On Wed, Dec 04, 2019 at 04:37:32PM +0100, Johannes Thumshirn wrote:
On Wed, Dec 04, 2019 at 05:17:09PM +0900, Naohiro Aota wrote:
[..]
+#define LEN (sizeof(device->fs_info->sb->s_id) + sizeof("(device )") - 1)
+ char devstr[LEN];
+ const int len = LEN;
+#undef LEN
Why not:
const int len = sizeof(device->fs_info->sb->s_id)
+ sizeof("(device )") - 1;
char devstr[len];
But that's bikeshedding territory I admit.
I once tried that way, but it shows a "warning: ISO C90 forbids array
‘devstr’ whose size can’t be evaluated". So, I avoided that.
+
+ if (!bdev_is_zoned(bdev))
+ return 0;
+
+ zone_info = kzalloc(sizeof(*zone_info), GFP_KERNEL);
+ if (!zone_info)
+ return -ENOMEM;
+
+ zone_sectors = bdev_zone_sectors(bdev);
+ ASSERT(is_power_of_2(zone_sectors));
+ zone_info->zone_size = (u64)zone_sectors << SECTOR_SHIFT;
+ zone_info->zone_size_shift = ilog2(zone_info->zone_size);
+ zone_info->nr_zones = nr_sectors >> ilog2(bdev_zone_sectors(bdev));
+ if (nr_sectors & (bdev_zone_sectors(bdev) - 1))
+ zone_info->nr_zones++;
You've already cached the return of bdev_zone_sectors(bdev) in
zone_sectors at the beginning of this block and if (x & (y-1)) is the
IS_ALIGNED() macro so the above should really be:
if (!IS_ALIGNED(nr_sectors, zone_sectors))
zone_info->nr_zones++;
Great. That's much clear.
+
+ zone_info->seq_zones = kcalloc(BITS_TO_LONGS(zone_info->nr_zones),
+ sizeof(*zone_info->seq_zones),
+ GFP_KERNEL);
zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
+ if (!zone_info->seq_zones) {
+ ret = -ENOMEM;
+ goto free_zone_info;
+ }
+
+ zone_info->empty_zones = kcalloc(BITS_TO_LONGS(zone_info->nr_zones),
+ sizeof(*zone_info->empty_zones),
+ GFP_KERNEL);
zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
Thanks, I'll use the bitmap allocation helpers in the next version.
+ if (!zone_info->empty_zones) {
+ ret = -ENOMEM;
+ goto free_seq_zones;
+ }
+
+ zones = kcalloc(BTRFS_REPORT_NR_ZONES,
+ sizeof(struct blk_zone), GFP_KERNEL);
+ if (!zones) {
+ ret = -ENOMEM;
+ goto free_empty_zones;
+ }
+
I personally would set nreported = 0 here instead in the declaration block. I
had to scroll up to see what's the initial value, so I think it makes more
sense to initialize it to 0 here.
OK, I'll do so.
+ /* Get zones type */
+ while (sector < nr_sectors) {
+ nr_zones = BTRFS_REPORT_NR_ZONES;
+ ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT, zones,
+ &nr_zones);
+ if (ret)
+ goto free_zones;
+
+ for (i = 0; i < nr_zones; i++) {
+ if (zones[i].type == BLK_ZONE_TYPE_SEQWRITE_REQ)
+ set_bit(nreported, zone_info->seq_zones);
+ if (zones[i].cond == BLK_ZONE_COND_EMPTY)
+ set_bit(nreported, zone_info->empty_zones);
+ nreported++;
+ }
+ sector = zones[nr_zones - 1].start + zones[nr_zones - 1].len;
+ }
+
+ if (nreported != zone_info->nr_zones) {
+ btrfs_err_in_rcu(device->fs_info,
+ "inconsistent number of zones on %s (%u / %u)",
+ rcu_str_deref(device->name), nreported,
+ zone_info->nr_zones);
+ ret = -EIO;
+ goto free_zones;
+ }
+
+ kfree(zones);
+
+ device->zone_info = zone_info;
+
+ devstr[0] = 0;
+ if (device->fs_info)
+ snprintf(devstr, len, " (device %s)",
+ device->fs_info->sb->s_id);
+
+ rcu_read_lock();
+ pr_info(
+"BTRFS info%s: host-%s zoned block device %s, %u zones of %llu sectors",
+ devstr,
+ bdev_zoned_model(bdev) == BLK_ZONED_HM ? "managed" : "aware",
+ rcu_str_deref(device->name), zone_info->nr_zones,
+ zone_info->zone_size >> SECTOR_SHIFT);
+ rcu_read_unlock();
btrfs_info_in_rcu()?
Since this function is called before btrfs set "fs_info->sb->s_id",
btrfs_info_in_rcu() prints like "BTRFS info (device <unknown>) ...", which
is annoying. I intentionally used pr_info() and rcu_read_{lock,unlock} here
to show a cleaner print.
+
+ return 0;
+
+free_zones:
+ kfree(zones);
+free_empty_zones:
+ kfree(zone_info->empty_zones);
bitmap_free(zone_info->empty_zones);
+free_seq_zones:
+ kfree(zone_info->seq_zones);
bitmap_free(zone_info->seq_zones);
+free_zone_info:
+ kfree(zone_info);
+
+ return ret;
+}
+
+void btrfs_destroy_dev_zone_info(struct btrfs_device *device)
+{
+ struct btrfs_zoned_device_info *zone_info = device->zone_info;
+
+ if (!zone_info)
+ return;
+
+ kfree(zone_info->seq_zones);
+ kfree(zone_info->empty_zones);
bitmap_free(zone_info->seq_zones);
bitmap_free(zone_info->empty_zones);
Thanks,
Johannes
