Commit 1a928378 authored by Ming Lei's avatar Ming Lei Committed by Martin K. Petersen
Browse files

scsi: core: Simplify LLD module reference counting 

Swap two statements in scsi_device_put() now that it is guaranteed that
SCSI hosts outlive SCSI devices. Remove the reference counting code from
scsi_sysfs.c that became superfluous because SCSI hosts now outlive SCSI
devices.

Link: https://lore.kernel.org/r/20220728221851.1822295-4-bvanassche@acm.org


Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.garry@huawei.com>
Reviewed-by: default avatarMike Christie <michael.christie@oracle.com>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
[ bvanassche: Extracted this patch from a larger patch ]
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 16728aab

drivers/scsi/scsi.c

+6 −3
Original line number Diff line number Diff line
@@ -586,10 +586,13 @@ EXPORT_SYMBOL(scsi_device_get); 
 */

void scsi_device_put(struct scsi_device *sdev)

{

	struct module *mod = sdev->host->hostt->module;



	/*

	 * Decreasing the module reference count before the device reference

	 * count is safe since scsi_remove_host() only returns after all

	 * devices have been removed.

	 */

	module_put(sdev->host->hostt->module);

	put_device(&sdev->sdev_gendev);

	module_put(mod);

}

EXPORT_SYMBOL(scsi_device_put);

drivers/scsi/scsi_sysfs.c

+0 −9
Original line number Diff line number Diff line
@@ -452,9 +452,6 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work) 
	struct scsi_vpd *vpd_pg0 = NULL, *vpd_pg89 = NULL;

	struct scsi_vpd *vpd_pgb0 = NULL, *vpd_pgb1 = NULL, *vpd_pgb2 = NULL;

	unsigned long flags;

	struct module *mod;



	mod = sdev->host->hostt->module;



	scsi_dh_release_device(sdev);
@@ -521,17 +518,11 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work) 


	if (parent)

		put_device(parent);

	module_put(mod);

}



static void scsi_device_dev_release(struct device *dev)

{

	struct scsi_device *sdp = to_scsi_device(dev);



	/* Set module pointer as NULL in case of module unloading */

	if (!try_module_get(sdp->host->hostt->module))

		sdp->host->hostt->module = NULL;



	execute_in_process_context(scsi_device_dev_release_usercontext,

				   &sdp->ew);

}