]>
Commit | Line | Data |
---|---|---|
a86c6181 AT |
1 | /* |
2 | * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com | |
3 | * Written by Alex Tomas <alex@clusterfs.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public Licens | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- | |
17 | */ | |
18 | ||
19 | #ifndef _LINUX_EXT4_EXTENTS | |
20 | #define _LINUX_EXT4_EXTENTS | |
21 | ||
22 | #include <linux/ext4_fs.h> | |
23 | ||
24 | /* | |
25 | * with AGRESSIVE_TEST defined capacity of index/leaf blocks | |
26 | * become very little, so index split, in-depth growing and | |
27 | * other hard changes happens much more often | |
28 | * this is for debug purposes only | |
29 | */ | |
30 | #define AGRESSIVE_TEST_ | |
31 | ||
32 | /* | |
33 | * with EXTENTS_STATS defined number of blocks and extents | |
34 | * are collected in truncate path. they'll be showed at | |
35 | * umount time | |
36 | */ | |
37 | #define EXTENTS_STATS__ | |
38 | ||
39 | /* | |
40 | * if CHECK_BINSEARCH defined, then results of binary search | |
41 | * will be checked by linear search | |
42 | */ | |
43 | #define CHECK_BINSEARCH__ | |
44 | ||
45 | /* | |
46 | * if EXT_DEBUG is defined you can use 'extdebug' mount option | |
47 | * to get lots of info what's going on | |
48 | */ | |
49 | #define EXT_DEBUG__ | |
50 | #ifdef EXT_DEBUG | |
51 | #define ext_debug(a...) printk(a) | |
52 | #else | |
53 | #define ext_debug(a...) | |
54 | #endif | |
55 | ||
56 | /* | |
57 | * if EXT_STATS is defined then stats numbers are collected | |
58 | * these number will be displayed at umount time | |
59 | */ | |
60 | #define EXT_STATS_ | |
61 | ||
62 | ||
63 | /* | |
64 | * ext4_inode has i_block array (60 bytes total) | |
65 | * first 12 bytes store ext4_extent_header | |
66 | * the remain stores array of ext4_extent | |
67 | */ | |
68 | ||
69 | /* | |
70 | * this is extent on-disk structure | |
71 | * it's used at the bottom of the tree | |
72 | */ | |
73 | struct ext4_extent { | |
74 | __le32 ee_block; /* first logical block extent covers */ | |
75 | __le16 ee_len; /* number of blocks covered by extent */ | |
76 | __le16 ee_start_hi; /* high 16 bits of physical block */ | |
77 | __le32 ee_start; /* low 32 bigs of physical block */ | |
78 | }; | |
79 | ||
80 | /* | |
81 | * this is index on-disk structure | |
82 | * it's used at all the levels, but the bottom | |
83 | */ | |
84 | struct ext4_extent_idx { | |
85 | __le32 ei_block; /* index covers logical blocks from 'block' */ | |
86 | __le32 ei_leaf; /* pointer to the physical block of the next * | |
87 | * level. leaf or next index could bet here */ | |
88 | __le16 ei_leaf_hi; /* high 16 bits of physical block */ | |
89 | __u16 ei_unused; | |
90 | }; | |
91 | ||
92 | /* | |
93 | * each block (leaves and indexes), even inode-stored has header | |
94 | */ | |
95 | struct ext4_extent_header { | |
96 | __le16 eh_magic; /* probably will support different formats */ | |
97 | __le16 eh_entries; /* number of valid entries */ | |
98 | __le16 eh_max; /* capacity of store in entries */ | |
99 | __le16 eh_depth; /* has tree real underlaying blocks? */ | |
100 | __le32 eh_generation; /* generation of the tree */ | |
101 | }; | |
102 | ||
103 | #define EXT4_EXT_MAGIC cpu_to_le16(0xf30a) | |
104 | ||
105 | /* | |
106 | * array of ext4_ext_path contains path to some extent | |
107 | * creation/lookup routines use it for traversal/splitting/etc | |
108 | * truncate uses it to simulate recursive walking | |
109 | */ | |
110 | struct ext4_ext_path { | |
