1 /*
2 * common.h - Common definitions for both Kernel and user-mode utilities
3 *
4 * Copyright (C) 2005, 2006
5 * Avishay Traeger (avishay@gmail.com)
6 * Copyright (C) 2008, 2009
7 * Boaz Harrosh <ooo@electrozaur.com>
8 *
9 * Copyrights for code taken from ext2:
10 * Copyright (C) 1992, 1993, 1994, 1995
11 * Remy Card (card@masi.ibp.fr)
12 * Laboratoire MASI - Institut Blaise Pascal
13 * Universite Pierre et Marie Curie (Paris VI)
14 * from
15 * linux/fs/minix/inode.c
16 * Copyright (C) 1991, 1992 Linus Torvalds
17 *
18 * This file is part of exofs.
19 *
20 * exofs is free software; you can redistribute it and/or modify
21 * it under the terms of the GNU General Public License as published by
22 * the Free Software Foundation. Since it is based on ext2, and the only
23 * valid version of GPL for the Linux kernel is version 2, the only valid
24 * version of GPL for exofs is version 2.
25 *
26 * exofs is distributed in the hope that it will be useful,
27 * but WITHOUT ANY WARRANTY; without even the implied warranty of
28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
29 * GNU General Public License for more details.
30 *
31 * You should have received a copy of the GNU General Public License
32 * along with exofs; if not, write to the Free Software
33 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
34 */
35
36 #ifndef __EXOFS_COM_H__
37 #define __EXOFS_COM_H__
38
39 #include <linux/types.h>
40
41 #include <scsi/osd_attributes.h>
42 #include <scsi/osd_initiator.h>
43 #include <scsi/osd_sec.h>
44
45 /****************************************************************************
46 * Object ID related defines
47 * NOTE: inode# = object ID - EXOFS_OBJ_OFF
48 ****************************************************************************/
49 #define EXOFS_MIN_PID 0x10000 /* Smallest partition ID */
50 #define EXOFS_OBJ_OFF 0x10000 /* offset for objects */
51 #define EXOFS_SUPER_ID 0x10000 /* object ID for on-disk superblock */
52 #define EXOFS_DEVTABLE_ID 0x10001 /* object ID for on-disk device table */
53 #define EXOFS_ROOT_ID 0x10002 /* object ID for root directory */
54
55 /* exofs Application specific page/attribute */
56 /* Inode attrs */
57 # define EXOFS_APAGE_FS_DATA (OSD_APAGE_APP_DEFINED_FIRST + 3)
58 # define EXOFS_ATTR_INODE_DATA 1
59 # define EXOFS_ATTR_INODE_FILE_LAYOUT 2
60 # define EXOFS_ATTR_INODE_DIR_LAYOUT 3
61 /* Partition attrs */
62 # define EXOFS_APAGE_SB_DATA (0xF0000000U + 3)
63 # define EXOFS_ATTR_SB_STATS 1
64
65 /*
66 * The maximum number of files we can have is limited by the size of the
67 * inode number. This is the largest object ID that the file system supports.
68 * Object IDs 0, 1, and 2 are always in use (see above defines).
69 */
70 enum {
71 EXOFS_MAX_INO_ID = (sizeof(ino_t) * 8 == 64) ? ULLONG_MAX :
72 (1ULL << (sizeof(ino_t) * 8ULL - 1ULL)),
73 EXOFS_MAX_ID = (EXOFS_MAX_INO_ID - 1 - EXOFS_OBJ_OFF),
74 };
75
76 /****************************************************************************
77 * Misc.
78 ****************************************************************************/
79 #define EXOFS_BLKSHIFT 12
80 #define EXOFS_BLKSIZE (1UL << EXOFS_BLKSHIFT)
81
82 /****************************************************************************
83 * superblock-related things
84 ****************************************************************************/
85 #define EXOFS_SUPER_MAGIC 0x5DF5
86
87 /*
88 * The file system control block - stored in object EXOFS_SUPER_ID's data.
89 * This is where the in-memory superblock is stored on disk.
90 */
91 enum {EXOFS_FSCB_VER = 1, EXOFS_DT_VER = 1};
92 struct exofs_fscb {
93 __le64 s_nextid; /* Only used after mkfs */
94 __le64 s_numfiles; /* Only used after mkfs */
95 __le32 s_version; /* == EXOFS_FSCB_VER */
96 __le16 s_magic; /* Magic signature */
97 __le16 s_newfs; /* Non-zero if this is a new fs */
98
99 /* From here on it's a static part, only written by mkexofs */
100 __le64 s_dev_table_oid; /* Resurved, not used */
101 __le64 s_dev_table_count; /* == 0 means no dev_table */
102 } __packed;
103
104 /*
105 * This struct is set on the FS partition's attributes.
106 * [EXOFS_APAGE_SB_DATA, EXOFS_ATTR_SB_STATS] and is written together
107 * with the create command, to atomically persist the sb writeable information.
108 */
109 struct exofs_sb_stats {
110 __le64 s_nextid; /* Highest object ID used */
111 __le64 s_numfiles; /* Number of files on fs */
112 } __packed;
113
114 /*
115 * Describes the raid used in the FS. It is part of the device table.
116 * This here is taken from the pNFS-objects definition. In exofs we
117 * use one raid policy through-out the filesystem. (NOTE: the funny
118 * alignment at beginning. We take care of it at exofs_device_table.
