From: trondmy@kernel.org
To: linux-nfs@vger.kernel.org
Subject: [PATCH v3 02/11] SUNRPC: Close a race with transport setup and module put
Date: Tue, 10 Nov 2020 18:18:57 -0500 [thread overview]
Message-ID: <20201110231906.863446-3-trondmy@kernel.org> (raw)
In-Reply-To: <20201110231906.863446-2-trondmy@kernel.org>
From: Trond Myklebust <trond.myklebust@hammerspace.com>
After we've looked up the transport module, we need to ensure it can't
go away until we've finished running the transport setup code.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
net/sunrpc/xprt.c | 44 +++++++++++++++++++++++++++++++++-----------
1 file changed, 33 insertions(+), 11 deletions(-)
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 1660a4b03352..29de33ea53d6 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -157,6 +157,32 @@ xprt_class_release(const struct xprt_class *t)
module_put(t->owner);
}
+static const struct xprt_class *
+xprt_class_find_by_ident_locked(int ident)
+{
+ const struct xprt_class *t;
+
+ list_for_each_entry(t, &xprt_list, list) {
+ if (t->ident != ident)
+ continue;
+ if (!try_module_get(t->owner))
+ continue;
+ return t;
+ }
+ return NULL;
+}
+
+static const struct xprt_class *
+xprt_class_find_by_ident(int ident)
+{
+ const struct xprt_class *t;
+
+ spin_lock(&xprt_list_lock);
+ t = xprt_class_find_by_ident_locked(ident);
+ spin_unlock(&xprt_list_lock);
+ return t;
+}
+
static const struct xprt_class *
xprt_class_find_by_netid_locked(const char *netid)
{
@@ -1929,21 +1955,17 @@ static void xprt_init(struct rpc_xprt *xprt, struct net *net)
struct rpc_xprt *xprt_create_transport(struct xprt_create *args)
{
struct rpc_xprt *xprt;
- struct xprt_class *t;
+ const struct xprt_class *t;
- spin_lock(&xprt_list_lock);
- list_for_each_entry(t, &xprt_list, list) {
- if (t->ident == args->ident) {
- spin_unlock(&xprt_list_lock);
- goto found;
- }
+ t = xprt_class_find_by_ident(args->ident);
+ if (!t) {
+ dprintk("RPC: transport (%d) not supported\n", args->ident);
+ return ERR_PTR(-EIO);
}
- spin_unlock(&xprt_list_lock);
- dprintk("RPC: transport (%d) not supported\n", args->ident);
- return ERR_PTR(-EIO);
-found:
xprt = t->setup(args);
+ xprt_class_release(t);
+
if (IS_ERR(xprt))
goto out;
if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT)
--
2.28.0
next prev parent reply other threads:[~2020-11-10 23:29 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 23:18 [PATCH v3 00/11] Add RDMA support to the pNFS file+flexfiles data channels trondmy
2020-11-10 23:18 ` [PATCH v3 01/11] SUNRPC: xprt_load_transport() needs to support the netid "rdma6" trondmy
2020-11-10 23:18 ` trondmy [this message]
2020-11-10 23:18 ` [PATCH v3 03/11] SUNRPC: Add a helper to return the transport identifier given a netid trondmy
2020-11-10 23:18 ` [PATCH v3 04/11] NFS: Switch mount code to use xprt_find_transport_ident() trondmy
2020-11-10 23:19 ` [PATCH v3 05/11] SUNRPC: Remove unused function xprt_load_transport() trondmy
2020-11-10 23:19 ` [PATCH v3 06/11] NFSv4/pNFS: Use connections to a DS that are all of the same protocol family trondmy
2020-11-10 23:19 ` [PATCH v3 07/11] pNFS: Add helpers for allocation/free of struct nfs4_pnfs_ds_addr trondmy
2020-11-10 23:19 ` [PATCH v3 08/11] NFSv4/pNFS: Store the transport type in " trondmy
2020-11-10 23:19 ` [PATCH v3 09/11] pNFS/flexfiles: Fix up layoutstats reporting for non-TCP transports trondmy
2020-11-10 23:19 ` [PATCH v3 10/11] SUNRPC: Fix up open coded kmemdup_nul() trondmy
2020-11-10 23:19 ` [PATCH v3 11/11] pNFS: Clean up open coded xdr string decoding trondmy
2020-11-10 23:42 ` [PATCH v3 00/11] Add RDMA support to the pNFS file+flexfiles data channels Trond Myklebust
2020-11-13 12:48 ` Mkrtchyan, Tigran
2020-11-13 21:30 ` Mkrtchyan, Tigran
2020-11-13 22:45 ` Trond Myklebust
2020-11-13 23:46 ` Mkrtchyan, Tigran
2020-11-14 14:29 ` Trond Myklebust
2020-11-16 20:55 ` Mkrtchyan, Tigran
2020-11-17 14:50 ` Mkrtchyan, Tigran
2020-11-26 17:17 ` Mkrtchyan, Tigran
2020-12-01 10:59 ` Mkrtchyan, Tigran
2020-12-01 14:44 ` Mkrtchyan, Tigran
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