From 7e86845a0346efc95fddaa97ce5cd6a8bda8c71c Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 4 Jun 2024 15:45:24 -0400 Subject: rpcrdma: Implement generic device removal Commit e87a911fed07 ("nvme-rdma: use ib_client API to detect device removal") explains the benefits of handling device removal outside of the CM event handler. Sketch in an IB device removal notification mechanism that can be used by both the client and server side RPC-over-RDMA transport implementations. Suggested-by: Sagi Grimberg Signed-off-by: Chuck Lever Reviewed-by: Sagi Grimberg Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/Makefile | 2 +- net/sunrpc/xprtrdma/ib_client.c | 181 ++++++++++++++++++++++++++++++++++++++++ net/sunrpc/xprtrdma/module.c | 18 +++- 3 files changed, 197 insertions(+), 4 deletions(-) create mode 100644 net/sunrpc/xprtrdma/ib_client.c (limited to 'net/sunrpc') diff --git a/net/sunrpc/xprtrdma/Makefile b/net/sunrpc/xprtrdma/Makefile index 55b21bae866d..3232aa23cdb4 100644 --- a/net/sunrpc/xprtrdma/Makefile +++ b/net/sunrpc/xprtrdma/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_SUNRPC_XPRT_RDMA) += rpcrdma.o -rpcrdma-y := transport.o rpc_rdma.o verbs.o frwr_ops.o \ +rpcrdma-y := transport.o rpc_rdma.o verbs.o frwr_ops.o ib_client.o \ svc_rdma.o svc_rdma_backchannel.o svc_rdma_transport.o \ svc_rdma_sendto.o svc_rdma_recvfrom.o svc_rdma_rw.o \ svc_rdma_pcl.o module.o diff --git a/net/sunrpc/xprtrdma/ib_client.c b/net/sunrpc/xprtrdma/ib_client.c new file mode 100644 index 000000000000..a938c19c3490 --- /dev/null +++ b/net/sunrpc/xprtrdma/ib_client.c @@ -0,0 +1,181 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause +/* + * Copyright (c) 2024 Oracle. All rights reserved. + */ + +/* #include +#include */ +#include +#include +#include +#include + +#include +#include + +#include "xprt_rdma.h" +#include + +/* Per-ib_device private data for rpcrdma */ +struct rpcrdma_device { + struct kref rd_kref; + unsigned long rd_flags; + struct ib_device *rd_device; + struct xarray rd_xa; + struct completion rd_done; +}; + +#define RPCRDMA_RD_F_REMOVING (0) + +static struct ib_client rpcrdma_ib_client; + +/* + * Listeners have no associated device, so we never register them. + * Note that ib_get_client_data() does not check if @device is + * NULL for us. + */ +static struct rpcrdma_device *rpcrdma_get_client_data(struct ib_device *device) +{ + if (!device) + return NULL; + return ib_get_client_data(device, &rpcrdma_ib_client); +} + +/** + * rpcrdma_rn_register - register to get device removal notifications + * @device: device to monitor + * @rn: notification object that wishes to be notified + * @done: callback to notify caller of device removal + * + * Returns zero on success. The callback in rn_done is guaranteed + * to be invoked when the device is removed, unless this notification + * is unregistered first. + * + * On failure, a negative errno is returned. + */ +int rpcrdma_rn_register(struct ib_device *device, + struct rpcrdma_notification *rn, + void (*done)(struct rpcrdma_notification *rn)) +{ + struct rpcrdma_device *rd = rpcrdma_get_client_data(device); + + if (!rd || test_bit(RPCRDMA_RD_F_REMOVING, &rd->rd_flags)) + return -ENETUNREACH; + + kref_get(&rd->rd_kref); + if (xa_alloc(&rd->rd_xa, &rn->rn_index, rn, xa_limit_32b, GFP_KERNEL) < 0) + return -ENOMEM; + rn->rn_done = done; + return 0; +} + +static void rpcrdma_rn_release(struct kref *kref) +{ + struct rpcrdma_device *rd = container_of(kref, struct