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* sunrpc: remove unused xpo_prep_reply_hdr callbackVasily Averin2018-12-271-1/+0
| | | | | | | | | | | xpo_prep_reply_hdr are not used now. It was defined for tcp transport only, however it cannot be called indirectly, so let's move it to its caller and remove unused callback. Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Optimize the logic that selects the R_key to invalidateChuck Lever2018-11-281-0/+1
| | | | | | | | | | | | | | o Select the R_key to invalidate while the CPU cache still contains the received RPC Call transport header, rather than waiting until we're about to send the RPC Reply. o Choose Send With Invalidate if there is exactly one distinct R_key in the received transport header. If there's more than one, the client will have to perform local invalidation after it has already waited for remote invalidation. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Increase the default connection credit limitChuck Lever2018-10-291-6/+7
| | | | | | | | | | | | Reduce queuing on clients by allowing more credits by default. 64 is the default NFSv4.1 slot table size on Linux clients. This size prevents the credit limit from putting RPC requests to sleep again after they have already slept waiting for a session slot. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove unused svc_rdma_op_ctxtChuck Lever2018-05-111-21/+0
| | | | | | | Clean up: Eliminate a structure that is no longer used. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Persistently allocate and DMA-map Send buffersChuck Lever2018-05-111-2/+6
| | | | | | | | | | | | | | | | While sending each RPC Reply, svc_rdma_sendto allocates and DMA- maps a separate buffer where the RPC/RDMA transport header is constructed. The buffer is unmapped and released in the Send completion handler. This is significant per-RPC overhead, especially for small RPCs. Instead, allocate and DMA-map a buffer, and cache it in each svc_rdma_send_ctxt. This buffer and its mapping can be re-used for each RPC, saving the cost of memory allocation and DMA mapping. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove post_send_wrChuck Lever2018-05-111-3/+0
| | | | | | | | Clean up: Now that the send_wr is part of the svc_rdma_send_ctxt, svc_rdma_post_send_wr is nearly empty. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Don't overrun the SGE array in svc_rdma_send_ctxtChuck Lever2018-05-111-6/+3
| | | | | | | | | | | | | | | | | | | | | Receive buffers are always the same size, but each Send WR has a variable number of SGEs, based on the contents of the xdr_buf being sent. While assembling a Send WR, keep track of the number of SGEs so that we don't exceed the device's maximum, or walk off the end of the Send SGE array. For now the Send path just fails if it exceeds the maximum. The current logic in svc_rdma_accept bases the maximum number of Send SGEs on the largest NFS request that can be sent or received. In the transport layer, the limit is actually based on the capabilities of the underlying device, not on properties of the Upper Layer Protocol. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Introduce svc_rdma_send_ctxtChuck Lever2018-05-111-12/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | svc_rdma_op_ctxt's are pre-allocated and maintained on a per-xprt free list. This eliminates the overhead of calling kmalloc / kfree, both of which grab a globally shared lock that disables interrupts. Introduce a replacement to svc_rdma_op_ctxt's that is built especially for the svcrdma Send path. Subsequent patches will take advantage of this new structure by allocating real resources which are then cached in these objects. The allocations are freed when the transport is torn down. I've renamed the structure so that static type checking can be used to ensure that uses of op_ctxt and send_ctxt are not confused. As an additional clean up, structure fields are renamed to conform with kernel coding conventions. Additional clean ups: - Handle svc_rdma_send_ctxt_get allocation failure at each call site, rather than pre-allocating and hoping we guessed correctly - All send_ctxt_put call-sites request page freeing, so remove the @free_pages argument - All send_ctxt_put call-sites unmap SGEs, so fold that into svc_rdma_send_ctxt_put Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Clean up Send SGE accountingChuck Lever2018-05-111-1/+1
| | | | | | | | | Clean up: Since there's already a svc_rdma_op_ctxt being passed around with the running count of mapped SGEs, drop unneeded parameters to svc_rdma_post_send_wr(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Refactor svc_rdma_dma_map_bufChuck Lever2018-05-111-7/+0
| | | | | | | | Clean up: svc_rdma_dma_map_buf does mostly the same thing as svc_rdma_dma_map_page, so let's fold these together. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Allocate recv_ctxt's on CPU handling ReceivesChuck Lever2018-05-111-0/+1
