Added spinlocks

src/kernel/kmain.c

@@ -57,7 +57,7 @@ extern void kmain(kernel_info_t *kernel_info){
     pic_init(0x20);
     pic_setmask(0x0, PIC1_DATA);
     pic_setmask(0x0, PIC2_DATA);
-    
+    vfs_init();
     fcreate("/dev", FS_FILE_IS_DIR);
     fcreate("/dev/disk", FS_FILE_IS_DIR);
     fcreate("/tmp", FS_FILE_IS_DIR);

src/kernel/shared/spinlock.h

@@ -0,0 +1,13 @@
+#include <stdatomic.h>
+
+typedef struct spinlock{
+    atomic_flag lock;
+}spinlock_t;
+
+inline void spinlock_acquire(spinlock_t spinlock){
+    // atomic_compare_exchange_strong(&spinlock.lock, &spinlock.unlocked, spinlock.locked);
+    while(atomic_flag_test_and_set_explicit(&spinlock.lock, memory_order_acquire));
+}
+inline void spinlock_release(spinlock_t spinlock){
+    atomic_flag_clear_explicit(&spinlock.lock, memory_order_release);
+}

src/kernel/system/vfs.c

@@ -3,6 +3,7 @@
 #include "../shared/kstdlib.h"
 #include "../shared/memory.h"
 #include "../shared/string.h"
+#include "../shared/spinlock.h"
 #define MODULE_NAME "KVFS"
 
 // !TODO: Modify code to become thread-safe
@@ -13,9 +14,17 @@
 //     return;
 // }
 
+spinlock_t vfs_lock;
+
+void vfs_init(){
+    spinlock_release(vfs_lock);
+}
+
 vfile_t *fcreate(char *path, FS_FILE_FLAGS flags){
     // return 0;
+    spinlock_acquire(vfs_lock);
     vfile_t *returnable = vfcreate(get_root_dir(), path, flags);
+    spinlock_release(vfs_lock);
     return 0;
 }
 
@@ -60,9 +69,11 @@ vfile_t *vfcreate(vfile_t *parent_dir, char *relpath, FS_FILE_FLAGS flags){
 }
 
 int fdelete(vfile_t *file_entry){
+    spinlock_acquire(vfs_lock);
     if(!file_entry || !file_entry->fileops || !file_entry->fileops->delete){
         return 0;
     }
+    spinlock_release(vfs_lock);
     return file_entry->fileops->delete(file_entry);
 }
 

src/kernel/system/vfs.h

@@ -37,6 +37,8 @@ typedef struct virtual_file{
     
 }vfile_t;
 
+void vfs_init();
+
 // vfile_t *rfopen(char *name, vfile_t dir);
 vfile_t *fcreate(char *path, FS_FILE_FLAGS flags);
 int fdelete(vfile_t* file_entry);

src/kmodules/disk_driver.c

@@ -379,7 +379,8 @@ int ata_read(vfile_t *file, uint8_t *ptr, uint32_t offset, uint32_t count) {
     transferring_pid = cpid;
     
     outb(bm_base, 0x09); 
-    asm("sti");
+    // asm("sti"); // TODO: Make it so that instead of sti(), restore interrupt flag
+    if(!api(MODULE_API_IS_INTERRUPT)) asm("sti");
     
     uint8_t status = inb(ctrl_base);
     uint8_t bm_status = inb(bm_base + 2);