diff options
| -rw-r--r-- | fs/sysfs/symlink.c | 88 |
1 files changed, 42 insertions, 46 deletions
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index 3eac20c..5f66c44 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; } |
