Commit e15766e9 authored by Lars Ellenberg's avatar Lars Ellenberg Committed by Philipp Reisner
Browse files

drbd: improvements to activate/deactivate multiple activity log extents 



Recent commit drbd: get rid of bio_split, allow bios of "arbitrary" size
had a reference count leak: it only deactivated the first of several
activity log extents for intervals crossing extent boundaries.

This commit generalizes on bios spanning multiple activity log extents
in drbd_al_begin_io, and adds the necessary loop around lc_put in
drbd_al_complete_io as well.

Signed-off-by: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
parent 23361cf3

drivers/block/drbd/drbd_actlog.c

+23 −23
Original line number Diff line number Diff line
@@ -209,20 +209,16 @@ void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i) 
{

	/* for bios crossing activity log extent boundaries,

	 * we may need to activate two extents in one go */

	unsigned int enr[2];

	struct lc_element *al_ext[2] = { NULL, NULL };

	struct update_al_work al_work;

	unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);

	unsigned last = (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);

	unsigned enr;



	D_ASSERT(atomic_read(&mdev->local_cnt) > 0);



	enr[0] = i->sector >> (AL_EXTENT_SHIFT-9);

	enr[1] = (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);

	wait_event(mdev->al_wait, (al_ext[0] = _al_get(mdev, enr[0])));

	if (enr[0] != enr[1])

		wait_event(mdev->al_wait, (al_ext[1] = _al_get(mdev, enr[1])));

	for (enr = first; enr <= last; enr++)

		wait_event(mdev->al_wait, _al_get(mdev, enr) != NULL);



	if (al_ext[0]->lc_number != enr[0] ||

	    (al_ext[1] && al_ext[1]->lc_number != enr[1])) {

	if (mdev->act_log->pending_changes) {

		/* drbd_al_write_transaction(mdev,al_ext,enr);

		 * recurses into generic_make_request(), which

		 * disallows recursion, bios being serialized on the
@@ -239,8 +235,8 @@ void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i) 


		/* Double check: it may have been committed by someone else,

		 * while we have been waiting for the lock. */

		if (al_ext[0]->lc_number != enr[0] ||

		    (al_ext[1] && al_ext[1]->lc_number != enr[1])) {

		if (mdev->act_log->pending_changes) {

			struct update_al_work al_work;

			init_completion(&al_work.event);

			al_work.w.cb = w_al_write_transaction;

			al_work.w.mdev = mdev;
@@ -264,24 +260,28 @@ void drbd_al_begin_io(struct drbd_conf *mdev, struct drbd_interval *i) 


void drbd_al_complete_io(struct drbd_conf *mdev, struct drbd_interval *i)

{

	unsigned int enr = (i->sector >> (AL_EXTENT_SHIFT-9));

	/* for bios crossing activity log extent boundaries,

	 * we may need to activate two extents in one go */

	unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);

	unsigned last = (i->sector + (i->size >> 9) - 1) >> (AL_EXTENT_SHIFT-9);

	unsigned enr;

	struct lc_element *extent;

	unsigned long flags;

	bool wake = false;



	spin_lock_irqsave(&mdev->al_lock, flags);



	for (enr = first; enr <= last; enr++) {

		extent = lc_find(mdev->act_log, enr);



		if (!extent) {

		spin_unlock_irqrestore(&mdev->al_lock, flags);

			dev_err(DEV, "al_complete_io() called on inactive extent %u\n", enr);

		return;

			continue;

		}



		if (lc_put(mdev->act_log, extent) == 0)

		wake_up(&mdev->al_wait);



			wake = true;

	}

	spin_unlock_irqrestore(&mdev->al_lock, flags);

	wake_up(&mdev->al_wait);

}



#if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)

CRA Git | Maintained and supported by SUSTech CRA and CCSE