This patchset adds a new config option, recheck_wwid, to help deal with
devices getting remapped. It's based on Chongyun's patch. 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. To deal with this, the code also triggers a
rescan of the device.
Changes from v1:
0001: New patch to cleanup trailing whitespace stripping, as suggested
by Martin
0002: New patch to simplify the uid_attribute checking code
0003: Numerous changes based on Martin's review.
- The option is now simply on or off instead of having a time
limit, since the overhead of checking the vpd page isn't too
high.
- The option can now be set in the devices section as well.
- handle_path_wwid_change() consistently uses a constant for
the strings.
- handle_path_wwid_change() grabs a reference to the udev device
and then removes the path first, before triggering the uevent.
- handle_path_wwid_change() and uev_update_path() now trigger a
rescan of the path device, when the wwid has changed, to
update the sysfs info.
- the code now determines if it is safe to recheck the wwid the
same way it does for the uid fallback code.
- When I was retesting I couldn't trigger add uevents on paths
being remapped. I suspect I never could, and was accidentally
looking at the add uevents for the new LUN that was mapped
to the old LUN id, instead of seeing add event when the old
LUN was remapped to a new LUN id. This means that the
uev_add_path() code is unnecessary, as Martin suspected. It's
been removed.
Benjamin Marzinski (3):
libmultipath: cleanup code to strip wwid trailing spaces
libmultipath: cleanup uid_attribute checking code
multipathd: add recheck_wwid option to verify the path wwid
libmultipath/config.c | 2 +
libmultipath/config.h | 2 +
libmultipath/configure.c | 4 +-
libmultipath/configure.h | 2 +
libmultipath/defaults.h | 1 +
libmultipath/dict.c | 11 +++++
libmultipath/discovery.c | 35 +++++++-------
libmultipath/discovery.h | 1 +
libmultipath/libmultipath.version | 6 +++
libmultipath/propsel.c | 21 +++++++++
libmultipath/propsel.h | 1 +
libmultipath/structs.h | 7 +++
multipath/multipath.conf.5 | 14 ++++++
multipathd/cli_handlers.c | 9 ++++
multipathd/main.c | 78 +++++++++++++++++++++++++++++++
multipathd/main.h | 2 +
16 files changed, 176 insertions(+), 20 deletions(-)
--
2.17.2
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