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mei: no need to check return value of debugfs_create functions

PATCH Superseded Greg Kroah-Hartman 2 participants 5 messages Jun 11, 2019 – Jun 19, 2019

Subsystems (4)
Char and misc drivers Intel management engine (mei) Genwqe (IBM Generic Workqueue Card) VMware balloon driver
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Greg Kroah-Hartman

author maintainer
#0 lore raw

PATCH 1/1 mei: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this.

Cc Tomas Winkler <[email protected]>
Cc Arnd Bergmann <[email protected]>
Cc [email protected]
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/misc/genwqe/card_base.c      |   5 -
 drivers/misc/genwqe/card_base.h      |   2 +-
 drivers/misc/genwqe/card_debugfs.c   | 165 +++++----------------------
 drivers/misc/genwqe/card_dev.c       |   6 +-
 drivers/misc/mei/debugfs.c           |  47 ++------
 drivers/misc/mei/main.c              |   8 +-
 drivers/misc/mei/mei_dev.h           |   7 +-
 drivers/misc/mic/card/mic_debugfs.c  |  18 +--
 drivers/misc/mic/cosm/cosm_debugfs.c |   4 -
 drivers/misc/mic/host/mic_debugfs.c  |   4 -
 drivers/misc/mic/scif/scif_debugfs.c |   5 -
 drivers/misc/mic/vop/vop_debugfs.c   |   4 -
 drivers/misc/ti-st/st_kim.c          |   4 -
 drivers/misc/vmw_balloon.c           |  19 +--
 14 files changed, 51 insertions(+), 247 deletions(-)
drivers/misc/genwqe/card_base.c +0 -5
index d137d0fab9bf..f9f329651037 100644
@@ -1377,10 +1377,6 @@ static int __init genwqe_init_module(void)
 	class_genwqe->devnode = genwqe_devnode;
 
 	debugfs_genwqe = debugfs_create_dir(GENWQE_DEVNAME, NULL);
-	if (!debugfs_genwqe) {
-		rc = -ENOMEM;
-		goto err_out;
-	}
 
 	rc = pci_register_driver(&genwqe_driver);
 	if (rc != 0) {

@@ -1392,7 +1388,6 @@ static int __init genwqe_init_module(void)
 
  err_out0:
 	debugfs_remove(debugfs_genwqe);
- err_out:
 	class_destroy(class_genwqe);
 	return rc;
 }
drivers/misc/genwqe/card_base.h +1 -1
index 77ed3967c5b0..d9e4a6e5fe3c 100644
@@ -445,7 +445,7 @@ int  genwqe_device_create(struct genwqe_dev *cd);
 int  genwqe_device_remove(struct genwqe_dev *cd);
 
 /* debugfs */
-int  genwqe_init_debugfs(struct genwqe_dev *cd);
+void genwqe_init_debugfs(struct genwqe_dev *cd);
 void genqwe_exit_debugfs(struct genwqe_dev *cd);
 
 int  genwqe_read_softreset(struct genwqe_dev *cd);
drivers/misc/genwqe/card_debugfs.c +30 -135

194 lines not on this page · raw message

drivers/misc/genwqe/card_dev.c +1 -5
index 8c1b63a4337b..b5942e8943ef 100644
@@ -1307,14 +1307,10 @@ int genwqe_device_create(struct genwqe_dev *cd)
 		goto err_cdev;
 	}
 
-	rc = genwqe_init_debugfs(cd);
-	if (rc != 0)
-		goto err_debugfs;
+	genwqe_init_debugfs(cd);
 
 	return 0;
 
- err_debugfs:
-	device_destroy(cd->class_genwqe, cd->devnum_genwqe);
  err_cdev:
 	cdev_del(&cd->cdev_genwqe);
  err_add:
drivers/misc/mei/debugfs.c +11 -36

58 lines not on this page · raw message

drivers/misc/mei/main.c +1 -7
index ad02097d7fee..f894d1f8a53e 100644
@@ -984,16 +984,10 @@ int mei_register(struct mei_device *dev, struct device *parent)
 		goto err_dev_create;
 	}
 
