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path: root/net/sunrpc/xprtrdma/verbs.c
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2020-04-20xprtrdma: Fix trace point use-after-free raceChuck Lever
It's not safe to use resources pointed to by the @send_wr of ib_post_send() _after_ that function returns. Those resources are typically freed by the Send completion handler, which can run before ib_post_send() returns. Thus the trace points currently around ib_post_send() in the client's RPC/RDMA transport are a hazard, even when they are disabled. Rearrange them so that they touch the Work Request only _before_ ib_post_send() is invoked. Fixes: ab03eff58eb5 ("xprtrdma: Add trace points in RPC Call transmit paths") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-04-20xprtrdma: Restore wake-up-all to rpcrdma_cm_event_handler()Chuck Lever
Commit e28ce90083f0 ("xprtrdma: kmalloc rpcrdma_ep separate from rpcrdma_xprt") erroneously removed a xprt_force_disconnect() call from the "transport disconnect" path. The result was that the client no longer responded to server-side disconnect requests. Restore that call. Fixes: e28ce90083f0 ("xprtrdma: kmalloc rpcrdma_ep separate from rpcrdma_xprt") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-03-27xprtrdma: kmalloc rpcrdma_ep separate from rpcrdma_xprtChuck Lever
Change the rpcrdma_xprt_disconnect() function so that it no longer waits for the DISCONNECTED event. This prevents blocking if the remote is unresponsive. In rpcrdma_xprt_disconnect(), the transport's rpcrdma_ep is detached. Upon return from rpcrdma_xprt_disconnect(), the transport (r_xprt) is ready immediately for a new connection. The RDMA_CM_DEVICE_REMOVAL and RDMA_CM_DISCONNECTED events are now handled almost identically. However, because the lifetimes of rpcrdma_xprt structures and rpcrdma_ep structures are now independent, creating an rpcrdma_ep needs to take a module ref count. The ep now owns most of the hardware resources for a transport. Also, a kref is needed to ensure that rpcrdma_ep sticks around long enough for the cm_event_handler to finish. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-03-27xprtrdma: Extract sockaddr from struct rdma_cm_idChuck Lever
rpcrdma_cm_event_handler() is always passed an @id pointer that is valid. However, in a subsequent patch, we won't be able to extract an r_xprt in every case. So instead of using the r_xprt's presentation address strings, extract them from struct rdma_cm_id. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-03-27xprtrdma: Merge struct rpcrdma_ia into struct rpcrdma_epChuck Lever
I eventually want to allocate rpcrdma_ep separately from struct rpcrdma_xprt so that on occasion there can be more than one ep per xprt. The new struct rpcrdma_ep will contain all the fields currently in rpcrdma_ia and in rpcrdma_ep. This is all the device and CM settings for the connection, in addition to per-connection settings negotiated with the remote. Take this opportunity to rename the existing ep fields from rep_* to re_* to disambiguate these from struct rpcrdma_rep. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-03-27xprtrdma: Disconnect on flushed completionChuck Lever
Completion errors after a disconnect often occur much sooner than a CM_DISCONNECT event. Use this to try to detect connection loss more quickly. Note that other kernel ULPs do take care to disconnect explicitly when a WR is flushed. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-03-27xprtrdma: Remove rpcrdma_ia::ri_flagsChuck Lever
Clean up: The upper layer serializes calls to xprt_rdma_close, so there is no need for an atomic bit operation, saving 8 bytes in rpcrdma_ia. This enables merging rpcrdma_ia_remove directly into the disconnect logic. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-03-27xprtrdma: Invoke rpcrdma_ia_open in the connect workerChuck Lever
Move rdma_cm_id creation into rpcrdma_ep_create() so that it is now responsible for allocating all per-connection hardware resources. With this clean-up, all three arms of the switch statement in rpcrdma_ep_connect are exactly the same now, thus the switch can be removed. Because device removal behaves a little differently than disconnection, there is a little more work to be done before rpcrdma_ep_destroy() can release the connection's rdma_cm_id. So it is not quite symmetrical with rpcrdma_ep_create() yet. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-03-27xprtrdma: Allocate Protection Domain in rpcrdma_ep_create()Chuck Lever
