freebsd-nq/sys/ufs
Konstantin Belousov 3ab0160340 Avoid LOR between vfs_busy() lock and covered vnode lock on quotaon().
The vfs_busy() is after covered vnode lock in the global lock order, but
since quotaon() does recursive VFS call to open quota file, we usually
end up locking covered vnode after mp is busied in sys_quotactl().

Change the interface of VFS_QUOTACTL(), requiring that mp was unbusied
by fs code, and do not try to pick up vfs_busy() reference in ufs quotaon,
esp. if vfs_busy cannot succeed due to unmount being performed.

Reported and tested by:	pho
MFC after:	1 week
2012-01-08 23:06:53 +00:00
..
ffs Migrate ufs and ext2fs from skpc() to memcchr(). 2012-01-01 20:47:33 +00:00
ufs Avoid LOR between vfs_busy() lock and covered vnode lock on quotaon(). 2012-01-08 23:06:53 +00:00