Export dm name build & split functions.

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.00.23 - 
 ====================================
+  Export dm name build & split functions.
   Use O_NOATIME on devices if available.
   Write log message when each segtype/format gets initialised.
   New commands 'segtypes' and 'formats'.

lib/activate/dev_manager.c

@@ -165,89 +165,6 @@ static inline void _clear_flag(struct dev_layer *dl, int bit)
 	dl->flags &= ~(1 << bit);
 }
 
-/*
- * Device layer names are all of the form <vg>-<lv>-<layer>, any
- * other hyphens that appear in these names are quoted with yet
- * another hyphen.  The top layer of any device has no layer
- * name.  eg, vg0-lvol0.
- */
-static void _count_hyphens(const char *str, size_t *len, int *hyphens)
-{
-	const char *ptr;
-
-	for (ptr = str; *ptr; ptr++, (*len)++)
-		if (*ptr == '-')
-			(*hyphens)++;
-}
-
-/*
- * Copies a string, quoting hyphens with hyphens.
- */
-static void _quote_hyphens(char **out, const char *src)
-{
-	while (*src) {
-		if (*src == '-')
-			*(*out)++ = '-';
-
-		*(*out)++ = *src++;
-	}
-}
-
-/*
- * <vg>-<lv>-<layer> or if !layer just <vg>-<lv>.
- */
-static char *_build_name(struct pool *mem, const char *vg,
-			 const char *lv, const char *layer)
-{
-	size_t len = 0;
-	int hyphens = 0;
-	char *r, *out;
-
-	_count_hyphens(vg, &len, &hyphens);
-	_count_hyphens(lv, &len, &hyphens);
-
-	if (layer && *layer)
-		_count_hyphens(layer, &len, &hyphens);
-
-	len += hyphens + 2;
-
-	if (!(r = pool_alloc(mem, len))) {
-		stack;
-		return NULL;
-	}
-
-	out = r;
-	_quote_hyphens(&out, vg);
-	*out++ = '-';
-	_quote_hyphens(&out, lv);
-
-	if (layer && *layer) {
-		*out++ = '-';
-		_quote_hyphens(&out, layer);
-	}
-	*out = '\0';
-
-	return r;
-}
-
-/* Find start of LV component in hyphenated name */
-static char *_find_lv_name(char *vg)
-{
-	char *c = vg;
-
-	while (*c && *(c + 1)) {
-		if (*c == '-') {
-			if (*(c + 1) == '-')
-				c++;
-			else
-				return (c + 1);
-		}
-		c++;
-	}
-
-	return NULL;
-}
-
 static char *_build_dlid(struct pool *mem, const char *lvid, const char *layer)
 {
 	char *dlid;
@@ -519,10 +436,16 @@ static int _percent(struct dev_manager *dm, const char *name, const char *uuid,
 	return 0;
 }
 
-static int _rename(struct dev_layer *dl, char *newname)
+static int _rename(struct dev_manager *dm, struct dev_layer *dl, char *newname)
 {
 	int r = 1;
 	struct dm_task *dmt;
+	char *vgname, *lvname, *layer;
+
+	if (!split_dm_name(dm->mem, dl->name, &vgname, &lvname, &layer)) {
+		log_error("Couldn't split up dm layer name %s", dl->name);
+		return 0;
+	}
 
 	log_verbose("Renaming %s to %s", dl->name, newname);
 
@@ -537,11 +460,13 @@ static int _rename(struct dev_layer *dl, char *newname)
 		goto out;
 	}
 
-	if (!(r = dm_task_run(dmt)))
+	if (!(r = dm_task_run(dmt))) {
 		log_error("Couldn't rename device '%s'.", dl->name);
+		goto out;
+	}
 
 	if (r && _get_flag(dl, VISIBLE))
-		fs_rename_lv(dl->lv, newname, _find_lv_name(dl->name));
+		fs_rename_lv(dl->lv, newname, lvname);
 
 	dl->name = newname;
 
@@ -1052,7 +977,7 @@ int dev_manager_info(struct dev_manager *dm, const struct logical_volume *lv,
 	/*
 	 * Build a name for the top layer.
 	 */
-	if (!(name = _build_name(dm->mem, lv->vg->name, lv->name, NULL))) {
+	if (!(name = build_dm_name(dm->mem, lv->vg->name, lv->name, NULL))) {
 		stack;
 		return 0;
 	}
@@ -1077,7 +1002,7 @@ int dev_manager_snapshot_percent(struct dev_manager *dm,
 	/*
 	 * Build a name for the top layer.
 	 */
-	if (!(name = _build_name(dm->mem, lv->vg->name, lv->name, NULL))) {
+	if (!(name = build_dm_name(dm->mem, lv->vg->name, lv->name, NULL))) {
 		stack;
 		return 0;
 	}
@@ -1109,7 +1034,7 @@ int dev_manager_mirror_percent(struct dev_manager *dm,
 	/*
 	 * Build a name for the top layer.
 	 */
-	if (!(name = _build_name(dm->mem, lv->vg->name, lv->name, NULL))) {
+	if (!(name = build_dm_name(dm->mem, lv->vg->name, lv->name, NULL))) {
 		stack;
 		return 0;
 	}
@@ -1173,7 +1098,7 @@ static struct dev_layer *_create_layer(struct dev_manager *dm,
 	char *name, *dlid;
 	struct dev_layer *dl;
 
