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 EA5A2338939 for ; Wed, 5 Nov 2025 17:42:14 +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=1762364535; cv=none; b=qVmDGqbsOFnwKS8yJ4SoPC9Z5SPiwVGRpc93WzE+SwELYXgRO7qrdQZtj8H4BlppZttVaFCNpSZo0BJsKs5OLoh2BYIWHWUAq8r2T8cBrfdEZ7HTfVsIImd9pc55j9ONnE++ON5i/qYnCByC3Ig/RxvCSa3j3kTdV7uKSLVpdj4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762364535; c=relaxed/simple; bh=6OSK4jspctei28moowJKeVH1kMOoNXKe8CN1hdQUjIo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LIVn0BwhJrFo+hZtsaJXQji41cDH8Q1rrN+CQtmr7fQN1DlVvC+9HbQhLfSngqqZMfXqCqykAq2Tj6gpdSF2ZAesdO7ThfD2EgffwqvIQwn7qogTtvOZUJc/5rPFIxhLX35DmXOsDVK6jJRMDUASiyjHgmfXI/OqGmEbsJia9fQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=t27m3FGu; 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="t27m3FGu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45552C4CEF5; Wed, 5 Nov 2025 17:42:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762364534; bh=6OSK4jspctei28moowJKeVH1kMOoNXKe8CN1hdQUjIo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t27m3FGua24S+7a4K3tfcupV97p7ilYWhYQJR100ZlYjjZwH9JtJgvrdpFp3yH2C2 zjtLIGK4cETRwTdhMHWBJ5uabS79+fDsi150/uJF4xJ97WKoB0RJlImLYQMqjPpWiL inIWm9V7xllDXuxBZImmMoWw9tXEkpL3GqSJ3Vn8qXdbbrvZGvutCJezcyVF4/IKnT 8j9lIIDBo2Fe7EELFObXLnM9PEuz1FgXL2bK+T3hwUFPBTvBEVyNy+graB59hpD4o3 r2lKRVRJcmQOl8RtSXejWvhmUL1QKjCtsOTlamGIzkJsF+J3KamNsNtgdH8C8lmAFo FaX5K/h/srQ6g== From: Mike Snitzer To: Chuck Lever , Jeff Layton Cc: linux-nfs@vger.kernel.org Subject: [PATCH v4 2/3] NFSD: add new NFSD_IO_DIRECT variants that may override stable_how Date: Wed, 5 Nov 2025 12:42:09 -0500 Message-ID: <20251105174210.54023-3-snitzer@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20251105174210.54023-1-snitzer@kernel.org> References: <20251105174210.54023-1-snitzer@kernel.org> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit NFSD_IO_DIRECT_WRITE_FILE_SYNC is direct IO with stable_how=NFS_FILE_SYNC. NFSD_IO_DIRECT_WRITE_DATA_SYNC is direct IO with stable_how=NFS_DATA_SYNC. The stable_how associated with each is a hint in the form of a "floor" value for stable_how. Meaning if the client provided stable_how is already of higher value it will not be changed. These permutations of NFSD_IO_DIRECT allow to experiment with also elevating stable_how and sending it back to the client. Which for NFSD_IO_DIRECT_WRITE_FILE_SYNC will cause the client to elide its COMMIT. Signed-off-by: Mike Snitzer --- fs/nfsd/debugfs.c | 7 ++++++- fs/nfsd/nfsd.h | 2 ++ fs/nfsd/vfs.c | 46 ++++++++++++++++++++++++++++++++++------------ 3 files changed, 42 insertions(+), 13 deletions(-) diff --git a/fs/nfsd/debugfs.c b/fs/nfsd/debugfs.c index 7f44689e0a53..8538e29ed2ab 100644 --- a/fs/nfsd/debugfs.c +++ b/fs/nfsd/debugfs.c @@ -68,7 +68,7 @@ static int nfsd_io_cache_read_set(void *data, u64 val) case NFSD_IO_DIRECT: /* * Must disable splice_read when enabling - * NFSD_IO_DONTCACHE. + * NFSD_IO_DONTCACHE and NFSD_IO_DIRECT. */ nfsd_disable_splice_read = true; nfsd_io_cache_read = val; @@ -90,6 +90,9 @@ DEFINE_DEBUGFS_ATTRIBUTE(nfsd_io_cache_read_fops, nfsd_io_cache_read_get, * Contents: * %0: NFS WRITE will use buffered IO * %1: NFS WRITE will use dontcache (buffered IO