mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
![Josh Boyer](/assets/img/avatar_default.png)
Purely in-memory filesystems do not use the inode hash as the dcache tells us if an entry already exists. As a result, they do not call unlock_new_inode, and thus directory inodes do not get put into a different lockdep class for i_sem. We need the different lockdep classes, because the locking order for i_mutex is different for directory inodes and regular inodes. Directory inodes can do "readdir()", which takes i_mutex *before* possibly taking mm->mmap_sem (due to a page fault while copying the directory entry to user space). In contrast, regular inodes can be mmap'ed, which takes mm->mmap_sem before accessing i_mutex. The two cases can never happen for the same inode, so no real deadlock can occur, but without the different lockdep classes, lockdep cannot understand that. As a result, if CONFIG_DEBUG_LOCK_ALLOC is set, this can lead to false positives from lockdep like below: find/645 is trying to acquire lock: (&mm->mmap_sem){++++++}, at: [<ffffffff81109514>] might_fault+0x5c/0xac but task is already holding lock: (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffff81149f34>] vfs_readdir+0x5b/0xb4 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#15){+.+.+.}: [<ffffffff8108ac26>] lock_acquire+0xbf/0x103 [<ffffffff814db822>] __mutex_lock_common+0x4c/0x361 [<ffffffff814dbc46>] mutex_lock_nested+0x40/0x45 [<ffffffff811daa87>] hugetlbfs_file_mmap+0x82/0x110 [<ffffffff81111557>] mmap_region+0x258/0x432 [<ffffffff811119dd>] do_mmap_pgoff+0x2ac/0x306 [<ffffffff81111b4f>] sys_mmap_pgoff+0x118/0x16a [<ffffffff8100c858>] sys_mmap+0x22/0x24 [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b -> #0 (&mm->mmap_sem){++++++}: [<ffffffff8108a4bc>] __lock_acquire+0xa1a/0xcf7 [<ffffffff8108ac26>] lock_acquire+0xbf/0x103 [<ffffffff81109541>] might_fault+0x89/0xac [<ffffffff81149cff>] filldir+0x6f/0xc7 [<ffffffff811586ea>] dcache_readdir+0x67/0x205 [<ffffffff81149f54>] vfs_readdir+0x7b/0xb4 [<ffffffff8114a073>] sys_getdents+0x7e/0xd1 [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b This patch moves the directory vs file lockdep annotation into a helper function that can be called by in-memory filesystems and has hugetlbfs call it. Signed-off-by: Josh Boyer <jwboyer@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1680 lines
43 KiB
C
1680 lines
43 KiB
C
/*
|
|
* (C) 1997 Linus Torvalds
|
|
* (C) 1999 Andrea Arcangeli <andrea@suse.de> (dynamic inode allocation)
|
|
*/
|
|
#include <linux/fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/dcache.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/writeback.h>
|
|
#include <linux/module.h>
|
|
#include <linux/backing-dev.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/rwsem.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/fsnotify.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/async.h>
|
|
#include <linux/posix_acl.h>
|
|
#include <linux/prefetch.h>
|
|
#include <linux/ima.h>
|
|
#include <linux/cred.h>
|
|
#include <linux/buffer_head.h> /* for inode_has_buffers */
|
|
#include "internal.h"
|
|
|
|
/*
|
|
* Inode locking rules:
|
|
*
|
|
* inode->i_lock protects:
|
|
* inode->i_state, inode->i_hash, __iget()
|
|
* inode->i_sb->s_inode_lru_lock protects:
|
|
* inode->i_sb->s_inode_lru, inode->i_lru
|
|
* inode_sb_list_lock protects:
|
|
* sb->s_inodes, inode->i_sb_list
|
|
* bdi->wb.list_lock protects:
|
|
* bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list
|
|
* inode_hash_lock protects:
|
|
* inode_hashtable, inode->i_hash
|
|
*
|
|
* Lock ordering:
|
|
*
|
|
* inode_sb_list_lock
|
|
* inode->i_lock
|
|
* inode->i_sb->s_inode_lru_lock
|
|
*
|
|
* bdi->wb.list_lock
|
|
* inode->i_lock
|
|
*
|
|
* inode_hash_lock
|
|
* inode_sb_list_lock
|
|
* inode->i_lock
|
|
*
|
|
* iunique_lock
|
|
* inode_hash_lock
|
|
*/
|
|
|
|
static unsigned int i_hash_mask __read_mostly;
|
|
static unsigned int i_hash_shift __read_mostly;
|
|
static struct hlist_head *inode_hashtable __read_mostly;
|
|
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_hash_lock);
|
|
|
|
__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock);
|
|
|
|
/*
|
|
* Empty aops. Can be used for the cases where the user does not
|
|
* define any of the address_space operations.
|
|
*/
|
|
const struct address_space_operations empty_aops = {
|
|
};
|
|
EXPORT_SYMBOL(empty_aops);
|
|
|
|
/*
|
|
* Statistics gathering..
|
|
*/
|
|
struct inodes_stat_t inodes_stat;
|
|
|
|
static DEFINE_PER_CPU(unsigned int, nr_inodes);
|
|
static DEFINE_PER_CPU(unsigned int, nr_unused);
|
|
|
|
static struct kmem_cache *inode_cachep __read_mostly;
|
|
|
|
static int get_nr_inodes(void)
|
|
{
|
|
int i;
|
|
int sum = 0;
|
|
for_each_possible_cpu(i)
|
|
sum += per_cpu(nr_inodes, i);
|
|
return sum < 0 ? 0 : sum;
|
|
}
|
|
|
|
static inline int get_nr_inodes_unused(void)
|
|
{
|
|
int i;
|
|
int sum = 0;
|
|
for_each_possible_cpu(i)
|
|
sum += per_cpu(nr_unused, i);
|
|
return sum < 0 ? 0 : sum;
|
|
}
|
|
|
|
int get_nr_dirty_inodes(void)
|
|
{
|
|
/* not actually dirty inodes, but a wild approximation */
|
|
int nr_dirty = get_nr_inodes() - get_nr_inodes_unused();
|
|
return nr_dirty > 0 ? nr_dirty : 0;
|
|
}
|
|
|
|
/*
|
|
* Handle nr_inode sysctl
|
|
*/
|
|
#ifdef CONFIG_SYSCTL
|
|
int proc_nr_inodes(ctl_table *table, int write,
|
|
void __user *buffer, size_t *lenp, loff_t *ppos)
|
|
{
|
|
inodes_stat.nr_inodes = get_nr_inodes();
|
|
inodes_stat.nr_unused = get_nr_inodes_unused();
|
|
return proc_dointvec(table, write, buffer, lenp, ppos);
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* inode_init_always - perform inode structure intialisation
|
|
* @sb: superblock inode belongs to
|
|
* @inode: inode to initialise
|
|
*
|
|
* These are initializations that need to be done on every inode
|
|
* allocation as the fields are not initialised by slab allocation.
|
|
*/
|
|
int inode_init_always(struct super_block *sb, struct inode *inode)
|
|
{
|
|
static const struct inode_operations empty_iops;
|
|
static const struct file_operations empty_fops;
|
|
struct address_space *const mapping = &inode->i_data;
|
|
|
|
inode->i_sb = sb;
|
|
inode->i_blkbits = sb->s_blocksize_bits;
|
|
inode->i_flags = 0;
|
|
atomic_set(&inode->i_count, 1);
|
|
inode->i_op = &empty_iops;
|
|
inode->i_fop = &empty_fops;
|
|
inode->i_nlink = 1;
|
|
inode->i_opflags = 0;
|
|
inode->i_uid = 0;
|
|
inode->i_gid = 0;
|
|
atomic_set(&inode->i_writecount, 0);
|
|
inode->i_size = 0;
|
|
inode->i_blocks = 0;
|
|
inode->i_bytes = 0;
|
|
inode->i_generation = 0;
|
|
#ifdef CONFIG_QUOTA
|
|
memset(&inode->i_dquot, 0, sizeof(inode->i_dquot));
|
|
#endif
|
|
inode->i_pipe = NULL;
|
|
inode->i_bdev = NULL;
|
|
inode->i_cdev = NULL;
|
|
inode->i_rdev = 0;
|
|
inode->dirtied_when = 0;
|
|
|
|
if (security_inode_alloc(inode))
|
|
goto out;
|
|
spin_lock_init(&inode->i_lock);
|
|
lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key);
|
|
|
|
mutex_init(&inode->i_mutex);
|
|
lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key);
|
|
|
|
atomic_set(&inode->i_dio_count, 0);
|
|
|
|
mapping->a_ops = &empty_aops;
|
|
mapping->host = inode;
|
|
mapping->flags = 0;
|
|
mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE);
|
|
mapping->assoc_mapping = NULL;
|
|
mapping->backing_dev_info = &default_backing_dev_info;
|
|
mapping->writeback_index = 0;
|
|
|
|
/*
|
|
* If the block_device provides a backing_dev_info for client
|
|
* inodes then use that. Otherwise the inode share the bdev's
|
|
* backing_dev_info.
