| Message ID | 20210125180115.22936-3-vgoyal@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | vhost-user: Shutdown/Flush slave channel properly | expand |
On Mon, 25 Jan 2021 13:01:11 -0500 Vivek Goyal <vgoyal@redhat.com> wrote: > dev->slave_mutex needs to be taken when sending messages on slave_fd. > Currently _vu_queue_notify() does not do that. > > Introduce a helper vu_message_slave_send_receive() which sends as well > as receive response. Use this helper in all the paths which send > message on slave_fd channel. > Does this fix any known bug ? > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > --- LGTM Reviewed-by: Greg Kurz <groug@kaod.org> > subprojects/libvhost-user/libvhost-user.c | 50 ++++++++++++----------- > 1 file changed, 27 insertions(+), 23 deletions(-) > > diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c > index 4cf4aef63d..7a56c56dc8 100644 > --- a/subprojects/libvhost-user/libvhost-user.c > +++ b/subprojects/libvhost-user/libvhost-user.c > @@ -403,7 +403,7 @@ vu_send_reply(VuDev *dev, int conn_fd, VhostUserMsg *vmsg) > * Processes a reply on the slave channel. > * Entered with slave_mutex held and releases it before exit. > * Returns true on success. > - * *payload is written on success > + * *payload is written on success, if payload is not NULL. > */ > static bool > vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg, > @@ -427,7 +427,9 @@ vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg, > goto out; > } > > - *payload = msg_reply.payload.u64; > + if (payload) { > + *payload = msg_reply.payload.u64; > + } > result = true; > > out: > @@ -435,6 +437,25 @@ out: > return result; > } > > +/* Returns true on success, false otherwise */ > +static bool > +vu_message_slave_send_receive(VuDev *dev, VhostUserMsg *vmsg, uint64_t *payload) > +{ > + pthread_mutex_lock(&dev->slave_mutex); > + if (!vu_message_write(dev, dev->slave_fd, vmsg)) { > + pthread_mutex_unlock(&dev->slave_mutex); > + return false; > + } > + > + if ((vmsg->flags & VHOST_USER_NEED_REPLY_MASK) == 0) { > + pthread_mutex_unlock(&dev->slave_mutex); > + return true; > + } > + > + /* Also unlocks the slave_mutex */ > + return vu_process_message_reply(dev, vmsg, payload); > +} > + > /* Kick the log_call_fd if required. */ > static void > vu_log_kick(VuDev *dev) > @@ -1340,16 +1361,8 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd, > return false; > } > > - pthread_mutex_lock(&dev->slave_mutex); > - if (!vu_message_write(dev, dev->slave_fd, &vmsg)) { > - pthread_mutex_unlock(&dev->slave_mutex); > - return false; > - } > - > - /* Also unlocks the slave_mutex */ > - res = vu_process_message_reply(dev, &vmsg, &payload); > + res = vu_message_slave_send_receive(dev, &vmsg, &payload); > res = res && (payload == 0); > - > return res; > } > > @@ -2395,10 +2408,7 @@ static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync) > vmsg.flags |= VHOST_USER_NEED_REPLY_MASK; > } > > - vu_message_write(dev, dev->slave_fd, &vmsg); > - if (ack) { > - vu_message_read_default(dev, dev->slave_fd, &vmsg); > - } > + vu_message_slave_send_receive(dev, &vmsg, NULL); > return; > } > > @@ -2942,17 +2952,11 @@ int64_t vu_fs_cache_request(VuDev *dev, VhostUserSlaveRequest req, int fd, > return -EINVAL; > } > > - pthread_mutex_lock(&dev->slave_mutex); > - if (!vu_message_write(dev, dev->slave_fd, &vmsg)) { > - pthread_mutex_unlock(&dev->slave_mutex); > - return -EIO; > - } > - > - /* Also unlocks the slave_mutex */ > - res = vu_process_message_reply(dev, &vmsg, &payload); > + res = vu_message_slave_send_receive(dev, &vmsg, &payload); > if (!res) { > return -EIO; > } > + > /* > * Payload is delivered as uint64_t but is actually signed for > * errors.
