summaryrefslogtreecommitdiffstats
path: root/fs/sysfs/symlink.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/sysfs/symlink.c')
-rw-r--r--fs/sysfs/symlink.c219
1 files changed, 43 insertions, 176 deletions
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 3ae3f1bf1a0..aecb15f8455 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -11,109 +11,73 @@
*/
#include <linux/fs.h>
-#include <linux/gfp.h>
-#include <linux/mount.h>
#include <linux/module.h>
#include <linux/kobject.h>
-#include <linux/namei.h>
#include <linux/mutex.h>
#include <linux/security.h>
#include "sysfs.h"
-static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd,
- struct kobject *target,
+static int sysfs_do_create_link_sd(struct kernfs_node *parent,
+ struct kobject *target_kobj,
const char *name, int warn)
{
- struct sysfs_dirent *target_sd = NULL;
- struct sysfs_dirent *sd = NULL;
- struct sysfs_addrm_cxt acxt;
- enum kobj_ns_type ns_type;
- int error;
+ struct kernfs_node *kn, *target = NULL;
- BUG_ON(!name || !parent_sd);
+ BUG_ON(!name || !parent);
/*
- * We don't own @target and it may be removed at any time.
+ * We don't own @target_kobj and it may be removed at any time.
* Synchronize using sysfs_symlink_target_lock. See
* sysfs_remove_dir() for details.
*/
spin_lock(&sysfs_symlink_target_lock);
- if (target->sd)
- target_sd = sysfs_get(target->sd);
+ if (target_kobj->sd) {
+ target = target_kobj->sd;
+ kernfs_get(target);
+ }
spin_unlock(&sysfs_symlink_target_lock);
- error = -ENOENT;
- if (!target_sd)
- goto out_put;
-
- error = -ENOMEM;
- sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK);
- if (!sd)
- goto out_put;
+ if (!target)
+ return -ENOENT;
- ns_type = sysfs_ns_type(parent_sd);
- if (ns_type)
- sd->s_ns = target_sd->s_ns;
- sd->s_symlink.target_sd = target_sd;
- target_sd = NULL; /* reference is now owned by the symlink */
-
- sysfs_addrm_start(&acxt);
- /* Symlinks must be between directories with the same ns_type */
- if (!ns_type ||
- (ns_type == sysfs_ns_type(sd->s_symlink.target_sd->s_parent))) {
- if (warn)
- error = sysfs_add_one(&acxt, sd, parent_sd);
- else
- error = __sysfs_add_one(&acxt, sd, parent_sd);
- } else {
- error = -EINVAL;
- WARN(1, KERN_WARNING
- "sysfs: symlink across ns_types %s/%s -> %s/%s\n",
- parent_sd->s_name,
- sd->s_name,
- sd->s_symlink.target_sd->s_parent->s_name,
- sd->s_symlink.target_sd->s_name);
- }
- sysfs_addrm_finish(&acxt);
+ kn = kernfs_create_link(parent, name, target);
+ kernfs_put(target);
- if (error)
- goto out_put;
+ if (!IS_ERR(kn))
+ return 0;
- return 0;
-
- out_put:
- sysfs_put(target_sd);
- sysfs_put(sd);
- return error;
+ if (warn && PTR_ERR(kn) == -EEXIST)
+ sysfs_warn_dup(parent, name);
+ return PTR_ERR(kn);
}
/**
* sysfs_create_link_sd - create symlink to a given object.
- * @sd: directory we're creating the link in.
+ * @kn: directory we're creating the link in.
* @target: object we're pointing to.
* @name: name of the symlink.
*/
-int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target,
+int sysfs_create_link_sd(struct kernfs_node *kn, struct kobject *target,
const char *name)
{
- return sysfs_do_create_link_sd(sd, target, name, 1);
+ return sysfs_do_create_link_sd(kn, target, name, 1);
}
static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target,
const char *name, int warn)
{
- struct sysfs_dirent *parent_sd = NULL;
+ struct kernfs_node *parent = NULL;
if (!kobj)
- parent_sd = &sysfs_root;
+ parent = sysfs_root_kn;
else
- parent_sd = kobj->sd;
+ parent = kobj->sd;
- if (!parent_sd)
+ if (!parent)
return -EFAULT;
- return sysfs_do_create_link_sd(parent_sd, target, name, warn);
+ return sysfs_do_create_link_sd(parent, target, name, warn);
}
/**
@@ -164,10 +128,10 @@ void sysfs_delete_link(struct kobject *kobj, struct kobject *targ,
* sysfs_remove_dir() for details.
