zfs: recognize zpools formatted with features support

Currently no features are implemented, only the zpool version 5000 that
indicating the features support, is recognized. Since it is possible for
OpenZFS to create a pool with features support enabled, but without
enabling any actual feature, this change enables U-Boot to read such
pools.

Signed-off-by: WHR <msl0000023508@gmail.com>
diff --git a/fs/zfs/zfs.c b/fs/zfs/zfs.c
index c44e7ec..06221e6 100644
--- a/fs/zfs/zfs.c
+++ b/fs/zfs/zfs.c
@@ -333,6 +333,12 @@
 	return 0;
 }
 
+static inline int
+is_supported_spa_version(uint64_t version) {
+	return version == FEATURES_SUPPORTED_SPA_VERSION ||
+		(version > 0 && version <= SPA_VERSION);
+}
+
 /*
  * Three pieces of information are needed to verify an uberblock: the magic
  * number, the version number, and the checksum.
@@ -354,14 +360,12 @@
 		return ZFS_ERR_BAD_FS;
 	}
 
-	if (zfs_to_cpu64(uber->ub_magic, LITTLE_ENDIAN) == UBERBLOCK_MAGIC
-		&& zfs_to_cpu64(uber->ub_version, LITTLE_ENDIAN) > 0
-		&& zfs_to_cpu64(uber->ub_version, LITTLE_ENDIAN) <= SPA_VERSION)
+	if (zfs_to_cpu64(uber->ub_magic, LITTLE_ENDIAN) == UBERBLOCK_MAGIC &&
+		is_supported_spa_version(zfs_to_cpu64(uber->ub_version, LITTLE_ENDIAN)))
 		endian = LITTLE_ENDIAN;
 
-	if (zfs_to_cpu64(uber->ub_magic, BIG_ENDIAN) == UBERBLOCK_MAGIC
-		&& zfs_to_cpu64(uber->ub_version, BIG_ENDIAN) > 0
-		&& zfs_to_cpu64(uber->ub_version, BIG_ENDIAN) <= SPA_VERSION)
+	if (zfs_to_cpu64(uber->ub_magic, BIG_ENDIAN) == UBERBLOCK_MAGIC &&
+		is_supported_spa_version(zfs_to_cpu64(uber->ub_version, BIG_ENDIAN)))
 		endian = BIG_ENDIAN;
 
 	if (endian == UNKNOWN_ENDIAN) {
@@ -1787,7 +1791,7 @@
 		return ZFS_ERR_BAD_FS;
 	}
 
-	if (version > SPA_VERSION) {
+	if (!is_supported_spa_version(version)) {
 		free(nvlist);
 		printf("SPA version too new %llu > %llu\n",
 			   (unsigned long long) version,