From: Bart Van Assche <bvanassche@acm.org>
Date: Sat, 15 Oct 2022 00:24:17 +0000 (-0700)
Subject: scsi: core: Remove the put_device() call from scsi_device_get()
X-Git-Tag: v6.2-rc1~97^2~123
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=195fae206ef20a29b09f281b6db8ea30fafaa908;p=thirdparty%2Fkernel%2Flinux.git

scsi: core: Remove the put_device() call from scsi_device_get()

scsi_device_get() may be called from atomic context, e.g. by
shost_for_each_device(). A later commit will allow put_device() to sleep
for SCSI devices. Hence remove the put_device() call from
scsi_device_get().

According to Rusty Russell's "Module Refcount and Stuff mini-FAQ", calling
module_put() from atomic context is allowed since considerable time. See
also https://lkml.org/lkml/2002/11/18/330.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
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/20221015002418.30955-8-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 c59eac7a32f2a..9feb0323bc44a 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -563,14 +563,14 @@ int scsi_device_get(struct scsi_device *sdev)
 {
 	if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL)
 		goto fail;
-	if (!get_device(&sdev->sdev_gendev))
-		goto fail;
 	if (!try_module_get(sdev->host->hostt->module))
-		goto fail_put_device;
+		goto fail;
+	if (!get_device(&sdev->sdev_gendev))
+		goto fail_put_module;
 	return 0;
 
-fail_put_device:
-	put_device(&sdev->sdev_gendev);
+fail_put_module:
+	module_put(sdev->host->hostt->module);
 fail:
 	return -ENXIO;
 }