-	ret = mei_dbgfs_register(dev, dev_name(clsdev));
-	if (ret) {
-		dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
-		goto err_dev_dbgfs;
-	}
+	mei_dbgfs_register(dev, dev_name(clsdev));
 
 	return 0;
 
-err_dev_dbgfs:
-	device_destroy(mei_class, devno);
 err_dev_create:
 	cdev_del(&dev->cdev);
 err_dev_add:
drivers/misc/mei/mei_dev.h +2 -5
index fca832fcac57..f71a023aed3c 100644
@@ -718,13 +718,10 @@ bool mei_hbuf_acquire(struct mei_device *dev);
 bool mei_write_is_idle(struct mei_device *dev);
 
 #if IS_ENABLED(CONFIG_DEBUG_FS)
-int mei_dbgfs_register(struct mei_device *dev, const char *name);
+void mei_dbgfs_register(struct mei_device *dev, const char *name);
 void mei_dbgfs_deregister(struct mei_device *dev);
 #else
-static inline int mei_dbgfs_register(struct mei_device *dev, const char *name)
-{
-	return 0;
-}
+static inline void mei_dbgfs_register(struct mei_device *dev, const char *name) {}
 static inline void mei_dbgfs_deregister(struct mei_device *dev) {}
 #endif /* CONFIG_DEBUG_FS */
drivers/misc/mic/card/mic_debugfs.c +2 -16
index 7a4140874888..fa2b5fefb791 100644
@@ -63,25 +63,13 @@ DEFINE_SHOW_ATTRIBUTE(mic_intr);
  */
 void __init mic_create_card_debug_dir(struct mic_driver *mdrv)
 {
-	struct dentry *d;
-
 	if (!mic_dbg)
 		return;
 
 	mdrv->dbg_dir = debugfs_create_dir(mdrv->name, mic_dbg);
-	if (!mdrv->dbg_dir) {
-		dev_err(mdrv->dev, "Cant create dbg_dir %s\n", mdrv->name);
-		return;
-	}
-
-	d = debugfs_create_file("intr_test", 0444, mdrv->dbg_dir,
-		mdrv, &mic_intr_fops);
 
-	if (!d) {
-		dev_err(mdrv->dev,
-			"Cant create dbg intr_test %s\n", mdrv->name);
-		return;
-	}
+	debugfs_create_file("intr_test", 0444, mdrv->dbg_dir, mdrv,
+			    &mic_intr_fops);
 }
 
 /**

@@ -101,8 +89,6 @@ void mic_delete_card_debug_dir(struct mic_driver *mdrv)
 void __init mic_init_card_debugfs(void)
 {
 	mic_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
-	if (!mic_dbg)
-		pr_err("can't create debugfs dir\n");
 }
 
 /**
drivers/misc/mic/cosm/cosm_debugfs.c +0 -4
index 71c216d0504d..340ea7171411 100644
@@ -105,8 +105,6 @@ void cosm_create_debug_dir(struct cosm_device *cdev)
 
 	scnprintf(name, sizeof(name), "mic%d", cdev->index);
 	cdev->dbg_dir = debugfs_create_dir(name, cosm_dbg);
-	if (!cdev->dbg_dir)
-		return;
 
 	debugfs_create_file("log_buf", 0444, cdev->dbg_dir, cdev,
 			    &log_buf_fops);

@@ -125,8 +123,6 @@ void cosm_delete_debug_dir(struct cosm_device *cdev)
 void cosm_init_debugfs(void)
 {
 	cosm_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
-	if (!cosm_dbg)
-		pr_err("can't create debugfs dir\n");
 }
 
 void cosm_exit_debugfs(void)
drivers/misc/mic/host/mic_debugfs.c +0 -4
index c6e3c764699f..370f98c7b752 100644
@@ -125,8 +125,6 @@ void mic_create_debug_dir(struct mic_device *mdev)
 
 	scnprintf(name, sizeof(name), "mic%d", mdev->id);
 	mdev->dbg_dir = debugfs_create_dir(name, mic_dbg);
-	if (!mdev->dbg_dir)
-		return;
 
 	debugfs_create_file("smpt", 0444, mdev->dbg_dir, mdev,
 			    &mic_smpt_fops);

