From 47e6f7423b9196ad6832d26cae52b7015f81ee7f Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 2 Mar 2018 22:56:53 +0100 Subject: btrfs: add support for 3-copy replication (raid1c3) Add new block group profile to store 3 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-copy RAID1. The minimum number of devices is 3, the maximum number of devices/chunks that can be lost/damaged is 2. Like RAID6 but with 33% space utilization. Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 4 ++-- fs/btrfs/super.c | 2 ++ fs/btrfs/volumes.c | 19 +++++++++++++++++-- fs/btrfs/volumes.h | 2 ++ include/uapi/linux/btrfs.h | 3 ++- include/uapi/linux/btrfs_tree.h | 6 +++++- 6 files changed, 30 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 1c8f01eaf27c..aa1b437fb951 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -57,9 +57,9 @@ struct btrfs_ref; * filesystem data as well that can be used to read data in order to repair * read errors on other disks. * - * Current value is derived from RAID1 with 2 copies. + * Current value is derived from RAID1C3 with 3 copies. */ -#define BTRFS_MAX_MIRRORS (2 + 1) +#define BTRFS_MAX_MIRRORS (3 + 1) #define BTRFS_MAX_LEVEL 8 diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 3f49407cc2aa..a5aff138e2e0 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1935,6 +1935,8 @@ static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info, num_stripes = nr_devices; else if (type & BTRFS_BLOCK_GROUP_RAID1) num_stripes = 2; + else if (type & BTRFS_BLOCK_GROUP_RAID1C3) + num_stripes = 3; else if (type & BTRFS_BLOCK_GROUP_RAID10) num_stripes = 4; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index e6c458d99722..d17835fbd52f 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -58,6 +58,18 @@ const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = { .bg_flag = BTRFS_BLOCK_GROUP_RAID1, .mindev_error = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET, }, + [BTRFS_RAID_RAID1C3] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 0, + .devs_min = 3, + .tolerated_failures = 2, + .devs_increment = 3, + .ncopies = 3, + .raid_name = "raid1c3", + .bg_flag = BTRFS_BLOCK_GROUP_RAID1C3, + .mindev_error = BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET, + }, [BTRFS_RAID_DUP] = { .sub_stripes = 1, .dev_stripes = 2, @@ -4839,8 +4851,11 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, sort(devices_info, ndevs, sizeof(struct btrfs_device_info), btrfs_cmp_device_info, NULL); - /* round down to number of usable stripes */ - ndevs = round_down(ndevs, devs_increment); + /* + * Round down to number of usable stripes, devs_increment can be any + * number so we can't use round_down() + */ + ndevs -= ndevs % devs_increment; if (ndevs < devs_min) { ret = -ENOSPC; diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index ac4ba8c57283..a4e26b84e1b9 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -545,6 +545,8 @@ static inline enum btrfs_raid_types btrfs_bg_flags_to_raid_index(u64 flags) return BTRFS_RAID_RAID10; else if (flags & BTRFS_BLOCK_GROUP_RAID1) return BTRFS_RAID_RAID1; + else if (flags & BTRFS_BLOCK_GROUP_RAID1C3) + return BTRFS_RAID_RAID1C3; else if (flags & BTRFS_BLOCK_GROUP_DUP) return BTRFS_RAID_DUP; else if (flags & BTRFS_BLOCK_GROUP_RAID0) diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index 3ee0678c0a83..ba22f91a3f5b 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -831,7 +831,8 @@ enum btrfs_err_code { BTRFS_ERROR_DEV_TGT_REPLACE, BTRFS_ERROR_DEV_MISSING_NOT_FOUND, BTRFS_ERROR_DEV_ONLY_WRITABLE, - BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS + BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS, + BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET, }; #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \ diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h index 5160be1d7332..52b2964b0311 100644 --- a/include/uapi/linux/btrfs_tree.h +++ b/include/uapi/linux/btrfs_tree.h @@ -841,6 +841,7 @@ struct btrfs_dev_replace_item { #define BTRFS_BLOCK_GROUP_RAID10 (1ULL << 6) #define BTRFS_BLOCK_GROUP_RAID5 (1ULL << 7) #define BTRFS_BLOCK_GROUP_RAID6 (1ULL << 8) +#define BTRFS_BLOCK_GROUP_RAID1C3 (1ULL << 9) #define BTRFS_BLOCK_GROUP_RESERVED (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \ BTRFS_SPACE_INFO_GLOBAL_RSV) @@ -852,6 +853,7 @@ enum btrfs_raid_types { BTRFS_RAID_SINGLE, BTRFS_RAID_RAID5, BTRFS_RAID_RAID6, + BTRFS_RAID_RAID1C3, BTRFS_NR_RAID_TYPES }; @@ -861,6 +863,7 @@ enum btrfs_raid_types { #define BTRFS_BLOCK_GROUP_PROFILE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \ BTRFS_BLOCK_GROUP_RAID1 | \ + BTRFS_BLOCK_GROUP_RAID1C3 | \ BTRFS_BLOCK_GROUP_RAID5 | \ BTRFS_BLOCK_GROUP_RAID6 | \ BTRFS_BLOCK_GROUP_DUP | \ @@ -868,7 +871,8 @@ enum btrfs_raid_types { #define BTRFS_BLOCK_GROUP_RAID56_MASK (BTRFS_BLOCK_GROUP_RAID5 | \ BTRFS_BLOCK_GROUP_RAID6) -#define BTRFS_BLOCK_GROUP_RAID1_MASK (BTRFS_BLOCK_GROUP_RAID1) +#define BTRFS_BLOCK_GROUP_RAID1_MASK (BTRFS_BLOCK_GROUP_RAID1 | \ + BTRFS_BLOCK_GROUP_RAID1C3) /* * We need a bit for restriper to be able to tell when chunks of type -- cgit v1.2.3