[PATCH] SYSFS: Allow boot time switching between deprecated and modern sysfs layout

[PATCH] SYSFS: Allow boot time switching between deprecated and modern sysfs layout

[Andi Kleen]

From: Andi Kleen <ak@linux.intel.com>

I have some systems which need legacy sysfs due to old udev versions,
and it's a big hazzle to compile separate kernels for them.

This patch turns CONFIG_SYSFS_DEPRECATED into a run time option
that can be switched on/off the kernel command line. This way
the same binary can be used in both cases with just a option
on the command line.

The old CONFIG_SYSFS_DEPRECATED_V2 option is still there to set
the default. I kept the weird name to not break existing
config files.

Also the compat code can be still completely disabled by undefining
CONFIG_SYSFS_DEPRECATED_SWITCH -- just the optimizer takes
care of this now instead of lots of ifdefs. This makes the code
look nicer.

This is a tree sweep for core/scsi/block/sound/core. There weren't
that many users and the changes were straight forward so I just did them
all in one go without splitting up.

Cc: axboe@kernel.dk
Cc: tiwai@suse.de
Cc: James.Bottomley@HansenPartnership.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 Documentation/kernel-parameters.txt |    9 ++
 block/genhd.c                       |    8 +-
 drivers/base/bus.c                  |   12 ++--
 drivers/base/class.c                |    6 +-
 drivers/base/core.c                 |  150 +++++++++++++++++++++--------------
 drivers/scsi/hosts.c                |    5 +-
 drivers/scsi/scsi_scan.c            |    5 +-
 fs/partitions/check.c               |   19 ++---
 include/linux/device.h              |    7 ++
 include/sound/core.h                |   10 +--
 init/Kconfig                        |   30 +++++--
 sound/core/init.c                   |   14 +---
 12 files changed, 158 insertions(+), 117 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index f084af0..a452600 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2357,6 +2357,15 @@ and is between 256 and 4096 characters. It is defined in the file
 
 	switches=	[HW,M68k]
 
+	sysfs.deprecated=0|1 [KNL] 
+			Enable/disable old style sysfs layout for old udev
+			on older distributions. When this option is enabled
+			very new udev will not work anymore. When this option
+			is disabled (or CONFIG_SYSFS_DEPRECATED not compiled)
+			in older udev will not work anymore.
+			Default depends on CONFIG_SYSFS_DEPRECATED_V2 set in 
+			the kernel configuration.
+
 	sysrq_always_enabled
 			[KNL]
 			Ignore sysrq setting - this boot parameter will
diff --git a/block/genhd.c b/block/genhd.c
index 59a2db6..d0b9f83 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -18,13 +18,12 @@
 #include <linux/buffer_head.h>
 #include <linux/mutex.h>
 #include <linux/idr.h>
+#include <linux/device.h>
 
 #include "blk.h"
 
 static DEFINE_MUTEX(block_class_lock);
-#ifndef CONFIG_SYSFS_DEPRECATED
 struct kobject *block_depr;
-#endif
 
 /* for extended dynamic devt allocation, currently only one major is used */
 #define MAX_EXT_DEVT		(1 << MINORBITS)
@@ -803,10 +802,9 @@ static int __init genhd_device_init(void)
 
 	register_blkdev(BLOCK_EXT_MAJOR, "blkext");
 
-#ifndef CONFIG_SYSFS_DEPRECATED
 	/* create top-level block dir */
-	block_depr = kobject_create_and_add("block", NULL);
-#endif
+	if (!sysfs_deprecated)
+		block_depr = kobject_create_and_add("block", NULL);
 	return 0;
 }
 
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index eb1b7fa..36a535f 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -16,6 +16,7 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/string.h>
+#include <linux/device.h>
 #include "base.h"
 #include "power/power.h"
 
@@ -440,21 +441,20 @@ static void device_remove_attrs(struct bus_type *bus, struct device *dev)
 	}
 }
 
-#ifdef CONFIG_SYSFS_DEPRECATED
 static int make_deprecated_bus_links(struct device *dev)
 {
+	if (!sysfs_deprecated)
+		return 0;
+
 	return sysfs_create_link(&dev->kobj,
 				 &dev->bus->p->subsys.kobj, "bus");
 }
 
 static void remove_deprecated_bus_links(struct device *dev)
 {
-	sysfs_remove_link(&dev->kobj, "bus");
+	if (sysfs_deprecated)
+		sysfs_remove_link(&dev->kobj, "bus");
 }
-#else
-static inline int make_deprecated_bus_links(struct device *dev) { return 0; }
-static inline void remove_deprecated_bus_links(struct device *dev) { }
-#endif
 
 /**
  * bus_add_device - add device to bus
diff --git a/drivers/base/class.c b/drivers/base/class.c
index 8e231d0..0433d27 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -184,9 +184,9 @@ int __class_register(struct class *cls, struct lock_class_key *key)
 	if (!cls->dev_kobj)
 		cls->dev_kobj = sysfs_dev_char_kobj;
 
-#if defined(CONFIG_SYSFS_DEPRECATED) && defined(CONFIG_BLOCK)
+#if defined(CONFIG_BLOCK)
 	/* let the block class directory show up in the root of sysfs */
-	if (cls != &block_class)
+	if (sysfs_deprecated && cls != &block_class)
 		cp->class_subsys.kobj.kset = class_kset;
 #else
 	cp->class_subsys.kobj.kset = class_kset;
@@ -276,7 +276,7 @@ void class_destroy(struct class *cls)
 	class_unregister(cls);
 }
 
