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Message-ID: <45765771-0f1f-7a4e-0593-9f65c7fe1668@interlog.com>
Date:   Thu, 17 Nov 2022 17:51:27 -0500
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Reply-To: dgilbert@interlog.com
Subject: Re: [PATCH linux-next] scsi: scsi_debug: use sysfs_emit() to instead
 of scnprintf()
Content-Language: en-CA
To:     guo.ziliang@zte.com.cn, jejb@linux.ibm.com
Cc:     martin.petersen@oracle.com, linux-scsi@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <202211170940036248332@zte.com.cn>
From:   Douglas Gilbert <dgilbert@interlog.com>
In-Reply-To: <202211170940036248332@zte.com.cn>
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On 2022-11-16 20:40, guo.ziliang@zte.com.cn wrote:
> From: guo ziliang <guo.ziliang@zte.com.cn>
> Replace the open-code with sysfs_emit() to simplify the code.
> 
> Signed-off-by: guo ziliang <guo.ziliang@zte.com.cn>

Acked-by: Douglas Gilbert <dgilbert@interlog.com>

Thanks.

> ---
>   drivers/scsi/scsi_debug.c | 78 +++++++++++++++++++++++------------------------
>   1 file changed, 38 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index a86db97..7bd4d2a7 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -6075,7 +6075,7 @@ static int scsi_debug_show_info(struct seq_file *m, struct Scsi_Host *host)
> 
>   static ssize_t delay_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_jdelay);
> +       return sysfs_emit(buf, "%d\n", sdebug_jdelay);
>   }
>   /* Returns -EBUSY if jdelay is being changed and commands are queued. The unit
>    * of delay is jiffies.
> @@ -6115,7 +6115,7 @@ static ssize_t delay_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t ndelay_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_ndelay);
> +       return sysfs_emit(buf, "%d\n", sdebug_ndelay);
>   }
>   /* Returns -EBUSY if ndelay is being changed and commands are queued */
>   /* If > 0 and accepted then sdebug_jdelay is set to JDELAY_OVERRIDDEN */
> @@ -6156,7 +6156,7 @@ static ssize_t ndelay_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t opts_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "0x%x\n", sdebug_opts);
> +       return sysfs_emit(buf, "0x%x\n", sdebug_opts);
>   }
> 
>   static ssize_t opts_store(struct device_driver *ddp, const char *buf,
> @@ -6186,7 +6186,7 @@ static ssize_t opts_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t ptype_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_ptype);
> +       return sysfs_emit(buf, "%d\n", sdebug_ptype);
>   }
>   static ssize_t ptype_store(struct device_driver *ddp, const char *buf,
>                             size_t count)
> @@ -6209,7 +6209,7 @@ static ssize_t ptype_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t dsense_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_dsense);
> +       return sysfs_emit(buf, "%d\n", sdebug_dsense);
>   }
>   static ssize_t dsense_store(struct device_driver *ddp, const char *buf,
>                              size_t count)
> @@ -6226,7 +6226,7 @@ static ssize_t dsense_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t fake_rw_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_fake_rw);
> +       return sysfs_emit(buf, "%d\n", sdebug_fake_rw);
>   }
>   static ssize_t fake_rw_store(struct device_driver *ddp, const char *buf,
>                               size_t count)
> @@ -6274,7 +6274,7 @@ static ssize_t fake_rw_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t no_lun_0_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_no_lun_0);
> +       return sysfs_emit(buf, "%d\n", sdebug_no_lun_0);
>   }
>   static ssize_t no_lun_0_store(struct device_driver *ddp, const char *buf,
>                                size_t count)
> @@ -6291,7 +6291,7 @@ static ssize_t no_lun_0_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t num_tgts_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_num_tgts);
> +       return sysfs_emit(buf, "%d\n", sdebug_num_tgts);
>   }
>   static ssize_t num_tgts_store(struct device_driver *ddp, const char *buf,
>                                size_t count)
> @@ -6309,13 +6309,13 @@ static ssize_t num_tgts_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t dev_size_mb_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_dev_size_mb);
> +       return sysfs_emit(buf, "%d\n", sdebug_dev_size_mb);
>   }
>   static DRIVER_ATTR_RO(dev_size_mb);
> 
>   static ssize_t per_host_store_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_per_host_store);
