fs/xfs/xfs_dir2_sf.h

   1 /*
   2  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would 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 License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #ifndef __XFS_DIR2_SF_H__
  19 #define __XFS_DIR2_SF_H__
  20
  21 /*
  22  * Directory layout when stored internal to an inode.
  23  *
  24  * Small directories are packed as tightly as possible so as to
  25  * fit into the literal area of the inode.
  26  */
  27
  28 struct uio;
  29 struct xfs_dabuf;
  30 struct xfs_da_args;
  31 struct xfs_dir2_block;
  32 struct xfs_inode;
  33 struct xfs_mount;
  34 struct xfs_trans;
  35
  36 /*
  37  * Maximum size of a shortform directory.
  38  */
  39 #define XFS_DIR2_SF_MAX_SIZE    \
  40         (XFS_DINODE_MAX_SIZE - (uint)sizeof(xfs_dinode_core_t) - \
  41          (uint)sizeof(xfs_agino_t))
  42
  43 /*
  44  * Inode number stored as 8 8-bit values.
  45  */
  46 typedef struct { __uint8_t i[8]; } xfs_dir2_ino8_t;
  47
  48 /*
  49  * Inode number stored as 4 8-bit values.
  50  * Works a lot of the time, when all the inode numbers in a directory
  51  * fit in 32 bits.
  52  */
  53 typedef struct { __uint8_t i[4]; } xfs_dir2_ino4_t;
  54
  55 typedef union {
  56         xfs_dir2_ino8_t i8;
  57         xfs_dir2_ino4_t i4;
  58 } xfs_dir2_inou_t;
  59 #define XFS_DIR2_MAX_SHORT_INUM ((xfs_ino_t)0xffffffffULL)
  60
  61 /*
  62  * Normalized offset (in a data block) of the entry, really xfs_dir2_data_off_t.
  63  * Only need 16 bits, this is the byte offset into the single block form.
  64  */
  65 typedef struct { __uint8_t i[2]; } xfs_dir2_sf_off_t;
  66
  67 /*
  68  * The parent directory has a dedicated field, and the self-pointer must
  69  * be calculated on the fly.
  70  *
  71  * Entries are packed toward the top as tightly as possible.  The header
  72  * and the elements must be memcpy'd out into a work area to get correct
  73  * alignment for the inode number fields.
  74  */
  75 typedef struct xfs_dir2_sf_hdr {
  76         __uint8_t               count;          /* count of entries */
  77         __uint8_t               i8count;        /* count of 8-byte inode #s */
  78         xfs_dir2_inou_t         parent;         /* parent dir inode number */
  79 } xfs_dir2_sf_hdr_t;
  80
  81 typedef struct xfs_dir2_sf_entry {
  82         __uint8_t               namelen;        /* actual name length */
  83         xfs_dir2_sf_off_t       offset;         /* saved offset */
  84         __uint8_t               name[1];        /* name, variable size */
  85         xfs_dir2_inou_t         inumber;        /* inode number, var. offset */
  86 } xfs_dir2_sf_entry_t;
  87
  88 typedef struct xfs_dir2_sf {
  89         xfs_dir2_sf_hdr_t       hdr;            /* shortform header */
  90         xfs_dir2_sf_entry_t     list[1];        /* shortform entries */
  91 } xfs_dir2_sf_t;
  92
  93 #define XFS_DIR2_SF_HDR_SIZE(i8count)   xfs_dir2_sf_hdr_size(i8count)
  94 static inline int xfs_dir2_sf_hdr_size(int i8count)
  95 {
  96         return ((uint)sizeof(xfs_dir2_sf_hdr_t) - \
  97                 ((i8count) == 0) * \
  98                 ((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
  99 }
 100
 101 #define XFS_DIR2_SF_INUMBERP(sfep)      xfs_dir2_sf_inumberp(sfep)
 102 static inline xfs_dir2_inou_t *xfs_dir2_sf_inumberp(xfs_dir2_sf_entry_t *sfep)
 103 {
 104         return (xfs_dir2_inou_t *)&(sfep)->name[(sfep)->namelen];
 105 }
 106
 107 #define XFS_DIR2_SF_GET_INUMBER(sfp, from) \
 108         xfs_dir2_sf_get_inumber(sfp, from)
 109 static inline xfs_intino_t
 110 xfs_dir2_sf_get_inumber(xfs_dir2_sf_t *sfp, xfs_dir2_inou_t *from)
