sysfs: move sysfs_dirent->s_children into sysfs_dirent->s_dir

Children list head is only meaninful for directory nodes.  Move it
into s_dir.  This doesn't save any space currently but it will with
further changes.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 12 insertions, 10 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 48a3ed4f4537..4ad9422566a8 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -26,7 +26,7 @@ static DEFINE_IDA(sysfs_ino_ida);
  *      @sd: sysfs_dirent of interest
  *
  *      Link @sd into its sibling list which starts from
- *      sd->s_parent->s_children.
+ *      sd->s_parent->s_dir.children.
  *
  *      Locking:
  *      mutex_lock(sysfs_mutex)
@@ -40,9 +40,9 @@ static void sysfs_link_sibling(struct sysfs_dirent *sd)
 
         /* Store directory entries in order by ino.  This allows
          * readdir to properly restart without having to add a
-         * cursor into the s_children list.
+         * cursor into the s_dir.children list.
          */
-        for (pos = &parent_sd->s_children; *pos; pos = &(*pos)->s_sibling) {
+        for (pos = &parent_sd->s_dir.children; *pos; pos = &(*pos)->s_sibling) {
                 if (sd->s_ino < (*pos)->s_ino)
                         break;
         }
@@ -55,7 +55,7 @@ static void sysfs_link_sibling(struct sysfs_dirent *sd)
  *      @sd: sysfs_dirent of interest
  *
  *      Unlink @sd from its sibling list which starts from
- *      sd->s_parent->s_children.
+ *      sd->s_parent->s_dir.children.
  *
  *      Locking:
  *      mutex_lock(sysfs_mutex)
@@ -64,7 +64,8 @@ static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
 {
         struct sysfs_dirent **pos;
 
-        for (pos = &sd->s_parent->s_children; *pos; pos = &(*pos)->s_sibling) {
+        for (pos = &sd->s_parent->s_dir.children; *pos;
+             pos = &(*pos)->s_sibling) {
                 if (*pos == sd) {
                         *pos = sd->s_sibling;
                         sd->s_sibling = NULL;
@@ -570,7 +571,7 @@ struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
 {
         struct sysfs_dirent *sd;
 
-        for (sd = parent_sd->s_children; sd; sd = sd->s_sibling)
+        for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling)
                 if (!strcmp(sd->s_name, name))
                         return sd;
         return NULL;
@@ -722,7 +723,7 @@ static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
 
         pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);
         sysfs_addrm_start(&acxt, dir_sd);
-        pos = &dir_sd->s_children;
+        pos = &dir_sd->s_dir.children;
         while (*pos) {
                 struct sysfs_dirent *sd = *pos;
 
@@ -922,7 +923,7 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
                 mutex_lock(&sysfs_mutex);
 
                 /* Skip the dentries we have already reported */
-                pos = parent_sd->s_children;
+                pos = parent_sd->s_dir.children;
                 while (pos && (filp->f_pos > pos->s_ino))
                         pos = pos->s_sibling;
 
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index c40fb9fdd04c..2210cf0005fe 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -127,7 +127,7 @@ static int sysfs_count_nlink(struct sysfs_dirent *sd)
         struct sysfs_dirent *child;
         int nr = 0;
 
-        for (child = sd->s_children; child; child = child->s_sibling)
+        for (child = sd->s_dir.children; child; child = child->s_sibling)
                 if (sysfs_type(child) == SYSFS_DIR)
                         nr++;
 
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 60405a6e4c22..42b0327d1624 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -1,6 +1,8 @@
 /* type-specific structures for sysfs_dirent->s_* union members */
 struct sysfs_elem_dir {
         struct kobject          *kobj;
+        /* children list starts here and goes through sd->s_sibling */
+        struct sysfs_dirent     *children;
 };
 
 struct sysfs_elem_symlink {
@@ -28,7 +30,6 @@ struct sysfs_dirent {
         atomic_t                s_active;
         struct sysfs_dirent     *s_parent;
         struct sysfs_dirent     *s_sibling;
-        struct sysfs_dirent     *s_children;
         const char              *s_name;
 
         union {