w/ dropbehind) + * %2: NFS WRITE will use direct IO with stable_how=NFS_UNSTABLE + * %3: NFS WRITE will use direct IO with stable_how=NFS_DATA_SYNC + * %4: NFS WRITE will use direct IO with stable_how=NFS_FILE_SYNC * * This setting takes immediate effect for all NFS versions, * all exports, and in all NFSD net namespaces. @@ -109,6 +112,8 @@ static int nfsd_io_cache_write_set(void *data, u64 val) case NFSD_IO_BUFFERED: case NFSD_IO_DONTCACHE: case NFSD_IO_DIRECT: + case NFSD_IO_DIRECT_WRITE_DATA_SYNC: + case NFSD_IO_DIRECT_WRITE_FILE_SYNC: nfsd_io_cache_write = val; break; default: diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index e4263326ca4a..10eca169392b 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -161,6 +161,8 @@ enum { NFSD_IO_BUFFERED, NFSD_IO_DONTCACHE, NFSD_IO_DIRECT, + NFSD_IO_DIRECT_WRITE_DATA_SYNC, + NFSD_IO_DIRECT_WRITE_FILE_SYNC, }; extern u64 nfsd_io_cache_read __read_mostly; diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index a4700c917c72..1b61185e96a9 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1367,15 +1367,45 @@ nfsd_write_dio_iters_init(struct bio_vec *bvec, unsigned int nvecs, args->flags_buffered |= IOCB_DONTCACHE; } +static void +nfsd_init_write_kiocb_from_stable(u32 stable_floor, + struct kiocb *kiocb, + u32 *stable_how) +{ + if (stable_floor < *stable_how) + return; /* stable_how already set higher */ + + *stable_how = stable_floor; + + switch (stable_floor) { + case NFS_FILE_SYNC: + /* persist data and timestamps */ + kiocb->ki_flags |= IOCB_DSYNC | IOCB_SYNC; + break; + case NFS_DATA_SYNC: + /* persist data only */ + kiocb->ki_flags |= IOCB_DSYNC; + break; + } +} + static noinline_for_stack int nfsd_direct_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, u32 *stable_how, unsigned int nvecs, unsigned long *cnt, struct kiocb *kiocb) { + u32 stable_floor = NFS_UNSTABLE; struct nfsd_write_dio_args args; ssize_t host_err; unsigned int i; + if (nfsd_io_cache_write == NFSD_IO_DIRECT_WRITE_FILE_SYNC) + stable_floor = NFS_FILE_SYNC; + else if (nfsd_io_cache_write == NFSD_IO_DIRECT_WRITE_DATA_SYNC) + stable_floor = NFS_DATA_SYNC; + if (stable_floor != NFS_UNSTABLE) + nfsd_init_write_kiocb_from_stable(stable_floor, kiocb, + stable_how); args.nf = nf; nfsd_write_dio_iters_init(rqstp->rq_bvec, nvecs, kiocb, *cnt, &args); @@ -1461,18 +1491,8 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, stable = NFS_UNSTABLE; init_sync_kiocb(&kiocb, file); kiocb.ki_pos = offset; - if (likely(!fhp->fh_use_wgather)) { - switch (stable) { - case NFS_FILE_SYNC: - /* persist data and timestamps */ - kiocb.ki_flags |= IOCB_DSYNC | IOCB_SYNC; - break; - case NFS_DATA_SYNC: - /* persist data only */ - kiocb.ki_flags |= IOCB_DSYNC; - break; - } - } + if (likely(!fhp->fh_use_wgather)) + nfsd_init_write_kiocb_from_stable(stable, &kiocb, stable_how); nvecs = xdr_buf_to_bvec(rqstp->rq_bvec, rqstp->rq_maxpages, payload); @@ -1482,6 +1502,8 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, switch (nfsd_io_cache_write) { case NFSD_IO_DIRECT: + case NFSD_IO_DIRECT_WRITE_DATA_SYNC: + case NFSD_IO_DIRECT_WRITE_FILE_SYNC: host_err = nfsd_direct_write(rqstp, fhp, nf, stable_how, nvecs, cnt, &kiocb); stable = *stable_how; -- 2.44.0