[3/4] xen/blkback: simplify free_persistent_gnts() interface
Commit Message
The interface of free_persistent_gnts() can be simplified, as there is
only a single caller of free_persistent_gnts() and the 2nd and 3rd
parameters are easily obtainable via the ring pointer, which is passed
as the first parameter anyway.
Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/block/xen-blkback/blkback.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
@@ -239,9 +239,9 @@ static void put_persistent_gnt(struct xen_blkif_ring *ring,
atomic_dec(&ring->persistent_gnt_in_use);
}
-static void free_persistent_gnts(struct xen_blkif_ring *ring, struct rb_root *root,
- unsigned int num)
+static void free_persistent_gnts(struct xen_blkif_ring *ring)
{
+ struct rb_root *root = &ring->persistent_gnts;
struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct persistent_gnt *persistent_gnt;
@@ -249,6 +249,9 @@ static void free_persistent_gnts(struct xen_blkif_ring *ring, struct rb_root *ro
int segs_to_unmap = 0;
struct gntab_unmap_queue_data unmap_data;
+ if (RB_EMPTY_ROOT(root))
+ return;
+
unmap_data.pages = pages;
unmap_data.unmap_ops = unmap;
unmap_data.kunmap_ops = NULL;
@@ -277,9 +280,11 @@ static void free_persistent_gnts(struct xen_blkif_ring *ring, struct rb_root *ro
rb_erase(&persistent_gnt->node, root);
kfree(persistent_gnt);
- num--;
+ ring->persistent_gnt_c--;
}
- BUG_ON(num != 0);
+
+ BUG_ON(!RB_EMPTY_ROOT(&ring->persistent_gnts));
+ BUG_ON(ring->persistent_gnt_c != 0);
}
void xen_blkbk_unmap_purged_grants(struct work_struct *work)
@@ -631,12 +636,7 @@ int xen_blkif_schedule(void *arg)
void xen_blkbk_free_caches(struct xen_blkif_ring *ring)
{
/* Free all persistent grant pages */
- if (!RB_EMPTY_ROOT(&ring->persistent_gnts))
- free_persistent_gnts(ring, &ring->persistent_gnts,
- ring->persistent_gnt_c);
-
- BUG_ON(!RB_EMPTY_ROOT(&ring->persistent_gnts));
- ring->persistent_gnt_c = 0;
+ free_persistent_gnts(ring);
/* Since we are shutting down remove all pages from the buffer */
gnttab_page_cache_shrink(&ring->free_pages, 0 /* All */);