Re: [PATCH 0/7] btrfs: avoid some unnecessary commit of empty transactions

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

在 2024/5/23 00:06, fdmanana@kernel.org 写道:
> From: Filipe Manana <fdmanana@suse.com>
>
> A few places can unnecessarily create an empty transaction and then commit
> it, when the goal is just to catch the current transaction and wait for
> its commit to complete. This results in wasting IO, time and rotation of
> the precious backup roots in the super block. Details in the change logs.
> The patches are all independent, except patch 4 that applies on top of
> patch 3 (but could have been done in any order really, they are independent).

Looks good to me.

Reviewed-by: Qu Wenruo <wqu@suse.com>

Have you considered outputting a warning if we're committing an empty
transaction (for debug build)?

That would prevent such problem from happening again.

Thanks,
Qu
>
> Filipe Manana (7):
>    btrfs: qgroup: avoid start/commit empty transaction when flushing reservations
>    btrfs: avoid create and commit empty transaction when committing super
>    btrfs: send: make ensure_commit_roots_uptodate() simpler and more efficient
>    btrfs: send: avoid create/commit empty transaction at ensure_commit_roots_uptodate()
>    btrfs: scrub: avoid create/commit empty transaction at finish_extent_writes_for_zoned()
>    btrfs: add and use helper to commit the current transaction
>    btrfs: send: get rid of the label and gotos at ensure_commit_roots_uptodate()
>
>   fs/btrfs/disk-io.c     |  8 +-------
>   fs/btrfs/qgroup.c      | 31 +++++--------------------------
>   fs/btrfs/scrub.c       |  6 +-----
>   fs/btrfs/send.c        | 32 ++++++++------------------------
>   fs/btrfs/space-info.c  |  9 +--------
>   fs/btrfs/super.c       | 11 +----------
>   fs/btrfs/transaction.c | 19 +++++++++++++++++++
>   fs/btrfs/transaction.h |  1 +
>   8 files changed, 37 insertions(+), 80 deletions(-)
>