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* svcrdma: Remove DMA map accountingChuck Lever2016-11-302-11/+3
| | | | | | | | | | | | | | | | 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 Lever2016-11-302-16/+16
| | | | | | | | | | | | | | | 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 Lever2016-11-302-67/+39
| | | | | | | | | | | | | | | | | | | | | | | | | 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: Clear xpt_bc_xps in xprt_setup_rdma_bc() error exit armChuck Lever2016-11-301-0/+1
| | | | | | | | Logic copied from xs_setup_bc_tcp(). Fixes: 39a9beab5acb ('rpc: share one xps between all backchannels') Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* svcrdma: backchannel cannot share a page for send and rcv buffersChuck Lever2016-11-011-3/+10
| | | | | | | | | | | The underlying transport releases the page pointed to by rq_buffer during xprt_rdma_bc_send_request. When the backchannel reply arrives, rq_rbuffer then points to freed memory. Fixes: 68778945e46f ('SUNRPC: Separate buffer pointers for RPC ...') Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* sunrpc: fix some missing rq_rbuffer assignmentsJeff Layton2016-10-281-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We've been seeing some crashes in testing that look like this: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8135ce99>] memcpy_orig+0x29/0x110 PGD 212ca2067 PUD 212ca3067 PMD 0 Oops: 0002 [#1] SMP Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ppdev parport_pc i2c_piix4 sg parport i2c_core virtio_balloon pcspkr acpi_cpufreq nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod ata_generic pata_acpi virtio_scsi 8139too ata_piix libata 8139cp mii virtio_pci floppy virtio_ring serio_raw virtio CPU: 1 PID: 1540 Comm: nfsd Not tainted 4.9.0-rc1 #39 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007 task: ffff88020d7ed200 task.stack: ffff880211838000 RIP: 0010:[<ffffffff8135ce99>] [<ffffffff8135ce99>] memcpy_orig+0x29/0x110 RSP: 0018:ffff88021183bdd0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff88020d7fa000 RCX: 000000f400000000 RDX: 0000000000000014 RSI: ffff880212927020 RDI: 0000000000000000 RBP: ffff88021183be30 R08: 01000000ef896996 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff880211704ca8 R13: ffff88021473f000 R14: 00000000ef896996 R15: ffff880211704800 FS: 0000000000000000(0000) GS:ffff88021fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000212ca1000 CR4: 00000000000006e0 Stack: ffffffffa01ea087 ffffffff63400001 ffff880215145e00 ffff880211bacd00 ffff88021473f2b8 0000000000000004 00000000d0679d67 ffff880211bacd00 ffff88020d7fa000 ffff88021473f000 0000000000000000 ffff88020d7faa30 Call Trace: [<ffffffffa01ea087>] ? svc_tcp_recvfrom+0x5a7/0x790 [sunrpc] [<ffffffffa01f84d8>] svc_recv+0xad8/0xbd0 [sunrpc] [<ffffffffa0262d5e>] nfsd+0xde/0x160 [nfsd] [<ffffffffa0262c80>] ? nfsd_destroy+0x60/0x60 [nfsd] [<ffffffff810a9418>] kthread+0xd8/0xf0 [<ffffffff816dbdbf>] ret_from_fork+0x1f/0x40 [<ffffffff810a9340>] ? kthread_park+0x60/0x60 Code: 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe 7c 35 48 83 ea 20 48 83 ea 20 4c 8b 06 4c 8b 4e 08 4c 8b 56 10 4c 8b 5e 18 48 8d 76 20 <4c> 89 07 4c 89 4f 08 4c 89 57 10 4c 89 5f 18 48 8d 7f 20 73 d4 RIP [<ffffffff8135ce99>] memcpy_orig+0x29/0x110 RSP <ffff88021183bdd0> CR2: 0000000000000000 Both Bruce and Eryu ran a bisect here and found that the problematic patch was 68778945e46 (SUNRPC: Separate buffer pointers for RPC Call and Reply messages). That patch changed rpc_xdr_encode to use a new rq_rbuffer pointer to set up the receive buffer, but didn't change all of the necessary codepaths to set it properly. In particular the backchannel setup was missing. We need to set rq_rbuffer whenever rq_buffer is set. Ensure that it is. Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Chuck Lever <chuck.lever@oracle.com> Reported-by: Eryu Guan <guaneryu@gmail.com> Tested-by: Eryu Guan <guaneryu@gmail.com> Fixes: 68778945e46 "SUNRPC: Separate buffer pointers..." Reported-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* Merge tag 'nfs-for-4.9-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds2016-10-138-411/+566
