With the thread pool disabled, we add the requests in the queue to a GList, processing by iterating over there afterwards. For adding them, we're using "g_list_prepend()", which is more efficient but causes the requests to be processed in reverse order, breaking the read-ahead and request-merging optimizations in the host for sequential operations. According to the documentation, if you need to process the request in-order, using "g_list_prepend()" and then reversing the list with "g_list_reverse()" is more efficient than using "g_list_append()", so let's do it that way. Testing on a spinning disk (to boost the increase of read-ahead and request-merging) shows a 4x improvement on sequential write fio test: Test: fio --directory=/mnt/virtio-fs --filename=fio-file1 --runtime=20 --iodepth=16 --size=4G --direct=1 --blocksize=4K --ioengine libaio --rw write --name seqwrite-libaio Without "g_list_reverse()": ... Jobs: 1 (f=1): [W(1)][100.0%][w=22.4MiB/s][w=5735 IOPS][eta 00m:00s] seqwrite-libaio: (groupid=0, jobs=1): err= 0: pid=710: Tue Aug 24 12:58:16 2021 write: IOPS=5709, BW=22.3MiB/s (23.4MB/s)(446MiB/20002msec); 0 zone resets ... With "g_list_reverse()": ... Jobs: 1 (f=1): [W(1)][100.0%][w=84.0MiB/s][w=21.5k IOPS][eta 00m:00s] seqwrite-libaio: (groupid=0, jobs=1): err= 0: pid=716: Tue Aug 24 13:00:15 2021 write: IOPS=21.3k, BW=83.1MiB/s (87.2MB/s)(1663MiB/20001msec); 0 zone resets ... Signed-off-by: Sergio Lopez <slp@redhat.com> Message-Id: <20210824131158.39970-1-slp@redhat.com> Reviewed-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
1084 lines
32 KiB
C
1084 lines
32 KiB
C
/*
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* virtio-fs glue for FUSE
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* Copyright (C) 2018 Red Hat, Inc. and/or its affiliates
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*
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* Authors:
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* Dave Gilbert <dgilbert@redhat.com>
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*
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* Implements the glue between libfuse and libvhost-user
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*
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* This program can be distributed under the terms of the GNU LGPLv2.
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* See the file COPYING.LIB
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*/
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#include "qemu/osdep.h"
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#include "qemu/iov.h"
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#include "qapi/error.h"
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#include "fuse_i.h"
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#include "standard-headers/linux/fuse.h"
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#include "fuse_misc.h"
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#include "fuse_opt.h"
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#include "fuse_virtio.h"
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#include <sys/eventfd.h>
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#include <sys/socket.h>
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#include <sys/un.h>
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#include <grp.h>
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#include "libvhost-user.h"
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struct fv_VuDev;
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struct fv_QueueInfo {
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pthread_t thread;
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/*
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* This lock protects the VuVirtq preventing races between
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* fv_queue_thread() and fv_queue_worker().
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*/
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pthread_mutex_t vq_lock;
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struct fv_VuDev *virtio_dev;
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/* Our queue index, corresponds to array position */
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int qidx;
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int kick_fd;
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int kill_fd; /* For killing the thread */
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};
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/* A FUSE request */
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typedef struct {
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VuVirtqElement elem;
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struct fuse_chan ch;
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/* Used to complete requests that involve no reply */
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bool reply_sent;
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} FVRequest;
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/*
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* We pass the dev element into libvhost-user
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* and then use it to get back to the outer
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* container for other data.
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*/
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struct fv_VuDev {
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VuDev dev;
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struct fuse_session *se;
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/*
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* Either handle virtqueues or vhost-user protocol messages. Don't do
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* both at the same time since that could lead to race conditions if
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* virtqueues or memory tables change while another thread is accessing
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* them.
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*
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* The assumptions are:
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* 1. fv_queue_thread() reads/writes to virtqueues and only reads VuDev.
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* 2. virtio_loop() reads/writes virtqueues and VuDev.
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*/
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pthread_rwlock_t vu_dispatch_rwlock;
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/*
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* The following pair of fields are only accessed in the main
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* virtio_loop
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*/
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size_t nqueues;
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struct fv_QueueInfo **qi;
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};
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/* From spec */
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struct virtio_fs_config {
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char tag[36];
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uint32_t num_queues;
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};
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/* Callback from libvhost-user */
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static uint64_t fv_get_features(VuDev *dev)
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{
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return 1ULL << VIRTIO_F_VERSION_1;
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}
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/* Callback from libvhost-user */
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static void fv_set_features(VuDev *dev, uint64_t features)
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{
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}
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/*
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* Callback from libvhost-user if there's a new fd we're supposed to listen
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* to, typically a queue kick?
