On Wed, Aug 13 2014 at 2:53pm -0400, Benjamin Marzinski <bmarzins@xxxxxxxxxx> wrote: > This is different solution to the problem of multipath not being able to > reload devices with failed paths than the one that Hannes first proposed. > It adds a list of dm_devs to the mapped_device structure. All of the table > lists point to devices on this list. The list keeps track of how many tables > are accessing these devices, and locks them to deal with tables being created > and destroyed at the same time. This avoids the issue of having tables that > list devices for which the kernel is not holding any reference, and which > can disappear and come back as a completely different device if userspace > drops its reference. This also allows these devices to be reinstated without > another table reload. > > The other patch deals with issues I discovered while tracking down why > multipath devices with no valid paths would hang on table reload. It turns > out that multipath_map can no longer be called after a table reload until > queue_io is cleared, but multipath map was previously the function that > usually cleared queue_io. I've done a first pass review of the code changes and overlayed a cleanup patch in this branch: https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/log/?h=devel I'll do another pass of review tomorrow and perform a full regression test as well as a targetted test of loading various multipath tables with no devices. If all looks good I'll get it staged for 3.18. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