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull NFS client updates from Anna Schumaker: "Highlights include: Stable bugfixes: - sunrpc: fix writ espace race causing stalls - NFS: Fix inode corruption in nfs_prime_dcache() - NFSv4: Don't report revoked delegations as valid in nfs_have_delegation() - NFSv4: nfs4_copy_delegation_stateid() must fail if the delegation is invalid - NFSv4: Open state recovery must account for file permission changes - NFSv4.2: Fix a reference leak in nfs42_proc_layoutstats_generic Features: - Add support for tracking multiple layout types with an ordered list - Add support for using multiple backchannel threads on the client - Add support for pNFS file layout session trunking - Delay xprtrdma use of DMA API (for device driver removal) - Add support for xprtrdma remote invalidation - Add support for larger xprtrdma inline thresholds - Use a scatter/gather list for sending xprtrdma RPC calls - Add support for the CB_NOTIFY_LOCK callback - Improve hashing sunrpc auth_creds by using both uid and gid Bugfixes: - Fix xprtrdma use of DMA API - Validate filenames before adding to the dcache - Fix corruption of xdr->nwords in xdr_copy_to_scratch - Fix setting buffer length in xdr_set_next_buffer() - Don't deadlock the state manager on the SEQUENCE status flags - Various delegation and stateid related fixes - Retry operations if an interrupted slot receives EREMOTEIO - Make nfs boot time y2038 safe" * tag 'nfs-for-4.9-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (100 commits) NFSv4.2: Fix a reference leak in nfs42_proc_layoutstats_generic fs: nfs: Make nfs boot time y2038 safe sunrpc: replace generic auth_cred hash with auth-specific function sunrpc: add RPCSEC_GSS hash_cred() function sunrpc: add auth_unix hash_cred() function sunrpc: add generic_auth hash_cred() function sunrpc: add hash_cred() function to rpc_authops struct Retry operation on EREMOTEIO on an interrupted slot pNFS: Fix atime updates on pNFS clients sunrpc: queue work on system_power_efficient_wq NFSv4.1: Even if the stateid is OK, we may need to recover the open modes NFSv4: If recovery failed for a specific open stateid, then don't retry NFSv4: Fix retry issues with nfs41_test/free_stateid NFSv4: Open state recovery must account for file permission changes NFSv4: Mark the lock and open stateids as invalid after freeing them NFSv4: Don't test open_stateid unless it is set NFSv4: nfs4_do_handle_exception() handle revoke/expiry of a single stateid NFS: Always call nfs_inode_find_state_and_recover() when revoking a delegation NFSv4: Fix a race when updating an open_stateid NFSv4: Fix a race in nfs_inode_reclaim_delegation() ...
| * xprtrdma: use complete() instead complete_all()Daniel Wagner2016-09-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is only one waiter for the completion, therefore there is no need to use complete_all(). Let's make that clear by using complete() instead of complete_all(). The usage pattern of the completion is: waiter context waker context frwr_op_unmap_sync() reinit_completion() ib_post_send() wait_for_completion() frwr_wc_localinv_wake() complete() Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Cc: Anna Schumaker <Anna.Schumaker@Netapp.com> Cc: Trond Myklebust <trond.myklebust@primarydata.com> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: linux-nfs@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Eliminate rpcrdma_receive_worker()Chuck Lever2016-09-193-12/+5
| | | | | | | | | | | | | | Clean up: the extra layer of indirection doesn't add value. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Rename rpcrdma_receive_wc()Chuck Lever2016-09-191-3/+3
| | | | | | | | | | | | | | | | | | | | Clean up: When converting xprtrdma to use the new CQ API, I missed a spot. The naming convention elsewhere is: {svc_rdma,rpcrdma}_wc_{operation} Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrmda: Report address of frmr, not mwChuck Lever2016-09-191-2/+6
| | | | | | | | | | | | | | | | Tie frwr debugging messages together by always reporting the address of the frwr. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Support larger inline thresholdsChuck Lever2016-09-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The Version One default inline threshold is still 1KB. But allow testing with thresholds up to 64KB. This maximum is somewhat arbitrary. There's no fundamental architectural limit I'm aware of, but it's good to keep the size of Receive buffers reasonable. Now that Send can use a s/g list, a Send buffer is only as large as each RPC requires. Receive buffers are always the size of the inline threshold, however. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Use gathered Send for large inline messagesChuck Lever2016-09-195-185/+207
