| Message ID | 155053494523.24125.14949515989661790146.stgit@noble.brown (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | More lustre patches from obdclass | expand |
> This lock is only used to protect typ_refcnt, so change > that to a refcount_t and discard the lock. > > The lock also covers calls to try_module_get and module_put, > but this serves no purpose as it does not prevent the module > from being unloaded. > > Finally, the return value for the call to try_module_get is > ignored, which is not safe. Looks good. I do need to test this work tho. > Signed-off-by: NeilBrown <neilb@suse.com> > --- > drivers/staging/lustre/lustre/include/obd.h | 3 +- > drivers/staging/lustre/lustre/mdc/mdc_request.c | 2 + > drivers/staging/lustre/lustre/mgc/mgc_request.c | 2 + > drivers/staging/lustre/lustre/obdclass/genops.c | 30 +++++++++----------- > drivers/staging/lustre/lustre/obdclass/lu_object.c | 2 + > 5 files changed, 18 insertions(+), 21 deletions(-) > > diff --git a/drivers/staging/lustre/lustre/include/obd.h b/drivers/staging/lustre/lustre/include/obd.h > index 50f33f400075..a67eb9a14879 100644 > --- a/drivers/staging/lustre/lustre/include/obd.h > +++ b/drivers/staging/lustre/lustre/include/obd.h > @@ -102,9 +102,8 @@ struct obd_type { > struct obd_ops *typ_dt_ops; > struct md_ops *typ_md_ops; > struct dentry *typ_debugfs_entry; > - int typ_refcnt; > + refcount_t typ_refcnt; > struct lu_device_type *typ_lu; > - spinlock_t obd_type_lock; > struct kobject typ_kobj; > }; > #define typ_name typ_kobj.name > diff --git a/drivers/staging/lustre/lustre/mdc/mdc_request.c b/drivers/staging/lustre/lustre/mdc/mdc_request.c > index 3eb89ec80b7e..db2c045aa1cd 100644 > --- a/drivers/staging/lustre/lustre/mdc/mdc_request.c > +++ b/drivers/staging/lustre/lustre/mdc/mdc_request.c > @@ -2540,7 +2540,7 @@ static int mdc_init_ea_size(struct obd_export *exp, u32 easize, u32 def_easize) > static int mdc_precleanup(struct obd_device *obd) > { > /* Failsafe, ok if racy */ > - if (obd->obd_type->typ_refcnt <= 1) > + if (refcount_read(&obd->obd_type->typ_refcnt) <= 1) > libcfs_kkuc_group_rem(0, KUC_GRP_HSM); > > mdc_changelog_cdev_finish(obd); > diff --git a/drivers/staging/lustre/lustre/mgc/mgc_request.c b/drivers/staging/lustre/lustre/mgc/mgc_request.c > index a4dfdc08cc48..a6ee715921b8 100644 > --- a/drivers/staging/lustre/lustre/mgc/mgc_request.c > +++ b/drivers/staging/lustre/lustre/mgc/mgc_request.c > @@ -715,7 +715,7 @@ static int mgc_cleanup(struct obd_device *obd) > /* COMPAT_146 - old config logs may have added profiles we don't > * know about > */ > - if (obd->obd_type->typ_refcnt <= 1) > + if (refcount_read(&obd->obd_type->typ_refcnt) <= 1) > /* Only for the last mgc */ > class_del_profiles(); > > diff --git a/drivers/staging/lustre/lustre/obdclass/genops.c b/drivers/staging/lustre/lustre/obdclass/genops.c > index 775e4fa4f6a8..a3437c2d07bb 100644 > --- a/drivers/staging/lustre/lustre/obdclass/genops.c > +++ b/drivers/staging/lustre/lustre/obdclass/genops.c > @@ -112,15 +112,17 @@ static struct obd_type *class_get_type(const char *name) > } > } > if (type) { > - spin_lock(&type->obd_type_lock); > - type->typ_refcnt++; > - try_module_get(type->typ_dt_ops->owner); > - spin_unlock(&type->obd_type_lock); > - /* class_search_type() returned a counted reference, > - * but we don't need that count any more as > - * we have one through typ_refcnt. > - */ > - kobject_put(&type->typ_kobj); > + if (try_module_get(type->typ_dt_ops->owner)) { > + refcount_inc(&type->typ_refcnt); > + /* class_search_type() returned a counted reference, > + * but we don't need that count any more as > + * we have one through typ_refcnt. > + */ > + kobject_put(&type->typ_kobj); > + } else { > + kobject_put(&type->typ_kobj); > + type = NULL; > + } > } > return type; > } > @@ -128,10 +130,7 @@ static struct obd_type *class_get_type(const char *name) > void class_put_type(struct obd_type *type) > { > LASSERT(type); > - spin_lock(&type->obd_type_lock); > - type->typ_refcnt--; > - module_put(type->typ_dt_ops->owner); > - spin_unlock(&type->obd_type_lock); > + refcount_dec(&type->typ_refcnt); > } > > static void class_sysfs_release(struct kobject *kobj) > @@ -191,7 +190,6 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops, > /* md_ops is optional */ > if (md_ops) > *type->typ_md_ops = *md_ops; > - spin_lock_init(&type->obd_type_lock); > > rc = kobject_add(&type->typ_kobj, &lustre_kset->kobj, "%s", name); > if (rc) > @@ -225,8 +223,8 @@ int class_unregister_type(const char *name) > return -EINVAL; > } > > - if (type->typ_refcnt) { > - CERROR("type %s has refcount (%d)\n", name, type->typ_refcnt); > + if (refcount_read(&type->typ_refcnt)) { > + CERROR("type %s has refcount (%d)\n", name, refcount_read(&type->typ_refcnt)); > /* This is a bad situation, let's make the best of it */ > /* Remove ops, but leave the name for debugging */ > kfree(type->typ_dt_ops); > diff --git a/drivers/staging/lustre/lustre/obdclass/lu_object.c b/drivers/staging/lustre/lustre/obdclass/lu_object.c > index 639c298b6a90..69a56cca99f2 100644 > --- a/drivers/staging/lustre/lustre/obdclass/lu_object.c > +++ b/drivers/staging/lustre/lustre/obdclass/lu_object.c > @@ -1267,7 +1267,7 @@ void lu_stack_fini(const struct lu_env *env, struct lu_device *top) > next = ldt->ldt_ops->ldto_device_free(env, scan); > type = ldt->ldt_obd_type; > if (type) { > - type->typ_refcnt--; > + refcount_dec(&type->typ_refcnt); > class_put_type(type); > } > } > > >
diff --git a/drivers/staging/lustre/lustre/include/obd.h b/drivers/staging/lustre/lustre/include/obd.h index 50f33f400075..a67eb9a14879 100644 --- a/drivers/staging/lustre/lustre/include/obd.h +++ b/drivers/staging/lustre/lustre/include/obd.h @@ -102,9 +102,8 @@ struct obd_type { struct obd_ops *typ_dt_ops; struct md_ops *typ_md_ops; struct dentry *typ_debugfs_entry; - int typ_refcnt; + refcount_t typ_refcnt; struct lu_device_type *typ_lu; - spinlock_t obd_type_lock; struct kobject typ_kobj; }; #define typ_name typ_kobj.name diff --git a/drivers/staging/lustre/lustre/mdc/mdc_request.c b/drivers/staging/lustre/lustre/mdc/mdc_request.c index 3eb89ec80b7e..db2c045aa1cd 100644 --- a/drivers/staging/lustre/lustre/mdc/mdc_request.c +++ b/drivers/staging/lustre/lustre/mdc/mdc_request.c @@ -2540,7 +2540,7 @@ static int mdc_init_ea_size(struct obd_export *exp, u32 easize, u32 def_easize) static int mdc_precleanup(struct obd_device *obd) { /* Failsafe, ok if racy */ - if (obd->obd_type->typ_refcnt <= 1) + if (refcount_read(&obd->obd_type->typ_refcnt) <= 1) libcfs_kkuc_group_rem(0, KUC_GRP_HSM); mdc_changelog_cdev_finish(obd); diff --git a/drivers/staging/lustre/lustre/mgc/mgc_request.c b/drivers/staging/lustre/lustre/mgc/mgc_request.c index a4dfdc08cc48..a6ee715921b8 100644 --- a/drivers/staging/lustre/lustre/mgc/mgc_request.c +++ b/drivers/staging/lustre/lustre/mgc/mgc_request.c @@ -715,7 +715,7 @@ static int mgc_cleanup(struct obd_device *obd) /* COMPAT_146 - old config logs may