// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2000-2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*/
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#include "xfs.h"
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#include <linux/backing-dev.h>
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#include "xfs_message.h"
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#include "xfs_trace.h"
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void *
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kmem_alloc(size_t size, xfs_km_flags_t flags)
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{
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int retries = 0;
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gfp_t lflags = kmem_flags_convert(flags);
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void *ptr;
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trace_kmem_alloc(size, flags, _RET_IP_);
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do {
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ptr = kmalloc(size, lflags);
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if (ptr || (flags & KM_MAYFAIL))
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return ptr;
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if (!(++retries % 100))
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xfs_err(NULL,
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"%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
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current->comm, current->pid,
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(unsigned int)size, __func__, lflags);
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congestion_wait(BLK_RW_ASYNC, HZ/50);
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} while (1);
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}
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/*
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* __vmalloc() will allocate data pages and auxiliary structures (e.g.
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* pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context here. Hence
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* we need to tell memory reclaim that we are in such a context via
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* PF_MEMALLOC_NOFS to prevent memory reclaim re-entering the filesystem here
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* and potentially deadlocking.
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*/
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static void *
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__kmem_vmalloc(size_t size, xfs_km_flags_t flags)
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{
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unsigned nofs_flag = 0;
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void *ptr;
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gfp_t lflags = kmem_flags_convert(flags);
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if (flags & KM_NOFS)
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nofs_flag = memalloc_nofs_save();
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ptr = __vmalloc(size, lflags);
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if (flags & KM_NOFS)
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memalloc_nofs_restore(nofs_flag);
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return ptr;
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}
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/*
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* Same as kmem_alloc_large, except we guarantee the buffer returned is aligned
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* to the @align_mask. We only guarantee alignment up to page size, we'll clamp
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* alignment at page size if it is larger. vmalloc always returns a PAGE_SIZE
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* aligned region.
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*/
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void *
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kmem_alloc_io(size_t size, int align_mask, xfs_km_flags_t flags)
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{
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void *ptr;
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trace_kmem_alloc_io(size, flags, _RET_IP_);
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if (WARN_ON_ONCE(align_mask >= PAGE_SIZE))
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align_mask = PAGE_SIZE - 1;
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ptr = kmem_alloc(size, flags | KM_MAYFAIL);
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if (ptr) {
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if (!((uintptr_t)ptr & align_mask))
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return ptr;
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kfree(ptr);
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}
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return __kmem_vmalloc(size, flags);
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}
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void *
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kmem_alloc_large(size_t size, xfs_km_flags_t flags)
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{
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void *ptr;
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trace_kmem_alloc_large(size, flags, _RET_IP_);
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ptr = kmem_alloc(size, flags | KM_MAYFAIL);
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if (ptr)
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return ptr;
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return __kmem_vmalloc(size, flags);
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}
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