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Kernel/Storage: Use more locking in the IDE code

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This change should make it less possible for race conditions to happen
and cause fatal errors when accessing the hardware.
This commit is contained in:
Liav A 2021-03-27 09:53:59 +03:00 • committed by Andreas Kling
parent 8b446fb579
commit b96e4c1308
3 changed files with 58 additions and 44 deletions
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55
Kernel/Storage/IDEChannel.cpp
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@ -94,11 +94,12 @@ UNMAP_AFTER_INIT IDEChannel::~IDEChannel()
void IDEChannel::start_request(AsyncBlockDeviceRequest& request, bool is_slave, u16 capabilities)
{
ScopedSpinLock lock(m_request_lock);
LOCKER(m_lock);
VERIFY(m_current_request.is_null());
dbgln_if(PATA_DEBUG, "IDEChannel::start_request");
m_current_request = &request;
m_current_request = request;
m_current_request_block_index = 0;
m_current_request_flushing_cache = false;
@ -120,13 +121,11 @@ void IDEChannel::complete_current_request(AsyncDeviceRequest::RequestResult resu
// before Processor::deferred_call_queue returns!
g_io_work->queue([this, result]() {
dbgln_if(PATA_DEBUG, "IDEChannel::complete_current_request result: {}", (int)result);
ScopedSpinLock lock(m_request_lock);
LOCKER(m_lock);
VERIFY(m_current_request);
auto& request = *m_current_request;
m_current_request = nullptr;
lock.unlock();
request.complete(result);
auto current_request = m_current_request;
m_current_request.clear();
current_request->complete(result);
});
}
@ -145,6 +144,7 @@ static void print_ide_status(u8 status)
void IDEChannel::try_disambiguate_error()
{
VERIFY(m_lock.is_locked());
dbgln("IDEChannel: Error cause:");
switch (m_device_error) {
@ -208,10 +208,12 @@ void IDEChannel::handle_irq(const RegisterState&)
// Now schedule reading/writing the buffer as soon as we leave the irq handler.
// This is important so that we can safely access the buffers, which could
// trigger page faults
Processor::deferred_call_queue([this]() {
g_io_work->queue([this]() {
LOCKER(m_lock);
ScopedSpinLock lock(m_request_lock);
if (m_current_request->request_type() == AsyncBlockDeviceRequest::Read) {
dbgln_if(PATA_DEBUG, "IDEChannel: Read block {}/{}", m_current_request_block_index, m_current_request->block_count());
if (ata_do_read_sector()) {
if (++m_current_request_block_index >= m_current_request->block_count()) {
complete_current_request(AsyncDeviceRequest::Success);
@ -355,6 +357,8 @@ UNMAP_AFTER_INIT void IDEChannel::detect_disks()
void IDEChannel::ata_access(Direction direction, bool slave_request, u64 lba, u8 block_count, u16 capabilities)
{
VERIFY(m_lock.is_locked());
VERIFY(m_request_lock.is_locked());
LBAMode lba_mode;
u8 head = 0;
@ -403,6 +407,9 @@ void IDEChannel::send_ata_io_command(LBAMode lba_mode, Direction direction) cons
bool IDEChannel::ata_do_read_sector()
{
VERIFY(m_lock.is_locked());
VERIFY(m_request_lock.is_locked());
VERIFY(!m_current_request.is_null());
dbgln_if(PATA_DEBUG, "IDEChannel::ata_do_read_sector");
auto& request = *m_current_request;
auto out_buffer = request.buffer().offset(m_current_request_block_index * 512);
@ -422,18 +429,21 @@ bool IDEChannel::ata_do_read_sector()
// FIXME: This doesn't quite work and locks up reading LBA 3.
void IDEChannel::ata_read_sectors(bool slave_request, u16 capabilities)
{
auto& request = *m_current_request;
VERIFY(request.block_count() <= 256);
VERIFY(m_lock.is_locked());
VERIFY(!m_current_request.is_null());
VERIFY(m_current_request->block_count() <= 256);
ScopedSpinLock m_lock(m_request_lock);
dbgln_if(PATA_DEBUG, "IDEChannel::ata_read_sectors");
auto lba = request.block_index();
dbgln_if(PATA_DEBUG, "IDEChannel: Reading {} sector(s) @ LBA {}", request.block_count(), lba);
ata_access(Direction::Read, slave_request, lba, request.block_count(), capabilities);
dbgln_if(PATA_DEBUG, "IDEChannel: Reading {} sector(s) @ LBA {}", m_current_request->block_count(), m_current_request->block_index());
ata_access(Direction::Read, slave_request, m_current_request->block_index(), m_current_request->block_count(), capabilities);
}
void IDEChannel::ata_do_write_sector()
{
VERIFY(m_lock.is_locked());
VERIFY(m_request_lock.is_locked());
VERIFY(!m_current_request.is_null());
auto& request = *m_current_request;
io_delay();
@ -457,14 +467,13 @@ void IDEChannel::ata_do_write_sector()
// FIXME: I'm assuming this doesn't work based on the fact PIO read doesn't work.
void IDEChannel::ata_write_sectors(bool slave_request, u16 capabilities)
{
auto& request = *m_current_request;
VERIFY(m_lock.is_locked());
VERIFY(!m_current_request.is_null());
VERIFY(m_current_request->block_count() <= 256);
VERIFY(request.block_count() <= 256);
auto start_sector = request.block_index();
u32 count = request.block_count();
dbgln_if(PATA_DEBUG, "IDEChannel: Writing {} sector(s) @ LBA {}", count, start_sector);
ata_access(Direction::Write, slave_request, start_sector, request.block_count(), capabilities);
ScopedSpinLock m_lock(m_request_lock);
dbgln_if(PATA_DEBUG, "IDEChannel: Writing {} sector(s) @ LBA {}", m_current_request->block_count(), m_current_request->block_index());
ata_access(Direction::Write, slave_request, m_current_request->block_index(), m_current_request->block_count(), capabilities);
ata_do_write_sector();
}
}