|
|
*/
|
|
if (sb->s_bdev) {
|
|
struct backing_dev_info *bdi;
|
|
|
|
bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
|
|
mapping->backing_dev_info = bdi;
|
|
}
|
|
inode->i_private = NULL;
|
|
inode->i_mapping = mapping;
|
|
#ifdef CONFIG_FS_POSIX_ACL
|
|
inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
|
|
#endif
|
|
|
|
#ifdef CONFIG_FSNOTIFY
|
|
inode->i_fsnotify_mask = 0;
|
|
#endif
|
|
|
|
this_cpu_inc(nr_inodes);
|
|
|
|
return 0;
|
|
out:
|
|
return -ENOMEM;
|
|
}
|
|
EXPORT_SYMBOL(inode_init_always);
|
|
|
|
static struct inode *alloc_inode(struct super_block *sb)
|
|
{
|
|
struct inode *inode;
|
|
|
|
if (sb->s_op->alloc_inode)
|
|
inode = sb->s_op->alloc_inode(sb);
|
|
else
|
|
inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL);
|
|
|
|
if (!inode)
|
|
return NULL;
|
|
|
|
if (unlikely(inode_init_always(sb, inode))) {
|
|
if (inode->i_sb->s_op->destroy_inode)
|
|
inode->i_sb->s_op->destroy_inode(inode);
|
|
else
|
|
kmem_cache_free(inode_cachep, inode);
|
|
return NULL;
|
|
}
|
|
|
|
return inode;
|
|
}
|
|
|
|
void free_inode_nonrcu(struct inode *inode)
|
|
{
|
|
kmem_cache_free(inode_cachep, inode);
|
|
}
|
|
EXPORT_SYMBOL(free_inode_nonrcu);
|
|
|
|
void __destroy_inode(struct inode *inode)
|
|
{
|
|
BUG_ON(inode_has_buffers(inode));
|
|
security_inode_free(inode);
|
|
fsnotify_inode_delete(inode);
|
|
#ifdef CONFIG_FS_POSIX_ACL
|
|
if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED)
|
|
posix_acl_release(inode->i_acl);
|
|
if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED)
|
|
posix_acl_release(inode->i_default_acl);
|
|
#endif
|
|
this_cpu_dec(nr_inodes);
|
|
}
|
|
EXPORT_SYMBOL(__destroy_inode);
|
|
|
|
static void i_callback(struct rcu_head *head)
|
|
{
|
|
struct inode *inode = container_of(head, struct inode, i_rcu);
|
|
INIT_LIST_HEAD(&inode->i_dentry);
|
|
kmem_cache_free(inode_cachep, inode);
|
|
}
|
|
|
|
static void destroy_inode(struct inode *inode)
|
|
{
|
|
BUG_ON(!list_empty(&inode->i_lru));
|
|
__destroy_inode(inode);
|
|
if (inode->i_sb->s_op->destroy_inode)
|
|
inode->i_sb->s_op->destroy_inode(inode);
|
|
else
|
|
call_rcu(&inode->i_rcu, i_callback);
|
|
}
|
|
|
|
void address_space_init_once(struct address_space *mapping)
|
|
{
|
|
memset(mapping, 0, sizeof(*mapping));
|
|
INIT_RADIX_TREE(&mapping->page_tree, GFP_ATOMIC);
|
|
spin_lock_init(&mapping->tree_lock);
|
|
mutex_init(&mapping->i_mmap_mutex);
|
|
INIT_LIST_HEAD(&mapping->private_list);
|
|
spin_lock_init(&mapping->private_lock);
|
|
INIT_RAW_PRIO_TREE_ROOT(&mapping->i_mmap);
|
|
INIT_LIST_HEAD(&mapping->i_mmap_nonlinear);
|
|
}
|
|
EXPORT_SYMBOL(address_space_init_once);
|
|
|
|
/*
|
|
* These are initializations that only need to be done
|
|
* once, because the fields are idempotent across use
|
|
* of the inode, so let the slab aware of that.
|
|
*/
|
|
void inode_init_once(struct inode *inode)
|
|
{
|
|
memset(inode, 0, sizeof(*inode));
|
|
INIT_HLIST_NODE(&inode->i_hash);
|
|
INIT_LIST_HEAD(&inode->i_dentry);
|
|
INIT_LIST_HEAD(&inode->i_devices);
|
|
INIT_LIST_HEAD(&inode->i_wb_list);
|
|
INIT_LIST_HEAD(&inode->i_lru);
|
|
address_space_init_once(&inode->i_data);
|
|
i_size_ordered_init(inode);
|
|
#ifdef CONFIG_FSNOTIFY
|
|
INIT_HLIST_HEAD(&inode->i_fsnotify_marks);
|
|
#endif
|
|
}
|
|
EXPORT_SYMBOL(inode_init_once);
|
|
|
|
static void init_once(void *foo)
|
|
{
|
|
struct inode *inode = (struct inode *) foo;
|
|
|
|
inode_init_once(inode);
|
|
}
|
|
|
|
/*
|
|
* inode->i_lock must be held
|
|
*/
|
|
void __iget(struct inode *inode)
|
|
{
|
|
atomic_inc(&inode->i_count);
|
|
}
|
|
|
|
/*
|
|
* get additional reference to inode; caller must already hold one.
|
|
*/
|
|
void ihold(struct inode *inode)
|
|
{
|
|
WARN_ON(atomic_inc_return(&inode->i_count) < 2);
|
|
}
|
|
EXPORT_SYMBOL(ihold);
|
|
|
|
static void inode_lru_list_add(struct inode *inode)
|
|
{
|
|
spin_lock(&inode->i_sb->s_inode_lru_lock);
|
|
if (list_empty(&inode->i_lru)) {
|
|
list_add(&inode->i_lru, &inode->i_sb->s_inode_lru);
|
|
inode->i_sb->s_nr_inodes_unused++;
|
|
this_cpu_inc(nr_unused);
|
|
}
|
|
spin_unlock(&inode->i_sb->s_inode_lru_lock);
|
|
}
|
|
|
|
static void inode_lru_list_del(struct inode *inode)
|
|
{
|
|
spin_lock(&inode->i_sb->s_inode_lru_lock);
|
|
if (!list_empty(&inode->i_lru)) {
|
|
list_del_init(&inode->i_lru);
|
|
inode->i_sb->s_nr_inodes_unused--;
|
|
this_cpu_dec(nr_unused);
|
|
}
|
|
spin_unlock(&inode->i_sb->s_inode_lru_lock);
|
|
}
|
|
|
|
/**
|
|
* inode_sb_list_add - add inode to the superblock list of inodes
|
|
* @inode: inode to add
|
|
*/
|
|
void inode_sb_list_add(struct inode *inode)
|
|
{
|
|
spin_lock(&inode_sb_list_lock);
|
|
list_add(&inode->i_sb_list, &inode->i_sb->s_inodes);
|
|
spin_unlock(&inode_sb_list_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(inode_sb_list_add);
|
|
|
|
static inline void inode_sb_list_del(struct inode *inode)
|
|
{
|
|
if (!list_empty(&inode->i_sb_list)) {
|
|
spin_lock(&inode_sb_list_lock);
|
|
list_del_init(&inode->i_sb_list);
|
|
spin_unlock(&inode_sb_list_lock);
|
|
}
|
|
}
|
|
|
|
static unsigned long hash(struct super_block *sb, unsigned long hashval)
|
|
{
|
|
unsigned long tmp;
|
|
|
|
tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
|
|
L1_CACHE_BYTES;
|
|
tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> i_hash_shift);
|
|
return tmp & i_hash_mask;
|
|
}
|
|
|
|
/**
|
|
* __insert_inode_hash - hash an inode
|
|
* @inode: unhashed inode
|
|
* @hashval: unsigned long value used to locate this object in the
|
|
* inode_hashtable.
