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author | David Sterba <dsterba@suse.com> | 2018-03-02 22:56:53 +0100 |
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committer | David Sterba <dsterba@suse.com> | 2019-11-18 17:51:49 +0100 |
commit | 8d6fac0087e538173f34ca7431ed9b58581acf28 (patch) | |
tree | 83a1c2bc2bf18cb604ce09124c1933e06d845c4d /fs/btrfs/ctree.h | |
parent | 47e6f7423b9196ad6832d26cae52b7015f81ee7f (diff) | |
download | lwn-8d6fac0087e538173f34ca7431ed9b58581acf28.tar.gz lwn-8d6fac0087e538173f34ca7431ed9b58581acf28.zip |
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 <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/ctree.h')
-rw-r--r-- | fs/btrfs/ctree.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index aa1b437fb951..923a8804ae94 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 RAID1C3 with 3 copies. + * Current value is derived from RAID1C4 with 4 copies. */ -#define BTRFS_MAX_MIRRORS (3 + 1) +#define BTRFS_MAX_MIRRORS (4 + 1) #define BTRFS_MAX_LEVEL 8 |