1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17 */
18#include <linux/mm.h>
19#include <linux/highmem.h>
20#include <linux/slab.h>
21#include <linux/swap.h>
22#include <linux/blkdev.h>
23#include <linux/backing-dev.h>
24#include "kmem.h"
25#include "xfs_message.h"
26
27/*
28 * Greedy allocation.  May fail and may return vmalloced memory.
29 */
30void *
31kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize)
32{
33	void		*ptr;
34	size_t		kmsize = maxsize;
35
36	while (!(ptr = vzalloc(kmsize))) {
37		if ((kmsize >>= 1) <= minsize)
38			kmsize = minsize;
39	}
40	if (ptr)
41		*size = kmsize;
42	return ptr;
43}
44
45void *
46kmem_alloc(size_t size, xfs_km_flags_t flags)
47{
48	int	retries = 0;
49	gfp_t	lflags = kmem_flags_convert(flags);
50	void	*ptr;
51
52	do {
53		ptr = kmalloc(size, lflags);
54		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
55			return ptr;
56		if (!(++retries % 100))
57			xfs_err(NULL,
58		"possible memory allocation deadlock in %s (mode:0x%x)",
59					__func__, lflags);
60		congestion_wait(BLK_RW_ASYNC, HZ/50);
61	} while (1);
62}
63
64void *
65kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
66{
67	unsigned noio_flag = 0;
68	void	*ptr;
69	gfp_t	lflags;
70
71	ptr = kmem_zalloc(size, flags | KM_MAYFAIL);
72	if (ptr)
73		return ptr;
74
75	/*
76	 * __vmalloc() will allocate data pages and auxillary structures (e.g.
77	 * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
78	 * here. Hence we need to tell memory reclaim that we are in such a
79	 * context via PF_MEMALLOC_NOIO to prevent memory reclaim re-entering
80	 * the filesystem here and potentially deadlocking.
81	 */
82	if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
83		noio_flag = memalloc_noio_save();
84
85	lflags = kmem_flags_convert(flags);
86	ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
87
88	if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
89		memalloc_noio_restore(noio_flag);
90
91	return ptr;
92}
93
94void *
95kmem_realloc(const void *ptr, size_t newsize, size_t oldsize,
96	     xfs_km_flags_t flags)
97{
98	void	*new;
99
100	new = kmem_alloc(newsize, flags);
101	if (ptr) {
102		if (new)
103			memcpy(new, ptr,
104				((oldsize < newsize) ? oldsize : newsize));
105		kmem_free(ptr);
106	}
107	return new;
108}
109
110void *
111kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
112{
113	int	retries = 0;
114	gfp_t	lflags = kmem_flags_convert(flags);
115	void	*ptr;
116
117	do {
118		ptr = kmem_cache_alloc(zone, lflags);
119		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
120			return ptr;
121		if (!(++retries % 100))
122			xfs_err(NULL,
123		"possible memory allocation deadlock in %s (mode:0x%x)",
124					__func__, lflags);
125		congestion_wait(BLK_RW_ASYNC, HZ/50);
126	} while (1);
127}
128