Make a Protection Domain (PD) a per-connection resource rather than a per-transport resource. In other words, when the connection terminates, the PD is destroyed. Thus there is one less HW resource that remains allocated to a transport after a connection is closed. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-03-27xprtrdma: Refactor rpcrdma_ep_connect() and rpcrdma_ep_disconnect()Chuck Lever
Clean up: Simplify the synopses of functions in the connect and disconnect paths in preparation for combining the rpcrdma_ia and struct rpcrdma_ep structures. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-03-27xprtrdma: Clean up the post_send pathChuck Lever
Clean up: Simplify the synopses of functions in the post_send path by combining the struct rpcrdma_ia and struct rpcrdma_ep arguments. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-03-27xprtrdma: Refactor frwr_init_mr()Chuck Lever
Clean up: prepare for combining the rpcrdma_ia and rpcrdma_ep structures. Take the opportunity to rename the function to be consistent with the "subsystem _ object _ verb" naming scheme. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-03-27xprtrdma: Invoke rpcrdma_ep_create() in the connect workerChuck Lever
Refactor rpcrdma_ep_create(), rpcrdma_ep_disconnect(), and rpcrdma_ep_destroy(). rpcrdma_ep_create will be invoked at connect time instead of at transport set-up time. It will be responsible for allocating per- connection resources. In this patch it allocates the CQs and creates a QP. More to come. rpcrdma_ep_destroy() is the inverse functionality that is invoked at disconnect time. It will be responsible for releasing the CQs and QP. These changes should be safe to do because both connect and disconnect is guaranteed to be serialized by the transport send lock. This takes us another step closer to resolving the address and route only at connect time so that connection failover to another device will work correctly. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15xprtrdma: DMA map rr_rdma_buf as each rpcrdma_rep is createdChuck Lever
Clean up: This simplifies the logic in rpcrdma_post_recvs. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15xprtrdma: Destroy reps from previous connection instanceChuck Lever
To safely get rid of all rpcrdma_reps from a particular connection instance, xprtrdma has to wait until each of those reps is finished being used. A rep may be backing the rq_rcv_buf of an RPC that has just completed, for example. Since it is safe to invoke rpcrdma_rep_destroy() only in the Receive completion handler, simply mark reps remaining in the rb_all_reps list after the transport is drained. These will then be deleted as rpcrdma_post_recvs pulls them off the rep free list. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15xprtrdma: Destroy rpcrdma_rep when Receive is flushedChuck Lever
This reduces the hardware and memory footprint of an unconnected transport. At some point in the future, transport reconnect will allow resolving the destination IP address through a different device. The current change enables reps for the new connection to be allocated on whichever NUMA node the new device affines to after a reconnect. Note that this does not destroy _all_ the transport's reps... there will be a few that are still part of a running RPC completion. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15xprtrdma: Allocate and map transport header buffers at connect timeChuck Lever
Currently the underlying RDMA device is chosen at transport set-up time. But it will soon be at connect time instead. The maximum size of a transport header is based on device capabilities. Thus transport header buffers have to be allocated _after_ the underlying device has been chosen (via address and route resolution); ie, in the connect worker. Thus, move the allocation of transport header buffers to the connect worker, after the point at which the underlying RDMA device has been chosen. This also means the RDMA device is available to do a DMA mapping of these buffers at connect time, instead of in the hot I/O path. Make that optimization as well. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15xprtrdma: Refactor frwr_is_supportedChuck Lever
