Implement the file copy service for Linux guests on Hyper-V. This permits the
host to copy a file (over VMBUS) into the guest. This facility is part of
"guest integration services" supported on the Windows platform.
Here is a link that provides additional details on this functionality:
http://technet.microsoft.com/en-us/library/dn464282.aspx
In V1 version of the patch I have addressed comments from
Olaf Hering <[email protected]> and Dan Carpenter <[email protected]>
In V2 version of this patch I did some minor cleanup (making some globals
static). In V4 version of the patch I have addressed all of Olaf's
most recent set of comments/concerns.
Signed-off-by: K. Y. Srinivasan <[email protected]>
---
drivers/hv/Makefile | 2 +-
drivers/hv/hv_fcopy.c | 428 ++++++++++++++++++++++++++++++++++++++++++++
drivers/hv/hv_util.c | 10 +
include/linux/hyperv.h | 61 +++++++
tools/hv/hv_fcopy_daemon.c | 200 +++++++++++++++++++++
5 files changed, 700 insertions(+), 1 deletions(-)
create mode 100644 drivers/hv/hv_fcopy.c
create mode 100644 tools/hv/hv_fcopy_daemon.c
diff --git a/drivers/hv/Makefile b/drivers/hv/Makefile
index 0a74b56..5e4dfa4 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_snapshot.o
+hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o hv_fcopy.o
diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c
new file mode 100644
index 0000000..b6a74ed
--- /dev/null
+++ b/drivers/hv/hv_fcopy.c
@@ -0,0 +1,428 @@
+/*
+ * An implementation of file copy service.
+ *
+ * Copyright (C) 2014, Microsoft, Inc.
+ *
+ * Author : K. Y. Srinivasan <[email protected]>
+ *
+ * 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/semaphore.h>
+#include <linux/fs.h>
+#include <linux/nls.h>
+#include <linux/workqueue.h>
+#include <linux/cdev.h>
+#include <linux/hyperv.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+
+#define WIN8_SRV_MAJOR 1
+#define WIN8_SRV_MINOR 1
+#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
+
+/*
+ * Global state maintained for transaction that is being processed.
+ * For a class of integration services, including the "file copy service",
+ * the specified protocol is a "request/response" protocol which means that
+ * there can only be single outstanding transaction from the host at any
+ * given point in time. We use this to simplify memory management in this
+ * driver - we cache and process only one message at a time.
+ *
+ * While the request/response protocol is guaranteed by the host, we further
+ * ensure this by serializing packet processing in this driver - we do not
+ * read additional packets from the VMBUs until the current packet is fully
+ * handled.
+ *
+ * The transaction "active" state is set when we receive a request from the
+ * host and we cleanup this state when the transaction is completed - when we
+ * respond to the host with our response. When the transaction active state is
+ * set, we defer handling incoming packets.
+ */
+
+static struct {
+ bool active; /* transaction status - active or not */
+ int recv_len; /* number of bytes received. */
+ struct hv_fcopy_hdr *fcopy_msg; /* current message */
+ struct hv_start_fcopy message; /* sent to daemon */
+ struct vmbus_channel *recv_channel; /* chn we got the request */
+ u64 recv_req_id; /* request ID. */
+ void *fcopy_context; /* for the channel callback */
+ struct semaphore read_sema;
+} fcopy_transaction;
+
+static dev_t fcopy_dev;
+static bool opened; /* currently device opened */
+static struct task_struct *dtp; /* daemon task ptr */
+
+/*
+ * Before we can accept copy messages from the host, we need
+ * to handshake with the user level daemon. This state tracks
+ * if we are in the handshake phase.
+ */
+static bool in_hand_shake = true;
+static void fcopy_send_data(void);
+static void fcopy_respond_to_host(int error);
+static void fcopy_work_func(struct work_struct *dummy);
+static DECLARE_DELAYED_WORK(fcopy_work, fcopy_work_func);
+static u8 *recv_buffer;
+
+static void fcopy_work_func(struct work_struct *dummy)
+{
+ /*
+ * If the timer fires, the user-mode component has not responded;
+ * process the pending transaction.
