Re: [GIT PULL v5.1] libfuse: run fuse servers as a contained service

["Darrick J. Wong" <djwong@kernel.org>]

On Sat, May 02, 2026 at 06:26:16PM +0200, Bernd Schubert wrote:
> 
> 
> On 5/2/26 17:59, Bernd Schubert wrote:
> > 
> > 
> > On 5/1/26 00:49, Darrick J. Wong wrote:
> >> On Thu, Apr 30, 2026 at 11:34:06PM +0200, Bernd Schubert wrote:
> >>> Hi Darrick,
> >>>
> >>> On 4/30/26 23:18, Darrick J. Wong wrote:
> >>>> Hi Bernd,
> >>>>
> >>>> Please pull this branch with changes for libfuse.
> >>>>
> >>>> As usual, I did a test-merge with the main upstream branch as of a few
> >>>> minutes ago, and didn't see any conflicts.  Please let me know if you
> >>>> encounter any problems.
> >>>
> >>> pushed to my github branch. BSD build fails with
> >>>
> >>> 2026-04-30T21:25:16.3874802Z FAILED: [code=1] lib/libfuse3.so.3.19.0 
> >>> 2026-04-30T21:25:16.3906762Z cc  -o lib/libfuse3.so.3.19.0 lib/libfuse3.so.3.19.0.p/fuse.c.o lib/libfuse3.so.3.19.0.p/fuse_loop.c.o lib/libfuse3.so.3.19.0.p/fuse_loop_mt.c.o lib/libfuse3.so.3.19.0.p/fuse_lowlevel.c.o lib/libfuse3.so.3.19.0.p/fuse_opt.c.o lib/libfuse3.so.3.19.0.p/fuse_signals.c.o lib/libfuse3.so.3.19.0.p/buffer.c.o lib/libfuse3.so.3.19.0.p/cuse_lowlevel.c.o lib/libfuse3.so.3.19.0.p/helper.c.o lib/libfuse3.so.3.19.0.p/modules_subdir.c.o lib/libfuse3.so.3.19.0.p/mount_util.c.o lib/libfuse3.so.3.19.0.p/fuse_log.c.o lib/libfuse3.so.3.19.0.p/compat.c.o lib/libfuse3.so.3.19.0.p/util.c.o lib/libfuse3.so.3.19.0.p/mount_bsd.c.o lib/libfuse3.so.3.19.0.p/fuse_service_stub.c.o lib/libfuse3.so.3.19.0.p/modules_iconv.c.o -Wl,--as-needed -Wl,--no-undefined -shared -fPIC -Wl,-soname,libfuse3.so.4 -Wl,--version-script,/home/runner/work/libfuse/libfuse/lib/fuse_versionscript -pthread -Wl,--start-group -ldl -lrt -Wl,--end-group
> >>> 2026-04-30T21:25:16.3939590Z ld: error: version script assignment of 'FUSE_3.19' to symbol 'fuse_service_can_allow_other' failed: symbol not defined
> >>
> >> Aha, that function got left out of the stub. :(
> >>
> >> Annoyingly, on Linux the build succeeds despite the missing symbol
> >> when I tweak meson so that it doesn't build the service stuff.  I would
> >> have thought that --no-undefined would have done that, but alas.
> >>
> >> Sorry about that too.  The following patch fixes it.
> >>
> >> diff --git i/lib/fuse_service_stub.c w/lib/fuse_service_stub.c
> >> index d34df3891a6e31..231b98423df628 100644
> >> --- i/lib/fuse_service_stub.c
> >> +++ w/lib/fuse_service_stub.c
> >> @@ -49,12 +49,17 @@ int fuse_service_send_goodbye(struct fuse_service *sf, int error)
> >>  int fuse_service_accept(struct fuse_service **sfp)
> >>  {
> >>  	*sfp = NULL;
> >>  	return 0;
> >>  }
> >>  
> >> +bool fuse_service_can_allow_other(struct fuse_service *sf)
> >> +{
> >> +	return false;
> >> +}
> >> +
> >>  int fuse_service_append_args(struct fuse_service *sf,
> >>  			     struct fuse_args *existing_args)
> >>  {
> >>  	return -EOPNOTSUPP;
> >>  }
> >>  
> >>
> >>> 2026-04-30T21:25:16.3951874Z cc: error: linker command failed with exit code 1 (use -v to see invocation)
> >>> 2026-04-30T21:25:16.4291582Z [44/82] cc -Itest/test_teardown_watchdog.p -Itest -I../test -Iinclude -I../include -Ilib -I../lib -I. -I.. -fdiagnostics-color=always -
> >>>
> >>>
> >>> checkpatch, CodeChecker-cppcheck, CodeChecker-gcc also all fail. This CodeQL
> >>
> >> Not sure why checkpatch fails, this is what I got (Debian 13):
> >>
> >> $ git diff origin/master.. | ./checkpatch.pl --max-line-length=100 --no-tree --ignore MAINTAINERS,SPDX_LICENSE_TAG,COMMIT_MESSAGE,FILE_PATH_CHANGES,EMAIL_SUBJECT,AVOID_EXTERNS,GIT_COMMIT_ID,ENOSYS_SYSCALL,ENOSYS,FROM_SIGN_OFF_MISMATCH,QUOTED_COMMIT_ID,,PREFER_ATTRIBUTE_ALWAYS_UNUSED,PREFER_DEFINED_ATTRIBUTE_MACRO,STRCPY,STRNCPY -
> >> No typos will be found - file '/storage/home/djwong/cdev/work/libfuse/spelling.txt': No such file or directory
> >> No structs that should be const will be found - file '/storage/home/djwong/cdev/work/libfuse/const_structs.checkpatch': No such file or directory
> >> total: 0 errors, 0 warnings, 3908 lines checked
> >>
> >> Your patch has no obvious style problems and is ready for submission.
> >>
> >> NOTE: Ignored message types: AVOID_EXTERNS COMMIT_MESSAGE EMAIL_SUBJECT ENOSYS ENOSYS_SYSCALL FILE_PATH_CHANGES FROM_SIGN_OFF_MISMATCH GIT_COMMIT_ID MAINTAINERS PREFER_ATTRIBUTE_ALWAYS_UNUSED PREFER_DEFINED_ATTRIBUTE_MACRO QUOTED_COMMIT_ID SPDX_LICENSE_TAG STRCPY STRNCPY
> >>
> >> cppcheck had a few things to say, but none of it was about the changed
> >> lines.
> >>
> >>> report is funny
> >>>
> >>>> int mount_service_main(int argc, char *argv[])
> >>>> Warning
> >>>> Poorly documented large function