Refactor: Perform the "is supported" check in rpcrdma_ep_create() instead of in rpcrdma_ia_open(). frwr_open() is where most of the logic to query device attributes is already located. The current code displays a redundant error message when the device does not support FRWR. As an additional clean-up, this patch removes the extra message. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15xprtrdma: Eliminate per-transport "max pages"Chuck Lever
To support device hotplug and migrating a connection between devices of different capabilities, we have to guarantee that all in-kernel devices can support the same max NFS payload size (1 megabyte). This means that possibly one or two in-tree devices are no longer supported for NFS/RDMA because they cannot support 1MB rsize/wsize. The only one I confirmed was cxgb3, but it has already been removed from the kernel. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15xprtrdma: Refactor initialization of ep->rep_max_requestsChuck Lever
Clean up: there is no need to keep two copies of the same value. Also, in subsequent patches, rpcrdma_ep_create() will be called in the connect worker rather than at set-up time. Minor fix: Initialize the transport's sendctx to the value based on the capabilities of the underlying device, not the maximum setting. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15xprtrdma: Make sendctx queue lifetime the same as connection lifetimeChuck Lever
The size of the sendctx queue depends on the value stored in ia->ri_max_send_sges. This value is determined by querying the underlying device. Eventually, rpcrdma_ia_open() and rpcrdma_ep_create() will be called in the connect worker rather than at transport set-up time. The underlying device will not have been chosen device set-up time. The sendctx queue will thus have to be created after the underlying device has been chosen via address and route resolution; in other words, in the connect worker. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15xprtrdma: Eliminate ri_max_send_sgesChuck Lever
Clean-up. The max_send_sge value also happens to be stored in ep->rep_attr. Let's keep just a single copy. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-14xprtrdma: Fix oops in Receive handler after device removalChuck Lever
Since v5.4, a device removal occasionally triggered this oops: Dec 2 17:13:53 manet kernel: BUG: unable to handle page fault for address: 0000000c00000219 Dec 2 17:13:53 manet kernel: #PF: supervisor read access in kernel mode Dec 2 17:13:53 manet kernel: #PF: error_code(0x0000) - not-present page Dec 2 17:13:53 manet kernel: PGD 0 P4D 0 Dec 2 17:13:53 manet kernel: Oops: 0000 [#1] SMP Dec 2 17:13:53 manet kernel: CPU: 2 PID: 468 Comm: kworker/2:1H Tainted: G W 5.4.0-00050-g53717e43af61 #883 Dec 2 17:13:53 manet kernel: Hardware name: Supermicro SYS-6028R-T/X10DRi, BIOS 1.1a 10/16/2015 Dec 2 17:13:53 manet kernel: Workqueue: ib-comp-wq ib_cq_poll_work [ib_core] Dec 2 17:13:53 manet kernel: RIP: 0010:rpcrdma_wc_receive+0x7c/0xf6 [rpcrdma] Dec 2 17:13:53 manet kernel: Code: 6d 8b 43 14 89 c1 89 45 78 48 89 4d 40 8b 43 2c 89 45 14 8b 43 20 89 45 18 48 8b 45 20 8b 53 14 48 8b 30 48 8b 40 10 48 8b 38 <48> 8b 87 18 02 00 00 48 85 c0 75 18 48 8b 05 1e 24 c4 e1 48 85 c0 Dec 2 17:13:53 manet kernel: RSP: 0018:ffffc900035dfe00 EFLAGS: 00010246 Dec 2 17:13:53 manet kernel: RAX: ffff888467290000 RBX: ffff88846c638400 RCX: 0000000000000048 Dec 2 17:13:53 manet kernel: RDX: 0000000000000048 RSI: 00000000f942e000 RDI: 0000000c00000001 Dec 2 17:13:53 manet kernel: RBP: ffff888467611b00 R08: ffff888464e4a3c4 R09: 0000000000000000 Dec 2 17:13:53 manet kernel: R10: ffffc900035dfc88 R11: fefefefefefefeff R12: ffff888865af4428 Dec 2 17:13:53 manet kernel: R13: ffff888466023000 R14: ffff88846c63f000 R15: 0000000000000010 Dec 2 17:13:53 manet kernel: FS: 0000000000000000(0000) GS:ffff88846fa80000(0000) knlGS:0000000000000000 Dec 2 17:13:53 manet kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Dec 2 17:13:53 manet kernel: CR2: 0000000c00000219 CR3: 0000000002009002 CR4: 00000000001606e0 Dec 2 17:13:53 manet kernel: Call Trace: Dec 2 17:13:53 manet kernel: __ib_process_cq+0x5c/0x14e [ib_core] Dec 2 17:13:53 manet kernel: ib_cq_poll_work+0x26/0x70 [ib_core] Dec 2 17:13:53 manet kernel: process_one_work+0x19d/0x2cd Dec 2 17:13:53 manet kernel: ? cancel_delayed_work_sync+0xf/0xf Dec 2 17:13:53 manet kernel: worker_thread+0x1a6/0x25a Dec 2 17:13:53 manet kernel: ? cancel_delayed_work_sync+0xf/0xf Dec 2 17:13:53 manet kernel: kthread+0xf4/0xf9 Dec 2 17:13:53 manet kernel: ? kthread_queue_delayed_work+0x74/0x74 Dec 2 17:13:53 manet