1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * malloc.h - NTFS kernel memory handling. Part of the Linux-NTFS project.
4 *
5 * Copyright (c) 2001-2005 Anton Altaparmakov
6 */
7
8#ifndef _LINUX_NTFS_MALLOC_H
9#define _LINUX_NTFS_MALLOC_H
10
11#include <linux/vmalloc.h>
12#include <linux/slab.h>
13#include <linux/highmem.h>
14
15/**
16 * __ntfs_malloc - allocate memory in multiples of pages
17 * @size: number of bytes to allocate
18 * @gfp_mask: extra flags for the allocator
19 *
20 * Internal function. You probably want ntfs_malloc_nofs()...
21 *
22 * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
23 * returns a pointer to the allocated memory.
24 *
25 * If there was insufficient memory to complete the request, return NULL.
26 * Depending on @gfp_mask the allocation may be guaranteed to succeed.
27 */
28static inline void *__ntfs_malloc(unsigned long size, gfp_t gfp_mask)
29{
30 if (likely(size <= PAGE_SIZE)) {
31 BUG_ON(!size);
32 /* kmalloc() has per-CPU caches so is faster for now. */
33 return kmalloc(PAGE_SIZE, flags: gfp_mask & ~__GFP_HIGHMEM);
34 /* return (void *)__get_free_page(gfp_mask); */
35 }
36 if (likely((size >> PAGE_SHIFT) < totalram_pages()))
37 return __vmalloc(size, gfp_mask);
38 return NULL;
39}
40
41/**
42 * ntfs_malloc_nofs - allocate memory in multiples of pages
43 * @size: number of bytes to allocate
44 *
45 * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
46 * returns a pointer to the allocated memory.
47 *
48 * If there was insufficient memory to complete the request, return NULL.
49 */
50static inline void *ntfs_malloc_nofs(unsigned long size)
51{
52 return __ntfs_malloc(size, GFP_NOFS | __GFP_HIGHMEM);
53}
54
55/**
56 * ntfs_malloc_nofs_nofail - allocate memory in multiples of pages
57 * @size: number of bytes to allocate
58 *
59 * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and
60 * returns a pointer to the allocated memory.
61 *
62 * This function guarantees that the allocation will succeed. It will sleep
63 * for as long as it takes to complete the allocation.
64 *
65 * If there was insufficient memory to complete the request, return NULL.
66 */
67static inline void *ntfs_malloc_nofs_nofail(unsigned long size)
68{
69 return __ntfs_malloc(size, GFP_NOFS | __GFP_HIGHMEM | __GFP_NOFAIL);
70}
71
72static inline void ntfs_free(void *addr)
73{
74 kvfree(addr);
75}
76
77#endif /* _LINUX_NTFS_MALLOC_H */
78

source code of linux/fs/ntfs/malloc.h