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

[safe/jmp/linux-2.6] / fs / 9p / vfs_file.c

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 3819a19..4d6d765 100644 (file)
--- 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;