xref: /openbmc/linux/fs/xfs/kmem.c (revision 293d5b43)
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  */
30 void *
31 kmem_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 
45 void *
46 kmem_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 	"%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
59 				current->comm, current->pid,
60 				(unsigned int)size, __func__, lflags);
61 		congestion_wait(BLK_RW_ASYNC, HZ/50);
62 	} while (1);
63 }
64 
65 void *
66 kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
67 {
68 	unsigned noio_flag = 0;
69 	void	*ptr;
70 	gfp_t	lflags;
71 
72 	ptr = kmem_zalloc(size, flags | KM_MAYFAIL);
73 	if (ptr)
74 		return ptr;
75 
76 	/*
77 	 * __vmalloc() will allocate data pages and auxillary structures (e.g.
78 	 * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
79 	 * here. Hence we need to tell memory reclaim that we are in such a
80 	 * context via PF_MEMALLOC_NOIO to prevent memory reclaim re-entering
81 	 * the filesystem here and potentially deadlocking.
82 	 */
83 	if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
84 		noio_flag = memalloc_noio_save();
85 
86 	lflags = kmem_flags_convert(flags);
87 	ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
88 
89 	if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
90 		memalloc_noio_restore(noio_flag);
91 
92 	return ptr;
93 }
94 
95 void *
96 kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
97 {
98 	int	retries = 0;
99 	gfp_t	lflags = kmem_flags_convert(flags);
100 	void	*ptr;
101 
102 	do {
103 		ptr = krealloc(old, newsize, lflags);
104 		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
105 			return ptr;
106 		if (!(++retries % 100))
107 			xfs_err(NULL,
108 	"%s(%u) possible memory allocation deadlock size %zu in %s (mode:0x%x)",
109 				current->comm, current->pid,
110 				newsize, __func__, lflags);
111 		congestion_wait(BLK_RW_ASYNC, HZ/50);
112 	} while (1);
113 }
114 
115 void *
116 kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
117 {
118 	int	retries = 0;
119 	gfp_t	lflags = kmem_flags_convert(flags);
120 	void	*ptr;
121 
122 	do {
123 		ptr = kmem_cache_alloc(zone, lflags);
124 		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
125 			return ptr;
126 		if (!(++retries % 100))
127 			xfs_err(NULL,
128 		"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
129 				current->comm, current->pid,
130 				__func__, lflags);
131 		congestion_wait(BLK_RW_ASYNC, HZ/50);
132 	} while (1);
133 }
134