From: Kanchan Joshi <joshi.k@xxxxxxxxxxx>
commit 35bc10b2eafbb701064b94f283b77c54d3304842 upstream.
Parallel write,read,zone-mgmt operations accessing/altering zone state
and write-pointer may get into race. Avoid the situation by using a new
spinlock for zoned device.
Concurrent zone-appends (on a zone) returning same write-pointer issue
is also avoided using this lock.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: e0489ed5daeb ("null_blk: Support REQ_OP_ZONE_APPEND")
Signed-off-by: Kanchan Joshi <joshi.k@xxxxxxxxxxx>
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/null_blk.h | 1 +
drivers/block/null_blk_zoned.c | 22 ++++++++++++++++++----
2 files changed, 19 insertions(+), 4 deletions(-)
--- a/drivers/block/null_blk.h
+++ b/drivers/block/null_blk.h
@@ -44,6 +44,7 @@ struct nullb_device {
unsigned int nr_zones;
struct blk_zone *zones;
sector_t zone_size_sects;
+ spinlock_t zone_lock;
unsigned long size; /* device size in MB */
unsigned long completion_nsec; /* time in ns to complete a request */
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -45,6 +45,7 @@ int null_init_zoned_dev(struct nullb_dev
if (!dev->zones)
return -ENOMEM;
+ spin_lock_init(&dev->zone_lock);
if (dev->zone_nr_conv >= dev->nr_zones) {
dev->zone_nr_conv = dev->nr_zones - 1;
pr_info("changed the number of conventional zones to %u",
@@ -131,8 +132,11 @@ int null_report_zones(struct gendisk *di
* So use a local copy to avoid corruption of the device zone
* array.
*/
+ spin_lock_irq(&dev->zone_lock);
memcpy(&zone, &dev->zones[first_zone + i],
sizeof(struct blk_zone));
+ spin_unlock_irq(&dev->zone_lock);
+
error = cb(&zone, i, data);
if (error)
return error;
@@ -277,18 +281,28 @@ static blk_status_t null_zone_mgmt(struc
blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_opf op,
sector_t sector, sector_t nr_sectors)
{
+ blk_status_t sts;
+ struct nullb_device *dev = cmd->nq->dev;
+
+ spin_lock_irq(&dev->zone_lock);
switch (op) {
case REQ_OP_WRITE:
- return null_zone_write(cmd, sector, nr_sectors, false);
+ sts = null_zone_write(cmd, sector, nr_sectors, false);
+ break;
case REQ_OP_ZONE_APPEND:
- return null_zone_write(cmd, sector, nr_sectors, true);
+ sts = null_zone_write(cmd, sector, nr_sectors, true);
+ break;
case REQ_OP_ZONE_RESET:
case REQ_OP_ZONE_RESET_ALL:
case REQ_OP_ZONE_OPEN:
case REQ_OP_ZONE_CLOSE:
case REQ_OP_ZONE_FINISH:
- return null_zone_mgmt(cmd, op, sector);
+ sts = null_zone_mgmt(cmd, op, sector);
+ break;
default:
- return null_process_cmd(cmd, op, sector, nr_sectors);
+ sts = null_process_cmd(cmd, op, sector, nr_sectors);
}
+ spin_unlock_irq(&dev->zone_lock);
+
+ return sts;
}
