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authorChristoph Hellwig <hch@lst.de>2015-10-08 10:25:41 +0200
committerTejun Heo <tj@kernel.org>2015-10-12 13:23:13 -0400
commit2aa8f5d63d9183ab185364d4ce849566ede0f301 (patch)
tree75e01ce75cac1abcb883847c18500da83bdef645 /drivers/ata
parent25c7ce7f7b511fc02b6eef95595af2cea80e2612 (diff)
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: Christoph Hellwig <hch@lst.de> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/libata-scsi.c22
1 files changed, 13 insertions, 9 deletions
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index ebcba8504ac0..560cedea2b40 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1757,6 +1757,15 @@ nothing_to_do:
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