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sys/dev/hyperv/utilities/hv_snapshot.c

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/*-
* Copyright (c) 2016 Microsoft Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/bus.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/taskqueue.h>
#include <sys/selinfo.h>
#include <sys/sysctl.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/kthread.h>
#include <sys/syscallsubr.h>
#include <sys/sysproto.h>
#include <sys/un.h>
#include <sys/endian.h>
#include <sys/sema.h>
#include <sys/signal.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <sys/mutex.h>
#include <sys/callout.h>
#include <dev/hyperv/include/hyperv.h>
#include <dev/hyperv/utilities/hv_utilreg.h>
#include <dev/hyperv/utilities/vmbus_icreg.h>
#include "hv_util.h"
#include "hv_snapshot.h"
#include "vmbus_if.h"
#define VSS_MAJOR 5
#define VSS_MINOR 0
#define VSS_MSGVER VMBUS_IC_VERSION(VSS_MAJOR, VSS_MINOR)
#define VSS_FWVER_MAJOR 3
#define VSS_FWVER VMBUS_IC_VERSION(VSS_FWVER_MAJOR, 0)
#define TIMEOUT_LIMIT (15) // seconds
enum hv_vss_op {
VSS_OP_CREATE = 0,
VSS_OP_DELETE,
VSS_OP_HOT_BACKUP,
VSS_OP_GET_DM_INFO,
VSS_OP_BU_COMPLETE,
/*
* Following operations are only supported with IC version >= 5.0
*/
VSS_OP_FREEZE, /* Freeze the file systems in the VM */
VSS_OP_THAW, /* Unfreeze the file systems */
VSS_OP_AUTO_RECOVER,
VSS_OP_COUNT /* Number of operations, must be last */
};
/*
* Header for all VSS messages.
*/
struct hv_vss_hdr {
struct vmbus_icmsg_hdr ic_hdr;
uint8_t operation;
uint8_t reserved[7];
} __attribute__((packed));
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Use __packed.

sepherosa_gmail.com: Use __packed.
/*
* Flag values for the hv_vss_check_feature. Here supports only
* one value.
*/
#define VSS_HBU_NO_AUTO_RECOVERY 0x00000005
struct hv_vss_check_feature {
uint32_t flags;
} __attribute__((packed));
struct hv_vss_check_dm_info {
uint32_t flags;
} __attribute__((packed));
struct hv_vss_msg {
union {
struct hv_vss_hdr vss_hdr;
} hdr;
union {
struct hv_vss_check_feature vss_cf;
struct hv_vss_check_dm_info dm_info;
} body;
} __attribute__((packed));
struct hv_vss_req {
struct hv_vss_opt_msg opt_msg; /* used to communicate with daemon */
struct hv_vss_msg msg; /* used to communicate with host */
} __attribute__((packed));
/* hv_vss debug control */
static int hv_vss_log = 0;
#define hv_vss_log_error(...) do { \
if (hv_vss_log > 0) \
log(LOG_ERR, "hv_vss: " __VA_ARGS__); \
} while (0)
#define hv_vss_log_info(...) do { \
if (hv_vss_log > 1) \
log(LOG_INFO, "hv_vss: " __VA_ARGS__); \
} while (0)
static const struct vmbus_ic_desc vmbus_vss_descs[] = {
{
.ic_guid = { .hv_guid = {
0x29, 0x2e, 0xfa, 0x35, 0x23, 0xea, 0x36, 0x42,
0x96, 0xae, 0x3a, 0x6e, 0xba, 0xcb, 0xa4, 0x40} },
.ic_desc = "Hyper-V VSS"
},
VMBUS_IC_DESC_END
};
static const char * vss_opt_name[] = {"None", "VSSCheck", "Freeze", "Thaw"};
/* character device prototypes */
static d_open_t hv_vss_dev_open;
static d_close_t hv_vss_dev_close;
static d_poll_t hv_vss_dev_daemon_poll;
static d_ioctl_t hv_vss_dev_daemon_ioctl;
static d_open_t hv_appvss_dev_open;
static d_close_t hv_appvss_dev_close;
static d_poll_t hv_appvss_dev_daemon_poll;
static d_ioctl_t hv_appvss_dev_daemon_ioctl;
typedef void vss_timeout_t(void *arg);
static vss_timeout_t hv_vss_freeze_thaw_timeout;
static vss_timeout_t hv_vss_check_timeout;
/* hv_vss character device structure */
static struct cdevsw hv_vss_cdevsw =
{
.d_version = D_VERSION,
.d_open = hv_vss_dev_open,
.d_close = hv_vss_dev_close,
.d_poll = hv_vss_dev_daemon_poll,
.d_ioctl = hv_vss_dev_daemon_ioctl,
.d_name = FS_VSS_DEV_NAME,
};
static struct cdevsw hv_appvss_cdevsw =
{
.d_version = D_VERSION,
.d_open = hv_appvss_dev_open,
.d_close = hv_appvss_dev_close,
.d_poll = hv_appvss_dev_daemon_poll,
.d_ioctl = hv_appvss_dev_daemon_ioctl,
.d_name = APP_VSS_DEV_NAME,
};
/*
* Global state to track and synchronize the transaction requests from the host.
