btrfs: extend balance filter limit to take minimum and maximum

The 'limit' filter is underdesigned, it should have been a range for
[min,max], with some relaxed semantics when one of the bounds is
missing. Besides that, using a full u64 for a single value is a waste of
bytes.

Let's fix both by extending the use of the u64 bytes for the [min,max]
range. This can be done in a backward compatible way, the range will be
interpreted only if the appropriate flag is set
(BTRFS_BALANCE_ARGS_LIMIT_RANGE).

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
David Sterba 2015-10-10 17:16:50 +02:00 committed by Chris Mason
parent 2849a85422
commit 12907fc798
4 changed files with 67 additions and 3 deletions

View file

@ -380,6 +380,7 @@ struct map_lookup {
#define BTRFS_BALANCE_ARGS_DRANGE (1ULL << 3)
#define BTRFS_BALANCE_ARGS_VRANGE (1ULL << 4)
#define BTRFS_BALANCE_ARGS_LIMIT (1ULL << 5)
#define BTRFS_BALANCE_ARGS_LIMIT_RANGE (1ULL << 6)
#define BTRFS_BALANCE_ARGS_MASK \
(BTRFS_BALANCE_ARGS_PROFILES | \