1 files changed, 20 insertions, 23 deletions

diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
index a02cfb9e3bc..844e288b957 100644
--- a/fs/xfs/kmem.c
+++ b/fs/xfs/kmem.c
@@ -63,25 +63,33 @@ kmem_alloc(size_t size, xfs_km_flags_t flags)
 }
 
 void *
-kmem_zalloc(size_t size, xfs_km_flags_t flags)
-{
-	void	*ptr;
-
-	ptr = kmem_alloc(size, flags);
-	if (ptr)
-		memset((char *)ptr, 0, (int)size);
-	return ptr;
-}
-
-void *
 kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
 {
+	unsigned noio_flag = 0;
 	void	*ptr;
+	gfp_t	lflags;
 
 	ptr = kmem_zalloc(size, flags | KM_MAYFAIL);
 	if (ptr)
 		return ptr;
-	return vzalloc(size);
+
+	/*
+	 * __vmalloc() will allocate data pages and auxillary structures (e.g.
+	 * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
+	 * here. Hence we need to tell memory reclaim that we are in such a
+	 * context via PF_MEMALLOC_NOIO to prevent memory reclaim re-entering
+	 * the filesystem here and potentially deadlocking.
+	 */
+	if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
+		noio_flag = memalloc_noio_save();
+
+	lflags = kmem_flags_convert(flags);
+	ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
+
+	if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
+		memalloc_noio_restore(noio_flag);
+
+	return ptr;
 }
 
 void
@@ -128,14 +136,3 @@ kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
 		congestion_wait(BLK_RW_ASYNC, HZ/50);
 	} while (1);
 }
-
-void *
-kmem_zone_zalloc(kmem_zone_t *zone, xfs_km_flags_t flags)
-{
-	void	*ptr;
-
-	ptr = kmem_zone_alloc(zone, flags);
-	if (ptr)
-		memset((char *)ptr, 0, kmem_cache_size(zone));
-	return ptr;
-}