fs/xfs/xfs_attr_sf.h

   1 /*
   2  * Copyright (c) 2000,2002,2005 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_ATTR_SF_H__
  19 #define __XFS_ATTR_SF_H__
  20
  21 /*
  22  * Attribute storage when stored inside the inode.
  23  *
  24  * Small attribute lists are packed as tightly as possible so as
  25  * to fit into the literal area of the inode.
  26  */
  27
  28 /*
  29  * Entries are packed toward the top as tight as possible.
  30  */
  31 typedef struct xfs_attr_shortform {
  32         struct xfs_attr_sf_hdr {        /* constant-structure header block */
  33                 __be16  totsize;        /* total bytes in shortform list */
  34                 __u8    count;  /* count of active entries */
  35         } hdr;
  36         struct xfs_attr_sf_entry {
  37                 __uint8_t namelen;      /* actual length of name (no NULL) */
  38                 __uint8_t valuelen;     /* actual length of value (no NULL) */
  39                 __uint8_t flags;        /* flags bits (see xfs_attr_leaf.h) */
  40                 __uint8_t nameval[1];   /* name & value bytes concatenated */
  41         } list[1];                      /* variable sized array */
  42 } xfs_attr_shortform_t;
  43 typedef struct xfs_attr_sf_hdr xfs_attr_sf_hdr_t;
  44 typedef struct xfs_attr_sf_entry xfs_attr_sf_entry_t;
  45
  46 /*
  47  * We generate this then sort it, attr_list() must return things in hash-order.
  48  */
  49 typedef struct xfs_attr_sf_sort {
  50         __uint8_t       entno;          /* entry number in original list */
  51         __uint8_t       namelen;        /* length of name value (no null) */
  52         __uint8_t       valuelen;       /* length of value */
  53         __uint8_t       flags;          /* flags bits (see xfs_attr_leaf.h) */
  54         xfs_dahash_t    hash;           /* this entry's hash value */
  55         char            *name;          /* name value, pointer into buffer */
  56 } xfs_attr_sf_sort_t;
  57
  58 #define XFS_ATTR_SF_ENTSIZE_BYNAME(nlen,vlen)   /* space name/value uses */ \
  59         (((int)sizeof(xfs_attr_sf_entry_t)-1 + (nlen)+(vlen)))
  60 #define XFS_ATTR_SF_ENTSIZE_MAX                 /* max space for name&value */ \
  61         ((1 << (NBBY*(int)sizeof(__uint8_t))) - 1)
  62 #define XFS_ATTR_SF_ENTSIZE(sfep)               /* space an entry uses */ \
  63         ((int)sizeof(xfs_attr_sf_entry_t)-1 + (sfep)->namelen+(sfep)->valuelen)
  64 #define XFS_ATTR_SF_NEXTENTRY(sfep)             /* next entry in struct */ \
  65         ((xfs_attr_sf_entry_t *)((char *)(sfep) + XFS_ATTR_SF_ENTSIZE(sfep)))
  66 #define XFS_ATTR_SF_TOTSIZE(dp)                 /* total space in use */ \
  67         (be16_to_cpu(((xfs_attr_shortform_t *)  \
  68                 ((dp)->i_afp->if_u1.if_data))->hdr.totsize))
  69
  70 #endif  /* __XFS_ATTR_SF_H__ */