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authorKanchan Joshi <joshi.k@samsung.com>2020-09-28 15:25:49 +0530
committerJens Axboe <axboe@kernel.dk>2020-10-27 20:40:42 -0600
commit35bc10b2eafbb701064b94f283b77c54d3304842 (patch)
tree661c7d397dc63b891f6c934f3658244e1de5edf2
parentf255c19b3ab46d3cad3b1b2e1036f4c926cb1d0c (diff)
null_blk: synchronization fix for zoned device
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@vger.kernel.org Fixes: e0489ed5daeb ("null_blk: Support REQ_OP_ZONE_APPEND") Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--drivers/block/null_blk.h1
-rw-r--r--drivers/block/null_blk_zoned.c22
2 files changed, 19 insertions, 4 deletions
diff --git a/drivers/block/null_blk.h b/drivers/block/null_blk.h
index d2e7db43a52a..3176b269b822 100644
--- a/drivers/block/null_blk.h
+++ b/drivers/block/null_blk.h
@@ -47,6 +47,7 @@ struct nullb_device {
unsigned int nr_zones_closed;
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 */
diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index 7d94f2d47a6a..98056c88926b 100644
--- 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_device *dev, struct request_queue *q)
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",
@@ -149,8 +150,11 @@ int null_report_zones(struct gendisk *disk, sector_t sector,
* 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;
@@ -499,18 +503,28 @@ static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
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;
}