*/
spin_lock(&sysfs_symlink_target_lock);
- if (targ->sd && sysfs_ns_type(kobj->sd))
- ns = targ->sd->s_ns;
+ if (targ->sd && kernfs_ns_enabled(kobj->sd))
+ ns = targ->sd->ns;
spin_unlock(&sysfs_symlink_target_lock);
- sysfs_hash_and_remove(kobj->sd, name, ns);
+ kernfs_remove_by_name_ns(kobj->sd, name, ns);
}
/**
@@ -177,14 +141,14 @@ void sysfs_delete_link(struct kobject *kobj, struct kobject *targ,
*/
void sysfs_remove_link(struct kobject *kobj, const char *name)
{
- struct sysfs_dirent *parent_sd = NULL;
+ struct kernfs_node *parent = NULL;
if (!kobj)
- parent_sd = &sysfs_root;
+ parent = sysfs_root_kn;
else
- parent_sd = kobj->sd;
+ parent = kobj->sd;
- sysfs_hash_and_remove(parent_sd, name, NULL);
+ kernfs_remove_by_name(parent, name);
}
EXPORT_SYMBOL_GPL(sysfs_remove_link);
@@ -201,130 +165,33 @@ EXPORT_SYMBOL_GPL(sysfs_remove_link);
int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *targ,
const char *old, const char *new, const void *new_ns)
{
- struct sysfs_dirent *parent_sd, *sd = NULL;
+ struct kernfs_node *parent, *kn = NULL;
const void *old_ns = NULL;
int result;
if (!kobj)
- parent_sd = &sysfs_root;
+ parent = sysfs_root_kn;
else
- parent_sd = kobj->sd;
+ parent = kobj->sd;
if (targ->sd)
- old_ns = targ->sd->s_ns;
+ old_ns = targ->sd->ns;
result = -ENOENT;
- sd = sysfs_get_dirent_ns(parent_sd, old, old_ns);
- if (!sd)
+ kn = kernfs_find_and_get_ns(parent, old, old_ns);
+ if (!kn)
goto out;
result = -EINVAL;
- if (sysfs_type(sd) != SYSFS_KOBJ_LINK)
+ if (kernfs_type(kn) != KERNFS_LINK)
goto out;
- if (sd->s_symlink.target_sd->s_dir.kobj != targ)
+ if (kn->symlink.target_kn->priv != targ)
goto out;
- result = sysfs_rename(sd, parent_sd, new, new_ns);
+ result = kernfs_rename_ns(kn, parent, new, new_ns);
out:
- sysfs_put(sd);
+ kernfs_put(kn);
return result;
}
EXPORT_SYMBOL_GPL(sysfs_rename_link_ns);
-
-static int sysfs_get_target_path(struct sysfs_dirent *parent_sd,
- struct sysfs_dirent *target_sd, char *path)
-{
- struct sysfs_dirent *base, *sd;
- char *s = path;
- int len = 0;
-
- /* go up to the root, stop at the base */
- base = parent_sd;
- while (base->s_parent) {
- sd = target_sd->s_parent;
- while (sd->s_parent && base != sd)
- sd = sd->s_parent;
-
- if (base == sd)
- break;
-
- strcpy(s, "../");
- s += 3;
- base = base->s_parent;
- }
-
- /* determine end of target string for reverse fillup */
- sd = target_sd;
- while (sd->s_parent && sd != base) {
- len += strlen(sd->s_name) + 1;
- sd = sd->s_parent;
- }
-
- /* check limits */
- if (len < 2)
- return -EINVAL;
- len--;
- if ((s - path) + len > PATH_MAX)
- return -ENAMETOOLONG;
-
- /* reverse fillup of target string from target to base */
- sd = target_sd;
- while (sd->s_parent && sd != base) {
- int slen = strlen(sd->s_name);
-
- len -= slen;
- strncpy(s + len, sd->s_name, slen);
- if (len)
- s[--len] = '/';
-
- sd = sd->s_parent;
- }
-
- return 0;
-}
-
-static int sysfs_getlink(struct dentry *dentry, char *path)
-{
- struct sysfs_dirent *sd = dentry->d_fsdata;
- struct sysfs_dirent *parent_sd = sd->s_parent;
- struct sysfs_dirent *target_sd = sd->s_symlink.target_sd;
- int error;
-
- mutex_lock(&sysfs_mutex);
- error = sysfs_get_target_path(parent_sd, target_sd, path);
- mutex_unlock(&sysfs_mutex);
-
- return error;
-}
-
-static void *sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- int error = -ENOMEM;
- unsigned long page = get_zeroed_page(GFP_KERNEL);
- if (page) {
- error = sysfs_getlink(dentry, (char *) page);
- if (error < 0)
- free_page((unsigned long)page);
- }
- nd_set_link(nd, error ? ERR_PTR(error) : (char *)page);
- return NULL;
-}
-
-static void sysfs_put_link(struct dentry *dentry, struct nameidata *nd,
- void *cookie)
-{
- char *page = nd_get_link(nd);
- if (!IS_ERR(page))
- free_page((unsigned long)page);
-}
-
-const struct inode_operations sysfs_symlink_inode_operations = {
- .setxattr = sysfs_setxattr,
- .readlink = generic_readlink,
- .follow_link = sysfs_follow_link,
- .put_link = sysfs_put_link,
- .setattr = sysfs_setattr,
- .getattr = sysfs_getattr,
- .permission = sysfs_permission,
-};