sysfs: add sysfs_dirent->s_name
Add s_name to sysfs_dirent. This is to further reduce dependency to
the associated dentry. Name is copied for directories and symlinks
but not for attributes.
Where possible, name dereferences are converted to use sd->s_name.
sysfs_symlink->link_name and sysfs_get_name() are unused now and
removed.
This change allows symlink to be implemented using sysfs_dirent tree
proper, which is the last remaining dentry-dependent sysfs walk.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 5d50e1dd..6e8d6f5 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -54,10 +54,11 @@
if (sd->s_type & SYSFS_KOBJ_LINK) {
struct sysfs_symlink * sl = sd->s_element;
- kfree(sl->link_name);
kobject_put(sl->target_kobj);
kfree(sl);
}
+ if (sd->s_type & SYSFS_COPY_NAME)
+ kfree(sd->s_name);
kfree(sd->s_iattr);
sysfs_free_ino(sd->s_ino);
kmem_cache_free(sysfs_dir_cachep, sd);
@@ -94,29 +95,41 @@
.d_iput = sysfs_d_iput,
};
-struct sysfs_dirent *sysfs_new_dirent(void *element, umode_t mode, int type)
+struct sysfs_dirent *sysfs_new_dirent(const char *name, void *element,
+ umode_t mode, int type)
{
- struct sysfs_dirent * sd;
+ char *dup_name = NULL;
+ struct sysfs_dirent *sd = NULL;
+
+ if (type & SYSFS_COPY_NAME) {
+ name = dup_name = kstrdup(name, GFP_KERNEL);
+ if (!name)
+ goto err_out;
+ }
sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
if (!sd)
- return NULL;
+ goto err_out;
- if (sysfs_alloc_ino(&sd->s_ino)) {
- kmem_cache_free(sysfs_dir_cachep, sd);
- return NULL;
- }
+ if (sysfs_alloc_ino(&sd->s_ino))
+ goto err_out;
atomic_set(&sd->s_count, 1);
atomic_set(&sd->s_event, 1);
INIT_LIST_HEAD(&sd->s_children);
INIT_LIST_HEAD(&sd->s_sibling);
+ sd->s_name = name;
sd->s_element = element;
sd->s_mode = mode;
sd->s_type = type;
return sd;
+
+ err_out:
+ kfree(dup_name);
+ kmem_cache_free(sysfs_dir_cachep, sd);
+ return NULL;
}
void sysfs_attach_dirent(struct sysfs_dirent *sd,
@@ -148,8 +161,7 @@
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
if (sd->s_element) {
- const unsigned char *existing = sysfs_get_name(sd);
- if (strcmp(existing, new))
+ if (strcmp(sd->s_name, new))
continue;
else
return -EEXIST;
@@ -203,7 +215,7 @@
goto out_dput;
error = -ENOMEM;
- sd = sysfs_new_dirent(kobj, mode, SYSFS_DIR);
+ sd = sysfs_new_dirent(name, kobj, mode, SYSFS_DIR);
if (!sd)
goto out_drop;
sysfs_attach_dirent(sd, parent->d_fsdata, dentry);
@@ -334,9 +346,7 @@
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
if (sd->s_type & SYSFS_NOT_PINNED) {
- const unsigned char * name = sysfs_get_name(sd);
-
- if (strcmp(name, dentry->d_name.name))
+ if (strcmp(sd->s_name, dentry->d_name.name))
continue;
if (sd->s_type & SYSFS_KOBJ_LINK)
@@ -427,9 +437,11 @@
int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent,
const char *new_name)
{
+ struct sysfs_dirent *sd = kobj->dentry->d_fsdata;
+ struct sysfs_dirent *parent_sd = new_parent->d_fsdata;
+ struct dentry *new_dentry;
+ char *dup_name;
int error;
- struct dentry * new_dentry;
- struct sysfs_dirent *sd, *parent_sd;
if (!new_parent)
return -EFAULT;
@@ -457,22 +469,31 @@
if (new_dentry->d_inode)
goto out_dput;
- error = kobject_set_name(kobj, "%s", new_name);
- if (error)
+ /* rename kobject and sysfs_dirent */
+ error = -ENOMEM;
+ new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
+ if (!new_name)
goto out_drop;
+ error = kobject_set_name(kobj, "%s", new_name);
+ if (error)
+ goto out_free;
+
+ kfree(sd->s_name);
+ sd->s_name = new_name;
+
+ /* move under the new parent */
d_add(new_dentry, NULL);
d_move(kobj->dentry, new_dentry);
- sd = kobj->dentry->d_fsdata;
- parent_sd = new_parent->d_fsdata;
-
list_del_init(&sd->s_sibling);
list_add(&sd->s_sibling, &parent_sd->s_children);
error = 0;
goto out_unlock;
+ out_free:
+ kfree(dup_name);
out_drop:
d_drop(new_dentry);
out_dput:
@@ -535,7 +556,7 @@
struct sysfs_dirent * sd;
mutex_lock(&dentry->d_inode->i_mutex);
- sd = sysfs_new_dirent(NULL, 0, 0);
+ sd = sysfs_new_dirent("_DIR_", NULL, 0, 0);
if (sd)
sysfs_attach_dirent(sd, parent_sd, NULL);
mutex_unlock(&dentry->d_inode->i_mutex);
@@ -605,7 +626,7 @@
if (!next->s_element)
continue;
- name = sysfs_get_name(next);
+ name = next->s_name;
len = strlen(name);
ino = next->s_ino;
@@ -717,7 +738,7 @@
if (!shadow)
goto nomem;
- sd = sysfs_new_dirent(kobj, inode->i_mode, SYSFS_DIR);
+ sd = sysfs_new_dirent("_SHADOW_", kobj, inode->i_mode, SYSFS_DIR);
if (!sd)
goto nomem;
/* point to parent_sd but don't attach to it */