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An RPC Call message that is sent inline but that has a data payload (ie, one or more items in rq_snd_buf's page list) must be "pulled up:" - call_allocate has to reserve enough RPC Call buffer space to accommodate the data payload - call_transmit has to memcopy the rq_snd_buf's page list and tail into its head iovec before it is sent As the inline threshold is increased beyond its current 1KB default, however, this means data payloads of more than a few KB are copied by the host CPU. For example, if the inline threshold is increased just to 4KB, then NFS WRITE requests up to 4KB would involve a memcpy of the NFS WRITE's payload data into the RPC Call buffer. This is an undesirable amount of participation by the host CPU. The inline threshold may be much larger than 4KB in the future, after negotiation with a peer server. Instead of copying the components of rq_snd_buf into its head iovec, construct a gather list of these components, and send them all in place. The same approach is already used in the Linux server's RPC-over-RDMA reply path. This mechanism also eliminates the need for rpcrdma_tail_pullup, which is used to manage the XDR pad and trailing inline content when a Read list is present. This requires that the pages in rq_snd_buf's page list be DMA-mapped during marshaling, and unmapped when a data-bearing RPC is completed. This is slightly less efficient for very small I/O payloads, but significantly more efficient as data payload size and inline threshold increase past a kilobyte. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Basic support for Remote InvalidationChuck Lever2016-09-196-7/+44
| | | | | | | | | | | | | | | | | | | | | | | | Have frwr's ro_unmap_sync recognize an invalidated rkey that appears as part of a Receive completion. Local invalidation can be skipped for that rkey. Use an out-of-band signaling mechanism to indicate to the server that the client is prepared to receive RDMA Send With Invalidate. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Client-side support for rpcrdma_connect_privateChuck Lever2016-09-195-15/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Send an RDMA-CM private message on connect, and look for one during a connection-established event. Both sides can communicate their various implementation limits. Implementations that don't support this sideband protocol ignore it. Once the client knows the server's inline threshold maxima, it can adjust the use of Reply chunks, and eliminate most use of Position Zero Read chunks. Moderately-sized I/O can be done using a pure inline RDMA Send instead of RDMA operations that require memory registration. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Move recv_wr to struct rpcrdma_repChuck Lever2016-09-192-7/+7
| | | | | | | | | | | | | | | | | | Clean up: The fields in the recv_wr do not vary. There is no need to initialize them before each ib_post_recv(). This removes a large-ish data structure from the stack. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Move send_wr to struct rpcrdma_reqChuck Lever2016-09-194-24/+24
| | | | | | | | | | | | | | | | | | Clean up: Most of the fields in each send_wr do not vary. There is no need to initialize them before each ib_post_send(). This removes a large-ish data structure from the stack. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Simplify rpcrdma_ep_post_recv()Chuck Lever2016-09-194-11/+5
| | | | | | | | | | | | | | | | | | | | Clean up. Since commit fc66448549bb ("xprtrdma: Split the completion queue"), rpcrdma_ep_post_recv() no longer uses the "ep" argument. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Eliminate "ia" argument in rpcrdma_{alloc, free}_regbufChuck Lever2016-09-194-31/+23
| | | | | | | | | | | | | | Clean up. The "ia" argument is no longer used. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Delay DMA mapping Send and Receive buffersChuck Lever2016-09-194-26/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, each regbuf is allocated and DMA mapped at the same time. This is done during transport creation. When a device driver is unloaded, every DMA-mapped buffer in use by a transport has to be unmapped, and then remapped to the new device if the driver is loaded again. Remapping will have to be done _after_ the connect worker has set up the new device. But there's an ordering problem: call_allocate, which invokes xprt_rdma_allocate which calls rpcrdma_alloc_regbuf to allocate Send buffers, happens _before_ the connect worker can run to set up the new device. Instead, at transport creation, allocate each buffer, but leave it unmapped. Once the RPC carries these buffers into ->send_request, by which time a transport connection should have been established, check to see that the RPC's buffers have been DMA mapped. If not, map them there. When device driver unplug support is added, it will simply unmap all the transport's regbufs, but it doesn't have to deallocate the underlying memory. