ocfs2: zero tail of sparse files on truncate
Since we don't zero on extend anymore, truncate needs to be fixed up to zero
the part of a file between i_size and and end of it's cluster. Otherwise a
subsequent extend could expose bad data.
This introduced a new helper, which can be used in ocfs2_write().
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 2699f7ca..82cc92d 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -495,6 +495,17 @@
return index;
}
+static inline unsigned int ocfs2_pages_per_cluster(struct super_block *sb)
+{
+ unsigned int cbits = OCFS2_SB(sb)->s_clustersize_bits;
+ unsigned int pages_per_cluster = 1;
+
+ if (PAGE_CACHE_SHIFT < cbits)
+ pages_per_cluster = 1 << (cbits - PAGE_CACHE_SHIFT);
+
+ return pages_per_cluster;
+}
+
#define ocfs2_set_bit ext2_set_bit
#define ocfs2_clear_bit ext2_clear_bit
#define ocfs2_test_bit ext2_test_bit