o Split activate.c into a high level (remaining in activate.c) and low level (ll-activate.[hc]) API.

o  Creation of a device from an lv now lives in activate-lv.c

lib/Makefile.in

@@ -9,8 +9,10 @@ top_srcdir = @top_srcdir@
 VPATH = @srcdir@
 
 SOURCES=\
+	activate/activate-lv.c \
 	activate/activate.c \
 	activate/fs.c \
+	activate/ll-activate.c \
 	activate/names.c \
 	config/config.c \
 	datastruct/bitset.c \

lib/activate/activate-lv.c

@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2002 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#include "ll-activate.h"
+#include "lvm-string.h"
+#include "log.h"
+
+#include <libdevmapper.h>
+#include <linux/kdev_t.h>
+
+
+/*
+ * Emit a target for a given segment.
+ * FIXME: tidy this function.
+ */
+static int _emit_target(struct dm_task *dmt, struct stripe_segment *seg)
+{
+	char params[1024];
+	uint64_t esize = seg->lv->vg->extent_size;
+	uint32_t s, stripes = seg->stripes;
+	int w = 0, tw = 0, error = 0;
+	const char *no_space =
+		"Insufficient space to write target parameters.";
+	char *filler = "/dev/ioerror";
+	char *target;
+
+	if (stripes == 1) {
+		if (!seg->area[0].pv) {
+			target = "error";
+			error = 1;
+		}
+		else
+			target = "linear";
+	}
+
+	if (stripes > 1) {
+		target = "striped";
+		tw = lvm_snprintf(params, sizeof(params), "%u %u ",
+			      stripes, seg->stripe_size);
+
+		if (tw < 0) {
+			log_err(no_space);
+			return 0;
+		}
+
+		w = tw;
+	}
+
+	if (!error) {
+		for (s = 0; s < stripes; s++, w += tw) {
+			if (!seg->area[s].pv)
+				tw = lvm_snprintf(
+					params + w, sizeof(params) - w,
+			      		"%s 0%s", filler,
+			      		s == (stripes - 1) ? "" : " ");
+			else
+				tw = lvm_snprintf(
+					params + w, sizeof(params) - w,
+			      		"%s %" PRIu64 "%s",
+					dev_name(seg->area[s].pv->dev),
+			      		(seg->area[s].pv->pe_start +
+			         	 (esize * seg->area[s].pe)),
+			      		s == (stripes - 1) ? "" : " ");
+
+			if (tw < 0) {
+				log_err(no_space);
+				return 0;
+			}
+		}
+	}
+
+	log_very_verbose("Adding target: %" PRIu64 " %" PRIu64 " %s %s",
+		   esize * seg->le, esize * seg->len,
+		   target, params);
+
+	if (!dm_task_add_target(dmt, esize * seg->le, esize * seg->len,
+				target, params)) {
+		stack;
+		return 0;
+	}
+
+	return 1;
+}
+
+int _load(const char *name, struct logical_volume *lv, int task)
+{
+	int r = 0;
+	struct dm_task *dmt;
+	struct list *segh;
+	struct stripe_segment *seg;
+
+	log_very_verbose("Generating devmapper parameters for %s", lv->name);
+	if (!(dmt = setup_dm_task(name, task))) {
+		stack;
+		return 0;
+	}
+
+	list_iterate(segh, &lv->segments) {
+		seg = list_item(segh, struct stripe_segment);
+		if (!_emit_target(dmt, seg)) {
+			log_error("Unable to activate logical volume '%s'",
+				lv->name);
+			goto out;
+		}
+	}
+
+	if (!((lv->status & LVM_WRITE) && (lv->vg->status & LVM_WRITE))) {
+	    	if (!dm_task_set_ro(dmt)) {
+			log_error("Failed to set %s read-only during "
+				  "activation.", lv->name);
+			goto out;
+		} else
+			log_very_verbose("Activating %s read-only", lv->name);
+	}
+
+	if (lv->minor >= 0) {
+		if (!dm_task_set_minor(dmt, MINOR(lv->minor))) {
+			log_error("Failed to set minor number for %s to %d "
+				  "during activation.", lv->name, lv->minor);
+			goto out;
+		} else
+			log_very_verbose("Set minor number for %s to %d.",
+					 lv->name, lv->minor);
+	}
+
+	if (!(r = dm_task_run(dmt)))
+		stack;
+
+	log_verbose("Logical volume %s%s activated", lv->name,
+		    r == 1 ? "" : " not");
+
+ out:
+	dm_task_destroy(dmt);
+	return r;
+}
+
+int device_create_lv(const char *name, struct logical_volume *lv, int minor)
+{
+	log_very_verbose("Activating %s", name);
+	return _load(name, lv, DM_DEVICE_CREATE);
+}
+
+int device_reload_lv(const char *name, struct logical_volume *lv)
+{
+	log_very_verbose("Reactivating %s", name);
+	return _load(name, lv, DM_DEVICE_RELOAD);
+}

