[PATCH v8 03/12] block: allow dropping all zone write plugs on revalidation

[Damien Le Moal <dlemoal@kernel.org>]

In preparation for supporting storage element depopulation, modify the
function disk_revalidate_zones() to take an additional boolean parameter
drop_all_zwplugs to force removing all zone write plugs from a disk hash
table.  Removing all zone write plugs is done in the same manner as for a
capacity change, using the function disk_drop_zone_wplug() applied to all
hashed zone write plugs.

Calls to disk_revalidate_zones() with the argument drop_all_zwplugs set to
true will be used when restoring depopulated storage elements as such
operation clears all sequential zones, modifying them to be empty.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
---
 block/blk-zoned.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 600d6bd008ae..3761e634650e 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -2552,7 +2552,7 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx,
 	return ret;
 }
 
-static int disk_revalidate_zones(struct gendisk *disk)
+static int disk_revalidate_zones(struct gendisk *disk, bool drop_all_zwplugs)
 {
 	struct blk_revalidate_zone_args args = { };
 	struct blk_report_zones_args rep_args = {
@@ -2563,6 +2563,9 @@ static int disk_revalidate_zones(struct gendisk *disk)
 	int retries = 2;
 	int ret;
 
+	if (drop_all_zwplugs)
+		disk_for_all_zone_wplugs(disk, disk_drop_zone_wplug, NULL);
+
 again:
 	ret = disk_revalidate_capacity(disk, &args);
 	if (ret)
@@ -2647,7 +2650,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
 	 * eventually change the disk zone information.
 	 */
 	mutex_lock(&disk->zone_revalidate_mutex);
-	ret = disk_revalidate_zones(disk);
+	ret = disk_revalidate_zones(disk, false);
 	mutex_unlock(&disk->zone_revalidate_mutex);
 
 	return ret;
-- 
2.56.0