[lustre-devel] [PATCH 08/37] lustre: obdclass: don't copy ops structures in to new type.
James Simmons
jsimmons at infradead.org
Sun Feb 24 09:03:18 PST 2019
> The obd_ops and md_ops structures passed to class_register_type() are
> read-only, and have a lifetime that is exceeds the lifetime of the
> obd_type - they are static in a module which unregisters the type before
> being unloaded.
>
> So there is no need to copy the ops, just store a pointer.
>
> Also mark all the structures as read-only to confirm they don't get
> written. This is best-practice for structures of function pointers.
Reviewed-by: James Simmons <jsimmons at infradead.org>
> Signed-off-by: NeilBrown <neilb at suse.com>
> ---
> drivers/staging/lustre/lustre/include/obd.h | 4 ++--
> drivers/staging/lustre/lustre/include/obd_class.h | 3 ++-
> drivers/staging/lustre/lustre/lmv/lmv_obd.c | 4 ++--
> drivers/staging/lustre/lustre/lov/lov_obd.c | 2 +-
> drivers/staging/lustre/lustre/mdc/mdc_request.c | 4 ++--
> drivers/staging/lustre/lustre/mgc/mgc_request.c | 2 +-
> drivers/staging/lustre/lustre/obdclass/genops.c | 22 +++++---------------
> .../staging/lustre/lustre/obdecho/echo_client.c | 2 +-
> drivers/staging/lustre/lustre/osc/osc_request.c | 2 +-
> 9 files changed, 18 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/staging/lustre/lustre/include/obd.h b/drivers/staging/lustre/lustre/include/obd.h
> index a67eb9a14879..9cffda3741ce 100644
> --- a/drivers/staging/lustre/lustre/include/obd.h
> +++ b/drivers/staging/lustre/lustre/include/obd.h
> @@ -99,8 +99,8 @@ struct obd_info {
> };
>
> struct obd_type {
> - struct obd_ops *typ_dt_ops;
> - struct md_ops *typ_md_ops;
> + const struct obd_ops *typ_dt_ops;
> + const struct md_ops *typ_md_ops;
> struct dentry *typ_debugfs_entry;
> refcount_t typ_refcnt;
> struct lu_device_type *typ_lu;
> diff --git a/drivers/staging/lustre/lustre/include/obd_class.h b/drivers/staging/lustre/lustre/include/obd_class.h
> index a61c7950393c..7c2e248a8110 100644
> --- a/drivers/staging/lustre/lustre/include/obd_class.h
> +++ b/drivers/staging/lustre/lustre/include/obd_class.h
> @@ -60,7 +60,8 @@ struct lu_device_type;
>
> /* genops.c */
> struct obd_export *class_conn2export(struct lustre_handle *conn);
> -int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
> +int class_register_type(const struct obd_ops *dt_ops,
> + const struct md_ops *md_ops,
> const char *name, struct lu_device_type *ldt);
> int class_unregister_type(const char *name);
>
> diff --git a/drivers/staging/lustre/lustre/lmv/lmv_obd.c b/drivers/staging/lustre/lustre/lmv/lmv_obd.c
> index 1c7379b14f8c..35dff0e96bf7 100644
> --- a/drivers/staging/lustre/lustre/lmv/lmv_obd.c
> +++ b/drivers/staging/lustre/lustre/lmv/lmv_obd.c
> @@ -3044,7 +3044,7 @@ static int lmv_merge_attr(struct obd_export *exp,
> return 0;
> }
>
> -static struct obd_ops lmv_obd_ops = {
> +static const struct obd_ops lmv_obd_ops = {
> .owner = THIS_MODULE,
> .setup = lmv_setup,
> .cleanup = lmv_cleanup,
> @@ -3061,7 +3061,7 @@ static struct obd_ops lmv_obd_ops = {
> .quotactl = lmv_quotactl
> };
>
> -static struct md_ops lmv_md_ops = {
> +static const struct md_ops lmv_md_ops = {
> .get_root = lmv_get_root,
> .null_inode = lmv_null_inode,
> .close = lmv_close,
> diff --git a/drivers/staging/lustre/lustre/lov/lov_obd.c b/drivers/staging/lustre/lustre/lov/lov_obd.c
> index fd769c39b482..bad9538706f0 100644
> --- a/drivers/staging/lustre/lustre/lov/lov_obd.c
> +++ b/drivers/staging/lustre/lustre/lov/lov_obd.c
> @@ -1332,7 +1332,7 @@ static int lov_quotactl(struct obd_device *obd, struct obd_export *exp,
> return rc;
> }
>
> -static struct obd_ops lov_obd_ops = {
> +static const struct obd_ops lov_obd_ops = {
> .owner = THIS_MODULE,
> .setup = lov_setup,
> .cleanup = lov_cleanup,
> diff --git a/drivers/staging/lustre/lustre/mdc/mdc_request.c b/drivers/staging/lustre/lustre/mdc/mdc_request.c
> index db2c045aa1cd..72a5264b2d78 100644
> --- a/drivers/staging/lustre/lustre/mdc/mdc_request.c
> +++ b/drivers/staging/lustre/lustre/mdc/mdc_request.c