+ */
+ fcopy_respond_to_host(HV_E_FAIL);
+}
+
+static int fcopy_handle_handshake(u32 version)
+{
+ switch (version) {
+ case FCOPY_CURRENT_VERSION:
+ break;
+ default:
+ /*
+ * For now we will fail the registration.
+ * If and when we have multiple versions to
+ * deal with, we will be backward compatible.
+ * We will add this code when needed.
+ */
+ return -EINVAL;
+ }
+ pr_info("FCP: user-mode registering done. Daemon version: %d\n",
+ version);
+ fcopy_transaction.active = false;
+ if (fcopy_transaction.fcopy_context)
+ hv_fcopy_onchannelcallback(fcopy_transaction.fcopy_context);
+ in_hand_shake = false;
+ return sizeof(int);
+}
+
+static void fcopy_send_data(void)
+{
+ struct hv_start_fcopy *smsg_out = &fcopy_transaction.message;
+ int operation = fcopy_transaction.fcopy_msg->operation;
+ struct hv_start_fcopy *smsg_in;
+
+ /*
+ * The strings sent from the host are encoded in
+ * in utf16; convert it to utf8 strings.
+ * The host assures us that the utf16 strings will not exceed
+ * the max lengths specified. We will however, reserve room
+ * for the string terminating character - in the utf16s_utf8s()
+ * function we limit the size of the buffer where the converted
+ * string is placed to W_MAX_PATH -1 to guarantee
+ * that the strings can be properly terminated!
+ */
+
+ switch (operation) {
+ case START_FILE_COPY:
+ memset(smsg_out, 0, sizeof(struct hv_start_fcopy));
+ smsg_out->hdr.operation = operation;
+ smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
+
+ utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
+ UTF16_LITTLE_ENDIAN,
+ (__u8 *)smsg_out->file_name, W_MAX_PATH - 1);
+
+ utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
+ UTF16_LITTLE_ENDIAN,
+ (__u8 *)smsg_out->path_name, W_MAX_PATH - 1);
+
+ smsg_out->copy_flags = smsg_in->copy_flags;
+ smsg_out->file_size = smsg_in->file_size;
+ break;
+
+ default:
+ break;
+ }
+ up(&fcopy_transaction.read_sema);
+ return;
+}
+
+/*
+ * Send a response back to the host.
+ */
+
+static void
+fcopy_respond_to_host(int error)
+{
+ struct icmsg_hdr *icmsghdrp;
+ u32 buf_len;
+ struct vmbus_channel *channel;
+ u64 req_id;
+
+ /*
+ * Copy the global state for completing the transaction. Note that
+ * only one transaction can be active at a time.
+ */
+
+ buf_len = fcopy_transaction.recv_len;
+ channel = fcopy_transaction.recv_channel;
+ req_id = fcopy_transaction.recv_req_id;
+
+ fcopy_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);
+}
+
+void hv_fcopy_onchannelcallback(void *context)
+{
+ struct vmbus_channel *channel = context;
+ u32 recvlen;
+ u64 requestid;
+ struct hv_fcopy_hdr *fcopy_msg;
+ struct icmsg_hdr *icmsghdrp;
+ struct icmsg_negotiate *negop = NULL;
+ int util_fw_version;
+ int fcopy_srv_version;
+
+ if (fcopy_transaction.active) {
+ /*
+ * We will defer processing this callback once
+ * the current transaction is complete.
+ */
+ fcopy_transaction.fcopy_context = context;
+ return;
+ }
+
+ vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
+ &requestid);
+ if (recvlen <= 0)
+ return;
+
+ icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
+ sizeof(struct vmbuspipe_hdr)];
+ if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
+ util_fw_version = UTIL_FW_VERSION;
+ fcopy_srv_version = WIN8_SRV_VERSION;
+ vmbus_prep_negotiate_resp(icmsghdrp, negop, recv_buffer,
+ util_fw_version, fcopy_srv_version);
+ } else {
+ fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
+ sizeof(struct vmbuspipe_hdr) +
+ sizeof(struct icmsg_hdr)];
+
+ /*
+ * Stash away this global state for completing the
+ * transaction; note transactions are serialized.
