From: Karel Zak <kzak@redhat.com>
Date: Tue, 2 Jun 2026 10:25:27 +0000 (+0200)
Subject: libblkid: add blkid_evaluate_tag2() with flags
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4785da2de365bcc6be02a01ffb314eadc1c8eef9;p=thirdparty%2Futil-linux.git

libblkid: add blkid_evaluate_tag2() with flags

Add blkid_evaluate_tag2() that accepts flags to control tag
evaluation behavior. The BLKID_EVALUATE_NOPROBE flag disables
low-level device scanning (evaluate_by_scan), while keeping
udev symlink-based evaluation (evaluate_by_udev) functional.

The original blkid_evaluate_tag() is now a thin wrapper around
the new function with flags=0.

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

diff --git a/libblkid/docs/libblkid-sections.txt b/libblkid/docs/libblkid-sections.txt
index 308f8effdc..60a43b5024 100644
--- a/libblkid/docs/libblkid-sections.txt
+++ b/libblkid/docs/libblkid-sections.txt
@@ -1,6 +1,7 @@
 <SECTION>
 <FILE>evaluate</FILE>
 blkid_evaluate_tag
+blkid_evaluate_tag2
 blkid_evaluate_spec
 </SECTION>
 
diff --git a/libblkid/src/blkid.h.in b/libblkid/src/blkid.h.in
index 637d970f2a..8dfea21523 100644
--- a/libblkid/src/blkid.h.in
+++ b/libblkid/src/blkid.h.in
@@ -219,9 +219,14 @@ 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)
 			__ul_attribute__((warn_unused_result));
+extern char *blkid_evaluate_tag2(const char *token, const char *value,
+				blkid_cache *cache, int flags)
+			__ul_attribute__((warn_unused_result));
 extern char *blkid_evaluate_spec(const char *spec, blkid_cache *cache)
 			__ul_attribute__((warn_unused_result));
 
+#define BLKID_EVALUATE_NOPROBE	(1 << 0)	/* disable low-level device probing */
+
 /* probe.c */
 extern blkid_probe blkid_new_probe(void)
 			__ul_attribute__((warn_unused_result));
diff --git a/libblkid/src/evaluate.c b/libblkid/src/evaluate.c
index 11c26163a4..2618b9192d 100644
--- a/libblkid/src/evaluate.c
+++ b/libblkid/src/evaluate.c
@@ -218,18 +218,8 @@ static char *evaluate_by_scan(const char *token, const char *value,
 	return res;
 }
 
-/**
- * blkid_evaluate_tag:
- * @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)
- *
-* If the @value is NULL and @token is not in the NAME=value format, then return
-* a copy of the @token.
- *
- * Returns: allocated string with a device name.
- */
-char *blkid_evaluate_tag(const char *token, const char *value, blkid_cache *cache)
+static char *evaluate_tag(const char *token, const char *value,
+		blkid_cache *cache, int flags)
 {
 	struct blkid_config *conf = NULL;
 	char *t = NULL, *v = NULL;
@@ -260,7 +250,8 @@ char *blkid_evaluate_tag(const char *token, const char *value, blkid_cache *cach
 	for (i = 0; i < conf->nevals; i++) {
 		if (conf->eval[i] == BLKID_EVAL_UDEV)
 			ret = evaluate_by_udev(token, value, conf->uevent);
-		else if (conf->eval[i] == BLKID_EVAL_SCAN)
+		else if (conf->eval[i] == BLKID_EVAL_SCAN
+			 && !(flags & BLKID_EVALUATE_NOPROBE))
 			ret = evaluate_by_scan(token, value, cache, conf);
 		if (ret)
 			break;
@@ -274,6 +265,40 @@ out:
 	return ret;
 }
 
+/**
+ * blkid_evaluate_tag:
+ * @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)
+ *
+ * If the @value is NULL and @token is not in the NAME=value format, then return
+ * a copy of the @token.
+ *
+ * Returns: allocated string with a device name.
+ */
+char *blkid_evaluate_tag(const char *token, const char *value, blkid_cache *cache)
+{
+	return evaluate_tag(token, value, cache, 0);
+}
+
+/**
+ * blkid_evaluate_tag2:
+ * @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)
+ * @flags: BLKID_EVALUATE_* flags
+ *
+ * Same as blkid_evaluate_tag(), but with flags to control evaluation.
+ * The BLKID_EVALUATE_NOPROBE flag disables low-level device probing.
+ *
+ * Returns: allocated string with a device name.
+ */
+char *blkid_evaluate_tag2(const char *token, const char *value,
+		blkid_cache *cache, int flags)
+{
+	return evaluate_tag(token, value, cache, flags);
+}
+
 /**
  * blkid_evaluate_spec:
  * @spec: unparsed tag (e.g. "LABEL=foo") or path (e.g. /dev/dm-0)
diff --git a/libblkid/src/libblkid.sym b/libblkid/src/libblkid.sym
index 7b2263a1c4..01b6170f9c 100644
--- a/libblkid/src/libblkid.sym
+++ b/libblkid/src/libblkid.sym
@@ -191,3 +191,7 @@ BLKID_2_39 {
 BLKID_2_40 {
     blkid_wipe_all;
 } BLKID_2_39;
+
+BLKID_2_43 {
+    blkid_evaluate_tag2;
+} BLKID_2_40;