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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Qu Wenruo <wqu@suse.com>,
        David Sterba <dsterba@suse.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 10/42] btrfs: fix minimum number of chunk errors for DUP
Date:   Mon,  5 Aug 2019 15:02:36 +0200
Message-Id: <20190805124926.055875161@linuxfoundation.org>
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[ Upstream commit 0ee5f8ae082e1f675a2fb6db601c31ac9958a134 ]

The list of profiles in btrfs_chunk_max_errors lists DUP as a profile
DUP able to tolerate 1 device missing. Though this profile is special
with 2 copies, it still needs the device, unlike the others.

Looking at the history of changes, thre's no clear reason why DUP is
there, functions were refactored and blocks of code merged to one
helper.

d20983b40e828 Btrfs: fix writing data into the seed filesystem
  - factor code to a helper

de11cc12df173 Btrfs: don't pre-allocate btrfs bio
  - unrelated change, DUP still in the list with max errors 1

a236aed14ccb0 Btrfs: Deal with failed writes in mirrored configurations
  - introduced the max errors, leaves DUP and RAID1 in the same group

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/volumes.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 94b61afe996c8..70aa22a8a9cce 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5072,8 +5072,7 @@ static inline int btrfs_chunk_max_errors(struct map_lookup *map)
 
 	if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
 			 BTRFS_BLOCK_GROUP_RAID10 |
-			 BTRFS_BLOCK_GROUP_RAID5 |
-			 BTRFS_BLOCK_GROUP_DUP)) {
+			 BTRFS_BLOCK_GROUP_RAID5)) {
 		max_errors = 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
 		max_errors = 2;
-- 
2.20.1