NFS: move credential expiry tracking out of SUNRPC into NFS.

NFS needs to know when a credential is about to expire so that
it can modify write-back behaviour to finish the write inside the
expiry time.
It currently uses functions in SUNRPC code which make use of a
fairly complex callback scheme and flags in the generic credientials.

As I am working to discard the generic credentials, this has to change.

This patch moves the logic into NFS, in part by finding and caching
the low-level credential in the open_context.  We then make direct
cred-api calls on that.

This makes the code much simpler and removes a dependency on generic
rpc credentials.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 5b1eee4952b7..aea015743172 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -962,6 +962,7 @@ struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
         nfs_sb_active(dentry->d_sb);
         ctx->dentry = dget(dentry);
         ctx->cred = cred;
+        ctx->ll_cred = NULL;
         ctx->state = NULL;
         ctx->mode = f_mode;
         ctx->flags = 0;
@@ -1001,6 +1002,7 @@ static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
                 put_rpccred(ctx->cred);
         dput(ctx->dentry);
         nfs_sb_deactive(sb);
+        put_rpccred(ctx->ll_cred);
         kfree(ctx->mdsthreshold);
         kfree_rcu(ctx, rcu_head);
 }