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 /* zone_size in MBs to sectors. */
   6 #define ZONE_SIZE_SHIFT         11
   7
   8 static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
   9 {
  10         return sect >> ilog2(dev->zone_size_sects);
  11 }
  12
  13 int null_zone_init(struct nullb_device *dev)
  14 {
  15         sector_t dev_size = (sector_t)dev->size * 1024 * 1024;
  16         sector_t sector = 0;
  17         unsigned int i;
  18
  19         if (!is_power_of_2(dev->zone_size)) {
  20                 pr_err("zone_size must be power-of-two\n");
  21                 return -EINVAL;
  22         }
  23
  24         dev->zone_size_sects = dev->zone_size << ZONE_SIZE_SHIFT;
  25         dev->nr_zones = dev_size >>
  26                                 (SECTOR_SHIFT + ilog2(dev->zone_size_sects));
  27         dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct blk_zone),
  28                         GFP_KERNEL | __GFP_ZERO);
  29         if (!dev->zones)
  30                 return -ENOMEM;
  31
  32         if (dev->zone_nr_conv >= dev->nr_zones) {
  33                 dev->zone_nr_conv = dev->nr_zones - 1;
  34                 pr_info("changed the number of conventional zones to %u",
  35                         dev->zone_nr_conv);
  36         }
  37
  38         for (i = 0; i <  dev->zone_nr_conv; i++) {
  39                 struct blk_zone *zone = &dev->zones[i];
  40
  41                 zone->start = sector;
  42                 zone->len = dev->zone_size_sects;
  43                 zone->wp = zone->start + zone->len;
  44                 zone->type = BLK_ZONE_TYPE_CONVENTIONAL;
  45                 zone->cond = BLK_ZONE_COND_NOT_WP;
  46
  47                 sector += dev->zone_size_sects;
  48         }
  49
  50         for (i = dev->zone_nr_conv; i < dev->nr_zones; i++) {
  51                 struct blk_zone *zone = &dev->zones[i];
  52
  53                 zone->start = zone->wp = sector;
  54                 zone->len = dev->zone_size_sects;
  55                 zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
  56                 zone->cond = BLK_ZONE_COND_EMPTY;
  57
  58                 sector += dev->zone_size_sects;
  59         }
  60
  61         return 0;
  62 }
  63
  64 void null_zone_exit(struct nullb_device *dev)
  65 {
  66         kvfree(dev->zones);
  67 }
  68
  69 int null_report_zones(struct gendisk *disk, sector_t sector,
  70                 unsigned int nr_zones, report_zones_cb cb, void *data)
  71 {
  72         struct nullb *nullb = disk->private_data;
  73         struct nullb_device *dev = nullb->dev;
  74         unsigned int first_zone, i;
  75         struct blk_zone zone;
  76         int error;
  77
  78         first_zone = null_zone_no(dev, sector);
  79         if (first_zone >= dev->nr_zones)
  80                 return 0;
  81
  82         nr_zones = min(nr_zones, dev->nr_zones - first_zone);
  83         for (i = 0; i < nr_zones; i++) {
  84                 /*
  85                  * Stacked DM target drivers will remap the zone information by
  86                  * modifying the zone information passed to the report callback.
  87                  * So use a local copy to avoid corruption of the device zone
  88                  * array.
