Re: [PATCH 1/8] scsi: sd_zbc: Improve source code documentation

Damien Le Moal
2022-04-17T23:07:17Z

On 4/16/22 05:17, Bart Van Assche wrote:
> Add several kernel-doc headers. Declare input arrays const. Specify the
> array size in function declarations.
>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>

Looks good.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

> ---
> drivers/scsi/sd.h | 5 ++--
> drivers/scsi/sd_zbc.c | 54 ++++++++++++++++++++++++++++++++++++++++---
> 2 files changed, 53 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
> index 0a33a4b68ffb..4849cbe771a7 100644
> --- a/drivers/scsi/sd.h
> +++ b/drivers/scsi/sd.h
> @@ -222,7 +222,7 @@ static inline int sd_is_zoned(struct scsi_disk *sdkp)
> #ifdef CONFIG_BLK_DEV_ZONED
>
> void sd_zbc_release_disk(struct scsi_disk *sdkp);
> -int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buffer);
> +int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE]);
> int sd_zbc_revalidate_zones(struct scsi_disk *sdkp);
> blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
> unsigned char op, bool all);
> @@ -238,8 +238,7 @@ blk_status_t sd_zbc_prepare_zone_append(struct scsi_cmnd *cmd, sector_t *lba,
>
> static inline void sd_zbc_release_disk(struct scsi_disk *sdkp) {}
>
> -static inline int sd_zbc_read_zones(struct scsi_disk *sdkp,
> - unsigned char *buf)
> +static inline int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE])
> {
> return 0;
> }
> diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
> index 7f466280993b..925976ac5113 100644
> --- a/drivers/scsi/sd_zbc.c
> +++ b/drivers/scsi/sd_zbc.c
> @@ -20,6 +20,12 @@
>
> #include "sd.h"
>
> +/**
> + * sd_zbc_get_zone_wp_offset - Get zone write pointer offset.
> + * @zone: Zone for which to return the write pointer offset.
> + *
> + * Return: offset of the write pointer from the start of the zone.
> + */
> static unsigned int sd_zbc_get_zone_wp_offset(struct blk_zone *zone)
> {
> if (zone->type == ZBC_ZONE_TYPE_CONV)
> @@ -44,7 +50,20 @@ static unsigned int sd_zbc_get_zone_wp_offset(struct blk_zone *zone)
> }
> }
>
> -static int sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
> +/**
> + * sd_zbc_parse_report - Parse a SCSI zone descriptor
> + * @sdkp: SCSI disk pointer.
> + * @buf: SCSI zone descriptor.
> + * @idx: Index of the zone in the output of the REPORT ZONES command.
> + * @cb: Callback function pointer.
> + * @data: Second argument passed to @cb.
> + *
> + * Return: Value returned by @cb.
> + *
> + * Convert a SCSI zone descriptor into struct blk_zone format. Additionally,
> + * call @cb(blk_zone, @data).
> + */
> +static int sd_zbc_parse_report(struct scsi_disk *sdkp, const u8 buf[64],
> unsigned int idx, report_zones_cb cb, void *data)
> {
> struct scsi_device *sdp = sdkp->device;
> @@ -189,6 +208,17 @@ static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
> return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
> }
>
> +/**
> + * sd_zbc_report_zones - SCSI .report_zones() callback.
> + * @disk: Disk to report zones for.
> + * @sector: Start sector.
> + * @nr_zones: Maximum number of zones to report.
> + * @cb: Callback function called to report zone information.
> + * @data: Second argument passed to @cb.
> + *
> + * Called by the block layer to iterate over zone information. See also the
> + * disk->fops->report_zones() calls in block/blk-zoned.c.
> + */
> int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
> unsigned int nr_zones, report_zones_cb cb, void *data)
> {
> @@ -276,6 +306,10 @@ static int sd_zbc_update_wp_offset_cb(struct blk_zone *zone, unsigned int idx,
> return 0;
> }
>
> +/*
> + * An attempt to append a zone triggered an invalid write pointer error.
> + * Reread the write pointer of the zone(s) in which the append failed.
> + */
> static void sd_zbc_update_wp_offset_workfn(struct work_struct *work)
> {
> struct scsi_disk *sdkp;
> @@ -585,7 +619,7 @@ static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
> * sd_zbc_check_capacity - Check the device capacity
> * @sdkp: Target disk
> * @buf: command buffer
> - * @zblocks: zone size in number of blocks
> + * @zblocks: zone size in logical blocks
> *
> * Get the device zone size and check that the device capacity as reported
> * by READ CAPACITY matches the max_lba value (plus one) of the report zones
> @@ -696,6 +730,11 @@ static void sd_zbc_revalidate_zones_cb(struct gendisk *disk)
> swap(sdkp->zones_wp_offset, sdkp->rev_wp_offset);
> }
>
> +/*
> + * Call blk_revalidate_disk_zones() if any of the zoned disk properties have
> + * changed that make it necessary to call that function. Called by
> + * sd_revalidate_disk() after the gendisk capacity has been set.
> + */
> int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
> {
> struct gendisk *disk = sdkp->disk;
> @@ -774,7 +813,16 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
> return ret;
> }
>
> -int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
> +/**
> + * sd_zbc_read_zones - Read zone information and update the request queue
> + * @sdkp: SCSI disk pointer.
> + * @buf: 512 byte buffer used for storing SCSI command output.
> + *
> + * Read zone information and update the request queue zone characteristics and
> + * also the zoned device information in *sdkp. Called by sd_revalidate_disk()
> + * before the gendisk capacity has been set.
> + */
> +int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE])
> {
> struct gendisk *disk = sdkp->disk;
> struct request_queue *q = disk->queue;

--
Damien Le Moal
Western Digital Research