f2fs: clean up the unused variable additional_reserved_segments

additional_reserved_segments was introduced by
commit 300a842 ("f2fs: fix to reserve space for IO align feature"),
and its initialization was deleted by
commit 87161a2 ("f2fs: deprecate io_bits").

Signed-off-by: LongPing Wei <weilongping@oppo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Author: weilongping

fs/f2fs/f2fs.h

@@ -1064,7 +1064,6 @@ struct f2fs_sm_info {
 	unsigned int segment_count;	/* total # of segments */
 	unsigned int main_segments;	/* # of segments in main area */
 	unsigned int reserved_segments;	/* # of reserved segments */
-	unsigned int additional_reserved_segments;/* reserved segs for IO align feature */
 	unsigned int ovp_segments;	/* # of overprovision segments */
 
 	/* a threshold to reclaim prefree segments */

fs/f2fs/segment.h

@@ -522,8 +522,7 @@ static inline unsigned int free_segments(struct f2fs_sb_info *sbi)
 
 static inline unsigned int reserved_segments(struct f2fs_sb_info *sbi)
 {
-	return SM_I(sbi)->reserved_segments +
-			SM_I(sbi)->additional_reserved_segments;
+	return SM_I(sbi)->reserved_segments;
 }
 
 static inline unsigned int free_sections(struct f2fs_sb_info *sbi)

fs/f2fs/sysfs.c

@@ -501,9 +501,7 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 	if (a->struct_type == RESERVED_BLOCKS) {
 		spin_lock(&sbi->stat_lock);
 		if (t > (unsigned long)(sbi->user_block_count -
-				F2FS_OPTION(sbi).root_reserved_blocks -
-				SEGS_TO_BLKS(sbi,
-				SM_I(sbi)->additional_reserved_segments))) {
+				F2FS_OPTION(sbi).root_reserved_blocks)) {
 			spin_unlock(&sbi->stat_lock);
 			return -EINVAL;
 		}