* The VSS allows user to register their function to do freeze/thaw for application.
* VSS kernel will notify both vss daemon and user application if it is registered.
* The implementation state transition is illustrated by:
* https://clovertrail.github.io/assets/vssdot.png
*/
typedef struct hv_vss_sc {
struct hv_util_sc util_sc;
device_t dev;
struct task task;
/*
* mutex is used to protect access of list/queue,
* callout in request is also used this mutex.
*/
struct mtx pending_mutex;
/*
* req_free_list contains all free items
*/
LIST_HEAD(, hv_vss_req_internal) req_free_list;
/*
* msg was transferred from host to notify queue, and
* ack queue. Finally, it was recyled to free list.
*/
STAILQ_HEAD(, hv_vss_req_internal) to_notify_queue;
STAILQ_HEAD(, hv_vss_req_internal) to_ack_queue;
/* Indicates if daemon registered with driver */
boolean_t register_done;
boolean_t app_register_done;
/* cdev for file system freeze/thaw */
struct cdev *hv_vss_dev;
/* cdev for application freeze/thaw */
struct cdev *hv_appvss_dev;
struct proc *daemon_task;
struct proc *app_task;
struct selinfo hv_vss_selinfo;
struct selinfo hv_appvss_selinfo;
} hv_vss_sc;
typedef struct hv_vss_req_internal {
LIST_ENTRY(hv_vss_req_internal) link;
STAILQ_ENTRY(hv_vss_req_internal) slink;
struct hv_vss_req vss_req;
/* Rcv buffer for communicating with the host*/
uint8_t *rcv_buf;
/* Length of host message */
uint32_t host_msg_len;
/* Host message id */
uint64_t host_msg_id;
hv_vss_sc *sc;
struct callout callout;
} hv_vss_req_internal;
#define SEARCH_REMOVE_REQ_LOCKED(reqp, queue, link, tmp, id) \
do { \
STAILQ_FOREACH_SAFE(reqp, queue, link, tmp) { \
if (reqp->vss_req.opt_msg.msgid == id) { \
STAILQ_REMOVE(queue, \
reqp, hv_vss_req_internal, link); \
break; \
} \
} \
} while (0)
/*
* Callback routine that gets called whenever there is a message from host
*/
static void
hv_vss_callback(struct vmbus_channel *chan __unused, void *context)
{
hv_vss_sc *sc = (hv_vss_sc*)context;
if (sc->register_done) {
hv_vss_log_info("%s: Queuing work item\n", __func__);
taskqueue_enqueue(taskqueue_thread, &sc->task);
} else {
if (sc->daemon_task)
hv_vss_log_info("%s: daemon was killed!\n", __func__);
}
hv_vss_log_info("%s: received msg from host\n", __func__);
}
/*
* Send the response back to the host.
