4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: NeilBrown neilb@suse.com
commit b03e0ccb5ab9df3efbe51c87843a1ffbecbafa1f upstream.
The '2' argument means "wake up anything that is waiting". This is an inelegant part of the design and was added to help support management of suspend_lo/suspend_hi setting. Now that suspend_lo/hi is managed in mddev_suspend/resume, that need is gone. These is still a couple of places where we call 'quiesce' with an argument of '2', but they can safely be changed to call ->quiesce(.., 1); ->quiesce(.., 0) which achieve the same result at the small cost of pausing IO briefly.
This removes a small "optimization" from suspend_{hi,lo}_store, but it isn't clear that optimization served a useful purpose. The code now is a lot clearer.
Suggested-by: Shaohua Li shli@kernel.org Signed-off-by: NeilBrown neilb@suse.com Signed-off-by: Shaohua Li shli@fb.com Signed-off-by: Jack Wang jinpu.wang@profitbricks.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/md/md-cluster.c | 6 +++--- drivers/md/md.c | 34 ++++++++++------------------------ drivers/md/md.h | 9 ++++----- drivers/md/raid0.c | 2 +- drivers/md/raid1.c | 13 +++---------- drivers/md/raid10.c | 10 +++------- drivers/md/raid5-cache.c | 12 ++++++------ drivers/md/raid5-log.h | 2 +- drivers/md/raid5.c | 18 ++++++------------ 9 files changed, 37 insertions(+), 69 deletions(-)
--- a/drivers/md/md-cluster.c +++ b/drivers/md/md-cluster.c @@ -442,10 +442,11 @@ static void __remove_suspend_info(struct static void remove_suspend_info(struct mddev *mddev, int slot) { struct md_cluster_info *cinfo = mddev->cluster_info; + mddev->pers->quiesce(mddev, 1); spin_lock_irq(&cinfo->suspend_lock); __remove_suspend_info(cinfo, slot); spin_unlock_irq(&cinfo->suspend_lock); - mddev->pers->quiesce(mddev, 2); + mddev->pers->quiesce(mddev, 0); }
@@ -492,13 +493,12 @@ static void process_suspend_info(struct s->lo = lo; s->hi = hi; mddev->pers->quiesce(mddev, 1); - mddev->pers->quiesce(mddev, 0); spin_lock_irq(&cinfo->suspend_lock); /* Remove existing entry (if exists) before adding */ __remove_suspend_info(cinfo, slot); list_add(&s->list, &cinfo->suspend_list); spin_unlock_irq(&cinfo->suspend_lock); - mddev->pers->quiesce(mddev, 2); + mddev->pers->quiesce(mddev, 0); }
static void process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg) --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -4850,7 +4850,7 @@ suspend_lo_show(struct mddev *mddev, cha static ssize_t suspend_lo_store(struct mddev *mddev, const char *buf, size_t len) { - unsigned long long old, new; + unsigned long long new; int err;
err = kstrtoull(buf, 10, &new); @@ -4866,17 +4866,10 @@ suspend_lo_store(struct mddev *mddev, co if (mddev->pers == NULL || mddev->pers->quiesce == NULL) goto unlock; - old = mddev->suspend_lo; + mddev_suspend(mddev); mddev->suspend_lo = new; - if (new >= old) { - /* Shrinking suspended region */ - wake_up(&mddev->sb_wait); - mddev->pers->quiesce(mddev, 2); - } else { - /* Expanding suspended region - need to wait */ - mddev_suspend(mddev); - mddev_resume(mddev); - } + mddev_resume(mddev); + err = 0; unlock: mddev_unlock(mddev); @@ -4894,7 +4887,7 @@ suspend_hi_show(struct mddev *mddev, cha static ssize_t suspend_hi_store(struct mddev *mddev, const char *buf, size_t len) { - unsigned long long old, new; + unsigned long long new; int err;
err = kstrtoull(buf, 10, &new); @@ -4907,20 +4900,13 @@ suspend_hi_store(struct mddev *mddev, co if (err) return err; err = -EINVAL; - if (mddev->pers == NULL || - mddev->pers->quiesce == NULL) + if (mddev->pers == NULL) goto unlock; - old = mddev->suspend_hi; + + mddev_suspend(mddev); mddev->suspend_hi = new; - if (new <= old) { - /* Shrinking suspended region */ - wake_up(&mddev->sb_wait); - mddev->pers->quiesce(mddev, 2); - } else { - /* Expanding suspended region - need to wait */ - mddev_suspend(mddev); - mddev_resume(mddev); - } + mddev_resume(mddev); + err = 0; unlock: mddev_unlock(mddev); --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -546,12 +546,11 @@ struct md_personality int (*check_reshape) (struct mddev *mddev); int (*start_reshape) (struct mddev *mddev); void (*finish_reshape) (struct mddev *mddev); - /* quiesce moves between