On Fri, Mar 12, 2021 at 4:19 PM <schumaker.anna@xxxxxxxxx> wrote: > > From: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> > > It's possible for an NFS server to go down but come back up with a > different IP address. These patches provide a way for administrators to > handle this issue by providing a new IP address for xprt sockets to > connect to. > > Chuck has suggested some ideas for future work that could also use this > interface, such as: > - srcaddr: To move between network devices on the client > - type: "tcp", "rdma", "local" > - bound: 0 for autobind, or the result of the most recent rpcbind query > - connected: either true or false > - last: read-only timestamp of the last operation to use the transport > - device: A symlink to the physical network device > > Changes in v3: > - Rename functions and objects to make future expansion easier > - Put files under /sys/kernel/sunrpc/client/ instead of > /sys/kernel/sunrpc/net/, again for future expansions > - Clean up use of WARN_ON_ONCE() in xs_connect() > - Fix up locking, reference counting, and RCU usage > - Unconditionally create files so userspace tools don't need to guess > what is supported (We return an error message now instead) > > Changes in v2: > - Put files under /sys/kernel/sunrpc/ instead of /sys/net/sunrpc/ > - Rename file from "address" to "dstaddr" > > Thoughts? Reviewed-by/Tested-by this version. Works OK for me. I would like to note that the interface doesn't or rather perhaps cannot do any error checking. So if the "user" were to echo a nonsensical data into the sysfs (echo foobar > <sysfspath>), that breaks the existing connection. However, if a proper IP were to be entered to correct it, things will go back to normal. > Anna > > > Anna Schumaker (5): > sunrpc: Create a sunrpc directory under /sys/kernel/ > sunrpc: Create a client/ subdirectory in the sunrpc sysfs > sunrpc: Create per-rpc_clnt sysfs kobjects > sunrpc: Prepare xs_connect() for taking NULL tasks > sunrpc: Create a per-rpc_clnt file for managing the destination IP > address > > include/linux/sunrpc/clnt.h | 1 + > net/sunrpc/Makefile | 2 +- > net/sunrpc/clnt.c | 5 + > net/sunrpc/sunrpc_syms.c | 8 ++ > net/sunrpc/sysfs.c | 191 ++++++++++++++++++++++++++++++++++++ > net/sunrpc/sysfs.h | 20 ++++ > net/sunrpc/xprtsock.c | 2 +- > 7 files changed, 227 insertions(+), 2 deletions(-) > create mode 100644 net/sunrpc/sysfs.c > create mode 100644 net/sunrpc/sysfs.h > > -- > 2.29.2 >