*/
static void
hv_vss_respond_host(uint8_t *rcv_buf, struct vmbus_channel *ch,
uint32_t recvlen, uint64_t requestid, uint32_t error)
{
struct vmbus_icmsg_hdr *hv_icmsg_hdrp;
hv_icmsg_hdrp = (struct vmbus_icmsg_hdr *)rcv_buf;
hv_icmsg_hdrp->ic_status = error;
hv_icmsg_hdrp->ic_flags = HV_ICMSGHDRFLAG_TRANSACTION | HV_ICMSGHDRFLAG_RESPONSE;
error = vmbus_chan_send(ch, VMBUS_CHANPKT_TYPE_INBAND, 0,
rcv_buf, recvlen, requestid);
if (error)
hv_vss_log_info("%s: hv_vss_respond_host: sendpacket error:%d\n",
__func__, error);
}
static void
hv_vss_notify_host_result(struct hv_vss_req_internal *reqp, uint32_t status)
{
struct hv_vss_msg* msg = (struct hv_vss_msg *)reqp->rcv_buf;
hv_vss_sc *sc = reqp->sc;
if (reqp->vss_req.opt_msg.opt == HV_VSS_CHECK) {
msg->body.vss_cf.flags = VSS_HBU_NO_AUTO_RECOVERY;
hv_vss_log_info("%s, response %s to host\n",
__func__, status == HV_S_OK ? "HBU supp" : "HBU Not supp");
}
hv_vss_respond_host(reqp->rcv_buf, vmbus_get_channel(reqp->sc->dev),
reqp->host_msg_len, reqp->host_msg_id, status);
/* recycle the request */
mtx_lock(&sc->pending_mutex);
LIST_INSERT_HEAD(&sc->req_free_list, reqp, link);
mtx_unlock(&sc->pending_mutex);
}
static void
hv_vss_cp_vssreq_to_user(struct hv_vss_req_internal *reqp, struct hv_vss_opt_msg *userdata)
{
struct hv_vss_req *hv_vss_dev_buf;
hv_vss_dev_buf = &reqp->vss_req;
hv_vss_dev_buf->opt_msg.opt = HV_VSS_NONE;
switch (reqp->vss_req.msg.hdr.vss_hdr.operation) {
case VSS_OP_FREEZE:
hv_vss_dev_buf->opt_msg.opt = HV_VSS_FREEZE;
break;
case VSS_OP_THAW:
hv_vss_dev_buf->opt_msg.opt = HV_VSS_THAW;
break;
case VSS_OP_HOT_BACKUP:
hv_vss_dev_buf->opt_msg.opt = HV_VSS_CHECK;
break;
}
*userdata = hv_vss_dev_buf->opt_msg;
hv_vss_log_info("%s, read data from user for "
"%s (%ld) \n", __func__, vss_opt_name[userdata->opt], userdata->msgid);
}
/**
* Remove the request id from app notifiy or ack queue,
* and recyle the request by inserting it to free list.
*
* When app was notified but not yet sending ack, the request
* should locate in either notify queue or ack queue.
*/
static struct hv_vss_req_internal*
hv_vss_req_recyle(hv_vss_sc *sc, uint64_t req_id)
{
struct hv_vss_req_internal *reqp, *tmp;
mtx_lock(&sc->pending_mutex);
SEARCH_REMOVE_REQ_LOCKED(reqp, &sc->to_notify_queue, slink, tmp, req_id);
if (reqp == NULL)
SEARCH_REMOVE_REQ_LOCKED(reqp, &sc->to_ack_queue, slink, tmp, req_id);
if (reqp != NULL)
LIST_INSERT_HEAD(&sc->req_free_list, reqp, link);
mtx_unlock(&sc->pending_mutex);
return (reqp);
}
/**
* Actions for daemon who has been notified.
*/
static void
hv_vss_notified(hv_vss_sc *sc, struct hv_vss_opt_msg *userdata)
{
struct hv_vss_req_internal *reqp;
mtx_lock(&sc->pending_mutex);
if (!STAILQ_EMPTY(&sc->to_notify_queue)) {
reqp = STAILQ_FIRST(&sc->to_notify_queue);
hv_vss_cp_vssreq_to_user(reqp, userdata);
STAILQ_REMOVE_HEAD(&sc->to_notify_queue, slink);
/* insert the msg to queue for write */
STAILQ_INSERT_TAIL(&sc->to_ack_queue, reqp, slink);
userdata->status = VSS_SUCCESS;
} else {
/* Timeout occur, thus request was removed from queue. */
hv_vss_log_info("%s: notify queue is empty!\n", __func__);
userdata->status = VSS_FAIL;
}
mtx_unlock(&sc->pending_mutex);
}
static void
hv_vss_notify(hv_vss_sc *sc, struct hv_vss_req_internal *reqp, struct selinfo* sel)
{
uint32_t opt = reqp->vss_req.opt_msg.opt;
mtx_lock(&sc->pending_mutex);
STAILQ_INSERT_TAIL(&sc->to_notify_queue, reqp, slink);
mtx_unlock(&sc->pending_mutex);
selwakeup(sel);
hv_vss_log_info("%s: issuing query %s (%ld) to %s\n", __func__,
vss_opt_name[opt], reqp->vss_req.opt_msg.msgid,
&sc->hv_vss_selinfo == sel ? "daemon" : "app");
}
/**
* Actions for daemon who has acknowledged.
