diff options
| -rw-r--r-- | drivers/hv/Makefile | 2 | ||||
| -rw-r--r-- | drivers/hv/hv_snapshot.c | 287 | ||||
| -rw-r--r-- | drivers/hv/hv_util.c | 10 | ||||
| -rw-r--r-- | include/linux/hyperv.h | 69 | ||||
| -rw-r--r-- | include/uapi/linux/connector.h | 5 | ||||
| -rw-r--r-- | tools/hv/hv_vss_daemon.c | 220 |
6 files changed, 591 insertions, 2 deletions
diff --git a/drivers/hv/Makefile b/drivers/hv/Makefile index e6abfa02d8b..0a74b566118 100644 --- a/drivers/hv/Makefile +++ b/drivers/hv/Makefile @@ -5,4 +5,4 @@ obj-$(CONFIG_HYPERV_BALLOON) += hv_balloon.o hv_vmbus-y := vmbus_drv.o \ hv.o connection.o channel.o \ channel_mgmt.o ring_buffer.o -hv_utils-y := hv_util.o hv_kvp.o +hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c new file mode 100644 index 00000000000..8ad5653ce44 --- /dev/null +++ b/drivers/hv/hv_snapshot.c @@ -0,0 +1,287 @@ +/* + * An implementation of host initiated guest snapshot. + * + * + * Copyright (C) 2013, Microsoft, Inc. + * Author : K. Y. Srinivasan <kys@microsoft.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for more + * details. + * + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/net.h> +#include <linux/nls.h> +#include <linux/connector.h> +#include <linux/workqueue.h> +#include <linux/hyperv.h> + + + +/* + * Global state maintained for transaction that is being processed. + * Note that only one transaction can be active at any point in time. + * + * This state is set when we receive a request from the host; we + * cleanup this state when the transaction is completed - when we respond + * to the host with the key value. + */ + +static struct { + bool active; /* transaction status - active or not */ + int recv_len; /* number of bytes received. */ + struct vmbus_channel *recv_channel; /* chn we got the request */ + u64 recv_req_id; /* request ID. */ + struct hv_vss_msg *msg; /* current message */ +} vss_transaction; + + +static void vss_respond_to_host(int error); + +static struct cb_id vss_id = { CN_VSS_IDX, CN_VSS_VAL }; +static const char vss_name[] = "vss_kernel_module"; +static __u8 *recv_buffer; + +static void vss_send_op(struct work_struct *dummy); +static DECLARE_WORK(vss_send_op_work, vss_send_op); + +/* + * Callback when data is received from user mode. + */ + +static void +vss_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) +{ + struct hv_vss_msg *vss_msg; + + vss_msg = (struct hv_vss_msg *)msg->data; + + if (vss_msg->vss_hdr.operation == VSS_OP_REGISTER) { + pr_info("VSS daemon registered\n"); + vss_transaction.active = false; + if (vss_transaction.recv_channel != NULL) + hv_vss_onchannelcallback(vss_transaction.recv_channel); + return; + + } + vss_respond_to_host(vss_msg->error); +} + + +static void vss_send_op(struct work_struct *dummy) +{ + int op = vss_transaction.msg->vss_hdr.operation; + struct cn_msg *msg; + struct hv_vss_msg *vss_msg; + + msg = kzalloc(sizeof(*msg) + sizeof(*vss_msg), GFP_ATOMIC); + if (!msg) + return; + + vss_msg = (struct hv_vss_msg *)msg->data; + + msg->id.idx = CN_VSS_IDX; + msg->id.val = CN_VSS_VAL; + + vss_msg->vss_hdr.operation = op; + msg->len = sizeof(struct hv_vss_msg); + + cn_netlink_send(msg, 0, GFP_ATOMIC); + kfree(msg); + + return; +} + +/* + * Send a response back to the host. + */ + +static void +vss_respond_to_host(int error) +{ + struct icmsg_hdr *icmsghdrp; + u32 buf_len; + struct vmbus_channel *channel; + u64 req_id; + + /* + * If a transaction is not active; log and return. + */ + + if (!vss_transaction.active) { + /* + * This is a spurious call! + */ + pr_warn("VSS: Transaction not active\n"); + return; + } + /* + * Copy the global state for completing the transaction. Note that + * only one transaction can be active at a time. + */ + + buf_len = vss_transaction.recv_len; + channel = vss_transaction.recv_channel; + req_id = vss_transaction.recv_req_id; + vss_transaction.active = false; + + icmsghdrp = (struct icmsg_hdr *) + &recv_buffer[sizeof(struct vmbuspipe_hdr)]; + + if (channel->onchannel_callback == NULL) + /* + * We have raced with util driver being unloaded; + * silently return. + */ + return; + + icmsghdrp->status = error; + + icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE; + + vmbus_sendpacket(channel, recv_buffer, buf_len, req_id, + VM_PKT_DATA_INBAND, 0); + +} + +/* + * This callback is invoked when we get a VSS message from the host. + * The host ensures that only one VSS transaction can be active at a time. + */ + +void hv_vss_onchannelcallback(void *context) +{ + struct vmbus_channel *channel = context; + u32 recvlen; + u64 requestid; + struct hv_vss_msg *vss_msg; + + + struct icmsg_hdr *icmsghdrp; + struct icmsg_negotiate *negop = NULL; + + if (vss_transaction.active) { + /* + * We will defer processing this callback once + * the current transaction is complete. + */ + vss_transaction.recv_channel = channel; + return; + } + + vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen, + &requestid); + + if (recvlen > 0) { + icmsghdrp = (struct icmsg_hdr *)&recv_buffer[ + sizeof(struct vmbuspipe_hdr)]; + + if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) { + vmbus_prep_negotiate_resp(icmsghdrp, negop, + recv_buffer, MAX_SRV_VER, MAX_SRV_VER); + /* + * We currently negotiate the highest number the + * host has presented. If this version is not + * atleast 5.0, reject. + */ + negop = (struct icmsg_negotiate *)&recv_buffer[ + sizeof(struct vmbuspipe_hdr) + + sizeof(struct icmsg_hdr)]; + + if (negop->icversion_data[1].major < 5) + negop->icframe_vercnt = 0; + } else { + vss_msg = (struct hv_vss_msg *)&recv_buffer[ + sizeof(struct vmbuspipe_hdr) + + sizeof(struct icmsg_hdr)]; + + /* + * Stash away this global state for completing the + * transaction; note transactions are serialized. + */ + + vss_transaction.recv_len = recvlen; + vss_transaction.recv_channel = channel; + vss_transaction.recv_req_id = requestid; + vss_transaction.active = true; + vss_transaction.msg = (struct hv_vss_msg *)vss_msg; + + switch (vss_msg->vss_hdr.operation) { + /* + * Initiate a "freeze/thaw" + * operation in the guest. + * We respond to the host once + * the operation is complete. + * + * We send the message to the + * user space daemon and the + * operation is performed in + * the daemon. + */ + case VSS_OP_FREEZE: + case VSS_OP_THAW: + schedule_work(&vss_send_op_work); + return; + + case VSS_OP_HOT_BACKUP: + vss_msg->vss_cf.flags = + VSS_HBU_NO_AUTO_RECOVERY; + vss_respond_to_host(0); + return; + + case VSS_OP_GET_DM_INFO: + vss_msg->dm_info.flags = 0; + vss_respond_to_host(0); + return; + + default: + vss_respond_to_host(0); + return; + + } + + } + + icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION + | ICMSGHDRFLAG_RESPONSE; + + vmbus_sendpacket(channel, recv_buffer, + recvlen, requestid, + VM_PKT_DATA_INBAND, 0); + } + +} + +int +hv_vss_init(struct hv_util_service *srv) +{ + int err; + + err = cn_add_callback(&vss_id, vss_name, vss_cn_callback); + if (err) + return err; + recv_buffer = srv->recv_buffer; + + /* + * When this driver loads, the user level daemon that + * processes the host requests may not yet be running. + * Defer processing channel callbacks until the daemon + * has registered. + */ + vss_transaction.active = true; + return 0; +} + +void hv_vss_deinit(void) +{ + cn_del_callback(&vss_id); + cancel_work_sync(&vss_send_op_work); +} diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c index 1d4cbd8e826..2f561c5dfe2 100644 --- a/drivers/hv/hv_util.c +++ b/drivers/hv/hv_util.c @@ -49,6 +49,12 @@ static struct hv_util_service