Fix ChangeLog

git-svn-id: svn://svn.debian.org/svn/parted/upstream/trunk@820 2d424fd7-7fe2-0310-af74-8bc65edeb173

1 files changed, 441 insertions, 0 deletions

diff --git a/libparted/device.c b/libparted/device.c
new file mode 100644
index 0000000..36729e0
--- /dev/null
+++ b/libparted/device.c
@@ -0,0 +1,441 @@
+/*
+    libparted - a library for manipulating disk partitions
+    Copyright (C) 1999 - 2001, 2005 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 of the License, 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+*/
+
+/** \file device.c */
+
+/**
+ * \addtogroup PedDevice
+ *
+ * \brief Device access.
+ * 
+ * When ped_device_probe_all() is called, libparted attempts to detect all
+ * devices.  It constructs a list which can be accessed with
+ * ped_device_get_next().
+ * 
+ * If you want to use a device that isn't on the list, use
+ * ped_device_get().  Also, there may be OS-specific constructors, for creating
+ * devices from file descriptors, stores, etc.  For example,
+ * ped_device_new_from_store().
+ *
+ * @{
+ */
+
+#define _GNU_SOURCE 1
+
+#include "config.h"
+
+#include <parted/parted.h>
+#include <parted/debug.h>
+
+#include <limits.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+static PedDevice*	devices; /* legal advice says: initialized to NULL,
+				    under section 6.7.8 part 10
+				    of ISO/EIC 9899:1999 */
+
+#ifndef HAVE_CANONICALIZE_FILE_NAME
+char *
+canonicalize_file_name (const char *name)
+{
+	char *	buf;
+	int	size;
+	char *	result;
+
+#ifdef PATH_MAX
+	size = PATH_MAX;
+#else
+	/* Bigger is better; realpath has no way todo bounds checking.  */
+	size = 4096;
+#endif
+
+	/* Just in case realpath does not NULL terminate the string
+	 * or it just fits in SIZE without a NULL terminator.  */
+	buf = calloc (size + 1, 1);
+	if (! buf) {
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	result = realpath (name, buf);
+	if (! result)
+		free (buf);
+
+	return result;
+}
+#endif /* !HAVE_CANONICALIZE_FILE_NAME */
+
+static void
+_device_register (PedDevice* dev)
+{
+	PedDevice*	walk;
+	for (walk = devices; walk && walk->next; walk = walk->next);
+	if (walk)
+		walk->next = dev;
+	else
+		devices = dev;
+	dev->next = NULL;
+}
+
+static void
+_device_unregister (PedDevice* dev)
+{
+	PedDevice*	walk;
+	PedDevice*	last = NULL;
+
+	for (walk = devices; walk != NULL; last = walk, walk = walk->next) {
+		if (walk == dev) break;
+	}
+
+	if (last)
+		last->next = dev->next;
+	else
+		devices = dev->next;
+}
+
+/**
+ * Returns the next device that was detected by ped_device_probe_all(), or
+ * calls to ped_device_get_next().
+ * If dev is NULL, returns the first device.
+ *
+ * \return NULL if dev is the last device.
+ */
+PedDevice*
+ped_device_get_next (const PedDevice* dev)
+{
+	if (dev)
+		return dev->next;
+	else
+		return devices;
+}
+
+void
+_ped_device_probe (const char* path)
+{
+	PedDevice*	dev;
+
+	PED_ASSERT (path != NULL, return);
+
+	ped_exception_fetch_all ();
+	dev = ped_device_get (path);
+	if (!dev)
+		ped_exception_catch ();
+	ped_exception_leave_all ();
+}
+
+/**
+ * Attempts to detect all devices.
+ */
+void
+ped_device_probe_all ()
+{
+	ped_architecture->dev_ops->probe_all ();
+}
+
+/**
+ * Close/free all devices.
+ * Called by ped_done(), so you do not need to worry about it.
+ */
+void
+ped_device_free_all ()
+{
+	while (devices)
+		ped_device_destroy (devices);
+}
+
+/**
+ * Gets the device "name", where name is usually the block device, e.g.
+ * /dev/sdb.  If the device wasn't detected with ped_device_probe_all(),
+ * an attempt will be made to detect it again.  If it is found, it will
+ * be added to the list.
