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xen/blkfront: fix memory allocation flags in blkfront_setup_indirect()
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Commit 1d5c76e ("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: 1d5c76e ("xen-blkfront: switch kcalloc to kvcalloc for large array allocation")
Cc: [email protected]
Signed-off-by: Juergen Gross <[email protected]>
Reviewed-by: Boris Ostrovsky <[email protected]>
Acked-by: Roger Pau Monné <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Juergen Gross <[email protected]>
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jgross1 committed Apr 7, 2020
1 parent 0102e4e commit 3a169c0
Showing 1 changed file with 12 additions and 5 deletions.
17 changes: 12 additions & 5 deletions drivers/block/xen-blkfront.c
Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand All @@ -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 &&
Expand All @@ -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;

Expand All @@ -2271,6 +2275,9 @@ static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo)
__free_page(indirect_page);
}
}

memalloc_noio_restore(memflags);

return -ENOMEM;
}

Expand Down

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