1 files changed, 42 insertions, 46 deletions

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;
 }