This switches the NVMe host driver to use libmultipath. That library is very heavily based on the NVMe multipath code, so the change over should hopefully be straightforward. There is often a direct replacement for functions.
The multipath functionality in nvme_ns_head and nvme_ns structures are replaced with the mpath_head and mpath_device structures. It's hard to switch to libmulipath in a step-by-step fashion without breaking builds or functionality. To make the series reviewable, I took the approach of adding libmultipath-based code, which would initially be unused, and then finally making the full switch. I think that more testing is required here and any help on that would be appreciated. The series is based on v7.2-rc1 and libmultipath v3. Full series also available at https://github.com/johnpgarry/linux/tree/scsi-multipath-v7.2-v3 Differences to v2 (apart from porting changes for v3 libmultipath): - rebase Differences to v1 (apart from porting changes for v2 libmultipath): - always depend on LIBMULTIAPTH and drop nvme_ns_head.ns_count - add nvme_add_ns() and nvme_delete_ns() - init .drv_module (Nilay) - condense code John Garry (10): nvme-multipath: add initial support for using libmultipath nvme-multipath: add nvme_mpath_available_path() nvme-multipath: add nvme_mpath_{add, remove}_cdev() nvme-multipath: add nvme_mpath_is_{disabled, optimised} nvme-multipath: add nvme_mpath_cdev_ioctl() nvme-multipath: add uring_cmd support nvme-multipath: add nvme_mpath_synchronize() nvme-multipath: add nvme_{add,delete}_ns() nvme-multipath: add nvme_mpath_head_queue_if_no_path() nvme-multipath: switch to use libmultipath drivers/nvme/host/Kconfig | 1 + drivers/nvme/host/core.c | 89 ++-- drivers/nvme/host/ioctl.c | 110 ++-- drivers/nvme/host/multipath.c | 928 +++++++--------------------------- drivers/nvme/host/nvme.h | 135 +++-- drivers/nvme/host/pr.c | 18 - drivers/nvme/host/sysfs.c | 89 +--- 7 files changed, 339 insertions(+), 1031 deletions(-) -- 2.43.7
