drbd: cleanup ondisk meta data layout calculations and defines (ae8bf312) · Commits · 戴 / test

drivers/block/drbd/drbd_actlog.c

+22 −6

Original line number	Diff line number	Diff line
		@@ -209,7 +209,8 @@ int drbd_md_sync_page_io(struct drbd_conf mdev, struct drbd_backing_dev bdev,
		current->comm, current->pid, __func__,
		(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");

		err = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, MD_BLOCK_SIZE);
		/* we do all our meta data IO in aligned 4k blocks. */
		err = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, 4096);
		if (err) {
		dev_err(DEV, "drbd_md_sync_page_io(,%llus,%s) failed with error %d\n",
		(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ", err);
		@@ -350,6 +351,24 @@ static unsigned int rs_extent_to_bm_page(unsigned int rs_enr)
		(BM_EXT_SHIFT - BM_BLOCK_SHIFT));
		}

		static sector_t al_tr_number_to_on_disk_sector(struct drbd_conf *mdev)
		{
		const unsigned int stripes = 1;
		const unsigned int stripe_size_4kB = MD_32kB_SECT/MD_4kB_SECT;

		/* transaction number, modulo on-disk ring buffer wrap around */
		unsigned int t = mdev->al_tr_number % (stripe_size_4kB * stripes);

		/* ... to aligned 4k on disk block */
		t = ((t % stripes) * stripe_size_4kB) + t/stripes;

		/* ... to 512 byte sector in activity log */
		t *= 8;

		/* ... plus offset to the on disk position */
		return mdev->ldev->md.md_offset + mdev->ldev->md.al_offset + t;
		}

		static int
		_al_write_transaction(struct drbd_conf *mdev)
		{
		@@ -432,13 +451,12 @@ _al_write_transaction(struct drbd_conf *mdev)
		if (mdev->al_tr_cycle >= mdev->act_log->nr_elements)
		mdev->al_tr_cycle = 0;

		sector = mdev->ldev->md.md_offset
		+ mdev->ldev->md.al_offset
		+ mdev->al_tr_pos * (MD_BLOCK_SIZE>>9);
		sector = al_tr_number_to_on_disk_sector(mdev);

		crc = crc32c(0, buffer, 4096);
		buffer->crc32c = cpu_to_be32(crc);

		/* normal execution path goes through all three branches */
		if (drbd_bm_write_hinted(mdev))
		err = -EIO;
		/* drbd_chk_io_error done already */
		@@ -446,8 +464,6 @@ _al_write_transaction(struct drbd_conf *mdev)
		err = -EIO;
		drbd_chk_io_error(mdev, 1, DRBD_META_IO_ERROR);
		} else {
		/* advance ringbuffer position and transaction counter */
		mdev->al_tr_pos = (mdev->al_tr_pos + 1) % (MD_AL_SECTORS*512/MD_BLOCK_SIZE);
		mdev->al_tr_number++;
		}

drivers/block/drbd/drbd_bitmap.c

+12 −1

Original line number	Diff line number	Diff line
		@@ -612,6 +612,17 @@ static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len)
		}
		}

		/* For the layout, see comment above drbd_md_set_sector_offsets(). */
		static u64 drbd_md_on_disk_bits(struct drbd_backing_dev *ldev)
		{
		u64 bitmap_sectors;
		if (ldev->md.al_offset == 8)
		bitmap_sectors = ldev->md.md_size_sect - ldev->md.bm_offset;
		else
		bitmap_sectors = ldev->md.al_offset - ldev->md.bm_offset;
		return bitmap_sectors << (9 + 3);
		}

		/*
		* make sure the bitmap has enough room for the attached storage,
		* if necessary, resize.
		@@ -668,7 +679,7 @@ int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity, int set_new_bits)
		words = ALIGN(bits, 64) >> LN2_BPL;

		if (get_ldev(mdev)) {
		u64 bits_on_disk = ((u64)mdev->ldev->md.md_size_sect-MD_BM_OFFSET) << 12;
		u64 bits_on_disk = drbd_md_on_disk_bits(mdev->ldev);
		put_ldev(mdev);
		if (bits > bits_on_disk) {
		dev_info(DEV, "bits = %lu\n", bits);

drivers/block/drbd/drbd_int.h

+50 −36

Original line number	Diff line number	Diff line
		@@ -753,13 +753,8 @@ struct drbd_md {
		u32 flags;
		u32 md_size_sect;

		s32 al_offset; /* signed relative sector offset to al area */
		s32 al_offset; /* signed relative sector offset to activity log */
		s32 bm_offset; /* signed relative sector offset to bitmap */

