Author: mav
Date: Sun Nov 27 05:59:17 2016
New Revision: 309206
URL: https://svnweb.freebsd.org/changeset/base/309206
Log:
MFC r308608:
Use providergone method to cover race between destroy and g_access().
Modified:
stable/10/sys/geom/mirror/g_mirror.c
stable/10/sys/geom/mirror/g_mirror.h
Directory Properties:
stable/10/ (props changed)
Modified: stable/10/sys/geom/mirror/g_mirror.c
==============================================================================
--- stable/10/sys/geom/mirror/g_mirror.c Sun Nov 27 05:58:47 2016
(r309205)
+++ stable/10/sys/geom/mirror/g_mirror.c Sun Nov 27 05:59:17 2016
(r309206)
@@ -84,12 +84,12 @@ SYSCTL_UINT(_kern_geom_mirror, OID_AUTO,
static eventhandler_tag g_mirror_post_sync = NULL;
static int g_mirror_shutdown = 0;
-static int g_mirror_destroy_geom(struct gctl_req *req, struct g_class *mp,
- struct g_geom *gp);
+static g_ctl_destroy_geom_t g_mirror_destroy_geom;
static g_taste_t g_mirror_taste;
+static g_init_t g_mirror_init;
+static g_fini_t g_mirror_fini;
+static g_provgone_t g_mirror_providergone;
static g_resize_t g_mirror_resize;
-static void g_mirror_init(struct g_class *mp);
-static void g_mirror_fini(struct g_class *mp);
struct g_class g_mirror_class = {
.name = G_MIRROR_CLASS_NAME,
@@ -99,6 +99,7 @@ struct g_class g_mirror_class = {
.destroy_geom = g_mirror_destroy_geom,
.init = g_mirror_init,
.fini = g_mirror_fini,
+ .providergone = g_mirror_providergone,
.resize = g_mirror_resize
};
@@ -513,6 +514,26 @@ g_mirror_destroy_disk(struct g_mirror_di
}
static void
+g_mirror_free_device(struct g_mirror_softc *sc)
+{
+
+ mtx_destroy(&sc->sc_queue_mtx);
+ mtx_destroy(&sc->sc_events_mtx);
+ mtx_destroy(&sc->sc_done_mtx);
+ sx_destroy(&sc->sc_lock);
+ free(sc, M_MIRROR);
+}
+
+static void
+g_mirror_providergone(struct g_provider *pp)
+{
+ struct g_mirror_softc *sc = pp->private;
+
+ if ((--sc->sc_refcnt) == 0)
+ g_mirror_free_device(sc);
+}
+
+static void
g_mirror_destroy_device(struct g_mirror_softc *sc)
{
struct g_mirror_disk *disk;
@@ -554,12 +575,10 @@ g_mirror_destroy_device(struct g_mirror_
g_wither_geom(sc->sc_sync.ds_geom, ENXIO);
G_MIRROR_DEBUG(0, "Device %s destroyed.", gp->name);
g_wither_geom(gp, ENXIO);
- g_topology_unlock();
- mtx_destroy(&sc->sc_queue_mtx);
- mtx_destroy(&sc->sc_events_mtx);
- mtx_destroy(&sc->sc_done_mtx);
sx_xunlock(&sc->sc_lock);
- sx_destroy(&sc->sc_lock);
+ if ((--sc->sc_refcnt) == 0)
+ g_mirror_free_device(sc);
+ g_topology_unlock();
}
static void
@@ -872,7 +891,7 @@ g_mirror_flush_done(struct bio *bp)
struct bio *pbp;
pbp = bp->bio_parent;
- sc = pbp->bio_to->geom->softc;
+ sc = pbp->bio_to->private;
mtx_lock(&sc->sc_done_mtx);
if (pbp->bio_error == 0)
pbp->bio_error = bp->bio_error;
@@ -909,7 +928,7 @@ g_mirror_regular_request(struct bio *bp)
g_topology_assert_not();
pbp = bp->bio_parent;
- sc = pbp->bio_to->geom->softc;
+ sc = pbp->bio_to->private;
bp->bio_from->index--;
if (bp->bio_cmd == BIO_WRITE)
sc->sc_writes--;
@@ -1033,7 +1052,7 @@ g_mirror_candelete(struct bio *bp)
struct g_mirror_disk *disk;
int *val;
- sc = bp->bio_to->geom->softc;
+ sc = bp->bio_to->private;
LIST_FOREACH(disk, &sc->sc_disks, d_next) {
if (disk->d_flags & G_MIRROR_DISK_FLAG_CANDELETE)
break;
@@ -1058,7 +1077,7 @@ g_mirror_kernel_dump(struct bio *bp)
* we will not be able to read the dump after the reboot if it will be
* connected and synchronized later. Can we do something better?