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*/
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static void fv_set_watch(VuDev *dev, int fd, int condition, vu_watch_cb cb,
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void *data)
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{
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fuse_log(FUSE_LOG_WARNING, "%s: TODO! fd=%d\n", __func__, fd);
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}
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/*
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* Callback from libvhost-user if we're no longer supposed to listen on an fd
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*/
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static void fv_remove_watch(VuDev *dev, int fd)
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{
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fuse_log(FUSE_LOG_WARNING, "%s: TODO! fd=%d\n", __func__, fd);
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}
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/* Callback from libvhost-user to panic */
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static void fv_panic(VuDev *dev, const char *err)
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{
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fuse_log(FUSE_LOG_ERR, "%s: libvhost-user: %s\n", __func__, err);
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/* TODO: Allow reconnects?? */
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exit(EXIT_FAILURE);
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}
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/*
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* Copy from an iovec into a fuse_buf (memory only)
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* Caller must ensure there is space
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*/
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static size_t copy_from_iov(struct fuse_buf *buf, size_t out_num,
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const struct iovec *out_sg,
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size_t max)
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{
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void *dest = buf->mem;
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size_t copied = 0;
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while (out_num && max) {
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size_t onelen = out_sg->iov_len;
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onelen = MIN(onelen, max);
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memcpy(dest, out_sg->iov_base, onelen);
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dest += onelen;
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copied += onelen;
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out_sg++;
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out_num--;
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max -= onelen;
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}
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return copied;
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}
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/*
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* Skip 'skip' bytes in the iov; 'sg_1stindex' is set as
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* the index for the 1st iovec to read data from, and
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* 'sg_1stskip' is the number of bytes to skip in that entry.
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*
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* Returns True if there are at least 'skip' bytes in the iovec
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*
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*/
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static bool skip_iov(const struct iovec *sg, size_t sg_size,
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size_t skip,
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size_t *sg_1stindex, size_t *sg_1stskip)
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{
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size_t vec;
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for (vec = 0; vec < sg_size; vec++) {
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if (sg[vec].iov_len > skip) {
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*sg_1stskip = skip;
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*sg_1stindex = vec;
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return true;
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}
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skip -= sg[vec].iov_len;
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}
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*sg_1stindex = vec;
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*sg_1stskip = 0;
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return skip == 0;
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}
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/*
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* Copy from one iov to another, the given number of bytes
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* The caller must have checked sizes.
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*/
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static void copy_iov(struct iovec *src_iov, int src_count,
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struct iovec *dst_iov, int dst_count, size_t to_copy)
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{
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size_t dst_offset = 0;
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/* Outer loop copies 'src' elements */
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while (to_copy) {
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assert(src_count);
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size_t src_len = src_iov[0].iov_len;
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size_t src_offset = 0;
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if (src_len > to_copy) {
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src_len = to_copy;
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}
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/* Inner loop copies contents of one 'src' to maybe multiple dst. */
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while (src_len) {
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assert(dst_count);
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size_t dst_len = dst_iov[0].iov_len - dst_offset;
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if (dst_len > src_len) {
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dst_len = src_len;
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}
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memcpy(dst_iov[0].iov_base + dst_offset,
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src_iov[0].iov_base + src_offset, dst_len);
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src_len -= dst_len;
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to_copy -= dst_len;
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src_offset += dst_len;
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dst_offset += dst_len;
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assert(dst_offset <= dst_iov[0].iov_len);
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if (dst_offset == dst_iov[0].iov_len) {
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dst_offset = 0;
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dst_iov++;
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dst_count--;
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}
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}
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src_iov++;
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src_count--;
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}
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}
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/*
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* pthread_rwlock_rdlock() and pthread_rwlock_wrlock can fail if
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* a deadlock condition is detected or the current thread already
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* owns the lock. They can also fail, like pthread_rwlock_unlock(),
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* if the mutex wasn't properly initialized. None of these are ever
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* expected to happen.
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*/
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static void vu_dispatch_rdlock(struct fv_VuDev *vud)
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{
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int ret = pthread_rwlock_rdlock(&vud->vu_dispatch_rwlock);
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assert(ret == 0);
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}
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static void vu_dispatch_wrlock(struct fv_VuDev *vud)
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{
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int ret = pthread_rwlock_wrlock(&vud->vu_dispatch_rwlock);
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assert(ret == 0);
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}
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static void vu_dispatch_unlock(struct fv_VuDev *vud)
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{
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int ret = pthread_rwlock_unlock(&vud->vu_dispatch_rwlock);
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assert(ret == 0);
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}
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/*
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* Called back by ll whenever it wants to send a reply/message back
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* The 1st element of the iov starts with the fuse_out_header
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* 'unique'==0 means it's a notify message.
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*/
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int virtio_send_msg(struct fuse_session *se, struct fuse_chan *ch,
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struct iovec *iov, int count)
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{
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FVRequest *req = container_of(ch, FVRequest, ch);
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struct fv_QueueInfo *qi = ch->qi;
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VuDev *dev = &se->virtio_dev->dev;
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VuVirtq *q = vu_get_queue(dev, qi->qidx);
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VuVirtqElement *elem = &req->elem;
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int ret = 0;
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assert(count >= 1);
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assert(iov[0].iov_len >= sizeof(struct fuse_out_header));
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struct fuse_out_header *out = iov[0].iov_base;
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/* TODO: Endianness! */
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size_t tosend_len = iov_size(iov, count);
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/* unique == 0 is notification, which we don't support */
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assert(out->unique);
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assert(!req->reply_sent);
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/* The 'in' part of the elem is to qemu */
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unsigned int in_num = elem->in_num;
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struct iovec *in_sg = elem->in_sg;
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size_t in_len = iov_size(in_sg, in_num);
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fuse_log(FUSE_LOG_DEBUG, "%s: elem %d: with %d in desc of length %zd\n",
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__func__, elem->index, in_num, in_len);
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/*
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* The elem should have room for a 'fuse_out_header' (out from fuse)
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* plus the data based on the len in the header.
