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path: root/net/sunrpc/xprtrdma/verbs.c
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2018-01-23xprtrdma: Correct some documenting commentsChuck Lever
Fix kernel-doc warnings in net/sunrpc/xprtrdma/ . net/sunrpc/xprtrdma/verbs.c:1575: warning: No description found for parameter 'count' net/sunrpc/xprtrdma/verbs.c:1575: warning: Excess function parameter 'min_reqs' description in 'rpcrdma_ep_post_extra_recv' net/sunrpc/xprtrdma/backchannel.c:288: warning: No description found for parameter 'r_xprt' net/sunrpc/xprtrdma/backchannel.c:288: warning: Excess function parameter 'xprt' description in 'rpcrdma_bc_receive_call' Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-23xprtrdma: Instrument allocation/release of rpcrdma_req/rep objectsChuck Lever
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-23xprtrdma: Add trace points to instrument QP and CQ access upcallsChuck Lever
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-23xprtrdma: Add trace points for connect eventsChuck Lever
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-23xprtrdma: Add trace points to instrument MR allocation and recoveryChuck Lever
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-23xprtrdma: Add trace points to instrument memory invalidationChuck Lever
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-23xprtrdma: Add trace points in the RPC Reply handler pathsChuck Lever
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-23xprtrdma: Add trace points in RPC Call transmit pathsChuck Lever
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16xprtrdma: Introduce rpcrdma_mw_unmap_and_putChuck Lever
Clean up: Code review suggested that a common bit of code can be placed into a helper function, and this gives us fewer places to stick an "I DMA unmapped something" trace point. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16xprtrdma: Remove usage of "mw"Chuck Lever
Clean up: struct rpcrdma_mw was named after Memory Windows, but xprtrdma no longer supports a Memory Window registration mode. Rename rpcrdma_mw and its fields to reduce confusion and make the code more sensible to read. Renaming "mw" was suggested by Tom Talpey, the author of the original xprtrdma implementation. It's a good idea, but I haven't done this until now because it's a huge diffstat for no benefit other than code readability. However, I'm about to introduce static trace points that expose a few of xprtrdma's internal data structures. They should make sense in the trace report, and it's reasonable to treat trace points as a kernel API contract which might be difficult to change later. While I'm churning things up, two additional changes: - rename variables unhelpfully called "r" to "mr", to improve code clarity, and - rename the MR-related helper functions using the form "rpcrdma_mr_<verb>", to be consistent with other areas of the code. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16xprtrdma: Replace all usage of "frmr" with "frwr"Chuck Lever
Clean up: Over time, the industry has adopted the term "frwr" instead of "frmr". The term "frwr" is now more widely recognized. For the past couple of years I've attempted to add new code using "frwr" , but there still remains plenty of older code that still uses "frmr". Replace all usage of "frmr" to avoid confusion. While we're churning code, rename variables unhelpfully called "f" to "frwr", to improve code clarity. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16xprtrdma: Remove another sockaddr_storage field (cdata::addr)Chuck Lever
Save more space in struct rpcrdma_xprt by removing the redundant "addr" field from struct rpcrdma_create_data_internal. Wherever we have rpcrdma_xprt, we also have the rpc_xprt, which has a sockaddr_storage field with the same content. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16xprtrdma: Initialize the xprt address string array earlierChuck Lever
This makes the address strings available for debugging messages in earlier stages of transport set up. The first benefit is to get rid of the single-use rep_remote_addr field, saving 128+ bytes in struct rpcrdma_ep. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16xprtrdma: Remove ri_reminv_expectedChuck Lever
Clean up. Commit b5f0afbea4f2 ("xprtrdma: Per-connection pad optimization") should have removed this. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16xprtrdma: Per-mode handling for Remote InvalidationChuck Lever
Refactoring change: Remote Invalidation is particular to the memory registration mode that is use. Use a callout instead of a generic function to handle Remote Invalidation. This gets rid of the 8-byte flags field in struct rpcrdma_mw, of which only a single bit flag has been allocated. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-16xprtrdma: Fix backchannel allocation of extra rpcrdma_repsChuck Lever
