IDEDiskDevice: Detect disk errors and report failure to clients.

Previously we'd just fail silently if there was an I/O error of any kind.

Kernel/Ext2FileSystem.cpp

@@ -29,8 +29,10 @@ Ext2FS::~Ext2FS()
 ByteBuffer Ext2FS::read_super_block() const
 {
     auto buffer = ByteBuffer::create_uninitialized(1024);
-    device().read_block(2, buffer.pointer());
-    device().read_block(3, buffer.offset_pointer(512));
+    bool success = device().read_block(2, buffer.pointer());
+    ASSERT(success);
+    success = device().read_block(3, buffer.offset_pointer(512));
+    ASSERT(success);
     return buffer;
 }
 
@@ -220,7 +222,8 @@ bool Ext2FS::write_block_list_for_inode(InodeIndex inode_index, ext2_inode& e2in
             --remaining_blocks;
         }
         stream.fill_to_end(0);
-        write_block(e2inode.i_block[EXT2_IND_BLOCK], block_contents);
+        bool success = write_block(e2inode.i_block[EXT2_IND_BLOCK], block_contents);
+        ASSERT(success);
     }
 
     if (!remaining_blocks)
@@ -540,6 +543,7 @@ ssize_t Ext2FSInode::write_bytes(off_t offset, size_t count, const byte* data, F
         bool success = fs().write_block(block_list[bi], block);
         if (!success) {
             kprintf("Ext2FSInode::write_bytes: write_block(%u) failed (lbi: %u)\n", block_list[bi], bi);
+            ASSERT_NOT_REACHED();
             return -EIO;
         }
         remaining_count -= num_bytes_to_copy;
@@ -826,8 +830,9 @@ bool Ext2FS::write_ext2_inode(unsigned inode, const ext2_inode& e2inode)
     if (!block)
         return false;
     memcpy(reinterpret_cast<ext2_inode*>(block.offset_pointer(offset)), &e2inode, inode_size());
-    write_block(block_index, block);
-    return true;
+    bool success = write_block(block_index, block);
+    ASSERT(success);
+    return success;
 }
 
 Vector<Ext2FS::BlockIndex> Ext2FS::allocate_blocks(unsigned group, unsigned count)
@@ -956,7 +961,8 @@ bool Ext2FS::set_inode_allocation_state(unsigned index, bool newState)
         return true;
 
     bitmap.set(bit_index, newState);
-    write_block(bgd.bg_inode_bitmap + bitmap_block_index, block);
+    bool success = write_block(bgd.bg_inode_bitmap + bitmap_block_index, block);
+    ASSERT(success);
 
     // Update superblock
     auto& sb = *reinterpret_cast<ext2_super_block*>(m_cached_super_block.pointer());
@@ -998,7 +1004,8 @@ bool Ext2FS::set_block_allocation_state(GroupIndex group, BlockIndex bi, bool ne
         return true;
 
     bitmap.set(bit_index, new_state);
-    write_block(bgd.bg_block_bitmap + bitmap_block_index, block);
+    bool success = write_block(bgd.bg_block_bitmap + bitmap_block_index, block);
+    ASSERT(success);
 
     // Update superblock
     auto& sb = *reinterpret_cast<ext2_super_block*>(m_cached_super_block.pointer());

Kernel/IDEDiskDevice.cpp

@@ -60,17 +60,14 @@ unsigned IDEDiskDevice::block_size() const
 
 bool IDEDiskDevice::read_block(unsigned index, byte* out) const
 {
-    const_cast<IDEDiskDevice&>(*this).read_sectors(index, 1, out);
-    return true;
+    return const_cast<IDEDiskDevice&>(*this).read_sectors(index, 1, out);
 }
 
 bool IDEDiskDevice::write_block(unsigned index, const byte* data)
 {
-    write_sectors(index, 1, data);
-    return true;
+    return write_sectors(index, 1, data);
 }
 
-#ifdef DISK_DEBUG
 static void print_ide_status(byte status)
 {
     kprintf("DRQ=%u BUSY=%u DRDY=%u SRV=%u DF=%u CORR=%u IDX=%u ERR=%u\n",
@@ -83,7 +80,6 @@ static void print_ide_status(byte status)
             (status & IDX) != 0,
             (status & ERR) != 0);
 }
-#endif
 
 bool IDEDiskDevice::wait_for_irq()
 {
@@ -98,13 +94,21 @@ bool IDEDiskDevice::wait_for_irq()
 #ifdef DISK_DEBUG
     kprintf("disk: got interrupt!\n");
 #endif
+    memory_barrier();
     return true;
 }
 
 void IDEDiskDevice::handle_irq()
 {
-#ifdef DISK_DEBUG
     byte status = IO::in8(0x1f7);
+    if (status & ERR) {
+        print_ide_status(status);
+        m_device_error = IO::in8(0x1f1);
+        kprintf("IDEDiskDevice: Error %b!\n", m_device_error);
+    } else {
+        m_device_error = 0;
+    }
+#ifdef DISK_DEBUG
     kprintf("disk:interrupt: DRQ=%u BUSY=%u DRDY=%u\n", (status & DRQ) != 0, (status & BUSY) != 0, (status & DRDY) != 0);
 #endif
     m_interrupted = true;
@@ -206,6 +210,9 @@ bool IDEDiskDevice::read_sectors(dword start_sector, word count, byte* outbuf)
     enable_irq();
     wait_for_irq();
 
+    if (m_device_error)
+        return false;
+
     byte status = IO::in8(0x1f7);
     if (status & DRQ) {
 #ifdef DISK_DEBUG
@@ -265,5 +272,5 @@ bool IDEDiskDevice::write_sectors(dword start_sector, word count, const byte* da
     enable_irq();
     wait_for_irq();
 
-    return true;
+    return !m_device_error;
 }

Kernel/IDEDiskDevice.h

@@ -41,7 +41,8 @@ private:
     word m_cylinders { 0 };
     word m_heads { 0 };
     word m_sectors_per_track { 0 };
-    mutable volatile bool m_interrupted { false };
+    volatile bool m_interrupted { false };
+    volatile byte m_device_error { 0 };
 
 };