util_kvp = { .util_deinit = hv_kvp_deinit, }; +static struct hv_util_service util_vss = { + .util_cb = hv_vss_onchannelcallback, + .util_init = hv_vss_init, + .util_deinit = hv_vss_deinit, +}; + static void perform_shutdown(struct work_struct *dummy) { orderly_poweroff(true); @@ -339,6 +345,10 @@ static const struct hv_vmbus_device_id id_table[] = { { HV_KVP_GUID, .driver_data = (unsigned long)&util_kvp }, + /* VSS GUID */ + { HV_VSS_GUID, + .driver_data = (unsigned long)&util_vss + }, { }, }; diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index df77ba9a816..95d0850584d 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -27,6 +27,63 @@ #include <linux/types.h> + +/* + * Implementation of host controlled snapshot of the guest. + */ + +#define VSS_OP_REGISTER 128 + +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 { + __u8 operation; + __u8 reserved[7]; +} __attribute__((packed)); + + +/* + * Flag values for the hv_vss_check_feature. Linux supports only + * one value. + */ +#define VSS_HBU_NO_AUTO_RECOVERY 0x00000005 + +struct hv_vss_check_feature { + __u32 flags; +} __attribute__((packed)); + +struct hv_vss_check_dm_info { + __u32 flags; +} __attribute__((packed)); + +struct hv_vss_msg { + union { + struct hv_vss_hdr vss_hdr; + int error; + }; + union { + struct hv_vss_check_feature vss_cf; + struct hv_vss_check_dm_info dm_info; + }; +} __attribute__((packed)); + /* * An implementation of HyperV key value pair (KVP) functionality for Linux. * @@ -1253,6 +1310,14 @@ void vmbus_driver_unregister(struct hv_driver *hv_driver); } /* + * VSS (Backup/Restore) GUID + */ +#define HV_VSS_GUID \ + .guid = { \ + 0x29, 0x2e, 0xfa, 0x35, 0x23, 0xea, 0x36, 0x42, \ + 0x96, 0xae, 0x3a, 0x6e, 0xba, 0xcb, 0xa4, 0x40 \ + } +/* * Common header for Hyper-V ICs */ @@ -1356,6 +1421,10 @@ int hv_kvp_init(struct hv_util_service *); void hv_kvp_deinit(void); void hv_kvp_onchannelcallback(void *); +int hv_vss_init(struct hv_util_service *); +void hv_vss_deinit(void); +void hv_vss_onchannelcallback(void *); + /* * Negotiated version with the Host. */ diff --git a/include/uapi/linux/connector.h b/include/uapi/linux/connector.h index 8761a0349c7..4cb283505e4 100644 --- a/include/uapi/linux/connector.h +++ b/include/uapi/linux/connector.h @@ -44,8 +44,11 @@ #define CN_VAL_DRBD 0x1 #define CN_KVP_IDX 0x9 /* HyperV KVP */ #define CN_KVP_VAL 0x1 /* queries from the kernel */ +#define CN_VSS_IDX 0xA /* HyperV VSS */ +#define CN_VSS_VAL 0x1 /* queries from the kernel */ -#define CN_NETLINK_USERS 10 /* Highest index + 1 */ + +#define CN_NETLINK_USERS 11 /* Highest index + 1 */ /* * Maximum connector's message size. diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c new file mode 100644 index 00000000000..95269952aa9 --- /dev/null +++ b/tools/hv/hv_vss_daemon.c @@ -0,0 +1,220 @@ +/* + * An implementation of the host initiated guest snapshot for Hyper-V. + * + * + * Copyright (C) 2013, Microsoft, Inc. + * Author : K. Y. Srinivasan <kys@microsoft.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for more + * details. + * + */ + + +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/poll.h> +#include <linux/types.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <ctype.h> +#include <errno.h> +#include <arpa/inet.h> +#include <linux/connector.h> +#include <linux/hyperv.h> +#include <linux/netlink.h> +#include <syslog.h> + +static char vss_recv_buffer[4096]; +static char vss_send_buffer[4096]; +static struct sockaddr_nl addr; + +#ifndef SOL_NETLINK +#define SOL_NETLINK 270 +#endif + + +static int vss_operate(int operation) +{ + char *fs_op; + char cmd[512]; + char buf[512]; + FILE *file; + char *p; + char *x; + int error; + + switch (operation) { + case VSS_OP_FREEZE: + fs_op = "-f "; + break; + case VSS_OP_THAW: + fs_op = "-u "; + break; + } + + file = popen("mount | awk '/^\/dev\// { print $3}'", "r"); + if (file == NULL) + return; + + while ((p = fgets(buf, sizeof(buf), file)) != NULL) { + x = strchr(p, '\n'); + *x = '\0'; + if (!strncmp(p, "/", sizeof("/"))) + continue; + + sprintf(cmd, "%s %s %s", "fsfreeze ", fs_op, p); + syslog(LOG_INFO, "VSS cmd is %s\n", cmd); + error = system(cmd); + } + pclose(file); + + sprintf(cmd, "%s %s %s", "fsfreeze ", fs_op, "/"); + syslog(LOG_INFO, "VSS cmd is %s\n", cmd); + error = system(cmd); + + return error; +} + +static int netlink_send(int fd, struct cn_msg *msg) +{ + struct nlmsghdr *nlh; + unsigned int size; + struct msghdr message; + char buffer[64]; + struct iovec iov[2]; + + size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len); + + nlh = (struct nlmsghdr *)buffer; + nlh->nlmsg_seq = 0; + nlh->nlmsg_pid = getpid(); + nlh->nlmsg_type = NLMSG_DONE; + nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh)); + nlh->nlmsg_flags = 0; + + iov[0].iov_base = nlh; + iov[0].iov_len = sizeof(*nlh); + + iov[1].iov_base = msg; + iov[1].iov_len = size; + + memset(&message, 0, sizeof(message)); + message.msg_name = &addr; + message.msg_namelen = sizeof(addr); + message.msg_iov = iov; + message.msg_iovlen = 2; + + return sendmsg(fd, &message, 0); +} + +int main(void) +{ + int fd, len, nl_group; + int error; + struct cn_msg *message; + struct pollfd pfd; + struct nlmsghdr *incoming_msg; + struct cn_msg *incoming_cn_msg; + int op; + struct hv_vss_msg *vss_msg; + + daemon(1, 0); + openlog("Hyper-V VSS", 0, LOG_USER); + syslog(LOG_INFO, "VSS starting; pid is:%d", getpid()); + + fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR); + if (fd < 0) { + syslog(LOG_ERR, "netlink socket creation failed; error:%d", fd); + exit(EXIT_FAILURE); + } + addr.nl_family = AF_NETLINK; + addr.nl_pad = 0; + addr.nl_pid = 0; + addr.nl_groups = 0; + + + error = bind(fd, (struct sockaddr *)&addr, sizeof(addr)); + if (error < 0) { + syslog(LOG_ERR, "bind failed; error:%d", error); + close(fd); + exit(EXIT_FAILURE); + } + nl_group = CN_VSS_IDX; + setsockopt(fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &nl_group, sizeof(nl_group)); + /* + * Register ourselves with the kernel. + */ + message = (struct cn_msg *)vss_send_buffer; + message->id.idx = CN_VSS_IDX; + message->id.val = CN_VSS_VAL; + message->ack = 0; + vss_msg = (struct hv_vss_msg *)message->data; + vss_msg->vss_hdr.operation = VSS_OP_REGISTER; + + message->len = sizeof(struct hv_vss_msg); + + len = netlink_send(fd, message); + if (len < 0) { + syslog(LOG_ERR, "netlink_send failed; error:%d", len); + close(fd); + exit(EXIT_FAILURE); + } + + pfd.fd = fd; + + while (1) { + struct sockaddr *addr_p = (struct sockaddr *) &addr; + socklen_t addr_l = sizeof(addr); + pfd.events = POLLIN; + pfd.revents = 0; + poll(&pfd, 1, -1); + + len = recvfrom(fd, vss_recv_buffer, sizeof(vss_recv_buffer), 0, + addr_p, &addr_l); + + if (len < 0 || addr.nl_pid) { + syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s", + addr.nl_pid, errno, strerror(errno)); + close(fd); + return -1; + } + + incoming_msg = (struct nlmsghdr *)vss_recv_buffer; + + if (incoming_msg->nlmsg_type != NLMSG_DONE) + continue; + + incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg); + vss_msg = (struct hv_vss_msg *)incoming_cn_msg->data; + op = vss_msg->vss_hdr.operation; + error = HV_S_OK; + + switch (op) { + case VSS_OP_FREEZE: + case VSS_OP_THAW: + error = vss_operate(op); + if (error) + error = HV_E_FAIL; + break; + default: + syslog(LOG_ERR, "Illegal op:%d\n", op); + } + vss_msg->error = error; + len = netlink_send(fd, incoming_cn_msg); + if (len < 0) { + syslog(LOG_ERR, "net_link send failed; error:%d", len); + exit(EXIT_FAILURE); + } + } + +} |