Hi, This patch series aims to provide a more fine grained control over nvme's native multipathing, by allowing it to be switched on and off on a per-subsystem basis instead of a big global switch.
The prime use-case is for mixed scenarios where user might want to use nvme's native multipathing on one subset of subsystems and dm-multipath on another subset. For example using native for internal the PCIe NVMe and dm-mpath for the connection to an NVMe over Fabrics Array. The initial discussion for this was held at this year's LSF/MM and the architecture hasn't changed to what we've discussed there. The first patch does the said switch and Mike added two follow up patches to access the personality attribute from the block device's sysfs directory as well. I do have a blktests test for it as well but due to the fcloop but I reported I'm reluctant to include it in the series (or I would need to uncomment the rmmods). Johannes Thumshirn (1): nvme: provide a way to disable nvme mpath per subsystem Mike Snitzer (2): nvme multipath: added SUBSYS_ATTR_RW nvme multipath: add dev_attr_mpath_personality drivers/nvme/host/core.c | 112 ++++++++++++++++++++++++++++++++++++++++-- drivers/nvme/host/multipath.c | 34 +++++++++++-- drivers/nvme/host/nvme.h | 8 +++ 3 files changed, 144 insertions(+), 10 deletions(-) -- 2.16.3