> >>>> Poorly documented function: fewer than 2% comments for a function of 113 lines.
> >>>> CodeQL
> >>
> >> Hrmm.  I guess I'll have to figure out how to get those things running.
> >> That said, the stuff in mount_service.c is internal to libfuse (i.e.
> >> it's not public library API) so I didn't comment them as intensely.
> >> Would you like more?
> >>
> >>> I think I'm going to merge my sync fuse init series tomorrow.
> >>
> >> Yay!
> >>
> >>> Are you ok if skip posting another version of the series?
> >>
> >>                ^ is there an "I" here?  e.g. "...if I skip posting..."?
> >>
> >> /My/ normal practice (from xfs) was to repost the series as it was
> >> merged, followed by an announcement.  That way the mailing list is a
> >> complete record of what was merged.  However, very very few people
> >> actually do that, even in the kernel.
> >>
> >> I'm ok with you not posting another version of the series.
> >>
> >>> Or do you prefer to review the recent changes and last piece I'm going
> >>> to do tomorrow?
> >>
> >> Nah, just merge it.  I'll look over the changes once it's in the branch
> >> and if there's anything weird, you or I or anyone else can send patches.
> >> As long as you're not planning to tag it as a release, nothing's set in
> >> stone.
> >>
> >>> Basically my goal is to rebase your series against it immediately and
> >>> to merge your series during the next few days.
> >>
> >> <nod> Let me know what you want changed, I'll be around since I am not
> >> travelling anywhere for a couple of weeks. :)
> >>
> >> I can reflow changes into the patchset, or if you'd prefer, I can add
> >> them as new patches that would go on the end of the series.
> >>
> > 
> > Hi Darrick,
> > 
> > eventually merged my patches and made a quick rebase and conflict 
> > resolving with your branch. Github still reports plenty of issues ;)
> > 
> > Could you fix all of the checkpatch isssues? This one shows plenty
> > "util: hoist the fuse.conf parsing and setuid mode enforcement code"
> > 
> > bschubert2@imesrv6 libfuse.git>stg series
> > + mount_service-add-systemd
> > + mount_service-create-high
> > + mount_service-use-the-new
> > + mount_service-update-mtab
> >> util-hoist-the-fuse.conf
> > - util-fix-checkpatch-complaints
> > - mount_service-enable
> > - mount.fuse3-integrate-systemd
> > - mount_service-allow
> > - example-service_ll-create-a
> > - example-service-create-a
> > - nullfs-support-fuse-systemd
> > - meson-show-feature-summary
> > bschubert2@imesrv6 libfuse.git>.github/workflows/run-checkpatch.sh 
> > No typos will be found - file '/home/bschubert2/src/libfuse/libfuse.git/spelling.txt': No such file or directory
> > No structs that should be const will be found - file '/home/bschubert2/src/libfuse/libfuse.git/const_structs.checkpatch': No such file or directory
> > ERROR:GLOBAL_INITIALISERS: do not initialise globals to 0
> > #61: FILE: util/fuser_conf.c:33:
> > +int user_allow_other = 0;
> > 
> > WARNING:LINE_SPACING: Missing a blank line after declarations
> > #74: FILE: util/fuser_conf.c:46:
> > +	char *dest = buf;
> > +	while (1) {
> > 
> > ...
> > 
> > I don't have a strong opinion about these two above - feel 
> > free to disable them. However, in order to merge it, it would
> > be good to run without any checkpatch report.
> > And everything that cppcheck and gcc-checker reports, definitely 
> > need to be fixed.
> 
> Basically
> 
> cd <$FUSEDIR>
> BUILDDIR="build-without-examples"
> mkdir -p ${BUILDDIR}
> meson setup ${BUILDDIR} -Dexamples=false 
> ninja -C ${BUILDDIR}
> ./.github/workflows/codechecker.sh --gcc --codechecker --build-dir ${BUILDDIR}
> 
> gcc reports are starting here
> 
> bschubert2@imesrv6 libfuse.git>stg series
> + mount_service-add-systemd
> + mount_service-create-high
> + mount_service-use-the-new
> + mount_service-update-mtab
> + util-hoist-the-fuse.conf
> + util-fix-checkpatch-complaints
> + mount_service-enable
> > mount.fuse3-integrate-systemd
> 
> 
> bschubert2@imesrv6 libfuse.git>git show |head -n5
> commit f908bb1504eca167e156671dde957c2e7192b7d2
> Author: Darrick J. Wong <djwong@kernel.org>
> Date:   Wed Mar 4 13:48:55 2026 -0800
> 
>     mount.fuse3: integrate systemd service startup
> 
> 
> ---==== Severity Statistics ====----
> ----------------------------
> Severity | Number of reports
> ----------------------------
> MEDIUM   |                 1
> ----------------------------
> ----=================----
> 
> ----==== Checker Statistics ====----
> -----------------------------------------------------
> Checker name           | Severity | Number of reports
> -----------------------------------------------------
> gcc-deref-before-check | MEDIUM   |                 1

