From e5e0078f9cc3bf614ee15db07606641d9e252329 Mon Sep 17 00:00:00 2001
From: notsomeidiot123 <kiminosei321@gmail.com>
Date: Fri, 23 Jan 2026 15:37:43 -0500
Subject: [PATCH] Added spinlocks to ata_read() and ata_write(), fixed exiting
 DMA transfer too early

---
 src/kernel/system/scheduler.c |  1 +
 src/kmodules/disk_driver.c    | 19 ++++++++++++++-----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/kernel/system/scheduler.c b/src/kernel/system/scheduler.c
index 720b04b..33ae23c 100644
--- a/src/kernel/system/scheduler.c
+++ b/src/kernel/system/scheduler.c
@@ -73,6 +73,7 @@ void remove_process_queue(uint32_t pid){
     process_queue[old_index] = process_queue[last_queue_index];
     process_queue[last_queue_index] = 0;
     queue_length--;
+    current_queue_index--;
 }
 
 uint32_t spawn_new_process(cpu_registers_t defaultregs, char **argv, uint32_t argc, void *cr3){
diff --git a/src/kmodules/disk_driver.c b/src/kmodules/disk_driver.c
index 3acb838..a3d2dde 100644
--- a/src/kmodules/disk_driver.c
+++ b/src/kmodules/disk_driver.c
@@ -139,7 +139,8 @@ enum DRIVE_TYPE{
 uint32_t volatile transferring_disk_index = -1;
 uint32_t expected_ints = 0;
 uint32_t recieved_ints = 0;
-uint32_t transferring_pid = 0;
+uint32_t volatile transferring_pid = 0;
+// uint8_t volatile locked = 0;
 
 typedef struct drive_desc{
     uint32_t BARs[8];
@@ -193,7 +194,7 @@ uint32_t find_free_drive(){
 
 int ata_write(vfile_t *file, void *ptr, uint32_t offset, uint32_t count){
     if (count == 0) return -1;
-    
+    while(transferring_disk_index != -1);
     drive_t drive = drives[file->mount_id];
     uint16_t io_base = drive.BARs[0] &0xfffe;
     uint16_t ctrl_base = drive.BARs[1] &0xfffe;
@@ -287,7 +288,6 @@ int ata_write(vfile_t *file, void *ptr, uint32_t offset, uint32_t count){
 
 int ata_read(vfile_t *file, uint8_t *ptr, uint32_t offset, uint32_t count) {
     if (count == 0) return -1;
-    
     drive_t drive = drives[file->mount_id];
     uint16_t io_base = drive.BARs[0] &0xfffe;
     uint16_t ctrl_base = drive.BARs[1] &0xfffe;
@@ -298,6 +298,10 @@ int ata_read(vfile_t *file, uint8_t *ptr, uint32_t offset, uint32_t count) {
     api(MODULE_API_PRINT, MODULE_NAME, "%x, %x, %x, %x\n", io_base, ctrl_base, bm_base, api(MODULE_API_PADDR, prdt));
     uint32_t pages = (count + 4095) / 4096;
     
+    // api(MODULE_API_PRINT, MODULE_NAME, "pid: %x, index: %x\n", transferring_pid, transferring_disk_index);
+    // while(locked);
+    while(transferring_disk_index != -1);
+    // locked = 1;
     uint32_t sector_count = pages*8;
     // api(MODULE_API_PRINT, MODULE_NAME, "pages: %x, scount: %x\n", pages, sector_count);
     if (sector_count == 0) return -1;
@@ -370,7 +374,7 @@ int ata_read(vfile_t *file, uint8_t *ptr, uint32_t offset, uint32_t count) {
     // }
     // outb(bm_base, 0x00);
     uint32_t cpid = api(MODULE_API_GET_CPID);
-    api(MODULE_API_PRINT, MODULE_NAME, "Cpid: %x", cpid);
+    // api(MODULE_API_PRINT, MODULE_NAME, "Cpid: %x", cpid);
     api(MODULE_API_BLOCK_PID, cpid);
     transferring_pid = cpid;
     if(!is_interrupt){
@@ -399,10 +403,15 @@ cpu_registers_t *int_handler(cpu_registers_t * regs){
     if(status & 1){
         return regs;
     }
-    transferring_disk_index = -1;
+    // api(MODULE_API_PRINT, MODULE_NAME, "test");
+    if(recieved_ints < expected_ints){
+        return regs;
+    }
     outb(drives[transferring_disk_index].BARs[4] & ~3, 0x00);
+    transferring_disk_index = -1;
     api(MODULE_API_UNBLOCK_PID, transferring_pid);
     transferring_pid = 0;
+    locked = 0;
     return regs;
 }