[PATCH 10/13] vfs: Routnes for setting mob size and getting stats

[Pavel Emelyanov <xemul@parallels.com>]

Very simple ones, just to make the further patching simpler.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

---
 fs/dcache.c            |   30 ++++++++++++++++++++++++++++++
 include/linux/dcache.h |    7 +++++++
 2 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 51fb998..bdacea3 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -3006,6 +3006,36 @@ int dcache_new_mob(struct dentry *root)
 	return 0;
 }
 
+int dcache_set_mob_size(struct dentry *de, unsigned long size)
+{
+	struct dentry_mob *mob = de->d_mob;
+	unsigned long usage;
+
+	if (mob == &init_dentry_mob) /* for safety */
+		return 0;
+
+	mob->nr_dentry_max = size;
+	usage = percpu_counter_sum_positive(&mob->nr_dentry);
+	if (usage > mob->nr_dentry_max)
+		prune_dcache(mob, usage - mob->nr_dentry_max);
+
+	return 0;
+}
+
+int dcache_get_mob_stat(struct dentry *de, struct dentry_mob_stat __user *stat)
+{
+	struct dentry_mob *mob = de->d_mob;
+	struct dentry_mob_stat kstat;
+
+	kstat.nr_dentry = percpu_counter_sum_positive(&mob->nr_dentry);
+	kstat.nr_dentry_max = mob->nr_dentry_max;
+
+	if (copy_to_user(stat, &kstat, sizeof(kstat)))
+		return -EFAULT;
+
+	return 0;
+}
+
 static __initdata unsigned long dhash_entries;
 static int __init set_dhash_entries(char *str)
 {
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 3681307..0d13966 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -55,7 +55,14 @@ struct dentry_mob {
 };
 
 struct dentry;
+struct dentry_mob_stat {
+	unsigned long nr_dentry;
+	unsigned long nr_dentry_max;
+};
+
 int dcache_new_mob(struct dentry *root);
+int dcache_set_mob_size(struct dentry *de, unsigned long size);
+int dcache_get_mob_stat(struct dentry *de, struct dentry_mob_stat __user *stat);
 
 /*
  * Compare 2 name strings, return 0 if they match, otherwise non-zero.
-- 
1.5.5.6