-#ifdef CONFIG_SYSFS_DEPRECATED
+#ifdef CONFIG_SYSFS_DEPRECATED_SWITCH
 char *make_class_name(const char *name, struct kobject *kobj)
 {
 	char *class_name;
diff --git a/drivers/base/core.c b/drivers/base/core.c
index d1b2c9a..c8bf261 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -26,6 +26,21 @@
 #include "base.h"
 #include "power/power.h"
 
+#ifdef CONFIG_SYSFS_DEPRECATED_SWITCH
+#ifdef CONFIG_SYSFS_DEPRECATED_V2
+long sysfs_deprecated = 1;
+#else
+long sysfs_deprecated = 0;
+#endif
+
+static __init int setup_sysfs_deprecated(char *arg)
+{
+	return strict_strtol(arg, 10, &sysfs_deprecated);
+}
+
+early_param("sysfs.deprecated", setup_sysfs_deprecated);
+#endif
+
 int (*platform_notify)(struct device *dev) = NULL;
 int (*platform_notify_remove)(struct device *dev) = NULL;
 static struct kobject *dev_kobj;
@@ -203,8 +218,7 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj,
 	if (dev->driver)
 		add_uevent_var(env, "DRIVER=%s", dev->driver->name);
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	if (dev->class) {
+	if (sysfs_deprecated && dev->class) {
 		struct device *parent = dev->parent;
 
 		/* find first bus device in parent chain */
@@ -232,7 +246,6 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj,
 			add_uevent_var(env, "PHYSDEVDRIVER=%s",
 				       dev->driver->name);
 	}
-#endif
 
 	/* have the bus specific function add its stuff */
 	if (dev->bus && dev->bus->uevent) {
@@ -578,8 +591,7 @@ void device_initialize(struct device *dev)
 	set_dev_node(dev, -1);
 }
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-static struct kobject *get_device_parent(struct device *dev,
+static struct kobject *deprecated_get_device_parent(struct device *dev,
 					 struct device *parent)
 {
 	/* class devices without a parent live in /sys/class/<classname>/ */
@@ -592,10 +604,6 @@ static struct kobject *get_device_parent(struct device *dev,
 	return NULL;
 }
 
-static inline void cleanup_device_parent(struct device *dev) {}
-static inline void cleanup_glue_dir(struct device *dev,
-				    struct kobject *glue_dir) {}
-#else
 static struct kobject *virtual_device_parent(struct device *dev)
 {
 	static struct kobject *virtual_dir = NULL;
@@ -660,6 +668,9 @@ class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
 static struct kobject *get_device_parent(struct device *dev,
 					 struct device *parent)
 {
+	if (sysfs_deprecated)
+		return deprecated_get_device_parent(dev, parent);
+
 	if (dev->class) {
 		static DEFINE_MUTEX(gdp_mutex);
 		struct kobject *kobj = NULL;
@@ -707,6 +718,9 @@ static struct kobject *get_device_parent(struct device *dev,
 
 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 {
+	if (sysfs_deprecated)
+		return;
+
 	/* see if we live in a "glue" directory */
 	if (!glue_dir || !dev->class ||
 	    glue_dir->kset != &dev->class->p->class_dirs)
@@ -717,9 +731,9 @@ static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 
 static void cleanup_device_parent(struct device *dev)
 {
-	cleanup_glue_dir(dev, dev->kobj.parent);
+	if (!sysfs_deprecated)
+		cleanup_glue_dir(dev, dev->kobj.parent);
 }
-#endif
 
 static void setup_parent(struct device *dev, struct device *parent)
 {
@@ -729,27 +743,17 @@ static void setup_parent(struct device *dev, struct device *parent)
 		dev->kobj.parent = kobj;
 }
 
-static int device_add_class_symlinks(struct device *dev)
+static int deprecated_device_add_class_symlinks(struct device *dev)
 {
 	int error;
 
-	if (!dev->class)
-		return 0;
-
-	error = sysfs_create_link(&dev->kobj,
-				  &dev->class->p->class_subsys.kobj,
-				  "subsystem");
-	if (error)
-		goto out;
-
-#ifdef CONFIG_SYSFS_DEPRECATED
 	/* stacked class devices need a symlink in the class directory */
 	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
 	    device_is_not_partition(dev)) {
 		error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
 					  &dev->kobj, dev_name(dev));
 		if (error)
-			goto out_subsys;
+			return error;
 	}
 
 	if (dev->parent && device_is_not_partition(dev)) {
@@ -788,37 +792,52 @@ out_busid:
 	    device_is_not_partition(dev))
 		sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj,
 				  dev_name(dev));
-#else
-	/* link in the class directory pointing to the device */
-	error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
-				  &dev->kobj, dev_name(dev));
+	return error;
+}
+
+static int device_add_class_symlinks(struct device *dev)
+{
+	int error;
+
+	if (!dev->class)
+		return 0;
+
+	error = sysfs_create_link(&dev->kobj,
+				  &dev->class->p->class_subsys.kobj,
+				  "subsystem");
 	if (error)
-		goto out_subsys;
+		goto out;
 
-	if (dev->parent && device_is_not_partition(dev)) {
-		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
-					  "device");
+	if (sysfs_deprecated) { 
+		error = deprecated_device_add_class_symlinks(dev);
+		if (error) 
+			goto out_subsys;
+	} else {
+		/* link in the class directory pointing to the device */
+		error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
+					  &dev->kobj, dev_name(dev));
 		if (error)
-			goto out_busid;
+			goto out_subsys;
+
+		if (dev->parent && device_is_not_partition(dev)) {
+			error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
+						  "device");
+			if (error)
+				goto out_busid;
+		}
 	}
 	return 0;
 
 out_busid:
 	sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj, dev_name(dev));
-#endif
-
 out_subsys:
 	sysfs_remove_link(&dev->kobj, "subsystem");
 out:
 	return error;
 }
 
