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

Bernd Schubert
2026-05-02T15:59:09Z

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.

Thanks,
Bernd