Re: [PATCH] f2fs: support multiple devices
From: Darrick J. Wong
Date: Wed Nov 09 2016 - 18:05:33 EST
On Wed, Nov 09, 2016 at 03:57:53PM -0700, Andreas Dilger wrote:
> On Nov 9, 2016, at 1:56 PM, Jaegeuk Kim <jaegeuk@xxxxxxxxxx> wrote:
> >
> > 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.
>
> How will you integrate this into FIEMAP, since it is now possible if a
> file is split across multiple devices then it will return ambiguous block
> numbers for a file. I've been meaning to merge the FIEMAP handling in
> Lustre to support multiple devices in a single filesystem, so that this
> can be detected in userspace.
>
> struct ll_fiemap_extent {
> __u64 fe_logical; /* logical offset in bytes for the start of
> * the extent from the beginning of the file
> */
> __u64 fe_physical; /* physical offset in bytes for the start
> * of the extent from the beginning of the disk
> */
> __u64 fe_length; /* length in bytes for this extent */
> __u64 fe_reserved64[2];
> __u32 fe_flags; /* FIEMAP_EXTENT_* flags for this extent */
> __u32 fe_device; /* device number for this extent */
> __u32 fe_reserved[2];
> };
>
> This adds the 32-bit "fe_device" field, which would optionally be filled
> in by the filesystem (zero otherwise). It would return the kernel device
> number (i.e. st_dev), or for network filesystem (with FIEMAP_EXTENT_NET
> set) this could just return an integer device number since the device
> number is meaningless (and may conflict) on a remote system.
Same field size and similar meaning as the the fmr_device field in
GETFSMAP, at least for blockdev based filesystems. Intriguing.... ;)
For GETFSMAP the number in fmr_device is either a device-unique 32-bit
cookie or the implementer can set a magic FMH_OF_DEV_T flags bit marking
it as an actual dev_t.
What's the fe_device number mean for network filesystems? Magic unique
number?
> Since AFAIK Btrfs also has multiple device support there are an increasing
> number of places where this would be useful.
Ditto XFS.
--D
>
> Cheers, Andreas
>
> >
> > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> > ---
> > fs/f2fs/data.c | 55 ++++++++++++++++---
> > fs/f2fs/f2fs.h | 29 ++++++++--
> > fs/f2fs/segment.c | 119 +++++++++++++++++++++++++++++------------
> > fs/f2fs/super.c | 138 ++++++++++++++++++++++++++++++++++++++----------
> > include/linux/f2fs_fs.h | 10 +++-
> > 5 files changed, 277 insertions(+), 74 deletions(-)
> >
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index 47ded0c..e2be24e 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -88,6 +88,46 @@ static void f2fs_write_end_io(struct bio *bio)
> > }
> >
> > /*
> > + * Return true, if pre_bio's bdev is same as its target device.
> > + */
> > +struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
> > + block_t blk_addr, struct bio *bio)
> > +{
> > + struct block_device *bdev = sbi->sb->s_bdev;
> > + int i;
> > +
> > + for (i = 0; i < sbi->s_ndevs; i++) {
> > + if (FDEV(i).start_blk <= blk_addr &&
> > + FDEV(i).end_blk >= blk_addr) {
> > + blk_addr -= FDEV(i).start_blk;
> > + bdev = FDEV(i).bdev;
> > + break;
> > + }
> > + }
> > + if (bio) {
> > + bio->bi_bdev = bdev;
> > + bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
> > + }
> > + return bdev;
> > +}
> > +
> > +int f2fs_target_device_index(struct f2fs_sb_info *sbi, block_t blkaddr)
> > +{
> > + int i;
> > +
> > + for (i = 0; i < sbi->s_ndevs; i++)
> > + if (FDEV(i).start_blk <= blkaddr && FDEV(i).end_blk >= blkaddr)
> > + return i;
> > + return 0;
> > +}
> > +
> > +static bool __same_bdev(struct f2fs_sb_info *sbi,
> > + block_t blk_addr, struct bio *bio)
> > +{
> > + return f2fs_target_device(sbi, blk_addr, NULL) == bio->bi_bdev;
> > +}
> > +
> > +/*
> > * Low-level block read/write IO operations.
