fs/exofs/common.h

   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
 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__*/