|
|
*
|
|
* Add an inode to the inode hash for this superblock.
|
|
*/
|
|
void __insert_inode_hash(struct inode *inode, unsigned long hashval)
|
|
{
|
|
struct hlist_head *b = inode_hashtable + hash(inode->i_sb, hashval);
|
|
|
|
spin_lock(&inode_hash_lock);
|
|
spin_lock(&inode->i_lock);
|
|
hlist_add_head(&inode->i_hash, b);
|
|
spin_unlock(&inode->i_lock);
|
|
spin_unlock(&inode_hash_lock);
|
|
}
|
|
EXPORT_SYMBOL(__insert_inode_hash);
|
|
|
|
/**
|
|
* __remove_inode_hash - remove an inode from the hash
|
|
* @inode: inode to unhash
|
|
*
|
|
* Remove an inode from the superblock.
|
|
*/
|
|
void __remove_inode_hash(struct inode *inode)
|
|
{
|
|
spin_lock(&inode_hash_lock);
|
|
spin_lock(&inode->i_lock);
|
|
hlist_del_init(&inode->i_hash);
|
|
spin_unlock(&inode->i_lock);
|
|
spin_unlock(&inode_hash_lock);
|
|
}
|
|
EXPORT_SYMBOL(__remove_inode_hash);
|
|
|
|
void end_writeback(struct inode *inode)
|
|
{
|
|
might_sleep();
|
|
/*
|
|
* We have to cycle tree_lock here because reclaim can be still in the
|
|
* process of removing the last page (in __delete_from_page_cache())
|
|
* and we must not free mapping under it.
|
|
*/
|
|
spin_lock_irq(&inode->i_data.tree_lock);
|
|
BUG_ON(inode->i_data.nrpages);
|
|
spin_unlock_irq(&inode->i_data.tree_lock);
|
|
BUG_ON(!list_empty(&inode->i_data.private_list));
|
|
BUG_ON(!(inode->i_state & I_FREEING));
|
|
BUG_ON(inode->i_state & I_CLEAR);
|
|
inode_sync_wait(inode);
|
|
/* don't need i_lock here, no concurrent mods to i_state */
|
|
inode->i_state = I_FREEING | I_CLEAR;
|
|
}
|
|
EXPORT_SYMBOL(end_writeback);
|
|
|
|
/*
|
|
* Free the inode passed in, removing it from the lists it is still connected
|
|
* to. We remove any pages still attached to the inode and wait for any IO that
|
|
* is still in progress before finally destroying the inode.
|
|
*
|
|
* An inode must already be marked I_FREEING so that we avoid the inode being
|
|
* moved back onto lists if we race with other code that manipulates the lists
|
|
* (e.g. writeback_single_inode). The caller is responsible for setting this.
|
|
*
|
|
* An inode must already be removed from the LRU list before being evicted from
|
|
* the cache. This should occur atomically with setting the I_FREEING state
|
|
* flag, so no inodes here should ever be on the LRU when being evicted.
|
|
*/
|
|
static void evict(struct inode *inode)
|
|
{
|
|
const struct super_operations *op = inode->i_sb->s_op;
|
|
|
|
BUG_ON(!(inode->i_state & I_FREEING));
|
|
BUG_ON(!list_empty(&inode->i_lru));
|
|
|
|
if (!list_empty(&inode->i_wb_list))
|
|
inode_wb_list_del(inode);
|
|
|
|
inode_sb_list_del(inode);
|
|
|
|
if (op->evict_inode) {
|
|
op->evict_inode(inode);
|
|
} else {
|
|
if (inode->i_data.nrpages)
|
|
truncate_inode_pages(&inode->i_data, 0);
|
|
end_writeback(inode);
|
|
}
|
|
if (S_ISBLK(inode->i_mode) && inode->i_bdev)
|
|
bd_forget(inode);
|
|
if (S_ISCHR(inode->i_mode) && inode->i_cdev)
|
|
cd_forget(inode);
|
|
|
|
remove_inode_hash(inode);
|
|
|
|
spin_lock(&inode->i_lock);
|
|
wake_up_bit(&inode->i_state, __I_NEW);
|
|
BUG_ON(inode->i_state != (I_FREEING | I_CLEAR));
|
|
spin_unlock(&inode->i_lock);
|
|
|
|
destroy_inode(inode);
|
|
}
|
|
|
|
/*
|
|
* dispose_list - dispose of the contents of a local list
|
|
* @head: the head of the list to free
|
|
*
|
|
* Dispose-list gets a local list with local inodes in it, so it doesn't
|
|
* need to worry about list corruption and SMP locks.
|
|
*/
|
|
static void dispose_list(struct list_head *head)
|
|
{
|
|
while (!list_empty(head)) {
|
|
struct inode *inode;
|
|
|
|
inode = list_first_entry(head, struct inode, i_lru);
|
|
list_del_init(&inode->i_lru);
|
|
|
|
evict(inode);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* evict_inodes - evict all evictable inodes for a superblock
|
|
* @sb: superblock to operate on
|
|
*
|
|
* Make sure that no inodes with zero refcount are retained. This is
|
|
* called by superblock shutdown after having MS_ACTIVE flag removed,
|
|
* so any inode reaching zero refcount during or after that call will
|
|
* be immediately evicted.
|
|
*/
|
|
void evict_inodes(struct super_block *sb)
|
|
{
|
|
struct inode *inode, *next;
|
|
LIST_HEAD(dispose);
|
|
|
|
spin_lock(&inode_sb_list_lock);
|
|
list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) {
|
|
if (atomic_read(&inode->i_count))
|
|
continue;
|
|
|
|
spin_lock(&inode->i_lock);
|
|
if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) {
|
|
spin_unlock(&inode->i_lock);
|
|
continue;
|
|
}
|
|
|
|
inode->i_state |= I_FREEING;
|
|
inode_lru_list_del(inode);
|
|
spin_unlock(&inode->i_lock);
|
|
list_add(&inode->i_lru, &dispose);
|
|
}
|
|
spin_unlock(&inode_sb_list_lock);
|
|
|
|
dispose_list(&dispose);
|
|
}
|
|
|
|
/**
|
|
* invalidate_inodes - attempt to free all inodes on a superblock
|
|
* @sb: superblock to operate on
|
|
* @kill_dirty: flag to guide handling of dirty inodes
|
|
*
|
|
* Attempts to free all inodes for a given superblock. If there were any
|
|
* busy inodes return a non-zero value, else zero.
|
|
* If @kill_dirty is set, discard dirty inodes too, otherwise treat
|
|
* them as busy.
