Commit 2aa8f5d6 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Tejun Heo

libata: only call ->done once all per-tag ressources are released

When calling ->done before releasing resources we could run into a
race where the SCSI midlayer sends another command and races with
the resources beeing manipulated.  For libata this can't currently
happen as synchronization happens at a higher level, but I'd still
like to fix it to future proof libata and to avoid copy & paste
into SCSI drivers where this pattern has led to reproducible crashes.
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 25c7ce7f
......@@ -1757,6 +1757,15 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc)
return 1;
}
static void ata_qc_done(struct ata_queued_cmd *qc)
{
struct scsi_cmnd *cmd = qc->scsicmd;
void (*done)(struct scsi_cmnd *) = qc->scsidone;
ata_qc_free(qc);
done(cmd);
}
static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
......@@ -1784,9 +1793,7 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
if (need_sense && !ap->ops->error_handler)
ata_dump_status(ap->print_id, &qc->result_tf);
qc->scsidone(cmd);
ata_qc_free(qc);
ata_qc_done(qc);
}
/**
......@@ -2588,8 +2595,7 @@ static void atapi_sense_complete(struct ata_queued_cmd *qc)
ata_gen_passthru_sense(qc);
}
qc->scsidone(qc->scsicmd);
ata_qc_free(qc);
ata_qc_done(qc);
}
/* is it pointless to prefer PIO for "safety reasons"? */
......@@ -2684,8 +2690,7 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc)
qc->dev->sdev->locked = 0;
qc->scsicmd->result = SAM_STAT_CHECK_CONDITION;
qc->scsidone(cmd);
ata_qc_free(qc);
ata_qc_done(qc);
return;
}
......@@ -2729,8 +2734,7 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc)
cmd->result = SAM_STAT_GOOD;
}
qc->scsidone(cmd);
ata_qc_free(qc);
ata_qc_done(qc);
}
/**
* atapi_xlat - Initialize PACKET taskfile
......
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