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| author | David Sterba <dsterba@suse.com> | 2019-05-31 17:22:59 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2019-07-02 12:30:49 +0200 |
| commit | 71a9c4885e1dec0f8ec5e4b05ecd6fddd27fc6c1 (patch) | |
| tree | d185932e15d315e5cab53943a442c7e0b98d7c5f /fs/btrfs/ctree.h | |
| parent | a07e8a468e6a2f626b61078a4d1e63c181f099eb (diff) | |
btrfs: document BTRFS_MAX_MIRRORS
The real meaning of that constant is not clear from the context due to
the target device inclusion.
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/ctree.h')
| -rw-r--r-- | fs/btrfs/ctree.h | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index fb7435533478..31198499f175 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -46,7 +46,16 @@ struct btrfs_ref; #define BTRFS_MAGIC 0x4D5F53665248425FULL /* ascii _BHRfS_M, no null */ -#define BTRFS_MAX_MIRRORS 3 +/* + * Maximum number of mirrors that can be available for all profiles counting + * the target device of dev-replace as one. During an active device replace + * procedure, the target device of the copy operation is a mirror for the + * 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. + */ +#define BTRFS_MAX_MIRRORS (2 + 1) #define BTRFS_MAX_LEVEL 8 |