|
|
*/
|
|
int invalidate_inodes(struct super_block *sb, bool kill_dirty)
|
|
{
|
|
int busy = 0;
|
|
struct inode *inode, *next;
|
|
LIST_HEAD(dispose);
|
|
|
|
spin_lock(&inode_sb_list_lock);
|
|
list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) {
|
|
spin_lock(&inode->i_lock);
|
|
if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) {
|
|
spin_unlock(&inode->i_lock);
|
|
continue;
|
|
}
|
|
if (inode->i_state & I_DIRTY && !kill_dirty) {
|
|
spin_unlock(&inode->i_lock);
|
|
busy = 1;
|
|
continue;
|
|
}
|
|
if (atomic_read(&inode->i_count)) {
|
|
spin_unlock(&inode->i_lock);
|
|
busy = 1;
|
|
continue;
|
|
}
|
|
|
|
inode->i_state |= I_FREEING;
|
|
inode_lru_list_del(inode);
|
|
spin_unlock(&inode->i_lock);
|
|
list_add(&inode->i_lru, &dispose);
|
|
}
|
|
spin_unlock(&inode_sb_list_lock);
|
|
|
|
dispose_list(&dispose);
|
|
|
|
return busy;
|
|
}
|
|
|
|
static int can_unuse(struct inode *inode)
|
|
{
|
|
if (inode->i_state & ~I_REFERENCED)
|
|
return 0;
|
|
if (inode_has_buffers(inode))
|
|
return 0;
|
|
if (atomic_read(&inode->i_count))
|
|
return 0;
|
|
if (inode->i_data.nrpages)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Walk the superblock inode LRU for freeable inodes and attempt to free them.
|
|
* This is called from the superblock shrinker function with a number of inodes
|
|
* to trim from the LRU. Inodes to be freed are moved to a temporary list and
|
|
* then are freed outside inode_lock by dispose_list().
|
|
*
|
|
* Any inodes which are pinned purely because of attached pagecache have their
|
|
* pagecache removed. If the inode has metadata buffers attached to
|
|
* mapping->private_list then try to remove them.
|
|
*
|
|
* If the inode has the I_REFERENCED flag set, then it means that it has been
|
|
* used recently - the flag is set in iput_final(). When we encounter such an
|
|
* inode, clear the flag and move it to the back of the LRU so it gets another
|
|
* pass through the LRU before it gets reclaimed. This is necessary because of
|
|
* the fact we are doing lazy LRU updates to minimise lock contention so the
|
|
* LRU does not have strict ordering. Hence we don't want to reclaim inodes
|
|
* with this flag set because they are the inodes that are out of order.
|
|
*/
|
|
void prune_icache_sb(struct super_block *sb, int nr_to_scan)
|
|
{
|
|
LIST_HEAD(freeable);
|
|
int nr_scanned;
|
|
unsigned long reap = 0;
|
|
|
|
spin_lock(&sb->s_inode_lru_lock);
|
|
for (nr_scanned = nr_to_scan; nr_scanned >= 0; nr_scanned--) {
|
|
struct inode *inode;
|
|
|
|
if (list_empty(&sb->s_inode_lru))
|
|
break;
|
|
|
|
inode = list_entry(sb->s_inode_lru.prev, struct inode, i_lru);
|
|
|
|
/*
|
|
* we are inverting the sb->s_inode_lru_lock/inode->i_lock here,
|
|
* so use a trylock. If we fail to get the lock, just move the
|
|
* inode to the back of the list so we don't spin on it.
|
|
*/
|
|
if (!spin_trylock(&inode->i_lock)) {
|
|
list_move(&inode->i_lru, &sb->s_inode_lru);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Referenced or dirty inodes are still in use. Give them
|
|
* another pass through the LRU as we canot reclaim them now.
|
|
*/
|
|
if (atomic_read(&inode->i_count) ||
|
|
(inode->i_state & ~I_REFERENCED)) {
|
|
list_del_init(&inode->i_lru);
|
|
spin_unlock(&inode->i_lock);
|
|
sb->s_nr_inodes_unused--;
|
|
this_cpu_dec(nr_unused);
|
|
continue;
|
|
}
|
|
|
|
/* recently referenced inodes get one more pass */
|
|
if (inode->i_state & I_REFERENCED) {
|
|
inode->i_state &= ~I_REFERENCED;
|
|
list_move(&inode->i_lru, &sb->s_inode_lru);
|
|
spin_unlock(&inode->i_lock);
|
|
continue;
|
|
}
|
|
if (inode_has_buffers(inode) || inode->i_data.nrpages) {
|
|
__iget(inode);
|
|
spin_unlock(&inode->i_lock);
|
|
spin_unlock(&sb->s_inode_lru_lock);
|
|
if (remove_inode_buffers(inode))
|
|
reap += invalidate_mapping_pages(&inode->i_data,
|
|
0, -1);
|
|
iput(inode);
|
|
spin_lock(&sb->s_inode_lru_lock);
|
|
|
|
if (inode != list_entry(sb->s_inode_lru.next,
|
|
struct inode, i_lru))
|
|
continue; /* wrong inode or list_empty */
|
|
/* avoid lock inversions with trylock */
|
|
if (!spin_trylock(&inode->i_lock))
|
|
continue;
|
|
if (!can_unuse(inode)) {
|
|
spin_unlock(&inode->i_lock);
|
|
continue;
|
|
}
|
|
}
|
|
WARN_ON(inode->i_state & I_NEW);
|
|
inode->i_state |= I_FREEING;
|
|
spin_unlock(&inode->i_lock);
|
|
|
|
list_move(&inode->i_lru, &freeable);
|
|
sb->s_nr_inodes_unused--;
|
|
this_cpu_dec(nr_unused);
|
|
}
|
|
if (current_is_kswapd())
|
|
__count_vm_events(KSWAPD_INODESTEAL, reap);
|
|
else
|
|
__count_vm_events(PGINODESTEAL, reap);
|
|
spin_unlock(&sb->s_inode_lru_lock);
|
|
|
|
dispose_list(&freeable);
|
|
}
|
|
|
|
static void __wait_on_freeing_inode(struct inode *inode);
|
|
/*
|
|
* Called with the inode lock held.
|
|
*/
|
|
static struct inode *find_inode(struct super_block *sb,
|
|
struct hlist_head *head,
|
|
int (*test)(struct inode *, void *),
|
|
void *data)
|
|
{
|
|
struct hlist_node *node;
|
|
struct inode *inode = NULL;
|
|
|
|
repeat:
|
|
hlist_for_each_entry(inode, node, head, i_hash) {
|
|
spin_lock(&inode->i_lock);
|
|
if (inode->i_sb != sb) {
|
|
spin_unlock(&inode->i_lock);
|
|
continue;
|
|
}
|
|
if (!test(inode, data)) {
|
|
spin_unlock(&inode->i_lock);
|
|
continue;
|
|
}
|
|
if (inode->i_state & (I_FREEING|I_WILL_FREE)) {
|
|
__wait_on_freeing_inode(inode);
|
|
goto repeat;
|
|
}
|
|
__iget(inode);
|
|
spin_unlock(&inode->i_lock);
|
|
return inode;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* find_inode_fast is the fast path version of find_inode, see the comment at
|
|
* iget_locked for details.
|
|
*/
|
|
static struct inode *find_inode_fast(struct super_block *sb,
|
|
struct hlist_head *head, unsigned long ino)
|
|
{
|
|
struct hlist_node *node;
|
|
struct inode *inode = NULL;
|
|
|
|
repeat:
|
|
hlist_for_each_entry(inode, node, head, i_hash) {
|
|
spin_lock(&inode->i_lock);
|
|
if (inode->i_ino != ino) {
|
|
spin_unlock(&inode->i_lock);
|
|
continue;
|
|
}
|
|
if (inode->i_sb != sb) {
|
|
spin_unlock(&inode->i_lock);
|
|
continue;
|
|
}
|
|
if (inode->i_state & (I_FREEING|I_WILL_FREE)) {
|
|
__wait_on_freeing_inode(inode);
|
|
goto repeat;
|
|
}
|
|
__iget(inode);
|
|
spin_unlock(&inode->i_lock);
|
|
return inode;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Each cpu owns a range of LAST_INO_BATCH numbers.
|
|
* 'shared_last_ino' is dirtied only once out of LAST_INO_BATCH allocations,
|
|
* to renew the exhausted range.
|
|
*
|
|
* This does not significantly increase overflow rate because every CPU can
|
|
* consume at most LAST_INO_BATCH-1 unused inode numbers. So there is
|
|
* NR_CPUS*(LAST_INO_BATCH-1) wastage. At 4096 and 1024, this is ~0.1% of the
|
|
* 2^32 range, and is a worst-case. Even a 50% wastage would only increase
|
|
* overflow rate by 2x, which does not seem too significant.