| | | | | | | | | | | | | | | | | | There is a significant latency penalty when processing an ingress Receive if the Receive buffer resides in memory that is not on the same NUMA node as the the CPU handling completions for a CQ. The system administrator and the device driver determine which CPU handles completions. This CPU does not change during life of the CQ. Further the Upper Layer does not have any visibility of which CPU it is. Allocating Receive buffers in the Receive completion handler guarantees that Receive buffers are allocated on the preferred NUMA node for that CQ. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Persistently allocate and DMA-map Receive buffersChuck Lever2018-05-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current Receive path uses an array of pages which are allocated and DMA mapped when each Receive WR is posted, and then handed off to the upper layer in rqstp::rq_arg. The page flip releases unused pages in the rq_pages pagelist. This mechanism introduces a significant amount of overhead. So instead, kmalloc the Receive buffer, and leave it DMA-mapped while the transport remains connected. This confers a number of benefits: * Each Receive WR requires only one receive SGE, no matter how large the inline threshold is. This helps the server-side NFS/RDMA transport operate on less capable RDMA devices. * The Receive buffer is left allocated and mapped all the time. This relieves svc_rdma_post_recv from the overhead of allocating and DMA-mapping a fresh buffer. * svc_rdma_wc_receive no longer has to DMA unmap the Receive buffer. It has to DMA sync only the number of bytes that were received. * svc_rdma_build_arg_xdr no longer has to free a page in rq_pages for each page in the Receive buffer, making it a constant-time function. * The Receive buffer is now plugged directly into the rq_arg's head[0].iov_vec, and can be larger than a page without spilling over into rq_arg's page list. This enables simplification of the RDMA Read path in subsequent patches. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Simplify svc_rdma_recv_ctxt_putChuck Lever2018-05-111-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Currently svc_rdma_recv_ctxt_put's callers have to know whether they want to free the ctxt's pages or not. This means the human developers have to know when and why to set that free_pages argument. Instead, the ctxt should carry that information with it so that svc_rdma_recv_ctxt_put does the right thing no matter who is calling. We want to keep track of the number of pages in the Receive buffer separately from the number of pages pulled over by RDMA Read. This is so that the correct number of pages can be freed properly and that number is well-documented. So now, rc_hdr_count is the number of pages consumed by head[0] (ie., the page index where the Read chunk should start); and rc_page_count is always the number of pages that need to be released when the ctxt is put. The @free_pages argument is no longer needed. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove sc_rq_depthChuck Lever2018-05-111-1/+0
| | | | | | | | Clean up: No need to retain rq_depth in struct svcrdma_xprt, it is used only in svc_rdma_accept(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Introduce svc_rdma_recv_ctxtChuck Lever2018-05-111-1/+23
| | | | | | | | | | | | | | | | | | | | | | | svc_rdma_op_ctxt's are pre-allocated and maintained on a per-xprt free list. This eliminates the overhead of calling kmalloc / kfree, both of which grab a globally shared lock that disables interrupts. To reduce contention further, separate the use of these objects in the Receive and Send paths in svcrdma. Subsequent patches will take advantage of this separation by allocating real resources which are then cached in these objects. The allocations are freed when the transport is torn down. I've renamed the structure so that static type checking can be used to ensure that uses of op_ctxt and recv_ctxt are not confused. As an additional clean up, structure fields are renamed to conform with kernel coding conventions. As a final clean up, helpers related to recv_ctxt are moved closer to the functions that use them. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Add proper SPDX tags for NetApp-contributed sourceChuck Lever2018-05-111-0/+1
| | | | | Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Consult max_qp_init_rd_atom when accepting connectionsChuck Lever2018-03-201-3/+0
