qemu/tools/virtiofsd
Greg Kurz 45b04ef48d virtiofsd: Add basic support for FUSE_SYNCFS request
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>
2022-02-17 17:22:26 +00:00
..
50-qemu-virtiofsd.json.in virtiofsd: add vhost-user.json file 2020-01-23 16:41:36 +00:00
buffer.c tools/virtiofsd/buffer.c: replaced a calloc call with GLib's g_try_new0 2021-05-26 18:39:32 +01:00
fuse_common.h virtiofsd, fuse_lowlevel.c: Add capability to parse security context 2022-02-17 17:22:26 +00:00
fuse_i.h virtiofsd, fuse_lowlevel.c: Add capability to parse security context 2022-02-17 17:22:26 +00:00
fuse_log.c Clean up includes 2020-12-10 17:16:44 +01:00
fuse_log.h Clean up includes 2020-12-10 17:16:44 +01:00
fuse_lowlevel.c virtiofsd: Add basic support for FUSE_SYNCFS request 2022-02-17 17:22:26 +00:00
fuse_lowlevel.h virtiofsd: Add basic support for FUSE_SYNCFS request 2022-02-17 17:22:26 +00:00
fuse_misc.h Clean up includes 2020-12-10 17:16:44 +01:00
fuse_opt.c tools/virtiofsd/fuse_opt.c: Replaced a malloc with GLib's g_try_malloc 2021-05-26 18:39:32 +01:00
fuse_opt.h virtiofsd: Format imported files to qemu style 2020-01-23 16:41:36 +00:00
fuse_signals.c Clean up includes 2020-12-10 17:16:44 +01:00
fuse_virtio.c virtiofsd: Error on bad socket group name 2021-10-25 19:38:32 +01:00
fuse_virtio.h virtiofsd: cleanup allocated resource in se 2020-01-23 16:41:37 +00:00
helper.c virtiofsd: Add an option to enable/disable security label 2022-02-17 17:22:26 +00:00
meson.build libvhost-user: make it a meson subproject 2020-12-08 13:48:58 -05:00
passthrough_helpers.h virtiofsd: Format imported files to qemu style 2020-01-23 16:41:36 +00:00
passthrough_ll.c virtiofsd: Add basic support for FUSE_SYNCFS request 2022-02-17 17:22:26 +00:00
passthrough_seccomp.c virtiofsd: Add basic support for FUSE_SYNCFS request 2022-02-17 17:22:26 +00:00
passthrough_seccomp.h Clean up includes 2020-12-10 17:16:44 +01:00