freebsd-dev/sys/geom/geom_event.c

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/*-
* Copyright (c) 2002 Poul-Henning Kamp
* Copyright (c) 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Poul-Henning Kamp
* and NAI Labs, the Security Research Division of Network Associates, Inc.
* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
* DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* XXX: How do we in general know that objects referenced in events
* have not been destroyed before we get around to handle the event ?
*/
2003-06-11 06:49:16 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <geom/geom.h>
#include <geom/geom_int.h>
#include <machine/stdarg.h>
TAILQ_HEAD(event_tailq_head, g_event);
static struct event_tailq_head g_events = TAILQ_HEAD_INITIALIZER(g_events);
static u_int g_pending_events;
static TAILQ_HEAD(,g_provider) g_doorstep = TAILQ_HEAD_INITIALIZER(g_doorstep);
static struct mtx g_eventlock;
static int g_wither_work;
#define G_N_EVENTREFS 20
struct g_event {
TAILQ_ENTRY(g_event) events;
g_event_t *func;
void *arg;
int flag;
void *ref[G_N_EVENTREFS];
};
#define EV_DONE 0x80000
#define EV_WAKEUP 0x40000
#define EV_CANCELED 0x20000
#define EV_INPROGRESS 0x10000
void
g_waitidle(void)
{
g_topology_assert_not();
mtx_lock(&g_eventlock);
while (!TAILQ_EMPTY(&g_events))
msleep(&g_pending_events, &g_eventlock, PPAUSE,
"g_waitidle", hz/5);
mtx_unlock(&g_eventlock);
curthread->td_pflags &= ~TDP_GEOM;
}
#if 0
void
g_waitidlelock(void)
{
g_topology_assert();
mtx_lock(&g_eventlock);
while (!TAILQ_EMPTY(&g_events)) {
g_topology_unlock();
msleep(&g_pending_events, &g_eventlock, PPAUSE,
"g_waitidlel", hz/5);
g_topology_lock();
}
mtx_unlock(&g_eventlock);
}
#endif
Plumb device physical path reporting from CAM devices, through GEOM and DEVFS, and make it accessible via the diskinfo utility. Extend GEOM's generic attribute query mechanism into generic disk consumers. sys/geom/geom_disk.c: sys/geom/geom_disk.h: sys/cam/scsi/scsi_da.c: sys/cam/ata/ata_da.c: - Allow disk providers to implement a new method which can override the default BIO_GETATTR response, d_getattr(struct bio *). This function returns -1 if not handled, otherwise it returns 0 or an errno to be passed to g_io_deliver(). sys/cam/scsi/scsi_da.c: sys/cam/ata/ata_da.c: - Don't copy the serial number to dp->d_ident anymore, as the CAM XPT is now responsible for returning this information via d_getattr()->(a)dagetattr()->xpt_getatr(). sys/geom/geom_dev.c: - Implement a new ioctl, DIOCGPHYSPATH, which returns the GEOM attribute "GEOM::physpath", if possible. If the attribute request returns a zero-length string, ENOENT is returned. usr.sbin/diskinfo/diskinfo.c: - If the DIOCGPHYSPATH ioctl is successful, report physical path data when diskinfo is executed with the '-v' option. Submitted by: will Reviewed by: gibbs Sponsored by: Spectra Logic Corporation Add generic attribute change notification support to GEOM. sys/sys/geom/geom.h: Add a new attrchanged method field to both g_class and g_geom. sys/sys/geom/geom.h: sys/geom/geom_event.c: - Provide the g_attr_changed() function that providers can use to advertise attribute changes. - Perform delivery of attribute change notifications from a thread context via the standard GEOM event mechanism. sys/geom/geom_subr.c: Inherit the attrchanged method from class to geom (class instance). sys/geom/geom_disk.c: Provide disk_attr_changed() to provide g_attr_changed() access to consumers of the disk API. sys/cam/scsi/scsi_pass.c: sys/cam/scsi/scsi_da.c: sys/geom/geom_dev.c: sys/geom/geom_disk.c: Use attribute changed events to track updates to physical path information. sys/cam/scsi/scsi_da.c: Add AC_ADVINFO_CHANGED to the registered asynchronous CAM events for this driver. When this event occurs, and the updated buffer type references our physical path attribute, emit a GEOM attribute changed event via the disk_attr_changed() API. sys/cam/scsi/scsi_pass.c: Add AC_ADVINFO_CHANGED to the registered asynchronous CAM events for this driver. When this event occurs, update the physical patch devfs alias for this pass instance. Submitted by: gibbs Sponsored by: Spectra Logic Corporation
2011-06-14 17:10:32 +00:00
struct g_attrchanged_args {
struct g_provider *pp;
const char *attr;
};
static void
g_attr_changed_event(void *arg, int flag)
{
struct g_attrchanged_args *args;
struct g_provider *pp;
struct g_consumer *cp;
struct g_consumer *next_cp;
args = arg;
pp = args->pp;
g_topology_assert();
if (flag != EV_CANCEL && g_shutdown == 0) {
/*
* Tell all consumers of the change.
