From b9c44617f0cba905f541249c5d23069d7d82ef28 Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Date: Wed, 22 Aug 2012 17:35:11 +0300
Subject: [PATCH] --- yaml --- r: 329050 b: refs/heads/master c:
 8089ed792832e5d3dd219da435c5a08d969662b4 h: refs/heads/master v: v3

---
 [refs]                 |  2 +-
 trunk/fs/ubifs/debug.c | 20 +++++++++++---------
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/[refs] b/[refs]
index d243a9aee531..3d4d1390006c 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4b3e58a6d6c62b5457ff876fdfc79f66fff04cd2
+refs/heads/master: 8089ed792832e5d3dd219da435c5a08d969662b4
diff --git a/trunk/fs/ubifs/debug.c b/trunk/fs/ubifs/debug.c
index 1aaa9f519485..5dc993fdca87 100644
--- a/trunk/fs/ubifs/debug.c
+++ b/trunk/fs/ubifs/debug.c
@@ -2646,20 +2646,18 @@ static int power_cut_emulated(struct ubifs_info *c, int lnum, int write)
 	return 1;
 }
 
-static void cut_data(const void *buf, unsigned int len)
+static int corrupt_data(const struct ubifs_info *c, const void *buf,
+			unsigned int len)
 {
 	unsigned int from, to, i, ffs = chance(1, 2);
 	unsigned char *p = (void *)buf;
 
 	from = random32() % (len + 1);
-	if (chance(1, 2))
-		to = random32() % (len - from + 1);
-	else
-		to = len;
+	/* Corruption may only span one max. write unit */
+	to = min(len, ALIGN(from, c->max_write_size));
 
-	if (from < to)
-		ubifs_warn("filled bytes %u-%u with %s", from, to - 1,
-			   ffs ? "0xFFs" : "random data");
+	ubifs_warn("filled bytes %u-%u with %s", from, to - 1,
+		   ffs ? "0xFFs" : "random data");
 
 	if (ffs)
 		for (i = from; i < to; i++)
@@ -2667,6 +2665,8 @@ static void cut_data(const void *buf, unsigned int len)
 	else
 		for (i = from; i < to; i++)
 			p[i] = random32() % 0x100;
+
+	return to;
 }
 
 int dbg_leb_write(struct ubifs_info *c, int lnum, const void *buf,
@@ -2679,7 +2679,9 @@ int dbg_leb_write(struct ubifs_info *c, int lnum, const void *buf,
 
 	failing = power_cut_emulated(c, lnum, 1);
 	if (failing)
-		cut_data(buf, len);
+		len = corrupt_data(c, buf, len);
+	ubifs_warn("actually write %d bytes to LEB %d:%d (the buffer was corrupted)",
+		   len, lnum, offs);
 	err = ubi_leb_write(c->ubi, lnum, buf, offs, len);
 	if (err)
 		return err;