virtiofsd pull 2020-02-10

Coverity fixes and a reworked man page.
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Merge remote-tracking branch 'remotes/dgilbert-gitlab/tags/pull-virtiofs-20200210' into staging

virtiofsd pull 2020-02-10

Coverity fixes and a reworked man page.

# gpg: Signature made Mon 10 Feb 2020 17:26:29 GMT
# gpg:                using RSA key 45F5C71B4A0CB7FB977A9FA90516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>" [full]
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* remotes/dgilbert-gitlab/tags/pull-virtiofs-20200210:
  docs: add virtiofsd(1) man page
  virtiofsd: do_read missing NULL check
  virtiofsd: load_capng missing unlock
  virtiofsd: fv_create_listen_socket error path socket leak
  virtiofsd: Remove fuse_req_getgroups

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Maydell 2020-02-10 18:09:14 +00:00
commit e18e5501d8
10 changed files with 141 additions and 120 deletions

View File

@ -1613,6 +1613,7 @@ S: Supported
F: tools/virtiofsd/*
F: hw/virtio/vhost-user-fs*
F: include/hw/virtio/vhost-user-fs.h
F: docs/interop/virtiofsd.rst
virtio-input
M: Gerd Hoffmann <kraxel@redhat.com>

View File

@ -348,6 +348,9 @@ DOCS=qemu-doc.html qemu-doc.txt qemu.1
DOCS+=$(MANUAL_BUILDDIR)/interop/qemu-img.1
DOCS+=$(MANUAL_BUILDDIR)/interop/qemu-nbd.8
DOCS+=$(MANUAL_BUILDDIR)/interop/qemu-ga.8
ifeq ($(CONFIG_LINUX)$(CONFIG_SECCOMP)$(CONFIG_LIBCAP_NG),yyy)
DOCS+=$(MANUAL_BUILDDIR)/interop/virtiofsd.1
endif
DOCS+=$(MANUAL_BUILDDIR)/system/qemu-block-drivers.7
DOCS+=docs/interop/qemu-qmp-ref.html docs/interop/qemu-qmp-ref.txt docs/interop/qemu-qmp-ref.7
DOCS+=docs/interop/qemu-ga-ref.html docs/interop/qemu-ga-ref.txt docs/interop/qemu-ga-ref.7
@ -861,6 +864,9 @@ ifdef CONFIG_VIRTFS
$(INSTALL_DIR) "$(DESTDIR)$(mandir)/man1"
$(INSTALL_DATA) $(MANUAL_BUILDDIR)/interop/virtfs-proxy-helper.1 "$(DESTDIR)$(mandir)/man1"
endif
ifeq ($(CONFIG_LINUX)$(CONFIG_SECCOMP)$(CONFIG_LIBCAP_NG),yyy)
$(INSTALL_DATA) docs/interop/virtiofsd.1 "$(DESTDIR)$(mandir)/man1"
endif
install-datadir:
$(INSTALL_DIR) "$(DESTDIR)$(qemu_datadir)"
@ -1051,7 +1057,8 @@ $(MANUAL_BUILDDIR)/system/index.html: $(call manual-deps,system)
$(call build-manual,system,html)
$(call define-manpage-rule,interop,\
qemu-ga.8 qemu-img.1 qemu-nbd.8 qemu-trace-stap.1 virtfs-proxy-helper.1,\
qemu-ga.8 qemu-img.1 qemu-nbd.8 qemu-trace-stap.1\
virtiofsd.1 virtfs-proxy-helper.1,\
$(SRC_PATH/qemu-img-cmds.hx))
$(call define-manpage-rule,system,qemu-block-drivers.7)

View File

@ -27,5 +27,8 @@ man_pages = [
[], 1),
('virtfs-proxy-helper', 'virtfs-proxy-helper',
u'QEMU 9p virtfs proxy filesystem helper',
['M. Mohan Kumar'], 1)
['M. Mohan Kumar'], 1),
('virtiofsd', 'virtiofsd', u'QEMU virtio-fs shared file system daemon',
['Stefan Hajnoczi <stefanha@redhat.com>',
'Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>'], 1),
]

View File

@ -24,3 +24,4 @@ Contents:
vhost-user
vhost-user-gpu
virtfs-proxy-helper
virtiofsd

