From: NeilBrown <neilb@suse.com>
Date: Tue, 17 Oct 2017 03:24:09 +0000 (+1100)
Subject: md: forbid a RAID5 from having both a bitmap and a journal.
X-Git-Tag: v4.14.4~8
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a67936842ba66eb229e6322856fefd2310e0b3fb;p=platform%2Fkernel%2Flinux-rpi.git

md: forbid a RAID5 from having both a bitmap and a journal.

commit 230b55fa8d64007339319539f8f8e68114d08529 upstream.

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.

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index cae57b5..f425905 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/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 e019cf8..98ea863 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 928e24a..7aed69a 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -7156,6 +7156,13 @@ 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