*/
LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, next_cp) {
if (cp->geom->attrchanged != NULL)
cp->geom->attrchanged(cp, args->attr);
}
}
g_free(args);
}
int
g_attr_changed(struct g_provider *pp, const char *attr, int flag)
{
struct g_attrchanged_args *args;
int error;
args = g_malloc(sizeof *args, flag);
if (args == NULL)
return (ENOMEM);
args->pp = pp;
args->attr = attr;
error = g_post_event(g_attr_changed_event, args, flag, pp, NULL);
if (error != 0)
g_free(args);
return (error);
}
void
g_orphan_provider(struct g_provider *pp, int error)
{
/* G_VALID_PROVIDER(pp) We likely lack topology lock */
g_trace(G_T_TOPOLOGY, "g_orphan_provider(%p(%s), %d)",
pp, pp->name, error);
KASSERT(error != 0,
("g_orphan_provider(%p(%s), 0) error must be non-zero\n",
pp, pp->name));
pp->error = error;
mtx_lock(&g_eventlock);
KASSERT(!(pp->flags & G_PF_ORPHAN),
("g_orphan_provider(%p(%s)), already an orphan", pp, pp->name));
pp->flags |= G_PF_ORPHAN;
TAILQ_INSERT_TAIL(&g_doorstep, pp, orphan);
mtx_unlock(&g_eventlock);
wakeup(&g_wait_event);
}
/*
* This function is called once on each provider which the event handler
* finds on its g_doorstep.
*/
static void
g_orphan_register(struct g_provider *pp)
{
struct g_consumer *cp, *cp2;
int wf;
g_topology_assert();
G_VALID_PROVIDER(pp);
g_trace(G_T_TOPOLOGY, "g_orphan_register(%s)", pp->name);
g_cancel_event(pp);
wf = pp->flags & G_PF_WITHER;
pp->flags &= ~G_PF_WITHER;
/*
* Tell all consumers the bad news.
2003-03-09 10:02:31 +00:00
* Don't be surprised if they self-destruct.
*/
Implement media change notification for DA and CD removable media devices. It includes three parts: 1) Modifications to CAM to detect media media changes and report them to disk(9) layer. For modern SATA (and potentially UAS) devices it utilizes Asynchronous Notification mechanism to receive events from hardware. Active polling with TEST UNIT READY commands with 3 seconds period is used for incapable hardware. After that both CD and DA drivers work the same way, detecting two conditions: "NOT READY: Medium not present" after medium was detected previously, and "UNIT ATTENTION: Not ready to ready change, medium may have changed". First one reported to disk(9) as media removal, second as media insert/change. To reliably receive second event new AC_UNIT_ATTENTION async added to make UAs broadcasted to all periphs by generic error handling code in cam_periph_error(). 2) Modifications to GEOM core to handle media remove and change events. Media removal handled by spoiling all consumers attached to the provider. Media change event also schedules provider retaste after spoiling to probe new media. New flag G_CF_ORPHAN was added to consumers to reflect that consumer is in process of destruction. It allows retaste to create new geom instance of the same class, while previous one is still dying. 3) Modifications to some GEOM classes: DEV -- to report media change events to devd; VFS -- to handle spoiling same as orphan to prevent accessing replaced media. PART class already handles spoiling alike to orphan. Reviewed by: silence on geom@ and scsi@ Tested by: avg Sponsored by: iXsystems, Inc. / PC-BSD MFC after: 2 months
2012-07-29 11:51:48 +00:00
LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, cp2) {
KASSERT(cp->geom->orphan != NULL,
("geom %s has no orphan, class %s",
cp->geom->name, cp->geom->class->name));
/*
* XXX: g_dev_orphan method does deferred destroying
* and it is possible, that other event could already
* call the orphan method. Check consumer's flags to
* do not schedule it twice.
