1 /* 2 * dir.c 3 * 4 * PURPOSE 5 * Directory handling routines for the OSTA-UDF(tm) filesystem. 6 * 7 * COPYRIGHT 8 * This file is distributed under the terms of the GNU General Public 9 * License (GPL). Copies of the GPL can be obtained from: 10 * ftp://prep.ai.mit.edu/pub/gnu/GPL 11 * Each contributing author retains all rights to their own work. 12 * 13 * (C) 1998-2004 Ben Fennema 14 * 15 * HISTORY 16 * 17 * 10/05/98 dgb Split directory operations into its own file 18 * Implemented directory reads via do_udf_readdir 19 * 10/06/98 Made directory operations work! 20 * 11/17/98 Rewrote directory to support ICBTAG_FLAG_AD_LONG 21 * 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading 22 * across blocks. 23 * 12/12/98 Split out the lookup code to namei.c. bulk of directory 24 * code now in directory.c:udf_fileident_read. 25 */ 26 27 #include "udfdecl.h" 28 29 #include <linux/string.h> 30 #include <linux/errno.h> 31 #include <linux/mm.h> 32 #include <linux/slab.h> 33 #include <linux/smp_lock.h> 34 #include <linux/buffer_head.h> 35 36 #include "udf_i.h" 37 #include "udf_sb.h" 38 39 static int do_udf_readdir(struct inode *dir, struct file *filp, 40 filldir_t filldir, void *dirent) 41 { 42 struct udf_fileident_bh fibh; 43 struct fileIdentDesc *fi = NULL; 44 struct fileIdentDesc cfi; 45 int block, iblock; 46 loff_t nf_pos = (filp->f_pos - 1) << 2; 47 int flen; 48 char fname[UDF_NAME_LEN]; 49 char *nameptr; 50 uint16_t liu; 51 uint8_t lfi; 52 loff_t size = udf_ext0_offset(dir) + dir->i_size; 53 struct buffer_head *tmp, *bha[16]; 54 kernel_lb_addr eloc; 55 uint32_t elen; 56 sector_t offset; 57 int i, num; 58 unsigned int dt_type; 59 struct extent_position epos = { NULL, 0, {0, 0} }; 60 struct udf_inode_info *iinfo; 61 62 if (nf_pos >= size) 63 return 0; 64 65 if (nf_pos == 0) 66 nf_pos = udf_ext0_offset(dir); 67 68 fibh.soffset = fibh.eoffset = nf_pos & (dir->i_sb->s_blocksize - 1); 69 iinfo = UDF_I(dir); 70 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { 71 fibh.sbh = fibh.ebh = NULL; 72 } else if (inode_bmap(dir, nf_pos >> dir->i_sb->s_blocksize_bits, 73 &epos, &eloc, &elen, &offset) == (EXT_RECORDED_ALLOCATED >> 30)) { 74 block = udf_get_lb_pblock(dir->i_sb, eloc, offset); 75 if ((++offset << dir->i_sb->s_blocksize_bits) < elen) { 76 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) 77 epos.offset -= sizeof(short_ad); 78 else if (iinfo->i_alloc_type == 79 ICBTAG_FLAG_AD_LONG) 80 epos.offset -= sizeof(long_ad); 81 } else { 82 offset = 0; 83 } 84 85 if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) { 86 brelse(epos.bh); 87 return -EIO; 88 } 89 90 if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9)) - 1))) { 91 i = 16 >> (dir->i_sb->s_blocksize_bits - 9); 92 if (i + offset > (elen >> dir->i_sb->s_blocksize_bits)) 93 i = (elen >> dir->i_sb->s_blocksize_bits) - offset; 94 for (num = 0; i > 0; i--) { 95 block = udf_get_lb_pblock(dir->i_sb, eloc, offset + i); 96 tmp = udf_tgetblk(dir->i_sb, block); 97 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp)) 98 bha[num++] = tmp; 99 else 100 brelse(tmp); 101 } 102 if (num) { 103 ll_rw_block(READA, num, bha); 104 for (i = 0; i < num; i++) 105 brelse(bha[i]); 106 } 107 } 108 } else { 109 brelse(epos.bh); 