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 <bharrosh@panasas.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 # define EXOFS_APAGE_FS_DATA    (OSD_APAGE_APP_DEFINED_FIRST + 3)
  57 # define EXOFS_ATTR_INODE_DATA  1
  58 # define EXOFS_ATTR_INODE_FILE_LAYOUT   2
  59 # define EXOFS_ATTR_INODE_DIR_LAYOUT    3
  60
  61 /*
  62  * The maximum number of files we can have is limited by the size of the
  63  * inode number.  This is the largest object ID that the file system supports.
  64  * Object IDs 0, 1, and 2 are always in use (see above defines).
  65  */
  66 enum {
  67         EXOFS_MAX_INO_ID = (sizeof(ino_t) * 8 == 64) ? ULLONG_MAX :
  68                                         (1ULL << (sizeof(ino_t) * 8ULL - 1ULL)),
  69         EXOFS_MAX_ID     = (EXOFS_MAX_INO_ID - 1 - EXOFS_OBJ_OFF),
  70 };
  71
  72 /****************************************************************************
  73  * Misc.
  74  ****************************************************************************/
  75 #define EXOFS_BLKSHIFT  12
  76 #define EXOFS_BLKSIZE   (1UL << EXOFS_BLKSHIFT)
  77
  78 /****************************************************************************
  79  * superblock-related things
  80  ****************************************************************************/
  81 #define EXOFS_SUPER_MAGIC       0x5DF5
  82
  83 /*
  84  * The file system control block - stored in object EXOFS_SUPER_ID's data.
  85  * This is where the in-memory superblock is stored on disk.
  86  */
  87 enum {EXOFS_FSCB_VER = 1, EXOFS_DT_VER = 1};
  88 struct exofs_fscb {
  89         __le64  s_nextid;       /* Highest object ID used */
  90         __le64  s_numfiles;     /* Number of files on fs */
  91         __le32  s_version;      /* == EXOFS_FSCB_VER */
  92         __le16  s_magic;        /* Magic signature */
  93         __le16  s_newfs;        /* Non-zero if this is a new fs */
  94
  95         /* From here on it's a static part, only written by mkexofs */
  96         __le64  s_dev_table_oid;   /* Resurved, not used */
  97         __le64  s_dev_table_count; /* == 0 means no dev_table */
  98 } __packed;
  99
 100 /*
 101  * Describes the raid used in the FS. It is part of the device table.
 102  * This here is taken from the pNFS-objects definition. In exofs we
 103  * use one raid policy through-out the filesystem. (NOTE: the funny
 104  * alignment at begining. We take care of it at exofs_device_table.
 105  */
 106 struct exofs_dt_data_map {
 107         __le32  cb_num_comps;
 108         __le64  cb_stripe_unit;
 109         __le32  cb_group_width;
 110         __le32  cb_group_depth;
 111         __le32  cb_mirror_cnt;
 112         __le32  cb_raid_algorithm;
 113 } __packed;
 114
 115 /*
 116  * This is an osd device information descriptor. It is a single entry in
 117  * the exofs device table. It describes an osd target lun which
 118  * contains data belonging to this FS. (Same partition_id on all devices)
 119  */
 120 struct exofs_dt_device_info {
 121         __le32  systemid_len;
 122         u8      systemid[OSD_SYSTEMID_LEN];
 123         __le64  long_name_offset;       /* If !0 then offset-in-file */
 124         __le32  osdname_len;            /* */
 125         u8      osdname[44];            /* Embbeded, Ususally an asci uuid */
 126 } __packed;
 127
 128 /*
 129  * The EXOFS device table - stored in object EXOFS_DEVTABLE_ID's data.
 130  * It contains the raid used for this multy-device FS and an array of
 131  * participating devices.
 132  */
 133 struct exofs_device_table {
 134         __le32                          dt_version;     /* == EXOFS_DT_VER */
 135         struct exofs_dt_data_map        dt_data_map;    /* Raid policy to use */
 136
 137         /* Resurved space For future use. Total includeing this:
 138          * (8 * sizeof(le64))
 139          */
 140         __le64                          __Resurved[4];
 141
 142         __le64                          dt_num_devices; /* Array size */
 143         struct exofs_dt_device_info     dt_dev_table[]; /* Array of devices */
 144 } __packed;
 145
 146 /****************************************************************************
 147  * inode-related things
 148  ****************************************************************************/
 149 #define EXOFS_IDATA             5
 150
 151 /*
 152  * The file control block - stored in an object's attributes.  This is where
 153  * the in-memory inode is stored on disk.
