NFS: Fix the locking in nfs4_callback_getattr
The delegation is protected by RCU now, so we need to replace the
nfsi->rwsem protection with an rcu protected section.
Reported-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 7445dd0..930d10f 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -37,8 +37,8 @@
if (inode == NULL)
goto out_putclient;
nfsi = NFS_I(inode);
- down_read(&nfsi->rwsem);
- delegation = nfsi->delegation;
+ rcu_read_lock();
+ delegation = rcu_dereference(nfsi->delegation);
if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
goto out_iput;
res->size = i_size_read(inode);
@@ -53,7 +53,7 @@
args->bitmap[1];
res->status = 0;
out_iput:
- up_read(&nfsi->rwsem);
+ rcu_read_unlock();
iput(inode);
out_putclient:
nfs_put_client(clp);