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authorMing Lei <ming.lei@canonical.com>2013-02-23 00:34:22 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-24 01:50:16 (GMT)
commit4d769def244806562de1baa3acb39726131fbe6a (patch)
tree84987b35cf3915482790da45e97f4b62e9d97cbb /drivers
parentdb88175f41a29c1ffff1a6938a7969d206a47326 (diff)
downloadlinux-fsl-qoriq-4d769def244806562de1baa3acb39726131fbe6a.tar.xz
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@canonical.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Decotigny <david.decotigny@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jens Axboe <axboe@kernel.dk> Cc: Minchan Kim <minchan@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <oneukum@suse.de> Reviewed-by: Jiri Kosina <jkosina@suse.cz> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/core/hub.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 1775ad4..5480352 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);