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

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This reverts commit 85fbd722ad.

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Mika Westerberg 2019-10-04 13:00:25 +03:00 committed by Jens Axboe
parent a2b90f1121
commit 0e48f51cbb
2 changed files with 0 additions and 27 deletions
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21
drivers/ata/libata-scsi.c
View File

@ -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);

6
kernel/freezer.c
View File

@ -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);