This is a small tool which will read an entire disk(partition) using

1M blocks and optionally write the read data to a file or disk.

If a read error happens, the 1M block gets put on the end of the worklist
and will be retried with 64k blocksize.

If a read error happens again, the 64k block gets put at the end of the
worklist and will be retried with single sector reads.

The program keeps trying until you stop it.

You can refresh a disk:

	recoverdisk /dev/ad1 /dev/ad1

or salvage a floppy:

	recoverdisk /dev/fd0 myfloppy.flp

3 files changed, 170 insertions, 0 deletions

diff --git a/tools/tools/recoverdisk/Makefile b/tools/tools/recoverdisk/Makefile
new file mode 100644
index 0000000..f667aec
--- /dev/null
+++ b/tools/tools/recoverdisk/Makefile
@@ -0,0 +1,12 @@
+# $FreeBSD$
+
+PROG=	recoverdisk
+
+NOMAN=1
+
+WARNS?=	5
+
+.include <bsd.prog.mk>
+
+test:	${PROG}
+	./${PROG} /dev/ad0
diff --git a/tools/tools/recoverdisk/README b/tools/tools/recoverdisk/README
new file mode 100644
index 0000000..2f46cf3
--- /dev/null
+++ b/tools/tools/recoverdisk/README
@@ -0,0 +1,21 @@
+$FreeBSD$
+
+This is a small tool which will read an entire disk(partition) using
+1M blocks and optionally write the read data to a file or disk.
+ 
+If a read error happens, the 1M block gets put on the end of the worklist
+and will be retried with 64k blocksize.
+ 
+If a read error happens again, the 64k block gets put at the end of the
+worklist and will be retried with single sector reads.
+ 
+The program keeps trying until you stop it.
+
+You can refresh a disk:
+
+	recoverdisk /dev/ad1 /dev/ad1
+
+or salvage a floppy:
+
+	recoverdisk /dev/fd0 myfloppy.flp
+
diff --git a/tools/tools/recoverdisk/recoverdisk.c b/tools/tools/recoverdisk/recoverdisk.c
new file mode 100644
index 0000000..9151c3f
--- /dev/null
+++ b/tools/tools/recoverdisk/recoverdisk.c
@@ -0,0 +1,137 @@
+/*
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 42):
+ * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
+ * can do whatever you want with this stuff. If we meet some day, and you think
+ * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
+ * ----------------------------------------------------------------------------
+ *
+ * $FreeBSD$
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <err.h>
+#include <unistd.h>
+#include <sys/queue.h>
+#include <sys/disk.h>
+
+#define BIGSIZE		(1024 * 1024)
+#define MEDIUMSIZE	(64 * 1024)
+
+struct lump {
+	off_t			start;
+	off_t			len;
+	int			state;
+	TAILQ_ENTRY(lump)	list;
+};
+
+static TAILQ_HEAD(, lump) lumps = TAILQ_HEAD_INITIALIZER(lumps);
+
+
+static void
+new_lump(off_t start, off_t len, int state)
+{
+	struct lump *lp;
+
+	lp = malloc(sizeof *lp);
+	if (lp == NULL)
+		err(1, "Malloc failed");
+	lp->start = start;
+	lp->len = len;
+	lp->state = state;
+	TAILQ_INSERT_TAIL(&lumps, lp, list);
+}
+
+int
+main(int argc, const char **argv)
+{
+	int fdr, fdw;
+	struct lump *lp;
+	off_t 	t, d;
+	size_t i, j;
+	int error;
+	u_char *buf;
+	u_int sectorsize;
+
+
+	if (argc < 2)
+		errx(1, "Usage: %s source-drive [destination]", argv[0]);
+
+	buf = malloc(BIGSIZE);
+	if (buf == NULL)
+		err(1, "Cannot allocate %d bytes buffer", BIGSIZE);
+	fdr = open(argv[1], O_RDONLY);
+	if (fdr < 0)
+		err(1, "Cannot open read descriptor %s", argv[1]);
+	if (argc > 2) {
+		fdw = open(argv[2], O_WRONLY);
+		if (fdw < 0)
+			err(1, "Cannot open write descriptor %s", argv[2]);
+	} else {
+		fdw = -1;
+	}
+
+	error = ioctl(fdr, DIOCGSECTORSIZE, &sectorsize);
+	if (error < 0)
+		err(1, "DIOCGSECTORSIZE failed");
+
+	error = ioctl(fdr, DIOCGMEDIASIZE, &t);
+	if (error < 0)
+		err(1, "DIOCGMEDIASIZE failed");
+
+	new_lump(0, t, 0);
+	d = 0;
+
+	for (;;) {
+		lp = TAILQ_FIRST(&lumps);
+		if (lp == NULL)
+			break;
+		TAILQ_REMOVE(&lumps, lp, list);
+		while (lp->len > 0) {
+			i = BIGSIZE;
+			if (lp->len < BIGSIZE)
+				i = lp->len;
+			if (lp->state == 1)
+				i = MEDIUMSIZE;
+			if (lp->state > 1)
+				i = sectorsize;
+			printf("\r%13jd %7jd %13jd %3d %13jd %13jd %.8f",
+			    (intmax_t)lp->start,
+			    (intmax_t)i, 
+			    (intmax_t)lp->len,
+			    lp->state,
+			    (intmax_t)d,
+			    (intmax_t)(t - d),
+			    (double)d/(double)t);
+			if (i == 0) {
+				errx(1, "BOGUS i %10jd", (intmax_t)i);
+			}
+			fflush(stdout);
+			j = pread(fdr, buf, i, lp->start);
+			if (j == i) {
+				d += i;
+				if (fdw >= 0)
+					j = pwrite(fdw, buf, i, lp->start);
+				else
+					j = i;
+				if (j != i)
+					printf("\nWrite error at %jd/%d\n",
+					    lp->start, i);
+				lp->start += i;
+				lp->len -= i;
+				continue;
+			}
+			printf("\n%jd %d failed %d\n", lp->start, i, errno);
+			new_lump(lp->start, i, lp->state + 1);
+			lp->start += i;
+			lp->len -= i;
+		}
+		free(lp);
+	}
+	printf("\nCompleted\n");
+	exit (0);
+}
+