aboutsummaryrefslogtreecommitdiff
path: root/fs/xfs/kmem.c
blob: 1da94237a8cf1e55a39786ab3c7185b8fd516001 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#include "xfs.h"
#include <linux/backing-dev.h>
#include "xfs_message.h"
#include "xfs_trace.h"

void *
kmem_alloc(size_t size, xfs_km_flags_t flags)
{
	int	retries = 0;
	gfp_t	lflags = kmem_flags_convert(flags);
	void	*ptr;

	trace_kmem_alloc(size, flags, _RET_IP_);

	do {
		ptr = kmalloc(size, lflags);
		if (ptr || (flags & KM_MAYFAIL))
			return ptr;
		if (!(++retries % 100))
			xfs_err(NULL,
	"%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
				current->comm, current->pid,
				(unsigned int)size, __func__, lflags);
		congestion_wait(BLK_RW_ASYNC, HZ/50);
	} while (1);
}


/*
 * __vmalloc() will allocate data pages and auxiliary 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_NOFS to prevent memory reclaim re-entering the filesystem here
 * and potentially deadlocking.
 */
static void *
__kmem_vmalloc(size_t size, xfs_km_flags_t flags)
{
	unsigned nofs_flag = 0;
	void	*ptr;
	gfp_t	lflags = kmem_flags_convert(flags);

	if (flags & KM_NOFS)
		nofs_flag = memalloc_nofs_save();

	ptr = __vmalloc(size, lflags, PAGE_KERNEL);

	if (flags & KM_NOFS)
		memalloc_nofs_restore(nofs_flag);

	return ptr;
}

/*
 * Same as kmem_alloc_large, except we guarantee the buffer returned is aligned
 * to the @align_mask. We only guarantee alignment up to page size, we'll clamp
 * alignment at page size if it is larger. vmalloc always returns a PAGE_SIZE
 * aligned region.
 */
void *
kmem_alloc_io(size_t size, int align_mask, xfs_km_flags_t flags)
{
	void	*ptr;

	trace_kmem_alloc_io(size, flags, _RET_IP_);

	if (WARN_ON_ONCE(align_mask >= PAGE_SIZE))
		align_mask = PAGE_SIZE - 1;

	ptr = kmem_alloc(size, flags | KM_MAYFAIL);
	if (ptr) {
		if (!((uintptr_t)ptr & align_mask))
			return ptr;
		kfree(ptr);
	}
	return __kmem_vmalloc(size, flags);
}

void *
kmem_alloc_large(size_t size, xfs_km_flags_t flags)
{
	void	*ptr;

	trace_kmem_alloc_large(size, flags, _RET_IP_);

	ptr = kmem_alloc(size, flags | KM_MAYFAIL);
	if (ptr)
		return ptr;
	return __kmem_vmalloc(size, flags);
}

void *
kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
{
	int	retries = 0;
	gfp_t	lflags = kmem_flags_convert(flags);
	void	*ptr;

	trace_kmem_realloc(newsize, flags, _RET_IP_);

	do {
		ptr = krealloc(old, newsize, lflags);
		if (ptr || (flags & KM_MAYFAIL))
			return ptr;
		if (!(++retries % 100))
			xfs_err(NULL,
	"%s(%u) possible memory allocation deadlock size %zu in %s (mode:0x%x)",
				current->comm, current->pid,
				newsize, __func__, lflags);
		congestion_wait(BLK_RW_ASYNC, HZ/50);
	} while (1);
}

void *
kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
{
	int	retries = 0;
	gfp_t	lflags = kmem_flags_convert(flags);
	void	*ptr;

	trace_kmem_zone_alloc(kmem_cache_size(zone), flags, _RET_IP_);
	do {
		ptr = kmem_cache_alloc(zone, lflags);
		if (ptr || (flags & KM_MAYFAIL))
			return ptr;
		if (!(++retries % 100))
			xfs_err(NULL,
		"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
				current->comm, current->pid,
				__func__, lflags);
		congestion_wait(BLK_RW_ASYNC, HZ/50);
	} while (1);
}