Commits
Guo Chao committed 5370019dc2d
loopdev: fix a deadlock bd_mutex and lo_ctl_mutex can be held in different order. Path #1: blkdev_open blkdev_get __blkdev_get (hold bd_mutex) lo_open (hold lo_ctl_mutex) Path #2: blkdev_ioctl lo_ioctl (hold lo_ctl_mutex) lo_set_capacity (hold bd_mutex) Lockdep does not report it, because path #2 actually holds a subclass of lo_ctl_mutex. This subclass seems creep into the code by mistake. The patch author actually just mentioned it in the changelog, see commit f028f3b2 ("loop: fix circular locking in loop_clr_fd()"), also see: http://marc.info/?l=linux-kernel&m=123806169129727&w=2 Path #2 hold bd_mutex to call bd_set_size(), I've protected it with i_mutex in a previous patch, so drop bd_mutex at this site. Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: M. Hindess <hindessm@uk.ibm.com> Cc: Nikanth Karthikesan <knikanth@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>