stable inclusion
from stable-5.10.67
commit 240a7025a6f89f9596c36134bd07f3855c56c712
bugzilla: 182619 https://gitee.com/openeuler/kernel/issues/I4EWO7

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=240a7025a6f89f9596c36134bd07f3855c56c712

--------------------------------

[ Upstream commit e7006de6 ]

We cannot detect a (perhaps buggy) controller that is sending us
a completion for a request that was already completed (for example
sending a completion twice), this phenomenon was seen in the wild
a few times.

So to protect against this, we use the upper 4 msbits of the nvme sqe
command_id to use as a 4-bit generation counter and verify it matches
the existing request generation that is incrementing on every execution.

The 16-bit command_id structure now is constructed by:
| xxxx | xxxxxxxxxxxx |
  gen    request tag

This means that we are giving up some possible queue depth as 12 bits
allow for a maximum queue depth of 4095 instead of 65536, however we
never create such long queues anyways so no real harm done.
Suggested-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Acked-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NDaniel Wagner <dwagner@suse.de>
Tested-by: NDaniel Wagner <dwagner@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>