On 28.10.2015 23:05, Don Brace wrote:
> Fix a NULL pointer issue in the driver when devices are removed
> during a reset.
>
> Signed-off-by: Don Brace <don.br...@pmcs.com>
> ---
> drivers/block/cciss.h | 1 +
> drivers/scsi/hpsa.c | 16 ++++++++++++++++
> drivers/scsi/hpsa.h | 1 +
> 3 files changed, 18 insertions(+)
>
> diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
> index 7fda30e..f8b8c6b 100644
> --- a/drivers/block/cciss.h
> +++ b/drivers/block/cciss.h
> @@ -155,6 +155,7 @@ struct ctlr_info
> size_t reply_pool_size;
> unsigned char reply_pool_wraparound;
> u32 *blockFetchTable;
> + u8 reset_in_progress;
> };
>
> /* Defining the diffent access_methods
> diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
> index ced0d4c..08a761c 100644
> --- a/drivers/scsi/hpsa.c
> +++ b/drivers/scsi/hpsa.c
> @@ -1670,6 +1670,15 @@ static void adjust_hpsa_scsi_table(struct ctlr_info
> *h, int hostno,
> int nadded, nremoved;
> struct Scsi_Host *sh = NULL;
>
> + /*
> + * A reset can cause a device status to change
> + * re-schedule the scan to see what happened.
> + */
> + if (h->reset_in_progress) {
> + h->drv_req_rescan = 1;
> + return;
> + }
> +
If another process start the reset at this point will you get the
the same Null pointer issue as before? Isn't some kind of
exclusive access protection needed ?
-tm
> added = kzalloc(sizeof(*added) * HPSA_MAX_DEVICES, GFP_KERNEL);
> removed = kzalloc(sizeof(*removed) * HPSA_MAX_DEVICES, GFP_KERNEL);
>
> @@ -1780,6 +1789,10 @@ static void adjust_hpsa_scsi_table(struct ctlr_info
> *h, int hostno,
> goto free_and_out;
>
> sh = h->scsi_host;
> + if (sh == NULL) {
> + dev_warn(&h->pdev->dev, "%s: scsi_host is null\n", __func__);
> + return;
> + }
> /* Notify scsi mid layer of any removed devices */
> for (i = 0; i < nremoved; i++) {
> if (removed[i] == NULL)
> @@ -5243,12 +5256,15 @@ static int hpsa_eh_device_reset_handler(struct
> scsi_cmnd *scsicmd)
>
> hpsa_show_dev_msg(KERN_WARNING, h, dev, "resetting");
>
> + h->reset_in_progress = 1;
> +
> /* send a reset to the SCSI LUN which the command was sent to */
> rc = hpsa_do_reset(h, dev, dev->scsi3addr, HPSA_RESET_TYPE_LUN,
> DEFAULT_REPLY_QUEUE);
> snprintf(msg, sizeof(msg), "reset %s",
> rc == 0 ? "completed successfully" : "failed");
> hpsa_show_dev_msg(KERN_WARNING, h, dev, msg);
> + h->reset_in_progress = 0;
> return rc == 0 ? SUCCESS : FAILED;
> }
>
> diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
> index b173c0e..dc113c1a 100644
> --- a/drivers/scsi/hpsa.h
> +++ b/drivers/scsi/hpsa.h
> @@ -271,6 +271,7 @@ struct ctlr_info {
> wait_queue_head_t abort_cmd_wait_queue;
> wait_queue_head_t event_sync_wait_queue;
> struct mutex reset_mutex;
> + u8 reset_in_progress;
> };
>
> struct offline_device_entry {
>
> --
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