4 files changed, 30 insertions, 25 deletions

diff --git a/kernel/drivers/ahci.c b/kernel/drivers/ahci.c
index 1fad0a3..34de443 100644
--- a/kernel/drivers/ahci.c
+++ b/kernel/drivers/ahci.c
@@ -485,6 +485,11 @@ int ahci_read(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
   return rc;
 }
 
+int ahci_has_data(vfs_inode_t *inode) {
+  (void)inode;
+  return 1;
+}
+
 void add_devfs_drive_file(u8 port) {
   static u8 num_drives_added = 0;
   char *path = "/sda";
@@ -492,7 +497,7 @@ void add_devfs_drive_file(u8 port) {
   num_drives_added++;
   vfs_inode_t *inode =
       devfs_add_file(path, ahci_read, ahci_write, NULL /*get_vm_object*/,
-                     1 /*has_data*/, 0 /*can_write*/, FS_TYPE_BLOCK_DEVICE);
+                     ahci_has_data, NULL /*can_write*/, FS_TYPE_BLOCK_DEVICE);
   inode->inode_num = port;
 }
 
diff --git a/kernel/drivers/keyboard.c b/kernel/drivers/keyboard.c
index fe4fe16..ab61d58 100644
--- a/kernel/drivers/keyboard.c
+++ b/kernel/drivers/keyboard.c
@@ -155,9 +155,11 @@ void int_keyboard(reg_t *frame) {
   ev.mode |= is_alt_down << 1;
   ev.mode |= is_ctrl_down << 2;
   fifo_object_write((u8 *)&ev, 0, sizeof(ev), keyboard_fifo);
-  if (kb_inode) {
-    kb_inode->has_data = keyboard_fifo->has_data;
-  }
+}
+
+int keyboard_has_data(vfs_inode_t *inode) {
+  (void)inode;
+  return keyboard_fifo->has_data;
 }
 
 void install_keyboard(void) {
@@ -168,15 +170,14 @@ void install_keyboard(void) {
 int keyboard_read(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
   (void)offset;
 
-  if (0 == fd->inode->has_data) {
+  int rc = fifo_object_read(buffer, 0, len, keyboard_fifo);
+  if (0 == rc) {
     return -EAGAIN;
   }
-  int rc = fifo_object_read(buffer, 0, len, keyboard_fifo);
-  fd->inode->has_data = keyboard_fifo->has_data;
   return rc;
 }
 
 void add_keyboard(void) {
-  kb_inode = devfs_add_file("/keyboard", keyboard_read, NULL, NULL, 0, 0,
-                            FS_TYPE_CHAR_DEVICE);
+  kb_inode = devfs_add_file("/keyboard", keyboard_read, NULL, NULL,
+                            keyboard_has_data, NULL, FS_TYPE_CHAR_DEVICE);
 }
diff --git a/kernel/drivers/mouse.c b/kernel/drivers/mouse.c
index 4b0696a..93e3be6 100644
--- a/kernel/drivers/mouse.c
+++ b/kernel/drivers/mouse.c
@@ -19,26 +19,25 @@ struct mouse_event {
   u8 y;
 };
 
+int fs_mouse_has_data(vfs_inode_t *inode) {
+  FIFO_FILE *f = inode->internal_object;
+  return f->has_data;
+}
+
 int fs_mouse_write(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
-  int rc = fifo_object_write(buffer, offset, len, fd->inode->internal_object);
   FIFO_FILE *f = fd->inode->internal_object;
-  mouse_inode->has_data = f->has_data;
-  return rc;
+  return fifo_object_write(buffer, offset, len, f);
 }
 
 int fs_mouse_read(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
   FIFO_FILE *f = fd->inode->internal_object;
-  if (!mouse_inode->has_data) {
-    return 0;
-  }
-  int rc = fifo_object_read(buffer, offset, len, f);
-  mouse_inode->has_data = f->has_data;
-  return rc;
+  return fifo_object_read(buffer, offset, len, f);
 }
 
 void add_mouse(void) {
-  mouse_inode = devfs_add_file("/mouse", fs_mouse_read, fs_mouse_write, NULL, 0,
-                               0, FS_TYPE_CHAR_DEVICE);
+  mouse_inode =
+      devfs_add_file("/mouse", fs_mouse_read, fs_mouse_write, NULL,
+                     fs_mouse_has_data, always_can_write, FS_TYPE_CHAR_DEVICE);
   mouse_inode->internal_object = create_fifo_object();
   // Don't look at this
   int fd = vfs_open("/dev/mouse", O_RDWR, 0);
diff --git a/kernel/drivers/vbe.c b/kernel/drivers/vbe.c
index e67a3d9..c0603d6 100644
--- a/kernel/drivers/vbe.c
+++ b/kernel/drivers/vbe.c
@@ -37,7 +37,7 @@ int display_driver_init(multiboot_info_t *mbi) {
   framebuffer_physical = mbi->framebuffer_addr;
   framebuffer =
       mmu_map_frames((void *)(u32)mbi->framebuffer_addr, framebuffer_size);
-  if(!framebuffer) {
+  if (!framebuffer) {
     return 0;
   }
 
@@ -68,8 +68,8 @@ int display_info_read(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
 }
 
 void add_vbe_device(void) {
-  devfs_add_file("/vbe", NULL, NULL, vbe_get_vm_object, 1, 1,
-                 FS_TYPE_BLOCK_DEVICE);
-  devfs_add_file("/display_info", display_info_read, NULL, NULL, 1, 0,
-                 FS_TYPE_BLOCK_DEVICE);
+  devfs_add_file("/vbe", NULL, NULL, vbe_get_vm_object, always_has_data,
+                 always_can_write, FS_TYPE_BLOCK_DEVICE);
+  devfs_add_file("/display_info", display_info_read, NULL, NULL,
+                 always_has_data, NULL, FS_TYPE_BLOCK_DEVICE);
 }