drivers/block/null_blk_zoned.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/vmalloc.h>
   3 #include "null_blk.h"
   4
   5 #define MB_TO_SECTS(mb) (((sector_t)mb * SZ_1M) >> SECTOR_SHIFT)
   6
   7 static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
   8 {
   9         return sect >> ilog2(dev->zone_size_sects);
  10 }
  11
  12 int null_zone_init(struct nullb_device *dev)
  13 {
  14         sector_t dev_capacity_sects;
  15         sector_t sector = 0;
  16         unsigned int i;
  17
  18         if (!is_power_of_2(dev->zone_size)) {
  19                 pr_err("zone_size must be power-of-two\n");
  20                 return -EINVAL;
  21         }
  22         if (dev->zone_size > dev->size) {
  23                 pr_err("Zone size larger than device capacity\n");
  24                 return -EINVAL;
  25         }
  26
  27         dev_capacity_sects = MB_TO_SECTS(dev->size);
  28         dev->zone_size_sects = MB_TO_SECTS(dev->zone_size);
  29         dev->nr_zones = dev_capacity_sects >> ilog2(dev->zone_size_sects);
  30         if (dev_capacity_sects & (dev->zone_size_sects - 1))
  31                 dev->nr_zones++;
  32
  33         dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct blk_zone),
  34                         GFP_KERNEL | __GFP_ZERO);
  35         if (!dev->zones)
  36                 return -ENOMEM;
  37
  38         if (dev->zone_nr_conv >= dev->nr_zones) {
  39                 dev->zone_nr_conv = dev->nr_zones - 1;
  40                 pr_info("changed the number of conventional zones to %u",
  41                         dev->zone_nr_conv);
  42         }
  43
  44         for (i = 0; i <  dev->zone_nr_conv; i++) {
  45                 struct blk_zone *zone = &dev->zones[i];
  46
  47                 zone->start = sector;
  48                 zone->len = dev->zone_size_sects;
  49                 zone->wp = zone->start + zone->len;
  50                 zone->type = BLK_ZONE_TYPE_CONVENTIONAL;
  51                 zone->cond = BLK_ZONE_COND_NOT_WP;
  52
  53                 sector += dev->zone_size_sects;
  54         }
  55
  56         for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
  57                 struct blk_zone *zone = &dev->zones[i];
  58
  59                 zone->start = zone->wp = sector;
  60                 if (zone->start + dev->zone_size_sects > dev_capacity_sects)
  61                         zone->len = dev_capacity_sects - zone->start;
  62                 else
  63                         zone->len = dev->zone_size_sects;
  64                 zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
  65                 zone->cond = BLK_ZONE_COND_EMPTY;
  66
  67                 sector += dev->zone_size_sects;
  68         }
  69
  70         return 0;
  71 }
  72
  73 void null_zone_exit(struct nullb_device *dev)
  74 {
  75         kvfree(dev->zones);
  76         dev->zones = NULL;
  77 }
  78
  79 int null_zone_report(struct gendisk *disk, sector_t sector,
  80                      struct blk_zone *zones, unsigned int *nr_zones)
  81 {
  82         struct nullb *nullb = disk->private_data;
  83         struct nullb_device *dev = nullb->dev;
  84         unsigned int zno, nrz = 0;
  85
  86         zno = null_zone_no(dev, sector);
  87         if (zno < dev->nr_zones) {
  88                 nrz = min_t(unsigned int, *nr_zones, dev->nr_zones - zno);
  89                 memcpy(zones, &dev->zones[zno], nrz * sizeof(struct blk_zone));
  90         }
  91
  92         *nr_zones = nrz;
  93
  94         return 0;
  95 }
  96
  97 static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
  98                      unsigned int nr_sectors)
  99 {
 100         struct nullb_device *dev = cmd->nq->dev;
 101         unsigned int zno = null_zone_no(dev, sector);
 102         struct blk_zone *zone = &dev->zones[zno];
 103
 104         switch (zone->cond) {
 105         case BLK_ZONE_COND_FULL:
 106                 /* Cannot write to a full zone */
 107                 cmd->error = BLK_STS_IOERR;
 108                 return BLK_STS_IOERR;
 109         case BLK_ZONE_COND_EMPTY:
 110         case BLK_ZONE_COND_IMP_OPEN:
 111                 /* Writes must be at the write pointer position */
 112                 if (sector != zone->wp)
 113                         return BLK_STS_IOERR;
 114
 115                 if (zone->cond == BLK_ZONE_COND_EMPTY)
 116                         zone->cond = BLK_ZONE_COND_IMP_OPEN;
 117
 118                 zone->wp += nr_sectors;
 119                 if (zone->wp == zone->start + zone->len)
 120                         zone->cond = BLK_ZONE_COND_FULL;
 121                 break;
 122         case BLK_ZONE_COND_NOT_WP:
 123                 break;
 124         default:
 125                 /* Invalid zone condition */
 126                 return BLK_STS_IOERR;
 127         }
 128         return BLK_STS_OK;
 129 }
 130
 131 static blk_status_t null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
 132 {
 133         struct nullb_device *dev = cmd->nq->dev;
 134         unsigned int zno = null_zone_no(dev, sector);
 135         struct blk_zone *zone = &dev->zones[zno];
 136         size_t i;
 137
 138         switch (req_op(cmd->rq)) {
 139         case REQ_OP_ZONE_RESET_ALL:
 140                 for (i = 0; i < dev->nr_zones; i++) {
 141                         if (zone[i].type == BLK_ZONE_TYPE_CONVENTIONAL)
 142                                 continue;
 143                         zone[i].cond = BLK_ZONE_COND_EMPTY;
 144                         zone[i].wp = zone[i].start;
 145                 }
 146                 break;
 147         case REQ_OP_ZONE_RESET:
 148                 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
 149                         return BLK_STS_IOERR;
 150
 151                 zone->cond = BLK_ZONE_COND_EMPTY;
 152                 zone->wp = zone->start;
 153                 break;
 154         default:
 155                 return BLK_STS_NOTSUPP;
 156         }
 157         return BLK_STS_OK;
 158 }
 159
 160 blk_status_t null_handle_zoned(struct nullb_cmd *cmd, enum req_opf op,
 161                                sector_t sector, sector_t nr_sectors)
 162 {
 163         switch (op) {
 164         case REQ_OP_WRITE:
 165                 return null_zone_write(cmd, sector, nr_sectors);
 166         case REQ_OP_ZONE_RESET:
 167         case REQ_OP_ZONE_RESET_ALL:
 168                 return null_zone_reset(cmd, sector);
 169         default:
 170                 return BLK_STS_OK;
 171         }
 172 }