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

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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>
This commit is contained in:
Tejun Heo 2007-08-02 21:38:03 +09:00 committed by Greg Kroah-Hartman
parent ff869de7bf
commit 41fc1c2745
5 changed files with 16 additions and 32 deletions
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21
fs/sysfs/dir.c
View file

@ -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);

4
fs/sysfs/file.c
View file

@ -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);

17
fs/sysfs/inode.c
View file

@ -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;

4
fs/sysfs/symlink.c
View file

@ -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;

2
fs/sysfs/sysfs.h
View file

@ -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);