9p: move dirread to fs layer

Currently reading a directory is implemented in the client code.
This function is not actually a wire operation, but a meta operation 
which calls read operations and processes the results.

This patch moves this functionality to the fs layer and calls component
wire operations instead of constructing their packets.  This provides a 
cleaner separation and will help when we reorganize the client functions
and protocol processing methods.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>




diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index e298fe1..d7d0ac5 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -69,32 +69,54 @@
 static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 {
 	int over;
+	struct p9_stat st;
+	int err;
 	struct p9_fid *fid;
-	struct v9fs_session_info *v9ses;
-	struct inode *inode;
-	struct p9_stat *st;
+	int buflen;
+	char *statbuf;
+	int n, i = 0;
 
 	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
-	inode = filp->f_path.dentry->d_inode;
-	v9ses = v9fs_inode2v9ses(inode);
 	fid = filp->private_data;
-	while ((st = p9_client_dirread(fid, filp->f_pos)) != NULL) {
-		if (IS_ERR(st))
-			return PTR_ERR(st);
 
-		over = filldir(dirent, st->name.str, st->name.len, filp->f_pos,
-			v9fs_qid2ino(&st->qid), dt_type(st));
+	buflen = fid->clnt->msize - P9_IOHDRSZ;
+	statbuf = kmalloc(buflen, GFP_KERNEL);
+	if (!statbuf)
+		return -ENOMEM;
 
-		if (over)
+	while (1) {
+		err = v9fs_file_readn(filp, statbuf, NULL, fid->rdir_fpos,
+									buflen);
+		if (err <= 0)
 			break;
 
-		filp->f_pos += st->size;
-		kfree(st);
-		st = NULL;
+		n = err;
+		while (i < n) {
+			err = p9_deserialize_stat(statbuf + i, buflen-i, &st,
+							fid->clnt->dotu);
+			if (!err) {
+				err = -EIO;
+				goto free_and_exit;
+			}
+
+			i += err;
+			fid->rdir_fpos += err;
+
+			over = filldir(dirent, st.name.str, st.name.len,
+			    filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
+
+			filp->f_pos += st.size;
+
+			if (over) {
+				err = 0;
+				goto free_and_exit;
+			}
+		}
 	}
 
-	kfree(st);
-	return 0;
+free_and_exit:
+	kfree(statbuf);
+	return err;
 }