From 4b30ee58ee64c64f59fd876e4afa6ed82caef3a4 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 11 Sep 2013 22:29:06 -0400 Subject: [PATCH] sysfs: remove ktype->namespace() invocations in symlink code There's no reason for sysfs to be calling ktype->namespace(). It is backwards, obfuscates what's going on and unnecessarily tangles two separate layers. There are two places where symlink code calls ktype->namespace(). * sysfs_do_create_link_sd() calls it to find out the namespace tag of the target directory. Unless symlinking races with cross-namespace renaming, this equals @target_sd->s_ns. * sysfs_rename_link() uses it to find out the new namespace to rename to and the new namespace can be different from the existing one. The function is renamed to sysfs_rename_link_ns() with an explicit @ns argument and the ktype->namespace() invocation is shifted to the device layer. While this patch replaces ktype->namespace() invocation with the recorded result in @target_sd, this shouldn't result in any behvior difference. Signed-off-by: Tejun Heo Cc: Eric W. Biederman Cc: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 8 +++++--- fs/sysfs/symlink.c | 16 +++++++--------- include/linux/sysfs.h | 16 ++++++++++++---- 3 files changed, 24 insertions(+), 16 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index c7cfadcf6752..3335000be2dc 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1881,6 +1881,7 @@ EXPORT_SYMBOL_GPL(device_destroy); */ int device_rename(struct device *dev, const char *new_name) { + struct kobject *kobj = &dev->kobj; char *old_device_name = NULL; int error; @@ -1898,13 +1899,14 @@ int device_rename(struct device *dev, const char *new_name) } if (dev->class) { - error = sysfs_rename_link(&dev->class->p->subsys.kobj, - &dev->kobj, old_device_name, new_name); + error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj, + kobj, old_device_name, + new_name, kobject_namespace(kobj)); if (error) goto out; } - error = kobject_rename(&dev->kobj, new_name); + error = kobject_rename(kobj, new_name); if (error) goto out; diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index 2dd4507d9edd..12d58ada3e6d 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -52,7 +52,7 @@ static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd, ns_type = sysfs_ns_type(parent_sd); if (ns_type) - sd->s_ns = target->ktype->namespace(target); + sd->s_ns = target_sd->s_ns; sd->s_symlink.target_sd = target_sd; target_sd = NULL; /* reference is now owned by the symlink */ @@ -181,19 +181,20 @@ void sysfs_remove_link(struct kobject *kobj, const char *name) EXPORT_SYMBOL_GPL(sysfs_remove_link); /** - * sysfs_rename_link - rename symlink in object's directory. + * sysfs_rename_link_ns - 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. + * @new_ns: new namespace 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) +int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *targ, + const char *old, const char *new, const void *new_ns) { struct sysfs_dirent *parent_sd, *sd = NULL; - const void *old_ns = NULL, *new_ns = NULL; + const void *old_ns = NULL; int result; if (!kobj) @@ -215,16 +216,13 @@ int sysfs_rename_link(struct kobject *kobj, struct kobject *targ, if (sd->s_symlink.target_sd->s_dir.kobj != targ) goto out; - if (sysfs_ns_type(parent_sd)) - new_ns = targ->ktype->namespace(targ); - result = sysfs_rename(sd, parent_sd, new_ns, new); out: sysfs_put(sd); return result; } -EXPORT_SYMBOL_GPL(sysfs_rename_link); +EXPORT_SYMBOL_GPL(sysfs_rename_link_ns); 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 7f56bad3be82..c792f73ac7fa 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -213,8 +213,9 @@ 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 sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target, + const char *old_name, const char *new_name, + const void *new_ns); void sysfs_delete_link(struct kobject *dir, struct kobject *targ, const char *name); @@ -340,8 +341,9 @@ 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) +static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t, + const char *old_name, + const char *new_name, const void *ns) { return 0; } @@ -454,4 +456,10 @@ static inline void sysfs_remove_file(struct kobject *kobj, return sysfs_remove_file_ns(kobj, attr, NULL); } +static inline int sysfs_rename_link(struct kobject *kobj, struct kobject *target, + const char *old_name, const char *new_name) +{ + return sysfs_rename_link_ns(kobj, target, old_name, new_name, NULL); +} + #endif /* _SYSFS_H_ */