The backchannel code uses rpcrdma_recv_buffer_put to add new reps to the free rep list. This also decrements rb_recv_count, which spoofs the receive overrun logic in rpcrdma_buffer_get_rep. Commit 9b06688bc3b9 ("xprtrdma: Fix additional uses of spin_lock_irqsave(rb_lock)") replaced the original open-coded list_add with a call to rpcrdma_recv_buffer_put(), but then a year later, commit 05c974669ece ("xprtrdma: Fix receive buffer accounting") added rep accounting to rpcrdma_recv_buffer_put. It was an oversight to let the backchannel continue to use this function. The fix this, let's combine the "add to free list" logic with rpcrdma_create_rep. Also, do not allocate RPCRDMA_MAX_BC_REQUESTS rpcrdma_reps in rpcrdma_buffer_create and then allocate additional rpcrdma_reps in rpcrdma_bc_setup_reps. Allocating the extra reps during backchannel set-up is sufficient. Fixes: 05c974669ece ("xprtrdma: Fix receive buffer accounting") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-12-15xprtrdma: Spread reply processing over more CPUsChuck Lever
Commit d8f532d20ee4 ("xprtrdma: Invoke rpcrdma_reply_handler directly from RECV completion") introduced a performance regression for NFS I/O small enough to not need memory registration. In multi- threaded benchmarks that generate primarily small I/O requests, IOPS throughput is reduced by nearly a third. This patch restores the previous level of throughput. Because workqueues are typically BOUND (in particular ib_comp_wq, nfsiod_workqueue, and rpciod_workqueue), NFS/RDMA workloads tend to aggregate on the CPU that is handling Receive completions. The usual approach to addressing this problem is to create a QP and CQ for each CPU, and then schedule transactions on the QP for the CPU where you want the transaction to complete. The transaction then does not require an extra context switch during completion to end up on the same CPU where the transaction was started. This approach doesn't work for the Linux NFS/RDMA client because currently the Linux NFS client does not support multiple connections per client-server pair, and the RDMA core API does not make it straightforward for ULPs to determine which CPU is responsible for handling Receive completions for a CQ. So for the moment, record the CPU number in the rpcrdma_req before the transport sends each RPC Call. Then during Receive completion, queue the RPC completion on that same CPU. Additionally, move all RPC completion processing to the deferred handler so that even RPCs with simple small replies complete on the CPU that sent the corresponding RPC Call. Fixes: d8f532d20ee4 ("xprtrdma: Invoke rpcrdma_reply_handler ...") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17xprtrdma: Update copyright noticesChuck Lever
Credit work contributed by Oracle engineers since 2014. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17xprtrdma: Remove include for linux/prefetch.hChuck Lever
Clean up. This include should have been removed by commit 23826c7aeac7 ("xprtrdma: Serialize credit accounting again"). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17xprtrdma: Put Send CQ in IB_POLL_WORKQUEUE modeChuck Lever
Lift the Send and LocalInv completion handlers out of soft IRQ mode to make room for other work. Also, move the Send CQ to a different CPU than the CPU where the Receive CQ is running, for improved scalability. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17xprtrdma: Remove atomic send completion countingChuck Lever
The sendctx circular queue now guarantees that xprtrdma cannot overflow the Send Queue, so remove the remaining bits of the original Send WQE counting mechanism. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17xprtrdma: RPC completion should wait for Send completionChuck Lever
When an RPC Call includes a file data payload, that payload can come from pages in the page cache, or a user buffer (for direct I/O). If the payload can fit inline, xprtrdma includes it in the Send using a scatter-gather technique. xprtrdma mustn't allow the RPC consumer to re-use the memory where that payload resides before the Send completes. Otherwise, the new contents of that memory would be exposed by an HCA retransmit of the Send operation. So, block RPC completion on Send completion, but only in the case where a separate file data payload is part of the Send. This prevents the reuse of that memory while it is still part of a Send operation without an undue cost to other cases. Waiting is avoided in the common case because typically the Send will have completed long before the RPC Reply arrives. These days, an RPC timeout will trigger a disconnect, which tears down the QP. The disconnect flushes all waiting Sends. This bounds the amount of time the reply handler has to wait for a Send completion. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17xprtrdma: Add a field of bit flags to struct rpcrdma_reqChuck Lever
We have one boolean flag in rpcrdma_req today. I'd like to add more flags, so convert that boolean to a bit flag. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17xprtrdma: Add data structure to manage RDMA Send argumentsChuck Lever
