Chuck Lever f5e13d700a SUNRPC: Fix NFSD's request deferral on RDMA transports ... commit 773f91b2cf upstream. Trond Myklebust reports an NFSD crash in svc_rdma_sendto(). Further investigation shows that the crash occurred while NFSD was handling a deferred request. This patch addresses two inter-related issues that prevent request deferral from working correctly for RPC/RDMA requests: 1. Prevent the crash by ensuring that the original svc_rqst::rq_xprt_ctxt value is available when the request is revisited. Otherwise svc_rdma_sendto() does not have a Receive context available with which to construct its reply. 2. Possibly since before commit 71641d99ce ("svcrdma: Properly compute .len and .buflen for received RPC Calls"), svc_rdma_recvfrom() did not include the transport header in the returned xdr_buf. There should have been no need for svc_defer() and friends to save and restore that header, as of that commit. This issue is addressed in a backport-friendly way by simply having svc_rdma_recvfrom() set rq_xprt_hlen to zero unconditionally, just as svc_tcp_recvfrom() does. This enables svc_deferred_recv() to correctly reconstruct an RPC message received via RPC/RDMA. Reported-by: Trond Myklebust <trondmy@hammerspace.com> Link: https://lore.kernel.org/linux-nfs/82662b7190f26fb304eb0ab1bb04279072439d4e.camel@hammerspace.com/ Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-04-20 09:34:18 +02:00
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Makefile	svcrdma: Add a "parsed chunk list" data structure	2020-11-30 13:00:22 -05:00
backchannel.c	xprtrdma: Eliminate rpcrdma_post_sends()	2021-08-09 16:42:25 -04:00
frwr_ops.c	xprtrdma: Add an xprtrdma_post_send_err tracepoint	2021-08-09 16:42:18 -04:00
module.c	SUNRPC: xprt_load_transport() needs to support the netid "rdma6"	2020-12-02 14:05:52 -05:00
rpc_rdma.c	xprtrdma: Revert 586a0787ce	2021-05-27 08:46:19 -04:00
svc_rdma.c	svcrdma: Deprecate stat variables that are no longer used	2021-01-25 09:36:28 -05:00
svc_rdma_backchannel.c	svcrdma: Normalize Send page handling	2021-03-22 13:22:13 -04:00
svc_rdma_pcl.c	svcrdma: Add a "parsed chunk list" data structure	2020-11-30 13:00:22 -05:00
svc_rdma_recvfrom.c	SUNRPC: Fix NFSD's request deferral on RDMA transports	2022-04-20 09:34:18 +02:00
svc_rdma_rw.c	svcrdma: Convert rdma->sc_rw_ctxts to llist	2021-08-17 11:47:53 -04:00
svc_rdma_sendto.c	svcrdma: Relieve contention on sc_send_lock.	2021-08-17 11:47:53 -04:00
svc_rdma_transport.c	svcrdma: xpt_bc_xprt is already clear in __svc_rdma_free()	2021-08-19 08:29:32 -04:00
transport.c	SUNRPC/xprt: async tasks mustn't block waiting for memory	2022-04-13 20:59:12 +02:00
verbs.c	xprtrdma: fix pointer derefs in error cases of rpcrdma_ep_create	2022-02-23 12:03:19 +01:00
xprt_rdma.h	xprtrdma: Eliminate rpcrdma_post_sends()	2021-08-09 16:42:25 -04:00