sysfs: Factor out sysfs_rename from sysfs_rename_dir and sysfs_move_dir

These two functions do 90% of the same work and it doesn't significantly obfuscate the function to allow both the parent dir and the name to change at the same time. So merge them together to simplify maintenance, and increase testing. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

sysfs: Factor out sysfs_rename from sysfs_rename_dir and sysfs_move_dir
These two functions do 90% of the same work and it doesn't significantly obfuscate the function to allow both the parent dir and the name to change at the same time. So merge them together to simplify maintenance, and increase testing. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Eric W. Biederman · Greg Kroah-Hartman
1 parent 832b6af198
Showing 2 changed files with 32 additions and 33 deletions Side-by-side Diff
fs/sysfs/dir.c
fs/sysfs/sysfs.h
@@ -760,31 +760,43 @@
 	__sysfs_remove_dir(sd);
 }
  
-int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
+int sysfs_rename(struct sysfs_dirent *sd,
+	struct sysfs_dirent *new_parent_sd, const char *new_name)
 {
-	struct sysfs_dirent *sd = kobj->sd;
 	const char *dup_name = NULL;
 	int error;
  
 	mutex_lock(&sysfs_mutex);
  
 	error = 0;
-	if (strcmp(sd->s_name, new_name) == 0)
+	if ((sd->s_parent == new_parent_sd) &&
+	    (strcmp(sd->s_name, new_name) == 0))
 		goto out;	/* nothing to rename */
  
 	error = -EEXIST;
-	if (sysfs_find_dirent(sd->s_parent, new_name))
+	if (sysfs_find_dirent(new_parent_sd, new_name))
 		goto out;
  
 	/* rename sysfs_dirent */
-	error = -ENOMEM;
-	new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
-	if (!new_name)
-		goto out;
+	if (strcmp(sd->s_name, new_name) != 0) {
+		error = -ENOMEM;
+		new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
+		if (!new_name)
+			goto out;
  
-	dup_name = sd->s_name;
-	sd->s_name = new_name;
+		dup_name = sd->s_name;
+		sd->s_name = new_name;
+	}
  
+	/* Remove from old parent's list and insert into new parent's list. */
+	if (sd->s_parent != new_parent_sd) {
+		sysfs_unlink_sibling(sd);
+		sysfs_get(new_parent_sd);
+		sysfs_put(sd->s_parent);
+		sd->s_parent = new_parent_sd;
+		sysfs_link_sibling(sd);
+	}
+
 	error = 0;
  out:
 	mutex_unlock(&sysfs_mutex);
  
  
  
@@ -792,37 +804,21 @@
 	return error;
 }
  
+int sysfs_rename_dir(struct kobject *kobj, const char *new_name)
+{
+	return sysfs_rename(kobj->sd, kobj->sd->s_parent, new_name);
+}
+
 int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
 {
 	struct sysfs_dirent *sd = kobj->sd;
 	struct sysfs_dirent *new_parent_sd;
-	int error;
  
 	BUG_ON(!sd->s_parent);
-
-	mutex_lock(&sysfs_mutex);
-	new_parent_sd = (new_parent_kobj && new_parent_kobj->sd) ?
+	new_parent_sd = new_parent_kobj && new_parent_kobj->sd ?
 		new_parent_kobj->sd : &sysfs_root;
  
-	error = 0;
-	if (sd->s_parent == new_parent_sd)
-		goto out;	/* nothing to move */
-
-	error = -EEXIST;
-	if (sysfs_find_dirent(new_parent_sd, sd->s_name))
-		goto out;
-
-	/* Remove from old parent's list and insert into new parent's list. */
-	sysfs_unlink_sibling(sd);
-	sysfs_get(new_parent_sd);
-	sysfs_put(sd->s_parent);
-	sd->s_parent = new_parent_sd;
-	sysfs_link_sibling(sd);
-
-	error = 0;
-out:
-	mutex_unlock(&sysfs_mutex);
-	return error;
+	return sysfs_rename(sd, new_parent_sd, sd->s_name);
 }
  
 /* Relationship between s_mode and the DT_xxx types */
@@ -130,6 +130,9 @@
 			struct sysfs_dirent **p_sd);
 void sysfs_remove_subdir(struct sysfs_dirent *sd);
  
