xref: /openbmc/linux/fs/xfs/kmem.c (revision 2169e6da)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #include <linux/sched/mm.h>
7 #include <linux/backing-dev.h>
8 #include "kmem.h"
9 #include "xfs_message.h"
10 
11 void *
12 kmem_alloc(size_t size, xfs_km_flags_t flags)
13 {
14 	int	retries = 0;
15 	gfp_t	lflags = kmem_flags_convert(flags);
16 	void	*ptr;
17 
18 	do {
19 		ptr = kmalloc(size, lflags);
20 		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
21 			return ptr;
22 		if (!(++retries % 100))
23 			xfs_err(NULL,
24 	"%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
25 				current->comm, current->pid,
26 				(unsigned int)size, __func__, lflags);
27 		congestion_wait(BLK_RW_ASYNC, HZ/50);
28 	} while (1);
29 }
30 
31 void *
32 kmem_alloc_large(size_t size, xfs_km_flags_t flags)
33 {
34 	unsigned nofs_flag = 0;
35 	void	*ptr;
36 	gfp_t	lflags;
37 
38 	ptr = kmem_alloc(size, flags | KM_MAYFAIL);
39 	if (ptr)
40 		return ptr;
41 
42 	/*
43 	 * __vmalloc() will allocate data pages and auxillary structures (e.g.
44 	 * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
45 	 * here. Hence we need to tell memory reclaim that we are in such a
46 	 * context via PF_MEMALLOC_NOFS to prevent memory reclaim re-entering
47 	 * the filesystem here and potentially deadlocking.
48 	 */
49 	if (flags & KM_NOFS)
50 		nofs_flag = memalloc_nofs_save();
51 
52 	lflags = kmem_flags_convert(flags);
53 	ptr = __vmalloc(size, lflags, PAGE_KERNEL);
54 
55 	if (flags & KM_NOFS)
56 		memalloc_nofs_restore(nofs_flag);
57 
58 	return ptr;
59 }
60 
61 void *
62 kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
63 {
64 	int	retries = 0;
65 	gfp_t	lflags = kmem_flags_convert(flags);
66 	void	*ptr;
67 
68 	do {
69 		ptr = krealloc(old, newsize, lflags);
70 		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
71 			return ptr;
72 		if (!(++retries % 100))
73 			xfs_err(NULL,
74 	"%s(%u) possible memory allocation deadlock size %zu in %s (mode:0x%x)",
75 				current->comm, current->pid,
76 				newsize, __func__, lflags);
77 		congestion_wait(BLK_RW_ASYNC, HZ/50);
78 	} while (1);
79 }
80 
81 void *
82 kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
83 {
84 	int	retries = 0;
85 	gfp_t	lflags = kmem_flags_convert(flags);
86 	void	*ptr;
87 
88 	do {
89 		ptr = kmem_cache_alloc(zone, lflags);
90 		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
91 			return ptr;
92 		if (!(++retries % 100))
93 			xfs_err(NULL,
94 		"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
95 				current->comm, current->pid,
96 				__func__, lflags);
97 		congestion_wait(BLK_RW_ASYNC, HZ/50);
98 	} while (1);
99 }
100