efi_loader: disk: install FILE_SYSTEM_PROTOCOL only if available

In the current implementation, EFI_SIMPLEFILE_SYSTEM_PROTOCOL is always
installed to all the partitions even if some of them may house no file
system.

With this patch, that protocol will be installed only if any file system
exists.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
index 9007a5f77f3d05950cf37e066c03f43ff1c295e7..861fcaf3747ff87f5d946b380a18d55fac55f360 100644 (file)
--- a/lib/efi_loader/efi_disk.c
+++ b/lib/efi_loader/efi_disk.c
@@ -9,6 +9,7 @@
 #include <blk.h>
 #include <dm.h>
 #include <efi_loader.h>
+#include <fs.h>
 #include <part.h>
 #include <malloc.h>
 
@@ -262,6 +263,27 @@ efi_fs_from_path(struct efi_device_path *full_path)
        return handler->protocol_interface;
 }
 
+/**
+ * efi_fs_exists() - check if a partition bears a file system
+ *
+ * @desc:      block device descriptor
+ * @part:      partition number
+ * Return:     1 if a file system exists on the partition
+ *             0 otherwise
+ */
+static int efi_fs_exists(struct blk_desc *desc, int part)
+{
+       if (fs_set_blk_dev_with_part(desc, part))
+               return 0;
+
+       if (fs_get_type() == FS_TYPE_ANY)
+               return 0;
+
+       fs_close();
+
+       return 1;
+}
+
 /*
  * Create a handle for a partition or disk
  *
@@ -315,7 +337,7 @@ static efi_status_t efi_disk_add_dev(
                               diskobj->dp);
        if (ret != EFI_SUCCESS)
                return ret;
-       if (part >= 1) {
+       if (part >= 1 && efi_fs_exists(desc, part)) {
                diskobj->volume = efi_simple_file_system(desc, part,
                                                         diskobj->dp);
                ret = efi_add_protocol(&diskobj->header,