*/
static void
hv_vss_daemon_acked(hv_vss_sc *sc, struct hv_vss_opt_msg *userdata)
{
struct hv_vss_req_internal *reqp, *tmp;
uint64_t req_id;
int opt;
uint32_t status;
opt = userdata->opt;
req_id = userdata->msgid;
status = userdata->status;
mtx_lock(&sc->pending_mutex);
SEARCH_REMOVE_REQ_LOCKED(reqp, &sc->to_ack_queue, slink, tmp, req_id);
mtx_unlock(&sc->pending_mutex);
if (reqp == NULL) {
hv_vss_log_info("%s Timeout: fail to find daemon ack request\n",
__func__);
userdata->status = VSS_FAIL;
return;
}
KASSERT(opt == reqp->vss_req.opt_msg.opt, ("Mismatched VSS operation!"));
hv_vss_log_info("%s, get response %d from daemon for %s (%ld) \n", __func__,
status, vss_opt_name[opt], req_id);
switch (opt) {
case HV_VSS_CHECK:
case HV_VSS_FREEZE:
callout_drain(&reqp->callout);
hv_vss_notify_host_result(reqp,
status == VSS_SUCCESS ? HV_S_OK : HV_E_FAIL);
break;
case HV_VSS_THAW:
if (sc->app_register_done) {
if (status == VSS_SUCCESS) {
hv_vss_notify(sc, reqp, &sc->hv_appvss_selinfo);
} else {
/* handle error */
callout_drain(&reqp->callout);
hv_vss_notify_host_result(reqp, HV_E_FAIL);
}
} else {
callout_drain(&reqp->callout);
hv_vss_notify_host_result(reqp,
status == VSS_SUCCESS ? HV_S_OK : HV_E_FAIL);
}
break;
}
}
/**
* Actions for app who has acknowledged.
*/
static void
hv_vss_app_acked(hv_vss_sc *sc, struct hv_vss_opt_msg *userdata)
{
struct hv_vss_req_internal *reqp, *tmp;
uint64_t req_id;
int opt;
uint8_t status;
opt = userdata->opt;
req_id = userdata->msgid;
status = userdata->status;
mtx_lock(&sc->pending_mutex);
SEARCH_REMOVE_REQ_LOCKED(reqp, &sc->to_ack_queue, slink, tmp, req_id);
mtx_unlock(&sc->pending_mutex);
if (reqp == NULL) {
hv_vss_log_info("%s Timeout: fail to find app ack request\n",
__func__);
userdata->status = VSS_FAIL;
return;
}
KASSERT(opt == reqp->vss_req.opt_msg.opt, ("Mismatched VSS operation!"));
hv_vss_log_info("%s, get response %d from app for %s (%ld) \n",
__func__, status, vss_opt_name[opt], req_id);
if (sc->register_done) {
switch (opt) {
case HV_VSS_CHECK:
case HV_VSS_FREEZE:
if (status == VSS_SUCCESS) {
hv_vss_notify(sc, reqp, &sc->hv_vss_selinfo);
} else {
/* handle error */
callout_drain(&reqp->callout);
hv_vss_notify_host_result(reqp, HV_E_FAIL);
}
break;
case HV_VSS_THAW:
callout_drain(&reqp->callout);
hv_vss_notify_host_result(reqp,
status == VSS_SUCCESS ? HV_S_OK : HV_E_FAIL);
break;
}
} else {
hv_vss_log_info("%s, Fatal: vss daemon was killed\n", __func__);
}
}
static int
hv_vss_dev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
{
struct proc *td_proc;
td_proc = td->td_proc;
hv_vss_sc *sc = (hv_vss_sc*)dev->si_drv1;
hv_vss_log_info("%s: %s opens device \"%s\" successfully.\n",
__func__, td_proc->p_comm, FS_VSS_DEV_NAME);
if (sc->register_done)
return (-EBUSY);
