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Commit 6a35c45f authored by Philipp Reisner's avatar Philipp Reisner
Browse files

drbd: Ensure that an epoch contains only requests of one kind 



The assert in drbd_req.c:755 forces us to have only requests of
one kind in an epoch. The two kinds we distinguish here are:
local-only or mirrored.

Signed-off-by: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
parent 2deb8336

drivers/block/drbd/drbd_main.c

+6 −1
Original line number Diff line number Diff line
@@ -1261,9 +1261,14 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns, 
	if (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED)

		drbd_resume_al(mdev);



	if (os.conn == C_AHEAD && ns.conn != C_AHEAD)

	/* Start a new epoch in case we start to mirror write requests */

	if (!drbd_should_do_remote(os) && drbd_should_do_remote(ns))

		tl_forget(mdev);



	/* Do not add local-only requests to an epoch with mirrored requests */

	if (drbd_should_do_remote(os) && !drbd_should_do_remote(ns))

		set_bit(CREATE_BARRIER, &mdev->flags);



	ascw = kmalloc(sizeof(*ascw), GFP_ATOMIC);

	if (ascw) {

		ascw->os = os;

drivers/block/drbd/drbd_req.c

+4 −25
Original line number Diff line number Diff line
@@ -762,27 +762,6 @@ static int drbd_may_do_local_read(struct drbd_conf *mdev, sector_t sector, int s 
	return 0 == drbd_bm_count_bits(mdev, sbnr, ebnr);

}



static bool drbd_should_do_remote(struct drbd_conf *mdev)

{

	union drbd_state s = mdev->state;



	return s.pdsk == D_UP_TO_DATE ||

		(s.pdsk >= D_INCONSISTENT &&

		 s.conn >= C_WF_BITMAP_T &&

		 s.conn < C_AHEAD);

	/* Before proto 96 that was >= CONNECTED instead of >= C_WF_BITMAP_T.

	   That is equivalent since before 96 IO was frozen in the C_WF_BITMAP*

	   states. */

}

static bool drbd_should_send_oos(struct drbd_conf *mdev)

{

	union drbd_state s = mdev->state;



	return s.conn == C_AHEAD || s.conn == C_WF_BITMAP_S;

	/* pdsk = D_INCONSISTENT as a consequence. Protocol 96 check not necessary

	   since we enter state C_AHEAD only if proto >= 96 */

}



static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio, unsigned long start_time)

{

	const int rw = bio_rw(bio);
@@ -854,8 +833,8 @@ static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio, uns 
		drbd_al_begin_io(mdev, sector);

	}



	remote = remote && drbd_should_do_remote(mdev);

	send_oos = rw == WRITE && drbd_should_send_oos(mdev);

	remote = remote && drbd_should_do_remote(mdev->state);

	send_oos = rw == WRITE && drbd_should_send_oos(mdev->state);

	D_ASSERT(!(remote && send_oos));



	if (!(local || remote) && !is_susp(mdev->state)) {
@@ -896,8 +875,8 @@ static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio, uns 
	}



	if (remote || send_oos) {

		remote = drbd_should_do_remote(mdev);

		send_oos = rw == WRITE && drbd_should_send_oos(mdev);

		remote = drbd_should_do_remote(mdev->state);

		send_oos = rw == WRITE && drbd_should_send_oos(mdev->state);

		D_ASSERT(!(remote && send_oos));



		if (!(remote || send_oos))

drivers/block/drbd/drbd_req.h

+18 −0
Original line number Diff line number Diff line
@@ -360,4 +360,22 @@ static inline int req_mod(struct drbd_request *req, 


	return rv;

}



static inline bool drbd_should_do_remote(union drbd_state s)

{

	return s.pdsk == D_UP_TO_DATE ||

		(s.pdsk >= D_INCONSISTENT &&

		 s.conn >= C_WF_BITMAP_T &&

		 s.conn < C_AHEAD);

	/* Before proto 96 that was >= CONNECTED instead of >= C_WF_BITMAP_T.

	   That is equivalent since before 96 IO was frozen in the C_WF_BITMAP*

	   states. */

}

static inline bool drbd_should_send_oos(union drbd_state s)

{

	return s.conn == C_AHEAD || s.conn == C_WF_BITMAP_S;

	/* pdsk = D_INCONSISTENT as a consequence. Protocol 96 check not necessary

	   since we enter state C_AHEAD only if proto >= 96 */

}



#endif