drbd: new on-disk activity log transaction format
Use a new on-disk transaction format for the activity log, which allows for multiple changes to the active set per transaction. Using 4k transaction blocks, we can now get rid of the work-around code to deal with devices not supporting 512 byte logical block size. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This commit is contained in:
Lars Ellenberg
Philipp Reisner
parent
46a15bc3ec
commit
7ad651b522
@ -24,21 +24,67 @@
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*/
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#include <linux/slab.h>
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#include <linux/crc32c.h>
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#include <linux/drbd.h>
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#include <linux/drbd_limits.h>
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#include <linux/dynamic_debug.h>
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#include "drbd_int.h"
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#include "drbd_wrappers.h"
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/* We maintain a trivial checksum in our on disk activity log.
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* With that we can ensure correct operation even when the storage
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* device might do a partial (last) sector write while losing power.
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*/
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struct __packed al_transaction {
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u32 magic;
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u32 tr_number;
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struct __packed {
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u32 pos;
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u32 extent; } updates[1 + AL_EXTENTS_PT];
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u32 xor_sum;
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/* all fields on disc in big endian */
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struct __packed al_transaction_on_disk {
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/* don't we all like magic */
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__be32 magic;
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/* to identify the most recent transaction block
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* in the on disk ring buffer */
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__be32 tr_number;
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/* checksum on the full 4k block, with this field set to 0. */
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__be32 crc32c;
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/* type of transaction, special transaction types like:
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* purge-all, set-all-idle, set-all-active, ... to-be-defined */
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__be16 transaction_type;
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/* we currently allow only a few thousand extents,
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* so 16bit will be enough for the slot number. */
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/* how many updates in this transaction */
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__be16 n_updates;
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/* maximum slot number, "al-extents" in drbd.conf speak.
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* Having this in each transaction should make reconfiguration
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* of that parameter easier. */
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__be16 context_size;
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/* slot number the context starts with */
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__be16 context_start_slot_nr;
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/* Some reserved bytes. Expected usage is a 64bit counter of
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* sectors-written since device creation, and other data generation tag
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* supporting usage */
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__be32 __reserved[4];
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/* --- 36 byte used --- */
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/* Reserve space for up to AL_UPDATES_PER_TRANSACTION changes
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* in one transaction, then use the remaining byte in the 4k block for
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* context information. "Flexible" number of updates per transaction
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* does not help, as we have to account for the case when all update
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* slots are used anyways, so it would only complicate code without
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* additional benefit.
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*/
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__be16 update_slot_nr[AL_UPDATES_PER_TRANSACTION];
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/* but the extent number is 32bit, which at an extent size of 4 MiB
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* allows to cover device sizes of up to 2**54 Byte (16 PiB) */
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__be32 update_extent_nr[AL_UPDATES_PER_TRANSACTION];
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/* --- 420 bytes used (36 + 64*6) --- */
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/* 4096 - 420 = 3676 = 919 * 4 */
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__be32 context[AL_CONTEXT_PER_TRANSACTION];
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};
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struct update_odbm_work {
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@ -48,11 +94,8 @@ struct update_odbm_work {
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struct update_al_work {
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struct drbd_work w;
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struct lc_element *al_ext;
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struct completion event;
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unsigned int enr;
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/* if old_enr != LC_FREE, write corresponding bitmap sector, too */
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unsigned int old_enr;
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int err;
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};
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struct drbd_atodb_wait {
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@ -107,67 +150,30 @@ static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
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int drbd_md_sync_page_io(struct drbd_conf *mdev, struct drbd_backing_dev *bdev,
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sector_t sector, int rw)
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{
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int logical_block_size, mask, ok;
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int offset = 0;
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int ok;
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struct page *iop = mdev->md_io_page;
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D_ASSERT(mutex_is_locked(&mdev->md_io_mutex));
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BUG_ON(!bdev->md_bdev);
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logical_block_size = bdev_logical_block_size(bdev->md_bdev);
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if (logical_block_size == 0)
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logical_block_size = MD_SECTOR_SIZE;
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/* in case logical_block_size != 512 [ s390 only? ] */
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if (logical_block_size != MD_SECTOR_SIZE) {
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mask = (logical_block_size / MD_SECTOR_SIZE) - 1;
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D_ASSERT(mask == 1 || mask == 3 || mask == 7);
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D_ASSERT(logical_block_size == (mask+1) * MD_SECTOR_SIZE);
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offset = sector & mask;
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sector = sector & ~mask;
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iop = mdev->md_io_tmpp;
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if (rw & WRITE) {
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/* these are GFP_KERNEL pages, pre-allocated
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* on device initialization */
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void *p = page_address(mdev->md_io_page);
