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2019-02-06svcrdma: Remove syslog warnings in work completion handlersChuck Lever1-8/+1
These can result in a lot of log noise, and are able to be triggered by client misbehavior. Since there are trace points in these handlers now, there's no need to spam the log. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-02-06svcrpc: fix unlikely races preventing queueing of socketsJ. Bruce Fields1-1/+2
In the rpc server, When something happens that might be reason to wake up a thread to do something, what we do is - modify xpt_flags, sk_sock->flags, xpt_reserved, or xpt_nr_rqsts to indicate the new situation - call svc_xprt_enqueue() to decide whether to wake up a thread. svc_xprt_enqueue may require multiple conditions to be true before queueing up a thread to handle the xprt. In the SMP case, one of the other CPU's may have set another required condition, and in that case, although both CPUs run svc_xprt_enqueue(), it's possible that neither call sees the writes done by the other CPU in time, and neither one recognizes that all the required conditions have been set. A socket could therefore be ignored indefinitely. Add memory barries to ensure that any svc_xprt_enqueue() call will always see the conditions changed by other CPUs before deciding to ignore a socket. I've never seen this race reported. In the unlikely event it happens, another event will usually come along and the problem will fix itself. So I don't think this is worth backporting to stable. Chuck tried this patch and said "I don't see any performance regressions, but my server has only a single last-level CPU cache." Tested-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-11-29svcrdma: Optimize the logic that selects the R_key to invalidateChuck Lever1-0/+63
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>
2018-08-24Merge tag 'nfsd-4.19-1' of git://linux-nfs.org/~bfields/linuxLinus Torvalds1-3/+6
Pull nfsd updates from Bruce Fields: "Chuck Lever fixed a problem with NFSv4.0 callbacks over GSS from multi-homed servers. The only new feature is a minor bit of protocol (change_attr_type) which the client doesn't even use yet. Other than that, various bugfixes and cleanup" * tag 'nfsd-4.19-1' of git://linux-nfs.org/~bfields/linux: (27 commits) sunrpc: Add comment defining gssd upcall API keywords nfsd: Remove callback_cred nfsd: Use correct credential for NFSv4.0 callback with GSS sunrpc: Extract target name into svc_cred sunrpc: Enable the kernel to specify the hostname part of service principals sunrpc: Don't use stack buffer with scatterlist rpc: remove unneeded variable 'ret' in rdma_listen_handler nfsd: use true and false for boolean values nfsd: constify write_op[] fs/nfsd: Delete invalid assignment statements in nfsd4_decode_exchange_id NFSD: Handle full-length symlinks NFSD: Refactor the generic write vector fill helper svcrdma: Clean up Read chunk path svcrdma: Avoid releasing a page in svc_xprt_release() nfsd: Mark expected switch fall-through sunrpc: remove redundant variables 'checksumlen','blocksize' and 'data' nfsd: fix leaked file lock with nfs exported overlayfs nfsd: don't advertise a SCSI layout for an unsupported request_queue nfsd: fix corrupted reply to badly ordered compound nfsd: clarify check_op_ordering ...