|
|
*
|
|
* On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
|
|
* error if st_ino won't fit in target struct field. Use 32bit counter
|
|
* here to attempt to avoid that.
|
|
*/
|
|
#define LAST_INO_BATCH 1024
|
|
static DEFINE_PER_CPU(unsigned int, last_ino);
|
|
|
|
unsigned int get_next_ino(void)
|
|
{
|
|
unsigned int *p = &get_cpu_var(last_ino);
|
|
unsigned int res = *p;
|
|
|
|
#ifdef CONFIG_SMP
|
|
if (unlikely((res & (LAST_INO_BATCH-1)) == 0)) {
|
|
static atomic_t shared_last_ino;
|
|
int next = atomic_add_return(LAST_INO_BATCH, &shared_last_ino);
|
|
|
|
res = next - LAST_INO_BATCH;
|
|
}
|
|
#endif
|
|
|
|
*p = ++res;
|
|
put_cpu_var(last_ino);
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(get_next_ino);
|
|
|
|
/**
|
|
* new_inode_pseudo - obtain an inode
|
|
* @sb: superblock
|
|
*
|
|
* Allocates a new inode for given superblock.
|
|
* Inode wont be chained in superblock s_inodes list
|
|
* This means :
|
|
* - fs can't be unmount
|
|
* - quotas, fsnotify, writeback can't work
|
|
*/
|
|
struct inode *new_inode_pseudo(struct super_block *sb)
|
|
{
|
|
struct inode *inode = alloc_inode(sb);
|
|
|
|
if (inode) {
|
|
spin_lock(&inode->i_lock);
|
|
inode->i_state = 0;
|
|
spin_unlock(&inode->i_lock);
|
|
INIT_LIST_HEAD(&inode->i_sb_list);
|
|
}
|
|
return inode;
|
|
}
|
|
|
|
/**
|
|
* new_inode - obtain an inode
|
|
* @sb: superblock
|
|
*
|
|
* Allocates a new inode for given superblock. The default gfp_mask
|
|
* for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE.
|
|
* If HIGHMEM pages are unsuitable or it is known that pages allocated
|
|
* for the page cache are not reclaimable or migratable,
|
|
* mapping_set_gfp_mask() must be called with suitable flags on the
|
|
* newly created inode's mapping
|
|
*
|
|
*/
|
|
struct inode *new_inode(struct super_block *sb)
|
|
{
|
|
struct inode *inode;
|
|
|
|
spin_lock_prefetch(&inode_sb_list_lock);
|
|
|
|
inode = new_inode_pseudo(sb);
|
|
if (inode)
|
|
inode_sb_list_add(inode);
|
|
return inode;
|
|
}
|
|
EXPORT_SYMBOL(new_inode);
|
|
|
|
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
|
void lockdep_annotate_inode_mutex_key(struct inode *inode)
|
|
{
|
|
if (S_ISDIR(inode->i_mode)) {
|
|
struct file_system_type *type = inode->i_sb->s_type;
|
|
|
|
/* Set new key only if filesystem hasn't already changed it */
|
|
if (!lockdep_match_class(&inode->i_mutex,
|
|
&type->i_mutex_key)) {
|
|
/*
|
|
* ensure nobody is actually holding i_mutex
|
|
*/
|
|
mutex_destroy(&inode->i_mutex);
|
|
mutex_init(&inode->i_mutex);
|
|
lockdep_set_class(&inode->i_mutex,
|
|
&type->i_mutex_dir_key);
|
|
}
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(lockdep_annotate_inode_mutex_key);
|
|
#endif
|
|
|
|
/**
|
|
* unlock_new_inode - clear the I_NEW state and wake up any waiters
|
|
* @inode: new inode to unlock
|
|
*
|
|
* Called when the inode is fully initialised to clear the new state of the
|
|
* inode and wake up anyone waiting for the inode to finish initialisation.
|
|
*/
|
|
void unlock_new_inode(struct inode *inode)
|
|
{
|
|
lockdep_annotate_inode_mutex_key(inode);
|
|
spin_lock(&inode->i_lock);
|
|
WARN_ON(!(inode->i_state & I_NEW));
|
|
inode->i_state &= ~I_NEW;
|
|
wake_up_bit(&inode->i_state, __I_NEW);
|
|
spin_unlock(&inode->i_lock);
|
|
}
|
|
EXPORT_SYMBOL(unlock_new_inode);
|
|
|
|
/**
|
|
* iget5_locked - obtain an inode from a mounted file system
|
|
* @sb: super block of file system
|
|
* @hashval: hash value (usually inode number) to get
|
|
* @test: callback used for comparisons between inodes
|
|
* @set: callback used to initialize a new struct inode
|
|
* @data: opaque data pointer to pass to @test and @set
|
|
*
|
|
* Search for the inode specified by @hashval and @data in the inode cache,
|
|
* and if present it is return it with an increased reference count. This is
|
|
* a generalized version of iget_locked() for file systems where the inode
|
|
* number is not sufficient for unique identification of an inode.
|
|
*
|
|
* If the inode is not in cache, allocate a new inode and return it locked,
|
|
* hashed, and with the I_NEW flag set. The file system gets to fill it in
|
|
* before unlocking it via unlock_new_inode().
|
|
*
|
|
* Note both @test and @set are called with the inode_hash_lock held, so can't
|
|
* sleep.
|
|
*/
|
|
struct inode *iget5_locked(struct super_block *sb, unsigned long hashval,
|
|
int (*test)(struct inode *, void *),
|
|
int (*set)(struct inode *, void *), void *data)
|
|
{
|
|
struct hlist_head *head = inode_hashtable + hash(sb, hashval);
|
|
struct inode *inode;
|
|
|
|
spin_lock(&inode_hash_lock);
|
|
inode = find_inode(sb, head, test, data);
|
|
spin_unlock(&inode_hash_lock);
|
|
|
|
if (inode) {
|
|
wait_on_inode(inode);
|
|
return inode;
|
|
}
|
|
|
|
inode = alloc_inode(sb);
|
|
if (inode) {
|
|
struct inode *old;
|
|
|
|
spin_lock(&inode_hash_lock);
|
|
/* We released the lock, so.. */
|
|
old = find_inode(sb, head, test, data);
|
|
if (!old) {
|
|
if (set(inode, data))
|
|
goto set_failed;
|
|
|
|
spin_lock(&inode->i_lock);
|
|
inode->i_state = I_NEW;
|
|
hlist_add_head(&inode->i_hash, head);
|
|
spin_unlock(&inode->i_lock);
|
|
inode_sb_list_add(inode);
|
|
spin_unlock(&inode_hash_lock);
|
|
|
|
/* Return the locked inode with I_NEW set, the
|
|
* caller is responsible for filling in the contents
|
|
*/
|
|
return inode;
|
|
}
|
|
|
|
/*
|
|
* Uhhuh, somebody else created the same inode under
|
|
* us. Use the old inode instead of the one we just
|
|
* allocated.
|
|
*/
|
|
spin_unlock(&inode_hash_lock);
|
|
destroy_inode(inode);
|
|
inode = old;
|
|
wait_on_inode(inode);
|
|
}
|
|
return inode;
|
|
|
|
set_failed:
|
|
spin_unlock(&inode_hash_lock);
|
|
destroy_inode(inode);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(iget5_locked);
|
|
|
|
/**
|
|
* iget_locked - obtain an inode from a mounted file system
|
|
* @sb: super block of file system
|
|
* @ino: inode number to get
|
|
*
|
|
* Search for the inode specified by @ino in the inode cache and if present
|
|
* return it with an increased reference count. This is for file systems
|
|
* where the inode number is sufficient for unique identification of an inode.
|
|
*
|
|
* If the inode is not in cache, allocate a new inode and return it locked,
|
|
* hashed, and with the I_NEW flag set. The file system gets to fill it in
|
|
* before unlocking it via unlock_new_inode().
