sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changes

1 files changed, 20 insertions, 0 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 6ad41390fa74..228659612c0d 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -430,6 +430,23 @@ static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
 	return 0;
 }
 
+/**
+ * nilfs_segctor_zeropad_segsum - zero pad the rest of the segment summary area
+ * @sci: segment constructor object
+ *
+ * nilfs_segctor_zeropad_segsum() zero-fills unallocated space at the end of
+ * the current segment summary block.
+ */
+static void nilfs_segctor_zeropad_segsum(struct nilfs_sc_info *sci)
+{
+	struct nilfs_segsum_pointer *ssp;
+
+	ssp = sci->sc_blk_cnt > 0 ? &sci->sc_binfo_ptr : &sci->sc_finfo_ptr;
+	if (ssp->offset < ssp->bh->b_size)
+		memset(ssp->bh->b_data + ssp->offset, 0,
+		       ssp->bh->b_size - ssp->offset);
+}
+
 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
 {
 	sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
@@ -438,6 +455,7 @@ static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
 				* The current segment is filled up
 				* (internal code)
 				*/
+	nilfs_segctor_zeropad_segsum(sci);
 	sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
 	return nilfs_segctor_reset_segment_buffer(sci);
 }
@@ -542,6 +560,7 @@ static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
 		goto retry;
 	}
 	if (unlikely(required)) {
+		nilfs_segctor_zeropad_segsum(sci);
 		err = nilfs_segbuf_extend_segsum(segbuf);
 		if (unlikely(err))
 			goto failed;
@@ -1533,6 +1552,7 @@ static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
 		nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
 		sci->sc_stage = prev_stage;
 	}
+	nilfs_segctor_zeropad_segsum(sci);
 	nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
 	return 0;