Re: [PATCH v4 0/4] btrfs: sysfs: set / query btrfs chunk size

[Josef Bacik <josef@toxicpanda.com>]

On Fri, Oct 29, 2021 at 11:39:46AM -0700, Stefan Roesch wrote:
> Motivation:
> The btrfs allocator is currently not ideal for all workloads. It tends
> to suffer from overallocating data block groups and underallocating
> metadata block groups. This results in filesystems becoming read-only
> even though there is plenty of "free" space.
> 
> This is naturally confusing and distressing to users.
> 
> Patches:
> 1) Store the stripe and chunk size in the btrfs_space_info structure
> 2) Add a sysfs entry to expose the above information
> 3) Add a sysfs entry to force a space allocation
> 4) Increase the default size of the metadata chunk allocation to 5GB
>    for volumes greater than 50GB.
> 
> Testing:
>   A new test is being added to the xfstest suite. For reference the
>   corresponding patch has the title:
>     [PATCH] btrfs: Test chunk allocation with different sizes
> 
>   In addition also manual testing has been performed.
>     - Run xfstests with the changes and the new test. It does not
>       show new diffs.
>     - Test with storage devices 10G, 20G, 30G, 50G, 60G
>       - Default allocation
>       - Increase of chunk size
>       - If the stripe size is > the free space, it allocates
>         free space - 1MB. The 1MB is left as free space.
>       - If the device has a storage size > 50G, it uses a 5GB
>         chunk size for new allocations.
> 
> Stefan Roesch (4):
>   btrfs: store chunk size in space-info struct.
>   btrfs: expose chunk size in sysfs.
>   btrfs: add force_chunk_alloc sysfs entry to force allocation
>   btrfs: increase metadata alloc size to 5GB for volumes > 50GB
> 

You can add

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

to the series, thanks,

Josef