From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: [PATCH v5 2/8] md: Neither resync nor reshape while the system is frozen Date: Mon, 2 Oct 2017 15:52:12 -0700 Message-ID: <20171002225218.18548-3-bart.vanassche@wdc.com> References: <20171002225218.18548-1-bart.vanassche@wdc.com> Return-path: In-Reply-To: <20171002225218.18548-1-bart.vanassche@wdc.com> Sender: linux-block-owner@vger.kernel.org To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , "Martin K . Petersen" , =Oleksandr Natalenko , "Luis R . Rodriguez" , Bart Van Assche , Shaohua Li , linux-raid@vger.kernel.org, Ming Lei , Hannes Reinecke , Johannes Thumshirn List-Id: linux-raid.ids Some people use the md driver on laptops and use the suspend and resume functionality. Since it is essential that submitting of new I/O requests stops before a hibernation image is created, interrupt the md resync and reshape actions if the system is being frozen. Note: the resync and reshape will restart after the system is resumed and a message similar to the following will appear in the system log: md: md0: data-check interrupted. Additionally, only allow resync or reshape activity to be started after system freezing is over. Signed-off-by: Bart Van Assche Cc: Shaohua Li Cc: linux-raid@vger.kernel.org Cc: Ming Lei Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Johannes Thumshirn --- drivers/md/md.c | 37 ++++++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 3f7426120a3b..a2cf2a93b0cb 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -66,6 +66,7 @@ #include #include #include +#include #include #include "md.h" @@ -7450,7 +7451,8 @@ static int md_thread(void *arg) wait_event_interruptible_timeout (thread->wqueue, - test_bit(THREAD_WAKEUP, &thread->flags) + (test_bit(THREAD_WAKEUP, &thread->flags) && + atomic_read(&system_freezing_cnt) == 0) || kthread_should_stop() || kthread_should_park(), thread->timeout); @@ -8961,6 +8963,37 @@ static void md_stop_all_writes(void) mdelay(1000*1); } +/* + * Ensure that neither resyncing nor reshaping occurs while the system is + * frozen. + */ +static int md_notify_pm(struct notifier_block *bl, unsigned long state, + void *unused) +{ + struct mddev *mddev; + struct list_head *tmp; + + pr_debug("%s: state = %ld; system_freezing_cnt = %d\n", __func__, state, + atomic_read(&system_freezing_cnt)); + + switch (state) { + case PM_HIBERNATION_PREPARE: + md_stop_all_writes(); + break; + case PM_POST_HIBERNATION: + rcu_read_lock(); + for_each_mddev(mddev, tmp) + wake_up(&mddev->thread->wqueue); + rcu_read_unlock(); + break; + } + return NOTIFY_DONE; +} + +static struct notifier_block md_pm_notifier = { + .notifier_call = md_notify_pm, +}; + static int md_notify_reboot(struct notifier_block *this, unsigned long code, void *x) { @@ -9007,6 +9040,7 @@ static int __init md_init(void) md_probe, NULL, NULL); register_reboot_notifier(&md_reboot_notifier); + register_pm_notifier(&md_pm_notifier); raid_table_header = register_sysctl_table(raid_root_table); md_geninit(); @@ -9246,6 +9280,7 @@ static __exit void md_exit(void) unregister_blkdev(MD_MAJOR,"md"); unregister_blkdev(mdp_major, "mdp"); + unregister_pm_notifier(&md_pm_notifier); unregister_reboot_notifier(&md_reboot_notifier); unregister_sysctl_table(raid_table_header); -- 2.14.1