/*
* linux/fs/inode.c
*
* (C) 1997 Linus Torvalds
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/dcache.h>
#include <linux/init.h>
#include <linux/quotaops.h>
#include <linux/slab.h>
#include <linux/writeback.h>
#include <linux/module.h>
#include <linux/backing-dev.h>
#include <linux/wait.h>
#include <linux/hash.h>
#include <linux/swap.h>
#include <linux/security.h>
#include <linux/pagemap.h>
#include <linux/cdev.h>
#include <linux/bootmem.h>
#include <linux/inotify.h>
#include <linux/mount.h>
/*
* This is needed for the following functions:
* - inode_has_buffers
* - invalidate_inode_buffers
* - invalidate_bdev
*
* FIXME: remove all knowledge of the buffer layer from this file
*/
#include <linux/buffer_head.h>
/*
* New inode.c implementation.
*
* This implementation has the basic premise of trying
* to be extremely low-overhead and SMP-safe, yet be
* simple enough to be "obviously correct".
*
* Famous last words.
*/
/* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */
/* #define INODE_PARANOIA 1 */
/* #define INODE_DEBUG 1 */
/*
* Inode lookup is no longer as critical as it used to be:
* most of the lookups are going to be through the dcache.
*/
#define I_HASHBITS i_hash_shift
#define I_HASHMASK i_hash_mask
static unsigned int i_hash_mask __read_mostly;
static unsigned int i_hash_shift __read_mostly;
/*
* Each inode can be on two separate lists. One is
* the hash list of the inode, used for lookups. The
* other linked list is the "type" list:
* "in_use" - valid inode, i_count > 0, i_nlink > 0
* "dirty" - as "in_use" but also dirty
* "unused" - valid inode, i_count = 0
*
* A "dirty" list is maintained for each super block,
* allowing for low-overhead inode sync() operations.
*/
LIST_HEAD(inode_in_use);
LIST_HEAD(inode_unused);
static struct hlist_head *inode_hashtable __read_mostly;
/*
* A simple spinlock to protect the list manipulations.
*
* NOTE! You also have to own the lock if you change
* the i_state of an inode while it is in use..
*/
DEFINE_SPINLOCK(inode_lock);
/*
* iprune_mutex provides exclusion between the kswapd or try_to_free_pages
* icache shrinking path, and the umount path. Without this exclusion,
* by the time prune_icache calls iput for the inode whose pages it has
* been invalidating, or by the time it calls clear_inode & destroy_inode
* from its final dispose_list, the struct super_block they refer to
* (for inode->i_sb->s_op) may already have been freed and reused.
*/
static DEFINE_MUTEX(iprune_mutex);
/*
* Statistics gathering..
*/
struct