-static void device_remove_class_symlinks(struct device *dev)
+static void deprecated_device_remove_class_symlinks(struct device *dev)
 {
-	if (!dev->class)
-		return;
-
-#ifdef CONFIG_SYSFS_DEPRECATED
 	if (dev->parent && device_is_not_partition(dev)) {
 		char *class_name;
 
@@ -834,12 +853,21 @@ static void device_remove_class_symlinks(struct device *dev)
 	    device_is_not_partition(dev))
 		sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj,
 				  dev_name(dev));
-#else
-	if (dev->parent && device_is_not_partition(dev))
-		sysfs_remove_link(&dev->kobj, "device");
+}
 
-	sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj, dev_name(dev));
-#endif
+static void device_remove_class_symlinks(struct device *dev)
+{
+	if (!dev->class)
+		return;
+
+	if (sysfs_deprecated) {
+		deprecated_device_remove_class_symlinks(dev);
+	} else {
+		if (dev->parent && device_is_not_partition(dev))
+			sysfs_remove_link(&dev->kobj, "device");
+
+		sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj, dev_name(dev));
+	}
 
 	sysfs_remove_link(&dev->kobj, "subsystem");
 }
@@ -1613,10 +1641,8 @@ int device_rename(struct device *dev, const char *new_name)
 	pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
 		 __func__, new_name);
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	if ((dev->class) && (dev->parent))
+	if (sysfs_deprecated && (dev->class) && (dev->parent))
 		old_class_name = make_class_name(dev->class->name, &dev->kobj);
-#endif
 
 	old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
 	if (!old_device_name) {
@@ -1624,20 +1650,17 @@ int device_rename(struct device *dev, const char *new_name)
 		goto out;
 	}
 
-#ifndef CONFIG_SYSFS_DEPRECATED
-	if (dev->class) {
+	if (sysfs_deprecated && dev->class) {
 		error = sysfs_rename_link(&dev->class->p->class_subsys.kobj,
 			&dev->kobj, old_device_name, new_name);
 		if (error)
 			goto out;
 	}
-#endif
 	error = kobject_rename(&dev->kobj, new_name);
 	if (error)
 		goto out;
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	if (old_class_name) {
+	if (sysfs_deprecated && old_class_name) {
 		new_class_name = make_class_name(dev->class->name, &dev->kobj);
 		if (new_class_name) {
 			error = sysfs_rename_link(&dev->parent->kobj,
@@ -1646,7 +1669,6 @@ int device_rename(struct device *dev, const char *new_name)
 						  new_class_name);
 		}
 	}
-#endif
 
 out:
 	put_device(dev);
@@ -1659,13 +1681,12 @@ out:
 }
 EXPORT_SYMBOL_GPL(device_rename);
 
-static int device_move_class_links(struct device *dev,
-				   struct device *old_parent,
-				   struct device *new_parent)
+static int deprecated_device_move_class_links(struct device *dev,
+					      struct device *old_parent,
+					      struct device *new_parent)
 {
-	int error = 0;
-#ifdef CONFIG_SYSFS_DEPRECATED
 	char *class_name;
+	int error = 0;
 
 	class_name = make_class_name(dev->class->name, &dev->kobj);
 	if (!class_name) {
@@ -1690,14 +1711,23 @@ static int device_move_class_links(struct device *dev,
 out:
 	kfree(class_name);
 	return error;
-#else
+}
+
+static int device_move_class_links(struct device *dev,
+				   struct device *old_parent,
+				   struct device *new_parent)
+{
+	int error = 0;
+
+	if (sysfs_deprecated)
+		return deprecated_device_move_class_links(dev, old_parent, 
+							  new_parent);
 	if (old_parent)
 		sysfs_remove_link(&dev->kobj, "device");
 	if (new_parent)
 		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
 					  "device");
 	return error;
-#endif
 }
 
 /**
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 8a8f803..bf63d9e 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -411,9 +411,8 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
 
 	device_initialize(&shost->shost_gendev);
 	dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
-#ifndef CONFIG_SYSFS_DEPRECATED
-	shost->shost_gendev.bus = &scsi_bus_type;
-#endif
+	if (!sysfs_deprecated)
+		shost->shost_gendev.bus = &scsi_bus_type;
 	shost->shost_gendev.type = &scsi_host_type;
 
 	device_initialize(&shost->shost_dev);
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 3d0a1e6..c0856d9 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -417,9 +417,8 @@ static struct scsi_target *scsi_alloc_target(struct device *parent,
 	starget->reap_ref = 1;
 	dev->parent = get_device(parent);
 	dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
-#ifndef CONFIG_SYSFS_DEPRECATED
-	dev->bus = &scsi_bus_type;
-#endif
+	if (!sysfs_deprecated)
+		dev->bus = &scsi_bus_type;
 	dev->type = &scsi_target_type;
 	starget->id = id;
 	starget->channel = channel;
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 79fbf3f..137bf97 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -513,14 +513,14 @@ void register_disk(struct gendisk *disk)
 
 	if (device_add(ddev))
 		return;
-#ifndef CONFIG_SYSFS_DEPRECATED
-	err = sysfs_create_link(block_depr, &ddev->kobj,
-				kobject_name(&ddev->kobj));
-	if (err) {
-		device_del(ddev);
-		return;
+	if (!sysfs_deprecated) {
+		err = sysfs_create_link(block_depr, &ddev->kobj,
+					kobject_name(&ddev->kobj));
+		if (err) {
+			device_del(ddev);
+			return;
+		}
 	}
-#endif
 	disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
 	disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
 
