[PATCH] driver core: Suppress sysfs warnings for device_rename().

From: Cornelia Huck
Date: Tue May 20 2008 - 07:00:22 EST


OK, here is an actually-compiled patch with proper description and
s-o-b. Comments?

-----

driver core: Suppress sysfs warnings for device_rename().

Renaming network devices to an already existing name is not
something we want sysfs to print a scary warning for, since the
callers can deal with this correctly. So let's introduce
sysfs_create_link_nowarn() which gets rid of the common warning.

Signed-off-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>

---
drivers/base/core.c | 17 ++++++++---------
fs/sysfs/dir.c | 37 +++++++++++++++++++++++++++++++++++--
fs/sysfs/symlink.c | 41 +++++++++++++++++++++++++++++++++--------
fs/sysfs/sysfs.h | 1 +
include/linux/sysfs.h | 10 ++++++++++
5 files changed, 87 insertions(+), 19 deletions(-)

Index: linux-2.6/drivers/base/core.c
===================================================================
--- linux-2.6.orig/drivers/base/core.c
+++ linux-2.6/drivers/base/core.c
@@ -1287,8 +1287,9 @@ int device_rename(struct device *dev, ch
if (old_class_name) {
new_class_name = make_class_name(dev->class->name, &dev->kobj);
if (new_class_name) {
- error = sysfs_create_link(&dev->parent->kobj,
- &dev->kobj, new_class_name);
+ error = sysfs_create_link_nowarn(&dev->parent->kobj,
+ &dev->kobj,
+ new_class_name);
if (error)
goto out;
sysfs_remove_link(&dev->parent->kobj, old_class_name);
@@ -1296,13 +1297,11 @@ int device_rename(struct device *dev, ch
}
#else
if (dev->class) {
- sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
- error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
- dev->bus_id);
- if (error) {
- dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
- __func__, error);
- }
+ error = sysfs_create_link_nowarn(&dev->class->subsys.kobj,
+ &dev->kobj, dev->bus_id);
+ if (!error)
+ sysfs_remove_link(&dev->class->subsys.kobj,
+ old_device_name);
}
#endif

Index: linux-2.6/fs/sysfs/dir.c
===================================================================
--- linux-2.6.orig/fs/sysfs/dir.c
+++ linux-2.6/fs/sysfs/dir.c
@@ -398,7 +398,7 @@ void sysfs_addrm_start(struct sysfs_addr
}

/**
- * sysfs_add_one - add sysfs_dirent to parent
+ * __sysfs_add_one - add sysfs_dirent to parent without warning
* @acxt: addrm context to use
* @sd: sysfs_dirent to be added
*
@@ -417,7 +417,7 @@ void sysfs_addrm_start(struct sysfs_addr
* 0 on success, -EEXIST if entry with the given name already
* exists.
*/
-int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
{
if (sysfs_find_dirent(acxt->parent_sd, sd->s_name)) {
printk(KERN_WARNING "sysfs: duplicate filename '%s' "
@@ -439,6 +439,39 @@ int sysfs_add_one(struct sysfs_addrm_cxt
}

/**
+ * sysfs_add_one - add sysfs_dirent to parent
+ * @acxt: addrm context to use
+ * @sd: sysfs_dirent to be added
+ *
+ * Get @acxt->parent_sd and set sd->s_parent to it and increment
+ * nlink of parent inode if @sd is a directory and link into the
+ * children list of the parent.
+ *
+ * This function should be called between calls to
+ * sysfs_addrm_start() and sysfs_addrm_finish() and should be
+ * passed the same @acxt as passed to sysfs_addrm_start().
+ *
+ * LOCKING:
+ * Determined by sysfs_addrm_start().
+ *
+ * RETURNS:
+ * 0 on success, -EEXIST if entry with the given name already
+ * exists.
+ */
+int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+{
+ int ret;
+
+ ret = __sysfs_add_one(acxt, sd);
+ if (ret == -EEXIST) {
+ printk(KERN_WARNING "sysfs: duplicate filename '%s' "
+ "can not be created\n", sd->s_name);
+ WARN_ON(1);
+ }
+ return ret;
+}
+
+/**
* sysfs_remove_one - remove sysfs_dirent from parent
* @acxt: addrm context to use
* @sd: sysfs_dirent to be removed
Index: linux-2.6/fs/sysfs/symlink.c
===================================================================
--- linux-2.6.orig/fs/sysfs/symlink.c
+++ linux-2.6/fs/sysfs/symlink.c
@@ -19,13 +19,8 @@