@@ -155,8 +153,6 @@ void mic_delete_debug_dir(struct mic_device *mdev)
 void __init mic_init_debugfs(void)
 {
 	mic_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
-	if (!mic_dbg)
-		pr_err("can't create debugfs dir\n");
 }
 
 /**
drivers/misc/mic/scif/scif_debugfs.c +0 -5
index a6820480105a..8fe38e7ca6e6 100644
@@ -103,11 +103,6 @@ DEFINE_SHOW_ATTRIBUTE(scif_rma);
 void __init scif_init_debugfs(void)
 {
 	scif_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
-	if (!scif_dbg) {
-		dev_err(scif_info.mdev.this_device,
-			"can't create debugfs dir scif\n");
-		return;
-	}
 
 	debugfs_create_file("scif_dev", 0444, scif_dbg, NULL, &scif_dev_fops);
 	debugfs_create_file("scif_rma", 0444, scif_dbg, NULL, &scif_rma_fops);
drivers/misc/mic/vop/vop_debugfs.c +0 -4
index 2ccef52aca23..d4551d522188 100644
@@ -186,10 +186,6 @@ void vop_init_debugfs(struct vop_info *vi)
 
 	snprintf(name, sizeof(name), "%s%d", KBUILD_MODNAME, vi->vpdev->dnode);
 	vi->dbg = debugfs_create_dir(name, NULL);
-	if (!vi->dbg) {
-		pr_err("can't create debugfs dir vop\n");
-		return;
-	}
 	debugfs_create_file("dp", 0444, vi->dbg, vi, &vop_dp_fops);
 	debugfs_create_file("vdev_info", 0444, vi->dbg, vi, &vop_vdev_info_fops);
 }
drivers/misc/ti-st/st_kim.c +0 -4
index e7cfdbd1f66d..93821c11bff9 100644
@@ -761,10 +761,6 @@ static int kim_probe(struct platform_device *pdev)
 	pr_info("sysfs entries created\n");
 
 	kim_debugfs_dir = debugfs_create_dir("ti-st", NULL);
-	if (!kim_debugfs_dir) {
-		pr_err(" debugfs entries creation failed ");
-		return 0;
-	}
 
 	debugfs_create_file("version", S_IRUGO, kim_debugfs_dir,
 				kim_gdata, &version_fops);
drivers/misc/vmw_balloon.c +3 -16
index ad807d5a3141..fdf5ad757226 100644
@@ -1516,19 +1516,10 @@ static int vmballoon_debug_show(struct seq_file *f, void *offset)
 
 DEFINE_SHOW_ATTRIBUTE(vmballoon_debug);
 
-static int __init vmballoon_debugfs_init(struct vmballoon *b)
+static void __init vmballoon_debugfs_init(struct vmballoon *b)
 {
-	int error;
-
 	b->dbg_entry = debugfs_create_file("vmmemctl", S_IRUGO, NULL, b,
 					   &vmballoon_debug_fops);
-	if (IS_ERR(b->dbg_entry)) {
-		error = PTR_ERR(b->dbg_entry);
-		pr_err("failed to create debugfs entry, error: %d\n", error);
-		return error;
-	}
-
-	return 0;
 }
 
 static void __exit vmballoon_debugfs_exit(struct vmballoon *b)

@@ -1541,9 +1532,8 @@ static void __exit vmballoon_debugfs_exit(struct vmballoon *b)
 
 #else
 
-static inline int vmballoon_debugfs_init(struct vmballoon *b)
+static inline void vmballoon_debugfs_init(struct vmballoon *b)
 {
-	return 0;
 }
 
 static inline void vmballoon_debugfs_exit(struct vmballoon *b)

@@ -1555,7 +1545,6 @@ static inline void vmballoon_debugfs_exit(struct vmballoon *b)
 static int __init vmballoon_init(void)
 {
 	enum vmballoon_page_size_type page_size;
-	int error;
 
 	/*
 	 * Check if we are running on VMware's hypervisor and bail out

@@ -1571,9 +1560,7 @@ static int __init vmballoon_init(void)
 
 	INIT_DELAYED_WORK(&balloon.dwork, vmballoon_work);
 
-	error = vmballoon_debugfs_init(&balloon);
-	if (error)
-		return error;
+	vmballoon_debugfs_init(&balloon);
 
 	spin_lock_init(&balloon.comm_lock);
 	init_rwsem(&balloon.conf_sem);
Signature · 1 line
2.22.0
author maintainer
#1 lore raw
Quoted 8 lines · Greg Kroah-Hartman

When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this.