sc->register_done = true;
hv_vss_callback(vmbus_get_channel(sc->dev), dev->si_drv1);
sc->daemon_task = curproc;
return (0);
}
static int
hv_vss_dev_close(struct cdev *dev, int fflag __unused, int devtype __unused,
struct thread *td)
{
struct proc *td_proc;
td_proc = td->td_proc;
hv_vss_sc *sc = (hv_vss_sc*)dev->si_drv1;
hv_vss_log_info("%s: %s closes device \"%s\"\n",
__func__, td_proc->p_comm, FS_VSS_DEV_NAME);
sc->register_done = false;
return (0);
}
static int
hv_vss_dev_daemon_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
{
struct proc *td_proc;
hv_vss_sc *sc;
td_proc = td->td_proc;
sc = (hv_vss_sc*)dev->si_drv1;
hv_vss_log_info("%s: %s invoked vss ioctl\n", __func__, td_proc->p_comm);
struct hv_vss_opt_msg* userdata = (struct hv_vss_opt_msg*)data;
switch(cmd) {
case IOCHVVSSREAD:
hv_vss_notified(sc, userdata);
break;
case IOCHVVSSWRITE:
hv_vss_daemon_acked(sc, userdata);
break;
}
return (0);
}
/*
* hv_vss_daemon poll invokes this function to check if data is available
* for daemon to read.
*/
static int
hv_vss_dev_daemon_poll(struct cdev *dev, int events, struct thread *td)
{
int revent = 0;
hv_vss_sc *sc = (hv_vss_sc*)dev->si_drv1;
mtx_lock(&sc->pending_mutex);
/**
* if there is data ready, inform daemon's poll
*/
if (!STAILQ_EMPTY(&sc->to_notify_queue)) {
revent = POLLIN;
}
mtx_unlock(&sc->pending_mutex);
selrecord(td, &sc->hv_vss_selinfo);
hv_vss_log_info("%s return 0x%x\n", __func__, revent);
return (revent);
}
static int
hv_appvss_dev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
{
struct proc *td_proc;
td_proc = td->td_proc;
hv_vss_sc *sc = (hv_vss_sc*)dev->si_drv1;
hv_vss_log_info("%s: %s opens device \"%s\" successfully.\n",
__func__, td_proc->p_comm, APP_VSS_DEV_NAME);
if (sc->app_register_done)
return (-EBUSY);
sc->app_register_done = true;
sc->app_task = curproc;
return (0);
}
static int
hv_appvss_dev_close(struct cdev *dev, int fflag __unused, int devtype __unused,
struct thread *td)
{
struct proc *td_proc;
td_proc = td->td_proc;
hv_vss_sc *sc = (hv_vss_sc*)dev->si_drv1;
hv_vss_log_info("%s: %s closes device \"%s\".\n",
__func__, td_proc->p_comm, APP_VSS_DEV_NAME);
sc->app_register_done = false;
return (0);
}
static int
hv_appvss_dev_daemon_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
{
struct proc *td_proc;
hv_vss_sc *sc;
td_proc = td->td_proc;
sc = (hv_vss_sc*)dev->si_drv1;
hv_vss_log_info("%s: %s invoked vss ioctl\n", __func__, td_proc->p_comm);
struct hv_vss_opt_msg* userdata = (struct hv_vss_opt_msg*)data;
switch(cmd) {
case IOCHVVSSREAD:
hv_vss_notified(sc, userdata);
break;
case IOCHVVSSWRITE:
hv_vss_app_acked(sc, userdata);
break;
}
return (0);
}
/*
* hv_vss_daemon poll invokes this function to check if data is available
* for daemon to read.
