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devd kernel improvements:

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1) Record all device events when devctl is enabled, rather than just when
   devd has devctl open.  This is necessary to prevent races between when
   a device arrives, and when devd starts.
2) Add hw.bus.devctl_disable to disable devctl, this can also be set as a
   tunable.
3) Fix async support. Reset nonblocking and async_td in open.  remove
   async flags.
4) Free all memory when devctl is disabled.

Approved by: re (blanket)
This commit is contained in:
Warner Losh 2002-11-30 00:49:43 +00:00
parent 406259c133
commit 304f10ce4a
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=107398
1 changed files with 38 additions and 21 deletions
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59
sys/kern/subr_bus.c
View file

@ -54,6 +54,8 @@
#include <vm/uma.h>
SYSCTL_NODE(_hw, OID_AUTO, bus, CTLFLAG_RW, NULL, NULL);
/*
* Used to attach drivers to devclasses.
*/
@ -200,6 +202,13 @@ void print_devclass_list(void);
* tested since 3.4 or 2.2.8!
*/
static int sysctl_devctl_disable(SYSCTL_HANDLER_ARGS);
static int devctl_disable = 0;
TUNABLE_INT("hw.bus.devctl_disable", &devctl_disable);
SYSCTL_PROC(_hw_bus, OID_AUTO, devctl_disable,
CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, sysctl_devctl_disable,
"I", "devctl disable");
static d_open_t devopen;
static d_close_t devclose;
static d_read_t devread;
@ -235,7 +244,6 @@ struct dev_softc
{
int inuse;
int nonblock;
int async;
struct mtx mtx;
struct cv cv;
struct selinfo sel;
@ -261,27 +269,17 @@ devopen(dev_t dev, int oflags, int devtype, d_thread_t *td)
return (EBUSY);
/* move to init */
devsoftc.inuse = 1;
devsoftc.nonblock = 0;
devsoftc.async_td = NULL;
return (0);
}
static int
devclose(dev_t dev, int fflag, int devtype, d_thread_t *td)
{
struct dev_event_info *n1;
devsoftc.inuse = 0;
mtx_lock(&devsoftc.mtx);
cv_broadcast(&devsoftc.cv);
/*
* See note in devread. If we deside to keep data until read, then
* remove the following while loop. XXX
*/
while (!TAILQ_EMPTY(&devsoftc.devq)) {
n1 = TAILQ_FIRST(&devsoftc.devq);
TAILQ_REMOVE(&devsoftc.devq, n1, dei_link);
free(n1->dei_data, M_BUS);
free(n1, M_BUS);
}
mtx_unlock(&devsoftc.mtx);
return (0);
@ -337,14 +335,10 @@ devioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, d_thread_t *td)
devsoftc.nonblock = 0;
return (0);
case FIOASYNC:
if (*(int*)data) {
devsoftc.async = 1;
if (*(int*)data)
devsoftc.async_td = td;
}
else {
devsoftc.async = 0;
else
devsoftc.async_td = NULL;
}
return (0);
/* (un)Support for other fcntl() calls. */
@ -408,7 +402,7 @@ devaddq(const char *type, const char *what, device_t dev)
char *loc;
const char *parstr;
if (!devsoftc.inuse)
if (devctl_disable)
return;
n1 = malloc(sizeof(*n1), M_BUS, M_NOWAIT);
if (n1 == NULL)
@ -487,6 +481,30 @@ devnomatch(device_t dev)
return;
}
static int
sysctl_devctl_disable(SYSCTL_HANDLER_ARGS)
{
struct dev_event_info *n1;
int dis, error;
dis = devctl_disable;
error = sysctl_handle_int(oidp, &dis, 0, req);
if (error || !req->newptr)
return (error);
mtx_lock(&devsoftc.mtx);
devctl_disable = dis;
if (dis) {
while (!TAILQ_EMPTY(&devsoftc.devq)) {
n1 = TAILQ_FIRST(&devsoftc.devq);
TAILQ_REMOVE(&devsoftc.devq, n1, dei_link);
free(n1->dei_data, M_BUS);
free(n1, M_BUS);
}
}
mtx_unlock(&devsoftc.mtx);
return (0);
}
/* End of /dev/devctl code */
TAILQ_HEAD(,device) bus_data_devices;
@ -2458,7 +2476,6 @@ print_devclass_list(void)
* We might like to add the ability to scan devclasses and/or drivers to
* determine what else is currently loaded/available.
*/
SYSCTL_NODE(_hw, OID_AUTO, bus, CTLFLAG_RW, NULL, NULL);
static int
sysctl_bus(SYSCTL_HANDLER_ARGS)