@@ -737,8 +737,7 @@ void del_gendisk(struct gendisk *disk)
 	kobject_put(disk->part0.holder_dir);
 	kobject_put(disk->slave_dir);
 	disk->driverfs_dev = NULL;
-#ifndef CONFIG_SYSFS_DEPRECATED
-	sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
-#endif
+	if (!sysfs_deprecated)
+		sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
 	device_del(disk_to_dev(disk));
 }
diff --git a/include/linux/device.h b/include/linux/device.h
index 516feca..fb30f45 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -751,4 +751,11 @@ do {						     \
 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
+
+#ifndef CONFIG_SYSFS_DEPRECATED_SWITCH
+#define sysfs_deprecated 0
+#else
+extern long sysfs_deprecated;
+#endif
+
 #endif /* _DEVICE_H_ */
diff --git a/include/sound/core.h b/include/sound/core.h
index 89e0ac1..181b1be 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -29,6 +29,7 @@
 #include <linux/pm.h>			/* pm_message_t */
 #include <linux/device.h>
 #include <linux/stringify.h>
+#include <linux/device.h>
 
 /* number of supported soundcards */
 #ifdef CONFIG_SND_DYNAMIC_MINORS
@@ -133,9 +134,7 @@ struct snd_card {
 	int free_on_last_close;		/* free in context of file_release */
 	wait_queue_head_t shutdown_sleep;
 	struct device *dev;		/* device assigned to this card */
-#ifndef CONFIG_SYSFS_DEPRECATED
 	struct device *card_dev;	/* cardX object for sysfs */
-#endif
 
 #ifdef CONFIG_PM
 	unsigned int power_state;	/* power state */
@@ -196,11 +195,8 @@ struct snd_minor {
 /* return a device pointer linked to each sound device as a parent */
 static inline struct device *snd_card_get_device_link(struct snd_card *card)
 {
-#ifdef CONFIG_SYSFS_DEPRECATED
-	return card ? card->dev : NULL;
-#else
-	return card ? card->card_dev : NULL;
-#endif
+	struct device *dev = sysfs_deprecated ? card->dev : card->card_dev;
+	return card ? dev : NULL;
 }
 
 /* sound.c */
diff --git a/init/Kconfig b/init/Kconfig
index 2de5b1c..ae69ed0 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -655,17 +655,19 @@ endif # CGROUPS
 config MM_OWNER
 	bool
 
-config SYSFS_DEPRECATED
-	bool
-
-config SYSFS_DEPRECATED_V2
-	bool "enable deprecated sysfs features to support old userspace tools"
+config SYSFS_DEPRECATED_SWITCH
+	bool "allow enabling deprecated sysfs layout at boot time"
 	depends on SYSFS
 	default n
-	select SYSFS_DEPRECATED
 	help
-	  This option switches the layout of sysfs to the deprecated
-	  version. Do not use it on recent distributions.
+	  Support runtime switching of the deprecated and modern
+	  sysfs layout. Generally the modern layout is needed for newer
+	  distributions and deprecated for very old distributions with
+	  old udev.
+
+	  The default is modern layout unless CONFIG_SYSFS_DEPRECATED_V2
+	  is set. The old layout can be forced by setting 
+	  sysfs.deprecated=1 on the kernel command line.
 
 	  The current sysfs layout features a unified device tree at
 	  /sys/devices/, which is able to express a hierarchy between
@@ -678,6 +680,16 @@ config SYSFS_DEPRECATED_V2
 	  subsystems will suppress the creation of some devices which
 	  depend on the unified device tree.
 
+# use select, not depend, on DEPRECATED_SWITCH to not break old configs
+config SYSFS_DEPRECATED_V2
+	bool "enable deprecated sysfs features to support old userspace tools"
+	depends on SYSFS
+	default n
+	select SYSFS_DEPRECATED_SWITCH
+	help
+	  This option switches the layout of sysfs to the deprecated
+	  version. Do not use it on recent distributions.
+
 	  This option is not a pure compatibility option that can
 	  be safely enabled on newer distributions. It will change the
 	  layout of sysfs to the non-extensible deprecated version,
@@ -690,7 +702,7 @@ config SYSFS_DEPRECATED_V2
 	  older userspace tools, you might need to say Y here. Do not say Y,
 	  if the original kernel, that came with your distribution, has
 	  this option set to N.
-
+	  
 config RELAY
 	bool "Kernel->user space relay support (formerly relayfs)"
 	help
diff --git a/sound/core/init.c b/sound/core/init.c
index ec4a50c..1ad1583 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -395,12 +395,10 @@ int snd_card_disconnect(struct snd_card *card)
 		snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 
 	snd_info_card_disconnect(card);
-#ifndef CONFIG_SYSFS_DEPRECATED
-	if (card->card_dev) {
+	if (!sysfs_deprecated && card->card_dev) {
 		device_unregister(card->card_dev);
 		card->card_dev = NULL;
 	}
-#endif
 #ifdef CONFIG_PM
 	wake_up(&card->power_sleep);
 #endif
@@ -573,7 +571,6 @@ void snd_card_set_id(struct snd_card *card, const char *nid)
 }
 EXPORT_SYMBOL(snd_card_set_id);
 
-#ifndef CONFIG_SYSFS_DEPRECATED
 static ssize_t
 card_id_show_attr(struct device *dev,
 		  struct device_attribute *attr, char *buf)
@@ -630,7 +627,6 @@ card_number_show_attr(struct device *dev,
 
 static struct device_attribute card_number_attrs =
 	__ATTR(number, S_IRUGO, card_number_show_attr, NULL);
-#endif /* CONFIG_SYSFS_DEPRECATED */
 