On Thu, Jan 28, 2021 at 03:31:23PM +0100, Greg Kurz wrote: > On Mon, 25 Jan 2021 13:01:11 -0500 > Vivek Goyal <vgoyal@redhat.com> wrote: > > > dev->slave_mutex needs to be taken when sending messages on slave_fd. > > Currently _vu_queue_notify() does not do that. > > > > Introduce a helper vu_message_slave_send_receive() which sends as well > > as receive response. Use this helper in all the paths which send > > message on slave_fd channel. > > > > Does this fix any known bug ? I am not aware of any bug. This fix is based on code inspection. Also I wanted a central place/function to send messages on slave channel so that I can check state of slave channel (open/close) and act accordingly. Otherwise I will have to do the check at every place which is trying to send/receive message on slave channel. Vivek > > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > > --- > > LGTM > > Reviewed-by: Greg Kurz <groug@kaod.org> > > > subprojects/libvhost-user/libvhost-user.c | 50 ++++++++++++----------- > > 1 file changed, 27 insertions(+), 23 deletions(-) > > > > diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c > > index 4cf4aef63d..7a56c56dc8 100644 > > --- a/subprojects/libvhost-user/libvhost-user.c > > +++ b/subprojects/libvhost-user/libvhost-user.c > > @@ -403,7 +403,7 @@ vu_send_reply(VuDev *dev, int conn_fd, VhostUserMsg *vmsg) > > * Processes a reply on the slave channel. > > * Entered with slave_mutex held and releases it before exit. > > * Returns true on success. > > - * *payload is written on success > > + * *payload is written on success, if payload is not NULL. > > */ > > static bool > > vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg, > > @@ -427,7 +427,9 @@ vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg, > > goto out; > > } > > > > - *payload = msg_reply.payload.u64; > > + if (payload) { > > + *payload = msg_reply.payload.u64; > > + } > > result = true; > > > > out: > > @@ -435,6 +437,25 @@ out: > > return result; > > } > > > > +/* Returns true on success, false otherwise */ > > +static bool > > +vu_message_slave_send_receive(VuDev *dev, VhostUserMsg *vmsg, uint64_t *payload) > > +{ > > + pthread_mutex_lock(&dev->slave_mutex); > > + if (!vu_message_write(dev, dev->slave_fd, vmsg)) { > > + pthread_mutex_unlock(&dev->slave_mutex); > > + return false; > > + } > > + > > + if ((vmsg->flags & VHOST_USER_NEED_REPLY_MASK) == 0) { > > + pthread_mutex_unlock(&dev->slave_mutex); > > + return true; > > + } > > + > > + /* Also unlocks the slave_mutex */ > > + return vu_process_message_reply(dev, vmsg, payload); > > +} > > + > > /* Kick the log_call_fd if required. */ > > static void > > vu_log_kick(VuDev *dev) > > @@ -1340,16 +1361,8 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd, > > return false; > > } > > > > - pthread_mutex_lock(&dev->slave_mutex); > > - if (!vu_message_write(dev, dev->slave_fd, &vmsg)) { > > - pthread_mutex_unlock(&dev->slave_mutex); > > - return false; > > - } > > - > > - /* Also unlocks the slave_mutex */ > > - res = vu_process_message_reply(dev, &vmsg, &payload); > > + res = vu_message_slave_send_receive(dev, &vmsg, &payload); > > res = res && (payload == 0); > > - > > return res; > > } > > > > @@ -2395,10 +2408,7 @@ static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync) > > vmsg.flags |= VHOST_USER_NEED_REPLY_MASK; > > } > > > > - vu_message_write(dev, dev->slave_fd, &vmsg); > > - if (ack) { > > - vu_message_read_default(dev, dev->slave_fd, &vmsg); > > - } > > + vu_message_slave_send_receive(dev, &vmsg, NULL); > > return; > > } > > > > @@ -2942,17 +2952,11 @@ int64_t vu_fs_cache_request(VuDev *dev, VhostUserSlaveRequest req, int fd, > > return -EINVAL; > > } > > > > - pthread_mutex_lock(&dev->slave_mutex); > > - if (!vu_message_write(dev, dev->slave_fd, &vmsg)) { > > - pthread_mutex_unlock(&dev->slave_mutex); > > - return -EIO; > > - } > > - > > - /* Also unlocks the slave_mutex */ > > - res = vu_process_message_reply(dev, &vmsg, &payload); > > + res = vu_message_slave_send_receive(dev, &vmsg, &payload); > > if (!res) { > > return -EIO; > > } > > + > > /* > > * Payload is delivered as uint64_t but is actually signed for > > * errors. >