quiescence states - * 0 - fully active - * 1 - no new requests allowed - * others - reserved + /* quiesce suspends or resumes internal processing. + * 1 - stop new actions and wait for action io to complete + * 0 - return to normal behaviour */ - void (*quiesce) (struct mddev *mddev, int state); + void (*quiesce) (struct mddev *mddev, int quiesce); /* takeover is used to transition an array from one * personality to another. The new personality must be able * to handle the data in the current layout. --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -768,7 +768,7 @@ static void *raid0_takeover(struct mddev return ERR_PTR(-EINVAL); }
-static void raid0_quiesce(struct mddev *mddev, int state) +static void raid0_quiesce(struct mddev *mddev, int quiesce) { }
--- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -3276,21 +3276,14 @@ static int raid1_reshape(struct mddev *m return 0; }
-static void raid1_quiesce(struct mddev *mddev, int state) +static void raid1_quiesce(struct mddev *mddev, int quiesce) { struct r1conf *conf = mddev->private;
- switch(state) { - case 2: /* wake for suspend */ - wake_up(&conf->wait_barrier); - break; - case 1: + if (quiesce) freeze_array(conf, 0); - break; - case 0: + else unfreeze_array(conf); - break; - } }
static void *raid1_takeover(struct mddev *mddev) --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -3838,18 +3838,14 @@ static void raid10_free(struct mddev *md kfree(conf); }
-static void raid10_quiesce(struct mddev *mddev, int state) +static void raid10_quiesce(struct mddev *mddev, int quiesce) { struct r10conf *conf = mddev->private;
- switch(state) { - case 1: + if (quiesce) raise_barrier(conf, 0); - break; - case 0: + else lower_barrier(conf); - break; - } }
static int raid10_resize(struct mddev *mddev, sector_t sectors) --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -1589,21 +1589,21 @@ void r5l_wake_reclaim(struct r5l_log *lo md_wakeup_thread(log->reclaim_thread); }
-void r5l_quiesce(struct r5l_log *log, int state) +void r5l_quiesce(struct r5l_log *log, int quiesce) { struct mddev *mddev; - if (!log || state == 2) + if (!log) return; - if (state == 0) - kthread_unpark(log->reclaim_thread->tsk); - else if (state == 1) { + + if (quiesce) { /* make sure r5l_write_super_and_discard_space exits */ mddev = log->rdev->mddev; wake_up(&mddev->sb_wait); kthread_park(log->reclaim_thread->tsk); r5l_wake_reclaim(log, MaxSector); r5l_do_reclaim(log); - } + } else + kthread_unpark(log->reclaim_thread->tsk); }
bool r5l_log_disk_error(struct r5conf *conf) --- a/drivers/md/raid5-log.h +++ b/drivers/md/raid5-log.h @@ -9,7 +9,7 @@ extern void r5l_write_stripe_run(struct extern void r5l_flush_stripe_to_raid(struct r5l_log *log); extern void r5l_stripe_write_finished(struct stripe_head *sh); extern int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio); -extern void r5l_quiesce(struct r5l_log *log, int state); +extern void r5l_quiesce(struct r5l_log *log, int quiesce); extern bool r5l_log_disk_error(struct r5conf *conf); extern bool r5c_is_writeback(struct r5l_log *log); extern int --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -8003,16 +8003,12 @@ static void raid5_finish_reshape(struct } }
-static void raid5_quiesce(struct mddev *mddev, int state) +static void raid5_quiesce(struct mddev *mddev, int quiesce) { struct r5conf *conf = mddev->private;
- switch(state) { - case 2: /* resume for a suspend */ - wake_up(&conf->wait_for_overlap); - break; - - case 1: /* stop all writes */ + if (quiesce) { + /* stop all writes */ lock_all_device_hash_locks_irq(conf); /* '2' tells resync/reshape to pause so that all * active stripes can drain @@ -8028,17 +8024,15 @@ static void raid5_quiesce(struct mddev * unlock_all_device_hash_locks_irq(conf); /* allow reshape to continue */ wake_up(&conf->wait_for_overlap); - break; - - case 0: /* re-enable writes */ + } else { + /* re-enable writes */ lock_all_device_hash_locks_irq(conf); conf->quiesce = 0; wake_up(&conf->wait_for_quiescent); wake_up(&conf->wait_for_overlap); unlock_all_device_hash_locks_irq(conf); - break; } - r5l_quiesce(conf->log, state); + r5l_quiesce(conf->log, quiesce); }
static void *raid45_takeover_raid0(struct mddev *mddev, int level)