kernel/kernel-rt/centos/patches/0016-Revert-commit-f049cf1a7b.patch

From b5dad6e67f9704968ca7d4daf1715667cddafa3d Mon Sep 17 00:00:00 2001
From: Jiping Ma <jiping.ma2@windriver.com>
Date: Wed, 8 Dec 2021 18:34:59 -0800
Subject: [PATCH 2/2] Revert commit f049cf1a7b

commit f049cf1a7b "scsi: sd: Rely on the driver core for asynchronous
probing"

This reverts commit f049cf1a7b6737c75884247c3f6383ef104d255a,
and it is a clean revert, there is not any conflict.

Signed-off-by: M. Vefa Bicakci <vefa.bicakci@windriver.com>
Signed-off-by: Jiping Ma <jiping.ma2@windriver.com>
---
 drivers/scsi/scsi.c      | 12 +++++++++---
 drivers/scsi/scsi_pm.c   |  6 +++++-
 drivers/scsi/scsi_priv.h |  1 +
 drivers/scsi/sd.c        | 12 +++++++++---
 4 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 24619c3bebd5..3080292a16cd 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -86,10 +86,15 @@ unsigned int scsi_logging_level;
 EXPORT_SYMBOL(scsi_logging_level);
 #endif
 
+/* sd, scsi core and power management need to coordinate flushing async actions */
+ASYNC_DOMAIN(scsi_sd_probe_domain);
+EXPORT_SYMBOL(scsi_sd_probe_domain);
+
 /*
- * Domain for asynchronous system resume operations.  It is marked 'exclusive'
- * to avoid being included in the async_synchronize_full() that is invoked by
- * dpm_resume().
+ * Separate domain (from scsi_sd_probe_domain) to maximize the benefit of
+ * asynchronous system resume operations.  It is marked 'exclusive' to avoid
+ * being included in the async_synchronize_full() that is invoked by
+ * dpm_resume()
  */
 ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain);
 EXPORT_SYMBOL(scsi_sd_pm_domain);
@@ -799,6 +804,7 @@ static void __exit exit_scsi(void)
 	scsi_exit_devinfo();
 	scsi_exit_procfs();
 	scsi_exit_queue();
+	async_unregister_domain(&scsi_sd_probe_domain);
 }
 
 subsys_initcall(init_scsi);
diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
index 3717eea37ecb..b3d71b516213 100644
--- a/drivers/scsi/scsi_pm.c
+++ b/drivers/scsi/scsi_pm.c
@@ -175,7 +175,11 @@ static int scsi_bus_resume_common(struct device *dev,
 
 static int scsi_bus_prepare(struct device *dev)
 {
-	if (scsi_is_host_device(dev)) {
+	if (scsi_is_sdev_device(dev)) {
+		/* sd probing uses async_schedule.  Wait until it finishes. */
+		async_synchronize_full_domain(&scsi_sd_probe_domain);
+
+	} else if (scsi_is_host_device(dev)) {
 		/* Wait until async scanning is finished */
 		scsi_complete_async_scans();
 	}
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 180636d54982..c43456f0870c 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -172,6 +172,7 @@ static inline void scsi_autopm_put_host(struct Scsi_Host *h) {}
 #endif /* CONFIG_PM */
 
 extern struct async_domain scsi_sd_pm_domain;
+extern struct async_domain scsi_sd_probe_domain;
 
 /* scsi_dh.c */
 #ifdef CONFIG_SCSI_DH
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 2e22ee4501e7..e6c70475f084 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -616,7 +616,6 @@ static struct scsi_driver sd_template = {
 		.name		= "sd",
 		.owner		= THIS_MODULE,
 		.probe		= sd_probe,
-		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
 		.remove		= sd_remove,
 		.shutdown	= sd_shutdown,
 		.pm		= &sd_pm_ops,
@@ -3364,8 +3363,12 @@ static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
 	return 0;
 }
 
-static void sd_probe_part2(struct scsi_disk *sdkp)
+/*
+ * The asynchronous part of sd_probe
+ */
+static void sd_probe_async(void *data, async_cookie_t cookie)
 {
+	struct scsi_disk *sdkp = data;
 	struct scsi_device *sdp;
 	struct gendisk *gd;
 	u32 index;
@@ -3424,6 +3427,7 @@ static void sd_probe_part2(struct scsi_disk *sdkp)
 	sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
 		  sdp->removable ? "removable " : "");
 	scsi_autopm_put_device(sdp);
+	put_device(&sdkp->dev);
 }
 
 /**
@@ -3517,7 +3521,8 @@ static int sd_probe(struct device *dev)
 
 	dev_set_drvdata(dev, sdkp);
 
-	sd_probe_part2(sdkp);
+	get_device(&sdkp->dev);	/* prevent release before async_schedule */
+	async_schedule_domain(sd_probe_async, sdkp, &scsi_sd_probe_domain);
 
 	return 0;
 
@@ -3554,6 +3559,7 @@ static int sd_remove(struct device *dev)
 	scsi_autopm_get_device(sdkp->device);
 
 	async_synchronize_full_domain(&scsi_sd_pm_domain);
+	async_synchronize_full_domain(&scsi_sd_probe_domain);
 	device_del(&sdkp->dev);
 	del_gendisk(sdkp->disk);
 	sd_shutdown(dev);
-- 
2.31.1