-	if (!(name = _build_name(dm->mem, lv->vg->name, lv->name, layer))) {
+	if (!(name = build_dm_name(dm->mem, lv->vg->name, lv->name, layer))) {
 		stack;
 		return NULL;
 	}
@@ -1618,11 +1543,11 @@ static int _create_rec(struct dev_manager *dm, struct dev_layer *dl)
 	if (dl->info.exists) {
 		if ((suffix = rindex(dl->dlid, '-')))
 			suffix++;
-		newname = _build_name(dm->mem, dm->vg_name, dl->lv->name,
+		newname = build_dm_name(dm->mem, dm->vg_name, dl->lv->name,
 					suffix);
 		if (strcmp(newname, dl->name)) {
 			if (!_suspend_parents(dm, dl) ||
-			    !_suspend(dl) || !_rename(dl, newname)) {
+			    !_suspend(dl) || !_rename(dm, dl, newname)) {
 				stack;
 				return 0;
 			}
@@ -2227,7 +2152,7 @@ int dev_manager_lv_mknodes(const struct logical_volume *lv)
 {
 	char *name;
 
-	if (!(name = _build_name(lv->vg->cmd->mem, lv->vg->name,
+	if (!(name = build_dm_name(lv->vg->cmd->mem, lv->vg->name,
 				   lv->name, NULL))) {
 		stack;
 		return 0;

lib/misc/lvm-string.c

@@ -16,6 +16,7 @@
 #include "lib.h"
 #include "lvm-types.h"
 #include "lvm-string.h"
+#include "pool.h"
 
 #include <ctype.h>
 
@@ -98,3 +99,107 @@ int split_words(char *buffer, unsigned max, char **argv)
 
 	return arg;
 }
+
+/*
+ * Device layer names are all of the form <vg>-<lv>-<layer>, any
+ * other hyphens that appear in these names are quoted with yet
+ * another hyphen.  The top layer of any device has no layer
+ * name.  eg, vg0-lvol0.
+ */
+static void _count_hyphens(const char *str, size_t *len, int *hyphens)
+{
+	const char *ptr;
+
+	for (ptr = str; *ptr; ptr++, (*len)++)
+		if (*ptr == '-')
+			(*hyphens)++;
+}
+
+/*
+ * Copies a string, quoting hyphens with hyphens.
+ */
+static void _quote_hyphens(char **out, const char *src)
+{
+	while (*src) {
+		if (*src == '-')
+			*(*out)++ = '-';
+
+		*(*out)++ = *src++;
+	}
+}
+
+/*
+ * <vg>-<lv>-<layer> or if !layer just <vg>-<lv>.
+ */
+char *build_dm_name(struct pool *mem, const char *vg,
+		    const char *lv, const char *layer)
+{
+	size_t len = 0;
+	int hyphens = 0;
+	char *r, *out;
+
+	_count_hyphens(vg, &len, &hyphens);
+	_count_hyphens(lv, &len, &hyphens);
+
+	if (layer && *layer)
+		_count_hyphens(layer, &len, &hyphens);
+
+	len += hyphens + 2;
+
+	if (!(r = pool_alloc(mem, len))) {
+		stack;
+		return NULL;
+	}
+
+	out = r;
+	_quote_hyphens(&out, vg);
+	*out++ = '-';
+	_quote_hyphens(&out, lv);
+
+	if (layer && *layer) {
+		*out++ = '-';
+		_quote_hyphens(&out, layer);
+	}
+	*out = '\0';
+
+	return r;
+}
+
+/*
+ * Remove hyphen quoting from a component of a name.
+ * NULL-terminates the component and returns start of next component.
+ */
+static char *_unquote(char *component)
+{
+	char *c = component;
+	char *o = c;
+
+	while (*c) {
+		if (*(c + 1)) {
+			if (*c == '-') {
+				if (*(c + 1) == '-')
+					c++;
+				else
+					break;
+			}
+		}
+		*o = *c;
+		o++;
+		c++;
+	}
+
+	*o = '\0';
+	return (c + 1);
+}
+
+int split_dm_name(struct pool *mem, const char *dmname,
+		  char **vgname, char **lvname, char **layer)
+{
+	if (!(*vgname = pool_strdup(mem, dmname)))
+		return 0;
+
+	_unquote(*layer = _unquote(*lvname = _unquote(*vgname)));
+
+	return 1;
+}
+

lib/misc/lvm-string.h

@@ -19,6 +19,8 @@
 #include <stdio.h>
 #include <stdarg.h>
 
+struct pool;
+
 /*
  * On error, up to glibc 2.0.6, snprintf returned -1 if buffer was too small;
  * From glibc 2.1 it returns number of chars (excl. trailing null) that would 
@@ -32,4 +34,10 @@ int emit_to_buffer(char **buffer, size_t *size, const char *fmt, ...);
 
 int split_words(char *buffer, unsigned max, char **argv);
 
+char *build_dm_name(struct pool *mem, const char *vg,
+                    const char *lv, const char *layer);
+
+int split_dm_name(struct pool *mem, const char *dmname,
+                  char **vgname, char **lvname, char **layer);
+
 #endif