		/* u32 al_nr_extents; important for restoring the AL
		* is stored into ldev->dc.al_extents, which in turn
		* gets applied to act_log->nr_elements
		*/
		};

		struct drbd_backing_dev {
		@@ -1009,7 +1004,6 @@ struct drbd_conf {
		struct lru_cache act_log; / activity log */
		unsigned int al_tr_number;
		int al_tr_cycle;
		int al_tr_pos; /* position of the next transaction in the journal */
		wait_queue_head_t seq_wait;
		atomic_t packet_seq;
		unsigned int peer_seq;
		@@ -1151,21 +1145,41 @@ extern int drbd_bmio_clear_n_write(struct drbd_conf *mdev);
		extern void drbd_ldev_destroy(struct drbd_conf *mdev);

		/* Meta data layout
		We reserve a 128MB Block (4k aligned)
		* either at the end of the backing device
		* or on a separate meta data device. */
		*
		* We currently have two possible layouts.
		* Offsets in (512 byte) sectors.
		* external:
		* \|----------- md_size_sect ------------------\|
		* [ 4k superblock ][ activity log ][ Bitmap ]
		* \| al_offset == 8 \|
		* \| bm_offset = al_offset + X \|
		* ==> bitmap sectors = md_size_sect - bm_offset
		*
		* Variants:
		* old, indexed fixed size meta data:
		*
		* internal:
		* \|----------- md_size_sect ------------------\|
		* [data.....][ Bitmap ][ activity log ][ 4k superblock ][padding*]
		* \| al_offset < 0 \|
		* \| bm_offset = al_offset - Y \|
		* ==> bitmap sectors = Y = al_offset - bm_offset
		*
		* [padding*] are zero or up to 7 unused 512 Byte sectors to the
		* end of the device, so that the [4k superblock] will be 4k aligned.
		*
		* The activity log consists of 4k transaction blocks,
		* which are written in a ring-buffer, or striped ring-buffer like fashion,
		* which are writtensize used to be fixed 32kB,
		* but is about to become configurable.
		*/

		/* The following numbers are sectors */
		/* Allows up to about 3.8TB, so if you want more,
		/* Our old fixed size meta data layout
		* allows up to about 3.8TB, so if you want more,
		* you need to use the "flexible" meta data format. */
		#define MD_RESERVED_SECT (128LU << 11) /* 128 MB, unit sectors */
		#define MD_AL_OFFSET 8 /* 8 Sectors after start of meta area */
		#define MD_AL_SECTORS 64 /* = 32 kB on disk activity log ring buffer */
		#define MD_BM_OFFSET (MD_AL_OFFSET + MD_AL_SECTORS)

		/* we do all meta data IO in 4k blocks */
		#define MD_BLOCK_SHIFT 12
		#define MD_BLOCK_SIZE (1<<MD_BLOCK_SHIFT)
		#define MD_128MB_SECT (128LLU << 11) /* 128 MB, unit sectors */
		#define MD_4kB_SECT 8
		#define MD_32kB_SECT 64

		/* One activity log extent represents 4M of storage */
		#define AL_EXTENT_SHIFT 22
		@@ -1255,7 +1269,6 @@ struct bm_extent {

		/* in one sector of the bitmap, we have this many activity_log extents. */
		#define AL_EXT_PER_BM_SECT (1 << (BM_EXT_SHIFT - AL_EXTENT_SHIFT))
		#define BM_WORDS_PER_AL_EXT (1 << (AL_EXTENT_SHIFT-BM_BLOCK_SHIFT-LN2_BPL))

		#define BM_BLOCKS_PER_BM_EXT_B (BM_EXT_SHIFT - BM_BLOCK_SHIFT)
		#define BM_BLOCKS_PER_BM_EXT_MASK ((1<<BM_BLOCKS_PER_BM_EXT_B) - 1)
		@@ -1275,16 +1288,18 @@ struct bm_extent {
		*/

		#define DRBD_MAX_SECTORS_32 (0xffffffffLU)
		#define DRBD_MAX_SECTORS_BM \
		((MD_RESERVED_SECT - MD_BM_OFFSET) * (1LL<<(BM_EXT_SHIFT-9)))
		#if DRBD_MAX_SECTORS_BM < DRBD_MAX_SECTORS_32
		#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_BM
		#define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_BM
		#elif !defined(CONFIG_LBDAF) && BITS_PER_LONG == 32
		/* we have a certain meta data variant that has a fixed on-disk size of 128
		* MiB, of which 4k are our "superblock", and 32k are the fixed size activity
		* log, leaving this many sectors for the bitmap.
		*/