> @@ -2569,7 +2569,7 @@ static int mdc_process_config(struct obd_device *obd, u32 len, void *buf)
> return count > 0 ? 0 : count;
> }
>
> -static struct obd_ops mdc_obd_ops = {
> +static const struct obd_ops mdc_obd_ops = {
> .owner = THIS_MODULE,
> .setup = mdc_setup,
> .precleanup = mdc_precleanup,
> @@ -2591,7 +2591,7 @@ static struct obd_ops mdc_obd_ops = {
> .quotactl = mdc_quotactl,
> };
>
> -static struct md_ops mdc_md_ops = {
> +static const struct md_ops mdc_md_ops = {
> .get_root = mdc_get_root,
> .null_inode = mdc_null_inode,
> .close = mdc_close,
> diff --git a/drivers/staging/lustre/lustre/mgc/mgc_request.c b/drivers/staging/lustre/lustre/mgc/mgc_request.c
> index a6ee715921b8..3ff0bf1c4a22 100644
> --- a/drivers/staging/lustre/lustre/mgc/mgc_request.c
> +++ b/drivers/staging/lustre/lustre/mgc/mgc_request.c
> @@ -1817,7 +1817,7 @@ static int mgc_process_config(struct obd_device *obd, u32 len, void *buf)
> return rc;
> }
>
> -static struct obd_ops mgc_obd_ops = {
> +static const struct obd_ops mgc_obd_ops = {
> .owner = THIS_MODULE,
> .setup = mgc_setup,
> .precleanup = mgc_precleanup,
> diff --git a/drivers/staging/lustre/lustre/obdclass/genops.c b/drivers/staging/lustre/lustre/obdclass/genops.c
> index a3437c2d07bb..d013e9a358f1 100644
> --- a/drivers/staging/lustre/lustre/obdclass/genops.c
> +++ b/drivers/staging/lustre/lustre/obdclass/genops.c
> @@ -142,8 +142,6 @@ static void class_sysfs_release(struct kobject *kobj)
> if (type->typ_lu)
> lu_device_type_fini(type->typ_lu);
>
> - kfree(type->typ_md_ops);
> - kfree(type->typ_dt_ops);
> kfree(type);
> }
>
> @@ -154,7 +152,8 @@ static struct kobj_type class_ktype = {
>
> #define CLASS_MAX_NAME 1024
>
> -int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
> +int class_register_type(const struct obd_ops *dt_ops,
> + const struct md_ops *md_ops,
> const char *name,
> struct lu_device_type *ldt)
> {
> @@ -179,17 +178,8 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
> type->typ_kobj.kset = lustre_kset;
> kobject_init(&type->typ_kobj, &class_ktype);
>
> - type->typ_dt_ops = kzalloc(sizeof(*type->typ_dt_ops), GFP_NOFS);
> - type->typ_md_ops = kzalloc(sizeof(*type->typ_md_ops), GFP_NOFS);
> -
> - if (!type->typ_dt_ops ||
> - !type->typ_md_ops)
> - goto failed;
> -
> - *type->typ_dt_ops = *dt_ops;
> - /* md_ops is optional */
> - if (md_ops)
> - *type->typ_md_ops = *md_ops;
> + type->typ_dt_ops = dt_ops;
> + type->typ_md_ops = md_ops;
>
> rc = kobject_add(&type->typ_kobj, &lustre_kset->kobj, "%s", name);
> if (rc)
> @@ -227,8 +217,8 @@ int class_unregister_type(const char *name)
> 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);
> - kfree(type->typ_md_ops);
> + type->typ_dt_ops = NULL;
> + type->typ_md_ops = NULL;
> kobject_put(&type->typ_kobj);
> return -EBUSY;
> }
> diff --git a/drivers/staging/lustre/lustre/obdecho/echo_client.c b/drivers/staging/lustre/lustre/obdecho/echo_client.c
> index 317123fd27cb..baf34c85c4b5 100644
> --- a/drivers/staging/lustre/lustre/obdecho/echo_client.c
> +++ b/drivers/staging/lustre/lustre/obdecho/echo_client.c
> @@ -1676,7 +1676,7 @@ static int echo_client_disconnect(struct obd_export *exp)
> return rc;
> }
>
> -static struct obd_ops echo_client_obd_ops = {
> +static const struct obd_ops echo_client_obd_ops = {
> .owner = THIS_MODULE,
> .iocontrol = echo_client_iocontrol,
> .connect = echo_client_connect,
> diff --git a/drivers/staging/lustre/lustre/osc/osc_request.c b/drivers/staging/lustre/lustre/osc/osc_request.c
> index 3fedfaf249c4..442b4355d946 100644
> --- a/drivers/staging/lustre/lustre/osc/osc_request.c
> +++ b/drivers/staging/lustre/lustre/osc/osc_request.c
> @@ -2988,7 +2988,7 @@ static int osc_process_config(struct obd_device *obd, u32 len, void *buf)
> return osc_process_config_base(obd, buf);
> }
>
> -static struct obd_ops osc_obd_ops = {
> +static const struct obd_ops osc_obd_ops = {
> .owner = THIS_MODULE,
> .setup = osc_setup,
> .precleanup = osc_precleanup,
>
>
>
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