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*/
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if (in_len < sizeof(struct fuse_out_header)) {
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fuse_log(FUSE_LOG_ERR, "%s: elem %d too short for out_header\n",
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__func__, elem->index);
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ret = -E2BIG;
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goto err;
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}
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if (in_len < tosend_len) {
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fuse_log(FUSE_LOG_ERR, "%s: elem %d too small for data len %zd\n",
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__func__, elem->index, tosend_len);
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ret = -E2BIG;
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goto err;
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}
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copy_iov(iov, count, in_sg, in_num, tosend_len);
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vu_dispatch_rdlock(qi->virtio_dev);
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pthread_mutex_lock(&qi->vq_lock);
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vu_queue_push(dev, q, elem, tosend_len);
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vu_queue_notify(dev, q);
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pthread_mutex_unlock(&qi->vq_lock);
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vu_dispatch_unlock(qi->virtio_dev);
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req->reply_sent = true;
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err:
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return ret;
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}
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/*
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* Callback from fuse_send_data_iov_* when it's virtio and the buffer
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* is a single FD with FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK
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* We need send the iov and then the buffer.
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* Return 0 on success
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*/
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int virtio_send_data_iov(struct fuse_session *se, struct fuse_chan *ch,
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struct iovec *iov, int count, struct fuse_bufvec *buf,
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size_t len)
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{
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FVRequest *req = container_of(ch, FVRequest, ch);
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struct fv_QueueInfo *qi = ch->qi;
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VuDev *dev = &se->virtio_dev->dev;
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VuVirtq *q = vu_get_queue(dev, qi->qidx);
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VuVirtqElement *elem = &req->elem;
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int ret = 0;
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g_autofree struct iovec *in_sg_cpy = NULL;
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assert(count >= 1);
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assert(iov[0].iov_len >= sizeof(struct fuse_out_header));
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struct fuse_out_header *out = iov[0].iov_base;
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/* TODO: Endianness! */
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size_t iov_len = iov_size(iov, count);
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size_t tosend_len = iov_len + len;
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out->len = tosend_len;
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fuse_log(FUSE_LOG_DEBUG, "%s: count=%d len=%zd iov_len=%zd\n", __func__,
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count, len, iov_len);
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/* unique == 0 is notification which we don't support */
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assert(out->unique);
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assert(!req->reply_sent);
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/* The 'in' part of the elem is to qemu */
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unsigned int in_num = elem->in_num;
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struct iovec *in_sg = elem->in_sg;
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size_t in_len = iov_size(in_sg, in_num);
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fuse_log(FUSE_LOG_DEBUG, "%s: elem %d: with %d in desc of length %zd\n",
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__func__, elem->index, in_num, in_len);
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/*
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* The elem should have room for a 'fuse_out_header' (out from fuse)
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* plus the data based on the len in the header.
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*/
|
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if (in_len < sizeof(struct fuse_out_header)) {
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fuse_log(FUSE_LOG_ERR, "%s: elem %d too short for out_header\n",
|
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__func__, elem->index);
|
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return E2BIG;
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}
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if (in_len < tosend_len) {
|
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fuse_log(FUSE_LOG_ERR, "%s: elem %d too small for data len %zd\n",
