VFS: Populate the initial filesystem based on the initial ramdisk

kernel/src/InitRD.cpp

@@ -1,6 +1,7 @@
 #include "InitRD.h"
 #include "arch/MMU.h"
 #include "boot/bootboot.h"
+#include "fs/VFS.h"
 
 TarStream g_initrd;
 extern const BOOTBOOT bootboot;
@@ -11,3 +12,29 @@ void InitRD::initialize()
 
     g_initrd.initialize((void*)virtual_initrd_address, bootboot.initrd_size);
 }
+
+static Result<void> vfs_create_dir_if_not_exists(const char* path)
+{
+    auto rc = VFS::create_directory(path);
+    if (rc.has_error())
+    {
+        if (rc.error() == EEXIST) return {};
+        return rc.release_error();
+    }
+    return {};
+}
+
+Result<void> InitRD::populate_vfs()
+{
+    TarStream::Entry entry;
+    while (TRY(g_initrd.read_next_entry(entry)))
+    {
+        if (entry.type == TarStream::EntryType::RegularFile)
+        {
+            auto file = TRY(VFS::create_file(entry.name));
+            file->write(entry.data(), 0, entry.size);
+        }
+        else if (entry.type == TarStream::EntryType::Directory) { TRY(vfs_create_dir_if_not_exists(entry.name)); }
+    }
+    return {};
+}

kernel/src/InitRD.h

@@ -6,4 +6,5 @@ extern TarStream g_initrd;
 namespace InitRD
 {
     void initialize();
+    Result<void> populate_vfs();
 }

kernel/src/fs/VFS.cpp

@@ -15,18 +15,12 @@ namespace VFS
     {
         auto parser = TRY(PathParser::create(path));
 
-        kdbgln("vfs: trying to resolve path %s", path);
-
         SharedPtr<Inode> current_inode = root_fs->root_inode();
 
         // FIXME: Properly handle relative paths.
 
         const char* section;
-        while (parser.next().try_set_value(section))
-        {
-            kdbgln("vfs: searching for entry '%s' in inode %zu", section, current_inode->inode_number());
-            current_inode = TRY(current_inode->find(section));
-        }
+        while (parser.next().try_set_value(section)) { current_inode = TRY(current_inode->find(section)); }
 
         return current_inode;
     }
@@ -40,8 +34,22 @@ namespace VFS
 
         auto child_name = TRY(parser.basename());
 
-        kdbgln("vfs: creating directory '%s' in parent '%s'", child_name.chars(), parent_path.chars());
+        // kdbgln("vfs: creating directory '%s' in parent '%s'", child_name.chars(), parent_path.chars());
 
         return parent_inode->create_subdirectory(child_name.chars());
     }
+
+    Result<SharedPtr<Inode>> create_file(const char* path)
+    {
+        auto parser = TRY(PathParser::create(path));
+        auto parent_path = TRY(parser.dirname());
+
+        auto parent_inode = TRY(resolve_path(parent_path.chars()));
+
+        auto child_name = TRY(parser.basename());
+
+        // kdbgln("vfs: creating file '%s' in parent '%s'", child_name.chars(), parent_path.chars());
+
+        return parent_inode->create_file(child_name.chars());
+    }
 }

kernel/src/fs/VFS.h

@@ -79,6 +79,7 @@ namespace VFS
     Result<SharedPtr<Inode>> resolve_path(const char* path);
 
     Result<SharedPtr<Inode>> create_directory(const char* path);
+    Result<SharedPtr<Inode>> create_file(const char* path);
 
     Inode& root_inode();
 }

kernel/src/main.cpp

@@ -51,37 +51,7 @@ static Result<void> try_init_vfs()
 {
     VFS::root_fs = TRY(TmpFS::FileSystem::create());
 
-    VFS::Inode& root_inode = VFS::root_inode();
-
-    kinfoln("root inode number: %zu", root_inode.inode_number());
-
-    kinfoln("root inode's '.' entry inode number: %zu", TRY(root_inode.find("."))->inode_number());
-    kinfoln("root inode's '..' entry inode number: %zu", TRY(root_inode.find(".."))->inode_number());
-
-    TRY(VFS::create_directory("/etc/"));
-
-    kinfoln("root inode's 'etc' entry inode number: %zu", TRY(root_inode.find("etc"))->inode_number());
-
-    auto& etc = *TRY(root_inode.find("etc"));
-
-    kinfoln("etc inode's '.' entry inode number: %zu", TRY(etc.find("."))->inode_number());
-    kinfoln("etc inode's '..' entry inode number: %zu", TRY(etc.find(".."))->inode_number());
-
-    TRY(etc.create_file("passwd"));
-
-    kinfoln("etc inode's 'passwd' entry inode number: %zu", TRY(etc.find("passwd"))->inode_number());
-
-    auto& passwd = *TRY(VFS::resolve_path("/etc/passwd"));
-
-    kinfoln("/etc/passwd's inode number: %zu", passwd.inode_number());
-
-    const char* data = "hello, world!";
-    TRY(passwd.write((const u8*)data, 0, 14));
-
-    char output[14];
-    TRY(passwd.read((u8*)output, 0, 14));
-
-    kinfoln("/etc/passwd contents: '%s'", output);
+    InitRD::populate_vfs();
 
     return {};
 }
@@ -94,6 +64,7 @@ static void init_vfs()
 static Result<void> try_init_userspace()
 {
     TarStream::Entry entry;
+    g_initrd.rewind();
     while (TRY(g_initrd.read_next_entry(entry)))
     {
         if (entry.type == TarStream::EntryType::RegularFile)