Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 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 | /* |
Robert P. J. Day | bbf2f9f | 2007-02-17 19:20:16 +0100 | [diff] [blame] | 25 | * With AGGRESSIVE_TEST defined, the capacity of index/leaf blocks |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 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. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 29 | */ |
Robert P. J. Day | bbf2f9f | 2007-02-17 19:20:16 +0100 | [diff] [blame] | 30 | #define AGGRESSIVE_TEST_ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 31 | |
| 32 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 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. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 36 | */ |
| 37 | #define EXTENTS_STATS__ |
| 38 | |
| 39 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 40 | * If CHECK_BINSEARCH is defined, then the results of the binary search |
| 41 | * will also be checked by linear search. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 42 | */ |
| 43 | #define CHECK_BINSEARCH__ |
| 44 | |
| 45 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 46 | * If EXT_DEBUG is defined you can use the 'extdebug' mount option |
| 47 | * to get lots of info about what's going on. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 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 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 57 | * If EXT_STATS is defined then stats numbers are collected. |
| 58 | * These number will be displayed at umount time. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 59 | */ |
| 60 | #define EXT_STATS_ |
| 61 | |
| 62 | |
| 63 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 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. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 67 | */ |
| 68 | |
| 69 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 70 | * This is the extent on-disk structure. |
| 71 | * It's used at the bottom of the tree. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 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 */ |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 77 | __le32 ee_start; /* low 32 bits of physical block */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 78 | }; |
| 79 | |
| 80 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 81 | * This is index on-disk structure. |
| 82 | * It's used at all the levels except the bottom. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 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 * |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 87 | * level. leaf or next index could be there */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 88 | __le16 ei_leaf_hi; /* high 16 bits of physical block */ |
| 89 | __u16 ei_unused; |
| 90 | }; |
| 91 | |
| 92 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 93 | * Each block (leaves and indexes), even inode-stored has header. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 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 */ |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 99 | __le16 eh_depth; /* has tree real underlying blocks? */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 100 | __le32 eh_generation; /* generation of the tree */ |
| 101 | }; |
| 102 | |
| 103 | #define EXT4_EXT_MAGIC cpu_to_le16(0xf30a) |
| 104 | |
| 105 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame] | 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. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 109 | */ |
| 110 | struct ext4_ext_path { |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 111 | ext4_fsblk_t p_block; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 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 | |
Suparna Bhattacharya | 471d401 | 2006-10-11 01:21:06 -0700 | [diff] [blame] | 144 | #define EXT_MAX_LEN ((1UL << 15) - 1) |
| 145 | |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 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__) \ |
Dave Kleikamp | 8c55e20 | 2007-05-24 13:04:54 -0400 | [diff] [blame] | 154 | (le16_to_cpu((__path__)->p_hdr->eh_entries) \ |
| 155 | < le16_to_cpu((__path__)->p_hdr->eh_max)) |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 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 *); |
Amit Arora | 25d14f9 | 2007-05-24 13:04:13 -0400 | [diff] [blame] | 193 | extern unsigned int ext4_ext_check_overlap(struct inode *, struct ext4_extent *, struct ext4_ext_path *); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 194 | extern int ext4_ext_insert_extent(handle_t *, struct inode *, struct ext4_ext_path *, struct ext4_extent *); |
| 195 | extern int ext4_ext_walk_space(struct inode *, unsigned long, unsigned long, ext_prepare_callback, void *); |
| 196 | extern struct ext4_ext_path * ext4_ext_find_extent(struct inode *, int, struct ext4_ext_path *); |
| 197 | |
| 198 | #endif /* _LINUX_EXT4_EXTENTS */ |
| 199 | |