> > */
> > static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
> > @@ -97,8 +137,7 @@ static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
> >
> > bio = f2fs_bio_alloc(npages);
> >
> > - bio->bi_bdev = sbi->sb->s_bdev;
> > - bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
> > + f2fs_target_device(sbi, blk_addr, bio);
> > bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
> > bio->bi_private = is_read ? NULL : sbi;
> >
> > @@ -273,7 +312,8 @@ void f2fs_submit_page_mbio(struct f2fs_io_info *fio)
> > down_write(&io->io_rwsem);
> >
> > if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
> > - (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags)))
> > + (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags) ||
> > + !__same_bdev(sbi, fio->new_blkaddr, io->bio)))
> > __submit_merged_bio(io);
> > alloc_new:
> > if (io->bio == NULL) {
> > @@ -965,7 +1005,6 @@ static struct bio *f2fs_grab_bio(struct inode *inode, block_t blkaddr,
> > {
> > struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > struct fscrypt_ctx *ctx = NULL;
> > - struct block_device *bdev = sbi->sb->s_bdev;
> > struct bio *bio;
> >
> > if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
> > @@ -983,8 +1022,7 @@ static struct bio *f2fs_grab_bio(struct inode *inode, block_t blkaddr,
> > fscrypt_release_ctx(ctx);
> > return ERR_PTR(-ENOMEM);
> > }
> > - bio->bi_bdev = bdev;
> > - bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blkaddr);
> > + f2fs_target_device(sbi, blkaddr, bio);
> > bio->bi_end_io = f2fs_read_end_io;
> > bio->bi_private = ctx;
> >
> > @@ -1079,7 +1117,8 @@ static int f2fs_mpage_readpages(struct address_space *mapping,
> > * This page will go to BIO. Do we need to send this
> > * BIO off first?
> > */
> > - if (bio && (last_block_in_bio != block_nr - 1)) {
> > + if (bio && (last_block_in_bio != block_nr - 1 ||
> > + !__same_bdev(F2FS_I_SB(inode), block_nr, bio))) {
> > submit_and_realloc:
> > __submit_bio(F2FS_I_SB(inode), bio, DATA);
> > bio = NULL;
> > @@ -1738,6 +1777,8 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
> > return 0;
> > if (test_opt(F2FS_I_SB(inode), LFS))
> > return 0;
> > + if (F2FS_I_SB(inode)->s_ndevs)
> > + return 0;
> >
> > trace_f2fs_direct_IO_enter(inode, offset, count, rw);
> >
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 9650514..1737c45 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -730,6 +730,20 @@ 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 */
> > @@ -778,10 +792,8 @@ 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 */
> > @@ -897,6 +909,8 @@ 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;
> >
> > @@ -2159,6 +2173,9 @@ 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);
> > @@ -2446,11 +2463,15 @@ 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
> >
> > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> > index 7fb7dd3..ef727d1 100644
> > --- a/fs/f2fs/segment.c
> > +++ b/fs/f2fs/segment.c
> > @@ -403,6 +403,33 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
> > }
> > }
> >
> > +static int __submit_flush_wait(struct block_device *bdev)
> > +{
> > + struct bio *bio = f2fs_bio_alloc(0);
> > + int ret;
> > +
> > + bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_FLUSH);
> > + bio->bi_bdev = bdev;
> > + ret = submit_bio_wait(bio);
> > + bio_put(bio);
> > + return ret;
> > +}
> > +
> > +static int submit_flush_wait(struct f2fs_sb_info *sbi)
> > +{
> > + int ret = __submit_flush_wait(sbi->sb->s_bdev);
> > + int i;
> > +
> > + if (sbi->s_ndevs && !ret) {
> > + for (i = 1; i < sbi->s_ndevs; i++) {
> > + ret = __submit_flush_wait(FDEV(i).bdev);
