btrfs: zoned: fix full zone super block reading on ZNS

commit 02ca9e6fb5f66a031df4fac508b8e477ca69e918 upstream.

When both of the superblock zones are full, we need to check which
superblock is newer. The calculation of last superblock position is wrong
as it does not consider zone_capacity and uses the length.

Fixes: 9658b72ef300 ("btrfs: zoned: locate superblock position using zone capacity")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 41adb097b8239eaac03293b27b905ae87ae46ed4..250c4755ec12d6aa062ece89b2732d7c6bf62069 100644 (file)
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -121,10 +121,9 @@ static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
                int i;
 
                for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
-                       u64 bytenr;
-
-                       bytenr = ((zones[i].start + zones[i].len)
-                                  << SECTOR_SHIFT) - BTRFS_SUPER_INFO_SIZE;
+                       u64 zone_end = (zones[i].start + zones[i].capacity) << SECTOR_SHIFT;
+                       u64 bytenr = ALIGN_DOWN(zone_end, BTRFS_SUPER_INFO_SIZE) -
+                                               BTRFS_SUPER_INFO_SIZE;
 
                        page[i] = read_cache_page_gfp(mapping,
                                        bytenr >> PAGE_SHIFT, GFP_NOFS);