From 7ce5146113d07e6220e7bd7b220c5f83f99a20e3 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 21 Apr 2022 11:30:15 -0700 Subject: [PATCH] scsi: sd: sd_zbc: Improve source code documentation Add several kernel-doc headers. Declare input arrays const. Specify the array size in function declarations. Link: https://lore.kernel.org/r/20220421183023.3462291-2-bvanassche@acm.org Reviewed-by: Damien Le Moal Reviewed-by: Himanshu Madhani Acked-by: Douglas Gilbert Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen --- drivers/scsi/sd.h | 5 ++-- drivers/scsi/sd_zbc.c | 55 ++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 54 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h index 0a33a4b68ffbc..4849cbe771a7c 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 7f466280993bb..2ae44bc52a5f2 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 +50,21 @@ 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 relative to the first zone reported by the current + * sd_zbc_report_zones() call. + * @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 +209,17 @@ 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 +307,10 @@ 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 +620,7 @@ 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 +731,11 @@ 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 +814,16 @@ unlock: 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; -- 2.39.5