On Thu, Apr 23, 2015 at 12:48 AM, Christoph Hellwig <hch@xxxxxx> wrote:
> The 3w-9xxx driver needs to tear down the dma mappings before returning
> the command to the midlayer, as there is no guarantee the sglist and
> count are valid after that point. Also remove the dma mapping helpers
> which have another inherent race due to the request_id index.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> drivers/scsi/3w-9xxx.c | 57 ++++++++++++--------------------------------------
> drivers/scsi/3w-9xxx.h | 5 -----
> 2 files changed, 13 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
> index 7600639..c3224b6 100644
> --- a/drivers/scsi/3w-9xxx.c
> +++ b/drivers/scsi/3w-9xxx.c
> @@ -149,7 +149,6 @@ static int twa_reset_sequence(TW_Device_Extension *tw_dev, int soft_reset);
> static int twa_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id, char *cdb, int use_sg, TW_SG_Entry *sglistarg);
> static void twa_scsiop_execute_scsi_complete(TW_Device_Extension *tw_dev, int request_id);
> static char *twa_string_lookup(twa_message_type *table, unsigned int aen_code);
> -static void twa_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id);
>
> /* Functions */
>
> @@ -1340,11 +1339,11 @@ static irqreturn_t twa_interrupt(int irq, void *dev_instance)
> }
>
> /* Now complete the io */
> + scsi_dma_unmap(cmd);
> + cmd->scsi_done(cmd);
> tw_dev->state[request_id] = TW_S_COMPLETED;
> twa_free_request_id(tw_dev, request_id);
> tw_dev->posted_request_count--;
> - tw_dev->srb[request_id]->scsi_done(tw_dev->srb[request_id]);
> - twa_unmap_scsi_data(tw_dev, request_id);
> }
>
> /* Check for valid status after each drain */
> @@ -1402,26 +1401,6 @@ static void twa_load_sgl(TW_Device_Extension *tw_dev, TW_Command_Full *full_comm
> }
> } /* End twa_load_sgl() */
>
> -/* This function will perform a pci-dma mapping for a scatter gather list */
> -static int twa_map_scsi_sg_data(TW_Device_Extension *tw_dev, int request_id)
> -{
> - int use_sg;
> - struct scsi_cmnd *cmd = tw_dev->srb[request_id];
> -
> - use_sg = scsi_dma_map(cmd);
> - if (!use_sg)
> - return 0;
> - else if (use_sg < 0) {
> - TW_PRINTK(tw_dev->host, TW_DRIVER, 0x1c, "Failed to map scatter gather list");
> - return 0;
> - }
> -
> - cmd->SCp.phase = TW_PHASE_SGLIST;
> - cmd->SCp.have_data_in = use_sg;
> -
> - return use_sg;
> -} /* End twa_map_scsi_sg_data() */
> -
> /* This function will poll for a response interrupt of a request */
> static int twa_poll_response(TW_Device_Extension *tw_dev, int request_id, int seconds)
> {
> @@ -1600,9 +1579,11 @@ static int twa_reset_device_extension(TW_Device_Extension *tw_dev)
> (tw_dev->state[i] != TW_S_INITIAL) &&
> (tw_dev->state[i] != TW_S_COMPLETED)) {
> if (tw_dev->srb[i]) {
> - tw_dev->srb[i]->result = (DID_RESET << 16);
> - tw_dev->srb[i]->scsi_done(tw_dev->srb[i]);
> - twa_unmap_scsi_data(tw_dev, i);
> + struct scsi_cmnd * cmd = tw_dev->srb[i];
> +
> + cmd->result = (DID_RESET << 16);
> + scsi_dma_unmap(cmd);
> + cmd->scsi_done(cmd);
> }
> }
> }
> @@ -1781,21 +1762,18 @@ static int twa_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_
> /* Save the scsi command for use by the ISR */
> tw_dev->srb[request_id] = SCpnt;
>
> - /* Initialize phase to zero */
> - SCpnt->SCp.phase = TW_PHASE_INITIAL;
> -
> retval = twa_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL);
> switch (retval) {
> case SCSI_MLQUEUE_HOST_BUSY:
> + scsi_dma_unmap(SCpnt);
> twa_free_request_id(tw_dev, request_id);
> - twa_unmap_scsi_data(tw_dev, request_id);
> break;
> case 1:
> - tw_dev->state[request_id] = TW_S_COMPLETED;
> - twa_free_request_id(tw_dev, request_id);
> - twa_unmap_scsi_data(tw_dev, request_id);
> SCpnt->result = (DID_ERROR << 16);
> + scsi_dma_unmap(SCpnt);
> done(SCpnt);
> + tw_dev->state[request_id] = TW_S_COMPLETED;
> + twa_free_request_id(tw_dev, request_id);
> retval = 0;
> }
> out:
> @@ -1863,8 +1841,8 @@ static int twa_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id,
> command_packet->sg_list[0].address = TW_CPU_TO_SGL(tw_dev->generic_buffer_phys[request_id]);
> command_packet->sg_list[0].length = cpu_to_le32(TW_MIN_SGL_LENGTH);
> } else {
> - sg_count = twa_map_scsi_sg_data(tw_dev, request_id);
> - if (sg_count == 0)
> + sg_count = scsi_dma_map(srb);
> + if (sg_count < 0)
> goto out;
>
> scsi_for_each_sg(srb, sg, sg_count, i) {
> @@ -1979,15 +1957,6 @@ static char *twa_string_lookup(twa_message_type *table, unsigned int code)
> return(table[index].text);
> } /* End twa_string_lookup() */
>
> -/* This function will perform a pci-dma unmap */
> -static void twa_unmap_scsi_data(TW_Device_Extension *tw_dev, int request_id)
> -{
> - struct scsi_cmnd *cmd = tw_dev->srb[request_id];
> -
> - if (cmd->SCp.phase == TW_PHASE_SGLIST)
> - scsi_dma_unmap(cmd);
> -} /* End twa_unmap_scsi_data() */
> -
> /* This function gets called when a disk is coming on-line */
> static int twa_slave_configure(struct scsi_device *sdev)
> {
> diff --git a/drivers/scsi/3w-9xxx.h b/drivers/scsi/3w-9xxx.h
> index 040f721..0fdc83c 100644
> --- a/drivers/scsi/3w-9xxx.h
> +++ b/drivers/scsi/3w-9xxx.h
> @@ -324,11 +324,6 @@ static twa_message_type twa_error_table[] = {
> #define TW_CURRENT_DRIVER_BUILD 0
> #define TW_CURRENT_DRIVER_BRANCH 0
>
> -/* Phase defines */
> -#define TW_PHASE_INITIAL 0
> -#define TW_PHASE_SINGLE 1
> -#define TW_PHASE_SGLIST 2
> -
> /* Misc defines */
> #define TW_9550SX_DRAIN_COMPLETED 0xFFFF
> #define TW_SECTOR_SIZE 512
> --
> 1.9.1
>
> --
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Acked-by: Adam Radford <aradford@xxxxxxxxx>
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