f2fs: support multiple devices

This patch implements multiple devices support for f2fs.
Given multiple devices by mkfs.f2fs, f2fs shows them entirely as one big
volume under one f2fs instance.

Internal block management is very simple, but we will modify block allocation
and background GC policy to boost IO speed by exploiting them accoording to
each device speed.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 109 insertions, 29 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index eca9aea9834e..4ccbb860ad06 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -713,6 +713,19 @@ static void destroy_percpu_info(struct f2fs_sb_info *sbi)
 	percpu_counter_destroy(&sbi->total_valid_inode_count);
 }
 
+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, FMODE_EXCL);
+#ifdef CONFIG_BLK_DEV_ZONED
+		kfree(FDEV(i).blkz_type);
+#endif
+	}
+	kfree(sbi->devs);
+}
+
 static void f2fs_put_super(struct super_block *sb)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
@@ -773,6 +786,8 @@ static void f2fs_put_super(struct super_block *sb)
 		crypto_free_shash(sbi->s_chksum_driver);
 	kfree(sbi->raw_super);
 
+	destroy_device_list(sbi);
+
 	destroy_percpu_info(sbi);
 	kfree(sbi);
 }
@@ -1516,9 +1531,9 @@ static int init_percpu_info(struct f2fs_sb_info *sbi)
 }
 
 #ifdef CONFIG_BLK_DEV_ZONED
-static int init_blkz_info(struct f2fs_sb_info *sbi)
+static int init_blkz_info(struct f2fs_sb_info *sbi, int devi)
 {
-	struct block_device *bdev = sbi->sb->s_bdev;
+	struct block_device *bdev = FDEV(devi).bdev;
 	sector_t nr_sectors = bdev->bd_part->nr_sects;
 	sector_t sector = 0;
 	struct blk_zone *zones;
@@ -1529,15 +1544,21 @@ static int init_blkz_info(struct f2fs_sb_info *sbi)
 	if (!f2fs_sb_mounted_blkzoned(sbi->sb))
 		return 0;
 
+	if (sbi->blocks_per_blkz && sbi->blocks_per_blkz !=
+				SECTOR_TO_BLOCK(bdev_zone_size(bdev)))
+		return -EINVAL;
 	sbi->blocks_per_blkz = SECTOR_TO_BLOCK(bdev_zone_size(bdev));
+	if (sbi->log_blocks_per_blkz && sbi->log_blocks_per_blkz !=
+				__ilog2_u32(sbi->blocks_per_blkz))
+		return -EINVAL;
 	sbi->log_blocks_per_blkz = __ilog2_u32(sbi->blocks_per_blkz);
-	sbi->nr_blkz = SECTOR_TO_BLOCK(nr_sectors) >>
-		sbi->log_blocks_per_blkz;
+	FDEV(devi).nr_blkz = SECTOR_TO_BLOCK(nr_sectors) >>
+					sbi->log_blocks_per_blkz;
 	if (nr_sectors & (bdev_zone_size(bdev) - 1))
-		sbi->nr_blkz++;
+		FDEV(devi).nr_blkz++;
 
-	sbi->blkz_type = kmalloc(sbi->nr_blkz, GFP_KERNEL);
-	if (!sbi->blkz_type)
+	FDEV(devi).blkz_type = kmalloc(FDEV(devi).nr_blkz, GFP_KERNEL);
+	if (!FDEV(devi).blkz_type)
 		return -ENOMEM;
 
 #define F2FS_REPORT_NR_ZONES   4096
@@ -1562,7 +1583,7 @@ static int init_blkz_info(struct f2fs_sb_info *sbi)
 		}
 
 		for (i = 0; i < nr_zones; i++) {
-			sbi->blkz_type[n] = zones[i].type;
+			FDEV(devi).blkz_type[n] = zones[i].type;
 			sector += zones[i].len;
 			n++;
 		}
@@ -1666,6 +1687,77 @@ int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover)
 	return err;
 }
 
