tree 616dd718e94a1e5e8ca536114d5fb91fa780bbc8
parent a17184a911195c274104df98a79bec10f57e735d
author NeilBrown <neilb@suse.de> 1202290796 -0800
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1202323279 -0800

md: fix use-after-free bug when dropping an rdev from an md array

Due to possible deadlock issues we need to use a schedule work to kobject_del
an 'rdev' object from a different thread.

A recent change means that kobject_add no longer gets a refernce, and
kobject_del doesn't put a reference.  Consequently, we need to explicitly hold
a reference to ensure that the last reference isn't dropped before the
scheduled work get a chance to call kobject_del.

Also, rename delayed_delete to md_delayed_delete to that it is more obvious in
a stack trace which code is to blame.

Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>