1 files changed, 70 insertions, 80 deletions

diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 7b9c5bfde920..2f86e0422290 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -11,71 +11,39 @@
 
 #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)
-{
-        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;
-}
-
 /**
  *      sysfs_create_link - create symlink between two objects.
  *      @kobj:  object whose directory we're creating the link in.
@@ -84,24 +52,57 @@ exit1:
  */
 int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char * name)
 {
-        struct dentry *dentry = NULL;
-        int error = -EEXIST;
+        struct sysfs_dirent *parent_sd = NULL;
+        struct sysfs_dirent *target_sd = NULL;
+        struct sysfs_dirent *sd = NULL;
+        struct sysfs_addrm_cxt acxt;
+        int error;
 
         BUG_ON(!name);
 
         if (!kobj) {
                 if (sysfs_mount && sysfs_mount->mnt_sb)
-                        dentry = sysfs_mount->mnt_sb->s_root;
+                        parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata;
         } else
-                dentry = kobj->dentry;
+                parent_sd = kobj->sd;
+
+        error = -EFAULT;
+        if (!parent_sd)
+                goto out_put;
+
+        /* target->sd can go away beneath us but is protected with
+         * sysfs_assoc_lock.  Fetch target_sd from it.
+         */
+        spin_lock(&sysfs_assoc_lock);
+        if (target->sd)
+                target_sd = sysfs_get(target->sd);
+        spin_unlock(&sysfs_assoc_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;
+        sd->s_elem.symlink.target_sd = target_sd;
 
-        if (!dentry)
-                return -EFAULT;
+        sysfs_addrm_start(&acxt, parent_sd);
 
-        mutex_lock(&dentry->d_inode->i_mutex);
-        if (!sysfs_dirent_exist(dentry->d_fsdata, name))
-                error = sysfs_add_link(dentry, name, target);
-        mutex_unlock(&dentry->d_inode->i_mutex);
+        if (!sysfs_find_dirent(parent_sd, name)) {
+                sysfs_add_one(&acxt, sd);
+                sysfs_link_sibling(sd);
+        }
+
+        if (sysfs_addrm_finish(&acxt))
+                return 0;
+
+        error = -EEXIST;
+        /* fall through */
+ out_put:
+        sysfs_put(target_sd);
+        sysfs_put(sd);
         return error;
 }
 
@@ -114,17 +115,17 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char
 
 void sysfs_remove_link(struct kobject * kobj, const char * name)
 {
-        sysfs_hash_and_remove(kobj->dentry,name);
+        sysfs_hash_and_remove(kobj->sd, 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;
 
@@ -133,7 +134,7 @@ static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target,
         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;
@@ -141,27 +142,16 @@ static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target,
 
 static int sysfs_getlink(struct dentry *dentry, char * path)
 {
-        struct kobject *kobj, *target_kobj;
-        int error = 0;
+        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;
 
-        kobj = sysfs_get_kobject(dentry->d_parent);
-        if (!kobj)
-                return -EINVAL;
+        mutex_lock(&sysfs_mutex);
+        error = sysfs_get_target_path(parent_sd, target_sd, path);
+        mutex_unlock(&sysfs_mutex);
 
-        target_kobj = sysfs_get_kobject(dentry);
-        if (!target_kobj) {
-                kobject_put(kobj);
-                return -EINVAL;
-        }
-
-        down_read(&sysfs_rename_sem);
-        error = sysfs_get_target_path(kobj, target_kobj, path);
-        up_read(&sysfs_rename_sem);
-        
-        kobject_put(kobj);
-        kobject_put(target_kobj);
         return error;
-
 }
 
 static void *sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)