fs/9p: add 9P2000.L unlinkat operation

unlinkat - Remove a directory entry

size[4] Tunlinkat tag[2] dirfid[4] name[s] flag[4]
size[4] Runlinkat tag[2]

older Tremove have the below request format

size[4] Tremove tag[2] fid[4]

The remove message is used to remove a directory entry either file or directory
The remove opreation is actually a directory opertation and should ideally have
dirfid, if not we cannot represent the fid on server with anything other than
name. We will have to derive the directory name from fid in the Tremove request.

NOTE: The operation doesn't clunk the unlink fid.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/net/9p/client.c b/net/9p/client.c
index c4b77f38358..a953baa3624 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1303,6 +1303,29 @@ error:
 }
 EXPORT_SYMBOL(p9_client_remove);
 
+int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
+{
+	int err = 0;
+	struct p9_req_t *req;
+	struct p9_client *clnt;
+
+	P9_DPRINTK(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
+		   dfid->fid, name, flags);
+
+	clnt = dfid->clnt;
+	req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
+	if (IS_ERR(req)) {
+		err = PTR_ERR(req);
+		goto error;
+	}
+	P9_DPRINTK(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
+
+	p9_free_req(clnt, req);
+error:
+	return err;
+}
+EXPORT_SYMBOL(p9_client_unlinkat);
+
 int
 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
 								u32 count)