suse man page for deactivate_locked_super

DEACTIVATE_LOCKED_SU(9) 					   The Linux VFS					   DEACTIVATE_LOCKED_SU(9)

NAME
       deactivate_locked_super - drop an active reference to superblock

SYNOPSIS
       void deactivate_locked_super(struct super_block * s);

ARGUMENTS
       s
	   superblock to deactivate

DESCRIPTION
       Equivalent of up_write(s->s_umount); deactivate_super(s);, except that it does not unlock it until it's all over. As the result, it's safe
       to use to dispose of new superblock on ->get_sb failure exits - nobody will see the sucker until it's all over. Equivalent using up_write +
       deactivate_super is safe for that purpose only if superblock is either safe to use or has NULL ->s_root when we unlock.

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010						   DEACTIVATE_LOCKED_SU(9)