kernel: ret_from_fork+0x24/0x30 The proximal cause is that this rpcrdma_rep has a rr_rdmabuf that is still pointing to the old ib_device, which has been freed. The only way that is possible is if this rpcrdma_rep was not destroyed by rpcrdma_ia_remove. Debugging showed that was indeed the case: this rpcrdma_rep was still in use by a completing RPC at the time of the device removal, and thus wasn't on the rep free list. So, it was not found by rpcrdma_reps_destroy(). The fix is to introduce a list of all rpcrdma_reps so that they all can be found when a device is removed. That list is used to perform only regbuf DMA unmapping, replacing that call to rpcrdma_reps_destroy(). Meanwhile, to prevent corruption of this list, I've moved the destruction of temp rpcrdma_rep objects to rpcrdma_post_recvs(). rpcrdma_xprt_drain() ensures that post_recvs (and thus rep_destroy) is not invoked while rpcrdma_reps_unmap is walking rb_all_reps, thus protecting the rb_all_reps list. Fixes: b0b227f071a0 ("xprtrdma: Use an llist to manage free rpcrdma_reps") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-14xprtrdma: Fix completion wait during device removalChuck Lever
I've found that on occasion, "rmmod <dev>" will hang while if an NFS is under load. Ensure that ri_remove_done is initialized only just before the transport is woken up to force a close. This avoids the completion possibly getting initialized again while the CM event handler is waiting for a wake-up. Fixes: bebd031866ca ("xprtrdma: Support unplugging an HCA from under an NFS mount") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-14xprtrdma: Fix create_qp crash on device unloadChuck Lever
On device re-insertion, the RDMA device driver crashes trying to set up a new QP: Nov 27 16:32:06 manet kernel: BUG: kernel NULL pointer dereference, address: 00000000000001c0 Nov 27 16:32:06 manet kernel: #PF: supervisor write access in kernel mode Nov 27 16:32:06 manet kernel: #PF: error_code(0x0002) - not-present page Nov 27 16:32:06 manet kernel: PGD 0 P4D 0 Nov 27 16:32:06 manet kernel: Oops: 0002 [#1] SMP Nov 27 16:32:06 manet kernel: CPU: 1 PID: 345 Comm: kworker/u28:0 Tainted: G W 5.4.0 #852 Nov 27 16:32:06 manet kernel: Hardware name: Supermicro SYS-6028R-T/X10DRi, BIOS 1.1a 10/16/2015 Nov 27 16:32:06 manet kernel: Workqueue: xprtiod xprt_rdma_connect_worker [rpcrdma] Nov 27 16:32:06 manet kernel: RIP: 0010:atomic_try_cmpxchg+0x2/0x12 Nov 27 16:32:06 manet kernel: Code: ff ff 48 8b 04 24 5a c3 c6 07 00 0f 1f 40 00 c3 31 c0 48 81 ff 08 09 68 81 72 0c 31 c0 48 81 ff 83 0c 68 81 0f 92 c0 c3 8b 06 <f0> 0f b1 17 0f 94 c2 84 d2 75 02 89 06 88 d0 c3 53 ba 01 00 00 00 Nov 27 16:32:06 manet kernel: RSP: 0018:ffffc900035abbf0 EFLAGS: 00010046 Nov 27 16:32:06 manet kernel: RAX: 0000000000000000 RBX: 00000000000001c0 RCX: 0000000000000000 Nov 27 16:32:06 manet kernel: RDX: 0000000000000001 RSI: ffffc900035abbfc RDI: 00000000000001c0 Nov 27 16:32:06 manet kernel: RBP: ffffc900035abde0 R08: 000000000000000e R09: ffffffffffffc000 Nov 27 16:32:06 manet kernel: R10: 0000000000000000 R11: 000000000002e800 R12: ffff88886169d9f8 Nov 27 16:32:06 manet kernel: R13: ffff88886169d9f4 R14: 0000000000000246 R15: 0000000000000000 Nov 27 16:32:06 manet kernel: FS: 0000000000000000(0000) GS:ffff88846fa40000(0000) knlGS:0000000000000000 Nov 27 16:32:06 manet kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Nov 27 16:32:06 manet kernel: CR2: 00000000000001c0 CR3: 0000000002009006 CR4: 00000000001606e0 Nov 27 16:32:06 manet kernel: Call Trace: Nov 27 16:32:06 manet kernel: do_raw_spin_lock+0x2f/0x5a Nov 27 16:32:06 manet kernel: create_qp_common.isra.47+0x856/0xadf [mlx4_ib] Nov 27 16:32:06 manet kernel: ? slab_post_alloc_hook.isra.60+0xa/0x1a Nov 27 16:32:06 manet kernel: ? __kmalloc+0x125/0x139 Nov 27 16:32:06 manet kernel: mlx4_ib_create_qp+0x57f/0x972 [mlx4_ib] The fix is to copy the qp_init_attr struct that was just created by rpcrdma_ep_create() instead of using the one from the previous connection instance. Fixes: 98ef77d1aaa7 ("xprtrdma: Send Queue size grows after a reconnect") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24xprtrdma: Replace dprintk() in rpcrdma_update_connect_private()Chuck Lever
Clean up: Use a single trace point to record each connection's negotiated inline thresholds and the computed maximum byte size of transport headers. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24xprtrdma: Report the computed connect delayChuck Lever
