sysfs: make sysfs_add/remove_one() call link/unlink_sibling() implictly

When adding or removing a sysfs_dirent, the user used to be required
to call link/unlink separately.  It was for two reasons - code looked
like that before sysfs_addrm_cxt conversion and to avoid looping
through parent_sd->children list twice during removal.

Performance optimization during removal just isn't worth it.  Make
sysfs_add/remove_one() call sysfs_link/unlink_sibing() implicitly.
This makes code simpler albeit slightly less efficient.  This change
doesn't introduce any noticeable behavior change.

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>

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 9504d4c..354675a 100644 (file)
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -30,7 +30,7 @@ static DEFINE_IDA(sysfs_ino_ida);
  *     Locking:
  *     mutex_lock(sysfs_mutex)
  */
-void sysfs_link_sibling(struct sysfs_dirent *sd)
+static void sysfs_link_sibling(struct sysfs_dirent *sd)
 {
        struct sysfs_dirent *parent_sd = sd->s_parent;
 
@@ -49,7 +49,7 @@ void sysfs_link_sibling(struct sysfs_dirent *sd)
  *     Locking:
  *     mutex_lock(sysfs_mutex)
  */
-void sysfs_unlink_sibling(struct sysfs_dirent *sd)
+static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
 {
        struct sysfs_dirent **pos;
 
@@ -500,6 +500,8 @@ void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
                inc_nlink(acxt->parent_inode);
 
        acxt->cnt++;
+
+       sysfs_link_sibling(sd);
 }
 
 /**
@@ -521,7 +523,9 @@ void 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)
 {
-       BUG_ON(sd->s_sibling || (sd->s_flags & SYSFS_FLAG_REMOVED));
+       BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED);
+
+       sysfs_unlink_sibling(sd);
 
        sd->s_flags |= SYSFS_FLAG_REMOVED;
        sd->s_sibling = acxt->removed;
@@ -697,10 +701,8 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
        /* link in */
        sysfs_addrm_start(&acxt, parent_sd);
 
-       if (!sysfs_find_dirent(parent_sd, name)) {
+       if (!sysfs_find_dirent(parent_sd, name))
                sysfs_add_one(&acxt, sd);
-               sysfs_link_sibling(sd);
-       }
 
        if (!sysfs_addrm_finish(&acxt)) {
                sysfs_put(sd);
@@ -821,7 +823,6 @@ static void remove_dir(struct sysfs_dirent *sd)
        struct sysfs_addrm_cxt acxt;
 
        sysfs_addrm_start(&acxt, sd->s_parent);
-       sysfs_unlink_sibling(sd);
        sysfs_remove_one(&acxt, sd);
        sysfs_addrm_finish(&acxt);
 }
@@ -846,11 +847,9 @@ static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
        while (*pos) {
                struct sysfs_dirent *sd = *pos;
 
-               if (sysfs_type(sd) && sysfs_type(sd) != SYSFS_DIR) {
-                       *pos = sd->s_sibling;
-                       sd->s_sibling = NULL;
+               if (sysfs_type(sd) && sysfs_type(sd) != SYSFS_DIR)
                        sysfs_remove_one(&acxt, sd);
-               } else
+               else
                        pos = &(*pos)->s_sibling;
        }
        sysfs_addrm_finish(&acxt);

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index b21d11b..ea0e494 100644 (file)
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -405,10 +405,8 @@ int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr,
 
        sysfs_addrm_start(&acxt, dir_sd);
 
-       if (!sysfs_find_dirent(dir_sd, attr->name)) {
+       if (!sysfs_find_dirent(dir_sd, attr->name))
                sysfs_add_one(&acxt, sd);
-               sysfs_link_sibling(sd);
-       }
 
        if (!sysfs_addrm_finish(&acxt)) {
                sysfs_put(sd);

diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index 45128b7..efb4062 100644 (file)
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -189,25 +189,16 @@ void sysfs_instantiate(struct dentry *dentry, struct inode *inode)
 int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name)
 {
        struct sysfs_addrm_cxt acxt;
-       struct sysfs_dirent **pos, *sd;
+       struct sysfs_dirent *sd;
 
        if (!dir_sd)
                return -ENOENT;
 
        sysfs_addrm_start(&acxt, dir_sd);
 
-       for (pos = &dir_sd->s_children; *pos; pos = &(*pos)->s_sibling) {
-               sd = *pos;
-
-               if (!sysfs_type(sd))
-                       continue;
-               if (!strcmp(sd->s_name, name)) {
-                       *pos = sd->s_sibling;
-                       sd->s_sibling = NULL;
-                       sysfs_remove_one(&acxt, sd);
-                       break;
-               }
-       }
+       sd = sysfs_find_dirent(dir_sd, name);
+       if (sd)
+               sysfs_remove_one(&acxt, sd);
 
        if (sysfs_addrm_finish(&acxt))
                return 0;

diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 9048453..c129f30 100644 (file)
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -92,10 +92,8 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char
 
        sysfs_addrm_start(&acxt, parent_sd);
 
-       if (!sysfs_find_dirent(parent_sd, name)) {
+       if (!sysfs_find_dirent(parent_sd, name))
                sysfs_add_one(&acxt, sd);
-               sysfs_link_sibling(sd);
-       }
 
        if (!sysfs_addrm_finish(&acxt)) {
                error = -EEXIST;

diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index b55e510..32b8b64 100644 (file)
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -56,8 +56,6 @@ extern struct sysfs_dirent sysfs_root;
 extern struct kmem_cache *sysfs_dir_cachep;
 
 extern struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
-extern void sysfs_link_sibling(struct sysfs_dirent *sd);
-extern void sysfs_unlink_sibling(struct sysfs_dirent *sd);
 extern struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
 extern void sysfs_put_active(struct sysfs_dirent *sd);
 extern struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);