04e1532fc5
More graciously handle processing messages and watch events inline prior to threads being up and running. MFC after: 1 month
260 lines
6.3 KiB
C
260 lines
6.3 KiB
C
/*
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* xenbus_dev.c
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*
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* Driver giving user-space access to the kernel's xenbus connection
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* to xenstore.
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*
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* Copyright (c) 2005, Christian Limpach
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* Copyright (c) 2005, Rusty Russell, IBM Corporation
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*
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* This file may be distributed separately from the Linux kernel, or
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* incorporated into other software packages, subject to the following license:
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this source file (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy, modify,
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* merge, publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/types.h>
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#include <sys/cdefs.h>
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#include <sys/errno.h>
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#include <sys/uio.h>
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <sys/kernel.h>
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#include <sys/malloc.h>
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#include <sys/conf.h>
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#include <machine/xen/xen-os.h>
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#include <machine/xen/hypervisor.h>
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#include <machine/xen/xenbus.h>
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#include <machine/xen/hypervisor.h>
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#include <xen/xenbus/xenbus_comms.h>
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#define kmalloc(size, unused) malloc(size, M_DEVBUF, M_WAITOK)
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#define BUG_ON PANIC_IF
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#define semaphore sema
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#define rw_semaphore sema
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#define DEFINE_SPINLOCK(lock) struct mtx lock
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#define DECLARE_MUTEX(lock) struct sema lock
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#define u32 uint32_t
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#define simple_strtoul strtoul
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struct xenbus_dev_transaction {
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LIST_ENTRY(xenbus_dev_transaction) list;
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struct xenbus_transaction handle;
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};
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struct xenbus_dev_data {
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/* In-progress transaction. */
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LIST_HEAD(xdd_list_head, xenbus_dev_transaction) transactions;
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/* Partial request. */
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unsigned int len;
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union {
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struct xsd_sockmsg msg;
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char buffer[PAGE_SIZE];
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} u;
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/* Response queue. */
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#define MASK_READ_IDX(idx) ((idx)&(PAGE_SIZE-1))
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char read_buffer[PAGE_SIZE];
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unsigned int read_cons, read_prod;
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int read_waitq;
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};
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#if 0
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static struct proc_dir_entry *xenbus_dev_intf;
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#endif
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static int
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xenbus_dev_read(struct cdev *dev, struct uio *uio, int ioflag)
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{
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int i = 0;
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struct xenbus_dev_data *u = dev->si_drv1;
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if (wait_event_interruptible(&u->read_waitq,
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u->read_prod != u->read_cons))
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return EINTR;
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for (i = 0; i < uio->uio_iov[0].iov_len; i++) {
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if (u->read_cons == u->read_prod)
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break;
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copyout(&u->read_buffer[MASK_READ_IDX(u->read_cons)], (char *)uio->uio_iov[0].iov_base+i, 1);
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u->read_cons++;
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uio->uio_resid--;
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}
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return 0;
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}
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static void queue_reply(struct xenbus_dev_data *u,
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char *data, unsigned int len)
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{
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int i;
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for (i = 0; i < len; i++, u->read_prod++)
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u->read_buffer[MASK_READ_IDX(u->read_prod)] = data[i];
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BUG_ON((u->read_prod - u->read_cons) > sizeof(u->read_buffer));
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wakeup(&u->read_waitq);
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}
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static int
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xenbus_dev_write(struct cdev *dev, struct uio *uio, int ioflag)
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{
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int err = 0;
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struct xenbus_dev_data *u = dev->si_drv1;
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struct xenbus_dev_transaction *trans;
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void *reply;
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int len = uio->uio_iov[0].iov_len;
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if ((len + u->len) > sizeof(u->u.buffer))
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return EINVAL;
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if (copyin(u->u.buffer + u->len, uio->uio_iov[0].iov_base, len) != 0)
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return EFAULT;
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u->len += len;
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if (u->len < (sizeof(u->u.msg) + u->u.msg.len))
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return len;
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switch (u->u.msg.type) {
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case XS_TRANSACTION_START:
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case XS_TRANSACTION_END:
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case XS_DIRECTORY:
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case XS_READ:
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case XS_GET_PERMS:
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case XS_RELEASE:
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case XS_GET_DOMAIN_PATH:
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case XS_WRITE:
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case XS_MKDIR:
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case XS_RM:
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case XS_SET_PERMS:
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reply = xenbus_dev_request_and_reply(&u->u.msg);
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if (IS_ERR(reply)) {
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err = PTR_ERR(reply);
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} else {
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if (u->u.msg.type == XS_TRANSACTION_START) {
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trans = kmalloc(sizeof(*trans), GFP_KERNEL);
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trans->handle.id = simple_strtoul(reply, NULL, 0);
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LIST_INSERT_HEAD(&u->transactions, trans, list);
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} else if (u->u.msg.type == XS_TRANSACTION_END) {
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LIST_FOREACH(trans, &u->transactions,
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list)
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if (trans->handle.id ==
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u->u.msg.tx_id)
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break;
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#if 0 /* XXX does this mean the list is empty? */
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BUG_ON(&trans->list == &u->transactions);
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#endif
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LIST_REMOVE(trans, list);
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kfree(trans);
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}
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queue_reply(u, (char *)&u->u.msg, sizeof(u->u.msg));
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queue_reply(u, (char *)reply, u->u.msg.len);
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kfree(reply);
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}
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break;
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default:
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err = EINVAL;
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break;
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}
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if (err == 0) {
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u->len = 0;
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err = len;
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}
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return err;
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}
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static int xenbus_dev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
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{
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struct xenbus_dev_data *u;
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if (xen_start_info->store_evtchn == 0)
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return ENOENT;
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#if 0 /* XXX figure out if equiv needed */
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nonseekable_open(inode, filp);
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#endif
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u = kmalloc(sizeof(*u), GFP_KERNEL);
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if (u == NULL)
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return ENOMEM;
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memset(u, 0, sizeof(*u));
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LIST_INIT(&u->transactions);
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dev->si_drv1 = u;
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return 0;
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}
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static int xenbus_dev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
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{
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struct xenbus_dev_data *u = dev->si_drv1;
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struct xenbus_dev_transaction *trans, *tmp;
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LIST_FOREACH_SAFE(trans, &u->transactions, list, tmp) {
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xenbus_transaction_end(trans->handle, 1);
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LIST_REMOVE(trans, list);
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kfree(trans);
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}
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kfree(u);
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return 0;
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}
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static struct cdevsw xenbus_dev_cdevsw = {
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.d_version = D_VERSION,
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.d_read = xenbus_dev_read,
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.d_write = xenbus_dev_write,
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.d_open = xenbus_dev_open,
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.d_close = xenbus_dev_close,
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.d_name = "xenbus_dev",
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};
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static int
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xenbus_dev_sysinit(void)
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{
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make_dev(&xenbus_dev_cdevsw, 0, UID_ROOT, GID_WHEEL, 0400, "xenbus");
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return 0;
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}
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SYSINIT(xenbus_dev_sysinit, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, xenbus_dev_sysinit, NULL);
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/* SYSINIT NEEDED XXX */
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/*
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* Local variables:
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* c-file-style: "linux"
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* indent-tabs-mode: t
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* c-indent-level: 8
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* c-basic-offset: 8
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* tab-width: 8
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* End:
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*/
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