#include <linux/module.h>
#include <linux/kobject.h>
#include <linux/namei.h>
+#include <asm/semaphore.h>
#include "sysfs.h"
-static int object_depth(struct kobject * kobj)
+static int object_depth(struct sysfs_dirent *sd)
{
- struct kobject * p = kobj;
int depth = 0;
- do { depth++; } while ((p = p->parent));
+
+ for (; sd->s_parent; sd = sd->s_parent)
+ depth++;
+
return depth;
}
-static int object_path_length(struct kobject * kobj)
+static int object_path_length(struct sysfs_dirent * sd)
{
- struct kobject * p = kobj;
int length = 1;
- do {
- length += strlen(kobject_name(p)) + 1;
- p = p->parent;
- } while (p);
+
+ for (; sd->s_parent; sd = sd->s_parent)
+ length += strlen(sd->s_name) + 1;
+
return length;
}
-static void fill_object_path(struct kobject * kobj, char * buffer, int length)
+static void fill_object_path(struct sysfs_dirent *sd, char *buffer, int length)
{
- struct kobject * p;
-
--length;
- for (p = kobj; p; p = p->parent) {
- int cur = strlen(kobject_name(p));
+ for (; sd->s_parent; sd = sd->s_parent) {
+ int cur = strlen(sd->s_name);
/* back up enough to print this bus id with '/' */
length -= cur;
- strncpy(buffer + length,kobject_name(p),cur);
+ strncpy(buffer + length, sd->s_name, cur);
*(buffer + --length) = '/';
}
}
-static int sysfs_add_link(struct dentry * parent, const char * name, struct kobject * target)
+static int sysfs_add_link(struct sysfs_dirent * parent_sd, const char * name,
+ struct sysfs_dirent * target_sd)
{
- struct sysfs_dirent * parent_sd = parent->d_fsdata;
- struct sysfs_symlink * sl;
- int error = 0;
-
- error = -ENOMEM;
- sl = kmalloc(sizeof(*sl), GFP_KERNEL);
- if (!sl)
- goto exit1;
-
- sl->link_name = kmalloc(strlen(name) + 1, GFP_KERNEL);
- if (!sl->link_name)
- goto exit2;
-
- strcpy(sl->link_name, name);
- sl->target_kobj = kobject_get(target);
-
- error = sysfs_make_dirent(parent_sd, NULL, sl, S_IFLNK|S_IRWXUGO,
- SYSFS_KOBJ_LINK);
- if (!error)
- return 0;
-
- kobject_put(target);
- kfree(sl->link_name);
-exit2:
- kfree(sl);
-exit1:
- return error;
+ struct sysfs_dirent * sd;
+
+ sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK);
+ if (!sd)
+ return -ENOMEM;
+
+ sd->s_elem.symlink.target_sd = target_sd;
+ sysfs_attach_dirent(sd, parent_sd, NULL);
+ return 0;
}
/**
int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char * name)
{
struct dentry *dentry = NULL;
+ struct sysfs_dirent *parent_sd = NULL;
+ struct sysfs_dirent *target_sd = NULL;
int error = -EEXIST;
BUG_ON(!name);
if (!dentry)
return -EFAULT;
+ parent_sd = dentry->d_fsdata;
+
+ /* target->dentry can go away beneath us but is protected with
+ * kobj_sysfs_assoc_lock. Fetch target_sd from it.
+ */
+ spin_lock(&kobj_sysfs_assoc_lock);
+ if (target->dentry)
+ target_sd = sysfs_get(target->dentry->d_fsdata);
+ spin_unlock(&kobj_sysfs_assoc_lock);
+
+ if (!target_sd)
+ return -ENOENT;
mutex_lock(&dentry->d_inode->i_mutex);
if (!sysfs_dirent_exist(dentry->d_fsdata, name))
- error = sysfs_add_link(dentry, name, target);
+ error = sysfs_add_link(parent_sd, name, target_sd);
mutex_unlock(&dentry->d_inode->i_mutex);
+
+ if (error)
+ sysfs_put(target_sd);
+
return error;
}
sysfs_hash_and_remove(kobj->dentry,name);
}
-static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target,
- char *path)
+static int sysfs_get_target_path(struct sysfs_dirent * parent_sd,
+ struct sysfs_dirent * target_sd, char *path)
{
char * s;
int depth, size;
- depth = object_depth(kobj);
- size = object_path_length(target) + depth * 3 - 1;
+ depth = object_depth(parent_sd);
+ size = object_path_length(target_sd) + depth * 3 - 1;
if (size > PATH_MAX)
return -ENAMETOOLONG;
for (s = path; depth--; s += 3)
strcpy(s,"../");
- fill_object_path(target, path, size);
+ fill_object_path(target_sd, path, size);
pr_debug("%s: path = '%s'\n", __FUNCTION__, path);
return 0;
static int sysfs_getlink(struct dentry *dentry, char * path)
{
- struct kobject *kobj, *target_kobj;
- int error = 0;
-
- kobj = sysfs_get_kobject(dentry->d_parent);
- if (!kobj)
- return -EINVAL;
-
- target_kobj = sysfs_get_kobject(dentry);
- if (!target_kobj) {
- kobject_put(kobj);
- return -EINVAL;
- }
+ struct sysfs_dirent *sd = dentry->d_fsdata;
+ struct sysfs_dirent *parent_sd = sd->s_parent;
+ struct sysfs_dirent *target_sd = sd->s_elem.symlink.target_sd;
+ int error;
down_read(&sysfs_rename_sem);
- error = sysfs_get_target_path(kobj, target_kobj, path);
+ error = sysfs_get_target_path(parent_sd, target_sd, path);
up_read(&sysfs_rename_sem);
-
- kobject_put(kobj);
- kobject_put(target_kobj);
- return error;
+ return error;
}
static void *sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)
free_page((unsigned long)page);
}
-struct inode_operations sysfs_symlink_inode_operations = {
+const struct inode_operations sysfs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = sysfs_follow_link,
.put_link = sysfs_put_link,
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