mp: separate VFS read and write functions into internal implementations with locking

In preparation for the inevitable switch to a MP supported setup, I have added spinlocks to the VFS_Read and VFS_Write implementations

If I had forgotten to do this, everything would've blown up, the world would have ended, and Israel would no longer exist.

Signed-off-by: kaguya <vpshinomiya@protonmail.com>

src/fs/vfs.c

@@ -106,7 +106,7 @@ int VFS_Close(fd_t fd) {
     return resp;
 }
 
-int VFS_Read(fd_t fd, uint8_t* buf, size_t size)
+int VFS_Read_internal(fd_t fd, uint8_t* buf, size_t size)
 {
     if (fd < 0 || fd >= VFS_MAX_FDS)
         return -1;
@@ -154,7 +154,16 @@ int VFS_Read(fd_t fd, uint8_t* buf, size_t size)
     }
 }
 
-int VFS_Write(fd_t file, uint8_t* data, size_t size)
+int VFS_Read(fd_t fd, uint8_t* buf, size_t size)
+{
+    uint64_t flags;
+    spinlock_acquire_irqsave(&s_vfs_lock, &flags);
+    int resp = VFS_Read_internal(fd, buf, size);
+    spinlock_release_irqrestore(&s_vfs_lock, flags);
+    return resp;
+}
+
+int VFS_Write_internal(fd_t file, uint8_t* data, size_t size)
 {
     switch (file)
     {
@@ -210,3 +219,12 @@ int VFS_Write(fd_t file, uint8_t* data, size_t size)
 
     return -1;
 }
+
+int VFS_Write(fd_t file, uint8_t* data, size_t size)
+{
+    uint64_t flags;
+    spinlock_acquire_irqsave(&s_vfs_lock, &flags);
+    int resp = VFS_Write_internal(file, data, size);
+    spinlock_release_irqrestore(&s_vfs_lock, flags);
+    return resp;
+}