mirror of
https://github.com/kdave/btrfs-progs
synced 2024-12-15 02:45:44 +00:00
95d3f20b51
This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference
259 lines
6.1 KiB
C
259 lines
6.1 KiB
C
/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#ifndef __KERNCOMPAT
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#define __KERNCOMPAT
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#include <stdio.h>
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#include <stdlib.h>
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#include <errno.h>
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#include <string.h>
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#include <endian.h>
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#include <byteswap.h>
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#include <assert.h>
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#ifndef READ
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#define READ 0
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#define WRITE 1
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#define READA 2
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#endif
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#define gfp_t int
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#define get_cpu_var(p) (p)
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#define __get_cpu_var(p) (p)
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#define BITS_PER_LONG (sizeof(long) * 8)
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#define __GFP_BITS_SHIFT 20
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#define __GFP_BITS_MASK ((int)((1 << __GFP_BITS_SHIFT) - 1))
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#define GFP_KERNEL 0
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#define GFP_NOFS 0
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#define __read_mostly
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#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
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#define ULONG_MAX (~0UL)
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#define BUG() abort()
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#ifdef __CHECKER__
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#define __force __attribute__((force))
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#define __bitwise__ __attribute__((bitwise))
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#else
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#define __force
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#define __bitwise__
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#endif
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#ifndef __CHECKER__
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#include <asm/types.h>
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typedef __u32 u32;
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typedef __u64 u64;
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typedef __u16 u16;
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typedef __u8 u8;
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#else
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typedef unsigned int u32;
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typedef unsigned int __u32;
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typedef unsigned long long u64;
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typedef unsigned char u8;
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typedef unsigned short u16;
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#endif
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struct vma_shared { int prio_tree_node; };
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struct vm_area_struct {
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unsigned long vm_pgoff;
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unsigned long vm_start;
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unsigned long vm_end;
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struct vma_shared shared;
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};
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struct page {
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unsigned long index;
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};
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struct mutex {
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unsigned long lock;
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};
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#define mutex_init(m) \
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do { \
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(m)->lock = 1; \
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} while (0)
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static inline void mutex_lock(struct mutex *m)
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{
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m->lock--;
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}
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static inline void mutex_unlock(struct mutex *m)
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{
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m->lock++;
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}
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static inline int mutex_is_locked(struct mutex *m)
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{
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return (m->lock != 1);
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}
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#define cond_resched() do { } while (0)
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#define preempt_enable() do { } while (0)
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#define preempt_disable() do { } while (0)
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#define BITOP_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
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#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
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/**
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* __set_bit - Set a bit in memory
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* @nr: the bit to set
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* @addr: the address to start counting from
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*
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* Unlike set_bit(), this function is non-atomic and may be reordered.
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* If it's called on the same region of memory simultaneously, the effect
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* may be that only one operation succeeds.
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*/
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static inline void __set_bit(int nr, volatile unsigned long *addr)
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{
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unsigned long mask = BITOP_MASK(nr);
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unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
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*p |= mask;
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}
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static inline void __clear_bit(int nr, volatile unsigned long *addr)
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{
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unsigned long mask = BITOP_MASK(nr);
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unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
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*p &= ~mask;
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}
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/**
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* test_bit - Determine whether a bit is set
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* @nr: bit number to test
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* @addr: Address to start counting from
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*/
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static inline int test_bit(int nr, const volatile unsigned long *addr)
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{
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return 1UL & (addr[BITOP_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
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}
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/*
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* error pointer
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*/
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#define MAX_ERRNO 4095
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#define IS_ERR_VALUE(x) ((x) >= (unsigned long)-MAX_ERRNO)
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static inline void *ERR_PTR(long error)
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{
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return (void *) error;
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}
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static inline long PTR_ERR(const void *ptr)
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{
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return (long) ptr;
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}
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static inline long IS_ERR(const void *ptr)
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{
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return IS_ERR_VALUE((unsigned long)ptr);
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}
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/*
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* max/min macro
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*/
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#define min(x,y) ({ \
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typeof(x) _x = (x); \
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typeof(y) _y = (y); \
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(void) (&_x == &_y); \
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_x < _y ? _x : _y; })
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#define max(x,y) ({ \
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typeof(x) _x = (x); \
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typeof(y) _y = (y); \
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(void) (&_x == &_y); \
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_x > _y ? _x : _y; })
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#define min_t(type,x,y) \
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({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
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#define max_t(type,x,y) \
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({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
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/*
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* printk
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*/
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#define printk(fmt, args...) fprintf(stderr, fmt, ##args)
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#define KERN_CRIT ""
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#define KERN_ERR ""
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/*
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* kmalloc/kfree
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*/
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#define kmalloc(x, y) malloc(x)
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#define kzalloc(x, y) calloc(1, x)
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#define kstrdup(x, y) strdup(x)
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#define kfree(x) free(x)
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#define BUG_ON(c) assert(!(c))
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#define WARN_ON(c) assert(!(c))
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#undef offsetof
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#ifdef __compiler_offsetof
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#define offsetof(TYPE,MEMBER) __compiler_offsetof(TYPE,MEMBER)
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#else
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#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
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#endif
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#define container_of(ptr, type, member) ({ \
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const typeof( ((type *)0)->member ) *__mptr = (ptr); \
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(type *)( (char *)__mptr - offsetof(type,member) );})
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#ifdef __CHECKER__
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#define __CHECK_ENDIAN__
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#define __bitwise __bitwise__
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#else
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#define __bitwise
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#endif
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typedef u16 __bitwise __le16;
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typedef u16 __bitwise __be16;
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typedef u32 __bitwise __le32;
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typedef u32 __bitwise __be32;
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typedef u64 __bitwise __le64;
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typedef u64 __bitwise __be64;
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/* Macros to generate set/get funcs for the struct fields
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* assume there is a lefoo_to_cpu for every type, so lets make a simple
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* one for u8:
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*/
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#define le8_to_cpu(v) (v)
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#define cpu_to_le8(v) (v)
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#define __le8 u8
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#if __BYTE_ORDER == __BIG_ENDIAN
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#define cpu_to_le64(x) ((__force __le64)(u64)(bswap_64(x)))
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#define le64_to_cpu(x) ((__force u64)(__le64)(bswap_64(x)))
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#define cpu_to_le32(x) ((__force __le32)(u32)(bswap_32(x)))
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#define le32_to_cpu(x) ((__force u32)(__le32)(bswap_32(x)))
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#define cpu_to_le16(x) ((__force __le16)(u16)(bswap_16(x)))
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#define le16_to_cpu(x) ((__force u16)(__le16)(bswap_16(x)))
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#else
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#define cpu_to_le64(x) ((__force __le64)(u64)(x))
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#define le64_to_cpu(x) ((__force u64)(__le64)(x))
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#define cpu_to_le32(x) ((__force __le32)(u32)(x))
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#define le32_to_cpu(x) ((__force u32)(__le32)(x))
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#define cpu_to_le16(x) ((__force __le16)(u16)(x))
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#define le16_to_cpu(x) ((__force u16)(__le16)(x))
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#endif
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#endif
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#ifndef noinline
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#define noinline
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#endif
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