diff options
Diffstat (limited to 'drivers/block/drbd/drbd_int.h')
| -rw-r--r-- | drivers/block/drbd/drbd_int.h | 86 |
1 files changed, 50 insertions, 36 deletions
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index db504d0..60c89e5 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -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; } |