nfsd: Detect unhashed stids in nfsd4_verify_open_stid()
authorTrond Myklebust <trond.myklebust@primarydata.com>
Fri, 12 Jan 2018 22:42:30 +0000 (17:42 -0500)
committerJ. Bruce Fields <bfields@redhat.com>
Mon, 5 Feb 2018 22:13:16 +0000 (17:13 -0500)
commit4f1764172a0aa7395d12b96cae640ca1438c5085
treea29f5c6339d179a7975c76c221290c85137a193b
parentd0945caafcccac9d8f4d78f99e0eac9e60386381
nfsd: Detect unhashed stids in nfsd4_verify_open_stid()

The state of the stid is guaranteed by 2 locks:
- The nfs4_client 'cl_lock' spinlock
- The nfs4_ol_stateid 'st_mutex' mutex

so it is quite possible for the stid to be unhashed after lookup,
but before calling nfsd4_lock_ol_stateid(). So we do need to check
for a zero value for 'sc_type' in nfsd4_verify_open_stid().

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Checuk Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Fixes: 659aefb68eca "nfsd: Ensure we don't recognise lock stateids..."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
fs/nfsd/nfs4state.c