diff -urN ref/drivers/block/blkpg.c read_ahead/drivers/block/blkpg.c
--- ref/drivers/block/blkpg.c	Mon May  7 19:24:01 2001
+++ read_ahead/drivers/block/blkpg.c	Mon May  7 19:00:20 2001
@@ -224,7 +224,7 @@
 		case BLKRASET:
 			if(!capable(CAP_SYS_ADMIN))
 				return -EACCES;
-			if(!dev || arg > 0xff)
+			if(!dev || (int) arg > 0)
 				return -EINVAL;
 			read_ahead[MAJOR(dev)] = arg;
 			return 0;
diff -urN ref/drivers/md/lvm.c read_ahead/drivers/md/lvm.c
--- ref/drivers/md/lvm.c	Mon May  7 19:24:01 2001
+++ read_ahead/drivers/md/lvm.c	Mon May  7 19:23:26 2001
@@ -243,9 +243,13 @@
 
 #include "lvm-internal.h"
 
-#define	LVM_CORRECT_READ_AHEAD( a) \
-   if      ( a < LVM_MIN_READ_AHEAD || \
-             a > LVM_MAX_READ_AHEAD) a = LVM_MAX_READ_AHEAD;
+#define	LVM_CORRECT_READ_AHEAD(a)		\
+do {						\
+	if ((a) < LVM_MIN_READ_AHEAD ||		\
+	    (a) > LVM_MAX_READ_AHEAD)		\
+		(a) = LVM_DEFAULT_READ_AHEAD;	\
+	read_ahead[MAJOR_NR] = (a);		\
+} while(0)
 
 #ifndef WRITEA
 #  define WRITEA WRITE
@@ -935,6 +939,7 @@
 		    (long) arg > LVM_MAX_READ_AHEAD)
 			return -EINVAL;
 		lv_ptr->lv_read_ahead = (long) arg;
+		read_ahead[MAJOR_NR] = lv_ptr->lv_read_ahead;
 		break;
 
 
diff -urN ref/fs/block_dev.c read_ahead/fs/block_dev.c
--- ref/fs/block_dev.c	Mon May  7 19:24:01 2001
+++ read_ahead/fs/block_dev.c	Mon May  7 18:33:00 2001
@@ -87,10 +87,10 @@
 		      blocks = 1;
 		    } else {
 		      /* Read-ahead before write */
-		      blocks = read_ahead[MAJOR(dev)] / (BUFFERED_BLOCKSIZE >> 9) / 2;
+		      blocks = read_ahead[MAJOR(dev)] / (BUFFERED_BLOCKSIZE >> 9);
+		      blocks++;
 		      if (block + blocks > size) blocks = size - block;
 		      if (blocks > NBUF) blocks=NBUF;
-		      if (!blocks) blocks = 1;
 		      for(i=1; i<blocks; i++)
 		      {
 		        bhlist[i] = getblk (dev, block+i, BUFFERED_BLOCKSIZE);
diff -urN ref/include/linux/lvm.h read_ahead/include/linux/lvm.h
--- ref/include/linux/lvm.h	Mon May  7 19:24:01 2001
+++ read_ahead/include/linux/lvm.h	Mon May  7 19:22:51 2001
@@ -307,8 +307,9 @@
 #define	LVM_MAX_STRIPES		128	/* max # of stripes */
 #define	LVM_MAX_SIZE            ( 1024LU * 1024 / SECTOR_SIZE * 1024 * 1024)	/* 1TB[sectors] */
 #define	LVM_MAX_MIRRORS    	2	/* future use */
-#define	LVM_MIN_READ_AHEAD	2	/* minimum read ahead sectors */
-#define	LVM_MAX_READ_AHEAD	120	/* maximum read ahead sectors */
+#define	LVM_MIN_READ_AHEAD	0	/* minimum read ahead sectors */
+#define	LVM_DEFAULT_READ_AHEAD	1024	/* default read ahead sectors for 512k scsi segments */
+#define	LVM_MAX_READ_AHEAD	10000	/* maximum read ahead sectors */
 #define	LVM_MAX_LV_IO_TIMEOUT	60	/* seconds I/O timeout (future use) */
 #define	LVM_PARTITION           0xfe	/* LVM partition id */
 #define	LVM_NEW_PARTITION       0x8e	/* new LVM partition id (10/09/1999) */