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,
-};