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ecbcdf0c81
When locking the ctrl->lock spinlock IRQs need to be disabled to avoid a
dead lock. The new spin_lock() calls recently added produce the
following lockdep warning when running the blktest nvme/003:
================================
WARNING: inconsistent lock state
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
ksoftirqd/2/22 [HC0[0]:SC1[1]:HE0:SE0] takes:
ffff888276a8c4c0 (&ctrl->lock){+.?.}-{2:2}, at: nvme_keep_alive_end_io+0x50/0xc0
{SOFTIRQ-ON-W} state was registered at:
lock_acquire+0x164/0x500
_raw_spin_lock+0x28/0x40
nvme_get_effects_log+0x37/0x1c0
nvme_init_identify+0x9e4/0x14f0
nvme_reset_work+0xadd/0x2360
process_one_work+0x66b/0xb70
worker_thread+0x6e/0x6c0
kthread+0x1e7/0x210
ret_from_fork+0x22/0x30
irq event stamp: 1449221
hardirqs last enabled at (1449220): [<ffffffff81c58e69>] ktime_get+0xf9/0x140
hardirqs last disabled at (1449221): [<ffffffff83129665>] _raw_spin_lock_irqsave+0x25/0x60
softirqs last enabled at (1449210): [<ffffffff83400447>] __do_softirq+0x447/0x595
softirqs last disabled at (1449215): [<ffffffff81b489b5>] run_ksoftirqd+0x35/0x50
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&ctrl->lock);
<Interrupt>
lock(&ctrl->lock);
*** DEADLOCK ***
no locks held by ksoftirqd/2/22.
stack backtrace:
CPU: 2 PID: 22 Comm: ksoftirqd/2 Not tainted 5.8.0-rc4-eid-vmlocalyes-dbg-00157-g7236657c6b3a #1450
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-1 04/01/2014
Call Trace:
dump_stack+0xc8/0x11a
print_usage_bug.cold.63+0x235/0x23e
mark_lock+0xa9c/0xcf0
__lock_acquire+0xd9a/0x2b50
lock_acquire+0x164/0x500
_raw_spin_lock_irqsave+0x40/0x60
nvme_keep_alive_end_io+0x50/0xc0
blk_mq_end_request+0x158/0x210
nvme_complete_rq+0x146/0x500
nvme_loop_complete_rq+0x26/0x30 [nvme_loop]
blk_done_softirq+0x187/0x1e0
__do_softirq+0x118/0x595
run_ksoftirqd+0x35/0x50
smpboot_thread_fn+0x1d3/0x310
kthread+0x1e7/0x210
ret_from_fork+0x22/0x30
Fixes: be93e87e7802 ("nvme: support for multiple Command Sets Supported and Effects log pages")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Tested-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
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https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.