 111 {
 112         return ((sfp)->hdr.i8count == 0 ? \
 113                 (xfs_intino_t)XFS_GET_DIR_INO4((from)->i4) : \
 114                 (xfs_intino_t)XFS_GET_DIR_INO8((from)->i8));
 115 }
 116
 117 #define XFS_DIR2_SF_PUT_INUMBER(sfp,from,to) \
 118         xfs_dir2_sf_put_inumber(sfp,from,to)
 119 static inline void xfs_dir2_sf_put_inumber(xfs_dir2_sf_t *sfp, xfs_ino_t *from,
 120                                                 xfs_dir2_inou_t *to)
 121 {
 122         if ((sfp)->hdr.i8count == 0)
 123                 XFS_PUT_DIR_INO4(*(from), (to)->i4);
 124         else
 125                 XFS_PUT_DIR_INO8(*(from), (to)->i8);
 126 }
 127
 128 #define XFS_DIR2_SF_GET_OFFSET(sfep)    \
 129         xfs_dir2_sf_get_offset(sfep)
 130 static inline xfs_dir2_data_aoff_t
 131 xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t *sfep)
 132 {
 133         return INT_GET_UNALIGNED_16_BE(&(sfep)->offset.i);
 134 }
 135
 136 #define XFS_DIR2_SF_PUT_OFFSET(sfep,off) \
 137         xfs_dir2_sf_put_offset(sfep,off)
 138 static inline void
 139 xfs_dir2_sf_put_offset(xfs_dir2_sf_entry_t *sfep, xfs_dir2_data_aoff_t off)
 140 {
 141         INT_SET_UNALIGNED_16_BE(&(sfep)->offset.i, off);
 142 }
 143
 144 #define XFS_DIR2_SF_ENTSIZE_BYNAME(sfp,len)     \
 145         xfs_dir2_sf_entsize_byname(sfp,len)
 146 static inline int xfs_dir2_sf_entsize_byname(xfs_dir2_sf_t *sfp, int len)
 147 {
 148         return ((uint)sizeof(xfs_dir2_sf_entry_t) - 1 + (len) - \
 149                 ((sfp)->hdr.i8count == 0) * \
 150                 ((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
 151 }
 152
 153 #define XFS_DIR2_SF_ENTSIZE_BYENTRY(sfp,sfep)   \
 154         xfs_dir2_sf_entsize_byentry(sfp,sfep)
 155 static inline int
 156 xfs_dir2_sf_entsize_byentry(xfs_dir2_sf_t *sfp, xfs_dir2_sf_entry_t *sfep)
 157 {
 158         return ((uint)sizeof(xfs_dir2_sf_entry_t) - 1 + (sfep)->namelen - \
 159                 ((sfp)->hdr.i8count == 0) * \
 160                 ((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
 161 }
 162
 163 #define XFS_DIR2_SF_FIRSTENTRY(sfp)     xfs_dir2_sf_firstentry(sfp)
 164 static inline xfs_dir2_sf_entry_t *xfs_dir2_sf_firstentry(xfs_dir2_sf_t *sfp)
 165 {
 166         return ((xfs_dir2_sf_entry_t *) \
 167                 ((char *)(sfp) + XFS_DIR2_SF_HDR_SIZE(sfp->hdr.i8count)));
 168 }
 169
 170 #define XFS_DIR2_SF_NEXTENTRY(sfp,sfep) xfs_dir2_sf_nextentry(sfp,sfep)
 171 static inline xfs_dir2_sf_entry_t *
 172 xfs_dir2_sf_nextentry(xfs_dir2_sf_t *sfp, xfs_dir2_sf_entry_t *sfep)
 173 {
 174         return ((xfs_dir2_sf_entry_t *) \
 175                 ((char *)(sfep) + XFS_DIR2_SF_ENTSIZE_BYENTRY(sfp,sfep)));
 176 }
 177
 178 /*
 179  * Functions.
 180  */
 181 extern int xfs_dir2_block_sfsize(struct xfs_inode *dp,
 182                                  struct xfs_dir2_block *block,
 183                                  xfs_dir2_sf_hdr_t *sfhp);
 184 extern int xfs_dir2_block_to_sf(struct xfs_da_args *args, struct xfs_dabuf *bp,
 185                                 int size, xfs_dir2_sf_hdr_t *sfhp);
 186 extern int xfs_dir2_sf_addname(struct xfs_da_args *args);
 187 extern int xfs_dir2_sf_create(struct xfs_da_args *args, xfs_ino_t pino);
 188 extern int xfs_dir2_sf_getdents(struct xfs_inode *dp, struct uio *uio,
 189                                 int *eofp, struct xfs_dirent *dbp,
 190                                 xfs_dir2_put_t put);
 191 extern int xfs_dir2_sf_lookup(struct xfs_da_args *args);
 192 extern int xfs_dir2_sf_removename(struct xfs_da_args *args);
 193 extern int xfs_dir2_sf_replace(struct xfs_da_args *args);
 194
 195 #endif  /* __XFS_DIR2_SF_H__ */