| | | | | | | | | | | | | | | | | | The target needs to return the lesser of the client's Inbound RDMA Read Queue Depth (IRD), provided in the connection parameters, and the local device's Outbound RDMA Read Queue Depth (ORD). The latter limit is max_qp_init_rd_atom, not max_qp_rd_atom. The svcrdma_ord value caps the ORD value for iWARP transports, which do not exchange ORD/IRD values at connection time. Since no other Linux kernel RDMA-enabled storage target sees fit to provide this cap, I'm removing it here too. initiator_depth is a u8, so ensure the computed ORD value does not overflow that field. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Post Receives in the Receive completion handlerChuck Lever2018-01-181-2/+0
| | | | | | | | | This change improves Receive efficiency by posting Receives only on the same CPU that handles Receive completion. Improved latency and throughput has been noted with this change. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Clean up after converting svc_rdma_recvfrom to rdma_rw APIChuck Lever2017-07-121-4/+0
| | | | | | | | Clean up: Registration mode details are now handled by the rdma_rw API, and thus can be removed from svcrdma. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove frmr cacheChuck Lever2017-07-121-18/+0
| | | | | | | | | | Clean up: Now that the svc_rdma_recvfrom path uses the rdma_rw API, the details of Read sink buffer registration are dealt with by the kernel's RDMA core. This cache is no longer used, and can be removed. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove unused Read completion handlersChuck Lever2017-07-121-3/+1
| | | | | | | | | | | | | | Clean up: The generic RDMA R/W API conversion of svc_rdma_recvfrom replaced the Register, Read, and Invalidate completion handlers. Remove the old ones, which are no longer used. These handlers shared some helper code with svc_rdma_wc_send. Fold the wc_common helper back into the one remaining completion handler. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Use generic RDMA R/W API in RPC Call pathChuck Lever2017-07-121-14/+0
| | | | | | | | | | | | | | | | The current svcrdma recvfrom code path has a lot of detail about registration mode and the type of port (iWARP, IB, etc). Instead, use the RDMA core's generic R/W API. This shares code with other RDMA-enabled ULPs that manages the gory details of buffer registration and the posting of RDMA Read Work Requests. Since the Read list marshaling code is being replaced, I took the opportunity to replace C structure-based XDR encoding code with more portable code that uses pointer arithmetic. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Add recvfrom helpers to svc_rdma_rw.cChuck Lever2017-07-121-0/+3
| | | | | | | | | | | | | | | | | | svc_rdma_rw.c already contains helpers for the sendto path. Introduce helpers for the recvfrom path. The plan is to replace the local NFSD bespoke code that constructs and posts RDMA Read Work Requests with calls to the rdma_rw API. This shares code with other RDMA-enabled ULPs that manages the gory details of buffer registration and posting Work Requests. This new code also puts all RDMA_NOMSG-specific logic in one place. Lastly, the use of rqstp->rq_arg.pages is deprecated in favor of using rqstp->rq_pages directly, for clarity. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove svc_rdma_marshal.cChuck Lever2017-06-281-3/+0
| | | | | | | | | | | | svc_rdma_marshal.c has one remaining exported function -- svc_rdma_xdr_decode_req -- and it has a single call site. Take the same approach as the sendto path, and move this function into the source file where it is called. This is a refactoring change only. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Clean out old XDR encodersChuck Lever2017-04-251-4/+0
| | | | | | | | Clean up: These have been replaced and are no longer used. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove the req_map cacheChuck Lever2017-04-251-33/+1
| | | | | | | | req_maps are no longer used by the send path and can thus be removed. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove unused RDMA Write completion handlerChuck Lever2017-04-251-1/+0
| | | | | | | | Clean up. All RDMA Write completions are now handled by svc_rdma_wc_write_ctx. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Reduce size of sge array in struct svc_rdma_op_ctxtChuck Lever2017-04-251-2/+7
| | | | | | | | | | | The sge array in struct svc_rdma_op_ctxt is no longer used for sending RDMA Write WRs. It need only accommodate the construction of Send and Receive WRs. The maximum inline size is the largest payload it needs to handle now. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Clean up RPC-over-RDMA backchannel reply processingChuck Lever2017-04-251-1/+1
| | | | | | | | Replace C structure-based XDR decoding with pointer arithmetic. Pointer arithmetic is considered more portable. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Clean up RDMA_ERROR pathChuck Lever2017-04-251-5/+0
