Commit 3a169c0b authored by Juergen Gross's avatar Juergen Gross
Browse files

xen/blkfront: fix memory allocation flags in blkfront_setup_indirect() 



Commit 1d5c76e6 ("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: 1d5c76e6 ("xen-blkfront: switch kcalloc to kvcalloc for large array allocation")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: default avatarRoger Pau Monné <roger.pau@citrix.com>
Link: https://lore.kernel.org/r/20200403090034.8753-1-jgross@suse.com


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent 0102e4ef

drivers/block/xen-blkfront.c

+12 −5
Original line number Diff line number Diff line
@@ -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>
@@ -2189,10 +2190,12 @@ static void blkfront_setup_discard(struct blkfront_info *info) 


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;
@@ -2224,7 +2227,7 @@ static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo) 


		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);
@@ -2235,15 +2238,15 @@ static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo) 
		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 &&
@@ -2252,6 +2255,7 @@ static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo) 
		sg_init_table(rinfo->shadow[i].sg, psegs);

	}



	memalloc_noio_restore(memflags);



	return 0;
@@ -2271,6 +2275,9 @@ out_of_memory: 
			__free_page(indirect_page);

		}

	}



	memalloc_noio_restore(memflags);



	return -ENOMEM;

}

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