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, 25 insertions, 4 deletions

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 0496e82..96221b1 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -709,6 +709,20 @@ struct f2fs_bio_info {
 	struct rw_semaphore io_rwsem;	/* blocking op for bio */
 };
 
+#define FDEV(i)				(sbi->devs[i])
+#define RDEV(i)				(raw_super->devs[i])
+struct f2fs_dev_info {
+	struct block_device *bdev;
+	char path[MAX_PATH_LEN];
+	unsigned int total_segments;
+	block_t start_blk;
+	block_t end_blk;
+#ifdef CONFIG_BLK_DEV_ZONED
+	unsigned int nr_blkz;			/* Total number of zones */
+	u8 *blkz_type;				/* Array of zones type */
+#endif
+};
+
 enum inode_type {
 	DIR_INODE,			/* for dirty dir inode */
 	FILE_INODE,			/* for dirty regular/symlink inode */
@@ -757,10 +771,8 @@ struct f2fs_sb_info {
 #endif
 
 #ifdef CONFIG_BLK_DEV_ZONED
-	unsigned int nr_blkz;			/* Total number of zones */
 	unsigned int blocks_per_blkz;		/* F2FS blocks per zone */
 	unsigned int log_blocks_per_blkz;	/* log2 F2FS blocks per zone */
-	u8 *blkz_type;				/* Array of zones type */
 #endif
 
 	/* for node-related operations */
@@ -876,6 +888,8 @@ struct f2fs_sb_info {
 
 	/* For shrinker support */
 	struct list_head s_list;
+	int s_ndevs;				/* number of devices */
+	struct f2fs_dev_info *devs;		/* for device list */
 	struct mutex umount_mutex;
 	unsigned int shrinker_run_no;
 
@@ -2138,6 +2152,9 @@ void f2fs_submit_merged_bio_cond(struct f2fs_sb_info *, struct inode *,
 void f2fs_flush_merged_bios(struct f2fs_sb_info *);
 int f2fs_submit_page_bio(struct f2fs_io_info *);
 void f2fs_submit_page_mbio(struct f2fs_io_info *);
+struct block_device *f2fs_target_device(struct f2fs_sb_info *,
+				block_t, struct bio *);
+int f2fs_target_device_index(struct f2fs_sb_info *, block_t);
 void set_data_blkaddr(struct dnode_of_data *);
 void f2fs_update_data_blkaddr(struct dnode_of_data *, block_t);
 int reserve_new_blocks(struct dnode_of_data *, blkcnt_t);
@@ -2425,11 +2442,15 @@ static inline int f2fs_sb_mounted_blkzoned(struct super_block *sb)
 
 #ifdef CONFIG_BLK_DEV_ZONED
 static inline int get_blkz_type(struct f2fs_sb_info *sbi,
-				block_t blkaddr)
+			struct block_device *bdev, block_t blkaddr)
 {
 	unsigned int zno = blkaddr >> sbi->log_blocks_per_blkz;
+	int i;
 
-	return sbi->blkz_type[zno];
+	for (i = 0; i < sbi->s_ndevs; i++)
+		if (FDEV(i).bdev == bdev)
+			return FDEV(i).blkz_type[zno];
+	return -EINVAL;
 }
 #endif