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authorMing Lei <ming.lei@redhat.com>2021-10-08 07:01:18 +0200
committerMartin K. Petersen <martin.petersen@oracle.com>2021-10-13 04:08:23 +0200
commitf2b85040acec9a928b4eb1b57a989324e8e38d3f (patch)
tree1dab47ff0d111341e0e51737e94fe6fbc4072a6b
parentscsi: storvsc: Fix validation for unsolicited incoming packets (diff)
downloadlinux-f2b85040acec9a928b4eb1b57a989324e8e38d3f.tar.xz
linux-f2b85040acec9a928b4eb1b57a989324e8e38d3f.zip
scsi: core: Put LLD module refcnt after SCSI device is released
SCSI host release is triggered when SCSI device is freed. We have to make sure that the low-level device driver module won't be unloaded before SCSI host instance is released because shost->hostt is required in the release handler. Make sure to put LLD module refcnt after SCSI device is released. Fixes a kernel panic of 'BUG: unable to handle page fault for address' reported by Changhui and Yi. Link: https://lore.kernel.org/r/20211008050118.1440686-1-ming.lei@redhat.com Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reported-by: Changhui Zhong <czhong@redhat.com> Reported-by: Yi Zhang <yi.zhang@redhat.com> Tested-by: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-rw-r--r--drivers/scsi/scsi.c4
-rw-r--r--drivers/scsi/scsi_sysfs.c9
2 files changed, 12 insertions, 1 deletions
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index b241f9e3885c..291ecc33b1fe 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -553,8 +553,10 @@ EXPORT_SYMBOL(scsi_device_get);
*/
void scsi_device_put(struct scsi_device *sdev)
{
- module_put(sdev->host->hostt->module);
+ struct module *mod = sdev->host->hostt->module;
+
put_device(&sdev->sdev_gendev);
+ module_put(mod);
}
EXPORT_SYMBOL(scsi_device_put);
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 86793259e541..a35841b34bfd 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -449,9 +449,12 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work)
struct scsi_vpd *vpd_pg80 = NULL, *vpd_pg83 = NULL;
struct scsi_vpd *vpd_pg0 = NULL, *vpd_pg89 = 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);
parent = sdev->sdev_gendev.parent;
@@ -502,11 +505,17 @@ 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);
}