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Replace DMA_BIDIRECTIONALChuck Lever2016-09-194-35/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The use of DMA_BIDIRECTIONAL is discouraged by DMA-API.txt. Fortunately, xprtrdma now knows which direction I/O is going as soon as it allocates each regbuf. The RPC Call and Reply buffers are no longer the same regbuf. They can each be labeled correctly now. The RPC Reply buffer is never part of either a Send or Receive WR, but it can be part of Reply chunk, which is mapped and registered via ->ro_map . So it is not DMA mapped when it is allocated (DMA_NONE), to avoid a double- mapping. Since Receive buffers are no longer DMA_BIDIRECTIONAL and their contents are never modified by the host CPU, DMA-API-HOWTO.txt suggests that a DMA sync before posting each buffer should be unnecessary. (See my_card_interrupt_handler). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Use smaller buffers for RPC-over-RDMA headersChuck Lever2016-09-193-5/+7
| | | | | | | | | | | | | | | | | | | | Commit 949317464bc2 ("xprtrdma: Limit number of RDMA segments in RPC-over-RDMA headers") capped the number of chunks that may appear in RPC-over-RDMA headers. The maximum header size can be estimated and fixed to avoid allocating buffer space that is never used. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Initialize separate RPC call and reply buffersChuck Lever2016-09-193-59/+99
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RPC-over-RDMA needs to separate its RPC call and reply buffers. o When an RPC Call is sent, rq_snd_buf is DMA mapped for an RDMA Send operation using DMA_TO_DEVICE o If the client expects a large RPC reply, it DMA maps rq_rcv_buf as part of a Reply chunk using DMA_FROM_DEVICE The two mappings are for data movement in opposite directions. DMA-API.txt suggests that if these mappings share a DMA cacheline, bad things can happen. This could occur in the final bytes of rq_snd_buf and the first bytes of rq_rcv_buf if the two buffers happen to share a DMA cacheline. On x86_64 the cacheline size is typically 8 bytes, and RPC call messages are usually much smaller than the send buffer, so this hasn't been a noticeable problem. But the DMA cacheline size can be larger on other platforms. Also, often rq_rcv_buf starts most of the way into a page, thus an additional RDMA segment is needed to map and register the end of that buffer. Try to avoid that scenario to reduce the cost of registering and invalidating Reply chunks. Instead of carrying a single regbuf that covers both rq_snd_buf and rq_rcv_buf, each struct rpcrdma_req now carries one regbuf for rq_snd_buf and one regbuf for rq_rcv_buf. Some incidental changes worth noting: - To clear out some spaghetti, refactor xprt_rdma_allocate. - The value stored in rg_size is the same as the value stored in the iov.length field, so eliminate rg_size Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * SUNRPC: Add a transport-specific private field in rpc_rqstChuck Lever2016-09-194-12/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently there's a hidden and indirect mechanism for finding the rpcrdma_req that goes with an rpc_rqst. It depends on getting from the rq_buffer pointer in struct rpc_rqst to the struct rpcrdma_regbuf that controls that buffer, and then to the struct rpcrdma_req it goes with. This was done back in the day to avoid the need to add a per-rqst pointer or to alter the buf_free API when support for RPC-over-RDMA was introduced. I'm about to change the way regbuf's work to support larger inline thresholds. Now is a good time to replace this indirect mechanism with something that is more straightforward. I guess this should be considered a clean up. