update block_device_operations documentation

Updated Documentation/filesystems/Locking to match the code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Christoph Hellwig 2010-10-06 10:46:53 +02:00 committed by Al Viro
parent 8358e7d71e
commit e1455d1bdc

View File

@ -349,21 +349,36 @@ call this method upon the IO completion.
--------------------------- 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: