sd_zbc.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* SCSI Zoned Block commands
*
* Copyright (C) 2014-2015 SUSE Linux GmbH
* Written by: Hannes Reinecke <hare@suse.de>
* Modified by: Damien Le Moal <damien.lemoal@hgst.com>
* Modified by: Shaun Tancheff <shaun.tancheff@seagate.com>
*/
#include <linux/blkdev.h>
#include <linux/vmalloc.h>
#include <linux/sched/mm.h>
#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include "sd.h"
static int sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
unsigned int idx, report_zones_cb cb, void *data)
{
struct scsi_device *sdp = sdkp->device;
struct blk_zone zone = { 0 };
zone.type = buf[0] & 0x0f;
zone.cond = (buf[1] >> 4) & 0xf;
if (buf[1] & 0x01)
zone.reset = 1;
if (buf[1] & 0x02)
zone.non_seq = 1;
zone.len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
zone.start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
zone.wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
if (zone.type != ZBC_ZONE_TYPE_CONV &&
zone.cond == ZBC_ZONE_COND_FULL)
zone.wp = zone.start + zone.len;
return cb(&zone, idx, data);
}
/**
* sd_zbc_do_report_zones - Issue a REPORT ZONES scsi command.
* @sdkp: The target disk
* @buf: vmalloc-ed buffer to use for the reply
* @buflen: the buffer size
* @lba: Start LBA of the report
* @partial: Do partial report
*
* For internal use during device validation.
* Using partial=true can significantly speed up execution of a report zones
* command because the disk does not have to count all possible report matching
* zones and will only report the count of zones fitting in the command reply
* buffer.
*/
static int sd_zbc_do_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
unsigned int buflen, sector_t lba,
bool partial)
{
struct scsi_device *sdp = sdkp->device;
const int timeout = sdp->request_queue->rq_timeout;
struct scsi_sense_hdr sshdr;
unsigned char cmd[16];
unsigned int rep_len;
int result;
memset(cmd, 0, 16);
cmd[0] = ZBC_IN;
cmd[1] = ZI_REPORT_ZONES;
put_unaligned_be64(lba, &cmd[2]);
put_unaligned_be32(buflen, &cmd[10]);
if (partial)
cmd[14] = ZBC_REPORT_ZONE_PARTIAL;
result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
buf, buflen, &sshdr,
timeout, SD_MAX_RETRIES, NULL);
if (result) {
sd_printk(KERN_ERR, sdkp,
"REPORT ZONES start lba %llu failed\n", lba);
sd_print_result(sdkp, "REPORT ZONES", result);
if (driver_byte(result) == DRIVER_SENSE &&
scsi_sense_valid(&sshdr))
sd_print_sense_hdr(sdkp, &sshdr);
return -EIO;
}
rep_len = get_unaligned_be32(&buf[0]);
if (rep_len < 64) {
sd_printk(KERN_ERR, sdkp,
"REPORT ZONES report invalid length %u\n",
rep_len);
return -EIO;
}
return 0;
}
/**
* Allocate a buffer for report zones reply.
* @sdkp: The target disk
* @nr_zones: Maximum number of zones to report
* @buflen: Size of the buffer allocated
*
* Try to allocate a reply buffer for the number of requested zones.
* The size of the buffer allocated may be smaller than requested to
* satify the device constraint (max_hw_sectors, max_segments, etc).
*
* Return the address of the allocated buffer and update @buflen with
* the size of the allocated buffer.
*/
static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
unsigned int nr_zones, size_t *buflen)
{
struct request_queue *q = sdkp->disk->queue;
size_t bufsize;
void *buf;
/*
* Report zone buffer size should be at most 64B times the number of
* zones requested plus the 64B reply header, but should be at least
* SECTOR_SIZE for ATA devices.
* Make sure that this size does not exceed the hardware capabilities.
* Furthermore, since the report zone command cannot be split, make
* sure that the allocated buffer can always be mapped by limiting the
* number of pages allocated to the HBA max segments limit.