For debugging, the op_connect trace point should report the computed connect delay. We can then ensure that the delay is computed at the proper times, for example. As a further clean-up, remove a few low-value "heartbeat" trace points in the connect path. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24xprtrdma: Pull up sometimesChuck Lever
On some platforms, DMA mapping part of a page is more costly than copying bytes. Restore the pull-up code and use that when we think it's going to be faster. The heuristic for now is to pull-up when the size of the RPC message body fits in the buffer underlying the head iovec. Indeed, not involving the I/O MMU can help the RPC/RDMA transport scale better for tiny I/Os across more RDMA devices. This is because interaction with the I/O MMU is eliminated, as is handling a Send completion, for each of these small I/Os. Without the explicit unmapping, the NIC no longer needs to do a costly internal TLB shoot down for buffers that are just a handful of bytes. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24xprtrdma: Move the rpcrdma_sendctx::sc_wr fieldChuck Lever
Clean up: This field is not needed in the Send completion handler, so it can be moved to struct rpcrdma_req to reduce the size of struct rpcrdma_sendctx, and to reduce the amount of memory that is sloshed between the sending process and the Send completion process. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24xprtrdma: Remove rpcrdma_sendctx::sc_xprtChuck Lever
Micro-optimization: Save eight bytes in a frequently allocated structure. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24xprtrdma: Manage MRs in context of a single connectionChuck Lever
MRs are now allocated on demand so we can safely throw them away on disconnect. This way an idle transport can disconnect and it won't pin hardware MR resources. Two additional changes: - Now that all MRs are destroyed on disconnect, there's no need to check during header marshaling if a req has MRs to recycle. Each req is sent only once per connection, and now rl_registered is guaranteed to be empty when rpcrdma_marshal_req is invoked. - Because MRs are now destroyed in a WQ_MEM_RECLAIM context, they also must be allocated in a WQ_MEM_RECLAIM context. This reduces the likelihood that device driver memory allocation will trigger memory reclaim during NFS writeback. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24xprtrdma: Fix MR list handlingChuck Lever
Close some holes introduced by commit 6dc6ec9e04c4 ("xprtrdma: Cache free MRs in each rpcrdma_req") that could result in list corruption. In addition, the result that is tabulated in @count is no longer used, so @count is removed. Fixes: 6dc6ec9e04c4 ("xprtrdma: Cache free MRs in each rpcrdma_req") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24xprtrdma: Close window between waking RPC senders and posting ReceivesChuck Lever
A recent clean up attempted to separate Receive handling and RPC Reply processing, in the name of clean layering. Unfortunately, we can't do this because the Receive Queue has to be refilled _after_ the most recent credit update from the responder is parsed from the transport header, but _before_ we wake up the next RPC sender. That is right in the middle of rpcrdma_reply_handler(). Usually this isn't a problem because current responder implementations don't vary their credit grant. The one exception is when a connection is established: the grant goes from one to a much larger number on the first Receive. The requester MUST post enough Receives right then so that any outstanding requests can be sent without risking RNR and connection loss. Fixes: 6ceea36890a0 ("xprtrdma: Refactor Receive accounting") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24xprtrdma: Initialize rb_credits in one placeChuck Lever
Clean up/code de-duplication. Nit: RPC_CWNDSHIFT is incorrect as the initial value for xprt->cwnd. This mistake does not appear to have operational consequences, since the cwnd value is replaced with a valid value upon the first Receive completion. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24xprtrdma: Connection becomes unstable after a reconnectChuck Lever
