commit 26c0c75e69265961e891ed80b38fb62a548ab371
author J. Bruce Fields <bfields@citi.umich.edu> Sat Apr 24 15:35:43 2010 -0400
committer J. Bruce Fields <bfields@citi.umich.edu> Mon May 03 08:32:31 2010 -0400
tree 1ecbc767a1b2ad3e8f25d88e918076806d8c2eb1
parent e0c8233622cbd49d171bc57b60e725f2fb748750

nfsd4: fix unlikely race in session replay case

In the replay case, the

	renew_client(session->se_client);

happens after we've droppped the sessionid_lock, and without holding a
reference on the session; so there's nothing preventing the session
being freed before we get here.

Thanks to Benny Halevy for catching a bug in an earlier version of this
patch.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Benny Halevy <bhalevy@panasas.com>

fs/nfsd/nfs4proc.c

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index e147dbc..61282f8 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1027,6 +1027,7 @@
 	resp->rqstp = rqstp;
 	resp->cstate.minorversion = args->minorversion;
 	resp->cstate.replay_owner = NULL;
+	resp->cstate.session = NULL;
 	fh_init(&resp->cstate.current_fh, NFS4_FHSIZE);
 	fh_init(&resp->cstate.save_fh, NFS4_FHSIZE);
 	/* Use the deferral mechanism only for NFSv4.0 compounds */