 /**
  *  snd_card_register - register the soundcard
@@ -649,15 +645,13 @@ int snd_card_register(struct snd_card *card)
 
 	if (snd_BUG_ON(!card))
 		return -EINVAL;
-#ifndef CONFIG_SYSFS_DEPRECATED
-	if (!card->card_dev) {
+	if (!sysfs_deprecated && !card->card_dev) {
 		card->card_dev = device_create(sound_class, card->dev,
 					       MKDEV(0, 0), card,
 					       "card%i", card->number);
 		if (IS_ERR(card->card_dev))
 			card->card_dev = NULL;
 	}
-#endif
 	if ((err = snd_device_register_all(card)) < 0)
 		return err;
 	mutex_lock(&snd_card_mutex);
@@ -674,8 +668,7 @@ int snd_card_register(struct snd_card *card)
 	if (snd_mixer_oss_notify_callback)
 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 #endif
-#ifndef CONFIG_SYSFS_DEPRECATED
-	if (card->card_dev) {
+	if (!sysfs_deprecated && card->card_dev) {
 		err = device_create_file(card->card_dev, &card_id_attrs);
 		if (err < 0)
 			return err;
@@ -683,7 +676,6 @@ int snd_card_register(struct snd_card *card)
 		if (err < 0)
 			return err;
 	}
-#endif
 	return 0;
 }
 
-- 
1.7.1

Re: [PATCH] SYSFS: Allow boot time switching between deprecated and modern sysfs layout

[Greg KH]

[-- Attachment #1: Type: text/plain, Size: 961 bytes --]

On Wed, Sep 08, 2010 at 03:19:51PM +0200, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
> 
> I have some systems which need legacy sysfs due to old udev versions,
> and it's a big hazzle to compile separate kernels for them.
> 
> This patch turns CONFIG_SYSFS_DEPRECATED into a run time option
> that can be switched on/off the kernel command line. This way
> the same binary can be used in both cases with just a option
> on the command line.

Nice idea.  It will make testing easier for lots of people.

But, Kay and I just changed the logic in the kernel in this area,
getting rid of the CONFIG_SYSFS_DEPRECATED_V2 option entirely, to try to
make the code path smaller, only offering the "old" mode for block
devices, to keep kernels booting on userspace instances like what you
have.

So, could you respin this patch against the linux-next tree which has
Kay's patch in it?  Or, if it's easier, I've attached the patch below.

thanks,

greg k-h

[-- Attachment #2: driver-core-remove-config_sysfs_deprecated_v2-but-keep-it-for-block-devices.patch --]
[-- Type: text/x-patch, Size: 17292 bytes --]

>From foo@baz Sat Sep  4 22:33:14 PDT 2010
Date: Sat, 04 Sep 2010 22:33:14 -0700
To: Greg KH <greg@kroah.com>
From: Kay Sievers <kay.sievers@vrfy.org>
Subject: driver core: remove CONFIG_SYSFS_DEPRECATED_V2 but keep it for block devices

This patch removes the old CONFIG_SYSFS_DEPRECATED_V2 config option,
but it keeps the logic around to handle block devices in the old manner
as some people like to run new kernel versions on old (pre 2007/2008)
distros.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


---
 drivers/base/bus.c       |   22 -----
 drivers/base/class.c     |   19 ----
 drivers/base/core.c      |  194 ++++++-----------------------------------------
 drivers/scsi/hosts.c     |    2 
 drivers/scsi/scsi_scan.c |    2 
 include/sound/core.h     |    6 -
 init/Kconfig             |   42 +++-------
 sound/core/init.c        |   11 --
 8 files changed, 41 insertions(+), 257 deletions(-)

--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -440,22 +440,6 @@ static void device_remove_attrs(struct b
 	}
 }
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-static int make_deprecated_bus_links(struct device *dev)
-{
-	return sysfs_create_link(&dev->kobj,
-				 &dev->bus->p->subsys.kobj, "bus");
-}
-
-static void remove_deprecated_bus_links(struct device *dev)
-{
-	sysfs_remove_link(&dev->kobj, "bus");
-}
-#else
-static inline int make_deprecated_bus_links(struct device *dev) { return 0; }
-static inline void remove_deprecated_bus_links(struct device *dev) { }
-#endif
-
 /**
  * bus_add_device - add device to bus
  * @dev: device being added
@@ -482,15 +466,10 @@ int bus_add_device(struct device *dev)
 				&dev->bus->p->subsys.kobj, "subsystem");
 		if (error)
 			goto out_subsys;
-		error = make_deprecated_bus_links(dev);
-		if (error)
-			goto out_deprecated;
 		klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
 	}
 	return 0;
 