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void *hp = page_address(mdev->md_io_tmpp);
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ok = _drbd_md_sync_page_io(mdev, bdev, iop, sector,
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READ, logical_block_size);
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if (unlikely(!ok)) {
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dev_err(DEV, "drbd_md_sync_page_io(,%llus,"
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"READ [logical_block_size!=512]) failed!\n",
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(unsigned long long)sector);
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return 0;
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}
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memcpy(hp + offset*MD_SECTOR_SIZE, p, MD_SECTOR_SIZE);
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}
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}
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dev_dbg(DEV, "meta_data io: %s [%d]:%s(,%llus,%s)\n",
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current->comm, current->pid, __func__,
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(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");
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if (sector < drbd_md_first_sector(bdev) ||
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sector > drbd_md_last_sector(bdev))
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sector + 7 > drbd_md_last_sector(bdev))
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dev_alert(DEV, "%s [%d]:%s(,%llus,%s) out of range md access!\n",
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current->comm, current->pid, __func__,
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(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");
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ok = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, logical_block_size);
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ok = _drbd_md_sync_page_io(mdev, bdev, iop, sector, rw, MD_BLOCK_SIZE);
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if (unlikely(!ok)) {
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dev_err(DEV, "drbd_md_sync_page_io(,%llus,%s) failed!\n",
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(unsigned long long)sector, (rw & WRITE) ? "WRITE" : "READ");
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return 0;
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}
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if (logical_block_size != MD_SECTOR_SIZE && !(rw & WRITE)) {
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void *p = page_address(mdev->md_io_page);
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void *hp = page_address(mdev->md_io_tmpp);
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memcpy(p, hp + offset*MD_SECTOR_SIZE, MD_SECTOR_SIZE);
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}
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return ok;
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}
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@ -211,20 +217,34 @@ void drbd_al_begin_io(struct drbd_conf *mdev, sector_t sector)
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* current->bio_tail list now.
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* we have to delegate updates to the activity log
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* to the worker thread. */
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init_completion(&al_work.event);
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al_work.al_ext = al_ext;
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al_work.enr = enr;
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al_work.old_enr = al_ext->lc_number;
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al_work.w.cb = w_al_write_transaction;
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al_work.w.mdev = mdev;
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drbd_queue_work_front(&mdev->tconn->data.work, &al_work.w);
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wait_for_completion(&al_work.event);
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mdev->al_writ_cnt++;
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/* Serialize multiple transactions.
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* This uses test_and_set_bit, memory barrier is implicit.
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* Optimization potential:
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* first check for transaction number > old transaction number,
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* so not all waiters have to lock/unlock. */
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wait_event(mdev->al_wait, lc_try_lock_for_transaction(mdev->act_log));
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spin_lock_irq(&mdev->al_lock);
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lc_committed(mdev->act_log);
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spin_unlock_irq(&mdev->al_lock);
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/* Double check: it may have been committed by someone else,
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* while we have been waiting for the lock. */
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if (al_ext->lc_number != enr) {
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init_completion(&al_work.event);
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al_work.w.cb = w_al_write_transaction;
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al_work.w.mdev = mdev;
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drbd_queue_work_front(&mdev->tconn->data.work, &al_work.w);
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wait_for_completion(&al_work.event);
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mdev->al_writ_cnt++;
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spin_lock_irq(&mdev->al_lock);
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/* FIXME
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if (al_work.err)
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we need an "lc_cancel" here;
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*/
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lc_committed(mdev->act_log);
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spin_unlock_irq(&mdev->al_lock);
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}
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lc_unlock(mdev->act_log);
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wake_up(&mdev->al_wait);
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}
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}
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@ -283,95 +303,118 @@ w_al_write_transaction(struct drbd_work *w, int unused)
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{
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struct update_al_work *aw = container_of(w, struct update_al_work, w);
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struct drbd_conf *mdev = w->mdev;
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struct lc_element *updated = aw->al_ext;
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const unsigned int new_enr = aw->enr;
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const unsigned int evicted = aw->old_enr;
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struct al_transaction *buffer;
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struct al_transaction_on_disk *buffer;
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struct lc_element *e;
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sector_t sector;
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int i, n, mx;
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unsigned int extent_nr;
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u32 xor_sum = 0;
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int i, mx;
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unsigned extent_nr;
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unsigned crc = 0;
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if (!get_ldev(mdev)) {
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dev_err(DEV,
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"disk is %s, cannot start al transaction (-%d +%d)\n",
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drbd_disk_str(mdev->state.disk), evicted, new_enr);
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dev_err(DEV, "disk is %s, cannot start al transaction\n",
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drbd_disk_str(mdev->state.disk));
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aw->err = -EIO;
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complete(&((struct update_al_work *)w)->event);
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return 1;
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}
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/* do we have to do a bitmap write, first?
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* TODO reduce maximum latency:
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* submit both bios, then wait for both,
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* instead of doing two synchronous sector writes.
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* For now, we must not write the transaction,
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* if we cannot write out the bitmap of the evicted extent. */
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if (mdev->state.conn < C_CONNECTED && evicted != LC_FREE)
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drbd_bm_write_page(mdev, al_extent_to_bm_page(evicted));
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/* The bitmap write may have failed, causing a state change. */
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if (mdev->state.disk < D_INCONSISTENT) {
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dev_err(DEV,
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"disk is %s, cannot write al transaction (-%d +%d)\n",
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drbd_disk_str(mdev->state.disk), evicted, new_enr);
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"disk is %s, cannot write al transaction\n",
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drbd_disk_str(mdev->state.disk));
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aw->err = -EIO;
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complete(&((struct update_al_work *)w)->event);
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put_ldev(mdev);
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return 1;
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}
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mutex_lock(&mdev->md_io_mutex); /* protects md_io_buffer, al_tr_cycle, ... */
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buffer = (struct al_transaction *)page_address(mdev->md_io_page);
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buffer = page_address(mdev->md_io_page);
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buffer->magic = __constant_cpu_to_be32(DRBD_MAGIC);
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memset(buffer, 0, sizeof(*buffer));
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buffer->magic = cpu_to_be32(DRBD_AL_MAGIC);
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buffer->tr_number = cpu_to_be32(mdev->al_tr_number);
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n = lc_index_of(mdev->act_log, updated);
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i = 0;
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buffer->updates[0].pos = cpu_to_be32(n);
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buffer->updates[0].extent = cpu_to_be32(new_enr);
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/* Even though no one can start to change this list
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* once we set the LC_LOCKED -- from drbd_al_begin_io(),
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* lc_try_lock_for_transaction() --, someone may still
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* be in the process of changing it. */
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spin_lock_irq(&mdev->al_lock);
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list_for_each_entry(e, &mdev->act_log->to_be_changed, list) {
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if (i == AL_UPDATES_PER_TRANSACTION) {
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i++;
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break;
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}
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buffer->update_slot_nr[i] = cpu_to_be16(e->lc_index);
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buffer->update_extent_nr[i] = cpu_to_be32(e->lc_new_number);
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if (e->lc_number != LC_FREE)
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drbd_bm_mark_for_writeout(mdev,
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al_extent_to_bm_page(e->lc_number));
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i++;
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}
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spin_unlock_irq(&mdev->al_lock);
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BUG_ON(i > AL_UPDATES_PER_TRANSACTION);
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xor_sum ^= new_enr;
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buffer->n_updates = cpu_to_be16(i);
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for ( ; i < AL_UPDATES_PER_TRANSACTION; i++) {
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buffer->update_slot_nr[i] = cpu_to_be16(-1);
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buffer->update_extent_nr[i] = cpu_to_be32(LC_FREE);
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}
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mx = min_t(int, AL_EXTENTS_PT,
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buffer->context_size = cpu_to_be16(mdev->act_log->nr_elements);
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buffer->context_start_slot_nr = cpu_to_be16(mdev->al_tr_cycle);
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mx = min_t(int, AL_CONTEXT_PER_TRANSACTION,
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mdev->act_log->nr_elements - mdev->al_tr_cycle);
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for (i = 0; i < mx; i++) {
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unsigned idx = mdev->al_tr_cycle + i;
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extent_nr = lc_element_by_index(mdev->act_log, idx)->lc_number;
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buffer->updates[i+1].pos = cpu_to_be32(idx);
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buffer->updates[i+1].extent = cpu_to_be32(extent_nr);
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xor_sum ^= extent_nr;
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buffer->context[i] = cpu_to_be32(extent_nr);
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}
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for (; i < AL_EXTENTS_PT; i++) {
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buffer->updates[i+1].pos = __constant_cpu_to_be32(-1);
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buffer->updates[i+1].extent = __constant_cpu_to_be32(LC_FREE);
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xor_sum ^= LC_FREE;
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}
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mdev->al_tr_cycle += AL_EXTENTS_PT;
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for (; i < AL_CONTEXT_PER_TRANSACTION; i++)
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buffer->context[i] = cpu_to_be32(LC_FREE);
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mdev->al_tr_cycle += AL_CONTEXT_PER_TRANSACTION;
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if (mdev->al_tr_cycle >= mdev->act_log->nr_elements)
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mdev->al_tr_cycle = 0;
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buffer->xor_sum = cpu_to_be32(xor_sum);
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sector = mdev->ldev->md.md_offset
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+ mdev->ldev->md.al_offset + mdev->al_tr_pos;
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+ mdev->ldev->md.al_offset
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+ mdev->al_tr_pos * (MD_BLOCK_SIZE>>9);
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if (!drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE))
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crc = crc32c(0, buffer, 4096);
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buffer->crc32c = cpu_to_be32(crc);
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if (drbd_bm_write_hinted(mdev))
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aw->err = -EIO;
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/* drbd_chk_io_error done already */
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else if (!drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) {
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aw->err = -EIO;
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drbd_chk_io_error(mdev, 1, true);
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if (++mdev->al_tr_pos >
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div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT))
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mdev->al_tr_pos = 0;
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D_ASSERT(mdev->al_tr_pos < MD_AL_MAX_SIZE);
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mdev->al_tr_number++;
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} else {
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/* advance ringbuffer position and transaction counter */
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mdev->al_tr_pos = (mdev->al_tr_pos + 1) % (MD_AL_SECTORS*512/MD_BLOCK_SIZE);
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mdev->al_tr_number++;
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}
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mutex_unlock(&mdev->md_io_mutex);
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complete(&((struct update_al_work *)w)->event);
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put_ldev(mdev);
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return 1;
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}
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/* FIXME
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* reading of the activity log,
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* and potentially dirtying of the affected bitmap regions,
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* should be done from userland only.
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* DRBD would simply always attach with an empty activity log,
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* and refuse to attach to something that looks like a crashed primary.
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*/
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/**
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* drbd_al_read_tr() - Read a single transaction from the on disk activity log
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* @mdev: DRBD device.
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@ -383,27 +426,39 @@ w_al_write_transaction(struct drbd_work *w, int unused)
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*/
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static int drbd_al_read_tr(struct drbd_conf *mdev,
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struct drbd_backing_dev *bdev,
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struct al_transaction *b,
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int index)
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{
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struct al_transaction_on_disk *b = page_address(mdev->md_io_page);
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sector_t sector;
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int rv, i;
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u32 xor_sum = 0;
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u32 crc;
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sector = bdev->md.md_offset + bdev->md.al_offset + index;
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sector = bdev->md.md_offset
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+ bdev->md.al_offset
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+ index * (MD_BLOCK_SIZE>>9);
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/* Dont process error normally,
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* as this is done before disk is attached! */
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if (!drbd_md_sync_page_io(mdev, bdev, sector, READ))
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return -1;
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rv = (b->magic == cpu_to_be32(DRBD_MAGIC));
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if (!expect(b->magic == cpu_to_be32(DRBD_AL_MAGIC)))
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return 0;
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for (i = 0; i < AL_EXTENTS_PT + 1; i++)
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xor_sum ^= be32_to_cpu(b->updates[i].extent);
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rv &= (xor_sum == be32_to_cpu(b->xor_sum));
|
||||
if (!expect(be16_to_cpu(b->n_updates) <= AL_UPDATES_PER_TRANSACTION))
|
||||
return 0;
|
||||
|
||||
return rv;
|
||||
if (!expect(be16_to_cpu(b->context_size) <= DRBD_AL_EXTENTS_MAX))
|
||||
return 0;
|
||||
|
||||
if (!expect(be16_to_cpu(b->context_start_slot_nr) < DRBD_AL_EXTENTS_MAX))
|
||||
return 0;
|
||||
|
||||
crc = be32_to_cpu(b->crc32c);
|
||||
b->crc32c = 0;
|
||||
if (!expect(crc == crc32c(0, b, 4096)))
|
||||
return 0;
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
/**
|
||||
@ -415,7 +470,7 @@ static int drbd_al_read_tr(struct drbd_conf *mdev,
|
||||
*/
|
||||
int drbd_al_read_log(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
|
||||
{
|
||||
struct al_transaction *buffer;
|
||||
struct al_transaction_on_disk *b;
|
||||
int i;
|
||||
int rv;
|
||||
int mx;
|
||||
@ -428,25 +483,36 @@ int drbd_al_read_log(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
|
||||
u32 to_tnr = 0;
|
||||
u32 cnr;
|
||||
|
||||
mx = div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT);
|
||||
/* Note that this is expected to be called with a newly created,
|
||||
* clean and all unused activity log of the "expected size".
|
||||
*/
|
||||
|
||||
/* lock out all other meta data io for now,
|
||||
* and make sure the page is mapped.
|
||||
*/
|
||||
mutex_lock(&mdev->md_io_mutex);
|
||||
buffer = page_address(mdev->md_io_page);
|
||||
b = page_address(mdev->md_io_page);
|
||||
|
||||
/* Always use the full ringbuffer space for now.
|
||||
* possible optimization: read in all of it,
|
||||
* then scan the in-memory pages. */
|
||||
|
||||
mx = (MD_AL_SECTORS*512/MD_BLOCK_SIZE);
|
||||
|
||||
/* Find the valid transaction in the log */
|
||||
for (i = 0; i <= mx; i++) {
|
||||
rv = drbd_al_read_tr(mdev, bdev, buffer, i);
|
||||
for (i = 0; i < mx; i++) {
|
||||
rv = drbd_al_read_tr(mdev, bdev, i);
|
||||
/* invalid data in that block */
|
||||
if (rv == 0)
|
||||
continue;
|
||||
|
||||
/* IO error */
|
||||
if (rv == -1) {
|
||||
mutex_unlock(&mdev->md_io_mutex);
|
||||
return 0;
|
||||
}
|
||||
cnr = be32_to_cpu(buffer->tr_number);
|
||||
|
||||
cnr = be32_to_cpu(b->tr_number);
|
||||
if (++found_valid == 1) {
|
||||
from = i;
|
||||
to = i;
|
||||
@ -454,8 +520,11 @@ int drbd_al_read_log(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
|
||||
to_tnr = cnr;
|
||||
continue;
|
||||
}
|
||||
|
||||
D_ASSERT(cnr != to_tnr);
|
||||
D_ASSERT(cnr != from_tnr);
|
||||
if ((int)cnr - (int)from_tnr < 0) {
|
||||
D_ASSERT(from_tnr - cnr + i - from == mx+1);
|
||||
D_ASSERT(from_tnr - cnr + i - from == mx);
|
||||
from = i;
|
||||
from_tnr = cnr;
|
||||
}
|
||||
@ -476,11 +545,10 @@ int drbd_al_read_log(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
|
||||
* dev_info(DEV, "Reading from %d to %d.\n",from,to); */
|
||||
i = from;
|
||||
while (1) {
|
||||
int j, pos;
|
||||
unsigned int extent_nr;
|
||||
unsigned int trn;
|
||||
struct lc_element *e;
|
||||
unsigned j, n, slot, extent_nr;
|
||||
|
||||
rv = drbd_al_read_tr(mdev, bdev, buffer, i);
|
||||
rv = drbd_al_read_tr(mdev, bdev, i);
|
||||
if (!expect(rv != 0))
|
||||
goto cancel;
|
||||
if (rv == -1) {
|
||||
@ -488,23 +556,55 @@ int drbd_al_read_log(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
|
||||
return 0;
|
||||
}
|
||||
|
||||
trn = be32_to_cpu(buffer->tr_number);
|
||||
/* deal with different transaction types.
|
||||
* not yet implemented */
|
||||
if (!expect(b->transaction_type == 0))
|
||||
goto cancel;
|
||||
|
||||
/* on the fly re-create/resize activity log?
|
||||
* will be a special transaction type flag. */
|
||||
if (!expect(be16_to_cpu(b->context_size) == mdev->act_log->nr_elements))
|
||||
goto cancel;
|
||||
if (!expect(be16_to_cpu(b->context_start_slot_nr) < mdev->act_log->nr_elements))
|
||||
goto cancel;
|
||||
|
||||
/* We are the only user of the activity log right now,
|
||||
* don't actually need to take that lock. */
|
||||
spin_lock_irq(&mdev->al_lock);
|
||||
|
||||
/* This loop runs backwards because in the cyclic
|
||||
elements there might be an old version of the
|
||||
updated element (in slot 0). So the element in slot 0
|
||||
can overwrite old versions. */
|
||||
for (j = AL_EXTENTS_PT; j >= 0; j--) {
|
||||
pos = be32_to_cpu(buffer->updates[j].pos);
|
||||
extent_nr = be32_to_cpu(buffer->updates[j].extent);
|
||||
/* first, apply the context, ... */
|
||||
for (j = 0, slot = be16_to_cpu(b->context_start_slot_nr);
|
||||
j < AL_CONTEXT_PER_TRANSACTION &&
|
||||
slot < mdev->act_log->nr_elements; j++, slot++) {
|
||||
extent_nr = be32_to_cpu(b->context[j]);
|
||||
e = lc_element_by_index(mdev->act_log, slot);
|
||||
if (e->lc_number != extent_nr) {
|
||||
if (extent_nr != LC_FREE)
|
||||
active_extents++;
|
||||
else
|
||||
active_extents--;
|
||||
}
|
||||
lc_set(mdev->act_log, extent_nr, slot);
|
||||
}
|
||||
|
||||
if (extent_nr == LC_FREE)
|
||||
continue;
|
||||
|
||||
lc_set(mdev->act_log, extent_nr, pos);
|
||||
active_extents++;
|
||||
/* ... then apply the updates,
|
||||
* which override the context information.
|
||||
* drbd_al_read_tr already did the rangecheck
|
||||
* on n <= AL_UPDATES_PER_TRANSACTION */
|
||||
n = be16_to_cpu(b->n_updates);
|
||||
for (j = 0; j < n; j++) {
|
||||
slot = be16_to_cpu(b->update_slot_nr[j]);
|
||||
extent_nr = be32_to_cpu(b->update_extent_nr[j]);
|
||||
if (!expect(slot < mdev->act_log->nr_elements))
|
||||
break;
|
||||
e = lc_element_by_index(mdev->act_log, slot);
|
||||
if (e->lc_number != extent_nr) {
|
||||
if (extent_nr != LC_FREE)
|
||||
active_extents++;
|
||||
else
|
||||
active_extents--;
|
||||
}
|
||||
lc_set(mdev->act_log, extent_nr, slot);
|
||||
}
|
||||
spin_unlock_irq(&mdev->al_lock);
|
||||
|
||||
@ -514,15 +614,12 @@ cancel:
|
||||
if (i == to)
|
||||
break;
|
||||
i++;
|
||||
if (i > mx)
|
||||
if (i >= mx)
|
||||
i = 0;
|
||||
}
|
||||
|
||||
mdev->al_tr_number = to_tnr+1;
|
||||
mdev->al_tr_pos = to;
|
||||
if (++mdev->al_tr_pos >
|
||||
div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT))
|
||||
mdev->al_tr_pos = 0;
|
||||
mdev->al_tr_pos = (to + 1) % (MD_AL_SECTORS*512/MD_BLOCK_SIZE);
|
||||
|
||||
/* ok, we are done with it */
|
||||
mutex_unlock(&mdev->md_io_mutex);
|
||||
|
||||
@ -1069,7 +1069,6 @@ struct drbd_conf {
|
||||
atomic_t pp_in_use_by_net; /* sendpage()d, still referenced by tcp */
|
||||
wait_queue_head_t ee_wait;
|
||||
struct page *md_io_page; /* one page buffer for md_io */
|
||||
struct page *md_io_tmpp; /* for logical_block_size != 512 */
|
||||
struct mutex md_io_mutex; /* protects the md_io_buffer */
|
||||
spinlock_t al_lock;
|
||||
wait_queue_head_t al_wait;
|
||||
@ -1259,22 +1258,39 @@ extern void drbd_ldev_destroy(struct drbd_conf *mdev);
|
||||
* either at the end of the backing device
|
||||
* or on a separate meta data device. */
|
||||
|
||||
#define MD_RESERVED_SECT (128LU << 11) /* 128 MB, unit sectors */
|
||||
/* The following numbers are sectors */
|
||||
#define MD_AL_OFFSET 8 /* 8 Sectors after start of meta area */
|
||||
#define MD_AL_MAX_SIZE 64 /* = 32 kb LOG ~ 3776 extents ~ 14 GB Storage */
|
||||
/* Allows up to about 3.8TB */
|
||||
#define MD_BM_OFFSET (MD_AL_OFFSET + MD_AL_MAX_SIZE)
|
||||
/* 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)
|
||||
|
||||
/* Since the smalles IO unit is usually 512 byte */
|
||||
#define MD_SECTOR_SHIFT 9
|
||||
#define MD_SECTOR_SIZE (1<<MD_SECTOR_SHIFT)
|
||||
/* we do all meta data IO in 4k blocks */
|
||||
#define MD_BLOCK_SHIFT 12
|
||||
#define MD_BLOCK_SIZE (1<<MD_BLOCK_SHIFT)
|
||||
|
||||
/* activity log */
|
||||
#define AL_EXTENTS_PT ((MD_SECTOR_SIZE-12)/8-1) /* 61 ; Extents per 512B sector */
|
||||
#define AL_EXTENT_SHIFT 22 /* One extent represents 4M Storage */
|
||||
/* One activity log extent represents 4M of storage */
|
||||
#define AL_EXTENT_SHIFT 22
|
||||
#define AL_EXTENT_SIZE (1<<AL_EXTENT_SHIFT)
|
||||
|
||||
/* We could make these currently hardcoded constants configurable
|
||||
* variables at create-md time (or even re-configurable at runtime?).
|
||||
* Which will require some more changes to the DRBD "super block"
|
||||
* and attach code.
|
||||
*
|
||||
* updates per transaction:
|
||||
* This many changes to the active set can be logged with one transaction.
|
||||
* This number is arbitrary.
|
||||
* context per transaction:
|
||||
* This many context extent numbers are logged with each transaction.
|
||||
* This number is resulting from the transaction block size (4k), the layout
|
||||
* of the transaction header, and the number of updates per transaction.
|
||||
* See drbd_actlog.c:struct al_transaction_on_disk
|
||||
* */
|
||||
#define AL_UPDATES_PER_TRANSACTION 64 // arbitrary
|
||||
#define AL_CONTEXT_PER_TRANSACTION 919 // (4096 - 36 - 6*64)/4
|
||||
|
||||
#if BITS_PER_LONG == 32
|
||||
#define LN2_BPL 5
|
||||
#define cpu_to_lel(A) cpu_to_le32(A)
|
||||
|
||||
@ -2841,10 +2841,6 @@ void drbd_ldev_destroy(struct drbd_conf *mdev)
|
||||
drbd_free_bc(mdev->ldev);
|
||||
mdev->ldev = NULL;);
|
||||
|
||||
if (mdev->md_io_tmpp) {
|
||||
__free_page(mdev->md_io_tmpp);
|
||||
mdev->md_io_tmpp = NULL;
|
||||
}
|
||||
clear_bit(GO_DISKLESS, &mdev->flags);
|
||||
}
|
||||
|
||||
|
||||
@ -527,7 +527,7 @@ static void drbd_md_set_sector_offsets(struct drbd_conf *mdev,
|
||||
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_MAX_SIZE;
|
||||
bdev->md.al_offset = -MD_AL_SECTORS;
|
||||
/* 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);
|
||||
@ -751,8 +751,8 @@ static int drbd_check_al_size(struct drbd_conf *mdev)
|
||||
unsigned int in_use;
|
||||
int i;
|
||||
|
||||
if (!expect(mdev->sync_conf.al_extents >= 7))
|
||||
mdev->sync_conf.al_extents = 127;
|
||||
if (!expect(mdev->sync_conf.al_extents >= DRBD_AL_EXTENTS_MIN))
|
||||
mdev->sync_conf.al_extents = DRBD_AL_EXTENTS_MIN;
|
||||
|
||||
if (mdev->act_log &&
|
||||
mdev->act_log->nr_elements == mdev->sync_conf.al_extents)
|
||||
@ -760,7 +760,7 @@ static int drbd_check_al_size(struct drbd_conf *mdev)
|
||||
|
||||
in_use = 0;
|
||||
t = mdev->act_log;
|
||||
n = lc_create("act_log", drbd_al_ext_cache, 1,
|
||||
n = lc_create("act_log", drbd_al_ext_cache, AL_UPDATES_PER_TRANSACTION,
|
||||
mdev->sync_conf.al_extents, sizeof(struct lc_element), 0);
|
||||
|
||||
if (n == NULL) {
|
||||
@ -932,7 +932,6 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
|
||||
union drbd_state ns, os;
|
||||
enum drbd_state_rv rv;
|
||||
int cp_discovered = 0;
|
||||
int logical_block_size;
|
||||
|
||||
drbd_reconfig_start(mdev);
|
||||
|
||||
@ -1087,25 +1086,6 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
|
||||
|
||||
drbd_md_set_sector_offsets(mdev, nbc);
|
||||
|
||||
/* allocate a second IO page if logical_block_size != 512 */
|
||||
logical_block_size = bdev_logical_block_size(nbc->md_bdev);
|
||||
if (logical_block_size == 0)
|
||||
logical_block_size = MD_SECTOR_SIZE;
|
||||
|
||||
if (logical_block_size != MD_SECTOR_SIZE) {
|
||||
if (!mdev->md_io_tmpp) {
|
||||
struct page *page = alloc_page(GFP_NOIO);
|
||||
if (!page)
|
||||
goto force_diskless_dec;
|
||||
|
||||
dev_warn(DEV, "Meta data's bdev logical_block_size = %d != %d\n",
|
||||
logical_block_size, MD_SECTOR_SIZE);
|
||||
dev_warn(DEV, "Workaround engaged (has performance impact).\n");
|
||||
|
||||
mdev->md_io_tmpp = page;
|
||||
}
|
||||
}
|
||||
|
||||
if (!mdev->bitmap) {
|
||||
if (drbd_bm_init(mdev)) {
|
||||
retcode = ERR_NOMEM;
|
||||
@ -1804,14 +1784,12 @@ static int drbd_nl_syncer_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *n
|
||||
|
||||
if (!expect(sc.rate >= 1))
|
||||
sc.rate = 1;
|
||||
if (!expect(sc.al_extents >= 7))
|
||||
sc.al_extents = 127; /* arbitrary minimum */
|
||||
#define AL_MAX ((MD_AL_MAX_SIZE-1) * AL_EXTENTS_PT)
|
||||
if (sc.al_extents > AL_MAX) {
|
||||
dev_err(DEV, "sc.al_extents > %d\n", AL_MAX);
|
||||
sc.al_extents = AL_MAX;
|
||||
}
|
||||
#undef AL_MAX
|
||||
|
||||
/* clip to allowed range */
|
||||
if (!expect(sc.al_extents >= DRBD_AL_EXTENTS_MIN))
|
||||
sc.al_extents = DRBD_AL_EXTENTS_MIN;
|
||||
if (!expect(sc.al_extents <= DRBD_AL_EXTENTS_MAX))
|
||||
sc.al_extents = DRBD_AL_EXTENTS_MAX;
|
||||
|
||||
/* to avoid spurious errors when configuring minors before configuring
|
||||
* the minors they depend on: if necessary, first create the minor we
|
||||
|
||||
@ -336,6 +336,10 @@ enum drbd_timeout_flag {
|
||||
#define DRBD_MAGIC 0x83740267
|
||||
#define DRBD_MAGIC_BIG 0x835a
|
||||
|
||||
/* how I came up with this magic?
|
||||
* base64 decode "actlog==" ;) */
|
||||
#define DRBD_AL_MAGIC 0x69cb65a2
|
||||
|
||||
/* these are of type "int" */
|
||||
#define DRBD_MD_INDEX_INTERNAL -1
|
||||
#define DRBD_MD_INDEX_FLEX_EXT -2
|
||||
|
||||
@ -102,10 +102,12 @@
|
||||
#define DRBD_RATE_DEF 250 /* kb/second */
|
||||
|
||||
/* less than 7 would hit performance unnecessarily.
|
||||
* 3833 is the largest prime that still does fit
|
||||
* into 64 sectors of activity log */
|
||||
* 919 slots context information per transaction,
|
||||
* 32k activity log, 4k transaction size,
|
||||
* one transaction in flight:
|
||||
* 919 * 7 = 6433 */
|
||||
#define DRBD_AL_EXTENTS_MIN 7
|
||||
#define DRBD_AL_EXTENTS_MAX 3833
|
||||
#define DRBD_AL_EXTENTS_MAX 6433
|
||||
#define DRBD_AL_EXTENTS_DEF 127
|
||||
|
||||
#define DRBD_AFTER_MIN -1
|
||||
|
||||
Loading…
Reference in New Issue
Block a user