#include <linux/prefetch.h>
#include <linux/buffer_head.h> /* for inode_has_buffers */
#include <linux/ratelimit.h>
+#include <linux/list_lru.h>
#include "internal.h"
/*
*
* inode->i_lock protects:
* inode->i_state, inode->i_hash, __iget()
- * inode->i_sb->s_inode_lru_lock protects:
+ * Inode LRU list locks protect:
* inode->i_sb->s_inode_lru, inode->i_lru
* inode_sb_list_lock protects:
* sb->s_inodes, inode->i_sb_list
*
* inode_sb_list_lock
* inode->i_lock
- * inode->i_sb->s_inode_lru_lock
+ * Inode LRU list locks
*
* bdi->wb.list_lock
* inode->i_lock
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++;
+ if (list_lru_add(&inode->i_sb->s_inode_lru, &inode->i_lru))
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--;
+
+ if (list_lru_del(&inode->i_sb->s_inode_lru, &inode->i_lru))
this_cpu_dec(nr_unused);
- }
- spin_unlock(&inode->i_sb->s_inode_lru_lock);
}
/**
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().
+ * Isolate the inode from the LRU in preparation for freeing it.
*
* Any inodes which are pinned purely because of attached pagecache have their
* pagecache removed. If the inode has metadata buffers attached to
* 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.
*/
-long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
+static enum lru_status
+inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
{
- LIST_HEAD(freeable);
- long nr_scanned;
- long freed = 0;
- unsigned long reap = 0;
+ struct list_head *freeable = arg;
+ struct inode *inode = container_of(item, struct inode, i_lru);
- spin_lock(&sb->s_inode_lru_lock);
- for (nr_scanned = nr_to_scan; nr_scanned >= 0; nr_scanned--) {
- struct inode *inode;
+ /*
+ * we are inverting the lru lock/inode->i_lock here, so use a trylock.
+ * If we fail to get the lock, just skip it.
+ */
+ if (!spin_trylock(&inode->i_lock))
+ return LRU_SKIP;
- if (list_empty(&sb->s_inode_lru))
- break;
+ /*
+ * 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);
+ this_cpu_dec(nr_unused);
+ return LRU_REMOVED;
+ }
- inode = list_entry(sb->s_inode_lru.prev, struct inode, i_lru);
+ /* recently referenced inodes get one more pass */
+ if (inode->i_state & I_REFERENCED) {
+ inode->i_state &= ~I_REFERENCED;
+ spin_unlock(&inode->i_lock);
+ return LRU_ROTATE;
+ }
- /*
- * 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;
+ if (inode_has_buffers(inode) || inode->i_data.nrpages) {
+ __iget(inode);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(lru_lock);
+ if (remove_inode_buffers(inode)) {
+ unsigned long reap;
+ reap = invalidate_mapping_pages(&inode->i_data, 0, -1);
+ if (current_is_kswapd())
+ __count_vm_events(KSWAPD_INODESTEAL, reap);
+ else
+ __count_vm_events(PGINODESTEAL, reap);
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed_slab += reap;
}
+ iput(inode);
+ spin_lock(lru_lock);
+ return LRU_RETRY;
+ }
- /*
- * 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;
- }
+ WARN_ON(inode->i_state & I_NEW);
+ inode->i_state |= I_FREEING;
+ spin_unlock(&inode->i_lock);
- /* 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);
+ this_cpu_dec(nr_unused);
+ return LRU_REMOVED;
+}
- list_move(&inode->i_lru, &freeable);
- sb->s_nr_inodes_unused--;
- this_cpu_dec(nr_unused);
- freed++;
- }
- if (current_is_kswapd())
- __count_vm_events(KSWAPD_INODESTEAL, reap);
- else
- __count_vm_events(PGINODESTEAL, reap);
- spin_unlock(&sb->s_inode_lru_lock);
- if (current->reclaim_state)
- current->reclaim_state->reclaimed_slab += reap;
+/*
+ * 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().
+ */
+long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan)
+{
+ LIST_HEAD(freeable);
+ long freed;
+ freed = list_lru_walk(&sb->s_inode_lru, inode_lru_isolate,
+ &freeable, nr_to_scan);
dispose_list(&freeable);
return freed;
}
if (sb->s_op && sb->s_op->nr_cached_objects)
fs_objects = sb->s_op->nr_cached_objects(sb);
- total_objects = sb->s_nr_dentry_unused +
- sb->s_nr_inodes_unused + fs_objects + 1;
+ inodes = list_lru_count(&sb->s_inode_lru);
+ total_objects = sb->s_nr_dentry_unused + inodes + fs_objects + 1;
/* proportion the scan between the caches */
dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
total_objects);
- inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
- total_objects);
+ inodes = mult_frac(sc->nr_to_scan, inodes, total_objects);
/*
* prune the dcache first as the icache is pinned by it, then
total_objects = sb->s_op->nr_cached_objects(sb);
total_objects += sb->s_nr_dentry_unused;
- total_objects += sb->s_nr_inodes_unused;
+ total_objects += list_lru_count(&sb->s_inode_lru);
total_objects = vfs_pressure_ratio(total_objects);
drop_super(sb);
INIT_LIST_HEAD(&s->s_inodes);
INIT_LIST_HEAD(&s->s_dentry_lru);
spin_lock_init(&s->s_dentry_lru_lock);
- INIT_LIST_HEAD(&s->s_inode_lru);
- spin_lock_init(&s->s_inode_lru_lock);
+ list_lru_init(&s->s_inode_lru);
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
lockdep_set_class(&s->s_umount, &type->s_umount_key);