lib/activate/activate.c

@@ -6,6 +6,7 @@
 
 #include "metadata.h"
 #include "activate.h"
+#include "ll-activate.h"
 #include "display.h"
 #include "log.h"
 #include "fs.h"
@@ -13,8 +14,8 @@
 #include "names.h"
 
 #include <limits.h>
-#include <linux/kdev_t.h>
 
+#define _skip(fmt, args...) log_very_verbose("Skipping: " fmt , ## args)
 
 int library_version(char *version, size_t size)
 {
@@ -23,33 +24,6 @@ int library_version(char *version, size_t size)
 	return 1;
 }
 
-static struct dm_task *_setup_task_with_name(struct logical_volume *lv,
-					     const char *lv_name,
-				   	     int task)
-{
-	char name[128];
-	struct dm_task *dmt;
-
-	if (!(dmt = dm_task_create(task))) {
-		stack;
-		return NULL;
-	}
-
-	if (!build_dm_name(name, sizeof(name), lv->vg->name, lv_name)) {
-		stack;
-		return NULL;
-	}
-
-	dm_task_set_name(dmt, name);
-
-	return dmt;
-}
-
-static struct dm_task *_setup_task(struct logical_volume *lv, int task)
-{
-	return _setup_task_with_name(lv, lv->name, task);
-}
-
 int driver_version(char *version, size_t size)
 {
 	int r = 0;
@@ -75,48 +49,176 @@ int driver_version(char *version, size_t size)
 	return r;
 }
 
+static int _query(struct logical_volume *lv, int (*fn)(const char *))
+{
+	char buffer[128];
+
+	if (!build_dm_name(buffer, sizeof(buffer), "",
+			   lv->vg->name, lv->name)) {
+		stack;
+		return -1;
+	}
+
+	return fn(buffer);
+}
+
+int lv_active(struct logical_volume *lv)
+{
+	return _query(lv, device_active);
+}
+
+int lv_suspended(struct logical_volume *lv)
+{
+	return _query(lv, device_suspended);
+}
+
+int lv_open_count(struct logical_volume *lv)
+{
+	return _query(lv, device_open_count);
+}
+
 int lv_info(struct logical_volume *lv, struct dm_info *info)
 {
-	int r = 0;
+	char buffer[128];
-	struct dm_task *dmt;
 
-	log_very_verbose("Getting device info for %s", lv->name);
+	if (!build_dm_name(buffer, sizeof(buffer), "",
-	if (!(dmt = _setup_task(lv, DM_DEVICE_INFO))) {
+			   lv->vg->name, lv->name)) {
+		stack;
+		return -1;
+	}
+
+	return device_info(buffer, info);
+}
+
+
+int lv_activate(struct logical_volume *lv)
+{
+	char buffer[128];
+
+	if (test_mode()) {
+		_skip("Activation of '%s'.", lv->name);
+		return 0;
+	}
+
+	if (!build_dm_name(buffer, sizeof(buffer), "",
+			   lv->vg->name, lv->name)) {
 		stack;
 		return 0;
 	}
 
-	if (!dm_task_run(dmt)) {
+	if (!device_create_lv(buffer, lv, lv->minor)) {
 		stack;
-		goto out;
+		return 0;
 	}
 
