23.05.2012 21:32, Trond Myklebust написал:
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@xxxxxxxxxx>
---
fs/nfs/client.c | 5 +++++
fs/nfs/idmap.c | 1 +
2 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index e6070ea..4be85f9 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -456,6 +456,8 @@ 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)
@@ -587,6 +589,8 @@ found_client:
return ERR_PTR(error);
}
+ smp_rmb();
+
BUG_ON(clp->cl_cons_state != NFS_CS_READY);
dprintk("--> nfs_get_client() = %p [share]\n", clp);
@@ -598,6 +602,7 @@ found_client:
*/
void nfs_mark_client_ready(struct nfs_client *clp, int state)
{
+ smp_wmb();
BTW, why barrier is before assignment?
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 6ca949b..7d4e8dd 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;
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