| | | | | | | | | | | | | Now that svc_rdma_sendto has been renovated, svc_rdma_send_error can be refactored to reduce code duplication and remove C structure- based XDR encoding. It is also relocated to the source file that contains its only caller. This is a refactoring change only. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Use rdma_rw API in RPC reply pathChuck Lever2017-04-251-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current svcrdma sendto code path posts one RDMA Write WR at a time. Each of these Writes typically carries a small number of pages (for instance, up to 30 pages for mlx4 devices). That means a 1MB NFS READ reply requires 9 ib_post_send() calls for the Write WRs, and one for the Send WR carrying the actual RPC Reply message. Instead, use the new rdma_rw API. The details of Write WR chain construction and memory registration are taken care of in the RDMA core. svcrdma can focus on the details of the RPC-over-RDMA protocol. This gives three main benefits: 1. All Write WRs for one RDMA segment are posted in a single chain. As few as one ib_post_send() for each Write chunk. 2. The Write path can now use FRWR to register the Write buffers. If the device's maximum page list depth is large, this means a single Write WR is needed for each RPC's Write chunk data. 3. The new code introduces support for RPCs that carry both a Write list and a Reply chunk. This combination can be used for an NFSv4 READ where the data payload is large, and thus is removed from the Payload Stream, but the Payload Stream is still larger than the inline threshold. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Introduce local rdma_rw API helpersChuck Lever2017-04-251-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The plan is to replace the local bespoke code that constructs and posts RDMA Read and Write Work Requests with calls to the rdma_rw API. This shares code with other RDMA-enabled ULPs that manages the gory details of buffer registration and posting Work Requests. Some design notes: o The structure of RPC-over-RDMA transport headers is flexible, allowing multiple segments per Reply with arbitrary alignment, each with a unique R_key. Write and Send WRs continue to be built and posted in separate code paths. However, one whole chunk (with one or more RDMA segments apiece) gets exactly one ib_post_send and one work completion. o svc_xprt reference counting is modified, since a chain of rdma_rw_ctx structs generates one completion, no matter how many Write WRs are posted. o The current code builds the transport header as it is construct- ing Write WRs. I've replaced that with marshaling of transport header data items in a separate step. This is because the exact structure of client-provided segments may not align with the components of the server's reply xdr_buf, or the pages in the page list. Thus parts of each client-provided segment may be written at different points in the send path. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Eliminate RPCRDMA_SQ_DEPTH_MULTChuck Lever2017-04-251-1/+0
| | | | | | | | | | | | | | | | The Send Queue depth is temporarily reduced to 1 SQE per credit. The new rdma_rw API does an internal computation, during QP creation, to increase the depth of the Send Queue to handle RDMA Read and Write operations. This change has to come before the NFSD code paths are updated to use the rdma_rw API. Without this patch, rdma_rw_init_qp() increases the size of the SQ too much, resulting in memory allocation failures during QP creation. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Add svc_rdma_map_reply_hdr()Chuck Lever2017-04-251-0/+3
| | | | | | | | | Introduce a helper to DMA-map a reply's transport header before sending it. This will in part replace the map vector cache. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Move send_wr to svc_rdma_op_ctxtChuck Lever2017-04-251-0/+4
| | | | | | | | | | Clean up: Move the ib_send_wr off the stack, and move common code to post a Send Work Request into a helper. This is a refactoring change only. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Combine list fields in struct svc_rdma_op_ctxtChuck Lever2017-02-081-2/+1
| | | | | | | | | | Clean up: The free list and the dto_q list fields are never used at the same time. Reduce the size of struct svc_rdma_op_ctxt by combining these fields. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove unused sc_dto_q fieldChuck Lever2017-02-081-1/+0
| | | | | | | | | | | Clean up. Commit be99bb11400c ("svcrdma: Use new CQ API for RPC-over-RDMA server send CQs") removed code that used the sc_dto_q field, but neglected to remove sc_dto_q at the same time. Fixes: be99bb11400c ("svcrdma: Use new CQ API for RPC-over- ...") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Clean up RPC-over-RDMA Reply header encoderChuck Lever2017-02-081-5/+2
