Drivers: hv: fcopy: convert to hv_utils_transport
authorVitaly Kuznetsov <vkuznets@redhat.com>
Sun, 12 Apr 2015 01:07:53 +0000 (18:07 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 24 May 2015 19:17:41 +0000 (12:17 -0700)
Unify the code with the recently introduced hv_utils_transport. Netlink
communication is disabled for fcopy.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hv/hv_fcopy.c

index d1475e6aa9ac0fa118053d3654bb37017926bb5f..6a8ec9fb0869c14b764b9856f8edbe683d2cd188 100644 (file)
 
 #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>
-#include <linux/miscdevice.h>
 
 #include "hyperv_vmbus.h"
+#include "hv_utils_transport.h"
 
 #define WIN8_SRV_MAJOR         1
 #define WIN8_SRV_MINOR         1
@@ -53,18 +49,19 @@ static struct {
        int state;   /* hvutil_device_state */
        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 void fcopy_send_data(void);
 static void fcopy_respond_to_host(int error);
+static void fcopy_send_data(struct work_struct *dummy);
 static void fcopy_timeout_func(struct work_struct *dummy);
 static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func);
+static DECLARE_WORK(fcopy_send_work, fcopy_send_data);
+static const char fcopy_devname[] = "vmbus/hv_fcopy";
 static u8 *recv_buffer;
+static struct hvutil_transport *hvt;
 
 static void fcopy_timeout_func(struct work_struct *dummy)
 {
@@ -78,17 +75,6 @@ static void fcopy_timeout_func(struct work_struct *dummy)
        if (fcopy_transaction.state > HVUTIL_READY)
                fcopy_transaction.state = HVUTIL_READY;
 
-       /* In the case the user-space daemon crashes, hangs or is killed, we
-        * need to down the semaphore, otherwise, after the daemon starts next
-        * time, the obsolete data in fcopy_transaction.message or
-        * fcopy_transaction.fcopy_msg will be used immediately.
-        *
-        * NOTE: fcopy_read() happens to get the semaphore (very rare)? We're
-        * still OK, because we've reported the failure to the host.
-        */
-       if (down_trylock(&fcopy_transaction.read_sema))
-               ;
-
        hv_poll_channel(fcopy_transaction.fcopy_context,
                        hv_fcopy_onchannelcallback);
 }
@@ -115,11 +101,13 @@ static int fcopy_handle_handshake(u32 version)
        return 0;
 }
 
-static void fcopy_send_data(void)
+static void fcopy_send_data(struct work_struct *dummy)
 {
-       struct hv_start_fcopy *smsg_out = &fcopy_transaction.message;
+       struct hv_start_fcopy smsg_out;
        int operation = fcopy_transaction.fcopy_msg->operation;
        struct hv_start_fcopy *smsg_in;
+       void *out_src;
+       int rc, out_len;
 
        /*
         * The  strings sent from the host are encoded in
@@ -134,26 +122,39 @@ static void fcopy_send_data(void)
 
        switch (operation) {
        case START_FILE_COPY:
-               memset(smsg_out, 0, sizeof(struct hv_start_fcopy));
-               smsg_out->hdr.operation = operation;
+               out_len = sizeof(struct hv_start_fcopy);
+               memset(&smsg_out, 0, out_len);
+               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);
+                               (__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);
+                               (__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;
+               smsg_out.copy_flags = smsg_in->copy_flags;
+               smsg_out.file_size = smsg_in->file_size;
+               out_src = &smsg_out;
                break;
 
        default:
+               out_src = fcopy_transaction.fcopy_msg;
+               out_len = fcopy_transaction.recv_len;
                break;
        }
-       up(&fcopy_transaction.read_sema);
+
+       fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
+       rc = hvutil_transport_send(hvt, out_src, out_len);
+       if (rc) {
+               pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
+               if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
+                       fcopy_respond_to_host(HV_E_FAIL);
+                       fcopy_transaction.state = HVUTIL_READY;
+               }
+       }
        return;
 }
 
@@ -255,8 +256,8 @@ void hv_fcopy_onchannelcallback(void *context)
                /*
                 * Send the information to the user-level daemon.
                 */
+               schedule_work(&fcopy_send_work);
                schedule_delayed_work(&fcopy_timeout_work, 5*HZ);
-               fcopy_send_data();
                return;
        }
        icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
@@ -264,69 +265,16 @@ void hv_fcopy_onchannelcallback(void *context)
                        VM_PKT_DATA_INBAND, 0);
 }
 