  89                  */
  90                 memcpy(&zone, &dev->zones[first_zone + i],
  91                        sizeof(struct blk_zone));
  92                 error = cb(&zone, i, data);
  93                 if (error)
  94                         return error;
  95         }
  96
  97         return nr_zones;
  98 }
  99
 100 size_t null_zone_valid_read_len(struct nullb *nullb,
 101                                 sector_t sector, unsigned int len)
 102 {
 103         struct nullb_device *dev = nullb->dev;
 104         struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)];
 105         unsigned int nr_sectors = len >> SECTOR_SHIFT;
 106
 107         /* Read must be below the write pointer position */
 108         if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL ||
 109             sector + nr_sectors <= zone->wp)
 110                 return len;
 111
 112         if (sector > zone->wp)
 113                 return 0;
 114
 115         return (zone->wp - sector) << SECTOR_SHIFT;
 116 }
 117
 118 static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
 119                      unsigned int nr_sectors)
 120 {
 121         struct nullb_device *dev = cmd->nq->dev;
 122         unsigned int zno = null_zone_no(dev, sector);
 123         struct blk_zone *zone = &dev->zones[zno];
 124
 125         switch (zone->cond) {
 126         case BLK_ZONE_COND_FULL:
 127                 /* Cannot write to a full zone */
 128                 cmd->error = BLK_STS_IOERR;
 129                 return BLK_STS_IOERR;
 130         case BLK_ZONE_COND_EMPTY:
 131         case BLK_ZONE_COND_IMP_OPEN:
 132                 /* Writes must be at the write pointer position */
 133                 if (sector != zone->wp)
 134                         return BLK_STS_IOERR;
 135
 136                 if (zone->cond == BLK_ZONE_COND_EMPTY)
 137                         zone->cond = BLK_ZONE_COND_IMP_OPEN;
 138
 139                 zone->wp += nr_sectors;
 140                 if (zone->wp == zone->start + zone->len)
 141                         zone->cond = BLK_ZONE_COND_FULL;
 142                 break;
 143         case BLK_ZONE_COND_NOT_WP:
 144                 break;
 145         default:
 146                 /* Invalid zone condition */
 147                 return BLK_STS_IOERR;
 148         }
 149         return BLK_STS_OK;
 150 }
 151
 152 static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
 153                                    sector_t sector)
 154 {
 155         struct nullb_device *dev = cmd->nq->dev;
 156         struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)];
 157         size_t i;
 158
 159         switch (op) {
 160         case REQ_OP_ZONE_RESET_ALL:
 161                 for (i = 0; i < dev->nr_zones; i++) {
 162                         if (zone[i].type == BLK_ZONE_TYPE_CONVENTIONAL)
 163                                 continue;
 164                         zone[i].cond = BLK_ZONE_COND_EMPTY;
 165                         zone[i].wp = zone[i].start;
 166                 }
 167                 break;
 168         case REQ_OP_ZONE_RESET:
 169                 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
 170                         return BLK_STS_IOERR;
 171
 172                 zone->cond = BLK_ZONE_COND_EMPTY;
 173                 zone->wp = zone->start;
 174                 break;
 175         case REQ_OP_ZONE_OPEN:
 176                 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
 177                         return BLK_STS_IOERR;
 178                 if (zone->cond == BLK_ZONE_COND_FULL)
 179                         return BLK_STS_IOERR;
 180
 181                 zone->cond = BLK_ZONE_COND_EXP_OPEN;
 182                 break;
 183         case REQ_OP_ZONE_CLOSE:
 184                 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
 185                         return BLK_STS_IOERR;
 186                 if (zone->cond == BLK_ZONE_COND_FULL)
 187                         return BLK_STS_IOERR;
 188
 189                 zone->cond = BLK_ZONE_COND_CLOSED;
 190                 break;
 191         case REQ_OP_ZONE_FINISH:
 192                 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
 193                         return BLK_STS_IOERR;
 194
 195                 zone->cond = BLK_ZONE_COND_FULL;
 196                 zone->wp = zone->start + zone->len;
 197                 break;
 198         default:
 199                 return BLK_STS_NOTSUPP;
 200         }
 201         return BLK_STS_OK;
 202 }
 203
 204 blk_status_t null_handle_zoned(struct nullb_cmd *cmd, enum req_opf op,
 205                                sector_t sector, sector_t nr_sectors)
 206 {
 207         switch (op) {
 208         case REQ_OP_WRITE:
 209                 return null_zone_write(cmd, sector, nr_sectors);
 210         case REQ_OP_ZONE_RESET:
 211         case REQ_OP_ZONE_RESET_ALL:
 212         case REQ_OP_ZONE_OPEN:
 213         case REQ_OP_ZONE_CLOSE:
 214         case REQ_OP_ZONE_FINISH:
 215                 return null_zone_mgmt(cmd, op, sector);
 216         default:
 217                 return BLK_STS_OK;
 218         }
 219 }