rpcrdma_device, + rd_kref); + + trace_rpcrdma_client_completion(rd->rd_device); + complete(&rd->rd_done); +} + +/** + * rpcrdma_rn_unregister - stop device removal notifications + * @device: monitored device + * @rn: notification object that no longer wishes to be notified + */ +void rpcrdma_rn_unregister(struct ib_device *device, + struct rpcrdma_notification *rn) +{ + struct rpcrdma_device *rd = rpcrdma_get_client_data(device); + + if (!rd) + return; + + xa_erase(&rd->rd_xa, rn->rn_index); + kref_put(&rd->rd_kref, rpcrdma_rn_release); +} + +/** + * rpcrdma_add_one - ib_client device insertion callback + * @device: device about to be inserted + * + * Returns zero on success. xprtrdma private data has been allocated + * for this device. On failure, a negative errno is returned. + */ +static int rpcrdma_add_one(struct ib_device *device) +{ + struct rpcrdma_device *rd; + + rd = kzalloc(sizeof(*rd), GFP_KERNEL); + if (!rd) + return -ENOMEM; + + kref_init(&rd->rd_kref); + xa_init_flags(&rd->rd_xa, XA_FLAGS_ALLOC1); + rd->rd_device = device; + init_completion(&rd->rd_done); + ib_set_client_data(device, &rpcrdma_ib_client, rd); + + trace_rpcrdma_client_add_one(device); + return 0; +} + +/** + * rpcrdma_remove_one - ib_client device removal callback + * @device: device about to be removed + * @client_data: this module's private per-device data + * + * Upon return, all transports associated with @device have divested + * themselves from IB hardware resources. + */ +static void rpcrdma_remove_one(struct ib_device *device, + void *client_data) +{ + struct rpcrdma_device *rd = client_data; + struct rpcrdma_notification *rn; + unsigned long index; + + trace_rpcrdma_client_remove_one(device); + + set_bit(RPCRDMA_RD_F_REMOVING, &rd->rd_flags); + xa_for_each(&rd->rd_xa, index, rn) + rn->rn_done(rn); + + /* + * Wait only if there are still outstanding notification + * registrants for this device. + */ + if (!refcount_dec_and_test(&rd->rd_kref.refcount)) { + trace_rpcrdma_client_wait_on(device); + wait_for_completion(&rd->rd_done); + } + + trace_rpcrdma_client_remove_one_done(device); + kfree(rd); +} + +static struct ib_client rpcrdma_ib_client = { + .name = "rpcrdma", + .add = rpcrdma_add_one, + .remove = rpcrdma_remove_one, +}; + +/** + * rpcrdma_ib_client_unregister - unregister ib_client for xprtrdma + * + * cel: watch for orphaned rpcrdma_device objects on module unload + */ +void rpcrdma_ib_client_unregister(void) +{ + ib_unregister_client(&rpcrdma_ib_client); +} + +/** + * rpcrdma_ib_client_register - register ib_client for rpcrdma + * + * Returns zero on success, or a negative errno. + */ +int rpcrdma_ib_client_register(void) +{ + return ib_register_client(&rpcrdma_ib_client); +} diff --git a/net/sunrpc/xprtrdma/module.c b/net/sunrpc/xprtrdma/module.c index 45c5b41ac8dc..697f571d4c01 100644 --- a/net/sunrpc/xprtrdma/module.c +++ b/net/sunrpc/xprtrdma/module.c @@ -11,6 +11,7 @@ #include #include #include +#include #include @@ -30,21 +31,32 @@ static void __exit rpc_rdma_cleanup(void) { xprt_rdma_cleanup(); svc_rdma_cleanup(); + rpcrdma_ib_client_unregister(); } static int __init rpc_rdma_init(void) { int rc; + rc = rpcrdma_ib_client_register(); + if (rc) + goto out_rc; + rc = svc_rdma_init(); if (rc) - goto out; + goto out_ib_client; rc = xprt_rdma_init(); if (rc) - svc_rdma_cleanup(); + goto out_svc_rdma; -out: + return 0; + +out_svc_rdma: + svc_rdma_cleanup(); +out_ib_client: + rpcrdma_ib_client_unregister(); +out_rc: return rc; } -- cgit v1.2.3