-	if (!dm_task_get_info(dmt, info)) {
+	if (!fs_add_lv(lv, lv->minor)) {
 		stack;
-		goto out;
+		return 0;
+	}
+
+	return 1;
+}
+
+int lv_reactivate(struct logical_volume *lv)
+{
+	int r;
+	char buffer[128];
+
+	if (test_mode()) {
+		_skip("Reactivation of '%s'.", lv->name);
+		return 0;
+	}
+
+	if (!build_dm_name(buffer, sizeof(buffer), "",
+			   lv->vg->name, lv->name)) {
+		stack;
+		return 0;
+	}
+
+	if (!device_suspended(buffer) && !device_suspend(buffer)) {
+		stack;
+		return 0;
+	}
+
+	r = device_reload_lv(buffer, lv);
+
+	if (!device_resume(buffer)) {
+		stack;
+		return 0;
 	}
-	r = 1;
 
- out:
-	dm_task_destroy(dmt);
 	return r;
 }
 
+int lv_deactivate(struct logical_volume *lv)
+{
+	char buffer[128];
+
+	log_very_verbose("Deactivating %s", lv->name);
+	if (test_mode()) {
+		_skip("Deactivating '%s'.", lv->name);
+		return 0;
+	}
+
+	if (!build_dm_name(buffer, sizeof(buffer), "",
+			   lv->vg->name, lv->name)) {
+		stack;
+		return 0;
+	}
+
+	if (!device_deactivate(buffer)) {
+		stack;
+		return 0;
+	}
+
+	fs_del_lv(lv);
+
+	return 1;
+}
+
+int lv_suspend(struct logical_volume *lv)
+{
+	char buffer[128];
+
+	log_very_verbose("Suspending %s", lv->name);
+	if (test_mode()) {
+		_skip("Suspending '%s'.", lv->name);
+		return 0;
+	}
+
+	if (!build_dm_name(buffer, sizeof(buffer), "",
+			   lv->vg->name, lv->name)) {
+		stack;
+		return 0;
+	}
+
+	if (!device_suspend(buffer)) {
+		stack;
+		return 0;
+	}
+
+	fs_del_lv(lv);
+
+	return 1;
+}
+
 int lv_rename(const char *old_name, struct logical_volume *lv)
 {
 	int r = 0;
 	char new_name[PATH_MAX];
 	struct dm_task *dmt;
 
-	if (test_mode())
+	if (test_mode()) {
+		_skip("Rename '%s' to '%s'.", old_name, lv->name);
 		return 0;
+	}
 
-	if (!(dmt = _setup_task_with_name(lv, old_name, DM_DEVICE_RENAME))) {
+	if (!(dmt = setup_dm_task(old_name, DM_DEVICE_RENAME))) {
 		stack;
 		return 0;
 	}
 
-	if (!build_dm_name(new_name, sizeof(new_name),
+	if (!build_dm_name(new_name, sizeof(new_name), "",
 			   lv->vg->name, lv->name)) {
 		stack;
 		return 0;
@@ -136,259 +238,11 @@ int lv_rename(const char *old_name, struct logical_volume *lv)
 
 	fs_rename_lv(old_name, lv);
 
