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| author |   Weston Andros Adamson <dros@netapp.com> | 2012-10-30 17:01:40 -0400 |
|---|---|---|
| committer |   Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-11-04 14:43:38 -0500 |
| commit | 168e4b39d1afb79a7e3ea6c3bb246b4c82c6bdb9 (patch) | |
| tree | f5b591952b85baf4ec3a9c7c7e29d0667724eda4 /net/sunrpc/clnt.c | |
| parent | Linux 3.7-rc4 (diff) | |
| download | linux-dev-168e4b39d1afb79a7e3ea6c3bb246b4c82c6bdb9.tar.xz linux-dev-168e4b39d1afb79a7e3ea6c3bb246b4c82c6bdb9.zip | |
SUNRPC: add WARN_ON_ONCE for potential deadlock
rpc_shutdown_client should never be called from a workqueue context.
If it is, it could deadlock looping forever trying to kill tasks that are
assigned to the same kworker thread (and will never run rpc_exit_task).
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net/sunrpc/clnt.c')
| -rw-r--r-- | net/sunrpc/clnt.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index cdc7564b4512..dd2532c10324 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -607,6 +607,13 @@ EXPORT_SYMBOL_GPL(rpc_killall_tasks); */ void rpc_shutdown_client(struct rpc_clnt *clnt) { + /* + * To avoid deadlock, never call rpc_shutdown_client from a + * workqueue context! + */ + WARN_ON_ONCE(current->flags & PF_WQ_WORKER); + might_sleep(); + dprintk_rcu("RPC: shutting down %s client for %s\n", clnt->cl_protname, rcu_dereference(clnt->cl_xprt)->servername); |