-}
-
-static void prune_icache(int count)
-{
- struct super_block *sb, *p = NULL;
- int w_count;
- int unused = inodes_stat.nr_unused;
- int prune_ratio;
- int pruned;
-
- if (unused == 0 || count == 0)
- return;
- down_read(&iprune_sem);
- if (count >= unused)
- prune_ratio = 1;
- else
- prune_ratio = unused / count;
- spin_lock(&sb_lock);
- list_for_each_entry(sb, &super_blocks, s_list) {
- if (list_empty(&sb->s_instances))
- continue;
- if (sb->s_nr_inodes_unused == 0)
- continue;
- sb->s_count++;
- /* Now, we reclaim unused dentrins with fairness.
- * We reclaim them same percentage from each superblock.
- * We calculate number of dentries to scan on this sb
- * as follows, but the implementation is arranged to avoid
- * overflows:
- * number of dentries to scan on this sb =
- * count * (number of dentries on this sb /
- * number of dentries in the machine)
- */
- spin_unlock(&sb_lock);
- if (prune_ratio != 1)
- w_count = (sb->s_nr_inodes_unused / prune_ratio) + 1;
- else
- w_count = sb->s_nr_inodes_unused;
- pruned = w_count;
- /*
- * We need to be sure this filesystem isn't being unmounted,
- * otherwise we could race with generic_shutdown_super(), and
- * end up holding a reference to an inode while the filesystem
- * is unmounted. So we try to get s_umount, and make sure
- * s_root isn't NULL.
- */
- if (down_read_trylock(&sb->s_umount)) {
- if ((sb->s_root != NULL) &&
- (!list_empty(&sb->s_dentry_lru))) {
- shrink_icache_sb(sb, &w_count);
- pruned -= w_count;
- }
- up_read(&sb->s_umount);
- }
- spin_lock(&sb_lock);
- if (p)
- __put_super(p);
- count -= pruned;
- p = sb;
- /* more work left to do? */
- if (count <= 0)
- break;
- }
- if (p)
- __put_super(p);
- spin_unlock(&sb_lock);