[PATCH v3 07/20] block/xen-blkfront: Store a page rather a pfn in the grant structure
From: Julien Grall
Date: Fri Aug 07 2015 - 12:49:50 EST
All the usage of the field pfn are done using the same idiom:
pfn_to_page(grant->pfn)
This will return always the same page. Store directly the page in the
grant to clean up the code.
Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
Acked-by: Roger Pau Monnà <roger.pau@xxxxxxxxxx>
Reviewed-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
Changes in v3:
- Use the correct indentation in get_grant. The current
indentation (i.e without this patch) was wrong because it was
using space rather than tabulation.
- Add Roger's acked and Stefano's reviewed
- s/mfn/gfn based on the new naming
Changes in v2:
- Patch added
---
drivers/block/xen-blkfront.c | 39 +++++++++++++++++++--------------------
1 file changed, 19 insertions(+), 20 deletions(-)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index b235689..e431e82 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -68,7 +68,7 @@ enum blkif_state {
struct grant {
grant_ref_t gref;
- unsigned long pfn;
+ struct page *page;
struct list_head node;
};
@@ -221,7 +221,7 @@ static int fill_grant_buffer(struct blkfront_info *info, int num)
kfree(gnt_list_entry);
goto out_of_memory;
}
- gnt_list_entry->pfn = page_to_pfn(granted_page);
+ gnt_list_entry->page = granted_page;
}
gnt_list_entry->gref = GRANT_INVALID_REF;
@@ -236,7 +236,7 @@ out_of_memory:
&info->grants, node) {
list_del(&gnt_list_entry->node);
if (info->feature_persistent)
- __free_page(pfn_to_page(gnt_list_entry->pfn));
+ __free_page(gnt_list_entry->page);
kfree(gnt_list_entry);
i--;
}
@@ -245,8 +245,8 @@ out_of_memory:
}
static struct grant *get_grant(grant_ref_t *gref_head,
- unsigned long pfn,
- struct blkfront_info *info)
+ struct page *page,
+ struct blkfront_info *info)
{
struct grant *gnt_list_entry;
unsigned long buffer_gfn;
@@ -265,10 +265,10 @@ static struct grant *get_grant(grant_ref_t *gref_head,
gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head);
BUG_ON(gnt_list_entry->gref == -ENOSPC);
if (!info->feature_persistent) {
- BUG_ON(!pfn);
- gnt_list_entry->pfn = pfn;
+ BUG_ON(!page);
+ gnt_list_entry->page = page;
}
- buffer_gfn = pfn_to_gfn(gnt_list_entry->pfn);
+ buffer_gfn = xen_page_to_gfn(gnt_list_entry->page);
gnttab_grant_foreign_access_ref(gnt_list_entry->gref,
info->xbdev->otherend_id,
buffer_gfn, 0);
@@ -524,7 +524,7 @@ static int blkif_queue_rw_req(struct request *req)
if ((ring_req->operation == BLKIF_OP_INDIRECT) &&
(i % SEGS_PER_INDIRECT_FRAME == 0)) {
- unsigned long uninitialized_var(pfn);
+ struct page *uninitialized_var(page);
if (segments)
kunmap_atomic(segments);
@@ -541,15 +541,15 @@ static int blkif_queue_rw_req(struct request *req)
indirect_page = list_first_entry(&info->indirect_pages,
struct page, lru);
list_del(&indirect_page->lru);
- pfn = page_to_pfn(indirect_page);
+ page = indirect_page;
}
- gnt_list_entry = get_grant(&gref_head, pfn, info);
+ gnt_list_entry = get_grant(&gref_head, page, info);
info->shadow[id].indirect_grants[n] = gnt_list_entry;
- segments = kmap_atomic(pfn_to_page(gnt_list_entry->pfn));
+ segments = kmap_atomic(gnt_list_entry->page);
ring_req->u.indirect.indirect_grefs[n] = gnt_list_entry->gref;
}
- gnt_list_entry = get_grant(&gref_head, page_to_pfn(sg_page(sg)), info);
+ gnt_list_entry = get_grant(&gref_head, sg_page(sg), info);
ref = gnt_list_entry->gref;
info->shadow[id].grants_used[i] = gnt_list_entry;
@@ -560,7 +560,7 @@ static int blkif_queue_rw_req(struct request *req)
BUG_ON(sg->offset + sg->length > PAGE_SIZE);
- shared_data = kmap_atomic(pfn_to_page(gnt_list_entry->pfn));
+ shared_data = kmap_atomic(gnt_list_entry->page);
bvec_data = kmap_atomic(sg_page(sg));
/*
@@ -1001,7 +1001,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
info->persistent_gnts_c--;
}
if (info->feature_persistent)
- __free_page(pfn_to_page(persistent_gnt->pfn));
+ __free_page(persistent_gnt->page);
kfree(persistent_gnt);
}
}
@@ -1036,7 +1036,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
persistent_gnt = info->shadow[i].grants_used[j];
gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
if (info->feature_persistent)
- __free_page(pfn_to_page(persistent_gnt->pfn));
+ __free_page(persistent_gnt->page);
kfree(persistent_gnt);
}
@@ -1050,7 +1050,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
for (j = 0; j < INDIRECT_GREFS(segs); j++) {
persistent_gnt = info->shadow[i].indirect_grants[j];
gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
- __free_page(pfn_to_page(persistent_gnt->pfn));
+ __free_page(persistent_gnt->page);
kfree(persistent_gnt);
}
@@ -1101,8 +1101,7 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
if (bret->operation == BLKIF_OP_READ && info->feature_persistent) {
for_each_sg(s->sg, sg, nseg, i) {
BUG_ON(sg->offset + sg->length > PAGE_SIZE);
- shared_data = kmap_atomic(
- pfn_to_page(s->grants_used[i]->pfn));
+ shared_data = kmap_atomic(s->grants_used[i]->page);
bvec_data = kmap_atomic(sg_page(sg));
memcpy(bvec_data + sg->offset,
shared_data + sg->offset,
@@ -1153,7 +1152,7 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
* Add the used indirect page back to the list of
* available pages for indirect grefs.
*/
- indirect_page = pfn_to_page(s->indirect_grants[i]->pfn);
+ indirect_page = s->indirect_grants[i]->page;
list_add(&indirect_page->lru, &info->indirect_pages);
s->indirect_grants[i]->gref = GRANT_INVALID_REF;
list_add_tail(&s->indirect_grants[i]->node, &info->grants);
--
2.1.4
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