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Commit 4d4f270f authored by Roger Pau Monne's avatar Roger Pau Monne Committed by Konrad Rzeszutek Wilk
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xen-blkback: move free persistent grants code 



Move the code that frees persistent grants from the red-black tree
to a function. This will make it easier for other consumers to move
this to a common place.

Signed-off-by: default avatarRoger Pau Monné <roger.pau@citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent cb5bd4d1

drivers/block/xen-blkback/blkback.c

+37 −31
Original line number Diff line number Diff line
@@ -212,6 +212,39 @@ static struct persistent_gnt *get_persistent_gnt(struct rb_root *root, 
	return NULL;

}



static void free_persistent_gnts(struct rb_root *root, unsigned int num)

{

	struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];

	struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];

	struct persistent_gnt *persistent_gnt;

	int ret = 0;

	int segs_to_unmap = 0;



	foreach_grant(persistent_gnt, root, node) {

		BUG_ON(persistent_gnt->handle ==

			BLKBACK_INVALID_HANDLE);

		gnttab_set_unmap_op(&unmap[segs_to_unmap],

			(unsigned long) pfn_to_kaddr(page_to_pfn(

				persistent_gnt->page)),

			GNTMAP_host_map,

			persistent_gnt->handle);



		pages[segs_to_unmap] = persistent_gnt->page;

		rb_erase(&persistent_gnt->node, root);

		kfree(persistent_gnt);

		num--;



		if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST ||

			!rb_next(&persistent_gnt->node)) {

			ret = gnttab_unmap_refs(unmap, NULL, pages,

				segs_to_unmap);

			BUG_ON(ret);

			segs_to_unmap = 0;

		}

	}

	BUG_ON(num != 0);

}



/*

 * Retrieve from the 'pending_reqs' a free pending_req structure to be used.

 */
@@ -358,11 +391,6 @@ int xen_blkif_schedule(void *arg) 
{

	struct xen_blkif *blkif = arg;

	struct xen_vbd *vbd = &blkif->vbd;

	struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];

	struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];

	struct persistent_gnt *persistent_gnt;

	int ret = 0;

	int segs_to_unmap = 0;



	xen_blkif_get(blkif);
@@ -391,34 +419,12 @@ int xen_blkif_schedule(void *arg) 
	}



	/* Free all persistent grant pages */

	if (!RB_EMPTY_ROOT(&blkif->persistent_gnts)) {

		foreach_grant(persistent_gnt, &blkif->persistent_gnts, node) {

			BUG_ON(persistent_gnt->handle ==

				BLKBACK_INVALID_HANDLE);

			gnttab_set_unmap_op(&unmap[segs_to_unmap],

			    (unsigned long) pfn_to_kaddr(page_to_pfn(

				persistent_gnt->page)),

			    GNTMAP_host_map,

			    persistent_gnt->handle);



			pages[segs_to_unmap] = persistent_gnt->page;

			rb_erase(&persistent_gnt->node,

				&blkif->persistent_gnts);

			kfree(persistent_gnt);

			blkif->persistent_gnt_c--;



			if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST ||

				!rb_next(&persistent_gnt->node)) {

				ret = gnttab_unmap_refs(unmap, NULL, pages,

							segs_to_unmap);

				BUG_ON(ret);

				segs_to_unmap = 0;

			}

		}

	}

	if (!RB_EMPTY_ROOT(&blkif->persistent_gnts))

		free_persistent_gnts(&blkif->persistent_gnts,

			blkif->persistent_gnt_c);



	BUG_ON(blkif->persistent_gnt_c != 0);

	BUG_ON(!RB_EMPTY_ROOT(&blkif->persistent_gnts));

	blkif->persistent_gnt_c = 0;



	if (log_stats)

		print_stats(blkif);