Add another btrfs fix
diff --git a/queue-3.16/btrfs-ensure-that-a-dup-or-raid1-block-group-has-exactly-two-stripes.patch b/queue-3.16/btrfs-ensure-that-a-dup-or-raid1-block-group-has-exactly-two-stripes.patch
new file mode 100644
index 0000000..fc97193
--- /dev/null
+++ b/queue-3.16/btrfs-ensure-that-a-dup-or-raid1-block-group-has-exactly-two-stripes.patch
@@ -0,0 +1,50 @@
+From: Johannes Thumshirn <jthumshirn@suse.de>
+Date: Mon, 18 Feb 2019 11:28:37 +0100
+Subject: btrfs: ensure that a DUP or RAID1 block group has exactly two stripes
+
+commit 349ae63f40638a28c6fce52e8447c2d14b84cc0c upstream.
+
+We recently had a customer issue with a corrupted filesystem. When
+trying to mount this image btrfs panicked with a division by zero in
+calc_stripe_length().
+
+The corrupt chunk had a 'num_stripes' value of 1. calc_stripe_length()
+takes this value and divides it by the number of copies the RAID profile
+is expected to have to calculate the amount of data stripes. As a DUP
+profile is expected to have 2 copies this division resulted in 1/2 = 0.
+Later then the 'data_stripes' variable is used as a divisor in the
+stripe length calculation which results in a division by 0 and thus a
+kernel panic.
+
+When encountering a filesystem with a DUP block group and a
+'num_stripes' value unequal to 2, refuse mounting as the image is
+corrupted and will lead to unexpected behaviour.
+
+Code inspection showed a RAID1 block group has the same issues.
+
+Fixes: e06cd3dd7cea ("Btrfs: add validadtion checks for chunk loading")
+Reviewed-by: Qu Wenruo <wqu@suse.com>
+Reviewed-by: Nikolay Borisov <nborisov@suse.com>
+Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
+Reviewed-by: David Sterba <dsterba@suse.com>
+Signed-off-by: David Sterba <dsterba@suse.com>
+Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
+---
+ fs/btrfs/volumes.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/fs/btrfs/volumes.c
++++ b/fs/btrfs/volumes.c
+@@ -5884,10 +5884,10 @@ static int btrfs_check_chunk_valid(struc
+ }
+
+ if ((type & BTRFS_BLOCK_GROUP_RAID10 && sub_stripes != 2) ||
+- (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes < 1) ||
++ (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes != 2) ||
+ (type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) ||
+ (type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) ||
+- (type & BTRFS_BLOCK_GROUP_DUP && num_stripes > 2) ||
++ (type & BTRFS_BLOCK_GROUP_DUP && num_stripes != 2) ||
+ ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 &&
+ num_stripes != 1)) {
+ btrfs_err(root->fs_info,
diff --git a/queue-3.16/series b/queue-3.16/series
index 4cbd9ac..04a6049 100644
--- a/queue-3.16/series
+++ b/queue-3.16/series
@@ -48,6 +48,7 @@
btrfs-verify-that-every-chunk-has-corresponding-block-group-at-mount.patch
btrfs-tree-checker-check-level-for-leaves-and-nodes.patch
btrfs-tree-checker-fix-misleading-group-system-information.patch
+btrfs-ensure-that-a-dup-or-raid1-block-group-has-exactly-two-stripes.patch
dm-do-not-override-error-code-returned-from-dm_get_device.patch
dm-flakey-return-einval-on-interval-bounds-error-in-flakey_ctr.patch
dm-flakey-fix-reads-to-be-issued-if-drop_writes-configured.patch