|
|
*/
|
|
struct inode *iget_locked(struct super_block *sb, unsigned long ino)
|
|
{
|
|
struct hlist_head *head = inode_hashtable + hash(sb, ino);
|
|
struct inode *inode;
|
|
|
|
spin_lock(&inode_hash_lock);
|
|
inode = find_inode_fast(sb, head, ino);
|
|
spin_unlock(&inode_hash_lock);
|
|
if (inode) {
|
|
wait_on_inode(inode);
|
|
return inode;
|
|
}
|
|
|
|
inode = alloc_inode(sb);
|
|
if (inode) {
|
|
struct inode *old;
|
|
|
|
spin_lock(&inode_hash_lock);
|
|
/* We released the lock, so.. */
|
|
old = find_inode_fast(sb, head, ino);
|
|
if (!old) {
|
|
inode->i_ino = ino;
|
|
spin_lock(&inode->i_lock);
|
|
inode->i_state = I_NEW;
|
|
hlist_add_head(&inode->i_hash, head);
|
|
spin_unlock(&inode->i_lock);
|
|
inode_sb_list_add(inode);
|
|
spin_unlock(&inode_hash_lock);
|
|
|
|
/* Return the locked inode with I_NEW set, the
|
|
* caller is responsible for filling in the contents
|
|
*/
|
|
return inode;
|
|
}
|
|
|
|
/*
|
|
* Uhhuh, somebody else created the same inode under
|
|
* us. Use the old inode instead of the one we just
|
|
* allocated.
|
|
*/
|
|
spin_unlock(&inode_hash_lock);
|
|
destroy_inode(inode);
|
|
inode = old;
|
|
wait_on_inode(inode);
|
|
}
|
|
return inode;
|
|
}
|
|
EXPORT_SYMBOL(iget_locked);
|
|
|
|
/*
|
|
* search the inode cache for a matching inode number.
|
|
* If we find one, then the inode number we are trying to
|
|
* allocate is not unique and so we should not use it.
|
|
*
|
|
* Returns 1 if the inode number is unique, 0 if it is not.
|
|
*/
|
|
static int test_inode_iunique(struct super_block *sb, unsigned long ino)
|
|
{
|
|
struct hlist_head *b = inode_hashtable + hash(sb, ino);
|
|
struct hlist_node *node;
|
|
struct inode *inode;
|
|
|
|
spin_lock(&inode_hash_lock);
|
|
hlist_for_each_entry(inode, node, b, i_hash) {
|
|
if (inode->i_ino == ino && inode->i_sb == sb) {
|
|
spin_unlock(&inode_hash_lock);
|
|
return 0;
|
|
}
|
|
}
|
|
spin_unlock(&inode_hash_lock);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* iunique - get a unique inode number
|
|
* @sb: superblock
|
|
* @max_reserved: highest reserved inode number
|
|
*
|
|
* Obtain an inode number that is unique on the system for a given
|
|
* superblock. This is used by file systems that have no natural
|
|
* permanent inode numbering system. An inode number is returned that
|
|
* is higher than the reserved limit but unique.
|
|
*
|
|
* BUGS:
|
|
* With a large number of inodes live on the file system this function
|
|
* currently becomes quite slow.
|
|
*/
|
|
ino_t iunique(struct super_block *sb, ino_t max_reserved)
|
|
{
|
|
/*
|
|
* On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW
|
|
* error if st_ino won't fit in target struct field. Use 32bit counter
|
|
* here to attempt to avoid that.
|
|
*/
|
|
static DEFINE_SPINLOCK(iunique_lock);
|
|
static unsigned int counter;
|
|
ino_t res;
|
|
|
|
spin_lock(&iunique_lock);
|
|
do {
|
|
if (counter <= max_reserved)
|
|
counter = max_reserved + 1;
|
|
res = counter++;
|
|
} while (!test_inode_iunique(sb, res));
|
|
spin_unlock(&iunique_lock);
|
|
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(iunique);
|
|
|
|
struct inode *igrab(struct inode *inode)
|
|
{
|
|
spin_lock(&inode->i_lock);
|
|
if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) {
|
|
__iget(inode);
|
|
spin_unlock(&inode->i_lock);
|
|
} else {
|
|
spin_unlock(&inode->i_lock);
|
|
/*
|
|
* Handle the case where s_op->clear_inode is not been
|
|
* called yet, and somebody is calling igrab
|
|
* while the inode is getting freed.
|
|
*/
|
|
inode = NULL;
|
|
}
|
|
return inode;
|
|
}
|
|
EXPORT_SYMBOL(igrab);
|
|
|
|
/**
|
|
* ilookup5_nowait - search for an inode in the inode cache
|
|
* @sb: super block of file system to search
|
|
* @hashval: hash value (usually inode number) to search for
|
|
* @test: callback used for comparisons between inodes
|
|
* @data: opaque data pointer to pass to @test
|
|
*
|
|
* Search for the inode specified by @hashval and @data in the inode cache.
|
|
* If the inode is in the cache, the inode is returned with an incremented
|
|
* reference count.
|
|
*
|
|
* Note: I_NEW is not waited upon so you have to be very careful what you do
|
|
* with the returned inode. You probably should be using ilookup5() instead.
|
|
*
|
|
* Note2: @test is called with the inode_hash_lock held, so can't sleep.
|
|
*/
|
|
struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval,
|
|
int (*test)(struct inode *, void *), void *data)
|
|
{
|
|
struct hlist_head *head = inode_hashtable + hash(sb, hashval);
|
|
struct inode *inode;
|
|
|
|
spin_lock(&inode_hash_lock);
|
|
inode = find_inode(sb, head, test, data);
|
|
spin_unlock(&inode_hash_lock);
|
|
|
|
return inode;
|
|
}
|
|
EXPORT_SYMBOL(ilookup5_nowait);
|
|
|
|
/**
|
|
* ilookup5 - search for an inode in the inode cache
|
|
* @sb: super block of file system to search
|
|
* @hashval: hash value (usually inode number) to search for
|
|
* @test: callback used for comparisons between inodes
|
|
* @data: opaque data pointer to pass to @test
|
|
*
|
|
* Search for the inode specified by @hashval and @data in the inode cache,
|
|
* and if the inode is in the cache, return the inode with an incremented
|
|
* reference count. Waits on I_NEW before returning the inode.
|
|
* returned with an incremented reference count.
|
|
*
|
|
* This is a generalized version of ilookup() for file systems where the
|
|
* inode number is not sufficient for unique identification of an inode.
|
|
*
|
|
* Note: @test is called with the inode_hash_lock held, so can't sleep.
|
|
*/
|
|
struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
|
|
int (*test)(struct inode *, void *), void *data)
|
|
{
|
|
struct inode *inode = ilookup5_nowait(sb, hashval, test, data);
|
|
|
|
if (inode)
|
|
wait_on_inode(inode);
|
|
return inode;
|
|
}
|
|
EXPORT_SYMBOL(ilookup5);
|
|
|
|
/**
|
|
* ilookup - search for an inode in the inode cache
|
|
* @sb: super block of file system to search
|
|
* @ino: inode number to search for
|
|
*
|
|
* Search for the inode @ino in the inode cache, and if the inode is in the
|
|
* cache, the inode is returned with an incremented reference count.