*/
static int
hv_appvss_dev_daemon_poll(struct cdev *dev, int events, struct thread *td)
{
int revent = 0;
hv_vss_sc *sc = (hv_vss_sc*)dev->si_drv1;
mtx_lock(&sc->pending_mutex);
/**
* if there is data ready, inform daemon's poll
*/
if (!STAILQ_EMPTY(&sc->to_notify_queue)) {
revent = POLLIN;
}
mtx_unlock(&sc->pending_mutex);
selrecord(td, &sc->hv_appvss_selinfo);
hv_vss_log_info("%s return 0x%x\n", __func__, revent);
return (revent);
}
static void
hv_vss_timeout(void *arg)
{
hv_vss_req_internal *reqp = arg;
hv_vss_req_internal *request;
hv_vss_sc* sc = reqp->sc;
uint64_t req_id = reqp->vss_req.opt_msg.msgid;
hv_vss_log_info("%s request timeout\n", vss_opt_name[reqp->vss_req.opt_msg.opt]);
request = hv_vss_req_recyle(sc, req_id);
KASSERT(request != NULL, ("timeout but fail to find request"));
hv_vss_notify_host_result(reqp, HV_E_FAIL);
}
/*
* This routine is called whenever a message is received from the host
*/
static void
hv_vss_init_req(hv_vss_req_internal *reqp,
uint32_t recvlen, uint64_t requestid, uint8_t *vss_buf, hv_vss_sc *sc)
{
struct timespec vm_ts;
struct hv_vss_msg* msg = (struct hv_vss_msg *)vss_buf;
memset(reqp, 0, __offsetof(hv_vss_req_internal, callout));
reqp->host_msg_len = recvlen;
reqp->host_msg_id = requestid;
reqp->rcv_buf = vss_buf;
reqp->sc = sc;
memcpy(&reqp->vss_req.msg,
(struct hv_vss_msg *)vss_buf, sizeof(struct hv_vss_msg));
/* set the opt for users */
switch (msg->hdr.vss_hdr.operation) {
case VSS_OP_FREEZE:
reqp->vss_req.opt_msg.opt = HV_VSS_FREEZE;
break;
case VSS_OP_THAW:
reqp->vss_req.opt_msg.opt = HV_VSS_THAW;
break;
case VSS_OP_HOT_BACKUP:
reqp->vss_req.opt_msg.opt = HV_VSS_CHECK;
break;
}
/* Use a timestamp as msg request ID */
nanotime(&vm_ts);
reqp->vss_req.opt_msg.msgid = (vm_ts.tv_sec * NANOSEC) + vm_ts.tv_nsec;
}
static hv_vss_req_internal*
hv_vss_fetch_new_req(hv_vss_sc *sc)
{
hv_vss_req_internal *reqp;
if (LIST_EMPTY(&sc->req_free_list)) {
/* TODO Error: no buffer */
hv_vss_log_info("Error: No buffer\n");
return (NULL);
}
reqp = LIST_FIRST(&sc->req_free_list);
LIST_REMOVE(reqp, link);
return (reqp);
}
static hv_vss_req_internal*
hv_vss_get_new_req_locked(hv_vss_sc *sc)
{
if (!STAILQ_EMPTY(&sc->to_notify_queue) ||
!STAILQ_EMPTY(&sc->to_ack_queue)) {
/*
* There is request coming from host before
* finishing previous requests
*/
hv_vss_log_info("%s: Warning: there is new request "
"coming before finishing previous requests\n", __func__);
return (NULL);
}
return hv_vss_fetch_new_req(sc);
}
static void
hv_vss_start_notify(hv_vss_req_internal *reqp, uint32_t opt)
{
hv_vss_sc *sc = reqp->sc;
/*
* Freeze/Check notification sequence: kernel -> app -> daemon(fs)
* Thaw notification sequence: kernel -> daemon(fs) -> app
*
* We should wake up the daemon, in case it's doing poll().
* The response should be received after 5s, otherwise, trigger timeout.