		#define DRBD_MAX_SECTORS_FIXED_BM \
		((MD_128MB_SECT - MD_32kB_SECT - MD_4kB_SECT) * (1LL<<(BM_EXT_SHIFT-9)))
		#if !defined(CONFIG_LBDAF) && BITS_PER_LONG == 32
		#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_32
		#define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_32
		#else
		#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_BM
		#define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_FIXED_BM
		/* 16 TB in units of sectors */
		#if BITS_PER_LONG == 32
		/* adjust by one page worth of bitmap,
		@@ -1792,10 +1807,10 @@ static inline sector_t drbd_md_last_sector(struct drbd_backing_dev *bdev)
		switch (meta_dev_idx) {
		case DRBD_MD_INDEX_INTERNAL:
		case DRBD_MD_INDEX_FLEX_INT:
		return bdev->md.md_offset + MD_AL_OFFSET - 1;
		return bdev->md.md_offset + MD_4kB_SECT -1;
		case DRBD_MD_INDEX_FLEX_EXT:
		default:
		return bdev->md.md_offset + bdev->md.md_size_sect;
		return bdev->md.md_offset + bdev->md.md_size_sect -1;
		}
		}

		@@ -1861,13 +1876,11 @@ static inline sector_t drbd_md_ss__(struct drbd_conf *mdev,
		rcu_read_unlock();

		switch (meta_dev_idx) {
		default: /* external, some index */
		return MD_RESERVED_SECT * meta_dev_idx;
		default: /* external, some index; this is the old fixed size layout */
		return MD_128MB_SECT * meta_dev_idx;
		case DRBD_MD_INDEX_INTERNAL:
		/* with drbd08, internal meta data is always "flexible" */
		case DRBD_MD_INDEX_FLEX_INT:
		/* sizeof(struct md_on_disk_07) == 4k
		* position: last 4k aligned block of 4k size */
		if (!bdev->backing_bdev) {
		if (__ratelimit(&drbd_ratelimit_state)) {
		dev_err(DEV, "bdev->backing_bdev==NULL\n");
		@@ -1875,8 +1888,9 @@ static inline sector_t drbd_md_ss__(struct drbd_conf *mdev,
		}
		return 0;
		}
		return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL)
		- MD_AL_OFFSET;
		/* sizeof(struct md_on_disk_07) == 4k
		* position: last 4k aligned block of 4k size */
		return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) - 8;
		case DRBD_MD_INDEX_FLEX_EXT:
		return 0;
		}

drivers/block/drbd/drbd_main.c

+8 −3

Original line number	Diff line number	Diff line
		@@ -2834,6 +2834,7 @@ void conn_md_sync(struct drbd_tconn *tconn)
		rcu_read_unlock();
		}

		/* aligned 4kByte */
		struct meta_data_on_disk {
		u64 la_size; /* last agreed size. */
		u64 uuid[UI_SIZE]; /* UUIDs. */
		@@ -2843,13 +2844,13 @@ struct meta_data_on_disk {
		u32 magic;
		u32 md_size_sect;
		u32 al_offset; /* offset to this block */
		u32 al_nr_extents; /* important for restoring the AL */
		u32 al_nr_extents; /* important for restoring the AL (userspace) */
		/* `-- act_log->nr_elements <-- ldev->dc.al_extents */
		u32 bm_offset; /* offset to the bitmap, from here */
		u32 bm_bytes_per_bit; /* BM_BLOCK_SIZE */
		u32 la_peer_max_bio_size; /* last peer max_bio_size */
		u32 reserved_u32[3];

		u8 reserved_u8[4096 - (78 + 84)];
		} __packed;

		/**
		@@ -2862,6 +2863,10 @@ void drbd_md_sync(struct drbd_conf *mdev)
		sector_t sector;
		int i;

		/* Don't accidentally change the DRBD meta data layout. */
		BUILD_BUG_ON(UI_SIZE != 4);
		BUILD_BUG_ON(sizeof(struct meta_data_on_disk) != 4096);

		del_timer(&mdev->md_sync_timer);
		/* timer may be rearmed by drbd_md_mark_dirty() now. */
		if (!test_and_clear_bit(MD_DIRTY, &mdev->flags))
		@@ -2876,7 +2881,7 @@ void drbd_md_sync(struct drbd_conf *mdev)
		if (!buffer)
		goto out;

		memset(buffer, 0, 512);
		memset(buffer, 0, sizeof(*buffer));

		buffer->la_size = cpu_to_be64(drbd_get_capacity(mdev->this_bdev));
		for (i = UI_CURRENT; i < UI_SIZE; i++)

drivers/block/drbd/drbd_nl.c

+31 −11

Original line number	Diff line number	Diff line
		@@ -696,12 +696,32 @@ out:
		return 0;
		}

