driver core: Suppress sysfs warnings for device_rename().

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@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

5 files changed, 84 insertions, 14 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index c05b1159023e..7d5c63c81a59 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1345,8 +1345,9 @@ int device_rename(struct device *dev, char *new_name)
         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);
@@ -1354,8 +1355,8 @@ int device_rename(struct device *dev, char *new_name)
         }
 #else
         if (dev->class) {
-                error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
-                                          &dev->kobj, dev->bus_id);
+                error = sysfs_create_link_nowarn(&dev->class->p->class_subsys.kobj,
+                                                 &dev->kobj, dev->bus_id);
                 if (error)
                         goto out;
                 sysfs_remove_link(&dev->class->p->class_subsys.kobj,
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 8c0e4b92574f..c1a7efb310bf 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -398,7 +398,7 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
 }
 
 /**
- *      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_addrm_cxt *acxt,
  *      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))
                 return -EEXIST;
@@ -435,6 +435,39 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
 }
 
 /**
+ *      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
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 817f5966edca..a3ba217fbe74 100644
--- a/fs/sysfs/symlink.c
+++ b/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 * kobj, struct kobject * target, const char
         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 * kobj, struct kobject * target, const char
 }
 
 /**
+ *      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.
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index ce4e15f8aaeb..a5db496f71c7 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -107,6 +107,7 @@ struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
 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);
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 7858eac40aa7..37fa24152bd8 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -101,6 +101,9 @@ void sysfs_remove_bin_file(struct kobject *kobj, struct bin_attribute *attr);
 
 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,
@@ -180,6 +183,13 @@ static inline int sysfs_create_link(struct kobject *kobj,
         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)
 {
 }