The patch titled
Subject: usb: forbid memory allocation with I/O during bus reset
has been added to the -mm tree. Its filename is
usb-forbid-memory-allocation-with-i-o-during-bus-reset.patch
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------------------------------------------------------
From: Ming Lei <ming.lei@xxxxxxxxxxxxx>
Subject: usb: forbid memory allocation with I/O during bus reset
If one storage interface or usb network interface(iSCSI case) exists in
current configuration, memory allocation with GFP_KERNEL during
usb_device_reset() might trigger I/O transfer on the storage interface
itself and cause deadlock because the 'us->dev_mutex' is held in
.pre_reset() and the storage interface can't do I/O transfer when the
reset is triggered by other interface, or the error handling can't be
completed if the reset is triggered by the storage itself (error handling
path).
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Cc: David Decotigny <david.decotigny@xxxxxxxxxx>
Cc: Tom Herbert <therbert@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: Oliver Neukum <oneukum@xxxxxxx>
Cc: Jiri Kosina <jiri.kosina@xxxxxxxx>
Cc: Mel Gorman <mel@xxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/usb/core/hub.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff -puN drivers/usb/core/hub.c~usb-forbid-memory-allocation-with-i-o-during-bus-reset drivers/usb/core/hub.c
--- a/drivers/usb/core/hub.c~usb-forbid-memory-allocation-with-i-o-during-bus-reset
+++ a/drivers/usb/core/hub.c
@@ -5144,6 +5144,7 @@ int usb_reset_device(struct usb_device *
{
int ret;
int i;
+ unsigned int noio_flag;
struct usb_host_config *config = udev->actconfig;
if (udev->state == USB_STATE_NOTATTACHED ||
@@ -5153,6 +5154,17 @@ int usb_reset_device(struct usb_device *
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);
@@ -5197,6 +5209,7 @@ int usb_reset_device(struct usb_device *
}
usb_autosuspend_device(udev);
+ memalloc_noio_restore(noio_flag);
return ret;
}
EXPORT_SYMBOL_GPL(usb_reset_device);
_
Patches currently in -mm which might be from ming.lei@xxxxxxxxxxxxx are
origin.patch
linux-next.patch
mm-teach-mm-by-current-context-info-to-not-do-i-o-during-memory-allocation.patch
pm-runtime-introduce-pm_runtime_set_memalloc_noio.patch
block-genhdc-apply-pm_runtime_set_memalloc_noio-on-block-devices.patch
net-core-apply-pm_runtime_set_memalloc_noio-on-network-devices.patch
pm-runtime-force-memory-allocation-with-no-i-o-during-runtime-pm-callbcack.patch
usb-forbid-memory-allocation-with-i-o-during-bus-reset.patch
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