110 return -ENOENT; 111 } 112 113 while (nf_pos < size) { 114 filp->f_pos = (nf_pos >> 2) + 1; 115 116 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc, 117 &elen, &offset); 118 if (!fi) { 119 if (fibh.sbh != fibh.ebh) 120 brelse(fibh.ebh); 121 brelse(fibh.sbh); 122 brelse(epos.bh); 123 return 0; 124 } 125 126 liu = le16_to_cpu(cfi.lengthOfImpUse); 127 lfi = cfi.lengthFileIdent; 128 129 if (fibh.sbh == fibh.ebh) { 130 nameptr = fi->fileIdent + liu; 131 } else { 132 int poffset; /* Unpaded ending offset */ 133 134 poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi; 135 136 if (poffset >= lfi) { 137 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi); 138 } else { 139 nameptr = fname; 140 memcpy(nameptr, fi->fileIdent + liu, 141 lfi - poffset); 142 memcpy(nameptr + lfi - poffset, 143 fibh.ebh->b_data, poffset); 144 } 145 } 146 147 if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) { 148 if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE)) 149 continue; 150 } 151 152 if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) { 153 if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE)) 154 continue; 155 } 156 157 if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) { 158 iblock = parent_ino(filp->f_path.dentry); 159 flen = 2; 160 memcpy(fname, "..", flen); 161 dt_type = DT_DIR; 162 } else { 163 kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation); 164 165 iblock = udf_get_lb_pblock(dir->i_sb, tloc, 0); 166 flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi); 167 dt_type = DT_UNKNOWN; 168 } 169 170 if (flen) { 171 if (filldir(dirent, fname, flen, filp->f_pos, iblock, dt_type) < 0) { 172 if (fibh.sbh != fibh.ebh) 173 brelse(fibh.ebh); 174 brelse(fibh.sbh); 175 brelse(epos.bh); 176 return 0; 177 } 178 } 179 } /* end while */ 180 181 filp->f_pos = (nf_pos >> 2) + 1; 182 183 if (fibh.sbh != fibh.ebh) 184 brelse(fibh.ebh); 185 brelse(fibh.sbh); 186 brelse(epos.bh); 187 188 return 0; 189 } 190 191 /* 192 * udf_readdir 193 * 194 * PURPOSE 195 * Read a directory entry. 196 * 197 * DESCRIPTION 198 * Optional - sys_getdents() will return -ENOTDIR if this routine is not 199 * available. 200 * 201 * Refer to sys_getdents() in fs/readdir.c 202 * sys_getdents() -> . 203 * 204 * PRE-CONDITIONS 205 * filp Pointer to directory file. 206 * buf Pointer to directory entry buffer. 207 * filldir Pointer to filldir function. 208 * 209 * POST-CONDITIONS 210 * <return> >=0 on success. 211 * 212 * HISTORY 213 * July 1, 1997 - Andrew E. Mileski 214 * Written, tested, and released. 215 */ 216 217 static int udf_readdir(struct file *filp, void *dirent, filldir_t filldir) 218 { 219 struct inode *dir = filp->f_path.dentry->d_inode; 220 int result; 221 222 lock_kernel(); 223 224 if (filp->f_pos == 0) { 225 if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0) { 226 unlock_kernel(); 227 return 0; 228 } 229 filp->f_pos++; 230 } 231 232 result = do_udf_readdir(dir, filp, filldir, dirent); 233 unlock_kernel(); 234 return result; 235 } 236 237 /* readdir and lookup functions */ 238 const struct file_operations udf_dir_operations = { 239 .read = generic_read_dir, 240 .readdir = udf_readdir, 241 .ioctl = udf_ioctl, 242 .fsync = udf_fsync_file, 243 }; 244