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * SUNRPC: Separate buffer pointers for RPC Call and Reply messagesChuck Lever2016-09-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For xprtrdma, the RPC Call and Reply buffers are involved in real I/O operations. To start with, the DMA direction of the I/O for a Call is opposite that of a Reply. In the current arrangement, the Reply buffer address is on a four-byte alignment just past the call buffer. Would be friendlier on some platforms if that was at a DMA cache alignment instead. Because the current arrangement allocates a single memory region which contains both buffers, the RPC Reply buffer often contains a page boundary in it when the Call buffer is large enough (which is frequent). It would be a little nicer for setting up DMA operations (and possible registration of the Reply buffer) if the two buffers were separated, well-aligned, and contained as few page boundaries as possible. Now, I could just pad out the single memory region used for the pair of buffers. But frequently that would mean a lot of unused space to ensure the Reply buffer did not have a page boundary. Add a separate pointer to rpc_rqst that points right to the RPC Reply buffer. This makes no difference to xprtsock, but it will help xprtrdma in subsequent patches. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * SUNRPC: Generalize the RPC buffer release APIChuck Lever2016-09-193-18/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | xprtrdma needs to allocate the Call and Reply buffers separately. TBH, the reliance on using a single buffer for the pair of XDR buffers is transport implementation-specific. Instead of passing just the rq_buffer into the buf_free method, pass the task structure and let buf_free take care of freeing both XDR buffers at once. There's a micro-optimization here. In the common case, both xprt_release and the transport's buf_free method were checking if rq_buffer was NULL. Now the check is done only once per RPC. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * SUNRPC: Generalize the RPC buffer allocation APIChuck Lever2016-09-192-16/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | xprtrdma needs to allocate the Call and Reply buffers separately. TBH, the reliance on using a single buffer for the pair of XDR buffers is transport implementation-specific. Transports that want to allocate separate Call and Reply buffers will ignore the "size" argument anyway. Don't bother passing it. The buf_alloc method can't return two pointers. Instead, make the method's return value an error code, and set the rq_buffer pointer in the method itself. This gives call_allocate an opportunity to terminate an RPC instead of looping forever when a permanent problem occurs. If a request is just bogus, or the transport is in a state where it can't allocate resources for any request, there needs to be a way to kill the RPC right there and not loop. This immediately fixes a rare problem in the backchannel send path, which loops if the server happens to send a CB request whose call+reply size is larger than a page (which it shouldn't do yet). One more issue: looks like xprt_inject_disconnect was incorrectly placed in the failure path in call_allocate. It needs to be in the success path, as it is for other call-sites. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * SUNRPC: Refactor rpc_xdr_buf_init()Chuck Lever2016-09-191-11/+1
| | | | | | | | | | | | | | | | | | | | | | | | Clean up: there is some XDR initialization logic that is common to the forward channel and backchannel. Move it to an XDR header so it can be shared. rpc_rqst::rq_buffer points to a buffer containing big-endian data. Update its annotation as part of the clean up. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * xprtrdma: Eliminate INLINE_THRESHOLD macrosChuck Lever2016-09-194-15/+6
| | | | | | | | | | | | | | | | | | | | | | Clean up: r_xprt is already available everywhere these macros are invoked, so just dereference that directly. RPCRDMA_INLINE_PAD_VALUE is no longer used, so it can simply be removed. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* | Merge tag 'nfsd-4.9' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2016-10-134-35/+111
