From 5d0e26bb59a680a5d97db5b6629941603e8de229 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sat, 23 Nov 2013 17:21:50 -0500 Subject: [PATCH] sysfs, kernfs: introduce kernfs_create_link() Separate out kernfs symlink interface - kernfs_create_link() - which takes and returns sysfs_dirents, from sysfs_do_create_link_sd(). sysfs_do_create_link_sd() now just determines the parent and target sysfs_dirents and invokes the new interface and handles dup warning. This patch doesn't introduce behavior changes. v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/symlink.c | 78 +++++++++++++++++++++++++----------------- include/linux/kernfs.h | 9 +++++ 2 files changed, 56 insertions(+), 31 deletions(-) diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index 71583fc8100a..41138e91947a 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -21,14 +21,48 @@ #include "sysfs.h" +/** + * kernfs_create_link - create a symlink + * @parent: directory to create the symlink in + * @name: name of the symlink + * @target: target node for the symlink to point to + * + * Returns the created node on success, ERR_PTR() value on error. + */ +struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent, + const char *name, + struct sysfs_dirent *target) +{ + struct sysfs_dirent *sd; + struct sysfs_addrm_cxt acxt; + int error; + + sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK); + if (!sd) + return ERR_PTR(-ENOMEM); + + if (parent->s_flags & SYSFS_FLAG_NS) + sd->s_ns = target->s_ns; + sd->s_symlink.target_sd = target; + sysfs_get(target); /* ref owned by symlink */ + + sysfs_addrm_start(&acxt); + error = __sysfs_add_one(&acxt, sd, parent); + sysfs_addrm_finish(&acxt); + + if (!error) + return sd; + + sysfs_put(sd); + return ERR_PTR(error); +} + + static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd, struct kobject *target, const char *name, int warn) { - struct sysfs_dirent *target_sd = NULL; - struct sysfs_dirent *sd = NULL; - struct sysfs_addrm_cxt acxt; - int error; + struct sysfs_dirent *sd, *target_sd = NULL; BUG_ON(!name || !parent_sd); @@ -42,36 +76,18 @@ static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd, target_sd = sysfs_get(target->sd); spin_unlock(&sysfs_symlink_target_lock); - error = -ENOENT; if (!target_sd) - goto out_put; + return -ENOENT; - error = -ENOMEM; - sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK); - if (!sd) - goto out_put; - - if (parent_sd->s_flags & SYSFS_FLAG_NS) - sd->s_ns = target_sd->s_ns; - sd->s_symlink.target_sd = target_sd; - target_sd = NULL; /* reference is now owned by the symlink */ - - sysfs_addrm_start(&acxt); - if (warn) - error = sysfs_add_one(&acxt, sd, parent_sd); - else - error = __sysfs_add_one(&acxt, sd, parent_sd); - sysfs_addrm_finish(&acxt); - - if (error) - goto out_put; - - return 0; - - out_put: + sd = kernfs_create_link(parent_sd, name, target_sd); sysfs_put(target_sd); - sysfs_put(sd); - return error; + + if (!IS_ERR(sd)) + return 0; + + if (warn && PTR_ERR(sd) == -EEXIST) + sysfs_warn_dup(parent_sd, name); + return PTR_ERR(sd); } /** diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 83e151ad0619..fe6290d41776 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -8,17 +8,26 @@ #define __LINUX_KERNFS_H #include +#include struct sysfs_dirent; #ifdef CONFIG_SYSFS +struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent, + const char *name, + struct sysfs_dirent *target); void kernfs_remove(struct sysfs_dirent *sd); int kernfs_remove_by_name_ns(struct sysfs_dirent *parent, const char *name, const void *ns); #else /* CONFIG_SYSFS */ +static inline struct sysfs_dirent * +kernfs_create_link(struct sysfs_dirent *parent, const char *name, + struct sysfs_dirent *target) +{ return ERR_PTR(-ENOSYS); } + static inline void kernfs_remove(struct sysfs_dirent *sd) { } static inline int kernfs_remove_by_name_ns(struct sysfs_dirent *parent,