When running with multiple threads it can be tricky to handle
FUSE_INIT/FUSE_DESTROY in parallel with other request types or in
parallel with themselves. Serialize FUSE_INIT and FUSE_DESTROY so that
malicious clients cannot trigger race conditions.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Introduce a thread pool so that fv_queue_thread() just pops
VuVirtqElements and hands them to the thread pool. For the time being
only one worker thread is allowed since passthrough_ll.c is not
thread-safe yet. Future patches will lift this restriction so that
multiple FUSE requests can be processed in parallel.
The main new concept is struct FVRequest, which contains both
VuVirtqElement and struct fuse_chan. We now have fv_VuDev for a device,
fv_QueueInfo for a virtqueue, and FVRequest for a request. Some of
fv_QueueInfo's fields are moved into FVRequest because they are
per-request. The name FVRequest conforms to QEMU coding style and I
expect the struct fv_* types will be renamed in a future refactoring.
This patch series is not optimal. fbuf reuse is dropped so each request
does malloc(se->bufsize), but there is no clean and cheap way to keep
this with a thread pool. The vq_lock mutex is held for longer than
necessary, especially during the eventfd_write() syscall. Performance
can be improved in the future.
prctl(2) had to be added to the seccomp whitelist because glib invokes
it.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
fuse_buf_writev() only handles the normal write in which src is buffer
and dest is fd. Specially if src buffer represents guest physical
address that can't be mapped by the daemon process, IO must be bounced
back to the VMM to do it by fuse_buf_copy().
Signed-off-by: Jun Piao <piaojun@huawei.com>
Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Define fuse_buf_writev() which use pwritev and writev to improve io
bandwidth. Especially, the src bufs with 0 size should be skipped as
their mems are not *block_size* aligned which will cause writev failed
in direct io mode.
Signed-off-by: Jun Piao <piaojun@huawei.com>
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Since keep_cache(FOPEN_KEEP_CACHE) has no effect for directory as
described in fuse_common.h, use cache_readdir(FOPNE_CACHE_DIR) for
diretory open when cache=always mode.
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
When writeback mode is enabled (-o writeback), O_APPEND handling is
done in kernel. Therefore virtiofsd clears O_APPEND flag when open.
Otherwise O_APPEND flag takes precedence over pwrite() and write
data may corrupt.
Currently clearing O_APPEND flag is done in lo_open(), but we also
need the same operation in lo_create(). So, factor out the flag
update operation in lo_open() to update_open_flags() and call it
in both lo_open() and lo_create().
This fixes the failure of xfstest generic/069 in writeback mode
(which tests O_APPEND write data integrity).
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
If an application wants to do direct IO and opens a file with O_DIRECT
in guest, that does not necessarily mean that we need to bypass page
cache on host as well. So reset this flag on host.
If somebody needs to bypass page cache on host as well (and it is safe to
do so), we can add a knob in daemon later to control this behavior.
I check virtio-9p and they do reset O_DIRECT flag.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Eryu Guan <eguan@linux.alibaba.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Right now we always enable it regardless of given commandlines.
Fix it by setting the flag relying on the lo->flock bit.
Signed-off-by: Peng Tao <tao.peng@linux.alibaba.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
If thread A is using an inode it must not be deleted by thread B when
processing a FUSE_FORGET request.
The FUSE protocol itself already has a counter called nlookup that is
used in FUSE_FORGET messages. We cannot trust this counter since the
untrusted client can manipulate it via FUSE_FORGET messages.
Introduce a new refcount to keep inodes alive for the required lifespan.
lo_inode_put() must be called to release a reference. FUSE's nlookup
counter holds exactly one reference so that the inode stays alive as
long as the client still wants to remember it.
Note that the lo_inode->is_symlink field is moved to avoid creating a
hole in the struct due to struct field alignment.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This reference counter plays a specific role in the FUSE protocol. It's
not a generic object reference counter and the FUSE kernel code calls it
"nlookup".
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Introduce lo_dirp_put() so that FUSE_RELEASEDIR does not cause
use-after-free races with other threads that are accessing lo_dirp.