-      end:
+ end:
 	dm_task_destroy(dmt);
 	return r;
 }
 
-int lv_active(struct logical_volume *lv)
-{
-	int r = -1;
-	struct dm_info info;
-
-	if (!lv_info(lv, &info)) {
-		stack;
-		return r;
-	}
-
-	log_very_verbose("%s is%s active", lv->name, info.exists ? "":" not");
-	return info.exists;
-}
-
-int lv_suspended(struct logical_volume *lv)
-{
-	int r = -1;
-	struct dm_info info;
-
-	if (!lv_info(lv, &info)) {
-		stack;
-		return r;
-	}
-
-	log_very_verbose("%s is%s suspended", lv->name,
-			 info.suspended ? "":" not");
-	return info.suspended;
-}
-
-int lv_open_count(struct logical_volume *lv)
-{
-	int r = -1;
-	struct dm_info info;
-
-	if (!lv_info(lv, &info)) {
-		stack;
-		return r;
-	}
-
-	log_very_verbose("%s is open %d time(s)", lv->name, info.open_count);
-	return info.open_count;
-}
-
-/*
- * Emit a target for a given segment.
- */
-static int _emit_target(struct dm_task *dmt, struct stripe_segment *seg)
-{
-	char params[1024];
-	uint64_t esize = seg->lv->vg->extent_size;
-	uint32_t s, stripes = seg->stripes;
-	int w = 0, tw = 0, error = 0;
-	const char *no_space =
-		"Insufficient space to write target parameters.";
-	char *filler = "/dev/ioerror";
-	char *target;
-
-	if (stripes == 1) {
-		if (!seg->area[0].pv) {
-			target = "error";
-			error = 1;
-		}
-		else 
-			target = "linear";
-	}
-
-	if (stripes > 1) {
-		target = "striped";
-		tw = lvm_snprintf(params, sizeof(params), "%u %u ",
-			      stripes, seg->stripe_size);
-
-		if (tw < 0) {
-			log_err(no_space);
-			return 0;
-		}
-
-		w = tw;
-	}
-
-	if (!error) {
-		for (s = 0; s < stripes; s++, w += tw) {
-			if (!seg->area[s].pv)
-				tw = lvm_snprintf(
-					params + w, sizeof(params) - w,
-			      		"%s 0%s", filler,
-			      		s == (stripes - 1) ? "" : " ");
-			else
-				tw = lvm_snprintf(
-					params + w, sizeof(params) - w,
-			      		"%s %" PRIu64 "%s",
-					dev_name(seg->area[s].pv->dev),
-			      		(seg->area[s].pv->pe_start +
-			         	 (esize * seg->area[s].pe)),
-			      		s == (stripes - 1) ? "" : " ");
-
-			if (tw < 0) {
-				log_err(no_space);
-				return 0;
-			}
-		}
-	}
-
-	log_very_verbose("Adding target: %" PRIu64 " %" PRIu64 " %s %s",
-		   esize * seg->le, esize * seg->len,
-		   target, params);
-
-	if (!dm_task_add_target(dmt, esize * seg->le, esize * seg->len,
-				target, params)) {
-		stack;
-		return 0;
-	}
-
-	return 1;
-}
-
-int _load(struct logical_volume *lv, int task)
-{
-	int r = 0;
-	struct dm_task *dmt;
-	struct list *segh;
-	struct stripe_segment *seg;
-
-	log_very_verbose("Generating devmapper parameters for %s", lv->name);
-	if (!(dmt = _setup_task(lv, task))) {
-		stack;
-		return 0;
-	}
-
-	list_iterate(segh, &lv->segments) {
-		seg = list_item(segh, struct stripe_segment);
-		if (!_emit_target(dmt, seg)) {
-			log_error("Unable to activate logical volume '%s'",
-				lv->name);
-			goto out;
-		}
-	}
-
-	if (!((lv->status & LVM_WRITE) && (lv->vg->status & LVM_WRITE))) {
-	    	if (!dm_task_set_ro(dmt)) {
-			log_error("Failed to set %s read-only during "
-				  "activation.", lv->name);
-			goto out;
-		} else 
-			log_very_verbose("Activating %s read-only", lv->name);
-	}
-
-	if (lv->minor >= 0) {
-		if (!dm_task_set_minor(dmt, MINOR(lv->minor))) {
-			log_error("Failed to set minor number for %s to %d "
-				  "during activation.", lv->name, lv->minor);
-			goto out;
-		} else
-			log_very_verbose("Set minor number for %s to %d.",
-					 lv->name, lv->minor);
-	}
-
-	if (!(r = dm_task_run(dmt)))
-		stack;
-
-	log_verbose("Logical volume %s%s activated", lv->name,
-		    r == 1 ? "" : " not");
-
- out:
-	dm_task_destroy(dmt);
-	return r;
-}
-
-/* FIXME: Always display error msg */
-int lv_activate(struct logical_volume *lv)
-{
-	if (test_mode())
-		return 0;
-
-	log_very_verbose("Activating %s", lv->name);
-	return _load(lv, DM_DEVICE_CREATE) && fs_add_lv(lv);
-}
-
-int _suspend(struct logical_volume *lv, int sus)
-{
-	int r;
-	struct dm_task *dmt;
-	int task = sus ? DM_DEVICE_SUSPEND : DM_DEVICE_RESUME;
-
-	log_very_verbose("%s %s", sus ? "Suspending" : "Resuming", lv->name);
-	if (!(dmt = _setup_task(lv, task))) {
-		stack;
-		return 0;
-	}
-
-	if (!(r = dm_task_run(dmt)))
-		log_err("Couldn't %s device '%s'", sus ? "suspend" : "resume",
-			lv->name);
-
-	dm_task_destroy(dmt);
-	return r;
-}
-
-int lv_suspend(struct logical_volume *lv)
-{
-	return _suspend(lv, 1);
-}
-
-int lv_reactivate(struct logical_volume *lv)
-{
-	int r;
-
-	if (test_mode())
-		return 0;
-
-	if (!lv_suspended(lv) && !_suspend(lv, 1)) {
-		stack;
-		return 0;
-	}
-
-	r = _load(lv, DM_DEVICE_RELOAD);
-
-	if (!_suspend(lv, 0)) {
-		stack;
-		return 0;
-	}
-
-	return r;
-}
-
-
-int lv_deactivate(struct logical_volume *lv)
-{
-	int r;
-	struct dm_task *dmt;
-
-	log_very_verbose("Deactivating %s", lv->name);
-	if (test_mode())
-		return 0;
-
-	if (!(dmt = _setup_task(lv, DM_DEVICE_REMOVE))) {
-		stack;
-		return 0;
-	}
-
-	if (!(r = dm_task_run(dmt)))
-		stack;
-
-	dm_task_destroy(dmt);
-
-	fs_del_lv(lv);
-
-	return r;
-}
 
