1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4*4882a593Smuzhiyun * All Rights Reserved.
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun #include "xfs.h"
7*4882a593Smuzhiyun #include <linux/backing-dev.h>
8*4882a593Smuzhiyun #include "xfs_message.h"
9*4882a593Smuzhiyun #include "xfs_trace.h"
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun void *
kmem_alloc(size_t size,xfs_km_flags_t flags)12*4882a593Smuzhiyun kmem_alloc(size_t size, xfs_km_flags_t flags)
13*4882a593Smuzhiyun {
14*4882a593Smuzhiyun int retries = 0;
15*4882a593Smuzhiyun gfp_t lflags = kmem_flags_convert(flags);
16*4882a593Smuzhiyun void *ptr;
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun trace_kmem_alloc(size, flags, _RET_IP_);
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun do {
21*4882a593Smuzhiyun ptr = kmalloc(size, lflags);
22*4882a593Smuzhiyun if (ptr || (flags & KM_MAYFAIL))
23*4882a593Smuzhiyun return ptr;
24*4882a593Smuzhiyun if (!(++retries % 100))
25*4882a593Smuzhiyun xfs_err(NULL,
26*4882a593Smuzhiyun "%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
27*4882a593Smuzhiyun current->comm, current->pid,
28*4882a593Smuzhiyun (unsigned int)size, __func__, lflags);
29*4882a593Smuzhiyun congestion_wait(BLK_RW_ASYNC, HZ/50);
30*4882a593Smuzhiyun } while (1);
31*4882a593Smuzhiyun }
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun /*
35*4882a593Smuzhiyun * __vmalloc() will allocate data pages and auxiliary structures (e.g.
36*4882a593Smuzhiyun * pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context here. Hence
37*4882a593Smuzhiyun * we need to tell memory reclaim that we are in such a context via
38*4882a593Smuzhiyun * PF_MEMALLOC_NOFS to prevent memory reclaim re-entering the filesystem here
39*4882a593Smuzhiyun * and potentially deadlocking.
40*4882a593Smuzhiyun */
41*4882a593Smuzhiyun static void *
__kmem_vmalloc(size_t size,xfs_km_flags_t flags)42*4882a593Smuzhiyun __kmem_vmalloc(size_t size, xfs_km_flags_t flags)
43*4882a593Smuzhiyun {
44*4882a593Smuzhiyun unsigned nofs_flag = 0;
45*4882a593Smuzhiyun void *ptr;
46*4882a593Smuzhiyun gfp_t lflags = kmem_flags_convert(flags);
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun if (flags & KM_NOFS)
49*4882a593Smuzhiyun nofs_flag = memalloc_nofs_save();
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun ptr = __vmalloc(size, lflags);
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun if (flags & KM_NOFS)
54*4882a593Smuzhiyun memalloc_nofs_restore(nofs_flag);
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun return ptr;
57*4882a593Smuzhiyun }
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun /*
60*4882a593Smuzhiyun * Same as kmem_alloc_large, except we guarantee the buffer returned is aligned
61*4882a593Smuzhiyun * to the @align_mask. We only guarantee alignment up to page size, we'll clamp
62*4882a593Smuzhiyun * alignment at page size if it is larger. vmalloc always returns a PAGE_SIZE
63*4882a593Smuzhiyun * aligned region.
64*4882a593Smuzhiyun */
65*4882a593Smuzhiyun void *
kmem_alloc_io(size_t size,int align_mask,xfs_km_flags_t flags)66*4882a593Smuzhiyun kmem_alloc_io(size_t size, int align_mask, xfs_km_flags_t flags)
67*4882a593Smuzhiyun {
68*4882a593Smuzhiyun void *ptr;
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun trace_kmem_alloc_io(size, flags, _RET_IP_);
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun if (WARN_ON_ONCE(align_mask >= PAGE_SIZE))
73*4882a593Smuzhiyun align_mask = PAGE_SIZE - 1;
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun ptr = kmem_alloc(size, flags | KM_MAYFAIL);
76*4882a593Smuzhiyun if (ptr) {
77*4882a593Smuzhiyun if (!((uintptr_t)ptr & align_mask))
78*4882a593Smuzhiyun return ptr;
79*4882a593Smuzhiyun kfree(ptr);
80*4882a593Smuzhiyun }
81*4882a593Smuzhiyun return __kmem_vmalloc(size, flags);
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun void *
kmem_alloc_large(size_t size,xfs_km_flags_t flags)85*4882a593Smuzhiyun kmem_alloc_large(size_t size, xfs_km_flags_t flags)
86*4882a593Smuzhiyun {
87*4882a593Smuzhiyun void *ptr;
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun trace_kmem_alloc_large(size, flags, _RET_IP_);
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun ptr = kmem_alloc(size, flags | KM_MAYFAIL);
92*4882a593Smuzhiyun if (ptr)
93*4882a593Smuzhiyun return ptr;
94*4882a593Smuzhiyun return __kmem_vmalloc(size, flags);
95*4882a593Smuzhiyun }
96