From 4beb345b37fc099e98f40d20c94da6c07654005c Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 30 Jul 2014 08:27:02 -0400 Subject: [PATCH] nfsd: Ensure struct nfs4_client is unhashed before we try to destroy it When we remove the client_mutex protection, we will need to ensure that it can't be found by other threads while we're destroying it. Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 43 +++++++++++++++++++++++++++++++++---------- 1 file changed, 33 insertions(+), 10 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 52ec47de1185..cb630db015b0 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1588,12 +1588,23 @@ free_client(struct nfs4_client *clp) } /* must be called under the client_lock */ -static inline void +static void unhash_client_locked(struct nfs4_client *clp) { + struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); struct nfsd4_session *ses; - list_del(&clp->cl_lru); + /* Mark the client as expired! */ + clp->cl_time = 0; + /* Make it invisible */ + if (!list_empty(&clp->cl_idhash)) { + list_del_init(&clp->cl_idhash); + if (test_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags)) + rb_erase(&clp->cl_namenode, &nn->conf_name_tree); + else + rb_erase(&clp->cl_namenode, &nn->unconf_name_tree); + } + list_del_init(&clp->cl_lru); spin_lock(&clp->cl_lock); list_for_each_entry(ses, &clp->cl_sessions, se_perclnt) list_del_init(&ses->se_hash); @@ -1601,7 +1612,17 @@ unhash_client_locked(struct nfs4_client *clp) } static void -destroy_client(struct nfs4_client *clp) +unhash_client(struct nfs4_client *clp) +{ + struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); + + spin_lock(&nn->client_lock); + unhash_client_locked(clp); + spin_unlock(&nn->client_lock); +} + +static void +__destroy_client(struct nfs4_client *clp) { struct nfs4_openowner *oo; struct nfs4_delegation *dp; @@ -1634,22 +1655,24 @@ destroy_client(struct nfs4_client *clp) nfsd4_shutdown_callback(clp); if (clp->cl_cb_conn.cb_xprt) svc_xprt_put(clp->cl_cb_conn.cb_xprt); - list_del(&clp->cl_idhash); - if (test_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags)) - rb_erase(&clp->cl_namenode, &nn->conf_name_tree); - else - rb_erase(&clp->cl_namenode, &nn->unconf_name_tree); spin_lock(&nn->client_lock); - unhash_client_locked(clp); WARN_ON_ONCE(atomic_read(&clp->cl_refcount)); free_client(clp); spin_unlock(&nn->client_lock); } +static void +destroy_client(struct nfs4_client *clp) +{ + unhash_client(clp); + __destroy_client(clp); +} + static void expire_client(struct nfs4_client *clp) { + unhash_client(clp); nfsd4_client_record_remove(clp); - destroy_client(clp); + __destroy_client(clp); } static void copy_verf(struct nfs4_client *target, nfs4_verifier *source) -- 2.20.1