From 9e78c38ab30b14c1d6a07c61d57ac5e2f12fa568 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Wed, 1 May 2024 20:08:58 +0900 Subject: [PATCH] block: Hold a reference on zone write plugs to schedule submission Since a zone write plug BIO work is a field of struct blk_zone_wplug, we must ensure that a zone write plug is never freed when its BIO submission work is queued or running. Do this by holding a reference on the zone write plug when the submission work is scheduled for execution with queue_work() and releasing the reference at the end of the execution of the work function blk_zone_wplug_bio_work(). The helper function disk_zone_wplug_schedule_bio_work() is introduced to get a reference on a zone write plug and queue its work. This helper is used in disk_zone_wplug_unplug_bio() and disk_zone_wplug_handle_error(). Fixes: dd291d77cc90 ("block: Introduce zone write plugging") Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20240501110907.96950-6-dlemoal@kernel.org Signed-off-by: Jens Axboe --- block/blk-zoned.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 23ad1de0da62..78557f810f1d 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -1132,6 +1132,19 @@ bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) } EXPORT_SYMBOL_GPL(blk_zone_plug_bio); +static void disk_zone_wplug_schedule_bio_work(struct gendisk *disk, + struct blk_zone_wplug *zwplug) +{ + /* + * Take a reference on the zone write plug and schedule the submission + * of the next plugged BIO. blk_zone_wplug_bio_work() will release the + * reference we take here. + */ + WARN_ON_ONCE(!(zwplug->flags & BLK_ZONE_WPLUG_PLUGGED)); + atomic_inc(&zwplug->ref); + queue_work(disk->zone_wplugs_wq, &zwplug->bio_work); +} + static void disk_zone_wplug_unplug_bio(struct gendisk *disk, struct blk_zone_wplug *zwplug) { @@ -1151,8 +1164,8 @@ static void disk_zone_wplug_unplug_bio(struct gendisk *disk, /* Schedule submission of the next plugged BIO if we have one. */ if (!bio_list_empty(&zwplug->bio_list)) { + disk_zone_wplug_schedule_bio_work(disk, zwplug); spin_unlock_irqrestore(&zwplug->lock, flags); - queue_work(disk->zone_wplugs_wq, &zwplug->bio_work); return; } @@ -1252,14 +1265,14 @@ static void blk_zone_wplug_bio_work(struct work_struct *work) if (!bio) { zwplug->flags &= ~BLK_ZONE_WPLUG_PLUGGED; spin_unlock_irqrestore(&zwplug->lock, flags); - return; + goto put_zwplug; } if (!blk_zone_wplug_prepare_bio(zwplug, bio)) { /* Error recovery will decide what to do with the BIO. */ bio_list_add_head(&zwplug->bio_list, bio); spin_unlock_irqrestore(&zwplug->lock, flags); - return; + goto put_zwplug; } spin_unlock_irqrestore(&zwplug->lock, flags); @@ -1275,6 +1288,10 @@ static void blk_zone_wplug_bio_work(struct work_struct *work) */ if (bdev->bd_has_submit_bio) blk_queue_exit(bdev->bd_disk->queue); + +put_zwplug: + /* Drop the reference we took in disk_zone_wplug_schedule_bio_work(). */ + disk_put_zone_wplug(zwplug); } static unsigned int blk_zone_wp_offset(struct blk_zone *zone) @@ -1354,8 +1371,7 @@ static void disk_zone_wplug_handle_error(struct gendisk *disk, /* Restart BIO submission if we still have any BIO left. */ if (!bio_list_empty(&zwplug->bio_list)) { - WARN_ON_ONCE(!(zwplug->flags & BLK_ZONE_WPLUG_PLUGGED)); - queue_work(disk->zone_wplugs_wq, &zwplug->bio_work); + disk_zone_wplug_schedule_bio_work(disk, zwplug); goto unlock; } -- 2.20.1