From: Karel Zak <kzak@redhat.com>
Date: Thu, 17 Mar 2011 11:51:06 +0000 (+0100)
Subject: libblkid: add blkid_evaluate_spec()
X-Git-Tag: v2.20-rc1~434
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5298f72839cb44e2ae9d4407375674ba50f9b1c0;p=thirdparty%2Futil-linux.git

libblkid: add blkid_evaluate_spec()

The function blkid_evaluate_tag() is useful for tags only (e.g.
LABEL=foo). But we also need to address devices by tags OR paths in
many utils.

The function blkid_evaluate_spec() support this functionality without
extra care about the way how device is addressed. The tags as well as
paths are converted to the standardized device path.

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/lib/fsprobe.c b/lib/fsprobe.c
index 2d7be0e5bb..71d15f798e 100644
--- a/lib/fsprobe.c
+++ b/lib/fsprobe.c
@@ -53,26 +53,7 @@ fsprobe_parse_spec(const char *spec, char **name, char **value)
 char *
 fsprobe_get_devname_by_spec(const char *spec)
 {
-	char *name, *value;
-
-	if (!spec)
-		return NULL;
-	if (fsprobe_parse_spec(spec, &name, &value) != 0)
-		return NULL;				/* parse error */
-	if (name) {
-		char *nspec = NULL;
-
-		if (!strcmp(name,"LABEL"))
-			nspec = fsprobe_get_devname_by_label(value);
-		else if (!strcmp(name,"UUID"))
-			nspec = fsprobe_get_devname_by_uuid(value);
-
-		free(name);
-		free(value);
-		return nspec;
-	}
-
-	return canonicalize_path(spec);
+	return blkid_evaluate_spec(spec, blcache);
 }
 
 int
diff --git a/shlibs/blkid/src/blkid.h.in b/shlibs/blkid/src/blkid.h.in
index 46cbeb23b1..05527bed88 100644
--- a/shlibs/blkid/src/blkid.h.in
+++ b/shlibs/blkid/src/blkid.h.in
@@ -186,6 +186,7 @@ extern int blkid_safe_string(const char *str, char *str_safe, size_t len);
 extern int blkid_send_uevent(const char *devname, const char *action);
 extern char *blkid_evaluate_tag(const char *token, const char *value,
 				blkid_cache *cache);
+extern char *blkid_evaluate_spec(const char *spec, blkid_cache *cache);
 
 /* probe.c */
 extern blkid_probe blkid_new_probe(void);
diff --git a/shlibs/blkid/src/blkid.sym b/shlibs/blkid/src/blkid.sym
index 9df2ba3d33..e758ff1a60 100644
--- a/shlibs/blkid/src/blkid.sym
+++ b/shlibs/blkid/src/blkid.sym
@@ -39,7 +39,7 @@ local:
 
 
 /*
- * version(s) since util-linux 2.15
+ * symbols since util-linux 2.15
  */
 BLKID_2.15 {
 global:
@@ -67,7 +67,7 @@ global:
 } BLKID_1.0;
 
 /*
- * version(s) since util-linux 2.17
+ * symbols since util-linux 2.17
  */
 BLKID_2.17 {
 global:
@@ -117,7 +117,7 @@ global:
 } BLKID_2.15;
 
 /*
- * version(s) since util-linux 2.18
+ * symbols since util-linux 2.18
  */
 BLKID_2.18 {
 global:
@@ -130,3 +130,12 @@ global:
 	blkid_probe_get_wholedisk_devno;
 	blkid_probe_is_wholedisk;
 } BLKID_2.17;
+
+/*
+ * symbols since util-linux 2.20
+ */
+BLKID_2.20 {
+global:
+	blkid_evaluate_spec;
+} BLKID_2.18;
+
diff --git a/shlibs/blkid/src/evaluate.c b/shlibs/blkid/src/evaluate.c
index 0b1cd51f9e..88c6830e89 100644
--- a/shlibs/blkid/src/evaluate.c
+++ b/shlibs/blkid/src/evaluate.c
@@ -202,8 +202,8 @@ static char *evaluate_by_scan(const char *token, const char *value,
 
 /**
  * blkid_evaluate_tag:
- * @token: token name (e.g "LABEL" or "UUID")
- * @value: token data
+ * @token: token name (e.g "LABEL" or "UUID") or unparsed tag (e.g. "LABEL=foo")
+ * @value: token data (e.g. "foo")
  * @cache: pointer to cache (or NULL when you don't want to re-use the cache)
  *
  * Returns: allocated string with a device name.
@@ -259,20 +259,52 @@ out:
 	return ret;
 }
 
+/**
+ * blkid_evaluate_spec:
+ * @spec: unparsed tag (e.g. "LABEL=foo") or path (e.g. /dev/dm-0)
+ * @cache: pointer to cache (or NULL when you don't want to re-use the cache)
+ *
+ * All returned paths are canonicalized, device-mapper paths are converted
+ * to the /dev/mapper/<name> format.
+ *
+ * Returns: allocated string with a device name.
+ */
+char *blkid_evaluate_spec(const char *spec, blkid_cache *cache)
+{
+	char *t = NULL, *v = NULL, *res;
+
+	if (!spec)
+		return NULL;
+
+	if (strchr(spec, '=') &&
+	    blkid_parse_tag_string(spec, &t, &v) != 0)	/* parse error */
+		return NULL;
+
+	if (v)
+		res = blkid_evaluate_tag(t, v, cache);
+	else
+		res = canonicalize_path(spec);
+
+	free(t);
+	free(v);
+	return res;
+}
+
+
 #ifdef TEST_PROGRAM
 int main(int argc, char *argv[])
 {
 	blkid_cache cache = NULL;
 	char *res;
 
-	if (argc < 3) {
-		fprintf(stderr, "usage: %s <token> <value>\n", argv[0]);
+	if (argc < 2) {
+		fprintf(stderr, "usage: %s <tag> | <spec>\n", argv[0]);
 		return EXIT_FAILURE;
 	}
 
 	blkid_init_debug(0);
 
-	res = blkid_evaluate_tag(argv[1], argv[2], &cache);
+	res = blkid_evaluate_spec(argv[1], &cache);
 	if (res)
 		printf("%s\n", res);
 	if (cache)