sysfs: consolidate sysfs_dirent creation functions

Currently there are four functions to create sysfs_dirent -
__sysfs_new_dirent(), sysfs_new_dirent(), __sysfs_make_dirent() and
sysfs_make_dirent().  Other than sysfs_make_dirent(), no function has
two users if calls to implement other functions are excluded.

This patch consolidates sysfs_dirent creation functions into the
following two.

* sysfs_new_dirent() : allocate and initialize
* sysfs_attach_dirent() : attach to sysfs_dirent hierarchy and/or
			  associate with dentry

This simplifies interface and gives callers more flexibility.  This is
in preparation of object reference simplification.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 16 insertions, 5 deletions

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index b502c7197ec0..fd4b6dc03d2d 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -444,14 +444,25 @@ int sysfs_add_file(struct dentry * dir, const struct attribute * attr, int type)
 {
         struct sysfs_dirent * parent_sd = dir->d_fsdata;
         umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG;
-        int error = -EEXIST;
+        struct sysfs_dirent *sd;
+        int error = 0;
 
         mutex_lock(&dir->d_inode->i_mutex);
-        if (!sysfs_dirent_exist(parent_sd, attr->name))
-                error = sysfs_make_dirent(parent_sd, NULL, (void *)attr,
-                                          mode, type);
-        mutex_unlock(&dir->d_inode->i_mutex);
 
+        if (sysfs_dirent_exist(parent_sd, attr->name)) {
+                error = -EEXIST;
+                goto out_unlock;
+        }
+
+        sd = sysfs_new_dirent((void *)attr, mode, type);
+        if (!sd) {
+                error = -ENOMEM;
+                goto out_unlock;
+        }
+        sysfs_attach_dirent(sd, parent_sd, NULL);
+
+ out_unlock:
+        mutex_unlock(&dir->d_inode->i_mutex);
         return error;
 }