Commit 0e48f51c authored by Mika Westerberg's avatar Mika Westerberg Committed by Jens Axboe
Browse files

Revert "libata, freezer: avoid block device removal while system is frozen" 



This reverts commit 85fbd722.

The commit was added as a quick band-aid for a hang that happened when a
block device was removed during system suspend. Now that bdi_wq is not
freezable anymore the hang should not be possible and we can get rid of
this hack by reverting it.

Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a2b90f11

drivers/ata/libata-scsi.c

+0 −21
Original line number Diff line number Diff line
@@ -4791,27 +4791,6 @@ void ata_scsi_hotplug(struct work_struct *work) 
		return;

	}



	/*

	 * XXX - UGLY HACK

	 *

	 * The block layer suspend/resume path is fundamentally broken due

	 * to freezable kthreads and workqueue and may deadlock if a block

	 * device gets removed while resume is in progress.  I don't know

	 * what the solution is short of removing freezable kthreads and

	 * workqueues altogether.

	 *

	 * The following is an ugly hack to avoid kicking off device

	 * removal while freezer is active.  This is a joke but does avoid

	 * this particular deadlock scenario.

	 *

	 * https://bugzilla.kernel.org/show_bug.cgi?id=62801

	 * http://marc.info/?l=linux-kernel&m=138695698516487

	 */

#ifdef CONFIG_FREEZER

	while (pm_freezing)

		msleep(10);

#endif



	DPRINTK("ENTER\n");

	mutex_lock(&ap->scsi_scan_mutex);

kernel/freezer.c

+0 −6
Original line number Diff line number Diff line
@@ -22,12 +22,6 @@ EXPORT_SYMBOL(system_freezing_cnt); 
bool pm_freezing;

bool pm_nosig_freezing;



/*

 * Temporary export for the deadlock workaround in ata_scsi_hotplug().

 * Remove once the hack becomes unnecessary.

 */

EXPORT_SYMBOL_GPL(pm_freezing);



/* protects freezing and frozen transitions */

static DEFINE_SPINLOCK(freezer_lock);

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