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

This reverts commit 85fbd722ad0f5d64d1ad15888cd1eb2188bfb557.

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>

2 files changed, 0 insertions, 27 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 76d0f9de767b..58e09ffe8b9c 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -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);
 
diff --git a/kernel/freezer.c b/kernel/freezer.c
index c0738424bb43..dc520f01f99d 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -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);