2018-08-09svcrdma: Avoid releasing a page in svc_xprt_release()Chuck Lever1-3/+6
svc_xprt_release() invokes svc_free_res_pages(), which releases pages between rq_respages and rq_next_page. Historically, the RPC/RDMA transport has set these two pointers to be different by one, which means: - one page gets released when svc_recv returns 0. This normally happens whenever one or more RDMA Reads need to be dispatched to complete construction of an RPC Call. - one page gets released after every call to svc_send. In both cases, this released page is immediately refilled by svc_alloc_arg. There does not seem to be a reason for releasing this page. To avoid this unnecessary memory allocator traffic, set rq_next_page more carefully. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-07-25net/xprtrdma: Simplify ib_post_(send|recv|srq_recv)() callsBart Van Assche1-2/+1
Instead of declaring and passing a dummy 'bad_wr' pointer, pass NULL as third argument to ib_post_(send|recv|srq_recv)(). Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Acked-by: Anna Schumaker <Anna.Schumaker@netapp.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-06-08svcrdma: Fix incorrect return value/type in svc_rdma_post_recvsChuck Lever1-1/+1
This crept in during the development process and wasn't caught before I posted the "final" version. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 0b2613c5883f ('svcrdma: Allocate recv_ctxt's on CPU ... ') Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Persistently allocate and DMA-map Send buffersChuck Lever1-19/+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>
2018-05-11svcrdma: Remove post_send_wrChuck Lever1-1/+2
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>
2018-05-11svcrdma: Introduce svc_rdma_send_ctxtChuck Lever1-6/+7
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>
2018-05-11svcrdma: Clean up Send SGE accountingChuck Lever1-1/+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>
2018-05-11svcrdma: Allocate recv_ctxt's on CPU handling ReceivesChuck Lever1-16/+36
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>
2018-05-11svcrdma: Persistently allocate and DMA-map Receive buffersChuck Lever1-108/+60
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>
2018-05-11svcrdma: Preserve Receive buffer until svc_rdma_sendtoChuck Lever1-1/+1
Rather than releasing the incoming svc_rdma_recv_ctxt at the end of svc_rdma_recvfrom, hold onto it until svc_rdma_sendto. This permits the contents of the Receive buffer to be preserved through svc_process and then referenced directly in sendto as it constructs Write and Reply chunks to return to the client. The real changes will come in subsequent patches. Note: I cannot use ->xpo_release_rqst for this purpose because that is called _before_ ->xpo_sendto. svc_rdma_sendto uses information in the received Call transport header to construct the Reply transport header, which is preserved in the RPC's Receive buffer. The historical comment in svc_send() isn't helpful: it is already obvious that ->xpo_release_rqst is being called before ->xpo_sendto, but there is no explanation for this ordering going back to the beginning of the git era. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Simplify svc_rdma_recv_ctxt_putChuck Lever1-19/+22
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>
2018-05-11svcrdma: Introduce svc_rdma_recv_ctxtChuck Lever1-43/+275
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>
2018-05-11svcrdma: Trace key RDMA API eventsChuck Lever1-2/+0
This includes: * Posting on the Send and Receive queues * Send, Receive, Read, and Write completion * Connect upcalls * QP errors Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Trace key RPC/RDMA protocol eventsChuck Lever1-20/+16
This includes: * Transport accept and tear-down * Decisions about using Write and Reply chunks * Each RDMA segment that is handled * Whenever an RDMA_ERR is sent As a clean-up, I've standardized the order of the includes, and removed some now redundant dprintk call sites. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11svcrdma: Add proper SPDX tags for NetApp-contributed sourceChuck Lever1-0/+1
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-03-21svcrdma: Clean up rdma_build_arg_xdrChuck Lever1-17/+16
Clean up: The value of the byte_count parameter is already passed to rdma_build_arg_xdr as part of the svc_rdma_op_ctxt structure. Further, without the parameter called "byte_count" there is no need to have the abbreviated "bc" automatic variable. "bc" can now be called something more intuitive. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-01-18svcrdma: Post Receives in the Receive completion handlerChuck Lever1-8/+1
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>
2017-07-12svcrdma: Properly compute .len and .buflen for received RPC CallsChuck Lever1-10/+4
