From f049cf1a7b6737c75884247c3f6383ef104d255a Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 30 Apr 2019 14:39:18 -0700 Subject: scsi: sd: Rely on the driver core for asynchronous probing As explained during the 2018 LSF/MM session about increasing SCSI disk probing concurrency, the problems with the current probing approach are as follows: - The driver core is unaware of asynchronous SCSI LUN probing. wait_for_device_probe() waits for all asynchronous probes except asynchronous SCSI disk probes. - There is unnecessary serialization between sd_probe() and sd_remove(). This can lead to a deadlock. Hence this patch that modifies the sd driver such that it uses the driver core framework for asynchronous probing. The async domain and get_device()/put_device() pairs that became superfluous due to this change are removed. This patch does not affect the time needed for loading the scsi_debug kernel module with parameters delay=0 and max_luns=256. This patch depends on commit ef0ff68351be ("driver core: Probe devices asynchronously instead of the driver") that went upstream in kernel version v5.1-rc1. Cc: Lee Duncan Cc: Hannes Reinecke Cc: Luis Chamberlain Cc: Johannes Thumshirn Cc: Christoph Hellwig Cc: Pavel Machek Cc: Dan Williams Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen --- drivers/scsi/scsi_priv.h | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/scsi/scsi_priv.h') diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 5f21547b2ad2..cc2859d76d81 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -175,7 +175,6 @@ static inline void scsi_autopm_put_host(struct Scsi_Host *h) {} #endif /* CONFIG_PM */ extern struct async_domain scsi_sd_pm_domain; -extern struct async_domain scsi_sd_probe_domain; /* scsi_dh.c */ #ifdef CONFIG_SCSI_DH -- cgit v1.2.3