9p: Implement LOPEN

Implement 9p2000.L version of open(LOPEN) interface in 9p client.

For LOPEN, no need to convert the flags to and from 9p mode to VFS mode.

Synopsis:

    size[4] Tlopen tag[2] fid[4] mode[4]

    size[4] Rlopen tag[2] qid[13] iounit[4]

[Fix mode bit format - jvrao@linux.vnet.ibm.com]
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbegren <ericvh@gmail.com>

fs/9p/vfs_file.c

@@ -59,9 +59,13 @@ int v9fs_file_open(struct inode *inode, struct file *file)
 	struct p9_fid *fid;
 	int omode;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p \n", inode, file);
+	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file);
 	v9ses = v9fs_inode2v9ses(inode);
-	omode = v9fs_uflags2omode(file->f_flags, v9fs_proto_dotu(v9ses));
+	if (v9fs_proto_dotl(v9ses))
+		omode = file->f_flags;
+	else
+		omode = v9fs_uflags2omode(file->f_flags,
+					v9fs_proto_dotu(v9ses));
 	fid = file->private_data;
 	if (!fid) {
 		fid = v9fs_fid_clone(file->f_path.dentry);
@@ -73,11 +77,12 @@ int v9fs_file_open(struct inode *inode, struct file *file)
 			p9_client_clunk(fid);
 			return err;
 		}
-		if (omode & P9_OTRUNC) {
+		if (file->f_flags & O_TRUNC) {
 			i_size_write(inode, 0);
 			inode->i_blocks = 0;
 		}
-		if ((file->f_flags & O_APPEND) && (!v9fs_proto_dotu(v9ses)))
+		if ((file->f_flags & O_APPEND) &&
+			(!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)))
 			generic_file_llseek(file, 0, SEEK_END);
 	}
 

include/net/9p/9p.h

@@ -139,6 +139,8 @@ do { \
 enum p9_msg_t {
 	P9_TSTATFS = 8,
 	P9_RSTATFS,
+	P9_TLOPEN = 12,
+	P9_RLOPEN,
 	P9_TLCREATE = 14,
 	P9_RLCREATE,
 	P9_TSYMLINK = 16,

net/9p/client.c

@@ -1016,14 +1016,18 @@ int p9_client_open(struct p9_fid *fid, int mode)
 	struct p9_qid qid;
 	int iounit;
 
-	P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
-	err = 0;
 	clnt = fid->clnt;
+	P9_DPRINTK(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
+		p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
+	err = 0;
 
 	if (fid->mode != -1)
 		return -EINVAL;
 
-	req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
+	if (p9_is_proto_dotl(clnt))
+		req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
+	else
+		req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto error;
@@ -1035,10 +1039,9 @@ int p9_client_open(struct p9_fid *fid, int mode)
 		goto free_and_error;
 	}
 
-	P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
-				qid.type,
-				(unsigned long long)qid.path,
-				qid.version, iounit);
+	P9_DPRINTK(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
+		p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
+		(unsigned long long)qid.path, qid.version, iounit);
 
 	fid->mode = mode;
 	fid->iounit = iounit;