[PATCH 2/2] NFSv3: Add emulation of the lookupp() operation

From: trondmy@kernel.org
To: Daire Byrne <daire@dneg.com>
Cc: linux-nfs@vger.kernel.org
Subject: [PATCH 2/2] NFSv3: Add emulation of the lookupp() operation
Date: Mon, 19 Oct 2020 13:53:30 -0400	[thread overview]
Message-ID: <20201019175330.595894-3-trondmy@kernel.org> (raw)
In-Reply-To: <20201019175330.595894-2-trondmy@kernel.org>

From: Trond Myklebust <trond.myklebust@hammerspace.com>

In order to use the open_by_filehandle() operations on NFSv3, we need
to be able to emulate lookupp() so that nfs_get_parent() can be used
to convert disconnected dentries into connected ones.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/nfs3proc.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index a6a222435e9b..63d1979933f3 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -155,7 +155,8 @@ nfs3_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
 
 static int
 __nfs3_proc_lookup(struct inode *dir, const char *name, size_t len,
-		   struct nfs_fh *fhandle, struct nfs_fattr *fattr)
+		   struct nfs_fh *fhandle, struct nfs_fattr *fattr,
+		   unsigned short task_flags)
 {
 	struct nfs3_diropargs	arg = {
 		.fh		= NFS_FH(dir),
@@ -172,7 +173,6 @@ __nfs3_proc_lookup(struct inode *dir, const char *name, size_t len,
 		.rpc_resp	= &res,
 	};
 	int			status;
-	unsigned short task_flags = 0;
 
 	res.dir_attr = nfs_alloc_fattr();
 	if (res.dir_attr == NULL)
@@ -197,13 +197,25 @@ nfs3_proc_lookup(struct inode *dir, struct dentry *dentry,
 		 struct nfs_fh *fhandle, struct nfs_fattr *fattr,
 		 struct nfs4_label *label)
 {
+	unsigned short task_flags = 0;
+
 	/* Is this is an attribute revalidation, subject to softreval? */
 	if (nfs_lookup_is_soft_revalidate(dentry))
 		task_flags |= RPC_TASK_TIMEOUT;
 
 	dprintk("NFS call  lookup %pd2\n", dentry);
 	return __nfs3_proc_lookup(dir, dentry->d_name.name,
-				  dentry->d_name.len, fhandle, fattr);
+				  dentry->d_name.len, fhandle, fattr,
+				  task_flags);
+}
+
+static int nfs3_proc_lookupp(struct inode *inode, struct nfs_fh *fhandle,
+			     struct nfs_fattr *fattr, struct nfs4_label *label)
+{
+	const char *dotdot = "..";
+	const size_t len = sizeof(dotdot) - 1;
+
+	return __nfs3_proc_lookup(inode, dotdot, len, fhandle, fattr, 0);
 }
 
 static int nfs3_proc_access(struct inode *inode, struct nfs_access_entry *entry)
@@ -1012,6 +1024,7 @@ const struct nfs_rpc_ops nfs_v3_clientops = {
 	.getattr	= nfs3_proc_getattr,
 	.setattr	= nfs3_proc_setattr,
 	.lookup		= nfs3_proc_lookup,
+	.lookupp	= nfs3_proc_lookupp,
 	.access		= nfs3_proc_access,
 	.readlink	= nfs3_proc_readlink,
 	.create		= nfs3_proc_create,
-- 
2.26.2

