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
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -30,7 +30,7 @@
* 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 @@
* 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 @@
inc_nlink(acxt->parent_inode);
acxt->cnt++;
+
+ sysfs_link_sibling(sd);
}
/**
@@ -521,7 +523,9 @@
*/
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 @@
/* 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 @@
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 @@
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);