From 0e48f51cbbfbdb79149806de14dcb8bf0f01ca94 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Fri, 4 Oct 2019 13:00:25 +0300 Subject: [PATCH] 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 Signed-off-by: Mika Westerberg Signed-off-by: Jens Axboe --- drivers/ata/libata-scsi.c | 21 --------------------- kernel/freezer.c | 6 ------ 2 files changed, 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);