Problem statement: Recently Sagi Grimberg <sagi@grimberg.me> observed that kernel RDMA- enabled storage initiators don't handle delayed Send completion correctly. If Send completion is delayed beyond the end of a ULP transaction, the ULP may release resources that are still being used by the HCA to complete a long-running Send operation. This is a common design trait amongst our initiators. Most Send operations are faster than the ULP transaction they are part of. Waiting for a completion for these is typically unnecessary. Infrequently, a network partition or some other problem crops up where an ordering problem can occur. In NFS parlance, the RPC Reply arrives and completes the RPC, but the HCA is still retrying the Send WR that conveyed the RPC Call. In this case, the HCA can try to use memory that has been invalidated or DMA unmapped, and the connection is lost. If that memory has been re-used for something else (possibly not related to NFS), and the Send retransmission exposes that data on the wire. Thus we cannot assume that it is safe to release Send-related resources just because a ULP reply has arrived. After some analysis, we have determined that the completion housekeeping will not be difficult for xprtrdma: - Inline Send buffers are registered via the local DMA key, and are already left DMA mapped for the lifetime of a transport connection, thus no additional handling is necessary for those - Gathered Sends involving page cache pages _will_ need to DMA unmap those pages after the Send completes. But like inline send buffers, they are registered via the local DMA key, and thus will not need to be invalidated In addition, RPC completion will need to wait for Send completion in the latter case. However, nearly always, the Send that conveys the RPC Call will have completed long before the RPC Reply arrives, and thus no additional latency will be accrued. Design notes: In this patch, the rpcrdma_sendctx object is introduced, and a lock-free circular queue is added to manage a set of them per transport. The RPC client's send path already prevents sending more than one RPC Call at the same time. This allows us to treat the consumer side of the queue (rpcrdma_sendctx_get_locked) as if there is a single consumer thread. The producer side of the queue (rpcrdma_sendctx_put_locked) is invoked only from the Send completion handler, which is a single thread of execution (soft IRQ). The only care that needs to be taken is with the tail index, which is shared between the producer and consumer. Only the producer updates the tail index. The consumer compares the head with the tail to ensure that the a sendctx that is in use is never handed out again (or, expressed more conventionally, the queue is empty). When the sendctx queue empties completely, there are enough Sends outstanding that posting more Send operations can result in a Send Queue overflow. In this case, the ULP is told to wait and try again. This introduces strong Send Queue accounting to xprtrdma. As a final touch, Jason Gunthorpe <jgunthorpe@obsidianresearch.com> suggested a mechanism that does not require signaling every Send. We signal once every N Sends, and perform SGE unmapping of N Send operations during that one completion. Reported-by: Sagi Grimberg <sagi@grimberg.me> Suggested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17xprtrdma: Decode credits field in rpcrdma_reply_handlerChuck Lever
We need to decode and save the incoming rdma_credits field _after_ we know that the direction of the message is "forward direction Reply". Otherwise, the credits value in reverse direction Calls is also used to update the forward direction credits. It is safe to decode the rdma_credits field in rpcrdma_reply_handler now that rpcrdma_reply_handler is single-threaded. Receives complete in the same order as they were sent on the NFS server. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17xprtrdma: Invoke rpcrdma_reply_handler directly from RECV completionChuck Lever
I noticed that the soft IRQ thread looked pretty busy under heavy I/O workloads. perf suggested one area that was expensive was the queue_work() call in rpcrdma_wc_receive. That gave me some ideas. Instead of scheduling a separate worker to process RPC Replies, promote the Receive completion handler to IB_POLL_WORKQUEUE, and invoke rpcrdma_reply_handler directly. Note that the poll workqueue is single-threaded. In order to keep memory invalidation from serializing all RPC Replies, handle any necessary invalidation tasks in a separate multi-threaded workqueue. This provides a two-tier scheme, similar to OS I/O interrupt handlers: A fast interrupt handler that schedules the slow handler and re-enables the interrupt, and a slower handler that is invoked for any needed heavy lifting. Benefits include: - One less context switch for RPCs that don't register memory - Receive completion handling is moved out of soft IRQ context to make room for other users of soft IRQ - The same CPU core now DMA syncs and XDR decodes the Receive buffer Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-09-05xprtrdma: Use xprt_pin_rqst in rpcrdma_reply_handlerChuck Lever