|
|
*/
|
|
struct inode *ilookup(struct super_block *sb, unsigned long ino)
|
|
{
|
|
struct hlist_head *head = inode_hashtable + hash(sb, ino);
|
|
struct inode *inode;
|
|
|
|
spin_lock(&inode_hash_lock);
|
|
inode = find_inode_fast(sb, head, ino);
|
|
spin_unlock(&inode_hash_lock);
|
|
|
|
if (inode)
|
|
wait_on_inode(inode);
|
|
return inode;
|
|
}
|
|
EXPORT_SYMBOL(ilookup);
|
|
|
|
int insert_inode_locked(struct inode *inode)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
ino_t ino = inode->i_ino;
|
|
struct hlist_head *head = inode_hashtable + hash(sb, ino);
|
|
|
|
while (1) {
|
|
struct hlist_node *node;
|
|
struct inode *old = NULL;
|
|
spin_lock(&inode_hash_lock);
|
|
hlist_for_each_entry(old, node, head, i_hash) {
|
|
if (old->i_ino != ino)
|
|
continue;
|
|
if (old->i_sb != sb)
|
|
continue;
|
|
spin_lock(&old->i_lock);
|
|
if (old->i_state & (I_FREEING|I_WILL_FREE)) {
|
|
spin_unlock(&old->i_lock);
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
if (likely(!node)) {
|
|
spin_lock(&inode->i_lock);
|
|
inode->i_state |= I_NEW;
|
|
hlist_add_head(&inode->i_hash, head);
|
|
spin_unlock(&inode->i_lock);
|
|
spin_unlock(&inode_hash_lock);
|
|
return 0;
|
|
}
|
|
__iget(old);
|
|
spin_unlock(&old->i_lock);
|
|
spin_unlock(&inode_hash_lock);
|
|
wait_on_inode(old);
|
|
if (unlikely(!inode_unhashed(old))) {
|
|
iput(old);
|
|
return -EBUSY;
|
|
}
|
|
iput(old);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(insert_inode_locked);
|
|
|
|
int insert_inode_locked4(struct inode *inode, unsigned long hashval,
|
|
int (*test)(struct inode *, void *), void *data)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
struct hlist_head *head = inode_hashtable + hash(sb, hashval);
|
|
|
|
while (1) {
|
|
struct hlist_node *node;
|
|
struct inode *old = NULL;
|
|
|
|
spin_lock(&inode_hash_lock);
|
|
hlist_for_each_entry(old, node, head, i_hash) {
|
|
if (old->i_sb != sb)
|
|
continue;
|
|
if (!test(old, data))
|
|
continue;
|
|
spin_lock(&old->i_lock);
|
|
if (old->i_state & (I_FREEING|I_WILL_FREE)) {
|
|
spin_unlock(&old->i_lock);
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
if (likely(!node)) {
|
|
spin_lock(&inode->i_lock);
|
|
inode->i_state |= I_NEW;
|
|
hlist_add_head(&inode->i_hash, head);
|
|
spin_unlock(&inode->i_lock);
|
|
spin_unlock(&inode_hash_lock);
|
|
return 0;
|
|
}
|
|
__iget(old);
|
|
spin_unlock(&old->i_lock);
|
|
spin_unlock(&inode_hash_lock);
|
|
wait_on_inode(old);
|
|
if (unlikely(!inode_unhashed(old))) {
|
|
iput(old);
|
|
return -EBUSY;
|
|
}
|
|
iput(old);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(insert_inode_locked4);
|
|
|
|
|
|
int generic_delete_inode(struct inode *inode)
|
|
{
|
|
return 1;
|
|
}
|
|
EXPORT_SYMBOL(generic_delete_inode);
|
|
|
|
/*
|
|
* Normal UNIX filesystem behaviour: delete the
|
|
* inode when the usage count drops to zero, and
|
|
* i_nlink is zero.
|
|
*/
|
|
int generic_drop_inode(struct inode *inode)
|
|
{
|
|
return !inode->i_nlink || inode_unhashed(inode);
|
|
}
|
|
EXPORT_SYMBOL_GPL(generic_drop_inode);
|
|
|
|
/*
|
|
* Called when we're dropping the last reference
|
|
* to an inode.
|
|
*
|
|
* Call the FS "drop_inode()" function, defaulting to
|
|
* the legacy UNIX filesystem behaviour. If it tells
|
|
* us to evict inode, do so. Otherwise, retain inode
|
|
* in cache if fs is alive, sync and evict if fs is
|
|
* shutting down.
|
|
*/
|
|
static void iput_final(struct inode *inode)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
const struct super_operations *op = inode->i_sb->s_op;
|
|
int drop;
|
|
|
|
WARN_ON(inode->i_state & I_NEW);
|
|
|
|
if (op->drop_inode)
|
|
drop = op->drop_inode(inode);
|
|
else
|
|
drop = generic_drop_inode(inode);
|
|
|
|
if (!drop && (sb->s_flags & MS_ACTIVE)) {
|
|
inode->i_state |= I_REFERENCED;
|
|
if (!(inode->i_state & (I_DIRTY|I_SYNC)))
|
|
inode_lru_list_add(inode);
|
|
spin_unlock(&inode->i_lock);
|
|
return;
|
|
}
|
|
|
|
if (!drop) {
|
|
inode->i_state |= I_WILL_FREE;
|
|
spin_unlock(&inode->i_lock);
|
|
write_inode_now(inode, 1);
|
|
spin_lock(&inode->i_lock);
|
|
WARN_ON(inode->i_state & I_NEW);
|
|
inode->i_state &= ~I_WILL_FREE;
|
|
}
|
|
|
|
inode->i_state |= I_FREEING;
|
|
if (!list_empty(&inode->i_lru))
|
|
inode_lru_list_del(inode);
|
|
spin_unlock(&inode->i_lock);
|
|
|
|
evict(inode);
|
|
}
|
|
|
|
/**
|
|
* iput - put an inode
|
|
* @inode: inode to put
|
|
*
|
|
* Puts an inode, dropping its usage count. If the inode use count hits
|
|
* zero, the inode is then freed and may also be destroyed.
|
|
*
|
|
* Consequently, iput() can sleep.
|
|
*/
|
|
void iput(struct inode *inode)
|
|
{
|
|
if (inode) {
|
|
BUG_ON(inode->i_state & I_CLEAR);
|
|
|
|
if (atomic_dec_and_lock(&inode->i_count, &inode->i_lock))
|
|
iput_final(inode);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(iput);
|
|
|
|
/**
|
|
* bmap - find a block number in a file
|
|
* @inode: inode of file
|
|
* @block: block to find
|
|
*
|
|
* Returns the block number on the device holding the inode that
|
|
* is the disk block number for the block of the file requested.
|
|
* That is, asked for block 4 of inode 1 the function will return the
|
|
* disk block relative to the disk start that holds that block of the
|
|
* file.
|
|
*/
|
|
sector_t bmap(struct inode *inode, sector_t block)
|
|
{
|
|
sector_t res = 0;
|
|
if (inode->i_mapping->a_ops->bmap)
|
|
res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block);
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(bmap);
|
|
|
|
/*
|
|
* With relative atime, only update atime if the previous atime is
|
|
* earlier than either the ctime or mtime or if at least a day has
|
|
* passed since the last atime update.
|
|
*/
|
|
static int relatime_need_update(struct vfsmount *mnt, struct inode *inode,
|
|
struct timespec now)
|
|
{
|
|
|
|
if (!(mnt->mnt_flags & MNT_RELATIME))
|
|
return 1;
|
|
/*
|
|
* Is mtime younger than atime? If yes, update atime:
|
|
*/
|
|
if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0)
|
|
return 1;
|
|
/*
|
|
* Is ctime younger than atime? If yes, update atime:
|
|
*/
|
|
if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0)
|
|
return 1;
|
|
|
|
/*
|
|
* Is the previous atime value older than a day? If yes,
|
|
* update atime:
|
|
*/
|
|
if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60)
|
|
return 1;
|
|
/*
|
|
* Good, we can skip the atime update:
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* touch_atime - update the access time
|
|
* @mnt: mount the inode is accessed on
|
|
* @dentry: dentry accessed
|
|
*
|
|
* Update the accessed time on an inode and mark it for writeback.
|
|
* This function automatically handles read only file systems and media,
|
|
* as well as the "noatime" flag and inode specific "noatime" markers.