This is because xprt_request_get_cong() is allowing more than one RPC Call to be transmitted before the first Receive on the new connection. The first Receive fills the Receive Queue based on the server's credit grant. Before that Receive, there is only a single Receive WR posted because the client doesn't know the server's credit grant. Solution is to clear rq_cong on all outstanding rpc_rqsts when the the cwnd is reset. This is because an RPC/RDMA credit is good for one connection instance only. Fixes: 75891f502f5f ("SUNRPC: Support for congestion control ... ") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-09-26Merge tag 'nfs-for-5.4-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds
Pull NFS client updates from Anna Schumaker: "Stable bugfixes: - Dequeue the request from the receive queue while we're re-encoding # v4.20+ - Fix buffer handling of GSS MIC without slack # 5.1 Features: - Increase xprtrdma maximum transport header and slot table sizes - Add support for nfs4_call_sync() calls using a custom rpc_task_struct - Optimize the default readahead size - Enable pNFS filelayout LAYOUTGET on OPEN Other bugfixes and cleanups: - Fix possible null-pointer dereferences and memory leaks - Various NFS over RDMA cleanups - Various NFS over RDMA comment updates - Don't receive TCP data into a reset request buffer - Don't try to parse incomplete RPC messages - Fix congestion window race with disconnect - Clean up pNFS return-on-close error handling - Fixes for NFS4ERR_OLD_STATEID handling" * tag 'nfs-for-5.4-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (53 commits) pNFS/filelayout: enable LAYOUTGET on OPEN NFS: Optimise the default readahead size NFSv4: Handle NFS4ERR_OLD_STATEID in LOCKU NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE NFSv4: Fix OPEN_DOWNGRADE error handling pNFS: Handle NFS4ERR_OLD_STATEID on layoutreturn by bumping the state seqid NFSv4: Add a helper to increment stateid seqids NFSv4: Handle RPC level errors in LAYOUTRETURN NFSv4: Handle NFS4ERR_DELAY correctly in return-on-close NFSv4: Clean up pNFS return-on-close error handling pNFS: Ensure we do clear the return-on-close layout stateid on fatal errors NFS: remove unused check for negative dentry NFSv3: use nfs_add_or_obtain() to create and reference inodes NFS: Refactor nfs_instantiate() for dentry referencing callers SUNRPC: Fix congestion window race with disconnect SUNRPC: Don't try to parse incomplete RPC messages SUNRPC: Rename xdr_buf_read_netobj to xdr_buf_read_mic SUNRPC: Fix buffer handling of GSS MIC without slack SUNRPC: RPC level errors should always set task->tk_rpc_status SUNRPC: Don't receive TCP data into a request buffer that has been reset ...
2019-08-26xprtrdma: Send Queue size grows after a reconnectChuck Lever
Eli Dorfman reports that after a series of idle disconnects, an RPC/RDMA transport becomes unusable (rdma_create_qp returns -ENOMEM). Problem was tracked down to increasing Send Queue size after each reconnect. The rdma_create_qp() API does not promise to leave its @qp_init_attr parameter unaltered. In fact, some drivers do modify one or more of its fields. Thus our calls to rdma_create_qp must use a fresh copy of ib_qp_init_attr each time. This fix is appropriate for kernels dating back to late 2007, though it will have to be adapted, as the connect code has changed over the years. Reported-by: Eli Dorfman <eli@vastdata.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-26xprtrdma: Clear xprt->reestablish_timeout on closeChuck Lever
Ensure that the re-establishment delay does not grow exponentially on each good reconnect. This probably should have been part of commit 675dd90ad093 ("xprtrdma: Modernize ops->connect"). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-21xprtrdma: Optimize rpcrdma_post_recvs()Chuck Lever
Micro-optimization: In rpcrdma_post_recvs, since commit e340c2d6ef2a ("xprtrdma: Reduce the doorbell rate (Receive)"), the common case is to return without doing anything. Found with perf. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-21xprtrdma: Use an llist to manage free rpcrdma_repsChuck Lever
rpcrdma_rep objects are removed from their free list by only a single thread: the Receive completion handler. Thus that free list can be converted to an llist, where a single-threaded consumer and a multi-threaded producer (rpcrdma_buffer_put) can both access the llist without the need for any serialization. This eliminates spin lock contention between the Receive completion handler and rpcrdma_buffer_get, and makes the rep consumer wait- free. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-21xprtrdma: Remove rpcrdma_buffer::rb_mrlockChuck Lever