Also make lo_releasedir() atomic to prevent FUSE_RELEASEDIR racing with
itself. This prevents double-frees.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Hold the lock across both lo_map_get() and lo_map_remove() to prevent
races between two FUSE_RELEASE requests. In this case I don't see a
serious bug but it's safer to do things atomically.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
We call into libvhost-user from the virtqueue handler thread and the
vhost-user message processing thread without a lock. There is nothing
protecting the virtqueue handler thread if the vhost-user message
processing thread changes the virtqueue or memory table while it is
running.
This patch introduces a read-write lock. Virtqueue handler threads are
readers. The vhost-user message processing thread is a writer. This
will allow concurrency for multiqueue in the future while protecting
against fv_queue_thread() vs virtio_loop() races.
Note that the critical sections could be made smaller but it would be
more invasive and require libvhost-user changes. Let's start simple and
improve performance later, if necessary. Another option would be an
RCU-style approach with lighter-weight primitives.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
vu_socket_path is NULL when --fd=FDNUM was used. Use
fuse_lowlevel_is_virtio() instead.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Doing posix locks with-in guest kernel are not sufficient if a file/dir
is being shared by multiple guests. So we need the notion of daemon doing
the locks which are visible to rest of the guests.
Given posix locks are per process, one can not call posix lock API on host,
otherwise bunch of basic posix locks properties are broken. For example,
If two processes (A and B) in guest open the file and take locks on different
sections of file, if one of the processes closes the fd, it will close
fd on virtiofsd and all posix locks on file will go away. This means if
process A closes the fd, then locks of process B will go away too.
Similar other problems exist too.
This patch set tries to emulate posix locks while using open file
description locks provided on Linux.
Daemon provides two options (-o posix_lock, -o no_posix_lock) to enable
or disable posix locking in daemon. By default it is enabled.
There are few issues though.
- GETLK() returns pid of process holding lock. As we are emulating locks
using OFD, and these locks are not per process and don't return pid
of process, so GETLK() in guest does not reuturn process pid.
- As of now only F_SETLK is supported and not F_SETLKW. We can't block
the thread in virtiofsd for arbitrary long duration as there is only
one thread serving the queue. That means unlock request will not make
it to daemon and F_SETLKW will block infinitely and bring virtio-fs
to a halt. This is a solvable problem though and will require significant
changes in virtiofsd and kernel. Left as a TODO item for now.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
For fuse's queueinfo, both queueinfo array and queueinfos are allocated in
fv_queue_set_started() but not cleaned up when the daemon process quits.
This fixes the leak in proper places.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Eric Ren <renzhen@linux.alibaba.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Eric Ren <renzhen@linux.alibaba.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
lookup is a RO operations, PARALLEL_DIROPS can be enabled.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
virtiofsd can run multiply even if the vhost_user_socket is same path.
]# ./virtiofsd -o vhost_user_socket=/tmp/vhostqemu -o source=/tmp/share &
[1] 244965
virtio_session_mount: Waiting for vhost-user socket connection...
]# ./virtiofsd -o vhost_user_socket=/tmp/vhostqemu -o source=/tmp/share &
[2] 244966
virtio_session_mount: Waiting for vhost-user socket connection...
]#
The user will get confused about the situation and maybe the cause of the
unexpected problem. So it's better to prevent the multiple running.
Create a regular file under localstatedir directory to exclude the
vhost_user_socket. To create and lock the file, use qemu_write_pidfile()
because the API has some sanity checks and file lock.
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Applied fixes from Stefan's review and moved osdep include
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This offers an helper function for lo_data's cleanup.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
valgrind reported that lo.source is leaked on quiting, but it was defined
as (const char*) as it may point to a const string "/".
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This cleans up unfreed resources in se on quiting, including
se->virtio_dev, se->vu_socket_path, se->vu_socketfd.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Neither fuse_parse_cmdline() nor fuse_opt_parse() goes to the right place
to do cleanup.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Define HAVE_STRUCT_STAT_ST_ATIM to 1 if `st_atim' is member of `struct
stat' which means support nanosecond resolution for the file timestamp
fields.
Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Clear out our inodes and fd's on a 'destroy' - so we get rid
of them if we reboot the guest.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Improve performance of inode lookup by using a hash table.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
- Rename "cache=never" to "cache=none" to match 9p's similar option.
