2012-11-16 18:27:39

by Roger Pau Monne

Subject: [PATCH 1/2] xen-blkfront: free allocated page

Free the page allocated for the persistent grant.

Signed-off-by: Roger Pau Monné <[email protected]>
---
drivers/block/xen-blkfront.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index f1de806..96e9b00 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -806,6 +806,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
all_gnts = llist_del_all(&info->persistent_gnts);
llist_for_each_entry(persistent_gnt, all_gnts, node) {
gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
+ __free_page(pfn_to_page(persistent_gnt->pfn));
kfree(persistent_gnt);
}
info->persistent_gnts_c = 0;
--
1.7.7.5 (Apple Git-26)

2012-11-16 18:27:37

by Roger Pau Monne

Subject: [PATCH 2/2] 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: Roger Pau Monné <[email protected]>
---
drivers/block/xen-blkback/blkback.c | 68 +++++++++++++++++++----------------
1 files changed, 37 insertions(+), 31 deletions(-)

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index a059616..74374fb 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -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);
--
1.7.7.5 (Apple Git-26)