Cc Tomas Winkler <[email protected]>
Cc Arnd Bergmann <[email protected]>
Cc [email protected]
Signed-off-by Greg Kroah-Hartman <[email protected]>
Quoted 16 lines
---
 drivers/misc/genwqe/card_base.c      |   5 -
 drivers/misc/genwqe/card_base.h      |   2 +-
 drivers/misc/genwqe/card_debugfs.c   | 165 +++++----------------------
 drivers/misc/genwqe/card_dev.c       |   6 +-
 drivers/misc/mei/debugfs.c           |  47 ++------
 drivers/misc/mei/main.c              |   8 +-
 drivers/misc/mei/mei_dev.h           |   7 +-
 drivers/misc/mic/card/mic_debugfs.c  |  18 +--
 drivers/misc/mic/cosm/cosm_debugfs.c |   4 -
 drivers/misc/mic/host/mic_debugfs.c  |   4 -
 drivers/misc/mic/scif/scif_debugfs.c |   5 -
 drivers/misc/mic/vop/vop_debugfs.c   |   4 -
 drivers/misc/ti-st/st_kim.c          |   4 -
 drivers/misc/vmw_balloon.c           |  19 +--
 14 files changed, 51 insertions(+), 247 deletions(-)

Ugh, nope, wrong patch, need to break this one up, sorry...

greg k-h

author maintainer
#2 lore raw

PATCH v2 1/1 mei: no need to check return value of debugfs_create functions

In reply to Greg Kroah-Hartman

When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this.

Cc Tomas Winkler <[email protected]>
Cc Arnd Bergmann <[email protected]>
Cc [email protected]
Signed-off-by Greg Kroah-Hartman <[email protected]>

---
v2: break the patch up properly

 drivers/misc/mei/debugfs.c | 47 +++++++++-----------------------------
 drivers/misc/mei/main.c    |  8 +------
 drivers/misc/mei/mei_dev.h |  7 ++----
 3 files changed, 14 insertions(+), 48 deletions(-)
drivers/misc/mei/debugfs.c +11 -36
index 0970142bcace..df6bf8b81936 100644
@@ -233,47 +233,22 @@ void mei_dbgfs_deregister(struct mei_device *dev)
  *
  * @dev: the mei device structure
  * @name: the mei device name
- *
- * Return: 0 on success, <0 on failure.
  */
-int mei_dbgfs_register(struct mei_device *dev, const char *name)
+void mei_dbgfs_register(struct mei_device *dev, const char *name)
 {
-	struct dentry *dir, *f;
+	struct dentry *dir;
 
 	dir = debugfs_create_dir(name, NULL);
-	if (!dir)
-		return -ENOMEM;
-
 	dev->dbgfs_dir = dir;
 
