1 files changed, 23 insertions, 1 deletions

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index c6083132c4b8..0387e05cdb98 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -319,6 +319,9 @@ static void __cache_size_refresh(void)
 static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask,
                                enum data_mode *data_mode)
 {
+        unsigned noio_flag;
+        void *ptr;
+
         if (c->block_size <= DM_BUFIO_BLOCK_SIZE_SLAB_LIMIT) {
                 *data_mode = DATA_MODE_SLAB;
                 return kmem_cache_alloc(DM_BUFIO_CACHE(c), gfp_mask);
@@ -332,7 +335,26 @@ static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask,
         }
 
         *data_mode = DATA_MODE_VMALLOC;
-        return __vmalloc(c->block_size, gfp_mask, PAGE_KERNEL);
+
+        /*
+         * __vmalloc allocates the data pages and auxiliary structures with
+         * gfp_flags that were specified, but pagetables are always allocated
+         * with GFP_KERNEL, no matter what was specified as gfp_mask.
+         *
+         * Consequently, we must set per-process flag PF_MEMALLOC_NOIO so that
+         * all allocations done by this process (including pagetables) are done
+         * as if GFP_NOIO was specified.
+         */
+
+        if (gfp_mask & __GFP_NORETRY)
+                noio_flag = memalloc_noio_save();
+
+        ptr = __vmalloc(c->block_size, gfp_mask, PAGE_KERNEL);
+
+        if (gfp_mask & __GFP_NORETRY)
+                memalloc_noio_restore(noio_flag);
+
+        return ptr;
 }
 
 /*