Add a -Z option which zeroes unused blocks. It can be combined with -E,

in which case unused blocks are first zeroed and then erased.

Reviewed by:	mckusick
MFC after:	3 weeks

1 files changed, 4 insertions, 1 deletions

diff --git a/sbin/fsck_ffs/fsck.h b/sbin/fsck_ffs/fsck.h
index 7b45d48..45b242c 100644
--- a/sbin/fsck_ffs/fsck.h
+++ b/sbin/fsck_ffs/fsck.h
@@ -74,6 +74,7 @@
 #define	MINBUFS		10	/* minimum number of buffers required */
 #define	MAXBUFS		40	/* maximum space to allocate to buffers */
 #define	INOBUFSIZE	64*1024	/* size of buffer to read inodes in pass1 */
+#define	ZEROBUFSIZE	(dev_bsize * 128) /* size of zero buffer used by -Z */
 
 union dinode {
 	struct ufs1_dinode dp1;
@@ -306,7 +307,8 @@ char	yflag;			/* assume a yes response */
 int	bkgrdflag;		/* use a snapshot to run on an active system */
 int	bflag;			/* location of alternate super block */
 int	debug;			/* output debugging info */
-int	Eflag;			/* zero out empty data blocks */
+int	Eflag;			/* delete empty data blocks */
+int	Zflag;			/* zero empty data blocks */
 int	inoopt;			/* trim out unused inodes */
 char	ckclean;		/* only do work if not cleanly unmounted */
 int	cvtlevel;		/* convert to newer file system format */
@@ -402,6 +404,7 @@ int		blread(int fd, char *buf, ufs2_daddr_t blk, long size);
 void		bufinit(void);
 void		blwrite(int fd, char *buf, ufs2_daddr_t blk, ssize_t size);
 void		blerase(int fd, ufs2_daddr_t blk, long size);
+void		blzero(int fd, ufs2_daddr_t blk, long size);
 void		cacheino(union dinode *dp, ino_t inumber);
 void		catch(int);
 void		catchquit(int);