| | | | | | | | | | | | | | | | | | | | | | Replace C structure-based XDR decoding with pointer arithmetic. Pointer arithmetic is considered more portable, and is used throughout the kernel's existing XDR encoders. The gcc optimizer generates similar assembler code either way. Byte-swapping before a memory store on x86 typically results in an instruction pipeline stall. Avoid byte-swapping when encoding a new header. svcrdma currently doesn't alter a connection's credit grant value after the connection has been accepted, so it is effectively a constant. Cache the byte-swapped value in a separate field. Christoph suggested pulling the header encoding logic into the only function that uses it. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Another sendto chunk list parsing updateChuck Lever2017-02-081-1/+1
| | | | | | | | | | | Commit 5fdca6531434 ("svcrdma: Renovate sendto chunk list parsing") missed a spot. svc_rdma_xdr_get_reply_hdr_len() also assumes the Write list has only one Write chunk. There's no harm in making this code more general. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove svc_rdma_op_ctxt::wc_statusChuck Lever2016-11-301-1/+0
| | | | | | | | Clean up: Completion status is already reported in the individual completion handlers. Save a few bytes in struct svc_rdma_op_ctxt. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove DMA map accountingChuck Lever2016-11-301-2/+0
| | | | | | | | | | | | | | | | Clean up: sc_dma_used is not required for correct operation. It is simply a debugging tool to report when svcrdma has leaked DMA maps. However, manipulating an atomic has a measurable CPU cost, and DMA map accounting specific to svcrdma will be meaningless once svcrdma is converted to use the new generic r/w API. A similar kind of debug accounting can be done simply by enabling the IOMMU or by using CONFIG_DMA_API_DEBUG, CONFIG_IOMMU_DEBUG, and CONFIG_IOMMU_LEAK. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Remove BH-disabled spin locking in svc_rdma_send()Chuck Lever2016-11-301-1/+1
| | | | | | | | | | | | | | | svcrdma's current SQ accounting algorithm takes sc_lock and disables bottom-halves while posting all RDMA Read, Write, and Send WRs. This is relatively heavyweight serialization. And note that Write and Send are already fully serialized by the xpt_mutex. Using a single atomic_t should be all that is necessary to guarantee that ib_post_send() is called only when there is enough space on the send queue. This is what the other RDMA-enabled storage targets do. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Renovate sendto chunk list parsingChuck Lever2016-11-301-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | The current sendto code appears to support clients that provide only one of a Read list, a Write list, or a Reply chunk. My reading of that code is that it doesn't support the following cases: - Read list + Write list - Read list + Reply chunk - Write list + Reply chunk - Read list + Write list + Reply chunk The protocol allows more than one Read or Write chunk in those lists. Some clients do send a Read list and Reply chunk simultaneously. NFSv4 WRITE uses a Read list for the data payload, and a Reply chunk because the GETATTR result in the reply can contain a large object like an ACL. Generalize one of the sendto code paths needed to support all of the above cases, and attempt to ensure that only one pass is done through the RPC Call's transport header to gather chunk list information for building the reply. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: support Remote InvalidationChuck Lever2016-09-231-0/+1
| | | | | | | | | | | | | | | | | | | | | Support Remote Invalidation. A private message is exchanged with the client upon RDMA transport connect that indicates whether Send With Invalidation may be used by the server to send RPC replies. The invalidate_rkey is arbitrarily chosen from among rkeys present in the RPC-over-RDMA header's chunk lists. Send With Invalidate improves performance only when clients can recognize, while processing an RPC reply, that an rkey has already been invalidated. That has been submitted as a separate change. In the future, the RPC-over-RDMA protocol might support Remote Invalidation properly. The protocol needs to enable signaling between peers to indicate when Remote Invalidation can be used for each individual RPC. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Tail iovec leaves an orphaned DMA mappingChuck Lever2016-09-231-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | The ctxt's count field is overloaded to mean the number of pages in the ctxt->page array and the number of SGEs in the ctxt->sge array. Typically these two numbers are the same. However, when an inline RPC reply is constructed from an xdr_buf with a tail iovec, the head and tail often occupy the same page, but each are DMA mapped independently. In that case, ->count equals the number of pages, but it does not equal the number of SGEs. There's one more SGE, for the tail iovec. Hence there is one more DMA mapping than there are pages in the ctxt->page array. This isn't a real problem until the server's iommu is enabled. Then each RPC reply that has content in that iovec orphans a DMA mapping that consists of real resources. krb5i and krb5p always populate that tail iovec. After a couple million sent krb5i/p RPC replies, the NFS server starts behaving erratically. Reboot is needed to clear the problem. Fixes: 9d11b51ce7c1 ("svcrdma: Fix send_reply() scatter/gather set-up") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Generalize svc_rdma_xdr_decode_req()Chuck Lever2016-05-131-1/+1