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__func__, elem->index, tosend_len);
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return E2BIG;
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}
|
|
|
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/* TODO: Limit to 'len' */
|
|
|
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/* First copy the header data from iov->in_sg */
|
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copy_iov(iov, count, in_sg, in_num, iov_len);
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|
|
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/*
|
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* Build a copy of the the in_sg iov so we can skip bits in it,
|
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* including changing the offsets
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*/
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in_sg_cpy = g_new(struct iovec, in_num);
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memcpy(in_sg_cpy, in_sg, sizeof(struct iovec) * in_num);
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/* These get updated as we skip */
|
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struct iovec *in_sg_ptr = in_sg_cpy;
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unsigned int in_sg_cpy_count = in_num;
|
|
|
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/* skip over parts of in_sg that contained the header iov */
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iov_discard_front(&in_sg_ptr, &in_sg_cpy_count, iov_len);
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do {
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fuse_log(FUSE_LOG_DEBUG, "%s: in_sg_cpy_count=%d len remaining=%zd\n",
|
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__func__, in_sg_cpy_count, len);
|
|
|
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ret = preadv(buf->buf[0].fd, in_sg_ptr, in_sg_cpy_count,
|
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buf->buf[0].pos);
|
|
|
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if (ret == -1) {
|
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ret = errno;
|
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if (ret == EINTR) {
|
|
continue;
|
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}
|
|
fuse_log(FUSE_LOG_DEBUG, "%s: preadv failed (%m) len=%zd\n",
|
|
__func__, len);
|
|
return ret;
|
|
}
|
|
|
|
if (!ret) {
|
|
/* EOF case? */
|
|
fuse_log(FUSE_LOG_DEBUG, "%s: !ret len remaining=%zd\n", __func__,
|
|
len);
|
|
break;
|
|
}
|
|
fuse_log(FUSE_LOG_DEBUG, "%s: preadv ret=%d len=%zd\n", __func__,
|
|
ret, len);
|
|
|
|
len -= ret;
|
|
/* Short read. Retry reading remaining bytes */
|
|
if (len) {
|
|
fuse_log(FUSE_LOG_DEBUG, "%s: ret < len\n", __func__);
|
|
/* Skip over this much next time around */
|
|
iov_discard_front(&in_sg_ptr, &in_sg_cpy_count, ret);
|
|
buf->buf[0].pos += ret;
|
|
}
|
|
} while (len);
|
|
|
|
/* Need to fix out->len on EOF */
|
|
if (len) {
|
|
struct fuse_out_header *out_sg = in_sg[0].iov_base;
|
|
|
|
tosend_len -= len;
|
|
out_sg->len = tosend_len;
|
|
}
|
|
|
|
vu_dispatch_rdlock(qi->virtio_dev);
|
|
pthread_mutex_lock(&qi->vq_lock);
|
|
vu_queue_push(dev, q, elem, tosend_len);
|
|
vu_queue_notify(dev, q);
|
|
pthread_mutex_unlock(&qi->vq_lock);
|
|
vu_dispatch_unlock(qi->virtio_dev);
|
|
req->reply_sent = true;
|
|
return 0;
|
|
}
|
|
|
|
static __thread bool clone_fs_called;
|
|
|
|
/* Process one FVRequest in a thread pool */
|
|
static void fv_queue_worker(gpointer data, gpointer user_data)
|
|
{
|
|
struct fv_QueueInfo *qi = user_data;
|
|
struct fuse_session *se = qi->virtio_dev->se;
|
|
struct VuDev *dev = &qi->virtio_dev->dev;
|
|
FVRequest *req = data;
|
|
VuVirtqElement *elem = &req->elem;
|
|
struct fuse_buf fbuf = {};
|
|
bool allocated_bufv = false;
|
|
struct fuse_bufvec bufv;
|
|
struct fuse_bufvec *pbufv;
|
|
struct fuse_in_header inh;
|
|
|
|
assert(se->bufsize > sizeof(struct fuse_in_header));
|
|
|
|
if (!clone_fs_called) {
|
|
int ret;
|
|
|
|
/* unshare FS for xattr operation */
|
|
ret = unshare(CLONE_FS);
|
|
/* should not fail */
|
|
assert(ret == 0);
|
|
|
|
clone_fs_called = true;
|
|
}
|
|
|
|
/*
|
|
* An element contains one request and the space to send our response
|
|
* They're spread over multiple descriptors in a scatter/gather set
|
|
* and we can't trust the guest to keep them still; so copy in/out.
|
|
*/
|
|
fbuf.mem = g_malloc(se->bufsize);
|
|
|
|
fuse_mutex_init(&req->ch.lock);
|
|
req->ch.fd = -1;
|
|
req->ch.qi = qi;
|
|
|
|
/* The 'out' part of the elem is from qemu */
|
|
unsigned int out_num = elem->out_num;
|
|
struct iovec *out_sg = elem->out_sg;
|
|
size_t out_len = iov_size(out_sg, out_num);
|
|
fuse_log(FUSE_LOG_DEBUG,
|
|
"%s: elem %d: with %d out desc of length %zd\n",
|
|
__func__, elem->index, out_num, out_len);
|
|
|
|
/*
|
|
* The elem should contain a 'fuse_in_header' (in to fuse)
|
|
* plus the data based on the len in the header.
|
|
*/
|
|
if (out_len < sizeof(struct fuse_in_header)) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: elem %d too short for in_header\n",
|
|
__func__, elem->index);
|
|
assert(0); /* TODO */
|
|
}
|
|
if (out_len > se->bufsize) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: elem %d too large for buffer\n", __func__,
|
|
elem->index);
|
|
assert(0); /* TODO */
|
|
}
|
|
/* Copy just the fuse_in_header and look at it */
|
|
copy_from_iov(&fbuf, out_num, out_sg,
|
|
sizeof(struct fuse_in_header));
|
|
memcpy(&inh, fbuf.mem, sizeof(struct fuse_in_header));
|
|
|
|
pbufv = NULL; /* Compiler thinks an unitialised path */
|
|
if (inh.opcode == FUSE_WRITE &&
|
|
out_len >= (sizeof(struct fuse_in_header) +
|
|
sizeof(struct fuse_write_in))) {
|
|
/*
|
|
* For a write we don't actually need to copy the
|
|
* data, we can just do it straight out of guest memory
|
|
* but we must still copy the headers in case the guest
|
|
* was nasty and changed them while we were using them.