*/
if (cp->flags & G_CF_ORPHAN)
continue;
Implement media change notification for DA and CD removable media devices. It includes three parts: 1) Modifications to CAM to detect media media changes and report them to disk(9) layer. For modern SATA (and potentially UAS) devices it utilizes Asynchronous Notification mechanism to receive events from hardware. Active polling with TEST UNIT READY commands with 3 seconds period is used for incapable hardware. After that both CD and DA drivers work the same way, detecting two conditions: "NOT READY: Medium not present" after medium was detected previously, and "UNIT ATTENTION: Not ready to ready change, medium may have changed". First one reported to disk(9) as media removal, second as media insert/change. To reliably receive second event new AC_UNIT_ATTENTION async added to make UAs broadcasted to all periphs by generic error handling code in cam_periph_error(). 2) Modifications to GEOM core to handle media remove and change events. Media removal handled by spoiling all consumers attached to the provider. Media change event also schedules provider retaste after spoiling to probe new media. New flag G_CF_ORPHAN was added to consumers to reflect that consumer is in process of destruction. It allows retaste to create new geom instance of the same class, while previous one is still dying. 3) Modifications to some GEOM classes: DEV -- to report media change events to devd; VFS -- to handle spoiling same as orphan to prevent accessing replaced media. PART class already handles spoiling alike to orphan. Reviewed by: silence on geom@ and scsi@ Tested by: avg Sponsored by: iXsystems, Inc. / PC-BSD MFC after: 2 months
2012-07-29 11:51:48 +00:00
cp->flags |= G_CF_ORPHAN;
cp->geom->orphan(cp);
}
if (LIST_EMPTY(&pp->consumers) && wf)
g_destroy_provider(pp);
else
pp->flags |= wf;
#ifdef notyet
cp = LIST_FIRST(&pp->consumers);
if (cp != NULL)
return;
if (pp->geom->flags & G_GEOM_WITHER)
g_destroy_provider(pp);
#endif
}
static int
one_event(void)
{
struct g_event *ep;
struct g_provider *pp;
g_topology_assert();
mtx_lock(&g_eventlock);
TAILQ_FOREACH(pp, &g_doorstep, orphan) {
if (pp->nstart == pp->nend)
break;
}
if (pp != NULL) {
G_VALID_PROVIDER(pp);
TAILQ_REMOVE(&g_doorstep, pp, orphan);
mtx_unlock(&g_eventlock);
g_orphan_register(pp);
return (1);
}
ep = TAILQ_FIRST(&g_events);
if (ep == NULL) {
wakeup(&g_pending_events);
return (0);
}
if (ep->flag & EV_INPROGRESS) {
mtx_unlock(&g_eventlock);
return (1);
}
ep->flag |= EV_INPROGRESS;
mtx_unlock(&g_eventlock);
g_topology_assert();
ep->func(ep->arg, 0);
g_topology_assert();
mtx_lock(&g_eventlock);
TAILQ_REMOVE(&g_events, ep, events);
ep->flag &= ~EV_INPROGRESS;
if (ep->flag & EV_WAKEUP) {
ep->flag |= EV_DONE;
mtx_unlock(&g_eventlock);
wakeup(ep);
} else {
mtx_unlock(&g_eventlock);
g_free(ep);
}
return (1);
}
void
g_run_events()
{
for (;;) {
g_topology_lock();
while (one_event())
;
mtx_assert(&g_eventlock, MA_OWNED);
if (g_wither_work) {
g_wither_work = 0;
mtx_unlock(&g_eventlock);
g_wither_washer();
