From: Damien Le Moal <dlemoal@kernel.org>
To: linux-block@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
dm-devel@lists.linux.dev, Mike Snitzer <snitzer@redhat.com>
Subject: [PATCH v3 06/14] block: Unhash a zone write plug only if needed
Date: Wed, 1 May 2024 20:08:59 +0900 [thread overview]
Message-ID: <20240501110907.96950-7-dlemoal@kernel.org> (raw)
In-Reply-To: <20240501110907.96950-1-dlemoal@kernel.org>
Fix disk_remove_zone_wplug() to ensure that a zone write plug already
removed from a disk hash table of zone write plugs is not removed
again. Do this by checking the BLK_ZONE_WPLUG_UNHASHED flag of the plug
and calling hlist_del_init_rcu() only if the flag is not set.
Furthermore, since BIO completions can happen at any time, that is,
decrementing of the zone write plug reference count can happen at any
time, make sure to use disk_put_zone_wplug() instead of atomic_dec() to
ensure that the zone write plug is freed when its last reference is
dropped. In order to do this, disk_remove_zone_wplug() is moved after
the definition of disk_put_zone_wplug(). disk_should_remove_zone_wplug()
is moved as well to keep it together with disk_remove_zone_wplug().
To be consistent with this change, add a check in disk_put_zone_wplug()
to ensure that a zone write plug being freed was already removed from
the disk hash table.
Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
block/blk-zoned.c | 55 +++++++++++++++++++++++++++--------------------
1 file changed, 32 insertions(+), 23 deletions(-)
diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 78557f810f1d..2f61ba56dad2 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -476,29 +476,6 @@ static bool disk_insert_zone_wplug(struct gendisk *disk,
return true;
}
-static void disk_remove_zone_wplug(struct gendisk *disk,
- struct blk_zone_wplug *zwplug)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&disk->zone_wplugs_lock, flags);
- zwplug->flags |= BLK_ZONE_WPLUG_UNHASHED;
- atomic_dec(&zwplug->ref);
- hlist_del_init_rcu(&zwplug->node);
- spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags);
-}
-
-static inline bool disk_should_remove_zone_wplug(struct gendisk *disk,
- struct blk_zone_wplug *zwplug)
-{
- /* If the zone is still busy, the plug cannot be removed. */
- if (zwplug->flags & BLK_ZONE_WPLUG_BUSY)
- return false;
-
- /* We can remove zone write plugs for zones that are empty or full. */
- return !zwplug->wp_offset || zwplug->wp_offset >= disk->zone_capacity;
-}
-
static struct blk_zone_wplug *disk_get_zone_wplug(struct gendisk *disk,
sector_t sector)
{
@@ -534,11 +511,43 @@ static inline void disk_put_zone_wplug(struct blk_zone_wplug *zwplug)
if (atomic_dec_and_test(&zwplug->ref)) {
WARN_ON_ONCE(!bio_list_empty(&zwplug->bio_list));
WARN_ON_ONCE(!list_empty(&zwplug->link));
+ WARN_ON_ONCE(!(zwplug->flags & BLK_ZONE_WPLUG_UNHASHED));
call_rcu(&zwplug->rcu_head, disk_free_zone_wplug_rcu);
}
}
+static inline bool disk_should_remove_zone_wplug(struct gendisk *disk,
+ struct blk_zone_wplug *zwplug)
+{
+ /* If the zone is still busy, the plug cannot be removed. */
+ if (zwplug->flags & BLK_ZONE_WPLUG_BUSY)
+ return false;
+
+ /* We can remove zone write plugs for zones that are empty or full. */
+ return !zwplug->wp_offset || zwplug->wp_offset >= disk->zone_capacity;
+}
+
+static void disk_remove_zone_wplug(struct gendisk *disk,
+ struct blk_zone_wplug *zwplug)
+{
+ unsigned long flags;
+
+ /* If the zone write plug was already removed, we have nothing to do. */
+ if (zwplug->flags & BLK_ZONE_WPLUG_UNHASHED)
+ return;
+
+ /*
+ * Mark the zone write plug as unhashed and drop the extra reference we
+ * took when the plug was inserted in the hash table.
+ */
+ zwplug->flags |= BLK_ZONE_WPLUG_UNHASHED;
+ spin_lock_irqsave(&disk->zone_wplugs_lock, flags);
+ hlist_del_init_rcu(&zwplug->node);
+ spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags);
+ disk_put_zone_wplug(zwplug);
+}
+
static void blk_zone_wplug_bio_work(struct work_struct *work);
/*
--
2.44.0
next prev parent reply other threads:[~2024-05-01 11:09 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-01 11:08 [PATCH v3 00/14] Zone write plugging fixes and cleanup Damien Le Moal
2024-05-01 11:08 ` [PATCH v3 01/14] dm: Check that a zoned table leads to a valid mapped device Damien Le Moal
2024-05-01 11:08 ` [PATCH v3 02/14] block: Exclude conventional zones when faking max open limit Damien Le Moal
2024-05-02 5:52 ` Hannes Reinecke
2024-05-01 11:08 ` [PATCH v3 03/14] block: Fix zone write plug initialization from blk_revalidate_zone_cb() Damien Le Moal
2024-05-02 5:53 ` Hannes Reinecke
2024-05-01 11:08 ` [PATCH v3 04/14] block: Fix reference counting for zone write plugs in error state Damien Le Moal
2024-05-02 6:01 ` Hannes Reinecke
2024-05-02 9:37 ` Damien Le Moal
2024-05-01 11:08 ` [PATCH v3 05/14] block: Hold a reference on zone write plugs to schedule submission Damien Le Moal
2024-05-02 6:04 ` Hannes Reinecke
2024-05-01 11:08 ` Damien Le Moal [this message]
2024-05-02 6:05 ` [PATCH v3 06/14] block: Unhash a zone write plug only if needed Hannes Reinecke
2024-05-01 11:09 ` [PATCH v3 07/14] block: Do not remove zone write plugs still in use Damien Le Moal
2024-05-02 5:38 ` Christoph Hellwig
2024-05-02 6:09 ` Hannes Reinecke
2024-05-01 11:09 ` [PATCH v3 08/14] block: Fix flush request sector restore Damien Le Moal
2024-05-02 6:10 ` Hannes Reinecke
2024-05-01 11:09 ` [PATCH v3 09/14] block: Fix handling of non-empty flush write requests to zones Damien Le Moal
2024-05-02 6:11 ` Hannes Reinecke
2024-05-01 11:09 ` [PATCH v3 10/14] block: Improve blk_zone_write_plug_bio_merged() Damien Le Moal
2024-05-02 6:13 ` Hannes Reinecke
2024-05-01 11:09 ` [PATCH v3 11/14] block: Improve zone write request completion handling Damien Le Moal
2024-05-02 6:14 ` Hannes Reinecke
2024-05-01 11:09 ` [PATCH v3 12/14] block: Simplify blk_zone_write_plug_bio_endio() Damien Le Moal
2024-05-02 6:15 ` Hannes Reinecke
2024-05-01 11:09 ` [PATCH v3 13/14] block: Simplify zone write plug BIO abort Damien Le Moal
2024-05-02 6:15 ` Hannes Reinecke
2024-05-01 11:09 ` [PATCH v3 14/14] block: Cleanup blk_revalidate_zone_cb() Damien Le Moal
2024-05-02 6:17 ` Hannes Reinecke
2024-05-01 14:08 ` [PATCH v3 00/14] Zone write plugging fixes and cleanup Jens Axboe
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