--------------------------- block_device_operations -----------------------
prototypes:
- int (*open) (struct inode *, struct file *);
- int (*release) (struct inode *, struct file *);
- int (*ioctl) (struct inode *, struct file *, unsigned, unsigned long);
+ int (*open) (struct block_device *, fmode_t);
+ int (*release) (struct gendisk *, fmode_t);
+ int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
+ int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
+ int (*direct_access) (struct block_device *, sector_t, void **, unsigned long *);
int (*media_changed) (struct gendisk *);
+ void (*unlock_native_capacity) (struct gendisk *);
int (*revalidate_disk) (struct gendisk *);
+ int (*getgeo)(struct block_device *, struct hd_geometry *);
+ void (*swap_slot_free_notify) (struct block_device *, unsigned long);
locking rules:
- BKL bd_sem
-open: yes yes
-release: yes yes
-ioctl: yes no
+ BKL bd_mutex
+open: no yes
+release: no yes
+ioctl: no no
+compat_ioctl: no no
+direct_access: no no
media_changed: no no
+unlock_native_capacity: no no
revalidate_disk: no no
+getgeo: no no
+swap_slot_free_notify: no no (see below)
+
+media_changed, unlock_native_capacity and revalidate_disk are called only from
+check_disk_change().
+
+swap_slot_free_notify is called with swap_lock and sometimes the page lock
+held.
-The last two are called only from check_disk_change().
--------------------------- file_operations -------------------------------
prototypes:
ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
int (*readdir) (struct file *, void *, filldir_t);
unsigned int (*poll) (struct file *, struct poll_table_struct *);
- int (*ioctl) (struct inode *, struct file *, unsigned int,
- unsigned long);
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
aio_write: no
readdir: no
poll: no
-ioctl: yes (see below)
-unlocked_ioctl: no (see below)
+unlocked_ioctl: no
compat_ioctl: no
mmap: no
open: no
anything that resembles union-mount we won't have a struct file for all
components. And there are other reasons why the current interface is a mess...
-->ioctl() on regular files is superceded by the ->unlocked_ioctl() that
-doesn't take the BKL.
-
->read on directories probably must go away - we should just enforce -EISDIR
in sys_read() and friends.