| | | | | | | | | | Clean up: Pass in just the piece of the svc_rqst that is needed here. While we're in the area, add an informative documenting comment. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Use new CQ API for RPC-over-RDMA server send CQsChuck Lever2016-03-011-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Calling ib_poll_cq() to sort through WCs during a completion is a common pattern amongst RDMA consumers. Since commit 14d3a3b2498e ("IB: add a proper completion queue abstraction"), WC sorting can be handled by the IB core. By converting to this new API, svcrdma is made a better neighbor to other RDMA consumers, as it allows the core to schedule the delivery of completions more fairly amongst all active consumers. This new API also aims each completion at a function that is specific to the WR's opcode. Thus the ctxt->wr_op field and the switch in process_context is replaced by a set of methods that handle each completion type. Because each ib_cqe carries a pointer to a completion method, the core can now post operations on a consumer's QP, and handle the completions itself. The server's rdma_stat_sq_poll and rdma_stat_sq_prod metrics are no longer updated. As a clean up, the cq_event_handler, the dto_tasklet, and all associated locking is removed, as they are no longer referenced or used. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Use new CQ API for RPC-over-RDMA server receive CQsChuck Lever2016-03-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Calling ib_poll_cq() to sort through WCs during a completion is a common pattern amongst RDMA consumers. Since commit 14d3a3b2498e ("IB: add a proper completion queue abstraction"), WC sorting can be handled by the IB core. By converting to this new API, svcrdma is made a better neighbor to other RDMA consumers, as it allows the core to schedule the delivery of completions more fairly amongst all active consumers. Because each ib_cqe carries a pointer to a completion method, the core can now post operations on a consumer's QP, and handle the completions itself. svcrdma receive completions no longer use the dto_tasklet. Each polled Receive WC is now handled individually in soft IRQ context. The server transport's rdma_stat_rq_poll and rdma_stat_rq_prod metrics are no longer updated. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Use correct XID in error repliesChuck Lever2016-03-011-1/+1
| | | | | | | | | | | | | | | | | | | When constructing an error reply, svc_rdma_xdr_encode_error() needs to view the client's request message so it can get the failing request's XID. svc_rdma_xdr_decode_req() is supposed to return a pointer to the client's request header. But if it fails to decode the client's message (and thus an error reply is needed) it does not return the pointer. The server then sends a bogus XID in the error reply. Instead, unconditionally generate the pointer to the client's header in svc_rdma_recvfrom(), and pass that pointer to both functions. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com> Tested-by: Devesh Sharma <devesh.sharma@broadcom.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: Make RDMA_ERROR messages workChuck Lever2016-03-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Fix several issues with svc_rdma_send_error(): - Post a receive buffer to replace the one that was consumed by the incoming request - Posting a send should use DMA_TO_DEVICE, not DMA_FROM_DEVICE - No need to put_page _and_ free pages in svc_rdma_put_context - Make sure the sge is set up completely in case the error path goes through svc_rdma_unmap_dma() - Replace the use of ENOSYS, which has a reserved meaning Related fixes in svc_rdma_recvfrom(): - Don't leak the ctxt associated with the incoming request - Don't close the connection after sending an error reply - Let svc_rdma_send_error() figure out the right header error code As a last clean up, move svc_rdma_send_error() to svc_rdma_sendto.c with other similar functions. There is some common logic in these functions that could someday be combined to reduce code duplication. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com> Tested-by: Devesh Sharma <devesh.sharma@broadcom.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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