Commit a0d856df authored by Lars Ellenberg's avatar Lars Ellenberg Committed by Philipp Reisner
Browse files

drbd: base completion and destruction of requests on ref counts 



cherry-picked and adapted from drbd 9 devel branch

The logic for when to get or put a reference is in mod_rq_state().

To not get confused in the freeze/thaw respectively resend/restart
paths, or when cleaning up requests waiting for P_BARRIER_ACK, this
also introduces additional state flags:
RQ_COMPLETION_SUSP, and RQ_EXP_BARR_ACK.

Signed-off-by: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
parent b406777e

drivers/block/drbd/drbd_int.h

+2 −1
Original line number Diff line number Diff line
@@ -575,13 +575,14 @@ struct drbd_request { 


	struct list_head tl_requests; /* ring list in the transfer log */

	struct bio *master_bio;       /* master bio pointer */

	unsigned long rq_state; /* see comments above _req_mod() */

	unsigned long start_time;



	/* once it hits 0, we may complete the master_bio */

	atomic_t completion_ref;

	/* once it hits 0, we may destroy this drbd_request object */

	struct kref kref;



	unsigned rq_state; /* see comments above _req_mod() */

};



struct drbd_epoch {

drivers/block/drbd/drbd_main.c

+1 −1
Original line number Diff line number Diff line
@@ -210,7 +210,7 @@ void tl_release(struct drbd_tconn *tconn, unsigned int barrier_nr, 
	/* find latest not yet barrier-acked write request,

	 * count writes in its epoch. */

	list_for_each_entry(r, &tconn->transfer_log, tl_requests) {

		const unsigned long s = r->rq_state;

		const unsigned s = r->rq_state;

		if (!req) {

			if (!(s & RQ_WRITE))

				continue;

drivers/block/drbd/drbd_req.c

+265 −253

File changed.

Preview size limit exceeded, changes collapsed.

drivers/block/drbd/drbd_req.h

+9 −0
Original line number Diff line number Diff line
@@ -203,11 +203,18 @@ enum drbd_req_state_bits { 
	/* The peer has sent a retry ACK */

	__RQ_POSTPONED,



	/* would have been completed,

	 * but was not, because of drbd_suspended() */

	__RQ_COMPLETION_SUSP,



	/* We expect a receive ACK (wire proto B) */

	__RQ_EXP_RECEIVE_ACK,



	/* We expect a write ACK (wite proto C) */

	__RQ_EXP_WRITE_ACK,



	/* waiting for a barrier ack, did an extra kref_get */

	__RQ_EXP_BARR_ACK,

};



#define RQ_LOCAL_PENDING   (1UL << __RQ_LOCAL_PENDING)
@@ -230,8 +237,10 @@ enum drbd_req_state_bits { 
#define RQ_WRITE           (1UL << __RQ_WRITE)

#define RQ_IN_ACT_LOG      (1UL << __RQ_IN_ACT_LOG)

#define RQ_POSTPONED	   (1UL << __RQ_POSTPONED)

#define RQ_COMPLETION_SUSP (1UL << __RQ_COMPLETION_SUSP)

#define RQ_EXP_RECEIVE_ACK (1UL << __RQ_EXP_RECEIVE_ACK)

#define RQ_EXP_WRITE_ACK   (1UL << __RQ_EXP_WRITE_ACK)

#define RQ_EXP_BARR_ACK    (1UL << __RQ_EXP_BARR_ACK)



/* For waking up the frozen transfer log mod_req() has to return if the request

   should be counted in the epoch object*/

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