diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 0eab0d3..412a288 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -3487,6 +3487,7 @@
 {
 	int i, numpages = 0, ret = 0;
 	unsigned int csize = OCFS2_SB(inode->i_sb)->s_clustersize;
+	unsigned int ext_flags;
 	struct super_block *sb = inode->i_sb;
 	struct address_space *mapping = inode->i_mapping;
 	unsigned long index;
@@ -3499,7 +3500,7 @@
 		goto out;
 
 	ret = ocfs2_extent_map_get_blocks(inode, isize >> sb->s_blocksize_bits,
-					  phys, NULL);
+					  phys, NULL, &ext_flags);
 	if (ret) {
 		mlog_errno(ret);
 		goto out;
@@ -3509,6 +3510,11 @@
 	if (*phys == 0)
 		goto out;
 
+	/* Tail is marked as unwritten, we can count on write to zero
+	 * in that case. */
+	if (ext_flags & OCFS2_EXT_UNWRITTEN)
+		goto out;
+
 	next_cluster_bytes = ocfs2_align_bytes_to_clusters(inode->i_sb, isize);
 	index = isize >> PAGE_CACHE_SHIFT;
 	do {
@@ -3579,9 +3585,6 @@
 		goto out;
 	}
 
-	/*
-	 * Truncate on an i_size boundary - nothing more to do.
-	 */
 	if (numpages == 0)
 		goto out;
 
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 014f4f5..eb67c90 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -137,6 +137,7 @@
 			   struct buffer_head *bh_result, int create)
 {
 	int err = 0;
+	unsigned int ext_flags;
 	u64 p_blkno, past_eof;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 
@@ -153,7 +154,8 @@
 		goto bail;
 	}
 
-	err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, NULL);
+	err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, NULL,
+					  &ext_flags);
 	if (err) {
 		mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
 		     "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
@@ -171,7 +173,8 @@
 			"ino %lu, iblock %llu\n", inode->i_ino,
 			(unsigned long long)iblock);
 
-	if (p_blkno)
+	/* Treat the unwritten extent as a hole for zeroing purposes. */
+	if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
 		map_bh(bh_result, inode->i_sb, p_blkno);
 
 	if (!ocfs2_sparse_alloc(osb)) {
@@ -396,7 +399,7 @@
 		down_read(&OCFS2_I(inode)->ip_alloc_sem);
 	}
 
-	err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL);
+	err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL, NULL);
 
 	if (!INODE_JOURNAL(inode)) {
 		up_read(&OCFS2_I(inode)->ip_alloc_sem);
@@ -438,6 +441,7 @@
 	int ret;
 	u64 p_blkno, inode_blocks;
 	int contig_blocks;
+	unsigned int ext_flags;
 	unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
 	unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
 
@@ -458,7 +462,7 @@
 	/* This figures out the size of the next contiguous block, and
 	 * our logical offset */
 	ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
-					  &contig_blocks);
+					  &contig_blocks, &ext_flags);
 	if (ret) {
 		mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
 		     (unsigned long long)iblock);
@@ -478,8 +482,10 @@
 	/*
 	 * get_more_blocks() expects us to describe a hole by clearing
 	 * the mapped bit on bh_result().
+	 *
+	 * Consider an unwritten extent as a hole.
 	 */
-	if (p_blkno)
+	if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
 		map_bh(bh_result, inode->i_sb, p_blkno);
 	else {
 		/*
@@ -1111,7 +1117,8 @@
 		}
 	}
 
-	ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL);
+	ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
+					  NULL);
 	if (ret < 0) {
 
 		/*
@@ -1215,7 +1222,7 @@
 	 */
 	down_write(&OCFS2_I(inode)->ip_alloc_sem);
 
-	ret = ocfs2_get_clusters(inode, wc.w_cpos, &phys, NULL);
+	ret = ocfs2_get_clusters(inode, wc.w_cpos, &phys, NULL, NULL);
 	if (ret) {
 		mlog_errno(ret);
 		goto out_meta;
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index c914906..8d22e1e 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -379,7 +379,7 @@
 
 	status = ocfs2_extent_map_get_blocks(dir, (dir->i_blocks >>
 						   (sb->s_blocksize_bits - 9)),
-					     &p_blkno, NULL);
+					     &p_blkno, NULL, NULL);
 	if (status < 0) {
 		mlog_errno(status);
 		goto bail;
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index ea0ce41..eef6c18 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -70,9 +70,11 @@
 }
 
 int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
-		       u32 *p_cluster, u32 *num_clusters)
+		       u32 *p_cluster, u32 *num_clusters,
+		       unsigned int *extent_flags)
 {
 	int ret, i;
+	unsigned int flags = 0;
 	struct buffer_head *di_bh = NULL;
 	struct buffer_head *eb_bh = NULL;
 	struct ocfs2_dinode *di;
@@ -142,8 +144,13 @@
 
 		if (num_clusters)
 			*num_clusters = ocfs2_rec_clusters(el, rec) - coff;
+
+		flags = rec->e_flags;
 	}
 
