9p: move readn meta-function from client to fs layer

There are a couple of methods in the client code which aren't actually
wire operations.  To keep things organized cleaner, these operations are
being moved to the fs layer.

This patch moves the readn meta-function (which executes multiple wire
reads until a buffer is full) to the fs layer.

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

1 files changed, 53 insertions, 4 deletions

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 3819a19..4d6d765 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -120,23 +120,72 @@ static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
 }
 
 /**
- * v9fs_file_read - read from a file
+ * v9fs_file_readn - read from a file
  * @filp: file pointer to read
  * @data: data buffer to read data into
+ * @udata: user data buffer to read data into
  * @count: size of buffer
  * @offset: offset at which to read data
  *
  */
+
+ssize_t
+v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
+	       u64 offset)
+{
+	int n, total;
+	struct p9_fid *fid = filp->private_data;
+
+	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
+					(long long unsigned) offset, count);
+
+	n = 0;
+	total = 0;
+	do {
+		n = p9_client_read(fid, data, udata, offset, count);
+		if (n <= 0)
+			break;
+
+		if (data)
+			data += n;
+		if (udata)
+			udata += n;
+
+		offset += n;
+		count -= n;
+		total += n;
+	} while (count > 0 && n == (fid->clnt->msize - P9_IOHDRSZ));
+
+	if (n < 0)
+		total = n;
+
+	return total;
+}
+
+/**
+ * v9fs_file_read - read from a file
+ * @filp: file pointer to read
+ * @udata: user data buffer to read data into
+ * @count: size of buffer
+ * @offset: offset at which to read data
+ *
+ */
+
 static ssize_t
-v9fs_file_read(struct file *filp, char __user * data, size_t count,
+v9fs_file_read(struct file *filp, char __user *udata, size_t count,
 	       loff_t * offset)
 {
 	int ret;
 	struct p9_fid *fid;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "\n");
+	P9_DPRINTK(P9_DEBUG_VFS, "count %d offset %lld\n", count, *offset);
 	fid = filp->private_data;
-	ret = p9_client_read(fid, NULL, data, *offset, count);
+
+	if (count > (fid->clnt->msize - P9_IOHDRSZ))
+		ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
+	else
+		ret = p9_client_read(fid, NULL, udata, *offset, count);
+
 	if (ret > 0)
 		*offset += ret;