From 1dfddff5fcd869fcab0c52fafae099dfa435a935 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= Date: Wed, 23 Dec 2015 13:42:43 +0100 Subject: net: cdc_ncm: avoid changing RX/TX buffers on MTU changes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit NCM buffer sizes are negotiated with the device independently of the network device MTU. The RX buffers are allocated by the usbnet framework based on the rx_urb_size value set by cdc_ncm. A single RX buffer can hold a number of MTU sized packets. The default usbnet change_mtu ndo only modifies rx_urb_size if it is equal to hard_mtu. And the cdc_ncm driver will set rx_urb_size and hard_mtu independently of each other, based on dwNtbInMaxSize and dwNtbOutMaxSize respectively. It was therefore assumed that usbnet_change_mtu() would never touch rx_urb_size. This failed to consider the case where dwNtbInMaxSize and dwNtbOutMaxSize happens to be equal. Fix by implementing an NCM specific change_mtu ndo, modifying the netdev MTU without touching the buffer size settings. Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller --- include/linux/usb/cdc_ncm.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h index 1f6526c76ee8..3a375d07d0dc 100644 --- a/include/linux/usb/cdc_ncm.h +++ b/include/linux/usb/cdc_ncm.h @@ -138,6 +138,7 @@ struct cdc_ncm_ctx { }; u8 cdc_ncm_select_altsetting(struct usb_interface *intf); +int cdc_ncm_change_mtu(struct net_device *net, int new_mtu); int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting, int drvflags); void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf); struct sk_buff *cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign); -- cgit v1.2.3 From 21491412f2ec6f13d4104de734dec0ba659d092e Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 28 Dec 2015 13:01:22 -0700 Subject: block: add blk_start_queue_async() We currently only have an inline/sync helper to restart a stopped queue. If drivers need an async version, they have to roll their own. Add a generic helper instead. Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 0169ba2e2e64..c70e3588a48c 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -797,6 +797,7 @@ extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, extern int blk_queue_enter(struct request_queue *q, gfp_t gfp); extern void blk_queue_exit(struct request_queue *q); extern void blk_start_queue(struct request_queue *q); +extern void blk_start_queue_async(struct request_queue *q); extern void blk_stop_queue(struct request_queue *q); extern void blk_sync_queue(struct request_queue *q); extern void __blk_stop_queue(struct request_queue *q); -- cgit v1.2.3 From 6cdb18ad98a49f7e9b95d538a0614cde827404b8 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 29 Dec 2015 14:54:32 -0800 Subject: mm/vmstat: fix overflow in mod_zone_page_state() mod_zone_page_state() takes a "delta" integer argument. delta contains the number of pages that should be added or subtracted from a struct zone's vm_stat field. If a zone is larger than 8TB this will cause overflows. E.g. for a zone with a size slightly larger than 8TB the line mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages); in mm/page_alloc.c:free_area_init_core() will result in a negative result for the NR_ALLOC_BATCH entry within the zone's vm_stat, since 8TB contain 0x8xxxxxxx pages which will be sign extended to a negative value. Fix this by changing the delta argument to long type. This could fix an early boot problem seen on s390, where we have a 9TB system with only one node. ZONE_DMA contains 2GB and ZONE_NORMAL the rest. The system is trying to allocate a GFP_DMA page but ZONE_DMA is completely empty, so it tries to reclaim pages in an endless loop. This was seen on a heavily patched 3.10 kernel. One possible explaination seem to be the overflows caused by mod_zone_page_state(). Unfortunately I did not have the chance to verify that this patch actually fixes the problem, since I don't have access to the system right now. However the overflow problem does exist anyway. Given the description that a system with slightly less than 8TB does work, this seems to be a candidate for the observed problem. Signed-off-by: Heiko Carstens Cc: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/vmstat.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index 5dbc8b0ee567..3e5d9075960f 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -176,11 +176,11 @@ extern void zone_statistics(struct zone *, struct zone *, gfp_t gfp); #define sub_zone_page_state(__z, __i, __d) mod_zone_page_state(__z, __i, -(__d)) #ifdef CONFIG_SMP -void __mod_zone_page_state(struct zone *, enum zone_stat_item item, int); +void __mod_zone_page_state(struct zone *, enum zone_stat_item item, long); void __inc_zone_page_state(struct page *, enum zone_stat_item); void __dec_zone_page_state(struct page *, enum zone_stat_item); -void mod_zone_page_state(struct zone *, enum zone_stat_item, int); +void mod_zone_page_state(struct zone *, enum zone_stat_item, long); void inc_zone_page_state(struct page *, enum zone_stat_item); void dec_zone_page_state(struct page *, enum zone_stat_item); @@ -205,7 +205,7 @@ void set_pgdat_percpu_threshold(pg_data_t *pgdat, * The functions directly modify the zone and global counters. */ static inline void __mod_zone_page_state(struct zone *zone, - enum zone_stat_item item, int delta) + enum zone_stat_item item, long delta) { zone_page_state_add(delta, zone, item); } -- cgit v1.2.3