a15025660d
When Hyper-V host asks us to remove some util driver by closing the appropriate channel there is no easy way to force the current file descriptor holder to hang up but we can start to respond -EBADF to all operations asking it to exit gracefully. As we're setting hvt->mode from two separate contexts now we need to use a proper locking. 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>
53 lines
1.9 KiB
C
53 lines
1.9 KiB
C
/*
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* Kernel/userspace transport abstraction for Hyper-V util driver.
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*
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* Copyright (C) 2015, Vitaly Kuznetsov <vkuznets@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published
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* by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for more
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* details.
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*
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*/
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#ifndef _HV_UTILS_TRANSPORT_H
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#define _HV_UTILS_TRANSPORT_H
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#include <linux/connector.h>
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#include <linux/miscdevice.h>
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enum hvutil_transport_mode {
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HVUTIL_TRANSPORT_INIT = 0,
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HVUTIL_TRANSPORT_NETLINK,
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HVUTIL_TRANSPORT_CHARDEV,
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HVUTIL_TRANSPORT_DESTROY,
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};
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struct hvutil_transport {
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int mode; /* hvutil_transport_mode */
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struct file_operations fops; /* file operations */
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struct miscdevice mdev; /* misc device */
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struct cb_id cn_id; /* CN_*_IDX/CN_*_VAL */
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struct list_head list; /* hvt_list */
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int (*on_msg)(void *, int); /* callback on new user message */
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void (*on_reset)(void); /* callback when userspace drops */
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u8 *outmsg; /* message to the userspace */
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int outmsg_len; /* its length */
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wait_queue_head_t outmsg_q; /* poll/read wait queue */
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struct mutex lock; /* protects struct members */
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};
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struct hvutil_transport *hvutil_transport_init(const char *name,
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u32 cn_idx, u32 cn_val,
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int (*on_msg)(void *, int),
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void (*on_reset)(void));
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int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len);
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void hvutil_transport_destroy(struct hvutil_transport *hvt);
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#endif /* _HV_UTILS_TRANSPORT_H */
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