+ */
+
+ fcopy_transaction.active = true;
+ fcopy_transaction.recv_len = recvlen;
+ fcopy_transaction.recv_channel = channel;
+ fcopy_transaction.recv_req_id = requestid;
+ fcopy_transaction.fcopy_msg = fcopy_msg;
+
+ /*
+ * Send the information to the user-level daemon.
+ */
+ fcopy_send_data();
+ schedule_delayed_work(&fcopy_work, 5*HZ);
+ return;
+ }
+ icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
+ vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
+ VM_PKT_DATA_INBAND, 0);
+}
+
+/*
+ * Create a char device that can support read/write for passing
+ * the payload.
+ */
+static struct cdev fcopy_cdev;
+static struct class *cl;
+static struct device *sysfs_dev;
+
+static ssize_t fcopy_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ void *src;
+ size_t copy_size;
+ int operation;
+
+ /*
+ * Wait until there is something to be read.
+ */
+ if (down_interruptible(&fcopy_transaction.read_sema))
+ return -EINTR;
+
+ operation = fcopy_transaction.fcopy_msg->operation;
+
+ if (operation == START_FILE_COPY) {
+ src = &fcopy_transaction.message;
+ copy_size = sizeof(struct hv_start_fcopy);
+ if (count < copy_size)
+ return 0;
+ } else {
+ src = fcopy_transaction.fcopy_msg;
+ copy_size = sizeof(struct hv_do_fcopy);
+ if (count < copy_size)
+ return 0;
+ }
+ if (copy_to_user(buf, src, copy_size))
+ return -EFAULT;
+
+ return copy_size;
+}
+
+static ssize_t fcopy_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int response = 0;
+
+ if (count != sizeof(int))
+ return -EINVAL;
+
+ if (copy_from_user(&response, buf, sizeof(int)))
+ return -EFAULT;
+
+ if (in_hand_shake)
+ return fcopy_handle_handshake(response);
+
+ /*
+ * Complete the transaction by forwarding the result
+ * to the host. But first, cancel the timeout.
+ */
+ if (cancel_delayed_work_sync(&fcopy_work))
+ fcopy_respond_to_host(response);
+
+ return sizeof(int);
+}
+
+int fcopy_open(struct inode *inode, struct file *f)
+{
+ if (opened)
+ return -EBUSY;
+
+ /*
+ * The daemon is alive; setup the state.
+ */
+ opened = true;
+ dtp = current;
+ return 0;
+}
+
+int fcopy_release(struct inode *inode, struct file *f)
+{
+ /*
+ * The daemon has exited; reset the state.
+ */
+ in_hand_shake = true;
+ dtp = NULL;
+ opened = false;
+ return 0;
+}
+
+
+static const struct file_operations fcopy_fops = {
+ .read = fcopy_read,
+ .write = fcopy_write,
+ .release = fcopy_release,
+ .open = fcopy_open,
+};
+
+static int fcopy_dev_init(void)
+{
+ int result;
+
+ result = alloc_chrdev_region(&fcopy_dev, 1, 1, "hv_fcopy");
+ if (result < 0) {
+ pr_err("Cannot get major number\n");
+ return result;
+ }
+
+ cl = class_create(THIS_MODULE, "chardev");
+ if (IS_ERR(cl)) {
+ pr_err("Error creating fcopy class.\n");
+ result = PTR_ERR(cl);
+ goto err_unregister;
+ }
+
+ sysfs_dev = device_create(cl, NULL, fcopy_dev, "%s", "hv_fcopy");
+ if (IS_ERR(sysfs_dev)) {
+ pr_err("Device creation failed\n");
+ result = PTR_ERR(cl);
+ goto err_destroy_class;
+ }
+
+ cdev_init(&fcopy_cdev, &fcopy_fops);
+ fcopy_cdev.owner = THIS_MODULE;
+ fcopy_cdev.ops = &fcopy_fops;
+
+ result = cdev_add(&fcopy_cdev, fcopy_dev, 1);
+ if (result) {
+ pr_err("Cannot cdev_add\n");
+ goto err_destroy_device;
+ }
+ return result;
+
+err_destroy_device:
+ device_destroy(cl, fcopy_dev);
+err_destroy_class:
+ class_destroy(cl);
+err_unregister:
+ unregister_chrdev_region(fcopy_dev, 1);
+ return result;
+}
+
+static void fcopy_dev_deinit(void)
+{
+ /*
+ * first kill the daemon.
