sysfs: implement sysfs_open_dirent

Implement sysfs_open_dirent which represents an open file (attribute)
sysfs_dirent.  A file sysfs_dirent with one or more open files have
one sysfs_dirent and all sysfs_buffers (one for each open instance)
are linked to it.

sysfs_open_dirent doesn't actually do anything yet but will be used to
off-load things which are specific for open file sysfs_dirent from it.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 42b0327d1624..3adce7d5e4f7 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -1,3 +1,5 @@
+struct sysfs_open_dirent;
+
 /* type-specific structures for sysfs_dirent->s_* union members */
 struct sysfs_elem_dir {
         struct kobject          *kobj;
@@ -11,6 +13,7 @@ struct sysfs_elem_symlink {
 
 struct sysfs_elem_attr {
         struct attribute        *attr;
+        struct sysfs_open_dirent *open;
 };
 
 struct sysfs_elem_bin_attr {