have added profiles we don't * know about */ - if (obd->obd_type->typ_refcnt <= 1) + if (refcount_read(&obd->obd_type->typ_refcnt) <= 1) /* Only for the last mgc */ class_del_profiles(); diff --git a/drivers/staging/lustre/lustre/obdclass/genops.c b/drivers/staging/lustre/lustre/obdclass/genops.c index 775e4fa4f6a8..a3437c2d07bb 100644 --- a/drivers/staging/lustre/lustre/obdclass/genops.c +++ b/drivers/staging/lustre/lustre/obdclass/genops.c @@ -112,15 +112,17 @@ static struct obd_type *class_get_type(const char *name) } } if (type) { - spin_lock(&type->obd_type_lock); - type->typ_refcnt++; - try_module_get(type->typ_dt_ops->owner); - spin_unlock(&type->obd_type_lock); - /* class_search_type() returned a counted reference, - * but we don't need that count any more as - * we have one through typ_refcnt. - */ - kobject_put(&type->typ_kobj); + if (try_module_get(type->typ_dt_ops->owner)) { + refcount_inc(&type->typ_refcnt); + /* class_search_type() returned a counted reference, + * but we don't need that count any more as + * we have one through typ_refcnt. + */ + kobject_put(&type->typ_kobj); + } else { + kobject_put(&type->typ_kobj); + type = NULL; + } } return type; } @@ -128,10 +130,7 @@ static struct obd_type *class_get_type(const char *name) void class_put_type(struct obd_type *type) { LASSERT(type); - spin_lock(&type->obd_type_lock); - type->typ_refcnt--; - module_put(type->typ_dt_ops->owner); - spin_unlock(&type->obd_type_lock); + refcount_dec(&type->typ_refcnt); } static void class_sysfs_release(struct kobject *kobj) @@ -191,7 +190,6 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops, /* md_ops is optional */ if (md_ops) *type->typ_md_ops = *md_ops; - spin_lock_init(&type->obd_type_lock); rc = kobject_add(&type->typ_kobj, &lustre_kset->kobj, "%s", name); if (rc) @@ -225,8 +223,8 @@ int class_unregister_type(const char *name) return -EINVAL; } - if (type->typ_refcnt) { - CERROR("type %s has refcount (%d)\n", name, type->typ_refcnt); + if (refcount_read(&type->typ_refcnt)) { + CERROR("type %s has refcount (%d)\n", name, refcount_read(&type->typ_refcnt)); /* This is a bad situation, let's make the best of it */ /* Remove ops, but leave the name for debugging */ kfree(type->typ_dt_ops); diff --git a/drivers/staging/lustre/lustre/obdclass/lu_object.c b/drivers/staging/lustre/lustre/obdclass/lu_object.c index 639c298b6a90..69a56cca99f2 100644 --- a/drivers/staging/lustre/lustre/obdclass/lu_object.c +++ b/drivers/staging/lustre/lustre/obdclass/lu_object.c @@ -1267,7 +1267,7 @@ void lu_stack_fini(const struct lu_env *env, struct lu_device *top) next = ldt->ldt_ops->ldto_device_free(env, scan); type = ldt->ldt_obd_type; if (type) { - type->typ_refcnt--; + refcount_dec(&type->typ_refcnt); class_put_type(type); } }
This lock is only used to protect typ_refcnt, so change that to a refcount_t and discard the lock. The lock also covers calls to try_module_get and module_put, but this serves no purpose as it does not prevent the module from being unloaded. Finally, the return value for the call to try_module_get is ignored, which is not safe. Signed-off-by: NeilBrown <neilb@suse.com> --- drivers/staging/lustre/lustre/include/obd.h | 3 +- drivers/staging/lustre/lustre/mdc/mdc_request.c | 2 + drivers/staging/lustre/lustre/mgc/mgc_request.c | 2 + drivers/staging/lustre/lustre/obdclass/genops.c | 30 +++++++++----------- drivers/staging/lustre/lustre/obdclass/lu_object.c | 2 + 5 files changed, 18 insertions(+), 21 deletions(-)