-	f = debugfs_create_file("meclients", S_IRUSR, dir,
-				dev, &mei_dbgfs_fops_meclients);
-	if (!f) {
-		dev_err(dev->dev, "meclients: registration failed\n");
-		goto err;
-	}
-	f = debugfs_create_file("active", S_IRUSR, dir,
-				dev, &mei_dbgfs_fops_active);
-	if (!f) {
-		dev_err(dev->dev, "active: registration failed\n");
-		goto err;
-	}
-	f = debugfs_create_file("devstate", S_IRUSR, dir,
-				dev, &mei_dbgfs_fops_devstate);
-	if (!f) {
-		dev_err(dev->dev, "devstate: registration failed\n");
-		goto err;
-	}
-	f = debugfs_create_file("allow_fixed_address", S_IRUSR | S_IWUSR, dir,
-				&dev->allow_fixed_address,
-				&mei_dbgfs_fops_allow_fa);
-	if (!f) {
-		dev_err(dev->dev, "allow_fixed_address: registration failed\n");
-		goto err;
-	}
-	return 0;
-err:
-	mei_dbgfs_deregister(dev);
-	return -ENODEV;
+	debugfs_create_file("meclients", S_IRUSR, dir, dev,
+			    &mei_dbgfs_fops_meclients);
+	debugfs_create_file("active", S_IRUSR, dir, dev,
+			    &mei_dbgfs_fops_active);
+	debugfs_create_file("devstate", S_IRUSR, dir, dev,
+			    &mei_dbgfs_fops_devstate);
+	debugfs_create_file("allow_fixed_address", S_IRUSR | S_IWUSR, dir,
+			    &dev->allow_fixed_address,
+			    &mei_dbgfs_fops_allow_fa);
 }
drivers/misc/mei/main.c +1 -7
index ad02097d7fee..f894d1f8a53e 100644
@@ -984,16 +984,10 @@ int mei_register(struct mei_device *dev, struct device *parent)
 		goto err_dev_create;
 	}
 
-	ret = mei_dbgfs_register(dev, dev_name(clsdev));
-	if (ret) {
-		dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
-		goto err_dev_dbgfs;
-	}
+	mei_dbgfs_register(dev, dev_name(clsdev));
 
 	return 0;
 
-err_dev_dbgfs:
-	device_destroy(mei_class, devno);
 err_dev_create:
 	cdev_del(&dev->cdev);
 err_dev_add:
drivers/misc/mei/mei_dev.h +2 -5
index fca832fcac57..f71a023aed3c 100644
@@ -718,13 +718,10 @@ bool mei_hbuf_acquire(struct mei_device *dev);
 bool mei_write_is_idle(struct mei_device *dev);
 
 #if IS_ENABLED(CONFIG_DEBUG_FS)
-int mei_dbgfs_register(struct mei_device *dev, const char *name);
+void mei_dbgfs_register(struct mei_device *dev, const char *name);
 void mei_dbgfs_deregister(struct mei_device *dev);
 #else
-static inline int mei_dbgfs_register(struct mei_device *dev, const char *name)
-{
-	return 0;
-}
+static inline void mei_dbgfs_register(struct mei_device *dev, const char *name) {}
 static inline void mei_dbgfs_deregister(struct mei_device *dev) {}
 #endif /* CONFIG_DEBUG_FS */
Signature · 1 line
2.22.0
#3 lore raw
Quoted 4 lines

When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this.

Maybe need to mention that API has changed in patch ' ff9fb72bc07705c00795ca48631f7fffe24d2c6b' in 5.0 and create_dir() doesn't return NULL but ERR_PTR() and proper checking is done inside the debugfs functions. Not sure how critical is that but, but this should go probably to stable 5.0+ as well.
Ack otherwise.

Quoted 122 lines
Cc Tomas Winkler <[email protected]>
Cc Arnd Bergmann <[email protected]>
Cc [email protected]
Signed-off-by Greg Kroah-Hartman <[email protected]>

---
v2: break the patch up properly

 drivers/misc/mei/debugfs.c | 47 +++++++++-----------------------------
 drivers/misc/mei/main.c    |  8 +------
 drivers/misc/mei/mei_dev.h |  7 ++----
 3 files changed, 14 insertions(+), 48 deletions(-)
drivers/misc/mei/debugfs.c index renamed from drivers/misc/mei/debugfs.c +0 -0

0970142bcace..df6bf8b81936 100644

drivers/misc/mei/debugfs.c +11 -36
@@ -233,47 +233,22 @@ void mei_dbgfs_deregister(struct mei_device *dev)
  *
  * @dev: the mei device structure
  * @name: the mei device name
- *
- * Return: 0 on success, <0 on failure.
  */
-int mei_dbgfs_register(struct mei_device *dev, const char *name)
+void mei_dbgfs_register(struct mei_device *dev, const char *name)
 {
-	struct dentry *dir, *f;
+	struct dentry *dir;
 
 	dir = debugfs_create_dir(name, NULL);
-	if (!dir)
-		return -ENOMEM;
-
 	dev->dbgfs_dir = dir;
 