+int sysfs_rename(struct sysfs_dirent *sd,
+	struct sysfs_dirent *new_parent_sd, const char *new_name);
+
 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
 {
 	if (sd) {
...	...	@@ -760,31 +760,43 @@
760	760	__sysfs_remove_dir(sd);
761	761	}
762	762
763		-int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
	763	+int sysfs_rename(struct sysfs_dirent *sd,
	764	+ struct sysfs_dirent new_parent_sd, const char new_name)
764	765	{
765		- struct sysfs_dirent *sd = kobj->sd;
766	766	const char *dup_name = NULL;
767	767	int error;
768	768
769	769	mutex_lock(&sysfs_mutex);
770	770
771	771	error = 0;
772		- if (strcmp(sd->s_name, new_name) == 0)
	772	+ if ((sd->s_parent == new_parent_sd) &&
	773	+ (strcmp(sd->s_name, new_name) == 0))
773	774	goto out; /* nothing to rename */
774	775
775	776	error = -EEXIST;
776		- if (sysfs_find_dirent(sd->s_parent, new_name))
	777	+ if (sysfs_find_dirent(new_parent_sd, new_name))
777	778	goto out;
778	779
779	780	/* rename sysfs_dirent */
780		- error = -ENOMEM;
781		- new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
782		- if (!new_name)
783		- goto out;
	781	+ if (strcmp(sd->s_name, new_name) != 0) {
	782	+ error = -ENOMEM;
	783	+ new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
	784	+ if (!new_name)
	785	+ goto out;
784	786
785		- dup_name = sd->s_name;
786		- sd->s_name = new_name;
	787	+ dup_name = sd->s_name;
	788	+ sd->s_name = new_name;
	789	+ }
787	790
	791	+ /* Remove from old parent's list and insert into new parent's list. */
	792	+ if (sd->s_parent != new_parent_sd) {
	793	+ sysfs_unlink_sibling(sd);
	794	+ sysfs_get(new_parent_sd);
	795	+ sysfs_put(sd->s_parent);
	796	+ sd->s_parent = new_parent_sd;
	797	+ sysfs_link_sibling(sd);
	798	+ }
	799	+
788	800	error = 0;
789	801	out:
790	802	mutex_unlock(&sysfs_mutex);
791	803
792	804
793	805
...	...	@@ -792,37 +804,21 @@
792	804	return error;
793	805	}
794	806
	807	+int sysfs_rename_dir(struct kobject kobj, const char new_name)
	808	+{
	809	+ return sysfs_rename(kobj->sd, kobj->sd->s_parent, new_name);
	810	+}
	811	+
795	812	int sysfs_move_dir(struct kobject kobj, struct kobject new_parent_kobj)
796	813	{
797	814	struct sysfs_dirent *sd = kobj->sd;
798	815	struct sysfs_dirent *new_parent_sd;
799		- int error;
800	816
801	817	BUG_ON(!sd->s_parent);
802		-
803		- mutex_lock(&sysfs_mutex);
804		- new_parent_sd = (new_parent_kobj && new_parent_kobj->sd) ?
	818	+ new_parent_sd = new_parent_kobj && new_parent_kobj->sd ?
805	819	new_parent_kobj->sd : &sysfs_root;
806	820
807		- error = 0;
808		- if (sd->s_parent == new_parent_sd)
809		- goto out; /* nothing to move */
810		-
811		- error = -EEXIST;
812		- if (sysfs_find_dirent(new_parent_sd, sd->s_name))
813		- goto out;
814		-
815		- /* Remove from old parent's list and insert into new parent's list. */
816		- sysfs_unlink_sibling(sd);
817		- sysfs_get(new_parent_sd);
818		- sysfs_put(sd->s_parent);
819		- sd->s_parent = new_parent_sd;
820		- sysfs_link_sibling(sd);
821		-
822		- error = 0;
823		-out:
824		- mutex_unlock(&sysfs_mutex);
825		- return error;
	821	+ return sysfs_rename(sd, new_parent_sd, sd->s_name);
826	822	}
827	823
828	824	/* Relationship between s_mode and the DT_xxx types */
...	...	@@ -130,6 +130,9 @@
130	130	struct sysfs_dirent **p_sd);
131	131	void sysfs_remove_subdir(struct sysfs_dirent *sd);
132	132
	133	+int sysfs_rename(struct sysfs_dirent *sd,
	134	+ struct sysfs_dirent new_parent_sd, const char new_name);
	135	+
133	136	static inline struct sysfs_dirent __sysfs_get(struct sysfs_dirent sd)
134	137	{
135	138	if (sd) {