|
|
*/
|
|
fuse_log(FUSE_LOG_DEBUG, "%s: Write special case\n", __func__);
|
|
|
|
fbuf.size = copy_from_iov(&fbuf, out_num, out_sg,
|
|
sizeof(struct fuse_in_header) +
|
|
sizeof(struct fuse_write_in));
|
|
/* That copy reread the in_header, make sure we use the original */
|
|
memcpy(fbuf.mem, &inh, sizeof(struct fuse_in_header));
|
|
|
|
/* Allocate the bufv, with space for the rest of the iov */
|
|
pbufv = g_try_malloc(sizeof(struct fuse_bufvec) +
|
|
sizeof(struct fuse_buf) * out_num);
|
|
if (!pbufv) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: pbufv malloc failed\n",
|
|
__func__);
|
|
goto out;
|
|
}
|
|
|
|
allocated_bufv = true;
|
|
pbufv->count = 1;
|
|
pbufv->buf[0] = fbuf;
|
|
|
|
size_t iovindex, pbufvindex, iov_bytes_skip;
|
|
pbufvindex = 1; /* 2 headers, 1 fusebuf */
|
|
|
|
if (!skip_iov(out_sg, out_num,
|
|
sizeof(struct fuse_in_header) +
|
|
sizeof(struct fuse_write_in),
|
|
&iovindex, &iov_bytes_skip)) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: skip failed\n",
|
|
__func__);
|
|
goto out;
|
|
}
|
|
|
|
for (; iovindex < out_num; iovindex++, pbufvindex++) {
|
|
pbufv->count++;
|
|
pbufv->buf[pbufvindex].pos = ~0; /* Dummy */
|
|
pbufv->buf[pbufvindex].flags = 0;
|
|
pbufv->buf[pbufvindex].mem = out_sg[iovindex].iov_base;
|
|
pbufv->buf[pbufvindex].size = out_sg[iovindex].iov_len;
|
|
|
|
if (iov_bytes_skip) {
|
|
pbufv->buf[pbufvindex].mem += iov_bytes_skip;
|
|
pbufv->buf[pbufvindex].size -= iov_bytes_skip;
|
|
iov_bytes_skip = 0;
|
|
}
|
|
}
|
|
} else {
|
|
/* Normal (non fast write) path */
|
|
|
|
copy_from_iov(&fbuf, out_num, out_sg, se->bufsize);
|
|
/* That copy reread the in_header, make sure we use the original */
|
|
memcpy(fbuf.mem, &inh, sizeof(struct fuse_in_header));
|
|
fbuf.size = out_len;
|
|
|
|
/* TODO! Endianness of header */
|
|
|
|
/* TODO: Add checks for fuse_session_exited */
|
|
bufv.buf[0] = fbuf;
|
|
bufv.count = 1;
|
|
pbufv = &bufv;
|
|
}
|
|
pbufv->idx = 0;
|
|
pbufv->off = 0;
|
|
fuse_session_process_buf_int(se, pbufv, &req->ch);
|
|
|
|
out:
|
|
if (allocated_bufv) {
|
|
g_free(pbufv);
|
|
}
|
|
|
|
/* If the request has no reply, still recycle the virtqueue element */
|
|
if (!req->reply_sent) {
|
|
struct VuVirtq *q = vu_get_queue(dev, qi->qidx);
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "%s: elem %d no reply sent\n", __func__,
|
|
elem->index);
|
|
|
|
vu_dispatch_rdlock(qi->virtio_dev);
|
|
pthread_mutex_lock(&qi->vq_lock);
|
|
vu_queue_push(dev, q, elem, 0);
|
|
vu_queue_notify(dev, q);
|
|
pthread_mutex_unlock(&qi->vq_lock);
|
|
vu_dispatch_unlock(qi->virtio_dev);
|
|
}
|
|
|
|
pthread_mutex_destroy(&req->ch.lock);
|
|
g_free(fbuf.mem);
|
|
free(req);
|
|
}
|
|
|
|
/* Thread function for individual queues, created when a queue is 'started' */
|
|
static void *fv_queue_thread(void *opaque)
|
|
{
|
|
struct fv_QueueInfo *qi = opaque;
|
|
struct VuDev *dev = &qi->virtio_dev->dev;
|
|
struct VuVirtq *q = vu_get_queue(dev, qi->qidx);
|
|
struct fuse_session *se = qi->virtio_dev->se;
|
|
GThreadPool *pool = NULL;
|
|
GList *req_list = NULL;
|
|
|
|
if (se->thread_pool_size) {
|
|
fuse_log(FUSE_LOG_DEBUG, "%s: Creating thread pool for Queue %d\n",
|
|
__func__, qi->qidx);
|
|
pool = g_thread_pool_new(fv_queue_worker, qi, se->thread_pool_size,
|
|
FALSE, NULL);
|
|
if (!pool) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: g_thread_pool_new failed\n", __func__);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
fuse_log(FUSE_LOG_INFO, "%s: Start for queue %d kick_fd %d\n", __func__,
|
|
qi->qidx, qi->kick_fd);
|
|
while (1) {
|
|
struct pollfd pf[2];
|
|
|
|
pf[0].fd = qi->kick_fd;
|
|
pf[0].events = POLLIN;
|
|
pf[0].revents = 0;
|
|
pf[1].fd = qi->kill_fd;
|
|
pf[1].events = POLLIN;
|
|
pf[1].revents = 0;
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "%s: Waiting for Queue %d event\n", __func__,
|
|
qi->qidx);
|
|
int poll_res = ppoll(pf, 2, NULL, NULL);
|
|
|
|
if (poll_res == -1) {
|
|
if (errno == EINTR) {
|
|
fuse_log(FUSE_LOG_INFO, "%s: ppoll interrupted, going around\n",
|
|
__func__);
|
|
continue;
|
|
}
|
|
fuse_log(FUSE_LOG_ERR, "fv_queue_thread ppoll: %m\n");
|
|
break;
|
|
}
|
|
assert(poll_res >= 1);
|
|
if (pf[0].revents & (POLLERR | POLLHUP | POLLNVAL)) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: Unexpected poll revents %x Queue %d\n",
|
|
__func__, pf[0].revents, qi->qidx);
|
|
break;
|
|
}
|
|
