f2fs: fix to reset fields for unloaded curseg

In f2fs_allocate_data_block(), before skip allocating new segment
for DATA_PINNED log header, it needs to tag log header as unloaded
one to avoid skipping logic in locate_dirty_segment() and
__f2fs_save_inmem_curseg().
Signed-off-by: Chao Yu <chao@kernel.org>
Reviewed-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/segment.c

@@ -3108,12 +3108,16 @@ static int __allocate_new_segment(struct f2fs_sb_info *sbi, int type,
 	struct curseg_info *curseg = CURSEG_I(sbi, type);
 	unsigned int old_segno;
 
+	if (type == CURSEG_COLD_DATA_PINNED && !curseg->inited)
+		goto allocate;
+
 	if (!force && curseg->inited &&
 	    !curseg->next_blkoff &&
 	    !get_valid_blocks(sbi, curseg->segno, new_sec) &&
 	    !get_ckpt_valid_blocks(sbi, curseg->segno, new_sec))
 		return 0;
 
+allocate:
 	old_segno = curseg->segno;
 	if (new_curseg(sbi, type, true))
 		return -EAGAIN;
@@ -3458,6 +3462,13 @@ static void f2fs_randomize_chunk(struct f2fs_sb_info *sbi,
 		get_random_u32_inclusive(1, sbi->max_fragment_hole);
 }
 
+static void reset_curseg_fields(struct curseg_info *curseg)
+{
+	curseg->inited = false;
+	curseg->segno = NULL_SEGNO;
+	curseg->next_segno = 0;
+}
+
 int f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 		block_t old_blkaddr, block_t *new_blkaddr,
 		struct f2fs_summary *sum, int type,
@@ -3524,8 +3535,10 @@ int f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 	 */
 	if (segment_full) {
 		if (type == CURSEG_COLD_DATA_PINNED &&
-		    !((curseg->segno + 1) % sbi->segs_per_sec))
+		    !((curseg->segno + 1) % sbi->segs_per_sec)) {
+			reset_curseg_fields(curseg);
 			goto skip_new_segment;
+		}
 
 		if (from_gc) {
 			get_atssr_segment(sbi, type, se->type,
@@ -4601,9 +4614,7 @@ static int build_curseg(struct f2fs_sb_info *sbi)
 			array[i].seg_type = CURSEG_COLD_DATA;
 		else if (i == CURSEG_ALL_DATA_ATGC)
 			array[i].seg_type = CURSEG_COLD_DATA;
-		array[i].segno = NULL_SEGNO;
-		array[i].next_blkoff = 0;
-		array[i].inited = false;
+		reset_curseg_fields(&array[i]);
 	}
 	return restore_curseg_summaries(sbi);
 }