[PATCH] btrfs: cleanup btrfs_balance profile validity checks

[PATCH] btrfs: cleanup btrfs_balance profile validity checks

[Alexandru Moise]

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

Re: [PATCH] btrfs: cleanup btrfs_balance profile validity checks

[David Sterba]

On Sun, Aug 30, 2015 at 09:45:49PM +0000, Alexandru Moise wrote:
> 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,

The function name is not very descriptive, I'd pick something like
validate_convert_profile, otherwise ok.