On Tue, 2019-04-23 at 18:32 +0800, Ming Lei wrote:
> +/*
> + * Size of integrity meta data size is usually small, 1 inline sg
^^^^^^^^^^^^^^
Please change this into "metadata". Mentioning "size" twice is not
useful.
> + * should cover normal cases.
> + */
> +#define SCSI_INLINE_PROT_SG_CNT 1
> +
> static struct kmem_cache *scsi_sdb_cache;
> static struct kmem_cache *scsi_sense_cache;
> static struct kmem_cache *scsi_sense_isadma_cache;
> @@ -553,12 +559,21 @@ static void scsi_uninit_cmd(struct scsi_cmnd *cmd)
> }
> }
>
> +static inline bool scsi_prot_use_inline_sg(struct scsi_cmnd *cmd)
> +{
> + if (!scsi_prot_sglist(cmd))
> + return false;
Since scsi_prot_use_inline_sg() is only called if scsi_prot_sg_count() > 0,
is the above test necessary?
> + return cmd->prot_sdb->table.sgl ==
> + (struct scatterlist *)(cmd->prot_sdb + 1);
> +}
> +
> static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd)
> {
> if (cmd->sdb.table.nents)
> sg_free_table_chained(&cmd->sdb.table, true);
> - if (scsi_prot_sg_count(cmd))
> - sg_free_table_chained(&cmd->prot_sdb->table, true);
> + if (scsi_prot_sg_count(cmd) && !scsi_prot_use_inline_sg(cmd))
> + sg_free_table_chained(&cmd->prot_sdb->table, false);
> }
>
> static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
> @@ -1044,9 +1059,11 @@ blk_status_t scsi_init_io(struct scsi_cmnd *cmd)
> }
>
> ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
> -
> - if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
> - prot_sdb->table.sgl)) {
> + if (ivecs <= SCSI_INLINE_PROT_SG_CNT)
> + prot_sdb->table.nents = prot_sdb->table.orig_nents =
> + SCSI_INLINE_PROT_SG_CNT;
Please call sg_init_table() instead of open-coding it.
> + else if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
> + NULL)) {
> ret = BLK_STS_RESOURCE;
> goto out_free_sgtables;
> }
Bart.
