drivers/block/null_blk_zoned.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/vmalloc.h>
   3 #include <linux/sizes.h>
   4 #include "null_blk.h"
   5
   6 #define MB_TO_SECTS(mb) (((sector_t)mb * SZ_1M) >> SECTOR_SHIFT)
   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_capacity_sects;
  16         sector_t sector = 0;
  17         unsigned int i;
  18
  19         if (!is_power_of_2(dev->zone_size)) {
  20                 pr_err("null_blk: zone_size must be power-of-two\n");
  21                 return -EINVAL;
  22         }
  23         if (dev->zone_size > dev->size) {
  24                 pr_err("Zone size larger than device capacity\n");
  25                 return -EINVAL;
  26         }
  27
  28         dev_capacity_sects = MB_TO_SECTS(dev->size);
  29         dev->zone_size_sects = MB_TO_SECTS(dev->zone_size);
  30         dev->nr_zones = dev_capacity_sects >> ilog2(dev->zone_size_sects);
  31         if (dev_capacity_sects & (dev->zone_size_sects - 1))
  32                 dev->nr_zones++;
  33
  34         dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct blk_zone),
  35                         GFP_KERNEL | __GFP_ZERO);
  36         if (!dev->zones)
  37                 return -ENOMEM;
  38
  39         for (i = 0; i < dev->nr_zones; i++) {
  40                 struct blk_zone *zone = &dev->zones[i];
  41
  42                 zone->start = zone->wp = sector;
  43                 if (zone->start + dev->zone_size_sects > dev_capacity_sects)
  44                         zone->len = dev_capacity_sects - zone->start;
  45                 else
  46                         zone->len = dev->zone_size_sects;
  47                 zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
  48                 zone->cond = BLK_ZONE_COND_EMPTY;
  49
  50                 sector += dev->zone_size_sects;
  51         }
  52
  53         return 0;
  54 }
  55
  56 void null_zone_exit(struct nullb_device *dev)
  57 {
  58         kvfree(dev->zones);
  59         dev->zones = NULL;
  60 }
  61
  62 static void null_zone_fill_bio(struct nullb_device *dev, struct bio *bio,
  63                                unsigned int zno, unsigned int nr_zones)
  64 {
  65         struct blk_zone_report_hdr *hdr = NULL;
  66         struct bio_vec bvec;
  67         struct bvec_iter iter;
  68         void *addr;
  69         unsigned int zones_to_cpy;
  70
  71         bio_for_each_segment(bvec, bio, iter) {
  72                 addr = kmap_atomic(bvec.bv_page);
  73
  74                 zones_to_cpy = bvec.bv_len / sizeof(struct blk_zone);
  75
  76                 if (!hdr) {
  77                         hdr = (struct blk_zone_report_hdr *)addr;
  78                         hdr->nr_zones = nr_zones;
  79                         zones_to_cpy--;
  80                         addr += sizeof(struct blk_zone_report_hdr);
  81                 }
  82
  83                 zones_to_cpy = min_t(unsigned int, zones_to_cpy, nr_zones);
  84
  85                 memcpy(addr, &dev->zones[zno],
  86                                 zones_to_cpy * sizeof(struct blk_zone));
  87
  88                 kunmap_atomic(addr);
  89
  90                 nr_zones -= zones_to_cpy;
  91                 zno += zones_to_cpy;
  92
  93                 if (!nr_zones)
  94                         break;
  95         }
  96 }
  97
  98 blk_status_t null_zone_report(struct nullb *nullb, struct bio *bio)
  99 {
 100         struct nullb_device *dev = nullb->dev;
 101         unsigned int zno = null_zone_no(dev, bio->bi_iter.bi_sector);
 102         unsigned int nr_zones = dev->nr_zones - zno;
 103         unsigned int max_zones;
 104
 105         max_zones = (bio->bi_iter.bi_size / sizeof(struct blk_zone)) - 1;
 106         nr_zones = min_t(unsigned int, nr_zones, max_zones);
 107         null_zone_fill_bio(nullb->dev, bio, zno, nr_zones);
 108
 109         return BLK_STS_OK;
 110 }
 111
 112 void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
 113                      unsigned int nr_sectors)
 114 {
 115         struct nullb_device *dev = cmd->nq->dev;
 116         unsigned int zno = null_zone_no(dev, sector);
 117         struct blk_zone *zone = &dev->zones[zno];
 118
 119         switch (zone->cond) {
 120         case BLK_ZONE_COND_FULL:
 121                 /* Cannot write to a full zone */
 122                 cmd->error = BLK_STS_IOERR;
 123                 break;
 124         case BLK_ZONE_COND_EMPTY:
 125         case BLK_ZONE_COND_IMP_OPEN:
 126                 /* Writes must be at the write pointer position */
 127                 if (sector != zone->wp) {
 128                         cmd->error = BLK_STS_IOERR;
 129                         break;
 130                 }
 131
 132                 if (zone->cond == BLK_ZONE_COND_EMPTY)
 133                         zone->cond = BLK_ZONE_COND_IMP_OPEN;
 134
 135                 zone->wp += nr_sectors;
 136                 if (zone->wp == zone->start + zone->len)
 137                         zone->cond = BLK_ZONE_COND_FULL;
 138                 break;
 139         default:
 140                 /* Invalid zone condition */
 141                 cmd->error = BLK_STS_IOERR;
 142                 break;
 143         }
 144 }
 145
 146 void null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
 147 {
 148         struct nullb_device *dev = cmd->nq->dev;
 149         unsigned int zno = null_zone_no(dev, sector);
 150         struct blk_zone *zone = &dev->zones[zno];
 151
 152         zone->cond = BLK_ZONE_COND_EMPTY;
 153         zone->wp = zone->start;
 154 }