fs/udf/dir.c

   1 /*
   2  * dir.c
   3  *
   4  * PURPOSE
   5  *  Directory handling routines for the OSTA-UDF(tm) filesystem.
   6  *
   7  * CONTACTS
   8  *      E-mail regarding any portion of the Linux UDF file system should be
   9  *      directed to the development team mailing list (run by majordomo):
  10  *              linux_udf@hootie.lvld.hp.com
  11  *
  12  * COPYRIGHT
  13  *      This file is distributed under the terms of the GNU General Public
  14  *      License (GPL). Copies of the GPL can be obtained from:
  15  *              ftp://prep.ai.mit.edu/pub/gnu/GPL
  16  *      Each contributing author retains all rights to their own work.
  17  *
  18  *  (C) 1998-1999 Ben Fennema
  19  *
  20  * HISTORY
  21  *
  22  *  10/05/98 dgb  Split directory operations into it's own file
  23  *                Implemented directory reads via do_udf_readdir
  24  *  10/06/98      Made directory operations work!
  25  *  11/17/98      Rewrote directory to support ICB_FLAG_AD_LONG
  26  *  11/25/98 blf  Rewrote directory handling (readdir+lookup) to support reading
  27  *                across blocks.
  28  *  12/12/98      Split out the lookup code to namei.c. bulk of directory
  29  *                code now in directory.c:udf_fileident_read.
  30  */
  31
  32 #include "udfdecl.h"
  33
  34 #if defined(__linux__) && defined(__KERNEL__)
  35 #include <linux/version.h>
  36 #include "udf_i.h"
  37 #include "udf_sb.h"
  38 #include <linux/string.h>
  39 #include <linux/errno.h>
  40 #include <linux/mm.h>
  41 #include <linux/malloc.h>
  42 #include <linux/udf_fs.h>
  43 #endif
  44
  45 /* Prototypes for file operations */
  46 static int udf_readdir(struct file *, void *, filldir_t);
  47 static int do_udf_readdir(struct inode *, struct file *, filldir_t, void *);
  48
  49 /* readdir and lookup functions */
  50
  51 static struct file_operations udf_dir_operations = {
  52         NULL,                   /* lllseek */
  53         NULL,                   /* read */
  54         NULL,                   /* write */
  55         udf_readdir,    /* readdir */
  56         NULL,                   /* poll */
  57         udf_ioctl,              /* ioctl */
  58         NULL,                   /* mmap */
  59         NULL,                   /* open */
  60         NULL,                   /* flush */
  61         NULL,                   /* release */
  62         udf_sync_file,  /* fsync */
  63         NULL,                   /* fasync */
  64         NULL,                   /* check_media_change */
  65         NULL,                   /* revalidate */
  66         NULL                    /* lock */
  67 };
  68
  69 struct inode_operations udf_dir_inode_operations = {
  70         &udf_dir_operations,
  71 #ifdef CONFIG_UDF_RW
  72         udf_create,     /* create */
  73 #else
  74         NULL,                   /* create */
  75 #endif
  76         udf_lookup,             /* lookup */
  77 #ifdef CONFIG_UDF_RW
  78         udf_link,               /* link */
  79         udf_unlink,             /* unlink */
  80         udf_symlink,    /* symlink */
  81         udf_mkdir,              /* mkdir */
  82         udf_rmdir,              /* rmdir */
  83         udf_mknod,              /* mknod */
  84         udf_rename,             /* rename */
  85 #else
  86         NULL,                   /* link */
  87         NULL,                   /* unlink */
  88         NULL,                   /* symlink */
  89         NULL,                   /* mkdir */
  90         NULL,                   /* rmdir */
  91         NULL,                   /* mknod */
  92         NULL,                   /* rename */
  93 #endif
  94         NULL,                   /* readlink */
  95         NULL,                   /* follow_link */
  96         NULL,                   /* get_block */
  97         NULL,                   /* readpage */
  98         NULL,                   /* writepage */
  99         NULL,                   /* flushpage */
 100         NULL,                   /* truncate */
 101         NULL,                   /* permission */
 102         NULL,                   /* smap */
 103         NULL                    /* revalidate */
 104 };
 105
 106 /*
 107  * udf_readdir
 108  *
 109  * PURPOSE
 110  *      Read a directory entry.
 111  *
 112  * DESCRIPTION
 113  *      Optional - sys_getdents() will return -ENOTDIR if this routine is not
 114  *      available.
 115  *
 116  *      Refer to sys_getdents() in fs/readdir.c
 117  *      sys_getdents() -> .
 118  *
 119  * PRE-CONDITIONS
 120  *      filp                    Pointer to directory file.
 121  *      buf                     Pointer to directory entry buffer.
 122  *      filldir                 Pointer to filldir function.
 123  *
 124  * POST-CONDITIONS
 125  *      <return>                >=0 on success.
 126  *
 127  * HISTORY
 128  *      July 1, 1997 - Andrew E. Mileski
 129  *      Written, tested, and released.
