From 48d66b9749e39e0d4cc37d635df3f18906af38a6 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 3 Mar 2015 20:28:59 -0500 Subject: NFSv4: Fix a race in NFSv4.1 server trunking discovery We do not want to allow a race with another NFS mount to cause nfs41_walk_client_list() to establish a lease on our nfs_client before we're done checking for trunking. Signed-off-by: Trond Myklebust --- fs/nfs/client.c | 2 +- fs/nfs/nfs4client.c | 9 ++++----- fs/nfs/nfs4state.c | 14 ++++++++++++-- 3 files changed, 17 insertions(+), 8 deletions(-) (limited to 'fs') diff --git a/fs/nfs/client.c b/fs/nfs/client.c index f9f4845db989..19874151e95c 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -433,7 +433,7 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat static bool nfs_client_init_is_complete(const struct nfs_client *clp) { - return clp->cl_cons_state != NFS_CS_INITING; + return clp->cl_cons_state <= NFS_CS_READY; } int nfs_wait_client_init_complete(const struct nfs_client *clp) diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c index 8646af9b11d2..86d6214ea022 100644 --- a/fs/nfs/nfs4client.c +++ b/fs/nfs/nfs4client.c @@ -621,6 +621,9 @@ int nfs41_walk_client_list(struct nfs_client *new, spin_lock(&nn->nfs_client_lock); list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) { + if (pos == new) + goto found; + if (pos->rpc_ops != new->rpc_ops) continue; @@ -639,10 +642,6 @@ int nfs41_walk_client_list(struct nfs_client *new, prev = pos; status = nfs_wait_client_init_complete(pos); - if (pos->cl_cons_state == NFS_CS_SESSION_INITING) { - nfs4_schedule_lease_recovery(pos); - status = nfs4_wait_clnt_recover(pos); - } spin_lock(&nn->nfs_client_lock); if (status < 0) break; @@ -668,7 +667,7 @@ int nfs41_walk_client_list(struct nfs_client *new, */ if (!nfs4_match_client_owner_id(pos, new)) continue; - +found: atomic_inc(&pos->cl_count); *result = pos; status = 0; diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 5ad908e9ce9c..d8b43f0e08fc 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -346,9 +346,19 @@ int nfs41_discover_server_trunking(struct nfs_client *clp, status = nfs4_proc_exchange_id(clp, cred); if (status != NFS4_OK) return status; - set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state); - return nfs41_walk_client_list(clp, result, cred); + status = nfs41_walk_client_list(clp, result, cred); + if (status < 0) + return status; + if (clp != *result) + return 0; + + set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state); + nfs4_schedule_state_manager(clp); + status = nfs_wait_client_init_complete(clp); + if (status < 0) + nfs_put_client(clp); + return status; } #endif /* CONFIG_NFS_V4_1 */ -- cgit v1.2.3