From: Junaid Shahid <junaids@google.com>
Date: Thu, 18 May 2017 19:00:51 +0000 (-0700)
Subject: dm ioctl: restore __GFP_HIGH in copy_params()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=8c1e2162f27b319da913683143c0c6c09b083ebb;p=linux.git

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>
---

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 0555b4410e059..41852ae287a58 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) {