Adopt the use of xprt_pin_rqst to eliminate contention between Call-side users of rb_lock and the use of rb_lock in rpcrdma_reply_handler. This replaces the mechanism introduced in 431af645cf66 ("xprtrdma: Fix client lock-up after application signal fires"). Use recv_lock to quickly find the completing rqst, pin it, then drop the lock. At that point invalidation and pull-up of the Reply XDR can be done. Both are often expensive operations. Finally, take recv_lock again to signal completion to the RPC layer. It also protects adjustment of "cwnd". This greatly reduces the amount of time a lock is held by the reply handler. Comparing lock_stat results shows a marked decrease in contention on rb_lock and recv_lock. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> [trond.myklebust@primarydata.com: Remove call to rpcrdma_buffer_put() from the "out_norqst:" path in rpcrdma_reply_handler.] Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-08xprtrdma: Clean up XDR decoding in rpcrdma_update_granted_credits()Chuck Lever
Clean up: Replace C-structure based XDR decoding for consistency with other areas. struct rpcrdma_rep is rearranged slightly so that the relevant fields are in cache when the Receive completion handler is invoked. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-08-08xprtrdma: Remove rpcrdma_rep::rr_lenChuck Lever
This field is no longer used outside the Receive completion handler. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-08-08xprtrdma: Remove opcode check in Receive completion handlerChuck Lever
Clean up: The opcode check is no longer necessary, because since commit 2fa8f88d8892 ("xprtrdma: Use new CQ API for RPC-over-RDMA client send CQs"), this completion handler is invoked only for RECV work requests. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-08-08xprtrdma: Add xdr_init_decode to rpcrdma_reply_handler()Chuck Lever
Transport header decoding deals with untrusted input data, therefore decoding this header needs to be hardened. Adopt the same infrastructure that is used when XDR decoding NFS replies. This is slightly more CPU-intensive than the replaced code, but we're not adding new atomics, locking, or context switches. The cost is manageable. Start by initializing an xdr_stream in rpcrdma_reply_handler(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-13xprtrdma: Demote "connect" log messagesChuck Lever
Some have complained about the log messages generated when xprtrdma opens or closes a connection to a server. When an NFS mount is mostly idle these can appear every few minutes as the client idles out the connection and reconnects. Connection and disconnection is a normal part of operation, and not exceptional, so change these to dprintk's for now. At some point all of these will be converted to tracepoints, but that's for another day. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-13xprtrdma: Fix client lock-up after application signal firesChuck Lever
After a signal, the RPC client aborts synchronous RPCs running on behalf of the signaled application. The server is still executing those RPCs, and will write the results back into the client's memory when it's done. By the time the server writes the results, that memory is likely being used for other purposes. Therefore xprtrdma has to immediately invalidate all memory regions used by those aborted RPCs to prevent the server's writes from clobbering that re-used memory. With FMR memory registration, invalidation takes a relatively long time. In fact, the invalidation is often still running when the server tries to write the results into the memory regions that are being invalidated. This sets up a race between two processes: 1. After the signal, xprt_rdma_free calls ro_unmap_safe. 2. While ro_unmap_safe is still running, the server replies and rpcrdma_reply_handler runs, calling ro_unmap_sync. Both processes invoke ib_unmap_fmr on the same FMR. The mlx4 driver allows two ib_unmap_fmr calls on the same FMR at the same time, but HCAs generally don't tolerate this. Sometimes this can result in a system crash. If the HCA happens to survive, rpcrdma_reply_handler continues. It removes the rpc_rqst from rq_list and releases the transport_lock. This enables xprt_rdma_free to run in another process, and the rpc_rqst is released while rpcrdma_reply_handler is still waiting for the ib_unmap_fmr call to finish. But further down in rpcrdma_reply_handler, the transport_lock is taken again, and "rqst" is dereferenced. If "rqst" has already been released, this triggers a general protection fault. Since bottom- halves are disabled, the system locks up. Address both issues by reversing the order of the xprt_lookup_rqst call and the ro_unmap_sync call. Introduce a separate lookup mechanism for rpcrdma_req's to enable calling ro_unmap_sync before xprt_lookup_rqst. Now the handler takes the transport_lock once and holds it for the XID lookup and RPC completion. BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305 Fixes: 68791649a725 ('xprtrdma: Invalidate in the RPC reply ... ') Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-13xprtrdma: Rename rpcrdma_req::rl_freeChuck Lever
