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 9A4C948C8CC; Tue, 5 May 2026 16:38:24 +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=1777999104; cv=none; b=g/rrKB5oc7OV06eiFAmKUrikMeYYo8eG8rQSMMDovh2JUNbcc+MY4vav+L2pn4ohSbYa+E8Fr6WpjIrBvdxfVWvdi5iZB2WJlBmN3A8Ya90wSHBdguVF9Wnxix8ntQCUNU/jngUCUaosUh236Ve0vOVPhkL6eCsrBFkt5H1o9iA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777999104; c=relaxed/simple; bh=CEJUEhi4GebLQMwAuNoV+9ZZmtfw+cenrqexC157EhQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=i5+fCFD5v/Avf3+Mx+9xK46r692ylgw/c5d7gx3ASlpNSiTvEunNu9YLtJGdZjI746uD759gz4b0iM0cG6LOLFG65D9En3C4t3zKiVDTls8yleeK9kr8vaLUFpNNbyvaAwSk08GCN8GHc9Ci+NdZmEL5DkUSY7zxMfdQDvDsfEE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IxvN78/V; 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="IxvN78/V" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D33BC2BCF4; Tue, 5 May 2026 16:38:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777999104; bh=CEJUEhi4GebLQMwAuNoV+9ZZmtfw+cenrqexC157EhQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IxvN78/VMN6+D6N3hjxXWIR1aQpn9wSA35igMEiXAzfmAj2pUQOlhPlxf5/TG5sno 4yElhWui5GxPrLSIAyfnzQUGnBli7dPRnBCv6yOfsci1bclPX5PyitdXnZPgSz7Hs4 bwsuZUoT/W65ZTd4pSWHaGkDkVh1iW8nneP35PbcJpnAnkeDMR8vV7YmJd4YZGafZZ GCpwrOHqM9mBwee+MYKmYT5DaTn3CCXlefhXNDJidl/g3xMXJ+cAh6KYKg0uJg9fiN rVU98iXXn8ErGoCEaKZVAamvhuDKLCBHNHskWo6adbdc/Z505HU1kH3prTB5Yv9TSH vT4VQtFox6u4g== Date: Tue, 5 May 2026 09:38:23 -0700 From: "Darrick J. Wong" To: Bernd Schubert Cc: joannelkoong@gmail.com, neal@gompa.dev, fuse-devel@lists.linux.dev, linux-fsdevel@vger.kernel.org, miklos@szeredi.hu Subject: Re: [PATCH 2/2] libfuse: always send the subtype to the kernel when using fsconfig() Message-ID: <20260505163823.GB7739@frogsfrogsfrogs> References: <177795853450.1133476.8692790530314969678.stgit@frogsfrogsfrogs> <177795853491.1133476.14673788941960394877.stgit@frogsfrogsfrogs> <3b37a5be-c3c8-461d-8382-04ae86de81cc@bsbernd.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3b37a5be-c3c8-461d-8382-04ae86de81cc@bsbernd.com> On Tue, May 05, 2026 at 09:41:59AM +0200, Bernd Schubert wrote: > > > On 5/5/26 07:23, Darrick J. Wong wrote: > > From: Darrick J. Wong > > > > Although it's possible to supply a filesystem subtype when calling > > fsopen(), it does not pass the stuff after the dot to the mount option > > parsing mechanism like the legacy mount() call does. Therefore, it's > > necessary to pass the subtype explicitly via fsconfig() or else the > > subtype will be missing from the /proc/mounts output. > > > > For example, fuse4fs with the old mount API produces this: > > > > /dev/sda /mnt fuse.ext4 rw,nosuid,nodev,relatime,user_id=0,group_id=0 0 0 > > > > But with the new mount API, we only get: > > > > /dev/sda /mnt fuse rw,nosuid,nodev,relatime,user_id=0,group_id=0 0 0 > > > > ...which breaks fstests, which requires the fsname to match the string > > that it passes to mount -t. Update the comment in mount_service.c to > > match this requirement. > > > > Fixes: 14cb7b93bb9688 ("Add support for the new linux mount API") > > Signed-off-by: "Darrick J. Wong" > > --- > > lib/mount_fsmount.c | 13 +++++++++++++ > > util/mount_service.c | 3 ++- > > 2 files changed, 15 insertions(+), 1 deletion(-) > > > > > > diff --git a/lib/mount_fsmount.c b/lib/mount_fsmount.c > > index 615271b09758c3..5e13b34ccfc610 100644 > > --- a/lib/mount_fsmount.c > > +++ b/lib/mount_fsmount.c > > @@ -359,6 +359,19 @@ int fuse_kern_fsmount(const char *mnt, unsigned long flags, int blkdev, > > goto out_free; > > } > > > > + /* Configure subtype */ > > + if (subtype) { > > + res = fsconfig(fsfd, FSCONFIG_SET_STRING, "subtype", > > + subtype, 0); > > + if (res) { > > + err = -errno; > > + log_fsconfig_kmsg(fsfd); > > + fprintf(stderr, "fuse: fsconfig subtype failed: %s\n", > > + strerror(-err)); > > + goto out_free; > > + } > > + } > > + > > /* Configure source */ > > res = fsconfig(fsfd, FSCONFIG_SET_STRING, "source", source, 0); > > if (res == -1) { > > Oh yes, that had slipped through. Going to apply this. Thanks! > > diff --git a/util/mount_service.c b/util/mount_service.c > > index bc5940bc900dad..3fbabfdd69300d 100644 > > --- a/util/mount_service.c > > +++ b/util/mount_service.c > > @@ -821,7 +821,8 @@ static void try_fsopen(struct mount_service *mo) > > /* > > * As of Linux 7.0 you can pass subtypes to fsopen, but the manpage for > > * fsopen only says that you can pass any value of the second column of > > - * /proc/filesystems into fsopen. > > + * /proc/filesystems into fsopen. You must still call fsconfig() for > > + * the subtype separately, however. > > */ > > mo->fsopenfd = fsopen(fsname(mo), FSOPEN_CLOEXEC); > > } > > > > Can we integrate that into you series separately, as it is not merged yet? I'll separate this hunk into a separate patch. --D > > Thanks, > Bernd >