+ */
+ if (dtp != NULL)
+ send_sig(SIGKILL, dtp, 0);
+ opened = false;
+ device_destroy(cl, fcopy_dev);
+ class_destroy(cl);
+ cdev_del(&fcopy_cdev);
+ unregister_chrdev_region(fcopy_dev, 1);
+}
+
+int hv_fcopy_init(struct hv_util_service *srv)
+{
+ 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.
+ */
+ fcopy_transaction.active = true;
+ sema_init(&fcopy_transaction.read_sema, 0);
+
+ return fcopy_dev_init();
+}
+
+void hv_fcopy_deinit(void)
+{
+ cancel_delayed_work_sync(&fcopy_work);
+ fcopy_dev_deinit();
+}
diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
index 62dfd246..efc5e83 100644
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -82,6 +82,12 @@ static struct hv_util_service util_vss = {
.util_deinit = hv_vss_deinit,
};
+static struct hv_util_service util_fcopy = {
+ .util_cb = hv_fcopy_onchannelcallback,
+ .util_init = hv_fcopy_init,
+ .util_deinit = hv_fcopy_deinit,
+};
+
static void perform_shutdown(struct work_struct *dummy)
{
orderly_poweroff(true);
@@ -401,6 +407,10 @@ static const struct hv_vmbus_device_id id_table[] = {
{ HV_VSS_GUID,
.driver_data = (unsigned long)&util_vss
},
+ /* File copy GUID */
+ { HV_FCOPY_GUID,
+ .driver_data = (unsigned long)&util_fcopy
+ },
{ },
};
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 15da677..9d2e168 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -26,6 +26,7 @@
#define _HYPERV_H
#include <linux/types.h>
+#include <linux/uuid.h>
/*
* Framework version for util services.
@@ -96,6 +97,51 @@ struct hv_vss_msg {
} __attribute__((packed));
/*
+ * Implementation of a host to guest copy facility.
+ */
+
+#define FCOPY_VERSION_0 0
+#define FCOPY_CURRENT_VERSION FCOPY_VERSION_0
+#define W_MAX_PATH 260
+
+enum hv_fcopy_op {
+ START_FILE_COPY = 0,
+ WRITE_TO_FILE,
+ COMPLETE_FCOPY,
+ CANCEL_FCOPY,
+};
+
+struct hv_fcopy_hdr {
+ __u32 operation;
+ uuid_le service_id0; /* currently unused */
+ uuid_le service_id1; /* currently unused */
+} __attribute__((packed));
+
+#define OVER_WRITE 0x1
+#define CREATE_PATH 0x2
+
+struct hv_start_fcopy {
+ struct hv_fcopy_hdr hdr;
+ __u16 file_name[W_MAX_PATH];
+ __u16 path_name[W_MAX_PATH];
+ __u32 copy_flags;
+ __u64 file_size;
+} __attribute__((packed));
+
+/*
+ * The file is chunked into fragments.
+ */
+#define DATA_FRAGMENT (6 * 1024)
+
+struct hv_do_fcopy {
+ struct hv_fcopy_hdr hdr;
+ __u64 offset;
+ __u32 size;
+ __u8 data[DATA_FRAGMENT];
+};
+
+
+/*
* An implementation of HyperV key value pair (KVP) functionality for Linux.
*
*
@@ -1352,6 +1398,17 @@ void vmbus_driver_unregister(struct hv_driver *hv_driver);
}
/*
+ * Guest File Copy Service
+ * {34D14BE3-DEE4-41c8-9AE7-6B174977C192}
+ */
+
+#define HV_FCOPY_GUID \
+ .guid = { \
+ 0xE3, 0x4B, 0xD1, 0x34, 0xE4, 0xDE, 0xC8, 0x41, \
+ 0x9A, 0xE7, 0x6B, 0x17, 0x49, 0x77, 0xC1, 0x92 \
+ }
+
+/*
* Common header for Hyper-V ICs
*/
@@ -1459,6 +1516,10 @@ int hv_vss_init(struct hv_util_service *);
void hv_vss_deinit(void);
void hv_vss_onchannelcallback(void *);
+int hv_fcopy_init(struct hv_util_service *);
+void hv_fcopy_deinit(void);
+void hv_fcopy_onchannelcallback(void *);
+
/*
* Negotiated version with the Host.
