Re: [PATCH v2 1/1] scsi: qla2xxx: replace non-standard flexible array purex_item.iocb

Gustavo A. R. Silva
2025-07-30T03:45:05Z

Hi Bryan,

I wonder if you could run your tests on the patch below and let me
know if it passes. If it does, I'll go ahead and submit it as a
proper patch (including your Tested-by tag) to the SCSI list.

Thank you!
-Gustavo

>
> The (untested) patch below avoids the use of `struct_group_tagged()`
> and the casts to `struct purex_item *`:
>
> diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
> index cb95b7b12051..4bdf8adf04ed 100644
> --- a/drivers/scsi/qla2xxx/qla_def.h
> +++ b/drivers/scsi/qla2xxx/qla_def.h
> @@ -4890,9 +4890,7 @@ struct purex_item {
>                              struct purex_item *pkt);
>         atomic_t in_use;
>         uint16_t size;
> -       struct {
> -               uint8_t iocb[64];
> -       } iocb;
> +       uint8_t iocb[] __counted_by(size);
>  };
>
>  #include "qla_edif.h"
> @@ -5101,7 +5099,6 @@ typedef struct scsi_qla_host {
>                 struct list_head head;
>                 spinlock_t lock;
>         } purex_list;
> -       struct purex_item default_item;
>
>         struct name_list_extended gnl;
>         /* Count of active session/fcport */
> @@ -5130,6 +5127,10 @@ typedef struct scsi_qla_host {
>  #define DPORT_DIAG_IN_PROGRESS                 BIT_0
>  #define DPORT_DIAG_CHIP_RESET_IN_PROGRESS      BIT_1
>         uint16_t dport_status;
> +
> +       TRAILING_OVERLAP(struct purex_item, default_item, iocb,
> +               uint8_t __default_item_iocb[QLA_DEFAULT_PAYLOAD_SIZE];
> +       );
>  } scsi_qla_host_t;
>
>  struct qla27xx_image_status {
> diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
> index c4c6b5c6658c..4559b490614d 100644
> --- a/drivers/scsi/qla2xxx/qla_isr.c
> +++ b/drivers/scsi/qla2xxx/qla_isr.c
> @@ -1077,17 +1077,17 @@ static struct purex_item *
>  qla24xx_alloc_purex_item(scsi_qla_host_t *vha, uint16_t size)
>  {
>         struct purex_item *item = NULL;
> -       uint8_t item_hdr_size = sizeof(*item);
>
>         if (size > QLA_DEFAULT_PAYLOAD_SIZE) {
> -               item = kzalloc(item_hdr_size +
> -                   (size - QLA_DEFAULT_PAYLOAD_SIZE), GFP_ATOMIC);
> +               item = kzalloc(struct_size(item, iocb, size), GFP_ATOMIC);
>         } else {
>                 if (atomic_inc_return(&vha->default_item.in_use) == 1) {
>                         item = &vha->default_item;
>                         goto initialize_purex_header;
>                 } else {
> -                       item = kzalloc(item_hdr_size, GFP_ATOMIC);
> +                       item = kzalloc(
> +                               struct_size(item, iocb, QLA_DEFAULT_PAYLOAD_SIZE),
> +                               GFP_ATOMIC);
>                 }
>         }
>         if (!item) {
> @@ -1127,17 +1127,16 @@ qla24xx_queue_purex_item(scsi_qla_host_t *vha, struct purex_item *pkt,
>   * @vha: SCSI driver HA context
>   * @pkt: ELS packet
>   */
> -static struct purex_item
> -*qla24xx_copy_std_pkt(struct scsi_qla_host *vha, void *pkt)
> +static struct purex_item *
> +qla24xx_copy_std_pkt(struct scsi_qla_host *vha, void *pkt)
>  {
>         struct purex_item *item;
>
> -       item = qla24xx_alloc_purex_item(vha,
> -                                       QLA_DEFAULT_PAYLOAD_SIZE);
> +       item = qla24xx_alloc_purex_item(vha, QLA_DEFAULT_PAYLOAD_SIZE);
>         if (!item)
>                 return item;
>
> -       memcpy(&item->iocb, pkt, sizeof(item->iocb));
> +       memcpy(&item->iocb, pkt, QLA_DEFAULT_PAYLOAD_SIZE);
>         return item;
>  }
>
> diff --git a/drivers/scsi/qla2xxx/qla_nvme.c b/drivers/scsi/qla2xxx/qla_nvme.c
> index 8ee2e337c9e1..92488890bc04 100644
> --- a/drivers/scsi/qla2xxx/qla_nvme.c
> +++ b/drivers/scsi/qla2xxx/qla_nvme.c
> @@ -1308,7 +1308,7 @@ void qla2xxx_process_purls_iocb(void **pkt, struct rsp_que **rsp)
>
>         ql_dbg(ql_dbg_unsol, vha, 0x2121,
>                "PURLS OP[%01x] size %d xchg addr 0x%x portid %06x\n",
> -              item->iocb.iocb[3], item->size, uctx->exchange_address,
> +              item->iocb[3], item->size, uctx->exchange_address,
>                fcport->d_id.b24);
>         /* +48    0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
>          * ----- -----------------------------------------------
> diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
> index d4b484c0fd9d..253f802605d6 100644
> --- a/drivers/scsi/qla2xxx/qla_os.c
> +++ b/drivers/scsi/qla2xxx/qla_os.c
> @@ -6459,9 +6459,10 @@ void qla24xx_process_purex_rdp(struct scsi_qla_host *vha,
>  void
>  qla24xx_free_purex_item(struct purex_item *item)
>  {
> -       if (item == &item->vha->default_item)
> +       if (item == &item->vha->default_item) {
>                 memset(&item->vha->default_item, 0, sizeof(struct purex_item));
> -       else
> +               memset(&item->vha->__default_item_iocb, 0, QLA_DEFAULT_PAYLOAD_SIZE);
> +       } else
>                 kfree(item);
>
> Thanks
> -Gustavo