f2fs: don't reopen the main block device in f2fs_scan_devices

f2fs_scan_devices reopens the main device since the very beginning, which
has always been useless, and also means that we don't pass the right
holder for the reopen, which now leads to a warning as the core super.c
holder ops aren't passed in for the reopen.

Fixes: 3c62be1 ("f2fs: support multiple devices")
Fixes: 0718afd ("block: introduce holder ops")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Author: Christoph Hellwig

fs/f2fs/super.c

@@ -1561,7 +1561,8 @@ static void destroy_device_list(struct f2fs_sb_info *sbi)
 	int i;
 
 	for (i = 0; i < sbi->s_ndevs; i++) {
-		blkdev_put(FDEV(i).bdev, sbi->sb->s_type);
+		if (i > 0)
+			blkdev_put(FDEV(i).bdev, sbi->sb->s_type);
 #ifdef CONFIG_BLK_DEV_ZONED
 		kvfree(FDEV(i).blkz_seq);
 #endif
@@ -4190,16 +4191,12 @@ static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
 	sbi->aligned_blksize = true;
 
 	for (i = 0; i < max_devices; i++) {
-
-		if (i > 0 && !RDEV(i).path[0])
+		if (i == 0)
+			FDEV(0).bdev = sbi->sb->s_bdev;
+		else if (!RDEV(i).path[0])
 			break;
 
-		if (max_devices == 1) {
-			/* Single zoned block device mount */
-			FDEV(0).bdev =
-				blkdev_get_by_dev(sbi->sb->s_bdev->bd_dev, mode,
-						  sbi->sb->s_type, NULL);
-		} else {
+		if (max_devices > 1) {
 			/* Multi-device mount */
 			memcpy(FDEV(i).path, RDEV(i).path, MAX_PATH_LEN);
 			FDEV(i).total_segments =
@@ -4215,10 +4212,9 @@ static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
 				FDEV(i).end_blk = FDEV(i).start_blk +
 					(FDEV(i).total_segments <<
 					sbi->log_blocks_per_seg) - 1;
+				FDEV(i).bdev = blkdev_get_by_path(FDEV(i).path,
+					mode, sbi->sb->s_type, NULL);
 			}
-			FDEV(i).bdev = blkdev_get_by_path(FDEV(i).path, mode,
-							  sbi->sb->s_type,
-							  NULL);
 		}
 		if (IS_ERR(FDEV(i).bdev))
 			return PTR_ERR(FDEV(i).bdev);