On 01/01/2017 12:39 PM, James Bottomley wrote:
On Sun, 2017-01-01 at 11:33 -0500, David Miller wrote:
From: Bart Van Assche <bart.vanass...@sandisk.com>
Date: Sun, 1 Jan 2017 14:22:11 +0000
My recommendation is to revert commit 18f6084a989b ("scsi: mpt3sas: Fix
secure erase premature termination"). Since the mpt3sas driver uses the
single-queue approach and since the SCSI core unlocks the block layer
request queue lock before the .queuecommand callback function is called,
multiple threads can execute that callback function (scsih_qcmd() in this
case) simultaneously. This means that using scsi_internal_device_block()
from inside .queuecommand to serialize SCSI command execution is wrong.
But this causes a regression for the thing being fixed by that
commit.
Right, we don't do that; that's why I didn't list it as one of the
options.
Why don't we figure out what that semantics that commit was trying to
achieve and implement that properly?
Now that I look at the reviews, each of the reviewers said what the
correct thing to do was: return SAM_STAT_BUSY if SATL commands are
outstanding like the spec says. You all get negative brownie points
for not insisting on a rework.
Does this patch (compile tested only) fix the problems for everyone?
Hi,
Yes, with this patch applied my system boots :)
...
@@ -4083,6 +4077,16 @@ scsih_qcmd(struct Scsi_Host *shost, struct scsi_cmnd
*scmd)
return 0;
}
+ /*
+ * Bug work around for firmware SATL handling
+ */
+ if (sas_device_priv_data->ata_command_pending) {
+ scmd->result = SAM_STAT_BUSY;
+ scmd->scsi_done(scmd);
+ return 0;
+ }
+ set_satl_pending(scmd, true);
+
sas_target_priv_data = sas_device_priv_data->sas_target;
/* invalid device handle */
I was also wondering if 2 threads could both fall through and do:
'set_satl_pending(scmd, true)'; ?
Afaict there is nothing preventing that race?
Thanks,
-Jason
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