This is a note to let you know that I've just added the patch titled s390/qeth: unbreak OSM and OSN support to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: s390-qeth-unbreak-osm-and-osn-support.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Wed May 31 09:13:34 JST 2017 From: Julian Wiedmann <jwi@xxxxxxxxxxxxxxxxxx> Date: Wed, 10 May 2017 19:07:52 +0200 Subject: s390/qeth: unbreak OSM and OSN support From: Julian Wiedmann <jwi@xxxxxxxxxxxxxxxxxx> [ Upstream commit 2d2ebb3ed0c6acfb014f98e427298673a5d07b82 ] commit b4d72c08b358 ("qeth: bridgeport support - basic control") broke the support for OSM and OSN devices as follows: As OSM and OSN are L2 only, qeth_core_probe_device() does an early setup by loading the l2 discipline and calling qeth_l2_probe_device(). In this context, adding the l2-specific bridgeport sysfs attributes via qeth_l2_create_device_attributes() hits a BUG_ON in fs/sysfs/group.c, since the basic sysfs infrastructure for the device hasn't been established yet. Note that OSN actually has its own unique sysfs attributes (qeth_osn_devtype), so the additional attributes shouldn't be created at all. For OSM, add a new qeth_l2_devtype that contains all the common and l2-specific sysfs attributes. When qeth_core_probe_device() does early setup for OSM or OSN, assign the corresponding devtype so that the ccwgroup probe code creates the full set of sysfs attributes. This allows us to skip qeth_l2_create_device_attributes() in case of an early setup. Any device that can't do early setup will initially have only the generic sysfs attributes, and when it's probed later qeth_l2_probe_device() adds the l2-specific attributes. If an early-setup device is removed (by calling ccwgroup_ungroup()), device_unregister() will - using the devtype - delete the l2-specific attributes before qeth_l2_remove_device() is called. So make sure to not remove them twice. What complicates the issue is that qeth_l2_probe_device() and qeth_l2_remove_device() is also called on a device when its layer2 attribute changes (ie. its layer mode is switched). For early-setup devices this wouldn't work properly - we wouldn't remove the l2-specific attributes when switching to L3. But switching the layer mode doesn't actually make any sense; we already decided that the device can only operate in L2! So just refuse to switch the layer mode on such devices. Note that OSN doesn't have a layer2 attribute, so we only need to special-case OSM. Based on an initial patch by Ursula Braun. Fixes: b4d72c08b358 ("qeth: bridgeport support - basic control") Signed-off-by: Julian Wiedmann <jwi@xxxxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/s390/net/qeth_core.h | 4 ++++ drivers/s390/net/qeth_core_main.c | 17 +++++++++-------- drivers/s390/net/qeth_core_sys.c | 22 ++++++++++++++-------- drivers/s390/net/qeth_l2.h | 2 ++ drivers/s390/net/qeth_l2_main.c | 17 +++++++++++++---- drivers/s390/net/qeth_l2_sys.c | 8 ++++++++ drivers/s390/net/qeth_l3_main.c | 1 + 7 files changed, 51 insertions(+), 20 deletions(-) --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -718,6 +718,7 @@ enum qeth_discipline_id { }; struct qeth_discipline { + const struct device_type *devtype; void (*start_poll)(struct ccw_device *, int, unsigned long); qdio_handler_t *input_handler; qdio_handler_t *output_handler; @@ -893,6 +894,9 @@ extern struct qeth_discipline qeth_l2_di extern struct qeth_discipline qeth_l3_discipline; extern const struct attribute_group *qeth_generic_attr_groups[]; extern const struct attribute_group *qeth_osn_attr_groups[]; +extern const struct attribute_group qeth_device_attr_group; +extern const struct attribute_group qeth_device_blkt_group; +extern const struct device_type qeth_generic_devtype; extern struct workqueue_struct *qeth_wq; int qeth_card_hw_is_reachable(struct qeth_card *); --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -5462,10 +5462,12 @@ void qeth_core_free_discipline(struct qe card->discipline = NULL; } -static const struct device_type qeth_generic_devtype = { +const struct device_type qeth_generic_devtype = { .name = "qeth_generic", .groups = qeth_generic_attr_groups, }; +EXPORT_SYMBOL_GPL(qeth_generic_devtype); + static const struct device_type qeth_osn_devtype = { .name = "qeth_osn", .groups = qeth_osn_attr_groups, @@ -5591,23 +5593,22 @@ static int qeth_core_probe_device(struct goto err_card; } - if (card->info.type == QETH_CARD_TYPE_OSN) - gdev->dev.type = &qeth_osn_devtype; - else - gdev->dev.type = &qeth_generic_devtype; - switch (card->info.type) { case QETH_CARD_TYPE_OSN: case QETH_CARD_TYPE_OSM: rc = qeth_core_load_discipline(card, QETH_DISCIPLINE_LAYER2); if (rc) goto err_card; + + gdev->dev.type = (card->info.type != QETH_CARD_TYPE_OSN) + ? card->discipline->devtype + : &qeth_osn_devtype; rc = card->discipline->setup(card->gdev); if (rc) goto err_disc; - case QETH_CARD_TYPE_OSD: - case QETH_CARD_TYPE_OSX: + break; default: + gdev->dev.type = &qeth_generic_devtype; break; } --- a/drivers/s390/net/qeth_core_sys.c +++ b/drivers/s390/net/qeth_core_sys.c @@ -413,12 +413,16 @@ static ssize_t qeth_dev_layer2_store(str if (card->options.layer2 == newdis) goto out; - else { - card->info.mac_bits = 0; - if (card->discipline) { - card->discipline->remove(card->gdev); - qeth_core_free_discipline(card); - } + if (card->info.type == QETH_CARD_TYPE_OSM) { + /* fixed layer, can't switch */ + rc = -EOPNOTSUPP; + goto out; + } + + card->info.mac_bits = 0; + if (card->discipline) { + card->discipline->remove(card->gdev); + qeth_core_free_discipline(card); } rc = qeth_core_load_discipline(card, newdis); @@ -705,10 +709,11 @@ static struct attribute *qeth_blkt_devic &dev_attr_inter_jumbo.attr, NULL, }; -static struct attribute_group qeth_device_blkt_group = { +const struct attribute_group qeth_device_blkt_group = { .name = "blkt", .attrs = qeth_blkt_device_attrs, }; +EXPORT_SYMBOL_GPL(qeth_device_blkt_group); static struct attribute *qeth_device_attrs[] = { &dev_attr_state.attr, @@ -728,9 +733,10 @@ static struct attribute *qeth_device_att &dev_attr_switch_attrs.attr, NULL, }; -static struct attribute_group qeth_device_attr_group = { +const struct attribute_group qeth_device_attr_group = { .attrs = qeth_device_attrs, }; +EXPORT_SYMBOL_GPL(qeth_device_attr_group); const struct attribute_group *qeth_generic_attr_groups[] = { &qeth_device_attr_group, --- a/drivers/s390/net/qeth_l2.h +++ b/drivers/s390/net/qeth_l2.h @@ -8,6 +8,8 @@ #include "qeth_core.h" +extern const struct attribute_group *qeth_l2_attr_groups[]; + int qeth_l2_create_device_attributes(struct device *); void qeth_l2_remove_device_attributes(struct device *); void qeth_l2_setup_bridgeport_attrs(struct qeth_card *card); --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -1021,14 +1021,21 @@ static int qeth_l2_stop(struct net_devic return 0; } +static const struct device_type qeth_l2_devtype = { + .name = "qeth_layer2", + .groups = qeth_l2_attr_groups, +}; + static int qeth_l2_probe_device(struct ccwgroup_device *gdev) { struct qeth_card *card = dev_get_drvdata(&gdev->dev); int rc; - rc = qeth_l2_create_device_attributes(&gdev->dev); - if (rc) - return rc; + if (gdev->dev.type == &qeth_generic_devtype) { + rc = qeth_l2_create_device_attributes(&gdev->dev); + if (rc) + return rc; + } INIT_LIST_HEAD(&card->vid_list); hash_init(card->mac_htable); card->options.layer2 = 1; @@ -1040,7 +1047,8 @@ static void qeth_l2_remove_device(struct { struct qeth_card *card = dev_get_drvdata(&cgdev->dev); - qeth_l2_remove_device_attributes(&cgdev->dev); + if (cgdev->dev.type == &qeth_generic_devtype) + qeth_l2_remove_device_attributes(&cgdev->dev); qeth_set_allowed_threads(card, 0, 1); wait_event(card->wait_q, qeth_threads_running(card, 0xffffffff) == 0); @@ -1437,6 +1445,7 @@ static int qeth_l2_control_event(struct } struct qeth_discipline qeth_l2_discipline = { + .devtype = &qeth_l2_devtype, .start_poll = qeth_qdio_start_poll, .input_handler = (qdio_handler_t *) qeth_qdio_input_handler, .output_handler = (qdio_handler_t *) qeth_qdio_output_handler, --- a/drivers/s390/net/qeth_l2_sys.c +++ b/drivers/s390/net/qeth_l2_sys.c @@ -272,3 +272,11 @@ void qeth_l2_setup_bridgeport_attrs(stru } else qeth_bridgeport_an_set(card, 0); } + +const struct attribute_group *qeth_l2_attr_groups[] = { + &qeth_device_attr_group, + &qeth_device_blkt_group, + /* l2 specific, see l2_{create,remove}_device_attributes(): */ + &qeth_l2_bridgeport_attr_group, + NULL, +}; --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -3453,6 +3453,7 @@ static int qeth_l3_control_event(struct } struct qeth_discipline qeth_l3_discipline = { + .devtype = &qeth_generic_devtype, .start_poll = qeth_qdio_start_poll, .input_handler = (qdio_handler_t *) qeth_qdio_input_handler, .output_handler = (qdio_handler_t *) qeth_qdio_output_handler, Patches currently in stable-queue which might be from jwi@xxxxxxxxxxxxxxxxxx are queue-4.9/s390-qeth-unbreak-osm-and-osn-support.patch queue-4.9/s390-qeth-avoid-null-pointer-dereference-on-osn.patch queue-4.9/s390-qeth-handle-sysfs-error-during-initialization.patch queue-4.9/s390-qeth-add-missing-hash-table-initializations.patch