MD_RECOVERY_RUNNING will always be set when trying to register a new sync_thread, however, if md_start_sync() turns out to do nothing, MD_RECOVERY_RUNNING will be cleared in this case. And during the race window, action_store() will return -EBUSY, which will cause some mdadm tests to fail. For example:
The test 07reshape5intr will add a new disk to array, then start reshape: mdadm /dev/md0 --add /dev/xxx mdadm --grow /dev/md0 -n 3 And add_bound_rdev() from mdadm --add will set MD_RECOVERY_NEEDED, then during the race windown, mdadm --grow will fail. Fix the problem by waiting in action_store() during the race window, fail only if sync_thread is registered. Signed-off-by: Yu Kuai <[email protected]> --- drivers/md/md.c | 85 +++++++++++++++++++------------------------------ drivers/md/md.h | 2 -- 2 files changed, 33 insertions(+), 54 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 5e3c3c109412..3890ae86449a 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -752,7 +752,6 @@ int mddev_init(struct mddev *mddev) mutex_init(&mddev->open_mutex); mutex_init(&mddev->reconfig_mutex); - mutex_init(&mddev->sync_mutex); mutex_init(&mddev->suspend_mutex); mutex_init(&mddev->bitmap_info.mutex); INIT_LIST_HEAD(&mddev->disks); @@ -5020,34 +5019,6 @@ void md_unfrozen_sync_thread(struct mddev *mddev) } EXPORT_SYMBOL_GPL(md_unfrozen_sync_thread); -static void idle_sync_thread(struct mddev *mddev) -{ - mutex_lock(&mddev->sync_mutex); - clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); - - if (mddev_lock(mddev)) { - mutex_unlock(&mddev->sync_mutex); - return; - } - - stop_sync_thread(mddev, false); - mutex_unlock(&mddev->sync_mutex); -} - -static void frozen_sync_thread(struct mddev *mddev) -{ - mutex_lock(&mddev->sync_mutex); - set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); - - if (mddev_lock(mddev)) { - mutex_unlock(&mddev->sync_mutex); - return; - } - - stop_sync_thread(mddev, false); - mutex_unlock(&mddev->sync_mutex); -} - static int mddev_start_reshape(struct mddev *mddev) { int ret; @@ -5055,24 +5026,13 @@ static int mddev_start_reshape(struct mddev *mddev) if (mddev->pers->start_reshape == NULL) return -EINVAL; - ret = mddev_lock(mddev); - if (ret) - return ret; - - if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) { - mddev_unlock(mddev); - return -EBUSY; - } - if (mddev->reshape_position == MaxSector || mddev->pers->check_reshape == NULL || mddev->pers->check_reshape(mddev)) { clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); ret = mddev->pers->start_reshape(mddev); - if (ret) { - mddev_unlock(mddev); + if (ret) return ret; - } } else { /* * If reshape is still in progress, and md_check_recovery() can @@ -5082,7 +5042,6 @@ static int mddev_start_reshape(struct mddev *mddev) clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); } - mddev_unlock(mddev); sysfs_notify_dirent_safe(mddev->sysfs_degraded); return 0; } @@ -5096,36 +5055,53 @@ action_store(struct mddev *mddev, const char *page, size_t len) if (!mddev->pers || !mddev->pers->sync_request) return -EINVAL; +retry: + if (work_busy(&mddev->sync_work)) + flush_work(&mddev->sync_work); + + ret = mddev_lock(mddev); + if (ret) + return ret; + + if (work_busy(&mddev->sync_work)) { + mddev_unlock(mddev); + goto retry; + } + action = md_sync_action_by_name(page); /* TODO: mdadm rely on "idle" to start sync_thread. */ if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) { switch (action) { case ACTION_FROZEN: - frozen_sync_thread(mddev); - return len; + md_frozen_sync_thread(mddev); + ret = len; + goto out; case ACTION_IDLE: - idle_sync_thread(mddev); + md_idle_sync_thread(mddev); break; case ACTION_RESHAPE: case ACTION_RECOVER: case ACTION_CHECK: case ACTION_REPAIR: case ACTION_RESYNC: - return -EBUSY; + ret = -EBUSY; + goto out; default: - return -EINVAL; + ret = -EINVAL; + goto out; } } else { switch (action) { case ACTION_FROZEN: set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); - return len; + ret = len; + goto out; case ACTION_RESHAPE: clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); ret = mddev_start_reshape(mddev); if (ret) - return ret; + goto out; break; case ACTION_RECOVER: clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); @@ -5143,7 +5119,8 @@ action_store(struct mddev *mddev, const char *page, size_t len) clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); break; default: - return -EINVAL; + ret = -EINVAL; + goto out; } } @@ -5151,14 +5128,18 @@ action_store(struct mddev *mddev, const char *page, size_t len) /* A write to sync_action is enough to justify * canceling read-auto mode */ - flush_work(&mddev->sync_work); mddev->ro = MD_RDWR; md_wakeup_thread(mddev->sync_thread); } + set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); md_wakeup_thread(mddev->thread); sysfs_notify_dirent_safe(mddev->sysfs_action); - return len; + ret = len; + +out: + mddev_unlock(mddev); + return ret; } static struct md_sysfs_entry md_scan_mode = diff --git a/drivers/md/md.h b/drivers/md/md.h index 018f3292a25c..f7afc5a46031 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -595,8 +595,6 @@ struct mddev { */ struct list_head deleting; - /* Used to synchronize idle and frozen for action_store() */ - struct mutex sync_mutex; /* The sequence number for sync thread */ atomic_t sync_seq; -- 2.39.2
