From 7cb32942d91a501b2df944928ccc9e6590ab237b Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 12 Feb 2010 19:22:25 -0800 Subject: [PATCH] sysfs: Implement sysfs_rename_link Because of rename ordering problems we occassionally give false warnings about invalid sysfs operations. So using sysfs_rename create a sysfs_rename_link function that doesn't need strange workarounds. Cc: Benjamin Thery Cc: Daniel Lezcano Acked-by: Serge Hallyn Acked-by: Tejun Heo Signed-off-by: Eric W. Biederman Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/symlink.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/sysfs.h | 9 +++++++++ 2 files changed, 47 insertions(+) diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index c5eff49fa41b..1b9a3a1e8a17 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -123,6 +123,44 @@ void sysfs_remove_link(struct kobject * kobj, const char * name) sysfs_hash_and_remove(parent_sd, name); } +/** + * sysfs_rename_link - rename symlink in object's directory. + * @kobj: object we're acting for. + * @targ: object we're pointing to. + * @old: previous name of the symlink. + * @new: new name of the symlink. + * + * A helper function for the common rename symlink idiom. + */ +int sysfs_rename_link(struct kobject *kobj, struct kobject *targ, + const char *old, const char *new) +{ + struct sysfs_dirent *parent_sd, *sd = NULL; + int result; + + if (!kobj) + parent_sd = &sysfs_root; + else + parent_sd = kobj->sd; + + result = -ENOENT; + sd = sysfs_get_dirent(parent_sd, old); + if (!sd) + goto out; + + result = -EINVAL; + if (sysfs_type(sd) != SYSFS_KOBJ_LINK) + goto out; + if (sd->s_symlink.target_sd->s_dir.kobj != targ) + goto out; + + result = sysfs_rename(sd, parent_sd, new); + +out: + sysfs_put(sd); + return result; +} + static int sysfs_get_target_path(struct sysfs_dirent *parent_sd, struct sysfs_dirent *target_sd, char *path) { diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 5b8f80f5aca6..d77cde6d0498 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -151,6 +151,9 @@ int __must_check sysfs_create_link_nowarn(struct kobject *kobj, const char *name); void sysfs_remove_link(struct kobject *kobj, const char *name); +int sysfs_rename_link(struct kobject *kobj, struct kobject *target, + const char *old_name, const char *new_name); + int __must_check sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp); int sysfs_update_group(struct kobject *kobj, @@ -255,6 +258,12 @@ static inline void sysfs_remove_link(struct kobject *kobj, const char *name) { } +static inline int sysfs_rename_link(struct kobject *k, struct kobject *t, + const char *old_name, const char *new_name) +{ + return 0; +} + static inline int sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp) { -- 2.20.1