fs/file.c: replace alloc_fdmem() with kvmalloc() alternative

There is no real reason to duplicate kvmalloc* helpers so drop
alloc_fdmem and replace it with the appropriate library function.

Link: http://lkml.kernel.org/r/20170531155145.17111-2-mhocko@kernel.orgSigned-off-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/file.c

@@ -30,21 +30,6 @@ unsigned int sysctl_nr_open_min = BITS_PER_LONG;
 unsigned int sysctl_nr_open_max =
 	__const_min(INT_MAX, ~(size_t)0/sizeof(void *)) & -BITS_PER_LONG;
 
-static void *alloc_fdmem(size_t size)
-{
-	/*
-	 * Very large allocations can stress page reclaim, so fall back to
-	 * vmalloc() if the allocation size will be considered "large" by the VM.
-	 */
-	if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
-		void *data = kmalloc(size, GFP_KERNEL_ACCOUNT |
-				     __GFP_NOWARN | __GFP_NORETRY);
-		if (data != NULL)
-			return data;
-	}
-	return __vmalloc(size, GFP_KERNEL_ACCOUNT, PAGE_KERNEL);
-}
-
 static void __free_fdtable(struct fdtable *fdt)
 {
 	kvfree(fdt->fd);
@@ -131,13 +116,14 @@ static struct fdtable * alloc_fdtable(unsigned int nr)
 	if (!fdt)
 		goto out;
 	fdt->max_fds = nr;
-	data = alloc_fdmem(nr * sizeof(struct file *));
+	data = kvmalloc_array(nr, sizeof(struct file *), GFP_KERNEL_ACCOUNT);
 	if (!data)
 		goto out_fdt;
 	fdt->fd = data;
 
-	data = alloc_fdmem(max_t(size_t,
-				 2 * nr / BITS_PER_BYTE + BITBIT_SIZE(nr), L1_CACHE_BYTES));
+	data = kvmalloc(max_t(size_t,
+				 2 * nr / BITS_PER_BYTE + BITBIT_SIZE(nr), L1_CACHE_BYTES),
+				 GFP_KERNEL_ACCOUNT);
 	if (!data)
 		goto out_arr;
 	fdt->open_fds = data;