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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Mike Christie <mchristi@redhat.com>,
        Bodo Stroesser <bstroesser@ts.fujitsu.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 63/83] scsi: target: tcmu: reset_ring should reset TCMU_DEV_BIT_BROKEN
Date:   Fri,  1 May 2020 15:23:42 +0200
Message-Id: <20200501131540.585278307@linuxfoundation.org>
In-Reply-To: <20200501131524.004332640@linuxfoundation.org>
References: <20200501131524.004332640@linuxfoundation.org>
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From: Bodo Stroesser <bstroesser@ts.fujitsu.com>

[ Upstream commit 066f79a5fd6d1b9a5cc57b5cd445b3e4bb68a5b2 ]

In case command ring buffer becomes inconsistent, tcmu sets device flag
TCMU_DEV_BIT_BROKEN.  If the bit is set, tcmu rejects new commands from LIO
core with TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, and no longer processes
completions from the ring.  The reset_ring attribute can be used to
completely clean up the command ring, so after reset_ring the ring no
longer is inconsistent.

Therefore reset_ring also should reset bit TCMU_DEV_BIT_BROKEN to allow
normal processing.

Link: https://lore.kernel.org/r/20200409101026.17872-1-bstroesser@ts.fujitsu.com
Acked-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/target/target_core_user.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 35be1be87d2a1..9425354aef99c 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -2073,6 +2073,7 @@ static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
 	mb->cmd_tail = 0;
 	mb->cmd_head = 0;
 	tcmu_flush_dcache_range(mb, sizeof(*mb));
+	clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
 
 	del_timer(&udev->cmd_timer);
 
-- 
2.20.1