Oh, that's concerning.  Could you figure out exactly what it's
complaining about and send that to me, please?

--D

> -----------------------------------------------------
> ----=================----
> 
> ----==== File Statistics ====----
> --------------------------------
> File name    | Number of reports
> --------------------------------
> mount.fuse.c |                 1
> --------------------------------
> ----=================----
> 
> ----======== Summary ========----
> ----------------------------------------------
> Number of processed analyzer result files | 45
> Number of analyzer reports                | 1 
> ----------------------------------------------
> ----=================----
> 
> To view statistics in a browser run:
> > firefox /home/bschubert2/src/libfuse/libfuse.git/build-without-examples/codechecker-html/statistics.html
> 
> To view the results in a browser run:
> > firefox /home/bschubert2/src/libfuse/libfuse.git/build-without-examples/codechecker-html/index.html
> [INFO 2026-05-02 18:25] - ----==== Summary ====----
> [INFO 2026-05-02 18:25] - Up-to-date analysis results
> [INFO 2026-05-02 18:25] -   gcc: 37
> [INFO 2026-05-02 18:25] - Outdated analysis results
> [INFO 2026-05-02 18:25] - Failed to analyze
> [INFO 2026-05-02 18:25] - Missing analysis results
> [INFO 2026-05-02 18:25] -   clangsa: 37
> [INFO 2026-05-02 18:25] -   clang-tidy: 37
> [INFO 2026-05-02 18:25] -   cppcheck: 37
> [INFO 2026-05-02 18:25] -   infer: 37
> [INFO 2026-05-02 18:25] - Total analyzed compilation commands: 45
> [INFO 2026-05-02 18:25] - Total available compilation commands: 45
> [INFO 2026-05-02 18:25] - ----=================----
> bschubert2@imesrv6 libfuse.git>
> 
> 
> 
>