> +       return sysfs_emit(buf, "%d\n", sdebug_per_host_store);
>   }
> 
>   static ssize_t per_host_store_store(struct device_driver *ddp, const char *buf,
> @@ -6333,13 +6333,13 @@ static ssize_t per_host_store_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t num_parts_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_num_parts);
> +       return sysfs_emit(buf, "%d\n", sdebug_num_parts);
>   }
>   static DRIVER_ATTR_RO(num_parts);
> 
>   static ssize_t every_nth_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_every_nth);
> +       return sysfs_emit(buf, "%d\n", sdebug_every_nth);
>   }
>   static ssize_t every_nth_store(struct device_driver *ddp, const char *buf,
>                                 size_t count)
> @@ -6371,7 +6371,7 @@ static ssize_t every_nth_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t lun_format_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", (int)sdebug_lun_am);
> +       return sysfs_emit(buf, "%d\n", (int)sdebug_lun_am);
>   }
>   static ssize_t lun_format_store(struct device_driver *ddp, const char *buf,
>                                  size_t count)
> @@ -6408,7 +6408,7 @@ static ssize_t lun_format_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t max_luns_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_max_luns);
> +       return sysfs_emit(buf, "%d\n", sdebug_max_luns);
>   }
>   static ssize_t max_luns_store(struct device_driver *ddp, const char *buf,
>                                size_t count)
> @@ -6447,7 +6447,7 @@ static ssize_t max_luns_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t max_queue_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_max_queue);
> +       return sysfs_emit(buf, "%d\n", sdebug_max_queue);
>   }
>   /* N.B. max_queue can be changed while there are queued commands. In flight
>    * commands beyond the new max_queue will be completed. */
> @@ -6484,12 +6484,12 @@ static ssize_t max_queue_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t host_max_queue_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_host_max_queue);
> +       return sysfs_emit(buf, "%d\n", sdebug_host_max_queue);
>   }
> 
>   static ssize_t no_rwlock_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_no_rwlock);
> +       return sysfs_emit(buf, "%d\n", sdebug_no_rwlock);
>   }
> 
>   static ssize_t no_rwlock_store(struct device_driver *ddp, const char *buf, size_t count)
> @@ -6512,19 +6512,19 @@ static ssize_t no_rwlock_store(struct device_driver *ddp, const char *buf, size_
> 
>   static ssize_t no_uld_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_no_uld);
> +       return sysfs_emit(buf, "%d\n", sdebug_no_uld);
>   }
>   static DRIVER_ATTR_RO(no_uld);
> 
>   static ssize_t scsi_level_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_scsi_level);
> +       return sysfs_emit(buf, "%d\n", sdebug_scsi_level);
>   }
>   static DRIVER_ATTR_RO(scsi_level);
> 
>   static ssize_t virtual_gb_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_virtual_gb);
> +       return sysfs_emit(buf, "%d\n", sdebug_virtual_gb);
>   }
>   static ssize_t virtual_gb_store(struct device_driver *ddp, const char *buf,
>                                  size_t count)
> @@ -6564,7 +6564,7 @@ static ssize_t virtual_gb_store(struct device_driver *ddp, const char *buf,
>   static ssize_t add_host_show(struct device_driver *ddp, char *buf)
>   {
>          /* absolute number of hosts currently active is what is shown */
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_num_hosts);
> +       return sysfs_emit(buf, "%d\n", sdebug_num_hosts);
>   }
> 
>   static ssize_t add_host_store(struct device_driver *ddp, const char *buf,
> @@ -6607,7 +6607,7 @@ static ssize_t add_host_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t vpd_use_hostno_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_vpd_use_hostno);
> +       return sysfs_emit(buf, "%d\n", sdebug_vpd_use_hostno);
>   }
>   static ssize_t vpd_use_hostno_store(struct device_driver *ddp, const char *buf,
>                                      size_t count)
> @@ -6624,7 +6624,7 @@ static ssize_t vpd_use_hostno_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t statistics_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", (int)sdebug_statistics);
> +       return sysfs_emit(buf, "%d\n", (int)sdebug_statistics);
>   }
>   static ssize_t statistics_store(struct device_driver *ddp, const char *buf,
>                                  size_t count)
