On 24.10.2015 21:52, Don Brace wrote:
> Fix a NULL pointer issue in the driver when devices are removed
> during a reset.
>
> Signed-off-by: Don Brace <don.brace@xxxxxxxx>
> ---
> 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..036fb0f 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;
> + atomic_t reset_in_progress;
> };
>
> /* Defining the diffent access_methods
> diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
> index 3520d75..714bb76 100644
> --- a/drivers/scsi/hpsa.c
> +++ b/drivers/scsi/hpsa.c
> @@ -1656,6 +1656,11 @@ static void adjust_hpsa_scsi_table(struct ctlr_info *h, int hostno,
> int nadded, nremoved;
> struct Scsi_Host *sh = NULL;
>
> + if (atomic_read(&h->reset_in_progress)) {
> + h->drv_req_rescan = 1;
> + return;
> + }
Is it safe, what happens when a reset is invoked at this point?
Is it possible to somehow reuse the scan_lock or scan_finished
and change the logic and wait with the reset?
(maybe break and reschedule the scan)
Btw. why is an atomic variable needed here?
--tm
> +
> added = kzalloc(sizeof(*added) * HPSA_MAX_DEVICES, GFP_KERNEL);
> removed = kzalloc(sizeof(*removed) * HPSA_MAX_DEVICES, GFP_KERNEL);
>
> @@ -1764,8 +1769,14 @@ 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])
> + continue;
> if (removed[i]->expose_state & HPSA_SCSI_ADD) {
> struct scsi_device *sdev =
> scsi_device_lookup(sh, removed[i]->bus,
> @@ -1790,6 +1801,8 @@ static void adjust_hpsa_scsi_table(struct ctlr_info *h, int hostno,
>
> /* Notify scsi mid layer of any added devices */
> for (i = 0; i < nadded; i++) {
> + if (!added[i])
> + continue;
> if (!(added[i]->expose_state & HPSA_SCSI_ADD))
> continue;
> if (scsi_add_device(sh, added[i]->bus,
> @@ -5227,12 +5240,15 @@ static int hpsa_eh_device_reset_handler(struct scsi_cmnd *scsicmd)
>
> hpsa_show_dev_msg(__stringify(KERN_WARNING), h, dev, "resetting");
>
> + atomic_set(&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(__stringify(KERN_WARNING), h, dev, msg);
> + atomic_set(&h->reset_in_progress, 0);
> return rc == 0 ? SUCCESS : FAILED;
> }
>
> diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
> index 642c8ce..c7c1697 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;
> + atomic_t reset_in_progress;
> };
>
> struct offline_device_entry {
>
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