g_topology_unlock();
} else {
g_topology_unlock();
msleep(&g_wait_event, &g_eventlock, PRIBIO | PDROP,
"-", TAILQ_EMPTY(&g_doorstep) ? 0 : hz / 10);
}
}
/* NOTREACHED */
}
void
g_cancel_event(void *ref)
{
struct g_event *ep, *epn;
struct g_provider *pp;
u_int n;
mtx_lock(&g_eventlock);
TAILQ_FOREACH(pp, &g_doorstep, orphan) {
if (pp != ref)
continue;
TAILQ_REMOVE(&g_doorstep, pp, orphan);
break;
}
TAILQ_FOREACH_SAFE(ep, &g_events, events, epn) {
if (ep->flag & EV_INPROGRESS)
continue;
for (n = 0; n < G_N_EVENTREFS; n++) {
if (ep->ref[n] == NULL)
break;
if (ep->ref[n] != ref)
continue;
TAILQ_REMOVE(&g_events, ep, events);
ep->func(ep->arg, EV_CANCEL);
mtx_assert(&g_eventlock, MA_OWNED);
if (ep->flag & EV_WAKEUP) {
ep->flag |= (EV_DONE|EV_CANCELED);
wakeup(ep);
} else {
g_free(ep);
}
break;
}
}
if (TAILQ_EMPTY(&g_events))
wakeup(&g_pending_events);
mtx_unlock(&g_eventlock);
}
static int
g_post_event_x(g_event_t *func, void *arg, int flag, int wuflag, struct g_event **epp, va_list ap)
{
struct g_event *ep;
void *p;
u_int n;
g_trace(G_T_TOPOLOGY, "g_post_event_x(%p, %p, %d, %d)",
2005-05-18 21:53:08 +00:00
func, arg, flag, wuflag);
KASSERT(wuflag == 0 || wuflag == EV_WAKEUP,
("Wrong wuflag in g_post_event_x(0x%x)", wuflag));
ep = g_malloc(sizeof *ep, flag | M_ZERO);
if (ep == NULL)
return (ENOMEM);
ep->flag = wuflag;
for (n = 0; n < G_N_EVENTREFS; n++) {
p = va_arg(ap, void *);
if (p == NULL)
break;
g_trace(G_T_TOPOLOGY, " ref %p", p);
ep->ref[n] = p;
}
KASSERT(p == NULL, ("Too many references to event"));
ep->func = func;
ep->arg = arg;
mtx_lock(&g_eventlock);
TAILQ_INSERT_TAIL(&g_events, ep, events);
mtx_unlock(&g_eventlock);
wakeup(&g_wait_event);
if (epp != NULL)
*epp = ep;
curthread->td_pflags |= TDP_GEOM;
return (0);
}
int
g_post_event(g_event_t *func, void *arg, int flag, ...)
{
va_list ap;
int i;
KASSERT(flag == M_WAITOK || flag == M_NOWAIT,
("Wrong flag to g_post_event"));
va_start(ap, flag);
i = g_post_event_x(func, arg, flag, 0, NULL, ap);
va_end(ap);
return (i);
}
void
g_do_wither()
{
mtx_lock(&g_eventlock);
g_wither_work = 1;
mtx_unlock(&g_eventlock);
wakeup(&g_wait_event);
}
/*
* XXX: It might actually be useful to call this function with topology held.
* XXX: This would ensure that the event gets created before anything else
* XXX: changes. At present all users have a handle on things in some other
* XXX: way, so this remains an XXX for now.
*/
int
g_waitfor_event(g_event_t *func, void *arg, int flag, ...)
{
va_list ap;
struct g_event *ep;
int error;
g_topology_assert_not();
KASSERT(flag == M_WAITOK || flag == M_NOWAIT,
("Wrong flag to g_post_event"));
va_start(ap, flag);
error = g_post_event_x(func, arg, flag, EV_WAKEUP, &ep, ap);
va_end(ap);
if (error)
return (error);
mtx_lock(&g_eventlock);
while (!(ep->flag & EV_DONE))
msleep(ep, &g_eventlock, PRIBIO, "g_waitfor_event", hz);
if (ep->flag & EV_CANCELED)
error = EAGAIN;
mtx_unlock(&g_eventlock);
g_free(ep);
return (error);
}
void
g_event_init()
{
mtx_init(&g_eventlock, "GEOM orphanage", NULL, MTX_DEF);
}