*/
switch (opt) {
case VSS_OP_FREEZE:
case VSS_OP_HOT_BACKUP:
if (sc->app_register_done)
hv_vss_notify(sc, reqp, &sc->hv_appvss_selinfo);
else
hv_vss_notify(sc, reqp, &sc->hv_vss_selinfo);
callout_reset_sbt(&reqp->callout, SBT_1S * TIMEOUT_LIMIT, 0,
hv_vss_timeout, reqp, 0);
break;
case VSS_OP_THAW:
hv_vss_notify(sc, reqp, &sc->hv_vss_selinfo);
callout_reset_sbt(&reqp->callout, SBT_1S * TIMEOUT_LIMIT, 0,
hv_vss_timeout, reqp, 0);
break;
}
}
/*
* Function to read the vss request buffer from host
sepherosa_gmail.comUnsubmitted
Not Done
Inline Actions

callout_reset(..., hz * sec, );

sepherosa_gmail.com: callout_reset(..., hz * sec, );
* and interact with daemon
*/
static void
hv_vss_process_request(void *context, int pending __unused)
{
uint8_t *vss_buf;
struct vmbus_channel *channel;
uint32_t recvlen = 0;
uint64_t requestid;
struct vmbus_icmsg_hdr *icmsghdrp;
int ret = 0;
hv_vss_sc *sc;
hv_vss_req_internal *reqp;
hv_vss_log_info("%s: entering hv_vss_process_request\n", __func__);
sc = (hv_vss_sc*)context;
vss_buf = sc->util_sc.receive_buffer;
channel = vmbus_get_channel(sc->dev);
recvlen = sc->util_sc.ic_buflen;
ret = vmbus_chan_recv(channel, vss_buf, &recvlen, &requestid);
KASSERT(ret != ENOBUFS, ("hvvss recvbuf is not large enough"));
/* XXX check recvlen to make sure that it contains enough data */
while ((ret == 0) && (recvlen > 0)) {
icmsghdrp = (struct vmbus_icmsg_hdr *)vss_buf;
if (icmsghdrp->ic_type == HV_ICMSGTYPE_NEGOTIATE) {
ret = vmbus_ic_negomsg(&sc->util_sc, vss_buf,
&recvlen, VSS_FWVER, VSS_MSGVER);
hv_vss_respond_host(vss_buf, vmbus_get_channel(sc->dev),
recvlen, requestid, ret);
hv_vss_log_info("%s: version negotiated\n", __func__);
} else {
struct hv_vss_msg* msg = (struct hv_vss_msg *)vss_buf;
switch(msg->hdr.vss_hdr.operation) {
case VSS_OP_FREEZE:
case VSS_OP_THAW:
case VSS_OP_HOT_BACKUP:
mtx_lock(&sc->pending_mutex);
reqp = hv_vss_get_new_req_locked(sc);
mtx_unlock(&sc->pending_mutex);
if (reqp == NULL) {
/* ignore this request from host */
break;
}
hv_vss_init_req(reqp, recvlen, requestid, vss_buf, sc);
hv_vss_log_info("%s: receive %s (%ld) from host\n",
__func__,
vss_opt_name[reqp->vss_req.opt_msg.opt],
reqp->vss_req.opt_msg.msgid);
hv_vss_start_notify(reqp, msg->hdr.vss_hdr.operation);
break;
case VSS_OP_GET_DM_INFO:
hv_vss_log_info("%s: receive GET_DM_INFO from host\n",
__func__);
msg->body.dm_info.flags = 0;
hv_vss_respond_host(vss_buf, vmbus_get_channel(sc->dev),
recvlen, requestid, HV_S_OK);
break;
default:
device_printf(sc->dev, "Unknown opt from host: %d\n",
msg->hdr.vss_hdr.operation);
break;
}
}
/*
* Try reading next buffer
*/
recvlen = sc->util_sc.ic_buflen;
ret = vmbus_chan_recv(channel, vss_buf, &recvlen, &requestid);
KASSERT(ret != ENOBUFS, ("hvvss recvbuf is not large enough"));
/* XXX check recvlen to make sure that it contains enough data */
hv_vss_log_info("%s: read: context %p, ret =%d, recvlen=%d\n",
__func__, context, ret, recvlen);
}
}
static int
hv_vss_probe(device_t dev)
{
return (vmbus_ic_probe(dev, vmbus_vss_descs));
}
static int
hv_vss_init_send_receive_queue(device_t dev)
{
hv_vss_sc *sc = (hv_vss_sc*)device_get_softc(dev);
int i;
