* fhandler.cc (fhandler_base::open): Always add GENERIC_READ access

        when opening raw disk devices.
        * fhandler_floppy.cc (fhandler_dev_floppy::lseek): Implement bytewise
        access.
        * fhandler_raw.cc (fhandler_dev_raw::open): Always open raw disk device
        binary.
        (fhandler_dev_raw::raw_write): Don't drop read buffer content when
        writing after read.

4 files changed, 101 insertions, 6 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 838f25372..b0db4a5a9 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,14 @@
+Mon Feb  5 17:00:00 2001  Corinna Vinschen <corinna@vinschen.de>
+
+	* fhandler.cc (fhandler_base::open): Always add GENERIC_READ access
+	when opening raw disk devices.
+	* fhandler_floppy.cc (fhandler_dev_floppy::lseek): Implement bytewise
+	access.
+	* fhandler_raw.cc (fhandler_dev_raw::open): Always open raw disk device
+	binary.
+	(fhandler_dev_raw::raw_write): Don't drop read buffer content when
+	writing after read.
+
 Mon Feb  5 13:30:00 2001  Corinna Vinschen <corinna@vinschen.de>
 
 	* mmap.cc (mmap_record::fixup_map): New method to duplicate
diff --git a/winsup/cygwin/fhandler.cc b/winsup/cygwin/fhandler.cc
index f6779614a..1c9e600a8 100644
--- a/winsup/cygwin/fhandler.cc
+++ b/winsup/cygwin/fhandler.cc
@@ -324,6 +324,12 @@ fhandler_base::open (int flags, mode_t mode)
       access_ = GENERIC_READ | GENERIC_WRITE;
     }
 
+  /* Allow reliable lseek on disk devices. */
+  if (get_device () == FH_FLOPPY)
+    {
+      access_ |= GENERIC_READ;
+    }
+
   /* FIXME: O_EXCL handling?  */
 
   if ((flags & O_TRUNC) && ((flags & O_ACCMODE) != O_RDONLY))
diff --git a/winsup/cygwin/fhandler_floppy.cc b/winsup/cygwin/fhandler_floppy.cc
index ec48c91f3..a767443b9 100644
--- a/winsup/cygwin/fhandler_floppy.cc
+++ b/winsup/cygwin/fhandler_floppy.cc
@@ -15,6 +15,7 @@ details. */
 #include <errno.h>
 #include <unistd.h>
 #include "fhandler.h"
+#include "cygerrno.h"
 
 /**********************************************************************/
 /* fhandler_dev_floppy */
@@ -78,9 +79,81 @@ fhandler_dev_floppy::close (void)
 off_t
 fhandler_dev_floppy::lseek (off_t offset, int whence)
 {
-  /* FIXME: Need to implement better. */
-  offset = (offset / 512) * 512;
-  return fhandler_base::lseek (offset, whence);
+  int ret;
+  DWORD off;
+  char buf[512];
+
+  if (whence == SEEK_SET)
+    {
+      if (offset < 0)
+        {
+	  set_errno (EINVAL);
+	  return -1;
+	}
+
+      /* Invalidate buffer. */
+      ret = writebuf ();
+      if (ret)
+	return ret;
+      devbufstart = devbufend = 0;
+
+      off = (offset / 512) * 512;
+
+      if (SetFilePointer (get_handle (), off, NULL, FILE_BEGIN)
+          == INVALID_SET_FILE_POINTER)
+        {
+	  __seterrno ();
+	  return -1;
+	}
+      return raw_read (buf, offset - off);
+    }
+  else if (whence == SEEK_CUR)
+    {
+      DWORD low;
+      LONG high = 0;
+
+      low = SetFilePointer (get_handle (), 0, &high, FILE_CURRENT);
+      if (low == INVALID_SET_FILE_POINTER && GetLastError ())
+	{
+	  __seterrno ();
+	  return -1;
+	}
+      long long cur = (long long) high << 32 + low;
+      if (is_writing)
+	cur += devbufend - devbufstart;
+      else
+	cur -= devbufend - devbufstart;
+      
+      /* Invalidate buffer. */
+      ret = writebuf ();
+      if (ret)
+	return ret;
+      devbufstart = devbufend = 0;
+
+      cur += offset;
+      if (cur < 0)
+	{
+	  set_errno (EINVAL);
+	  return -1;
+	}
+
+      long long set = (cur / 512) * 512;
+      high = set >> 32;
+      low = set & 0xffffffff;
+
+      off = cur - set;
+
+      low = SetFilePointer (get_handle (), low, &high, FILE_BEGIN);
+      if (low == INVALID_SET_FILE_POINTER && GetLastError ())
+	{
+	  __seterrno ();
+	  return -1;
+	}
+      return raw_read (buf, off);
+    }
+  /* SEEK_END is not supported on raw disk devices. */
+  set_errno (EINVAL);
+  return -1;
 }
 
 int
diff --git a/winsup/cygwin/fhandler_raw.cc b/winsup/cygwin/fhandler_raw.cc
index 70cf8284c..d8ecf61ea 100644
--- a/winsup/cygwin/fhandler_raw.cc
+++ b/winsup/cygwin/fhandler_raw.cc
@@ -135,8 +135,10 @@ fhandler_dev_raw::open (const char *path, int flags, mode_t)
 
   set_name (path, real_path.get_win32 ());
 
-  /* Always open a raw device existing */
-  ret = fhandler_base::open (path, flags & ~(O_CREAT | O_TRUNC));
+  /* Always open a raw device existing and binary. */
+  flags &= ~(O_CREAT | O_TRUNC);
+  flags |= O_BINARY;
+  ret = fhandler_base::open (path, flags);
   if (ret)
     {
       if (devbufsiz > 1L)
@@ -334,7 +336,10 @@ fhandler_dev_raw::raw_write (const void *ptr, size_t len)
     }
 
   if (!is_writing)
-    devbufstart = devbufend = 0;
+    {
+      devbufend = devbufstart;
+      devbufstart = 0;
+    }
   is_writing = 1;
 
   if (devbuf)