From: Damien Le Moal <dlemoal@kernel.org>
Date: Mon, 29 May 2023 16:32:37 +0900
Subject: block: fix revalidate performance regression
Patch-mainline: v6.4-rc5
Git-commit: 47fe1c3064c6bc1bfa3c032ff78e603e5dd6e5bc
References: bsc#1216057
The scsi driver function sd_read_block_characteristics() always calls
disk_set_zoned() to a disk zoned model correctly, in case the device
model changed. This is done even for regular disks to set the zoned
model to BLK_ZONED_NONE and free any zone related resources if the drive
previously was zoned.
This behavior significantly impact the time it takes to revalidate disks
on a large system as the call to disk_clear_zone_settings() done from
disk_set_zoned() for the BLK_ZONED_NONE case results in the device
request queued to be frozen, even if there are no zone resources to
free.
Avoid this overhead for non-zoned devices by not calling
disk_clear_zone_settings() in disk_set_zoned() if the device model
was already set to BLK_ZONED_NONE, which is always the case for regular
devices.
Reported by: Brian Bunker <brian@purestorage.com>
Fixes: 508aebb80527 ("block: introduce blk_queue_clear_zone_settings()")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230529073237.1339862-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Martin Wilck <mwilck@suse.com>
---
block/blk-settings.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -908,6 +908,7 @@ static bool disk_has_partitions(struct g
void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model)
{
struct request_queue *q = disk->queue;
+ unsigned int old_model = q->limits.zoned;
switch (model) {
case BLK_ZONED_HM:
@@ -945,7 +946,7 @@ void blk_queue_set_zoned(struct gendisk
*/
blk_queue_zone_write_granularity(q,
queue_logical_block_size(q));
- } else {
+ } else if (old_model != BLK_ZONED_NONE) {
blk_queue_clear_zone_settings(q);
}
}