From 0520a938e11c34a5ffc422b9316b85e294b0fbb2 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Sun, 11 Sep 2016 12:58:59 -0300
Subject: Linux-libre 4.7.3-gnu

---
 fs/aufs/module.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 52 insertions(+), 8 deletions(-)

(limited to 'fs/aufs/module.c')

diff --git a/fs/aufs/module.c b/fs/aufs/module.c
index ede9a232a..5092b4bd6 100644
--- a/fs/aufs/module.c
+++ b/fs/aufs/module.c
@@ -10,13 +10,57 @@
 #include <linux/seq_file.h>
 #include "aufs.h"
 
-void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp)
+/* shrinkable realloc */
+void *au_krealloc(void *p, unsigned int new_sz, gfp_t gfp, int may_shrink)
 {
-	if (new_sz <= nused)
-		return p;
+	size_t sz;
+	int diff;
+
+	sz = 0;
+	diff = -1;
+	if (p) {
+#if 0 /* unused */
+		if (!new_sz) {
+			au_delayed_kfree(p);
+			p = NULL;
+			goto out;
+		}
+#else
+		AuDebugOn(!new_sz);
+#endif
+		sz = ksize(p);
+		diff = au_kmidx_sub(sz, new_sz);
+	}
+	if (sz && !diff)
+		goto out;
+
+	if (sz < new_sz)
+		/* expand or SLOB */
+		p = krealloc(p, new_sz, gfp);
+	else if (new_sz < sz && may_shrink) {
+		/* shrink */
+		void *q;
+
+		q = kmalloc(new_sz, gfp);
+		if (q) {
+			if (p) {
+				memcpy(q, p, new_sz);
+				au_delayed_kfree(p);
+			}
+			p = q;
+		} else
+			p = NULL;
+	}
 
-	p = krealloc(p, new_sz, gfp);
-	if (p)
+out:
+	return p;
+}
+
+void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp,
+		   int may_shrink)
+{
+	p = au_krealloc(p, new_sz, gfp, may_shrink);
+	if (p && new_sz > nused)
 		memset(p + nused, 0, new_sz - nused);
 	return p;
 }
@@ -38,9 +82,9 @@ static void au_do_dfree(struct work_struct *work __maybe_unused)
 		head = &au_dfree.cache[AuCache_##idx].llist;		\
 		node = llist_del_all(head);				\
 		for (; node; node = next) {				\
-			struct au_##name *p =				\
-				p = llist_entry(node, struct au_##name,	\
-						lnode);			\
+			struct au_##name *p				\
+				= llist_entry(node, struct au_##name,	\
+					      lnode);			\
 			next = llist_next(node);			\
 			au_cache_free_##name(p);			\
 		}							\
-- 
cgit v1.2.3-54-g00ecf