[PATCH] RPC,NFS: new rpc_pipefs patch

 Currently rpc_mkdir/rpc_rmdir and rpc_mkpipe/mk_unlink have an API that's
 a little unfortunate.  They take a path relative to the rpc_pipefs root and
 thus need to perform a full lookup.  If you look at debugfs or usbfs they
 always store the dentry for directories they created and thus can pass in
 a dentry + single pathname component pair into their equivalents of the
 above functions.

 And in fact rpc_pipefs actually stores a dentry for all but one component so
 this change not only simplifies the core rpc_pipe code but also the callers.

 Unfortuntately this code path is only used by the NFS4 idmapper and
 AUTH_GSSAPI for which I don't have a test enviroment.  Could someone give
 it a spin?  It's the last bit needed before we can rework the
 lookup_hash API

 Signed-off-by: Christoph Hellwig <hch@lst.de>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 3 insertions, 7 deletions

diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index ffb8df91dc34..1d0a5bf0d264 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -66,7 +66,6 @@ struct idmap_hashtable {
 };
 
 struct idmap {
-        char                  idmap_path[48];
         struct dentry        *idmap_dentry;
         wait_queue_head_t     idmap_wq;
         struct idmap_msg      idmap_im;
@@ -102,11 +101,8 @@ nfs_idmap_new(struct nfs4_client *clp)
 
         memset(idmap, 0, sizeof(*idmap));
 
-        snprintf(idmap->idmap_path, sizeof(idmap->idmap_path),
-            "%s/idmap", clp->cl_rpcclient->cl_pathname);
-
-        idmap->idmap_dentry = rpc_mkpipe(idmap->idmap_path,
-            idmap, &idmap_upcall_ops, 0);
+        idmap->idmap_dentry = rpc_mkpipe(clp->cl_rpcclient->cl_dentry,
+                        "idmap", idmap, &idmap_upcall_ops, 0);
         if (IS_ERR(idmap->idmap_dentry)) {
                 kfree(idmap);
                 return;
@@ -128,7 +124,7 @@ nfs_idmap_delete(struct nfs4_client *clp)
 
         if (!idmap)
                 return;
-        rpc_unlink(idmap->idmap_path);
+        rpc_unlink(idmap->idmap_dentry);
         clp->cl_idmap = NULL;
         kfree(idmap);
 }