 int activate_lvs_in_vg(struct volume_group *vg)
 {

lib/activate/activate.h

@@ -1,7 +1,7 @@
 /*
  * Copyright (C) 2001 Sistina Software (UK) Limited.
  *
- * This file is released under the GPL.
+ * This file is released under the LGPL.
  */
 
 #ifndef LVM_ACTIVATE_H
@@ -9,25 +9,28 @@
 
 #include <libdevmapper.h>
 
-/* FIXME Snapshot handling? */
-
 int driver_version(char *version, size_t size);
 int library_version(char *version, size_t size);
 
+/*
+ * Status functions.
+ */
 int lv_active(struct logical_volume *lv);
 int lv_suspended(struct logical_volume *lv);
 int lv_open_count(struct logical_volume *lv);
 int lv_info(struct logical_volume *lv, struct dm_info *info);
-int lv_rename(const char *old_name, struct logical_volume *lv);
 
+/*
+ * Activation proper.
+ */
 int lv_activate(struct logical_volume *lv);
 int lv_reactivate(struct logical_volume *lv);
 int lv_deactivate(struct logical_volume *lv);
 int lv_suspend(struct logical_volume *lv);
+int lv_rename(const char *old_name, struct logical_volume *lv);
 
 /*
- * Return number of LVs in the VG that are
+ * Return number of LVs in the VG that are active.
- * active.
  */
 int lvs_in_vg_activated(struct volume_group *vg);
 int lvs_in_vg_opened(struct volume_group *vg);
@@ -38,9 +41,8 @@ int lvs_in_vg_opened(struct volume_group *vg);
 int lv_update_write_access(struct logical_volume *lv);
 
 /*
- * Activate all LVs in the VG.  Ignore any that
+ * Activate all LVs in the VG.  Ignore any that are already
- * are already active.  Return number
+ * active.  Return number activated.
- * activated.
  */
 int activate_lvs_in_vg(struct volume_group *vg);
 

lib/activate/fs.c

@@ -62,7 +62,8 @@ static int _mk_link(struct logical_volume *lv)
 	char lv_path[PATH_MAX], link_path[PATH_MAX];
 	struct stat buf;
 