- Rename CACHE_NORMAL constant to CACHE_AUTO to match the "cache=auto"
option.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Inititialize the root inode in a single place.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
dgilbert:
with fix suggested by Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
The Linux file handle APIs (struct export_operations) can access inodes
that are not attached to parents because path name traversal is not
performed. Refuse if there is no parent in lo_do_lookup().
Also clean up lo_do_lookup() while we're here.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
...because the attributes sent in the READDIRPLUS reply would be discarded
anyway.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Kill the threads we've started when the queues get stopped.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
With improvements by:
Signed-off-by: Eryu Guan <eguan@linux.alibaba.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Handle a
mount
hard reboot (without unmount)
mount
we get another 'init' which FUSE doesn't normally expect.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Allow init->destroy->init for mount->umount->mount
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
virtiofsd has some threads, so we see a lot of logs with debug option.
It would be useful for debugging if we can see the timestamp.
Add nano second timestamp, which got by get_clock(), to the log with
FUSE_LOG_DEBUG level if the syslog option isn't set.
The log is like as:
# ./virtiofsd -d -o vhost_user_socket=/tmp/vhostqemu0 -o source=/tmp/share0 -o cache=auto
...
[5365943125463727] [ID: 00000002] fv_queue_thread: Start for queue 0 kick_fd 9
[5365943125568644] [ID: 00000002] fv_queue_thread: Waiting for Queue 0 event
[5365943125573561] [ID: 00000002] fv_queue_thread: Got queue event on Queue 0
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
virtiofsd has some threads, so we see a lot of logs with debug option.
It would be useful for debugging if we can identify the specific thread
from the log.
Add ID, which is got by gettid(), to the log with FUSE_LOG_DEBUG level
so that we can grep the specific thread.
The log is like as:
]# ./virtiofsd -d -o vhost_user_socket=/tmp/vhostqemu0 -o source=/tmp/share0 -o cache=auto
...
[ID: 00000097] unique: 12696, success, outsize: 120
[ID: 00000097] virtio_send_msg: elem 18: with 2 in desc of length 120
[ID: 00000003] fv_queue_thread: Got queue event on Queue 1
[ID: 00000003] fv_queue_thread: Queue 1 gave evalue: 1 available: in: 65552 out: 80
[ID: 00000003] fv_queue_thread: Waiting for Queue 1 event
[ID: 00000071] fv_queue_worker: elem 33: with 2 out desc of length 80 bad_in_num=0 bad_out_num=0
[ID: 00000071] unique: 12694, opcode: READ (15), nodeid: 2, insize: 80, pid: 2014
[ID: 00000071] lo_read(ino=2, size=65536, off=131072)
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
added rework as suggested by Daniel P. Berrangé during review
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Introduce "-o log_level=" command line option to specify current log
level (priority), valid values are "debug info warn err", e.g.
./virtiofsd -o log_level=debug ...
So only log priority higher than "debug" will be printed to
stderr/syslog. And the default level is info.
The "-o debug"/"-d" options are kept, and imply debug log level.
Signed-off-by: Eryu Guan <eguan@linux.alibaba.com>
dgilbert: Reworked for libfuse's log_func
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
with fix by:
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Sometimes collecting output from stderr is inconvenient or does not fit
within the overall logging architecture. Add syslog(3) support for
cases where stderr cannot be used.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
dgilbert: Reworked as a logging function
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Some FUSE message replies contain padding fields that are not
initialized by libfuse. This is fine in traditional FUSE applications
because the kernel is trusted. virtiofsd does not trust the guest and
must not expose uninitialized memory.
Use C struct initializers to automatically zero out memory. Not all of
these code changes are strictly necessary but they will prevent future
information leaks if the structs are extended.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
virtiofsd can exceed the default open file descriptor limit easily on
most systems. Take advantage of the fact that it runs as root to raise
the limit.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
If client requested killing setuid/setgid bits on file being written, drop
CAP_FSETID capability so that setuid/setgid bits are cleared upon write
automatically.
pjdfstest chown/12.t needs this.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
dgilbert: reworked for libcap-ng
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
libcap-ng reads /proc during capng_get_caps_process, and virtiofsd's
sandboxing doesn't have /proc mounted; thus we have to do the
caps read before we sandbox it and save/restore the state.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Caller can set FUSE_WRITE_KILL_PRIV in write_flags. Parse it and pass it
to the filesystem.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Only allow system calls that are needed by virtiofsd. All other system
calls cause SIGSYS to be directed at the thread and the process will
coredump.