> @@ -6646,37 +6646,37 @@ static ssize_t statistics_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t sector_size_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%u\n", sdebug_sector_size);
> +       return sysfs_emit(buf, "%u\n", sdebug_sector_size);
>   }
>   static DRIVER_ATTR_RO(sector_size);
> 
>   static ssize_t submit_queues_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", submit_queues);
> +       return sysfs_emit(buf, "%d\n", submit_queues);
>   }
>   static DRIVER_ATTR_RO(submit_queues);
> 
>   static ssize_t dix_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_dix);
> +       return sysfs_emit(buf, "%d\n", sdebug_dix);
>   }
>   static DRIVER_ATTR_RO(dix);
> 
>   static ssize_t dif_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_dif);
> +       return sysfs_emit(buf, "%d\n", sdebug_dif);
>   }
>   static DRIVER_ATTR_RO(dif);
> 
>   static ssize_t guard_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%u\n", sdebug_guard);
> +       return sysfs_emit(buf, "%u\n", sdebug_guard);
>   }
>   static DRIVER_ATTR_RO(guard);
> 
>   static ssize_t ato_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_ato);
> +       return sysfs_emit(buf, "%d\n", sdebug_ato);
>   }
>   static DRIVER_ATTR_RO(ato);
> 
> @@ -6685,8 +6685,7 @@ static ssize_t map_show(struct device_driver *ddp, char *buf)
>          ssize_t count = 0;
> 
>          if (!scsi_debug_lbp())
> -               return scnprintf(buf, PAGE_SIZE, "0-%u\n",
> -                                sdebug_store_sectors);
> +               return sysfs_emit(buf, "0-%u\n", sdebug_store_sectors);
> 
>          if (sdebug_fake_rw == 0 && !xa_empty(per_store_ap)) {
>                  struct sdeb_store_info *sip = xa_load(per_store_ap, 0);
> @@ -6704,7 +6703,7 @@ static ssize_t map_show(struct device_driver *ddp, char *buf)
> 
>   static ssize_t random_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_random);
> +       return sysfs_emit(buf, "%d\n", sdebug_random);
>   }
> 
>   static ssize_t random_store(struct device_driver *ddp, const char *buf,
> @@ -6722,7 +6721,7 @@ static ssize_t random_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t removable_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_removable ? 1 : 0);
> +       return sysfs_emit(buf, "%d\n", sdebug_removable ? 1 : 0);
>   }
>   static ssize_t removable_store(struct device_driver *ddp, const char *buf,
>                                 size_t count)
> @@ -6739,7 +6738,7 @@ static ssize_t removable_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t host_lock_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", !!sdebug_host_lock);
> +       return sysfs_emit(buf, "%d\n", !!sdebug_host_lock);
>   }
>   /* N.B. sdebug_host_lock does nothing, kept for backward compatibility */
>   static ssize_t host_lock_store(struct device_driver *ddp, const char *buf,
> @@ -6757,7 +6756,7 @@ static ssize_t host_lock_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t strict_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", !!sdebug_strict);
> +       return sysfs_emit(buf, "%d\n", !!sdebug_strict);
>   }
>   static ssize_t strict_store(struct device_driver *ddp, const char *buf,
>                              size_t count)
> @@ -6774,13 +6773,13 @@ static ssize_t strict_store(struct device_driver *ddp, const char *buf,
> 
>   static ssize_t uuid_ctl_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", !!sdebug_uuid_ctl);
> +       return sysfs_emit(buf, "%d\n", !!sdebug_uuid_ctl);
>   }
>   static DRIVER_ATTR_RO(uuid_ctl);
> 
>   static ssize_t cdb_len_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_cdb_len);
> +       return sysfs_emit(buf, "%d\n", sdebug_cdb_len);
>   }
>   static ssize_t cdb_len_store(struct device_driver *ddp, const char *buf,
>                               size_t count)
> @@ -6831,14 +6830,13 @@ static int sdeb_zbc_model_str(const char *cp)
> 
>   static ssize_t zbc_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%s\n",
> -                        zbc_model_strs_a[sdeb_zbc_model]);
> +       return sysfs_emit(buf, "%s\n", zbc_model_strs_a[sdeb_zbc_model]);
>   }
>   static DRIVER_ATTR_RO(zbc);
> 
>   static ssize_t tur_ms_to_ready_show(struct device_driver *ddp, char *buf)
>   {
> -       return scnprintf(buf, PAGE_SIZE, "%d\n", sdeb_tur_ms_to_ready);
> +       return sysfs_emit(buf, "%d\n", sdeb_tur_ms_to_ready);
>   }
>   static DRIVER_ATTR_RO(tur_ms_to_ready);
> 
> --
> 1.8.3.1