From: Mikulas Patocka Date: Wed, 10 Jul 2013 22:41:15 +0000 (+0100) Subject: dm ioctl: set noio flag to avoid __vmalloc deadlock X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1c0e883e86ece31880fac2f84b260545d66a39e0;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git dm ioctl: set noio flag to avoid __vmalloc deadlock Set noio flag while calling __vmalloc() because it doesn't fully respect gfp flags to avoid a possible deadlock (see commit 502624bdad3dba45dfaacaf36b7d83e39e74b2d2). This should be backported to stable kernels 3.8 and newer. The kernel 3.8 doesn't have memalloc_noio_save(), so we should set and restore process flag PF_MEMALLOC instead. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Alasdair G Kergon --- diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index aa04f0224642..81a79b739e97 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1644,7 +1644,10 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern } if (!dmi) { + unsigned noio_flag; + noio_flag = memalloc_noio_save(); dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH, PAGE_KERNEL); + memalloc_noio_restore(noio_flag); if (dmi) *param_flags |= DM_PARAMS_VMALLOC; }