[PATCH] btrfs: cleanup btrfs_balance profile validity checks

Alexandru Moise
2015-08-30T18:46:09Z

Improve readability by generalizing the profile validity checks,
I had to read through those if statements half a dozen times on my
first try just to get an idea of what's happening there.

Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
---
fs/btrfs/volumes.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index fbe7c10..d23bc26 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3454,6 +3454,15 @@ static void __cancel_balance(struct btrfs_fs_info *fs_info)
atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
}

+/* Non-zero return value signifies invalidity */
+static inline int balance_relocate_invalid(struct btrfs_balance_args *bctl_arg,
+ u64 allowed)
+{
+ return ((bctl_arg->flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (!alloc_profile_is_valid(bctl_arg->target, 1) ||
+ (bctl_arg->target & ~allowed)));
+}
+
/*
* Should be called with both balance and volume mutexes held
*/
@@ -3511,27 +3520,21 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
if (num_devices > 3)
allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_RAID6);
- if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
- (!alloc_profile_is_valid(bctl->data.target, 1) ||
- (bctl->data.target & ~allowed))) {
+ if (balance_relocate_invalid(&bctl->data, allowed)) {
btrfs_err(fs_info, "unable to start balance with target "
"data profile %llu",
bctl->data.target);
ret = -EINVAL;
goto out;
}
- if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
- (!alloc_profile_is_valid(bctl->meta.target, 1) ||
- (bctl->meta.target & ~allowed))) {
+ if (balance_relocate_invalid(&bctl->meta, allowed)) {
btrfs_err(fs_info,
"unable to start balance with target metadata profile %llu",
bctl->meta.target);
ret = -EINVAL;
goto out;
}
- if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
- (!alloc_profile_is_valid(bctl->sys.target, 1) ||
- (bctl->sys.target & ~allowed))) {
+ if (balance_relocate_invalid(&bctl->sys, allowed)) {
btrfs_err(fs_info,
"unable to start balance with target system profile %llu",
bctl->sys.target);
--
2.5.0