-out_deprecated:
-	sysfs_remove_link(&dev->kobj, "subsystem");
 out_subsys:
 	sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
 out_id:
@@ -530,7 +509,6 @@ void bus_remove_device(struct device *de
 {
 	if (dev->bus) {
 		sysfs_remove_link(&dev->kobj, "subsystem");
-		remove_deprecated_bus_links(dev);
 		sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
 				  dev_name(dev));
 		device_remove_attrs(dev->bus, dev);
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -276,25 +276,6 @@ void class_destroy(struct class *cls)
 	class_unregister(cls);
 }
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-char *make_class_name(const char *name, struct kobject *kobj)
-{
-	char *class_name;
-	int size;
-
-	size = strlen(name) + strlen(kobject_name(kobj)) + 2;
-
-	class_name = kmalloc(size, GFP_KERNEL);
-	if (!class_name)
-		return NULL;
-
-	strcpy(class_name, name);
-	strcat(class_name, ":");
-	strcat(class_name, kobject_name(kobj));
-	return class_name;
-}
-#endif
-
 /**
  * class_dev_iter_init - initialize class device iterator
  * @iter: class iterator to initialize
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -203,37 +203,6 @@ static int dev_uevent(struct kset *kset,
 	if (dev->driver)
 		add_uevent_var(env, "DRIVER=%s", dev->driver->name);
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	if (dev->class) {
-		struct device *parent = dev->parent;
-
-		/* find first bus device in parent chain */
-		while (parent && !parent->bus)
-			parent = parent->parent;
-		if (parent && parent->bus) {
-			const char *path;
-
-			path = kobject_get_path(&parent->kobj, GFP_KERNEL);
-			if (path) {
-				add_uevent_var(env, "PHYSDEVPATH=%s", path);
-				kfree(path);
-			}
-
-			add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
-
-			if (parent->driver)
-				add_uevent_var(env, "PHYSDEVDRIVER=%s",
-					       parent->driver->name);
-		}
-	} else if (dev->bus) {
-		add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
-
-		if (dev->driver)
-			add_uevent_var(env, "PHYSDEVDRIVER=%s",
-				       dev->driver->name);
-	}
-#endif
-
 	/* have the bus specific function add its stuff */
 	if (dev->bus && dev->bus->uevent) {
 		retval = dev->bus->uevent(dev, env);
@@ -578,24 +547,6 @@ void device_initialize(struct device *de
 	set_dev_node(dev, -1);
 }
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-static struct kobject *get_device_parent(struct device *dev,
-					 struct device *parent)
-{
-	/* class devices without a parent live in /sys/class/<classname>/ */
-	if (dev->class && (!parent || parent->class != dev->class))
-		return &dev->class->p->class_subsys.kobj;
-	/* all other devices keep their parent */
-	else if (parent)
-		return &parent->kobj;
-
-	return NULL;
-}
-
-static inline void cleanup_device_parent(struct device *dev) {}
-static inline void cleanup_glue_dir(struct device *dev,
-				    struct kobject *glue_dir) {}
-#else
 static struct kobject *virtual_device_parent(struct device *dev)
 {
 	static struct kobject *virtual_dir = NULL;
@@ -666,6 +617,14 @@ static struct kobject *get_device_parent
 		struct kobject *parent_kobj;
 		struct kobject *k;
 
+#ifdef CONFIG_SYSFS_DEPRECATED
+		/* block disks show up in /sys/block */
+		if (dev->class == &block_class) {
+			if (parent && parent->class == &block_class)
+				return &parent->kobj;
+			return &block_class.p->class_subsys.kobj;
+		}
+#endif
 		/*
 		 * If we have no parent, we live in "virtual".
 		 * Class-devices with a non class-device as parent, live
@@ -719,7 +678,6 @@ static void cleanup_device_parent(struct
 {
 	cleanup_glue_dir(dev, dev->kobj.parent);
 }
-#endif
 
 static void setup_parent(struct device *dev, struct device *parent)
 {
@@ -742,70 +700,29 @@ static int device_add_class_symlinks(str
 	if (error)
 		goto out;
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	/* stacked class devices need a symlink in the class directory */
-	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
-	    device_is_not_partition(dev)) {
-		error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
-					  &dev->kobj, dev_name(dev));
-		if (error)
-			goto out_subsys;
-	}
-
 	if (dev->parent && device_is_not_partition(dev)) {
-		struct device *parent = dev->parent;
-		char *class_name;
-
-		/*
-		 * stacked class devices have the 'device' link
-		 * pointing to the bus device instead of the parent
-		 */
-		while (parent->class && !parent->bus && parent->parent)
-			parent = parent->parent;
-
-		error = sysfs_create_link(&dev->kobj,
-					  &parent->kobj,
+		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
 					  "device");
 		if (error)
-			goto out_busid;
-
-		class_name = make_class_name(dev->class->name,
-						&dev->kobj);
-		if (class_name)
-			error = sysfs_create_link(&dev->parent->kobj,
-						&dev->kobj, class_name);
-		kfree(class_name);
-		if (error)
-			goto out_device;
+			goto out_subsys;
 	}
-	return 0;
 
-out_device:
-	if (dev->parent && device_is_not_partition(dev))
-		sysfs_remove_link(&dev->kobj, "device");
-out_busid:
-	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
-	    device_is_not_partition(dev))
-		sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj,
-				  dev_name(dev));
-#else
+#ifdef CONFIG_SYSFS_DEPRECATED
+	/* /sys/block has directories and does not need symlinks */
+	if (dev->class == &block_class)
+		return 0;
+#endif
+
 	/* link in the class directory pointing to the device */
 	error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
 				  &dev->kobj, dev_name(dev));
 	if (error)
-		goto out_subsys;
+		goto out_device;
 
-	if (dev->parent && device_is_not_partition(dev)) {
-		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
-					  "device");
-		if (error)
-			goto out_busid;
-	}
 	return 0;
 
