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 = { .sbh = NULL, .ebh = NULL}; 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 unsigned char *fname = NULL; 49 unsigned 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 struct kernel_lb_addr eloc; 55 uint32_t elen; 56 sector_t offset; 57 int i, num, ret = 0; 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 goto out; 64 65 fname = kmalloc(UDF_NAME_LEN, GFP_NOFS); 66 if (!fname) { 67 ret = -ENOMEM; 68 goto out; 69 } 70 71 if (nf_pos == 0) 72 nf_pos = udf_ext0_offset(dir); 73 74 fibh.soffset = fibh.eoffset = nf_pos & (dir->i_sb->s_blocksize - 1); 75 iinfo = UDF_I(dir); 76 if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) { 77 if (inode_bmap(dir, nf_pos >> dir->i_sb->s_blocksize_bits, 78 &epos, &eloc, &elen, &offset) 79 != (EXT_RECORDED_ALLOCATED >> 30)) { 80 ret = -ENOENT; 81 goto out; 82 } 83 block = udf_get_lb_pblock(dir->i_sb, &eloc, offset); 84 if ((++offset << dir->i_sb->s_blocksize_bits) < elen) { 85 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) 86 epos.offset -= sizeof(struct short_ad); 87 else if (iinfo->i_alloc_type == 88 ICBTAG_FLAG_AD_LONG) 89 epos.offset -= sizeof(struct long_ad); 90 } else { 91 offset = 0; 92 } 93 94 if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) { 95 ret = -EIO; 96 goto out; 97 } 98 99 if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9)) - 1))) { 100 i = 16 >> (dir->i_sb->s_blocksize_bits - 9); 101 if (i + offset > (elen >> dir->i_sb->s_blocksize_bits)) 102 i = (elen >> dir->i_sb->s_blocksize_bits) - offset; 103 for (num = 0; i > 0; i--) { 104 block = udf_get_lb_pblock(dir->i_sb, &eloc, offset + i); 105 tmp = udf_tgetblk(dir->i_sb, block); 106 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp)) 107 bha[num++] = tmp; 108 else 109 brelse(tmp); 110 } 111 if (num) { 112 ll_rw_block(READA, num, bha); 113 for (i = 0; i < num; i++) 114 brelse(bha[i]); 115 } 116 } 117 } 118 119 while (nf_pos < size) { 120 filp->f_pos = (nf_pos >> 2) + 1; 121 122 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc, 123 &elen, &offset); 124 if (!fi) 125 goto out; 126 127 liu = le16_to_cpu(cfi.lengthOfImpUse); 128 lfi = cfi.lengthFileIdent; 129 130 if (fibh.sbh == fibh.ebh) { 131 nameptr = fi->fileIdent + liu; 132 } else { 133 int poffset; /* Unpaded ending offset */ 134 135 poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi; 136 137 if (poffset >= lfi) { 138 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi); 139 } else { 140 nameptr = fname; 141 memcpy(nameptr, fi->fileIdent + liu, 142 lfi - poffset); 143 memcpy(nameptr + lfi - poffset, 144 fibh.ebh->b_data, poffset); 145 } 146 } 147 148 if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) { 149 if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE)) 150 continue; 151 } 152 153 if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) { 154 if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE)) 155 continue; 156 } 157 158 if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) { 159 iblock = parent_ino(filp->f_path.dentry); 160 flen = 2; 161 memcpy(fname, "..", flen); 162 dt_type = DT_DIR; 163 } else { 164 struct kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation); 165 166 iblock = udf_get_lb_pblock(dir->i_sb, &tloc, 0); 167 flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi); 168 dt_type = DT_UNKNOWN; 169 } 170 171 if (flen && filldir(dirent, fname, flen, filp->f_pos, 172 iblock, dt_type) < 0) 173 goto out; 174 } /* end while */ 175 176 filp->f_pos = (nf_pos >> 2) + 1; 177 178 out: 179 if (fibh.sbh != fibh.ebh) 180 brelse(fibh.ebh); 181 brelse(fibh.sbh); 182 brelse(epos.bh); 183 kfree(fname); 184 185 return ret; 186 } 187 188 static int udf_readdir(struct file *filp, void *dirent, filldir_t filldir) 189 { 190 struct inode *dir = filp->f_path.dentry->d_inode; 191 int result; 192 193 lock_kernel(); 194 195 if (filp->f_pos == 0) { 196 if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0) { 197 unlock_kernel(); 198 return 0; 199 } 200 filp->f_pos++; 201 } 202 203 result = do_udf_readdir(dir, filp, filldir, dirent); 204 unlock_kernel(); 205 return result; 206 } 207 208 /* readdir and lookup functions */ 209 const struct file_operations udf_dir_operations = { 210 .llseek = generic_file_llseek, 211 .read = generic_read_dir, 212 .readdir = udf_readdir, 213 .unlocked_ioctl = udf_ioctl, 214 .fsync = generic_file_fsync, 215 }; 216