120
docs/interop/virtiofsd.rst Normal file
View File

@ -0,0 +1,120 @@
QEMU virtio-fs shared file system daemon
========================================
Synopsis
--------
**virtiofsd** [*OPTIONS*]
Description
-----------
Share a host directory tree with a guest through a virtio-fs device. This
program is a vhost-user backend that implements the virtio-fs device. Each
virtio-fs device instance requires its own virtiofsd process.
This program is designed to work with QEMU's ``--device vhost-user-fs-pci``
but should work with any virtual machine monitor (VMM) that supports
vhost-user. See the Examples section below.
This program must be run as the root user. Upon startup the program will
switch into a new file system namespace with the shared directory tree as its
root. This prevents "file system escapes" due to symlinks and other file
system objects that might lead to files outside the shared directory. The
program also sandboxes itself using seccomp(2) to prevent ptrace(2) and other
vectors that could allow an attacker to compromise the system after gaining
control of the virtiofsd process.
Options
-------
.. program:: virtiofsd
.. option:: -h, --help
Print help.
.. option:: -V, --version
Print version.
.. option:: -d
Enable debug output.
.. option:: --syslog
Print log messages to syslog instead of stderr.
.. option:: -o OPTION
* debug -
Enable debug output.
* flock|no_flock -
Enable/disable flock. The default is ``no_flock``.
* log_level=LEVEL -
Print only log messages matching LEVEL or more severe. LEVEL is one of
``err``, ``warn``, ``info``, or ``debug``. The default is ``info``.
* norace -
Disable racy fallback. The default is false.
* posix_lock|no_posix_lock -
Enable/disable remote POSIX locks. The default is ``posix_lock``.
* readdirplus|no_readdirplus -
Enable/disable readdirplus. The default is ``readdirplus``.
* source=PATH -
Share host directory tree located at PATH. This option is required.
* timeout=TIMEOUT -
I/O timeout in seconds. The default depends on cache= option.
* writeback|no_writeback -
Enable/disable writeback cache. The cache alows the FUSE client to buffer
and merge write requests. The default is ``no_writeback``.
* xattr|no_xattr -
Enable/disable extended attributes (xattr) on files and directories. The
default is ``no_xattr``.
.. option:: --socket-path=PATH
Listen on vhost-user UNIX domain socket at PATH.
.. option:: --fd=FDNUM
Accept connections from vhost-user UNIX domain socket file descriptor FDNUM.
The file descriptor must already be listening for connections.
.. option:: --thread-pool-size=NUM
Restrict the number of worker threads per request queue to NUM. The default
is 64.
.. option:: --cache=none|auto|always
Select the desired trade-off between coherency and performance. ``none``
forbids the FUSE client from caching to achieve best coherency at the cost of
performance. ``auto`` acts similar to NFS with a 1 second metadata cache
timeout. ``always`` sets a long cache lifetime at the expense of coherency.
Examples
--------
Export ``/var/lib/fs/vm001/`` on vhost-user UNIX domain socket
``/var/run/vm001-vhost-fs.sock``:
::
host# virtiofsd --socket-path=/var/run/vm001-vhost-fs.sock -o source=/var/lib/fs/vm001
host# qemu-system-x86_64 \
-chardev socket,id=char0,path=/var/run/vm001-vhost-fs.sock \
-device vhost-user-fs-pci,chardev=char0,tag=myfs \
-object memory-backend-memfd,id=mem,size=4G,share=on \
-numa node,memdev=mem \
...
guest# mount -t virtiofs myfs /mnt

View File

@ -1006,26 +1006,6 @@ void fuse_exit(struct fuse *f);
*/
struct fuse_context *fuse_get_context(void);
/**
* Get the current supplementary group IDs for the current request
*
* Similar to the getgroups(2) system call, except the return value is
* always the total number of group IDs, even if it is larger than the
* specified size.
*
* The current fuse kernel module in linux (as of 2.6.30) doesn't pass
* the group list to userspace, hence this function needs to parse
* "/proc/$TID/task/$TID/status" to get the group IDs.
*
* This feature may not be supported on all operating systems. In
* such a case this function will return -ENOSYS.
*
* @param size size of given array
* @param list array of group IDs to be filled in
* @return the total number of supplementary group IDs or -errno on failure
*/
int fuse_getgroups(int size, gid_t list[]);
/**
* Check if the current request has already been interrupted
*