-	if (!build_dm_path(lv_path, sizeof(lv_path), lv->vg->name, lv->name)) {
+	if (!build_dm_path(lv_path, sizeof(lv_path), "",
+			   lv->vg->name, lv->name)) {
 		log_error("Couldn't create destination pathname for "
 			  "logical volume link for %s", lv->name);
 		return 0;
@@ -126,7 +127,7 @@ static int _rm_link(struct logical_volume *lv, const char *lv_name)
 	return 1;
 }
 
-int fs_add_lv(struct logical_volume *lv)
+int fs_add_lv(struct logical_volume *lv, int minor)
 {
 	if (!_mk_dir(lv->vg) ||
 	    !_mk_link(lv)) {

lib/activate/fs.h

@@ -15,7 +15,7 @@
  * symbolic links to the dm device.
  */
 
-int fs_add_lv(struct logical_volume *lv);
+int fs_add_lv(struct logical_volume *lv, int minor);
 int fs_del_lv(struct logical_volume *lv);
 int fs_rename_lv(const char *old_name, struct logical_volume *lv);
 

lib/activate/ll-activate.c

@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) 2002 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#include "ll-activate.h"
+#include "log.h"
+
+struct dm_task *setup_dm_task(const char *name, int task)
+{
+	struct dm_task *dmt;
+
+	if (!(dmt = dm_task_create(task))) {
+		stack;
+		return NULL;
+	}
+
+	dm_task_set_name(dmt, name);
+
+	return dmt;
+}
+
+int device_info(const char *name, struct dm_info *info)
+{
+	int r = 0;
+	struct dm_task *dmt;
+
+	log_very_verbose("Getting device info for %s", name);
+	if (!(dmt = setup_dm_task(name, DM_DEVICE_INFO))) {
+		stack;
+		return 0;
+	}
+
+	if (!dm_task_run(dmt)) {
+		stack;
+		goto out;
+	}
+
+	if (!dm_task_get_info(dmt, info)) {
+		stack;
+		goto out;
+	}
+	r = 1;
+
+ out:
+	dm_task_destroy(dmt);
+	return r;
+}
+
+int device_active(const char *name)
+{
+	struct dm_info info;
+
+	if (!device_info(name, &info)) {
+		stack;
+		return -1;
+	}
+
+	log_very_verbose("%s is%s active", name, info.exists ? "" : " not");
+	return info.exists;
+}
+
+int device_suspended(const char *name)
+{
+	struct dm_info info;
+
+	if (!device_info(name, &info)) {
+		stack;
+		return -1;
+	}
+
+	log_very_verbose("%s is%s suspended", name,
+			 info.suspended ? "" : " not");
+	return info.suspended;
+}
+
+int device_open_count(const char *name)
+{
+	struct dm_info info;
+
+	if (!device_info(name, &info)) {
+		stack;
+		return -1;
+	}
+
+	log_very_verbose("%s is open %d time(s)", name, info.open_count);
+	return info.open_count;
+}
+
+
+int device_deactivate(const char *name)
+{
+	int r;
+	struct dm_task *dmt;
+
+	log_very_verbose("Deactivating '%s'.", name);
+
+	if (!(dmt = setup_dm_task(name, DM_DEVICE_REMOVE))) {
+		stack;
+		return 0;
+	}
+
+	if (!(r = dm_task_run(dmt)))
+		stack;
+
+	dm_task_destroy(dmt);
+
+	return r;
+}
+
+static int _suspend(const char *name, int sus)
+{
+	int r;
+	struct dm_task *dmt;
+	int task = sus ? DM_DEVICE_SUSPEND : DM_DEVICE_RESUME;
+
+	log_very_verbose("%s %s", sus ? "Suspending" : "Resuming", name);
+	if (!(dmt = setup_dm_task(name, task))) {
+		stack;
+		return 0;
+	}
+
+	if (!(r = dm_task_run(dmt)))
+		log_err("Couldn't %s device '%s'", sus ? "suspend" : "resume",
+			name);
+
+	dm_task_destroy(dmt);
+	return r;
+}
+
+int device_suspend(const char *name)
+{
+	return _suspend(name, 1);
+}
+
+int device_resume(const char *name)
+{
+	return _suspend(name, 0);
+}

