Re: [PATCH v6 0/2] btrfs: Don't block system suspend during fstrim

[Qu Wenruo]

在 2024/9/18 06:03, Luca Stefani 写道:
> Changes since v5:
> * Make chunk size a define
> * Remove superfluous trim_interrupted checks
>    after moving them to trim_no_bitmap/trim_bitmaps
>
> Changes since v4:
> * Set chunk size to 1G
> * Set proper error return codes in case of interruption
> * Dropped fstrim_range fixup as pulled in -next
>
> Changes since v3:
> * Went back to manual chunk size
>
> Changes since v2:
> * Use blk_alloc_discard_bio directly
> * Reset ret to ERESTARTSYS
>
> Changes since v1:
> * Use bio_discard_limit to calculate chunk size
> * Makes use of the split chunks
>
> Original discussion: https://lore.kernel.org/lkml/20240822164908.4957-1-luca.stefani.ge1@xxxxxxxxx/
> v1: https://lore.kernel.org/lkml/20240902114303.922472-1-luca.stefani.ge1@xxxxxxxxx/
> v2: https://lore.kernel.org/lkml/20240902205828.943155-1-luca.stefani.ge1@xxxxxxxxx/
> v3: https://lore.kernel.org/lkml/20240903071625.957275-4-luca.stefani.ge1@xxxxxxxxx/
> v4: https://lore.kernel.org/lkml/20240916101615.116164-1-luca.stefani.ge1@xxxxxxxxx/
> v5: https://lore.kernel.org/lkml/20240916125707.127118-1-luca.stefani.ge1@xxxxxxxxx/
Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>

> ---
>
> NB: I didn't change btrfs_discard_workfn yet to add error checks
> as I don't know what semantics we should have in that case.
> The work queue is always re-scheduled and created with WQ_FREEZABLE
> so it should be automatically frozen. Shall I simply add some logs?

And that is for async discard, which has a much smaller discard size and 
iops limits.

The main part of large discard is the free extents discarding, which is 
already addressed by your patch correctly now.

IIRC we do not need to bother that much for it.

Thanks,
Qu

> ---
>
> Luca Stefani (2):
>    btrfs: Split remaining space to discard in chunks
>    btrfs: Don't block system suspend during fstrim
>
>   fs/btrfs/extent-tree.c      | 26 +++++++++++++++++++++-----
>   fs/btrfs/free-space-cache.c |  4 ++--
>   fs/btrfs/free-space-cache.h |  6 ++++++
>   fs/btrfs/volumes.h          |  1 +
>   4 files changed, 30 insertions(+), 7 deletions(-)