6.18-stable review patch. If anyone has any objections, please let me know.
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From: Damien Le Moal dlemoal@kernel.org
commit bba4322e3f303b2d656e748be758320b567f046f upstream.
Modify disk_update_zone_resources() to freeze the device queue before updating the number of zones, zone capacity and other zone related resources. The locking order resulting from the call to queue_limits_commit_update_frozen() is preserved, that is, the queue limits lock is first taken by calling queue_limits_start_update() before freezing the queue, and the queue is unfrozen after executing queue_limits_commit_update(), which replaces the call to queue_limits_commit_update_frozen().
This change ensures that there are no in-flights I/Os when the zone resources are updated due to a zone revalidation. In case of error when the limits are applied, directly call disk_free_zone_resources() from disk_update_zone_resources() while the disk queue is still frozen to avoid needing to freeze & unfreeze the queue again in blk_revalidate_disk_zones(), thus simplifying that function code a little.
Fixes: 0b83c86b444a ("block: Prevent potential deadlock in blk_revalidate_disk_zones()") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal dlemoal@kernel.org Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Johannes Thumshirn johannes.thumshirn@wdc.com Reviewed-by: Chaitanya Kulkarni kch@nvidia.com Reviewed-by: Hannes Reinecke hare@suse.de Reviewed-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- block/blk-zoned.c | 42 ++++++++++++++++++++++++------------------ 1 file changed, 24 insertions(+), 18 deletions(-)
--- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -1516,8 +1516,13 @@ static int disk_update_zone_resources(st { struct request_queue *q = disk->queue; unsigned int nr_seq_zones, nr_conv_zones; - unsigned int pool_size; + unsigned int pool_size, memflags; struct queue_limits lim; + int ret = 0; + + lim = queue_limits_start_update(q); + + memflags = blk_mq_freeze_queue(q);
disk->nr_zones = args->nr_zones; disk->zone_capacity = args->zone_capacity; @@ -1527,11 +1532,10 @@ static int disk_update_zone_resources(st if (nr_conv_zones >= disk->nr_zones) { pr_warn("%s: Invalid number of conventional zones %u / %u\n", disk->disk_name, nr_conv_zones, disk->nr_zones); - return -ENODEV; + ret = -ENODEV; + goto unfreeze; }
- lim = queue_limits_start_update(q); - /* * Some devices can advertize zone resource limits that are larger than * the number of sequential zones of the zoned block device, e.g. a @@ -1568,7 +1572,15 @@ static int disk_update_zone_resources(st }
commit: - return queue_limits_commit_update_frozen(q, &lim); + ret = queue_limits_commit_update(q, &lim); + +unfreeze: + if (ret) + disk_free_zone_resources(disk); + + blk_mq_unfreeze_queue(q, memflags); + + return ret; }
static int blk_revalidate_conv_zone(struct blk_zone *zone, unsigned int idx, @@ -1733,7 +1745,7 @@ int blk_revalidate_disk_zones(struct gen sector_t zone_sectors = q->limits.chunk_sectors; sector_t capacity = get_capacity(disk); struct blk_revalidate_zone_args args = { }; - unsigned int noio_flag; + unsigned int memflags, noio_flag; int ret = -ENOMEM;
if (WARN_ON_ONCE(!blk_queue_is_zoned(q))) @@ -1783,20 +1795,14 @@ int blk_revalidate_disk_zones(struct gen ret = -ENODEV; }
- /* - * Set the new disk zone parameters only once the queue is frozen and - * all I/Os are completed. - */ if (ret > 0) - ret = disk_update_zone_resources(disk, &args); - else - pr_warn("%s: failed to revalidate zones\n", disk->disk_name); - if (ret) { - unsigned int memflags = blk_mq_freeze_queue(q); + return disk_update_zone_resources(disk, &args);
- disk_free_zone_resources(disk); - blk_mq_unfreeze_queue(q, memflags); - } + pr_warn("%s: failed to revalidate zones\n", disk->disk_name); + + memflags = blk_mq_freeze_queue(q); + disk_free_zone_resources(disk); + blk_mq_unfreeze_queue(q, memflags);
return ret; }