When an RPC-over-RDMA request is received, the Receive buffer contains a Transport Header possibly followed by an RPC message. Even though rq_arg.head[0] (as passed to NFSD) does not contain the Transport Header header, currently rq_arg.len includes the size of the Transport Header. That violates the intent of the xdr_buf API contract. .buflen should include everything, but .len should be exactly the length of the RPC message in the buffer. The rq_arg fields are summed together at the end of svc_rdma_recvfrom to obtain the correct return value. rq_arg.len really ought to contain the correct number of bytes already, but it currently doesn't due to the above misbehavior. Let's instead ensure that .buflen includes the length of the transport header, and that .len is always equal to head.iov_len + .page_len + tail.iov_len . Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-07-12svcrdma: Use generic RDMA R/W API in RPC Call pathChuck Lever1-441/+106
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>
2017-06-28svcrdma: Don't account for Receive queue "starvation"Chuck Lever1-15/+6
>From what I can tell, calling ->recvfrom when there is no work to do is a normal part of operation. This is the only way svc_recv can tell when there is no more data ready to receive on the transport. Neither the TCP nor the UDP transport implementations have a "starve" metric. The cost of receive starvation accounting is bumping an atomic, which results in extra (IMO unnecessary) bus traffic between CPU sockets, while holding a spin lock. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-06-28svcrdma: Improve Reply chunk sanity checkingChuck Lever1-6/+11
Identify malformed transport headers and unsupported chunk combinations as early as possible. - Ensure that segment lengths are not crazy. - Ensure that the Reply chunk's segment count is not crazy. With a 1KB inline threshold, the largest number of Write segments that can be conveyed is about 60 (for a RDMA_NOMSG Reply message). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-06-28svcrdma: Improve Write chunk sanity checkingChuck Lever1-5/+47
Identify malformed transport headers and unsupported chunk combinations as early as possible. - Reject RPC-over-RDMA messages that contain more than one Write chunk, since this implementation does not support more than one per message. - Ensure that segment lengths are not crazy. - Ensure that the chunk's segment count is not crazy. With a 1KB inline threshold, the largest number of Write segments that can be conveyed is about 60 (for a RDMA_NOMSG Reply message). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-06-28svcrdma: Improve Read chunk sanity checkingChuck Lever1-18/+37
Identify malformed transport headers and unsupported chunk combinations as early as possible. - Reject RPC-over-RDMA messages that contain more than one Read chunk, since this implementation currently does not support more than one per RPC transaction. - Ensure that segment lengths are not crazy. - Remove the segment count check. With a 1KB inline threshold, the largest number of Read segments that can be conveyed is about 40 (for a RDMA_NOMSG Call message). This is nowhere near RPCSVC_MAXPAGES. As far as I can tell, that was just a sanity check and does not enforce an implementation limit. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-06-28svcrdma: Remove svc_rdma_marshal.cChuck Lever1-0/+126
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>
2017-04-26svcrdma: Clean up RPC-over-RDMA backchannel reply processingChuck Lever1-12/+15
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>
2017-04-26svcrdma: Clean up RDMA_ERROR pathChuck Lever1-1/+51
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>
2017-02-08svcrdma: Poll CQs in "workqueue" modeChuck Lever1-3/+3
svcrdma calls svc_xprt_put() in its completion handlers, which currently run in IRQ context. However, svc_xprt_put() is meant to be invoked in process context, not in IRQ context. After the last transport reference is gone, it directly calls a transport release function that expects to run in process context. Change the CQ polling modes to IB_POLL_WORKQUEUE so that svcrdma invokes svc_xprt_put() only in process context. As an added benefit, bottom half-disabled spin locking can be eliminated from I/O paths. 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>
2017-02-08svcrdma: Combine list fields in struct svc_rdma_op_ctxtChuck Lever1-8/+6
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>
2017-01-13svcrdma: avoid duplicate dma unmapping during error recoverySriharsha Basavapatna1-2/+0
In rdma_read_chunk_frmr() when ib_post_send() fails, the error code path invokes ib_dma_unmap_sg() to unmap the sg list. It then invokes svc_rdma_put_frmr() which in turn tries to unmap the same sg list through ib_dma_unmap_sg() again. This second unmap is invalid and could lead to problems when the iova being unmapped is subsequently reused. Remove the call to unmap in rdma_read_chunk_frmr() and let svc_rdma_put_frmr() handle it. Fixes: 412a15c0fe53 ("svcrdma: Port to new memory registration API") Cc: stable@vger.kernel.org Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-12-01svcrdma: Remove unused variable in rdma_copy_tail()Chuck Lever1-2/+0
Clean up. linux-2.6/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c: In function ‘rdma_copy_tail’: linux-2.6/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c:376:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable] int ret; ^ Fixes: a97c331f9aa9 ("svcrdma: Handle additional inline content") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-12-01svcrdma: Remove svc_rdma_op_ctxt::wc_statusChuck Lever1-2/+2
