From b1027439dff844675f6c0df97a1b1d190791a699 Mon Sep 17 00:00:00 2001 From: Bryan Schumaker Date: Wed, 20 Jun 2012 14:35:28 -0400 Subject: [PATCH] NFS: Force the legacy idmapper to be single threaded It was initially coded under the assumption that there would only be one request at a time, so use a lock to enforce this requirement.. Signed-off-by: Bryan Schumaker CC: stable@vger.kernel.org [3.4+] Signed-off-by: Trond Myklebust --- fs/nfs/idmap.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c index b5b86a05059c..864c51e4b400 100644 --- a/fs/nfs/idmap.c +++ b/fs/nfs/idmap.c @@ -57,6 +57,11 @@ unsigned int nfs_idmap_cache_timeout = 600; static const struct cred *id_resolver_cache; static struct key_type key_type_id_resolver_legacy; +struct idmap { + struct rpc_pipe *idmap_pipe; + struct key_construction *idmap_key_cons; + struct mutex idmap_mutex; +}; /** * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields @@ -310,9 +315,11 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen, name, namelen, type, data, data_size, NULL); if (ret < 0) { + mutex_lock(&idmap->idmap_mutex); ret = nfs_idmap_request_key(&key_type_id_resolver_legacy, name, namelen, type, data, data_size, idmap); + mutex_unlock(&idmap->idmap_mutex); } return ret; } @@ -354,11 +361,6 @@ static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *typ /* idmap classic begins here */ module_param(nfs_idmap_cache_timeout, int, 0644); -struct idmap { - struct rpc_pipe *idmap_pipe; - struct key_construction *idmap_key_cons; -}; - enum { Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err }; @@ -469,6 +471,7 @@ nfs_idmap_new(struct nfs_client *clp) return error; } idmap->idmap_pipe = pipe; + mutex_init(&idmap->idmap_mutex); clp->cl_idmap = idmap; return 0;