-out_busid:
-	sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj, dev_name(dev));
-#endif
+out_device:
+	sysfs_remove_link(&dev->kobj, "device");
 
 out_subsys:
 	sysfs_remove_link(&dev->kobj, "subsystem");
@@ -818,30 +735,14 @@ static void device_remove_class_symlinks
 	if (!dev->class)
 		return;
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	if (dev->parent && device_is_not_partition(dev)) {
-		char *class_name;
-
-		class_name = make_class_name(dev->class->name, &dev->kobj);
-		if (class_name) {
-			sysfs_remove_link(&dev->parent->kobj, class_name);
-			kfree(class_name);
-		}
-		sysfs_remove_link(&dev->kobj, "device");
-	}
-
-	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
-	    device_is_not_partition(dev))
-		sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj,
-				  dev_name(dev));
-#else
 	if (dev->parent && device_is_not_partition(dev))
 		sysfs_remove_link(&dev->kobj, "device");
-
-	sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj, dev_name(dev));
-#endif
-
 	sysfs_remove_link(&dev->kobj, "subsystem");
+#ifdef CONFIG_SYSFS_DEPRECATED
+	if (dev->class == &block_class)
+		return;
+#endif
+	sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj, dev_name(dev));
 }
 
 /**
@@ -1613,41 +1514,23 @@ int device_rename(struct device *dev, co
 	pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
 		 __func__, new_name);
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	if ((dev->class) && (dev->parent))
-		old_class_name = make_class_name(dev->class->name, &dev->kobj);
-#endif
-
 	old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
 	if (!old_device_name) {
 		error = -ENOMEM;
 		goto out;
 	}
 
-#ifndef CONFIG_SYSFS_DEPRECATED
 	if (dev->class) {
 		error = sysfs_rename_link(&dev->class->p->class_subsys.kobj,
 			&dev->kobj, old_device_name, new_name);
 		if (error)
 			goto out;
 	}
-#endif
+
 	error = kobject_rename(&dev->kobj, new_name);
 	if (error)
 		goto out;
 
-#ifdef CONFIG_SYSFS_DEPRECATED
-	if (old_class_name) {
-		new_class_name = make_class_name(dev->class->name, &dev->kobj);
-		if (new_class_name) {
-			error = sysfs_rename_link(&dev->parent->kobj,
-						  &dev->kobj,
-						  old_class_name,
-						  new_class_name);
-		}
-	}
-#endif
-
 out:
 	put_device(dev);
 
@@ -1664,40 +1547,13 @@ static int device_move_class_links(struc
 				   struct device *new_parent)
 {
 	int error = 0;
-#ifdef CONFIG_SYSFS_DEPRECATED
-	char *class_name;
 
-	class_name = make_class_name(dev->class->name, &dev->kobj);
-	if (!class_name) {
-		error = -ENOMEM;
-		goto out;
-	}
-	if (old_parent) {
-		sysfs_remove_link(&dev->kobj, "device");
-		sysfs_remove_link(&old_parent->kobj, class_name);
-	}
-	if (new_parent) {
-		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
-					  "device");
-		if (error)
-			goto out;
-		error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
-					  class_name);
-		if (error)
-			sysfs_remove_link(&dev->kobj, "device");
-	} else
-		error = 0;
-out:
-	kfree(class_name);
-	return error;
-#else
 	if (old_parent)
 		sysfs_remove_link(&dev->kobj, "device");
 	if (new_parent)
 		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
 					  "device");
 	return error;
-#endif
 }
 
 /**
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -411,9 +411,7 @@ struct Scsi_Host *scsi_host_alloc(struct
 
 	device_initialize(&shost->shost_gendev);
 	dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
-#ifndef CONFIG_SYSFS_DEPRECATED
 	shost->shost_gendev.bus = &scsi_bus_type;
-#endif
 	shost->shost_gendev.type = &scsi_host_type;
 
 	device_initialize(&shost->shost_dev);
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -417,9 +417,7 @@ static struct scsi_target *scsi_alloc_ta
 	starget->reap_ref = 1;
 	dev->parent = get_device(parent);
 	dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
-#ifndef CONFIG_SYSFS_DEPRECATED
 	dev->bus = &scsi_bus_type;
-#endif
 	dev->type = &scsi_target_type;
 	starget->id = id;
 	starget->channel = channel;
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -133,9 +133,7 @@ struct snd_card {
 	int free_on_last_close;		/* free in context of file_release */
 	wait_queue_head_t shutdown_sleep;
 	struct device *dev;		/* device assigned to this card */
-#ifndef CONFIG_SYSFS_DEPRECATED
 	struct device *card_dev;	/* cardX object for sysfs */
-#endif
 
 #ifdef CONFIG_PM
 	unsigned int power_state;	/* power state */
@@ -196,11 +194,7 @@ struct snd_minor {
 /* return a device pointer linked to each sound device as a parent */
 static inline struct device *snd_card_get_device_link(struct snd_card *card)
 {
-#ifdef CONFIG_SYSFS_DEPRECATED
-	return card ? card->dev : NULL;
-#else
 	return card ? card->card_dev : NULL;
-#endif
 }
 
 /* sound.c */
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -656,40 +656,24 @@ config MM_OWNER
 	bool
 
 config SYSFS_DEPRECATED
-	bool
-
-config SYSFS_DEPRECATED_V2
 	bool "enable deprecated sysfs features to support old userspace tools"
 	depends on SYSFS
 	default n
-	select SYSFS_DEPRECATED
 	help
-	  This option switches the layout of sysfs to the deprecated
-	  version. Do not use it on recent distributions.
-
-	  The current sysfs layout features a unified device tree at
-	  /sys/devices/, which is able to express a hierarchy between
-	  class devices. If the deprecated option is set to Y, the
-	  unified device tree is split into a bus device tree at
-	  /sys/devices/ and several individual class device trees at
-	  /sys/class/. The class and bus devices will be connected by
-	  "<subsystem>:<name>" and the "device" links. The "block"
-	  class devices, will not show up in /sys/class/block/. Some
-	  subsystems will suppress the creation of some devices which
-	  depend on the unified device tree.
-
-	  This option is not a pure compatibility option that can
-	  be safely enabled on newer distributions. It will change the
-	  layout of sysfs to the non-extensible deprecated version,
-	  and disable some features, which can not be exported without
-	  confusing older userspace tools. Since 2007/2008 all major
-	  distributions do not enable this option, and ship no tools which
-	  depend on the deprecated layout or this option.
+	  This option switches the layout of the "block" class devices, to not
+	  show up in /sys/class/block/, but only in /sys/block/.
 
