The following error will occur on some (possibly all) kernels
because blk_init_queue() will try to take the spinlock before
we initialize it.
BUG: spinlock bad magic on CPU#0, zpool/4054
lock: 0xffff88021a73de60, .magic: 00000000,
.owner: <none>/-1, .owner_cpu: 0
Pid: 4054, comm: zpool Not tainted 3.9.3 #11
Call Trace:
[<ffffffff81478ef8>] spin_dump+0x8c/0x91
[<ffffffff81478f1e>] spin_bug+0x21/0x26
[<ffffffff812da097>] do_raw_spin_lock+0x127/0x130
[<ffffffff8147d851>] _raw_spin_lock_irq+0x21/0x30
[<ffffffff812c2c1e>] cfq_init_queue+0x1fe/0x350
[<ffffffff812aacb8>] elevator_init+0x78/0x140
[<ffffffff812b2677>] blk_init_allocated_queue+0x87/0xb0
[<ffffffff812b26d5>] blk_init_queue_node+0x35/0x70
[<ffffffff812b271e>] blk_init_queue+0xe/0x10
[<ffffffff8125211b>] __zvol_create_minor+0x24b/0x620
[<ffffffff81253264>] zvol_create_minors_cb+0x24/0x30
[<ffffffff811bd9ca>] dmu_objset_find_spa+0xea/0x510
[<ffffffff811bda71>] dmu_objset_find_spa+0x191/0x510
[<ffffffff81253ea2>] zvol_create_minors+0x92/0x180
[<ffffffff811f8d80>] spa_open_common+0x250/0x380
[<ffffffff811f8ece>] spa_open+0xe/0x10
[<ffffffff8122817e>] pool_status_check.part.22+0x1e/0x80
[<ffffffff81228a55>] zfsdev_ioctl+0x155/0x190
[<ffffffff8116a695>] do_vfs_ioctl+0x325/0x5a0
[<ffffffff8116a950>] sys_ioctl+0x40/0x80
[<ffffffff814812c9>] ? do_page_fault+0x9/0x10
[<ffffffff81483929>] system_call_fastpath+0x16/0x1b
zd0: unknown partition table
We fix this by calling spin_lock_init before blk_init_queue.
The manner in which zvol_init() initializes structures is
suspectible to a race between initialization and a probe on
a zvol. We reorganize zvol_init() to prevent that.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2a3871d4bc