+ */
+PedDevice*
+ped_device_get (const char* path)
+{
+	PedDevice*	walk;
+	char*		normal_path;
+
+	PED_ASSERT (path != NULL, return NULL);
+	normal_path = canonicalize_file_name (path);
+	if (!normal_path)
+		/* Well, maybe it is just that the file does not exist.
+		 * Try it anyway.  */
+		normal_path = strdup (path);
+	if (!normal_path)
+		return NULL;
+
+	for (walk = devices; walk != NULL; walk = walk->next) {
+		if (!strcmp (walk->path, normal_path)) {
+			ped_free (normal_path);
+			return walk;
+		}
+	}
+
+	walk = ped_architecture->dev_ops->_new (normal_path);
+	ped_free (normal_path);
+	if (!walk)
+		return NULL;
+	_device_register (walk);
+	return walk;
+}
+
+/**
+ * Destroys a device and removes it from the device list, and frees
+ * all resources associated with the device (all resources allocated
+ * when the device was created).
+ */
+void
+ped_device_destroy (PedDevice* dev)
+{
+	_device_unregister (dev);
+
+	while (dev->open_count) {
+		if (!ped_device_close (dev))
+			break;
+	}
+
+	ped_architecture->dev_ops->destroy (dev);
+}
+
+int
+ped_device_is_busy (PedDevice* dev)
+{
+	return ped_architecture->dev_ops->is_busy (dev);
+}
+
+/**
+ * Attempt to open a device to allow use of read, write and sync functions.
+ *
+ * The meaning of "open" is architecture-dependent.  Apart from requesting
+ * access to the device from the operating system, it does things like flushing
+ * caches.
+ * \note May allocate resources.  Any resources allocated here will
+ * be freed by a final ped_device_close().  (ped_device_open() may be
+ * called multiple times -- it's a ref-count-like mechanism)
+ *
+ * \return zero on failure
+ */
+int
+ped_device_open (PedDevice* dev)
+{
+	int	status;
+
+	PED_ASSERT (dev != NULL, return 0);
+	PED_ASSERT (!dev->external_mode, return 0);
+
+	if (dev->open_count)
+		status = ped_architecture->dev_ops->refresh_open (dev);
+	else
+		status = ped_architecture->dev_ops->open (dev);
+	if (status)
+		dev->open_count++;
+	return status;
+}
+
+/**
+ * Close dev.
+ * If this is the final close, then resources allocated by
+ * ped_device_open() are freed.
+ *
+ * \return zero on failure
+ */
+int
+ped_device_close (PedDevice* dev)
+{
+	PED_ASSERT (dev != NULL, return 0);
+	PED_ASSERT (!dev->external_mode, return 0);
+	PED_ASSERT (dev->open_count > 0, return 0);
+
+	if (--dev->open_count)
+		return ped_architecture->dev_ops->refresh_close (dev);
+	else
+		return ped_architecture->dev_ops->close (dev);
+}
+
+/**
+ * Begins external access mode.  External access mode allows you to
+ * safely do IO on the device.  If a PedDevice is open, then you should
+ * not do any IO on that device, e.g. by calling an external program
+ * like e2fsck, unless you put it in external access mode.  You should
+ * not use any libparted commands that do IO to a device, e.g.
+ * ped_file_system_{open|resize|copy}, ped_disk_{read|write}), while
+ * a device is in external access mode.
+ * Also, you should not ped_device_close() a device, while it is
+ * in external access mode.
+ * Note: ped_device_begin_external_access_mode() does things like
+ * tell the kernel to flush its caches.
+ *
+ * Close a device while pretending it is still open.
+ * This is useful for temporarily suspending libparted access to the device
+ * in order for an external program to access it.
+ * (Running external programs while the device is open can cause cache
+ * coherency problems.)
+ *
+ * In particular, this function keeps track of dev->open_count, so that
+ * reference counting isn't screwed up.
+ *
+ * \return zero on failure.
+ */
+int
+ped_device_begin_external_access (PedDevice* dev)
+{
+	PED_ASSERT (dev != NULL, return 0);
+	PED_ASSERT (!dev->external_mode, return 0);
+
+	dev->external_mode = 1;
+	if (dev->open_count)
+		return ped_architecture->dev_ops->close (dev);
+	else
+		return 1;
+}
+
+/**
+ * \brief Complementary function to ped_device_begin_external_access.