> > + if (ret)
> > + break;
> > + }
> > + }
> > + return ret;
> > +}
> > +
> > static int issue_flush_thread(void *data)
> > {
> > struct f2fs_sb_info *sbi = data;
> > @@ -413,25 +440,18 @@ static int issue_flush_thread(void *data)
> > return 0;
> >
> > if (!llist_empty(&fcc->issue_list)) {
> > - struct bio *bio;
> > struct flush_cmd *cmd, *next;
> > int ret;
> >
> > - bio = f2fs_bio_alloc(0);
> > -
> > fcc->dispatch_list = llist_del_all(&fcc->issue_list);
> > fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
> >
> > - bio->bi_bdev = sbi->sb->s_bdev;
> > - bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_FLUSH);
> > - ret = submit_bio_wait(bio);
> > -
> > + ret = submit_flush_wait(sbi);
> > llist_for_each_entry_safe(cmd, next,
> > fcc->dispatch_list, llnode) {
> > cmd->ret = ret;
> > complete(&cmd->wait);
> > }
> > - bio_put(bio);
> > fcc->dispatch_list = NULL;
> > }
> >
> > @@ -452,15 +472,11 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi)
> > return 0;
> >
> > if (!test_opt(sbi, FLUSH_MERGE) || !atomic_read(&fcc->submit_flush)) {
> > - struct bio *bio = f2fs_bio_alloc(0);
> > int ret;
> >
> > atomic_inc(&fcc->submit_flush);
> > - bio->bi_bdev = sbi->sb->s_bdev;
> > - bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_FLUSH);
> > - ret = submit_bio_wait(bio);
> > + ret = submit_flush_wait(sbi);
> > atomic_dec(&fcc->submit_flush);
> > - bio_put(bio);
> > return ret;
> > }
> >
> > @@ -637,14 +653,18 @@ static void f2fs_submit_bio_wait_endio(struct bio *bio)
> >
> > /* this function is copied from blkdev_issue_discard from block/blk-lib.c */
> > static int __f2fs_issue_discard_async(struct f2fs_sb_info *sbi,
> > - block_t blkstart, block_t blklen)
> > + struct block_device *bdev, block_t blkstart, block_t blklen)
> > {
> > - struct block_device *bdev = sbi->sb->s_bdev;
> > struct bio *bio = NULL;
> > int err;
> >
> > trace_f2fs_issue_discard(sbi->sb, blkstart, blklen);
> >
> > + if (sbi->s_ndevs) {
> > + int devi = f2fs_target_device_index(sbi, blkstart);
> > +
> > + blkstart -= FDEV(devi).start_blk;
> > + }
> > err = __blkdev_issue_discard(bdev,
> > SECTOR_FROM_BLOCK(blkstart),
> > SECTOR_FROM_BLOCK(blklen),
> > @@ -662,18 +682,24 @@ static int __f2fs_issue_discard_async(struct f2fs_sb_info *sbi,
> > }
> >
> > #ifdef CONFIG_BLK_DEV_ZONED
> > -static int f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
> > - block_t blkstart, block_t blklen)
> > +static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
> > + struct block_device *bdev, block_t blkstart, block_t blklen)
> > {
> > - sector_t sector = SECTOR_FROM_BLOCK(blkstart);
> > sector_t nr_sects = SECTOR_FROM_BLOCK(blklen);
> > - struct block_device *bdev = sbi->sb->s_bdev;
> > + sector_t sector;
> > + int devi = 0;
> >
> > - if (nr_sects != bdev_zone_size(bdev)) {
> > + if (sbi->s_ndevs) {
> > + devi = f2fs_target_device_index(sbi, blkstart);
> > + blkstart -= FDEV(devi).start_blk;
> > + }
> > + sector = SECTOR_FROM_BLOCK(blkstart);
> > +
> > + if (sector % bdev_zone_size(bdev) || nr_sects != bdev_zone_size(bdev)) {
> > f2fs_msg(sbi->sb, KERN_INFO,
> > - "Unaligned discard attempted (sector %llu + %llu)",
> > - (unsigned long long)sector,
> > - (unsigned long long)nr_sects);
> > + "(%d) %s: Unaligned discard attempted (block %x + %x)",
> > + devi, sbi->s_ndevs ? FDEV(devi).path: "",
> > + blkstart, blklen);
> > return -EIO;
> > }
> >
> > @@ -682,14 +708,12 @@ static int f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
> > * use regular discard if the drive supports it. For sequential
> > * zones, reset the zone write pointer.