*/
- sc = bp->bio_to->geom->softc;
+ sc = bp->bio_to->private;
disk = LIST_FIRST(&sc->sc_disks);
gkd = (struct g_kerneldump *)bp->bio_data;
@@ -1118,7 +1137,7 @@ g_mirror_start(struct bio *bp)
{
struct g_mirror_softc *sc;
- sc = bp->bio_to->geom->softc;
+ sc = bp->bio_to->private;
/*
* If sc == NULL or there are no valid disks, provider's error
* should be set and g_mirror_start() should not be called at all.
@@ -1625,7 +1644,7 @@ g_mirror_register_request(struct bio *bp
{
struct g_mirror_softc *sc;
- sc = bp->bio_to->geom->softc;
+ sc = bp->bio_to->private;
switch (bp->bio_cmd) {
case BIO_READ:
switch (sc->sc_balance) {
@@ -1791,7 +1810,6 @@ g_mirror_try_destroy(struct g_mirror_sof
} else {
g_topology_unlock();
g_mirror_destroy_device(sc);
- free(sc, M_MIRROR);
}
return (1);
}
@@ -2103,6 +2121,8 @@ g_mirror_launch_provider(struct g_mirror
}
}
}
+ pp->private = sc;
+ sc->sc_refcnt++;
sc->sc_provider = pp;
g_error_provider(pp, 0);
g_topology_unlock();
@@ -2877,9 +2897,7 @@ g_mirror_access(struct g_provider *pp, i
G_MIRROR_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name, acr,
acw, ace);
- sc = pp->geom->softc;
- if (sc == NULL && acr <= 0 && acw <= 0 && ace <= 0)
- return (0);
+ sc = pp->private;
KASSERT(sc != NULL, ("NULL softc (provider=%s).", pp->name));
g_topology_unlock();
@@ -2938,6 +2956,7 @@ g_mirror_create(struct g_class *mp, cons
sc->sc_idle = 1;
sc->sc_last_write = time_uptime;
sc->sc_writes = 0;
+ sc->sc_refcnt = 1;
sx_init(&sc->sc_lock, "gmirror:lock");
bioq_init(&sc->sc_queue);
mtx_init(&sc->sc_queue_mtx, "gmirror:queue", NULL, MTX_DEF);
@@ -2968,12 +2987,8 @@ g_mirror_create(struct g_class *mp, cons
G_MIRROR_DEBUG(1, "Cannot create kernel thread for %s.",
sc->sc_name);
g_destroy_geom(sc->sc_sync.ds_geom);
- mtx_destroy(&sc->sc_done_mtx);
- mtx_destroy(&sc->sc_events_mtx);
- mtx_destroy(&sc->sc_queue_mtx);
- sx_destroy(&sc->sc_lock);
g_destroy_geom(sc->sc_geom);
- free(sc, M_MIRROR);
+ g_mirror_free_device(sc);
return (NULL);
}
@@ -2996,8 +3011,6 @@ g_mirror_destroy(struct g_mirror_softc *
struct g_mirror_disk *disk;
g_topology_assert_not();
- if (sc == NULL)
- return (ENXIO);
sx_assert(&sc->sc_lock, SX_XLOCKED);
if (sc->sc_provider_open != 0) {
@@ -3047,7 +3060,6 @@ g_mirror_destroy(struct g_mirror_softc *
G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, &sc->sc_worker);
sx_xlock(&sc->sc_lock);
g_mirror_destroy_device(sc);
- free(sc, M_MIRROR);
return (0);
}
Modified: stable/10/sys/geom/mirror/g_mirror.h
==============================================================================
--- stable/10/sys/geom/mirror/g_mirror.h Sun Nov 27 05:58:47 2016
(r309205)
+++ stable/10/sys/geom/mirror/g_mirror.h Sun Nov 27 05:59:17 2016
(r309206)
@@ -207,6 +207,7 @@ struct g_mirror_softc {
int sc_idle; /* DIRTY flags removed. */
time_t sc_last_write;
u_int sc_writes;
+ u_int sc_refcnt; /* Number of softc references */
TAILQ_HEAD(, g_mirror_event) sc_events;
struct mtx sc_events_mtx;
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