mbcache: fix shrinker function return value

The shrinker function is supposed to return the number of cache
entries after shrinking, not before shrinking.  Fix that.

Based on a patch from Wang Sheng-Hui <crosslonelyover@gmail.com>.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Andreas Gruenbacher 2010-07-21 19:44:45 +02:00 committed by Al Viro
parent 2aec7c5232
commit e566d48c9b

View File

@ -176,22 +176,12 @@ static int
mb_cache_shrink_fn(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
{
LIST_HEAD(free_list);
struct list_head *l, *ltmp;
struct mb_cache *cache;
struct mb_cache_entry *entry, *tmp;
int count = 0;
spin_lock(&mb_cache_spinlock);
list_for_each(l, &mb_cache_list) {
struct mb_cache *cache =
list_entry(l, struct mb_cache, c_cache_list);
mb_debug("cache %s (%d)", cache->c_name,
atomic_read(&cache->c_entry_count));
count += atomic_read(&cache->c_entry_count);
}
mb_debug("trying to free %d entries", nr_to_scan);
if (nr_to_scan == 0) {
spin_unlock(&mb_cache_spinlock);
goto out;
}
spin_lock(&mb_cache_spinlock);
while (nr_to_scan-- && !list_empty(&mb_cache_lru_list)) {
struct mb_cache_entry *ce =
list_entry(mb_cache_lru_list.next,
@ -199,12 +189,15 @@ mb_cache_shrink_fn(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
list_move_tail(&ce->e_lru_list, &free_list);
__mb_cache_entry_unhash(ce);
}
spin_unlock(&mb_cache_spinlock);
list_for_each_safe(l, ltmp, &free_list) {
__mb_cache_entry_forget(list_entry(l, struct mb_cache_entry,
e_lru_list), gfp_mask);
list_for_each_entry(cache, &mb_cache_list, c_cache_list) {
mb_debug("cache %s (%d)", cache->c_name,
atomic_read(&cache->c_entry_count));
count += atomic_read(&cache->c_entry_count);
}
spin_unlock(&mb_cache_spinlock);
list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
__mb_cache_entry_forget(entry, gfp_mask);
}
out:
return (count / 100) * sysctl_vfs_cache_pressure;
}