From: Daniel Golle <daniel@makrotopia.org>
Date: Fri, 19 Mar 2021 12:13:33 +0000 (+0000)
Subject: partname: allow skipping existing 'rootfs_data' partition
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=964d1e3af0e111bad6d393f8a3be702e334c2398;p=project%2Ffstools.git

partname: allow skipping existing 'rootfs_data' partition

Apparently some devices with eMMC (e.g. ZyXEL NBG6817) got an exsiting
GPT partition called 'rootfs_data'. This partition is then selected
as rootfs_data eventhough it may not be suitable for that (too small)
or serve another purpose (ie. used by vendor firmware).
To avoid this, check if the kernel cmdline contains a variable
fstools_ignore_partname=1 and if so, skip partname detection of volumes
alltogether.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---

diff --git a/libfstools/partname.c b/libfstools/partname.c
index 4560125..5d4fde5 100644
--- a/libfstools/partname.c
+++ b/libfstools/partname.c
@@ -85,7 +85,7 @@ static char* get_cmdline_val(const char* name, char* out, int len)
 			continue;
 
 		strncpy(out, &sep[1], len);
-		out[len-1] = 0;
+		out[len-1] = '\0';
 		return out;
 	}
 
@@ -120,6 +120,11 @@ static struct volume *partname_volume_find(char *name)
 	bool found = false;
 	glob_t gl;
 
+	if (get_cmdline_val("fstools_ignore_partname", rootparam, sizeof(rootparam))) {
+		if (!strcmp("1", rootparam))
+			return NULL;
+	}
+
 	if (get_cmdline_val("root", rootparam, sizeof(rootparam))) {
 		rootdev = rootdevname(rootparam);
 		/* find partition on same device as rootfs */