On Tue, Mar 3, 2020 at 10:28 AM Leon Romanovsky <leon@xxxxxxxxxx> wrote:
>
> On Fri, Feb 21, 2020 at 11:46:56AM +0100, Jack Wang wrote:
> > Hi all,
> >
> > Here is v9 of the RTRS (former IBTRS) RDMA Transport Library and the
> > corresponding RNBD (former IBNBD) RDMA Network Block Device, which includes
> > changes to address comments from the community.
> >
> > Introduction
> > -------------
> >
> > RTRS (RDMA Transport) is a reliable high speed transport library
> > which allows for establishing connection between client and server
> > machines via RDMA. It is based on RDMA-CM, so expect also to support RoCE
> > and iWARP, but we mainly tested in IB environment. It is optimized to
> > transfer (read/write) IO blocks in the sense that it follows the BIO
> > semantics of providing the possibility to either write data from a
> > scatter-gather list to the remote side or to request ("read") data
> > transfer from the remote side into a given set of buffers.
> >
> > RTRS is multipath capable and provides I/O fail-over and load-balancing
> > functionality, i.e. in RTRS terminology, an RTRS path is a set of RDMA
> > connections and particular path is selected according to the load-balancing
> > policy. It can be used for other components beside RNBD.
> >
> > Module parameter always_invalidate is introduced for the security problem
> > discussed in LPC RDMA MC 2019. When always_invalidate=Y, on the server side we
> > invalidate each rdma buffer before we hand it over to RNBD server and
> > then pass it to the block layer. A new rkey is generated and registered for the
> > buffer after it returns back from the block layer and RNBD server.
> > The new rkey is sent back to the client along with the IO result.
> > The procedure is the default behaviour of the driver. This invalidation and
> > registration on each IO causes performance drop of up to 20%. A user of the
> > driver may choose to load the modules with this mechanism switched off
> > (always_invalidate=N), if he understands and can take the risk of a malicious
> > client being able to corrupt memory of a server it is connected to. This might
> > be a reasonable option in a scenario where all the clients and all the servers
> > are located within a secure datacenter.
> >
> > RNBD (RDMA Network Block Device) is a pair of kernel modules
> > (client and server) that allow for remote access of a block device on
> > the server over RTRS protocol. After being mapped, the remote block
> > devices can be accessed on the client side as local block devices.
> > Internally RNBD uses RTRS as an RDMA transport library.
> >
> > Commits for kernel can be found here:
> > https://github.com/ionos-enterprise/ibnbd/commits/linux-5.6-rc2-ibnbd-v9
> >
> > Testing
> > -------
> >
> > All the changes have been tested with our regression testsuite in our staging environment
> > in IONOS data center. it's around 200 testcases, for both always_invalidate=N and
> > always_invalidate=Y configurations.
> >
> > Changelog
> > ---------
> > v9:
> > o Rebased to linux-5.6-rc2
> > o Update Date/Kernel version in Documentation
> > o Update description in Kconfig for RNBD
> > o rtrs-clt: inline rtrs_clt_decrease_inflight
> > o rtrs-clt: only track inflight for Min_inflight policy
> > v8:
> > o Rebased to linux-5.5-rc7
> > o Reviewed likey/unlikely usage, only keep the one in IO path suggested by Leon Romanovsky
> > o Reviewed inline usage, remove inline for functions longer than 5 lines of code suggested by Leon
> > o Removed 2 WARN_ON suggested by Leon
> > o Removed 2 empty lines between copyright suggested by Leon
> > o Makefile: remove compat include for upstream suggested by Leon
> > o rtrs-clt: remove module parameters suggested by Leon
> > o drop rnbd_clt_dev_is_mapped
> > o rnbd-clt: clean up rnbd_rerun_if_needed
> > o rtrs-srv: remove reset_all sysfs
> > o rtrs stats: remove wc_completion stats
> > o rtrs-clt: enhance doc for rtrs_clt_change_state
> > o rtrs-clt: remove unused rtrs_permit_from_pdu
> > * https://lore.kernel.org/linux-block/20200124204753.13154-1-jinpuwang@xxxxxxxxx/
> > v7:
> > o Rebased to linux-5.5-rc6
> > o Implement code-style/readability/API/Documentation etc suggestions by Bart van Assche
> > o Make W=1 clean
> > o New benchmark results for Mellanox ConnectX-5
> > o second try adding MAINTAINERS entries in alphabetical order as Gal Pressman suggested
> > * https://lore.kernel.org/linux-block/20200116125915.14815-1-jinpuwang@xxxxxxxxx/
> > v6:
> > o Rebased to linux-5.5-rc4
> > o Fix typo in my email address in first patch
> > o Cleanup copyright as suggested by Leon Romanovsky
> > o Remove 2 redudant kobject_del in error path as suggested by Leon Romanovsky
> > o Add MAINTAINERS entries in alphabetical order as Gal Pressman suggested
> > * https://lore.kernel.org/linux-block/20191230102942.18395-1-jinpuwang@xxxxxxxxx/
> > v5:
> > o Fix the security problem pointed out by Jason
> > o Implement code-style/readability/API/etc suggestions by Bart van Assche
> > o Rename IBTRS and IBNBD to RTRS and RNBD accordingly
> > o Fileio mode support in rnbd-srv has been removed.
> > * https://lore.kernel.org/linux-block/20191220155109.8959-1-jinpuwang@xxxxxxxxx/
> > v4:
> > o Protocol extended to transport IO priorities
> > o Support for Mellanox ConnectX-4/X-5
> > o Minor sysfs extentions (display access mode on server side)
> > o Bug fixes: cleaning up sysfs folders, race on deallocation of resources
> > o Style fixes
> > * https://lore.kernel.org/linux-block/20190620150337.7847-1-jinpuwang@xxxxxxxxx/
> > v3:
> > o Sparse fixes:
> > - le32 -> le16 conversion
> > - pcpu and RCU wrong declaration
> > - sysfs: dynamically alloc array of sockaddr structures to reduce
> > size of a stack frame
> > o Rename sysfs folder on client and server sides to show source and
> > destination addresses of the connection, i.e.:
> > .../<session-name>/paths/<src@dst>/
> > o Remove external inclusions from Makefiles.
> > * https://lore.kernel.org/linux-block/20180606152515.25807-1-roman.penyaev@xxxxxxxxxxxxxxxx/
> > v2:
> > o IBNBD:
> > - No legacy request IO mode, only MQ is left.
> > o IBTRS:
> > - No FMR registration, only FR is left.
> > * https://lore.kernel.org/linux-block/20180518130413.16997-1-roman.penyaev@xxxxxxxxxxxxxxxx/
> > v1:
> > o IBTRS: load-balancing and IO fail-over using multipath features were added.
> > o Major parts of the code were rewritten, simplified and overall code
> > size was reduced by a quarter.
> > * https://lore.kernel.org/linux-block/20180202140904.2017-1-roman.penyaev@xxxxxxxxxxxxxxxx/
> > v0:
> > o Initial submission
> > * https://lore.kernel.org/linux-block/1490352343-20075-1-git-send-email-jinpu.wangl@xxxxxxxxxxxxxxxx/
> >
> > As always, please review and share your comments, and consider to merge to
> > upstream.
> >
> > Thanks.
> >
>
> I still see module parameters and prints after allocation failures.
I will remove all prints after allocation failure, will also review
and remove unneeded module parameters.
Thanks!
