From 61c90765e131e63ead773b9b99167415e246a945 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Thu, 28 Dec 2023 20:55:51 +0800 Subject: [PATCH] md: remove redundant check of 'mddev->sync_thread' The lifetime of sync_thread: 1) Set MD_RECOVERY_NEEDED and wake up daemon thread (by ioctl/sysfs or other events); 2) Daemon thread woke up, md_check_recovery() found that MD_RECOVERY_NEEDED is set: a) try to grab reconfig_mutex; b) set MD_RECOVERY_RUNNING; c) clear MD_RECOVERY_NEEDED, and then queue sync_work; 3) md_start_sync() choose sync_action, then register sync_thread; 4) md_do_sync() is done, set MD_RECOVERY_DONE and wake up daemon thread; 5) Daemon thread woke up, md_check_recovery() found that MD_RECOVERY_DONE is set: a) try to grab reconfig_mutex; b) unregister sync_thread; c) clear MD_RECOVERY_RUNNING and MD_RECOVERY_DONE; Hence there is no such case that MD_RECOVERY_RUNNING is not set, while sync_thread is registered. Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20231228125553.2697765-2-yukuai1@huaweicloud.com --- drivers/md/md.c | 14 ++++---------- drivers/md/raid5.c | 6 ++---- 2 files changed, 6 insertions(+), 14 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 2266358d80746..9b6b34ab9d1d4 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -3339,8 +3339,7 @@ static ssize_t new_offset_store(struct md_rdev *rdev, if (kstrtoull(buf, 10, &new_offset) < 0) return -EINVAL; - if (mddev->sync_thread || - test_bit(MD_RECOVERY_RUNNING,&mddev->recovery)) + if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) return -EBUSY; if (new_offset == rdev->data_offset) /* reset is always permitted */ @@ -4013,8 +4012,7 @@ level_store(struct mddev *mddev, const char *buf, size_t len) */ rv = -EBUSY; - if (mddev->sync_thread || - test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) || + if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) || mddev->reshape_position != MaxSector || mddev->sysfs_active) goto out_unlock; @@ -6408,7 +6406,6 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev) mutex_lock(&mddev->open_mutex); if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) || - mddev->sync_thread || test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) { pr_warn("md: %s still in use.\n",mdname(mddev)); err = -EBUSY; @@ -6461,7 +6458,6 @@ static int do_md_stop(struct mddev *mddev, int mode, mutex_lock(&mddev->open_mutex); if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) || mddev->sysfs_active || - mddev->sync_thread || test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) { pr_warn("md: %s still in use.\n",mdname(mddev)); mutex_unlock(&mddev->open_mutex); @@ -7307,8 +7303,7 @@ static int update_size(struct mddev *mddev, sector_t num_sectors) * of each device. If num_sectors is zero, we find the largest size * that fits. */ - if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) || - mddev->sync_thread) + if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) return -EBUSY; if (!md_is_rdwr(mddev)) return -EROFS; @@ -7345,8 +7340,7 @@ static int update_raid_disks(struct mddev *mddev, int raid_disks) if (raid_disks <= 0 || (mddev->max_disks && raid_disks >= mddev->max_disks)) return -EINVAL; - if (mddev->sync_thread || - test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) || + if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) || test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) || mddev->reshape_position != MaxSector) return -EBUSY; diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 8497880135ee4..14f2cf75abbd7 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -6967,10 +6967,8 @@ raid5_store_stripe_size(struct mddev *mddev, const char *page, size_t len) pr_debug("md/raid: change stripe_size from %lu to %lu\n", conf->stripe_size, new); - if (mddev->sync_thread || - test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) || - mddev->reshape_position != MaxSector || - mddev->sysfs_active) { + if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) || + mddev->reshape_position != MaxSector || mddev->sysfs_active) { err = -EBUSY; goto out_unlock; } -- 2.30.2