1 files changed, 77 insertions, 0 deletions
diff --git a/libdiskfs/node-rdwr.c b/libdiskfs/node-rdwr.c
new file mode 100644
index 00000000..ed94df44
--- /dev/null
+++ b/libdiskfs/node-rdwr.c
@@ -0,0 +1,77 @@
+/*
+   Copyright (C) 1994, 1995, 1996 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "priv.h"
+
+/* Reading and writing of files. this is called by other filesystem
+   routines and handles extension of files automatically.  NP is the
+   node to be read or written, and must be locked.  DATA will be
+   written or filled.  OFF identifies where in thi fel the I/O is to
+   take place (-1 is not allowed).  AMT is the size of DATA and tells
+   how much to copy.  DIR is 1 for writing and 0 for reading.  CRED is
+   the user doing the access (only used to validate attempted file
+   extension).  For reads, *AMTREAD is filled with the amount actually
+   read.  */
+error_t
+diskfs_node_rdwr (struct node *np,
+		  char *data,
+		  off_t off,
+		  size_t amt,
+		  int dir,
+		  struct protid *cred,
+		  size_t *amtread)
+{
+  error_t err;
+
+  iohelp_get_conch (&np->conch);
+
+  if (dir)
+    while (off + amt > np->allocsize)
+      {
+	err = diskfs_grow (np, off + amt, cred);
+	if (err)
+	  return err;
+	if (np->filemod_reqs)
+	  diskfs_notice_filechange (np, FILE_CHANGED_EXTEND, 0, off + amt);
+      }
+
+  if (off + amt > np->dn_stat.st_size)
+    {
+      if (dir)
+	{
+	  np->dn_stat.st_size = off + amt;
+	  np->dn_set_ctime = 1;
+	}
+      else
+	amt = np->dn_stat.st_size - off;
+    }
+
+  if (amtread)
+    *amtread = amt;
+  else
+    amtread = &amt;
+  err = _diskfs_rdwr_internal (np, data, off, amtread, dir, 0);
+  if (*amtread && diskfs_synchronous)
+    {
+      if (dir)
+	diskfs_file_update (np, 1);
+      else
+	diskfs_node_update (np, 1);
+    }
+
+  return err;
+}