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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.

David Sterba committed 8 years ago

Commit 8d6fac01 parent 47e6f746 files · +24 −3Browse files

Showing the changes to include/uapi/linux (2 of 6 files). Show all

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2 files
  1. include/uapi/linux/btrfs.h +1 −0
  2. include/uapi/linux/btrfs_tree.h +5 −1
include/uapi/linux/btrfs.h+1−0
@@ -833,6 +833,7 @@ enum btrfs_err_code { · 832 unmodified lines
833 BTRFS_ERROR_DEV_ONLY_WRITABLE,833 BTRFS_ERROR_DEV_ONLY_WRITABLE,
834 BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS,834 BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS,
835 BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET,835 BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET,
836 BTRFS_ERROR_DEV_RAID1C4_MIN_NOT_MET,
836};837};
837 838
838#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \839#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
include/uapi/linux/btrfs_tree.h+5−1
@@ -842,6 +842,7 @@ struct btrfs_dev_replace_item { · 841 unmodified lines
842#define BTRFS_BLOCK_GROUP_RAID5 (1ULL << 7)842#define BTRFS_BLOCK_GROUP_RAID5 (1ULL << 7)
843#define BTRFS_BLOCK_GROUP_RAID6 (1ULL << 8)843#define BTRFS_BLOCK_GROUP_RAID6 (1ULL << 8)
844#define BTRFS_BLOCK_GROUP_RAID1C3 (1ULL << 9)844#define BTRFS_BLOCK_GROUP_RAID1C3 (1ULL << 9)
845#define BTRFS_BLOCK_GROUP_RAID1C4 (1ULL << 10)
845#define BTRFS_BLOCK_GROUP_RESERVED (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \846#define BTRFS_BLOCK_GROUP_RESERVED (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \
846 BTRFS_SPACE_INFO_GLOBAL_RSV)847 BTRFS_SPACE_INFO_GLOBAL_RSV)
847 848
@@ -854,6 +855,7 @@ enum btrfs_raid_types { · 6 unmodified lines
854 BTRFS_RAID_RAID5,855 BTRFS_RAID_RAID5,
855 BTRFS_RAID_RAID6,856 BTRFS_RAID_RAID6,
856 BTRFS_RAID_RAID1C3,857 BTRFS_RAID_RAID1C3,
858 BTRFS_RAID_RAID1C4,
857 BTRFS_NR_RAID_TYPES859 BTRFS_NR_RAID_TYPES
858};860};
859 861
@@ -864,6 +866,7 @@ enum btrfs_raid_types { · 4 unmodified lines
864#define BTRFS_BLOCK_GROUP_PROFILE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \866#define BTRFS_BLOCK_GROUP_PROFILE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \
865 BTRFS_BLOCK_GROUP_RAID1 | \867 BTRFS_BLOCK_GROUP_RAID1 | \
866 BTRFS_BLOCK_GROUP_RAID1C3 | \868 BTRFS_BLOCK_GROUP_RAID1C3 | \
869 BTRFS_BLOCK_GROUP_RAID1C4 | \
867 BTRFS_BLOCK_GROUP_RAID5 | \870 BTRFS_BLOCK_GROUP_RAID5 | \
868 BTRFS_BLOCK_GROUP_RAID6 | \871 BTRFS_BLOCK_GROUP_RAID6 | \
869 BTRFS_BLOCK_GROUP_DUP | \872 BTRFS_BLOCK_GROUP_DUP | \
@@ -872,7 +875,8 @@ enum btrfs_raid_types { · 2 unmodified lines
872 BTRFS_BLOCK_GROUP_RAID6)875 BTRFS_BLOCK_GROUP_RAID6)
873 876
874#define BTRFS_BLOCK_GROUP_RAID1_MASK (BTRFS_BLOCK_GROUP_RAID1 | \877#define BTRFS_BLOCK_GROUP_RAID1_MASK (BTRFS_BLOCK_GROUP_RAID1 | \
875 BTRFS_BLOCK_GROUP_RAID1C3)878 BTRFS_BLOCK_GROUP_RAID1C3 | \
879 BTRFS_BLOCK_GROUP_RAID1C4)
876 880
877/*881/*
878 * We need a bit for restriper to be able to tell when chunks of type882 * We need a bit for restriper to be able to tell when chunks of type