libf2fs: Fix calculation of usable segments for single zoned

There was a bug that did not subtract the super block area when calculating the usable segments for a single zoned device with a conventional zone. This bug resulted in incorrect the overprovision and reserved area. <256MiB legacy block + zoned block w/ 32MiB zone size> Info: Overprovision ratio = 3.570% Info: Overprovision segments = 656 (GC reserved = 560) <8 conventional zone + 1016 sequential zone w/ 32MiB zone size> Info: Overprovision ratio = 3.700% Info: Overprovision segments = 676 (GC reserved = 578) This patch fixes the bug by subtracting the super block area when there is only one zoned device. Signed-off-by: Yonggil Song <[email protected]> Signed-off-by: Jaegeuk Kim <[email protected]>
jaegeuk · Oct 7, 2024 · 6aaf95b · 6aaf95b
1 parent c8de910
commit 6aaf95b
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/lib/libf2fs_zoned.c b/lib/libf2fs_zoned.c
@@ -555,6 +555,11 @@ uint32_t f2fs_get_usable_segments(struct f2fs_super_block *sb)
 	}
 	usable_segs -= (get_sb(main_blkaddr) - get_sb(segment0_blkaddr)) >>
 						get_sb(log_blocks_per_seg);
+
+	/* single zoned device needs to remove a super block area */
+	if (c.ndevs == 1)
+		usable_segs -= (get_sb(segment0_blkaddr) >> get_sb(log_blocks_per_seg));
+
 	return usable_segs;
 #endif
 	return get_sb(segment_count_main);