*/
diff --git a/tools/hv/hv_fcopy_daemon.c b/tools/hv/hv_fcopy_daemon.c
new file mode 100644
index 0000000..1d2986d
--- /dev/null
+++ b/tools/hv/hv_fcopy_daemon.c
@@ -0,0 +1,200 @@
+/*
+ * An implementation of host to guest copy functionality for Linux.
+ *
+ * Copyright (C) 2014, Microsoft, Inc.
+ *
+ * Author : K. Y. Srinivasan <[email protected]>
+ *
+ * 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 <linux/kdev_t.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include <linux/hyperv.h>
+#include <syslog.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <dirent.h>
+
+static int target_fd;
+static char target_fname[W_MAX_PATH];
+
+static int hv_start_fcopy(struct hv_start_fcopy *smsg)
+{
+ int error = HV_E_FAIL;
+ char *q, *p;
+
+ /*
+ * If possile append a path seperator to the path.
+ */
+ if (strlen((char *)smsg->path_name) < (W_MAX_PATH - 2))
+ strcat((char *)smsg->path_name, "/");
+
+ p = (char *)smsg->path_name;
+ snprintf(target_fname, sizeof(target_fname), "%s/%s",
+ (char *)smsg->path_name, smsg->file_name);
+
+ syslog(LOG_INFO, "Target file name: %s", target_fname);
+ /*
+ * Check to see if the path is already in place; if not,
+ * create if required.
+ */
+ while ((q = strchr(p, '/')) != NULL) {
+ if (q == p) {
+ p++;
+ continue;
+ }
+ *q = '\0';
+ if (access((char *)smsg->path_name, F_OK)) {
+ if (smsg->copy_flags & CREATE_PATH) {
+ if (mkdir((char *)smsg->path_name, 0755)) {
+ syslog(LOG_ERR, "Failed to create %s",
+ (char *)smsg->path_name);
+ goto done;
+ }
+ } else {
+ syslog(LOG_ERR, "Invalid path: %s",
+ (char *)smsg->path_name);
+ goto done;
+ }
+ }
+ p = q + 1;
+ *q = '/';
+ }
+
+ if (!access(target_fname, F_OK)) {
+ syslog(LOG_INFO, "File: %s exists", target_fname);
+ if (!smsg->copy_flags & OVER_WRITE)
+ goto done;
+ }
+
+ target_fd = open(target_fname, O_RDWR | O_CREAT | O_CLOEXEC, 0744);
+ if (target_fd == -1) {
+ syslog(LOG_INFO, "Open Failed: %s", strerror(errno));
+ goto done;
+ }
+
+ error = 0;
+done:
+ return error;
+}
+
+static int hv_copy_data(struct hv_do_fcopy *cpmsg)
+{
+ ssize_t bytes_written;
+
+ bytes_written = pwrite(target_fd, cpmsg->data, cpmsg->size,
+ cpmsg->offset);
+
+ if (bytes_written != cpmsg->size)
+ return HV_E_FAIL;
+
+ return 0;
+}
+
+static int hv_copy_finished(void)
+{
+ close(target_fd);
+ return 0;
+}
+static int hv_copy_cancel(void)
+{
+ close(target_fd);
+ unlink(target_fname);
+ return 0;
+
+}
+
+int main(void)
+{
+ int fd, fcopy_fd, len;
+ int error = 0;
+ int version = FCOPY_CURRENT_VERSION;
+ char *buffer[4096 * 2];
+ struct hv_fcopy_hdr *in_msg;
+
+ if (daemon(1, 0)) {
+ syslog(LOG_ERR, "daemon() failed; error: %s", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ openlog("HV_FCOPY", 0, LOG_USER);
+ syslog(LOG_INFO, "HV_FCOPY starting; pid is:%d", getpid());
+
+ fcopy_fd = open("/dev/hv_fcopy", O_RDWR);
+
+ if (fcopy_fd < 0) {
+ syslog(LOG_ERR, "open /dev/hv_fcopy failed; error: %d %s",
+ errno, strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ /*
+ * Register with the kernel.
