From: Juergen Gross jgross@suse.com
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@vger.kernel.org Signed-off-by: Juergen Gross jgross@suse.com Reviewed-by: Boris Ostrovsky boris.ostrovsky@oracle.com Acked-by: Roger Pau Monné roger.pau@citrix.com Link: https://lore.kernel.org/r/20200403090034.8753-1-jgross@suse.com Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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> @@ -2189,10 +2190,12 @@ 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; @@ -2224,7 +2227,7 @@ 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); @@ -2235,15 +2238,15 @@ 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 && @@ -2252,6 +2255,7 @@ static int blkfront_setup_indirect(struc 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; }