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: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
[ bvanassche: Extracted this patch from a larger patch ]
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Ming Lei 2022-07-28 15:18:50 -07:00 committed by Martin K. Petersen
parent 16728aaba6
commit 1a9283782d
2 changed files with 6 additions and 12 deletions

View File

@ -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);

View File

@ -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);
}