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull nfsd updates from Bruce Fields: "Some RDMA work and some good bugfixes, and two new features that could benefit from user testing: - Anna Schumacker contributed a simple NFSv4.2 COPY implementation. COPY is already supported on the client side, so a call to copy_file_range() on a recent client should now result in a server-side copy that doesn't require all the data to make a round trip to the client and back. - Jeff Layton implemented callbacks to notify clients when contended locks become available, which should reduce latency on workloads with contended locks" * tag 'nfsd-4.9' of git://linux-nfs.org/~bfields/linux: NFSD: Implement the COPY call nfsd: handle EUCLEAN nfsd: only WARN once on unmapped errors exportfs: be careful to only return expected errors. nfsd4: setclientid_confirm with unmatched verifier should fail nfsd: randomize SETCLIENTID reply to help distinguish servers nfsd: set the MAY_NOTIFY_LOCK flag in OPEN replies nfs: add a new NFS4_OPEN_RESULT_MAY_NOTIFY_LOCK constant nfsd: add a LRU list for blocked locks nfsd: have nfsd4_lock use blocking locks for v4.1+ locks nfsd: plumb in a CB_NOTIFY_LOCK operation NFSD: fix corruption in notifier registration svcrdma: support Remote Invalidation svcrdma: Server-side support for rpcrdma_connect_private rpcrdma: RDMA/CM private message data structure svcrdma: Skip put_page() when send_reply() fails svcrdma: Tail iovec leaves an orphaned DMA mapping nfsd: fix dprintk in nfsd4_encode_getdeviceinfo nfsd: eliminate cb_minorversion field nfsd: don't set a FL_LAYOUT lease for flexfiles layouts
| * | svcrdma: support Remote InvalidationChuck Lever2016-09-232-6/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Server-side support for rpcrdma_connect_privateChuck Lever2016-09-231-4/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prepare to receive an RDMA-CM private message when handling a new connection attempt, and send a similar message as part of connection acceptance. Both sides can communicate their various implementation limits. Implementations that don't support this sideband protocol ignore it. 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: Skip put_page() when send_reply() failsChuck Lever2016-09-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Message from syslogd@klimt at Aug 18 17:00:37 ... kernel:page:ffffea0020639b00 count:0 mapcount:0 mapping: (null) index:0x0 Aug 18 17:00:37 klimt kernel: flags: 0x2fffff80000000() Aug 18 17:00:37 klimt kernel: page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0) Aug 18 17:00:37 klimt kernel: kernel BUG at /home/cel/src/linux/linux-2.6/include/linux/mm.h:445! Aug 18 17:00:37 klimt kernel: RIP: 0010:[<ffffffffa05c21c1>] svc_rdma_sendto+0x641/0x820 [rpcrdma] send_reply() assigns its page argument as the first page of ctxt. On error, send_reply() already invokes svc_rdma_put_context(ctxt, 1); which does a put_page() on that very page. No need to do that again as svc_rdma_sendto exits. Fixes: 3e1eeb980822 ("svcrdma: Close connection when a send error occurs") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * | svcrdma: Tail iovec leaves an orphaned DMA mappingChuck Lever2016-09-234-26/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | Merge tag 'for-linus' of ↵Linus Torvalds2016-10-092-2/+2
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma Pull main rdma updates from Doug Ledford: "This is the main pull request for the rdma stack this release. The code has been through 0day and I had it tagged for linux-next testing for a couple days. Summary: - updates to mlx5 - updates to mlx4 (two conflicts, both minor and easily resolved) - updates to iw_cxgb4 (one conflict, not so obvious to resolve, proper resolution is to keep the code in cxgb4_main.c as it is in Linus' tree as attach_uld was refactored and moved into cxgb4_uld.c) - improvements to uAPI (moved vendor specific API elements to uAPI area) - add hns-roce driver and hns and hns-roce ACPI reset support - conversion of all rdma code away from deprecated create_singlethread_workqueue - security improvement: remove unsafe ib_get_dma_mr (breaks lustre in staging)" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (75 commits) staging/lustre: Disable InfiniBand support iw_cxgb4: add fast-path for small REG_MR operations cxgb4: advertise support for FR_NSMR_TPTE_WR IB/core: correctly handle rdma_rw_init_mrs() failure IB/srp: Fix infinite loop when FMR sg[0].offset != 0 IB/srp: Remove an unused argument IB/core: Improve ib_map_mr_sg() documentation IB/mlx4: Fix possible vl/sl field mismatch in LRH header in QP1 packets IB/mthca: Move user vendor structures IB/nes: Move user vendor structures IB/ocrdma: Move user vendor structures IB/mlx4: Move user vendor structures IB/cxgb4: Move user vendor structures IB/cxgb3: Move user vendor structures IB/mlx5: Move and decouple user vendor structures IB/{core,hw}: Add constant for node_desc ipoib: Make ipoib_warn ratelimited IB/mlx4/alias_GUID: Remove deprecated create_singlethread_workqueue IB/ipoib_verbs: Remove deprecated create_singlethread_workqueue IB/ipoib: Remove deprecated create_singlethread_workqueue ...
