block: bd_link_disk_holder() should hold on to holder_dir
authorTejun Heo <tj@kernel.org>
Thu, 24 Feb 2011 08:56:32 +0000 (09:56 +0100)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 24 Feb 2011 16:55:55 +0000 (08:55 -0800)
commite7407d1619713f4b1fdff3a485e1bd8e77bd480d
tree18def7871239d5de7dea8cb115badb53d64fccb4
parent8074b26f67165bf045d92e778c9c10dc5e207fc6
block: bd_link_disk_holder() should hold on to holder_dir

The new implementation of bd_link_disk_holder() added by 49731baa41d
(block: restore multiple bd_link_disk_holder() support) didn't get an
extra reference for the holder_dir kobject of the slave bdev; however,
bdev kills holder_dir on removal, not release, so if the slave bdev is
removed while there are holder links, the holder_dir will be destroyed
while there still are holder links, which leads to oops later when
bd_unlink_disk_order() tries to remove those links.

Make bd_link_disk_holder() grab an extra reference for the slave's
holder_dir and put it in bd_unlink_disk_holder().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@intel.com>
Tested-by: "Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@intel.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/block_dev.c