f2fs: allow direct io of pinned files for zoned storage

Since the allocation happens in conventional LU for zoned storage, we
can allow direct io for that.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -833,7 +833,8 @@ static bool f2fs_force_buffered_io(struct inode *inode, int rw)
 	 * for blkzoned device, fallback direct IO to buffered IO, so
 	 * all IOs can be serialized by log-structured write.
 	 */
-	if (f2fs_sb_has_blkzoned(sbi) && (rw == WRITE))
+	if (f2fs_sb_has_blkzoned(sbi) && (rw == WRITE) &&
+	    !f2fs_is_pinned_file(inode))
 		return true;
 	if (is_sbi_flag_set(sbi, SBI_CP_DISABLED))
 		return true;