#include "sysfs.h"

-/**
- * sysfs_create_link - create symlink between two objects.
- * @kobj: object whose directory we're creating the link in.
- * @target: object we're pointing to.
- * @name: name of the symlink.
- */
-int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char * name)
+static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target,
+ const char *name, int warn)
{
struct sysfs_dirent *parent_sd = NULL;
struct sysfs_dirent *target_sd = NULL;
@@ -65,7 +60,10 @@ int sysfs_create_link(struct kobject * k
target_sd = NULL; /* reference is now owned by the symlink */

sysfs_addrm_start(&acxt, parent_sd);
- error = sysfs_add_one(&acxt, sd);
+ if (warn)
+ error = sysfs_add_one(&acxt, sd);
+ else
+ error = __sysfs_add_one(&acxt, sd);
sysfs_addrm_finish(&acxt);

if (error)
@@ -80,6 +78,33 @@ int sysfs_create_link(struct kobject * k
}

/**
+ * sysfs_create_link - create symlink between two objects.
+ * @kobj: object whose directory we're creating the link in.
+ * @target: object we're pointing to.
+ * @name: name of the symlink.
+ */
+int sysfs_create_link(struct kobject *kobj, struct kobject *target,
+ const char *name)
+{
+ return sysfs_do_create_link(kobj, target, name, 1);
+}
+
+/**
+ * sysfs_create_link_nowarn - create symlink between two objects.
+ * @kobj: object whose directory we're creating the link in.
+ * @target: object we're pointing to.
+ * @name: name of the symlink.
+ *
+ * This function does the same as sysf_create_link(), but it
+ * doesn't warn if the link already exists.
+ */
+int sysfs_create_link_nowarn(struct kobject *kobj, struct kobject *target,
+ const char *name)
+{
+ return sysfs_do_create_link(kobj, target, name, 0);
+}
+
+/**
* sysfs_remove_link - remove symlink in object's directory.
* @kobj: object we're acting for.
* @name: name of the symlink to remove.
Index: linux-2.6/fs/sysfs/sysfs.h
===================================================================
--- linux-2.6.orig/fs/sysfs/sysfs.h
+++ linux-2.6/fs/sysfs/sysfs.h
@@ -107,6 +107,7 @@ struct sysfs_dirent *sysfs_get_active_tw
void sysfs_put_active_two(struct sysfs_dirent *sd);
void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
struct sysfs_dirent *parent_sd);
+int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
Index: linux-2.6/include/linux/sysfs.h
===================================================================
--- linux-2.6.orig/include/linux/sysfs.h
+++ linux-2.6/include/linux/sysfs.h
@@ -103,6 +103,9 @@ void sysfs_remove_bin_file(struct kobjec

int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target,
const char *name);
+int __must_check sysfs_create_link_nowarn(struct kobject *kobj,
+ struct kobject *target,
+ const char *name);
void sysfs_remove_link(struct kobject *kobj, const char *name);

int __must_check sysfs_create_group(struct kobject *kobj,
@@ -182,6 +185,13 @@ static inline int sysfs_create_link(stru
return 0;
}

+static inline int sysfs_create_link_nowarn(struct kobject *kobj,
+ struct kobject *target,
+ const char *name)
+{
+ return 0;
+}
+
static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
{
}
--
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