On Mon, Sep 25, 2017 at 01:29:18PM -0700, Bart Van Assche wrote: > 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 device quiescing starts, make the > md resync and reshape threads freezable. > > Signed-off-by: Bart Van Assche <[email protected]> > Cc: Shaohua Li <[email protected]> > Cc: [email protected] > Cc: Ming Lei <[email protected]> > Cc: Christoph Hellwig <[email protected]> > Cc: Hannes Reinecke <[email protected]> > Cc: Johannes Thumshirn <[email protected]> > --- > drivers/md/md.c | 21 +++++++++++++-------- > 1 file changed, 13 insertions(+), 8 deletions(-) > > diff --git a/drivers/md/md.c b/drivers/md/md.c > index 08fcaebc61bd..26a12bd0db65 100644 > --- a/drivers/md/md.c > +++ b/drivers/md/md.c > @@ -66,6 +66,7 @@ > #include <linux/raid/md_u.h> > #include <linux/slab.h> > #include <linux/percpu-refcount.h> > +#include <linux/freezer.h> > > #include <trace/events/block.h> > #include "md.h" > @@ -7424,6 +7425,7 @@ static int md_thread(void *arg) > */ > > allow_signal(SIGKILL); > + set_freezable(); > while (!kthread_should_stop()) { > > /* We need to wait INTERRUPTIBLE so that > @@ -7434,7 +7436,7 @@ static int md_thread(void *arg) > if (signal_pending(current)) > flush_signals(current); > > - wait_event_interruptible_timeout > + wait_event_freezable_timeout > (thread->wqueue, > test_bit(THREAD_WAKEUP, &thread->flags) > || kthread_should_stop() || kthread_should_park(), > @@ -8133,6 +8135,8 @@ void md_do_sync(struct md_thread *thread) > return; > } > > + set_freezable(); > + > if (mddev_is_clustered(mddev)) { > ret = md_cluster_ops->resync_start(mddev); > if (ret) > @@ -8324,7 +8328,7 @@ void md_do_sync(struct md_thread *thread) > mddev->curr_resync_completed > mddev->resync_max > )) { > /* time to update curr_resync_completed */ > - wait_event(mddev->recovery_wait, > + wait_event_freezable(mddev->recovery_wait, > atomic_read(&mddev->recovery_active) == 0); > mddev->curr_resync_completed = j; > if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && > @@ -8342,10 +8346,10 @@ void md_do_sync(struct md_thread *thread) > * to avoid triggering warnings. > */ > flush_signals(current); /* just in case */ > - wait_event_interruptible(mddev->recovery_wait, > - mddev->resync_max > j > - || test_bit(MD_RECOVERY_INTR, > - &mddev->recovery)); > + wait_event_freezable(mddev->recovery_wait, > + mddev->resync_max > j || > + test_bit(MD_RECOVERY_INTR, > + &mddev->recovery)); > } > > if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) > @@ -8421,7 +8425,7 @@ void md_do_sync(struct md_thread *thread) > * Give other IO more of a chance. > * The faster the devices, the less we wait. > */ > - wait_event(mddev->recovery_wait, > + wait_event_freezable(mddev->recovery_wait, > > !atomic_read(&mddev->recovery_active)); > } > } > @@ -8433,7 +8437,8 @@ void md_do_sync(struct md_thread *thread) > * this also signals 'finished resyncing' to md_stop > */ > blk_finish_plug(&plug); > - wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active)); > + wait_event_freezable(mddev->recovery_wait, > + !atomic_read(&mddev->recovery_active)); > > if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && > !test_bit(MD_RECOVERY_INTR, &mddev->recovery) && > -- > 2.14.1 >
Just test this patch a bit and the following failure of freezing task is triggered during suspend: [ 38.903513] PM: suspend entry (deep) [ 38.904443] PM: Syncing filesystems ... done. [ 38.983591] Freezing user space processes ... (elapsed 0.002 seconds) done. [ 38.987522] OOM killer disabled. [ 38.987962] Freezing remaining freezable tasks ... [ 58.998872] Freezing of tasks failed after 20.008 seconds (1 tasks refusing to freeze, wq_busy=0): [ 59.002539] md127_resync D 0 1618 2 0x80000000 [ 59.004954] Call Trace: [ 59.006162] __schedule+0x41f/0xa50 [ 59.007704] schedule+0x3d/0x90 [ 59.009305] raid1_sync_request+0x2da/0xd10 [raid1] [ 59.011505] ? remove_wait_queue+0x70/0x70 [ 59.013352] md_do_sync+0xdfa/0x12c0 [ 59.014955] ? remove_wait_queue+0x70/0x70 [ 59.016336] md_thread+0x1a8/0x1e0 [ 59.016770] ? md_thread+0x1a8/0x1e0 [ 59.017250] kthread+0x155/0x190 [ 59.017662] ? sync_speed_show+0xa0/0xa0 [ 59.018217] ? kthread_create_on_node+0x70/0x70 [ 59.018858] ret_from_fork+0x2a/0x40 [ 59.019403] Restarting kernel threads ... done. [ 59.024586] OOM killer enabled. [ 59.025124] Restarting tasks ... done. [ 59.045906] PM: suspend exit [ 97.919428] systemd-journald[227]: Sent WATCHDOG=1 notification. [ 101.002695] md: md127: data-check done. -- Ming
