When trying to deduce the diskname from the name so we can run

parallel fsck's one per drive, use the shortest prefix ending in
a digit rather than the longest prefix ending in a digit.

This makes "/dev/ad0s1a" and "/dev/ad0s2a" appear to both reside
on the disk "/dev/ad0" and consequently they will be fsck'ed
sequentially rather than in parallel as now.

In general this heuristic is rather soft and errorprone.  For
instance ccd may often reside on two or more physical disks.  A
good solution would be to look for passes larger than 1 until no
disks are found in a particular pass, that way people could put
ccd stripes in pass 3... and have them fsck'ed sequentially.

Reviewed by:	mjacob

2 files changed, 13 insertions, 8 deletions

diff --git a/sbin/fsck/fsck.8 b/sbin/fsck/fsck.8
index a358007..edef23e 100644
--- a/sbin/fsck/fsck.8
+++ b/sbin/fsck/fsck.8
@@ -65,9 +65,9 @@ Filesystems with pass number 1 (normally just the root filesystem)
 are checked one at a time.
 When pass 1 completes, all remaining filesystems are checked,
 running one process per disk drive.
-The disk drive containing each filesystem is inferred from the longest prefix
+The disk drive containing each filesystem is inferred from the shortest prefix
 of the device name that ends in a digit; the remaining characters are assumed
-to be the partition designator.
+to be the partition and slice designator.
 .Pp
 The options are as follows:
 .Bl -tag -width indent
diff --git a/sbin/fsck/preen.c b/sbin/fsck/preen.c
index bd72d6b..e00e84e 100644
--- a/sbin/fsck/preen.c
+++ b/sbin/fsck/preen.c
@@ -259,12 +259,17 @@ finddisk(name)
 	size_t len = 0;
 	struct diskentry *d;
 
-	for (len = strlen(name), p = name + len - 1; p >= name; --p)
-		if (isdigit(*p)) {
-			len = p - name + 1;
-			break;
-		}
-	if (p < name)
+	p = strrchr(name, '/');
+	if (p == NULL)
+		p = name;
+	else
+		p++;
+	for (; *p && !isdigit(*p); p++)
+		continue;
+	for (; *p && isdigit(*p); p++)
+		continue;
+	len = p - name;
+	if (len == 0)
 		len = strlen(name);
 
 	TAILQ_FOREACH(d, &diskh, d_entries)