dm ioctl: restore __GFP_HIGH in copy_params()

Commit d224e9381897 ("drivers/md/dm-ioctl.c: use kvmalloc rather than
opencoded variant") left out the __GFP_HIGH flag when converting from
__vmalloc to kvmalloc.  This can cause the DM ioctl to fail in some low
memory situations where it wouldn't have failed earlier.  Add __GFP_HIGH
back to avoid any potential regression.

Fixes: d224e9381897 ("drivers/md/dm-ioctl.c: use kvmalloc rather than opencoded variant")
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 0555b4410e05..41852ae287a5 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1710,12 +1710,13 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern
         }
 
         /*
-         * Try to avoid low memory issues when a device is suspended.
+         * Use __GFP_HIGH to avoid low memory issues when a device is
+         * suspended and the ioctl is needed to resume it.
          * Use kmalloc() rather than vmalloc() when we can.
          */
         dmi = NULL;
         noio_flag = memalloc_noio_save();
-        dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL);
+        dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL | __GFP_HIGH);
         memalloc_noio_restore(noio_flag);
 
         if (!dmi) {