diff options
| author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2013-03-19 21:16:43 +0400 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2013-03-23 04:13:59 +0400 |
| commit | ae8bf312e97d554b6aa32e7b2ceb993812ad0835 (patch) | |
| tree | 7ed6d4fcf6385c1dbc694cf4f43f884436ae104a /drivers/block/drbd/drbd_actlog.c | |
| parent | 9114d79569a3fb858a7ecb1f21cb1dec93dc2f21 (diff) | |
| download | linux-ae8bf312e97d554b6aa32e7b2ceb993812ad0835.tar.xz | |
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_actlog.c')
| -rw-r--r-- | drivers/block/drbd/drbd_actlog.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c index 92510f8ad013..b230d91ec430 100644 --- a/drivers/block/drbd/drbd_actlog.c +++ b/drivers/block/drbd/drbd_actlog.c @@ -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++; } |