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

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

On Wed, Mar 04, 2026 at 08:29:35PM +0100, Bernd Schubert wrote:
> 
> 
> On 3/4/26 19:06, Darrick J. Wong wrote:
> > On Wed, Mar 04, 2026 at 09:06:52AM -0800, Darrick J. Wong wrote:
> >> On Wed, Mar 04, 2026 at 02:36:03PM +0100, Bernd Schubert wrote:
> >>>
> >>>
> >>> On 3/4/26 01:11, 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.
> >>>
> >>> Hi Darrick,
> >>>
> >>> quite some problems actually ;)
> >>>
> >>> https://github.com/libfuse/libfuse/pull/1444
> >>>
> >>> Basically everything fails.  Build test with
> >>
> >> Doh :(
> >>
> >>> ../../../home/runner/work/libfuse/libfuse/lib/fuse_service.c:24:10:
> >>> fatal error: 'systemd/sd-daemon.h' file not found
> >>>    24 | #include <systemd/sd-daemon.h>
> >>>
> >>>
> >>> Two issues here:
> >>> a) meson is not testing for sd-daemon.h?
> >>
> >> Hrm.  meson.build *should* have this clause to detect systemd:
> >>
> >> # Check for systemd support
> >> systemd_system_unit_dir = get_option('systemdsystemunitdir')
> >> if systemd_system_unit_dir == ''
> >>   systemd = dependency('systemd', required: false)
> >>   if systemd.found()
> >>      systemd_system_unit_dir = systemd.get_variable(pkgconfig: 'systemd_system_unit_dir')
> >>   endif
> >> endif
> >>
> >> if systemd_system_unit_dir == ''
> >>   warning('could not determine systemdsystemunitdir, systemd stuff will not be installed')
> >> else
> >>   private_cfg.set_quoted('SYSTEMD_SYSTEM_UNIT_DIR', systemd_system_unit_dir)
> >>   private_cfg.set('HAVE_SYSTEMD', true)
> >> endif
> >>
> >> # Check for libc SCM_RIGHTS support (aka Linux)
> >> code = '''
> >> #include <sys/socket.h>
> >> int main(void) {
> >>     int moo = SCM_RIGHTS;
> >>     return moo;
> >> }'''
> >> if cc.links(code, name: 'libc SCM_RIGHTS support')
> >>   private_cfg.set('HAVE_SCM_RIGHTS', true)
> >> endif
> >>
> >> if private_cfg.get('HAVE_SCM_RIGHTS', false) and private_cfg.get('HAVE_SYSTEMD', false)
> >>   private_cfg.set('HAVE_SERVICEMOUNT', true)
> >> endif
> >>
> >>
> >> But apparently it built fuse_service.c anyway?  I'll have to look deeper
> >> into what github ci did, since the pkgconfig fil... oh crikey.
> >>
> >> systemd-dev contains the systemd.pc file, so the systemd.get_variable
> >> call succeeds and returns a path, thereby enabling the build.  However,
> >> the header files are in libsystemd-dev, and neither package depends on
> >> the other.
> >>
> >> So I clearly need to test for the presence of sd-daemon.h in that first
> >> clause that determines if HAVE_SYSTEMD gets set.
> 
> Or link test for systemd

<nod> Hilariously we only need a single #define out of that header file:
SD_LISTEN_FDS_START