| * | IB/core: add support to create a unsafe global rkey to ib_create_pdChristoph Hellwig2016-09-232-2/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | Instead of exposing ib_get_dma_mr to ULPs and letting them use it more or less unchecked, this moves the capability of creating a global rkey into the RDMA core, where it can be easily audited. It also prints a warning everytime this feature is used as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Reviewed-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
* | xprtrdma: Fix receive buffer accountingChuck Lever2016-09-062-12/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An RPC can terminate before its reply arrives, if a credential problem or a soft timeout occurs. After this happens, xprtrdma reports it is out of Receive buffers. A Receive buffer is posted before each RPC is sent, and returned to the buffer pool when a reply is received. If no reply is received for an RPC, that Receive buffer remains posted. But xprtrdma tries to post another when the next RPC is sent. If this happens a few dozen times, there are no receive buffers left to be posted at send time. I don't see a way for a transport connection to recover at that point, and it will spit warnings and unnecessarily delay RPCs on occasion for its remaining lifetime. Commit 1e465fd4ff47 ("xprtrdma: Replace send and receive arrays") removed a little bit of logic to detect this case and not provide a Receive buffer so no more buffers are posted, and then transport operation continues correctly. We didn't understand what that logic did, and it wasn't commented, so it was removed as part of the overhaul to support backchannel requests. Restore it, but be wary of the need to keep extra Receives posted to deal with backchannel requests. Fixes: 1e465fd4ff47 ("xprtrdma: Replace send and receive arrays") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* | xprtrdma: Revert 3d4cf35bd4fa ("xprtrdma: Reply buffer exhaustion...")Chuck Lever2016-09-061-5/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | Receive buffer exhaustion, if it were to actually occur, would be catastrophic. However, when there are no reply buffers to post, that means all of them have already been posted and are waiting for incoming replies. By design, there can never be more RPCs in flight than there are available receive buffers. A receive buffer can be left posted after an RPC exits without a received reply; say, due to a credential problem or a soft timeout. This does not result in fewer posted receive buffers than there are pending RPCs, and there is already logic in xprtrdma to deal appropriately with this case. It also looks like the "+ 2" that was removed was accidentally accommodating the number of extra receive buffers needed for receiving backchannel requests. That will need to be addressed by another patch. Fixes: 3d4cf35bd4fa ("xprtrdma: Reply buffer exhaustion can be...") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* xprtrdma: fix semicolon.cocci warningskbuild test robot2016-07-191-1/+1
| | | | | | | | | | | | | net/sunrpc/xprtrdma/verbs.c:798:2-3: Unneeded semicolon Remove unneeded semicolon. Generated by: scripts/coccinelle/misc/semicolon.cocci CC: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* xprtrdma: No direct data placement with krb5i and krb5pChuck Lever2016-07-111-2/+10
| | | | | | | | | | | | | | | | | | | | Direct data placement is not allowed when using flavors that guarantee integrity or privacy. When such security flavors are in effect, don't allow the use of Read and Write chunks for moving individual data items. All messages larger than the inline threshold are sent via Long Call or Long Reply. On my systems (CX-3 Pro on FDR), for small I/O operations, the use of Long messages adds only around 5 usecs of latency in each direction. Note that when integrity or encryption is used, the host CPU touches every byte in these messages. Even if it could be used, data movement offload doesn't buy much in this case. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* xprtrdma: Clean up fixup_copy_count accountingChuck Lever2016-07-111-13/+13
| | | | | | | | | | | | | | fixup_copy_count should count only the number of bytes copied to the page list. The head and tail are now always handled without a data copy. And the debugging at the end of rpcrdma_inline_fixup() is also no longer necessary, since copy_len will be non-zero when there is reply data in the tail (a normal and valid case). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* xprtrdma: Update only specific fields in private receive bufferChuck Lever2016-07-111-4/+9
| | | | | | | | | | | Now that rpcrdma_inline_fixup() updates only two fields in rq_rcv_buf, a full memcpy of that structure to rq_private_buf is unwarranted. Updating rq_private_buf fields only where needed also better documents what is going on. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* xprtrdma: Do not update {head, tail}.iov_len in rpcrdma_inline_fixup()Chuck Lever2016-07-111-28/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While trying NFSv4.0/RDMA with sec=krb5p, I noticed small NFS READ operations failed. After the client unwrapped the NFS READ reply message, the NFS READ XDR decoder was not able to decode the reply. The message was "Server cheating in reply", with the reported number of received payload bytes being zero. Applications reported a read(2) that returned -1/EIO. The problem is rpcrdma_inline_fixup() sets the tail.iov_len to zero when the incoming reply fits entirely in the head iovec. The zero tail.iov_len confused xdr_buf_trim(), which then mangled the actual reply data instead of simply removing the trailing GSS checksum. As near as I can tell, RPC transports are not supposed to update the