From 230b55fa8d64007339319539f8f8e68114d08529 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.com>
Date: Tue, 17 Oct 2017 14:24:09 +1100
Subject: [PATCH] md: forbid a RAID5 from having both a bitmap and a journal.
Git-commit: 230b55fa8d64007339319539f8f8e68114d08529
Patch-mainline: v4.15-rc1
References: bsc#1093023

Having both a bitmap and a journal is pointless.
Attempting to do so can corrupt the bitmap if the journal
replay happens before the bitmap is initialized.
Rather than try to avoid this corruption, simply
refuse to allow arrays with both a bitmap and a journal.
So: - if raid5_run sees both are present, fail.
 - if adding a bitmap finds a journal is present, fail
 - if adding a journal finds a bitmap is present, fail.

Cc: stable@vger.kernel.org (4.10+)
Signed-off-by: NeilBrown <neilb@suse.com>
Tested-by: Joshua Kinard <kumba@gentoo.org>
Acked-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/md-bitmap.c | 6 ++++++
 drivers/md/md.c        | 2 +-
 drivers/md/raid5.c     | 7 +++++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index b843b53b0f65..d1b3b60669ea 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -1816,6 +1816,12 @@ struct bitmap *bitmap_create(struct mddev *mddev, int slot)
 
 	BUG_ON(file && mddev->bitmap_info.offset);
 
+	if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
+		pr_notice("md/raid:%s: array with journal cannot have bitmap\n",
+			  mdname(mddev));
+		return ERR_PTR(-EBUSY);
+	}
+
 	bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
 	if (!bitmap)
 		return ERR_PTR(-ENOMEM);
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 97afb28c6f51..6f25e3f1a1cf 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6362,7 +6362,7 @@ static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
 					break;
 				}
 			}
-			if (has_journal) {
+			if (has_journal || mddev->bitmap) {
 				export_rdev(rdev);
 				return -EBUSY;
 			}
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index a21dbd22a2fb..a8732955f130 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -7159,6 +7159,13 @@ static int raid5_run(struct mddev *mddev)
 			min_offset_diff = diff;
 	}
 
+	if ((test_bit(MD_HAS_JOURNAL, &mddev->flags) || journal_dev) &&
+	    (mddev->bitmap_info.offset || mddev->bitmap_info.file)) {
+		pr_notice("md/raid:%s: array cannot have both journal and bitmap\n",
+			  mdname(mddev));
+		return -EINVAL;
+	}
+
 	if (mddev->reshape_position != MaxSector) {
 		/* Check that we can continue the reshape.
 		 * Difficulties arise if the stripe we would write to
-- 
2.16.3