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| author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2013-03-19 18:16:43 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2013-03-22 18:13:59 -0600 |
| commit | ae8bf312e97d554b6aa32e7b2ceb993812ad0835 (patch) | |
| tree | 7ed6d4fcf6385c1dbc694cf4f43f884436ae104a /drivers/block/drbd/drbd_bitmap.c | |
| parent | 9114d79569a3fb858a7ecb1f21cb1dec93dc2f21 (diff) | |
| download | lwn-ae8bf312e97d554b6aa32e7b2ceb993812ad0835.tar.gz lwn-ae8bf312e97d554b6aa32e7b2ceb993812ad0835.zip | |
drbd: cleanup ondisk meta data layout calculations and defines
Add a comment about our meta data layout variants,
and rename a few defines (e.g. MD_RESERVED_SECT -> MD_128MB_SECT)
to make it clear that they are short hand for fixed constants,
and not arbitrarily to be redefined as one may see fit.
Properly pad struct meta_data_on_disk to 4kB,
and initialize to zero not only the first 512 Byte,
but all of it in drbd_md_sync().
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/drbd/drbd_bitmap.c')
| -rw-r--r-- | drivers/block/drbd/drbd_bitmap.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c index 8dc29502dc08..64fbb8385cdc 100644 --- a/drivers/block/drbd/drbd_bitmap.c +++ b/drivers/block/drbd/drbd_bitmap.c @@ -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); |