4.4-stable patches

added patches:
	dm-bufio-fix-deadlock-with-loop-device.patch
	usb-handle-usb3-remote-wakeup-for-lpm-enabled-devices-correctly.patch

diff --git a/queue-4.4/dm-bufio-fix-deadlock-with-loop-device.patch b/queue-4.4/dm-bufio-fix-deadlock-with-loop-device.patch
new file mode 100644 (file)
index 0000000..4162417
--- /dev/null
+++ b/queue-4.4/dm-bufio-fix-deadlock-with-loop-device.patch
@@ -0,0 +1,47 @@
+From bd293d071ffe65e645b4d8104f9d8fe15ea13862 Mon Sep 17 00:00:00 2001
+From: Junxiao Bi <junxiao.bi@oracle.com>
+Date: Tue, 9 Jul 2019 17:17:19 -0700
+Subject: dm bufio: fix deadlock with loop device
+
+From: Junxiao Bi <junxiao.bi@oracle.com>
+
+commit bd293d071ffe65e645b4d8104f9d8fe15ea13862 upstream.
+
+When thin-volume is built on loop device, if available memory is low,
+the following deadlock can be triggered:
+
+One process P1 allocates memory with GFP_FS flag, direct alloc fails,
+memory reclaim invokes memory shrinker in dm_bufio, dm_bufio_shrink_scan()
+runs, mutex dm_bufio_client->lock is acquired, then P1 waits for dm_buffer
+IO to complete in __try_evict_buffer().
+
+But this IO may never complete if issued to an underlying loop device
+that forwards it using direct-IO, which allocates memory using
+GFP_KERNEL (see: do_blockdev_direct_IO()).  If allocation fails, memory
+reclaim will invoke memory shrinker in dm_bufio, dm_bufio_shrink_scan()
+will be invoked, and since the mutex is already held by P1 the loop
+thread will hang, and IO will never complete.  Resulting in ABBA
+deadlock.
+
+Cc: stable@vger.kernel.org
+Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
+Signed-off-by: Mike Snitzer <snitzer@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/md/dm-bufio.c |    4 +---
+ 1 file changed, 1 insertion(+), 3 deletions(-)
+
+--- a/drivers/md/dm-bufio.c
++++ b/drivers/md/dm-bufio.c
+@@ -1561,9 +1561,7 @@ dm_bufio_shrink_scan(struct shrinker *sh
+       unsigned long freed;
+ 
+       c = container_of(shrink, struct dm_bufio_client, shrinker);
+-      if (sc->gfp_mask & __GFP_FS)
+-              dm_bufio_lock(c);
+-      else if (!dm_bufio_trylock(c))
++      if (!dm_bufio_trylock(c))
+               return SHRINK_STOP;
+ 
+       freed  = __scan(c, sc->nr_to_scan, sc->gfp_mask);

diff --git a/queue-4.4/series b/queue-4.4/series
index 5734698cbd6eb05226ef5854c48043525d919350..f24fb0142c8d991524e7078d35f954df33e72133 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -82,3 +82,5 @@ powerpc-watchpoint-restore-nv-gprs-while-returning-from-exception.patch
 ecryptfs-fix-a-couple-type-promotion-bugs.patch
 intel_th-msu-fix-single-mode-with-disabled-iommu.patch
 bluetooth-add-smp-workaround-microsoft-surface-precision-mouse-bug.patch
+usb-handle-usb3-remote-wakeup-for-lpm-enabled-devices-correctly.patch
+dm-bufio-fix-deadlock-with-loop-device.patch

diff --git a/queue-4.4/usb-handle-usb3-remote-wakeup-for-lpm-enabled-devices-correctly.patch b/queue-4.4/usb-handle-usb3-remote-wakeup-for-lpm-enabled-devices-correctly.patch
new file mode 100644 (file)
index 0000000..8371b0b
--- /dev/null
+++ b/queue-4.4/usb-handle-usb3-remote-wakeup-for-lpm-enabled-devices-correctly.patch
@@ -0,0 +1,59 @@
+From e244c4699f859cf7149b0781b1894c7996a8a1df Mon Sep 17 00:00:00 2001
+From: "Lee, Chiasheng" <chiasheng.lee@intel.com>
+Date: Thu, 20 Jun 2019 10:56:04 +0300
+Subject: usb: Handle USB3 remote wakeup for LPM enabled devices correctly
+
+From: Lee, Chiasheng <chiasheng.lee@intel.com>
+
+commit e244c4699f859cf7149b0781b1894c7996a8a1df upstream.
+
+With Link Power Management (LPM) enabled USB3 links transition to low
+power U1/U2 link states from U0 state automatically.
+
+Current hub code detects USB3 remote wakeups by checking if the software
+state still shows suspended, but the link has transitioned from suspended
+U3 to enabled U0 state.
+
+As it takes some time before the hub thread reads the port link state
+after a USB3 wake notification, the link may have transitioned from U0
+to U1/U2, and wake is not detected by hub code.
+
+Fix this by handling U1/U2 states in the same way as U0 in USB3 wakeup
+handling
+
+This patch should be added to stable kernels since 4.13 where LPM was
+kept enabled during suspend/resume
+
+Cc: <stable@vger.kernel.org> # v4.13+
+Signed-off-by: Lee, Chiasheng <chiasheng.lee@intel.com>
+Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/usb/core/hub.c |    7 +++++--
+ 1 file changed, 5 insertions(+), 2 deletions(-)
+
+--- a/drivers/usb/core/hub.c
++++ b/drivers/usb/core/hub.c
+@@ -3479,6 +3479,7 @@ static int hub_handle_remote_wakeup(stru
+       struct usb_device *hdev;
+       struct usb_device *udev;
+       int connect_change = 0;
++      u16 link_state;
+       int ret;
+ 
+       hdev = hub->hdev;
+@@ -3488,9 +3489,11 @@ static int hub_handle_remote_wakeup(stru
+                       return 0;
+               usb_clear_port_feature(hdev, port, USB_PORT_FEAT_C_SUSPEND);
+       } else {
++              link_state = portstatus & USB_PORT_STAT_LINK_STATE;
+               if (!udev || udev->state != USB_STATE_SUSPENDED ||
+-                               (portstatus & USB_PORT_STAT_LINK_STATE) !=
+-                               USB_SS_PORT_LS_U0)
++                              (link_state != USB_SS_PORT_LS_U0 &&
++                               link_state != USB_SS_PORT_LS_U1 &&
++                               link_state != USB_SS_PORT_LS_U2))
+                       return 0;
+       }
+