+	if (extent_flags)
+		*extent_flags = flags;
+
 out:
 	brelse(di_bh);
 	brelse(eb_bh);
@@ -155,7 +162,7 @@
  * all while the map is in the process of being updated.
  */
 int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
-				int *ret_count)
+				int *ret_count, unsigned int *extent_flags)
 {
 	int ret;
 	int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
@@ -164,7 +171,8 @@
 
 	cpos = ocfs2_blocks_to_clusters(inode->i_sb, v_blkno);
 
-	ret = ocfs2_get_clusters(inode, cpos, &p_cluster, &num_clusters);
+	ret = ocfs2_get_clusters(inode, cpos, &p_cluster, &num_clusters,
+				 extent_flags);
 	if (ret) {
 		mlog_errno(ret);
 		goto out;
diff --git a/fs/ocfs2/extent_map.h b/fs/ocfs2/extent_map.h
index 625d0ee..0031c59 100644
--- a/fs/ocfs2/extent_map.h
+++ b/fs/ocfs2/extent_map.h
@@ -26,8 +26,8 @@
 #define _EXTENT_MAP_H
 
 int ocfs2_get_clusters(struct inode *inode, u32 v_cluster, u32 *p_cluster,
-		       u32 *num_clusters);
+		       u32 *num_clusters, unsigned int *extent_flags);
 int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
-				int *ret_count);
+				int *ret_count, unsigned int *extent_flags);
 
 #endif  /* _EXTENT_MAP_H */
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 3617601..f516619 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1127,6 +1127,7 @@
 				       size_t count)
 {
 	int ret = 0;
+	unsigned int extent_flags;
 	u32 cpos, clusters, extent_len, phys_cpos;
 	struct super_block *sb = inode->i_sb;
 
@@ -1134,13 +1135,14 @@
 	clusters = ocfs2_clusters_for_bytes(sb, pos + count) - cpos;
 
 	while (clusters) {
-		ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &extent_len);
+		ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &extent_len,
+					 &extent_flags);
 		if (ret < 0) {
 			mlog_errno(ret);
 			goto out;
 		}
 
-		if (phys_cpos == 0) {
+		if (phys_cpos == 0 || (extent_flags & OCFS2_EXT_UNWRITTEN)) {
 			ret = 1;
 			break;
 		}
diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 78c99b5..310049b 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -1105,7 +1105,8 @@
 		return NULL;
 	}
 
-	tmperr = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL);
+	tmperr = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
+					     NULL);
 	if (tmperr < 0) {
 		mlog_errno(tmperr);
 		goto fail;
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index 2e2e04f..db77e09 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -670,7 +670,7 @@
 	       (inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9))) {
 
 		status = ocfs2_extent_map_get_blocks(inode, v_blkno,
-						     &p_blkno, &p_blocks);
+						     &p_blkno, &p_blocks, NULL);
 		if (status < 0) {
 			mlog_errno(status);
 			goto bail;
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index 5755e07..395859e 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -1511,7 +1511,8 @@
 		goto bail;
 	}
 
-	status = ocfs2_extent_map_get_blocks(inode, 0, &p_blkno, &p_blocks);
+	status = ocfs2_extent_map_get_blocks(inode, 0, &p_blkno, &p_blocks,
+					     NULL);
 	if (status < 0) {
 		mlog_errno(status);
 		goto bail;
diff --git a/fs/ocfs2/slot_map.c b/fs/ocfs2/slot_map.c
index f4416e7..d921a28 100644
--- a/fs/ocfs2/slot_map.c
+++ b/fs/ocfs2/slot_map.c
@@ -197,7 +197,7 @@
 		goto bail;
 	}
 
-	status = ocfs2_extent_map_get_blocks(inode, 0ULL, &blkno, NULL);
+	status = ocfs2_extent_map_get_blocks(inode, 0ULL, &blkno, NULL, NULL);
 	if (status < 0) {
 		mlog_errno(status);
 		goto bail;