From: Juergen Gross <jgross@xxxxxxxx>
commit 3a169c0be75b59dd85d159493634870cdec6d3c4 upstream.
Commit 1d5c76e664333 ("xen-blkfront: switch kcalloc to kvcalloc for
large array allocation") didn't fix the issue it was meant to, as the
flags for allocating the memory are GFP_NOIO, which will lead the
memory allocation falling back to kmalloc().
So instead of GFP_NOIO use GFP_KERNEL and do all the memory allocation
in blkfront_setup_indirect() in a memalloc_noio_{save,restore} section.
Fixes: 1d5c76e664333 ("xen-blkfront: switch kcalloc to kvcalloc for large array allocation")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200403090034.8753-1-jgross@xxxxxxxx
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/xen-blkfront.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -47,6 +47,7 @@
#include <linux/bitmap.h>
#include <linux/list.h>
#include <linux/workqueue.h>
+#include <linux/sched/mm.h>
#include <xen/xen.h>
#include <xen/xenbus.h>
@@ -2188,10 +2189,12 @@ static void blkfront_setup_discard(struc
static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo)
{
- unsigned int psegs, grants;
+ unsigned int psegs, grants, memflags;
int err, i;
struct blkfront_info *info = rinfo->dev_info;
+ memflags = memalloc_noio_save();
+
if (info->max_indirect_segments == 0) {
if (!HAS_EXTRA_REQ)
grants = BLKIF_MAX_SEGMENTS_PER_REQUEST;
@@ -2223,7 +2226,7 @@ static int blkfront_setup_indirect(struc
BUG_ON(!list_empty(&rinfo->indirect_pages));
for (i = 0; i < num; i++) {
- struct page *indirect_page = alloc_page(GFP_NOIO);
+ struct page *indirect_page = alloc_page(GFP_KERNEL);
if (!indirect_page)
goto out_of_memory;
list_add(&indirect_page->lru, &rinfo->indirect_pages);
@@ -2234,15 +2237,15 @@ static int blkfront_setup_indirect(struc
rinfo->shadow[i].grants_used =
kvcalloc(grants,
sizeof(rinfo->shadow[i].grants_used[0]),
- GFP_NOIO);
+ GFP_KERNEL);
rinfo->shadow[i].sg = kvcalloc(psegs,
sizeof(rinfo->shadow[i].sg[0]),
- GFP_NOIO);
+ GFP_KERNEL);
if (info->max_indirect_segments)
rinfo->shadow[i].indirect_grants =
kvcalloc(INDIRECT_GREFS(grants),
sizeof(rinfo->shadow[i].indirect_grants[0]),
- GFP_NOIO);
+ GFP_KERNEL);
if ((rinfo->shadow[i].grants_used == NULL) ||
(rinfo->shadow[i].sg == NULL) ||
(info->max_indirect_segments &&
@@ -2251,6 +2254,7 @@ static int blkfront_setup_indirect(struc
sg_init_table(rinfo->shadow[i].sg, psegs);
}
+ memalloc_noio_restore(memflags);
return 0;
@@ -2270,6 +2274,9 @@ out_of_memory:
__free_page(indirect_page);
}
}
+
+ memalloc_noio_restore(memflags);
+
return -ENOMEM;
}
