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gerrit-public.fairphone.software / kernel / msm-4.9 / f392a938f3cc36a2abe68db9286bd864c3b2f7dd / . / fs / btrfs / struct-funcs.c
blob: c5715a60554c8c0a45851d08e89d98fdc3865a28 [file] [log] [blame]
Chris Mason0f827312007-10-15 16:18:56 -0400[diff] [blame]1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/highmem.h>
20#define BTRFS_SETGET_FUNCS(name, type, member, bits) \
21u##bits btrfs_##name(struct extent_buffer *eb, \
22 type *s) \
23{ \
24 unsigned long offset = (unsigned long)s + \
25 offsetof(type, member); \
26 __le##bits *tmp; \
27 /* ugly, but we want the fast path here */ \
28 if (eb->map_token && offset >= eb->map_start && \
29 offset + sizeof(((type *)0)->member) <= eb->map_start + \
30 eb->map_len) { \
31 tmp = (__le##bits *)(eb->kaddr + offset - \
32 eb->map_start); \
33 return le##bits##_to_cpu(*tmp); \
34 } \
35 { \
36 int err; \
37 char *map_token; \
38 char *kaddr; \
39 int unmap_on_exit = (eb->map_token == NULL); \
40 unsigned long map_start; \
41 unsigned long map_len; \
42 __le##bits res; \
43 err = map_extent_buffer(eb, offset, \
44 sizeof(((type *)0)->member), \
45 &map_token, &kaddr, \
46 &map_start, &map_len, KM_USER1); \
47 if (err) { \
48 read_eb_member(eb, s, type, member, &res); \
49 return le##bits##_to_cpu(res); \
50 } \
51 tmp = (__le##bits *)(kaddr + offset - map_start); \
52 res = le##bits##_to_cpu(*tmp); \
53 if (unmap_on_exit) \
54 unmap_extent_buffer(eb, map_token, KM_USER1); \
55 return res; \
56 } \
57} \
58void btrfs_set_##name(struct extent_buffer *eb, \
59 type *s, u##bits val) \
60{ \
61 unsigned long offset = (unsigned long)s + \
62 offsetof(type, member); \
63 __le##bits *tmp; \
64 /* ugly, but we want the fast path here */ \
65 if (eb->map_token && offset >= eb->map_start && \
66 offset + sizeof(((type *)0)->member) <= eb->map_start + \
67 eb->map_len) { \
68 tmp = (__le##bits *)(eb->kaddr + offset - \
69 eb->map_start); \
70 *tmp = cpu_to_le##bits(val); \
71 return; \
72 } \
73 { \
74 int err; \
75 char *map_token; \
76 char *kaddr; \
77 int unmap_on_exit = (eb->map_token == NULL); \
78 unsigned long map_start; \
79 unsigned long map_len; \
80 err = map_extent_buffer(eb, offset, \
81 sizeof(((type *)0)->member), \
82 &map_token, &kaddr, \
83 &map_start, &map_len, KM_USER1); \
84 if (err) { \
85 val = cpu_to_le##bits(val); \
86 write_eb_member(eb, s, type, member, &val); \
87 return; \
88 } \
89 tmp = (__le##bits *)(kaddr + offset - map_start); \
90 *tmp = cpu_to_le##bits(val); \
91 if (unmap_on_exit) \
92 unmap_extent_buffer(eb, map_token, KM_USER1); \
93 } \
94}
95
96#include "ctree.h"
97
Chris Masone644d022007-11-06 15:09:29 -0500[diff] [blame]98void btrfs_node_key(struct extent_buffer *eb,
99 struct btrfs_disk_key *disk_key, int nr)
100{
101 unsigned long ptr = btrfs_node_key_ptr_offset(nr);
102 if (eb->map_token && ptr >= eb->map_start &&
103 ptr + sizeof(*disk_key) <= eb->map_start + eb->map_len) {
104 memcpy(disk_key, eb->kaddr + ptr - eb->map_start,
105 sizeof(*disk_key));
106 return;
107 } else if (eb->map_token) {
108 unmap_extent_buffer(eb, eb->map_token, KM_USER1);
109 eb->map_token = NULL;
110 }
111 read_eb_member(eb, (struct btrfs_key_ptr *)ptr,
112 struct btrfs_key_ptr, key, disk_key);
113}