Merge Linaro linux 4.9.62 into linux-4.9

Signed-off-by: Xiaobo Xie <xiaobo.xie@nxp.com>

1 files changed, 30 insertions, 2 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 4485a48..67957f5 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -277,6 +277,33 @@ static inline int dname_external(const struct dentry *dentry)
 	return dentry->d_name.name != dentry->d_iname;
 }
 
+void take_dentry_name_snapshot(struct name_snapshot *name, struct dentry *dentry)
+{
+	spin_lock(&dentry->d_lock);
+	if (unlikely(dname_external(dentry))) {
+		struct external_name *p = external_name(dentry);
+		atomic_inc(&p->u.count);
+		spin_unlock(&dentry->d_lock);
+		name->name = p->name;
+	} else {
+		memcpy(name->inline_name, dentry->d_iname, DNAME_INLINE_LEN);
+		spin_unlock(&dentry->d_lock);
+		name->name = name->inline_name;
+	}
+}
+EXPORT_SYMBOL(take_dentry_name_snapshot);
+
+void release_dentry_name_snapshot(struct name_snapshot *name)
+{
+	if (unlikely(name->name != name->inline_name)) {
+		struct external_name *p;
+		p = container_of(name->name, struct external_name, name[0]);
+		if (unlikely(atomic_dec_and_test(&p->u.count)))
+			kfree_rcu(p, u.head);
+	}
+}
+EXPORT_SYMBOL(release_dentry_name_snapshot);
+
 static inline void __d_set_inode_and_type(struct dentry *dentry,
 					  struct inode *inode,
 					  unsigned type_flags)
@@ -1133,11 +1160,12 @@ void shrink_dcache_sb(struct super_block *sb)
 		LIST_HEAD(dispose);
 
 		freed = list_lru_walk(&sb->s_dentry_lru,
-			dentry_lru_isolate_shrink, &dispose, UINT_MAX);
+			dentry_lru_isolate_shrink, &dispose, 1024);
 
 		this_cpu_sub(nr_dentry_unused, freed);
 		shrink_dentry_list(&dispose);
-	} while (freed > 0);
+		cond_resched();
+	} while (list_lru_count(&sb->s_dentry_lru) > 0);
 }
 EXPORT_SYMBOL(shrink_dcache_sb);