const int max_list = 4; /* It is big enough for the list */
struct hv_vss_req_internal* reqp;
LIST_INIT(&sc->req_free_list);
STAILQ_INIT(&sc->to_notify_queue);
STAILQ_INIT(&sc->to_ack_queue);
for (i = 0; i < max_list; i++) {
reqp = malloc(sizeof(struct hv_vss_req_internal),
M_DEVBUF, M_WAITOK|M_ZERO);
LIST_INSERT_HEAD(&sc->req_free_list, reqp, link);
callout_init_mtx(&reqp->callout, &sc->pending_mutex, 0);
}
return (0);
}
static int
hv_vss_destroy_send_receive_queue(device_t dev)
{
hv_vss_sc *sc = (hv_vss_sc*)device_get_softc(dev);
hv_vss_req_internal* reqp;
while (!LIST_EMPTY(&sc->req_free_list)) {
reqp = LIST_FIRST(&sc->req_free_list);
LIST_REMOVE(reqp, link);
free(reqp, M_DEVBUF);
}
while (!STAILQ_EMPTY(&sc->to_notify_queue)) {
reqp = STAILQ_FIRST(&sc->to_notify_queue);
STAILQ_REMOVE_HEAD(&sc->to_notify_queue, slink);
free(reqp, M_DEVBUF);
}
while (!STAILQ_EMPTY(&sc->to_ack_queue)) {
reqp = STAILQ_FIRST(&sc->to_ack_queue);
STAILQ_REMOVE_HEAD(&sc->to_ack_queue, slink);
free(reqp, M_DEVBUF);
}
return (0);
}
static int
hv_vss_attach(device_t dev)
{
int error;
struct sysctl_oid_list *child;
struct sysctl_ctx_list *ctx;
hv_vss_sc *sc = (hv_vss_sc*)device_get_softc(dev);
sc->dev = dev;
mtx_init(&sc->pending_mutex, "hv_vss pending mutex",
NULL, MTX_DEF);
ctx = device_get_sysctl_ctx(dev);
child = SYSCTL_CHILDREN(device_get_sysctl_tree(dev));
SYSCTL_ADD_INT(ctx, child, OID_AUTO, "hv_vss_log",
CTLFLAG_RWTUN, &hv_vss_log, 0, "Hyperv VSS service log level");
TASK_INIT(&sc->task, 0, hv_vss_process_request, sc);
/* create character device for file system freeze/thaw */
error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
&sc->hv_vss_dev,
&hv_vss_cdevsw,
0,
UID_ROOT,
GID_WHEEL,
0640,
FS_VSS_DEV_NAME);
if (error != 0) {
hv_vss_log_info("Fail to create '%s': %d\n", FS_VSS_DEV_NAME, error);
return (error);
}
sc->hv_vss_dev->si_drv1 = sc;
/* create character device for application freeze/thaw */
error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
&sc->hv_appvss_dev,
&hv_appvss_cdevsw,
0,
UID_ROOT,
GID_WHEEL,
0640,
APP_VSS_DEV_NAME);
if (error != 0) {
hv_vss_log_info("Fail to create '%s': %d\n", APP_VSS_DEV_NAME, error);
return (error);
}
sc->hv_appvss_dev->si_drv1 = sc;
hv_vss_init_send_receive_queue(dev);
return hv_util_attach(dev, hv_vss_callback);
}
static int
hv_vss_detach(device_t dev)
{
hv_vss_sc *sc = (hv_vss_sc*)device_get_softc(dev);
if (sc->daemon_task != NULL) {
PROC_LOCK(sc->daemon_task);
kern_psignal(sc->daemon_task, SIGKILL);
PROC_UNLOCK(sc->daemon_task);
}
if (sc->app_task != NULL) {
PROC_LOCK(sc->app_task);
kern_psignal(sc->app_task, SIGKILL);
PROC_UNLOCK(sc->app_task);
}
hv_vss_destroy_send_receive_queue(dev);
destroy_dev(sc->hv_vss_dev);
destroy_dev(sc->hv_appvss_dev);
return hv_util_detach(dev);
}
static device_method_t vss_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, hv_vss_probe),
DEVMETHOD(device_attach, hv_vss_attach),
DEVMETHOD(device_detach, hv_vss_detach),
{ 0, 0 }
};
static driver_t vss_driver = { "hvvss", vss_methods, sizeof(hv_vss_sc)};
static devclass_t vss_devclass;
DRIVER_MODULE(hv_vss, vmbus, vss_driver, vss_devclass, NULL, NULL);
MODULE_VERSION(hv_vss, 1);
MODULE_DEPEND(hv_vss, vmbus, 1, 1, 1);