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 /* Prototypes for file operations */ 40 static int udf_readdir(struct file *, void *, filldir_t); 41 static int do_udf_readdir(struct inode *, struct file *, filldir_t, void *); 42 43 /* readdir and lookup functions */ 44 45 const struct file_operations udf_dir_operations = { 46 .read = generic_read_dir, 47 .readdir = udf_readdir, 48 .ioctl = udf_ioctl, 49 .fsync = udf_fsync_file, 50 }; 51 52 /* 53 * udf_readdir 54 * 55 * PURPOSE 56 * Read a directory entry. 57 * 58 * DESCRIPTION 59 * Optional - sys_getdents() will return -ENOTDIR if this routine is not 60 * available. 61 * 62 * Refer to sys_getdents() in fs/readdir.c 63 * sys_getdents() -> . 64 * 65 * PRE-CONDITIONS 66 * filp Pointer to directory file. 67 * buf Pointer to directory entry buffer. 68 * filldir Pointer to filldir function. 69 * 70 * POST-CONDITIONS 71 * <return> >=0 on success. 72 * 73 * HISTORY 74 * July 1, 1997 - Andrew E. Mileski 75 * Written, tested, and released. 76 */ 77 78 int udf_readdir(struct file *filp, void *dirent, filldir_t filldir) 79 { 80 struct inode *dir = filp->f_path.dentry->d_inode; 81 int result; 82 83 lock_kernel(); 84 85 if (filp->f_pos == 0) { 86 if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0) { 87 unlock_kernel(); 88 return 0; 89 } 90 filp->f_pos++; 91 } 92 93 result = do_udf_readdir(dir, filp, filldir, dirent); 94 unlock_kernel(); 95 return result; 96 } 97 98 static int 99 do_udf_readdir(struct inode *dir, struct file *filp, filldir_t filldir, 100 void *dirent) 101 { 102 struct udf_fileident_bh fibh; 103 struct fileIdentDesc *fi = NULL; 104 struct fileIdentDesc cfi; 105 int block, iblock; 106 loff_t nf_pos = filp->f_pos - 1; 107 int flen; 108 char fname[UDF_NAME_LEN]; 109 char *nameptr; 110 uint16_t liu; 111 uint8_t lfi; 112 loff_t size = (udf_ext0_offset(dir) + dir->i_size) >> 2; 113 struct buffer_head *tmp, *bha[16]; 114 kernel_lb_addr eloc; 115 uint32_t elen; 116 sector_t offset; 117 int i, num; 118 unsigned int dt_type; 119 struct extent_position epos = { NULL, 0, {0, 0} }; 120 121 if (nf_pos >= size) 122 return 0; 123 124 if (nf_pos == 0) 125 nf_pos = (udf_ext0_offset(dir) >> 2); 126 127 fibh.soffset = fibh.eoffset = (nf_pos & ((dir->i_sb->s_blocksize - 1) >> 2)) << 2; 128 if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB) { 129 fibh.sbh = fibh.ebh = NULL; 130 } else if (inode_bmap(dir, nf_pos >> (dir->i_sb->s_blocksize_bits - 2), 131 &epos, &eloc, &elen, &offset) == (EXT_RECORDED_ALLOCATED >> 30)) { 132 block = udf_get_lb_pblock(dir->i_sb, eloc, offset); 133 if ((++offset << dir->i_sb->s_blocksize_bits) < elen) { 134 if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_SHORT) 135 epos.offset -= sizeof(short_ad); 136 else if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_LONG) 137 epos.offset -= sizeof(long_ad); 138 } else { 139 offset = 0; 140 } 141 142 if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) { 143 brelse(epos.bh); 144 return -EIO; 145 } 146 147 if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9)) - 1))) { 148 i = 16 >> (dir->i_sb->s_blocksize_bits - 9); 149 if (i + offset > (elen >> dir->i_sb->s_blocksize_bits)) 150 i = (elen >> dir->i_sb->s_blocksize_bits) - offset; 151 for (num = 0; i > 0; i--) { 152 block = udf_get_lb_pblock(dir->i_sb, eloc, offset + i); 153 tmp = udf_tgetblk(dir->i_sb, block); 154 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp)) 155 bha[num++] = tmp; 156 else 157 brelse(tmp); 158 } 159 if (num) { 160 ll_rw_block(READA, num, bha); 161 for (i = 0; i < num; i++) 162 brelse(bha[i]); 163 } 164 } 165 } else { 166 brelse(epos.bh); 167 return -ENOENT; 168 } 169 170 while (nf_pos < size) { 171 filp->f_pos = nf_pos + 1; 172 173 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc, 174 &elen, &offset); 175 if (!fi) { 176 if (fibh.sbh != fibh.ebh) 177 brelse(fibh.ebh); 178 brelse(fibh.sbh); 179 brelse(epos.bh); 180 return 0; 181 } 182 183 liu = le16_to_cpu(cfi.lengthOfImpUse); 184 lfi = cfi.lengthFileIdent; 185 186 if (fibh.sbh == fibh.ebh) { 187 nameptr = fi->fileIdent + liu; 188 } else { 189 int poffset; /* Unpaded ending offset */ 190 191 poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi; 192 193 if (poffset >= lfi) { 194 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi); 195 } else { 196 nameptr = fname; 197 memcpy(nameptr, fi->fileIdent + liu, 198 lfi - poffset); 199 memcpy(nameptr + lfi - poffset, 200 fibh.ebh->b_data, poffset); 201 } 202 } 203 204 if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) { 205 if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE)) 206 continue; 207 } 208 209 if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) { 210 if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE)) 211 continue; 212 } 213 214 if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) { 215 iblock = parent_ino(filp->f_path.dentry); 216 flen = 2; 217 memcpy(fname, "..", flen); 218 dt_type = DT_DIR; 219 } else { 220 kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation); 221 222 iblock = udf_get_lb_pblock(dir->i_sb, tloc, 0); 223 flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi); 224 dt_type = DT_UNKNOWN; 225 } 226 227 if (flen) { 228 if (filldir(dirent, fname, flen, filp->f_pos, iblock, dt_type) < 0) { 229 if (fibh.sbh != fibh.ebh) 230 brelse(fibh.ebh); 231 brelse(fibh.sbh); 232 brelse(epos.bh); 233 return 0; 234 } 235 } 236 } /* end while */ 237 238 filp->f_pos = nf_pos + 1; 239 240 if (fibh.sbh != fibh.ebh) 241 brelse(fibh.ebh); 242 brelse(fibh.sbh); 243 brelse(epos.bh); 244 245 return 0; 246 } 247