* allowing for low-overhead inode sync() operations.
*/
-LIST_HEAD(inode_in_use);
-LIST_HEAD(inode_unused);
+static LIST_HEAD(inode_unused);
static struct hlist_head *inode_hashtable __read_mostly;
/*
*/
struct inodes_stat_t inodes_stat;
+static struct percpu_counter nr_inodes __cacheline_aligned_in_smp;
+static struct percpu_counter nr_inodes_unused __cacheline_aligned_in_smp;
+
static struct kmem_cache *inode_cachep __read_mostly;
+static inline int get_nr_inodes(void)
+{
+ return percpu_counter_sum_positive(&nr_inodes);
+}
+
+static inline int get_nr_inodes_unused(void)
+{
+ return percpu_counter_sum_positive(&nr_inodes_unused);
+}
+
+int get_nr_dirty_inodes(void)
+{
+ 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
+
static void wake_up_inode(struct inode *inode)
{
/*
inode->i_fsnotify_mask = 0;
#endif
+ percpu_counter_inc(&nr_inodes);
+
return 0;
out:
return -ENOMEM;
if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED)
posix_acl_release(inode->i_default_acl);
#endif
+ percpu_counter_dec(&nr_inodes);
}
EXPORT_SYMBOL(__destroy_inode);
-void destroy_inode(struct inode *inode)
+static void destroy_inode(struct inode *inode)
{
__destroy_inode(inode);
if (inode->i_sb->s_op->destroy_inode)
INIT_HLIST_NODE(&inode->i_hash);
INIT_LIST_HEAD(&inode->i_dentry);
INIT_LIST_HEAD(&inode->i_devices);
+ INIT_LIST_HEAD(&inode->i_list);
INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC);
spin_lock_init(&inode->i_data.tree_lock);
spin_lock_init(&inode->i_data.i_mmap_lock);
*/
void __iget(struct inode *inode)
{
- if (atomic_inc_return(&inode->i_count) != 1)
- return;
+ atomic_inc(&inode->i_count);
+}
+
+static void inode_lru_list_add(struct inode *inode)
+{
+ if (list_empty(&inode->i_list)) {
+ list_add(&inode->i_list, &inode_unused);
+ percpu_counter_inc(&nr_inodes_unused);
+ }
+}
+
+static void inode_lru_list_del(struct inode *inode)
+{
+ if (!list_empty(&inode->i_list)) {
+ list_del_init(&inode->i_list);
+ percpu_counter_dec(&nr_inodes_unused);
+ }
+}
+
+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_HASHBITS);
+ return tmp & I_HASHMASK;
+}
- if (!(inode->i_state & (I_DIRTY|I_SYNC)))
- list_move(&inode->i_list, &inode_in_use);
- inodes_stat.nr_unused--;
+/**
+ * __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 *head = inode_hashtable + hash(inode->i_sb, hashval);
+ spin_lock(&inode_lock);
+ hlist_add_head(&inode->i_hash, head);
+ spin_unlock(&inode_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.
+ */
+static void __remove_inode_hash(struct inode *inode)
+{
+ hlist_del_init(&inode->i_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_lock);
+ hlist_del_init(&inode->i_hash);
+ spin_unlock(&inode_lock);
}
+EXPORT_SYMBOL(remove_inode_hash);
void end_writeback(struct inode *inode)
{
*/
static void dispose_list(struct list_head *head)
{
- int nr_disposed = 0;
-
while (!list_empty(head)) {
struct inode *inode;
inode = list_first_entry(head, struct inode, i_list);
- list_del(&inode->i_list);
+ list_del_init(&inode->i_list);
evict(inode);
spin_lock(&inode_lock);
- hlist_del_init(&inode->i_hash);
+ __remove_inode_hash(inode);
list_del_init(&inode->i_sb_list);
spin_unlock(&inode_lock);
wake_up_inode(inode);
destroy_inode(inode);
- nr_disposed++;
}
- spin_lock(&inode_lock);
- inodes_stat.nr_inodes -= nr_disposed;
- spin_unlock(&inode_lock);
}
/*
static int invalidate_list(struct list_head *head, struct list_head *dispose)
{
struct list_head *next;
- int busy = 0, count = 0;
+ int busy = 0;
next = head->next;
for (;;) {
list_move(&inode->i_list, dispose);
WARN_ON(inode->i_state & I_NEW);
inode->i_state |= I_FREEING;
- count++;
+ if (!(inode->i_state & (I_DIRTY | I_SYNC)))
+ percpu_counter_dec(&nr_inodes_unused);
continue;
}
busy = 1;
}
- /* only unused inodes may be cached with i_count zero */
- inodes_stat.nr_unused -= count;
return busy;
}
return busy;
}
-EXPORT_SYMBOL(invalidate_inodes);
static int can_unuse(struct inode *inode)
{
- if (inode->i_state)
+ if (inode->i_state & ~I_REFERENCED)
return 0;
if (inode_has_buffers(inode))
return 0;
}
/*
- * Scan `goal' inodes on the unused list for freeable ones. They are moved to
- * a temporary list and then are freed outside inode_lock by dispose_list().
+ * Scan `goal' inodes on the unused list for freeable ones. They 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. We expect the final iput() on that inode to add it to
- * the front of the inode_unused list. So look for it there and if the
- * inode is still freeable, proceed. The right inode is found 99.9% of the
- * time in testing on a 4-way.
+ * pagecache removed. If the inode has metadata buffers attached to
+ * mapping->private_list then try to remove them.
*
- * 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.
