From 74dbbdd7fdc11763f4698d2f3e684cf4446951e6 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 6 May 2009 01:07:50 -0400 Subject: New helper: deactivate_locked_super() Does equivalent of up_write(&s->s_umount); deactivate_super(s); However, it does not 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 if superblock is either safe to use or has NULL ->s_root when we unlock. Normally filesystems take the required precautions, but a) we do have bugs in that area in some of them. b) up_write/deactivate_super sequence is extremely common, so the helper makes sense anyway. Signed-off-by: Al Viro --- include/linux/fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/fs.h b/include/linux/fs.h index 5bed436..11484d0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1775,6 +1775,7 @@ void kill_block_super(struct super_block *sb); void kill_anon_super(struct super_block *sb); void kill_litter_super(struct super_block *sb); void deactivate_super(struct super_block *sb); +void deactivate_locked_super(struct super_block *sb); int set_anon_super(struct super_block *s, void *data); struct super_block *sget(struct file_system_type *type, int (*test)(struct super_block *,void *), -- cgit v1.1