o dm_activate/dm_close

driver/device-mapper/device-mapper.h

@@ -28,34 +28,29 @@
 #ifndef DEVICE_MAPPER_H
 #define DEVICE_MAPPER_H
 
+#ifdef __KERNEL__
+
 #include <linux/major.h>
 
 /* FIXME: steal LVM's devices for now */
 #define DM_BLK_MAJOR LVM_BLK_MAJOR
-#define DM_CTL_MAJOR LVM_CHAR_MAJOR
-
-#define DM_NAME_LEN 64
 
+struct mapped_device;
 typedef unsigned int offset_t;
 
-struct dm_request {
-	int minor;		/* -1 indicates no preference */
-	char name[DM_NAME_LEN];
-};
-
-#define	MAPPED_DEVICE_CREATE _IOWR(DM_CTL_MAJOR, 0, struct dm_request)
-#define MAPPED_DEVICE_DESTROY _IOW(DM_CTL_MAJOR, 1, struct dm_request)
-
-#ifdef __KERNEL__
-typedef int (*dm_ctr_fn)(offset_t b, offset_t e,
+typedef int (*dm_ctr_fn)(offset_t b, offset_t e, struct mapped_device *md,
 			 const char *context, void **result);
 typedef void (*dm_dtr_fn)(void *c);
 typedef int (*dm_map_fn)(struct buffer_head *bh, void *context);
 
 int register_map_target(const char *name, dm_ctr_fn ctr, dm_dtr_fn dtr,
 			dm_map_fn map);
-#endif
 
+/* contructors should call this to make sure any destination devices
+   are handled correctly (ie. opened/closed) */
+int dm_add_device(struct mapped_device *md, kdev_t dev);
+
+#endif
 #endif
 
 /*

driver/device-mapper/dm-target.c

@@ -82,7 +82,8 @@ int register_map_target(const char *name, dm_ctr_fn ctr,
  *
  * 'linear' target maps a linear range of a device
  */
-int _io_err_ctr(offset_t b, offset_t e, const char *context, void **result)
+int _io_err_ctr(offset_t b, offset_t e, struct mapped_device *md,
+		const char *context, void **result)
 {
 	/* this takes no arguments */
 	*result = 0;
@@ -106,7 +107,8 @@ struct linear_c {
 	int offset;		/* FIXME: we need a signed offset type */
 };
 
-int _linear_ctr(offset_t b, offset_t e, const char *context, void **result)
+int _linear_ctr(offset_t b, offset_t e, struct mapped_device *md,
+		const char *context, void **result)
 {
 	/* context string should be of the form:
 	 *  <major> <minor> <offset>
@@ -138,7 +140,10 @@ int _linear_ctr(offset_t b, offset_t e, const char *context, void **result)
 	lc->dev = MKDEV(major, minor);
 	lc->offset = start - b;
 
-	/* FIXME: we should open the PV */
+	if (!dm_add_device(md, lc->dev)) {
+		kfree(lc);
+		return 0;
+	}
 
 	*result = lc;
 	return 1;

driver/device-mapper/dm.c

@@ -97,10 +97,8 @@
  * implement most LVM features (omitting striped volumes and
  * snapshots).
  *
- * At the moment this driver has a temporary ioctl interface, but I will
- * move this to a read/write interface on either a /proc file or a
- * char device.  This will allow scripts to simply cat a text mapping
- * table in order to set up a volume.
+ * The driver is controlled through a /proc interface...
+ * FIXME: finish
  *
  * At the moment the table assumes 32 bit keys (sectors), the move to
  * 64 bits will involve no interface changes, since the tables will be
@@ -439,7 +437,7 @@ struct mapped_device *dm_find_minor(int minor)
 	return md;
 }
 
-static int dm_create(int minor, const char *name)
+int dm_create(int minor, const char *name)
 {
 	struct mapped_device *md;
 
@@ -462,10 +460,11 @@ static int dm_create(int minor, const char *name)
 	up_write(&_dev_lock);
 }
 
-static int dm_remove(const char *name, int minor)
+int dm_remove(const char *name, int minor)
 {
 	struct mapped_device *md;
 	int minor;
+	struct dev_list *d, *n;
 
 	down_write(&_dev_lock);
 	if (!(md = __find_dev(name))) {
@@ -474,6 +473,10 @@ static int dm_remove(const char *name, int minor)
 	}
 
 	dm_clear_table(md);
+	for (d = md->devices; d; d = n) {
+		n = d->next;
+		kfree(d);
+	}
 
 	minor = MINOR(md->dev);
 	_free_dev(md);
@@ -482,6 +485,57 @@ static int dm_remove(const char *name, int minor)
 	return 0;
 }
 
+int dm_add_device(struct mapped_device *md, kdev_t dev)
+{
+	struct dev_list *d = kmalloc(sizeof(*d));
+
+	if (!d)
+		return 0;
+
+	d->dev = dev;
+	d->next = md->devices;
+	md->devices = d;
+	return 1;
+}
+
+int dm_activate(struct mapped_device *md)
+{
+	int ret;
+	struct dev_list *d, *od;
+
+	if (is_active(md))
+		return 1;
+
+	/* open all the devices */
+	for (d = md->devices; d; d = d->next)
+		if ((ret = _open_dev(d->dev)))
+			goto bad;
+
+	return 0;
+
+ bad:
+
+	od = d;
+	for (d = md->devices; d != od; d = d->next)
+		_close_dev(d->dev);
+
+	return ret;
+}
+
+void dm_suspend(struct mapped_device *md)
+{
+	struct dev_list *d;
+	if (!is_active(md))
+		return;
+
+	/* close all the devices */
+	for (d = md->devices; d; d = d->next)
+		_close_dev(d->dev));
+
+	set_active(md, 0);
+}
+
+
 /*
  * module hooks
  */

driver/device-mapper/dm.h

@@ -39,6 +39,11 @@ enum {
 	DM_ACTIVE,
 };
 
+struct dev_list {
+	kdev_t dev;
+	struct dev_list *next;
+};
+
 struct mapped_device {
 	kdev_t dev;
 	char name[DM_NAME_LEN];
@@ -59,6 +64,9 @@ struct mapped_device {
 
 	/* used by dm-fs.c */
 	devfs_handle_t devfs_entry;
+
+	/* a list of devices used by this md */
+	struct dev_list *devices;
 };
 
 /* dm-target.c */
@@ -74,13 +82,12 @@ struct target {
 struct target *dm_get_target(const char *name);
 int dm_std_targets(void);
 
-
 /* dm.c */
 struct mapped_device *dm_find_name(const char *name);
 struct mapped_device *dm_find_minor(int minor);
 
-void dm_suspend(struct mapped_device *md);
 void dm_activate(struct mapped_device *md);
+void dm_suspend(struct mapped_device *md);
 
 /* dm-table.c */
 int dm_start_table(struct mapped_device *md);