-	  If you are using a new kernel on an older distribution, or use
-	  older userspace tools, you might need to say Y here. Do not say Y,
-	  if the original kernel, that came with your distribution, has
-	  this option set to N.
+	  This option allows new kernels to run on old distributions and tools,
+	  which might get confused by /sys/class/block/. Since 2007/2008 all
+	  major distributions and tools handle this just fine.
+
+	  Recent distributions and userspace tools after 2009/2010 depend on
+	  the existence of /sys/class/block/, and will not work with this
+	  option enabled.
+
+	  Only if you are using a new kernel on an old distribution, you might
+	  need to say Y here. Never say Y, if the original kernel, that came
+	  with your distribution, has not set this option.
 
 config RELAY
 	bool "Kernel->user space relay support (formerly relayfs)"
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -395,12 +395,10 @@ int snd_card_disconnect(struct snd_card
 		snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 
 	snd_info_card_disconnect(card);
-#ifndef CONFIG_SYSFS_DEPRECATED
 	if (card->card_dev) {
 		device_unregister(card->card_dev);
 		card->card_dev = NULL;
 	}
-#endif
 #ifdef CONFIG_PM
 	wake_up(&card->power_sleep);
 #endif
@@ -573,7 +571,6 @@ void snd_card_set_id(struct snd_card *ca
 }
 EXPORT_SYMBOL(snd_card_set_id);
 
-#ifndef CONFIG_SYSFS_DEPRECATED
 static ssize_t
 card_id_show_attr(struct device *dev,
 		  struct device_attribute *attr, char *buf)
@@ -630,7 +627,6 @@ card_number_show_attr(struct device *dev
 
 static struct device_attribute card_number_attrs =
 	__ATTR(number, S_IRUGO, card_number_show_attr, NULL);
-#endif /* CONFIG_SYSFS_DEPRECATED */
 
 /**
  *  snd_card_register - register the soundcard
@@ -649,7 +645,7 @@ int snd_card_register(struct snd_card *c
 
 	if (snd_BUG_ON(!card))
 		return -EINVAL;
-#ifndef CONFIG_SYSFS_DEPRECATED
+
 	if (!card->card_dev) {
 		card->card_dev = device_create(sound_class, card->dev,
 					       MKDEV(0, 0), card,
@@ -657,7 +653,7 @@ int snd_card_register(struct snd_card *c
 		if (IS_ERR(card->card_dev))
 			card->card_dev = NULL;
 	}
-#endif
+
 	if ((err = snd_device_register_all(card)) < 0)
 		return err;
 	mutex_lock(&snd_card_mutex);
@@ -674,7 +670,6 @@ int snd_card_register(struct snd_card *c
 	if (snd_mixer_oss_notify_callback)
 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 #endif
-#ifndef CONFIG_SYSFS_DEPRECATED
 	if (card->card_dev) {
 		err = device_create_file(card->card_dev, &card_id_attrs);
 		if (err < 0)
@@ -683,7 +678,7 @@ int snd_card_register(struct snd_card *c
 		if (err < 0)
 			return err;
 	}
-#endif
+
 	return 0;
 }
 

Re: [PATCH] SYSFS: Allow boot time switching between deprecated and modern sysfs layout

[Andi Kleen]

On Wed, 8 Sep 2010 06:55:30 -0700
Greg KH <greg@kroah.com> wrote:

> But, Kay and I just changed the logic in the kernel in this area,
> getting rid of the CONFIG_SYSFS_DEPRECATED_V2 option entirely, to try
> to make the code path smaller, only offering the "old" mode for block
> devices, to keep kernels booting on userspace instances like what you
> have.

That will likely break my user space, it relies on the old style
net set up (opensuse 10.0) for network configuration. 
That was the main reason I did this patch.


> 
> So, could you respin this patch against the linux-next tree which has
> Kay's patch in it?  Or, if it's easier, I've attached the patch below.

I can test your patch first, but to be honest I doubt it'll work on the
10.0 roots.

-Andi


-- 
ak@linux.intel.com -- Speaking for myself only.

Re: [PATCH] SYSFS: Allow boot time switching between deprecated and modern sysfs layout II

[Andi Kleen]

On Wed, 8 Sep 2010 16:02:35 +0200
Andi Kleen <andi@firstfloor.org> wrote:

> On Wed, 8 Sep 2010 06:55:30 -0700
> Greg KH <greg@kroah.com> wrote:
> 
> > But, Kay and I just changed the logic in the kernel in this area,
> > getting rid of the CONFIG_SYSFS_DEPRECATED_V2 option entirely, to
> > try to make the code path smaller, only offering the "old" mode for
> > block devices, to keep kernels booting on userspace instances like
> > what you have.
> 
> That will likely break my user space, it relies on the old style
> net set up (opensuse 10.0) for network configuration. 
> That was the main reason I did this patch.

... Just tested it. Never mind, it looks the old style network
configuration seems to work still with this patch and my 
earlier pessimistic assumptions were incorrect.

Don't see any misfunction so it looks like the new patch
is ok.

I'll respin my patch on top of this.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.