> > */
> > - switch (get_blkz_type(sbi, blkstart)) {
> > + switch (get_blkz_type(sbi, bdev, blkstart)) {
> >
> > case BLK_ZONE_TYPE_CONVENTIONAL:
> > if (!blk_queue_discard(bdev_get_queue(bdev)))
> > return 0;
> > - return __f2fs_issue_discard_async(sbi, blkstart,
> > - blklen);
> > -
> > + return __f2fs_issue_discard_async(sbi, bdev, blkstart, blklen);
> > case BLK_ZONE_TYPE_SEQWRITE_REQ:
> > case BLK_ZONE_TYPE_SEQWRITE_PREF:
> > trace_f2fs_issue_reset_zone(sbi->sb, blkstart);
> > @@ -702,14 +726,45 @@ static int f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
> > }
> > #endif
> >
> > +static int __issue_discard_async(struct f2fs_sb_info *sbi,
> > + struct block_device *bdev, block_t blkstart, block_t blklen)
> > +{
> > +#ifdef CONFIG_BLK_DEV_ZONED
> > + if (f2fs_sb_mounted_blkzoned(sbi->sb) &&
> > + bdev_zoned_model(bdev) != BLK_ZONED_NONE)
> > + return __f2fs_issue_discard_zone(sbi, bdev, blkstart, blklen);
> > +#endif
> > + return __f2fs_issue_discard_async(sbi, bdev, blkstart, blklen);
> > +}
> > +
> > static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
> > block_t blkstart, block_t blklen)
> > {
> > + sector_t start = blkstart, len = 0;
> > + struct block_device *bdev;
> > struct seg_entry *se;
> > unsigned int offset;
> > block_t i;
> > + int err = 0;
> > +
> > + bdev = f2fs_target_device(sbi, blkstart, NULL);
> > +
> > + for (i = blkstart; i < blkstart + blklen; i++, len++) {
> > + if (i != start) {
> > + struct block_device *bdev2 =
> > + f2fs_target_device(sbi, i, NULL);
> > +
> > + if (bdev2 != bdev) {
> > + err = __issue_discard_async(sbi, bdev,
> > + start, len);
> > + if (err)
> > + return err;
> > + bdev = bdev2;
> > + start = i;
> > + len = 0;
> > + }
> > + }
> >
> > - for (i = blkstart; i < blkstart + blklen; i++) {
> > se = get_seg_entry(sbi, GET_SEGNO(sbi, i));
> > offset = GET_BLKOFF_FROM_SEG0(sbi, i);
> >
> > @@ -717,11 +772,9 @@ static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
> > sbi->discard_blks--;
> > }
> >
> > -#ifdef CONFIG_BLK_DEV_ZONED
> > - if (f2fs_sb_mounted_blkzoned(sbi->sb))
> > - return f2fs_issue_discard_zone(sbi, blkstart, blklen);
> > -#endif
> > - return __f2fs_issue_discard_async(sbi, blkstart, blklen);
> > + if (len)
> > + err = __issue_discard_async(sbi, bdev, start, len);
> > + return err;
> > }
> >
> > static void __add_discard_entry(struct f2fs_sb_info *sbi,
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index eca9aea..4ccbb86 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 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> > "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 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> > 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 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> >
> > 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 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> > 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);
> > diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> > index 422630b..cea41a1 100644
> > --- a/include/linux/f2fs_fs.h
> > +++ b/include/linux/f2fs_fs.h
> > @@ -52,10 +52,17 @@
> >
> > #define VERSION_LEN 256
> > #define MAX_VOLUME_NAME 512
> > +#define MAX_PATH_LEN 64
> > +#define MAX_DEVICES 8
> >
> > /*
> > * For superblock
> > */
> > +struct f2fs_device {
> > + __u8 path[MAX_PATH_LEN];
> > + __le32 total_segments;
> > +} __packed;
> > +
> > struct f2fs_super_block {
> > __le32 magic; /* Magic Number */
> > __le16 major_ver; /* Major Version */
> > @@ -94,7 +101,8 @@ struct f2fs_super_block {
> > __le32 feature; /* defined features */
> > __u8 encryption_level; /* versioning level for encryption */
> > __u8 encrypt_pw_salt[16]; /* Salt used for string2key algorithm */
> > - __u8 reserved[871]; /* valid reserved region */
> > + struct f2fs_device devs[MAX_DEVICES]; /* device list */
> > + __u8 reserved[327]; /* valid reserved region */
> > } __packed;
> >
> > /*
> > --
> > 2.8.3
>
> Cheers, Andreas