+ *
+ * \note does things like tell the kernel to flush the device's cache.
+ *
+ * \return zero on failure.
+ */
+int
+ped_device_end_external_access (PedDevice* dev)
+{
+	PED_ASSERT (dev != NULL, return 0);
+	PED_ASSERT (dev->external_mode, return 0);
+
+	dev->external_mode = 0;
+	if (dev->open_count)
+		return ped_architecture->dev_ops->open (dev);
+	else
+		return 1;
+}
+
+/**
+ * \internal Read count sectors from dev into buffer, beginning with sector
+ * start.
+ * 
+ * \return zero on failure.
+ */
+int
+ped_device_read (const PedDevice* dev, void* buffer, PedSector start,
+		 PedSector count)
+{
+	PED_ASSERT (dev != NULL, return 0);
+	PED_ASSERT (buffer != NULL, return 0);
+	PED_ASSERT (!dev->external_mode, return 0);
+	PED_ASSERT (dev->open_count > 0, return 0);
+
+	return (ped_architecture->dev_ops->read) (dev, buffer, start, count);
+}
+
+/**
+ * \internal Write count sectors from buffer to dev, starting at sector
+ * start.
+ * 
+ * \return zero on failure.
+ *
+ * \sa PedDevice::sector_size
+ * \sa PedDevice::phys_sector_size
+ */
+int
+ped_device_write (PedDevice* dev, const void* buffer, PedSector start,
+		  PedSector count)
+{
+	PED_ASSERT (dev != NULL, return 0);
+	PED_ASSERT (buffer != NULL, return 0);
+	PED_ASSERT (!dev->external_mode, return 0);
+	PED_ASSERT (dev->open_count > 0, return 0);
+
+	return (ped_architecture->dev_ops->write) (dev, buffer, start, count);
+}
+
+PedSector
+ped_device_check (PedDevice* dev, void* buffer, PedSector start,
+		  PedSector count)
+{
+	PED_ASSERT (dev != NULL, return 0);
+	PED_ASSERT (!dev->external_mode, return 0);
+	PED_ASSERT (dev->open_count > 0, return 0);
+
+	return (ped_architecture->dev_ops->check) (dev, buffer, start, count);
+}
+
+/**
+ * \internal Flushes all write-behind caches that might be holding up
+ * writes.
+ * It is slow because it guarantees cache coherency among all relevant caches.
+ *
+ * \return zero on failure
+ */
+int
+ped_device_sync (PedDevice* dev)
+{
+	PED_ASSERT (dev != NULL, return 0);
+	PED_ASSERT (!dev->external_mode, return 0);
+	PED_ASSERT (dev->open_count > 0, return 0);
+
+	return ped_architecture->dev_ops->sync (dev);
+}
+
+/**
+ * \internal Flushes all write-behind caches that might be holding writes.
+ * \warning Does NOT ensure cache coherency with other caches.
+ * If you need cache coherency, use ped_device_sync() instead.
+ *
+ * \return zero on failure
+ */
+int
+ped_device_sync_fast (PedDevice* dev)
+{
+	PED_ASSERT (dev != NULL, return 0);
+	PED_ASSERT (!dev->external_mode, return 0);
+	PED_ASSERT (dev->open_count > 0, return 0);
+
+	return ped_architecture->dev_ops->sync_fast (dev);
+}
+
+/**
+ * Get a constraint that represents hardware requirements on alignment and
+ * geometry.
+ * This is, for example, important for media that have a physical sector
+ * size that is a multiple of the logical sector size.
+ *
+ * \warning This function is experimental for physical sector sizes not equal to
+ *          2^9.
+ */
+PedConstraint*
+ped_device_get_constraint (PedDevice* dev)
+{
+        int multiplier = dev->phys_sector_size / dev->sector_size;
+
+        PedAlignment* start_align = ped_alignment_new (multiplier, multiplier);
+        
+        PedConstraint* c = ped_constraint_new (
+                                start_align, ped_alignment_any,
+                                ped_geometry_new (dev, 0, dev->length),
+                                ped_geometry_new (dev, 0, dev->length),
+                                1, dev->length);
+
+        return c;
+}
+
+/** @} */
+