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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: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Roger Pau Monne 2012-11-16 19:26:48 +01:00 committed by Konrad Rzeszutek Wilk
parent cb5bd4d19b
commit 4d4f270f18
1 changed files with 37 additions and 31 deletions
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68
drivers/block/xen-blkback/blkback.c
View File

@ -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);
if (!RB_EMPTY_ROOT(&blkif->persistent_gnts))
free_persistent_gnts(&blkif->persistent_gnts,
blkif->persistent_gnt_c);
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;
}
}
}
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);