diff --git a/fastboot/engine.cpp b/fastboot/engine.cpp
index 63e8971..44796d7 100644
--- a/fastboot/engine.cpp
+++ b/fastboot/engine.cpp
@@ -88,24 +88,6 @@
     return true;
 }
 
-
-// Return true if this partition is supported by the fastboot format command.
-// It is also used to determine if we should first erase a partition before
-// flashing it with an ext4 filesystem.  See needs_erase()
-//
-// Not all devices report the filesystem type, so don't report any errors,
-// just return false.
-bool fb_format_supported(usb_handle *usb, const char *partition, const char *type_override) {
-    if (type_override) {
-        return fs_get_generator(type_override) != nullptr;
-    }
-    std::string partition_type;
-    if (!fb_getvar(usb, std::string("partition-type:") + partition, &partition_type)) {
-        return false;
-    }
-    return fs_get_generator(partition_type.c_str()) != nullptr;
-}
-
 static int cb_default(Action* a, int status, const char* resp) {
     if (status) {
         fprintf(stderr,"FAILED (%s)\n", resp);
diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index 6b845a0..226f3ef 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -44,6 +44,7 @@
 #include <unistd.h>
 
 #include <base/parseint.h>
+#include <base/strings.h>
 #include <sparse/sparse.h>
 #include <ziparchive/zip_archive.h>
 
@@ -575,6 +576,9 @@
         return 0;
     }
 
+    // Some bootloaders (angler, for example) send spurious whitespace too.
+    max_download_size = android::base::Trim(max_download_size);
+
     uint64_t limit;
     if (!android::base::ParseUint(max_download_size.c_str(), &limit)) {
         fprintf(stderr, "couldn't parse max-download-size '%s'\n", max_download_size.c_str());
@@ -614,8 +618,12 @@
 // Until we get lazy inode table init working in make_ext4fs, we need to
 // erase partitions of type ext4 before flashing a filesystem so no stale
 // inodes are left lying around.  Otherwise, e2fsck gets very upset.
-static bool needs_erase(usb_handle* usb, const char* part) {
-    return !fb_format_supported(usb, part, nullptr);
+static bool needs_erase(usb_handle* usb, const char* partition) {
+    std::string partition_type;
+    if (!fb_getvar(usb, std::string("partition-type:") + partition, &partition_type)) {
+        return false;
+    }
+    return partition_type == "ext4";
 }
 
 static int load_buf_fd(usb_handle* usb, int fd, struct fastboot_buffer* buf) {
@@ -889,7 +897,7 @@
         partition_size = size_override;
     }
 
-    gen = fs_get_generator(partition_type.c_str());
+    gen = fs_get_generator(partition_type);
     if (!gen) {
         if (skip_if_not_supported) {
             fprintf(stderr, "Erase successful, but not automatically formatting.\n");
@@ -1059,8 +1067,11 @@
         } else if(!strcmp(*argv, "erase")) {
             require(2);
 
-            if (!fb_format_supported(usb, argv[1], nullptr)) {
-                fprintf(stderr, "******** Did you mean to fastboot format this partition?\n");
+            std::string partition_type;
+            if (fb_getvar(usb, std::string("partition-type:") + argv[1], &partition_type) &&
+                fs_get_generator(partition_type) != nullptr) {
+                fprintf(stderr, "******** Did you mean to fastboot format this %s partition?\n",
+                        partition_type.c_str());
             }
 
             fb_queue_erase(argv[1]);
diff --git a/fastboot/fastboot.h b/fastboot/fastboot.h
index a66c211..9e33531 100644
--- a/fastboot/fastboot.h
+++ b/fastboot/fastboot.h
@@ -50,7 +50,6 @@
 
 /* engine.c - high level command queue engine */
 bool fb_getvar(usb_handle* usb, const std::string& key, std::string* value);
-bool fb_format_supported(usb_handle* usb, const char* partition, const char* type_override);
 void fb_queue_flash(const char *ptn, void *data, uint32_t sz);
 void fb_queue_flash_sparse(const char *ptn, struct sparse_file *s, uint32_t sz);
 void fb_queue_erase(const char *ptn);
diff --git a/fastboot/fs.cpp b/fastboot/fs.cpp
index c58a505..90d8474 100644
--- a/fastboot/fs.cpp
+++ b/fastboot/fs.cpp
@@ -39,9 +39,9 @@
 #endif
 };
 
-const struct fs_generator* fs_get_generator(const char* fs_type) {
+const struct fs_generator* fs_get_generator(const std::string& fs_type) {
     for (size_t i = 0; i < sizeof(generators) / sizeof(*generators); i++) {
-        if (strcmp(generators[i].fs_type, fs_type) == 0) {
+        if (fs_type == generators[i].fs_type) {
             return generators + i;
         }
     }
diff --git a/fastboot/fs.h b/fastboot/fs.h
index 8444081..289488b 100644
--- a/fastboot/fs.h
+++ b/fastboot/fs.h
@@ -5,8 +5,7 @@
 
 struct fs_generator;
 
-const struct fs_generator* fs_get_generator(const char *fs_type);
+const struct fs_generator* fs_get_generator(const std::string& fs_type);
 int fs_generator_generate(const struct fs_generator* gen, int tmpFileNo, long long partSize);
 
 #endif
-