Kernel: Allow creating FIFOs in tmpfs

kernel/include/kernel/FS/TmpFS/Inode.h

@@ -82,6 +82,29 @@ namespace Kernel
 		friend class TmpInode;
 	};
 
+	// NOTE: this is just a dummy, when opening a fifo a pipe is created
+	class TmpFIFOInode : public TmpInode
+	{
+	public:
+		static BAN::ErrorOr<BAN::RefPtr<TmpFIFOInode>> create_new(TmpFileSystem&, mode_t, uid_t, gid_t);
+		~TmpFIFOInode();
+
+	protected:
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override { return BAN::Error::from_errno(ENODEV); }
+		virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan) override { return BAN::Error::from_errno(ENODEV); }
+		virtual BAN::ErrorOr<void> truncate_impl(size_t) override { return BAN::Error::from_errno(ENODEV); }
+
+		virtual bool can_read_impl() const override { return false; }
+		virtual bool can_write_impl() const override { return false; }
+		virtual bool has_error_impl() const override { return false; }
+		virtual bool has_hungup_impl() const override { return false; }
+
+	private:
+		TmpFIFOInode(TmpFileSystem&, ino_t, const TmpInodeInfo&);
+
+		friend class TmpInode;
+	};
+
 	class TmpSocketInode : public TmpInode
 	{
 	public:

kernel/kernel/FS/TmpFS/Inode.cpp

@@ -408,7 +408,32 @@ namespace Kernel
 		return {};
 	}
 
+	/* FIFO INODE */
+
+	BAN::ErrorOr<BAN::RefPtr<TmpFIFOInode>> TmpFIFOInode::create_new(TmpFileSystem& fs, mode_t mode, uid_t uid, gid_t gid)
+	{
+		auto info = create_inode_info(Mode::IFIFO | mode, uid, gid);
+		ino_t ino = TRY(fs.allocate_inode(info));
+
+		auto* inode_ptr = new TmpFIFOInode(fs, ino, info);
+		if (inode_ptr == nullptr)
+			return BAN::Error::from_errno(ENOMEM);
+
+		return BAN::RefPtr<TmpFIFOInode>::adopt(inode_ptr);
+	}
+
+	TmpFIFOInode::TmpFIFOInode(TmpFileSystem& fs, ino_t ino, const TmpInodeInfo& info)
+		: TmpInode(fs, ino, info)
+	{
+		ASSERT(mode().ififo());
+	}
+
+	TmpFIFOInode::~TmpFIFOInode()
+	{
+	}
+
 	/* SOCKET INODE */
+
 	BAN::ErrorOr<BAN::RefPtr<TmpSocketInode>> TmpSocketInode::create_new(TmpFileSystem& fs, mode_t mode, uid_t uid, gid_t gid)
 	{
 		auto info = create_inode_info(Mode::IFSOCK | mode, uid, gid);
@@ -679,6 +704,9 @@ namespace Kernel
 			case Mode::IFLNK:
 				new_inode = TRY(TmpSymlinkInode::create_new(m_fs, mode, uid, gid, ""_sv));
 				break;
+			case Mode::IFIFO:
+				new_inode = TRY(TmpFIFOInode::create_new(m_fs, mode, uid, gid));
+				break;
 			case Mode::IFSOCK:
 				new_inode = TRY(TmpSocketInode::create_new(m_fs, mode, uid, gid));
 				break;