From e7ecdad37eb105e12e3b5e5d5699a4166a29f533 Mon Sep 17 00:00:00 2001
From: Lukas Czerner <lczerner@redhat.com>
Date: Mon, 1 Jul 2013 08:12:39 -0400
Subject: [PATCH] --- yaml --- r: 377635 b: refs/heads/master c:
 e1be3a928ee0b0b2a893695e6dd5c5dbe293af16 h: refs/heads/master i:   377633:
 f481d79f81a26f678e59b18564813fb1ffa8ff81   377631:
 f8981d7ac684863ced82230661efa863d00cc651 v: v3

---
 [refs]                |  2 +-
 trunk/fs/ext4/inode.c | 17 ++++++++++-------
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/[refs] b/[refs]
index 627643fd2750..3676cd2a525b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 42c832debbbf819f6c4ad8601baa559c44105ba4
+refs/heads/master: e1be3a928ee0b0b2a893695e6dd5c5dbe293af16
diff --git a/trunk/fs/ext4/inode.c b/trunk/fs/ext4/inode.c
index 09942341dfae..502a9e1f5aa3 100644
--- a/trunk/fs/ext4/inode.c
+++ b/trunk/fs/ext4/inode.c
@@ -3424,33 +3424,36 @@ int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
 {
 	struct super_block *sb = inode->i_sb;
 	struct address_space *mapping = inode->i_mapping;
-	unsigned partial = lstart & (sb->s_blocksize - 1);
+	unsigned partial_start, partial_end;
 	ext4_fsblk_t start, end;
 	loff_t byte_end = (lstart + length - 1);
 	int err = 0;
 
+	partial_start = lstart & (sb->s_blocksize - 1);
+	partial_end = byte_end & (sb->s_blocksize - 1);
+
 	start = lstart >> sb->s_blocksize_bits;
 	end = byte_end >> sb->s_blocksize_bits;
 
 	/* Handle partial zero within the single block */
-	if (start == end) {
+	if (start == end &&
+	    (partial_start || (partial_end != sb->s_blocksize - 1))) {
 		err = ext4_block_zero_page_range(handle, mapping,
 						 lstart, length);
 		return err;
 	}
 	/* Handle partial zero out on the start of the range */
-	if (partial) {
+	if (partial_start) {
 		err = ext4_block_zero_page_range(handle, mapping,
 						 lstart, sb->s_blocksize);
 		if (err)
 			return err;
 	}
 	/* Handle partial zero out on the end of the range */
-	partial = byte_end & (sb->s_blocksize - 1);
-	if (partial != sb->s_blocksize - 1)
+	if (partial_end != sb->s_blocksize - 1)
 		err = ext4_block_zero_page_range(handle, mapping,
-						 byte_end - partial,
-						 partial + 1);
+						 byte_end - partial_end,
+						 partial_end + 1);
 	return err;
 }