Clean up: I'm about to use the rl_free field for purposes other than a free list. So use a more generic name. This is a refactoring change only. BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305 Fixes: 68791649a725 ('xprtrdma: Invalidate in the RPC reply ... ') Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-13xprtrdma: Pre-mark remotely invalidated MRsChuck Lever
There are rare cases where an rpcrdma_req and its matched rpcrdma_rep can be re-used, via rpcrdma_buffer_put, while the RPC reply handler is still using that req. This is typically due to a signal firing at just the wrong instant. As part of closing this race window, avoid using the wrong rpcrdma_rep to detect remotely invalidated MRs. Mark MRs as invalidated while we are sure the rep is still OK to use. BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305 Fixes: 68791649a725 ('xprtrdma: Invalidate in the RPC reply ... ') Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25xprtrdma: Annotate receive workqueueChuck Lever
Micro-optimize the receive workqueue by marking it's anchor "read- mostly." Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25xprtrdma: Revert commit d0f36c46deeaChuck Lever
Device removal is now adequately supported. Pinning the underlying device driver to prevent removal while an NFS mount is active is no longer necessary. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25xprtrdma: Restore transport after device removalChuck Lever
After a device removal, enable the transport connect worker to restore normal operation if there is another device with connectivity to the server. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25xprtrdma: Refactor rpcrdma_ep_connectChuck Lever
I'm about to add another arm to if (ep->rep_connected != 0) It will be cleaner to use a switch statement here. We'll be looking for a couple of specific errnos, or "anything else," basically to sort out the difference between a normal reconnect and recovery from device removal. This is a refactoring change only. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25xprtrdma: Support unplugging an HCA from under an NFS mountChuck Lever
The device driver for the underlying physical device associated with an RPC-over-RDMA transport can be removed while RPC-over-RDMA transports are still in use (ie, while NFS filesystems are still mounted and active). The IB core performs a connection event upcall to request that consumers free all RDMA resources associated with a transport. There may be pending RPCs when this occurs. Care must be taken to release associated resources without leaving references that can trigger a subsequent crash if a signal or soft timeout occurs. We rely on the caller of the transport's ->close method to ensure that the previous RPC task has invoked xprt_release but the transport remains write-locked. A DEVICE_REMOVE upcall forces a disconnect then sleeps. When ->close is invoked, it destroys the transport's H/W resources, then wakes the upcall, which completes and allows the core driver unload to continue. BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=266 Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25xprtrdma: Use same device when mapping or syncing DMA buffersChuck Lever
When the underlying device driver is reloaded, ia->ri_device will be replaced. All cached copies of that device pointer have to be updated as well. Commit 54cbd6b0c6b9 ("xprtrdma: Delay DMA mapping Send and Receive buffers") added the rg_device field to each regbuf. As part of handling a device removal, rpcrdma_dma_unmap_regbuf is invoked on all regbufs for a transport. Simply calling rpcrdma_dma_map_regbuf for each Receive buffer after the driver has been reloaded should reinitialize rg_device correctly for every case except rpcrdma_wc_receive, which still uses rpcrdma_rep::rr_device. Ensure the same device that was used to map a Receive buffer is also used to sync it in rpcrdma_wc_receive by using rg_device there instead of rr_device. This is the only use of rr_device, so it can be removed. The use of regbufs in the send path is also updated, for completeness. Fixes: 54cbd6b0c6b9 ("xprtrdma: Delay DMA mapping Send and ... ") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25xprtrdma: Refactor rpcrdma_ia_open()Chuck Lever
In order to unload a device driver and reload it, xprtrdma will need to close a transport's interface adapter, and then call rpcrdma_ia_open again, possibly finding a different interface adapter. Make rpcrdma_ia_open safe to call on the same transport multiple times. This is a refactoring change only. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25xprtrdma: Cancel refresh worker during buffer shutdownChuck Lever
Trying to create MRs while the transport is being torn down can cause a crash. Fixes: e2ac236c0b65 ("xprtrdma: Allocate MRs on demand") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-03-17xprtrdma: Squelch kbuild sparse complaintChuck Lever
