sysfs: use sysfs_mutex to protect the sysfs_dirent tree

As kobj sysfs dentries and inodes are gonna be made reclaimable,
i_mutex can't be used to protect sysfs_dirent tree.  Use sysfs_mutex
globally instead.  As the whole tree is protected with sysfs_mutex,
there is no reason to keep sysfs_rename_sem.  Drop it.

While at it, add docbook comments to functions which require
sysfs_mutex locking.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 457267721f4..26051616ed1 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -82,7 +82,7 @@ extern void sysfs_drop_dentry(struct sysfs_dirent *sd);
 extern int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
 
 extern spinlock_t sysfs_assoc_lock;
-extern struct rw_semaphore sysfs_rename_sem;
+extern struct mutex sysfs_mutex;
 extern struct super_block * sysfs_sb;
 extern const struct file_operations sysfs_dir_operations;
 extern const struct file_operations sysfs_file_operations;