|
|
*/
|
|
void touch_atime(struct vfsmount *mnt, struct dentry *dentry)
|
|
{
|
|
struct inode *inode = dentry->d_inode;
|
|
struct timespec now;
|
|
|
|
if (inode->i_flags & S_NOATIME)
|
|
return;
|
|
if (IS_NOATIME(inode))
|
|
return;
|
|
if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))
|
|
return;
|
|
|
|
if (mnt->mnt_flags & MNT_NOATIME)
|
|
return;
|
|
if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))
|
|
return;
|
|
|
|
now = current_fs_time(inode->i_sb);
|
|
|
|
if (!relatime_need_update(mnt, inode, now))
|
|
return;
|
|
|
|
if (timespec_equal(&inode->i_atime, &now))
|
|
return;
|
|
|
|
if (mnt_want_write(mnt))
|
|
return;
|
|
|
|
inode->i_atime = now;
|
|
mark_inode_dirty_sync(inode);
|
|
mnt_drop_write(mnt);
|
|
}
|
|
EXPORT_SYMBOL(touch_atime);
|
|
|
|
/**
|
|
* file_update_time - update mtime and ctime time
|
|
* @file: file accessed
|
|
*
|
|
* Update the mtime and ctime members of an inode and mark the inode
|
|
* for writeback. Note that this function is meant exclusively for
|
|
* usage in the file write path of filesystems, and filesystems may
|
|
* choose to explicitly ignore update via this function with the
|
|
* S_NOCMTIME inode flag, e.g. for network filesystem where these
|
|
* timestamps are handled by the server.
|
|
*/
|
|
|
|
void file_update_time(struct file *file)
|
|
{
|
|
struct inode *inode = file->f_path.dentry->d_inode;
|
|
struct timespec now;
|
|
enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0;
|
|
|
|
/* First try to exhaust all avenues to not sync */
|
|
if (IS_NOCMTIME(inode))
|
|
return;
|
|
|
|
now = current_fs_time(inode->i_sb);
|
|
if (!timespec_equal(&inode->i_mtime, &now))
|
|
sync_it = S_MTIME;
|
|
|
|
if (!timespec_equal(&inode->i_ctime, &now))
|
|
sync_it |= S_CTIME;
|
|
|
|
if (IS_I_VERSION(inode))
|
|
sync_it |= S_VERSION;
|
|
|
|
if (!sync_it)
|
|
return;
|
|
|
|
/* Finally allowed to write? Takes lock. */
|
|
if (mnt_want_write_file(file))
|
|
return;
|
|
|
|
/* Only change inode inside the lock region */
|
|
if (sync_it & S_VERSION)
|
|
inode_inc_iversion(inode);
|
|
if (sync_it & S_CTIME)
|
|
inode->i_ctime = now;
|
|
if (sync_it & S_MTIME)
|
|
inode->i_mtime = now;
|
|
mark_inode_dirty_sync(inode);
|
|
mnt_drop_write(file->f_path.mnt);
|
|
}
|
|
EXPORT_SYMBOL(file_update_time);
|
|
|
|
int inode_needs_sync(struct inode *inode)
|
|
{
|
|
if (IS_SYNC(inode))
|
|
return 1;
|
|
if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(inode_needs_sync);
|
|
|
|
int inode_wait(void *word)
|
|
{
|
|
schedule();
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(inode_wait);
|
|
|
|
/*
|
|
* If we try to find an inode in the inode hash while it is being
|
|
* deleted, we have to wait until the filesystem completes its
|
|
* deletion before reporting that it isn't found. This function waits
|
|
* until the deletion _might_ have completed. Callers are responsible
|
|
* to recheck inode state.
|
|
*
|
|
* It doesn't matter if I_NEW is not set initially, a call to
|
|
* wake_up_bit(&inode->i_state, __I_NEW) after removing from the hash list
|
|
* will DTRT.
|
|
*/
|
|
static void __wait_on_freeing_inode(struct inode *inode)
|
|
{
|
|
wait_queue_head_t *wq;
|
|
DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW);
|
|
wq = bit_waitqueue(&inode->i_state, __I_NEW);
|
|
prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
|
|
spin_unlock(&inode->i_lock);
|
|
spin_unlock(&inode_hash_lock);
|
|
schedule();
|
|
finish_wait(wq, &wait.wait);
|
|
spin_lock(&inode_hash_lock);
|
|
}
|
|
|
|
static __initdata unsigned long ihash_entries;
|
|
static int __init set_ihash_entries(char *str)
|
|
{
|
|
if (!str)
|
|
return 0;
|
|
ihash_entries = simple_strtoul(str, &str, 0);
|
|
return 1;
|
|
}
|
|
__setup("ihash_entries=", set_ihash_entries);
|
|
|
|
/*
|
|
* Initialize the waitqueues and inode hash table.
|
|
*/
|
|
void __init inode_init_early(void)
|
|
{
|
|
int loop;
|
|
|
|
/* If hashes are distributed across NUMA nodes, defer
|
|
* hash allocation until vmalloc space is available.
|
|
*/
|
|
if (hashdist)
|
|
return;
|
|
|
|
inode_hashtable =
|
|
alloc_large_system_hash("Inode-cache",
|
|
sizeof(struct hlist_head),
|
|
ihash_entries,
|
|
14,
|
|
HASH_EARLY,
|
|
&i_hash_shift,
|
|
&i_hash_mask,
|
|
0);
|
|
|
|
for (loop = 0; loop < (1 << i_hash_shift); loop++)
|
|
INIT_HLIST_HEAD(&inode_hashtable[loop]);
|
|
}
|
|
|
|
void __init inode_init(void)
|
|
{
|
|
int loop;
|
|
|
|
/* inode slab cache */
|
|
inode_cachep = kmem_cache_create("inode_cache",
|
|
sizeof(struct inode),
|
|
0,
|
|
(SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|
|
|
SLAB_MEM_SPREAD),
|
|
init_once);
|
|
|
|
/* Hash may have been set up in inode_init_early */
|
|
if (!hashdist)
|
|
return;
|
|
|
|
inode_hashtable =
|
|
alloc_large_system_hash("Inode-cache",
|
|
sizeof(struct hlist_head),
|
|
ihash_entries,
|
|
14,
|
|
0,
|
|
&i_hash_shift,
|
|
&i_hash_mask,
|
|
0);
|
|
|
|
for (loop = 0; loop < (1 << i_hash_shift); loop++)
|
|
INIT_HLIST_HEAD(&inode_hashtable[loop]);
|
|
}
|
|
|
|
void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev)
|
|
{
|
|
inode->i_mode = mode;
|
|
if (S_ISCHR(mode)) {
|
|
inode->i_fop = &def_chr_fops;
|
|
inode->i_rdev = rdev;
|
|
} else if (S_ISBLK(mode)) {
|
|
inode->i_fop = &def_blk_fops;
|
|
inode->i_rdev = rdev;
|
|
} else if (S_ISFIFO(mode))
|
|
inode->i_fop = &def_fifo_fops;
|
|
else if (S_ISSOCK(mode))
|
|
inode->i_fop = &bad_sock_fops;
|
|
else
|
|
printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o) for"
|
|
" inode %s:%lu\n", mode, inode->i_sb->s_id,
|
|
inode->i_ino);
|
|
}
|
|
EXPORT_SYMBOL(init_special_inode);
|
|
|
|
/**
|
|
* inode_init_owner - Init uid,gid,mode for new inode according to posix standards
|
|
* @inode: New inode
|
|
* @dir: Directory inode
|
|
* @mode: mode of the new inode
|
|
*/
|
|
void inode_init_owner(struct inode *inode, const struct inode *dir,
|
|
mode_t mode)
|
|
{
|
|
inode->i_uid = current_fsuid();
|
|
if (dir && dir->i_mode & S_ISGID) {
|
|
inode->i_gid = dir->i_gid;
|
|
if (S_ISDIR(mode))
|
|
mode |= S_ISGID;
|
|
} else
|
|
inode->i_gid = current_fsgid();
|
|
inode->i_mode = mode;
|
|
}
|
|
EXPORT_SYMBOL(inode_init_owner);
|
|
|
|
/**
|
|
* inode_owner_or_capable - check current task permissions to inode
|
|
* @inode: inode being checked
|
|
*
|
|
* Return true if current either has CAP_FOWNER to the inode, or
|
|
* owns the file.
|
|
*/
|
|
bool inode_owner_or_capable(const struct inode *inode)
|
|
{
|
|
struct user_namespace *ns = inode_userns(inode);
|
|
|
|
if (current_user_ns() == ns && current_fsuid() == inode->i_uid)
|
|
return true;
|
|
if (ns_capable(ns, CAP_FOWNER))
|
|
return true;
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL(inode_owner_or_capable);
|