head.iov_len, page_len, or tail.iov_len fields in the receive XDR buffer when handling an incoming RPC reply message. These fields contain the length of each component of the XDR buffer, and hence the maximum number of bytes of reply data that can be stored in each XDR buffer component. I've concluded this because: - This is how xdr_partial_copy_from_skb() appears to behave - rpcrdma_inline_fixup() already does not alter page_len - call_decode() compares rq_private_buf and rq_rcv_buf and WARNs if they are not exactly the same Unfortunately, as soon as I tried the simple fix to just remove the line that sets tail.iov_len to zero, I saw that the logic that appends the implicit Write chunk pad inline depends on inline_fixup setting tail.iov_len to zero. To address this, re-organize the tail iovec handling logic to use the same approach as with the head iovec: simply point tail.iov_base to the correct bytes in the receive buffer. While I remember all this, write down the conclusion in documenting comments. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* xprtrdma: rpcrdma_inline_fixup() overruns the receive page listChuck Lever2016-07-111-5/+11
| | | | | | | | | | When the remaining length of an incoming reply is longer than the XDR buf's page_len, switch over to the tail iovec instead of copying more than page_len bytes into the page list. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* xprtrdma: Chunk list encoders no longer share one rl_segments arrayChuck Lever2016-07-112-53/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, all three chunk list encoders each use a portion of the one rl_segments array in rpcrdma_req. This is because the MWs for each chunk list were preserved in rl_segments so that ro_unmap could find and invalidate them after the RPC was complete. However, now that MWs are placed on a per-req linked list as they are registered, there is no longer any information in rpcrdma_mr_seg that is shared between ro_map and ro_unmap_{sync,safe}, and thus nothing in rl_segments needs to be preserved after rpcrdma_marshal_req is complete. Thus the rl_segments array can be used now just for the needs of each rpcrdma_convert_iovs call. Once each chunk list is encoded, the next chunk list encoder is free to re-use all of rl_segments. This means all three chunk lists in one RPC request can now each encode a full size data payload with no increase in the size of rl_segments. This is a key requirement for Kerberos support, since both the Call and Reply for a single RPC transaction are conveyed via Long messages (RDMA Read/Write). Both can be large. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* xprtrdma: Place registered MWs on a per-req listChuck Lever2016-07-116-139/+94
| | | | | | | | | | | | | | | | | | | Instead of placing registered MWs sparsely into the rl_segments array, place these MWs on a per-req list. ro_unmap_{sync,safe} can then simply pull those MWs off the list instead of walking through the array. This change significantly reduces the size of struct rpcrdma_req by removing nsegs and rl_mw from every array element. As an additional clean-up, chunk co-ordinates are returned in the "*mw" output argument so they are no longer needed in every array element. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* xprtrdma: Release orphaned MRs immediatelyChuck Lever2016-07-112-12/+26
| | | | | | | | | | Instead of leaving orphaned MRs to be released when the transport is destroyed, release them immediately. The MR free list can now be replenished if it becomes exhausted. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* xprtrdma: Allocate MRs on demandChuck Lever2016-07-115-124/+114
| | | | | | | | | | | | | | | | | | | | | | | | | Frequent MR list exhaustion can impact I/O throughput, so enough MRs are always created during transport set-up to prevent running out. This means more MRs are created than most workloads need. Commit 94f58c58c0b4 ("xprtrdma: Allow Read list and Reply chunk simultaneously") introduced support for sending two chunk lists per RPC, which consumes more MRs per RPC. Instead of trying to provision more MRs, introduce a mechanism for allocating MRs on demand. A few MRs are allocated during transport set-up to kick things off. This significantly reduces the average number of MRs per transport while allowing the MR count to grow for workloads or devices that need more MRs. FRWR with mlx4 allocated almost 400 MRs per transport before this patch. Now it starts with 32. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* xprtrdma: Chunk list encoders must not return zeroChuck Lever2016-07-113-3/+7
| | | | | | | | | | Clean up, based on code audit: Remove the possibility that the chunk list XDR encoders can return zero, which would be interpreted as a NULL. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* xprtrdma: Honor ->send_request API contractChuck Lever2016-07-115-24/+39
| | | | | | | | | | | | | | | | | | | | | Commit c93c62231cf5 ("xprtrdma: Disconnect on registration failure") added a disconnect for some RPC marshaling failures. This is needed only in a handful of cases, but it was triggering for simple stuff like temporary resource shortages. Try to straighten this out. Fix up the lower layers so they don't return -ENOMEM or other error codes that the RPC client's FSM doesn't explicitly recognize. Also fix up the places in the send_request path that do want a disconnect. For example, when ib_post_send or ib_post_recv fail, this is a sign that there is a send or receive queue resource miscalculation. That should be rare, and is a sign of a software bug. But xprtrdma can recover: disconnect to reset the transport and start over. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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