btrfs: zoned: fix zone number to sector/physical calculation

In btrfs_get_dev_zone_info(), we have "u32 sb_zone" and calculate "sector_t
sector" by shifting it. But, this "sector" is calculated in 32bit, leading
it to be 0 for the 2nd superblock copy.

Since zone number is u32, shifting it to sector (sector_t) or physical
address (u64) can easily trigger a missing cast bug like this.

This commit introduces helpers to convert zone number to sector/LBA, so we
won't fall into the same pitfall again.

Reported-by: Dmitry Fomichev <Dmitry.Fomichev@wdc.com>
Fixes: 12659251ca5d ("btrfs: implement log-structured superblock for ZONED mode")
CC: stable@vger.kernel.org # 5.11+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 1bb8ee9..f1f3b10 100644 (file)
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -150,6 +150,18 @@ static inline u32 sb_zone_number(int shift, int mirror)
        return (u32)zone;
 }
 
+static inline sector_t zone_start_sector(u32 zone_number,
+                                        struct block_device *bdev)
+{
+       return (sector_t)zone_number << ilog2(bdev_zone_sectors(bdev));
+}
+
+static inline u64 zone_start_physical(u32 zone_number,
+                                     struct btrfs_zoned_device_info *zone_info)
+{
+       return (u64)zone_number << zone_info->zone_size_shift;
+}
+
 /*
  * Emulate blkdev_report_zones() for a non-zoned device. It slices up the block
  * device into static sized chunks and fake a conventional zone on each of
@@ -405,8 +417,8 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
                if (sb_zone + 1 >= zone_info->nr_zones)
                        continue;
 
-               sector = sb_zone << (zone_info->zone_size_shift - SECTOR_SHIFT);
-               ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT,
+               ret = btrfs_get_dev_zones(device,
+                                         zone_start_physical(sb_zone, zone_info),
                                          &zone_info->sb_zones[sb_pos],
                                          &nr_zones);
                if (ret)
@@ -721,7 +733,7 @@ int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
        if (sb_zone + 1 >= nr_zones)
                return -ENOENT;
 
-       ret = blkdev_report_zones(bdev, sb_zone << zone_sectors_shift,
+       ret = blkdev_report_zones(bdev, zone_start_sector(sb_zone, bdev),
                                  BTRFS_NR_SB_LOG_ZONES, copy_zone_info_cb,
                                  zones);
        if (ret < 0)
@@ -826,7 +838,7 @@ int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
                return -ENOENT;
 
        return blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
-                               sb_zone << zone_sectors_shift,
+                               zone_start_sector(sb_zone, bdev),
                                zone_sectors * BTRFS_NR_SB_LOG_ZONES, GFP_NOFS);
 }
 
@@ -878,7 +890,8 @@ u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
                        if (!(end <= sb_zone ||
                              sb_zone + BTRFS_NR_SB_LOG_ZONES <= begin)) {
                                have_sb = true;
-                               pos = ((u64)sb_zone + BTRFS_NR_SB_LOG_ZONES) << shift;
+                               pos = zone_start_physical(
+                                       sb_zone + BTRFS_NR_SB_LOG_ZONES, zinfo);
                                break;
                        }