scsi: core: Release SCSI devices synchronously

All upstream scsi_device_put() calls happen from thread context. Hence
simplify scsi_device_put() by always calling the release function
synchronously. This commit prepares for constifying the SCSI host template
by removing an assignment that clears the module pointer in the SCSI host
template.

scsi_device_dev_release_usercontext() was introduced in 2006 via
commit 65110b216895 ("[SCSI] fix wrong context bugs in SCSI").

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.garry@huawei.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221015002418.30955-9-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 9feb032..1426b9b 100644 (file)
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -588,6 +588,8 @@ void scsi_device_put(struct scsi_device *sdev)
 {
        struct module *mod = sdev->host->hostt->module;
 
+       might_sleep();
+
        put_device(&sdev->sdev_gendev);
        module_put(mod);
 }

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index c95177c..f2a345c 100644 (file)
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -441,20 +441,15 @@ static void scsi_device_cls_release(struct device *class_dev)
        put_device(&sdev->sdev_gendev);
 }
 
-static void scsi_device_dev_release_usercontext(struct work_struct *work)
+static void scsi_device_dev_release(struct device *dev)
 {
-       struct scsi_device *sdev;
+       struct scsi_device *sdev = to_scsi_device(dev);
        struct device *parent;
        struct list_head *this, *tmp;
        struct scsi_vpd *vpd_pg80 = NULL, *vpd_pg83 = NULL;
        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;
-
-       sdev = container_of(work, struct scsi_device, ew.work);
-
-       mod = sdev->host->hostt->module;
 
        scsi_dh_release_device(sdev);
 
@@ -518,19 +513,6 @@ 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);
 }
 
 static struct class sdev_class = {

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index c36656d..24bdbf7 100644 (file)
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -236,7 +236,6 @@ struct scsi_device {
        struct device           sdev_gendev,
                                sdev_dev;
 
-       struct execute_work     ew; /* used to get process context on put */
        struct work_struct      requeue_work;
 
        struct scsi_device_handler *handler;