[dm-devel] [RFC PATCH 00/20] "Foreign" NVMe support for multipath-tools
Martin Wilck
mwilck at suse.com
Tue Feb 20 13:26:38 UTC 2018
Hello Christophe,
This patch series adds limited support for "foreign" multipath devices
to multipath and multipathd, and implements the respective API for
"native" NVMe multipath devices. The implementation is done using
a shared library approach similar to checkers, so other non-dm multipath
implementations could hook into this API easily.
"Limited support" means here that multipath and multipathd are able
to print information about "foreign" multipath maps with the commands
"multipath -l[l]", "multipathd show topology", "multipathd show maps", and
"multipathd show paths", and that multipathd checks the devices in the
checker loop and prints log messages if something interesting is detected.
No support for other functionality such real health monitoring or
administration is currently planned, although it might be be doable
by extending the code from this patch set.
Sample output from multipathd with this patch set:
multipathd show topology
sys0:NQN:subsysname (uuid.96926ba3-b207-437c-902c-4a4df6538c3f) [nvme] nvme0n1 NVMe,Linux,4.15.0-r
size=2097152 features='n/a' hwhandler='n/a' wp=rw
`-+- policy='n/a' prio=n/a status=n/a
|- 0:1:1 nvme0c1n1 0:0 n/a n/a live
|- 0:2:1 nvme0c2n1 0:0 n/a n/a live
|- 0:3:1 nvme0c3n1 0:0 n/a n/a live
`- 0:4:1 nvme0c4n1 0:0 n/a n/a live
The first part of the set (01/20-09/20) consists only of cleanup patches, improving the
usage of "const" qualifiers in the part of the code I've been working with.
(I'm routinely trying to do at least some cleanup work when I look more deeply
into parts of the code). These patches don't change functionality. 10/20 and
11/20 are two minor helpers for the patches that follow.
Patch 12/20 and 15/20 represent the actual new APIs. Patch 13, 14 change the
libmultipath printing code to work with the strongly simplified "generic"
multipath API from patch 12/20. This allows to provide foreign library code
without replicating the complex data structures libmultipath is using
internally, and yet use libmultipath's native printing code for displaying
map and path properties.
Patch 15/20 defines the actual API for "foreign" libraries. It is built on
top of the "generic" API which defines the data structures with which objects
like multipath maps and paths are described.
Patch 17/20 and 20/20 provide the implementation of NVMe native multipath
support using these APIs. Patch 18/20 and 19/20 contain the necessary changes
to multipath and multipathd to call into the new APIs.
The patch set is based on the previous multipath-tools patches I
sent to dm-devel:
- "[PATCH v2 00/20] Various multipath-tools fixes" ff.
- "[PATCH 0/7] multipath-tools: uevent processing fixes and unit tests" ff.
(7/7 replaced by "[PATCH v2] multipathd: ignore uevents for non-mpath
devices")
- "[PATCH 1/3] multipath.rules: handle NVME devices" ff.
- "[PATCH] libmultipath: increase path product_id/rev field size for NVMe"
To try and reduce confusion, the full series is available here:
https://github.com/openSUSE/multipath-tools/tree/upstream-queue
Reviews and comments are of course welcome.
Best Regards,
Martin
Martin Wilck (20):
multipath(d)/Makefile: add explicit dependency on libraries
libmultipath: remove unused "stdout helpers"
libmultipath: get rid of selector "hack" in print.c
libmultipath: parser: use call-by-value for "snprint" methods
libmultipath: don't update path groups when printing
libmultipath/print: use "const" where appropriate
libmultipath: use "const" in devmapper code
libmultipath: fix compiler warnings for -Wcast-qual
multipath-tools: Makefile.inc: use -Werror=cast-qual
libmultipath: add vector_free_const()
libmultipath: add vector_convert()
libmultipath: "generic multipath" interface
libmultipath: print: convert API to generic data type
libmultipath: print: use generic API for get_x_layout()
libmultipath: API for foreign multipath handling
libmultipath/print: add "%G - foreign" wildcard
libmultipath/foreign: nvme foreign library
multipath: use foreign API
multipathd: use foreign API
libmultipath: foreign/nvme: implement path display
Makefile | 1 +
Makefile.inc | 1 +
kpartx/devmapper.c | 3 +-
libmpathcmd/mpath_cmd.c | 2 +-
libmultipath/Makefile | 2 +-
libmultipath/checkers/rbd.c | 4 +-
libmultipath/configure.c | 1 +
libmultipath/configure.h | 1 -
libmultipath/devmapper.c | 35 +-
libmultipath/devmapper.h | 16 +-
libmultipath/dict.c | 206 ++++++------
libmultipath/discovery.c | 22 +-
libmultipath/discovery.h | 6 +-
libmultipath/dm-generic.c | 70 ++++
libmultipath/dm-generic.h | 41 +++
libmultipath/dmparser.c | 2 +-
libmultipath/foreign.c | 471 ++++++++++++++++++++++++++
libmultipath/foreign.h | 322 ++++++++++++++++++
libmultipath/foreign/Makefile | 30 ++
libmultipath/foreign/nvme.c | 756 ++++++++++++++++++++++++++++++++++++++++++
libmultipath/generic.c | 41 +++
libmultipath/generic.h | 136 ++++++++
libmultipath/list.h | 6 +-
libmultipath/memory.h | 8 +-
libmultipath/parser.c | 9 +-
libmultipath/parser.h | 12 +-
libmultipath/pgpolicies.c | 11 +-
libmultipath/print.c | 397 +++++++++++++---------
libmultipath/print.h | 81 +++--
libmultipath/structs.c | 16 +-
libmultipath/structs.h | 9 +-
libmultipath/uevent.c | 6 +-
libmultipath/util.c | 6 +-
libmultipath/vector.h | 30 ++
multipath/Makefile | 2 +-
multipath/main.c | 14 +
multipathd/Makefile | 2 +-
multipathd/cli_handlers.c | 40 ++-
multipathd/main.c | 53 ++-
39 files changed, 2500 insertions(+), 371 deletions(-)
create mode 100644 libmultipath/dm-generic.c
create mode 100644 libmultipath/dm-generic.h
create mode 100644 libmultipath/foreign.c
create mode 100644 libmultipath/foreign.h
create mode 100644 libmultipath/foreign/Makefile
create mode 100644 libmultipath/foreign/nvme.c
create mode 100644 libmultipath/generic.c
create mode 100644 libmultipath/generic.h
--
2.16.1
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