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// 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);
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);
}
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