Author: royger
Date: Mon Feb 16 09:53:43 2015
New Revision: 278844
URL: https://svnweb.freebsd.org/changeset/base/278844
Log:
xen: fix xenstore dev
Xenstore user-space device has two problems currently:
- It does not correctly handle concurrent clients, because it's storing
each client data in dev->si_drv1.
- It does not correctly free this data when the client closes the device.
In order to solve both of this issues store the per-client data using
cdevpriv, which also comes with a hook in order to perform the necessary
cleanup on device close.
While there also make the device eternal.
Sponsored by: Citrix Systems R&D
Reported and Tested by: thompsa
MFC after: 2 weeks
Modified:
head/sys/dev/xen/xenstore/xenstore_dev.c
Modified: head/sys/dev/xen/xenstore/xenstore_dev.c
==============================================================================
--- head/sys/dev/xen/xenstore/xenstore_dev.c Mon Feb 16 07:01:02 2015
(r278843)
+++ head/sys/dev/xen/xenstore/xenstore_dev.c Mon Feb 16 09:53:43 2015
(r278844)
@@ -77,7 +77,11 @@ static int
xs_dev_read(struct cdev *dev, struct uio *uio, int ioflag)
{
int error;
- struct xs_dev_data *u = dev->si_drv1;
+ struct xs_dev_data *u;
+
+ error = devfs_get_cdevpriv((void **)&u);
+ if (error != 0)
+ return (error);
while (u->read_prod == u->read_cons) {
error = tsleep(u, PCATCH, "xsdread", hz/10);
@@ -115,11 +119,15 @@ static int
xs_dev_write(struct cdev *dev, struct uio *uio, int ioflag)
{
int error;
- struct xs_dev_data *u = dev->si_drv1;
+ struct xs_dev_data *u;
struct xs_dev_transaction *trans;
void *reply;
int len = uio->uio_resid;
+ error = devfs_get_cdevpriv((void **)&u);
+ if (error != 0)
+ return (error);
+
if ((len + u->len) > sizeof(u->u.buffer))
return (EINVAL);
@@ -177,25 +185,10 @@ xs_dev_write(struct cdev *dev, struct ui
return (error);
}
-static int
-xs_dev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
-{
- struct xs_dev_data *u;
-
-#if 0 /* XXX figure out if equiv needed */
- nonseekable_open(inode, filp);
-#endif
- u = malloc(sizeof(*u), M_XENSTORE, M_WAITOK|M_ZERO);
- LIST_INIT(&u->transactions);
- dev->si_drv1 = u;
-
- return (0);
-}
-
-static int
-xs_dev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
+static void
+xs_dev_dtor(void *arg)
{
- struct xs_dev_data *u = dev->si_drv1;
+ struct xs_dev_data *u = arg;
struct xs_dev_transaction *trans, *tmp;
LIST_FOREACH_SAFE(trans, &u->transactions, list, tmp) {
@@ -205,7 +198,21 @@ xs_dev_close(struct cdev *dev, int fflag
}
free(u, M_XENSTORE);
- return (0);
+}
+
+static int
+xs_dev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
+{
+ struct xs_dev_data *u;
+ int error;
+
+ u = malloc(sizeof(*u), M_XENSTORE, M_WAITOK|M_ZERO);
+ LIST_INIT(&u->transactions);
+ error = devfs_set_cdevpriv(u, xs_dev_dtor);
+ if (error != 0)
+ free(u, M_XENSTORE);
+
+ return (error);
}
static struct cdevsw xs_dev_cdevsw = {
@@ -213,7 +220,6 @@ static struct cdevsw xs_dev_cdevsw = {
.d_read = xs_dev_read,
.d_write = xs_dev_write,
.d_open = xs_dev_open,
- .d_close = xs_dev_close,
.d_name = "xs_dev",
};
@@ -262,8 +268,8 @@ xs_dev_attach(device_t dev)
{
struct cdev *xs_cdev;
- xs_cdev = make_dev(&xs_dev_cdevsw, 0, UID_ROOT, GID_WHEEL, 0400,
- "xen/xenstore");
+ xs_cdev = make_dev_credf(MAKEDEV_ETERNAL, &xs_dev_cdevsw, 0, NULL,
+ UID_ROOT, GID_WHEEL, 0400, "xen/xenstore");
if (xs_cdev == NULL)
return (EINVAL);
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