f2fs: maintain six open zones for zoned devices

To keep six open zone constraints, make them not to be open over six
open zones.
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/data.c

@@ -383,6 +383,17 @@ static void f2fs_write_end_io(struct bio *bio)
 	bio_put(bio);
 }
 
+#ifdef CONFIG_BLK_DEV_ZONED
+static void f2fs_zone_write_end_io(struct bio *bio)
+{
+	struct f2fs_bio_info *io = (struct f2fs_bio_info *)bio->bi_private;
+
+	bio->bi_private = io->bi_private;
+	complete(&io->zone_wait);
+	f2fs_write_end_io(bio);
+}
+#endif
+
 struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
 		block_t blk_addr, sector_t *sector)
 {
@@ -639,6 +650,11 @@ int f2fs_init_write_merge_io(struct f2fs_sb_info *sbi)
 			INIT_LIST_HEAD(&sbi->write_io[i][j].io_list);
 			INIT_LIST_HEAD(&sbi->write_io[i][j].bio_list);
 			init_f2fs_rwsem(&sbi->write_io[i][j].bio_list_lock);
+#ifdef CONFIG_BLK_DEV_ZONED
+			init_completion(&sbi->write_io[i][j].zone_wait);
+			sbi->write_io[i][j].zone_pending_bio = NULL;
+			sbi->write_io[i][j].bi_private = NULL;
+#endif
 		}
 	}
 
@@ -965,6 +981,26 @@ int f2fs_merge_page_bio(struct f2fs_io_info *fio)
 	return 0;
 }
 
+#ifdef CONFIG_BLK_DEV_ZONED
+static bool is_end_zone_blkaddr(struct f2fs_sb_info *sbi, block_t blkaddr)
+{
+	int devi = 0;
+
+	if (f2fs_is_multi_device(sbi)) {
+		devi = f2fs_target_device_index(sbi, blkaddr);
+		if (blkaddr < FDEV(devi).start_blk ||
+		    blkaddr > FDEV(devi).end_blk) {
+			f2fs_err(sbi, "Invalid block %x", blkaddr);
+			return false;
+		}
+		blkaddr -= FDEV(devi).start_blk;
+	}
+	return bdev_zoned_model(FDEV(devi).bdev) == BLK_ZONED_HM &&
+		f2fs_blkz_is_seq(sbi, devi, blkaddr) &&
+		(blkaddr % sbi->blocks_per_blkz == sbi->blocks_per_blkz - 1);
+}
+#endif
+
 void f2fs_submit_page_write(struct f2fs_io_info *fio)
 {
 	struct f2fs_sb_info *sbi = fio->sbi;
@@ -975,6 +1011,16 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
 	f2fs_bug_on(sbi, is_read_io(fio->op));
 
 	f2fs_down_write(&io->io_rwsem);
+
+#ifdef CONFIG_BLK_DEV_ZONED
+	if (f2fs_sb_has_blkzoned(sbi) && btype < META && io->zone_pending_bio) {
+		wait_for_completion_io(&io->zone_wait);
+		bio_put(io->zone_pending_bio);
+		io->zone_pending_bio = NULL;
+		io->bi_private = NULL;
+	}
+#endif
+
 next:
 	if (fio->in_list) {
 		spin_lock(&io->io_lock);
@@ -1038,6 +1084,18 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
 	if (fio->in_list)
 		goto next;
 out:
+#ifdef CONFIG_BLK_DEV_ZONED
+	if (f2fs_sb_has_blkzoned(sbi) && btype < META &&
+			is_end_zone_blkaddr(sbi, fio->new_blkaddr)) {
+		bio_get(io->bio);
+		reinit_completion(&io->zone_wait);
+		io->bi_private = io->bio->bi_private;
+		io->bio->bi_private = io;
+		io->bio->bi_end_io = f2fs_zone_write_end_io;
+		io->zone_pending_bio = io->bio;
+		__submit_merged_bio(io);
+	}
+#endif
 	if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
 				!f2fs_is_checkpoint_ready(sbi))
 		__submit_merged_bio(io);

fs/f2fs/f2fs.h

@@ -1218,6 +1218,11 @@ struct f2fs_bio_info {
 	struct bio *bio;		/* bios to merge */
 	sector_t last_block_in_bio;	/* last block number */
 	struct f2fs_io_info fio;	/* store buffered io info. */
+#ifdef CONFIG_BLK_DEV_ZONED
+	struct completion zone_wait;	/* condition value for the previous open zone to close */
+	struct bio *zone_pending_bio;	/* pending bio for the previous zone */
+	void *bi_private;		/* previous bi_private for pending bio */
+#endif
 	struct f2fs_rwsem io_rwsem;	/* blocking op for bio */
 	spinlock_t io_lock;		/* serialize DATA/NODE IOs */
 	struct list_head io_list;	/* track fios */