devfs: Do not create overlapping partitions

Until now it has been possible to create overlapping partitions. Go away
from that and allow to create partitions only in unallocated areas of a
device. This lowers the risk of having inconsistent partitioning and
increases the chance that inconsistent partitioning is recognized by
the user.

We had explicit overlap checking for the environment partition which
becomes unnecessary with this change and is removed.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.barebox.org/20211011073025.4187545-1-s.hauer@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 1 insertions, 69 deletions

diff --git a/common/startup.c b/common/startup.c
index f72902fc53..f53b73f81a 100644
--- a/common/startup.c
+++ b/common/startup.c
@@ -68,70 +68,6 @@ static int mount_root(void)
 fs_initcall(mount_root);
 #endif
 
-#ifdef CONFIG_ENV_HANDLING
-static bool region_overlap(loff_t starta, loff_t lena,
-			   loff_t startb, loff_t lenb)
-{
-	if (starta + lena <= startb)
-		return 0;
-	if (startb + lenb <= starta)
-		return 0;
-	return 1;
-}
-
-static int check_overlap(const char *path)
-{
-	struct cdev *cenv, *cdisk, *cpart;
-	const char *name;
-
-	name = devpath_to_name(path);
-
-	if (name == path)
-		/*
-		 * no /dev/ in front, so *path is some file. No need to
-		 * check further.
-		 */
-		return 0;
-
-	cenv = cdev_by_name(name);
-	if (!cenv)
-		return -EINVAL;
-
-	if (cenv->mtd)
-		return 0;
-
-	cdisk = cenv->master;
-
-	if (!cdisk)
-		return 0;
-
-	list_for_each_entry(cpart, &cdisk->partitions, partition_entry) {
-		if (cpart == cenv)
-			continue;
-
-		if (region_overlap(cpart->offset, cpart->size,
-				   cenv->offset, cenv->size))
-			goto conflict;
-	}
-
-	return 0;
-
-conflict:
-	pr_err("Environment partition (0x%08llx-0x%08llx) "
-		"overlaps with partition %s (0x%08llx-0x%08llx), not using it\n",
-		cenv->offset, cenv->offset + cenv->size - 1,
-		cpart->name,
-		cpart->offset, cpart->offset + cpart->size - 1);
-
-	return -EINVAL;
-}
-#else
-static int check_overlap(const char *path)
-{
-	return 0;
-}
-#endif
-
 static int load_environment(void)
 {
 	const char *default_environment_path;
@@ -143,11 +79,7 @@ static int load_environment(void)
 		defaultenv_load("/env", 0);
 
 	if (IS_ENABLED(CONFIG_ENV_HANDLING)) {
-		ret = check_overlap(default_environment_path);
-		if (ret)
-			default_environment_path_set(NULL);
-		else
-			envfs_load(default_environment_path, "/env", 0);
+		envfs_load(default_environment_path, "/env", 0);
 	} else {
 		if (IS_ENABLED(CONFIG_DEFAULT_ENVIRONMENT))
 			pr_notice("No support for persistent environment. Using default environment\n");