From 8d6fac0087e538173f34ca7431ed9b58581acf28 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 2 Mar 2018 22:56:53 +0100 Subject: btrfs: add support for 4-copy replication (raid1c4) Add new block group profile to store 4 copies in a simliar way that current RAID1 does. The profile attributes and constraints are defined in the raid table and used by the same code that already handles the 2- and 3-copy RAID1. The minimum number of devices is 4, the maximum number of devices/chunks that can be lost/damaged is 3. There is no comparable traditional RAID level, the profile is added for future needs to accompany triple-parity and beyond. Signed-off-by: David Sterba --- fs/btrfs/super.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/btrfs/super.c') diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index a5aff138e2e0..a98c3c71fc54 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1937,6 +1937,8 @@ static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info, num_stripes = 2; else if (type & BTRFS_BLOCK_GROUP_RAID1C3) num_stripes = 3; + else if (type & BTRFS_BLOCK_GROUP_RAID1C4) + num_stripes = 4; else if (type & BTRFS_BLOCK_GROUP_RAID10) num_stripes = 4; -- cgit v1.2.3-70-g09d2