block: rework zone reporting
Avoid the need to allocate a potentially large array of struct blk_zone
in the block layer by switching the ->report_zones method interface to
a callback model. Now the caller simply supplies a callback that is
executed on each reported zone, and private data for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 76f4cfd..e8f9661 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -440,14 +440,48 @@ static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
return dm_get_geometry(md, geo);
}
-static int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
- struct blk_zone *zones, unsigned int *nr_zones)
-{
#ifdef CONFIG_BLK_DEV_ZONED
+int dm_report_zones_cb(struct blk_zone *zone, unsigned int idx, void *data)
+{
+ struct dm_report_zones_args *args = data;
+ sector_t sector_diff = args->tgt->begin - args->start;
+
+ /*
+ * Ignore zones beyond the target range.
+ */
+ if (zone->start >= args->start + args->tgt->len)
+ return 0;
+
+ /*
+ * Remap the start sector and write pointer position of the zone
+ * to match its position in the target range.
+ */
+ zone->start += sector_diff;
+ if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) {
+ if (zone->cond == BLK_ZONE_COND_FULL)
+ zone->wp = zone->start + zone->len;
+ else if (zone->cond == BLK_ZONE_COND_EMPTY)
+ zone->wp = zone->start;
+ else
+ zone->wp += sector_diff;
+ }
+
+ args->next_sector = zone->start + zone->len;
+ return args->orig_cb(zone, args->zone_idx++, args->orig_data);
+}
+EXPORT_SYMBOL_GPL(dm_report_zones_cb);
+
+static int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
+ unsigned int nr_zones, report_zones_cb cb, void *data)
+{
struct mapped_device *md = disk->private_data;
- struct dm_target *tgt;
struct dm_table *map;
int srcu_idx, ret;
+ struct dm_report_zones_args args = {
+ .next_sector = sector,
+ .orig_data = data,
+ .orig_cb = cb,
+ };
if (dm_suspended_md(md))
return -EAGAIN;
@@ -456,32 +490,30 @@ static int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
if (!map)
return -EIO;
- tgt = dm_table_find_target(map, sector);
- if (!tgt) {
- ret = -EIO;
- goto out;
- }
+ do {
+ struct dm_target *tgt;
- /*
- * If we are executing this, we already know that the block device
- * is a zoned device and so each target should have support for that
- * type of drive. A missing report_zones method means that the target
- * driver has a problem.
- */
- if (WARN_ON(!tgt->type->report_zones)) {
- ret = -EIO;
- goto out;
- }
+ tgt = dm_table_find_target(map, args.next_sector);
+ if (WARN_ON_ONCE(!tgt->type->report_zones)) {
+ ret = -EIO;
+ goto out;
+ }
- ret = tgt->type->report_zones(tgt, sector, zones, nr_zones);
+ args.tgt = tgt;
+ ret = tgt->type->report_zones(tgt, &args, nr_zones);
+ if (ret < 0)
+ goto out;
+ } while (args.zone_idx < nr_zones &&
+ args.next_sector < get_capacity(disk));
+ ret = args.zone_idx;
out:
dm_put_live_table(md, srcu_idx);
return ret;
-#else
- return -ENOTSUPP;
-#endif
}
+#else
+#define dm_blk_report_zones NULL
+#endif /* CONFIG_BLK_DEV_ZONED */
static int dm_prepare_ioctl(struct mapped_device *md, int *srcu_idx,
struct block_device **bdev)
@@ -1207,51 +1239,6 @@ void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
}
EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
-/*
- * The zone descriptors obtained with a zone report indicate
- * zone positions within the underlying device of the target. The zone
- * descriptors must be remapped to match their position within the dm device.
- */
-void dm_remap_zone_report(struct dm_target *ti, sector_t start,
- struct blk_zone *zones, unsigned int *nr_zones)
-{
-#ifdef CONFIG_BLK_DEV_ZONED
- struct blk_zone *zone;
- unsigned int nrz = *nr_zones;
- int i;
-
- /*
- * Remap the start sector and write pointer position of the zones in
- * the array. Since we may have obtained from the target underlying
- * device more zones that the target size, also adjust the number
- * of zones.
- */
- for (i = 0; i < nrz; i++) {
- zone = zones + i;
- if (zone->start >= start + ti->len) {
- memset(zone, 0, sizeof(struct blk_zone) * (nrz - i));
- break;
- }
-
- zone->start = zone->start + ti->begin - start;
- if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
- continue;
-
- if (zone->cond == BLK_ZONE_COND_FULL)
- zone->wp = zone->start + zone->len;
- else if (zone->cond == BLK_ZONE_COND_EMPTY)
- zone->wp = zone->start;
- else
- zone->wp = zone->wp + ti->begin - start;
- }
-
- *nr_zones = i;
-#else /* !CONFIG_BLK_DEV_ZONED */
- *nr_zones = 0;
-#endif
-}
-EXPORT_SYMBOL_GPL(dm_remap_zone_report);
-
static blk_qc_t __map_bio(struct dm_target_io *tio)
{
int r;