if (pf[1].revents & (POLLERR | POLLHUP | POLLNVAL)) {
|
|
fuse_log(FUSE_LOG_ERR,
|
|
"%s: Unexpected poll revents %x Queue %d killfd\n",
|
|
__func__, pf[1].revents, qi->qidx);
|
|
break;
|
|
}
|
|
if (pf[1].revents) {
|
|
fuse_log(FUSE_LOG_INFO, "%s: kill event on queue %d - quitting\n",
|
|
__func__, qi->qidx);
|
|
break;
|
|
}
|
|
assert(pf[0].revents & POLLIN);
|
|
fuse_log(FUSE_LOG_DEBUG, "%s: Got queue event on Queue %d\n", __func__,
|
|
qi->qidx);
|
|
|
|
eventfd_t evalue;
|
|
if (eventfd_read(qi->kick_fd, &evalue)) {
|
|
fuse_log(FUSE_LOG_ERR, "Eventfd_read for queue: %m\n");
|
|
break;
|
|
}
|
|
/* Mutual exclusion with virtio_loop() */
|
|
vu_dispatch_rdlock(qi->virtio_dev);
|
|
pthread_mutex_lock(&qi->vq_lock);
|
|
/* out is from guest, in is too guest */
|
|
unsigned int in_bytes, out_bytes;
|
|
vu_queue_get_avail_bytes(dev, q, &in_bytes, &out_bytes, ~0, ~0);
|
|
|
|
fuse_log(FUSE_LOG_DEBUG,
|
|
"%s: Queue %d gave evalue: %zx available: in: %u out: %u\n",
|
|
__func__, qi->qidx, (size_t)evalue, in_bytes, out_bytes);
|
|
|
|
while (1) {
|
|
FVRequest *req = vu_queue_pop(dev, q, sizeof(FVRequest));
|
|
if (!req) {
|
|
break;
|
|
}
|
|
|
|
req->reply_sent = false;
|
|
|
|
if (!se->thread_pool_size) {
|
|
req_list = g_list_prepend(req_list, req);
|
|
} else {
|
|
g_thread_pool_push(pool, req, NULL);
|
|
}
|
|
}
|
|
|
|
pthread_mutex_unlock(&qi->vq_lock);
|
|
vu_dispatch_unlock(qi->virtio_dev);
|
|
|
|
/* Process all the requests. */
|
|
if (!se->thread_pool_size && req_list != NULL) {
|
|
req_list = g_list_reverse(req_list);
|
|
g_list_foreach(req_list, fv_queue_worker, qi);
|
|
g_list_free(req_list);
|
|
req_list = NULL;
|
|
}
|
|
}
|
|
|
|
if (pool) {
|
|
g_thread_pool_free(pool, FALSE, TRUE);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void fv_queue_cleanup_thread(struct fv_VuDev *vud, int qidx)
|
|
{
|
|
int ret;
|
|
struct fv_QueueInfo *ourqi;
|
|
|
|
assert(qidx < vud->nqueues);
|
|
ourqi = vud->qi[qidx];
|
|
|
|
/* Kill the thread */
|
|
if (eventfd_write(ourqi->kill_fd, 1)) {
|
|
fuse_log(FUSE_LOG_ERR, "Eventfd_write for queue %d: %s\n",
|
|
qidx, strerror(errno));
|
|
}
|
|
ret = pthread_join(ourqi->thread, NULL);
|
|
if (ret) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: Failed to join thread idx %d err %d\n",
|
|
__func__, qidx, ret);
|
|
}
|
|
pthread_mutex_destroy(&ourqi->vq_lock);
|
|
close(ourqi->kill_fd);
|
|
ourqi->kick_fd = -1;
|
|
g_free(vud->qi[qidx]);
|
|
vud->qi[qidx] = NULL;
|
|
}
|
|
|
|
/* Callback from libvhost-user on start or stop of a queue */
|
|
static void fv_queue_set_started(VuDev *dev, int qidx, bool started)
|
|
{
|
|
struct fv_VuDev *vud = container_of(dev, struct fv_VuDev, dev);
|
|
struct fv_QueueInfo *ourqi;
|
|
|
|
fuse_log(FUSE_LOG_INFO, "%s: qidx=%d started=%d\n", __func__, qidx,
|
|
started);
|
|
assert(qidx >= 0);
|
|
|
|
/*
|
|
* Ignore additional request queues for now. passthrough_ll.c must be
|
|
* audited for thread-safety issues first. It was written with a
|
|
* well-behaved client in mind and may not protect against all types of
|
|
* races yet.
|
|
*/
|
|
if (qidx > 1) {
|
|
fuse_log(FUSE_LOG_ERR,
|
|
"%s: multiple request queues not yet implemented, please only "
|
|
"configure 1 request queue\n",
|
|
__func__);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
if (started) {
|
|
/* Fire up a thread to watch this queue */
|
|
if (qidx >= vud->nqueues) {
|
|
vud->qi = g_realloc_n(vud->qi, qidx + 1, sizeof(vud->qi[0]));
|
|
memset(vud->qi + vud->nqueues, 0,
|
|
sizeof(vud->qi[0]) * (1 + (qidx - vud->nqueues)));
|
|
vud->nqueues = qidx + 1;
|
|
}
|
|
if (!vud->qi[qidx]) {
|
|
vud->qi[qidx] = g_new0(struct fv_QueueInfo, 1);
|
|
vud->qi[qidx]->virtio_dev = vud;
|
|
vud->qi[qidx]->qidx = qidx;
|
|
} else {
|
|
/* Shouldn't have been started */
|
|
assert(vud->qi[qidx]->kick_fd == -1);
|
|
}
|
|
ourqi = vud->qi[qidx];
|
|
ourqi->kick_fd = dev->vq[qidx].kick_fd;
|
|
|
|
ourqi->kill_fd = eventfd(0, EFD_CLOEXEC | EFD_SEMAPHORE);
|
|
assert(ourqi->kill_fd != -1);
|
|
pthread_mutex_init(&ourqi->vq_lock, NULL);
|
|
|
|
if (pthread_create(&ourqi->thread, NULL, fv_queue_thread, ourqi)) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: Failed to create thread for queue %d\n",
|
|
__func__, qidx);
|
|
assert(0);
|
|
}
|
|
} else {
|
|
/*
|
|
* Temporarily drop write-lock taken in virtio_loop() so that
|
|
* the queue thread doesn't block in virtio_send_msg().