Clean up: Now that the free list is used sparingly, get rid of the separate spin lock protecting it. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-21xprtrdma: Cache free MRs in each rpcrdma_reqChuck Lever
Instead of a globally-contended MR free list, cache MRs in each rpcrdma_req as they are released. This means acquiring and releasing an MR will be lock-free in the common case, even outside the transport send lock. The original idea of per-rpcrdma_req MR free lists was suggested by Shirley Ma <shirley.ma@oracle.com> several years ago. I just now figured out how to make that idea work with on-demand MR allocation. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20xprtrdma: Ensure creating an MR does not trigger FS writebackChuck Lever
Probably would be good to also pass GFP flags to ib_alloc_mr. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20xprtrdma: Move rpcrdma_mr_get out of frwr_mapChuck Lever
Refactor: Retrieve an MR and handle error recovery entirely in rpc_rdma.c, as this is not a device-specific function. Note that since commit 89f90fe1ad8b ("SUNRPC: Allow calls to xprt_transmit() to drain the entire transmit queue"), the xprt_transmit function handles the cond_resched. The transport no longer has to do this itself. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20xprtrdma: Combine rpcrdma_mr_put and rpcrdma_mr_unmap_and_putChuck Lever
Clean up. There is only one remaining rpcrdma_mr_put call site, and it can be directly replaced with unmap_and_put because mr->mr_dir is set to DMA_NONE just before the call. Now all the call sites do a DMA unmap, and we can just rename mr_unmap_and_put to mr_put, which nicely matches mr_get. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20xprtrdma: Simplify rpcrdma_mr_popChuck Lever
Clean up: rpcrdma_mr_pop call sites check if the list is empty first. Let's replace the list_empty with less costly logic. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20xprtrdma: Rename rpcrdma_buffer::rb_allChuck Lever
Clean up: There are other "all" list heads. For code clarity distinguish this one as for use only for MRs by renaming it. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20xprtrdma: Rename CQE field in Receive trace pointsChuck Lever
Make the field name the same for all trace points that handle pointers to struct rpcrdma_rep. That makes it easy to grep for matching rep points in trace output. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20xprtrdma: Boost maximum transport header sizeChuck Lever
Although I haven't seen any performance results that justify it, I've received several complaints that NFS/RDMA no longer supports a maximum rsize and wsize of 1MB. These days it is somewhat smaller. To simplify the logic that determines whether a chunk list is necessary, the implementation uses a fixed maximum size of the transport header. Currently that maximum size is 256 bytes, one quarter of the default inline threshold size for RPC/RDMA v1. Since commit a78868497c2e ("xprtrdma: Reduce max_frwr_depth"), the size of chunks is also smaller to take advantage of inline page lists in device internal MR data structures. The combination of these two design choices has reduced the maximum NFS rsize and wsize that can be used for most RNIC/HCAs. Increasing the maximum transport header size and the maximum number of RDMA segments it can contain increases the negotiated maximum rsize/wsize on common RNIC/HCAs. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-05rdma: Enable ib_alloc_cq to spread work over a device's comp_vectorsChuck Lever
Send and Receive completion is handled on a single CPU selected at the time each Completion Queue is allocated. Typically this is when an initiator instantiates an RDMA transport, or when a target accepts an RDMA connection. Some ULPs cannot open a connection per CPU to spread completion workload across available CPUs and MSI vectors. For such ULPs, provide an API that allows the RDMA core to select a completion vector based on the device's complement of available comp_vecs. ULPs that invoke ib_alloc_cq() with only comp_vector 0 are converted to use the new API so that their completion workloads interfere less with each other. Suggested-by: HÃ¥kon Bugge <haakon.bugge@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Cc: <linux-cifs@vger.kernel.org> Cc: <v9fs-developer@lists.sourceforge.net> Link: https://lore.kernel.org/r/20190729171923.13428.52555.stgit@manet.1015granger.net Signed-off-by: Doug Ledford <dledford@redhat.com>