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>
2016-12-01svcrdma: Remove DMA map accountingChuck Lever1-1/+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>
2016-12-01svcrdma: Renovate sendto chunk list parsingChuck Lever1-0/+14
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>
2016-09-23svcrdma: Tail iovec leaves an orphaned DMA mappingChuck Lever1-1/+1
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>
2016-05-25Merge tag 'nfsd-4.7' of git://linux-nfs.org/~bfields/linuxLinus Torvalds1-26/+8
Pull nfsd updates from Bruce Fields: "A very quiet cycle for nfsd, mainly just an RDMA update from Chuck Lever" * tag 'nfsd-4.7' of git://linux-nfs.org/~bfields/linux: sunrpc: fix stripping of padded MIC tokens svcrpc: autoload rdma module svcrdma: Generalize svc_rdma_xdr_decode_req() svcrdma: Eliminate code duplication in svc_rdma_recvfrom() svcrdma: Drain QP before freeing svcrdma_xprt svcrdma: Post Receives only for forward channel requests svcrdma: Remove superfluous line from rdma_read_chunks() svcrdma: svc_rdma_put_context() is invoked twice in Send error path svcrdma: Do not add XDR padding to xdr_buf page vector svcrdma: Support IPv6 with NFS/RDMA nfsd: handle seqid wraparound in nfsd4_preprocess_layout_stateid Remove unnecessary allocation
2016-05-13svcrdma: Generalize svc_rdma_xdr_decode_req()Chuck Lever1-1/+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>
2016-05-13svcrdma: Eliminate code duplication in svc_rdma_recvfrom()Chuck Lever1-21/+5
Clean up. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-05-13svcrdma: Remove superfluous line from rdma_read_chunks()Chuck Lever1-3/+1
Clean up: svc_rdma_get_read_chunk() already returns a pointer to the Read list. No need to set "ch" again to the value it already contains. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-05-13svcrdma: Do not add XDR padding to xdr_buf page vectorChuck Lever1-1/+1
An xdr_buf has a head, a vector of pages, and a tail. Each RPC request is presented to the NFS server contained in an xdr_buf. The RDMA transport would like to supply the NFS server with only the NFS WRITE payload bytes in the page vector. In some common cases, that would allow the NFS server to swap those pages right into the target file's page cache. Have the transport's RDMA Read logic put XDR pad bytes in the tail iovec, and not in the pages that hold the data payload. The NFSv3 WRITE XDR decoder is finicky about the lengths involved, so make sure it is looking in the correct places when computing the total length of the incoming NFS WRITE request. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-05-13IB/core: Enhance ib_map_mr_sg()Bart Van Assche1-1/+1
The SRP initiator allows to set max_sectors to a value that exceeds the largest amount of data that can be mapped at once with an mlx4 HCA using fast registration and a page size of 4 KB. Hence modify ib_map_mr_sg() such that it can map partial sg-elements. If an sg-element has been mapped partially, let the caller know which fraction has been mapped by adjusting *sg_offset. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Tested-by: Laurence Oberman <loberman@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-05-13IB/core: Add passing an offset into the SG to ib_map_mr_sgChristoph Hellwig1-1/+1
Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Steve Wise <swise@opengridcomputing.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-03-02svcrdma: Use new CQ API for RPC-over-RDMA server send CQsChuck Lever1-6/+8
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>
2016-03-02svcrdma: Remove close_out exit pathChuck Lever1-11/+1
Clean up: close_out is reached only when ctxt == NULL and XPT_CLOSE is already set. 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>
2016-03-02svcrdma: Hook up the logic to return ERR_CHUNKChuck Lever1-0/+4
RFC 5666 Section 4.2 states: > When the peer detects an RPC-over-RDMA header version that it does > not support (currently this document defines only version 1), it > replies with an error code of ERR_VERS, and provides the low and > high inclusive version numbers it does, in fact, support. And: > When other decoding errors are detected in the header or chunks, > either an RPC decode error MAY be returned or the RPC/RDMA error > code ERR_CHUNK MUST be returned. The Linux NFS server does throw ERR_VERS when a client sends it a request whose rdma_version is not "one." But it does not return ERR_CHUNK when a header decoding error occurs. It just drops the request. To improve protocol extensibility, it should reject invalid values in the rdma_proc field instead of treating them all like RDMA_MSG. Otherwise clients can't detect when the server doesn't support new rdma_proc values. 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>
2016-03-02svcrdma: Use correct XID in error repliesChuck Lever1-1/+2
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>
2016-03-02svcrdma: Make RDMA_ERROR messages workChuck Lever1-10/+9
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>