Restricting system calls reduces the kernel attack surface and limits
what the process can do when compromised.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
with additional entries by:
Signed-off-by: Ganesh Maharaj Mahalingam <ganesh.mahalingam@intel.com>
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: piaojun <piaojun@huawei.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Eric Ren <renzhen@linux.alibaba.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
virtiofsd needs access to /proc/self/fd. Let's move to a new pid
namespace so that a compromised process cannot see another other
processes running on the system.
One wrinkle in this approach: unshare(CLONE_NEWPID) affects *child*
processes and not the current process. Therefore we need to fork the
pid 1 process that will actually run virtiofsd and leave a parent in
waitpid(2). This is not the same thing as daemonization and parent
processes should not notice a difference.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
If the process is compromised there should be no network access. Use an
empty network namespace to sandbox networking.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Use a mount namespace with the shared directory tree mounted at "/" and
no other mounts.
This prevents symlink escape attacks because symlink targets are
resolved only against the shared directory and cannot go outside it.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Peng Tao <tao.peng@linux.alibaba.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Sandboxing will remove /proc from the mount namespace so we can no
longer build string paths into "/proc/self/fd/...".
Keep an O_PATH file descriptor so we can still re-open fds via
/proc/self/fd.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Construct a fake dirent for the root directory's ".." entry. This hides
the parent directory from the FUSE client.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Each FUSE operation involves parsing the input buffer. Currently the
code assumes the input buffer is large enough for the expected
arguments. This patch uses fuse_mbuf_iter to check the size.
Most operations are simple to convert. Some are more complicated due to
variable-length inputs or different sizes depending on the protocol
version.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
There is a small change in behavior: if fuse_write_in->size doesn't
match the input buffer size then the request is failed. Previously
write requests with 1 fuse_buf element would truncate to
fuse_write_in->size.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Introduce an API for consuming bytes from a buffer with size checks.
All FUSE operations will be converted to use this safe API instead of
void *inarg.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Pass the write iov pointing to guest RAM all the way through rather
than copying the data.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Let fuse_session_process_buf_int take a fuse_bufvec * instead of a
fuse_buf; and then through to do_write_buf - where in the best
case it can pass that straight through to op.write_buf without copying
(other than skipping a header).
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Several FUSE requests contain single path components. A correct FUSE
client sends well-formed path components but there is currently no input
validation in case something went wrong or the client is malicious.
Refuse ".", "..", and paths containing '/' when we expect a path
component.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
We have two operations that cannot be done race-free on a symlink in
certain cases: utimes and link.
Add racy fallback for these if the race-free method doesn't work. We do
our best to avoid races even in this case:
- get absolute path by reading /proc/self/fd/NN symlink
- lookup parent directory: after this we are safe against renames in
ancestors
- lookup name in parent directory, and verify that we got to the original
inode, if not retry the whole thing
Both utimes(2) and link(2) hold i_lock on the inode across the operation,
so a racing rename/delete by this fuse instance is not possible, only from
other entities changing the filesystem.
If the "norace" option is given, then disable the racy fallbacks.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Do not expose file descriptor numbers to clients. This prevents the
abuse of internal file descriptors (like stdin/stdout).
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Fix from:
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
dgilbert:
Added lseek
Reviewed-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Do not expose lo_dirp pointers to clients.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Do not expose lo_inode pointers to clients.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
A layer of indirection is needed because passthrough_ll cannot expose
pointers or file descriptor numbers to untrusted clients. Malicious
clients could send invalid pointers or file descriptors in order to
crash or exploit the file system daemon.
lo_map provides an integer key->value mapping. This will be used for
ino and fh fields in the patches that follow.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
We need to create files in the caller's context. Otherwise after
creating a file, the caller might not be able to do file operations on
that file.
Changed effective uid/gid to caller's uid/gid, create file and then
switch back to uid/gid 0.
