@@ -45,6 +45,7 @@ struct nullb_device {
unsigned int nr_zones_imp_open;
unsigned int nr_zones_exp_open;
unsigned int nr_zones_closed;
+ unsigned int imp_close_zone_no;
struct blk_zone *zones;
sector_t zone_size_sects;
bool need_zone_res_mgmt;
@@ -91,6 +91,7 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
pr_info("zone_max_open limit disabled, limit >= zone count\n");
}
dev->need_zone_res_mgmt = dev->zone_max_active || dev->zone_max_open;
+ dev->imp_close_zone_no = dev->zone_nr_conv;
for (i = 0; i < dev->zone_nr_conv; i++) {
struct blk_zone *zone = &dev->zones[i];
@@ -282,13 +283,24 @@ static blk_status_t __null_close_zone(struct nullb_device *dev,
return BLK_STS_OK;
}
-static void null_close_first_imp_zone(struct nullb_device *dev)
+static void null_close_imp_open_zone(struct nullb_device *dev)
{
- unsigned int i;
+ struct blk_zone *zone;
+ unsigned int zno, i;
+
+ zno = dev->imp_close_zone_no;
+ if (zno >= dev->nr_zones)
+ zno = dev->zone_nr_conv;
for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
- if (dev->zones[i].cond == BLK_ZONE_COND_IMP_OPEN) {
- __null_close_zone(dev, &dev->zones[i]);
+ zone = &dev->zones[zno];
+ zno++;
+ if (zno >= dev->nr_zones)
+ zno = dev->zone_nr_conv;
+
+ if (zone->cond == BLK_ZONE_COND_IMP_OPEN) {
+ __null_close_zone(dev, zone);
+ dev->imp_close_zone_no = zno;
return;
}
}
@@ -316,7 +328,7 @@ static blk_status_t null_check_open(struct nullb_device *dev)
if (dev->nr_zones_imp_open) {
if (null_check_active(dev) == BLK_STS_OK) {
- null_close_first_imp_zone(dev);
+ null_close_imp_open_zone(dev);
return BLK_STS_OK;
}
}
When open zone resource management is enabled, that is, when a null_blk zoned device is created with zone_max_open different than 0, implicitly or explicitly opening a zone may require implicitly closing a zone that is already implicitly open. This operation is done using the function null_close_first_imp_zone(), which search for an implicitly open zone to close starting from the first sequential zone. This implementation is simple but may result in the same being constantly implicitly closed and then implicitly reopened on write, namely, the lowest numbered zone that is being written. Avoid this by starting the search for an implicitly open zone starting from the zone following the last zone that was implicitly closed. The function null_close_first_imp_zone() is renamed null_close_imp_open_zone(). Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> --- drivers/block/null_blk.h | 1 + drivers/block/null_blk_zoned.c | 22 +++++++++++++++++----- 2 files changed, 18 insertions(+), 5 deletions(-)