lib/activate/ll-activate.h

@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2002 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef _LVM_LL_ACTIVATE_H
+#define _LVM_LL_ACTIVATE_H
+
+#include "metadata.h"
+
+#include <libdevmapper.h>
+
+/*
+ * Prepares a new dm_task.
+ */
+struct dm_task *setup_dm_task(const char *name, int task);
+
+
+/*
+ * Query functions.  'name' is the device node name in the
+ * device-mapper dir.
+ */
+int device_info(const char *name, struct dm_info *info);
+int device_active(const char *name);
+int device_suspended(const char *name);
+int device_open_count(const char *name);
+
+
+/*
+ * Functions to manipulate an already active device.
+ */
+int device_deactivate(const char *name);
+int device_suspend(const char *name);
+int device_resume(const char *name);
+
+
+/*
+ * Creates a device with a mapping table as specified by the lv.
+ */
+int device_create_lv(const char *name, struct logical_volume *lv, int minor);
+int device_reload_lv(const char *name, struct logical_volume *lv);
+
+
+/*
+ * Layers the origin device above an already active 'real'
+ * device.
+ */
+int device_create_origin(struct logical_volume *lv,
+			 const char *real, int minor);
+
+
+/*
+ * Creates a snapshot device for a given origin and exception
+ * storage area.
+ */
+int device_create_snapshot(struct logical_volume *lv,
+			   const char *origin, const char *cow_device,
+			   int minor);
+
+#endif

lib/activate/names.c

@@ -16,7 +16,7 @@
  * seperated by a single ':', any colons in the vg name are
  * doubled up to form a pair.
  */
-int build_dm_name(char *buffer, size_t len,
+int build_dm_name(char *buffer, size_t len, const char *prefix,
 		  const char *vg_name, const char *lv_name)
 {
 	char *out;
@@ -36,7 +36,7 @@ int build_dm_name(char *buffer, size_t len,
 	if (!len)
 		return 0;
 
-	if (lvm_snprintf(out, len, ":%s", lv_name) == -1) {
+	if (lvm_snprintf(out, len, ":%s%s", prefix, lv_name) == -1) {
 		log_err("Couldn't build logical volume name.");
 		return 0;
 	}
@@ -44,12 +44,13 @@ int build_dm_name(char *buffer, size_t len,
 	return 1;
 }
 
-int build_dm_path(char *buffer, size_t len,
+int build_dm_path(char *buffer, size_t len, const char *prefix,
 		  const char *vg_name, const char *lv_name)
 {
 	char dev_name[PATH_MAX];
 
-	if (!build_dm_name(dev_name, sizeof(dev_name), vg_name, lv_name)) {
+	if (!build_dm_name(dev_name, sizeof(dev_name),
+			   prefix, vg_name, lv_name)) {
 		stack;
 		return 0;
 	}

lib/activate/names.h

@@ -21,14 +21,14 @@
  * The name of the device-mapper device for a particular LV.
  * eg, vg0:music
  */
-int build_dm_name(char *buffer, size_t len,
+int build_dm_name(char *buffer, size_t len, const char *prefix,
 		  const char *vg_name, const char *lv_name);
 
 /*
  * The path of the device-mapper device for a particular LV.
  * eg, /dev/device-mapper/vg0:music
  */
-int build_dm_path(char *buffer, size_t len,
+int build_dm_path(char *buffer, size_t len, const char *prefix,
 		  const char *vg_name, const char *lv_name);
 
 /*

lib/log/log.h

@@ -72,7 +72,7 @@ void print_log(int level, const char *file, int line, const char *format, ...)
 #define log_err(x...) plog(_LOG_ERR, x)
 #define log_fatal(x...) plog(_LOG_FATAL, x)
 
-#define stack log_debug( "s" )	/* Backtrace on error */
+#define stack log_debug("<stack>")	/* Backtrace on error */
 
 #define log_error(fmt, args...) log_err(fmt , ## args)
 #define log_print(fmt, args...) log_warn(fmt , ## args)