xref: /OK3568_Linux_fs/buildroot/package/busybox/0006-Support-PARTLABEL.patch (revision 4882a59341e53eb6f0b4789bf948001014eff981)

From a3c839f7ca05ecd424be293f49e90f36845b8b8b Mon Sep 17 00:00:00 2001
From: Jeffy Chen <jeffy.chen@rock-chips.com>
Date: Fri, 25 Nov 2022 19:39:30 +0800
Subject: [PATCH 6/8] Support PARTLABEL

Tested on RK3588 EVB:
busybox mount PARTLABEL=rootfs /media/

Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
---
 include/volume_id.h                       |  1 +
 util-linux/volume_id/get_devname.c        | 59 +++++++++++++++++++----
 util-linux/volume_id/volume_id_internal.h |  1 +
 3 files changed, 52 insertions(+), 9 deletions(-)

diff --git a/include/volume_id.h b/include/volume_id.h
index a83da89..afb76e4 100644
--- a/include/volume_id.h
+++ b/include/volume_id.h
@@ -20,6 +20,7 @@

 char *get_devname_from_label(const char *spec);
 char *get_devname_from_uuid(const char *spec);
+char *get_devname_from_partlabel(const char *spec);
 void display_uuid_cache(int scan_devices);

 /* Returns:
diff --git a/util-linux/volume_id/get_devname.c b/util-linux/volume_id/get_devname.c
index 00cfb28..61d0461 100644
--- a/util-linux/volume_id/get_devname.c
+++ b/util-linux/volume_id/get_devname.c
@@ -24,15 +24,16 @@ static struct uuidCache_s {
 //	int major, minor;
 	char *device;
 	char *label;
+	char *partlabel;
 	char *uc_uuid; /* prefix makes it easier to grep for */
 	IF_FEATURE_BLKID_TYPE(const char *type;)
 } *uuidCache;

 #if !ENABLE_FEATURE_BLKID_TYPE
-#define get_label_uuid(fd, label, uuid, type) \
-	get_label_uuid(fd, label, uuid)
-#define uuidcache_addentry(device, label, uuid, type) \
-	uuidcache_addentry(device, label, uuid)
+#define get_label_uuid(fd, label, partlabel, uuid, type) \
+	get_label_uuid(fd, label, partlabel, uuid)
+#define uuidcache_addentry(device, label, partlabel, uuid, type) \
+	uuidcache_addentry(device, label, partlabel, uuid)
 #endif

 /* Returns !0 on error.
@@ -40,11 +41,13 @@ static struct uuidCache_s {
  * (and they can't be NULL, although they can be "").
  * NB: closes fd. */
 static int
-get_label_uuid(int fd, char **label, char **uuid, const char **type)
+get_label_uuid(int fd, char **label, char **partlabel, char **uuid, const char **type)
 {
 	int rv = 1;
 	uint64_t size;
 	struct volume_id *vid;
+	struct stat st;
+	char *uevent;

 	/* fd is owned by vid now */
 	vid = volume_id_open_node(fd);
@@ -55,12 +58,30 @@ get_label_uuid(int fd, char **label, char **uuid, const char **type)
 	if (volume_id_probe_all(vid, /*0,*/ size) != 0)
 		goto ret;

-	if (vid->label[0] != '\0' || vid->uuid[0] != '\0'
+	fstat(fd, &st);
+	uevent = xasprintf("/sys/dev/block/%d:%d/uevent",
+			   major(st.st_rdev), minor(st.st_rdev));
+	if (uevent) {
+		FILE *rfile = fopen_for_read(uevent);
+		if (rfile) {
+			const char *line;
+			while ((line = xmalloc_fgetline(rfile)) != NULL) {
+				if (sscanf(line, "PARTNAME=%s",
+					   vid->partlabel) > 0)
+					break;
+			}
+			fclose(rfile);
+		}
+		free(uevent);
+	}
+
+	if (vid->label[0] != '\0' || vid->partlabel[0] != '\0' || vid->uuid[0] != '\0'
 #if ENABLE_FEATURE_BLKID_TYPE
 	 || vid->type != NULL
 #endif
 	) {
 		*label = xstrndup(vid->label, sizeof(vid->label));
+		*partlabel = xstrndup(vid->partlabel, sizeof(vid->partlabel));
 		*uuid  = xstrndup(vid->uuid, sizeof(vid->uuid));
 #if ENABLE_FEATURE_BLKID_TYPE
 		*type = vid->type;
@@ -77,7 +98,7 @@ get_label_uuid(int fd, char **label, char **uuid, const char **type)

