diff --git a/e2fsprogs/e2fsck/pass4.c b/e2fsprogs/e2fsck/pass4.c
new file mode 100644
index 0000000..a9e49f1
--- /dev/null
+++ b/e2fsprogs/e2fsck/pass4.c
@@ -0,0 +1,178 @@
+/*
+ * pass4.c -- pass #4 of e2fsck: Check reference counts
+ *
+ * Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ *
+ * Pass 4 frees the following data structures:
+ * 	- A bitmap of which inodes are in bad blocks.	(inode_bb_map)
+ * 	- A bitmap of which inodes are imagic inodes.	(inode_imagic_map)
+ */
+
+#include "e2fsck.h"
+#include "problem.h"
+
+/*
+ * This routine is called when an inode is not connected to the
+ * directory tree.
+ * 
+ * This subroutine returns 1 then the caller shouldn't bother with the
+ * rest of the pass 4 tests.
+ */
+static int disconnect_inode(e2fsck_t ctx, ext2_ino_t i)
+{
+	ext2_filsys fs = ctx->fs;
+	struct ext2_inode	inode;
+	struct problem_context	pctx;
+
+	e2fsck_read_inode(ctx, i, &inode, "pass4: disconnect_inode");
+	clear_problem_context(&pctx);
+	pctx.ino = i;
+	pctx.inode = &inode;
+	
+	/*
+	 * Offer to delete any zero-length files that does not have
+	 * blocks.  If there is an EA block, it might have useful
+	 * information, so we won't prompt to delete it, but let it be
+	 * reconnected to lost+found.
+	 */
+	if (!inode.i_blocks && (LINUX_S_ISREG(inode.i_mode) ||
+				LINUX_S_ISDIR(inode.i_mode))) {
+		if (fix_problem(ctx, PR_4_ZERO_LEN_INODE, &pctx)) {
+			ext2fs_icount_store(ctx->inode_link_info, i, 0);
+			inode.i_links_count = 0;
+			inode.i_dtime = time(0);
+			e2fsck_write_inode(ctx, i, &inode,
+					   "disconnect_inode");
+			/*
+			 * Fix up the bitmaps...
+			 */
+			e2fsck_read_bitmaps(ctx);
+			ext2fs_unmark_inode_bitmap(ctx->inode_used_map, i);
+			ext2fs_unmark_inode_bitmap(ctx->inode_dir_map, i);
+			ext2fs_inode_alloc_stats2(fs, i, -1,
+						  LINUX_S_ISDIR(inode.i_mode));
+			return 0;
+		}
+	}
+	
+	/*
+	 * Prompt to reconnect.
+	 */
+	if (fix_problem(ctx, PR_4_UNATTACHED_INODE, &pctx)) {
+		if (e2fsck_reconnect_file(ctx, i))
+			ext2fs_unmark_valid(fs);
+	} else {
+		/*
+		 * If we don't attach the inode, then skip the
+		 * i_links_test since there's no point in trying to
+		 * force i_links_count to zero.
+		 */
+		ext2fs_unmark_valid(fs);
+		return 1;
+	}
+	return 0;
+}
+
+
+void e2fsck_pass4(e2fsck_t ctx)
+{
+	ext2_filsys fs = ctx->fs;
+	ext2_ino_t	i;
+	struct ext2_inode	inode;
+#ifdef RESOURCE_TRACK
+	struct resource_track	rtrack;
+#endif
+	struct problem_context	pctx;
+	__u16	link_count, link_counted;
+	char	*buf = 0;
+	int	group, maxgroup;
+	
+#ifdef RESOURCE_TRACK
+	init_resource_track(&rtrack);
+#endif
+
+#ifdef MTRACE
+	mtrace_print("Pass 4");
+#endif
+
+	clear_problem_context(&pctx);
+
+	if (!(ctx->options & E2F_OPT_PREEN))
+		fix_problem(ctx, PR_4_PASS_HEADER, &pctx);
+
+	group = 0;
+	maxgroup = fs->group_desc_count;
+	if (ctx->progress)
+		if ((ctx->progress)(ctx, 4, 0, maxgroup))
+			return;
+	
+	for (i=1; i <= fs->super->s_inodes_count; i++) {
+		if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
+			return;
+		if ((i % fs->super->s_inodes_per_group) == 0) {
+			group++;
+			if (ctx->progress)
+				if ((ctx->progress)(ctx, 4, group, maxgroup))
+					return;
+		}
+		if (i == EXT2_BAD_INO ||
+		    (i > EXT2_ROOT_INO && i < EXT2_FIRST_INODE(fs->super)))
+			continue;
+		if (!(ext2fs_test_inode_bitmap(ctx->inode_used_map, i)) ||
+		    (ctx->inode_imagic_map &&
+		     ext2fs_test_inode_bitmap(ctx->inode_imagic_map, i)) ||
+		    (ctx->inode_bb_map &&
+		     ext2fs_test_inode_bitmap(ctx->inode_bb_map, i)))
+			continue;
+		ext2fs_icount_fetch(ctx->inode_link_info, i, &link_count);
+		ext2fs_icount_fetch(ctx->inode_count, i, &link_counted);
+		if (link_counted == 0) {
+			if (!buf)
+				buf = e2fsck_allocate_memory(ctx,
+				     fs->blocksize, "bad_inode buffer");
+			if (e2fsck_process_bad_inode(ctx, 0, i, buf))
+				continue;
+			if (disconnect_inode(ctx, i))
+				continue;
+			ext2fs_icount_fetch(ctx->inode_link_info, i,
+					    &link_count);
+			ext2fs_icount_fetch(ctx->inode_count, i,
+					    &link_counted);
+		}
+		if (link_counted != link_count) {
+			e2fsck_read_inode(ctx, i, &inode, "pass4");
+			pctx.ino = i;
+			pctx.inode = &inode;
+			if (link_count != inode.i_links_count) {
+				pctx.num = link_count;
+				fix_problem(ctx,
+					    PR_4_INCONSISTENT_COUNT, &pctx);
+			}
+			pctx.num = link_counted;
+			if (fix_problem(ctx, PR_4_BAD_REF_COUNT, &pctx)) {
+				inode.i_links_count = link_counted;
+				e2fsck_write_inode(ctx, i, &inode, "pass4");
+			}
+		}
+	}
+	ext2fs_free_icount(ctx->inode_link_info); ctx->inode_link_info = 0;
+	ext2fs_free_icount(ctx->inode_count); ctx->inode_count = 0;
+	ext2fs_free_inode_bitmap(ctx->inode_bb_map);
+	ctx->inode_bb_map = 0;
+	ext2fs_free_inode_bitmap(ctx->inode_imagic_map);
+	ctx->inode_imagic_map = 0;
+	if (buf)
+		ext2fs_free_mem(&buf);
+#ifdef RESOURCE_TRACK
+	if (ctx->options & E2F_OPT_TIME2) {
+		e2fsck_clear_progbar(ctx);
+		print_resource_track(_("Pass 4"), &rtrack);
+	}
+#endif
+}
+