*/
nr_zones = min(nr_zones, sdkp->nr_zones);
bufsize = roundup((nr_zones + 1) * 64, SECTOR_SIZE);
bufsize = min_t(size_t, bufsize,
queue_max_hw_sectors(q) << SECTOR_SHIFT);
bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
while (bufsize >= SECTOR_SIZE) {
buf = __vmalloc(bufsize,
GFP_KERNEL | __GFP_ZERO | __GFP_NORETRY,
PAGE_KERNEL);
if (buf) {
*buflen = bufsize;
return buf;
}
bufsize >>= 1;
}
return NULL;
}
/**
* sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
* @sdkp: The target disk
*/
static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
{
return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
}
int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
unsigned int nr_zones, report_zones_cb cb, void *data)
{
struct scsi_disk *sdkp = scsi_disk(disk);
sector_t capacity = logical_to_sectors(sdkp->device, sdkp->capacity);
unsigned int nr, i;
unsigned char *buf;
size_t offset, buflen = 0;
int zone_idx = 0;
int ret;
if (!sd_is_zoned(sdkp))
/* Not a zoned device */
return -EOPNOTSUPP;
if (!capacity)
/* Device gone or invalid */
return -ENODEV;
buf = sd_zbc_alloc_report_buffer(sdkp, nr_zones, &buflen);
if (!buf)
return -ENOMEM;
while (zone_idx < nr_zones && sector < capacity) {
ret = sd_zbc_do_report_zones(sdkp, buf, buflen,
sectors_to_logical(sdkp->device, sector), true);
if (ret)
goto out;
offset = 0;
nr = min(nr_zones, get_unaligned_be32(&buf[0]) / 64);
if (!nr)
break;
for (i = 0; i < nr && zone_idx < nr_zones; i++) {
offset += 64;
ret = sd_zbc_parse_report(sdkp, buf + offset, zone_idx,
cb, data);
if (ret)
goto out;
zone_idx++;
}
sector += sd_zbc_zone_sectors(sdkp) * i;
}
ret = zone_idx;
out:
kvfree(buf);
return ret;
}
/**
* sd_zbc_setup_zone_mgmt_cmnd - Prepare a zone ZBC_OUT command. The operations
* can be RESET WRITE POINTER, OPEN, CLOSE or FINISH.
* @cmd: the command to setup
* @op: Operation to be performed
* @all: All zones control
*
* Called from sd_init_command() for REQ_OP_ZONE_RESET, REQ_OP_ZONE_RESET_ALL,
* REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE or REQ_OP_ZONE_FINISH requests.
*/
blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
unsigned char op, bool all)
{
struct request *rq = cmd->request;
struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
sector_t sector = blk_rq_pos(rq);
sector_t block = sectors_to_logical(sdkp->device, sector);
if (!sd_is_zoned(sdkp))
/* Not a zoned device */
return BLK_STS_IOERR;
if (sdkp->device->changed)
return BLK_STS_IOERR;
if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
/* Unaligned request */
return BLK_STS_IOERR;
cmd->cmd_len = 16;
memset(cmd->cmnd, 0, cmd->cmd_len);
cmd->cmnd[0] = ZBC_OUT;
cmd->cmnd[1] = op;
if (all)
cmd->cmnd[14] = 0x1;
else
put_unaligned_be64(block, &cmd->cmnd[2]);
rq->timeout = SD_TIMEOUT;
cmd->sc_data_direction = DMA_NONE;
cmd->transfersize = 0;
cmd->allowed = 0;
return BLK_STS_OK;
}
/**
* sd_zbc_complete - ZBC command post processing.
* @cmd: Completed command
* @good_bytes: Command reply bytes
* @sshdr: command sense header
*
* Called from sd_done(). Process report zones reply and handle reset zone
* and write commands errors.
*/
void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
struct scsi_sense_hdr *sshdr)
{
int result = cmd->result;
struct request *rq = cmd->request;
if (op_is_zone_mgmt(req_op(rq)) &&
result &&
sshdr->sense_key == ILLEGAL_REQUEST &&
sshdr->asc == 0x24) {
/*
* INVALID FIELD IN CDB error: a zone management command was
* attempted on a conventional zone. Nothing to worry about,
* so be quiet about the error.
*/
rq->rq_flags |= RQF_QUIET;
}
}
/**
* sd_zbc_check_zoned_characteristics - Check zoned block device characteristics
* @sdkp: Target disk
* @buf: Buffer where to store the VPD page data
*
* Read VPD page B6, get information and check that reads are unconstrained.
*/
static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
unsigned char *buf)
{
if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
sd_printk(KERN_NOTICE, sdkp,
"Read zoned characteristics VPD page failed\n");
return -ENODEV;
}
if (sdkp->device->type != TYPE_ZBC) {
/* Host-aware */
sdkp->urswrz = 1;
sdkp->zones_optimal_open = get_unaligned_be32(&buf[8]);
sdkp->zones_optimal_nonseq = get_unaligned_be32(&buf[12]);
sdkp->zones_max_open = 0;
} else {
/* Host-managed */
sdkp->urswrz = buf[4] & 1;
sdkp->zones_optimal_open = 0;
sdkp->zones_optimal_nonseq = 0;
sdkp->zones_max_open = get_unaligned_be32(&buf[16]);
}
/*
* Check for unconstrained reads: host-managed devices with
* constrained reads (drives failing read after write pointer)
* are not supported.
