Initial checkin

1 files changed, 101 insertions, 0 deletions

diff --git a/storeio/dev.h b/storeio/dev.h
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+++ b/storeio/dev.h
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+/* store `device' I/O
+
+   Copyright (C) 1995, 1996 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   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. */
+
+#ifndef __DEV_H__
+#define __DEV_H__
+
+#include <mach.h>
+#include <device/device.h>
+#include <rwlock.h>
+#include <hurd/store.h>
+
+/* Information about a kernel device.  */
+struct dev
+{
+  /* The device to which we're doing io.  */
+  struct store *store;
+
+  /* A bitmask corresponding to the part of an offset that lies within a
+     device block.  */
+  unsigned block_mask;
+
+  /* Lock to arbitrate I/O through this device.  Block I/O can occur in
+     parallel, and requires only a reader-lock.
+     Non-block I/O is always serialized, and requires a writer-lock.  */
+  struct rwlock io_lock;
+
+  /* Non-block I/O is buffered through BUF.  BUF_OFFS is the device offset
+     corresponding to the start of BUF (which holds one block); if it is -1,
+     then BUF is inactive.  */
+  char *buf;
+  off_t buf_offs;
+  int buf_dirty;
+
+  struct pager *pager;
+  struct mutex pager_lock;
+
+  /* The current owner of the open device.  For terminals, this affects
+     controlling terminal behavior (see term_become_ctty).  For all objects
+     this affects old-style async IO.  Negative values represent pgrps.  This
+     has nothing to do with the owner of a file (as returned by io_stat, and
+     as used for various permission checks by filesystems).  An owner of 0
+     indicates that there is no owner.  */
+  pid_t owner;
+};
+
+/* Returns a pointer to a new device structure in DEV for the device
+   NAME, with the given FLAGS.  If BLOCK_SIZE is non-zero, it should be the
+   desired block size, and must be a multiple of the device block size.
+   If an error occurs, the error code is returned, otherwise 0.  */
+error_t dev_open (struct store_parsed *name, int flags, struct dev **dev);
+
+/* Free DEV and any resources it consumes.  */
+void dev_close (struct dev *dev);
+
+/* Returns in MEMOBJ the port for a memory object backed by the storage on
+   DEV.  Returns 0 or the error code if an error occurred.  */
+error_t dev_get_memory_object(struct dev *dev, memory_object_t *memobj);
+
+/* Try to stop all paging activity on DEV, returning true if we were
+   successful.  If NOSYNC is true, then we won't write back any (kernel)
+   cached pages to the device.  */
+int dev_stop_paging (struct dev *dev, int nosync);
+
+/* Try and write out any pending writes to DEV.  If WAIT is true, will wait
+   for any paging activity to cease.  */
+error_t dev_sync (struct dev *dev, int wait);
+
+#ifdef MSG
+char *brep(vm_address_t buf, vm_size_t len);
+#endif
+
+/* Write LEN bytes from BUF to DEV, returning the amount actually written in
+   AMOUNT.  If successful, 0 is returned, otherwise an error code is
+   returned.  */
+error_t dev_write (struct dev *dev, off_t offs, char *buf, size_t len,
+		   size_t *amount);
+
+/* Read up to AMOUNT bytes from DEV, returned in BUF and LEN in the with the
+   usual mach memory result semantics.  If successful, 0 is returned,
+   otherwise an error code is returned.  */
+error_t dev_read (struct dev *dev, off_t offs, size_t amount,
+		  char **buf, size_t *len);
+
+#endif /* !__DEV_H__ */