Re: [PATCH 5.4.y] s390/dasd: Use correct lock while counting channel queue length

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
❌ Build failures detected
⚠️ Found matching upstream commit but patch is missing proper reference to it

Found matching upstream commit: ccc45cb4e7271c74dbb27776ae8f73d84557f5c6


Status in newer kernel trees:
6.13.y | Present (exact SHA1)
6.12.y | Present (exact SHA1)
6.6.y | Present (exact SHA1)
6.1.y | Present (different SHA1: 1e1e2ee0cf7f)

Note: The patch differs from the upstream commit:
---
Failed to apply patch cleanly.
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.4.y        |  Failed     |  N/A       |

Build Errors:
Patch failed to apply on stable/linux-5.4.y. Reject:

diff a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c	(rejected hunks)
@@ -516,10 +516,10 @@ static int dasd_ioctl_information(struct dasd_block *block,
 
 	memcpy(dasd_info->type, base->discipline->name, 4);
 
-	spin_lock_irqsave(&block->queue_lock, flags);
+	spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
 	list_for_each(l, &base->ccw_queue)
 		dasd_info->chanq_len++;
-	spin_unlock_irqrestore(&block->queue_lock, flags);
+	spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
 
 	rc = 0;
 	if (copy_to_user(argp, dasd_info,