Merge branch 'akpm' (more incoming from Andrew)

Merge second patch-bomb from Andrew Morton:

 - A little DM fix

 - the MM queue

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (154 commits)
  ksm: allocate roots when needed
  mm: cleanup "swapcache" in do_swap_page
  mm,ksm: swapoff might need to copy
  mm,ksm: FOLL_MIGRATION do migration_entry_wait
  ksm: shrink 32-bit rmap_item back to 32 bytes
  ksm: treat unstable nid like in stable tree
  ksm: add some comments
  tmpfs: fix mempolicy object leaks
  tmpfs: fix use-after-free of mempolicy object
  mm/fadvise.c: drain all pagevecs if POSIX_FADV_DONTNEED fails to discard all pages
  mm: export mmu notifier invalidates
  mm: accelerate mm_populate() treatment of THP pages
  mm: use long type for page counts in mm_populate() and get_user_pages()
  mm: accurately document nr_free_*_pages functions with code comments
  HWPOISON: change order of error_states[]'s elements
  HWPOISON: fix misjudgement of page_action() for errors on mlocked pages
  memcg: stop warning on memcg_propagate_kmem
  net: change type of virtio_chan->p9_max_pages
  vmscan: change type of vm_total_pages to unsigned long
  fs/nfsd: change type of max_delegations, nfsd_drc_max_mem and nfsd_drc_mem_used
  ...

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 1775ad471edd..5480352f984d 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -5177,6 +5177,7 @@ int usb_reset_device(struct usb_device *udev)
 {
         int ret;
         int i;
+        unsigned int noio_flag;
         struct usb_host_config *config = udev->actconfig;
 
         if (udev->state == USB_STATE_NOTATTACHED ||
@@ -5186,6 +5187,17 @@ int usb_reset_device(struct usb_device *udev)
                 return -EINVAL;
         }
 
+        /*
+         * Don't allocate memory with GFP_KERNEL in current
+         * context to avoid possible deadlock if usb mass
+         * storage interface or usbnet interface(iSCSI case)
+         * is included in current configuration. The easist
+         * approach is to do it for every device reset,
+         * because the device 'memalloc_noio' flag may have
+         * not been set before reseting the usb device.
+         */
+        noio_flag = memalloc_noio_save();
+
         /* Prevent autosuspend during the reset */
         usb_autoresume_device(udev);
 
@@ -5230,6 +5242,7 @@ int usb_reset_device(struct usb_device *udev)
         }
 
         usb_autosuspend_device(udev);
+        memalloc_noio_restore(noio_flag);
         return ret;
 }
 EXPORT_SYMBOL_GPL(usb_reset_device);