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linux-next/drivers/hv/hv_utils_transport.h
Vitaly Kuznetsov e9c18ae6eb Drivers: hv: util: move waiting for release to hv_utils_transport itself
Waiting for release_event in all three drivers introduced issues on release
as on_reset() hook is not always called. E.g. if the device was never
opened we will never get the completion.

Move the waiting code to hvutil_transport_destroy() and make sure it is
only called when the device is open. hvt->lock serialization should
guarantee the absence of races.

Fixes: 5a66fecbf6 ("Drivers: hv: util: kvp: Fix a rescind processing issue")
Fixes: 20951c7535 ("Drivers: hv: util: Fcopy: Fix a rescind processing issue")
Fixes: d77044d142 ("Drivers: hv: util: Backup: Fix a rescind processing issue")

Reported-by: Dexuan Cui <decui@microsoft.com>
Tested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-16 16:42:00 +09:00

56 lines
2.1 KiB
C

/*
* Kernel/userspace transport abstraction for Hyper-V util driver.
*
* Copyright (C) 2015, Vitaly Kuznetsov <vkuznets@redhat.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.
*
*/
#ifndef _HV_UTILS_TRANSPORT_H
#define _HV_UTILS_TRANSPORT_H
#include <linux/connector.h>
#include <linux/miscdevice.h>
enum hvutil_transport_mode {
HVUTIL_TRANSPORT_INIT = 0,
HVUTIL_TRANSPORT_NETLINK,
HVUTIL_TRANSPORT_CHARDEV,
HVUTIL_TRANSPORT_DESTROY,
};
struct hvutil_transport {
int mode; /* hvutil_transport_mode */
struct file_operations fops; /* file operations */
struct miscdevice mdev; /* misc device */
struct cb_id cn_id; /* CN_*_IDX/CN_*_VAL */
struct list_head list; /* hvt_list */
int (*on_msg)(void *, int); /* callback on new user message */
void (*on_reset)(void); /* callback when userspace drops */
void (*on_read)(void); /* callback on message read */
u8 *outmsg; /* message to the userspace */
int outmsg_len; /* its length */
wait_queue_head_t outmsg_q; /* poll/read wait queue */
struct mutex lock; /* protects struct members */
struct completion release; /* synchronize with fd release */
};
struct hvutil_transport *hvutil_transport_init(const char *name,
u32 cn_idx, u32 cn_val,
int (*on_msg)(void *, int),
void (*on_reset)(void));
int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len,
void (*on_read_cb)(void));
void hvutil_transport_destroy(struct hvutil_transport *hvt);
#endif /* _HV_UTILS_TRANSPORT_H */