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>
1 file changed