+ */
+ if ((write(fcopy_fd, &version, sizeof(int))) != sizeof(int)) {
+ syslog(LOG_ERR, "Registration failed: %s", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ while (1) {
+ /*
+ * In this loop we process fcopy messages after the
+ * handshake is complete.
+ */
+
+ len = pread(fcopy_fd, buffer, (4096 * 2), 0);
+ if (len <= 0) {
+ if (!error) {
+ syslog(LOG_ERR, "Read error: %s",
+ strerror(errno));
+ error = HV_E_FAIL;
+ }
+ continue;
+ }
+ in_msg = (struct hv_fcopy_hdr *)buffer;
+
+ switch (in_msg->operation) {
+ case START_FILE_COPY:
+ error = hv_start_fcopy((struct hv_start_fcopy *)in_msg);
+ break;
+ case WRITE_TO_FILE:
+ error = hv_copy_data((struct hv_do_fcopy *)in_msg);
+ break;
+ case COMPLETE_FCOPY:
+ error = hv_copy_finished();
+ break;
+ case CANCEL_FCOPY:
+ error = hv_copy_cancel();
+ break;
+
+ default:
+ syslog(LOG_ERR, "Unknown operation: %d",
+ in_msg->operation);
+
+ }
+
+ if (pwrite(fcopy_fd, &error, sizeof(int), 0) != sizeof(int)) {
+ syslog(LOG_ERR, "pwrite failed: %s", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+ }
+}
--
1.7.4.1
On Tue, Jan 21, K. Y. Srinivasan wrote:
> Implement the file copy service for Linux guests on Hyper-V. This permits the
> host to copy a file (over VMBUS) into the guest. This facility is part of
> "guest integration services" supported on the Windows platform.
> Here is a link that provides additional details on this functionality:
Looks ok to me now. Thanks.
> +++ b/include/linux/hyperv.h
> @@ -26,6 +26,7 @@
> #define _HYPERV_H
>
> #include <linux/types.h>
> +#include <linux/uuid.h>
uuid.h is also include in the __KERNEL__ section later in the file.
Olaf
On Tue, Jan 21, 2014 at 05:43:53PM -0800, K. Y. Srinivasan wrote:
> +/*
> + * Create a char device that can support read/write for passing
> + * the payload.
> + */
> +static struct cdev fcopy_cdev;
> +static struct class *cl;
> +static struct device *sysfs_dev;
Why not just be a misc device, you only want 1 minor number for a char
device:
> +static int fcopy_dev_init(void)
> +{
> + int result;
> +
> + result = alloc_chrdev_region(&fcopy_dev, 1, 1, "hv_fcopy");
See, one minor.
> + if (result < 0) {
> + pr_err("Cannot get major number\n");
> + return result;
> + }
> +
> + cl = class_create(THIS_MODULE, "chardev");
That's a _really_ generic name, come on, you know better than that.
> + if (IS_ERR(cl)) {
> + pr_err("Error creating fcopy class.\n");
Your error string is wrong :(
> + result = PTR_ERR(cl);
> + goto err_unregister;
> + }
> +
> + sysfs_dev = device_create(cl, NULL, fcopy_dev, "%s", "hv_fcopy");
A device at the root of sysfs? No, you have a bus to hang devices off
of, use that. What do you need this device for anyway?
> + if (IS_ERR(sysfs_dev)) {
> + pr_err("Device creation failed\n");
> + result = PTR_ERR(cl);
> + goto err_destroy_class;
> + }
> +
> + cdev_init(&fcopy_cdev, &fcopy_fops);
> + fcopy_cdev.owner = THIS_MODULE;
> + fcopy_cdev.ops = &fcopy_fops;
> +
> + result = cdev_add(&fcopy_cdev, fcopy_dev, 1);
Ah, to get udev to pay attention to the char device, no, just use a misc
device, should make this whole code a lot simpler and more "obvious" as
to what you want/need.
