efi_loader: correct file creation

The EFI shell expects that after opening a file with EFI_FILE_MODE_CREATE
GetInfo() succeeds. Up to now we do not actually create the file when
method Open() of the EFI_FILE_PROTOCOL is called.

If method Open() of the EFI_FILE_PROTOCOL is called with
EFI_FILE_MODE_CREATE and the file does not yet exist, call fs_write() with
a buffer size of zero to actually create the file.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c
index be3e55f4d87bc2b6438328c631f118cbfb140bdd..e7ea2466fe425f3842a71e74cda59eb410ef6518 100644 (file)
--- a/lib/efi_loader/efi_file.c
+++ b/lib/efi_loader/efi_file.c
@@ -134,6 +134,25 @@ static int sanitize_path(char *path)
        return 0;
 }
 
+/**
+ * efi_create_file() - create file or directory
+ *
+ * @fh:                        file handle
+ * @attributes:                attributes for newly created file
+ * Returns:            0 for success
+ */
+static int efi_create_file(struct file_handle *fh, u64 attributes)
+{
+       loff_t actwrite;
+       void *buffer = &actwrite;
+
+       if (attributes & EFI_FILE_DIRECTORY)
+               return fs_mkdir(fh->path);
+       else
+               return fs_write(fh->path, map_to_sysmem(buffer), 0, 0,
+                               &actwrite);
+}
+
 /**
  * file_open() - open a file handle
  *
@@ -176,6 +195,7 @@ static struct efi_file_handle *file_open(struct file_system *fs,
 
        if (parent) {
                char *p = fh->path;
+               int exists;
 
                if (plen > 0) {
                        strcpy(p, parent->path);
@@ -192,18 +212,17 @@ static struct efi_file_handle *file_open(struct file_system *fs,
                if (set_blk_dev(fh))
                        goto error;
 
-               if ((mode & EFI_FILE_MODE_CREATE) &&
-                   (attributes & EFI_FILE_DIRECTORY)) {
-                       if (fs_mkdir(fh->path))
-                               goto error;
-               } else if (!((mode & EFI_FILE_MODE_CREATE) ||
-                            fs_exists(fh->path)))
-                       goto error;
-
+               exists = fs_exists(fh->path);
                /* fs_exists() calls fs_close(), so open file system again */
                if (set_blk_dev(fh))
                        goto error;
 
+               if (!exists) {
+                       if (!(mode & EFI_FILE_MODE_CREATE) ||
+                           efi_create_file(fh, attributes))
+                               goto error;
+               }
+
                /* figure out if file is a directory: */
                fh->isdir = is_dir(fh);
        } else {