-	f = debugfs_create_file("meclients", S_IRUSR, dir,
-				dev, &mei_dbgfs_fops_meclients);
-	if (!f) {
-		dev_err(dev->dev, "meclients: registration failed\n");
-		goto err;
-	}
-	f = debugfs_create_file("active", S_IRUSR, dir,
-				dev, &mei_dbgfs_fops_active);
-	if (!f) {
-		dev_err(dev->dev, "active: registration failed\n");
-		goto err;
-	}
-	f = debugfs_create_file("devstate", S_IRUSR, dir,
-				dev, &mei_dbgfs_fops_devstate);
-	if (!f) {
-		dev_err(dev->dev, "devstate: registration failed\n");
-		goto err;
-	}
-	f = debugfs_create_file("allow_fixed_address", S_IRUSR | S_IWUSR,
 dir,
-				&dev->allow_fixed_address,
-				&mei_dbgfs_fops_allow_fa);
-	if (!f) {
-		dev_err(dev->dev, "allow_fixed_address: registration
 failed\n");
-		goto err;
-	}
-	return 0;
-err:
-	mei_dbgfs_deregister(dev);
-	return -ENODEV;
+	debugfs_create_file("meclients", S_IRUSR, dir, dev,
+			    &mei_dbgfs_fops_meclients);
+	debugfs_create_file("active", S_IRUSR, dir, dev,
+			    &mei_dbgfs_fops_active);
+	debugfs_create_file("devstate", S_IRUSR, dir, dev,
+			    &mei_dbgfs_fops_devstate);
+	debugfs_create_file("allow_fixed_address", S_IRUSR | S_IWUSR, dir,
+			    &dev->allow_fixed_address,
+			    &mei_dbgfs_fops_allow_fa);

}

drivers/misc/mei/main.c index renamed from drivers/misc/mei/main.c +0 -0

ad02097d7fee..f894d1f8a53e 100644

drivers/misc/mei/main.c +1 -7
@@ -984,16 +984,10 @@ int mei_register(struct mei_device *dev, struct
 device *parent)
 		goto err_dev_create;
 	}
 
-	ret = mei_dbgfs_register(dev, dev_name(clsdev));
-	if (ret) {
-		dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
-		goto err_dev_dbgfs;
-	}
+	mei_dbgfs_register(dev, dev_name(clsdev));
 
 	return 0;
 
-err_dev_dbgfs:
-	device_destroy(mei_class, devno);
 err_dev_create:
 	cdev_del(&dev->cdev);

err_dev_add:

drivers/misc/mei/mei_dev.h index renamed from drivers/misc/mei/mei_dev.h +0 -0

fca832fcac57..f71a023aed3c 100644

drivers/misc/mei/mei_dev.h +3 -3
@@ -718,13 +718,10 @@ bool mei_hbuf_acquire(struct mei_device *dev);
 bool mei_write_is_idle(struct mei_device *dev);
 
 #if IS_ENABLED(CONFIG_DEBUG_FS)
-int mei_dbgfs_register(struct mei_device *dev, const char *name);
+void mei_dbgfs_register(struct mei_device *dev, const char *name);
 void mei_dbgfs_deregister(struct mei_device *dev);  #else -static inline int
 mei_dbgfs_register(struct mei_device *dev, const char *name) -{
-	return 0;
-}
+static inline void mei_dbgfs_register(struct mei_device *dev, const
+char *name) {}
 static inline void mei_dbgfs_deregister(struct mei_device *dev) {}  #endif /*

CONFIG_DEBUG_FS */

--
2.22.0

author maintainer
#4 lore raw
Quoted 8 lines · Tomas
Quoted 4 lines

When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this.

Maybe need to mention that API has changed in patch ' ff9fb72bc07705c00795ca48631f7fffe24d2c6b' in 5.0 and create_dir() doesn't return NULL but ERR_PTR() and proper checking is done inside the debugfs functions. Not sure how critical is that but, but this should go probably to stable 5.0+ as well.

It's not critical at all, the odds of an error ever returning, or NULL, from debugfs before is just as rare as it is today :)

Quoted 1 line

Ack otherwise.

great, thanks for reviewing it.

greg k-h