From 1570e678819e53723dfdd5c8b668d1b75d4ced8f Mon Sep 17 00:00:00 2001 From: Liav A Date: Fri, 10 Apr 2020 00:36:39 +0300 Subject: [PATCH] Kernel: Allow again to boot with partitioned disk This change ensures that we don't return a zero value blindly from DiskPartition write/read methods. Fixes #1719. --- Kernel/Devices/DiskPartition.cpp | 29 +++++++++++++++++++++++++++++ Kernel/Devices/DiskPartition.h | 4 ++-- 2 files changed, 31 insertions(+), 2 deletions(-) diff --git a/Kernel/Devices/DiskPartition.cpp b/Kernel/Devices/DiskPartition.cpp index ac6504dad9..3e23371271 100644 --- a/Kernel/Devices/DiskPartition.cpp +++ b/Kernel/Devices/DiskPartition.cpp @@ -25,6 +25,7 @@ */ #include +#include // #define OFFD_DEBUG @@ -47,6 +48,34 @@ DiskPartition::~DiskPartition() { } +ssize_t DiskPartition::read(FileDescription& file_description, u8* buffer, ssize_t length) +{ + // FIXME: This is a hacky solution, but works fine for now... + off_t current_offset = file_description.seek(0, SEEK_CUR); + auto new_offset = current_offset + (m_block_offset * m_device->block_size()); + if ((new_offset / m_device->block_size()) > m_block_limit || ((new_offset + length) / m_device->block_size()) > m_block_limit) { + return 0; + } + file_description.seek(new_offset, SEEK_SET); + auto result = m_device->read(file_description, buffer, length); + file_description.seek(current_offset, SEEK_SET); + return result; +} + +ssize_t DiskPartition::write(FileDescription& file_description, const u8* buffer, ssize_t length) +{ + // FIXME: This is a hacky solution, but works fine for now... + off_t current_offset = file_description.seek(0, SEEK_CUR); + auto new_offset = current_offset + (m_block_offset * m_device->block_size()); + if ((new_offset / m_device->block_size()) > m_block_limit || ((new_offset + length) / m_device->block_size()) > m_block_limit) { + return 0; + } + file_description.seek(new_offset, SEEK_SET); + auto result = m_device->write(file_description, buffer, length); + file_description.seek(current_offset, SEEK_SET); + return result; +} + bool DiskPartition::read_blocks(unsigned index, u16 count, u8* out) { #ifdef OFFD_DEBUG diff --git a/Kernel/Devices/DiskPartition.h b/Kernel/Devices/DiskPartition.h index 7f910e957f..06feec61b8 100644 --- a/Kernel/Devices/DiskPartition.h +++ b/Kernel/Devices/DiskPartition.h @@ -40,9 +40,9 @@ public: virtual bool write_blocks(unsigned index, u16 count, const u8*) override; // ^BlockDevice - virtual ssize_t read(FileDescription&, u8*, ssize_t) override { return 0; } + virtual ssize_t read(FileDescription&, u8*, ssize_t) override; virtual bool can_read(const FileDescription&) const override { return true; } - virtual ssize_t write(FileDescription&, const u8*, ssize_t) override { return 0; } + virtual ssize_t write(FileDescription&, const u8*, ssize_t) override; virtual bool can_write(const FileDescription&) const override { return true; } private: