diff options
author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2010-12-15 08:59:11 +0100 |
---|---|---|
committer | Philipp Reisner <philipp.reisner@linbit.com> | 2011-03-10 11:43:19 +0100 |
commit | 19f843aa08e2d8f87a09b4c2edc43b00638423a8 (patch) | |
tree | 49919bd17ba7e03eb7cb76175910714d55704997 /drivers/block/drbd/drbd_actlog.c | |
parent | drbd: store in-core bitmap little endian, regardless of architecture (diff) | |
download | linux-19f843aa08e2d8f87a09b4c2edc43b00638423a8.tar.xz linux-19f843aa08e2d8f87a09b4c2edc43b00638423a8.zip |
drbd: bitmap keep track of changes vs on-disk bitmap
When we set or clear bits in a bitmap page,
also set a flag in the page->private pointer.
This allows us to skip writes of unchanged pages.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Diffstat (limited to 'drivers/block/drbd/drbd_actlog.c')
-rw-r--r-- | drivers/block/drbd/drbd_actlog.c | 132 |
1 files changed, 29 insertions, 103 deletions
diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c index e3f0f4d31d75..090fc2ce0df4 100644 --- a/drivers/block/drbd/drbd_actlog.c +++ b/drivers/block/drbd/drbd_actlog.c @@ -262,6 +262,33 @@ void drbd_al_complete_io(struct drbd_conf *mdev, sector_t sector) spin_unlock_irqrestore(&mdev->al_lock, flags); } +#if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT) +/* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT + * are still coupled, or assume too much about their relation. + * Code below will not work if this is violated. + * Will be cleaned up with some followup patch. + */ +# error FIXME +#endif + +static unsigned int al_extent_to_bm_page(unsigned int al_enr) +{ + return al_enr >> + /* bit to page */ + ((PAGE_SHIFT + 3) - + /* al extent number to bit */ + (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)); +} + +static unsigned int rs_extent_to_bm_page(unsigned int rs_enr) +{ + return rs_enr >> + /* bit to page */ + ((PAGE_SHIFT + 3) - + /* al extent number to bit */ + (BM_EXT_SHIFT - BM_BLOCK_SHIFT)); +} + int w_al_write_transaction(struct drbd_conf *mdev, struct drbd_work *w, int unused) { @@ -289,7 +316,7 @@ w_al_write_transaction(struct drbd_conf *mdev, struct drbd_work *w, int unused) * For now, we must not write the transaction, * if we cannot write out the bitmap of the evicted extent. */ if (mdev->state.conn < C_CONNECTED && evicted != LC_FREE) - drbd_bm_write_sect(mdev, evicted/AL_EXT_PER_BM_SECT); + drbd_bm_write_page(mdev, al_extent_to_bm_page(evicted)); /* The bitmap write may have failed, causing a state change. */ if (mdev->state.disk < D_INCONSISTENT) { @@ -636,105 +663,6 @@ out_bio_put: } /** - * drbd_al_to_on_disk_bm() - * Writes bitmap parts covered by active AL extents - * @mdev: DRBD device. - * - * Called when we detach (unconfigure) local storage, - * or when we go from R_PRIMARY to R_SECONDARY role. - */ -void drbd_al_to_on_disk_bm(struct drbd_conf *mdev) -{ - int i, nr_elements; - unsigned int enr; - struct bio **bios; - struct drbd_atodb_wait wc; - - ERR_IF (!get_ldev_if_state(mdev, D_ATTACHING)) - return; /* sorry, I don't have any act_log etc... */ - - wait_event(mdev->al_wait, lc_try_lock(mdev->act_log)); - - nr_elements = mdev->act_log->nr_elements; - - /* GFP_KERNEL, we are not in anyone's write-out path */ - bios = kzalloc(sizeof(struct bio *) * nr_elements, GFP_KERNEL); - if (!bios) - goto submit_one_by_one; - - atomic_set(&wc.count, 0); - init_completion(&wc.io_done); - wc.mdev = mdev; - wc.error = 0; - - for (i = 0; i < nr_elements; i++) { - enr = lc_element_by_index(mdev->act_log, i)->lc_number; - if (enr == LC_FREE) - continue; - /* next statement also does atomic_inc wc.count and local_cnt */ - if (atodb_prepare_unless_covered(mdev, bios, - enr/AL_EXT_PER_BM_SECT, - &wc)) - goto free_bios_submit_one_by_one; - } - - /* unnecessary optimization? */ - lc_unlock(mdev->act_log); - wake_up(&mdev->al_wait); - - /* all prepared, submit them */ - for (i = 0; i < nr_elements; i++) { - if (bios[i] == NULL) - break; - if (drbd_insert_fault(mdev, DRBD_FAULT_MD_WR)) { - bios[i]->bi_rw = WRITE; - bio_endio(bios[i], -EIO); - } else { - submit_bio(WRITE, bios[i]); - } - } - - /* always (try to) flush bitmap to stable storage */ - drbd_md_flush(mdev); - - /* In case we did not submit a single IO do not wait for - * them to complete. ( Because we would wait forever here. ) - * - * In case we had IOs and they are already complete, there - * is not point in waiting anyways. - * Therefore this if () ... */ - if (atomic_read(&wc.count)) - wait_for_completion(&wc.io_done); - - put_ldev(mdev); - - kfree(bios); - return; - - free_bios_submit_one_by_one: - /* free everything by calling the endio callback directly. */ - for (i = 0; i < nr_elements && bios[i]; i++) - bio_endio(bios[i], 0); - - kfree(bios); - - submit_one_by_one: - dev_warn(DEV, "Using the slow drbd_al_to_on_disk_bm()\n"); - - for (i = 0; i < mdev->act_log->nr_elements; i++) { - enr = lc_element_by_index(mdev->act_log, i)->lc_number; - if (enr == LC_FREE) - continue; - /* Really slow: if we have al-extents 16..19 active, - * sector 4 will be written four times! Synchronous! */ - drbd_bm_write_sect(mdev, enr/AL_EXT_PER_BM_SECT); - } - - lc_unlock(mdev->act_log); - wake_up(&mdev->al_wait); - put_ldev(mdev); -} - -/** * drbd_al_apply_to_bm() - Sets the bitmap to diry(1) where covered ba active AL extents * @mdev: DRBD device. */ @@ -813,7 +741,7 @@ static int w_update_odbm(struct drbd_conf *mdev, struct drbd_work *w, int unused return 1; } - drbd_bm_write_sect(mdev, udw->enr); + drbd_bm_write_page(mdev, rs_extent_to_bm_page(udw->enr)); put_ldev(mdev); kfree(udw); @@ -893,7 +821,6 @@ static void drbd_try_clear_on_disk_bm(struct drbd_conf *mdev, sector_t sector, dev_warn(DEV, "Kicking resync_lru element enr=%u " "out with rs_failed=%d\n", ext->lce.lc_number, ext->rs_failed); - set_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags); } ext->rs_left = rs_left; ext->rs_failed = success ? 0 : count; @@ -912,7 +839,6 @@ static void drbd_try_clear_on_disk_bm(struct drbd_conf *mdev, sector_t sector, drbd_queue_work_front(&mdev->data.work, &udw->w); } else { dev_warn(DEV, "Could not kmalloc an udw\n"); - set_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags); } } } else { |