f65e6fba | 111 | ext4_fsblk_t p_block; |
a86c6181 AT |
112 | __u16 p_depth; |
113 | struct ext4_extent *p_ext; | |
114 | struct ext4_extent_idx *p_idx; | |
115 | struct ext4_extent_header *p_hdr; | |
116 | struct buffer_head *p_bh; | |
117 | }; | |
118 | ||
119 | /* | |
120 | * structure for external API | |
121 | */ | |
122 | ||
123 | #define EXT4_EXT_CACHE_NO 0 | |
124 | #define EXT4_EXT_CACHE_GAP 1 | |
125 | #define EXT4_EXT_CACHE_EXTENT 2 | |
126 | ||
127 | /* | |
128 | * to be called by ext4_ext_walk_space() | |
129 | * negative retcode - error | |
130 | * positive retcode - signal for ext4_ext_walk_space(), see below | |
131 | * callback must return valid extent (passed or newly created) | |
132 | */ | |
133 | typedef int (*ext_prepare_callback)(struct inode *, struct ext4_ext_path *, | |
134 | struct ext4_ext_cache *, | |
135 | void *); | |
136 | ||
137 | #define EXT_CONTINUE 0 | |
138 | #define EXT_BREAK 1 | |
139 | #define EXT_REPEAT 2 | |
140 | ||
141 | ||
142 | #define EXT_MAX_BLOCK 0xffffffff | |
143 | ||
471d4011 SB |
144 | #define EXT_MAX_LEN ((1UL << 15) - 1) |
145 | ||
a86c6181 AT |
146 | |
147 | #define EXT_FIRST_EXTENT(__hdr__) \ | |
148 | ((struct ext4_extent *) (((char *) (__hdr__)) + \ | |
149 | sizeof(struct ext4_extent_header))) | |
150 | #define EXT_FIRST_INDEX(__hdr__) \ | |
151 | ((struct ext4_extent_idx *) (((char *) (__hdr__)) + \ | |
152 | sizeof(struct ext4_extent_header))) | |
153 | #define EXT_HAS_FREE_INDEX(__path__) \ | |
154 | (le16_to_cpu((__path__)->p_hdr->eh_entries) \ | |
155 | < le16_to_cpu((__path__)->p_hdr->eh_max)) | |
156 | #define EXT_LAST_EXTENT(__hdr__) \ | |
157 | (EXT_FIRST_EXTENT((__hdr__)) + le16_to_cpu((__hdr__)->eh_entries) - 1) | |
158 | #define EXT_LAST_INDEX(__hdr__) \ | |
159 | (EXT_FIRST_INDEX((__hdr__)) + le16_to_cpu((__hdr__)->eh_entries) - 1) | |
160 | #define EXT_MAX_EXTENT(__hdr__) \ | |
161 | (EXT_FIRST_EXTENT((__hdr__)) + le16_to_cpu((__hdr__)->eh_max) - 1) | |
162 | #define EXT_MAX_INDEX(__hdr__) \ | |
163 | (EXT_FIRST_INDEX((__hdr__)) + le16_to_cpu((__hdr__)->eh_max) - 1) | |
164 | ||
165 | static inline struct ext4_extent_header *ext_inode_hdr(struct inode *inode) | |
166 | { | |
167 | return (struct ext4_extent_header *) EXT4_I(inode)->i_data; | |
168 | } | |
169 | ||
170 | static inline struct ext4_extent_header *ext_block_hdr(struct buffer_head *bh) | |
171 | { | |
172 | return (struct ext4_extent_header *) bh->b_data; | |
173 | } | |
174 | ||
175 | static inline unsigned short ext_depth(struct inode *inode) | |
176 | { | |
177 | return le16_to_cpu(ext_inode_hdr(inode)->eh_depth); | |
178 | } | |
179 | ||
180 | static inline void ext4_ext_tree_changed(struct inode *inode) | |
181 | { | |
182 | EXT4_I(inode)->i_ext_generation++; | |
183 | } | |
184 | ||
185 | static inline void | |
186 | ext4_ext_invalidate_cache(struct inode *inode) | |
187 | { | |
188 | EXT4_I(inode)->i_cached_extent.ec_type = EXT4_EXT_CACHE_NO; | |
189 | } | |
190 | ||
191 | extern int ext4_extent_tree_init(handle_t *, struct inode *); | |
192 | extern int ext4_ext_calc_credits_for_insert(struct inode *, struct ext4_ext_path *); | |
193 | extern int ext4_ext_insert_extent(handle_t *, struct inode *, struct ext4_ext_path *, struct ext4_extent *); | |
194 | extern int ext4_ext_walk_space(struct inode *, unsigned long, unsigned long, ext_prepare_callback, void *); | |
195 | extern struct ext4_ext_path * ext4_ext_find_extent(struct inode *, int, struct ext4_ext_path *); | |
196 | ||
197 | #endif /* _LINUX_EXT4_EXTENTS */ | |
198 |