From 4c3c796aca02883ad35bb117468938cc4022ca41 Mon Sep 17 00:00:00 2001
From: Yuan Can <yuancan@huawei.com>
Date: Sat, 5 Nov 2022 09:43:22 +0000
Subject: [PATCH] ntb: intel: Fix error handling in intel_ntb_pci_driver_init()
Git-commit: 4c3c796aca02883ad35bb117468938cc4022ca41
Patch-mainline: v6.5-rc1
References: git-fixes

A problem about ntb_hw_intel create debugfs failed is triggered with the
following log given:

 [  273.112733] Intel(R) PCI-E Non-Transparent Bridge Driver 2.0
 [  273.115342] debugfs: Directory 'ntb_hw_intel' with parent '/' already present!

The reason is that intel_ntb_pci_driver_init() returns
pci_register_driver() directly without checking its return value, if
pci_register_driver() failed, it returns without destroy the newly created
debugfs, resulting the debugfs of ntb_hw_intel can never be created later.

 intel_ntb_pci_driver_init()
   debugfs_create_dir() # create debugfs directory
   pci_register_driver()
     driver_register()
       bus_add_driver()
         priv = kzalloc(...) # OOM happened
   # return without destroy debugfs directory

Fix by removing debugfs when pci_register_driver() returns error.

Fixes: e26a5843f7f5 ("NTB: Split ntb_hw_intel and ntb_transport drivers")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/ntb/hw/intel/ntb_hw_gen1.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/ntb/hw/intel/ntb_hw_gen1.c b/drivers/ntb/hw/intel/ntb_hw_gen1.c
index 84772013812b..60a4ebc7bf35 100644
--- a/drivers/ntb/hw/intel/ntb_hw_gen1.c
+++ b/drivers/ntb/hw/intel/ntb_hw_gen1.c
@@ -2064,12 +2064,17 @@ static struct pci_driver intel_ntb_pci_driver = {
 
 static int __init intel_ntb_pci_driver_init(void)
 {
+	int ret;
 	pr_info("%s %s\n", NTB_DESC, NTB_VER);
 
 	if (debugfs_initialized())
 		debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
 
-	return pci_register_driver(&intel_ntb_pci_driver);
+	ret = pci_register_driver(&intel_ntb_pci_driver);
+	if (ret)
+		debugfs_remove_recursive(debugfs_dir);
+
+	return ret;
 }
 module_init(intel_ntb_pci_driver_init);
 
-- 
2.35.3