		/* initializes the md.*_offset members, so we are able to find
		* the on disk meta data */
		/* Initializes the md.*_offset members, so we are able to find
		* the on disk meta data.
		*
		* We currently have two possible layouts:
		* external:
		* \|----------- md_size_sect ------------------\|
		* [ 4k superblock ][ activity log ][ Bitmap ]
		* \| al_offset == 8 \|
		* \| bm_offset = al_offset + X \|
		* ==> bitmap sectors = md_size_sect - bm_offset
		*
		* internal:
		* \|----------- md_size_sect ------------------\|
		* [data.....][ Bitmap ][ activity log ][ 4k superblock ]
		* \| al_offset < 0 \|
		* \| bm_offset = al_offset - Y \|
		* ==> bitmap sectors = Y = al_offset - bm_offset
		*
		* Activity log size used to be fixed 32kB,
		* but is about to become configurable.
		*/
		static void drbd_md_set_sector_offsets(struct drbd_conf *mdev,
		struct drbd_backing_dev *bdev)
		{
		sector_t md_size_sect = 0;
		unsigned int al_size_sect = MD_32kB_SECT;
		int meta_dev_idx;

		rcu_read_lock();
		@@ -710,23 +730,23 @@ static void drbd_md_set_sector_offsets(struct drbd_conf *mdev,
		switch (meta_dev_idx) {
		default:
		/* v07 style fixed size indexed meta data */
		bdev->md.md_size_sect = MD_RESERVED_SECT;
		bdev->md.md_size_sect = MD_128MB_SECT;
		bdev->md.md_offset = drbd_md_ss__(mdev, bdev);
		bdev->md.al_offset = MD_AL_OFFSET;
		bdev->md.bm_offset = MD_BM_OFFSET;
		bdev->md.al_offset = MD_4kB_SECT;
		bdev->md.bm_offset = MD_4kB_SECT + al_size_sect;
		break;
		case DRBD_MD_INDEX_FLEX_EXT:
		/* just occupy the full device; unit: sectors */
		bdev->md.md_size_sect = drbd_get_capacity(bdev->md_bdev);
		bdev->md.md_offset = 0;
		bdev->md.al_offset = MD_AL_OFFSET;
		bdev->md.bm_offset = MD_BM_OFFSET;
		bdev->md.al_offset = MD_4kB_SECT;
		bdev->md.bm_offset = MD_4kB_SECT + al_size_sect;
		break;
		case DRBD_MD_INDEX_INTERNAL:
		case DRBD_MD_INDEX_FLEX_INT:
		bdev->md.md_offset = drbd_md_ss__(mdev, bdev);
		/* al size is still fixed */
		bdev->md.al_offset = -MD_AL_SECTORS;
		bdev->md.al_offset = -al_size_sect;
		/* we need (slightly less than) ~ this much bitmap sectors: */
		md_size_sect = drbd_get_capacity(bdev->backing_bdev);
		md_size_sect = ALIGN(md_size_sect, BM_SECT_PER_EXT);
		@@ -735,11 +755,11 @@ static void drbd_md_set_sector_offsets(struct drbd_conf *mdev,

		/* plus the "drbd meta data super block",
		* and the activity log; */
		md_size_sect += MD_BM_OFFSET;
		md_size_sect += MD_4kB_SECT + al_size_sect;

		bdev->md.md_size_sect = md_size_sect;
		/* bitmap offset is adjusted by 'super' block size */
		bdev->md.bm_offset = -md_size_sect + MD_AL_OFFSET;
		bdev->md.bm_offset = -md_size_sect + MD_4kB_SECT;
		break;
		}
		rcu_read_unlock();
		@@ -1416,7 +1436,7 @@ int drbd_adm_attach(struct sk_buff skb, struct genl_info info)
		min_md_device_sectors = (2<<10);
		} else {
		max_possible_sectors = DRBD_MAX_SECTORS;
		min_md_device_sectors = MD_RESERVED_SECT * (new_disk_conf->meta_dev_idx + 1);
		min_md_device_sectors = MD_128MB_SECT * (new_disk_conf->meta_dev_idx + 1);
		}

		if (drbd_get_capacity(nbc->md_bdev) < min_md_device_sectors) {

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