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-rw-r--r--include/linux/ext4_fs_extents.h232
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diff --git a/include/linux/ext4_fs_extents.h b/include/linux/ext4_fs_extents.h
deleted file mode 100644
index 1285c583b2d8..000000000000
--- a/include/linux/ext4_fs_extents.h
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@@ -1,232 +0,0 @@
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 AGGRESSIVE_TEST defined, the capacity of index/leaf blocks
26 * becomes very small, so index split, in-depth growing and
27 * other hard changes happen much more often.
28 * This is for debug purposes only.
29 */
30#define AGGRESSIVE_TEST_
31
32/*
33 * With EXTENTS_STATS defined, the number of blocks and extents
34 * are collected in the truncate path. They'll be shown at
35 * umount time.
36 */
37#define EXTENTS_STATS__
38
39/*
40 * If CHECK_BINSEARCH is defined, then the results of the binary search
41 * will also be checked by linear search.
42 */
43#define CHECK_BINSEARCH__
44
45/*
46 * If EXT_DEBUG is defined you can use the 'extdebug' mount option
47 * to get lots of info about 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 * The first 12 bytes store ext4_extent_header;
66 * the remainder stores an array of ext4_extent.
67 */
68
69/*
70 * This is the extent on-disk structure.
71 * It's used at the bottom of the tree.
72 */
73struct 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_lo; /* low 32 bits of physical block */
78};
79
80/*
81 * This is index on-disk structure.
82 * It's used at all the levels except the bottom.
83 */
84struct ext4_extent_idx {
85 __le32 ei_block; /* index covers logical blocks from 'block' */
86 __le32 ei_leaf_lo; /* pointer to the physical block of the next *
87 * level. leaf or next index could be there */
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 */
95struct 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 underlying 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 */
110struct ext4_ext_path {
111 ext4_fsblk_t p_block;
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#define EXT_MAX_BLOCK 0xffffffff
129
130/*
131 * EXT_INIT_MAX_LEN is the maximum number of blocks we can have in an
132 * initialized extent. This is 2^15 and not (2^16 - 1), since we use the
133 * MSB of ee_len field in the extent datastructure to signify if this
134 * particular extent is an initialized extent or an uninitialized (i.e.
135 * preallocated).
136 * EXT_UNINIT_MAX_LEN is the maximum number of blocks we can have in an
137 * uninitialized extent.
138 * If ee_len is <= 0x8000, it is an initialized extent. Otherwise, it is an
139 * uninitialized one. In other words, if MSB of ee_len is set, it is an
140 * uninitialized extent with only one special scenario when ee_len = 0x8000.
141 * In this case we can not have an uninitialized extent of zero length and
142 * thus we make it as a special case of initialized extent with 0x8000 length.
143 * This way we get better extent-to-group alignment for initialized extents.
144 * Hence, the maximum number of blocks we can have in an *initialized*
145 * extent is 2^15 (32768) and in an *uninitialized* extent is 2^15-1 (32767).
