From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AB3543C38 for ; Thu, 31 Jul 2025 20:54:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753995262; cv=none; b=u5bWLnPwlZisAToof2w2Tul/Ul3Qi7Jwd7CjR1E8AaQ8RW4TX8t1RfA4z1eyKX1SThKufAmVac8vdHWBxEMavQhGk324/WZaNRk8mSn6nyIUlHVAsWvIuSUPLTz2lngmadDljC+VLS5S96zGfxNsMBQceWTkYDfviJOgo7SxEFU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753995262; c=relaxed/simple; bh=ewu2rtLOA44I23XiJ9g7Q+1njp6FM8ofwfg3fRtu9RA=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=mX7/6pN6sRFfqnbHX5mv6GCsaKpZNgMPgW0U89oF2kpILJ/M84aasV+PkT8Hy5EmiMpojCz5AlwKvcBGMyNcUTTLhuZrw2QrwLRmZRx1VGhWRdLZAUR9CNMQoS388u//yVXXkaE3WQwKSSdUZDn4+inIf92ZumM5WSWMbBEjyiA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YRk/ptFg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YRk/ptFg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E6B5C4CEEF; Thu, 31 Jul 2025 20:54:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753995262; bh=ewu2rtLOA44I23XiJ9g7Q+1njp6FM8ofwfg3fRtu9RA=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=YRk/ptFgAHAyyNE1pmb5/ym0oo1fqw4rLhbFXKpKyuAbNQ3sB4OyW9kneGNjbasOP unOp0Ak6ZXnnnxPcdt5BjEwNY4cAa79wjaYm3UBpizezPijOM1AZQ8n7b/iIbcywRW EVTHjl6GGl+T4L+vS8dohbLihv/q7FqSWmkj0xjFDFmsgjiCS4k4z1cdkXn9KL6sV5 BYJXctixeEjfstYt1+YKoZ3uIAsHPboNAVlWA6ih/rydCp+GuidjpjTRKHLECl8h3L xR0NOBxRTjs3+vIc2/74Xbgr/3je73QXX+JvreaWpxzXx/dz67oG8ZkW2k232Bm71B jezYixvTtlc4Q== Message-ID: Subject: Re: [PATCH v2 2/4] NFSD: prepare nfsd_vfs_write() to use O_DIRECT on misaligned WRITEs From: Jeff Layton To: Mike Snitzer , Chuck Lever Cc: linux-nfs@vger.kernel.org Date: Thu, 31 Jul 2025 16:54:21 -0400 In-Reply-To: <20250731194448.88816-3-snitzer@kernel.org> References: <20250731194448.88816-1-snitzer@kernel.org> <20250731194448.88816-3-snitzer@kernel.org> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=mQINBE6V0TwBEADXhJg7s8wFDwBMEvn0qyhAnzFLTOCHooMZyx7XO7dAiIhDSi7G1NPxw n8jdFUQMCR/GlpozMFlSFiZXiObE7sef9rTtM68ukUyZM4pJ9l0KjQNgDJ6Fr342Htkjxu/kFV1Wv egyjnSsFt7EGoDjdKqr1TS9syJYFjagYtvWk/UfHlW09X+jOh4vYtfX7iYSx/NfqV3W1D7EDi0PqV T2h6v8i8YqsATFPwO4nuiTmL6I40ZofxVd+9wdRI4Db8yUNA4ZSP2nqLcLtFjClYRBoJvRWvsv4lm 0OX6MYPtv76hka8lW4mnRmZqqx3UtfHX/hF/zH24Gj7A6sYKYLCU3YrI2Ogiu7/ksKcl7goQjpvtV 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DIO-aligned). Doing so in a > preliminary commit just allows for indentation and slight > transformation to be more easily understood and reviewed. >=20 > Signed-off-by: Mike Snitzer > --- > fs/nfsd/vfs.c | 50 ++++++++++++++++++++++++++++++-------------------- > 1 file changed, 30 insertions(+), 20 deletions(-) >=20 > diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c > index 35c29b8ade9c3..e4855c32dad12 100644 > --- a/fs/nfsd/vfs.c > +++ b/fs/nfsd/vfs.c > @@ -1341,7 +1341,6 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_f= h *fhp, > struct super_block *sb =3D file_inode(file)->i_sb; > struct kiocb kiocb; > struct svc_export *exp; > - struct iov_iter iter; > errseq_t since; > __be32 nfserr; > int host_err; > @@ -1349,6 +1348,9 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_f= h *fhp, > unsigned int pflags =3D current->flags; > bool restore_flags =3D false; > unsigned int nvecs; > + struct iov_iter iter_stack[1]; > + struct iov_iter *iter =3D iter_stack; > + unsigned int n_iters =3D 0; > =20 > trace_nfsd_write_opened(rqstp, fhp, offset, *cnt); > =20 > @@ -1378,14 +1380,15 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc= _fh *fhp, > kiocb.ki_flags |=3D IOCB_DSYNC; > =20 > nvecs =3D xdr_buf_to_bvec(rqstp->rq_bvec, rqstp->rq_maxpages, payload); > - iov_iter_bvec(&iter, ITER_SOURCE, rqstp->rq_bvec, nvecs, *cnt); > + iov_iter_bvec(&iter[0], ITER_SOURCE, rqstp->rq_bvec, nvecs, *cnt); > + n_iters++; > =20 > switch (nfsd_io_cache_write) { > case NFSD_IO_DIRECT: > /* direct I/O must be aligned to device logical sector size */ > if (nf->nf_dio_mem_align && nf->nf_dio_offset_align && > (((offset | *cnt) & (nf->nf_dio_offset_align-1)) =3D=3D 0) && > - iov_iter_is_aligned(&iter, nf->nf_dio_mem_align - 1, > + iov_iter_is_aligned(&iter[0], nf->nf_dio_mem_align - 1, > nf->nf_dio_offset_align - 1)) > kiocb.ki_flags =3D IOCB_DIRECT; > break; > @@ -1396,25 +1399,32 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc= _fh *fhp, > break; > } > =20 > - since =3D READ_ONCE(file->f_wb_err); > - if (verf) > - nfsd_copy_write_verifier(verf, nn); > - host_err =3D vfs_iocb_iter_write(file, &kiocb, &iter); > - if (host_err < 0) { > - commit_reset_write_verifier(nn, rqstp, host_err); > - goto out_nfserr; > - } > - *cnt =3D host_err; > - nfsd_stats_io_write_add(nn, exp, *cnt); > - fsnotify_modify(file); > - host_err =3D filemap_check_wb_err(file->f_mapping, since); > - if (host_err < 0) > - goto out_nfserr; > + *cnt =3D 0; > + for (int i =3D 0; i < n_iters; i++) { > + since =3D READ_ONCE(file->f_wb_err); > + if (verf) > + nfsd_copy_write_verifier(verf, nn); > =20 Once you remove the above bits outside the loop, you can add: Reviewed-by: Jeff Layton