On Thu, 28 Jan 2021 09:48:35 -0500 Vivek Goyal <vgoyal@redhat.com> wrote: > On Thu, Jan 28, 2021 at 03:31:23PM +0100, Greg Kurz wrote: > > On Mon, 25 Jan 2021 13:01:11 -0500 > > Vivek Goyal <vgoyal@redhat.com> wrote: > > > > > dev->slave_mutex needs to be taken when sending messages on slave_fd. > > > Currently _vu_queue_notify() does not do that. > > > > > > Introduce a helper vu_message_slave_send_receive() which sends as well > > > as receive response. Use this helper in all the paths which send > > > message on slave_fd channel. > > > > > > > Does this fix any known bug ? > > I am not aware of any bug. This fix is based on code inspection. > > Also I wanted a central place/function to send messages on slave channel > so that I can check state of slave channel (open/close) and act > accordingly. Otherwise I will have to do the check at every place > which is trying to send/receive message on slave channel. > Makes sense. Thanks for the clarification. > Vivek > > > > > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > > > --- > > > > LGTM > > > > Reviewed-by: Greg Kurz <groug@kaod.org> > > > > > subprojects/libvhost-user/libvhost-user.c | 50 ++++++++++++----------- > > > 1 file changed, 27 insertions(+), 23 deletions(-) > > > > > > diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c > > > index 4cf4aef63d..7a56c56dc8 100644 > > > --- a/subprojects/libvhost-user/libvhost-user.c > > > +++ b/subprojects/libvhost-user/libvhost-user.c > > > @@ -403,7 +403,7 @@ vu_send_reply(VuDev *dev, int conn_fd, VhostUserMsg *vmsg) > > > * Processes a reply on the slave channel. > > > * Entered with slave_mutex held and releases it before exit. > > > * Returns true on success. > > > - * *payload is written on success > > > + * *payload is written on success, if payload is not NULL. > > > */ > > > static bool > > > vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg, > > > @@ -427,7 +427,9 @@ vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg, > > > goto out; > > > } > > > > > > - *payload = msg_reply.payload.u64; > > > + if (payload) { > > > + *payload = msg_reply.payload.u64; > > > + } > > > result = true; > > > > > > out: > > > @@ -435,6 +437,25 @@ out: > > > return result; > > > } > > > > > > +/* Returns true on success, false otherwise */ > > > +static bool > > > +vu_message_slave_send_receive(VuDev *dev, VhostUserMsg *vmsg, uint64_t *payload) > > > +{ > > > + pthread_mutex_lock(&dev->slave_mutex); > > > + if (!vu_message_write(dev, dev->slave_fd, vmsg)) { > > > + pthread_mutex_unlock(&dev->slave_mutex); > > > + return false; > > > + } > > > + > > > + if ((vmsg->flags & VHOST_USER_NEED_REPLY_MASK) == 0) { > > > + pthread_mutex_unlock(&dev->slave_mutex); > > > + return true; > > > + } > > > + > > > + /* Also unlocks the slave_mutex */ > > > + return vu_process_message_reply(dev, vmsg, payload); > > > +} > > > + > > > /* Kick the log_call_fd if required. */ > > > static void > > > vu_log_kick(VuDev *dev) > > > @@ -1340,16 +1361,8 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd, > > > return false; > > > } > > > > > > - pthread_mutex_lock(&dev->slave_mutex); > > > - if (!vu_message_write(dev, dev->slave_fd, &vmsg)) { > > > - pthread_mutex_unlock(&dev->slave_mutex); > > > - return false; > > > - } > > > - > > > - /* Also unlocks the slave_mutex */ > > > - res = vu_process_message_reply(dev, &vmsg, &payload); > > > + res = vu_message_slave_send_receive(dev, &vmsg, &payload); > > > res = res && (payload == 0); > > > - > > > return res; > > > } > > > > > > @@ -2395,10 +2408,7 @@ static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync) > > > vmsg.flags |= VHOST_USER_NEED_REPLY_MASK; > > > } > > > > > > - vu_message_write(dev, dev->slave_fd, &vmsg); > > > - if (ack) { > > > - vu_message_read_default(dev, dev->slave_fd, &vmsg); > > > - } > > > + vu_message_slave_send_receive(dev, &vmsg, NULL); > > > return; > > > } > > > > > > @@ -2942,17 +2952,11 @@ int64_t vu_fs_cache_request(VuDev *dev, VhostUserSlaveRequest req, int fd, > > > return -EINVAL; > > > } > > > > > > - pthread_mutex_lock(&dev->slave_mutex); > > > - if (!vu_message_write(dev, dev->slave_fd, &vmsg)) { > > > - pthread_mutex_unlock(&dev->slave_mutex); > > > - return -EIO; > > > - } > > > - > > > - /* Also unlocks the slave_mutex */ > > > - res = vu_process_message_reply(dev, &vmsg, &payload); > > > + res = vu_message_slave_send_receive(dev, &vmsg, &payload); > > > if (!res) { > > > return -EIO; > > > } > > > + > > > /* > > > * Payload is delivered as uint64_t but is actually signed for > > > * errors. > > >
diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c index 4cf4aef63d..7a56c56dc8 100644 --- a/subprojects/libvhost-user/libvhost-user.c +++ b/subprojects/libvhost-user/libvhost-user.c @@ -403,7 +403,7 @@ vu_send_reply(VuDev *dev, int conn_fd, VhostUserMsg *vmsg) * Processes a reply on the slave channel. * Entered with slave_mutex held and releases it before exit. * Returns true on success. - * *payload is written on success + * *payload is written on success, if payload is not NULL. */ static bool vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg, @@ -427,7 +427,9 @@ vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg, goto out; } - *payload = msg_reply.payload.u64; + if (payload) { + *payload = msg_reply.payload.u64; + } result = true; out: @@ -435,6 +437,25 @@ out: return result; } +/* Returns true on success, false otherwise */ +static bool +vu_message_slave_send_receive(VuDev *dev, VhostUserMsg *vmsg, uint64_t *payload) +{ + pthread_mutex_lock(&dev->slave_mutex); + if (!vu_message_write(dev, dev->slave_fd, vmsg)) { + pthread_mutex_unlock(&dev->slave_mutex); + return false; + } + + if ((vmsg->flags & VHOST_USER_NEED_REPLY_MASK) == 0) { + pthread_mutex_unlock(&dev->slave_mutex); + return true; + } + + /* Also unlocks the slave_mutex */ + return vu_process_message_reply(dev, vmsg, payload); +} + /* Kick the log_call_fd if required. */ static void vu_log_kick(VuDev *dev) @@ -1340,16 +1361,8 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd, return false; } - pthread_mutex_lock(&dev->slave_mutex); - if (!vu_message_write(dev, dev->slave_fd, &vmsg)) { - pthread_mutex_unlock(&dev->slave_mutex); - return false; - } - - /* Also unlocks the slave_mutex */ - res = vu_process_message_reply(dev, &vmsg, &payload); + res = vu_message_slave_send_receive(dev, &vmsg, &payload); res = res && (payload == 0); - return res; } @@ -2395,10 +2408,7 @@ static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync) vmsg.flags |= VHOST_USER_NEED_REPLY_MASK; } - vu_message_write(dev, dev->slave_fd, &vmsg); - if (ack) { - vu_message_read_default(dev, dev->slave_fd, &vmsg); - } + vu_message_slave_send_receive(dev, &vmsg, NULL); return; } @@ -2942,17 +2952,11 @@ int64_t vu_fs_cache_request(VuDev *dev, VhostUserSlaveRequest req, int fd, return -EINVAL; } - pthread_mutex_lock(&dev->slave_mutex); - if (!vu_message_write(dev, dev->slave_fd, &vmsg)) { - pthread_mutex_unlock(&dev->slave_mutex); - return -EIO; - } - - /* Also unlocks the slave_mutex */ - res = vu_process_message_reply(dev, &vmsg, &payload); + res = vu_message_slave_send_receive(dev, &vmsg, &payload); if (!res) { return -EIO; } + /* * Payload is delivered as uint64_t but is actually signed for * errors.
dev->slave_mutex needs to be taken when sending messages on slave_fd. Currently _vu_queue_notify() does not do that. Introduce a helper vu_message_slave_send_receive() which sends as well as receive response. Use this helper in all the paths which send message on slave_fd channel. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- subprojects/libvhost-user/libvhost-user.c | 50 ++++++++++++----------- 1 file changed, 27 insertions(+), 23 deletions(-)