libhandle/jdm.c

   1 /*
   2  * Copyright (c) 1995, 2001-2002, 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 Lesser General Public License
   7  * as 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 Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser 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
  19 #include <xfs/libxfs.h>
  20
  21 /* attributes.h (purposefully) unavailable to xfsprogs, make do */
  22 struct attrlist_cursor { __u32 opaque[4]; };
  23
  24 #include <xfs/handle.h>
  25 #include <xfs/jdm.h>
  26
  27 /* internal fshandle - typecast to a void for external use */
  28 #define FSHANDLE_SZ             8
  29 typedef struct fshandle {
  30         char fsh_space[FSHANDLE_SZ];
  31 } fshandle_t;
  32
  33 /* private file handle - for use by open_by_fshandle */
  34 #define FILEHANDLE_SZ           24
  35 #define FILEHANDLE_SZ_FOLLOWING 14
  36 #define FILEHANDLE_SZ_PAD       2
  37 typedef struct filehandle {
  38         fshandle_t fh_fshandle;         /* handle of fs containing this inode */
  39         int16_t fh_sz_following;        /* bytes in handle after this member */
  40         char fh_pad[FILEHANDLE_SZ_PAD]; /* padding, must be zeroed */
  41         __uint32_t fh_gen;              /* generation count */
  42         xfs_ino_t fh_ino;               /* 64 bit ino */
  43 } filehandle_t;
  44
  45
  46 static void
  47 jdm_fill_filehandle( filehandle_t *handlep,
  48                      fshandle_t *fshandlep,
  49                      xfs_bstat_t *statp )
  50 {
  51         handlep->fh_fshandle = *fshandlep;
  52         handlep->fh_sz_following = FILEHANDLE_SZ_FOLLOWING;
  53         bzero(handlep->fh_pad, FILEHANDLE_SZ_PAD);
  54         handlep->fh_gen = statp->bs_gen;
  55         handlep->fh_ino = statp->bs_ino;
  56 }
  57
  58 jdm_fshandle_t *
  59 jdm_getfshandle( char *mntpnt )
  60 {
  61         fshandle_t *fshandlep;
  62         size_t fshandlesz;
  63         char resolved[MAXPATHLEN];
  64
  65         /* sanity checks */
  66         ASSERT( sizeof( fshandle_t ) == FSHANDLE_SZ );
  67         ASSERT( sizeof( filehandle_t ) == FILEHANDLE_SZ );
  68         ASSERT( sizeof( filehandle_t )
  69                 -
  70                 offsetofmember( filehandle_t, fh_pad )
  71                 ==
  72                 FILEHANDLE_SZ_FOLLOWING );
  73         ASSERT( sizeofmember( filehandle_t, fh_pad ) == FILEHANDLE_SZ_PAD );
  74         ASSERT( FILEHANDLE_SZ_PAD == sizeof( int16_t ));
  75
  76         fshandlep = 0; /* for lint */
  77         fshandlesz = sizeof( *fshandlep );
  78
  79         if (!realpath( mntpnt, resolved ))
  80                 return NULL;
  81
  82         if (path_to_fshandle( resolved, ( void ** )&fshandlep, &fshandlesz ))
  83                 return NULL;
  84
  85         assert( fshandlesz == sizeof( *fshandlep ));
  86
  87         return ( jdm_fshandle_t * )fshandlep;
  88 }
  89
  90
  91 /* externally visible functions */
  92
  93 void
  94 jdm_new_filehandle( jdm_filehandle_t **handlep,
  95                     size_t *hlen,
  96                     jdm_fshandle_t *fshandlep,
  97                     xfs_bstat_t *statp)
  98 {
  99         /* allocate and fill filehandle */
 100         *hlen = sizeof(filehandle_t);
 101         *handlep = (filehandle_t *) malloc(*hlen);
 102
 103         if (*handlep)
 104                 jdm_fill_filehandle(*handlep, (fshandle_t *) fshandlep, statp);
 105 }
 106
 107 /* ARGSUSED */
 108 void
 109 jdm_delete_filehandle( jdm_filehandle_t *handlep, size_t hlen )
 110 {
 111         free(handlep);
 112 }
 113
 114 intgen_t
 115 jdm_open( jdm_fshandle_t *fshp, xfs_bstat_t *statp, intgen_t oflags )
 116 {
 117         register fshandle_t *fshandlep = ( fshandle_t * )fshp;
 118         filehandle_t filehandle;
 119         intgen_t fd;
 120
 121         jdm_fill_filehandle( &filehandle, fshandlep, statp );
 122         fd = open_by_fshandle( ( void * )&filehandle,
 123                              sizeof( filehandle ),
 124                              oflags );
 125         return fd;
 126 }
 127
 128 intgen_t
 129 jdm_readlink( jdm_fshandle_t *fshp,
 130               xfs_bstat_t *statp,
 131               char *bufp, size_t bufsz )
 132 {
 133         register fshandle_t *fshandlep = ( fshandle_t * )fshp;
 134         filehandle_t filehandle;
 135         intgen_t rval;
 136
 137         jdm_fill_filehandle( &filehandle, fshandlep, statp );
 138         rval = readlink_by_handle( ( void * )&filehandle,
 139                                    sizeof( filehandle ),
 140                                    ( void * )bufp,
 141                                    bufsz );
 142         return rval;
 143 }
 144
 145 int
 146 jdm_attr_multi( jdm_fshandle_t *fshp,
 147                 xfs_bstat_t *statp,
 148                 char *bufp, int rtrvcnt, int flags)
 149 {
 150         register fshandle_t *fshandlep = ( fshandle_t * )fshp;
 151         filehandle_t filehandle;
 152         int rval;
 153
 154         jdm_fill_filehandle( &filehandle, fshandlep, statp );
 155         rval = attr_multi_by_handle ( ( void * )&filehandle,
 156                                       sizeof( filehandle ),
 157                                       (void *) bufp,
 158                                       rtrvcnt, flags);
 159         return rval;
 160 }
 161
 162 int
 163 jdm_attr_list(  jdm_fshandle_t *fshp,
 164                 xfs_bstat_t *statp,
 165                 char *bufp, size_t bufsz, int flags,
 166                 struct attrlist_cursor *cursor)
 167 {
 168         register fshandle_t *fshandlep = ( fshandle_t * )fshp;
 169         filehandle_t filehandle;
 170         int rval;
 171
 172         jdm_fill_filehandle( &filehandle, fshandlep, statp );
 173         rval = attr_list_by_handle (( void * )&filehandle,
 174                         sizeof( filehandle ),
 175                         bufp, bufsz, flags, cursor);
 176         return rval;
 177 }