xref: /openbmc/linux/fs/xfs/kmem.c (revision 4cff79e9)
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/sched/mm.h>
20 #include <linux/highmem.h>
21 #include <linux/slab.h>
22 #include <linux/swap.h>
23 #include <linux/blkdev.h>
24 #include <linux/backing-dev.h>
25 #include "kmem.h"
26 #include "xfs_message.h"
27 
28 void *
29 kmem_alloc(size_t size, xfs_km_flags_t flags)
30 {
31 	int	retries = 0;
32 	gfp_t	lflags = kmem_flags_convert(flags);
33 	void	*ptr;
34 
35 	do {
36 		ptr = kmalloc(size, lflags);
37 		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
38 			return ptr;
39 		if (!(++retries % 100))
40 			xfs_err(NULL,
41 	"%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
42 				current->comm, current->pid,
43 				(unsigned int)size, __func__, lflags);
44 		congestion_wait(BLK_RW_ASYNC, HZ/50);
45 	} while (1);
46 }
47 
48 void *
49 kmem_alloc_large(size_t size, xfs_km_flags_t flags)
50 {
51 	unsigned nofs_flag = 0;
52 	void	*ptr;
53 	gfp_t	lflags;
54 
55 	ptr = kmem_alloc(size, flags | KM_MAYFAIL);
56 	if (ptr)
57 		return ptr;
58 
59 	/*
60 	 * __vmalloc() will allocate data pages and auxillary structures (e.g.
61 	 * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
62 	 * here. Hence we need to tell memory reclaim that we are in such a
63 	 * context via PF_MEMALLOC_NOFS to prevent memory reclaim re-entering
64 	 * the filesystem here and potentially deadlocking.
65 	 */
66 	if (flags & KM_NOFS)
67 		nofs_flag = memalloc_nofs_save();
68 
69 	lflags = kmem_flags_convert(flags);
70 	ptr = __vmalloc(size, lflags, PAGE_KERNEL);
71 
72 	if (flags & KM_NOFS)
73 		memalloc_nofs_restore(nofs_flag);
74 
75 	return ptr;
76 }
77 
78 void *
79 kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
80 {
81 	int	retries = 0;
82 	gfp_t	lflags = kmem_flags_convert(flags);
83 	void	*ptr;
84 
85 	do {
86 		ptr = krealloc(old, newsize, lflags);
87 		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
88 			return ptr;
89 		if (!(++retries % 100))
90 			xfs_err(NULL,
91 	"%s(%u) possible memory allocation deadlock size %zu in %s (mode:0x%x)",
92 				current->comm, current->pid,
93 				newsize, __func__, lflags);
94 		congestion_wait(BLK_RW_ASYNC, HZ/50);
95 	} while (1);
96 }
97 
98 void *
99 kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
100 {
101 	int	retries = 0;
102 	gfp_t	lflags = kmem_flags_convert(flags);
103 	void	*ptr;
104 
105 	do {
106 		ptr = kmem_cache_alloc(zone, lflags);
107 		if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
108 			return ptr;
109 		if (!(++retries % 100))
110 			xfs_err(NULL,
111 		"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
112 				current->comm, current->pid,
113 				__func__, lflags);
114 		congestion_wait(BLK_RW_ASYNC, HZ/50);
115 	} while (1);
116 }
117