146 */
147#define EXT_INIT_MAX_LEN (1UL << 15)
148#define EXT_UNINIT_MAX_LEN (EXT_INIT_MAX_LEN - 1)
149
150
151#define EXT_FIRST_EXTENT(__hdr__) \
152 ((struct ext4_extent *) (((char *) (__hdr__)) + \
153 sizeof(struct ext4_extent_header)))
154#define EXT_FIRST_INDEX(__hdr__) \
155 ((struct ext4_extent_idx *) (((char *) (__hdr__)) + \
156 sizeof(struct ext4_extent_header)))
157#define EXT_HAS_FREE_INDEX(__path__) \
158 (le16_to_cpu((__path__)->p_hdr->eh_entries) \
159 < le16_to_cpu((__path__)->p_hdr->eh_max))
160#define EXT_LAST_EXTENT(__hdr__) \
161 (EXT_FIRST_EXTENT((__hdr__)) + le16_to_cpu((__hdr__)->eh_entries) - 1)
162#define EXT_LAST_INDEX(__hdr__) \
163 (EXT_FIRST_INDEX((__hdr__)) + le16_to_cpu((__hdr__)->eh_entries) - 1)
164#define EXT_MAX_EXTENT(__hdr__) \
165 (EXT_FIRST_EXTENT((__hdr__)) + le16_to_cpu((__hdr__)->eh_max) - 1)
166#define EXT_MAX_INDEX(__hdr__) \
167 (EXT_FIRST_INDEX((__hdr__)) + le16_to_cpu((__hdr__)->eh_max) - 1)
168
169static inline struct ext4_extent_header *ext_inode_hdr(struct inode *inode)
170{
171 return (struct ext4_extent_header *) EXT4_I(inode)->i_data;
172}
173
174static inline struct ext4_extent_header *ext_block_hdr(struct buffer_head *bh)
175{
176 return (struct ext4_extent_header *) bh->b_data;
177}
178
179static inline unsigned short ext_depth(struct inode *inode)
180{
181 return le16_to_cpu(ext_inode_hdr(inode)->eh_depth);
182}
183
184static inline void ext4_ext_tree_changed(struct inode *inode)
185{
186 EXT4_I(inode)->i_ext_generation++;
187}
188
189static inline void
190ext4_ext_invalidate_cache(struct inode *inode)
191{
192 EXT4_I(inode)->i_cached_extent.ec_type = EXT4_EXT_CACHE_NO;
193}
194
195static inline void ext4_ext_mark_uninitialized(struct ext4_extent *ext)
196{
197 /* We can not have an uninitialized extent of zero length! */
198 BUG_ON((le16_to_cpu(ext->ee_len) & ~EXT_INIT_MAX_LEN) == 0);
199 ext->ee_len |= cpu_to_le16(EXT_INIT_MAX_LEN);
200}
201
202static inline int ext4_ext_is_uninitialized(struct ext4_extent *ext)
203{
204 /* Extent with ee_len of 0x8000 is treated as an initialized extent */
205 return (le16_to_cpu(ext->ee_len) > EXT_INIT_MAX_LEN);
206}
207
208static inline int ext4_ext_get_actual_len(struct ext4_extent *ext)
209{
210 return (le16_to_cpu(ext->ee_len) <= EXT_INIT_MAX_LEN ?
211 le16_to_cpu(ext->ee_len) :
212 (le16_to_cpu(ext->ee_len) - EXT_INIT_MAX_LEN));
213}
214
215extern ext4_fsblk_t idx_pblock(struct ext4_extent_idx *);
216extern void ext4_ext_store_pblock(struct ext4_extent *, ext4_fsblk_t);
217extern int ext4_extent_tree_init(handle_t *, struct inode *);
218extern int ext4_ext_calc_credits_for_insert(struct inode *, struct ext4_ext_path *);
219extern int ext4_ext_try_to_merge(struct inode *inode,
220 struct ext4_ext_path *path,
221 struct ext4_extent *);
222extern unsigned int ext4_ext_check_overlap(struct inode *, struct ext4_extent *, struct ext4_ext_path *);
223extern int ext4_ext_insert_extent(handle_t *, struct inode *, struct ext4_ext_path *, struct ext4_extent *);
224extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
225 struct ext4_ext_path *);
226extern int ext4_ext_search_left(struct inode *, struct ext4_ext_path *,
227 ext4_lblk_t *, ext4_fsblk_t *);
228extern int ext4_ext_search_right(struct inode *, struct ext4_ext_path *,
229 ext4_lblk_t *, ext4_fsblk_t *);
230extern void ext4_ext_drop_refs(struct ext4_ext_path *);
231#endif /* _LINUX_EXT4_EXTENTS */
232
generated by cgit v1.2.2 (git 2.25.0) at 2025-11-14 10:11:13 -0500