Re: [PATCH 05/20] btrfs: factor out set_parameters()

[Naohiro Aota <naohiro.aota@wdc.com>]

On Thu, Feb 06, 2020 at 11:40:37AM -0500, Josef Bacik wrote:
>On 2/6/20 5:41 AM, Naohiro Aota wrote:
>>Factor out set_parameters() from __btrfs_alloc_chunk(). This function
>>initialises parameters of "struct alloc_chunk_ctl" for allocation.
>>set_parameters() handles a common part of the initialisation to load the
>>RAID parameters from btrfs_raid_array. set_parameters_regular() decides
>>some parameters for its allocation.
>>
>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>>---
>>  fs/btrfs/volumes.c | 96 ++++++++++++++++++++++++++++------------------
>>  1 file changed, 59 insertions(+), 37 deletions(-)
>>
>>diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>>index cfde302bf297..a5d6f0b5ca70 100644
>>--- a/fs/btrfs/volumes.c
>>+++ b/fs/btrfs/volumes.c
>>@@ -4841,6 +4841,60 @@ struct alloc_chunk_ctl {
>>  	int ndevs;
>>  };
>>+static void set_parameters_regular(struct btrfs_fs_devices *fs_devices,
>>+				   struct alloc_chunk_ctl *ctl)
>
>init_alloc_chunk_ctl_policy_regular()
>
>>+{
>>+	u64 type = ctl->type;
>>+
>>+	if (type & BTRFS_BLOCK_GROUP_DATA) {
>>+		ctl->max_stripe_size = SZ_1G;
>>+		ctl->max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE;
>>+	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
>>+		/* for larger filesystems, use larger metadata chunks */
>>+		if (fs_devices->total_rw_bytes > 50ULL * SZ_1G)
>>+			ctl->max_stripe_size = SZ_1G;
>>+		else
>>+			ctl->max_stripe_size = SZ_256M;
>>+		ctl->max_chunk_size = ctl->max_stripe_size;
>>+	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
>>+		ctl->max_stripe_size = SZ_32M;
>>+		ctl->max_chunk_size = 2 * ctl->max_stripe_size;
>>+		ctl->devs_max = min_t(int, ctl->devs_max,
>>+				      BTRFS_MAX_DEVS_SYS_CHUNK);
>>+	} else {
>>+		BUG();
>>+	}
>>+
>>+	/* We don't want a chunk larger than 10% of writable space */
>>+	ctl->max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
>>+				  ctl->max_chunk_size);
>>+}
>>+
>>+static void set_parameters(struct btrfs_fs_devices *fs_devices,
>>+			   struct alloc_chunk_ctl *ctl)
>
>init_alloc_chunk_ctl().  These function names need to be more descriptive.  Thanks,

I see. I renamed these two.

Thanks,