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authorTrond Myklebust <trond.myklebust@primarydata.com>2014-03-02 22:03:12 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-03-23 21:38:16 -0700
commit40cb674a5a0cff49a46af150fb862229e545e908 (patch)
tree70ff507d94d2e04541ac9ea31ad04442b65ae6d3
parentcb67b44a0ddb8c1387ad2df82508b17b9b3f546d (diff)
NFS: Fix a delegation callback race
commit 755a48a7a4eb05b9c8424e3017d947b2961a60e0 upstream. The clean-up in commit 36281caa839f ended up removing a NULL pointer check that is needed in order to prevent an Oops in nfs_async_inode_return_delegation(). Reported-by: "Yan, Zheng" <zheng.z.yan@intel.com> Link: http://lkml.kernel.org/r/5313E9F6.2020405@intel.com Fixes: 36281caa839f (NFSv4: Further clean-ups of delegation stateid validation) Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/nfs/delegation.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 57db3244f4d..4b49a8c6cca 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -656,16 +656,19 @@ int nfs_async_inode_return_delegation(struct inode *inode,
rcu_read_lock();
delegation = rcu_dereference(NFS_I(inode)->delegation);
+ if (delegation == NULL)
+ goto out_enoent;
- if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) {
- rcu_read_unlock();
- return -ENOENT;
- }
+ if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
+ goto out_enoent;
nfs_mark_return_delegation(server, delegation);
rcu_read_unlock();
nfs_delegation_run_state_manager(clp);
return 0;
+out_enoent:
+ rcu_read_unlock();
+ return -ENOENT;
}
static struct inode *