-/*
- * Create a char device that can support read/write for passing
- * the payload.
- */
-
-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;
-
-       /*
-        * The channel may be rescinded and in this case, we will wakeup the
-        * the thread blocked on the semaphore and we will use the state to
-        * correctly handle this case.
-        */
-       if (fcopy_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
-               return -ENODEV;
-
-       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;
-
-       fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
-
-       return copy_size;
-}
-
-static ssize_t fcopy_write(struct file *file, const char __user *buf,
-                       size_t count, loff_t *ppos)
+/* Callback when data is received from userspace */
+static int fcopy_on_msg(void *msg, int len)
 {
-       int response = 0;
+       int *val = (int *)msg;
 
-       if (count != sizeof(int))
+       if (len != sizeof(int))
                return -EINVAL;
 
-       if (copy_from_user(&response, buf, sizeof(int)))
-               return -EFAULT;
-
-       if (fcopy_transaction.state == HVUTIL_DEVICE_INIT) {
-               if (fcopy_handle_handshake(response))
-                       return -EINVAL;
-               return sizeof(int);
-       }
+       if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
+               return fcopy_handle_handshake(*val);
 
        if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
                return -EINVAL;
@@ -337,78 +285,24 @@ static ssize_t fcopy_write(struct file *file, const char __user *buf,
         */
        if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
                fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
-               fcopy_respond_to_host(response);
+               fcopy_respond_to_host(*val);
                fcopy_transaction.state = HVUTIL_READY;
                hv_poll_channel(fcopy_transaction.fcopy_context,
                                hv_fcopy_onchannelcallback);
        }
 
-       return sizeof(int);
-}
-
-static int fcopy_open(struct inode *inode, struct file *f)
-{
-       /*
-        * The user level daemon that will open this device is
-        * really an extension of this driver. We can have only
-        * active open at a time.
-        */
-       if (fcopy_transaction.state != HVUTIL_DEVICE_INIT)
-               return -EBUSY;
-
        return 0;
 }
 
-/* XXX: there are still some tricky corner cases, e.g.,
- * In an SMP guest, when fcopy_release() runs between
- * schedule_delayed_work() and fcopy_send_data(), there is
- * still a chance an obsolete message will be queued.
- */
-static int fcopy_release(struct inode *inode, struct file *f)
+static void fcopy_on_reset(void)
 {
        /*
         * The daemon has exited; reset the state.
         */
        fcopy_transaction.state = HVUTIL_DEVICE_INIT;
 
-       if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
-               /* We haven't up()-ed the semaphore(very rare)? */
-               if (down_trylock(&fcopy_transaction.read_sema))
-                       ;
+       if (cancel_delayed_work_sync(&fcopy_timeout_work))
                fcopy_respond_to_host(HV_E_FAIL);
-       }
-       return 0;
-}
-
-
-static const struct file_operations fcopy_fops = {
-       .owner          = THIS_MODULE,
-       .read           = fcopy_read,
-       .write          = fcopy_write,
-       .release        = fcopy_release,
-       .open           = fcopy_open,
-};
-
-static struct miscdevice fcopy_misc = {
-       .minor          = MISC_DYNAMIC_MINOR,
-       .name           = "vmbus/hv_fcopy",
-       .fops           = &fcopy_fops,
-};
-
-static int fcopy_dev_init(void)
-{
-       return misc_register(&fcopy_misc);
-}
-
-static void fcopy_dev_deinit(void)
-{
-
-       /*
-        * Signal the semaphore as the device is
-        * going away.
-        */
-       up(&fcopy_transaction.read_sema);
-       misc_deregister(&fcopy_misc);
 }
 
 int hv_fcopy_init(struct hv_util_service *srv)
@@ -422,14 +316,18 @@ int hv_fcopy_init(struct hv_util_service *srv)
         * has registered.
         */
        fcopy_transaction.state = HVUTIL_DEVICE_INIT;
-       sema_init(&fcopy_transaction.read_sema, 0);
 
-       return fcopy_dev_init();
+       hvt = hvutil_transport_init(fcopy_devname, 0, 0,
+                                   fcopy_on_msg, fcopy_on_reset);
+       if (!hvt)
+               return -EFAULT;
+
+       return 0;
 }
 
 void hv_fcopy_deinit(void)
 {
        fcopy_transaction.state = HVUTIL_DEVICE_DYING;
        cancel_delayed_work_sync(&fcopy_timeout_work);
-       fcopy_dev_deinit();
+       hvutil_transport_destroy(hvt);
 }