> + if (result) {
> + pr_err("Cannot cdev_add\n");
> + goto err_destroy_device;
> + }
> + return result;
> +
> +err_destroy_device:
> + device_destroy(cl, fcopy_dev);
> +err_destroy_class:
> + class_destroy(cl);
> +err_unregister:
> + unregister_chrdev_region(fcopy_dev, 1);
> + return result;
Ugh, I hate the cdev interface, one of these days I'll fix it up, it's
so unwieldy...
> +static void fcopy_dev_deinit(void)
> +{
> + /*
> + * first kill the daemon.
> + */
> + if (dtp != NULL)
> + send_sig(SIGKILL, dtp, 0);
We kill userspace daemon's from the kernel? That's a recipe for
disaster...
Why? What does it matter here if the daemon keeps running, it should
fail gracefully if the character device is removed, right? If not, that
needs to be fixed anyway.
thanks,
greg k-h
> -----Original Message-----
> From: Greg KH [mailto:[email protected]]
> Sent: Friday, February 07, 2014 3:17 PM
> To: KY Srinivasan
> Cc: [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]
> Subject: Re: [PATCH V4 1/1] Drivers: hv: Implement the file copy service
>
> On Tue, Jan 21, 2014 at 05:43:53PM -0800, K. Y. Srinivasan wrote:
> > +/*
> > + * Create a char device that can support read/write for passing
> > + * the payload.
> > + */
> > +static struct cdev fcopy_cdev;
> > +static struct class *cl;
> > +static struct device *sysfs_dev;
>
> Why not just be a misc device, you only want 1 minor number for a char
> device:
>
> > +static int fcopy_dev_init(void)
> > +{
> > + int result;
> > +
> > + result = alloc_chrdev_region(&fcopy_dev, 1, 1, "hv_fcopy");
>
> See, one minor.
>
> > + if (result < 0) {
> > + pr_err("Cannot get major number\n");
> > + return result;
> > + }
> > +
> > + cl = class_create(THIS_MODULE, "chardev");
>
> That's a _really_ generic name, come on, you know better than that.
>
> > + if (IS_ERR(cl)) {
> > + pr_err("Error creating fcopy class.\n");
>
> Your error string is wrong :(
>
> > + result = PTR_ERR(cl);
> > + goto err_unregister;
> > + }
> > +
> > + sysfs_dev = device_create(cl, NULL, fcopy_dev, "%s", "hv_fcopy");
>
> A device at the root of sysfs? No, you have a bus to hang devices off
> of, use that. What do you need this device for anyway?
>
> > + if (IS_ERR(sysfs_dev)) {
> > + pr_err("Device creation failed\n");
> > + result = PTR_ERR(cl);
> > + goto err_destroy_class;
> > + }
> > +
> > + cdev_init(&fcopy_cdev, &fcopy_fops);
> > + fcopy_cdev.owner = THIS_MODULE;
> > + fcopy_cdev.ops = &fcopy_fops;
> > +
> > + result = cdev_add(&fcopy_cdev, fcopy_dev, 1);
>
> Ah, to get udev to pay attention to the char device, no, just use a misc
> device, should make this whole code a lot simpler and more "obvious" as
> to what you want/need.
>
> > + if (result) {
> > + pr_err("Cannot cdev_add\n");
> > + goto err_destroy_device;
> > + }
> > + return result;
> > +
> > +err_destroy_device:
> > + device_destroy(cl, fcopy_dev);
> > +err_destroy_class:
> > + class_destroy(cl);
> > +err_unregister:
> > + unregister_chrdev_region(fcopy_dev, 1);
> > + return result;
>
>
> Ugh, I hate the cdev interface, one of these days I'll fix it up, it's
> so unwieldy...
>
> > +static void fcopy_dev_deinit(void)
> > +{
> > + /*
> > + * first kill the daemon.
> > + */
> > + if (dtp != NULL)
> > + send_sig(SIGKILL, dtp, 0);
>
> We kill userspace daemon's from the kernel? That's a recipe for
> disaster...
>
> Why? What does it matter here if the daemon keeps running, it should
> fail gracefully if the character device is removed, right? If not, that
> needs to be fixed anyway.
Greg,
Thanks for the detailed comments; I will address these in the next version.
Regards,
K. Y