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 <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 71583fc..41138e9 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 @@
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);
}
/**