[libmultipath] better default blacklist rules

an LU with a scsi_id assigned UID of 36006016087711200afd8d0905137d911 was being blacklisted because the default blacklist includes a regular expression of the form "(ram | raw | loop | fd)[0-9]*" which happens to match the substring "fd8" in the UID.  I've fixed the problem by changing the blacklist regular expression to instead be "^(ram | raw | loop | fd)[0-9]*" since the intention is really to exclude devices from multipath discovery only when their name __begins__ with any of the prefixes within the parenthesis.  Turns out "fd" is the  only one of these listed prefixes which contains exclusively valid alpha-hexa-numeric characters.  The "fd" Characters should not mistakenly collide with hexa-numeric characters at the beginning of at least a scsi_id assigned block device UID since scsi_id is assigning either an alpha 0, 1, 2, or 3 to the first character of the UID string.

This problem is likely in all versions of multipath-tools since 0.4.4-pre7 when the use of both regcomp and regexec were first introduced.  

1 files changed, 3 insertions, 3 deletions

diff --git a/multipath.conf.synthetic b/multipath.conf.synthetic
index 3a018bd..8f6f7e8 100644
--- a/multipath.conf.synthetic
+++ b/multipath.conf.synthetic
@@ -16,9 +16,9 @@
 #}
 #devnode_blacklist {
 #        wwid 26353900f02796769
-#	devnode "(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
-#	devnode "hd[a-z][[0-9]*]"
-#	devnode "cciss!c[0-9]d[0-9]*[p[0-9]*]"
+#	devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
+#	devnode "^hd[a-z][[0-9]*]"
+#	devnode "^cciss!c[0-9]d[0-9]*[p[0-9]*]"
 #}
 #multipaths {
 #	multipath {