+static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	int i;
+
+	for (i = 0; i < MAX_DEVICES; i++) {
+		if (!RDEV(i).path[0])
+			return 0;
+
+		if (i == 0) {
+			sbi->devs = kzalloc(sizeof(struct f2fs_dev_info) *
+						MAX_DEVICES, GFP_KERNEL);
+			if (!sbi->devs)
+				return -ENOMEM;
+		}
+
+		memcpy(FDEV(i).path, RDEV(i).path, MAX_PATH_LEN);
+		FDEV(i).total_segments = le32_to_cpu(RDEV(i).total_segments);
+		if (i == 0) {
+			FDEV(i).start_blk = 0;
+			FDEV(i).end_blk = FDEV(i).start_blk +
+				(FDEV(i).total_segments <<
+				sbi->log_blocks_per_seg) - 1 +
+				le32_to_cpu(raw_super->segment0_blkaddr);
+		} else {
+			FDEV(i).start_blk = FDEV(i - 1).end_blk + 1;
+			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,
+					sbi->sb->s_mode, sbi->sb->s_type);
+		if (IS_ERR(FDEV(i).bdev))
+			return PTR_ERR(FDEV(i).bdev);
+
+		/* to release errored devices */
+		sbi->s_ndevs = i + 1;
+
+#ifdef CONFIG_BLK_DEV_ZONED
+		if (bdev_zoned_model(FDEV(i).bdev) == BLK_ZONED_HM &&
+				!f2fs_sb_mounted_blkzoned(sbi->sb)) {
+			f2fs_msg(sbi->sb, KERN_ERR,
+				"Zoned block device feature not enabled\n");
+			return -EINVAL;
+		}
+		if (bdev_zoned_model(FDEV(i).bdev) != BLK_ZONED_NONE) {
+			if (init_blkz_info(sbi, i)) {
+				f2fs_msg(sbi->sb, KERN_ERR,
+					"Failed to initialize F2FS blkzone information");
+				return -EINVAL;
+			}
+			f2fs_msg(sbi->sb, KERN_INFO,
+				"Mount Device [%2d]: %20s, %8u, %8x - %8x (zone: %s)",
+				i, FDEV(i).path,
+				FDEV(i).total_segments,
+				FDEV(i).start_blk, FDEV(i).end_blk,
+				bdev_zoned_model(FDEV(i).bdev) == BLK_ZONED_HA ?
+				"Host-aware" : "Host-managed");
+			continue;
+		}
+#endif
+		f2fs_msg(sbi->sb, KERN_INFO,
+			"Mount Device [%2d]: %20s, %8u, %8x - %8x",
+				i, FDEV(i).path,
+				FDEV(i).total_segments,
+				FDEV(i).start_blk, FDEV(i).end_blk);
+	}
+	return 0;
+}
+
 static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct f2fs_sb_info *sbi;
@@ -1724,15 +1816,7 @@ try_onemore:
 			 "Zoned block device support is not enabled\n");
 		goto free_sb_buf;
 	}
-#else
-	if (bdev_zoned_model(sb->s_bdev) == BLK_ZONED_HM &&
-	    !f2fs_sb_mounted_blkzoned(sb)) {
-		f2fs_msg(sb, KERN_ERR,
-			 "Zoned block device feature not enabled\n");
-		goto free_sb_buf;
-	}
 #endif
-
 	default_options(sbi);
 	/* parse mount options */
 	options = kstrdup((const char *)data, GFP_KERNEL);
@@ -1802,6 +1886,13 @@ try_onemore:
 		goto free_meta_inode;
 	}
 
+	/* Initialize device list */
+	err = f2fs_scan_devices(sbi);
+	if (err) {
+		f2fs_msg(sb, KERN_ERR, "Failed to find devices");
+		goto free_devices;
+	}
+
 	sbi->total_valid_node_count =
 				le32_to_cpu(sbi->ckpt->valid_node_count);
 	percpu_counter_set(&sbi->total_valid_inode_count,
@@ -1820,15 +1911,6 @@ try_onemore:
 
 	init_ino_entry_info(sbi);
 
-#ifdef CONFIG_BLK_DEV_ZONED
-	err = init_blkz_info(sbi);
-	if (err) {
-		f2fs_msg(sb, KERN_ERR,
-			"Failed to initialize F2FS blkzone information");
-		goto free_blkz;
-	}
-#endif
-
 	/* setup f2fs internal modules */
 	err = build_segment_manager(sbi);
 	if (err) {
@@ -2007,10 +2089,8 @@ free_nm:
 	destroy_node_manager(sbi);
 free_sm:
 	destroy_segment_manager(sbi);
-#ifdef CONFIG_BLK_DEV_ZONED
-free_blkz:
-	kfree(sbi->blkz_type);
-#endif
+free_devices:
+	destroy_device_list(sbi);
 	kfree(sbi->ckpt);
 free_meta_inode:
 	make_bad_inode(sbi->meta_inode);