This patchset adds a new config option, recheck_wwid_time, to help deal with devices getting remapped. It's based on Chongyun's patch, but instead of always checking if the LUN is remapped, users can set how many seconds the LUN must be down before it gets rechecked, or disable this checking entirely, since it is simply there to keep users from shooting themselves in the foot. Setting the value to 0 makes this always recheck when a path is restored. Unlike Chongyun's patch, it doesn't issue a remove uevent. I'm not actually sure what the purpose of the remove uevent was, since it doesn't cause the path to be removed, and multipath already removed it. Instead, it works like Martin's uev_update_path code, and re-adds the path after it removes it. There is one issue I noticed here. While udev will update the WWID in the database when it gets a new uevent, sysfs will still record the original WWID, so if multipathd ever fails back to using sysfs for the WWID, it will see the wrong value. Another possible check that I didn't include is this patchset is to have multipath look at the LUN number whenever it adds a new path to a multipath device. If the LUN number doesn't match the existing LUN numbers, all the old paths should have their wwids checked as soon as possible (immediately, if the path is up), since mismatching LUN numbers is a red flag that something has gone wrong. Benjamin Marzinski (2): libmultipath: fix use-after-free in uev_add_path multipathd: add recheck_wwid_time option to verify the path wwid libmultipath/config.c | 1 + libmultipath/config.h | 1 + libmultipath/configure.c | 4 +- libmultipath/configure.h | 2 + libmultipath/defaults.h | 1 + libmultipath/dict.c | 36 ++++++++++ libmultipath/libmultipath.version | 6 ++ libmultipath/structs.h | 10 +++ multipath/multipath.conf.5 | 18 +++++ multipathd/cli_handlers.c | 9 +++ multipathd/main.c | 107 +++++++++++++++++++++++++++--- multipathd/main.h | 2 + 12 files changed, 187 insertions(+), 10 deletions(-) -- 2.17.2 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
