[7/8] btrfs-progs: balance: enhance the limit fiter with range

Commit Message

David Sterba Oct. 16, 2015, 4:18 p.m. UTC

We can do more with the balance filer. Enhance it so we can specify also
the minimum number of block groups to process. The 'limit' filter now
accepts a range (a..b, can be partial) and needs kernel support.

The 'limit=value' filter is equivalent to 'limit=..value' but works on
older kernels as well.

The min/max values are 32bit, unlike the single-value limit which is
64bit.

Signed-off-by: David Sterba <[e-mail]>
---
 cmds-balance.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

Patch

diff --git a/cmds-balance.c b/cmds-balance.c
index 148039bdc503..05d48651b0b7 100644
--- a/cmds-balance.c
+++ b/cmds-balance.c
@@ -304,11 +304,19 @@  static int parse_filters(char *filters, struct btrfs_balance_args *args)
 				return 1;
 			}
 			if (parse_u64(value, &args->limit)) {
-				fprintf(stderr, "Invalid limit argument: %s\n",
-				       value);
-				return 1;
+				if (parse_range_u32(value, &args->limit_min,
+							&args->limit_max)) {
+					fprintf(stderr,
+						"Invalid limit argument: %s\n",
+					       value);
+					return 1;
+				}
+				args->flags &= ~BTRFS_BALANCE_ARGS_LIMIT;
+				args->flags |= BTRFS_BALANCE_ARGS_LIMITS;
+			} else {
+				args->flags &= ~BTRFS_BALANCE_ARGS_LIMITS;
+				args->flags |= BTRFS_BALANCE_ARGS_LIMIT;
 			}
-			args->flags |= BTRFS_BALANCE_ARGS_LIMIT;
 		} else {
 			fprintf(stderr, "Unrecognized balance option '%s'\n",
 				this_char);