 /* NB: we take ownership of (malloc'ed) label and uuid */
 static void
-uuidcache_addentry(char *device, /*int major, int minor,*/ char *label, char *uuid, const char *type)
+uuidcache_addentry(char *device, /*int major, int minor,*/ char *label, char *partlabel, char *uuid, const char *type)
 {
 	struct uuidCache_s *last;

@@ -94,6 +115,7 @@ uuidcache_addentry(char *device, /*int major, int minor,*/ char *label, char *uu
 //	last->minor = minor;
 	last->device = device;
 	last->label = label;
+	last->partlabel = partlabel;
 	last->uc_uuid = uuid;
 	IF_FEATURE_BLKID_TYPE(last->type = type;)
 }
@@ -244,6 +266,8 @@ void display_uuid_cache(int scan_devices)
 	if (uc->type)
 		printf(" TYPE=\"%s\"", uc->type);
 #endif
+		if (uc->partlabel[0])
+			printf(" PARTLABEL=\"%s\"", uc->partlabel);
 		bb_putchar('\n');
 		uc = uc->next;
 	}
@@ -253,6 +277,7 @@ int add_to_uuid_cache(const char *device)
 {
 	char *uuid = uuid; /* for compiler */
 	char *label = label;
+	char *partlabel = partlabel;
 #if ENABLE_FEATURE_BLKID_TYPE
 	const char *type = type;
 #endif
@@ -263,9 +288,9 @@ int add_to_uuid_cache(const char *device)
 		return 0;

 	/* get_label_uuid() closes fd in all cases (success & failure) */
-	if (get_label_uuid(fd, &label, &uuid, &type) == 0) {
+	if (get_label_uuid(fd, &label, &partlabel, &uuid, &type) == 0) {
 		/* uuidcache_addentry() takes ownership of all four params */
-		uuidcache_addentry(xstrdup(device), /*ma, mi,*/ label, uuid, type);
+		uuidcache_addentry(xstrdup(device), /*ma, mi,*/ label, partlabel, uuid, type);
 		return 1;
 	}
 	return 0;
@@ -288,6 +313,20 @@ char *get_devname_from_label(const char *spec)
 	return NULL;
 }

+char *get_devname_from_partlabel(const char *spec)
+{
+	struct uuidCache_s *uc;
+
+	uc = uuidcache_init(/*scan_devices:*/ 1);
+	while (uc) {
+		if (uc->partlabel[0] && strcmp(spec, uc->partlabel) == 0) {
+			return xstrdup(uc->device);
+		}
+		uc = uc->next;
+	}
+	return NULL;
+}
+
 char *get_devname_from_uuid(const char *spec)
 {
 	struct uuidCache_s *uc;
@@ -311,6 +350,8 @@ int resolve_mount_spec(char **fsname)
 		tmp = get_devname_from_uuid(*fsname + 5);
 	else if (is_prefixed_with(*fsname, "LABEL="))
 		tmp = get_devname_from_label(*fsname + 6);
+	else if (is_prefixed_with(*fsname, "PARTLABEL="))
+		tmp = get_devname_from_partlabel(*fsname + 10);

 	if (tmp == *fsname)
 		return 0; /* no UUID= or LABEL= prefix found */
diff --git a/util-linux/volume_id/volume_id_internal.h b/util-linux/volume_id/volume_id_internal.h
index b1e4448..d1d9d4d 100644
--- a/util-linux/volume_id/volume_id_internal.h
+++ b/util-linux/volume_id/volume_id_internal.h
@@ -76,6 +76,7 @@ struct volume_id {
 //	uint8_t		label_raw[VOLUME_ID_LABEL_SIZE];
 //	size_t		label_raw_len;
 	char		label[VOLUME_ID_LABEL_SIZE+1];
+	char		partlabel[VOLUME_ID_LABEL_SIZE+1];
 //	uint8_t		uuid_raw[VOLUME_ID_UUID_SIZE];
 //	size_t		uuid_raw_len;
 	/* uuid is stored in ASCII (not binary) form here: */
--
2.20.1