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authorTrond Myklebust <Trond.Myklebust@netapp.com>2012-05-23 13:26:10 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2012-05-23 15:24:59 -0400
commit54ac471c83aff6b1e068eb8029c797dc68a76e89 (patch)
tree3311a74fc6f5cdbedbe4e1da9bbbbaf6671050a2 /fs/nfs
parent4697bd5e9419348ef9fa9b55cefe4355ad9d3d01 (diff)
NFS: Add memory barriers to the nfs_client->cl_cons_state initialisation
Ensure that a process that uses the nfs_client->cl_cons_state test for whether the initialisation process is finished does not read stale data. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/client.c5
-rw-r--r--fs/nfs/idmap.c1
-rw-r--r--fs/nfs/nfs4proc.c1
3 files changed, 7 insertions, 0 deletions
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index d35664287e14..a50bdfbbc429 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -459,6 +459,8 @@ static bool nfs4_cb_match_client(const struct sockaddr *addr,
clp->cl_cons_state == NFS_CS_SESSION_INITING))
return false;
+ smp_rmb();
+
/* Match the version and minorversion */
if (clp->rpc_ops->version != 4 ||
clp->cl_minorversion != minorversion)
@@ -539,6 +541,8 @@ nfs_found_client(const struct nfs_client_initdata *cl_init,
return ERR_PTR(error);
}
+ smp_rmb();
+
BUG_ON(clp->cl_cons_state != NFS_CS_READY);
dprintk("<-- %s found nfs_client %p for %s\n",
@@ -597,6 +601,7 @@ nfs_get_client(const struct nfs_client_initdata *cl_init,
*/
void nfs_mark_client_ready(struct nfs_client *clp, int state)
{
+ smp_wmb();
clp->cl_cons_state = state;
wake_up_all(&nfs_client_active_wq);
}
diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index 861be75eb165..b5b86a05059c 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -548,6 +548,7 @@ restart:
/* Skip nfs_clients that failed to initialise */
if (clp->cl_cons_state < 0)
continue;
+ smp_rmb();
if (clp->rpc_ops != &nfs_v4_clientops)
continue;
cl_dentry = clp->cl_idmap->idmap_pipe->dentry;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index c856298def7d..8f39bb3ca1b3 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5621,6 +5621,7 @@ static int nfs41_check_session_ready(struct nfs_client *clp)
}
if (clp->cl_cons_state < NFS_CS_READY)
return -EPROTONOSUPPORT;
+ smp_rmb();
return 0;
}