Allow creating empty filesystem images

Support creating empty filesystem images by making the source directory
argument optional.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>
This commit is contained in:
Jo-Philipp Wich 2016-08-14 21:55:40 +02:00
parent 3af931b0b6
commit 484903e433

View File

@ -45,6 +45,27 @@ static int filter_dot(const struct dirent *d)
return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
}
static u32 build_default_directory_structure(time_t fixed_time)
{
u32 inode;
u32 root_inode;
struct dentry dentries = {
.filename = "lost+found",
.file_type = EXT4_FT_DIR,
.mode = S_IRWXU,
.uid = 0,
.gid = 0,
.mtime = (fixed_time != -1) ? fixed_time : 0,
};
root_inode = make_directory(0, 1, &dentries, 1);
inode = make_directory(root_inode, 0, NULL, 0);
*dentries.inode = inode;
inode_set_permissions(inode, dentries.mode,
dentries.uid, dentries.gid, dentries.mtime);
return root_inode;
}
/* Read a local directory and create the same tree in the generated filesystem.
Calls itself recursively with each directory in the given directory.
full_path is an absolute or relative path, with a trailing slash, to the
@ -367,11 +388,7 @@ int make_ext4fs_internal(int fd, const char *_directory,
if (setjmp(setjmp_env))
return EXIT_FAILURE; /* Handle a call to longjmp() */
if (_directory == NULL) {
fprintf(stderr, "Need a source directory\n");
return EXIT_FAILURE;
}
if (_directory)
directory = canonicalize_rel_slashes(_directory);
if (info.len <= 0)
@ -457,11 +474,15 @@ int make_ext4fs_internal(int fd, const char *_directory,
if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
ext4_create_resize_inode();
if (directory)
root_inode_num = build_directory_structure(directory, "", 0,
fs_config_func, verbose, fixed_time);
else
root_inode_num = build_default_directory_structure(fixed_time);
root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
inode_set_permissions(root_inode_num, root_mode, 0, 0,
(fixed_time != 1) ? fixed_time : 0);
ext4_update_free();