*/
if (!sdkp->urswrz) {
if (sdkp->first_scan)
sd_printk(KERN_NOTICE, sdkp,
"constrained reads devices are not supported\n");
return -ENODEV;
}
return 0;
}
/**
* sd_zbc_check_capacity - Check the device capacity
* @sdkp: Target disk
* @buf: command buffer
* @zblock: zone size in number of 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
* command reply for devices with RC_BASIS == 0.
*
* Returns 0 upon success or an error code upon failure.
*/
static int sd_zbc_check_capacity(struct scsi_disk *sdkp, unsigned char *buf,
u32 *zblocks)
{
u64 zone_blocks;
sector_t max_lba;
unsigned char *rec;
int ret;
/* Do a report zone to get max_lba and the size of the first zone */
ret = sd_zbc_do_report_zones(sdkp, buf, SD_BUF_SIZE, 0, false);
if (ret)
return ret;
if (sdkp->rc_basis == 0) {
/* The max_lba field is the capacity of this device */
max_lba = get_unaligned_be64(&buf[8]);
if (sdkp->capacity != max_lba + 1) {
if (sdkp->first_scan)
sd_printk(KERN_WARNING, sdkp,
"Changing capacity from %llu to max LBA+1 %llu\n",
(unsigned long long)sdkp->capacity,
(unsigned long long)max_lba + 1);
sdkp->capacity = max_lba + 1;
}
}
/* Get the size of the first reported zone */
rec = buf + 64;
zone_blocks = get_unaligned_be64(&rec[8]);
if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
if (sdkp->first_scan)
sd_printk(KERN_NOTICE, sdkp,
"Zone size too large\n");
return -EFBIG;
}
*zblocks = zone_blocks;
return 0;
}
int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
{
struct gendisk *disk = sdkp->disk;
unsigned int nr_zones;
u32 zone_blocks = 0;
int ret;
if (!sd_is_zoned(sdkp))
/*
* Device managed or normal SCSI disk,
* no special handling required
*/
return 0;
/* Check zoned block device characteristics (unconstrained reads) */
ret = sd_zbc_check_zoned_characteristics(sdkp, buf);
if (ret)
goto err;
/* Check the device capacity reported by report zones */
ret = sd_zbc_check_capacity(sdkp, buf, &zone_blocks);
if (ret != 0)
goto err;
/* The drive satisfies the kernel restrictions: set it up */
blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, sdkp->disk->queue);
blk_queue_required_elevator_features(sdkp->disk->queue,
ELEVATOR_F_ZBD_SEQ_WRITE);
nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
/* READ16/WRITE16 is mandatory for ZBC disks */
sdkp->device->use_16_for_rw = 1;
sdkp->device->use_10_for_rw = 0;
/*
* Revalidate the disk zone bitmaps once the block device capacity is
* set on the second revalidate execution during disk scan and if
* something changed when executing a normal revalidate.
*/
if (sdkp->first_scan) {
sdkp->zone_blocks = zone_blocks;
sdkp->nr_zones = nr_zones;
return 0;
}
if (sdkp->zone_blocks != zone_blocks ||
sdkp->nr_zones != nr_zones ||
disk->queue->nr_zones != nr_zones) {
ret = blk_revalidate_disk_zones(disk);
if (ret != 0)
goto err;
sdkp->zone_blocks = zone_blocks;
sdkp->nr_zones = nr_zones;
}
return 0;
err:
sdkp->capacity = 0;
return ret;
}
void sd_zbc_print_zones(struct scsi_disk *sdkp)
{
if (!sd_is_zoned(sdkp) || !sdkp->capacity)
return;
if (sdkp->capacity & (sdkp->zone_blocks - 1))
sd_printk(KERN_NOTICE, sdkp,
"%u zones of %u logical blocks + 1 runt zone\n",
sdkp->nr_zones - 1,
sdkp->zone_blocks);
else
sd_printk(KERN_NOTICE, sdkp,
"%u zones of %u logical blocks\n",
sdkp->nr_zones,
sdkp->zone_blocks);
}