3 files changed, 60 insertions, 105 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 337162935d21..4948d9bc405d 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -440,7 +440,7 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
 /**
  *      sysfs_remove_one - remove sysfs_dirent from parent
  *      @acxt: addrm context to use
- *      @sd: sysfs_dirent to be added
+ *      @sd: sysfs_dirent to be removed
  *
  *      Mark @sd removed and drop nlink of parent inode if @sd is a
  *      directory.  @sd is unlinked from the children list.
@@ -678,8 +678,10 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
         sd = sysfs_find_dirent(parent_sd, dentry->d_name.name);
 
         /* no such entry */
-        if (!sd)
+        if (!sd) {
+                ret = ERR_PTR(-ENOENT);
                 goto out_unlock;
+        }
 
         /* attach dentry and inode */
         inode = sysfs_get_inode(sd);
@@ -781,6 +783,7 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
         old_dentry = sysfs_get_dentry(sd);
         if (IS_ERR(old_dentry)) {
                 error = PTR_ERR(old_dentry);
+                old_dentry = NULL;
                 goto out;
         }
 
@@ -848,6 +851,7 @@ int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
         old_dentry = sysfs_get_dentry(sd);
         if (IS_ERR(old_dentry)) {
                 error = PTR_ERR(old_dentry);
+                old_dentry = NULL;
                 goto out;
         }
         old_parent = old_dentry->d_parent;
@@ -855,6 +859,7 @@ int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
         new_parent = sysfs_get_dentry(new_parent_sd);
         if (IS_ERR(new_parent)) {
                 error = PTR_ERR(new_parent);
+                new_parent = NULL;
                 goto out;
         }
 
@@ -878,7 +883,6 @@ again:
         error = 0;
         d_add(new_dentry, NULL);
         d_move(old_dentry, new_dentry);
-        dput(new_dentry);
 
         /* Remove from old parent's list and insert into new parent's list. */
         sysfs_unlink_sibling(sd);
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index b834f1709f9f..a271c87c4472 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -20,43 +20,6 @@
 
 #include "sysfs.h"
 
-#define to_sattr(a) container_of(a,struct subsys_attribute, attr)
-
-/*
- * Subsystem file operations.
- * These operations allow subsystems to have files that can be 
- * read/written. 
- */
-static ssize_t 
-subsys_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
-{
-        struct kset *kset = to_kset(kobj);
-        struct subsys_attribute * sattr = to_sattr(attr);
-        ssize_t ret = -EIO;
-
-        if (sattr->show)
-                ret = sattr->show(kset, page);
-        return ret;
-}
-
-static ssize_t 
-subsys_attr_store(struct kobject * kobj, struct attribute * attr, 
-                  const char * page, size_t count)
-{
-        struct kset *kset = to_kset(kobj);
-        struct subsys_attribute * sattr = to_sattr(attr);
-        ssize_t ret = -EIO;
-
-        if (sattr->store)
-                ret = sattr->store(kset, page, count);
-        return ret;
-}
-
-static struct sysfs_ops subsys_sysfs_ops = {
-        .show   = subsys_attr_show,
-        .store  = subsys_attr_store,
-};
-
 /*
  * There's one sysfs_buffer for each open file and one
  * sysfs_open_dirent for each sysfs_dirent with one or more open
@@ -66,7 +29,7 @@ static struct sysfs_ops subsys_sysfs_ops = {
  * sysfs_dirent->s_attr.open points to sysfs_open_dirent.  s_attr.open
  * is protected by sysfs_open_dirent_lock.
  */
-static spinlock_t sysfs_open_dirent_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(sysfs_open_dirent_lock);
 
 struct sysfs_open_dirent {
         atomic_t                refcnt;
@@ -354,31 +317,23 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
 {
         struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
         struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-        struct sysfs_buffer * buffer;
-        struct sysfs_ops * ops = NULL;
-        int error;
+        struct sysfs_buffer *buffer;
+        struct sysfs_ops *ops;
+        int error = -EACCES;
 
         /* need attr_sd for attr and ops, its parent for kobj */
         if (!sysfs_get_active_two(attr_sd))
                 return -ENODEV;
 
-        /* if the kobject has no ktype, then we assume that it is a subsystem
-         * itself, and use ops for it.
-         */
-        if (kobj->kset && kobj->kset->ktype)
-                ops = kobj->kset->ktype->sysfs_ops;
-        else if (kobj->ktype)
+        /* every kobject with an attribute needs a ktype assigned */
+        if (kobj->ktype && kobj->ktype->sysfs_ops)
                 ops = kobj->ktype->sysfs_ops;
-        else
-                ops = &subsys_sysfs_ops;
-
-        error = -EACCES;
-
-        /* No sysfs operations, either from having no subsystem,
-         * or the subsystem have no operations.
-         */
-        if (!ops)
+        else {
+                printk(KERN_ERR "missing sysfs attribute operations for "
+                       "kobject: %s\n", kobject_name(kobj));
+                WARN_ON(1);
                 goto err_out;
+        }
 
         /* File needs write support.
          * The inode's perms must say it's ok, 
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 3eac20c63c41..5f66c4466151 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -19,39 +19,6 @@
 
 #include "sysfs.h"
 
-static int object_depth(struct sysfs_dirent *sd)
-{
-        int depth = 0;
-
-        for (; sd->s_parent; sd = sd->s_parent)
-                depth++;
-
-        return depth;
-}
-
-static int object_path_length(struct sysfs_dirent * sd)
-{
-        int length = 1;
-
-        for (; sd->s_parent; sd = sd->s_parent)
-                length += strlen(sd->s_name) + 1;
-
-        return length;
-}
-
-static void fill_object_path(struct sysfs_dirent *sd, char *buffer, int length)
-{
-        --length;
-        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, sd->s_name, cur);
-                *(buffer + --length) = '/';
-        }
-}
-
 /**
  *      sysfs_create_link - create symlink between two objects.
  *      @kobj:  object whose directory we're creating the link in.
@@ -112,7 +79,6 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char
         return error;
 }
 
-
 /**
  *      sysfs_remove_link - remove symlink in object's directory.
  *      @kobj:  object we're acting for.
@@ -124,24 +90,54 @@ void sysfs_remove_link(struct kobject * kobj, const char * name)
         sysfs_hash_and_remove(kobj->sd, name);
 }
 
-static int sysfs_get_target_path(struct sysfs_dirent * parent_sd,
-                                 struct sysfs_dirent * target_sd, 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;
+        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;
+        }
 
-        depth = object_depth(parent_sd);
-        size = object_path_length(target_sd) + depth * 3 - 1;
-        if (size > PATH_MAX)
+        /* check limits */
+        if (len < 2)
+                return -EINVAL;
+        len--;
+        if ((s - path) + len > PATH_MAX)
                 return -ENAMETOOLONG;
 
-        pr_debug("%s: depth = %d, size = %d\n", __FUNCTION__, depth, size);
+        /* reverse fillup of target string from target to base */
+        sd = target_sd;
+        while (sd->s_parent && sd != base) {
+                int slen = strlen(sd->s_name);
 
-        for (s = path; depth--; s += 3)
-                strcpy(s,"../");
+                len -= slen;
+                strncpy(s + len, sd->s_name, slen);
+                if (len)
+                        s[--len] = '/';
 
-        fill_object_path(target_sd, path, size);
-        pr_debug("%s: path = '%s'\n", __FUNCTION__, path);
+                sd = sd->s_parent;
+        }
 
         return 0;
 }