On Thu, Aug 01, 2013 at 03:14:00PM +0200, Tomas Henzl wrote:
> From: Tomas Henzl <thenzl@xxxxxxxxxx>
>
> When the driver calls scsi_done and after that frees it's internal
> preallocated memory it can happen that a new job is enqueud before
> the memory is freed. The allocation fails and the message
> "cmd_alloc returned NULL" is shown.
> Patch below fixes it by moving cmd->scsi_done after cmd_free.
>
> Signed-off-by: Tomas Henzl <thenzl@xxxxxxxxxx>
> ---
> drivers/scsi/hpsa.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
> index d7df01e..48fa81e 100644
> --- a/drivers/scsi/hpsa.c
> +++ b/drivers/scsi/hpsa.c
> @@ -1180,8 +1180,8 @@ static void complete_scsi_command(struct CommandList *cp)
> scsi_set_resid(cmd, ei->ResidualCnt);
>
> if (ei->CommandStatus == 0) {
> - cmd->scsi_done(cmd);
> cmd_free(h, cp);
> + cmd->scsi_done(cmd);
> return;
> }
>
> @@ -1353,8 +1353,8 @@ static void complete_scsi_command(struct CommandList *cp)
> dev_warn(&h->pdev->dev, "cp %p returned unknown status %x\n",
> cp, ei->CommandStatus);
> }
> - cmd->scsi_done(cmd);
> cmd_free(h, cp);
> + cmd->scsi_done(cmd);
> }
>
> static void hpsa_pci_unmap(struct pci_dev *pdev,
> --
> 1.8.3.1
Oh, nice catch!!! Those mysterious and seemingly never reproducible
legends of the "cmd_alloc returned NULL" message that would show up
*extremely* infrequently are finally explained!
Ack.
-- steve
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