|
|
*/
|
|
vu_dispatch_unlock(vud);
|
|
fv_queue_cleanup_thread(vud, qidx);
|
|
vu_dispatch_wrlock(vud);
|
|
}
|
|
}
|
|
|
|
static bool fv_queue_order(VuDev *dev, int qidx)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static const VuDevIface fv_iface = {
|
|
.get_features = fv_get_features,
|
|
.set_features = fv_set_features,
|
|
|
|
/* Don't need process message, we've not got any at vhost-user level */
|
|
.queue_set_started = fv_queue_set_started,
|
|
|
|
.queue_is_processed_in_order = fv_queue_order,
|
|
};
|
|
|
|
/*
|
|
* Main loop; this mostly deals with events on the vhost-user
|
|
* socket itself, and not actual fuse data.
|
|
*/
|
|
int virtio_loop(struct fuse_session *se)
|
|
{
|
|
fuse_log(FUSE_LOG_INFO, "%s: Entry\n", __func__);
|
|
|
|
while (!fuse_session_exited(se)) {
|
|
struct pollfd pf[1];
|
|
bool ok;
|
|
pf[0].fd = se->vu_socketfd;
|
|
pf[0].events = POLLIN;
|
|
pf[0].revents = 0;
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "%s: Waiting for VU event\n", __func__);
|
|
int poll_res = ppoll(pf, 1, NULL, NULL);
|
|
|
|
if (poll_res == -1) {
|
|
if (errno == EINTR) {
|
|
fuse_log(FUSE_LOG_INFO, "%s: ppoll interrupted, going around\n",
|
|
__func__);
|
|
continue;
|
|
}
|
|
fuse_log(FUSE_LOG_ERR, "virtio_loop ppoll: %m\n");
|
|
break;
|
|
}
|
|
assert(poll_res == 1);
|
|
if (pf[0].revents & (POLLERR | POLLHUP | POLLNVAL)) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: Unexpected poll revents %x\n", __func__,
|
|
pf[0].revents);
|
|
break;
|
|
}
|
|
assert(pf[0].revents & POLLIN);
|
|
fuse_log(FUSE_LOG_DEBUG, "%s: Got VU event\n", __func__);
|
|
/* Mutual exclusion with fv_queue_thread() */
|
|
vu_dispatch_wrlock(se->virtio_dev);
|
|
|
|
ok = vu_dispatch(&se->virtio_dev->dev);
|
|
|
|
vu_dispatch_unlock(se->virtio_dev);
|
|
|
|
if (!ok) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: vu_dispatch failed\n", __func__);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Make sure all fv_queue_thread()s quit on exit, as we're about to
|
|
* free virtio dev and fuse session, no one should access them anymore.
|
|
*/
|
|
for (int i = 0; i < se->virtio_dev->nqueues; i++) {
|
|
if (!se->virtio_dev->qi[i]) {
|
|
continue;
|
|
}
|
|
|
|
fuse_log(FUSE_LOG_INFO, "%s: Stopping queue %d thread\n", __func__, i);
|
|
fv_queue_cleanup_thread(se->virtio_dev, i);
|
|
}
|
|
|
|
fuse_log(FUSE_LOG_INFO, "%s: Exit\n", __func__);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void strreplace(char *s, char old, char new)
|
|
{
|
|
for (; *s; ++s) {
|
|
if (*s == old) {
|
|
*s = new;
|
|
}
|
|
}
|
|
}
|
|
|
|
static bool fv_socket_lock(struct fuse_session *se)
|
|
{
|
|
g_autofree gchar *sk_name = NULL;
|
|
g_autofree gchar *pidfile = NULL;
|
|
g_autofree gchar *dir = NULL;
|
|
Error *local_err = NULL;
|
|
|
|
dir = qemu_get_local_state_pathname("run/virtiofsd");
|
|
|
|
if (g_mkdir_with_parents(dir, S_IRWXU) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: Failed to create directory %s: %s\n",
|
|
__func__, dir, strerror(errno));
|
|
return false;
|
|
}
|
|
|
|
sk_name = g_strdup(se->vu_socket_path);
|
|
strreplace(sk_name, '/', '.');
|
|
pidfile = g_strdup_printf("%s/%s.pid", dir, sk_name);
|
|
|
|
if (!qemu_write_pidfile(pidfile, &local_err)) {
|
|
error_report_err(local_err);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static int fv_create_listen_socket(struct fuse_session *se)
|
|
{
|
|
struct sockaddr_un un;
|
|
mode_t old_umask;
|
|
|
|
/* Nothing to do if fd is already initialized */
|
|
if (se->vu_listen_fd >= 0) {
|
|
return 0;
|
|
}
|
|
|
|
if (strlen(se->vu_socket_path) >= sizeof(un.sun_path)) {
|
|
fuse_log(FUSE_LOG_ERR, "Socket path too long\n");
|
|
return -1;
|
|
}
|
|
|
|
if (!strlen(se->vu_socket_path)) {
|
|
fuse_log(FUSE_LOG_ERR, "Socket path is empty\n");
|
|
return -1;
|
|
}
|
|
|
|
/* Check the vu_socket_path is already used */
|
|
if (!fv_socket_lock(se)) {
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Create the Unix socket to communicate with qemu
|
|
* based on QEMU's vhost-user-bridge
|
|
*/
|
|
unlink(se->vu_socket_path);
|
|
strcpy(un.sun_path, se->vu_socket_path);
|
|
size_t addr_len = sizeof(un);
|
|
|
|
int listen_sock = socket(AF_UNIX, SOCK_STREAM, 0);
|
|
if (listen_sock == -1) {
|
|
fuse_log(FUSE_LOG_ERR, "vhost socket creation: %m\n");
|
|
return -1;
|
|
}
|
|
un.sun_family = AF_UNIX;
|
|
|
|
/*
|
|
* Unfortunately bind doesn't let you set the mask on the socket,
|
|
* so set umask appropriately and restore it later.