 154  */
 155 struct exofs_fcb {
 156         __le64  i_size;                 /* Size of the file */
 157         __le16  i_mode;                 /* File mode */
 158         __le16  i_links_count;          /* Links count */
 159         __le32  i_uid;                  /* Owner Uid */
 160         __le32  i_gid;                  /* Group Id */
 161         __le32  i_atime;                /* Access time */
 162         __le32  i_ctime;                /* Creation time */
 163         __le32  i_mtime;                /* Modification time */
 164         __le32  i_flags;                /* File flags (unused for now)*/
 165         __le32  i_generation;           /* File version (for NFS) */
 166         __le32  i_data[EXOFS_IDATA];    /* Short symlink names and device #s */
 167 };
 168
 169 #define EXOFS_INO_ATTR_SIZE     sizeof(struct exofs_fcb)
 170
 171 /* This is the Attribute the fcb is stored in */
 172 static const struct __weak osd_attr g_attr_inode_data = ATTR_DEF(
 173         EXOFS_APAGE_FS_DATA,
 174         EXOFS_ATTR_INODE_DATA,
 175         EXOFS_INO_ATTR_SIZE);
 176
 177 /****************************************************************************
 178  * dentry-related things
 179  ****************************************************************************/
 180 #define EXOFS_NAME_LEN  255
 181
 182 /*
 183  * The on-disk directory entry
 184  */
 185 struct exofs_dir_entry {
 186         __le64          inode_no;               /* inode number           */
 187         __le16          rec_len;                /* directory entry length */
 188         u8              name_len;               /* name length            */
 189         u8              file_type;              /* umm...file type        */
 190         char            name[EXOFS_NAME_LEN];   /* file name              */
 191 };
 192
 193 enum {
 194         EXOFS_FT_UNKNOWN,
 195         EXOFS_FT_REG_FILE,
 196         EXOFS_FT_DIR,
 197         EXOFS_FT_CHRDEV,
 198         EXOFS_FT_BLKDEV,
 199         EXOFS_FT_FIFO,
 200         EXOFS_FT_SOCK,
 201         EXOFS_FT_SYMLINK,
 202         EXOFS_FT_MAX
 203 };
 204
 205 #define EXOFS_DIR_PAD                   4
 206 #define EXOFS_DIR_ROUND                 (EXOFS_DIR_PAD - 1)
 207 #define EXOFS_DIR_REC_LEN(name_len) \
 208         (((name_len) + offsetof(struct exofs_dir_entry, name)  + \
 209           EXOFS_DIR_ROUND) & ~EXOFS_DIR_ROUND)
 210
 211 /*
 212  * The on-disk (optional) layout structure.
 213  * sits in an EXOFS_ATTR_INODE_FILE_LAYOUT or EXOFS_ATTR_INODE_DIR_LAYOUT
 214  * attribute, attached to any inode, usually to a directory.
 215  */
 216
 217 enum exofs_inode_layout_gen_functions {
 218         LAYOUT_MOVING_WINDOW = 0,
 219         LAYOUT_IMPLICT = 1,
 220 };
 221
 222 struct exofs_on_disk_inode_layout {
 223         __le16 gen_func; /* One of enum exofs_inode_layout_gen_functions */
 224         __le16 pad;
 225         union {
 226                 /* gen_func == LAYOUT_MOVING_WINDOW (default) */
 227                 struct exofs_layout_sliding_window {
 228                         __le32 num_devices; /* first n devices in global-table*/
 229                 } sliding_window __packed;
 230
 231                 /* gen_func == LAYOUT_IMPLICT */
 232                 struct exofs_layout_implict_list {
 233                         struct exofs_dt_data_map data_map;
 234                         /* Variable array of size data_map.cb_num_comps. These
 235                          * are device indexes of the devices in the global table
 236                          */
 237                         __le32 dev_indexes[];
 238                 } implict __packed;
 239         };
 240 } __packed;
 241
 242 static inline size_t exofs_on_disk_inode_layout_size(unsigned max_devs)
 243 {
 244         return sizeof(struct exofs_on_disk_inode_layout) +
 245                 max_devs * sizeof(__le32);
 246 }
 247
 248 #endif /*ifndef __EXOFS_COM_H__*/