nfs: have ff_layout_get_ds_cred take a reference to the cred
In later patches, we're going to want to allow the creds to be updated
when we get a new layout with updated creds. Have this function take
a reference to the cred that is later put once the call has been
dispatched.
Also, prepare for this change by ensuring we follow RCU rules when
getting a reference to the cred as well.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
index a0dbf94..baee229 100644
--- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c
+++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
@@ -338,6 +338,25 @@
return 0;
}
+static struct rpc_cred *
+ff_layout_get_mirror_cred(struct nfs4_ff_layout_mirror *mirror, u32 iomode)
+{
+ struct rpc_cred *cred, **pcred;
+
+ pcred = &mirror->cred;
+
+ rcu_read_lock();
+ do {
+ cred = rcu_dereference(*pcred);
+ if (!cred)
+ break;
+
+ cred = get_rpccred_rcu(cred);
+ } while(!cred);
+ rcu_read_unlock();
+ return cred;
+}
+
struct nfs_fh *
nfs4_ff_layout_select_ds_fh(struct pnfs_layout_segment *lseg, u32 mirror_idx)
{
@@ -435,10 +454,13 @@
struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx);
struct rpc_cred *cred;
- if (mirror && mirror->cred)
- cred = mirror->cred;
- else
- cred = mdscred;
+ if (mirror) {
+ cred = ff_layout_get_mirror_cred(mirror, lseg->pls_range.iomode);
+ if (!cred)
+ cred = get_rpccred(mdscred);
+ } else {
+ cred = get_rpccred(mdscred);
+ }
return cred;
}