119 */
120 struct exofs_dt_data_map {
121 __le32 cb_num_comps;
122 __le64 cb_stripe_unit;
123 __le32 cb_group_width;
124 __le32 cb_group_depth;
125 __le32 cb_mirror_cnt;
126 __le32 cb_raid_algorithm;
127 } __packed;
128
129 /*
130 * This is an osd device information descriptor. It is a single entry in
131 * the exofs device table. It describes an osd target lun which
132 * contains data belonging to this FS. (Same partition_id on all devices)
133 */
134 struct exofs_dt_device_info {
135 __le32 systemid_len;
136 u8 systemid[OSD_SYSTEMID_LEN];
137 __le64 long_name_offset; /* If !0 then offset-in-file */
138 __le32 osdname_len; /* */
139 u8 osdname[44]; /* Embbeded, Usually an asci uuid */
140 } __packed;
141
142 /*
143 * The EXOFS device table - stored in object EXOFS_DEVTABLE_ID's data.
144 * It contains the raid used for this multy-device FS and an array of
145 * participating devices.
146 */
147 struct exofs_device_table {
148 __le32 dt_version; /* == EXOFS_DT_VER */
149 struct exofs_dt_data_map dt_data_map; /* Raid policy to use */
150
151 /* Resurved space For future use. Total includeing this:
152 * (8 * sizeof(le64))
153 */
154 __le64 __Resurved[4];
155
156 __le64 dt_num_devices; /* Array size */
157 struct exofs_dt_device_info dt_dev_table[]; /* Array of devices */
158 } __packed;
159
160 /****************************************************************************
161 * inode-related things
162 ****************************************************************************/
163 #define EXOFS_IDATA 5
164
165 /*
166 * The file control block - stored in an object's attributes. This is where
167 * the in-memory inode is stored on disk.
168 */
169 struct exofs_fcb {
170 __le64 i_size; /* Size of the file */
171 __le16 i_mode; /* File mode */
172 __le16 i_links_count; /* Links count */
173 __le32 i_uid; /* Owner Uid */
174 __le32 i_gid; /* Group Id */
175 __le32 i_atime; /* Access time */
176 __le32 i_ctime; /* Creation time */
177 __le32 i_mtime; /* Modification time */
178 __le32 i_flags; /* File flags (unused for now)*/
179 __le32 i_generation; /* File version (for NFS) */
180 __le32 i_data[EXOFS_IDATA]; /* Short symlink names and device #s */
181 };
182
183 #define EXOFS_INO_ATTR_SIZE sizeof(struct exofs_fcb)
184
185 /* This is the Attribute the fcb is stored in */
186 static const struct __weak osd_attr g_attr_inode_data = ATTR_DEF(
187 EXOFS_APAGE_FS_DATA,
188 EXOFS_ATTR_INODE_DATA,
189 EXOFS_INO_ATTR_SIZE);
190
191 /****************************************************************************
192 * dentry-related things
193 ****************************************************************************/
194 #define EXOFS_NAME_LEN 255
195
196 /*
197 * The on-disk directory entry
198 */
199 struct exofs_dir_entry {
200 __le64 inode_no; /* inode number */
201 __le16 rec_len; /* directory entry length */
202 u8 name_len; /* name length */
203 u8 file_type; /* umm...file type */
204 char name[EXOFS_NAME_LEN]; /* file name */
205 };
206
207 enum {
208 EXOFS_FT_UNKNOWN,
209 EXOFS_FT_REG_FILE,
210 EXOFS_FT_DIR,
211 EXOFS_FT_CHRDEV,
212 EXOFS_FT_BLKDEV,
213 EXOFS_FT_FIFO,
214 EXOFS_FT_SOCK,
215 EXOFS_FT_SYMLINK,
216 EXOFS_FT_MAX
217 };
218
219 #define EXOFS_DIR_PAD 4
220 #define EXOFS_DIR_ROUND (EXOFS_DIR_PAD - 1)
221 #define EXOFS_DIR_REC_LEN(name_len) \
222 (((name_len) + offsetof(struct exofs_dir_entry, name) + \
223 EXOFS_DIR_ROUND) & ~EXOFS_DIR_ROUND)
224
225 /*
226 * The on-disk (optional) layout structure.
227 * sits in an EXOFS_ATTR_INODE_FILE_LAYOUT or EXOFS_ATTR_INODE_DIR_LAYOUT
228 * attribute, attached to any inode, usually to a directory.
229 */
230
231 enum exofs_inode_layout_gen_functions {
232 LAYOUT_MOVING_WINDOW = 0,
233 LAYOUT_IMPLICT = 1,
234 };
235
236 struct exofs_on_disk_inode_layout {
237 __le16 gen_func; /* One of enum exofs_inode_layout_gen_functions */
238 __le16 pad;
239 union {
240 /* gen_func == LAYOUT_MOVING_WINDOW (default) */
241 struct exofs_layout_sliding_window {
242 __le32 num_devices; /* first n devices in global-table*/
243 } sliding_window __packed;
244
245 /* gen_func == LAYOUT_IMPLICT */
246 struct exofs_layout_implict_list {
247 struct exofs_dt_data_map data_map;
248 /* Variable array of size data_map.cb_num_comps. These
249 * are device indexes of the devices in the global table
250 */
251 __le32 dev_indexes[];
252 } implict __packed;
253 };
254 } __packed;
255
exofs_on_disk_inode_layout_size(unsigned max_devs)256 static inline size_t exofs_on_disk_inode_layout_size(unsigned max_devs)
257 {
258 return sizeof(struct exofs_on_disk_inode_layout) +
259 max_devs * sizeof(__le32);
260 }
261
262 #endif /*ifndef __EXOFS_COM_H__*/
263