|
|
*/
|
|
if (se->vu_socket_group) {
|
|
old_umask = umask(S_IROTH | S_IWOTH | S_IXOTH);
|
|
} else {
|
|
old_umask = umask(S_IRGRP | S_IWGRP | S_IXGRP |
|
|
S_IROTH | S_IWOTH | S_IXOTH);
|
|
}
|
|
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;
|
|
}
|
|
if (se->vu_socket_group) {
|
|
struct group *g = getgrnam(se->vu_socket_group);
|
|
if (g) {
|
|
if (chown(se->vu_socket_path, -1, g->gr_gid) == -1) {
|
|
fuse_log(FUSE_LOG_WARNING,
|
|
"vhost socket failed to set group to %s (%d): %m\n",
|
|
se->vu_socket_group, g->gr_gid);
|
|
}
|
|
}
|
|
}
|
|
umask(old_umask);
|
|
|
|
if (listen(listen_sock, 1) == -1) {
|
|
fuse_log(FUSE_LOG_ERR, "vhost socket listen: %m\n");
|
|
close(listen_sock);
|
|
return -1;
|
|
}
|
|
|
|
se->vu_listen_fd = listen_sock;
|
|
return 0;
|
|
}
|
|
|
|
int virtio_session_mount(struct fuse_session *se)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* Test that unshare(CLONE_FS) works. fv_queue_worker() will need it. It's
|
|
* an unprivileged system call but some Docker/Moby versions are known to
|
|
* reject it via seccomp when CAP_SYS_ADMIN is not given.
|
|
*
|
|
* Note that the program is single-threaded here so this syscall has no
|
|
* visible effect and is safe to make.
|
|
*/
|
|
ret = unshare(CLONE_FS);
|
|
if (ret == -1 && errno == EPERM) {
|
|
fuse_log(FUSE_LOG_ERR, "unshare(CLONE_FS) failed with EPERM. If "
|
|
"running in a container please check that the container "
|
|
"runtime seccomp policy allows unshare.\n");
|
|
return -1;
|
|
}
|
|
|
|
ret = fv_create_listen_socket(se);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
se->fd = -1;
|
|
|
|
fuse_log(FUSE_LOG_INFO, "%s: Waiting for vhost-user socket connection...\n",
|
|
__func__);
|
|
int data_sock = accept(se->vu_listen_fd, NULL, NULL);
|
|
if (data_sock == -1) {
|
|
fuse_log(FUSE_LOG_ERR, "vhost socket accept: %m\n");
|
|
close(se->vu_listen_fd);
|
|
return -1;
|
|
}
|
|
close(se->vu_listen_fd);
|
|
se->vu_listen_fd = -1;
|
|
fuse_log(FUSE_LOG_INFO, "%s: Received vhost-user socket connection\n",
|
|
__func__);
|
|
|
|
/* TODO: Some cleanup/deallocation! */
|
|
se->virtio_dev = g_new0(struct fv_VuDev, 1);
|
|
|
|
se->vu_socketfd = data_sock;
|
|
se->virtio_dev->se = se;
|
|
pthread_rwlock_init(&se->virtio_dev->vu_dispatch_rwlock, NULL);
|
|
if (!vu_init(&se->virtio_dev->dev, 2, se->vu_socketfd, fv_panic, NULL,
|
|
fv_set_watch, fv_remove_watch, &fv_iface)) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: vu_init failed\n", __func__);
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void virtio_session_close(struct fuse_session *se)
|
|
{
|
|
close(se->vu_socketfd);
|
|
|
|
if (!se->virtio_dev) {
|
|
return;
|
|
}
|
|
|
|
g_free(se->virtio_dev->qi);
|
|
pthread_rwlock_destroy(&se->virtio_dev->vu_dispatch_rwlock);
|
|
g_free(se->virtio_dev);
|
|
se->virtio_dev = NULL;
|
|
}
|