From: John Garry <john.garry@huawei.com> stable inclusion from linux-4.19.198 commit 029028f4e90be206950c31fb2adadcbb1f0b32c0 -------------------------------- [ Upstream commit ea2f0f77538c50739b9fb4de4700cee5535e1f77 ] The sysfs handling function sdev_store_queue_depth() enforces that the sdev queue depth cannot exceed shost can_queue. The initial sdev queue depth comes from shost cmd_per_lun. However, the LLDD may manually set cmd_per_lun to be larger than can_queue, which leads to an initial sdev queue depth greater than can_queue. Such an issue was reported in [0], which caused a hang. That has since been fixed in commit fc09acb7de31 ("scsi: scsi_debug: Fix cmd_per_lun, set to max_queue"). Stop this possibly happening for other drivers by capping shost cmd_per_lun at shost can_queue. [0] https://lore.kernel.org/linux-scsi/YHaez6iN2HHYxYOh@T590/ Link: https://lore.kernel.org/r/1621434662-173079-1-git-send-email-john.garry@huaw... Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: John Garry <john.garry@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/scsi/hosts.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 7150164c5ed95..6ea48a095290d 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -218,6 +218,9 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, goto fail; } + shost->cmd_per_lun = min_t(short, shost->cmd_per_lun, + shost->can_queue); + error = scsi_init_sense_cache(shost); if (error) goto fail; -- 2.25.1