> >>
> >>> a.1) If not available needs to disable that service? Because I don't
> >>> think BSD has support for systemd.
> >>
> >> <nod>
> >>
> >>> b) .github/workflow/*.yml files need to be adjusted to add in the new
> >>> dependency.
> >>
> >> Oh, ok.  The 'apt install' lines should probably add in systemd-dev.
> >>
> >>> Please also have a look at checkpatch (which is a plain linux copy) and
> >>> the spelling test failures.
> >>
> >> Ok, will do.
> > 
> > ...and the immediate problem that I run into is that all the logs are
> > hidden behind a login wall so I cannot read them. :(
> > 
> > (It leaked enough about the spelling errors that I can fix those, and
> > I can run checkpatch locally, but I don't know what else went wrong with
> > the bsd build or the abi check.)
> > 
> 
> 
> BSD errors are actually a bit tricky, because it runs them in a VM, one has
> to look at "raw logs". I think ABI checks are failling as the normal build
> test because of the meson issue.
> BSD is this
> 
> 2026-03-04T13:17:20.5979965Z [14/82] cc -Ilib/libfuse3.so.3.19.0.p -Ilib -I../lib -Iinclude -I../include -I. -I.. -fdiagnostics-color=always -Wall -Winvalid-pch -Wextra -std=gnu11 -O2 -g -D_REENTRANT -DHAVE_LIBFUSE_PRIVATE_CONFIG_H -Wno-sign-compare -D_FILE_OFFSET_BITS=64 -Wstrict-prototypes -Wmissing-declarations -Wwrite-strings -fno-strict-aliasing -fPIC -pthread -DFUSE_USE_VERSION=317 '-DFUSERMOUNT_DIR="/usr/local/bin"' -MD -MQ lib/libfuse3.so.3.19.0.p/fuse_service_stub.c.o -MF lib/libfuse3.so.3.19.0.p/fuse_service_stub.c.o.d -o lib/libfuse3.so.3.19.0.p/fuse_service_stub.c.o -c ../lib/fuse_service_stub.c
> 2026-03-04T13:17:20.6004021Z FAILED: [code=1] lib/libfuse3.so.3.19.0.p/fuse_service_stub.c.o 
> 2026-03-04T13:17:20.6008119Z cc -Ilib/libfuse3.so.3.19.0.p -Ilib -I../lib -Iinclude -I../include -I. -I.. -fdiagnostics-color=always -Wall -Winvalid-pch -Wextra -std=gnu11 -O2 -g -D_REENTRANT -DHAVE_LIBFUSE_PRIVATE_CONFIG_H -Wno-sign-compare -D_FILE_OFFSET_BITS=64 -Wstrict-prototypes -Wmissing-declarations -Wwrite-strings -fno-strict-aliasing -fPIC -pthread -DFUSE_USE_VERSION=317 '-DFUSERMOUNT_DIR="/usr/local/bin"' -MD -MQ lib/libfuse3.so.3.19.0.p/fuse_service_stub.c.o -MF lib/libfuse3.so.3.19.0.p/fuse_service_stub.c.o.d -o lib/libfuse3.so.3.19.0.p/fuse_service_stub.c.o -c ../lib/fuse_service_stub.c
> 2026-03-04T13:17:20.6012011Z In file included from ../lib/fuse_service_stub.c:21:
> 2026-03-04T13:17:20.6013206Z ../include/fuse_service_priv.h:12:2: error: unknown type name '__be32'
> 2026-03-04T13:17:20.6013899Z    12 |         __be32 pos;
> 2026-03-04T13:17:20.6014268Z       |         ^
> 2026-03-04T13:17:20.6014789Z ../include/fuse_service_priv.h:13:2: error: unknown type name '__be32'
> 2026-03-04T13:17:20.6015421Z    13 |         __be32 len;
> 2026-03-04T13:17:20.6015779Z       |         ^
> 2026-03-04T13:17:20.6016510Z ../include/fuse_service_priv.h:17:2: error: unknown type name '__be32'
> 2026-03-04T13:17:20.6017130Z    17 |         __be32 magic;
> 2026-03-04T13:17:20.6017506Z       |         ^
> 2026-03-04T13:17:20.6018004Z ../include/fuse_service_priv.h:18:2: error: unknown type name '__be32'
> 2026-03-04T13:17:20.6018615Z    18 |         __be32 argc;
> 2026-03-04T13:17:20.6018988Z       |         ^

Hrmm, well at least on BSD I see that it's building the service stub,
which means that it didn't actually try to build any of the real systemd
service stuff at all.  I think this is due to fuse_service_stub.c
including fuse_service_priv.h unnecessarily.

--D

> 
> 
> Cheers,
> Bernd
>