![]() The iWARP protocol limits RDMA read requests to a single scatter entry. NFS/RDMA has code in rdma_read_max_sge() that is supposed to limit the sge_count for RDMA read requests to 1, but the code to do that is inside an #ifdef RDMA_TRANSPORT_IWARP block. In the mainline kernel at least, RDMA_TRANSPORT_IWARP is an enum and not a preprocessor #define, so the #ifdef'ed code is never compiled. In my test of a kernel build with -j8 on an NFS/RDMA mount, this problem eventually leads to trouble starting with: svcrdma: Error posting send = -22 svcrdma : RDMA_READ error = -22 and things go downhill from there. The trivial fix is to delete the #ifdef guard. The check seems to be a remnant of when the NFS/RDMA code was not merged and needed to compile against multiple kernel versions, although I don't think it ever worked as intended. In any case now that the code is upstream there's no need to test whether the RDMA_TRANSPORT_IWARP constant is defined or not. Without this patch, my kernel build on an NFS/RDMA mount using NetEffect adapters quickly and 100% reproducibly failed with an error like: ld: final link failed: Software caused connection abort With the patch applied I was able to complete a kernel build on the same setup. (Tom Tucker says this is "actually an _ancient_ remnant when it had to compile against iWARP vs. non-iWARP enabled OFA trees.") Signed-off-by: Roland Dreier <rolandd@cisco.com> Acked-by: Tom Tucker <tom@opengridcomputing.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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.. | ||
auth_gss | ||
xprtrdma | ||
auth.c | ||
auth_null.c | ||
auth_unix.c | ||
cache.c | ||
clnt.c | ||
Makefile | ||
rpc_pipe.c | ||
rpcb_clnt.c | ||
sched.c | ||
socklib.c | ||
stats.c | ||
sunrpc_syms.c | ||
svc.c | ||
svc_xprt.c | ||
svcauth.c | ||
svcauth_unix.c | ||
svcsock.c | ||
sysctl.c | ||
timer.c | ||
xdr.c | ||
xprt.c | ||
xprtsock.c |