Honor the expected behavior of syncfs() to synchronously flush all data
and metadata to disk on linux systems.
If virtiofsd is started with '-o announce_submounts', the client is
expected to send a FUSE_SYNCFS request for each individual submount.
In this case, we just create a new file descriptor on the submount
inode with lo_inode_open(), call syncfs() on it and close it. The
intermediary file is needed because O_PATH descriptors aren't
backed by an actual file and syncfs() would fail with EBADF.
If virtiofsd is started without '-o announce_submounts' or if the
client doesn't have the FUSE_CAP_SUBMOUNTS capability, the client
only sends a single FUSE_SYNCFS request for the root inode. The
server would thus need to track submounts internally and call
syncfs() on each of them. This will be implemented later.
Note that syncfs() might suffer from a time penalty if the submounts
are being hammered by some unrelated workload on the host. The only
solution to prevent that is to avoid shared mounts.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20220215181529.164070-2-groug@kaod.org>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
The virtiofsd currently crashes when used with glibc 2.35.
That is due to the rseq system call being added to every thread
creation [1][2].
[1]: https://www.efficios.com/blog/2019/02/08/linux-restartable-sequences/
[2]: https://sourceware.org/pipermail/libc-alpha/2022-February/136040.html
This happens not at daemon start, but when a guest connects
/usr/lib/qemu/virtiofsd -f --socket-path=/tmp/testvfsd -o sandbox=chroot \
-o source=/var/guests/j-virtiofs --socket-group=kvm
virtio_session_mount: Waiting for vhost-user socket connection...
# start ok, now guest will connect
virtio_session_mount: Received vhost-user socket connection
virtio_loop: Entry
fv_queue_set_started: qidx=0 started=1
fv_queue_set_started: qidx=1 started=1
Bad system call (core dumped)
We have to put rseq on the seccomp allowlist to avoid that the daemon
is crashing in this case.
Reported-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 20220209111456.3328420-1-christian.ehrhardt@canonical.com
[Moved rseq to its alphabetically ordered position in the seccomp
allowlist.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The virtiofsd currently crashes on s390x when doing something like
this in the guest:
mkdir -p /mnt/myfs
mount -t virtiofs myfs /mnt/myfs
touch /mnt/myfs/foo.txt
stat -f /mnt/myfs/foo.txt
The problem is that the fstatfs64 syscall is called in this case
from the virtiofsd. We have to put it on the seccomp allowlist to
avoid that the daemon gets killed in this case.
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2001728
Suggested-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210914123214.181885-1-thuth@redhat.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Patches in this series are going to make use of "umask" syscall.
So allow it.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20210622150852.1507204-5-vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Follow the inclusive terminology from the "Conscious Language in your
Open Source Projects" guidelines [*] and replace the words "whitelist"
appropriately.
[*] https://github.com/conscious-lang/conscious-lang-docs/blob/main/faq.md
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210205171817.2108907-3-philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This is how linux restarts some system calls after SIGSTOP/SIGCONT.
This is needed to avoid virtiofsd termination when resuming execution
under GDB for example.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210201193305.136390-1-groug@kaod.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This is how glibc implements lseek(2) on POWER.
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1917692
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210121171540.1449777-1-groug@kaod.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes, with the changes
to the following files manually reverted:
contrib/libvhost-user/libvhost-user-glib.h
contrib/libvhost-user/libvhost-user.c
contrib/libvhost-user/libvhost-user.h
contrib/plugins/hotblocks.c
contrib/plugins/hotpages.c
contrib/plugins/howvec.c
contrib/plugins/lockstep.c
linux-user/mips64/cpu_loop.c
linux-user/mips64/signal.c
linux-user/sparc64/cpu_loop.c
linux-user/sparc64/signal.c
linux-user/x86_64/cpu_loop.c
linux-user/x86_64/signal.c
target/s390x/gen-features.c
tests/fp/platform.h
tests/migration/s390x/a-b-bios.c
tests/plugin/bb.c
tests/plugin/empty.c
tests/plugin/insn.c
tests/plugin/mem.c
tests/test-rcu-simpleq.c
tests/test-rcu-slist.c
tests/test-rcu-tailq.c
tests/uefi-test-tools/UefiTestToolsPkg/BiosTablesTest/BiosTablesTest.c
contrib/plugins/, tests/plugin/, and tests/test-rcu-slist.c appear not
to include osdep.h intentionally. The remaining reverts are the same
as in commit bbfff19688.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201113061216.2483385-1-armbru@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Alexander Bulekov <alxndr@bu.edu>
Using st_dev is not sufficient to uniquely identify a mount: You can
mount the same device twice, but those are still separate trees, and
e.g. by mounting something else inside one of them, they may differ.
Using statx(), we can get a mount ID that uniquely identifies a mount.
If that is available, add it to the lo_inode key.
Most of this patch is taken from Miklos's mail here:
https://marc.info/?l=fuse-devel&m=160062521827983
(virtiofsd-use-mount-id.patch attachment)
Suggested-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20201102161859.156603-5-mreitz@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
On ppc, and some other archs, it looks like syslog ends up using 'send'
rather than 'sendto'.
Reference: https://github.com/kata-containers/kata-containers/issues/1050
Reported-by: amulmek1@in.ibm.com
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20201102150750.34565-1-dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
glib offers thread pools and it seems to support "exclusive" and "shared"
thread pools.
https://developer.gnome.org/glib/stable/glib-Thread-Pools.html#g-thread-pool-new
Currently we use "exlusive" thread pools but its performance seems to be
poor. I tried using "shared" thread pools and performance seems much
better. I posted performance results here.
https://www.redhat.com/archives/virtio-fs/2020-September/msg00080.html
So lets switch to shared thread pools. We can think of making it optional
once somebody can show in what cases exclusive thread pools offer better
results. For now, my simple performance tests across the board see
better results with shared thread pools.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20200921213216.GE13362@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
With seccomp fix from Miklos
Greg Kurz
Christian Ehrhardt
Thomas Huth
Vivek Goyal
Philippe Mathieu-Daudé
Markus Armbruster
Max Reitz
Dr. David Alan Gilbert
Paolo Bonzini