I got this warning on 2.6.34-rc7 (actually cea0d767c2 in -linus) running mdadm --stop /dev/md0 when /dev/md0 was an improperly assembled imsm array. See https://bugzilla.redhat.com/show_bug.cgi?id=592030 for how I got into this state in the first place. md: md0 stopped. md: unbind<sda> md: export_rdev(sda) ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.34-rc7 #1 ------------------------------------------------------- udisks-part-id/1152 is trying to acquire lock: (events){+.+.+.}, at: [<ffffffff81059342>] flush_workqueue+0x0/0xb9 but task is already holding lock: (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff81132f31>] __blkdev_get+0x91/0x3a8 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&bdev->bd_mutex){+.+.+.}: [<ffffffff8106fa76>] __lock_acquire+0xb74/0xd22 [<ffffffff8106fcf4>] lock_acquire+0xd0/0xf6 [<ffffffff81457feb>] __mutex_lock_common+0x4c/0x339 [<ffffffff8145839c>] mutex_lock_nested+0x3e/0x43 [<ffffffff81132f31>] __blkdev_get+0x91/0x3a8 [<ffffffff81133258>] blkdev_get+0x10/0x12 [<ffffffff811333ae>] open_by_devnum+0x2e/0x3f [<ffffffff81367df7>] lock_rdev+0x39/0xe4 [<ffffffff8136d52a>] md_import_device+0xbe/0x27b [<ffffffff8136d805>] new_dev_store+0x11e/0x173 [<ffffffff81367d9f>] md_attr_store+0x83/0xa2 [<ffffffff81163687>] sysfs_write_file+0x108/0x144 [<ffffffff8110c1db>] vfs_write+0xae/0x10b [<ffffffff8110c2f8>] sys_write+0x4a/0x6e [<ffffffff81002bdb>] system_call_fastpath+0x16/0x1b -> #3 (&new->reconfig_mutex){+.+.+.}: [<ffffffff8106fa76>] __lock_acquire+0xb74/0xd22 [<ffffffff8106fcf4>] lock_acquire+0xd0/0xf6 [<ffffffff81457feb>] __mutex_lock_common+0x4c/0x339 [<ffffffff81458316>] mutex_lock_interruptible_nested+0x3e/0x43 [<ffffffff81367cd9>] rdev_attr_store+0x65/0xa8 [<ffffffff81163687>] sysfs_write_file+0x108/0x144 [<ffffffff8110c1db>] vfs_write+0xae/0x10b [<ffffffff8110c2f8>] sys_write+0x4a/0x6e [<ffffffff81002bdb>] system_call_fastpath+0x16/0x1b -> #2 (s_active#55){++++.+}: [<ffffffff8106fa76>] __lock_acquire+0xb74/0xd22 [<ffffffff8106fcf4>] lock_acquire+0xd0/0xf6 [<ffffffff811642a2>] sysfs_deactivate+0xa0/0x109 [<ffffffff81164ab9>] sysfs_addrm_finish+0x36/0x55 [<ffffffff81164bbc>] sysfs_remove_dir+0x95/0xbe [<ffffffff812138d5>] kobject_del+0x16/0x37 [<ffffffff813651eb>] md_delayed_delete+0x1d/0x29 [<ffffffff81058a83>] worker_thread+0x266/0x35f [<ffffffff8105cb08>] kthread+0x9a/0xa2 [<ffffffff81003a14>] kernel_thread_helper+0x4/0x10 -> #1 ((&rdev->del_work)){+.+...}: [<ffffffff8106fa76>] __lock_acquire+0xb74/0xd22 [<ffffffff8106fcf4>] lock_acquire+0xd0/0xf6 [<ffffffff81058a7a>] worker_thread+0x25d/0x35f [<ffffffff8105cb08>] kthread+0x9a/0xa2 [<ffffffff81003a14>] kernel_thread_helper+0x4/0x10 -> #0 (events){+.+.+.}: [<ffffffff8106f920>] __lock_acquire+0xa1e/0xd22 [<ffffffff8106fcf4>] lock_acquire+0xd0/0xf6 [<ffffffff810593a5>] flush_workqueue+0x63/0xb9 [<ffffffff81059410>] flush_scheduled_work+0x15/0x17 [<ffffffff8136c00a>] md_open+0x3e/0x88 [<ffffffff81132f85>] __blkdev_get+0xe5/0x3a8 [<ffffffff81133258>] blkdev_get+0x10/0x12 [<ffffffff811332d0>] blkdev_open+0x76/0xac [<ffffffff8110a5a5>] __dentry_open+0x1bf/0x32f [<ffffffff8110a7f9>] nameidata_to_filp+0x3f/0x50 [<ffffffff81116110>] do_last+0x444/0x5b5 [<ffffffff81117c3f>] do_filp_open+0x1e7/0x5da [<ffffffff8110a2b7>] do_sys_open+0x63/0x10f [<ffffffff8110a396>] sys_open+0x20/0x22 [<ffffffff81002bdb>] system_call_fastpath+0x16/0x1b other info that might help us debug this: 1 lock held by udisks-part-id/1152: #0: (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff81132f31>] __blkdev_get+0x91/0x3a8 stack backtrace: Pid: 1152, comm: udisks-part-id Not tainted 2.6.34-rc7 #1 Call Trace: [<ffffffff8106ead9>] print_circular_bug+0xae/0xbd [<ffffffff8106f920>] __lock_acquire+0xa1e/0xd22 [<ffffffff8106fcf4>] lock_acquire+0xd0/0xf6 [<ffffffff81059342>] ? flush_workqueue+0x0/0xb9 [<ffffffff8106d08d>] ? lock_release_holdtime+0x34/0xe3 [<ffffffff810593a5>] flush_workqueue+0x63/0xb9 [<ffffffff81059342>] ? flush_workqueue+0x0/0xb9 [<ffffffff81459d83>] ? _raw_spin_unlock+0x2b/0x2f [<ffffffff81059410>] flush_scheduled_work+0x15/0x17 [<ffffffff8136c00a>] md_open+0x3e/0x88 [<ffffffff81132f85>] __blkdev_get+0xe5/0x3a8 [<ffffffff8113325a>] ? blkdev_open+0x0/0xac [<ffffffff8113325a>] ? blkdev_open+0x0/0xac [<ffffffff81133258>] blkdev_get+0x10/0x12 [<ffffffff811332d0>] blkdev_open+0x76/0xac [<ffffffff8110a5a5>] __dentry_open+0x1bf/0x32f [<ffffffff811d3387>] ? security_inode_permission+0x21/0x23 [<ffffffff8110a7f9>] nameidata_to_filp+0x3f/0x50 [<ffffffff81116110>] do_last+0x444/0x5b5 [<ffffffff81117c3f>] do_filp_open+0x1e7/0x5da [<ffffffff81459d83>] ? _raw_spin_unlock+0x2b/0x2f [<ffffffff8112112c>] ? alloc_fd+0x116/0x128 [<ffffffff8110a2b7>] do_sys_open+0x63/0x10f [<ffffffff8110a396>] sys_open+0x20/0x22 [<ffffffff81002bdb>] system_call_fastpath+0x16/0x1b -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
