Re: [PATCH v2] btrfs: move transaction abort message to __btrfs_abort_transaction()

[David Sterba <dsterba@suse.cz>]

On Wed, Apr 29, 2026 at 03:35:55PM +0100, Filipe Manana wrote:
> On Wed, Apr 29, 2026 at 3:33 PM David Sterba <dsterba@suse.com> wrote:
> >
> > The btrfs_abort_transaction() is called at the location where we want to
> > report the abort. It must be a macro so we get the correct line and
> > stack trace. This inlines the necessary code and the rest is pushed to
> > __btrfs_abort_transaction().
> >
> > There's a possibility to reduce the inlined code if we move the message
> > to the helper function as well, without loss of information. The
> > difference is only that the WARN will not print it inside the stack
> > report but after:
> >
> >   --[ cut here ]--
> >   WARNING: fs/btrfs/transaction.c:2045 at btrfs_commit_transaction+0xa21/0xd30 [btrfs], CPU#11: bonnie++/3377975
> >   ...
> >   --[ end trace ] --
> >   BTRFS error (device dm-0 state A): Transaction aborted (error -28)
> >
> > While previously there would be one more line like:
> >
> >   --[ cut here ]--
> >   BTRFS: Transaction aborted (error -28)
> >   WARNING: fs/btrfs/transaction.c:2045 at btrfs_commit_transaction+0xa21/0xd30 [btrfs], CPU#11: bonnie++/3377975
> >   ...
> >   --[ end trace ] --
> >
> > This removes about 20KiB of btrfs.ko on a release config.
> >
> > Signed-off-by: David Sterba <dsterba@suse.com>
> > ---
> >
> > v2:
> > - move message in __btrfs_abort_transaction() under 'first_hit', also to
> >   make the WRITE_ONCE() assignments immediate
> > - savings updated to 20K, it depends on the config and compiler, use an
> >   average of a few setups
> >
> >  fs/btrfs/transaction.c |  8 ++++++--
> >  fs/btrfs/transaction.h | 11 +----------
> >  2 files changed, 7 insertions(+), 12 deletions(-)
> >
> > diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
> > index 194f581b36f3..184fe976450e 100644
> > --- a/fs/btrfs/transaction.c
> > +++ b/fs/btrfs/transaction.c
> > @@ -2731,8 +2731,12 @@ void __cold __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
> >
> >         WRITE_ONCE(trans->aborted, error);
> >         WRITE_ONCE(trans->transaction->aborted, error);
> > -       if (first_hit && error == -ENOSPC)
> > -               btrfs_dump_space_info_for_trans_abort(fs_info);
> > +       if (first_hit) {
> > +               btrfs_err(trans->fs_info, "Transaction %llu aborted (error %d)",
> 
> There's already a local fs_info variable, no need to trans->fs_info.

Ah, copy&paste leftover, I'll fix it in for-next, thanks.