Use syscall(setresuid, ...) otherwise glibc does some magic to change EUID
in all threads, which is not what we want.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Add the --print-capabilities option as per vhost-user.rst "Backend
programs conventions". Currently there are no advertised features.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Install a vhost-user.json file describing virtiofsd. This allows
libvirt and other management tools to enumerate vhost-user backend
programs.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
According to vhost-user.rst "Backend program conventions", backend
programs should run in the foregound by default. Follow the
conventions so libvirt and other management tools can control virtiofsd
in a standard way.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Although --socket-path=PATH is useful for manual invocations, management
tools typically create the UNIX domain socket themselves and pass it to
the vhost-user device backend. This way QEMU can be launched
immediately with a valid socket. No waiting for the vhost-user device
backend is required when fd passing is used.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Readv the data straight into the guests buffer.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
With fix by:
Signed-off-by: Eryu Guan <eguan@linux.alibaba.com>
Reviewed-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Wire up the building of the virtiofsd in tools.
virtiofsd relies on Linux-specific system calls and seccomp. Anyone
wishing to port it to other host operating systems should do so
carefully and without reducing security.
Only allow building on Linux hosts.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Keep track of whether we sent a reply to a request; this is a bit
paranoid but it means:
a) We should always recycle an element even if there was an error
in the request
b) Never try and send two replies on one queue element
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Route fuse out messages back through the same queue elements
that had the command that triggered the request.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Pop queue elements off queues, copy the data from them and
pass that to fuse.
Note: 'out' in a VuVirtqElement is from QEMU
'in' in libfuse is into the daemon
So we read from the out iov's to get a fuse_in_header
When we get a kick we've got to read all the elements until the queue
is empty.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
In the queue thread poll the kick_fd we're passed.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Start a thread for each queue when we get notified it's been started.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
fix by:
Signed-off-by: Jun Piao <piaojun@huawei.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Add the get/set features callbacks.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Processes incoming requests on the vhost-user fd.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Listen on our unix socket for the connection from QEMU, when we get it
initialise vhost-user and dive into our own loop variant (currently
dummy).
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
When run with vhost-user options we conect to the QEMU instead
via a socket. Start this off by creating the socket.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
The -o source=PATH option will be used by most command-line invocations.
Let's document it!
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Add options to specify parameters for virtio-fs paths, i.e.
./virtiofsd -o vhost_user_socket=/tmp/vhostqemu
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
If caller has not sent file handle in request, then using inode, retrieve
the fd opened using O_PATH and use that to open file again and issue
fsync. This will be needed when dax_flush() calls fsync. At that time
we only have inode information (and not file).
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
1) Use correct CONFIG_FALLOCATE macro to check if fallocate() is supported.(i.e configure
script sets CONFIG_FALLOCATE intead of HAVE_FALLOCATE if fallocate() is supported)
2) Replace HAVE_POSIX_FALLOCATE with CONFIG_POSIX_FALLOCATE.
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Merged from two of Xiao Yang's patches
virtiofsd only supports major=7, minor>=31; trim out a lot of
old compatibility code.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
All of the fuse files include config.h and define GNU_SOURCE
where we don't have either under our build - remove them.
Fixup path to the kernel's fuse.h in the QEMUs world.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
QEMU's compiler enables warnings/errors for ignored values
and the (void) trick used in the fuse code isn't enough.
Turn all the return values into a return value on the function.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Notify reply support is unused by virtiofsd. The code would need to be
updated to validate input buffer sizes. Remove this unused code since
changes to it are untestable.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Classic FUSE file system daemons take a mountpoint argument but
virtiofsd exposes a vhost-user UNIX domain socket instead. The
mountpoint argument is not used by virtiofsd but the user is still
required to pass a dummy argument on the command-line.
Remove the mountpoint argument to clean up the command-line.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
There's a lot of the original fuse code we don't need; trim them down.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
with additional trimming by:
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
passthrough_ll is one of the examples in the upstream fuse project
and is the main part of our daemon here. It passes through requests
from fuse to the underlying filesystem, using syscalls as directly
as possible.
From libfuse fuse-3.8.0
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Fixed up 'GPL' to 'GPLv2' as per Dan's comments and consistent
with the 'LICENSE' file in libfuse; patch sent to libfuse to fix
it upstream.
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
fuse_lowlevel is one of the largest files from the library
and does most of the work. Add it separately to keep the diff
sizes small.
Again this is from upstream fuse-3.8.0
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Add most of the non-main .c files we need from upstream fuse-3.8.0
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Pull in headers fromlibfuse's upstream fuse-3.8.0
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