New complaint from kbuild for 4.9.y: net/sunrpc/xprtrdma/verbs.c:489:19: sparse: incompatible types in comparison expression (different type sizes) verbs.c: 489 max_sge = min(ia->ri_device->attrs.max_sge, RPCRDMA_MAX_SEND_SGES); I can't reproduce this running sparse here. Likewise, "make W=1 net/sunrpc/xprtrdma/verbs.o" never indicated any issue. A little poking suggests that because the range of its values is small, gcc can make the actual width of RPCRDMA_MAX_SEND_SGES smaller than the width of an unsigned integer. Fixes: 16f906d66cd7 ("xprtrdma: Reduce required number of send SGEs") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: stable@kernel.org Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-10xprtrdma: Refactor management of mw_list fieldChuck Lever
Clean up some duplicate code. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-10xprtrdma: Handle stale connection rejectionChuck Lever
A server rejects a connection attempt with STALE_CONNECTION when a client attempts to connect to a working remote service, but uses a QPN and GUID that corresponds to an old connection that was abandoned. This might occur after a client crashes and restarts. Fix rpcrdma_conn_upcall() to distinguish between a normal rejection and rejection of stale connection parameters. As an additional clean-up, remove the code that retries the connection attempt with different ORD/IRD values. Code audit of other ULP initiators shows no similar special case handling of initiator_depth or responder_resources. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-10xprtrdma: Reduce required number of send SGEsChuck Lever
The MAX_SEND_SGES check introduced in commit 655fec6987be ("xprtrdma: Use gathered Send for large inline messages") fails for devices that have a small max_sge. Instead of checking for a large fixed maximum number of SGEs, check for a minimum small number. RPC-over-RDMA will switch to using a Read chunk if an xdr_buf has more pages than can fit in the device's max_sge limit. This is considerably better than failing all together to mount the server. This fix supports devices that have as few as three send SGEs available. Reported-by: Selvin Xavier <selvin.xavier@broadcom.com> Reported-by: Devesh Sharma <devesh.sharma@broadcom.com> Reported-by: Honggang Li <honli@redhat.com> Reported-by: Ram Amrani <Ram.Amrani@cavium.com> Fixes: 655fec6987be ("xprtrdma: Use gathered Send for large ...") Cc: stable@vger.kernel.org # v4.9+ Tested-by: Honggang Li <honli@redhat.com> Tested-by: Ram Amrani <Ram.Amrani@cavium.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-10xprtrdma: Disable pad optimization by defaultChuck Lever
Commit d5440e27d3e5 ("xprtrdma: Enable pad optimization") made the Linux client omit XDR round-up padding in normal Read and Write chunks so that the client doesn't have to register and invalidate 3-byte memory regions that contain no real data. Unfortunately, my cheery 2014 assessment that this optimization "is supported now by both Linux and Solaris servers" was premature. We've found bugs in Solaris in this area since commit d5440e27d3e5 ("xprtrdma: Enable pad optimization") was merged (SYMLINK is the main offender). So for maximum interoperability, I'm disabling this optimization again. If a CM private message is exchanged when connecting, the client recognizes that the server is Linux, and enables the optimization for that connection. Until now the Solaris server bugs did not impact common operations, and were thus largely benign. Soon, less capable devices on Linux NFS/RDMA clients will make use of Read chunks more often, and these Solaris bugs will prevent interoperation in more cases. Fixes: 677eb17e94ed ("xprtrdma: Fix XDR tail buffer marshalling") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-02-10xprtrdma: Per-connection pad optimizationChuck Lever
Pad optimization is changed by echoing into /proc/sys/sunrpc/rdma_pad_optimize. This is a global setting, affecting all RPC-over-RDMA connections to all servers. The marshaling code picks up that value and uses it for decisions about how to construct each RPC-over-RDMA frame. Having it change suddenly in mid-operation can result in unexpected failures. And some servers a client mounts might need chunk round-up, while others don't. So instead, copy the pad_optimize setting into each connection's rpcrdma_ia when the transport is created, and use the copy, which can't change during the life of the connection, instead. This also removes a hack: rpcrdma_convert_iovs was using the remote-invalidation-expected flag to predict when it could leave out Write chunk padding. This is because the Linux server handles implicit XDR padding on Write chunks correctly, and only Linux servers can set the connection's remote-invalidation-expected flag. It's more sensible to use the pad optimization setting instead. Fixes: 677eb17e94ed ("xprtrdma: Fix XDR tail buffer marshalling") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-11-29xprtrdma: Shorten QP access error messageChuck Lever
Clean up: The convention for this type of warning message is not to show the function name or "RPC: ". Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>