*/
static void prune_icache(int nr_to_scan)
{
LIST_HEAD(freeable);
- int nr_pruned = 0;
int nr_scanned;
unsigned long reap = 0;
inode = list_entry(inode_unused.prev, struct inode, i_list);
- if (inode->i_state || atomic_read(&inode->i_count)) {
+ /*
+ * 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_list);
+ percpu_counter_dec(&nr_inodes_unused);
+ continue;
+ }
+
+ /* recently referenced inodes get one more pass */
+ if (inode->i_state & I_REFERENCED) {
list_move(&inode->i_list, &inode_unused);
+ inode->i_state &= ~I_REFERENCED;
continue;
}
if (inode_has_buffers(inode) || inode->i_data.nrpages) {
list_move(&inode->i_list, &freeable);
WARN_ON(inode->i_state & I_NEW);
inode->i_state |= I_FREEING;
- nr_pruned++;
+ percpu_counter_dec(&nr_inodes_unused);
}
- inodes_stat.nr_unused -= nr_pruned;
if (current_is_kswapd())
__count_vm_events(KSWAPD_INODESTEAL, reap);
else
return -1;
prune_icache(nr);
}
- return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
+ return (get_nr_inodes_unused() / 100) * sysctl_vfs_cache_pressure;
}
static struct shrinker icache_shrinker = {
return node ? inode : NULL;
}
-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_HASHBITS);
- return tmp & I_HASHMASK;
-}
-
static inline void
__inode_add_to_lists(struct super_block *sb, struct hlist_head *head,
struct inode *inode)
{
- inodes_stat.nr_inodes++;
- list_add(&inode->i_list, &inode_in_use);
list_add(&inode->i_sb_list, &sb->s_inodes);
if (head)
hlist_add_head(&inode->i_hash, head);
void unlock_new_inode(struct inode *inode)
{
#ifdef CONFIG_DEBUG_LOCK_ALLOC
- if (inode->i_mode & S_IFDIR) {
+ 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 */
return inode;
}
+/*
+ * 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;
+
+ hlist_for_each_entry(inode, node, b, i_hash) {
+ if (inode->i_ino == ino && inode->i_sb == sb)
+ return 0;
+ }
+
+ return 1;
+}
+
/**
* iunique - get a unique inode number
* @sb: superblock
* 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;
- struct inode *inode;
- struct hlist_head *head;
ino_t res;
spin_lock(&inode_lock);
+ spin_lock(&iunique_lock);
do {
if (counter <= max_reserved)
counter = max_reserved + 1;
res = counter++;
- head = inode_hashtable + hash(sb, res);
- inode = find_inode_fast(sb, head, res);
- } while (inode != NULL);
+ } while (!test_inode_iunique(sb, res));
+ spin_unlock(&iunique_lock);
spin_unlock(&inode_lock);
return res;
__iget(old);
spin_unlock(&inode_lock);
wait_on_inode(old);
- if (unlikely(!hlist_unhashed(&old->i_hash))) {
+ if (unlikely(!inode_unhashed(old))) {
iput(old);
return -EBUSY;
}
__iget(old);
spin_unlock(&inode_lock);
wait_on_inode(old);
- if (unlikely(!hlist_unhashed(&old->i_hash))) {
+ if (unlikely(!inode_unhashed(old))) {
iput(old);
return -EBUSY;
}
}
EXPORT_SYMBOL(insert_inode_locked4);
-/**
- * __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 *head = inode_hashtable + hash(inode->i_sb, hashval);
- spin_lock(&inode_lock);
- hlist_add_head(&inode->i_hash, head);
- spin_unlock(&inode_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_lock);
- hlist_del_init(&inode->i_hash);
- spin_unlock(&inode_lock);
-}
-EXPORT_SYMBOL(remove_inode_hash);
int generic_delete_inode(struct inode *inode)
{
*/
int generic_drop_inode(struct inode *inode)
{
- return !inode->i_nlink || hlist_unhashed(&inode->i_hash);
+ return !inode->i_nlink || inode_unhashed(inode);
}
EXPORT_SYMBOL_GPL(generic_drop_inode);
drop = generic_drop_inode(inode);
if (!drop) {
- if (!(inode->i_state & (I_DIRTY|I_SYNC)))
- list_move(&inode->i_list, &inode_unused);
- inodes_stat.nr_unused++;
if (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_lock);
return;
}
spin_lock(&inode_lock);
WARN_ON(inode->i_state & I_NEW);
inode->i_state &= ~I_WILL_FREE;
- inodes_stat.nr_unused--;
- hlist_del_init(&inode->i_hash);
+ __remove_inode_hash(inode);
}
- list_del_init(&inode->i_list);
- list_del_init(&inode->i_sb_list);
WARN_ON(inode->i_state & I_NEW);
inode->i_state |= I_FREEING;
- inodes_stat.nr_inodes--;
+
+ /*
+ * After we delete the inode from the LRU here, we avoid moving dirty
+ * inodes back onto the LRU now because I_FREEING is set and hence
+ * writeback_single_inode() won't move the inode around.
+ */
+ inode_lru_list_del(inode);
+
+ list_del_init(&inode->i_sb_list);
spin_unlock(&inode_lock);
evict(inode);
- spin_lock(&inode_lock);
- hlist_del_init(&inode->i_hash);
- spin_unlock(&inode_lock);
+ remove_inode_hash(inode);
wake_up_inode(inode);
BUG_ON(inode->i_state != (I_FREEING | I_CLEAR));
destroy_inode(inode);
SLAB_MEM_SPREAD),
init_once);
register_shrinker(&icache_shrinker);
+ percpu_counter_init(&nr_inodes, 0);
+ percpu_counter_init(&nr_inodes_unused, 0);
/* Hash may have been set up in inode_init_early */
if (!hashdist)
git.openpandora.org / pandora-kernel.git / blobdiff