View File

@ -1116,6 +1116,10 @@ static void do_read(fuse_req_t req, fuse_ino_t nodeid,
struct fuse_file_info fi;
arg = fuse_mbuf_iter_advance(iter, sizeof(*arg));
if (!arg) {
fuse_reply_err(req, EINVAL);
return;
}
memset(&fi, 0, sizeof(fi));
fi.fh = arg->fh;
@ -2667,83 +2671,6 @@ int fuse_lowlevel_is_virtio(struct fuse_session *se)
return !!se->virtio_dev;
}
#ifdef linux
int fuse_req_getgroups(fuse_req_t req, int size, gid_t list[])
{
char *buf;
size_t bufsize = 1024;
char path[128];
int ret;
int fd;
unsigned long pid = req->ctx.pid;
char *s;
sprintf(path, "/proc/%lu/task/%lu/status", pid, pid);
retry:
buf = malloc(bufsize);
if (buf == NULL) {
return -ENOMEM;
}
ret = -EIO;
fd = open(path, O_RDONLY);
if (fd == -1) {
goto out_free;
}
ret = read(fd, buf, bufsize);
close(fd);
if (ret < 0) {
ret = -EIO;
goto out_free;
}
if ((size_t)ret == bufsize) {
free(buf);
bufsize *= 4;
goto retry;
}
ret = -EIO;
s = strstr(buf, "\nGroups:");
if (s == NULL) {
goto out_free;
}
s += 8;
ret = 0;
while (1) {
char *end;
unsigned long val = strtoul(s, &end, 0);
if (end == s) {
break;
}
s = end;
if (ret < size) {
list[ret] = val;
}
ret++;
}
out_free:
free(buf);
return ret;
}
#else /* linux */
/*
* This is currently not implemented on other than Linux...
*/
int fuse_req_getgroups(fuse_req_t req, int size, gid_t list[])
{
(void)req;
(void)size;
(void)list;
return -ENOSYS;
}
#endif
void fuse_session_exit(struct fuse_session *se)
{
se->exited = 1;

View File

@ -1704,27 +1704,6 @@ void *fuse_req_userdata(fuse_req_t req);
*/
const struct fuse_ctx *fuse_req_ctx(fuse_req_t req);
/**
* Get the current supplementary group IDs for the specified request
*
* Similar to the getgroups(2) system call, except the return value is
* always the total number of group IDs, even if it is larger than the
* specified size.
*
* The current fuse kernel module in linux (as of 2.6.30) doesn't pass
* the group list to userspace, hence this function needs to parse
* "/proc/$TID/task/$TID/status" to get the group IDs.
*
* This feature may not be supported on all operating systems. In
* such a case this function will return -ENOSYS.
*
* @param req request handle
* @param size size of given array
* @param list array of group IDs to be filled in
* @return the total number of supplementary group IDs or -errno on failure
*/
int fuse_req_getgroups(fuse_req_t req, int size, gid_t list[]);
/**
* Callback function for an interrupt
*

View File

@ -916,6 +916,7 @@ static int fv_create_listen_socket(struct fuse_session *se)
old_umask = umask(0077);
if (bind(listen_sock, (struct sockaddr *)&un, addr_len) == -1) {
fuse_log(FUSE_LOG_ERR, "vhost socket bind: %m\n");
close(listen_sock);
umask(old_umask);
return -1;
}
@ -923,6 +924,7 @@ static int fv_create_listen_socket(struct fuse_session *se)
if (listen(listen_sock, 1) == -1) {
fuse_log(FUSE_LOG_ERR, "vhost socket listen: %m\n");
close(listen_sock);
return -1;
}

View File

@ -232,6 +232,7 @@ static int load_capng(void)
*/
cap.saved = capng_save_state();
if (!cap.saved) {
pthread_mutex_unlock(&cap.mutex);
fuse_log(FUSE_LOG_ERR, "capng_save_state (thread)\n");
return -EINVAL;
}