[PATCH 2/2 V2] xfs_repair: continue after xfs_bunmapi deadlock avoidance

[Eric Sandeen <sandeen@sandeen.net>]

xfs_bunmapi can legitimately return before all work is done, to
avoid deadlocks across AGs.

Sadly nobody told xfs_repair, so it fires an assert if this happens:

 phase6.c:1410: longform_dir2_rebuild: Assertion `done' failed. 

Fix this by calling back in until all work is done, as we do
in the kernel.

Fixes: 5a8bcc ("xfs: fix multi-AG deadlock in xfs_bunmapi")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1641116
Reported-by: Tomasz Torcz <tomek@pipebreaker.pl>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

V2: libxfs-ify the code, remove now-pointless assert, thanks Darrick!


diff --git a/repair/phase6.c b/repair/phase6.c
index e017326..bdbbbaa 100644
--- a/repair/phase6.c
+++ b/repair/phase6.c
@@ -1317,7 +1317,7 @@ longform_dir2_rebuild(
 	xfs_fileoff_t		lastblock;
 	xfs_inode_t		pip;
 	dir_hash_ent_t		*p;
-	int			done;
+	int			done = 0;
 
 	/*
 	 * trash directory completely and rebuild from scratch using the
@@ -1352,14 +1352,25 @@ longform_dir2_rebuild(
 			error);
 
 	/* free all data, leaf, node and freespace blocks */
-	error = -libxfs_bunmapi(tp, ip, 0, lastblock, XFS_BMAPI_METADATA, 0,
-				&done);
-	if (error) {
-		do_warn(_("xfs_bunmapi failed -- error - %d\n"), error);
-		goto out_bmap_cancel;
-	}
-
-	ASSERT(done);
+	while (!done) {
+	       error = -libxfs_bunmapi(tp, ip, 0, lastblock, XFS_BMAPI_METADATA,
+			               0, &done);
+	       if (error) {
+		       do_warn(_("xfs_bunmapi failed -- error - %d\n"), error);
+		       goto out_bmap_cancel;
+	       }
+	       error = -libxfs_defer_finish(&tp);
+	       if (error) {
+		       do_warn(("defer_finish failed -- error - %d\n"), error);
+		       goto out_bmap_cancel;
+	       }
+	       /*
+		* Close out trans and start the next one in the chain.
+		*/
+	       error = -libxfs_trans_roll_inode(&tp, ip);
+	       if (error)
+			goto out_bmap_cancel;
+        }
 
 	error = -libxfs_dir_init(tp, ip, &pip);
 	if (error) {