failed\n");
+		exit(1);
+	}
 
-	if (read(fd, bp->block, READ_SIZE) != READ_SIZE) {
+	if (read(fd, bp->block, secsz) != secsz) {
 		fprintf(stderr, "read error, sector %d\n", secnr);
-		bp->block = NULL;
+		blockhead = bp->next;
+		return NULL;
 	}
 
-	return bp->block;
+	return bp->block + blk_off;
 }
 
 int
diff --git a/kpartx/kpartx.h b/kpartx/kpartx.h
index 67edeb8..727632c 100644
--- a/kpartx/kpartx.h
+++ b/kpartx/kpartx.h
@@ -1,6 +1,7 @@
 #ifndef _KPARTX_H
 #define _KPARTX_H
 
+#include <stddef.h>
 #include <stdint.h>
 #include <sys/ioctl.h>
 
@@ -61,6 +62,7 @@ extern ptreader read_mac_pt;
 extern ptreader read_sun_pt;
 extern ptreader read_ps3_pt;
 
+int aligned_malloc(void **mem_p, size_t align, size_t *size_p);
 char *getblock(int fd, unsigned int secnr);
 
 static inline unsigned int