 130  */
 131
 132 int udf_readdir(struct file *filp, void *dirent, filldir_t filldir)
 133 {
 134         struct inode *dir = filp->f_dentry->d_inode;
 135         int result;
 136
 137         if (!dir)
 138            return -EBADF;
 139
 140         if (!S_ISDIR(dir->i_mode))
 141            return -ENOTDIR;
 142
 143         if ( filp->f_pos == 0 )
 144         {
 145                 if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino) < 0)
 146                         return 0;
 147         }
 148
 149         result = do_udf_readdir(dir, filp, filldir, dirent);
 150         UPDATE_ATIME(dir);
 151         return result;
 152 }
 153
 154 static int
 155 do_udf_readdir(struct inode * dir, struct file *filp, filldir_t filldir, void *dirent)
 156 {
 157         struct udf_fileident_bh fibh;
 158         struct FileIdentDesc *fi=NULL;
 159         struct FileIdentDesc cfi;
 160         int block, iblock;
 161         int nf_pos = filp->f_pos;
 162         int flen;
 163         char fname[255];
 164         char *nameptr;
 165         Uint16 liu;
 166         Uint8 lfi;
 167         int size = (UDF_I_EXT0OFFS(dir) + dir->i_size) >> 2;
 168         struct buffer_head * bh = NULL;
 169         lb_addr bloc, eloc;
 170         Uint32 extoffset, elen, offset;
 171
 172         if (nf_pos >= size)
 173                 return 1;
 174
 175         if (nf_pos == 0)
 176                 nf_pos = (UDF_I_EXT0OFFS(dir) >> 2);
 177
 178         fibh.soffset = fibh.eoffset = (nf_pos & ((dir->i_sb->s_blocksize - 1) >> 2)) << 2;
 179         if (inode_bmap(dir, nf_pos >> (dir->i_sb->s_blocksize_bits - 2),
 180                 &bloc, &extoffset, &eloc, &elen, &offset, &bh) == EXTENT_RECORDED_ALLOCATED)
 181         {
 182                 block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
 183                 if ((++offset << dir->i_sb->s_blocksize_bits) < elen)
 184                 {
 185                         if (UDF_I_ALLOCTYPE(dir) == ICB_FLAG_AD_SHORT)
 186                                 extoffset -= sizeof(short_ad);
 187                         else if (UDF_I_ALLOCTYPE(dir) == ICB_FLAG_AD_LONG)
 188                                 extoffset -= sizeof(long_ad);
 189                 }
 190                 else
 191                         offset = 0;
 192         }
 193         else
 194         {
 195                 udf_release_data(bh);
 196                 return 0;
 197         }
 198
 199         if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block, dir->i_sb->s_blocksize)))
 200         {
 201                 udf_release_data(bh);
 202                 return 0;
 203         }
 204
 205         while ( nf_pos < size )
 206         {
 207                 filp->f_pos = nf_pos;
 208
 209                 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &bloc, &extoffset, &offset, &bh);
 210
 211                 if (!fi)
 212                 {
 213                         if (fibh.sbh != fibh.ebh)
 214                                 udf_release_data(fibh.ebh);
 215                         udf_release_data(fibh.sbh);
 216                         udf_release_data(bh);
 217                         return 1;
 218                 }
 219
 220                 liu = le16_to_cpu(cfi.lengthOfImpUse);
 221                 lfi = cfi.lengthFileIdent;
 222
 223                 if (fibh.sbh == fibh.ebh)
 224                         nameptr = fi->fileIdent + liu;
 225                 else
 226                 {
 227                         int poffset;    /* Unpaded ending offset */
 228
 229                         poffset = fibh.soffset + sizeof(struct FileIdentDesc) + liu + lfi;
 230
 231                         if (poffset >= lfi)
 232                                 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
 233                         else
 234                         {
 235                                 nameptr = fname;
 236                                 memcpy(nameptr, fi->fileIdent + liu, lfi - poffset);
 237                                 memcpy(nameptr + lfi - poffset, fibh.ebh->b_data, poffset);
 238                         }
 239                 }
 240
 241                 if ( (cfi.fileCharacteristics & FILE_DELETED) != 0 )
 242                 {
 243                         if ( !IS_UNDELETE(dir->i_sb) )
 244                                 continue;
 245                 }
 246
 247                 if ( (cfi.fileCharacteristics & FILE_HIDDEN) != 0 )
 248                 {
 249                         if ( !IS_UNHIDE(dir->i_sb) )
 250                                 continue;
 251                 }
 252
 253                 iblock = udf_get_lb_pblock(dir->i_sb, lelb_to_cpu(cfi.icb.extLocation), 0);
 254
 255                 if (!lfi) /* parent directory */
 256                 {
 257                         if (filldir(dirent, "..", 2, filp->f_pos, filp->f_dentry->d_parent->d_inode->i_ino) < 0)
 258                         {
 259                                 if (fibh.sbh != fibh.ebh)
 260                                         udf_release_data(fibh.ebh);
 261                                 udf_release_data(fibh.sbh);
 262                                 udf_release_data(bh);
 263                                 return 1;
 264                         }
 265                 }
 266                 else
 267                 {
 268                         if ((flen = udf_get_filename(nameptr, fname, lfi)))
 269                         {
 270                                 if (filldir(dirent, fname, flen, filp->f_pos, iblock) < 0)
 271                                 {
 272                                         if (fibh.sbh != fibh.ebh)
 273                                                 udf_release_data(fibh.ebh);
 274                                         udf_release_data(fibh.sbh);
 275                                         udf_release_data(bh);
 276                                         return 1; /* halt enum */
 277                                 }
 278                         }
 279                         else
 280                         {
 281                                 udf_debug("size=%d, nf_pos=%d, liu=%d, lfi=%d\n", size, nf_pos, liu, lfi);
 282                         }
 283                 }
 284         } /* end while */
 285
 286         filp->f_pos = nf_pos;
 287
 288         if (fibh.sbh != fibh.ebh)
 289                 udf_release_data(fibh.ebh);
 290         udf_release_data(fibh.sbh);
 291         udf_release_data(bh);
 292
 293         if ( filp->f_pos >= size)
 294                 return 1;
 295         else
 296                 return 0;
 297 }